NEWS
author blanchet
Thu, 28 Jul 2011 16:32:39 +0200
changeset 44872 2b75760fa75e
parent 44841 3d204d261903
child 44886 a1507f567de6
permissions -rw-r--r--
no needless mangling
     1 Isabelle NEWS -- history user-relevant changes
     2 ==============================================
     3 
     4 New in this Isabelle version
     5 ----------------------------
     6 
     7 *** General ***
     8 
     9 * Theory loader: source files are identified by content via SHA1
    10 digests.  Discontinued former path/modtime identification and optional
    11 ISABELLE_FILE_IDENT plugin scripts.
    12 
    13 * Parallelization of nested Isar proofs is subject to
    14 Goal.parallel_proofs_threshold (default 100).  See also isabelle
    15 usedir option -Q.
    16 
    17 * Discontinued support for Poly/ML 5.2, which was the last version
    18 without proper multithreading and TimeLimit implementation.
    19 
    20 * Discontinued old lib/scripts/polyml-platform, which has been
    21 obsolete since Isabelle2009-2.
    22 
    23 * Theory loader: source files are exclusively located via the master
    24 directory of each theory node (where the .thy file itself resides).
    25 The global load path (such as src/HOL/Library) has been discontinued.
    26 Note that the path element ~~ may be used to reference theories in the
    27 Isabelle home folder -- for instance, "~~/src/HOL/Library/FuncSet".
    28 INCOMPATIBILITY.
    29 
    30 * Various optional external tools are referenced more robustly and
    31 uniformly by explicit Isabelle settings as follows:
    32 
    33   ISABELLE_CSDP   (formerly CSDP_EXE)
    34   ISABELLE_GHC    (formerly EXEC_GHC or GHC_PATH)
    35   ISABELLE_OCAML  (formerly EXEC_OCAML)
    36   ISABELLE_SWIPL  (formerly EXEC_SWIPL)
    37   ISABELLE_YAP    (formerly EXEC_YAP)
    38 
    39 Note that automated detection from the file-system or search path has
    40 been discontinued.  INCOMPATIBILITY.
    41 
    42 * Name space: former unsynchronized references are now proper
    43 configuration options, with more conventional names:
    44 
    45   long_names   ~> names_long
    46   short_names  ~> names_short
    47   unique_names ~> names_unique
    48 
    49 Minor INCOMPATIBILITY, need to declare options in context like this:
    50 
    51   declare [[names_unique = false]]
    52 
    53 * Literal facts `prop` may contain dummy patterns, e.g. `_ = _`.  Note
    54 that the result needs to be unique, which means fact specifications
    55 may have to be refined after enriching a proof context.
    56 
    57 * Isabelle/Isar reference manual provides more formal references in
    58 syntax diagrams.
    59 
    60 
    61 *** HOL ***
    62 
    63 * Classes bot and top require underlying partial order rather than preorder:
    64 uniqueness of bot and top is guaranteed.  INCOMPATIBILITY.
    65 
    66 * Class complete_lattice: generalized a couple of lemmas from sets;
    67 generalized theorems INF_cong and SUP_cong.  New type classes for complete
    68 boolean algebras and complete linear orderes.  Lemmas Inf_less_iff,
    69 less_Sup_iff, INF_less_iff, less_SUP_iff now reside in class complete_linorder.
    70 More consistent and less misunderstandable names:
    71   INFI_def ~> INF_def
    72   SUPR_def ~> SUP_def
    73   le_SUPI ~> le_SUP_I
    74   le_SUPI2 ~> le_SUP_I2
    75   le_INFI ~> le_INF_I
    76   INFI_bool_eq ~> INF_bool_eq
    77   SUPR_bool_eq ~> SUP_bool_eq
    78   INFI_apply ~> INF_apply
    79   SUPR_apply ~> SUP_apply
    80 INCOMPATIBILITY.
    81 
    82 * Theorem collections ball_simps and bex_simps do not contain theorems referring
    83 to UNION any longer;  these have been moved to collection UN_ball_bex_simps.
    84 INCOMPATIBILITY.
    85 
    86 * Archimedian_Field.thy:
    87     floor now is defined as parameter of a separate type class floor_ceiling.
    88  
    89 * Finite_Set.thy: more coherent development of fold_set locales:
    90 
    91     locale fun_left_comm ~> locale comp_fun_commute
    92     locale fun_left_comm_idem ~> locale comp_fun_idem
    93     
    94 Both use point-free characterisation; interpretation proofs may need adjustment.
    95 INCOMPATIBILITY.
    96 
    97 * Code generation:
    98   - theory Library/Code_Char_ord provides native ordering of characters
    99     in the target language.
   100   - commands code_module and code_library are legacy, use export_code instead. 
   101   - evaluator "SML" and method evaluation are legacy, use evaluator "code"
   102     and method eval instead.
   103   
   104 * Declare ext [intro] by default.  Rare INCOMPATIBILITY.
   105 
   106 * Nitpick:
   107   - Added "need" and "total_consts" options.
   108   - Reintroduced "show_skolems" option by popular demand.
   109   - Renamed attribute: nitpick_def ~> nitpick_unfold.
   110     INCOMPATIBILITY.
   111 
   112 * Sledgehammer:
   113   - sledgehammer available_provers ~> sledgehammer supported_provers.
   114     INCOMPATIBILITY.
   115   - Added support for SNARK and ToFoF-E on SystemOnTPTP and for simply typed
   116     TPTP problems (TFF).
   117   - Added "preplay_timeout", "slicing", "type_enc", "sound", "max_mono_iters",
   118     and "max_new_mono_instances" options.
   119   - Removed "explicit_apply" and "full_types" options as well as "Full Types"
   120     Proof General menu item. INCOMPATIBILITY.
   121 
   122 * Metis:
   123   - Removed "metisF" -- use "metis" instead. INCOMPATIBILITY.
   124   - Obsoleted "metisFT" -- use "metis (full_types)" instead. INCOMPATIBILITY.
   125 
   126 * "try":
   127   - Renamed "try_methods" and added "simp:", "intro:", "dest:", and "elim:"
   128     options. INCOMPATIBILITY.
   129   - Introduced "try" that not only runs "try_methods" but also "solve_direct",
   130     "sledgehammer", "quickcheck", and "nitpick".
   131 
   132 * Quickcheck:
   133   - Added "eval" option to evaluate terms for the found counterexample
   134     (currently only supported by the default (exhaustive) tester)
   135   - Added post-processing of terms to obtain readable counterexamples
   136     (currently only supported by the default (exhaustive) tester)
   137   - New counterexample generator quickcheck[narrowing] enables
   138     narrowing-based testing.
   139     It requires that the Glasgow Haskell compiler is installed and
   140     its location is known to Isabelle with the environment variable
   141     ISABELLE_GHC.
   142   - Removed quickcheck tester "SML" based on the SML code generator
   143     from HOL-Library
   144 
   145 * Function package: discontinued option "tailrec".
   146 INCOMPATIBILITY. Use partial_function instead.
   147 
   148 * HOL-Probability:
   149   - Caratheodory's extension lemma is now proved for ring_of_sets.
   150   - Infinite products of probability measures are now available.
   151   - Use extended reals instead of positive extended reals.
   152     INCOMPATIBILITY.
   153 
   154 
   155 *** Document preparation ***
   156 
   157 * Discontinued special treatment of hard tabulators, which are better
   158 avoided in the first place.  Implicit tab-width is 1.
   159 
   160 * Antiquotation @{rail} layouts railroad syntax diagrams, see also
   161 isar-ref manual.
   162 
   163 * Antiquotation @{value} evaluates the given term and presents its result.
   164 
   165 * Localized \isabellestyle switch can be used within blocks or groups
   166 like this:
   167 
   168   \isabellestyle{it}  %preferred default
   169   {\isabellestylett @{text "typewriter stuff"}}
   170 
   171 * New term style "isub" as ad-hoc conversion of variables x1, y23 into
   172 subscripted form x\<^isub>1, y\<^isub>2\<^isub>3.
   173 
   174 * Predefined LaTeX macros for Isabelle symbols \<bind> and \<then>
   175 (e.g. see ~~/src/HOL/Library/Monad_Syntax.thy).
   176 
   177 
   178 *** ML ***
   179 
   180 * The inner syntax of sort/type/term/prop supports inlined YXML
   181 representations within quoted string tokens.  By encoding logical
   182 entities via Term_XML (in ML or Scala) concrete syntax can be
   183 bypassed, which is particularly useful for producing bits of text
   184 under external program control.
   185 
   186 * Antiquotations for ML and document preparation are managed as theory
   187 data, which requires explicit setup.
   188 
   189 * Isabelle_Process.is_active allows tools to check if the official
   190 process wrapper is running (Isabelle/Scala/jEdit) or the old TTY loop
   191 (better known as Proof General).
   192 
   193 * Structure Proof_Context follows standard naming scheme.  Old
   194 ProofContext is still available for some time as legacy alias.
   195 
   196 * Structure Timing provides various operations for timing; supersedes
   197 former start_timing/end_timing etc.
   198 
   199 * Path.print is the official way to show file-system paths to users
   200 (including quotes etc.).
   201 
   202 * Inner syntax: identifiers in parse trees of generic categories
   203 "logic", "aprop", "idt" etc. carry position information (disguised as
   204 type constraints).  Occasional INCOMPATIBILITY with non-compliant
   205 translations that choke on unexpected type constraints.  Positions can
   206 be stripped in ML translations via Syntax.strip_positions /
   207 Syntax.strip_positions_ast, or via the syntax constant
   208 "_strip_positions" within parse trees.  As last resort, positions can
   209 be disabled via the configuration option Syntax.positions, which is
   210 called "syntax_positions" in Isar attribute syntax.
   211 
   212 * Discontinued special status of various ML structures that contribute
   213 to structure Syntax (Ast, Lexicon, Mixfix, Parser, Printer etc.): less
   214 pervasive content, no inclusion in structure Syntax.  INCOMPATIBILITY,
   215 refer directly to Ast.Constant, Lexicon.is_identifier,
   216 Syntax_Trans.mk_binder_tr etc.
   217 
   218 * Typed print translation: discontinued show_sorts argument, which is
   219 already available via context of "advanced" translation.
   220 
   221 * Refined PARALLEL_GOALS tactical: degrades gracefully for schematic
   222 goal states; body tactic needs to address all subgoals uniformly.
   223 
   224 * Slightly more special eq_list/eq_set, with shortcut involving
   225 pointer equality (assumes that eq relation is reflexive).
   226 
   227 * Classical tactics use proper Proof.context instead of historic types
   228 claset/clasimpset.  Old-style declarations like addIs, addEs, addDs
   229 operate directly on Proof.context.  Raw type claset retains its use as
   230 snapshot of the classical context, which can be recovered via
   231 (put_claset HOL_cs) etc.  Type clasimpset has been discontinued.
   232 INCOMPATIBILITY, classical tactics and derived proof methods require
   233 proper Proof.context.
   234 
   235 * Scala layer provides JVM method invocation service for static
   236 methods of type (String)String, see Invoke_Scala.method in ML.
   237 For example:
   238 
   239   Invoke_Scala.method "java.lang.System.getProperty" "java.home"
   240 
   241 
   242 
   243 New in Isabelle2011 (January 2011)
   244 ----------------------------------
   245 
   246 *** General ***
   247 
   248 * Experimental Prover IDE based on Isabelle/Scala and jEdit (see
   249 src/Tools/jEdit).  This also serves as IDE for Isabelle/ML, with
   250 useful tooltips and hyperlinks produced from its static analysis.  The
   251 bundled component provides an executable Isabelle tool that can be run
   252 like this:
   253 
   254   Isabelle2011/bin/isabelle jedit
   255 
   256 * Significantly improved Isabelle/Isar implementation manual.
   257 
   258 * System settings: ISABELLE_HOME_USER now includes ISABELLE_IDENTIFIER
   259 (and thus refers to something like $HOME/.isabelle/Isabelle2011),
   260 while the default heap location within that directory lacks that extra
   261 suffix.  This isolates multiple Isabelle installations from each
   262 other, avoiding problems with old settings in new versions.
   263 INCOMPATIBILITY, need to copy/upgrade old user settings manually.
   264 
   265 * Source files are always encoded as UTF-8, instead of old-fashioned
   266 ISO-Latin-1.  INCOMPATIBILITY.  Isabelle LaTeX documents might require
   267 the following package declarations:
   268 
   269   \usepackage[utf8]{inputenc}
   270   \usepackage{textcomp}
   271 
   272 * Explicit treatment of UTF-8 sequences as Isabelle symbols, such that
   273 a Unicode character is treated as a single symbol, not a sequence of
   274 non-ASCII bytes as before.  Since Isabelle/ML string literals may
   275 contain symbols without further backslash escapes, Unicode can now be
   276 used here as well.  Recall that Symbol.explode in ML provides a
   277 consistent view on symbols, while raw explode (or String.explode)
   278 merely give a byte-oriented representation.
   279 
   280 * Theory loader: source files are primarily located via the master
   281 directory of each theory node (where the .thy file itself resides).
   282 The global load path is still partially available as legacy feature.
   283 Minor INCOMPATIBILITY due to subtle change in file lookup: use
   284 explicit paths, relatively to the theory.
   285 
   286 * Special treatment of ML file names has been discontinued.
   287 Historically, optional extensions .ML or .sml were added on demand --
   288 at the cost of clarity of file dependencies.  Recall that Isabelle/ML
   289 files exclusively use the .ML extension.  Minor INCOMPATIBILTY.
   290 
   291 * Various options that affect pretty printing etc. are now properly
   292 handled within the context via configuration options, instead of
   293 unsynchronized references or print modes.  There are both ML Config.T
   294 entities and Isar declaration attributes to access these.
   295 
   296   ML (Config.T)                 Isar (attribute)
   297 
   298   eta_contract                  eta_contract
   299   show_brackets                 show_brackets
   300   show_sorts                    show_sorts
   301   show_types                    show_types
   302   show_question_marks           show_question_marks
   303   show_consts                   show_consts
   304   show_abbrevs                  show_abbrevs
   305 
   306   Syntax.ast_trace              syntax_ast_trace
   307   Syntax.ast_stat               syntax_ast_stat
   308   Syntax.ambiguity_level        syntax_ambiguity_level
   309 
   310   Goal_Display.goals_limit      goals_limit
   311   Goal_Display.show_main_goal   show_main_goal
   312 
   313   Method.rule_trace             rule_trace
   314 
   315   Thy_Output.display            thy_output_display
   316   Thy_Output.quotes             thy_output_quotes
   317   Thy_Output.indent             thy_output_indent
   318   Thy_Output.source             thy_output_source
   319   Thy_Output.break              thy_output_break
   320 
   321 Note that corresponding "..._default" references in ML may only be
   322 changed globally at the ROOT session setup, but *not* within a theory.
   323 The option "show_abbrevs" supersedes the former print mode
   324 "no_abbrevs" with inverted meaning.
   325 
   326 * More systematic naming of some configuration options.
   327 INCOMPATIBILITY.
   328 
   329   trace_simp  ~>  simp_trace
   330   debug_simp  ~>  simp_debug
   331 
   332 * Support for real valued configuration options, using simplistic
   333 floating-point notation that coincides with the inner syntax for
   334 float_token.
   335 
   336 * Support for real valued preferences (with approximative PGIP type):
   337 front-ends need to accept "pgint" values in float notation.
   338 INCOMPATIBILITY.
   339 
   340 * The IsabelleText font now includes Cyrillic, Hebrew, Arabic from
   341 DejaVu Sans.
   342 
   343 * Discontinued support for Poly/ML 5.0 and 5.1 versions.
   344 
   345 
   346 *** Pure ***
   347 
   348 * Command 'type_synonym' (with single argument) replaces somewhat
   349 outdated 'types', which is still available as legacy feature for some
   350 time.
   351 
   352 * Command 'nonterminal' (with 'and' separated list of arguments)
   353 replaces somewhat outdated 'nonterminals'.  INCOMPATIBILITY.
   354 
   355 * Command 'notepad' replaces former 'example_proof' for
   356 experimentation in Isar without any result.  INCOMPATIBILITY.
   357 
   358 * Locale interpretation commands 'interpret' and 'sublocale' accept
   359 lists of equations to map definitions in a locale to appropriate
   360 entities in the context of the interpretation.  The 'interpretation'
   361 command already provided this functionality.
   362 
   363 * Diagnostic command 'print_dependencies' prints the locale instances
   364 that would be activated if the specified expression was interpreted in
   365 the current context.  Variant "print_dependencies!" assumes a context
   366 without interpretations.
   367 
   368 * Diagnostic command 'print_interps' prints interpretations in proofs
   369 in addition to interpretations in theories.
   370 
   371 * Discontinued obsolete 'global' and 'local' commands to manipulate
   372 the theory name space.  Rare INCOMPATIBILITY.  The ML functions
   373 Sign.root_path and Sign.local_path may be applied directly where this
   374 feature is still required for historical reasons.
   375 
   376 * Discontinued obsolete 'constdefs' command.  INCOMPATIBILITY, use
   377 'definition' instead.
   378 
   379 * The "prems" fact, which refers to the accidental collection of
   380 foundational premises in the context, is now explicitly marked as
   381 legacy feature and will be discontinued soon.  Consider using "assms"
   382 of the head statement or reference facts by explicit names.
   383 
   384 * Document antiquotations @{class} and @{type} print classes and type
   385 constructors.
   386 
   387 * Document antiquotation @{file} checks file/directory entries within
   388 the local file system.
   389 
   390 
   391 *** HOL ***
   392 
   393 * Coercive subtyping: functions can be declared as coercions and type
   394 inference will add them as necessary upon input of a term.  Theory
   395 Complex_Main declares real :: nat => real and real :: int => real as
   396 coercions. A coercion function f is declared like this:
   397 
   398   declare [[coercion f]]
   399 
   400 To lift coercions through type constructors (e.g. from nat => real to
   401 nat list => real list), map functions can be declared, e.g.
   402 
   403   declare [[coercion_map map]]
   404 
   405 Currently coercion inference is activated only in theories including
   406 real numbers, i.e. descendants of Complex_Main.  This is controlled by
   407 the configuration option "coercion_enabled", e.g. it can be enabled in
   408 other theories like this:
   409 
   410   declare [[coercion_enabled]]
   411 
   412 * Command 'partial_function' provides basic support for recursive
   413 function definitions over complete partial orders.  Concrete instances
   414 are provided for i) the option type, ii) tail recursion on arbitrary
   415 types, and iii) the heap monad of Imperative_HOL.  See
   416 src/HOL/ex/Fundefs.thy and src/HOL/Imperative_HOL/ex/Linked_Lists.thy
   417 for examples.
   418 
   419 * Function package: f.psimps rules are no longer implicitly declared
   420 as [simp].  INCOMPATIBILITY.
   421 
   422 * Datatype package: theorems generated for executable equality (class
   423 "eq") carry proper names and are treated as default code equations.
   424 
   425 * Inductive package: now offers command 'inductive_simps' to
   426 automatically derive instantiated and simplified equations for
   427 inductive predicates, similar to 'inductive_cases'.
   428 
   429 * Command 'enriched_type' allows to register properties of the
   430 functorial structure of types.
   431 
   432 * Improved infrastructure for term evaluation using code generator
   433 techniques, in particular static evaluation conversions.
   434 
   435 * Code generator: Scala (2.8 or higher) has been added to the target
   436 languages.
   437 
   438 * Code generator: globbing constant expressions "*" and "Theory.*"
   439 have been replaced by the more idiomatic "_" and "Theory._".
   440 INCOMPATIBILITY.
   441 
   442 * Code generator: export_code without explicit file declaration prints
   443 to standard output.  INCOMPATIBILITY.
   444 
   445 * Code generator: do not print function definitions for case
   446 combinators any longer.
   447 
   448 * Code generator: simplification with rules determined with
   449 src/Tools/Code/code_simp.ML and method "code_simp".
   450 
   451 * Code generator for records: more idiomatic representation of record
   452 types.  Warning: records are not covered by ancient SML code
   453 generation any longer.  INCOMPATIBILITY.  In cases of need, a suitable
   454 rep_datatype declaration helps to succeed then:
   455 
   456   record 'a foo = ...
   457   ...
   458   rep_datatype foo_ext ...
   459 
   460 * Records: logical foundation type for records does not carry a
   461 '_type' suffix any longer (obsolete due to authentic syntax).
   462 INCOMPATIBILITY.
   463 
   464 * Quickcheck now by default uses exhaustive testing instead of random
   465 testing.  Random testing can be invoked by "quickcheck [random]",
   466 exhaustive testing by "quickcheck [exhaustive]".
   467 
   468 * Quickcheck instantiates polymorphic types with small finite
   469 datatypes by default. This enables a simple execution mechanism to
   470 handle quantifiers and function equality over the finite datatypes.
   471 
   472 * Quickcheck random generator has been renamed from "code" to
   473 "random".  INCOMPATIBILITY.
   474 
   475 * Quickcheck now has a configurable time limit which is set to 30
   476 seconds by default. This can be changed by adding [timeout = n] to the
   477 quickcheck command. The time limit for Auto Quickcheck is still set
   478 independently.
   479 
   480 * Quickcheck in locales considers interpretations of that locale for
   481 counter example search.
   482 
   483 * Sledgehammer:
   484   - Added "smt" and "remote_smt" provers based on the "smt" proof
   485     method. See the Sledgehammer manual for details ("isabelle doc
   486     sledgehammer").
   487   - Renamed commands:
   488     sledgehammer atp_info ~> sledgehammer running_provers
   489     sledgehammer atp_kill ~> sledgehammer kill_provers
   490     sledgehammer available_atps ~> sledgehammer available_provers
   491     INCOMPATIBILITY.
   492   - Renamed options:
   493     sledgehammer [atps = ...] ~> sledgehammer [provers = ...]
   494     sledgehammer [atp = ...] ~> sledgehammer [prover = ...]
   495     sledgehammer [timeout = 77 s] ~> sledgehammer [timeout = 77]
   496     (and "ms" and "min" are no longer supported)
   497     INCOMPATIBILITY.
   498 
   499 * Nitpick:
   500   - Renamed options:
   501     nitpick [timeout = 77 s] ~> nitpick [timeout = 77]
   502     nitpick [tac_timeout = 777 ms] ~> nitpick [tac_timeout = 0.777]
   503     INCOMPATIBILITY.
   504   - Added support for partial quotient types.
   505   - Added local versions of the "Nitpick.register_xxx" functions.
   506   - Added "whack" option.
   507   - Allow registration of quotient types as codatatypes.
   508   - Improved "merge_type_vars" option to merge more types.
   509   - Removed unsound "fast_descrs" option.
   510   - Added custom symmetry breaking for datatypes, making it possible to reach
   511     higher cardinalities.
   512   - Prevent the expansion of too large definitions.
   513 
   514 * Proof methods "metis" and "meson" now have configuration options
   515 "meson_trace", "metis_trace", and "metis_verbose" that can be enabled
   516 to diagnose these tools. E.g.
   517 
   518     using [[metis_trace = true]]
   519 
   520 * Auto Solve: Renamed "Auto Solve Direct".  The tool is now available
   521 manually as command 'solve_direct'.
   522 
   523 * The default SMT solver Z3 must be enabled explicitly (due to
   524 licensing issues) by setting the environment variable
   525 Z3_NON_COMMERCIAL in etc/settings of the component, for example.  For
   526 commercial applications, the SMT solver CVC3 is provided as fall-back;
   527 changing the SMT solver is done via the configuration option
   528 "smt_solver".
   529 
   530 * Remote SMT solvers need to be referred to by the "remote_" prefix,
   531 i.e. "remote_cvc3" and "remote_z3".
   532 
   533 * Added basic SMT support for datatypes, records, and typedefs using
   534 the oracle mode (no proofs).  Direct support of pairs has been dropped
   535 in exchange (pass theorems fst_conv snd_conv pair_collapse to the SMT
   536 support for a similar behavior).  Minor INCOMPATIBILITY.
   537 
   538 * Changed SMT configuration options:
   539   - Renamed:
   540     z3_proofs ~> smt_oracle (with inverted meaning)
   541     z3_trace_assms ~> smt_trace_used_facts
   542     INCOMPATIBILITY.
   543   - Added:
   544     smt_verbose
   545     smt_random_seed
   546     smt_datatypes
   547     smt_infer_triggers
   548     smt_monomorph_limit
   549     cvc3_options
   550     remote_cvc3_options
   551     remote_z3_options
   552     yices_options
   553 
   554 * Boogie output files (.b2i files) need to be declared in the theory
   555 header.
   556 
   557 * Simplification procedure "list_to_set_comprehension" rewrites list
   558 comprehensions applied to List.set to set comprehensions.  Occasional
   559 INCOMPATIBILITY, may be deactivated like this:
   560 
   561   declare [[simproc del: list_to_set_comprehension]]
   562 
   563 * Removed old version of primrec package.  INCOMPATIBILITY.
   564 
   565 * Removed simplifier congruence rule of "prod_case", as has for long
   566 been the case with "split".  INCOMPATIBILITY.
   567 
   568 * String.literal is a type, but not a datatype.  INCOMPATIBILITY.
   569 
   570 * Removed [split_format ... and ... and ...] version of
   571 [split_format].  Potential INCOMPATIBILITY.
   572 
   573 * Predicate "sorted" now defined inductively, with nice induction
   574 rules.  INCOMPATIBILITY: former sorted.simps now named sorted_simps.
   575 
   576 * Constant "contents" renamed to "the_elem", to free the generic name
   577 contents for other uses.  INCOMPATIBILITY.
   578 
   579 * Renamed class eq and constant eq (for code generation) to class
   580 equal and constant equal, plus renaming of related facts and various
   581 tuning.  INCOMPATIBILITY.
   582 
   583 * Dropped type classes mult_mono and mult_mono1.  INCOMPATIBILITY.
   584 
   585 * Removed output syntax "'a ~=> 'b" for "'a => 'b option".
   586 INCOMPATIBILITY.
   587 
   588 * Renamed theory Fset to Cset, type Fset.fset to Cset.set, in order to
   589 avoid confusion with finite sets.  INCOMPATIBILITY.
   590 
   591 * Abandoned locales equiv, congruent and congruent2 for equivalence
   592 relations.  INCOMPATIBILITY: use equivI rather than equiv_intro (same
   593 for congruent(2)).
   594 
   595 * Some previously unqualified names have been qualified:
   596 
   597   types
   598     bool ~> HOL.bool
   599     nat ~> Nat.nat
   600 
   601   constants
   602     Trueprop ~> HOL.Trueprop
   603     True ~> HOL.True
   604     False ~> HOL.False
   605     op & ~> HOL.conj
   606     op | ~> HOL.disj
   607     op --> ~> HOL.implies
   608     op = ~> HOL.eq
   609     Not ~> HOL.Not
   610     The ~> HOL.The
   611     All ~> HOL.All
   612     Ex ~> HOL.Ex
   613     Ex1 ~> HOL.Ex1
   614     Let ~> HOL.Let
   615     If ~> HOL.If
   616     Ball ~> Set.Ball
   617     Bex ~> Set.Bex
   618     Suc ~> Nat.Suc
   619     Pair ~> Product_Type.Pair
   620     fst ~> Product_Type.fst
   621     snd ~> Product_Type.snd
   622     curry ~> Product_Type.curry
   623     op : ~> Set.member
   624     Collect ~> Set.Collect
   625 
   626 INCOMPATIBILITY.
   627 
   628 * More canonical naming convention for some fundamental definitions:
   629 
   630     bot_bool_eq ~> bot_bool_def
   631     top_bool_eq ~> top_bool_def
   632     inf_bool_eq ~> inf_bool_def
   633     sup_bool_eq ~> sup_bool_def
   634     bot_fun_eq  ~> bot_fun_def
   635     top_fun_eq  ~> top_fun_def
   636     inf_fun_eq  ~> inf_fun_def
   637     sup_fun_eq  ~> sup_fun_def
   638 
   639 INCOMPATIBILITY.
   640 
   641 * More stylized fact names:
   642 
   643   expand_fun_eq ~> fun_eq_iff
   644   expand_set_eq ~> set_eq_iff
   645   set_ext       ~> set_eqI
   646   nat_number    ~> eval_nat_numeral
   647 
   648 INCOMPATIBILITY.
   649 
   650 * Refactoring of code-generation specific operations in theory List:
   651 
   652   constants
   653     null ~> List.null
   654 
   655   facts
   656     mem_iff ~> member_def
   657     null_empty ~> null_def
   658 
   659 INCOMPATIBILITY.  Note that these were not supposed to be used
   660 regularly unless for striking reasons; their main purpose was code
   661 generation.
   662 
   663 Various operations from the Haskell prelude are used for generating
   664 Haskell code.
   665 
   666 * Term "bij f" is now an abbreviation of "bij_betw f UNIV UNIV".  Term
   667 "surj f" is now an abbreviation of "range f = UNIV".  The theorems
   668 bij_def and surj_def are unchanged.  INCOMPATIBILITY.
   669 
   670 * Abolished some non-alphabetic type names: "prod" and "sum" replace
   671 "*" and "+" respectively.  INCOMPATIBILITY.
   672 
   673 * Name "Plus" of disjoint sum operator "<+>" is now hidden.  Write
   674 "Sum_Type.Plus" instead.
   675 
   676 * Constant "split" has been merged with constant "prod_case"; names of
   677 ML functions, facts etc. involving split have been retained so far,
   678 though.  INCOMPATIBILITY.
   679 
   680 * Dropped old infix syntax "_ mem _" for List.member; use "_ : set _"
   681 instead.  INCOMPATIBILITY.
   682 
   683 * Removed lemma "Option.is_none_none" which duplicates "is_none_def".
   684 INCOMPATIBILITY.
   685 
   686 * Former theory Library/Enum is now part of the HOL-Main image.
   687 INCOMPATIBILITY: all constants of the Enum theory now have to be
   688 referred to by its qualified name.
   689 
   690   enum    ~>  Enum.enum
   691   nlists  ~>  Enum.nlists
   692   product ~>  Enum.product
   693 
   694 * Theory Library/Monad_Syntax provides do-syntax for monad types.
   695 Syntax in Library/State_Monad has been changed to avoid ambiguities.
   696 INCOMPATIBILITY.
   697 
   698 * Theory Library/SetsAndFunctions has been split into
   699 Library/Function_Algebras and Library/Set_Algebras; canonical names
   700 for instance definitions for functions; various improvements.
   701 INCOMPATIBILITY.
   702 
   703 * Theory Library/Multiset provides stable quicksort implementation of
   704 sort_key.
   705 
   706 * Theory Library/Multiset: renamed empty_idemp ~> empty_neutral.
   707 INCOMPATIBILITY.
   708 
   709 * Session Multivariate_Analysis: introduced a type class for euclidean
   710 space.  Most theorems are now stated in terms of euclidean spaces
   711 instead of finite cartesian products.
   712 
   713   types
   714     real ^ 'n ~>  'a::real_vector
   715               ~>  'a::euclidean_space
   716               ~>  'a::ordered_euclidean_space
   717         (depends on your needs)
   718 
   719   constants
   720      _ $ _        ~> _ $$ _
   721      \<chi> x. _  ~> \<chi>\<chi> x. _
   722      CARD('n)     ~> DIM('a)
   723 
   724 Also note that the indices are now natural numbers and not from some
   725 finite type. Finite cartesian products of euclidean spaces, products
   726 of euclidean spaces the real and complex numbers are instantiated to
   727 be euclidean_spaces.  INCOMPATIBILITY.
   728 
   729 * Session Probability: introduced pextreal as positive extended real
   730 numbers.  Use pextreal as value for measures.  Introduce the
   731 Radon-Nikodym derivative, product spaces and Fubini's theorem for
   732 arbitrary sigma finite measures.  Introduces Lebesgue measure based on
   733 the integral in Multivariate Analysis.  INCOMPATIBILITY.
   734 
   735 * Session Imperative_HOL: revamped, corrected dozens of inadequacies.
   736 INCOMPATIBILITY.
   737 
   738 * Session SPARK (with image HOL-SPARK) provides commands to load and
   739 prove verification conditions generated by the SPARK Ada program
   740 verifier.  See also src/HOL/SPARK and src/HOL/SPARK/Examples.
   741 
   742 
   743 *** HOL-Algebra ***
   744 
   745 * Theorems for additive ring operations (locale abelian_monoid and
   746 descendants) are generated by interpretation from their multiplicative
   747 counterparts.  Names (in particular theorem names) have the mandatory
   748 qualifier 'add'.  Previous theorem names are redeclared for
   749 compatibility.
   750 
   751 * Structure "int_ring" is now an abbreviation (previously a
   752 definition).  This fits more natural with advanced interpretations.
   753 
   754 
   755 *** HOLCF ***
   756 
   757 * The domain package now runs in definitional mode by default: The
   758 former command 'new_domain' is now called 'domain'.  To use the domain
   759 package in its original axiomatic mode, use 'domain (unsafe)'.
   760 INCOMPATIBILITY.
   761 
   762 * The new class "domain" is now the default sort.  Class "predomain"
   763 is an unpointed version of "domain". Theories can be updated by
   764 replacing sort annotations as shown below.  INCOMPATIBILITY.
   765 
   766   'a::type ~> 'a::countable
   767   'a::cpo  ~> 'a::predomain
   768   'a::pcpo ~> 'a::domain
   769 
   770 * The old type class "rep" has been superseded by class "domain".
   771 Accordingly, users of the definitional package must remove any
   772 "default_sort rep" declarations.  INCOMPATIBILITY.
   773 
   774 * The domain package (definitional mode) now supports unpointed
   775 predomain argument types, as long as they are marked 'lazy'. (Strict
   776 arguments must be in class "domain".) For example, the following
   777 domain definition now works:
   778 
   779   domain natlist = nil | cons (lazy "nat discr") (lazy "natlist")
   780 
   781 * Theory HOLCF/Library/HOL_Cpo provides cpo and predomain class
   782 instances for types from main HOL: bool, nat, int, char, 'a + 'b,
   783 'a option, and 'a list.  Additionally, it configures fixrec and the
   784 domain package to work with these types.  For example:
   785 
   786   fixrec isInl :: "('a + 'b) u -> tr"
   787     where "isInl$(up$(Inl x)) = TT" | "isInl$(up$(Inr y)) = FF"
   788 
   789   domain V = VFun (lazy "V -> V") | VCon (lazy "nat") (lazy "V list")
   790 
   791 * The "(permissive)" option of fixrec has been replaced with a
   792 per-equation "(unchecked)" option. See
   793 src/HOL/HOLCF/Tutorial/Fixrec_ex.thy for examples. INCOMPATIBILITY.
   794 
   795 * The "bifinite" class no longer fixes a constant "approx"; the class
   796 now just asserts that such a function exists.  INCOMPATIBILITY.
   797 
   798 * Former type "alg_defl" has been renamed to "defl".  HOLCF no longer
   799 defines an embedding of type 'a defl into udom by default; instances
   800 of "bifinite" and "domain" classes are available in
   801 src/HOL/HOLCF/Library/Defl_Bifinite.thy.
   802 
   803 * The syntax "REP('a)" has been replaced with "DEFL('a)".
   804 
   805 * The predicate "directed" has been removed.  INCOMPATIBILITY.
   806 
   807 * The type class "finite_po" has been removed.  INCOMPATIBILITY.
   808 
   809 * The function "cprod_map" has been renamed to "prod_map".
   810 INCOMPATIBILITY.
   811 
   812 * The monadic bind operator on each powerdomain has new binder syntax
   813 similar to sets, e.g. "\<Union>\<sharp>x\<in>xs. t" represents
   814 "upper_bind\<cdot>xs\<cdot>(\<Lambda> x. t)".
   815 
   816 * The infix syntax for binary union on each powerdomain has changed
   817 from e.g. "+\<sharp>" to "\<union>\<sharp>", for consistency with set
   818 syntax.  INCOMPATIBILITY.
   819 
   820 * The constant "UU" has been renamed to "bottom".  The syntax "UU" is
   821 still supported as an input translation.
   822 
   823 * Renamed some theorems (the original names are also still available).
   824 
   825   expand_fun_below   ~> fun_below_iff
   826   below_fun_ext      ~> fun_belowI
   827   expand_cfun_eq     ~> cfun_eq_iff
   828   ext_cfun           ~> cfun_eqI
   829   expand_cfun_below  ~> cfun_below_iff
   830   below_cfun_ext     ~> cfun_belowI
   831   cont2cont_Rep_CFun ~> cont2cont_APP
   832 
   833 * The Abs and Rep functions for various types have changed names.
   834 Related theorem names have also changed to match. INCOMPATIBILITY.
   835 
   836   Rep_CFun  ~> Rep_cfun
   837   Abs_CFun  ~> Abs_cfun
   838   Rep_Sprod ~> Rep_sprod
   839   Abs_Sprod ~> Abs_sprod
   840   Rep_Ssum  ~> Rep_ssum
   841   Abs_Ssum  ~> Abs_ssum
   842 
   843 * Lemmas with names of the form *_defined_iff or *_strict_iff have
   844 been renamed to *_bottom_iff.  INCOMPATIBILITY.
   845 
   846 * Various changes to bisimulation/coinduction with domain package:
   847 
   848   - Definitions of "bisim" constants no longer mention definedness.
   849   - With mutual recursion, "bisim" predicate is now curried.
   850   - With mutual recursion, each type gets a separate coind theorem.
   851   - Variable names in bisim_def and coinduct rules have changed.
   852 
   853 INCOMPATIBILITY.
   854 
   855 * Case combinators generated by the domain package for type "foo" are
   856 now named "foo_case" instead of "foo_when".  INCOMPATIBILITY.
   857 
   858 * Several theorems have been renamed to more accurately reflect the
   859 names of constants and types involved.  INCOMPATIBILITY.
   860 
   861   thelub_const    ~> lub_const
   862   lub_const       ~> is_lub_const
   863   thelubI         ~> lub_eqI
   864   is_lub_lub      ~> is_lubD2
   865   lubI            ~> is_lub_lub
   866   unique_lub      ~> is_lub_unique
   867   is_ub_lub       ~> is_lub_rangeD1
   868   lub_bin_chain   ~> is_lub_bin_chain
   869   lub_fun         ~> is_lub_fun
   870   thelub_fun      ~> lub_fun
   871   thelub_cfun     ~> lub_cfun
   872   thelub_Pair     ~> lub_Pair
   873   lub_cprod       ~> is_lub_prod
   874   thelub_cprod    ~> lub_prod
   875   minimal_cprod   ~> minimal_prod
   876   inst_cprod_pcpo ~> inst_prod_pcpo
   877   UU_I            ~> bottomI
   878   compact_UU      ~> compact_bottom
   879   deflation_UU    ~> deflation_bottom
   880   finite_deflation_UU ~> finite_deflation_bottom
   881 
   882 * Many legacy theorem names have been discontinued.  INCOMPATIBILITY.
   883 
   884   sq_ord_less_eq_trans ~> below_eq_trans
   885   sq_ord_eq_less_trans ~> eq_below_trans
   886   refl_less            ~> below_refl
   887   trans_less           ~> below_trans
   888   antisym_less         ~> below_antisym
   889   antisym_less_inverse ~> po_eq_conv [THEN iffD1]
   890   box_less             ~> box_below
   891   rev_trans_less       ~> rev_below_trans
   892   not_less2not_eq      ~> not_below2not_eq
   893   less_UU_iff          ~> below_UU_iff
   894   flat_less_iff        ~> flat_below_iff
   895   adm_less             ~> adm_below
   896   adm_not_less         ~> adm_not_below
   897   adm_compact_not_less ~> adm_compact_not_below
   898   less_fun_def         ~> below_fun_def
   899   expand_fun_less      ~> fun_below_iff
   900   less_fun_ext         ~> fun_belowI
   901   less_discr_def       ~> below_discr_def
   902   discr_less_eq        ~> discr_below_eq
   903   less_unit_def        ~> below_unit_def
   904   less_cprod_def       ~> below_prod_def
   905   prod_lessI           ~> prod_belowI
   906   Pair_less_iff        ~> Pair_below_iff
   907   fst_less_iff         ~> fst_below_iff
   908   snd_less_iff         ~> snd_below_iff
   909   expand_cfun_less     ~> cfun_below_iff
   910   less_cfun_ext        ~> cfun_belowI
   911   injection_less       ~> injection_below
   912   less_up_def          ~> below_up_def
   913   not_Iup_less         ~> not_Iup_below
   914   Iup_less             ~> Iup_below
   915   up_less              ~> up_below
   916   Def_inject_less_eq   ~> Def_below_Def
   917   Def_less_is_eq       ~> Def_below_iff
   918   spair_less_iff       ~> spair_below_iff
   919   less_sprod           ~> below_sprod
   920   spair_less           ~> spair_below
   921   sfst_less_iff        ~> sfst_below_iff
   922   ssnd_less_iff        ~> ssnd_below_iff
   923   fix_least_less       ~> fix_least_below
   924   dist_less_one        ~> dist_below_one
   925   less_ONE             ~> below_ONE
   926   ONE_less_iff         ~> ONE_below_iff
   927   less_sinlD           ~> below_sinlD
   928   less_sinrD           ~> below_sinrD
   929 
   930 
   931 *** FOL and ZF ***
   932 
   933 * All constant names are now qualified internally and use proper
   934 identifiers, e.g. "IFOL.eq" instead of "op =".  INCOMPATIBILITY.
   935 
   936 
   937 *** ML ***
   938 
   939 * Antiquotation @{assert} inlines a function bool -> unit that raises
   940 Fail if the argument is false.  Due to inlining the source position of
   941 failed assertions is included in the error output.
   942 
   943 * Discontinued antiquotation @{theory_ref}, which is obsolete since ML
   944 text is in practice always evaluated with a stable theory checkpoint.
   945 Minor INCOMPATIBILITY, use (Theory.check_thy @{theory}) instead.
   946 
   947 * Antiquotation @{theory A} refers to theory A from the ancestry of
   948 the current context, not any accidental theory loader state as before.
   949 Potential INCOMPATIBILITY, subtle change in semantics.
   950 
   951 * Syntax.pretty_priority (default 0) configures the required priority
   952 of pretty-printed output and thus affects insertion of parentheses.
   953 
   954 * Syntax.default_root (default "any") configures the inner syntax
   955 category (nonterminal symbol) for parsing of terms.
   956 
   957 * Former exception Library.UnequalLengths now coincides with
   958 ListPair.UnequalLengths.
   959 
   960 * Renamed structure MetaSimplifier to Raw_Simplifier.  Note that the
   961 main functionality is provided by structure Simplifier.
   962 
   963 * Renamed raw "explode" function to "raw_explode" to emphasize its
   964 meaning.  Note that internally to Isabelle, Symbol.explode is used in
   965 almost all situations.
   966 
   967 * Discontinued obsolete function sys_error and exception SYS_ERROR.
   968 See implementation manual for further details on exceptions in
   969 Isabelle/ML.
   970 
   971 * Renamed setmp_noncritical to Unsynchronized.setmp to emphasize its
   972 meaning.
   973 
   974 * Renamed structure PureThy to Pure_Thy and moved most of its
   975 operations to structure Global_Theory, to emphasize that this is
   976 rarely-used global-only stuff.
   977 
   978 * Discontinued Output.debug.  Minor INCOMPATIBILITY, use plain writeln
   979 instead (or tracing for high-volume output).
   980 
   981 * Configuration option show_question_marks only affects regular pretty
   982 printing of types and terms, not raw Term.string_of_vname.
   983 
   984 * ML_Context.thm and ML_Context.thms are no longer pervasive.  Rare
   985 INCOMPATIBILITY, superseded by static antiquotations @{thm} and
   986 @{thms} for most purposes.
   987 
   988 * ML structure Unsynchronized is never opened, not even in Isar
   989 interaction mode as before.  Old Unsynchronized.set etc. have been
   990 discontinued -- use plain := instead.  This should be *rare* anyway,
   991 since modern tools always work via official context data, notably
   992 configuration options.
   993 
   994 * Parallel and asynchronous execution requires special care concerning
   995 interrupts.  Structure Exn provides some convenience functions that
   996 avoid working directly with raw Interrupt.  User code must not absorb
   997 interrupts -- intermediate handling (for cleanup etc.) needs to be
   998 followed by re-raising of the original exception.  Another common
   999 source of mistakes are "handle _" patterns, which make the meaning of
  1000 the program subject to physical effects of the environment.
  1001 
  1002 
  1003 
  1004 New in Isabelle2009-2 (June 2010)
  1005 ---------------------------------
  1006 
  1007 *** General ***
  1008 
  1009 * Authentic syntax for *all* logical entities (type classes, type
  1010 constructors, term constants): provides simple and robust
  1011 correspondence between formal entities and concrete syntax.  Within
  1012 the parse tree / AST representations, "constants" are decorated by
  1013 their category (class, type, const) and spelled out explicitly with
  1014 their full internal name.
  1015 
  1016 Substantial INCOMPATIBILITY concerning low-level syntax declarations
  1017 and translations (translation rules and translation functions in ML).
  1018 Some hints on upgrading:
  1019 
  1020   - Many existing uses of 'syntax' and 'translations' can be replaced
  1021     by more modern 'type_notation', 'notation' and 'abbreviation',
  1022     which are independent of this issue.
  1023 
  1024   - 'translations' require markup within the AST; the term syntax
  1025     provides the following special forms:
  1026 
  1027       CONST c   -- produces syntax version of constant c from context
  1028       XCONST c  -- literally c, checked as constant from context
  1029       c         -- literally c, if declared by 'syntax'
  1030 
  1031     Plain identifiers are treated as AST variables -- occasionally the
  1032     system indicates accidental variables via the error "rhs contains
  1033     extra variables".
  1034 
  1035     Type classes and type constructors are marked according to their
  1036     concrete syntax.  Some old translations rules need to be written
  1037     for the "type" category, using type constructor application
  1038     instead of pseudo-term application of the default category
  1039     "logic".
  1040 
  1041   - 'parse_translation' etc. in ML may use the following
  1042     antiquotations:
  1043 
  1044       @{class_syntax c}   -- type class c within parse tree / AST
  1045       @{term_syntax c}    -- type constructor c within parse tree / AST
  1046       @{const_syntax c}   -- ML version of "CONST c" above
  1047       @{syntax_const c}   -- literally c (checked wrt. 'syntax' declarations)
  1048 
  1049   - Literal types within 'typed_print_translations', i.e. those *not*
  1050     represented as pseudo-terms are represented verbatim.  Use @{class
  1051     c} or @{type_name c} here instead of the above syntax
  1052     antiquotations.
  1053 
  1054 Note that old non-authentic syntax was based on unqualified base
  1055 names, so all of the above "constant" names would coincide.  Recall
  1056 that 'print_syntax' and ML_command "set Syntax.trace_ast" help to
  1057 diagnose syntax problems.
  1058 
  1059 * Type constructors admit general mixfix syntax, not just infix.
  1060 
  1061 * Concrete syntax may be attached to local entities without a proof
  1062 body, too.  This works via regular mixfix annotations for 'fix',
  1063 'def', 'obtain' etc. or via the explicit 'write' command, which is
  1064 similar to the 'notation' command in theory specifications.
  1065 
  1066 * Discontinued unnamed infix syntax (legacy feature for many years) --
  1067 need to specify constant name and syntax separately.  Internal ML
  1068 datatype constructors have been renamed from InfixName to Infix etc.
  1069 Minor INCOMPATIBILITY.
  1070 
  1071 * Schematic theorem statements need to be explicitly markup as such,
  1072 via commands 'schematic_lemma', 'schematic_theorem',
  1073 'schematic_corollary'.  Thus the relevance of the proof is made
  1074 syntactically clear, which impacts performance in a parallel or
  1075 asynchronous interactive environment.  Minor INCOMPATIBILITY.
  1076 
  1077 * Use of cumulative prems via "!" in some proof methods has been
  1078 discontinued (old legacy feature).
  1079 
  1080 * References 'trace_simp' and 'debug_simp' have been replaced by
  1081 configuration options stored in the context. Enabling tracing (the
  1082 case of debugging is similar) in proofs works via
  1083 
  1084   using [[trace_simp = true]]
  1085 
  1086 Tracing is then active for all invocations of the simplifier in
  1087 subsequent goal refinement steps. Tracing may also still be enabled or
  1088 disabled via the ProofGeneral settings menu.
  1089 
  1090 * Separate commands 'hide_class', 'hide_type', 'hide_const',
  1091 'hide_fact' replace the former 'hide' KIND command.  Minor
  1092 INCOMPATIBILITY.
  1093 
  1094 * Improved parallelism of proof term normalization: usedir -p2 -q0 is
  1095 more efficient than combinations with -q1 or -q2.
  1096 
  1097 
  1098 *** Pure ***
  1099 
  1100 * Proofterms record type-class reasoning explicitly, using the
  1101 "unconstrain" operation internally.  This eliminates all sort
  1102 constraints from a theorem and proof, introducing explicit
  1103 OFCLASS-premises.  On the proof term level, this operation is
  1104 automatically applied at theorem boundaries, such that closed proofs
  1105 are always free of sort constraints.  INCOMPATIBILITY for tools that
  1106 inspect proof terms.
  1107 
  1108 * Local theory specifications may depend on extra type variables that
  1109 are not present in the result type -- arguments TYPE('a) :: 'a itself
  1110 are added internally.  For example:
  1111 
  1112   definition unitary :: bool where "unitary = (ALL (x::'a) y. x = y)"
  1113 
  1114 * Predicates of locales introduced by classes carry a mandatory
  1115 "class" prefix.  INCOMPATIBILITY.
  1116 
  1117 * Vacuous class specifications observe default sort.  INCOMPATIBILITY.
  1118 
  1119 * Old 'axclass' command has been discontinued.  INCOMPATIBILITY, use
  1120 'class' instead.
  1121 
  1122 * Command 'code_reflect' allows to incorporate generated ML code into
  1123 runtime environment; replaces immature code_datatype antiquotation.
  1124 INCOMPATIBILITY.
  1125 
  1126 * Code generator: simple concept for abstract datatypes obeying
  1127 invariants.
  1128 
  1129 * Code generator: details of internal data cache have no impact on the
  1130 user space functionality any longer.
  1131 
  1132 * Methods "unfold_locales" and "intro_locales" ignore non-locale
  1133 subgoals.  This is more appropriate for interpretations with 'where'.
  1134 INCOMPATIBILITY.
  1135 
  1136 * Command 'example_proof' opens an empty proof body.  This allows to
  1137 experiment with Isar, without producing any persistent result.
  1138 
  1139 * Commands 'type_notation' and 'no_type_notation' declare type syntax
  1140 within a local theory context, with explicit checking of the
  1141 constructors involved (in contrast to the raw 'syntax' versions).
  1142 
  1143 * Commands 'types' and 'typedecl' now work within a local theory
  1144 context -- without introducing dependencies on parameters or
  1145 assumptions, which is not possible in Isabelle/Pure.
  1146 
  1147 * Command 'defaultsort' has been renamed to 'default_sort', it works
  1148 within a local theory context.  Minor INCOMPATIBILITY.
  1149 
  1150 
  1151 *** HOL ***
  1152 
  1153 * Command 'typedef' now works within a local theory context -- without
  1154 introducing dependencies on parameters or assumptions, which is not
  1155 possible in Isabelle/Pure/HOL.  Note that the logical environment may
  1156 contain multiple interpretations of local typedefs (with different
  1157 non-emptiness proofs), even in a global theory context.
  1158 
  1159 * New package for quotient types.  Commands 'quotient_type' and
  1160 'quotient_definition' may be used for defining types and constants by
  1161 quotient constructions.  An example is the type of integers created by
  1162 quotienting pairs of natural numbers:
  1163 
  1164   fun
  1165     intrel :: "(nat * nat) => (nat * nat) => bool"
  1166   where
  1167     "intrel (x, y) (u, v) = (x + v = u + y)"
  1168 
  1169   quotient_type int = "nat * nat" / intrel
  1170     by (auto simp add: equivp_def expand_fun_eq)
  1171 
  1172   quotient_definition
  1173     "0::int" is "(0::nat, 0::nat)"
  1174 
  1175 The method "lifting" can be used to lift of theorems from the
  1176 underlying "raw" type to the quotient type.  The example
  1177 src/HOL/Quotient_Examples/FSet.thy includes such a quotient
  1178 construction and provides a reasoning infrastructure for finite sets.
  1179 
  1180 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
  1181 clash with new theory Quotient in Main HOL.
  1182 
  1183 * Moved the SMT binding into the main HOL session, eliminating
  1184 separate HOL-SMT session.
  1185 
  1186 * List membership infix mem operation is only an input abbreviation.
  1187 INCOMPATIBILITY.
  1188 
  1189 * Theory Library/Word.thy has been removed.  Use library Word/Word.thy
  1190 for future developements; former Library/Word.thy is still present in
  1191 the AFP entry RSAPPS.
  1192 
  1193 * Theorem Int.int_induct renamed to Int.int_of_nat_induct and is no
  1194 longer shadowed.  INCOMPATIBILITY.
  1195 
  1196 * Dropped theorem duplicate comp_arith; use semiring_norm instead.
  1197 INCOMPATIBILITY.
  1198 
  1199 * Dropped theorem RealPow.real_sq_order; use power2_le_imp_le instead.
  1200 INCOMPATIBILITY.
  1201 
  1202 * Dropped normalizing_semiring etc; use the facts in semiring classes
  1203 instead.  INCOMPATIBILITY.
  1204 
  1205 * Dropped several real-specific versions of lemmas about floor and
  1206 ceiling; use the generic lemmas from theory "Archimedean_Field"
  1207 instead.  INCOMPATIBILITY.
  1208 
  1209   floor_number_of_eq         ~> floor_number_of
  1210   le_floor_eq_number_of      ~> number_of_le_floor
  1211   le_floor_eq_zero           ~> zero_le_floor
  1212   le_floor_eq_one            ~> one_le_floor
  1213   floor_less_eq_number_of    ~> floor_less_number_of
  1214   floor_less_eq_zero         ~> floor_less_zero
  1215   floor_less_eq_one          ~> floor_less_one
  1216   less_floor_eq_number_of    ~> number_of_less_floor
  1217   less_floor_eq_zero         ~> zero_less_floor
  1218   less_floor_eq_one          ~> one_less_floor
  1219   floor_le_eq_number_of      ~> floor_le_number_of
  1220   floor_le_eq_zero           ~> floor_le_zero
  1221   floor_le_eq_one            ~> floor_le_one
  1222   floor_subtract_number_of   ~> floor_diff_number_of
  1223   floor_subtract_one         ~> floor_diff_one
  1224   ceiling_number_of_eq       ~> ceiling_number_of
  1225   ceiling_le_eq_number_of    ~> ceiling_le_number_of
  1226   ceiling_le_zero_eq         ~> ceiling_le_zero
  1227   ceiling_le_eq_one          ~> ceiling_le_one
  1228   less_ceiling_eq_number_of  ~> number_of_less_ceiling
  1229   less_ceiling_eq_zero       ~> zero_less_ceiling
  1230   less_ceiling_eq_one        ~> one_less_ceiling
  1231   ceiling_less_eq_number_of  ~> ceiling_less_number_of
  1232   ceiling_less_eq_zero       ~> ceiling_less_zero
  1233   ceiling_less_eq_one        ~> ceiling_less_one
  1234   le_ceiling_eq_number_of    ~> number_of_le_ceiling
  1235   le_ceiling_eq_zero         ~> zero_le_ceiling
  1236   le_ceiling_eq_one          ~> one_le_ceiling
  1237   ceiling_subtract_number_of ~> ceiling_diff_number_of
  1238   ceiling_subtract_one       ~> ceiling_diff_one
  1239 
  1240 * Theory "Finite_Set": various folding_XXX locales facilitate the
  1241 application of the various fold combinators on finite sets.
  1242 
  1243 * Library theory "RBT" renamed to "RBT_Impl"; new library theory "RBT"
  1244 provides abstract red-black tree type which is backed by "RBT_Impl" as
  1245 implementation.  INCOMPATIBILTY.
  1246 
  1247 * Theory Library/Coinductive_List has been removed -- superseded by
  1248 AFP/thys/Coinductive.
  1249 
  1250 * Theory PReal, including the type "preal" and related operations, has
  1251 been removed.  INCOMPATIBILITY.
  1252 
  1253 * Real: new development using Cauchy Sequences.
  1254 
  1255 * Split off theory "Big_Operators" containing setsum, setprod,
  1256 Inf_fin, Sup_fin, Min, Max from theory Finite_Set.  INCOMPATIBILITY.
  1257 
  1258 * Theory "Rational" renamed to "Rat", for consistency with "Nat",
  1259 "Int" etc.  INCOMPATIBILITY.
  1260 
  1261 * Constant Rat.normalize needs to be qualified.  INCOMPATIBILITY.
  1262 
  1263 * New set of rules "ac_simps" provides combined assoc / commute
  1264 rewrites for all interpretations of the appropriate generic locales.
  1265 
  1266 * Renamed theory "OrderedGroup" to "Groups" and split theory
  1267 "Ring_and_Field" into theories "Rings" and "Fields"; for more
  1268 appropriate and more consistent names suitable for name prefixes
  1269 within the HOL theories.  INCOMPATIBILITY.
  1270 
  1271 * Some generic constants have been put to appropriate theories:
  1272   - less_eq, less: Orderings
  1273   - zero, one, plus, minus, uminus, times, abs, sgn: Groups
  1274   - inverse, divide: Rings
  1275 INCOMPATIBILITY.
  1276 
  1277 * More consistent naming of type classes involving orderings (and
  1278 lattices):
  1279 
  1280     lower_semilattice                   ~> semilattice_inf
  1281     upper_semilattice                   ~> semilattice_sup
  1282 
  1283     dense_linear_order                  ~> dense_linorder
  1284 
  1285     pordered_ab_group_add               ~> ordered_ab_group_add
  1286     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
  1287     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
  1288     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
  1289     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
  1290     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
  1291     pordered_cancel_semiring            ~> ordered_cancel_semiring
  1292     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
  1293     pordered_comm_ring                  ~> ordered_comm_ring
  1294     pordered_comm_semiring              ~> ordered_comm_semiring
  1295     pordered_ring                       ~> ordered_ring
  1296     pordered_ring_abs                   ~> ordered_ring_abs
  1297     pordered_semiring                   ~> ordered_semiring
  1298 
  1299     ordered_ab_group_add                ~> linordered_ab_group_add
  1300     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
  1301     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
  1302     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
  1303     ordered_field                       ~> linordered_field
  1304     ordered_field_no_lb                 ~> linordered_field_no_lb
  1305     ordered_field_no_ub                 ~> linordered_field_no_ub
  1306     ordered_field_dense_linear_order    ~> dense_linordered_field
  1307     ordered_idom                        ~> linordered_idom
  1308     ordered_ring                        ~> linordered_ring
  1309     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
  1310     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
  1311     ordered_ring_strict                 ~> linordered_ring_strict
  1312     ordered_semidom                     ~> linordered_semidom
  1313     ordered_semiring                    ~> linordered_semiring
  1314     ordered_semiring_1                  ~> linordered_semiring_1
  1315     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
  1316     ordered_semiring_strict             ~> linordered_semiring_strict
  1317 
  1318   The following slightly odd type classes have been moved to a
  1319   separate theory Library/Lattice_Algebras:
  1320 
  1321     lordered_ab_group_add               ~> lattice_ab_group_add
  1322     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
  1323     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
  1324     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
  1325     lordered_ring                       ~> lattice_ring
  1326 
  1327 INCOMPATIBILITY.
  1328 
  1329 * Refined field classes:
  1330   - classes division_ring_inverse_zero, field_inverse_zero,
  1331     linordered_field_inverse_zero include rule inverse 0 = 0 --
  1332     subsumes former division_by_zero class;
  1333   - numerous lemmas have been ported from field to division_ring.
  1334 INCOMPATIBILITY.
  1335 
  1336 * Refined algebra theorem collections:
  1337   - dropped theorem group group_simps, use algebra_simps instead;
  1338   - dropped theorem group ring_simps, use field_simps instead;
  1339   - proper theorem collection field_simps subsumes former theorem
  1340     groups field_eq_simps and field_simps;
  1341   - dropped lemma eq_minus_self_iff which is a duplicate for
  1342     equal_neg_zero.
  1343 INCOMPATIBILITY.
  1344 
  1345 * Theory Finite_Set and List: some lemmas have been generalized from
  1346 sets to lattices:
  1347 
  1348   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
  1349   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
  1350   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
  1351   union_Union_fold_union        ~> sup_Sup_fold_sup
  1352   Inter_fold_inter              ~> Inf_fold_inf
  1353   Union_fold_union              ~> Sup_fold_sup
  1354   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
  1355   union_UNION_fold_union        ~> sup_SUPR_fold_sup
  1356   INTER_fold_inter              ~> INFI_fold_inf
  1357   UNION_fold_union              ~> SUPR_fold_sup
  1358 
  1359 * Theory "Complete_Lattice": lemmas top_def and bot_def have been
  1360 replaced by the more convenient lemmas Inf_empty and Sup_empty.
  1361 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
  1362 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
  1363 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
  1364 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
  1365 
  1366 * Reorganized theory Multiset: swapped notation of pointwise and
  1367 multiset order:
  1368 
  1369   - pointwise ordering is instance of class order with standard syntax
  1370     <= and <;
  1371   - multiset ordering has syntax <=# and <#; partial order properties
  1372     are provided by means of interpretation with prefix
  1373     multiset_order;
  1374   - less duplication, less historical organization of sections,
  1375     conversion from associations lists to multisets, rudimentary code
  1376     generation;
  1377   - use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union,
  1378     if needed.
  1379 
  1380 Renamed:
  1381 
  1382   multiset_eq_conv_count_eq  ~>  multiset_ext_iff
  1383   multi_count_ext  ~>  multiset_ext
  1384   diff_union_inverse2  ~>  diff_union_cancelR
  1385 
  1386 INCOMPATIBILITY.
  1387 
  1388 * Theory Permutation: replaced local "remove" by List.remove1.
  1389 
  1390 * Code generation: ML and OCaml code is decorated with signatures.
  1391 
  1392 * Theory List: added transpose.
  1393 
  1394 * Library/Nat_Bijection.thy is a collection of bijective functions
  1395 between nat and other types, which supersedes the older libraries
  1396 Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.
  1397 
  1398   Constants:
  1399   Nat_Int_Bij.nat2_to_nat         ~> prod_encode
  1400   Nat_Int_Bij.nat_to_nat2         ~> prod_decode
  1401   Nat_Int_Bij.int_to_nat_bij      ~> int_encode
  1402   Nat_Int_Bij.nat_to_int_bij      ~> int_decode
  1403   Countable.pair_encode           ~> prod_encode
  1404   NatIso.prod2nat                 ~> prod_encode
  1405   NatIso.nat2prod                 ~> prod_decode
  1406   NatIso.sum2nat                  ~> sum_encode
  1407   NatIso.nat2sum                  ~> sum_decode
  1408   NatIso.list2nat                 ~> list_encode
  1409   NatIso.nat2list                 ~> list_decode
  1410   NatIso.set2nat                  ~> set_encode
  1411   NatIso.nat2set                  ~> set_decode
  1412 
  1413   Lemmas:
  1414   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
  1415   Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
  1416   Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
  1417   Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
  1418   Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
  1419   Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
  1420   Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
  1421   Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
  1422   Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
  1423   Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
  1424   Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
  1425   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
  1426   Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode
  1427 
  1428 * Sledgehammer:
  1429   - Renamed ATP commands:
  1430     atp_info     ~> sledgehammer running_atps
  1431     atp_kill     ~> sledgehammer kill_atps
  1432     atp_messages ~> sledgehammer messages
  1433     atp_minimize ~> sledgehammer minimize
  1434     print_atps   ~> sledgehammer available_atps
  1435     INCOMPATIBILITY.
  1436   - Added user's manual ("isabelle doc sledgehammer").
  1437   - Added option syntax and "sledgehammer_params" to customize
  1438     Sledgehammer's behavior.  See the manual for details.
  1439   - Modified the Isar proof reconstruction code so that it produces
  1440     direct proofs rather than proofs by contradiction.  (This feature
  1441     is still experimental.)
  1442   - Made Isar proof reconstruction work for SPASS, remote ATPs, and in
  1443     full-typed mode.
  1444   - Added support for TPTP syntax for SPASS via the "spass_tptp" ATP.
  1445 
  1446 * Nitpick:
  1447   - Added and implemented "binary_ints" and "bits" options.
  1448   - Added "std" option and implemented support for nonstandard models.
  1449   - Added and implemented "finitize" option to improve the precision
  1450     of infinite datatypes based on a monotonicity analysis.
  1451   - Added support for quotient types.
  1452   - Added support for "specification" and "ax_specification"
  1453     constructs.
  1454   - Added support for local definitions (for "function" and
  1455     "termination" proofs).
  1456   - Added support for term postprocessors.
  1457   - Optimized "Multiset.multiset" and "FinFun.finfun".
  1458   - Improved efficiency of "destroy_constrs" optimization.
  1459   - Fixed soundness bugs related to "destroy_constrs" optimization and
  1460     record getters.
  1461   - Fixed soundness bug related to higher-order constructors.
  1462   - Fixed soundness bug when "full_descrs" is enabled.
  1463   - Improved precision of set constructs.
  1464   - Added "atoms" option.
  1465   - Added cache to speed up repeated Kodkod invocations on the same
  1466     problems.
  1467   - Renamed "MiniSatJNI", "zChaffJNI", "BerkMinAlloy", and
  1468     "SAT4JLight" to "MiniSat_JNI", "zChaff_JNI", "BerkMin_Alloy", and
  1469     "SAT4J_Light".  INCOMPATIBILITY.
  1470   - Removed "skolemize", "uncurry", "sym_break", "flatten_prop",
  1471     "sharing_depth", and "show_skolems" options.  INCOMPATIBILITY.
  1472   - Removed "nitpick_intro" attribute.  INCOMPATIBILITY.
  1473 
  1474 * Method "induct" now takes instantiations of the form t, where t is not
  1475   a variable, as a shorthand for "x == t", where x is a fresh variable.
  1476   If this is not intended, t has to be enclosed in parentheses.
  1477   By default, the equalities generated by definitional instantiations
  1478   are pre-simplified, which may cause parameters of inductive cases
  1479   to disappear, or may even delete some of the inductive cases.
  1480   Use "induct (no_simp)" instead of "induct" to restore the old
  1481   behaviour. The (no_simp) option is also understood by the "cases"
  1482   and "nominal_induct" methods, which now perform pre-simplification, too.
  1483   INCOMPATIBILITY.
  1484 
  1485 
  1486 *** HOLCF ***
  1487 
  1488 * Variable names in lemmas generated by the domain package have
  1489 changed; the naming scheme is now consistent with the HOL datatype
  1490 package.  Some proof scripts may be affected, INCOMPATIBILITY.
  1491 
  1492 * The domain package no longer defines the function "foo_copy" for
  1493 recursive domain "foo".  The reach lemma is now stated directly in
  1494 terms of "foo_take".  Lemmas and proofs that mention "foo_copy" must
  1495 be reformulated in terms of "foo_take", INCOMPATIBILITY.
  1496 
  1497 * Most definedness lemmas generated by the domain package (previously
  1498 of the form "x ~= UU ==> foo$x ~= UU") now have an if-and-only-if form
  1499 like "foo$x = UU <-> x = UU", which works better as a simp rule.
  1500 Proofs that used definedness lemmas as intro rules may break,
  1501 potential INCOMPATIBILITY.
  1502 
  1503 * Induction and casedist rules generated by the domain package now
  1504 declare proper case_names (one called "bottom", and one named for each
  1505 constructor).  INCOMPATIBILITY.
  1506 
  1507 * For mutually-recursive domains, separate "reach" and "take_lemma"
  1508 rules are generated for each domain, INCOMPATIBILITY.
  1509 
  1510   foo_bar.reach       ~> foo.reach  bar.reach
  1511   foo_bar.take_lemmas ~> foo.take_lemma  bar.take_lemma
  1512 
  1513 * Some lemmas generated by the domain package have been renamed for
  1514 consistency with the datatype package, INCOMPATIBILITY.
  1515 
  1516   foo.ind        ~> foo.induct
  1517   foo.finite_ind ~> foo.finite_induct
  1518   foo.coind      ~> foo.coinduct
  1519   foo.casedist   ~> foo.exhaust
  1520   foo.exhaust    ~> foo.nchotomy
  1521 
  1522 * For consistency with other definition packages, the fixrec package
  1523 now generates qualified theorem names, INCOMPATIBILITY.
  1524 
  1525   foo_simps  ~> foo.simps
  1526   foo_unfold ~> foo.unfold
  1527   foo_induct ~> foo.induct
  1528 
  1529 * The "fixrec_simp" attribute has been removed.  The "fixrec_simp"
  1530 method and internal fixrec proofs now use the default simpset instead.
  1531 INCOMPATIBILITY.
  1532 
  1533 * The "contlub" predicate has been removed.  Proof scripts should use
  1534 lemma contI2 in place of monocontlub2cont, INCOMPATIBILITY.
  1535 
  1536 * The "admw" predicate has been removed, INCOMPATIBILITY.
  1537 
  1538 * The constants cpair, cfst, and csnd have been removed in favor of
  1539 Pair, fst, and snd from Isabelle/HOL, INCOMPATIBILITY.
  1540 
  1541 
  1542 *** ML ***
  1543 
  1544 * Antiquotations for basic formal entities:
  1545 
  1546     @{class NAME}         -- type class
  1547     @{class_syntax NAME}  -- syntax representation of the above
  1548 
  1549     @{type_name NAME}     -- logical type
  1550     @{type_abbrev NAME}   -- type abbreviation
  1551     @{nonterminal NAME}   -- type of concrete syntactic category
  1552     @{type_syntax NAME}   -- syntax representation of any of the above
  1553 
  1554     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
  1555     @{const_abbrev NAME}  -- abbreviated constant
  1556     @{const_syntax NAME}  -- syntax representation of any of the above
  1557 
  1558 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
  1559 syntax constant (cf. 'syntax' command).
  1560 
  1561 * Antiquotation @{make_string} inlines a function to print arbitrary
  1562 values similar to the ML toplevel.  The result is compiler dependent
  1563 and may fall back on "?" in certain situations.
  1564 
  1565 * Diagnostic commands 'ML_val' and 'ML_command' may refer to
  1566 antiquotations @{Isar.state} and @{Isar.goal}.  This replaces impure
  1567 Isar.state() and Isar.goal(), which belong to the old TTY loop and do
  1568 not work with the asynchronous Isar document model.
  1569 
  1570 * Configuration options now admit dynamic default values, depending on
  1571 the context or even global references.
  1572 
  1573 * SHA1.digest digests strings according to SHA-1 (see RFC 3174).  It
  1574 uses an efficient external library if available (for Poly/ML).
  1575 
  1576 * Renamed some important ML structures, while keeping the old names
  1577 for some time as aliases within the structure Legacy:
  1578 
  1579   OuterKeyword  ~>  Keyword
  1580   OuterLex      ~>  Token
  1581   OuterParse    ~>  Parse
  1582   OuterSyntax   ~>  Outer_Syntax
  1583   PrintMode     ~>  Print_Mode
  1584   SpecParse     ~>  Parse_Spec
  1585   ThyInfo       ~>  Thy_Info
  1586   ThyLoad       ~>  Thy_Load
  1587   ThyOutput     ~>  Thy_Output
  1588   TypeInfer     ~>  Type_Infer
  1589 
  1590 Note that "open Legacy" simplifies porting of sources, but forgetting
  1591 to remove it again will complicate porting again in the future.
  1592 
  1593 * Most operations that refer to a global context are named
  1594 accordingly, e.g. Simplifier.global_context or
  1595 ProofContext.init_global.  There are some situations where a global
  1596 context actually works, but under normal circumstances one needs to
  1597 pass the proper local context through the code!
  1598 
  1599 * Discontinued old TheoryDataFun with its copy/init operation -- data
  1600 needs to be pure.  Functor Theory_Data_PP retains the traditional
  1601 Pretty.pp argument to merge, which is absent in the standard
  1602 Theory_Data version.
  1603 
  1604 * Sorts.certify_sort and derived "cert" operations for types and terms
  1605 no longer minimize sorts.  Thus certification at the boundary of the
  1606 inference kernel becomes invariant under addition of class relations,
  1607 which is an important monotonicity principle.  Sorts are now minimized
  1608 in the syntax layer only, at the boundary between the end-user and the
  1609 system.  Subtle INCOMPATIBILITY, may have to use Sign.minimize_sort
  1610 explicitly in rare situations.
  1611 
  1612 * Renamed old-style Drule.standard to Drule.export_without_context, to
  1613 emphasize that this is in no way a standard operation.
  1614 INCOMPATIBILITY.
  1615 
  1616 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
  1617 usual for resolution.  Rare INCOMPATIBILITY.
  1618 
  1619 * Renamed varify/unvarify operations to varify_global/unvarify_global
  1620 to emphasize that these only work in a global situation (which is
  1621 quite rare).
  1622 
  1623 * Curried take and drop in library.ML; negative length is interpreted
  1624 as infinity (as in chop).  Subtle INCOMPATIBILITY.
  1625 
  1626 * Proof terms: type substitutions on proof constants now use canonical
  1627 order of type variables.  INCOMPATIBILITY for tools working with proof
  1628 terms.
  1629 
  1630 * Raw axioms/defs may no longer carry sort constraints, and raw defs
  1631 may no longer carry premises.  User-level specifications are
  1632 transformed accordingly by Thm.add_axiom/add_def.
  1633 
  1634 
  1635 *** System ***
  1636 
  1637 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
  1638 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
  1639 proof terms are enabled unconditionally in the new HOL-Proofs image.
  1640 
  1641 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
  1642 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
  1643 respectively.
  1644 
  1645 * Old lib/scripts/polyml-platform is superseded by the
  1646 ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
  1647 variant, even on a 64 bit machine.  The following example setting
  1648 prefers 64 bit if available:
  1649 
  1650   ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"
  1651 
  1652 * The preliminary Isabelle/jEdit application demonstrates the emerging
  1653 Isabelle/Scala layer for advanced prover interaction and integration.
  1654 See src/Tools/jEdit or "isabelle jedit" provided by the properly built
  1655 component.
  1656 
  1657 * "IsabelleText" is a Unicode font derived from Bitstream Vera Mono
  1658 and Bluesky TeX fonts.  It provides the usual Isabelle symbols,
  1659 similar to the default assignment of the document preparation system
  1660 (cf. isabellesym.sty).  The Isabelle/Scala class Isabelle_System
  1661 provides some operations for direct access to the font without asking
  1662 the user for manual installation.
  1663 
  1664 
  1665 
  1666 New in Isabelle2009-1 (December 2009)
  1667 -------------------------------------
  1668 
  1669 *** General ***
  1670 
  1671 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
  1672 one backslash should be used, even in ML sources.
  1673 
  1674 
  1675 *** Pure ***
  1676 
  1677 * Locale interpretation propagates mixins along the locale hierarchy.
  1678 The currently only available mixins are the equations used to map
  1679 local definitions to terms of the target domain of an interpretation.
  1680 
  1681 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
  1682 loc" to print all interpretations of locale "loc" in the theory.
  1683 Interpretations in proofs are not shown.
  1684 
  1685 * Thoroughly revised locales tutorial.  New section on conditional
  1686 interpretation.
  1687 
  1688 * On instantiation of classes, remaining undefined class parameters
  1689 are formally declared.  INCOMPATIBILITY.
  1690 
  1691 
  1692 *** Document preparation ***
  1693 
  1694 * New generalized style concept for printing terms: @{foo (style) ...}
  1695 instead of @{foo_style style ...}  (old form is still retained for
  1696 backward compatibility).  Styles can be also applied for
  1697 antiquotations prop, term_type and typeof.
  1698 
  1699 
  1700 *** HOL ***
  1701 
  1702 * New proof method "smt" for a combination of first-order logic with
  1703 equality, linear and nonlinear (natural/integer/real) arithmetic, and
  1704 fixed-size bitvectors; there is also basic support for higher-order
  1705 features (esp. lambda abstractions).  It is an incomplete decision
  1706 procedure based on external SMT solvers using the oracle mechanism;
  1707 for the SMT solver Z3, this method is proof-producing.  Certificates
  1708 are provided to avoid calling the external solvers solely for
  1709 re-checking proofs.  Due to a remote SMT service there is no need for
  1710 installing SMT solvers locally.  See src/HOL/SMT.
  1711 
  1712 * New commands to load and prove verification conditions generated by
  1713 the Boogie program verifier or derived systems (e.g. the Verifying C
  1714 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
  1715 
  1716 * New counterexample generator tool 'nitpick' based on the Kodkod
  1717 relational model finder.  See src/HOL/Tools/Nitpick and
  1718 src/HOL/Nitpick_Examples.
  1719 
  1720 * New commands 'code_pred' and 'values' to invoke the predicate
  1721 compiler and to enumerate values of inductive predicates.
  1722 
  1723 * A tabled implementation of the reflexive transitive closure.
  1724 
  1725 * New implementation of quickcheck uses generic code generator;
  1726 default generators are provided for all suitable HOL types, records
  1727 and datatypes.  Old quickcheck can be re-activated importing theory
  1728 Library/SML_Quickcheck.
  1729 
  1730 * New testing tool Mirabelle for automated proof tools.  Applies
  1731 several tools and tactics like sledgehammer, metis, or quickcheck, to
  1732 every proof step in a theory.  To be used in batch mode via the
  1733 "mirabelle" utility.
  1734 
  1735 * New proof method "sos" (sum of squares) for nonlinear real
  1736 arithmetic (originally due to John Harison). It requires theory
  1737 Library/Sum_Of_Squares.  It is not a complete decision procedure but
  1738 works well in practice on quantifier-free real arithmetic with +, -,
  1739 *, ^, =, <= and <, i.e. boolean combinations of equalities and
  1740 inequalities between polynomials.  It makes use of external
  1741 semidefinite programming solvers.  Method "sos" generates a
  1742 certificate that can be pasted into the proof thus avoiding the need
  1743 to call an external tool every time the proof is checked.  See
  1744 src/HOL/Library/Sum_Of_Squares.
  1745 
  1746 * New method "linarith" invokes existing linear arithmetic decision
  1747 procedure only.
  1748 
  1749 * New command 'atp_minimal' reduces result produced by Sledgehammer.
  1750 
  1751 * New Sledgehammer option "Full Types" in Proof General settings menu.
  1752 Causes full type information to be output to the ATPs.  This slows
  1753 ATPs down considerably but eliminates a source of unsound "proofs"
  1754 that fail later.
  1755 
  1756 * New method "metisFT": A version of metis that uses full type
  1757 information in order to avoid failures of proof reconstruction.
  1758 
  1759 * New evaluator "approximate" approximates an real valued term using
  1760 the same method as the approximation method.
  1761 
  1762 * Method "approximate" now supports arithmetic expressions as
  1763 boundaries of intervals and implements interval splitting and Taylor
  1764 series expansion.
  1765 
  1766 * ML antiquotation @{code_datatype} inserts definition of a datatype
  1767 generated by the code generator; e.g. see src/HOL/Predicate.thy.
  1768 
  1769 * New theory SupInf of the supremum and infimum operators for sets of
  1770 reals.
  1771 
  1772 * New theory Probability, which contains a development of measure
  1773 theory, eventually leading to Lebesgue integration and probability.
  1774 
  1775 * Extended Multivariate Analysis to include derivation and Brouwer's
  1776 fixpoint theorem.
  1777 
  1778 * Reorganization of number theory, INCOMPATIBILITY:
  1779   - new number theory development for nat and int, in theories Divides
  1780     and GCD as well as in new session Number_Theory
  1781   - some constants and facts now suffixed with _nat and _int
  1782     accordingly
  1783   - former session NumberTheory now named Old_Number_Theory, including
  1784     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
  1785   - moved theory Pocklington from src/HOL/Library to
  1786     src/HOL/Old_Number_Theory
  1787 
  1788 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
  1789 lcm of finite and infinite sets. It is shown that they form a complete
  1790 lattice.
  1791 
  1792 * Class semiring_div requires superclass no_zero_divisors and proof of
  1793 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
  1794 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
  1795 generalized to class semiring_div, subsuming former theorems
  1796 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
  1797 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
  1798 INCOMPATIBILITY.
  1799 
  1800 * Refinements to lattice classes and sets:
  1801   - less default intro/elim rules in locale variant, more default
  1802     intro/elim rules in class variant: more uniformity
  1803   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
  1804     le_inf_iff
  1805   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
  1806     sup_aci)
  1807   - renamed ACI to inf_sup_aci
  1808   - new class "boolean_algebra"
  1809   - class "complete_lattice" moved to separate theory
  1810     "Complete_Lattice"; corresponding constants (and abbreviations)
  1811     renamed and with authentic syntax:
  1812     Set.Inf ~>    Complete_Lattice.Inf
  1813     Set.Sup ~>    Complete_Lattice.Sup
  1814     Set.INFI ~>   Complete_Lattice.INFI
  1815     Set.SUPR ~>   Complete_Lattice.SUPR
  1816     Set.Inter ~>  Complete_Lattice.Inter
  1817     Set.Union ~>  Complete_Lattice.Union
  1818     Set.INTER ~>  Complete_Lattice.INTER
  1819     Set.UNION ~>  Complete_Lattice.UNION
  1820   - authentic syntax for
  1821     Set.Pow
  1822     Set.image
  1823   - mere abbreviations:
  1824     Set.empty               (for bot)
  1825     Set.UNIV                (for top)
  1826     Set.inter               (for inf, formerly Set.Int)
  1827     Set.union               (for sup, formerly Set.Un)
  1828     Complete_Lattice.Inter  (for Inf)
  1829     Complete_Lattice.Union  (for Sup)
  1830     Complete_Lattice.INTER  (for INFI)
  1831     Complete_Lattice.UNION  (for SUPR)
  1832   - object-logic definitions as far as appropriate
  1833 
  1834 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
  1835 Un_subset_iff are explicitly deleted as default simp rules; then also
  1836 their lattice counterparts le_inf_iff and le_sup_iff have to be
  1837 deleted to achieve the desired effect.
  1838 
  1839 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
  1840 rules by default any longer; the same applies to min_max.inf_absorb1
  1841 etc.  INCOMPATIBILITY.
  1842 
  1843 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
  1844 pred_set_conv by default.  INCOMPATIBILITY.
  1845 
  1846 * Power operations on relations and functions are now one dedicated
  1847 constant "compow" with infix syntax "^^".  Power operation on
  1848 multiplicative monoids retains syntax "^" and is now defined generic
  1849 in class power.  INCOMPATIBILITY.
  1850 
  1851 * Relation composition "R O S" now has a more standard argument order:
  1852 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
  1853 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
  1854 break, since the O_assoc rule was not rewritten like this.  Fix using
  1855 O_assoc[symmetric].  The same applies to the curried version "R OO S".
  1856 
  1857 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
  1858 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
  1859 INCOMPATIBILITY.
  1860 
  1861 * Most rules produced by inductive and datatype package have mandatory
  1862 prefixes.  INCOMPATIBILITY.
  1863 
  1864 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
  1865 the attribute of the same name.  Each of the theorems in the list
  1866 DERIV_intros assumes composition with an additional function and
  1867 matches a variable to the derivative, which has to be solved by the
  1868 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
  1869 of most elementary terms.  Former Maclauren.DERIV_tac and
  1870 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
  1871 INCOMPATIBILITY.
  1872 
  1873 * Code generator attributes follow the usual underscore convention:
  1874     code_unfold     replaces    code unfold
  1875     code_post       replaces    code post
  1876     etc.
  1877   INCOMPATIBILITY.
  1878 
  1879 * Renamed methods:
  1880     sizechange -> size_change
  1881     induct_scheme -> induction_schema
  1882   INCOMPATIBILITY.
  1883 
  1884 * Discontinued abbreviation "arbitrary" of constant "undefined".
  1885 INCOMPATIBILITY, use "undefined" directly.
  1886 
  1887 * Renamed theorems:
  1888     Suc_eq_add_numeral_1 -> Suc_eq_plus1
  1889     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
  1890     Suc_plus1 -> Suc_eq_plus1
  1891     *anti_sym -> *antisym*
  1892     vector_less_eq_def -> vector_le_def
  1893   INCOMPATIBILITY.
  1894 
  1895 * Added theorem List.map_map as [simp].  Removed List.map_compose.
  1896 INCOMPATIBILITY.
  1897 
  1898 * Removed predicate "M hassize n" (<--> card M = n & finite M).
  1899 INCOMPATIBILITY.
  1900 
  1901 
  1902 *** HOLCF ***
  1903 
  1904 * Theory Representable defines a class "rep" of domains that are
  1905 representable (via an ep-pair) in the universal domain type "udom".
  1906 Instances are provided for all type constructors defined in HOLCF.
  1907 
  1908 * The 'new_domain' command is a purely definitional version of the
  1909 domain package, for representable domains.  Syntax is identical to the
  1910 old domain package.  The 'new_domain' package also supports indirect
  1911 recursion using previously-defined type constructors.  See
  1912 src/HOLCF/ex/New_Domain.thy for examples.
  1913 
  1914 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
  1915 on the left-hand side of an equation, and then performs
  1916 simplification.  Rewriting is done using rules declared with the
  1917 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
  1918 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
  1919 
  1920 * The pattern-match compiler in 'fixrec' can now handle constructors
  1921 with HOL function types.  Pattern-match combinators for the Pair
  1922 constructor are pre-configured.
  1923 
  1924 * The 'fixrec' package now produces better fixed-point induction rules
  1925 for mutually-recursive definitions:  Induction rules have conclusions
  1926 of the form "P foo bar" instead of "P <foo, bar>".
  1927 
  1928 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
  1929 been renamed to "below".  The name "below" now replaces "less" in many
  1930 theorem names.  (Legacy theorem names using "less" are still supported
  1931 as well.)
  1932 
  1933 * The 'fixrec' package now supports "bottom patterns".  Bottom
  1934 patterns can be used to generate strictness rules, or to make
  1935 functions more strict (much like the bang-patterns supported by the
  1936 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
  1937 examples.
  1938 
  1939 
  1940 *** ML ***
  1941 
  1942 * Support for Poly/ML 5.3.0, with improved reporting of compiler
  1943 errors and run-time exceptions, including detailed source positions.
  1944 
  1945 * Structure Name_Space (formerly NameSpace) now manages uniquely
  1946 identified entries, with some additional information such as source
  1947 position, logical grouping etc.
  1948 
  1949 * Theory and context data is now introduced by the simplified and
  1950 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
  1951 to be pure, but the old TheoryDataFun for mutable data (with explicit
  1952 copy operation) is still available for some time.
  1953 
  1954 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
  1955 provides a high-level programming interface to synchronized state
  1956 variables with atomic update.  This works via pure function
  1957 application within a critical section -- its runtime should be as
  1958 short as possible; beware of deadlocks if critical code is nested,
  1959 either directly or indirectly via other synchronized variables!
  1960 
  1961 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
  1962 wraps raw ML references, explicitly indicating their non-thread-safe
  1963 behaviour.  The Isar toplevel keeps this structure open, to
  1964 accommodate Proof General as well as quick and dirty interactive
  1965 experiments with references.
  1966 
  1967 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
  1968 parallel tactical reasoning.
  1969 
  1970 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
  1971 are similar to SUBPROOF, but are slightly more flexible: only the
  1972 specified parts of the subgoal are imported into the context, and the
  1973 body tactic may introduce new subgoals and schematic variables.
  1974 
  1975 * Old tactical METAHYPS, which does not observe the proof context, has
  1976 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
  1977 or Subgoal.FOCUS etc.
  1978 
  1979 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
  1980 functors have their own ML name space there is no point to mark them
  1981 separately.)  Minor INCOMPATIBILITY.
  1982 
  1983 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
  1984 
  1985 * Renamed several structures FooBar to Foo_Bar.  Occasional,
  1986 INCOMPATIBILITY.
  1987 
  1988 * Operations of structure Skip_Proof no longer require quick_and_dirty
  1989 mode, which avoids critical setmp.
  1990 
  1991 * Eliminated old Attrib.add_attributes, Method.add_methods and related
  1992 combinators for "args".  INCOMPATIBILITY, need to use simplified
  1993 Attrib/Method.setup introduced in Isabelle2009.
  1994 
  1995 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
  1996 back on global_simpset_of, global_claset_of, global_clasimpset_of as
  1997 last resort.  INCOMPATIBILITY.
  1998 
  1999 * Display.pretty_thm now requires a proper context (cf. former
  2000 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
  2001 or even Display.pretty_thm_without_context as last resort.
  2002 INCOMPATIBILITY.
  2003 
  2004 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
  2005 Syntax.pretty_typ/term directly, preferably with proper context
  2006 instead of global theory.
  2007 
  2008 
  2009 *** System ***
  2010 
  2011 * Further fine tuning of parallel proof checking, scales up to 8 cores
  2012 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
  2013 usedir option -q.
  2014 
  2015 * Support for additional "Isabelle components" via etc/components, see
  2016 also the system manual.
  2017 
  2018 * The isabelle makeall tool now operates on all components with
  2019 IsaMakefile, not just hardwired "logics".
  2020 
  2021 * Removed "compress" option from isabelle-process and isabelle usedir;
  2022 this is always enabled.
  2023 
  2024 * Discontinued support for Poly/ML 4.x versions.
  2025 
  2026 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
  2027 on a given logic image.  This requires the lighttpd webserver and is
  2028 currently supported on Linux only.
  2029 
  2030 
  2031 
  2032 New in Isabelle2009 (April 2009)
  2033 --------------------------------
  2034 
  2035 *** General ***
  2036 
  2037 * Simplified main Isabelle executables, with less surprises on
  2038 case-insensitive file-systems (such as Mac OS).
  2039 
  2040   - The main Isabelle tool wrapper is now called "isabelle" instead of
  2041     "isatool."
  2042 
  2043   - The former "isabelle" alias for "isabelle-process" has been
  2044     removed (should rarely occur to regular users).
  2045 
  2046   - The former "isabelle-interface" and its alias "Isabelle" have been
  2047     removed (interfaces are now regular Isabelle tools).
  2048 
  2049 Within scripts and make files, the Isabelle environment variables
  2050 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
  2051 respectively.  (The latter are still available as legacy feature.)
  2052 
  2053 The old isabelle-interface wrapper could react in confusing ways if
  2054 the interface was uninstalled or changed otherwise.  Individual
  2055 interface tool configuration is now more explicit, see also the
  2056 Isabelle system manual.  In particular, Proof General is now available
  2057 via "isabelle emacs".
  2058 
  2059 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
  2060 purge installed copies of Isabelle executables and re-run "isabelle
  2061 install -p ...", or use symlinks.
  2062 
  2063 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
  2064 old ~/isabelle, which was slightly non-standard and apt to cause
  2065 surprises on case-insensitive file-systems (such as Mac OS).
  2066 
  2067 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
  2068 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
  2069 care is required when using older releases of Isabelle.  Note that
  2070 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
  2071 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
  2072 
  2073 * Proofs of fully specified statements are run in parallel on
  2074 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
  2075 a regular 4-core machine, if the initial heap space is made reasonably
  2076 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
  2077 
  2078 * The main reference manuals ("isar-ref", "implementation", and
  2079 "system") have been updated and extended.  Formally checked references
  2080 as hyperlinks are now available uniformly.
  2081 
  2082 
  2083 *** Pure ***
  2084 
  2085 * Complete re-implementation of locales.  INCOMPATIBILITY in several
  2086 respects.  The most important changes are listed below.  See the
  2087 Tutorial on Locales ("locales" manual) for details.
  2088 
  2089 - In locale expressions, instantiation replaces renaming.  Parameters
  2090 must be declared in a for clause.  To aid compatibility with previous
  2091 parameter inheritance, in locale declarations, parameters that are not
  2092 'touched' (instantiation position "_" or omitted) are implicitly added
  2093 with their syntax at the beginning of the for clause.
  2094 
  2095 - Syntax from abbreviations and definitions in locales is available in
  2096 locale expressions and context elements.  The latter is particularly
  2097 useful in locale declarations.
  2098 
  2099 - More flexible mechanisms to qualify names generated by locale
  2100 expressions.  Qualifiers (prefixes) may be specified in locale
  2101 expressions, and can be marked as mandatory (syntax: "name!:") or
  2102 optional (syntax "name?:").  The default depends for plain "name:"
  2103 depends on the situation where a locale expression is used: in
  2104 commands 'locale' and 'sublocale' prefixes are optional, in
  2105 'interpretation' and 'interpret' prefixes are mandatory.  The old
  2106 implicit qualifiers derived from the parameter names of a locale are
  2107 no longer generated.
  2108 
  2109 - Command "sublocale l < e" replaces "interpretation l < e".  The
  2110 instantiation clause in "interpretation" and "interpret" (square
  2111 brackets) is no longer available.  Use locale expressions.
  2112 
  2113 - When converting proof scripts, mandatory qualifiers in
  2114 'interpretation' and 'interpret' should be retained by default, even
  2115 if this is an INCOMPATIBILITY compared to former behavior.  In the
  2116 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
  2117 in locale expressions range over a single locale instance only.
  2118 
  2119 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
  2120 In existing theorem specifications replace the includes element by the
  2121 respective context elements of the included locale, omitting those
  2122 that are already present in the theorem specification.  Multiple
  2123 assume elements of a locale should be replaced by a single one
  2124 involving the locale predicate.  In the proof body, declarations (most
  2125 notably theorems) may be regained by interpreting the respective
  2126 locales in the proof context as required (command "interpret").
  2127 
  2128 If using "includes" in replacement of a target solely because the
  2129 parameter types in the theorem are not as general as in the target,
  2130 consider declaring a new locale with additional type constraints on
  2131 the parameters (context element "constrains").
  2132 
  2133 - Discontinued "locale (open)".  INCOMPATIBILITY.
  2134 
  2135 - Locale interpretation commands no longer attempt to simplify goal.
  2136 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
  2137 methods intro_locales and unfold_locales to clarify.
  2138 
  2139 - Locale interpretation commands no longer accept interpretation
  2140 attributes.  INCOMPATIBILITY.
  2141 
  2142 * Class declaration: so-called "base sort" must not be given in import
  2143 list any longer, but is inferred from the specification.  Particularly
  2144 in HOL, write
  2145 
  2146     class foo = ...
  2147 
  2148 instead of
  2149 
  2150     class foo = type + ...
  2151 
  2152 * Class target: global versions of theorems stemming do not carry a
  2153 parameter prefix any longer.  INCOMPATIBILITY.
  2154 
  2155 * Class 'instance' command no longer accepts attached definitions.
  2156 INCOMPATIBILITY, use proper 'instantiation' target instead.
  2157 
  2158 * Recovered hiding of consts, which was accidentally broken in
  2159 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
  2160 makes c inaccessible; consider using ``hide (open) const c'' instead.
  2161 
  2162 * Slightly more coherent Pure syntax, with updated documentation in
  2163 isar-ref manual.  Removed locales meta_term_syntax and
  2164 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
  2165 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
  2166 directly in regular applications.
  2167 
  2168 * There is a new syntactic category "float_const" for signed decimal
  2169 fractions (e.g. 123.45 or -123.45).
  2170 
  2171 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
  2172 interface with 'setup' command instead.
  2173 
  2174 * Command 'local_setup' is similar to 'setup', but operates on a local
  2175 theory context.
  2176 
  2177 * The 'axiomatization' command now only works within a global theory
  2178 context.  INCOMPATIBILITY.
  2179 
  2180 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
  2181 hypotheses.  Sorts required in the course of reasoning need to be
  2182 covered by the constraints in the initial statement, completed by the
  2183 type instance information of the background theory.  Non-trivial sort
  2184 hypotheses, which rarely occur in practice, may be specified via
  2185 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
  2186 
  2187   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
  2188 
  2189 The result contains an implicit sort hypotheses as before --
  2190 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
  2191 normalization.
  2192 
  2193 * Generalized Isar history, with support for linear undo, direct state
  2194 addressing etc.
  2195 
  2196 * Changed defaults for unify configuration options:
  2197 
  2198   unify_trace_bound = 50 (formerly 25)
  2199   unify_search_bound = 60 (formerly 30)
  2200 
  2201 * Different bookkeeping for code equations (INCOMPATIBILITY):
  2202 
  2203   a) On theory merge, the last set of code equations for a particular
  2204      constant is taken (in accordance with the policy applied by other
  2205      parts of the code generator framework).
  2206 
  2207   b) Code equations stemming from explicit declarations (e.g. code
  2208      attribute) gain priority over default code equations stemming
  2209      from definition, primrec, fun etc.
  2210 
  2211 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
  2212 
  2213 * Unified theorem tables for both code generators.  Thus [code
  2214 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
  2215 
  2216 * Command 'find_consts' searches for constants based on type and name
  2217 patterns, e.g.
  2218 
  2219     find_consts "_ => bool"
  2220 
  2221 By default, matching is against subtypes, but it may be restricted to
  2222 the whole type.  Searching by name is possible.  Multiple queries are
  2223 conjunctive and queries may be negated by prefixing them with a
  2224 hyphen:
  2225 
  2226     find_consts strict: "_ => bool" name: "Int" -"int => int"
  2227 
  2228 * New 'find_theorems' criterion "solves" matches theorems that
  2229 directly solve the current goal (modulo higher-order unification).
  2230 
  2231 * Auto solve feature for main theorem statements: whenever a new goal
  2232 is stated, "find_theorems solves" is called; any theorems that could
  2233 solve the lemma directly are listed as part of the goal state.
  2234 Cf. associated options in Proof General Isabelle settings menu,
  2235 enabled by default, with reasonable timeout for pathological cases of
  2236 higher-order unification.
  2237 
  2238 
  2239 *** Document preparation ***
  2240 
  2241 * Antiquotation @{lemma} now imitates a regular terminal proof,
  2242 demanding keyword 'by' and supporting the full method expression
  2243 syntax just like the Isar command 'by'.
  2244 
  2245 
  2246 *** HOL ***
  2247 
  2248 * Integrated main parts of former image HOL-Complex with HOL.  Entry
  2249 points Main and Complex_Main remain as before.
  2250 
  2251 * Logic image HOL-Plain provides a minimal HOL with the most important
  2252 tools available (inductive, datatype, primrec, ...).  This facilitates
  2253 experimentation and tool development.  Note that user applications
  2254 (and library theories) should never refer to anything below theory
  2255 Main, as before.
  2256 
  2257 * Logic image HOL-Main stops at theory Main, and thus facilitates
  2258 experimentation due to shorter build times.
  2259 
  2260 * Logic image HOL-NSA contains theories of nonstandard analysis which
  2261 were previously part of former HOL-Complex.  Entry point Hyperreal
  2262 remains valid, but theories formerly using Complex_Main should now use
  2263 new entry point Hypercomplex.
  2264 
  2265 * Generic ATP manager for Sledgehammer, based on ML threads instead of
  2266 Posix processes.  Avoids potentially expensive forking of the ML
  2267 process.  New thread-based implementation also works on non-Unix
  2268 platforms (Cygwin).  Provers are no longer hardwired, but defined
  2269 within the theory via plain ML wrapper functions.  Basic Sledgehammer
  2270 commands are covered in the isar-ref manual.
  2271 
  2272 * Wrapper scripts for remote SystemOnTPTP service allows to use
  2273 sledgehammer without local ATP installation (Vampire etc.). Other
  2274 provers may be included via suitable ML wrappers, see also
  2275 src/HOL/ATP_Linkup.thy.
  2276 
  2277 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
  2278 menu.
  2279 
  2280 * The metis method no longer fails because the theorem is too trivial
  2281 (contains the empty clause).
  2282 
  2283 * The metis method now fails in the usual manner, rather than raising
  2284 an exception, if it determines that it cannot prove the theorem.
  2285 
  2286 * Method "coherent" implements a prover for coherent logic (see also
  2287 src/Tools/coherent.ML).
  2288 
  2289 * Constants "undefined" and "default" replace "arbitrary".  Usually
  2290 "undefined" is the right choice to replace "arbitrary", though
  2291 logically there is no difference.  INCOMPATIBILITY.
  2292 
  2293 * Command "value" now integrates different evaluation mechanisms.  The
  2294 result of the first successful evaluation mechanism is printed.  In
  2295 square brackets a particular named evaluation mechanisms may be
  2296 specified (currently, [SML], [code] or [nbe]).  See further
  2297 src/HOL/ex/Eval_Examples.thy.
  2298 
  2299 * Normalization by evaluation now allows non-leftlinear equations.
  2300 Declare with attribute [code nbe].
  2301 
  2302 * Methods "case_tac" and "induct_tac" now refer to the very same rules
  2303 as the structured Isar versions "cases" and "induct", cf. the
  2304 corresponding "cases" and "induct" attributes.  Mutual induction rules
  2305 are now presented as a list of individual projections
  2306 (e.g. foo_bar.inducts for types foo and bar); the old format with
  2307 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
  2308 rare situations a different rule is selected --- notably nested tuple
  2309 elimination instead of former prod.exhaust: use explicit (case_tac t
  2310 rule: prod.exhaust) here.
  2311 
  2312 * Attributes "cases", "induct", "coinduct" support "del" option.
  2313 
  2314 * Removed fact "case_split_thm", which duplicates "case_split".
  2315 
  2316 * The option datatype has been moved to a new theory Option.  Renamed
  2317 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
  2318 
  2319 * New predicate "strict_mono" classifies strict functions on partial
  2320 orders.  With strict functions on linear orders, reasoning about
  2321 (in)equalities is facilitated by theorems "strict_mono_eq",
  2322 "strict_mono_less_eq" and "strict_mono_less".
  2323 
  2324 * Some set operations are now proper qualified constants with
  2325 authentic syntax.  INCOMPATIBILITY:
  2326 
  2327     op Int ~>   Set.Int
  2328     op Un ~>    Set.Un
  2329     INTER ~>    Set.INTER
  2330     UNION ~>    Set.UNION
  2331     Inter ~>    Set.Inter
  2332     Union ~>    Set.Union
  2333     {} ~>       Set.empty
  2334     UNIV ~>     Set.UNIV
  2335 
  2336 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  2337 theory Set.
  2338 
  2339 * Auxiliary class "itself" has disappeared -- classes without any
  2340 parameter are treated as expected by the 'class' command.
  2341 
  2342 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  2343 
  2344 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  2345 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  2346 
  2347 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  2348 method "approximation".  It proves formulas on real values by using
  2349 interval arithmetic.  In the formulas are also the transcendental
  2350 functions sin, cos, tan, atan, ln, exp and the constant pi are
  2351 allowed. For examples see
  2352 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  2353 
  2354 * Theory "Reflection" now resides in HOL/Library.
  2355 
  2356 * Entry point to Word library now simply named "Word".
  2357 INCOMPATIBILITY.
  2358 
  2359 * Made source layout more coherent with logical distribution
  2360 structure:
  2361 
  2362     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  2363     src/HOL/Library/Code_Message.thy ~> src/HOL/
  2364     src/HOL/Library/GCD.thy ~> src/HOL/
  2365     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  2366     src/HOL/Library/Parity.thy ~> src/HOL/
  2367     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  2368     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  2369     src/HOL/Real/Lubs.thy ~> src/HOL/
  2370     src/HOL/Real/PReal.thy ~> src/HOL/
  2371     src/HOL/Real/Rational.thy ~> src/HOL/
  2372     src/HOL/Real/RComplete.thy ~> src/HOL/
  2373     src/HOL/Real/RealDef.thy ~> src/HOL/
  2374     src/HOL/Real/RealPow.thy ~> src/HOL/
  2375     src/HOL/Real/Real.thy ~> src/HOL/
  2376     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  2377     src/HOL/Complex/Complex.thy ~> src/HOL/
  2378     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  2379     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  2380     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  2381     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  2382     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  2383     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  2384     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  2385     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  2386     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  2387     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  2388     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  2389     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  2390     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  2391     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  2392     src/HOL/Real/Float ~> src/HOL/Library/
  2393     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  2394     src/HOL/Real/RealVector.thy ~> src/HOL/
  2395 
  2396     src/HOL/arith_data.ML ~> src/HOL/Tools
  2397     src/HOL/hologic.ML ~> src/HOL/Tools
  2398     src/HOL/simpdata.ML ~> src/HOL/Tools
  2399     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  2400     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  2401     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  2402     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  2403     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  2404     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  2405     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  2406 
  2407     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  2408     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  2409     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  2410     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  2411     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  2412     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  2413 
  2414 * If methods "eval" and "evaluation" encounter a structured proof
  2415 state with !!/==>, only the conclusion is evaluated to True (if
  2416 possible), avoiding strange error messages.
  2417 
  2418 * Method "sizechange" automates termination proofs using (a
  2419 modification of) the size-change principle.  Requires SAT solver.  See
  2420 src/HOL/ex/Termination.thy for examples.
  2421 
  2422 * Simplifier: simproc for let expressions now unfolds if bound
  2423 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  2424 
  2425 * Method "arith": Linear arithmetic now ignores all inequalities when
  2426 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  2427 
  2428 * New attribute "arith" for facts that should always be used
  2429 automatically by arithmetic. It is intended to be used locally in
  2430 proofs, e.g.
  2431 
  2432   assumes [arith]: "x > 0"
  2433 
  2434 Global usage is discouraged because of possible performance impact.
  2435 
  2436 * New classes "top" and "bot" with corresponding operations "top" and
  2437 "bot" in theory Orderings; instantiation of class "complete_lattice"
  2438 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  2439 
  2440 * Changed definition lemma "less_fun_def" in order to provide an
  2441 instance for preorders on functions; use lemma "less_le" instead.
  2442 INCOMPATIBILITY.
  2443 
  2444 * Theory Orderings: class "wellorder" moved here, with explicit
  2445 induction rule "less_induct" as assumption.  For instantiation of
  2446 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  2447 INCOMPATIBILITY.
  2448 
  2449 * Theory Orderings: added class "preorder" as superclass of "order".
  2450 INCOMPATIBILITY: Instantiation proofs for order, linorder
  2451 etc. slightly changed.  Some theorems named order_class.* now named
  2452 preorder_class.*.
  2453 
  2454 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  2455 "diag" to "Id_on".
  2456 
  2457 * Theory Finite_Set: added a new fold combinator of type
  2458 
  2459   ('a => 'b => 'b) => 'b => 'a set => 'b
  2460 
  2461 Occasionally this is more convenient than the old fold combinator
  2462 which is now defined in terms of the new one and renamed to
  2463 fold_image.
  2464 
  2465 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  2466 and "ring_simps" have been replaced by "algebra_simps" (which can be
  2467 extended with further lemmas!).  At the moment both still exist but
  2468 the former will disappear at some point.
  2469 
  2470 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  2471 class recpower.  Type-specific simp rules for various recpower types
  2472 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  2473 
  2474 rat_power_0    -> power_0
  2475 rat_power_Suc  -> power_Suc
  2476 realpow_0      -> power_0
  2477 realpow_Suc    -> power_Suc
  2478 complexpow_0   -> power_0
  2479 complexpow_Suc -> power_Suc
  2480 power_poly_0   -> power_0
  2481 power_poly_Suc -> power_Suc
  2482 
  2483 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  2484 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  2485 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  2486 of lemmas from Divides has been generalized from nat to class
  2487 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  2488 renames resulting from duplicate elimination:
  2489 
  2490     dvd_def_mod ~>          dvd_eq_mod_eq_0
  2491     zero_dvd_iff ~>         dvd_0_left_iff
  2492     dvd_0 ~>                dvd_0_right
  2493     DIVISION_BY_ZERO_DIV ~> div_by_0
  2494     DIVISION_BY_ZERO_MOD ~> mod_by_0
  2495     mult_div ~>             div_mult_self2_is_id
  2496     mult_mod ~>             mod_mult_self2_is_0
  2497 
  2498 * Theory IntDiv: removed many lemmas that are instances of class-based
  2499 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  2500 rename old lemmas as follows:
  2501 
  2502 dvd_diff               -> nat_dvd_diff
  2503 dvd_zminus_iff         -> dvd_minus_iff
  2504 mod_add1_eq            -> mod_add_eq
  2505 mod_mult1_eq           -> mod_mult_right_eq
  2506 mod_mult1_eq'          -> mod_mult_left_eq
  2507 mod_mult_distrib_mod   -> mod_mult_eq
  2508 nat_mod_add_left_eq    -> mod_add_left_eq
  2509 nat_mod_add_right_eq   -> mod_add_right_eq
  2510 nat_mod_div_trivial    -> mod_div_trivial
  2511 nat_mod_mod_trivial    -> mod_mod_trivial
  2512 zdiv_zadd_self1        -> div_add_self1
  2513 zdiv_zadd_self2        -> div_add_self2
  2514 zdiv_zmult_self1       -> div_mult_self2_is_id
  2515 zdiv_zmult_self2       -> div_mult_self1_is_id
  2516 zdvd_triv_left         -> dvd_triv_left
  2517 zdvd_triv_right        -> dvd_triv_right
  2518 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  2519 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  2520 zmod_zadd_left_eq      -> mod_add_left_eq
  2521 zmod_zadd_right_eq     -> mod_add_right_eq
  2522 zmod_zadd_self1        -> mod_add_self1
  2523 zmod_zadd_self2        -> mod_add_self2
  2524 zmod_zadd1_eq          -> mod_add_eq
  2525 zmod_zdiff1_eq         -> mod_diff_eq
  2526 zmod_zdvd_zmod         -> mod_mod_cancel
  2527 zmod_zmod_cancel       -> mod_mod_cancel
  2528 zmod_zmult_self1       -> mod_mult_self2_is_0
  2529 zmod_zmult_self2       -> mod_mult_self1_is_0
  2530 zmod_1                 -> mod_by_1
  2531 zdiv_1                 -> div_by_1
  2532 zdvd_abs1              -> abs_dvd_iff
  2533 zdvd_abs2              -> dvd_abs_iff
  2534 zdvd_refl              -> dvd_refl
  2535 zdvd_trans             -> dvd_trans
  2536 zdvd_zadd              -> dvd_add
  2537 zdvd_zdiff             -> dvd_diff
  2538 zdvd_zminus_iff        -> dvd_minus_iff
  2539 zdvd_zminus2_iff       -> minus_dvd_iff
  2540 zdvd_zmultD            -> dvd_mult_right
  2541 zdvd_zmultD2           -> dvd_mult_left
  2542 zdvd_zmult_mono        -> mult_dvd_mono
  2543 zdvd_0_right           -> dvd_0_right
  2544 zdvd_0_left            -> dvd_0_left_iff
  2545 zdvd_1_left            -> one_dvd
  2546 zminus_dvd_iff         -> minus_dvd_iff
  2547 
  2548 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  2549 
  2550 * The real numbers offer decimal input syntax: 12.34 is translated
  2551 into 1234/10^2. This translation is not reversed upon output.
  2552 
  2553 * Theory Library/Polynomial defines an abstract type 'a poly of
  2554 univariate polynomials with coefficients of type 'a.  In addition to
  2555 the standard ring operations, it also supports div and mod.  Code
  2556 generation is also supported, using list-style constructors.
  2557 
  2558 * Theory Library/Inner_Product defines a class of real_inner for real
  2559 inner product spaces, with an overloaded operation inner :: 'a => 'a
  2560 => real.  Class real_inner is a subclass of real_normed_vector from
  2561 theory RealVector.
  2562 
  2563 * Theory Library/Product_Vector provides instances for the product
  2564 type 'a * 'b of several classes from RealVector and Inner_Product.
  2565 Definitions of addition, subtraction, scalar multiplication, norms,
  2566 and inner products are included.
  2567 
  2568 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  2569 addition to the field operations, numerals and case syntax are also
  2570 supported.
  2571 
  2572 * Theory Library/Diagonalize provides constructive version of Cantor's
  2573 first diagonalization argument.
  2574 
  2575 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  2576 zlcm (for int); carried together from various gcd/lcm developements in
  2577 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  2578 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  2579 may recover tupled syntax as follows:
  2580 
  2581     hide (open) const gcd
  2582     abbreviation gcd where
  2583       "gcd == (%(a, b). GCD.gcd a b)"
  2584     notation (output)
  2585       GCD.gcd ("gcd '(_, _')")
  2586 
  2587 The same works for lcm, zgcd, zlcm.
  2588 
  2589 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  2590 instantiations for algebraic structures.  Removed some duplicate
  2591 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  2592 
  2593 * ML antiquotation @{code} takes a constant as argument and generates
  2594 corresponding code in background and inserts name of the corresponding
  2595 resulting ML value/function/datatype constructor binding in place.
  2596 All occurrences of @{code} with a single ML block are generated
  2597 simultaneously.  Provides a generic and safe interface for
  2598 instrumentalizing code generation.  See
  2599 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  2600 In future you ought to refrain from ad-hoc compiling generated SML
  2601 code on the ML toplevel.  Note that (for technical reasons) @{code}
  2602 cannot refer to constants for which user-defined serializations are
  2603 set.  Refer to the corresponding ML counterpart directly in that
  2604 cases.
  2605 
  2606 * Command 'rep_datatype': instead of theorem names the command now
  2607 takes a list of terms denoting the constructors of the type to be
  2608 represented as datatype.  The characteristic theorems have to be
  2609 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  2610 have disappeared in favour of existing ones:
  2611 
  2612     unit_induct                 ~> unit.induct
  2613     prod_induct                 ~> prod.induct
  2614     sum_induct                  ~> sum.induct
  2615     Suc_Suc_eq                  ~> nat.inject
  2616     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  2617 
  2618 
  2619 *** HOL-Algebra ***
  2620 
  2621 * New locales for orders and lattices where the equivalence relation
  2622 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  2623 locales use a record structure with field eq for the equivalence.
  2624 
  2625 * New theory of factorial domains.
  2626 
  2627 * Units_l_inv and Units_r_inv are now simp rules by default.
  2628 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  2629 and/or r_inv will now also require deletion of these lemmas.
  2630 
  2631 * Renamed the following theorems, INCOMPATIBILITY:
  2632 
  2633 UpperD ~> Upper_memD
  2634 LowerD ~> Lower_memD
  2635 least_carrier ~> least_closed
  2636 greatest_carrier ~> greatest_closed
  2637 greatest_Lower_above ~> greatest_Lower_below
  2638 one_zero ~> carrier_one_zero
  2639 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  2640 
  2641 
  2642 *** HOL-Nominal ***
  2643 
  2644 * Nominal datatypes can now contain type-variables.
  2645 
  2646 * Commands 'nominal_inductive' and 'equivariance' work with local
  2647 theory targets.
  2648 
  2649 * Nominal primrec can now works with local theory targets and its
  2650 specification syntax now conforms to the general format as seen in
  2651 'inductive' etc.
  2652 
  2653 * Method "perm_simp" honours the standard simplifier attributes
  2654 (no_asm), (no_asm_use) etc.
  2655 
  2656 * The new predicate #* is defined like freshness, except that on the
  2657 left hand side can be a set or list of atoms.
  2658 
  2659 * Experimental command 'nominal_inductive2' derives strong induction
  2660 principles for inductive definitions.  In contrast to
  2661 'nominal_inductive', which can only deal with a fixed number of
  2662 binders, it can deal with arbitrary expressions standing for sets of
  2663 atoms to be avoided.  The only inductive definition we have at the
  2664 moment that needs this generalisation is the typing rule for Lets in
  2665 the algorithm W:
  2666 
  2667  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  2668  -----------------------------------------------------------------
  2669          Gamma |- Let x be t1 in t2 : T2
  2670 
  2671 In this rule one wants to avoid all the binders that are introduced by
  2672 "close Gamma T1".  We are looking for other examples where this
  2673 feature might be useful.  Please let us know.
  2674 
  2675 
  2676 *** HOLCF ***
  2677 
  2678 * Reimplemented the simplification procedure for proving continuity
  2679 subgoals.  The new simproc is extensible; users can declare additional
  2680 continuity introduction rules with the attribute [cont2cont].
  2681 
  2682 * The continuity simproc now uses a different introduction rule for
  2683 solving continuity subgoals on terms with lambda abstractions.  In
  2684 some rare cases the new simproc may fail to solve subgoals that the
  2685 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  2686 Potential INCOMPATIBILITY.
  2687 
  2688 * Command 'fixrec': specification syntax now conforms to the general
  2689 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  2690 examples.  INCOMPATIBILITY.
  2691 
  2692 
  2693 *** ZF ***
  2694 
  2695 * Proof of Zorn's Lemma for partial orders.
  2696 
  2697 
  2698 *** ML ***
  2699 
  2700 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  2701 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  2702 depends on multithreading, so timouts will not work before Poly/ML
  2703 5.2.1!
  2704 
  2705 * High-level support for concurrent ML programming, see
  2706 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  2707 particularly convenient to organize independent functional
  2708 computations.  The concept of "synchronized variables" provides a
  2709 higher-order interface for components with shared state, avoiding the
  2710 delicate details of mutexes and condition variables.  (Requires
  2711 Poly/ML 5.2.1 or later.)
  2712 
  2713 * ML bindings produced via Isar commands are stored within the Isar
  2714 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  2715 become thread-safe and work with undo as expected (concerning
  2716 top-level bindings, not side-effects on global references).
  2717 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  2718 compiler at runtime; really global bindings need to be given outside a
  2719 theory.  (Requires Poly/ML 5.2 or later.)
  2720 
  2721 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  2722 context.  Top-level ML bindings are stored within the proof context in
  2723 a purely sequential fashion, disregarding the nested proof structure.
  2724 ML bindings introduced by 'ML_prf' are discarded at the end of the
  2725 proof.  (Requires Poly/ML 5.2 or later.)
  2726 
  2727 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  2728 and Method.setup, as well as Isar commands 'attribute_setup' and
  2729 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  2730 existing code accordingly, or use plain 'setup' together with old
  2731 Method.add_method.
  2732 
  2733 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  2734 to 'a -> thm, while results are always tagged with an authentic oracle
  2735 name.  The Isar command 'oracle' is now polymorphic, no argument type
  2736 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  2737 accordingly.  Note that extra performance may be gained by producing
  2738 the cterm carefully, avoiding slow Thm.cterm_of.
  2739 
  2740 * Simplified interface for defining document antiquotations via
  2741 ThyOutput.antiquotation, ThyOutput.output, and optionally
  2742 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  2743 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  2744 examples.
  2745 
  2746 * More systematic treatment of long names, abstract name bindings, and
  2747 name space operations.  Basic operations on qualified names have been
  2748 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  2749 Long_Name.append.  Old type bstring has been mostly replaced by
  2750 abstract type binding (see structure Binding), which supports precise
  2751 qualification by packages and local theory targets, as well as proper
  2752 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  2753 bstring values into Binding.name, or better pass through abstract
  2754 bindings everywhere.  See further src/Pure/General/long_name.ML,
  2755 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  2756 
  2757 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  2758 LocalTheory.note etc.) now refer to the *full* internal name, not the
  2759 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  2760 
  2761 * Disposed old type and term read functions (Sign.read_def_typ,
  2762 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  2763 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  2764 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  2765 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  2766 resort for legacy applications.
  2767 
  2768 * Disposed old declarations, tactics, tactic combinators that refer to
  2769 the simpset or claset of an implicit theory (such as Addsimps,
  2770 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  2771 embedded ML text, or local_simpset_of with a proper context passed as
  2772 explicit runtime argument.
  2773 
  2774 * Rules and tactics that read instantiations (read_instantiate,
  2775 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  2776 context, which is required for parsing and type-checking.  Moreover,
  2777 the variables are specified as plain indexnames, not string encodings
  2778 thereof.  INCOMPATIBILITY.
  2779 
  2780 * Generic Toplevel.add_hook interface allows to analyze the result of
  2781 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  2782 for theorem dependency output of transactions resulting in a new
  2783 theory state.
  2784 
  2785 * ML antiquotations: block-structured compilation context indicated by
  2786 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  2787 
  2788   @{binding name}                         - basic name binding
  2789   @{let ?pat = term}                      - term abbreviation (HO matching)
  2790   @{note name = fact}                     - fact abbreviation
  2791   @{thm fact}                             - singleton fact (with attributes)
  2792   @{thms fact}                            - general fact (with attributes)
  2793   @{lemma prop by method}                 - singleton goal
  2794   @{lemma prop by meth1 meth2}            - singleton goal
  2795   @{lemma prop1 ... propN by method}      - general goal
  2796   @{lemma prop1 ... propN by meth1 meth2} - general goal
  2797   @{lemma (open) ...}                     - open derivation
  2798 
  2799 
  2800 *** System ***
  2801 
  2802 * The Isabelle "emacs" tool provides a specific interface to invoke
  2803 Proof General / Emacs, with more explicit failure if that is not
  2804 installed (the old isabelle-interface script silently falls back on
  2805 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  2806 installation location of the Proof General distribution.
  2807 
  2808 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  2809 the Isabelle process into a JVM/Scala application.  See
  2810 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  2811 process wrapper has been discontinued.)
  2812 
  2813 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  2814 
  2815 * Various status messages (with exact source position information) are
  2816 emitted, if proper markup print mode is enabled.  This allows
  2817 user-interface components to provide detailed feedback on internal
  2818 prover operations.
  2819 
  2820 
  2821 
  2822 New in Isabelle2008 (June 2008)
  2823 -------------------------------
  2824 
  2825 *** General ***
  2826 
  2827 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  2828 and updated, with formally checked references as hyperlinks.
  2829 
  2830 * Theory loader: use_thy (and similar operations) no longer set the
  2831 implicit ML context, which was occasionally hard to predict and in
  2832 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  2833 provides a proper context already.
  2834 
  2835 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2836 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  2837 'use' within a theory file will do the job.
  2838 
  2839 * Name space merge now observes canonical order, i.e. the second space
  2840 is inserted into the first one, while existing entries in the first
  2841 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  2842 swap theory imports.
  2843 
  2844 * Syntax: symbol \<chi> is now considered a letter.  Potential
  2845 INCOMPATIBILITY in identifier syntax etc.
  2846 
  2847 * Outer syntax: string tokens no longer admit escaped white space,
  2848 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  2849 white space without escapes.
  2850 
  2851 * Outer syntax: string tokens may contain arbitrary character codes
  2852 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  2853 "foo_bar".
  2854 
  2855 
  2856 *** Pure ***
  2857 
  2858 * Context-dependent token translations.  Default setup reverts locally
  2859 fixed variables, and adds hilite markup for undeclared frees.
  2860 
  2861 * Unused theorems can be found using the new command 'unused_thms'.
  2862 There are three ways of invoking it:
  2863 
  2864 (1) unused_thms
  2865      Only finds unused theorems in the current theory.
  2866 
  2867 (2) unused_thms thy_1 ... thy_n -
  2868      Finds unused theorems in the current theory and all of its ancestors,
  2869      excluding the theories thy_1 ... thy_n and all of their ancestors.
  2870 
  2871 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  2872      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  2873      their ancestors, excluding the theories thy_1 ... thy_n and all of
  2874      their ancestors.
  2875 
  2876 In order to increase the readability of the list produced by
  2877 unused_thms, theorems that have been created by a particular instance
  2878 of a theory command such as 'inductive' or 'function' are considered
  2879 to belong to the same "group", meaning that if at least one theorem in
  2880 this group is used, the other theorems in the same group are no longer
  2881 reported as unused.  Moreover, if all theorems in the group are
  2882 unused, only one theorem in the group is displayed.
  2883 
  2884 Note that proof objects have to be switched on in order for
  2885 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  2886 usually the case when using Proof General with the default settings).
  2887 
  2888 * Authentic naming of facts disallows ad-hoc overwriting of previous
  2889 theorems within the same name space.  INCOMPATIBILITY, need to remove
  2890 duplicate fact bindings, or even accidental fact duplications.  Note
  2891 that tools may maintain dynamically scoped facts systematically, using
  2892 PureThy.add_thms_dynamic.
  2893 
  2894 * Command 'hide' now allows to hide from "fact" name space as well.
  2895 
  2896 * Eliminated destructive theorem database, simpset, claset, and
  2897 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  2898 update of theories within ML code.
  2899 
  2900 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  2901 INCOMPATIBILITY, object-logics depending on former Pure require
  2902 additional setup PureThy.old_appl_syntax_setup; object-logics
  2903 depending on former CPure need to refer to Pure.
  2904 
  2905 * Commands 'use' and 'ML' are now purely functional, operating on
  2906 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  2907 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  2908 INCOMPATIBILITY.
  2909 
  2910 * Command 'setup': discontinued implicit version with ML reference.
  2911 
  2912 * Instantiation target allows for simultaneous specification of class
  2913 instance operations together with an instantiation proof.
  2914 Type-checking phase allows to refer to class operations uniformly.
  2915 See src/HOL/Complex/Complex.thy for an Isar example and
  2916 src/HOL/Library/Eval.thy for an ML example.
  2917 
  2918 * Indexing of literal facts: be more serious about including only
  2919 facts from the visible specification/proof context, but not the
  2920 background context (locale etc.).  Affects `prop` notation and method
  2921 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  2922 situations.
  2923 
  2924 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  2925 "(open)" option, which used to expose internal bound variables to the
  2926 proof text.
  2927 
  2928 * Isar statements: removed obsolete case "rule_context".
  2929 INCOMPATIBILITY, better use explicit fixes/assumes.
  2930 
  2931 * Locale proofs: default proof step now includes 'unfold_locales';
  2932 hence 'proof' without argument may be used to unfold locale
  2933 predicates.
  2934 
  2935 
  2936 *** Document preparation ***
  2937 
  2938 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  2939 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  2940 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  2941 spot); renamed link color from "darkblue" to "linkcolor" (default
  2942 value unchanged, can be redefined via \definecolor); no longer sets
  2943 "a4paper" option (unnecessary or even intrusive).
  2944 
  2945 * Antiquotation @{lemma A method} proves proposition A by the given
  2946 method (either a method name or a method name plus (optional) method
  2947 arguments in parentheses) and prints A just like @{prop A}.
  2948 
  2949 
  2950 *** HOL ***
  2951 
  2952 * New primrec package.  Specification syntax conforms in style to
  2953 definition/function/....  No separate induction rule is provided.  The
  2954 "primrec" command distinguishes old-style and new-style specifications
  2955 by syntax.  The former primrec package is now named OldPrimrecPackage.
  2956 When adjusting theories, beware: constants stemming from new-style
  2957 primrec specifications have authentic syntax.
  2958 
  2959 * Metis prover is now an order of magnitude faster, and also works
  2960 with multithreading.
  2961 
  2962 * Metis: the maximum number of clauses that can be produced from a
  2963 theorem is now given by the attribute max_clauses.  Theorems that
  2964 exceed this number are ignored, with a warning printed.
  2965 
  2966 * Sledgehammer no longer produces structured proofs by default. To
  2967 enable, declare [[sledgehammer_full = true]].  Attributes
  2968 reconstruction_modulus, reconstruction_sorts renamed
  2969 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  2970 
  2971 * Method "induct_scheme" derives user-specified induction rules
  2972 from well-founded induction and completeness of patterns. This factors
  2973 out some operations that are done internally by the function package
  2974 and makes them available separately.  See
  2975 src/HOL/ex/Induction_Scheme.thy for examples.
  2976 
  2977 * More flexible generation of measure functions for termination
  2978 proofs: Measure functions can be declared by proving a rule of the
  2979 form "is_measure f" and giving it the [measure_function] attribute.
  2980 The "is_measure" predicate is logically meaningless (always true), and
  2981 just guides the heuristic.  To find suitable measure functions, the
  2982 termination prover sets up the goal "is_measure ?f" of the appropriate
  2983 type and generates all solutions by prolog-style backwards proof using
  2984 the declared rules.
  2985 
  2986 This setup also deals with rules like 
  2987 
  2988   "is_measure f ==> is_measure (list_size f)"
  2989 
  2990 which accommodates nested datatypes that recurse through lists.
  2991 Similar rules are predeclared for products and option types.
  2992 
  2993 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  2994 
  2995   INCOMPATIBILITIES:
  2996 
  2997   - Definitions of overloaded constants on sets have to be replaced by
  2998     definitions on => and bool.
  2999 
  3000   - Some definitions of overloaded operators on sets can now be proved
  3001     using the definitions of the operators on => and bool.  Therefore,
  3002     the following theorems have been renamed:
  3003 
  3004       subset_def   -> subset_eq
  3005       psubset_def  -> psubset_eq
  3006       set_diff_def -> set_diff_eq
  3007       Compl_def    -> Compl_eq
  3008       Sup_set_def  -> Sup_set_eq
  3009       Inf_set_def  -> Inf_set_eq
  3010       sup_set_def  -> sup_set_eq
  3011       inf_set_def  -> inf_set_eq
  3012 
  3013   - Due to the incompleteness of the HO unification algorithm, some
  3014     rules such as subst may require manual instantiation, if some of
  3015     the unknowns in the rule is a set.
  3016 
  3017   - Higher order unification and forward proofs:
  3018     The proof pattern
  3019 
  3020       have "P (S::'a set)" <...>
  3021       then have "EX S. P S" ..
  3022 
  3023     no longer works (due to the incompleteness of the HO unification
  3024     algorithm) and must be replaced by the pattern
  3025 
  3026       have "EX S. P S"
  3027       proof
  3028         show "P S" <...>
  3029       qed
  3030 
  3031   - Calculational reasoning with subst (or similar rules):
  3032     The proof pattern
  3033 
  3034       have "P (S::'a set)" <...>
  3035       also have "S = T" <...>
  3036       finally have "P T" .
  3037 
  3038     no longer works (for similar reasons as the previous example) and
  3039     must be replaced by something like
  3040 
  3041       have "P (S::'a set)" <...>
  3042       moreover have "S = T" <...>
  3043       ultimately have "P T" by simp
  3044 
  3045   - Tactics or packages written in ML code:
  3046     Code performing pattern matching on types via
  3047 
  3048       Type ("set", [T]) => ...
  3049 
  3050     must be rewritten. Moreover, functions like strip_type or
  3051     binder_types no longer return the right value when applied to a
  3052     type of the form
  3053 
  3054       T1 => ... => Tn => U => bool
  3055 
  3056     rather than
  3057 
  3058       T1 => ... => Tn => U set
  3059 
  3060 * Merged theories Wellfounded_Recursion, Accessible_Part and
  3061 Wellfounded_Relations to theory Wellfounded.
  3062 
  3063 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  3064 
  3065 * Class finite no longer treats UNIV as class parameter.  Use class
  3066 enum from theory Library/Enum instead to achieve a similar effect.
  3067 INCOMPATIBILITY.
  3068 
  3069 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  3070 and "Cons".  INCOMPATIBILITY.
  3071 
  3072 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  3073 Potential INCOMPATIBILITY.
  3074 
  3075 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  3076 injective_fst_snd removed, use split_eta and prod_eqI instead.
  3077 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  3078 
  3079 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  3080 the same name in theory Orderings:
  3081 
  3082   less_trans
  3083   less_linear
  3084   le_imp_less_or_eq
  3085   le_less_trans
  3086   less_le_trans
  3087   less_not_sym
  3088   less_asym
  3089 
  3090 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  3091 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  3092 and different variable names.
  3093 
  3094 * Library/Option_ord.thy: Canonical order on option type.
  3095 
  3096 * Library/RBT.thy: Red-black trees, an efficient implementation of
  3097 finite maps.
  3098 
  3099 * Library/Countable.thy: Type class for countable types.
  3100 
  3101 * Theory Int: The representation of numerals has changed.  The infix
  3102 operator BIT and the bit datatype with constructors B0 and B1 have
  3103 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  3104 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  3105 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  3106 accordingly.
  3107 
  3108 * Theory Nat: definition of <= and < on natural numbers no longer
  3109 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  3110 le_def and less_def have disappeared.  Consider lemmas not_less
  3111 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  3112 
  3113 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  3114 (whose purpose mainly is for various fold_set functionals) have been
  3115 abandoned in favor of the existing algebraic classes
  3116 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  3117 lower_semilattice (resp. upper_semilattice) and linorder.
  3118 INCOMPATIBILITY.
  3119 
  3120 * Theory Transitive_Closure: induct and cases rules now declare proper
  3121 case_names ("base" and "step").  INCOMPATIBILITY.
  3122 
  3123 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  3124 lattices.  The form set-specific version is available as
  3125 Inductive.lfp_ordinal_induct_set.
  3126 
  3127 * Renamed theorems "power.simps" to "power_int.simps".
  3128 INCOMPATIBILITY.
  3129 
  3130 * Class semiring_div provides basic abstract properties of semirings
  3131 with division and modulo operations.  Subsumes former class dvd_mod.
  3132 
  3133 * Merged theories IntDef, Numeral and IntArith into unified theory
  3134 Int.  INCOMPATIBILITY.
  3135 
  3136 * Theory Library/Code_Index: type "index" now represents natural
  3137 numbers rather than integers.  INCOMPATIBILITY.
  3138 
  3139 * New class "uminus" with operation "uminus" (split of from class
  3140 "minus" which now only has operation "minus", binary).
  3141 INCOMPATIBILITY.
  3142 
  3143 * Constants "card", "internal_split", "option_map" now with authentic
  3144 syntax.  INCOMPATIBILITY.
  3145 
  3146 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  3147 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  3148 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  3149 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  3150 Sup_set_def, le_def, less_def, option_map_def now with object
  3151 equality.  INCOMPATIBILITY.
  3152 
  3153 * Records. Removed K_record, and replaced it by pure lambda term
  3154 %x. c. The simplifier setup is now more robust against eta expansion.
  3155 INCOMPATIBILITY: in cases explicitly referring to K_record.
  3156 
  3157 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  3158 
  3159 * Library/ListVector: new theory of arithmetic vector operations.
  3160 
  3161 * Library/Order_Relation: new theory of various orderings as sets of
  3162 pairs.  Defines preorders, partial orders, linear orders and
  3163 well-orders on sets and on types.
  3164 
  3165 
  3166 *** ZF ***
  3167 
  3168 * Renamed some theories to allow to loading both ZF and HOL in the
  3169 same session:
  3170 
  3171   Datatype  -> Datatype_ZF
  3172   Inductive -> Inductive_ZF
  3173   Int       -> Int_ZF
  3174   IntDiv    -> IntDiv_ZF
  3175   Nat       -> Nat_ZF
  3176   List      -> List_ZF
  3177   Main      -> Main_ZF
  3178 
  3179 INCOMPATIBILITY: ZF theories that import individual theories below
  3180 Main might need to be adapted.  Regular theory Main is still
  3181 available, as trivial extension of Main_ZF.
  3182 
  3183 
  3184 *** ML ***
  3185 
  3186 * ML within Isar: antiquotation @{const name} or @{const
  3187 name(typargs)} produces statically-checked Const term.
  3188 
  3189 * Functor NamedThmsFun: data is available to the user as dynamic fact
  3190 (of the same name).  Removed obsolete print command.
  3191 
  3192 * Removed obsolete "use_legacy_bindings" function.
  3193 
  3194 * The ``print mode'' is now a thread-local value derived from a global
  3195 template (the former print_mode reference), thus access becomes
  3196 non-critical.  The global print_mode reference is for session
  3197 management only; user-code should use print_mode_value,
  3198 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  3199 
  3200 * Functions system/system_out provide a robust way to invoke external
  3201 shell commands, with propagation of interrupts (requires Poly/ML
  3202 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  3203 
  3204 
  3205 *** System ***
  3206 
  3207 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  3208 in accordance with Proof General 3.7, which prefers GNU emacs.
  3209 
  3210 * isatool tty runs Isabelle process with plain tty interaction;
  3211 optional line editor may be specified via ISABELLE_LINE_EDITOR
  3212 setting, the default settings attempt to locate "ledit" and "rlwrap".
  3213 
  3214 * isatool browser now works with Cygwin as well, using general
  3215 "javapath" function defined in Isabelle process environment.
  3216 
  3217 * YXML notation provides a simple and efficient alternative to
  3218 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  3219 isatool yxml as described in the Isabelle system manual.
  3220 
  3221 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  3222 provides general wrapper for managing an Isabelle process in a robust
  3223 fashion, with ``cooked'' output from stdin/stderr.
  3224 
  3225 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  3226 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  3227 
  3228 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  3229 way of changing the user's settings is via
  3230 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  3231 script.
  3232 
  3233 * Multithreading.max_threads := 0 refers to the number of actual CPU
  3234 cores of the underlying machine, which is a good starting point for
  3235 optimal performance tuning.  The corresponding usedir option -M allows
  3236 "max" as an alias for "0".  WARNING: does not work on certain versions
  3237 of Mac OS (with Poly/ML 5.1).
  3238 
  3239 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  3240 adverse effect of Isabelle flooding interactive front-ends (notably
  3241 ProofGeneral / XEmacs).
  3242 
  3243 
  3244 
  3245 New in Isabelle2007 (November 2007)
  3246 -----------------------------------
  3247 
  3248 *** General ***
  3249 
  3250 * More uniform information about legacy features, notably a
  3251 warning/error of "Legacy feature: ...", depending on the state of the
  3252 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  3253 legacy features will disappear eventually.
  3254 
  3255 * Theory syntax: the header format ``theory A = B + C:'' has been
  3256 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  3257 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  3258 
  3259 * Theory syntax: the old non-Isar theory file format has been
  3260 discontinued altogether.  Note that ML proof scripts may still be used
  3261 with Isar theories; migration is usually quite simple with the ML
  3262 function use_legacy_bindings.  INCOMPATIBILITY.
  3263 
  3264 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  3265 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  3266 quotes.
  3267 
  3268 * Theory loader: be more serious about observing the static theory
  3269 header specifications (including optional directories), but not the
  3270 accidental file locations of previously successful loads.  The strict
  3271 update policy of former update_thy is now already performed by
  3272 use_thy, so the former has been removed; use_thys updates several
  3273 theories simultaneously, just as 'imports' within a theory header
  3274 specification, but without merging the results.  Potential
  3275 INCOMPATIBILITY: may need to refine theory headers and commands
  3276 ROOT.ML which depend on load order.
  3277 
  3278 * Theory loader: optional support for content-based file
  3279 identification, instead of the traditional scheme of full physical
  3280 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  3281 (cf. the system manual).  The new scheme allows to work with
  3282 non-finished theories in persistent session images, such that source
  3283 files may be moved later on without requiring reloads.
  3284 
  3285 * Theory loader: old-style ML proof scripts being *attached* to a thy
  3286 file (with the same base name as the theory) are considered a legacy
  3287 feature, which will disappear eventually. Even now, the theory loader
  3288 no longer maintains dependencies on such files.
  3289 
  3290 * Syntax: the scope for resolving ambiguities via type-inference is
  3291 now limited to individual terms, instead of whole simultaneous
  3292 specifications as before. This greatly reduces the complexity of the
  3293 syntax module and improves flexibility by separating parsing and
  3294 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  3295 'fixes' etc.) are required in rare situations.
  3296 
  3297 * Syntax: constants introduced by new-style packages ('definition',
  3298 'abbreviation' etc.) are passed through the syntax module in
  3299 ``authentic mode''. This means that associated mixfix annotations
  3300 really stick to such constants, independently of potential name space
  3301 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  3302 trees are represented slightly differently, may need to adapt syntax
  3303 translations accordingly. Use CONST marker in 'translations' and
  3304 @{const_syntax} antiquotation in 'parse_translation' etc.
  3305 
  3306 * Legacy goal package: reduced interface to the bare minimum required
  3307 to keep existing proof scripts running.  Most other user-level
  3308 functions are now part of the OldGoals structure, which is *not* open
  3309 by default (consider isatool expandshort before open OldGoals).
  3310 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  3311 these tend to cause confusion about the actual goal (!) context being
  3312 used here, which is not necessarily the same as the_context().
  3313 
  3314 * Command 'find_theorems': supports "*" wild-card in "name:"
  3315 criterion; "with_dups" option.  Certain ProofGeneral versions might
  3316 support a specific search form (see ProofGeneral/CHANGES).
  3317 
  3318 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  3319 by default, which means that "prems" (and also "fixed variables") are
  3320 suppressed from proof state output.  Note that the ProofGeneral
  3321 settings mechanism allows to change and save options persistently, but
  3322 older versions of Isabelle will fail to start up if a negative prems
  3323 limit is imposed.
  3324 
  3325 * Local theory targets may be specified by non-nested blocks of
  3326 ``context/locale/class ... begin'' followed by ``end''.  The body may
  3327 contain definitions, theorems etc., including any derived mechanism
  3328 that has been implemented on top of these primitives.  This concept
  3329 generalizes the existing ``theorem (in ...)'' towards more versatility
  3330 and scalability.
  3331 
  3332 * Proof General interface: proper undo of final 'end' command;
  3333 discontinued Isabelle/classic mode (ML proof scripts).
  3334 
  3335 
  3336 *** Document preparation ***
  3337 
  3338 * Added antiquotation @{theory name} which prints the given name,
  3339 after checking that it refers to a valid ancestor theory in the
  3340 current context.
  3341 
  3342 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  3343 check the given source text as ML type/structure, printing verbatim.
  3344 
  3345 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  3346 "c args == rhs" given in the current context.  (Any number of
  3347 arguments may be given on the LHS.)
  3348 
  3349 
  3350 *** Pure ***
  3351 
  3352 * The 'class' package offers a combination of axclass and locale to
  3353 achieve Haskell-like type classes in Isabelle.  Definitions and
  3354 theorems within a class context produce both relative results (with
  3355 implicit parameters according to the locale context), and polymorphic
  3356 constants with qualified polymorphism (according to the class
  3357 context).  Within the body context of a 'class' target, a separate
  3358 syntax layer ("user space type system") takes care of converting
  3359 between global polymorphic consts and internal locale representation.
  3360 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  3361 "isatool doc classes" provides a tutorial.
  3362 
  3363 * Generic code generator framework allows to generate executable
  3364 code for ML and Haskell (including Isabelle classes).  A short usage
  3365 sketch:
  3366 
  3367     internal compilation:
  3368         export_code <list of constants (term syntax)> in SML
  3369     writing SML code to a file:
  3370         export_code <list of constants (term syntax)> in SML <filename>
  3371     writing OCaml code to a file:
  3372         export_code <list of constants (term syntax)> in OCaml <filename>
  3373     writing Haskell code to a bunch of files:
  3374         export_code <list of constants (term syntax)> in Haskell <filename>
  3375 
  3376     evaluating closed propositions to True/False using code generation:
  3377         method ``eval''
  3378 
  3379 Reasonable default setup of framework in HOL.
  3380 
  3381 Theorem attributs for selecting and transforming function equations theorems:
  3382 
  3383     [code fun]:        select a theorem as function equation for a specific constant
  3384     [code fun del]:    deselect a theorem as function equation for a specific constant
  3385     [code inline]:     select an equation theorem for unfolding (inlining) in place
  3386     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  3387 
  3388 User-defined serializations (target in {SML, OCaml, Haskell}):
  3389 
  3390     code_const <and-list of constants (term syntax)>
  3391       {(target) <and-list of const target syntax>}+
  3392 
  3393     code_type <and-list of type constructors>
  3394       {(target) <and-list of type target syntax>}+
  3395 
  3396     code_instance <and-list of instances>
  3397       {(target)}+
  3398         where instance ::= <type constructor> :: <class>
  3399 
  3400     code_class <and_list of classes>
  3401       {(target) <and-list of class target syntax>}+
  3402         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  3403 
  3404 code_instance and code_class only are effective to target Haskell.
  3405 
  3406 For example usage see src/HOL/ex/Codegenerator.thy and
  3407 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  3408 generation from Isabelle/HOL theories is available via "isatool doc
  3409 codegen".
  3410 
  3411 * Code generator: consts in 'consts_code' Isar commands are now
  3412 referred to by usual term syntax (including optional type
  3413 annotations).
  3414 
  3415 * Command 'no_translations' removes translation rules from theory
  3416 syntax.
  3417 
  3418 * Overloaded definitions are now actually checked for acyclic
  3419 dependencies.  The overloading scheme is slightly more general than
  3420 that of Haskell98, although Isabelle does not demand an exact
  3421 correspondence to type class and instance declarations.
  3422 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  3423 exotic versions of overloading -- at the discretion of the user!
  3424 
  3425 Polymorphic constants are represented via type arguments, i.e. the
  3426 instantiation that matches an instance against the most general
  3427 declaration given in the signature.  For example, with the declaration
  3428 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  3429 as c(nat).  Overloading is essentially simultaneous structural
  3430 recursion over such type arguments.  Incomplete specification patterns
  3431 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  3432 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  3433 Command 'print_theory' outputs the normalized system of recursive
  3434 equations, see section "definitions".
  3435 
  3436 * Configuration options are maintained within the theory or proof
  3437 context (with name and type bool/int/string), providing a very simple
  3438 interface to a poor-man's version of general context data.  Tools may
  3439 declare options in ML (e.g. using Attrib.config_int) and then refer to
  3440 these values using Config.get etc.  Users may change options via an
  3441 associated attribute of the same name.  This form of context
  3442 declaration works particularly well with commands 'declare' or
  3443 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  3444 very easy to avoid global references, which would not observe Isar
  3445 toplevel undo/redo and fail to work with multithreading.
  3446 
  3447 Various global ML references of Pure and HOL have been turned into
  3448 configuration options:
  3449 
  3450   Unify.search_bound		unify_search_bound
  3451   Unify.trace_bound		unify_trace_bound
  3452   Unify.trace_simp		unify_trace_simp
  3453   Unify.trace_types		unify_trace_types
  3454   Simplifier.simp_depth_limit	simp_depth_limit
  3455   Blast.depth_limit		blast_depth_limit
  3456   DatatypeProp.dtK		datatype_distinctness_limit
  3457   fast_arith_neq_limit  	fast_arith_neq_limit
  3458   fast_arith_split_limit	fast_arith_split_limit
  3459 
  3460 * Named collections of theorems may be easily installed as context
  3461 data using the functor NamedThmsFun (see also
  3462 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  3463 attributes; there is also a toplevel print command.  This facility is
  3464 just a common case of general context data, which is the preferred way
  3465 for anything more complex than just a list of facts in canonical
  3466 order.
  3467 
  3468 * Isar: command 'declaration' augments a local theory by generic
  3469 declaration functions written in ML.  This enables arbitrary content
  3470 being added to the context, depending on a morphism that tells the
  3471 difference of the original declaration context wrt. the application
  3472 context encountered later on.
  3473 
  3474 * Isar: proper interfaces for simplification procedures.  Command
  3475 'simproc_setup' declares named simprocs (with match patterns, and body
  3476 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  3477 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  3478 
  3479 * Isar: an extra pair of brackets around attribute declarations
  3480 abbreviates a theorem reference involving an internal dummy fact,
  3481 which will be ignored later --- only the effect of the attribute on
  3482 the background context will persist.  This form of in-place
  3483 declarations is particularly useful with commands like 'declare' and
  3484 'using', for example ``have A using [[simproc a]] by simp''.
  3485 
  3486 * Isar: method "assumption" (and implicit closing of subproofs) now
  3487 takes simple non-atomic goal assumptions into account: after applying
  3488 an assumption as a rule the resulting subgoals are solved by atomic
  3489 assumption steps.  This is particularly useful to finish 'obtain'
  3490 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  3491 without referring to the original premise "!!x. P x ==> thesis" in the
  3492 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  3493 more permissive.
  3494 
  3495 * Isar: implicit use of prems from the Isar proof context is
  3496 considered a legacy feature.  Common applications like ``have A .''
  3497 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  3498 referencing facts explicitly here improves readability and
  3499 maintainability of proof texts.
  3500 
  3501 * Isar: improper proof element 'guess' is like 'obtain', but derives
  3502 the obtained context from the course of reasoning!  For example:
  3503 
  3504   assume "EX x y. A x & B y"   -- "any previous fact"
  3505   then guess x and y by clarify
  3506 
  3507 This technique is potentially adventurous, depending on the facts and
  3508 proof tools being involved here.
  3509 
  3510 * Isar: known facts from the proof context may be specified as literal
  3511 propositions, using ASCII back-quote syntax.  This works wherever
  3512 named facts used to be allowed so far, in proof commands, proof
  3513 methods, attributes etc.  Literal facts are retrieved from the context
  3514 according to unification of type and term parameters.  For example,
  3515 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  3516 theorems in the current context, then these are valid literal facts:
  3517 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  3518 
  3519 There is also a proof method "fact" which does the same composition
  3520 for explicit goal states, e.g. the following proof texts coincide with
  3521 certain special cases of literal facts:
  3522 
  3523   have "A" by fact                 ==  note `A`
  3524   have "A ==> B" by fact           ==  note `A ==> B`
  3525   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  3526   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  3527 
  3528 * Isar: ":" (colon) is no longer a symbolic identifier character in
  3529 outer syntax.  Thus symbolic identifiers may be used without
  3530 additional white space in declarations like this: ``assume *: A''.
  3531 
  3532 * Isar: 'print_facts' prints all local facts of the current context,
  3533 both named and unnamed ones.
  3534 
  3535 * Isar: 'def' now admits simultaneous definitions, e.g.:
  3536 
  3537   def x == "t" and y == "u"
  3538 
  3539 * Isar: added command 'unfolding', which is structurally similar to
  3540 'using', but affects both the goal state and facts by unfolding given
  3541 rewrite rules.  Thus many occurrences of the 'unfold' method or
  3542 'unfolded' attribute may be replaced by first-class proof text.
  3543 
  3544 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  3545 and command 'unfolding' now all support object-level equalities
  3546 (potentially conditional).  The underlying notion of rewrite rule is
  3547 analogous to the 'rule_format' attribute, but *not* that of the
  3548 Simplifier (which is usually more generous).
  3549 
  3550 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  3551 premises of a theorem by n. Useful in conjunction with drule.
  3552 
  3553 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  3554 method expression within a sandbox consisting of the first N
  3555 sub-goals, which need to exist.  For example, ``simp_all [3]''
  3556 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  3557 simplifies all new goals that emerge from applying rule foo to the
  3558 originally first one.
  3559 
  3560 * Isar: schematic goals are no longer restricted to higher-order
  3561 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  3562 expected.
  3563 
  3564 * Isar: the conclusion of a long theorem statement is now either
  3565 'shows' (a simultaneous conjunction, as before), or 'obtains'
  3566 (essentially a disjunction of cases with local parameters and
  3567 assumptions).  The latter allows to express general elimination rules
  3568 adequately; in this notation common elimination rules look like this:
  3569 
  3570   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  3571     assumes "EX x. P x"
  3572     obtains x where "P x"
  3573 
  3574   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  3575     assumes "A & B"
  3576     obtains A and B
  3577 
  3578   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  3579     assumes "A | B"
  3580     obtains
  3581       A
  3582     | B
  3583 
  3584 The subsequent classical rules even refer to the formal "thesis"
  3585 explicitly:
  3586 
  3587   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  3588     obtains "~ thesis"
  3589 
  3590   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  3591     obtains "thesis ==> something"
  3592 
  3593 The actual proof of an 'obtains' statement is analogous to that of the
  3594 Isar proof element 'obtain', only that there may be several cases.
  3595 Optional case names may be specified in parentheses; these will be
  3596 available both in the present proof and as annotations in the
  3597 resulting rule, for later use with the 'cases' method (cf. attribute
  3598 case_names).
  3599 
  3600 * Isar: the assumptions of a long theorem statement are available as
  3601 "assms" fact in the proof context.  This is more appropriate than the
  3602 (historical) "prems", which refers to all assumptions of the current
  3603 context, including those from the target locale, proof body etc.
  3604 
  3605 * Isar: 'print_statement' prints theorems from the current theory or
  3606 proof context in long statement form, according to the syntax of a
  3607 top-level lemma.
  3608 
  3609 * Isar: 'obtain' takes an optional case name for the local context
  3610 introduction rule (default "that").
  3611 
  3612 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  3613 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  3614 to occur.
  3615 
  3616 * Pure: syntax "CONST name" produces a fully internalized constant
  3617 according to the current context.  This is particularly useful for
  3618 syntax translations that should refer to internal constant
  3619 representations independently of name spaces.
  3620 
  3621 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  3622 instead of "FOO ". This allows multiple binder declarations to coexist
  3623 in the same context.  INCOMPATIBILITY.
  3624 
  3625 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  3626 primitive that also works in a locale context (both for constants and
  3627 fixed variables). Type declaration and internal syntactic representation
  3628 of given constants retrieved from the context. Likewise, the
  3629 'no_notation' command allows to remove given syntax annotations from the
  3630 current context.
  3631 
  3632 * Isar/locales: new derived specification elements 'axiomatization',
  3633 'definition', 'abbreviation', which support type-inference, admit
  3634 object-level specifications (equality, equivalence).  See also the
  3635 isar-ref manual.  Examples:
  3636 
  3637   axiomatization
  3638     eq  (infix "===" 50) where
  3639     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  3640 
  3641   definition "f x y = x + y + 1"
  3642   definition g where "g x = f x x"
  3643 
  3644   abbreviation
  3645     neq  (infix "=!=" 50) where
  3646     "x =!= y == ~ (x === y)"
  3647 
  3648 These specifications may be also used in a locale context.  Then the
  3649 constants being introduced depend on certain fixed parameters, and the
  3650 constant name is qualified by the locale base name.  An internal
  3651 abbreviation takes care for convenient input and output, making the
  3652 parameters implicit and using the original short name.  See also
  3653 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  3654 entities from a monomorphic theory.
  3655 
  3656 Presently, abbreviations are only available 'in' a target locale, but
  3657 not inherited by general import expressions.  Also note that
  3658 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  3659 'translations' in common applications.  The "no_abbrevs" print mode
  3660 prevents folding of abbreviations in term output.
  3661 
  3662 Concrete syntax is attached to specified constants in internal form,
  3663 independently of name spaces.  The parse tree representation is
  3664 slightly different -- use 'notation' instead of raw 'syntax', and
  3665 'translations' with explicit "CONST" markup to accommodate this.
  3666 
  3667 * Pure/Isar: unified syntax for new-style specification mechanisms
  3668 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  3669 full type inference and dummy patterns ("_").  For example:
  3670 
  3671   definition "K x _ = x"
  3672 
  3673   inductive conj for A B
  3674   where "A ==> B ==> conj A B"
  3675 
  3676 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  3677 the current context.  Print mode "no_abbrevs" prevents inversion of
  3678 abbreviations on output.
  3679 
  3680 * Isar/locales: improved parameter handling: use of locales "var" and
  3681 "struct" no longer necessary; - parameter renamings are no longer
  3682 required to be injective.  For example, this allows to define
  3683 endomorphisms as locale endom = homom mult mult h.
  3684 
  3685 * Isar/locales: changed the way locales with predicates are defined.
  3686 Instead of accumulating the specification, the imported expression is
  3687 now an interpretation.  INCOMPATIBILITY: different normal form of
  3688 locale expressions.  In particular, in interpretations of locales with
  3689 predicates, goals repesenting already interpreted fragments are not
  3690 removed automatically.  Use methods `intro_locales' and
  3691 `unfold_locales'; see below.
  3692 
  3693 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  3694 provide backward reasoning on locales predicates.  The methods are
  3695 aware of interpretations and discharge corresponding goals.
  3696 `intro_locales' is less aggressive then `unfold_locales' and does not
  3697 unfold predicates to assumptions.
  3698 
  3699 * Isar/locales: the order in which locale fragments are accumulated
  3700 has changed.  This enables to override declarations from fragments due
  3701 to interpretations -- for example, unwanted simp rules.
  3702 
  3703 * Isar/locales: interpretation in theories and proof contexts has been
  3704 extended.  One may now specify (and prove) equations, which are
  3705 unfolded in interpreted theorems.  This is useful for replacing
  3706 defined concepts (constants depending on locale parameters) by
  3707 concepts already existing in the target context.  Example:
  3708 
  3709   interpretation partial_order ["op <= :: [int, int] => bool"]
  3710     where "partial_order.less (op <=) (x::int) y = (x < y)"
  3711 
  3712 Typically, the constant `partial_order.less' is created by a
  3713 definition specification element in the context of locale
  3714 partial_order.
  3715 
  3716 * Method "induct": improved internal context management to support
  3717 local fixes and defines on-the-fly. Thus explicit meta-level
  3718 connectives !!  and ==> are rarely required anymore in inductive goals
  3719 (using object-logic connectives for this purpose has been long
  3720 obsolete anyway). Common proof patterns are explained in
  3721 src/HOL/Induct/Common_Patterns.thy, see also
  3722 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  3723 examples.
  3724 
  3725 * Method "induct": improved handling of simultaneous goals. Instead of
  3726 introducing object-level conjunction, the statement is now split into
  3727 several conclusions, while the corresponding symbolic cases are nested
  3728 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  3729 see src/HOL/Induct/Common_Patterns.thy, for example.
  3730 
  3731 * Method "induct": mutual induction rules are now specified as a list
  3732 of rule sharing the same induction cases. HOL packages usually provide
  3733 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  3734 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  3735 mutual induction rules differently, i.e. like this:
  3736 
  3737   (induct rule: foo_bar.inducts)
  3738   (induct set: foo bar)
  3739   (induct pred: foo bar)
  3740   (induct type: foo bar)
  3741 
  3742 The ML function ProjectRule.projections turns old-style rules into the
  3743 new format.
  3744 
  3745 * Method "coinduct": dual of induction, see
  3746 src/HOL/Library/Coinductive_List.thy for various examples.
  3747 
  3748 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  3749 considered a legacy feature.
  3750 
  3751 * Attribute "symmetric" produces result with standardized schematic
  3752 variables (index 0).  Potential INCOMPATIBILITY.
  3753 
  3754 * Simplifier: by default the simplifier trace only shows top level
  3755 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  3756 default. Thus there is less danger of being flooded by the trace. The
  3757 trace indicates where parts have been suppressed.
  3758   
  3759 * Provers/classical: removed obsolete classical version of elim_format
  3760 attribute; classical elim/dest rules are now treated uniformly when
  3761 manipulating the claset.
  3762 
  3763 * Provers/classical: stricter checks to ensure that supplied intro,
  3764 dest and elim rules are well-formed; dest and elim rules must have at
  3765 least one premise.
  3766 
  3767 * Provers/classical: attributes dest/elim/intro take an optional
  3768 weight argument for the rule (just as the Pure versions).  Weights are
  3769 ignored by automated tools, but determine the search order of single
  3770 rule steps.
  3771 
  3772 * Syntax: input syntax now supports dummy variable binding "%_. b",
  3773 where the body does not mention the bound variable.  Note that dummy
  3774 patterns implicitly depend on their context of bounds, which makes
  3775 "{_. _}" match any set comprehension as expected.  Potential
  3776 INCOMPATIBILITY -- parse translations need to cope with syntactic
  3777 constant "_idtdummy" in the binding position.
  3778 
  3779 * Syntax: removed obsolete syntactic constant "_K" and its associated
  3780 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  3781 for example "A -> B" => "Pi A (%_. B)".
  3782 
  3783 * Pure: 'class_deps' command visualizes the subclass relation, using
  3784 the graph browser tool.
  3785 
  3786 * Pure: 'print_theory' now suppresses certain internal declarations by
  3787 default; use '!' option for full details.
  3788 
  3789 
  3790 *** HOL ***
  3791 
  3792 * Method "metis" proves goals by applying the Metis general-purpose
  3793 resolution prover (see also http://gilith.com/software/metis/).
  3794 Examples are in the directory MetisExamples.  WARNING: the
  3795 Isabelle/HOL-Metis integration does not yet work properly with
  3796 multi-threading.
  3797   
  3798 * Command 'sledgehammer' invokes external automatic theorem provers as
  3799 background processes.  It generates calls to the "metis" method if
  3800 successful. These can be pasted into the proof.  Users do not have to
  3801 wait for the automatic provers to return.  WARNING: does not really
  3802 work with multi-threading.
  3803 
  3804 * New "auto_quickcheck" feature tests outermost goal statements for
  3805 potential counter-examples.  Controlled by ML references
  3806 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  3807 5000 milliseconds).  Fails silently if statements is outside of
  3808 executable fragment, or any other codgenerator problem occurs.
  3809 
  3810 * New constant "undefined" with axiom "undefined x = undefined".
  3811 
  3812 * Added class "HOL.eq", allowing for code generation with polymorphic
  3813 equality.
  3814 
  3815 * Some renaming of class constants due to canonical name prefixing in
  3816 the new 'class' package:
  3817 
  3818     HOL.abs ~> HOL.abs_class.abs
  3819     HOL.divide ~> HOL.divide_class.divide
  3820     0 ~> HOL.zero_class.zero
  3821     1 ~> HOL.one_class.one
  3822     op + ~> HOL.plus_class.plus
  3823     op - ~> HOL.minus_class.minus
  3824     uminus ~> HOL.minus_class.uminus
  3825     op * ~> HOL.times_class.times
  3826     op < ~> HOL.ord_class.less
  3827     op <= > HOL.ord_class.less_eq
  3828     Nat.power ~> Power.power_class.power
  3829     Nat.size ~> Nat.size_class.size
  3830     Numeral.number_of ~> Numeral.number_class.number_of
  3831     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  3832     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  3833     Orderings.min ~> Orderings.ord_class.min
  3834     Orderings.max ~> Orderings.ord_class.max
  3835     Divides.op div ~> Divides.div_class.div
  3836     Divides.op mod ~> Divides.div_class.mod
  3837     Divides.op dvd ~> Divides.div_class.dvd
  3838 
  3839 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  3840 
  3841 a) User-defined constants using any of the names "plus", "minus",
  3842 "times", "less" or "less_eq". The standard syntax translations for
  3843 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  3844 names.
  3845 
  3846 b) Variables named "plus", "minus", "times", "less", "less_eq"
  3847 INCOMPATIBILITY: use more specific names.
  3848 
  3849 c) Permutative equations (e.g. "a + b = b + a")
  3850 Since the change of names also changes the order of terms, permutative
  3851 rewrite rules may get applied in a different order. Experience shows
  3852 that this is rarely the case (only two adaptions in the whole Isabelle
  3853 distribution).  INCOMPATIBILITY: rewrite proofs
  3854 
  3855 d) ML code directly refering to constant names
  3856 This in general only affects hand-written proof tactics, simprocs and
  3857 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  3858 Consider using @{const_name} antiquotation.
  3859 
  3860 * New class "default" with associated constant "default".
  3861 
  3862 * Function "sgn" is now overloaded and available on int, real, complex
  3863 (and other numeric types), using class "sgn".  Two possible defs of
  3864 sgn are given as equational assumptions in the classes sgn_if and
  3865 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  3866 INCOMPATIBILITY.
  3867 
  3868 * Locale "partial_order" now unified with class "order" (cf. theory
  3869 Orderings), added parameter "less".  INCOMPATIBILITY.
  3870 
  3871 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  3872 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  3873 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  3874 
  3875 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  3876 changed order of proof goals in instance proofs.
  3877 
  3878 * The transitivity reasoner for partial and linear orders is set up
  3879 for classes "order" and "linorder".  Instances of the reasoner are available
  3880 in all contexts importing or interpreting the corresponding locales.
  3881 Method "order" invokes the reasoner separately; the reasoner
  3882 is also integrated with the Simplifier as a solver.  Diagnostic
  3883 command 'print_orders' shows the available instances of the reasoner
  3884 in the current context.
  3885 
  3886 * Localized monotonicity predicate in theory "Orderings"; integrated
  3887 lemmas max_of_mono and min_of_mono with this predicate.
  3888 INCOMPATIBILITY.
  3889 
  3890 * Formulation of theorem "dense" changed slightly due to integration
  3891 with new class dense_linear_order.
  3892 
  3893 * Uniform lattice theory development in HOL.
  3894 
  3895     constants "meet" and "join" now named "inf" and "sup"
  3896     constant "Meet" now named "Inf"
  3897 
  3898     classes "meet_semilorder" and "join_semilorder" now named
  3899       "lower_semilattice" and "upper_semilattice"
  3900     class "lorder" now named "lattice"
  3901     class "comp_lat" now named "complete_lattice"
  3902 
  3903     Instantiation of lattice classes allows explicit definitions
  3904     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  3905 
  3906   INCOMPATIBILITY.  Theorem renames:
  3907 
  3908     meet_left_le            ~> inf_le1
  3909     meet_right_le           ~> inf_le2
  3910     join_left_le            ~> sup_ge1
  3911     join_right_le           ~> sup_ge2
  3912     meet_join_le            ~> inf_sup_ord
  3913     le_meetI                ~> le_infI
  3914     join_leI                ~> le_supI
  3915     le_meet                 ~> le_inf_iff
  3916     le_join                 ~> ge_sup_conv
  3917     meet_idempotent         ~> inf_idem
  3918     join_idempotent         ~> sup_idem
  3919     meet_comm               ~> inf_commute
  3920     join_comm               ~> sup_commute
  3921     meet_leI1               ~> le_infI1
  3922     meet_leI2               ~> le_infI2
  3923     le_joinI1               ~> le_supI1
  3924     le_joinI2               ~> le_supI2
  3925     meet_assoc              ~> inf_assoc
  3926     join_assoc              ~> sup_assoc
  3927     meet_left_comm          ~> inf_left_commute
  3928     meet_left_idempotent    ~> inf_left_idem
  3929     join_left_comm          ~> sup_left_commute
  3930     join_left_idempotent    ~> sup_left_idem
  3931     meet_aci                ~> inf_aci
  3932     join_aci                ~> sup_aci
  3933     le_def_meet             ~> le_iff_inf
  3934     le_def_join             ~> le_iff_sup
  3935     join_absorp2            ~> sup_absorb2
  3936     join_absorp1            ~> sup_absorb1
  3937     meet_absorp1            ~> inf_absorb1
  3938     meet_absorp2            ~> inf_absorb2
  3939     meet_join_absorp        ~> inf_sup_absorb
  3940     join_meet_absorp        ~> sup_inf_absorb
  3941     distrib_join_le         ~> distrib_sup_le
  3942     distrib_meet_le         ~> distrib_inf_le
  3943 
  3944     add_meet_distrib_left   ~> add_inf_distrib_left
  3945     add_join_distrib_left   ~> add_sup_distrib_left
  3946     is_join_neg_meet        ~> is_join_neg_inf
  3947     is_meet_neg_join        ~> is_meet_neg_sup
  3948     add_meet_distrib_right  ~> add_inf_distrib_right
  3949     add_join_distrib_right  ~> add_sup_distrib_right
  3950     add_meet_join_distribs  ~> add_sup_inf_distribs
  3951     join_eq_neg_meet        ~> sup_eq_neg_inf
  3952     meet_eq_neg_join        ~> inf_eq_neg_sup
  3953     add_eq_meet_join        ~> add_eq_inf_sup
  3954     meet_0_imp_0            ~> inf_0_imp_0
  3955     join_0_imp_0            ~> sup_0_imp_0
  3956     meet_0_eq_0             ~> inf_0_eq_0
  3957     join_0_eq_0             ~> sup_0_eq_0
  3958     neg_meet_eq_join        ~> neg_inf_eq_sup
  3959     neg_join_eq_meet        ~> neg_sup_eq_inf
  3960     join_eq_if              ~> sup_eq_if
  3961 
  3962     mono_meet               ~> mono_inf
  3963     mono_join               ~> mono_sup
  3964     meet_bool_eq            ~> inf_bool_eq
  3965     join_bool_eq            ~> sup_bool_eq
  3966     meet_fun_eq             ~> inf_fun_eq
  3967     join_fun_eq             ~> sup_fun_eq
  3968     meet_set_eq             ~> inf_set_eq
  3969     join_set_eq             ~> sup_set_eq
  3970     meet1_iff               ~> inf1_iff
  3971     meet2_iff               ~> inf2_iff
  3972     meet1I                  ~> inf1I
  3973     meet2I                  ~> inf2I
  3974     meet1D1                 ~> inf1D1
  3975     meet2D1                 ~> inf2D1
  3976     meet1D2                 ~> inf1D2
  3977     meet2D2                 ~> inf2D2
  3978     meet1E                  ~> inf1E
  3979     meet2E                  ~> inf2E
  3980     join1_iff               ~> sup1_iff
  3981     join2_iff               ~> sup2_iff
  3982     join1I1                 ~> sup1I1
  3983     join2I1                 ~> sup2I1
  3984     join1I1                 ~> sup1I1
  3985     join2I2                 ~> sup1I2
  3986     join1CI                 ~> sup1CI
  3987     join2CI                 ~> sup2CI
  3988     join1E                  ~> sup1E
  3989     join2E                  ~> sup2E
  3990 
  3991     is_meet_Meet            ~> is_meet_Inf
  3992     Meet_bool_def           ~> Inf_bool_def
  3993     Meet_fun_def            ~> Inf_fun_def
  3994     Meet_greatest           ~> Inf_greatest
  3995     Meet_lower              ~> Inf_lower
  3996     Meet_set_def            ~> Inf_set_def
  3997 
  3998     Sup_def                 ~> Sup_Inf
  3999     Sup_bool_eq             ~> Sup_bool_def
  4000     Sup_fun_eq              ~> Sup_fun_def
  4001     Sup_set_eq              ~> Sup_set_def
  4002 
  4003     listsp_meetI            ~> listsp_infI
  4004     listsp_meet_eq          ~> listsp_inf_eq
  4005 
  4006     meet_min                ~> inf_min
  4007     join_max                ~> sup_max
  4008 
  4009 * Added syntactic class "size"; overloaded constant "size" now has
  4010 type "'a::size ==> bool"
  4011 
  4012 * Internal reorganisation of `size' of datatypes: size theorems
  4013 "foo.size" are no longer subsumed by "foo.simps" (but are still
  4014 simplification rules by default!); theorems "prod.size" now named
  4015 "*.size".
  4016 
  4017 * Class "div" now inherits from class "times" rather than "type".
  4018 INCOMPATIBILITY.
  4019 
  4020 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  4021 Linorder etc.  have disappeared; operations defined in terms of
  4022 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  4023 
  4024 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  4025 
  4026 * HOL-Word: New extensive library and type for generic, fixed size
  4027 machine words, with arithemtic, bit-wise, shifting and rotating
  4028 operations, reflection into int, nat, and bool lists, automation for
  4029 linear arithmetic (by automatic reflection into nat or int), including
  4030 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  4031 arithmetic type classes, supporting automatic simplification of
  4032 numerals on all operations.
  4033 
  4034 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  4035 
  4036 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  4037 
  4038 * Code generator library theories:
  4039   - Code_Integer represents HOL integers by big integer literals in target
  4040     languages.
  4041   - Code_Char represents HOL characters by character literals in target
  4042     languages.
  4043   - Code_Char_chr like Code_Char, but also offers treatment of character
  4044     codes; includes Code_Integer.
  4045   - Executable_Set allows to generate code for finite sets using lists.
  4046   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  4047     denominator).
  4048   - Executable_Real implements a subset of real numbers, namly those
  4049     representable by rational numbers.
  4050   - Efficient_Nat implements natural numbers by integers, which in general will
  4051     result in higher efficency; pattern matching with 0/Suc is eliminated;
  4052     includes Code_Integer.
  4053   - Code_Index provides an additional datatype index which is mapped to
  4054     target-language built-in integers.
  4055   - Code_Message provides an additional datatype message_string which is isomorphic to
  4056     strings; messages are mapped to target-language strings.
  4057 
  4058 * New package for inductive predicates
  4059 
  4060   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  4061 
  4062     inductive
  4063       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  4064       for z_1 :: U_1 and ... and z_n :: U_m
  4065     where
  4066       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  4067     | ...
  4068 
  4069   with full support for type-inference, rather than
  4070 
  4071     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4072 
  4073     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  4074     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  4075 
  4076     inductive "s z_1 ... z_m"
  4077     intros
  4078       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  4079       ...
  4080 
  4081   For backward compatibility, there is a wrapper allowing inductive
  4082   sets to be defined with the new package via
  4083 
  4084     inductive_set
  4085       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4086       for z_1 :: U_1 and ... and z_n :: U_m
  4087     where
  4088       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  4089     | ...
  4090 
  4091   or
  4092 
  4093     inductive_set
  4094       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4095       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  4096       for z_1 :: U_1 and ... and z_n :: U_m
  4097     where
  4098       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  4099     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  4100     | ...
  4101 
  4102   if the additional syntax "p ..." is required.
  4103 
  4104   Numerous examples can be found in the subdirectories src/HOL/Auth,
  4105   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  4106 
  4107   INCOMPATIBILITIES:
  4108 
  4109   - Since declaration and definition of inductive sets or predicates
  4110     is no longer separated, abbreviations involving the newly
  4111     introduced sets or predicates must be specified together with the
  4112     introduction rules after the 'where' keyword (see above), rather
  4113     than before the actual inductive definition.
  4114 
  4115   - The variables in induction and elimination rules are now
  4116     quantified in the order of their occurrence in the introduction
  4117     rules, rather than in alphabetical order. Since this may break
  4118     some proofs, these proofs either have to be repaired, e.g. by
  4119     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  4120     statements of the form
  4121 
  4122       case (rule_i a_i_1 ... a_i_{k_i})
  4123 
  4124     or the old order of quantification has to be restored by explicitly adding
  4125     meta-level quantifiers in the introduction rules, i.e.
  4126 
  4127       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  4128 
  4129   - The format of the elimination rules is now
  4130 
  4131       p z_1 ... z_m x_1 ... x_n ==>
  4132         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  4133         ==> ... ==> P
  4134 
  4135     for predicates and
  4136 
  4137       (x_1, ..., x_n) : s z_1 ... z_m ==>
  4138         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  4139         ==> ... ==> P
  4140 
  4141     for sets rather than
  4142 
  4143       x : s z_1 ... z_m ==>
  4144         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  4145         ==> ... ==> P
  4146 
  4147     This may require terms in goals to be expanded to n-tuples
  4148     (e.g. using case_tac or simplification with the split_paired_all
  4149     rule) before the above elimination rule is applicable.
  4150 
  4151   - The elimination or case analysis rules for (mutually) inductive
  4152     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  4153     list of rules "p_1_..._p_k.elims" is no longer available.
  4154 
  4155 * New package "function"/"fun" for general recursive functions,
  4156 supporting mutual and nested recursion, definitions in local contexts,
  4157 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  4158 for small examples, and the separate tutorial on the function
  4159 package. The old recdef "package" is still available as before, but
  4160 users are encouraged to use the new package.
  4161 
  4162 * Method "lexicographic_order" automatically synthesizes termination
  4163 relations as lexicographic combinations of size measures. 
  4164 
  4165 * Case-expressions allow arbitrary constructor-patterns (including
  4166 "_") and take their order into account, like in functional
  4167 programming.  Internally, this is translated into nested
  4168 case-expressions; missing cases are added and mapped to the predefined
  4169 constant "undefined". In complicated cases printing may no longer show
  4170 the original input but the internal form. Lambda-abstractions allow
  4171 the same form of pattern matching: "% pat1 => e1 | ..." is an
  4172 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  4173 variable.
  4174 
  4175 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  4176 is an abbreviation for "of_nat :: nat => int". The simplification
  4177 rules for "of_nat" have been changed to work like "int" did
  4178 previously.  Potential INCOMPATIBILITY:
  4179   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  4180   - of_nat_diff and of_nat_mult are no longer default simp rules
  4181 
  4182 * Method "algebra" solves polynomial equations over (semi)rings using
  4183 Groebner bases. The (semi)ring structure is defined by locales and the
  4184 tool setup depends on that generic context. Installing the method for
  4185 a specific type involves instantiating the locale and possibly adding
  4186 declarations for computation on the coefficients.  The method is
  4187 already instantiated for natural numbers and for the axiomatic class
  4188 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  4189 CALCULEMUS 2007 for the general principles underlying this
  4190 architecture of context-aware proof-tools.
  4191 
  4192 * Method "ferrack" implements quantifier elimination over
  4193 special-purpose dense linear orders using locales (analogous to
  4194 "algebra"). The method is already installed for class
  4195 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  4196 rat, etc.
  4197 
  4198 * Former constant "List.op @" now named "List.append".  Use ML
  4199 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  4200 circumvent possible incompatibilities when working on ML level.
  4201 
  4202 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  4203 
  4204 * New function listsum :: 'a list => 'a for arbitrary monoids.
  4205 Special syntax: "SUM x <- xs. f x" (and latex variants)
  4206 
  4207 * New syntax for Haskell-like list comprehension (input only), eg.
  4208 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  4209 
  4210 * The special syntax for function "filter" has changed from [x :
  4211 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  4212 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  4213 
  4214 * [a..b] is now defined for arbitrary linear orders.  It used to be
  4215 defined on nat only, as an abbreviation for [a..<Suc b]
  4216 INCOMPATIBILITY.
  4217 
  4218 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  4219 
  4220 * New functions "sorted" and "sort" in src/HOL/List.thy.
  4221 
  4222 * New lemma collection field_simps (an extension of ring_simps) for
  4223 manipulating (in)equations involving division. Multiplies with all
  4224 denominators that can be proved to be non-zero (in equations) or
  4225 positive/negative (in inequations).
  4226 
  4227 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  4228 have been improved and renamed to ring_simps, group_simps and
  4229 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  4230 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  4231 
  4232 * Theory Library/Commutative_Ring: switched from recdef to function
  4233 package; constants add, mul, pow now curried.  Infix syntax for
  4234 algebraic operations.
  4235 
  4236 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  4237 INCOMPATIBILITY.
  4238 
  4239 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  4240 INCOMPATIBILITY.
  4241 
  4242 * HOL/records: generalised field-update to take a function on the
  4243 field rather than the new value: r(|A := x|) is translated to A_update
  4244 (K x) r The K-combinator that is internally used is called K_record.
  4245 INCOMPATIBILITY: Usage of the plain update functions has to be
  4246 adapted.
  4247  
  4248 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  4249 * x = 0, which are required for a semiring.  Richer structures do not
  4250 inherit from semiring_0 anymore, because this property is a theorem
  4251 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  4252 there is more to prove, but this is mostly trivial.
  4253 
  4254 * Class "recpower" is generalized to arbitrary monoids, not just
  4255 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  4256 commutativity or semiring properties additionally.
  4257 
  4258 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  4259 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  4260 better use 'abbreviation'.
  4261 
  4262 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  4263 
  4264 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  4265 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  4266 significant changes for setting up numeral syntax for types:
  4267   - New constants Numeral.pred and Numeral.succ instead
  4268       of former Numeral.bin_pred and Numeral.bin_succ.
  4269   - Use integer operations instead of bin_add, bin_mult and so on.
  4270   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  4271   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  4272 
  4273 See src/HOL/Integ/IntArith.thy for an example setup.
  4274 
  4275 * Command 'normal_form' computes the normal form of a term that may
  4276 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  4277 produces ``[b, c, a]'' (without proof).  This command is suitable for
  4278 heavy-duty computations because the functions are compiled to ML
  4279 first.  Correspondingly, a method "normalization" is provided.  See
  4280 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  4281 
  4282 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  4283 25 like -->); output depends on the "iff" print_mode, the default is
  4284 "A = B" (with priority 50).
  4285 
  4286 * Relations less (<) and less_eq (<=) are also available on type bool.
  4287 Modified syntax to disallow nesting without explicit parentheses,
  4288 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  4289 INCOMPATIBILITY.
  4290 
  4291 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  4292 
  4293 * Relation composition operator "op O" now has precedence 75 and binds
  4294 stronger than union and intersection. INCOMPATIBILITY.
  4295 
  4296 * The old set interval syntax "{m..n(}" (and relatives) has been
  4297 removed.  Use "{m..<n}" (and relatives) instead.
  4298 
  4299 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  4300 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  4301 ``declare [[simproc del: neq]]''.
  4302 
  4303 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  4304 True/False.
  4305 
  4306 * Theorem Cons_eq_map_conv no longer declared as "simp".
  4307 
  4308 * Theorem setsum_mult renamed to setsum_right_distrib.
  4309 
  4310 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  4311 ``rule'' method.
  4312 
  4313 * Reimplemented methods "sat" and "satx", with several improvements:
  4314 goals no longer need to be stated as "<prems> ==> False", equivalences
  4315 (i.e. "=" on type bool) are handled, variable names of the form
  4316 "lit_<n>" are no longer reserved, significant speedup.
  4317 
  4318 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  4319 zChaff is still supported as well.
  4320 
  4321 * 'inductive' and 'datatype': provide projections of mutual rules,
  4322 bundled as foo_bar.inducts;
  4323 
  4324 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  4325 Library.
  4326 
  4327 * Library: moved theory Accessible_Part to main HOL.
  4328 
  4329 * Library: added theory Coinductive_List of potentially infinite lists
  4330 as greatest fixed-point.
  4331 
  4332 * Library: added theory AssocList which implements (finite) maps as
  4333 association lists.
  4334 
  4335 * Method "evaluation" solves goals (i.e. a boolean expression)
  4336 efficiently by compiling it to ML.  The goal is "proved" (via an
  4337 oracle) if it evaluates to True.
  4338 
  4339 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  4340 also when invoked by the simplifier.  This results in the Simplifier
  4341 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  4342 Configuration option fast_arith_split_limit=0 recovers the old
  4343 behavior.
  4344 
  4345 * Support for hex (0x20) and binary (0b1001) numerals.
  4346 
  4347 * New method: reify eqs (t), where eqs are equations for an
  4348 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  4349 parameter, computes a term s::'b and a list xs::'a list and proves the
  4350 theorem I xs s = t. This is also known as reification or quoting. The
  4351 resulting theorem is applied to the subgoal to substitute t with I xs
  4352 s.  If t is omitted, the subgoal itself is reified.
  4353 
  4354 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  4355 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  4356 where f is supposed to be a computable function (in the sense of code
  4357 generattion). The method uses reify to compute s and xs as above then
  4358 applies corr_thm and uses normalization by evaluation to "prove" f s =
  4359 r and finally gets the theorem t = r, which is again applied to the
  4360 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  4361 
  4362 * Reflection: Automatic reification now handels binding, an example is
  4363 available in src/HOL/ex/ReflectionEx.thy
  4364 
  4365 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  4366 command 'statespace' that is similar to 'record', but introduces an
  4367 abstract specification based on the locale infrastructure instead of
  4368 HOL types.  This leads to extra flexibility in composing state spaces,
  4369 in particular multiple inheritance and renaming of components.
  4370 
  4371 
  4372 *** HOL-Complex ***
  4373 
  4374 * Hyperreal: Functions root and sqrt are now defined on negative real
  4375 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  4376 Nonnegativity side conditions have been removed from many lemmas, so
  4377 that more subgoals may now be solved by simplification; potential
  4378 INCOMPATIBILITY.
  4379 
  4380 * Real: new type classes formalize real normed vector spaces and
  4381 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  4382 and norm :: 'a => real.
  4383 
  4384 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  4385 reals into other types. The overloaded constant Reals :: 'a set is now
  4386 defined as range of_real; potential INCOMPATIBILITY.
  4387 
  4388 * Real: proper support for ML code generation, including 'quickcheck'.
  4389 Reals are implemented as arbitrary precision rationals.
  4390 
  4391 * Hyperreal: Several constants that previously worked only for the
  4392 reals have been generalized, so they now work over arbitrary vector
  4393 spaces. Type annotations may need to be added in some cases; potential
  4394 INCOMPATIBILITY.
  4395 
  4396   Infinitesimal  :: ('a::real_normed_vector) star set
  4397   HFinite        :: ('a::real_normed_vector) star set
  4398   HInfinite      :: ('a::real_normed_vector) star set
  4399   approx         :: ('a::real_normed_vector) star => 'a star => bool
  4400   monad          :: ('a::real_normed_vector) star => 'a star set
  4401   galaxy         :: ('a::real_normed_vector) star => 'a star set
  4402   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  4403   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  4404   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  4405   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  4406   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  4407   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  4408   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  4409   sgn            :: 'a::real_normed_vector => 'a
  4410   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  4411 
  4412 * Complex: Some complex-specific constants are now abbreviations for
  4413 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  4414 hnorm.  Other constants have been entirely removed in favor of the
  4415 polymorphic versions (INCOMPATIBILITY):
  4416 
  4417   approx        <-- capprox
  4418   HFinite       <-- CFinite
  4419   HInfinite     <-- CInfinite
  4420   Infinitesimal <-- CInfinitesimal
  4421   monad         <-- cmonad
  4422   galaxy        <-- cgalaxy
  4423   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  4424   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  4425   (ns)deriv     <-- (ns)cderiv
  4426 
  4427 
  4428 *** HOL-Algebra ***
  4429 
  4430 * Formalisation of ideals and the quotient construction over rings.
  4431 
  4432 * Order and lattice theory no longer based on records.
  4433 INCOMPATIBILITY.
  4434 
  4435 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  4436 greatest_closed.  INCOMPATIBILITY.
  4437 
  4438 * Method algebra is now set up via an attribute.  For examples see
  4439 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  4440 of algebraic structures.
  4441 
  4442 * Renamed theory CRing to Ring.
  4443 
  4444 
  4445 *** HOL-Nominal ***
  4446 
  4447 * Substantial, yet incomplete support for nominal datatypes (binding
  4448 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  4449 src/HOL/Nominal/Examples.  Prospective users should consult
  4450 http://isabelle.in.tum.de/nominal/
  4451 
  4452 
  4453 *** ML ***
  4454 
  4455 * ML basics: just one true type int, which coincides with IntInf.int
  4456 (even on SML/NJ).
  4457 
  4458 * ML within Isar: antiquotations allow to embed statically-checked
  4459 formal entities in the source, referring to the context available at
  4460 compile-time.  For example:
  4461 
  4462 ML {* @{sort "{zero,one}"} *}
  4463 ML {* @{typ "'a => 'b"} *}
  4464 ML {* @{term "%x. x"} *}
  4465 ML {* @{prop "x == y"} *}
  4466 ML {* @{ctyp "'a => 'b"} *}
  4467 ML {* @{cterm "%x. x"} *}
  4468 ML {* @{cprop "x == y"} *}
  4469 ML {* @{thm asm_rl} *}
  4470 ML {* @{thms asm_rl} *}
  4471 ML {* @{type_name c} *}
  4472 ML {* @{type_syntax c} *}
  4473 ML {* @{const_name c} *}
  4474 ML {* @{const_syntax c} *}
  4475 ML {* @{context} *}
  4476 ML {* @{theory} *}
  4477 ML {* @{theory Pure} *}
  4478 ML {* @{theory_ref} *}
  4479 ML {* @{theory_ref Pure} *}
  4480 ML {* @{simpset} *}
  4481 ML {* @{claset} *}
  4482 ML {* @{clasimpset} *}
  4483 
  4484 The same works for sources being ``used'' within an Isar context.
  4485 
  4486 * ML in Isar: improved error reporting; extra verbosity with
  4487 ML_Context.trace enabled.
  4488 
  4489 * Pure/General/table.ML: the join operations now works via exceptions
  4490 DUP/SAME instead of type option. This is simpler in simple cases, and
  4491 admits slightly more efficient complex applications.
  4492 
  4493 * Pure: 'advanced' translation functions (parse_translation etc.) now
  4494 use Context.generic instead of just theory.
  4495 
  4496 * Pure: datatype Context.generic joins theory/Proof.context and
  4497 provides some facilities for code that works in either kind of
  4498 context, notably GenericDataFun for uniform theory and proof data.
  4499 
  4500 * Pure: simplified internal attribute type, which is now always
  4501 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  4502 local (Proof.context) attributes have been discontinued, while
  4503 minimizing code duplication. Thm.rule_attribute and
  4504 Thm.declaration_attribute build canonical attributes; see also structure
  4505 Context for further operations on Context.generic, notably
  4506 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  4507 declarations and definitions.
  4508 
  4509 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  4510 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  4511 init only required for impure data. INCOMPATIBILITY: empty really need
  4512 to be empty (no dependencies on theory content!)
  4513 
  4514 * Pure/kernel: consts certification ignores sort constraints given in
  4515 signature declarations. (This information is not relevant to the
  4516 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  4517 potential INCOMPATIBILITY.
  4518 
  4519 * Pure: axiomatic type classes are now purely definitional, with
  4520 explicit proofs of class axioms and super class relations performed
  4521 internally. See Pure/axclass.ML for the main internal interfaces --
  4522 notably AxClass.define_class supercedes AxClass.add_axclass, and
  4523 AxClass.axiomatize_class/classrel/arity supersede
  4524 Sign.add_classes/classrel/arities.
  4525 
  4526 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  4527 global/local versions on theory vs. Proof.context have been
  4528 discontinued; Attrib.syntax and Method.syntax have been adapted
  4529 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  4530 attributes, methods, etc.
  4531 
  4532 * Pure: several functions of signature "... -> theory -> theory * ..."
  4533 have been reoriented to "... -> theory -> ... * theory" in order to
  4534 allow natural usage in combination with the ||>, ||>>, |-> and
  4535 fold_map combinators.
  4536 
  4537 * Pure: official theorem names (closed derivations) and additional
  4538 comments (tags) are now strictly separate.  Name hints -- which are
  4539 maintained as tags -- may be attached any time without affecting the
  4540 derivation.
  4541 
  4542 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  4543 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  4544 achieve the old behaviour.
  4545 
  4546 * Pure: the "Goal" constant is now called "prop", supporting a
  4547 slightly more general idea of ``protecting'' meta-level rule
  4548 statements.
  4549 
  4550 * Pure: Logic.(un)varify only works in a global context, which is now
  4551 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  4552 Logic.legacy_(un)varify as temporary workaround.
  4553 
  4554 * Pure: structure Name provides scalable operations for generating
  4555 internal variable names, notably Name.variants etc.  This replaces
  4556 some popular functions from term.ML:
  4557 
  4558   Term.variant		->  Name.variant
  4559   Term.variantlist	->  Name.variant_list
  4560   Term.invent_names	->  Name.invent_list
  4561 
  4562 Note that low-level renaming rarely occurs in new code -- operations
  4563 from structure Variable are used instead (see below).
  4564 
  4565 * Pure: structure Variable provides fundamental operations for proper
  4566 treatment of fixed/schematic variables in a context.  For example,
  4567 Variable.import introduces fixes for schematics of given facts and
  4568 Variable.export reverses the effect (up to renaming) -- this replaces
  4569 various freeze_thaw operations.
  4570 
  4571 * Pure: structure Goal provides simple interfaces for
  4572 init/conclude/finish and tactical prove operations (replacing former
  4573 Tactic.prove).  Goal.prove is the canonical way to prove results
  4574 within a given context; Goal.prove_global is a degraded version for
  4575 theory level goals, including a global Drule.standard.  Note that
  4576 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  4577 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  4578 in a locale context).
  4579 
  4580 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  4581 and type checking (Syntax.check_term etc.), with common combinations
  4582 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  4583 which are considered legacy and await removal.
  4584 
  4585 * Pure/Syntax: generic interfaces for type unchecking
  4586 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  4587 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  4588 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  4589 available for convenience, but refer to the very same operations using
  4590 a mere theory instead of a full context.
  4591 
  4592 * Isar: simplified treatment of user-level errors, using exception
  4593 ERROR of string uniformly.  Function error now merely raises ERROR,
  4594 without any side effect on output channels.  The Isar toplevel takes
  4595 care of proper display of ERROR exceptions.  ML code may use plain
  4596 handle/can/try; cat_error may be used to concatenate errors like this:
  4597 
  4598   ... handle ERROR msg => cat_error msg "..."
  4599 
  4600 Toplevel ML code (run directly or through the Isar toplevel) may be
  4601 embedded into the Isar toplevel with exception display/debug like
  4602 this:
  4603 
  4604   Isar.toplevel (fn () => ...)
  4605 
  4606 INCOMPATIBILITY, removed special transform_error facilities, removed
  4607 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  4608 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  4609 -- use plain ERROR instead.
  4610 
  4611 * Isar: theory setup now has type (theory -> theory), instead of a
  4612 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  4613 
  4614 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  4615 ProofContext.debug/verbose flags.
  4616 
  4617 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  4618 theory before entering a proof state.  Transactions now always see a
  4619 quasi-functional intermediate checkpoint, both in interactive and
  4620 batch mode.
  4621 
  4622 * Isar: simplified interfaces for outer syntax.  Renamed
  4623 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  4624 OuterSyntax.add_parsers -- this functionality is now included in
  4625 OuterSyntax.command etc.  INCOMPATIBILITY.
  4626 
  4627 * Simplifier: the simpset of a running simplification process now
  4628 contains a proof context (cf. Simplifier.the_context), which is the
  4629 very context that the initial simpset has been retrieved from (by
  4630 simpset_of/local_simpset_of).  Consequently, all plug-in components
  4631 (solver, looper etc.) may depend on arbitrary proof data.
  4632 
  4633 * Simplifier.inherit_context inherits the proof context (plus the
  4634 local bounds) of the current simplification process; any simproc
  4635 etc. that calls the Simplifier recursively should do this!  Removed
  4636 former Simplifier.inherit_bounds, which is already included here --
  4637 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  4638 specify an explicit context using Simplifier.context/theory_context.
  4639 
  4640 * Simplifier/Classical Reasoner: more abstract interfaces
  4641 change_simpset/claset for modifying the simpset/claset reference of a
  4642 theory; raw versions simpset/claset_ref etc. have been discontinued --
  4643 INCOMPATIBILITY.
  4644 
  4645 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  4646 "Trueprop" etc.
  4647 
  4648 
  4649 *** System ***
  4650 
  4651 * settings: the default heap location within ISABELLE_HOME_USER now
  4652 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  4653 Isabelle installations.
  4654 
  4655 * isabelle-process: option -S (secure mode) disables some critical
  4656 operations, notably runtime compilation and evaluation of ML source
  4657 code.
  4658 
  4659 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  4660 
  4661 * Support for parallel execution, using native multicore support of
  4662 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  4663 independent theories, according to the given theory header
  4664 specifications. The maximum number of worker threads is specified via
  4665 usedir option -M or the "max-threads" setting in Proof General. A
  4666 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  4667 to 6 on a 8-core machine.  User-code needs to observe certain
  4668 guidelines for thread-safe programming, see appendix A in the Isar
  4669 Implementation manual.
  4670 
  4671 
  4672 
  4673 New in Isabelle2005 (October 2005)
  4674 ----------------------------------
  4675 
  4676 *** General ***
  4677 
  4678 * Theory headers: the new header syntax for Isar theories is
  4679 
  4680   theory <name>
  4681   imports <theory1> ... <theoryN>
  4682   uses <file1> ... <fileM>
  4683   begin
  4684 
  4685 where the 'uses' part is optional.  The previous syntax
  4686 
  4687   theory <name> = <theory1> + ... + <theoryN>:
  4688 
  4689 will disappear in the next release.  Use isatool fixheaders to convert
  4690 existing theory files.  Note that there is no change in ancient
  4691 non-Isar theories now, but these will disappear soon.
  4692 
  4693 * Theory loader: parent theories can now also be referred to via
  4694 relative and absolute paths.
  4695 
  4696 * Command 'find_theorems' searches for a list of criteria instead of a
  4697 list of constants. Known criteria are: intro, elim, dest, name:string,
  4698 simp:term, and any term. Criteria can be preceded by '-' to select
  4699 theorems that do not match. Intro, elim, dest select theorems that
  4700 match the current goal, name:s selects theorems whose fully qualified
  4701 name contain s, and simp:term selects all simplification rules whose
  4702 lhs match term.  Any other term is interpreted as pattern and selects
  4703 all theorems matching the pattern. Available in ProofGeneral under
  4704 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  4705 
  4706   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  4707 
  4708 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  4709 matching the current goal as introduction rule and not having "HOL."
  4710 in their name (i.e. not being defined in theory HOL).
  4711 
  4712 * Command 'thms_containing' has been discontinued in favour of
  4713 'find_theorems'; INCOMPATIBILITY.
  4714 
  4715 * Communication with Proof General is now 8bit clean, which means that
  4716 Unicode text in UTF-8 encoding may be used within theory texts (both
  4717 formal and informal parts).  Cf. option -U of the Isabelle Proof
  4718 General interface.  Here are some simple examples (cf. src/HOL/ex):
  4719 
  4720   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  4721   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  4722 
  4723 * Improved efficiency of the Simplifier and, to a lesser degree, the
  4724 Classical Reasoner.  Typical big applications run around 2 times
  4725 faster.
  4726 
  4727 
  4728 *** Document preparation ***
  4729 
  4730 * Commands 'display_drafts' and 'print_drafts' perform simple output
  4731 of raw sources.  Only those symbols that do not require additional
  4732 LaTeX packages (depending on comments in isabellesym.sty) are
  4733 displayed properly, everything else is left verbatim.  isatool display
  4734 and isatool print are used as front ends (these are subject to the
  4735 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  4736 
  4737 * Command tags control specific markup of certain regions of text,
  4738 notably folding and hiding.  Predefined tags include "theory" (for
  4739 theory begin and end), "proof" for proof commands, and "ML" for
  4740 commands involving ML code; the additional tags "visible" and
  4741 "invisible" are unused by default.  Users may give explicit tag
  4742 specifications in the text, e.g. ''by %invisible (auto)''.  The
  4743 interpretation of tags is determined by the LaTeX job during document
  4744 preparation: see option -V of isatool usedir, or options -n and -t of
  4745 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  4746 \isadroptag.
  4747 
  4748 Several document versions may be produced at the same time via isatool
  4749 usedir (the generated index.html will link all of them).  Typical
  4750 specifications include ''-V document=theory,proof,ML'' to present
  4751 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  4752 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  4753 these parts without any formal replacement text.  The Isabelle site
  4754 default settings produce ''document'' and ''outline'' versions as
  4755 specified above.
  4756 
  4757 * Several new antiquotations:
  4758 
  4759   @{term_type term} prints a term with its type annotated;
  4760 
  4761   @{typeof term} prints the type of a term;
  4762 
  4763   @{const const} is the same as @{term const}, but checks that the
  4764   argument is a known logical constant;
  4765 
  4766   @{term_style style term} and @{thm_style style thm} print a term or
  4767   theorem applying a "style" to it
  4768 
  4769   @{ML text}
  4770 
  4771 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  4772 definitions, equations, inequations etc., 'concl' printing only the
  4773 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  4774 to print the specified premise.  TermStyle.add_style provides an ML
  4775 interface for introducing further styles.  See also the "LaTeX Sugar"
  4776 document practical applications.  The ML antiquotation prints
  4777 type-checked ML expressions verbatim.
  4778 
  4779 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  4780 and 'text' support optional locale specification '(in loc)', which
  4781 specifies the default context for interpreting antiquotations.  For
  4782 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  4783 
  4784 * Option 'locale=NAME' of antiquotations specifies an alternative
  4785 context interpreting the subsequent argument.  For example: @{thm
  4786 [locale=lattice] inf_assoc}.
  4787 
  4788 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  4789 a proof context.
  4790 
  4791 * Proper output of antiquotations for theory commands involving a
  4792 proof context (such as 'locale' or 'theorem (in loc) ...').
  4793 
  4794 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  4795 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  4796 
  4797 * isatool usedir: new option -C (default true) controls whether option
  4798 -D should include a copy of the original document directory; -C false
  4799 prevents unwanted effects such as copying of administrative CVS data.
  4800 
  4801 
  4802 *** Pure ***
  4803 
  4804 * Considerably improved version of 'constdefs' command.  Now performs
  4805 automatic type-inference of declared constants; additional support for
  4806 local structure declarations (cf. locales and HOL records), see also
  4807 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  4808 sequential dependencies of definitions within a single 'constdefs'
  4809 section; moreover, the declared name needs to be an identifier.  If
  4810 all fails, consider to fall back on 'consts' and 'defs' separately.
  4811 
  4812 * Improved indexed syntax and implicit structures.  First of all,
  4813 indexed syntax provides a notational device for subscripted
  4814 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  4815 expressions.  Secondly, in a local context with structure
  4816 declarations, number indexes \<^sub>n or the empty index (default
  4817 number 1) refer to a certain fixed variable implicitly; option
  4818 show_structs controls printing of implicit structures.  Typical
  4819 applications of these concepts involve record types and locales.
  4820 
  4821 * New command 'no_syntax' removes grammar declarations (and
  4822 translations) resulting from the given syntax specification, which is
  4823 interpreted in the same manner as for the 'syntax' command.
  4824 
  4825 * 'Advanced' translation functions (parse_translation etc.) may depend
  4826 on the signature of the theory context being presently used for
  4827 parsing/printing, see also isar-ref manual.
  4828 
  4829 * Improved 'oracle' command provides a type-safe interface to turn an
  4830 ML expression of type theory -> T -> term into a primitive rule of
  4831 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  4832 is already included here); see also FOL/ex/IffExample.thy;
  4833 INCOMPATIBILITY.
  4834 
  4835 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  4836 before); "cI" is no longer bound, use "c.intro" instead.
  4837 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  4838 axclasses vs. locales.
  4839 
  4840 * Improved internal renaming of symbolic identifiers -- attach primes
  4841 instead of base 26 numbers.
  4842 
  4843 * New flag show_question_marks controls printing of leading question
  4844 marks in schematic variable names.
  4845 
  4846 * In schematic variable names, *any* symbol following \<^isub> or
  4847 \<^isup> is now treated as part of the base name.  For example, the
  4848 following works without printing of awkward ".0" indexes:
  4849 
  4850   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  4851     by simp
  4852 
  4853 * Inner syntax includes (*(*nested*) comments*).
  4854 
  4855 * Pretty printer now supports unbreakable blocks, specified in mixfix
  4856 annotations as "(00...)".
  4857 
  4858 * Clear separation of logical types and nonterminals, where the latter
  4859 may only occur in 'syntax' specifications or type abbreviations.
  4860 Before that distinction was only partially implemented via type class
  4861 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  4862 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  4863 exotic syntax specifications may require further adaption
  4864 (e.g. Cube/Cube.thy).
  4865 
  4866 * Removed obsolete type class "logic", use the top sort {} instead.
  4867 Note that non-logical types should be declared as 'nonterminals'
  4868 rather than 'types'.  INCOMPATIBILITY for new object-logic
  4869 specifications.
  4870 
  4871 * Attributes 'induct' and 'cases': type or set names may now be
  4872 locally fixed variables as well.
  4873 
  4874 * Simplifier: can now control the depth to which conditional rewriting
  4875 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  4876 Limit.
  4877 
  4878 * Simplifier: simplification procedures may now take the current
  4879 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  4880 interface), which is very useful for calling the Simplifier
  4881 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  4882 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  4883 low-level mk_simproc no longer applies Logic.varify internally, to
  4884 allow for use in a context of fixed variables.
  4885 
  4886 * thin_tac now works even if the assumption being deleted contains !!
  4887 or ==>.  More generally, erule now works even if the major premise of
  4888 the elimination rule contains !! or ==>.
  4889 
  4890 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  4891 
  4892 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  4893 from Pure, which contains all common declarations already.  Both
  4894 theories are defined via plain Isabelle/Isar .thy files.
  4895 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  4896 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  4897 use isatool fixcpure to adapt your theory and ML sources.
  4898 
  4899 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  4900 selections of theorems in named facts via index ranges.
  4901 
  4902 * 'print_theorems': in theory mode, really print the difference
  4903 wrt. the last state (works for interactive theory development only),
  4904 in proof mode print all local facts (cf. 'print_facts');
  4905 
  4906 * 'hide': option '(open)' hides only base names.
  4907 
  4908 * More efficient treatment of intermediate checkpoints in interactive
  4909 theory development.
  4910 
  4911 * Code generator is now invoked via code_module (incremental code
  4912 generation) and code_library (modular code generation, ML structures
  4913 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  4914 must be quoted when used as identifiers.
  4915 
  4916 * New 'value' command for reading, evaluating and printing terms using
  4917 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  4918 quoted when used as identifier.
  4919 
  4920 
  4921 *** Locales ***
  4922 
  4923 * New commands for the interpretation of locale expressions in
  4924 theories (1), locales (2) and proof contexts (3).  These generate
  4925 proof obligations from the expression specification.  After the
  4926 obligations have been discharged, theorems of the expression are added
  4927 to the theory, target locale or proof context.  The synopsis of the
  4928 commands is a follows:
  4929 
  4930   (1) interpretation expr inst
  4931   (2) interpretation target < expr
  4932   (3) interpret expr inst
  4933 
  4934 Interpretation in theories and proof contexts require a parameter
  4935 instantiation of terms from the current context.  This is applied to
  4936 specifications and theorems of the interpreted expression.
  4937 Interpretation in locales only permits parameter renaming through the
  4938 locale expression.  Interpretation is smart in that interpretations
  4939 that are active already do not occur in proof obligations, neither are
  4940 instantiated theorems stored in duplicate.  Use 'print_interps' to
  4941 inspect active interpretations of a particular locale.  For details,
  4942 see the Isar Reference manual.  Examples can be found in
  4943 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  4944 
  4945 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  4946 'interpret' instead.
  4947 
  4948 * New context element 'constrains' for adding type constraints to
  4949 parameters.
  4950 
  4951 * Context expressions: renaming of parameters with syntax
  4952 redeclaration.
  4953 
  4954 * Locale declaration: 'includes' disallowed.
  4955 
  4956 * Proper static binding of attribute syntax -- i.e. types / terms /
  4957 facts mentioned as arguments are always those of the locale definition
  4958 context, independently of the context of later invocations.  Moreover,
  4959 locale operations (renaming and type / term instantiation) are applied
  4960 to attribute arguments as expected.
  4961 
  4962 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  4963 actual attributes; rare situations may require Attrib.attribute to
  4964 embed those attributes into Attrib.src that lack concrete syntax.
  4965 Attribute implementations need to cooperate properly with the static
  4966 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  4967 Attrib.XXX_thm etc. already do the right thing without further
  4968 intervention.  Only unusual applications -- such as "where" or "of"
  4969 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  4970 on the context and the facts involved -- may have to assign parsed
  4971 values to argument tokens explicitly.
  4972 
  4973 * Changed parameter management in theorem generation for long goal
  4974 statements with 'includes'.  INCOMPATIBILITY: produces a different
  4975 theorem statement in rare situations.
  4976 
  4977 * Locale inspection command 'print_locale' omits notes elements.  Use
  4978 'print_locale!' to have them included in the output.
  4979 
  4980 
  4981 *** Provers ***
  4982 
  4983 * Provers/hypsubst.ML: improved version of the subst method, for
  4984 single-step rewriting: it now works in bound variable contexts. New is
  4985 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  4986 rewrite a different subterm than the original subst method, which is
  4987 still available as 'simplesubst'.
  4988 
  4989 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  4990 and quasi orders.
  4991 
  4992 * Provers/trancl.ML: new transitivity reasoner for transitive and
  4993 reflexive-transitive closure of relations.
  4994 
  4995 * Provers/blast.ML: new reference depth_limit to make blast's depth
  4996 limit (previously hard-coded with a value of 20) user-definable.
  4997 
  4998 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  4999 is peformed already.  Object-logics merely need to finish their
  5000 initial simpset configuration as before.  INCOMPATIBILITY.
  5001 
  5002 
  5003 *** HOL ***
  5004 
  5005 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  5006 
  5007   syntax (epsilon)
  5008     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  5009 
  5010 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  5011 and x-symbol; use option '-m epsilon' to get it actually printed.
  5012 Moreover, the mathematically important symbolic identifier \<epsilon>
  5013 becomes available as variable, constant etc.  INCOMPATIBILITY,
  5014 
  5015 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  5016 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  5017 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  5018 support corresponding Isar calculations.
  5019 
  5020 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  5021 instead of ":".
  5022 
  5023 * theory SetInterval: changed the syntax for open intervals:
  5024 
  5025   Old       New
  5026   {..n(}    {..<n}
  5027   {)n..}    {n<..}
  5028   {m..n(}   {m..<n}
  5029   {)m..n}   {m<..n}
  5030   {)m..n(}  {m<..<n}
  5031 
  5032 The old syntax is still supported but will disappear in the next
  5033 release.  For conversion use the following Emacs search and replace
  5034 patterns (these are not perfect but work quite well):
  5035 
  5036   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  5037   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  5038 
  5039 * Theory Commutative_Ring (in Library): method comm_ring for proving
  5040 equalities in commutative rings; method 'algebra' provides a generic
  5041 interface.
  5042 
  5043 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  5044 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  5045 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  5046 be a tuple pattern.
  5047 
  5048 Some new syntax forms are available:
  5049 
  5050   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  5051   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  5052   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  5053   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  5054 
  5055 The latter form "\<Sum>x < k. e" used to be based on a separate
  5056 function "Summation", which has been discontinued.
  5057 
  5058 * theory Finite_Set: in structured induction proofs, the insert case
  5059 is now 'case (insert x F)' instead of the old counterintuitive 'case
  5060 (insert F x)'.
  5061 
  5062 * The 'refute' command has been extended to support a much larger
  5063 fragment of HOL, including axiomatic type classes, constdefs and
  5064 typedefs, inductive datatypes and recursion.
  5065 
  5066 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  5067 Requires zChaff with proof generation to be installed.  See
  5068 HOL/ex/SAT_Examples.thy for examples.
  5069 
  5070 * Datatype induction via method 'induct' now preserves the name of the
  5071 induction variable. For example, when proving P(xs::'a list) by
  5072 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  5073 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  5074 in unstructured proof scripts.
  5075 
  5076 * Reworked implementation of records.  Improved scalability for
  5077 records with many fields, avoiding performance problems for type
  5078 inference. Records are no longer composed of nested field types, but
  5079 of nested extension types. Therefore the record type only grows linear
  5080 in the number of extensions and not in the number of fields.  The
  5081 top-level (users) view on records is preserved.  Potential
  5082 INCOMPATIBILITY only in strange cases, where the theory depends on the
  5083 old record representation. The type generated for a record is called
  5084 <record_name>_ext_type.
  5085 
  5086 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  5087 proofs triggered by a record definition or a simproc (if
  5088 quick_and_dirty is enabled).  Definitions of large records can take
  5089 quite long.
  5090 
  5091 New simproc record_upd_simproc for simplification of multiple record
  5092 updates enabled by default.  Moreover, trivial updates are also
  5093 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  5094 occasionally, since simplification is more powerful by default.
  5095 
  5096 * typedef: proper support for polymorphic sets, which contain extra
  5097 type-variables in the term.
  5098 
  5099 * Simplifier: automatically reasons about transitivity chains
  5100 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  5101 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  5102 old proofs break occasionally as simplification may now solve more
  5103 goals than previously.
  5104 
  5105 * Simplifier: converts x <= y into x = y if assumption y <= x is
  5106 present.  Works for all partial orders (class "order"), in particular
  5107 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  5108 just like y <= x.
  5109 
  5110 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  5111 bound variable or a constant then the let is unfolded.  Otherwise
  5112 first a is simplified to b, and then f b is simplified to g. If
  5113 possible we abstract b from g arriving at "let x = b in h x",
  5114 otherwise we unfold the let and arrive at g.  The simproc can be
  5115 enabled/disabled by the reference use_let_simproc.  Potential
  5116 INCOMPATIBILITY since simplification is more powerful by default.
  5117 
  5118 * Classical reasoning: the meson method now accepts theorems as arguments.
  5119 
  5120 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  5121 jobs to provide advice on the provability of subgoals.
  5122 
  5123 * Theory OrderedGroup and Ring_and_Field: various additions and
  5124 improvements to faciliate calculations involving equalities and
  5125 inequalities.
  5126 
  5127 The following theorems have been eliminated or modified
  5128 (INCOMPATIBILITY):
  5129 
  5130   abs_eq             now named abs_of_nonneg
  5131   abs_of_ge_0        now named abs_of_nonneg
  5132   abs_minus_eq       now named abs_of_nonpos
  5133   imp_abs_id         now named abs_of_nonneg
  5134   imp_abs_neg_id     now named abs_of_nonpos
  5135   mult_pos           now named mult_pos_pos
  5136   mult_pos_le        now named mult_nonneg_nonneg
  5137   mult_pos_neg_le    now named mult_nonneg_nonpos
  5138   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  5139   mult_neg           now named mult_neg_neg
  5140   mult_neg_le        now named mult_nonpos_nonpos
  5141 
  5142 * The following lemmas in Ring_and_Field have been added to the simplifier:
  5143      
  5144      zero_le_square
  5145      not_square_less_zero 
  5146 
  5147   The following lemmas have been deleted from Real/RealPow:
  5148   
  5149      realpow_zero_zero
  5150      realpow_two
  5151      realpow_less
  5152      zero_le_power
  5153      realpow_two_le
  5154      abs_realpow_two
  5155      realpow_two_abs     
  5156 
  5157 * Theory Parity: added rules for simplifying exponents.
  5158 
  5159 * Theory List:
  5160 
  5161 The following theorems have been eliminated or modified
  5162 (INCOMPATIBILITY):
  5163 
  5164   list_all_Nil       now named list_all.simps(1)
  5165   list_all_Cons      now named list_all.simps(2)
  5166   list_all_conv      now named list_all_iff
  5167   set_mem_eq         now named mem_iff
  5168 
  5169 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  5170 asymptotic "big O" calculations.  See the notes in BigO.thy.
  5171 
  5172 
  5173 *** HOL-Complex ***
  5174 
  5175 * Theory RealDef: better support for embedding natural numbers and
  5176 integers in the reals.
  5177 
  5178 The following theorems have been eliminated or modified
  5179 (INCOMPATIBILITY):
  5180 
  5181   exp_ge_add_one_self  now requires no hypotheses
  5182   real_of_int_add      reversed direction of equality (use [symmetric])
  5183   real_of_int_minus    reversed direction of equality (use [symmetric])
  5184   real_of_int_diff     reversed direction of equality (use [symmetric])
  5185   real_of_int_mult     reversed direction of equality (use [symmetric])
  5186 
  5187 * Theory RComplete: expanded support for floor and ceiling functions.
  5188 
  5189 * Theory Ln is new, with properties of the natural logarithm
  5190 
  5191 * Hyperreal: There is a new type constructor "star" for making
  5192 nonstandard types.  The old type names are now type synonyms:
  5193 
  5194   hypreal = real star
  5195   hypnat = nat star
  5196   hcomplex = complex star
  5197 
  5198 * Hyperreal: Many groups of similarly-defined constants have been
  5199 replaced by polymorphic versions (INCOMPATIBILITY):
  5200 
  5201   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  5202 
  5203   starset      <-- starsetNat, starsetC
  5204   *s*          <-- *sNat*, *sc*
  5205   starset_n    <-- starsetNat_n, starsetC_n
  5206   *sn*         <-- *sNatn*, *scn*
  5207   InternalSets <-- InternalNatSets, InternalCSets
  5208 
  5209   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  5210   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  5211   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  5212   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  5213   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  5214 
  5215 * Hyperreal: Many type-specific theorems have been removed in favor of
  5216 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  5217 
  5218   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  5219   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  5220   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  5221   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  5222   right_minus <-- hypreal_add_minus
  5223   left_minus <-- {hypreal,hcomplex}_add_minus_left
  5224   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  5225   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  5226   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  5227   mult_1_right <-- hcomplex_mult_one_right
  5228   mult_zero_left <-- hcomplex_mult_zero_left
  5229   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  5230   right_distrib <-- hypnat_add_mult_distrib2
  5231   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  5232   right_inverse <-- hypreal_mult_inverse
  5233   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  5234   order_refl <-- {hypreal,hypnat}_le_refl
  5235   order_trans <-- {hypreal,hypnat}_le_trans
  5236   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  5237   order_less_le <-- {hypreal,hypnat}_less_le
  5238   linorder_linear <-- {hypreal,hypnat}_le_linear
  5239   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  5240   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  5241   add_nonneg_nonneg <-- hypreal_le_add_order
  5242 
  5243 * Hyperreal: Separate theorems having to do with type-specific
  5244 versions of constants have been merged into theorems that apply to the
  5245 new polymorphic constants (INCOMPATIBILITY):
  5246 
  5247   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  5248   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  5249   STAR_Un <-- {STAR,NatStar,STARC}_Un
  5250   STAR_Int <-- {STAR,NatStar,STARC}_Int
  5251   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  5252   STAR_subset <-- {STAR,NatStar,STARC}_subset
  5253   STAR_mem <-- {STAR,NatStar,STARC}_mem
  5254   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  5255   STAR_diff <-- {STAR,STARC}_diff
  5256   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  5257     STARC_hcomplex_of_complex}_image_subset
  5258   starset_n_Un <-- starset{Nat,C}_n_Un
  5259   starset_n_Int <-- starset{Nat,C}_n_Int
  5260   starset_n_Compl <-- starset{Nat,C}_n_Compl
  5261   starset_n_diff <-- starset{Nat,C}_n_diff
  5262   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  5263   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  5264   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  5265   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  5266   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  5267   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  5268   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  5269   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  5270   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  5271   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  5272   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  5273   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  5274   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  5275   starfun_diff <-- starfun{C,RC,CR}_diff
  5276   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  5277   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  5278   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  5279   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  5280   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  5281   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  5282   starfun_Id <-- starfunC_Id
  5283   starfun_approx <-- starfun{Nat,CR}_approx
  5284   starfun_capprox <-- starfun{C,RC}_capprox
  5285   starfun_abs <-- starfunNat_rabs
  5286   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  5287   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  5288   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  5289   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  5290   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  5291   starfun_add_approx <-- starfunCR_add_approx
  5292   starfun_inverse_inverse <-- starfunC_inverse_inverse
  5293   starfun_divide <-- starfun{C,CR,RC}_divide
  5294   starfun_n <-- starfun{Nat,C}_n
  5295   starfun_n_mult <-- starfun{Nat,C}_n_mult
  5296   starfun_n_add <-- starfun{Nat,C}_n_add
  5297   starfun_n_add_minus <-- starfunNat_n_add_minus
  5298   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  5299   starfun_n_minus <-- starfun{Nat,C}_n_minus
  5300   starfun_n_eq <-- starfun{Nat,C}_n_eq
  5301 
  5302   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  5303   star_n_minus <-- {hypreal,hcomplex}_minus
  5304   star_n_diff <-- {hypreal,hcomplex}_diff
  5305   star_n_mult <-- {hypreal,hcomplex}_mult
  5306   star_n_inverse <-- {hypreal,hcomplex}_inverse
  5307   star_n_le <-- {hypreal,hypnat}_le
  5308   star_n_less <-- {hypreal,hypnat}_less
  5309   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  5310   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  5311   star_n_abs <-- hypreal_hrabs
  5312   star_n_divide <-- hcomplex_divide
  5313 
  5314   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  5315   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  5316   star_of_diff <-- hypreal_of_real_diff
  5317   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  5318   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  5319   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  5320   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  5321   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  5322   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  5323   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  5324   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  5325   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  5326   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  5327   star_of_number_of <-- {hypreal,hcomplex}_number_of
  5328   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  5329   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  5330   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  5331   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  5332   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  5333   star_of_power <-- hypreal_of_real_power
  5334   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  5335 
  5336 * Hyperreal: new method "transfer" that implements the transfer
  5337 principle of nonstandard analysis. With a subgoal that mentions
  5338 nonstandard types like "'a star", the command "apply transfer"
  5339 replaces it with an equivalent one that mentions only standard types.
  5340 To be successful, all free variables must have standard types; non-
  5341 standard variables must have explicit universal quantifiers.
  5342 
  5343 * Hyperreal: A theory of Taylor series.
  5344 
  5345 
  5346 *** HOLCF ***
  5347 
  5348 * Discontinued special version of 'constdefs' (which used to support
  5349 continuous functions) in favor of the general Pure one with full
  5350 type-inference.
  5351 
  5352 * New simplification procedure for solving continuity conditions; it
  5353 is much faster on terms with many nested lambda abstractions (cubic
  5354 instead of exponential time).
  5355 
  5356 * New syntax for domain package: selector names are now optional.
  5357 Parentheses should be omitted unless argument is lazy, for example:
  5358 
  5359   domain 'a stream = cons "'a" (lazy "'a stream")
  5360 
  5361 * New command 'fixrec' for defining recursive functions with pattern
  5362 matching; defining multiple functions with mutual recursion is also
  5363 supported.  Patterns may include the constants cpair, spair, up, sinl,
  5364 sinr, or any data constructor defined by the domain package. The given
  5365 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  5366 syntax and examples.
  5367 
  5368 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  5369 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  5370 but the proof obligation additionally includes an admissibility
  5371 requirement. The packages generate instances of class cpo or pcpo,
  5372 with continuity and strictness theorems for Rep and Abs.
  5373 
  5374 * HOLCF: Many theorems have been renamed according to a more standard naming
  5375 scheme (INCOMPATIBILITY):
  5376 
  5377   foo_inject:  "foo$x = foo$y ==> x = y"
  5378   foo_eq:      "(foo$x = foo$y) = (x = y)"
  5379   foo_less:    "(foo$x << foo$y) = (x << y)"
  5380   foo_strict:  "foo$UU = UU"
  5381   foo_defined: "... ==> foo$x ~= UU"
  5382   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  5383 
  5384 
  5385 *** ZF ***
  5386 
  5387 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  5388 including the First Isomorphism Theorem (on quotienting by the kernel
  5389 of a homomorphism).
  5390 
  5391 * ZF/Simplifier: install second copy of type solver that actually
  5392 makes use of TC rules declared to Isar proof contexts (or locales);
  5393 the old version is still required for ML proof scripts.
  5394 
  5395 
  5396 *** Cube ***
  5397 
  5398 * Converted to Isar theory format; use locales instead of axiomatic
  5399 theories.
  5400 
  5401 
  5402 *** ML ***
  5403 
  5404 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  5405 for ||>, ||>>, |>>,
  5406 
  5407 * Pure/library.ML no longer defines its own option datatype, but uses
  5408 that of the SML basis, which has constructors NONE and SOME instead of
  5409 None and Some, as well as exception Option.Option instead of OPTION.
  5410 The functions the, if_none, is_some, is_none have been adapted
  5411 accordingly, while Option.map replaces apsome.
  5412 
  5413 * Pure/library.ML: the exception LIST has been given up in favour of
  5414 the standard exceptions Empty and Subscript, as well as
  5415 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  5416 superceded by the standard hd and tl functions etc.
  5417 
  5418 A number of basic list functions are no longer exported to the ML
  5419 toplevel, as they are variants of predefined functions.  The following
  5420 suggests how one can translate existing code:
  5421 
  5422     rev_append xs ys = List.revAppend (xs, ys)
  5423     nth_elem (i, xs) = List.nth (xs, i)
  5424     last_elem xs = List.last xs
  5425     flat xss = List.concat xss
  5426     seq fs = List.app fs
  5427     partition P xs = List.partition P xs
  5428     mapfilter f xs = List.mapPartial f xs
  5429 
  5430 * Pure/library.ML: several combinators for linear functional
  5431 transformations, notably reverse application and composition:
  5432 
  5433   x |> f                f #> g
  5434   (x, y) |-> f          f #-> g
  5435 
  5436 * Pure/library.ML: introduced/changed precedence of infix operators:
  5437 
  5438   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  5439   infix 2 ?;
  5440   infix 3 o oo ooo oooo;
  5441   infix 4 ~~ upto downto;
  5442 
  5443 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  5444 infix operators.
  5445 
  5446 * Pure/library.ML: natural list combinators fold, fold_rev, and
  5447 fold_map support linear functional transformations and nesting.  For
  5448 example:
  5449 
  5450   fold f [x1, ..., xN] y =
  5451     y |> f x1 |> ... |> f xN
  5452 
  5453   (fold o fold) f [xs1, ..., xsN] y =
  5454     y |> fold f xs1 |> ... |> fold f xsN
  5455 
  5456   fold f [x1, ..., xN] =
  5457     f x1 #> ... #> f xN
  5458 
  5459   (fold o fold) f [xs1, ..., xsN] =
  5460     fold f xs1 #> ... #> fold f xsN
  5461 
  5462 * Pure/library.ML: the following selectors on type 'a option are
  5463 available:
  5464 
  5465   the:               'a option -> 'a  (*partial*)
  5466   these:             'a option -> 'a  where 'a = 'b list
  5467   the_default: 'a -> 'a option -> 'a
  5468   the_list:          'a option -> 'a list
  5469 
  5470 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5471 basic operations for association lists, following natural argument
  5472 order; moreover the explicit equality predicate passed here avoids
  5473 potentially expensive polymorphic runtime equality checks.
  5474 The old functions may be expressed as follows:
  5475 
  5476   assoc = uncurry (AList.lookup (op =))
  5477   assocs = these oo AList.lookup (op =)
  5478   overwrite = uncurry (AList.update (op =)) o swap
  5479 
  5480 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5481 
  5482   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  5483   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  5484 
  5485 replacing make_keylist and keyfilter (occassionally used)
  5486 Naive rewrites:
  5487 
  5488   make_keylist = AList.make
  5489   keyfilter = AList.find (op =)
  5490 
  5491 * eq_fst and eq_snd now take explicit equality parameter, thus
  5492   avoiding eqtypes. Naive rewrites:
  5493 
  5494     eq_fst = eq_fst (op =)
  5495     eq_snd = eq_snd (op =)
  5496 
  5497 * Removed deprecated apl and apr (rarely used).
  5498   Naive rewrites:
  5499 
  5500     apl (n, op) =>>= curry op n
  5501     apr (op, m) =>>= fn n => op (n, m)
  5502 
  5503 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  5504 provides a reasonably efficient light-weight implementation of sets as
  5505 lists.
  5506 
  5507 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  5508 few new operations; existing lookup and update are now curried to
  5509 follow natural argument order (for use with fold etc.);
  5510 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  5511 
  5512 * Pure/General: output via the Isabelle channels of
  5513 writeln/warning/error etc. is now passed through Output.output, with a
  5514 hook for arbitrary transformations depending on the print_mode
  5515 (cf. Output.add_mode -- the first active mode that provides a output
  5516 function wins).  Already formatted output may be embedded into further
  5517 text via Output.raw; the result of Pretty.string_of/str_of and derived
  5518 functions (string_of_term/cterm/thm etc.) is already marked raw to
  5519 accommodate easy composition of diagnostic messages etc.  Programmers
  5520 rarely need to care about Output.output or Output.raw at all, with
  5521 some notable exceptions: Output.output is required when bypassing the
  5522 standard channels (writeln etc.), or in token translations to produce
  5523 properly formatted results; Output.raw is required when capturing
  5524 already output material that will eventually be presented to the user
  5525 a second time.  For the default print mode, both Output.output and
  5526 Output.raw have no effect.
  5527 
  5528 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  5529 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  5530 cumulative results are displayed at the end of a batch session.
  5531 
  5532 * Pure/General: File.sysify_path and File.quote_sysify path have been
  5533 replaced by File.platform_path and File.shell_path (with appropriate
  5534 hooks).  This provides a clean interface for unusual systems where the
  5535 internal and external process view of file names are different.
  5536 
  5537 * Pure: more efficient orders for basic syntactic entities: added
  5538 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  5539 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  5540 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  5541 orders now -- potential INCOMPATIBILITY for code that depends on a
  5542 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  5543 Library.sort_strings on result).
  5544 
  5545 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  5546 fold_types traverse types/terms from left to right, observing natural
  5547 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  5548 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  5549 
  5550 * Pure: name spaces have been refined, with significant changes of the
  5551 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  5552 to extern(_table).  The plain name entry path is superceded by a
  5553 general 'naming' context, which also includes the 'policy' to produce
  5554 a fully qualified name and external accesses of a fully qualified
  5555 name; NameSpace.extend is superceded by context dependent
  5556 Sign.declare_name.  Several theory and proof context operations modify
  5557 the naming context.  Especially note Theory.restore_naming and
  5558 ProofContext.restore_naming to get back to a sane state; note that
  5559 Theory.add_path is no longer sufficient to recover from
  5560 Theory.absolute_path in particular.
  5561 
  5562 * Pure: new flags short_names (default false) and unique_names
  5563 (default true) for controlling output of qualified names.  If
  5564 short_names is set, names are printed unqualified.  If unique_names is
  5565 reset, the name prefix is reduced to the minimum required to achieve
  5566 the original result when interning again, even if there is an overlap
  5567 with earlier declarations.
  5568 
  5569 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  5570 now 'extend', and 'merge' gets an additional Pretty.pp argument
  5571 (useful for printing error messages).  INCOMPATIBILITY.
  5572 
  5573 * Pure: major reorganization of the theory context.  Type Sign.sg and
  5574 Theory.theory are now identified, referring to the universal
  5575 Context.theory (see Pure/context.ML).  Actual signature and theory
  5576 content is managed as theory data.  The old code and interfaces were
  5577 spread over many files and structures; the new arrangement introduces
  5578 considerable INCOMPATIBILITY to gain more clarity:
  5579 
  5580   Context -- theory management operations (name, identity, inclusion,
  5581     parents, ancestors, merge, etc.), plus generic theory data;
  5582 
  5583   Sign -- logical signature and syntax operations (declaring consts,
  5584     types, etc.), plus certify/read for common entities;
  5585 
  5586   Theory -- logical theory operations (stating axioms, definitions,
  5587     oracles), plus a copy of logical signature operations (consts,
  5588     types, etc.); also a few basic management operations (Theory.copy,
  5589     Theory.merge, etc.)
  5590 
  5591 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  5592 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  5593 for convenience -- they merely return the theory.
  5594 
  5595 * Pure: type Type.tsig is superceded by theory in most interfaces.
  5596 
  5597 * Pure: the Isar proof context type is already defined early in Pure
  5598 as Context.proof (note that ProofContext.context and Proof.context are
  5599 aliases, where the latter is the preferred name).  This enables other
  5600 Isabelle components to refer to that type even before Isar is present.
  5601 
  5602 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  5603 typeK, constK, axiomK, oracleK), but provide explicit operations for
  5604 any of these kinds.  For example, Sign.intern typeK is now
  5605 Sign.intern_type, Theory.hide_space Sign.typeK is now
  5606 Theory.hide_types.  Also note that former
  5607 Theory.hide_classes/types/consts are now
  5608 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  5609 internalize their arguments!  INCOMPATIBILITY.
  5610 
  5611 * Pure: get_thm interface (of PureThy and ProofContext) expects
  5612 datatype thmref (with constructors Name and NameSelection) instead of
  5613 plain string -- INCOMPATIBILITY;
  5614 
  5615 * Pure: cases produced by proof methods specify options, where NONE
  5616 means to remove case bindings -- INCOMPATIBILITY in
  5617 (RAW_)METHOD_CASES.
  5618 
  5619 * Pure: the following operations retrieve axioms or theorems from a
  5620 theory node or theory hierarchy, respectively:
  5621 
  5622   Theory.axioms_of: theory -> (string * term) list
  5623   Theory.all_axioms_of: theory -> (string * term) list
  5624   PureThy.thms_of: theory -> (string * thm) list
  5625   PureThy.all_thms_of: theory -> (string * thm) list
  5626 
  5627 * Pure: print_tac now outputs the goal through the trace channel.
  5628 
  5629 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  5630 Reference Toplevel.debug (default false) controls detailed printing
  5631 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  5632 controls execution profiling -- set to 1 for time and 2 for space
  5633 (both increase the runtime).
  5634 
  5635 * Isar session: The initial use of ROOT.ML is now always timed,
  5636 i.e. the log will show the actual process times, in contrast to the
  5637 elapsed wall-clock time that the outer shell wrapper produces.
  5638 
  5639 * Simplifier: improved handling of bound variables (nameless
  5640 representation, avoid allocating new strings).  Simprocs that invoke
  5641 the Simplifier recursively should use Simplifier.inherit_bounds to
  5642 avoid local name clashes.  Failure to do so produces warnings
  5643 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  5644 for further details.
  5645 
  5646 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  5647 bindings for all theorems stored within a given theory; this may help
  5648 in porting non-Isar theories to Isar ones, while keeping ML proof
  5649 scripts for the time being.
  5650 
  5651 * ML operator HTML.with_charset specifies the charset begin used for
  5652 generated HTML files.  For example:
  5653 
  5654   HTML.with_charset "utf-8" use_thy "Hebrew";
  5655   HTML.with_charset "utf-8" use_thy "Chinese";
  5656 
  5657 
  5658 *** System ***
  5659 
  5660 * Allow symlinks to all proper Isabelle executables (Isabelle,
  5661 isabelle, isatool etc.).
  5662 
  5663 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  5664 isatool doc, isatool mkdir, display_drafts etc.).
  5665 
  5666 * isatool usedir: option -f allows specification of the ML file to be
  5667 used by Isabelle; default is ROOT.ML.
  5668 
  5669 * New isatool version outputs the version identifier of the Isabelle
  5670 distribution being used.
  5671 
  5672 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  5673 (containing Boolean satisfiability problems) into Isabelle/HOL
  5674 theories.
  5675 
  5676 
  5677 
  5678 New in Isabelle2004 (April 2004)
  5679 --------------------------------
  5680 
  5681 *** General ***
  5682 
  5683 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  5684   Replaces linorder.ML.
  5685 
  5686 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  5687   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  5688   (\<a>...\<z>), are now considered normal letters, and can therefore
  5689   be used anywhere where an ASCII letter (a...zA...Z) has until
  5690   now. COMPATIBILITY: This obviously changes the parsing of some
  5691   terms, especially where a symbol has been used as a binder, say
  5692   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  5693   as an identifier.  Fix it by inserting a space around former
  5694   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  5695   existing theory and ML files.
  5696 
  5697 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  5698 
  5699 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  5700   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  5701   a normal (but invisible) letter. For multiple letter subscripts repeat
  5702   \<^isub> like this: x\<^isub>1\<^isub>2.
  5703 
  5704 * Pure: There are now sub-/superscripts that can span more than one
  5705   character. Text between \<^bsub> and \<^esub> is set in subscript in
  5706   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  5707   superscript. The new control characters are not identifier parts.
  5708 
  5709 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  5710   content of "..." to the latex file instead of \isacntrl... . The "..."
  5711   may consist of any printable characters excluding the end bracket >.
  5712 
  5713 * Pure: Using new Isar command "finalconsts" (or the ML functions
  5714   Theory.add_finals or Theory.add_finals_i) it is now possible to
  5715   declare constants "final", which prevents their being given a definition
  5716   later.  It is useful for constants whose behaviour is fixed axiomatically
  5717   rather than definitionally, such as the meta-logic connectives.
  5718 
  5719 * Pure: 'instance' now handles general arities with general sorts
  5720   (i.e. intersections of classes),
  5721 
  5722 * Presentation: generated HTML now uses a CSS style sheet to make layout
  5723   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  5724   It can be changed to alter the colors/layout of generated pages.
  5725 
  5726 
  5727 *** Isar ***
  5728 
  5729 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  5730   cut_tac, subgoal_tac and thin_tac:
  5731   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  5732     locales are no longer forced to write Isar proof scripts.
  5733     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  5734     emulations.
  5735   - INCOMPATIBILITY: names of variables to be instantiated may no
  5736     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  5737     This is consistent with the instantiation attribute "where".
  5738 
  5739 * Attributes "where" and "of":
  5740   - Now take type variables of instantiated theorem into account when reading
  5741     the instantiation string.  This fixes a bug that caused instantiated
  5742     theorems to have too special types in some circumstances.
  5743   - "where" permits explicit instantiations of type variables.
  5744 
  5745 * Calculation commands "moreover" and "also" no longer interfere with
  5746   current facts ("this"), admitting arbitrary combinations with "then"
  5747   and derived forms.
  5748 
  5749 * Locales:
  5750   - Goal statements involving the context element "includes" no longer
  5751     generate theorems with internal delta predicates (those ending on
  5752     "_axioms") in the premise.
  5753     Resolve particular premise with <locale>.intro to obtain old form.
  5754   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  5755     specification and "includes" elements in goal statement.
  5756   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  5757     [intro?] and [elim?] (respectively) by default.
  5758   - Experimental command for instantiation of locales in proof contexts:
  5759         instantiate <label>[<attrs>]: <loc>
  5760     Instantiates locale <loc> and adds all its theorems to the current context
  5761     taking into account their attributes.  Label and attrs are optional
  5762     modifiers, like in theorem declarations.  If present, names of
  5763     instantiated theorems are qualified with <label>, and the attributes
  5764     <attrs> are applied after any attributes these theorems might have already.
  5765       If the locale has assumptions, a chained fact of the form
  5766     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  5767     are derived.  The command does not support old-style locales declared
  5768     with "locale (open)".
  5769       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  5770 
  5771 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  5772   (Isar) contexts.
  5773 
  5774 
  5775 *** HOL ***
  5776 
  5777 * Proof import: new image HOL4 contains the imported library from
  5778   the HOL4 system with about 2500 theorems. It is imported by
  5779   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  5780   can be used like any other Isabelle image.  See
  5781   HOL/Import/HOL/README for more information.
  5782 
  5783 * Simplifier:
  5784   - Much improved handling of linear and partial orders.
  5785     Reasoners for linear and partial orders are set up for type classes
  5786     "linorder" and "order" respectively, and are added to the default simpset
  5787     as solvers.  This means that the simplifier can build transitivity chains
  5788     to solve goals from the assumptions.
  5789   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  5790     of blast or auto after simplification become unnecessary because the goal
  5791     is solved by simplification already.
  5792 
  5793 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  5794     all proved in axiomatic type classes for semirings, rings and fields.
  5795 
  5796 * Numerics:
  5797   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  5798     now formalized using the Ring_and_Field theory mentioned above.
  5799   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  5800     than before, because now they are set up once in a generic manner.
  5801   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  5802     Look for the general versions in Ring_and_Field (and Power if they concern
  5803     exponentiation).
  5804 
  5805 * Type "rat" of the rational numbers is now available in HOL-Complex.
  5806 
  5807 * Records:
  5808   - Record types are now by default printed with their type abbreviation
  5809     instead of the list of all field types. This can be configured via
  5810     the reference "print_record_type_abbr".
  5811   - Simproc "record_upd_simproc" for simplification of multiple updates added
  5812     (not enabled by default).
  5813   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  5814     EX x. x = sel r to True (not enabled by default).
  5815   - Tactic "record_split_simp_tac" to split and simplify records added.
  5816 
  5817 * 'specification' command added, allowing for definition by
  5818   specification.  There is also an 'ax_specification' command that
  5819   introduces the new constants axiomatically.
  5820 
  5821 * arith(_tac) is now able to generate counterexamples for reals as well.
  5822 
  5823 * HOL-Algebra: new locale "ring" for non-commutative rings.
  5824 
  5825 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  5826   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  5827 
  5828 * HOL-Matrix: a first theory for matrices in HOL with an application of
  5829   matrix theory to linear programming.
  5830 
  5831 * Unions and Intersections:
  5832   The latex output syntax of UN and INT has been changed
  5833   from "\Union x \in A. B" to "\Union_{x \in A} B"
  5834   i.e. the index formulae has become a subscript.
  5835   Similarly for "\Union x. B", and for \Inter instead of \Union.
  5836 
  5837 * Unions and Intersections over Intervals:
  5838   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  5839   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  5840   like in normal math, and corresponding versions for < and for intersection.
  5841 
  5842 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  5843   lexicographic dictonary ordering has been added as "lexord".
  5844 
  5845 * ML: the legacy theory structures Int and List have been removed. They had
  5846   conflicted with ML Basis Library structures having the same names.
  5847 
  5848 * 'refute' command added to search for (finite) countermodels.  Only works
  5849   for a fragment of HOL.  The installation of an external SAT solver is
  5850   highly recommended.  See "HOL/Refute.thy" for details.
  5851 
  5852 * 'quickcheck' command: Allows to find counterexamples by evaluating
  5853   formulae under an assignment of free variables to random values.
  5854   In contrast to 'refute', it can deal with inductive datatypes,
  5855   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  5856   for examples.
  5857 
  5858 
  5859 *** HOLCF ***
  5860 
  5861 * Streams now come with concatenation and are part of the HOLCF image
  5862 
  5863 
  5864 
  5865 New in Isabelle2003 (May 2003)
  5866 ------------------------------
  5867 
  5868 *** General ***
  5869 
  5870 * Provers/simplifier:
  5871 
  5872   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  5873     Assumptions are now subject to complete mutual simplification,
  5874     not just from left to right. The simplifier now preserves
  5875     the order of assumptions.
  5876 
  5877     Potential INCOMPATIBILITY:
  5878 
  5879     -- simp sometimes diverges where the old version did
  5880        not, e.g. invoking simp on the goal
  5881 
  5882         [| P (f x); y = x; f x = f y |] ==> Q
  5883 
  5884        now gives rise to the infinite reduction sequence
  5885 
  5886         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  5887 
  5888        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  5889        kind of problem.
  5890 
  5891     -- Tactics combining classical reasoner and simplification (such as auto)
  5892        are also affected by this change, because many of them rely on
  5893        simp. They may sometimes diverge as well or yield a different numbers
  5894        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  5895        in case of problems. Sometimes subsequent calls to the classical
  5896        reasoner will fail because a preceeding call to the simplifier too
  5897        eagerly simplified the goal, e.g. deleted redundant premises.
  5898 
  5899   - The simplifier trace now shows the names of the applied rewrite rules
  5900 
  5901   - You can limit the number of recursive invocations of the simplifier
  5902     during conditional rewriting (where the simplifie tries to solve the
  5903     conditions before applying the rewrite rule):
  5904     ML "simp_depth_limit := n"
  5905     where n is an integer. Thus you can force termination where previously
  5906     the simplifier would diverge.
  5907 
  5908   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  5909 
  5910   - No longer aborts on failed congruence proof.  Instead, the
  5911     congruence is ignored.
  5912 
  5913 * Pure: New generic framework for extracting programs from constructive
  5914   proofs. See HOL/Extraction.thy for an example instantiation, as well
  5915   as HOL/Extraction for some case studies.
  5916 
  5917 * Pure: The main goal of the proof state is no longer shown by default, only
  5918 the subgoals. This behaviour is controlled by a new flag.
  5919    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  5920 (ML: Proof.show_main_goal).
  5921 
  5922 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  5923 rules whose conclusion matches subgoal 1:
  5924       PG menu: Isabelle/Isar -> Show me -> matching rules
  5925 The rules are ordered by how closely they match the subgoal.
  5926 In particular, rules that solve a subgoal outright are displayed first
  5927 (or rather last, the way they are printed).
  5928 (ML: ProofGeneral.print_intros())
  5929 
  5930 * Pure: New flag trace_unify_fail causes unification to print
  5931 diagnostic information (PG: in trace buffer) when it fails. This is
  5932 useful for figuring out why single step proofs like rule, erule or
  5933 assumption failed.
  5934 
  5935 * Pure: Locale specifications now produce predicate definitions
  5936 according to the body of text (covering assumptions modulo local
  5937 definitions); predicate "loc_axioms" covers newly introduced text,
  5938 while "loc" is cumulative wrt. all included locale expressions; the
  5939 latter view is presented only on export into the global theory
  5940 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  5941 on the old view without predicates;
  5942 
  5943 * Pure: predefined locales "var" and "struct" are useful for sharing
  5944 parameters (as in CASL, for example); just specify something like
  5945 ``var x + var y + struct M'' as import;
  5946 
  5947 * Pure: improved thms_containing: proper indexing of facts instead of
  5948 raw theorems; check validity of results wrt. current name space;
  5949 include local facts of proof configuration (also covers active
  5950 locales), cover fixed variables in index; may use "_" in term
  5951 specification; an optional limit for the number of printed facts may
  5952 be given (the default is 40);
  5953 
  5954 * Pure: disallow duplicate fact bindings within new-style theory files
  5955 (batch-mode only);
  5956 
  5957 * Provers: improved induct method: assumptions introduced by case
  5958 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  5959 the goal statement); "foo" still refers to all facts collectively;
  5960 
  5961 * Provers: the function blast.overloaded has been removed: all constants
  5962 are regarded as potentially overloaded, which improves robustness in exchange
  5963 for slight decrease in efficiency;
  5964 
  5965 * Provers/linorder: New generic prover for transitivity reasoning over
  5966 linear orders.  Note: this prover is not efficient!
  5967 
  5968 * Isar: preview of problems to finish 'show' now produce an error
  5969 rather than just a warning (in interactive mode);
  5970 
  5971 
  5972 *** HOL ***
  5973 
  5974 * arith(_tac)
  5975 
  5976  - Produces a counter example if it cannot prove a goal.
  5977    Note that the counter example may be spurious if the goal is not a formula
  5978    of quantifier-free linear arithmetic.
  5979    In ProofGeneral the counter example appears in the trace buffer.
  5980 
  5981  - Knows about div k and mod k where k is a numeral of type nat or int.
  5982 
  5983  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  5984    linear arithmetic fails. This takes account of quantifiers and divisibility.
  5985    Presburger arithmetic can also be called explicitly via presburger(_tac).
  5986 
  5987 * simp's arithmetic capabilities have been enhanced a bit: it now
  5988 takes ~= in premises into account (by performing a case split);
  5989 
  5990 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  5991 are distributed over a sum of terms;
  5992 
  5993 * New tactic "trans_tac" and method "trans" instantiate
  5994 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  5995 "<=", "<" and "=").
  5996 
  5997 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  5998 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  5999 
  6000 * 'typedef' command has new option "open" to suppress the set
  6001 definition;
  6002 
  6003 * functions Min and Max on finite sets have been introduced (theory
  6004 Finite_Set);
  6005 
  6006 * attribute [symmetric] now works for relations as well; it turns
  6007 (x,y) : R^-1 into (y,x) : R, and vice versa;
  6008 
  6009 * induct over a !!-quantified statement (say !!x1..xn):
  6010   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  6011 
  6012 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  6013 %x. None. Warning: empty_def now refers to the previously hidden definition
  6014 of the empty set.
  6015 
  6016 * Algebra: formalization of classical algebra.  Intended as base for
  6017 any algebraic development in Isabelle.  Currently covers group theory
  6018 (up to Sylow's theorem) and ring theory (Universal Property of
  6019 Univariate Polynomials).  Contributions welcome;
  6020 
  6021 * GroupTheory: deleted, since its material has been moved to Algebra;
  6022 
  6023 * Complex: new directory of the complex numbers with numeric constants,
  6024 nonstandard complex numbers, and some complex analysis, standard and
  6025 nonstandard (Jacques Fleuriot);
  6026 
  6027 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  6028 
  6029 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  6030 Fleuriot);
  6031 
  6032 * Real/HahnBanach: updated and adapted to locales;
  6033 
  6034 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  6035 Gray and Kramer);
  6036 
  6037 * UNITY: added the Meier-Sanders theory of progress sets;
  6038 
  6039 * MicroJava: bytecode verifier and lightweight bytecode verifier
  6040 as abstract algorithms, instantiated to the JVM;
  6041 
  6042 * Bali: Java source language formalization. Type system, operational
  6043 semantics, axiomatic semantics. Supported language features:
  6044 classes, interfaces, objects,virtual methods, static methods,
  6045 static/instance fields, arrays, access modifiers, definite
  6046 assignment, exceptions.
  6047 
  6048 
  6049 *** ZF ***
  6050 
  6051 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  6052 universe, etc.);
  6053 
  6054 * Main ZF: virtually all theories converted to new-style format;
  6055 
  6056 
  6057 *** ML ***
  6058 
  6059 * Pure: Tactic.prove provides sane interface for internal proofs;
  6060 omits the infamous "standard" operation, so this is more appropriate
  6061 than prove_goalw_cterm in many situations (e.g. in simprocs);
  6062 
  6063 * Pure: improved error reporting of simprocs;
  6064 
  6065 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  6066 up simprocs;
  6067 
  6068 
  6069 *** Document preparation ***
  6070 
  6071 * uses \par instead of \\ for line breaks in theory text. This may
  6072 shift some page breaks in large documents. To get the old behaviour
  6073 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  6074 
  6075 * minimized dependencies of isabelle.sty and isabellesym.sty on
  6076 other packages
  6077 
  6078 * \<euro> now needs package babel/greek instead of marvosym (which
  6079 broke \Rightarrow)
  6080 
  6081 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  6082 textcomp package)
  6083 
  6084 
  6085 
  6086 New in Isabelle2002 (March 2002)
  6087 --------------------------------
  6088 
  6089 *** Document preparation ***
  6090 
  6091 * greatly simplified document preparation setup, including more
  6092 graceful interpretation of isatool usedir -i/-d/-D options, and more
  6093 instructive isatool mkdir; users should basically be able to get
  6094 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  6095 users may run a separate document processing stage manually like this:
  6096 "isatool usedir -D output HOL Test && isatool document Test/output";
  6097 
  6098 * theory dependency graph may now be incorporated into documents;
  6099 isatool usedir -g true will produce session_graph.eps/.pdf for use
  6100 with \includegraphics of LaTeX;
  6101 
  6102 * proper spacing of consecutive markup elements, especially text
  6103 blocks after section headings;
  6104 
  6105 * support bold style (for single symbols only), input syntax is like
  6106 this: "\<^bold>\<alpha>" or "\<^bold>A";
  6107 
  6108 * \<bullet> is now output as bold \cdot by default, which looks much
  6109 better in printed text;
  6110 
  6111 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  6112 note that these symbols are currently unavailable in Proof General /
  6113 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  6114 
  6115 * isatool latex no longer depends on changed TEXINPUTS, instead
  6116 isatool document copies the Isabelle style files to the target
  6117 location;
  6118 
  6119 
  6120 *** Isar ***
  6121 
  6122 * Pure/Provers: improved proof by cases and induction;
  6123   - 'case' command admits impromptu naming of parameters (such as
  6124     "case (Suc n)");
  6125   - 'induct' method divinates rule instantiation from the inductive
  6126     claim; no longer requires excessive ?P bindings for proper
  6127     instantiation of cases;
  6128   - 'induct' method properly enumerates all possibilities of set/type
  6129     rules; as a consequence facts may be also passed through *type*
  6130     rules without further ado;
  6131   - 'induct' method now derives symbolic cases from the *rulified*
  6132     rule (before it used to rulify cases stemming from the internal
  6133     atomized version); this means that the context of a non-atomic
  6134     statement becomes is included in the hypothesis, avoiding the
  6135     slightly cumbersome show "PROP ?case" form;
  6136   - 'induct' may now use elim-style induction rules without chaining
  6137     facts, using ``missing'' premises from the goal state; this allows
  6138     rules stemming from inductive sets to be applied in unstructured
  6139     scripts, while still benefitting from proper handling of non-atomic
  6140     statements; NB: major inductive premises need to be put first, all
  6141     the rest of the goal is passed through the induction;
  6142   - 'induct' proper support for mutual induction involving non-atomic
  6143     rule statements (uses the new concept of simultaneous goals, see
  6144     below);
  6145   - append all possible rule selections, but only use the first
  6146     success (no backtracking);
  6147   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  6148   - undeclared rule case names default to numbers 1, 2, 3, ...;
  6149   - added 'print_induct_rules' (covered by help item in recent Proof
  6150     General versions);
  6151   - moved induct/cases attributes to Pure, methods to Provers;
  6152   - generic method setup instantiated for FOL and HOL;
  6153 
  6154 * Pure: support multiple simultaneous goal statements, for example
  6155 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  6156 meta-level mechanism, this acts as if several individual goals had
  6157 been stated separately; in particular common proof methods need to be
  6158 repeated in order to cover all claims; note that a single elimination
  6159 step is *not* sufficient to establish the two conjunctions, so this
  6160 fails:
  6161 
  6162   assume "A & B" then have A and B ..   (*".." fails*)
  6163 
  6164 better use "obtain" in situations as above; alternative refer to
  6165 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  6166 
  6167 * Pure: proper integration with ``locales''; unlike the original
  6168 version by Florian Kammller, Isar locales package high-level proof
  6169 contexts rather than raw logical ones (e.g. we admit to include
  6170 attributes everywhere); operations on locales include merge and
  6171 rename; support for implicit arguments (``structures''); simultaneous
  6172 type-inference over imports and text; see also HOL/ex/Locales.thy for
  6173 some examples;
  6174 
  6175 * Pure: the following commands have been ``localized'', supporting a
  6176 target locale specification "(in name)": 'lemma', 'theorem',
  6177 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  6178 stored both within the locale and at the theory level (exported and
  6179 qualified by the locale name);
  6180 
  6181 * Pure: theory goals may now be specified in ``long'' form, with
  6182 ad-hoc contexts consisting of arbitrary locale elements. for example
  6183 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  6184 definitions may be given, too); the result is a meta-level rule with
  6185 the context elements being discharged in the obvious way;
  6186 
  6187 * Pure: new proof command 'using' allows to augment currently used
  6188 facts after a goal statement ('using' is syntactically analogous to
  6189 'apply', but acts on the goal's facts only); this allows chained facts
  6190 to be separated into parts given before and after a claim, as in
  6191 ``from a and b have C using d and e <proof>'';
  6192 
  6193 * Pure: renamed "antecedent" case to "rule_context";
  6194 
  6195 * Pure: new 'judgment' command records explicit information about the
  6196 object-logic embedding (used by several tools internally); no longer
  6197 use hard-wired "Trueprop";
  6198 
  6199 * Pure: added 'corollary' command;
  6200 
  6201 * Pure: fixed 'token_translation' command;
  6202 
  6203 * Pure: removed obsolete 'exported' attribute;
  6204 
  6205 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  6206 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  6207 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  6208 
  6209 * Pure: method 'atomize' presents local goal premises as object-level
  6210 statements (atomic meta-level propositions); setup controlled via
  6211 rewrite rules declarations of 'atomize' attribute; example
  6212 application: 'induct' method with proper rule statements in improper
  6213 proof *scripts*;
  6214 
  6215 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  6216 now consider the syntactic context of assumptions, giving a better
  6217 chance to get type-inference of the arguments right (this is
  6218 especially important for locales);
  6219 
  6220 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  6221 mode;
  6222 
  6223 * Pure/obtain: the formal conclusion "thesis", being marked as
  6224 ``internal'', may no longer be reference directly in the text;
  6225 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  6226 situations;
  6227 
  6228 * Pure: generic 'sym' attribute which declares a rule both as pure
  6229 'elim?' and for the 'symmetric' operation;
  6230 
  6231 * Pure: marginal comments ``--'' may now occur just anywhere in the
  6232 text; the fixed correlation with particular command syntax has been
  6233 discontinued;
  6234 
  6235 * Pure: new method 'rules' is particularly well-suited for proof
  6236 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  6237 but often produces more compact proof terms with less detours;
  6238 
  6239 * Pure/Provers/classical: simplified integration with pure rule
  6240 attributes and methods; the classical "intro?/elim?/dest?"
  6241 declarations coincide with the pure ones; the "rule" method no longer
  6242 includes classically swapped intros; "intro" and "elim" methods no
  6243 longer pick rules from the context; also got rid of ML declarations
  6244 AddXIs/AddXEs/AddXDs; all of this has some potential for
  6245 INCOMPATIBILITY;
  6246 
  6247 * Provers/classical: attribute 'swapped' produces classical inversions
  6248 of introduction rules;
  6249 
  6250 * Provers/simplifier: 'simplified' attribute may refer to explicit
  6251 rules instead of full simplifier context; 'iff' attribute handles
  6252 conditional rules;
  6253 
  6254 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  6255 
  6256 * HOL: 'recdef' now fails on unfinished automated proofs, use
  6257 "(permissive)" option to recover old behavior;
  6258 
  6259 * HOL: 'inductive' no longer features separate (collective) attributes
  6260 for 'intros' (was found too confusing);
  6261 
  6262 * HOL: properly declared induction rules less_induct and
  6263 wf_induct_rule;
  6264 
  6265 
  6266 *** HOL ***
  6267 
  6268 * HOL: moved over to sane numeral syntax; the new policy is as
  6269 follows:
  6270 
  6271   - 0 and 1 are polymorphic constants, which are defined on any
  6272   numeric type (nat, int, real etc.);
  6273 
  6274   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  6275   binary representation internally;
  6276 
  6277   - type nat has special constructor Suc, and generally prefers Suc 0
  6278   over 1::nat and Suc (Suc 0) over 2::nat;
  6279 
  6280 This change may cause significant problems of INCOMPATIBILITY; here
  6281 are some hints on converting existing sources:
  6282 
  6283   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  6284   entities, so expressions involving "-" (unary or binary minus) need
  6285   to be spaced properly;
  6286 
  6287   - existing occurrences of "1" may need to be constraint "1::nat" or
  6288   even replaced by Suc 0; similar for old "2";
  6289 
  6290   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  6291 
  6292   - remove all special provisions on numerals in proofs;
  6293 
  6294 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  6295 representation (depends on bin_arith_simps in the default context);
  6296 
  6297 * HOL: symbolic syntax for x^2 (numeral 2);
  6298 
  6299 * HOL: the class of all HOL types is now called "type" rather than
  6300 "term"; INCOMPATIBILITY, need to adapt references to this type class
  6301 in axclass/classes, instance/arities, and (usually rare) occurrences
  6302 in typings (of consts etc.); internally the class is called
  6303 "HOL.type", ML programs should refer to HOLogic.typeS;
  6304 
  6305 * HOL/record package improvements:
  6306   - new derived operations "fields" to build a partial record section,
  6307     "extend" to promote a fixed record to a record scheme, and
  6308     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  6309     declared as simp by default;
  6310   - shared operations ("more", "fields", etc.) now need to be always
  6311     qualified) --- potential INCOMPATIBILITY;
  6312   - removed "make_scheme" operations (use "make" with "extend") --
  6313     INCOMPATIBILITY;
  6314   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  6315   - provides cases/induct rules for use with corresponding Isar
  6316     methods (for concrete records, record schemes, concrete more
  6317     parts, and schematic more parts -- in that order);
  6318   - internal definitions directly based on a light-weight abstract
  6319     theory of product types over typedef rather than datatype;
  6320 
  6321 * HOL: generic code generator for generating executable ML code from
  6322 specifications; specific support for HOL constructs such as inductive
  6323 datatypes and sets, as well as recursive functions; can be invoked
  6324 via 'generate_code' theory section;
  6325 
  6326 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  6327 
  6328 * HOL: consolidated and renamed several theories.  In particular:
  6329         Ord.thy has been absorbed into HOL.thy
  6330         String.thy has been absorbed into List.thy
  6331 
  6332 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  6333 (beware of argument permutation!);
  6334 
  6335 * HOL: linorder_less_split superseded by linorder_cases;
  6336 
  6337 * HOL/List: "nodups" renamed to "distinct";
  6338 
  6339 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  6340 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  6341   - Ex_def has changed, now need to use some_eq_ex
  6342 
  6343 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  6344 in this (rare) case use:
  6345 
  6346   delSWrapper "split_all_tac"
  6347   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  6348 
  6349 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  6350 MAY FAIL;
  6351 
  6352 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  6353 Isabelle's type classes, ^ on functions and relations has too general
  6354 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  6355 necessary to attach explicit type constraints;
  6356 
  6357 * HOL/Relation: the prefix name of the infix "O" has been changed from
  6358 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  6359 renamed accordingly (eg "compI" -> "rel_compI").
  6360 
  6361 * HOL: syntax translations now work properly with numerals and records
  6362 expressions;
  6363 
  6364 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  6365 of "lam" -- INCOMPATIBILITY;
  6366 
  6367 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  6368 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  6369 renamed "Product_Type.unit";
  6370 
  6371 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  6372 
  6373 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  6374 the "cases" method);
  6375 
  6376 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  6377 Florian Kammller);
  6378 
  6379 * HOL/IMP: updated and converted to new-style theory format; several
  6380 parts turned into readable document, with proper Isar proof texts and
  6381 some explanations (by Gerwin Klein);
  6382 
  6383 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  6384 
  6385 * HOL-Hyperreal is now a logic image;
  6386 
  6387 
  6388 *** HOLCF ***
  6389 
  6390 * Isar: consts/constdefs supports mixfix syntax for continuous
  6391 operations;
  6392 
  6393 * Isar: domain package adapted to new-style theory format, e.g. see
  6394 HOLCF/ex/Dnat.thy;
  6395 
  6396 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  6397 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  6398 lift.induct_tac, always use UU instead of Undef;
  6399 
  6400 * HOLCF/IMP: updated and converted to new-style theory;
  6401 
  6402 
  6403 *** ZF ***
  6404 
  6405 * Isar: proper integration of logic-specific tools and packages,
  6406 including theory commands '(co)inductive', '(co)datatype',
  6407 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  6408 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  6409 
  6410 * theory Main no longer includes AC; for the Axiom of Choice, base
  6411 your theory on Main_ZFC;
  6412 
  6413 * the integer library now covers quotients and remainders, with many
  6414 laws relating division to addition, multiplication, etc.;
  6415 
  6416 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  6417 typeless version of the formalism;
  6418 
  6419 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  6420 format;
  6421 
  6422 * ZF/Induct: new directory for examples of inductive definitions,
  6423 including theory Multiset for multiset orderings; converted to
  6424 new-style theory format;
  6425 
  6426 * ZF: many new theorems about lists, ordinals, etc.;
  6427 
  6428 
  6429 *** General ***
  6430 
  6431 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  6432 variable proof controls level of detail: 0 = no proofs (only oracle
  6433 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  6434 also ref manual for further ML interfaces;
  6435 
  6436 * Pure/axclass: removed obsolete ML interface
  6437 goal_subclass/goal_arity;
  6438 
  6439 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  6440 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  6441 separate tokens, so expressions involving minus need to be spaced
  6442 properly;
  6443 
  6444 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  6445 rather than "infixl" or "infixr";
  6446 
  6447 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  6448 sort constraint specifications in type inference; e.g. "x::_::foo"
  6449 ensures that the type of "x" is of sort "foo" (but not necessarily a
  6450 type variable);
  6451 
  6452 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  6453 control output of nested => (types); the default behavior is
  6454 "type_brackets";
  6455 
  6456 * Pure/syntax: builtin parse translation for "_constify" turns valued
  6457 tokens into AST constants;
  6458 
  6459 * Pure/syntax: prefer later declarations of translations and print
  6460 translation functions; potential INCOMPATIBILITY: need to reverse
  6461 multiple declarations for same syntax element constant;
  6462 
  6463 * Pure/show_hyps reset by default (in accordance to existing Isar
  6464 practice);
  6465 
  6466 * Provers/classical: renamed addaltern to addafter, addSaltern to
  6467 addSafter;
  6468 
  6469 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  6470 as well;
  6471 
  6472 * system: tested support for MacOS X; should be able to get Isabelle +
  6473 Proof General to work in a plain Terminal after installing Poly/ML
  6474 (e.g. from the Isabelle distribution area) and GNU bash alone
  6475 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  6476 support requires further installations, e.g. from
  6477 http://fink.sourceforge.net/);
  6478 
  6479 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  6480 
  6481 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  6482 of 40 MB), cf. ML_OPTIONS;
  6483 
  6484 * system: Proof General keywords specification is now part of the
  6485 Isabelle distribution (see etc/isar-keywords.el);
  6486 
  6487 * system: support for persistent Proof General sessions (refrain from
  6488 outdating all loaded theories on startup); user may create writable
  6489 logic images like this: ``isabelle -q HOL Test'';
  6490 
  6491 * system: smart selection of Isabelle process versus Isabelle
  6492 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  6493 run both "isabelle" and "Isabelle" even if file names are badly
  6494 damaged (executable inspects the case of the first letter of its own
  6495 name); added separate "isabelle-process" and "isabelle-interface";
  6496 
  6497 * system: refrain from any attempt at filtering input streams; no
  6498 longer support ``8bit'' encoding of old isabelle font, instead proper
  6499 iso-latin characters may now be used; the related isatools
  6500 "symbolinput" and "nonascii" have disappeared as well;
  6501 
  6502 * system: removed old "xterm" interface (the print modes "xterm" and
  6503 "xterm_color" are still available for direct use in a suitable
  6504 terminal);
  6505 
  6506 
  6507 
  6508 New in Isabelle99-2 (February 2001)
  6509 -----------------------------------
  6510 
  6511 *** Overview of INCOMPATIBILITIES ***
  6512 
  6513 * HOL: please note that theories in the Library and elsewhere often use the
  6514 new-style (Isar) format; to refer to their theorems in an ML script you must
  6515 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  6516 
  6517 * HOL: inductive package no longer splits induction rule aggressively,
  6518 but only as far as specified by the introductions given; the old
  6519 format may be recovered via ML function complete_split_rule or attribute
  6520 'split_rule (complete)';
  6521 
  6522 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  6523 gfp_Tarski to gfp_unfold;
  6524 
  6525 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  6526 
  6527 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  6528 relation); infix "^^" has been renamed "``"; infix "``" has been
  6529 renamed "`"; "univalent" has been renamed "single_valued";
  6530 
  6531 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  6532 operation;
  6533 
  6534 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  6535 
  6536 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  6537 
  6538 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  6539 consequence, it is no longer monotonic wrt. the local goal context
  6540 (which is now passed through the inductive cases);
  6541 
  6542 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  6543 \<gg> to \<ggreater>;
  6544 
  6545 
  6546 *** Document preparation ***
  6547 
  6548 * \isabellestyle{NAME} selects version of Isabelle output (currently
  6549 available: are "it" for near math-mode best-style output, "sl" for
  6550 slanted text style, and "tt" for plain type-writer; if no
  6551 \isabellestyle command is given, output is according to slanted
  6552 type-writer);
  6553 
  6554 * support sub/super scripts (for single symbols only), input syntax is
  6555 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  6556 
  6557 * some more standard symbols; see Appendix A of the system manual for
  6558 the complete list of symbols defined in isabellesym.sty;
  6559 
  6560 * improved isabelle style files; more abstract symbol implementation
  6561 (should now use \isamath{...} and \isatext{...} in custom symbol
  6562 definitions);
  6563 
  6564 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  6565 state; Note that presentation of goal states does not conform to
  6566 actual human-readable proof documents.  Please do not include goal
  6567 states into document output unless you really know what you are doing!
  6568 
  6569 * proper indentation of antiquoted output with proportional LaTeX
  6570 fonts;
  6571 
  6572 * no_document ML operator temporarily disables LaTeX document
  6573 generation;
  6574 
  6575 * isatool unsymbolize tunes sources for plain ASCII communication;
  6576 
  6577 
  6578 *** Isar ***
  6579 
  6580 * Pure: Isar now suffers initial goal statements to contain unbound
  6581 schematic variables (this does not conform to actual readable proof
  6582 documents, due to unpredictable outcome and non-compositional proof
  6583 checking); users who know what they are doing may use schematic goals
  6584 for Prolog-style synthesis of proven results;
  6585 
  6586 * Pure: assumption method (an implicit finishing) now handles actual
  6587 rules as well;
  6588 
  6589 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  6590 initial goal, declare "that" only as Pure intro (only for single
  6591 steps); the "that" rule assumption may now be involved in implicit
  6592 finishing, thus ".." becomes a feasible for trivial obtains;
  6593 
  6594 * Pure: default proof step now includes 'intro_classes'; thus trivial
  6595 instance proofs may be performed by "..";
  6596 
  6597 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  6598 statements as well;
  6599 
  6600 * Pure: more robust selection of calculational rules;
  6601 
  6602 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  6603 rule (as well as the assumption rule);
  6604 
  6605 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  6606 lemmas, using the graph browser tool;
  6607 
  6608 * Pure: predict failure of "show" in interactive mode;
  6609 
  6610 * Pure: 'thms_containing' now takes actual terms as arguments;
  6611 
  6612 * HOL: improved method 'induct' --- now handles non-atomic goals
  6613 (potential INCOMPATIBILITY); tuned error handling;
  6614 
  6615 * HOL: cases and induct rules now provide explicit hints about the
  6616 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  6617 any remaining facts are inserted into the goal verbatim;
  6618 
  6619 * HOL: local contexts (aka cases) may now contain term bindings as
  6620 well; the 'cases' and 'induct' methods new provide a ?case binding for
  6621 the result to be shown in each case;
  6622 
  6623 * HOL: added 'recdef_tc' command;
  6624 
  6625 * isatool convert assists in eliminating legacy ML scripts;
  6626 
  6627 
  6628 *** HOL ***
  6629 
  6630 * HOL/Library: a collection of generic theories to be used together
  6631 with main HOL; the theory loader path already includes this directory
  6632 by default; the following existing theories have been moved here:
  6633 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  6634 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  6635 
  6636 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  6637 modelling and verification task performed in Isabelle/HOL +
  6638 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  6639 
  6640 * HOL/Algebra: special summation operator SUM no longer exists, it has
  6641 been replaced by setsum; infix 'assoc' now has priority 50 (like
  6642 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  6643 'domain', this makes the theory consistent with mathematical
  6644 literature;
  6645 
  6646 * HOL basics: added overloaded operations "inverse" and "divide"
  6647 (infix "/"), syntax for generic "abs" operation, generic summation
  6648 operator \<Sum>;
  6649 
  6650 * HOL/typedef: simplified package, provide more useful rules (see also
  6651 HOL/subset.thy);
  6652 
  6653 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  6654 now expressed as a proper nested rule (old-style tactic scripts may
  6655 require atomize_strip_tac to cope with non-atomic premises);
  6656 
  6657 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  6658 to "split_conv" (old name still available for compatibility);
  6659 
  6660 * HOL: improved concrete syntax for strings (e.g. allows translation
  6661 rules with string literals);
  6662 
  6663 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  6664  and Fleuriot's mechanization of analysis, including the transcendental
  6665  functions for the reals;
  6666 
  6667 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  6668 
  6669 
  6670 *** CTT ***
  6671 
  6672 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  6673 "lam" is displayed as TWO lambda-symbols
  6674 
  6675 * CTT: theory Main now available, containing everything (that is, Bool
  6676 and Arith);
  6677 
  6678 
  6679 *** General ***
  6680 
  6681 * Pure: the Simplifier has been implemented properly as a derived rule
  6682 outside of the actual kernel (at last!); the overall performance
  6683 penalty in practical applications is about 50%, while reliability of
  6684 the Isabelle inference kernel has been greatly improved;
  6685 
  6686 * print modes "brackets" and "no_brackets" control output of nested =>
  6687 (types) and ==> (props); the default behaviour is "brackets";
  6688 
  6689 * Provers: fast_tac (and friends) now handle actual object-logic rules
  6690 as assumptions as well;
  6691 
  6692 * system: support Poly/ML 4.0;
  6693 
  6694 * system: isatool install handles KDE version 1 or 2;
  6695 
  6696 
  6697 
  6698 New in Isabelle99-1 (October 2000)
  6699 ----------------------------------
  6700 
  6701 *** Overview of INCOMPATIBILITIES ***
  6702 
  6703 * HOL: simplification of natural numbers is much changed; to partly
  6704 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  6705 issue the following ML commands:
  6706 
  6707   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  6708   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  6709 
  6710 * HOL: simplification no longer dives into case-expressions; this is
  6711 controlled by "t.weak_case_cong" for each datatype t;
  6712 
  6713 * HOL: nat_less_induct renamed to less_induct;
  6714 
  6715 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  6716 fixsome to patch .thy and .ML sources automatically;
  6717 
  6718   select_equality  -> some_equality
  6719   select_eq_Ex     -> some_eq_ex
  6720   selectI2EX       -> someI2_ex
  6721   selectI2         -> someI2
  6722   selectI          -> someI
  6723   select1_equality -> some1_equality
  6724   Eps_sym_eq       -> some_sym_eq_trivial
  6725   Eps_eq           -> some_eq_trivial
  6726 
  6727 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  6728 
  6729 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  6730 instead);
  6731 
  6732 * HOL: the recursion equations generated by 'recdef' are now called
  6733 f.simps instead of f.rules;
  6734 
  6735 * HOL: qed_spec_mp now also handles bounded ALL as well;
  6736 
  6737 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  6738 sometimes be needed;
  6739 
  6740 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  6741 
  6742 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  6743 
  6744 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  6745 product is now "<*>" instead of "Times"; the lexicographic product is
  6746 now "<*lex*>" instead of "**";
  6747 
  6748 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  6749 of main HOL, but was unused); better use HOL's datatype package;
  6750 
  6751 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  6752 the old syntax may be recovered as follows:
  6753 
  6754   syntax (symbols)
  6755     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  6756       (infixl "\\<oplus>" 100)
  6757 
  6758 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  6759 
  6760 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  6761 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  6762 internally;
  6763 
  6764 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  6765 changed from A/r to A//r;
  6766 
  6767 * ZF: new treatment of arithmetic (nat & int) may break some old
  6768 proofs;
  6769 
  6770 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  6771 rulify -> rule_format, elimify -> elim_format, ...);
  6772 
  6773 * Isar/Provers: intro/elim/dest attributes changed; renamed
  6774 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  6775 should have to change intro!! to intro? only); replaced "delrule" by
  6776 "rule del";
  6777 
  6778 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  6779 
  6780 * Provers: strengthened force_tac by using new first_best_tac;
  6781 
  6782 * LaTeX document preparation: several changes of isabelle.sty (see
  6783 lib/texinputs);
  6784 
  6785 
  6786 *** Document preparation ***
  6787 
  6788 * formal comments (text blocks etc.) in new-style theories may now
  6789 contain antiquotations of thm/prop/term/typ/text to be presented
  6790 according to latex print mode; concrete syntax is like this:
  6791 @{term[show_types] "f(x) = a + x"};
  6792 
  6793 * isatool mkdir provides easy setup of Isabelle session directories,
  6794 including proper document sources;
  6795 
  6796 * generated LaTeX sources are now deleted after successful run
  6797 (isatool document -c); may retain a copy somewhere else via -D option
  6798 of isatool usedir;
  6799 
  6800 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  6801 style files, achieving self-contained LaTeX sources and simplifying
  6802 LaTeX debugging;
  6803 
  6804 * old-style theories now produce (crude) LaTeX output as well;
  6805 
  6806 * browser info session directories are now self-contained (may be put
  6807 on WWW server seperately); improved graphs of nested sessions; removed
  6808 graph for 'all sessions';
  6809 
  6810 * several improvements in isabelle style files; \isabellestyle{it}
  6811 produces fake math mode output; \isamarkupheader is now \section by
  6812 default; see lib/texinputs/isabelle.sty etc.;
  6813 
  6814 
  6815 *** Isar ***
  6816 
  6817 * Isar/Pure: local results and corresponding term bindings are now
  6818 subject to Hindley-Milner polymorphism (similar to ML); this
  6819 accommodates incremental type-inference very nicely;
  6820 
  6821 * Isar/Pure: new derived language element 'obtain' supports
  6822 generalized existence reasoning;
  6823 
  6824 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  6825 support accumulation of results, without applying any rules yet;
  6826 useful to collect intermediate results without explicit name
  6827 references, and for use with transitivity rules with more than 2
  6828 premises;
  6829 
  6830 * Isar/Pure: scalable support for case-analysis type proofs: new
  6831 'case' language element refers to local contexts symbolically, as
  6832 produced by certain proof methods; internally, case names are attached
  6833 to theorems as "tags";
  6834 
  6835 * Isar/Pure: theory command 'hide' removes declarations from
  6836 class/type/const name spaces;
  6837 
  6838 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  6839 indicate potential overloading;
  6840 
  6841 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  6842 
  6843 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  6844 "{a,b,c}" instead of {a,b,c};
  6845 
  6846 * Isar/Pure now provides its own version of intro/elim/dest
  6847 attributes; useful for building new logics, but beware of confusion
  6848 with the version in Provers/classical;
  6849 
  6850 * Isar/Pure: the local context of (non-atomic) goals is provided via
  6851 case name 'antecedent';
  6852 
  6853 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  6854 to the current context is now done automatically);
  6855 
  6856 * Isar/Pure: theory command 'method_setup' provides a simple interface
  6857 for definining proof methods in ML;
  6858 
  6859 * Isar/Provers: intro/elim/dest attributes changed; renamed
  6860 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  6861 most cases, one should have to change intro!! to intro? only);
  6862 replaced "delrule" by "rule del";
  6863 
  6864 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  6865 'symmetric' attribute (the latter supercedes [RS sym]);
  6866 
  6867 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  6868 method modifier); 'simp' method: 'only:' modifier removes loopers as
  6869 well (including splits);
  6870 
  6871 * Isar/Provers: Simplifier and Classical methods now support all kind
  6872 of modifiers used in the past, including 'cong', 'iff', etc.
  6873 
  6874 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  6875 of Simplifier and Classical reasoner);
  6876 
  6877 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  6878 now support named cases; major packages (inductive, datatype, primrec,
  6879 recdef) support case names and properly name parameters;
  6880 
  6881 * Isar/HOL: new transitivity rules for substitution in inequalities --
  6882 monotonicity conditions are extracted to be proven at end of
  6883 calculations;
  6884 
  6885 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  6886 method anyway;
  6887 
  6888 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  6889 split_if split_if_asm; datatype package provides theorems foo.splits =
  6890 foo.split foo.split_asm for each datatype;
  6891 
  6892 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  6893 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  6894 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  6895 use "(cases (simplified))" method in proper proof texts);
  6896 
  6897 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  6898 
  6899 * Isar: names of theorems etc. may be natural numbers as well;
  6900 
  6901 * Isar: 'pr' command: optional arguments for goals_limit and
  6902 ProofContext.prems_limit; no longer prints theory contexts, but only
  6903 proof states;
  6904 
  6905 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  6906 additional print modes to be specified; e.g. "pr(latex)" will print
  6907 proof state according to the Isabelle LaTeX style;
  6908 
  6909 * Isar: improved support for emulating tactic scripts, including proof
  6910 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  6911 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  6912 (for HOL datatypes);
  6913 
  6914 * Isar: simplified (more robust) goal selection of proof methods: 1st
  6915 goal, all goals, or explicit goal specifier (tactic emulation); thus
  6916 'proof method scripts' have to be in depth-first order;
  6917 
  6918 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  6919 
  6920 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  6921 should instead use individual commands for printing items
  6922 (print_commands, print_methods etc.);
  6923 
  6924 * Isar: added 'nothing' --- the empty list of theorems;
  6925 
  6926 
  6927 *** HOL ***
  6928 
  6929 * HOL/MicroJava: formalization of a fragment of Java, together with a
  6930 corresponding virtual machine and a specification of its bytecode
  6931 verifier and a lightweight bytecode verifier, including proofs of
  6932 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  6933 Cornelia Pusch (see also the homepage of project Bali at
  6934 http://isabelle.in.tum.de/Bali/);
  6935 
  6936 * HOL/Algebra: new theory of rings and univariate polynomials, by
  6937 Clemens Ballarin;
  6938 
  6939 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  6940 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  6941 Rasmussen;
  6942 
  6943 * HOL/Lattice: fundamental concepts of lattice theory and order
  6944 structures, including duals, properties of bounds versus algebraic
  6945 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  6946 Theorem for complete lattices etc.; may also serve as a demonstration
  6947 for abstract algebraic reasoning using axiomatic type classes, and
  6948 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  6949 
  6950 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  6951 von Oheimb;
  6952 
  6953 * HOL/IMPP: extension of IMP with local variables and mutually
  6954 recursive procedures, by David von Oheimb;
  6955 
  6956 * HOL/Lambda: converted into new-style theory and document;
  6957 
  6958 * HOL/ex/Multiquote: example of multiple nested quotations and
  6959 anti-quotations -- basically a generalized version of de-Bruijn
  6960 representation; very useful in avoiding lifting of operations;
  6961 
  6962 * HOL/record: added general record equality rule to simpset; fixed
  6963 select-update simplification procedure to handle extended records as
  6964 well; admit "r" as field name;
  6965 
  6966 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  6967 other numeric types and also as the identity of groups, rings, etc.;
  6968 
  6969 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  6970 Types nat and int belong to this axclass;
  6971 
  6972 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  6973    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  6974    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  6975   two terms #m*u and #n*u are replaced by #(m+n)*u
  6976     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  6977   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  6978     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  6979 
  6980 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  6981 powerful prover for predicate logic but knows nothing of clasets; see
  6982 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  6983 
  6984 * HOL: new version of "case_tac" subsumes both boolean case split and
  6985 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  6986 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  6987 
  6988 * HOL: simplification no longer dives into case-expressions: only the
  6989 selector expression is simplified, but not the remaining arms; to
  6990 enable full simplification of case-expressions for datatype t, you may
  6991 remove t.weak_case_cong from the simpset, either globally (Delcongs
  6992 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  6993 
  6994 * HOL/recdef: the recursion equations generated by 'recdef' for
  6995 function 'f' are now called f.simps instead of f.rules; if all
  6996 termination conditions are proved automatically, these simplification
  6997 rules are added to the simpset, as in primrec; rules may be named
  6998 individually as well, resulting in a separate list of theorems for
  6999 each equation;
  7000 
  7001 * HOL/While is a new theory that provides a while-combinator. It
  7002 permits the definition of tail-recursive functions without the
  7003 provision of a termination measure. The latter is necessary once the
  7004 invariant proof rule for while is applied.
  7005 
  7006 * HOL: new (overloaded) notation for the set of elements below/above
  7007 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  7008 
  7009 * HOL: theorems impI, allI, ballI bound as "strip";
  7010 
  7011 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  7012 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  7013 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  7014 
  7015 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  7016 
  7017 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  7018 main HOL, but was unused);
  7019 
  7020 * HOL: fewer consts declared as global (e.g. have to refer to
  7021 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  7022 
  7023 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  7024 in case of overlap with user translations (e.g. judgements over
  7025 tuples); (note that the underlying logical represenation is still
  7026 bogus);
  7027 
  7028 
  7029 *** ZF ***
  7030 
  7031 * ZF: simplification automatically cancels common terms in arithmetic
  7032 expressions over nat and int;
  7033 
  7034 * ZF: new treatment of nat to minimize type-checking: all operators
  7035 coerce their operands to a natural number using the function natify,
  7036 making the algebraic laws unconditional;
  7037 
  7038 * ZF: as above, for int: operators coerce their operands to an integer
  7039 using the function intify;
  7040 
  7041 * ZF: the integer library now contains many of the usual laws for the
  7042 orderings, including $<=, and monotonicity laws for $+ and $*;
  7043 
  7044 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  7045 simplification;
  7046 
  7047 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  7048 to the simplifier and classical reasoner simultaneously;
  7049 
  7050 
  7051 *** General ***
  7052 
  7053 * Provers: blast_tac now handles actual object-logic rules as
  7054 assumptions; note that auto_tac uses blast_tac internally as well;
  7055 
  7056 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  7057 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  7058 
  7059 * Provers: delrules now handles destruct rules as well (no longer need
  7060 explicit make_elim);
  7061 
  7062 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  7063   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  7064 use instead the strong form,
  7065   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  7066 in HOL, FOL and ZF the function cla_make_elim will create such rules
  7067 from destruct-rules;
  7068 
  7069 * Provers: Simplifier.easy_setup provides a fast path to basic
  7070 Simplifier setup for new object-logics;
  7071 
  7072 * Pure: AST translation rules no longer require constant head on LHS;
  7073 
  7074 * Pure: improved name spaces: ambiguous output is qualified; support
  7075 for hiding of names;
  7076 
  7077 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  7078 XSYMBOL_HOME; no longer need to do manual configuration in most
  7079 situations;
  7080 
  7081 * system: compression of ML heaps images may now be controlled via -c
  7082 option of isabelle and isatool usedir (currently only observed by
  7083 Poly/ML);
  7084 
  7085 * system: isatool installfonts may handle X-Symbol fonts as well (very
  7086 useful for remote X11);
  7087 
  7088 * system: provide TAGS file for Isabelle sources;
  7089 
  7090 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  7091 order;
  7092 
  7093 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  7094 timing flag supersedes proof_timing and Toplevel.trace;
  7095 
  7096 * ML: new combinators |>> and |>>> for incremental transformations
  7097 with secondary results (e.g. certain theory extensions):
  7098 
  7099 * ML: PureThy.add_defs gets additional argument to indicate potential
  7100 overloading (usually false);
  7101 
  7102 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  7103 results;
  7104 
  7105 
  7106 
  7107 New in Isabelle99 (October 1999)
  7108 --------------------------------
  7109 
  7110 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  7111 
  7112 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  7113 are no longer simplified.  (This allows the simplifier to unfold recursive
  7114 functional programs.)  To restore the old behaviour, declare
  7115 
  7116     Delcongs [if_weak_cong];
  7117 
  7118 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  7119 complement;
  7120 
  7121 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  7122 
  7123 * HOL/datatype: mutual_induct_tac no longer exists --
  7124   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  7125 
  7126 * HOL/typedef: fixed type inference for representing set; type
  7127 arguments now have to occur explicitly on the rhs as type constraints;
  7128 
  7129 * ZF: The con_defs part of an inductive definition may no longer refer
  7130 to constants declared in the same theory;
  7131 
  7132 * HOL, ZF: the function mk_cases, generated by the inductive
  7133 definition package, has lost an argument.  To simplify its result, it
  7134 uses the default simpset instead of a supplied list of theorems.
  7135 
  7136 * HOL/List: the constructors of type list are now Nil and Cons;
  7137 
  7138 * Simplifier: the type of the infix ML functions
  7139         setSSolver addSSolver setSolver addSolver
  7140 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  7141 for packaging solvers. A solver is created via
  7142         mk_solver: string -> (thm list -> int -> tactic) -> solver
  7143 where the string argument is only a comment.
  7144 
  7145 
  7146 *** Proof tools ***
  7147 
  7148 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  7149 decision procedure for linear arithmetic. Currently it is used for
  7150 types `nat', `int', and `real' in HOL (see below); it can, should and
  7151 will be instantiated for other types and logics as well.
  7152 
  7153 * The simplifier now accepts rewrite rules with flexible heads, eg
  7154      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  7155   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  7156   matching.
  7157 
  7158 
  7159 *** General ***
  7160 
  7161 * New Isabelle/Isar subsystem provides an alternative to traditional
  7162 tactical theorem proving; together with the ProofGeneral/isar user
  7163 interface it offers an interactive environment for developing human
  7164 readable proof documents (Isar == Intelligible semi-automated
  7165 reasoning); for further information see isatool doc isar-ref,
  7166 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  7167 
  7168 * improved and simplified presentation of theories: better HTML markup
  7169 (including colors), graph views in several sizes; isatool usedir now
  7170 provides a proper interface for user theories (via -P option); actual
  7171 document preparation based on (PDF)LaTeX is available as well (for
  7172 new-style theories only); see isatool doc system for more information;
  7173 
  7174 * native support for Proof General, both for classic Isabelle and
  7175 Isabelle/Isar;
  7176 
  7177 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  7178 using the graph browser tool;
  7179 
  7180 * Isabelle manuals now also available as PDF;
  7181 
  7182 * theory loader rewritten from scratch (may not be fully
  7183 bug-compatible); old loadpath variable has been replaced by show_path,
  7184 add_path, del_path, reset_path functions; new operations such as
  7185 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  7186 isatool doc ref);
  7187 
  7188 * improved isatool install: option -k creates KDE application icon,
  7189 option -p DIR installs standalone binaries;
  7190 
  7191 * added ML_PLATFORM setting (useful for cross-platform installations);
  7192 more robust handling of platform specific ML images for SML/NJ;
  7193 
  7194 * the settings environment is now statically scoped, i.e. it is never
  7195 created again in sub-processes invoked from isabelle, isatool, or
  7196 Isabelle;
  7197 
  7198 * path element specification '~~' refers to '$ISABELLE_HOME';
  7199 
  7200 * in locales, the "assumes" and "defines" parts may be omitted if
  7201 empty;
  7202 
  7203 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  7204 long arrows);
  7205 
  7206 * new print_mode "HTML";
  7207 
  7208 * new flag show_tags controls display of tags of theorems (which are
  7209 basically just comments that may be attached by some tools);
  7210 
  7211 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  7212 mode and goal output format:
  7213 
  7214 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  7215 244c244
  7216 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  7217 ---
  7218 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  7219 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  7220 181c181
  7221 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  7222 ---
  7223 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  7224 
  7225 * function bind_thms stores lists of theorems (cf. bind_thm);
  7226 
  7227 * new shorthand tactics ftac, eatac, datac, fatac;
  7228 
  7229 * qed (and friends) now accept "" as result name; in that case the
  7230 theorem is not stored, but proper checks and presentation of the
  7231 result still apply;
  7232 
  7233 * theorem database now also indexes constants "Trueprop", "all",
  7234 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  7235 
  7236 
  7237 *** HOL ***
  7238 
  7239 ** HOL arithmetic **
  7240 
  7241 * There are now decision procedures for linear arithmetic over nat and
  7242 int:
  7243 
  7244 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  7245 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  7246 are treated as atomic; subformulae not involving type `nat' or `int'
  7247 are ignored; quantified subformulae are ignored unless they are
  7248 positive universal or negative existential. The tactic has to be
  7249 invoked by hand and can be a little bit slow. In particular, the
  7250 running time is exponential in the number of occurrences of `min' and
  7251 `max', and `-' on `nat'.
  7252 
  7253 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  7254 (negated) (in)equalities among the premises and the conclusion into
  7255 account (i.e. no compound formulae) and does not know about `min' and
  7256 `max', and `-' on `nat'. It is fast and is used automatically by the
  7257 simplifier.
  7258 
  7259 NB: At the moment, these decision procedures do not cope with mixed
  7260 nat/int formulae where the two parts interact, such as `m < n ==>
  7261 int(m) < int(n)'.
  7262 
  7263 * HOL/Numeral provides a generic theory of numerals (encoded
  7264 efficiently as bit strings); setup for types nat/int/real is in place;
  7265 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  7266 int, existing theories and proof scripts may require a few additional
  7267 type constraints;
  7268 
  7269 * integer division and remainder can now be performed on constant
  7270 arguments;
  7271 
  7272 * many properties of integer multiplication, division and remainder
  7273 are now available;
  7274 
  7275 * An interface to the Stanford Validity Checker (SVC) is available through the
  7276 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  7277 are proved automatically.  SVC must be installed separately, and its results
  7278 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  7279 invocation of the underlying oracle).  For SVC see
  7280   http://verify.stanford.edu/SVC
  7281 
  7282 * IsaMakefile: the HOL-Real target now builds an actual image;
  7283 
  7284 
  7285 ** HOL misc **
  7286 
  7287 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  7288 (in Isabelle/Isar) -- by Gertrud Bauer;
  7289 
  7290 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  7291 analysis for assembly languages with subtypes;
  7292 
  7293 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  7294 -- avoids syntactic ambiguities and treats state, transition, and
  7295 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  7296 changed syntax and (many) tactics;
  7297 
  7298 * HOL/inductive: Now also handles more general introduction rules such
  7299   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  7300   theorems are now maintained within the theory (maintained via the
  7301   "mono" attribute);
  7302 
  7303 * HOL/datatype: Now also handles arbitrarily branching datatypes
  7304   (using function types) such as
  7305 
  7306   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  7307 
  7308 * HOL/record: record_simproc (part of the default simpset) takes care
  7309 of selectors applied to updated records; record_split_tac is no longer
  7310 part of the default claset; update_defs may now be removed from the
  7311 simpset in many cases; COMPATIBILITY: old behavior achieved by
  7312 
  7313   claset_ref () := claset() addSWrapper record_split_wrapper;
  7314   Delsimprocs [record_simproc]
  7315 
  7316 * HOL/typedef: fixed type inference for representing set; type
  7317 arguments now have to occur explicitly on the rhs as type constraints;
  7318 
  7319 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  7320 names rather than an ML expression;
  7321 
  7322 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  7323 supplied later.  Program schemes can be defined, such as
  7324     "While B C s = (if B s then While B C (C s) else s)"
  7325 where the well-founded relation can be chosen after B and C have been given.
  7326 
  7327 * HOL/List: the constructors of type list are now Nil and Cons;
  7328 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  7329 course, ML tools referring to List.list.op # etc. have to be adapted;
  7330 
  7331 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  7332 disabled by default; run isabelle with option -m HOL to get back to
  7333 the original Gordon/HOL-style output;
  7334 
  7335 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  7336 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  7337 
  7338 * HOL basic syntax simplified (more orthogonal): all variants of
  7339 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  7340 Eps operator is provided as well: "SOME x. P[x]";
  7341 
  7342 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  7343 
  7344 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  7345 thus available for user theories;
  7346 
  7347 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  7348 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  7349 time;
  7350 
  7351 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  7352 several times and then mp;
  7353 
  7354 
  7355 *** LK ***
  7356 
  7357 * the notation <<...>> is now available as a notation for sequences of
  7358 formulas;
  7359 
  7360 * the simplifier is now installed
  7361 
  7362 * the axiom system has been generalized (thanks to Soren Heilmann)
  7363 
  7364 * the classical reasoner now has a default rule database
  7365 
  7366 
  7367 *** ZF ***
  7368 
  7369 * new primrec section allows primitive recursive functions to be given
  7370 directly (as in HOL) over datatypes and the natural numbers;
  7371 
  7372 * new tactics induct_tac and exhaust_tac for induction (or case
  7373 analysis) over datatypes and the natural numbers;
  7374 
  7375 * the datatype declaration of type T now defines the recursor T_rec;
  7376 
  7377 * simplification automatically does freeness reasoning for datatype
  7378 constructors;
  7379 
  7380 * automatic type-inference, with AddTCs command to insert new
  7381 type-checking rules;
  7382 
  7383 * datatype introduction rules are now added as Safe Introduction rules
  7384 to the claset;
  7385 
  7386 * the syntax "if P then x else y" is now available in addition to
  7387 if(P,x,y);
  7388 
  7389 
  7390 *** Internal programming interfaces ***
  7391 
  7392 * tuned simplifier trace output; new flag debug_simp;
  7393 
  7394 * structures Vartab / Termtab (instances of TableFun) offer efficient
  7395 tables indexed by indexname_ord / term_ord (compatible with aconv);
  7396 
  7397 * AxClass.axclass_tac lost the theory argument;
  7398 
  7399 * tuned current_goals_markers semantics: begin / end goal avoids
  7400 printing empty lines;
  7401 
  7402 * removed prs and prs_fn hook, which was broken because it did not
  7403 include \n in its semantics, forcing writeln to add one
  7404 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  7405 string -> unit if you really want to output text without newline;
  7406 
  7407 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  7408 plain output, interface builders may have to enable 'isabelle_font'
  7409 mode to get Isabelle font glyphs as before;
  7410 
  7411 * refined token_translation interface; INCOMPATIBILITY: output length
  7412 now of type real instead of int;
  7413 
  7414 * theory loader actions may be traced via new ThyInfo.add_hook
  7415 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  7416 your own database of information attached to *whole* theories -- as
  7417 opposed to intra-theory data slots offered via TheoryDataFun;
  7418 
  7419 * proper handling of dangling sort hypotheses (at last!);
  7420 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  7421 extra sort hypotheses that can be witnessed from the type signature;
  7422 the force_strip_shyps flag is gone, any remaining shyps are simply
  7423 left in the theorem (with a warning issued by strip_shyps_warning);
  7424 
  7425 
  7426 
  7427 New in Isabelle98-1 (October 1998)
  7428 ----------------------------------
  7429 
  7430 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  7431 
  7432 * several changes of automated proof tools;
  7433 
  7434 * HOL: major changes to the inductive and datatype packages, including
  7435 some minor incompatibilities of theory syntax;
  7436 
  7437 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  7438 called `inj_on';
  7439 
  7440 * HOL: removed duplicate thms in Arith:
  7441   less_imp_add_less  should be replaced by  trans_less_add1
  7442   le_imp_add_le      should be replaced by  trans_le_add1
  7443 
  7444 * HOL: unary minus is now overloaded (new type constraints may be
  7445 required);
  7446 
  7447 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  7448 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  7449 now taken as an integer constant.
  7450 
  7451 * Pure: ML function 'theory_of' renamed to 'theory';
  7452 
  7453 
  7454 *** Proof tools ***
  7455 
  7456 * Simplifier:
  7457   1. Asm_full_simp_tac is now more aggressive.
  7458      1. It will sometimes reorient premises if that increases their power to
  7459         simplify.
  7460      2. It does no longer proceed strictly from left to right but may also
  7461         rotate premises to achieve further simplification.
  7462      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  7463      old Asm_full_simp_tac in that it does not rotate premises.
  7464   2. The simplifier now knows a little bit about nat-arithmetic.
  7465 
  7466 * Classical reasoner: wrapper mechanism for the classical reasoner now
  7467 allows for selected deletion of wrappers, by introduction of names for
  7468 wrapper functionals.  This implies that addbefore, addSbefore,
  7469 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  7470 and that adding two tactics with the same name overwrites the first
  7471 one (emitting a warning).
  7472   type wrapper = (int -> tactic) -> (int -> tactic)
  7473   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  7474   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  7475   delWrapper, delSWrapper: claset *  string            -> claset
  7476   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  7477 
  7478 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  7479 semantics; addbefore now affects only the unsafe part of step_tac
  7480 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  7481 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  7482 by Force_tac;
  7483 
  7484 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  7485 compWrapper; added safe wrapper (and access functions for it);
  7486 
  7487 * HOL/split_all_tac is now much faster and fails if there is nothing
  7488 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  7489 and the names of the automatically generated variables have changed.
  7490 split_all_tac has moved within claset() from unsafe wrappers to safe
  7491 wrappers, which means that !!-bound variables are split much more
  7492 aggressively, and safe_tac and clarify_tac now split such variables.
  7493 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  7494 Note: the same holds for record_split_tac, which does the job of
  7495 split_all_tac for record fields.
  7496 
  7497 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  7498 permanently to the default simpset using Addsplits just like
  7499 Addsimps. They can be removed via Delsplits just like
  7500 Delsimps. Lower-case versions are also available.
  7501 
  7502 * HOL/Simplifier: The rule split_if is now part of the default
  7503 simpset. This means that the simplifier will eliminate all occurrences
  7504 of if-then-else in the conclusion of a goal. To prevent this, you can
  7505 either remove split_if completely from the default simpset by
  7506 `Delsplits [split_if]' or remove it in a specific call of the
  7507 simplifier using `... delsplits [split_if]'.  You can also add/delete
  7508 other case splitting rules to/from the default simpset: every datatype
  7509 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  7510 t is the name of the datatype).
  7511 
  7512 * Classical reasoner / Simplifier combination: new force_tac (and
  7513 derivatives Force_tac, force) combines rewriting and classical
  7514 reasoning (and whatever other tools) similarly to auto_tac, but is
  7515 aimed to solve the given subgoal completely.
  7516 
  7517 
  7518 *** General ***
  7519 
  7520 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  7521 and `goalw': the theory is no longer needed as an explicit argument -
  7522 the current theory context is used; assumptions are no longer returned
  7523 at the ML-level unless one of them starts with ==> or !!; it is
  7524 recommended to convert to these new commands using isatool fixgoal
  7525 (backup your sources first!);
  7526 
  7527 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  7528 the current theory context, and 'theory' to lookup stored theories;
  7529 
  7530 * new theory section 'locale' for declaring constants, assumptions and
  7531 definitions that have local scope;
  7532 
  7533 * new theory section 'nonterminals' for purely syntactic types;
  7534 
  7535 * new theory section 'setup' for generic ML setup functions
  7536 (e.g. package initialization);
  7537 
  7538 * the distribution now includes Isabelle icons: see
  7539 lib/logo/isabelle-{small,tiny}.xpm;
  7540 
  7541 * isatool install - install binaries with absolute references to
  7542 ISABELLE_HOME/bin;
  7543 
  7544 * isatool logo -- create instances of the Isabelle logo (as EPS);
  7545 
  7546 * print mode 'emacs' reserved for Isamode;
  7547 
  7548 * support multiple print (ast) translations per constant name;
  7549 
  7550 * theorems involving oracles are now printed with a suffixed [!];
  7551 
  7552 
  7553 *** HOL ***
  7554 
  7555 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  7556 
  7557 * HOL/inductive package reorganized and improved: now supports mutual
  7558 definitions such as
  7559 
  7560   inductive EVEN ODD
  7561     intrs
  7562       null "0 : EVEN"
  7563       oddI "n : EVEN ==> Suc n : ODD"
  7564       evenI "n : ODD ==> Suc n : EVEN"
  7565 
  7566 new theorem list "elims" contains an elimination rule for each of the
  7567 recursive sets; inductive definitions now handle disjunctive premises
  7568 correctly (also ZF);
  7569 
  7570 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  7571 "mutual_induct" no longer exists - the induction rule is always
  7572 contained in "induct";
  7573 
  7574 
  7575 * HOL/datatype package re-implemented and greatly improved: now
  7576 supports mutually recursive datatypes such as
  7577 
  7578   datatype
  7579     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  7580             | SUM ('a aexp) ('a aexp)
  7581             | DIFF ('a aexp) ('a aexp)
  7582             | NUM 'a
  7583   and
  7584     'a bexp = LESS ('a aexp) ('a aexp)
  7585             | AND ('a bexp) ('a bexp)
  7586             | OR ('a bexp) ('a bexp)
  7587 
  7588 as well as indirectly recursive datatypes such as
  7589 
  7590   datatype
  7591     ('a, 'b) term = Var 'a
  7592                   | App 'b ((('a, 'b) term) list)
  7593 
  7594 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  7595 induction on mutually / indirectly recursive datatypes.
  7596 
  7597 Primrec equations are now stored in theory and can be accessed via
  7598 <function_name>.simps.
  7599 
  7600 INCOMPATIBILITIES:
  7601 
  7602   - Theories using datatypes must now have theory Datatype as an
  7603     ancestor.
  7604   - The specific <typename>.induct_tac no longer exists - use the
  7605     generic induct_tac instead.
  7606   - natE has been renamed to nat.exhaust - use exhaust_tac
  7607     instead of res_inst_tac ... natE. Note that the variable
  7608     names in nat.exhaust differ from the names in natE, this
  7609     may cause some "fragile" proofs to fail.
  7610   - The theorems split_<typename>_case and split_<typename>_case_asm
  7611     have been renamed to <typename>.split and <typename>.split_asm.
  7612   - Since default sorts of type variables are now handled correctly,
  7613     some datatype definitions may have to be annotated with explicit
  7614     sort constraints.
  7615   - Primrec definitions no longer require function name and type
  7616     of recursive argument.
  7617 
  7618 Consider using isatool fixdatatype to adapt your theories and proof
  7619 scripts to the new package (backup your sources first!).
  7620 
  7621 
  7622 * HOL/record package: considerably improved implementation; now
  7623 includes concrete syntax for record types, terms, updates; theorems
  7624 for surjective pairing and splitting !!-bound record variables; proof
  7625 support is as follows:
  7626 
  7627   1) standard conversions (selectors or updates applied to record
  7628 constructor terms) are part of the standard simpset;
  7629 
  7630   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  7631 made part of standard simpset and claset via addIffs;
  7632 
  7633   3) a tactic for record field splitting (record_split_tac) is part of
  7634 the standard claset (addSWrapper);
  7635 
  7636 To get a better idea about these rules you may retrieve them via
  7637 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  7638 the name of your record type.
  7639 
  7640 The split tactic 3) conceptually simplifies by the following rule:
  7641 
  7642   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  7643 
  7644 Thus any record variable that is bound by meta-all will automatically
  7645 blow up into some record constructor term, consequently the
  7646 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  7647 solve record problems automatically.
  7648 
  7649 
  7650 * reorganized the main HOL image: HOL/Integ and String loaded by
  7651 default; theory Main includes everything;
  7652 
  7653 * automatic simplification of integer sums and comparisons, using cancellation;
  7654 
  7655 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  7656 
  7657 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  7658 
  7659 * many new identities for unions, intersections, set difference, etc.;
  7660 
  7661 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  7662 called split_if, split_split, split_sum_case and split_nat_case (to go
  7663 with add/delsplits);
  7664 
  7665 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  7666 (?x::unit) = (); this is made part of the default simpset, which COULD
  7667 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  7668 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  7669 unit_abs_eta_conv is added in order to counter the effect of
  7670 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  7671 %u.f();
  7672 
  7673 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  7674 makes more sense);
  7675 
  7676 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  7677   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  7678   disjointness reasoning but breaking a few old proofs.
  7679 
  7680 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  7681 to 'converse' from 'inverse' (for compatibility with ZF and some
  7682 literature);
  7683 
  7684 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  7685 the well-founded relation;
  7686 
  7687 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  7688     Compl A.  The "Compl" syntax remains available as input syntax for this
  7689     release ONLY.
  7690 
  7691 * HOL/Update: new theory of function updates:
  7692     f(a:=b) == %x. if x=a then b else f x
  7693 may also be iterated as in f(a:=b,c:=d,...);
  7694 
  7695 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  7696 
  7697 * HOL/List:
  7698   - new function list_update written xs[i:=v] that updates the i-th
  7699     list position. May also be iterated as in xs[i:=a,j:=b,...].
  7700   - new function `upt' written [i..j(] which generates the list
  7701     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  7702     bound write [i..j], which is a shorthand for [i..j+1(].
  7703   - new lexicographic orderings and corresponding wellfoundedness theorems.
  7704 
  7705 * HOL/Arith:
  7706   - removed 'pred' (predecessor) function;
  7707   - generalized some theorems about n-1;
  7708   - many new laws about "div" and "mod";
  7709   - new laws about greatest common divisors (see theory ex/Primes);
  7710 
  7711 * HOL/Relation: renamed the relational operator r^-1 "converse"
  7712 instead of "inverse";
  7713 
  7714 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  7715   of the multiset ordering;
  7716 
  7717 * directory HOL/Real: a construction of the reals using Dedekind cuts
  7718   (not included by default);
  7719 
  7720 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  7721 
  7722 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  7723   programs, i.e. different program variables may have different types.
  7724 
  7725 * calling (stac rew i) now fails if "rew" has no effect on the goal
  7726   [previously, this check worked only if the rewrite rule was unconditional]
  7727   Now rew can involve either definitions or equalities (either == or =).
  7728 
  7729 
  7730 *** ZF ***
  7731 
  7732 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  7733   only the theorems proved on ZF.ML;
  7734 
  7735 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  7736   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  7737   disjointness reasoning but breaking a few old proofs.
  7738 
  7739 * ZF/Update: new theory of function updates
  7740     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  7741   may also be iterated as in f(a:=b,c:=d,...);
  7742 
  7743 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  7744 
  7745 * calling (stac rew i) now fails if "rew" has no effect on the goal
  7746   [previously, this check worked only if the rewrite rule was unconditional]
  7747   Now rew can involve either definitions or equalities (either == or =).
  7748 
  7749 * case_tac provided for compatibility with HOL
  7750     (like the old excluded_middle_tac, but with subgoals swapped)
  7751 
  7752 
  7753 *** Internal programming interfaces ***
  7754 
  7755 * Pure: several new basic modules made available for general use, see
  7756 also src/Pure/README;
  7757 
  7758 * improved the theory data mechanism to support encapsulation (data
  7759 kind name replaced by private Object.kind, acting as authorization
  7760 key); new type-safe user interface via functor TheoryDataFun; generic
  7761 print_data function becomes basically useless;
  7762 
  7763 * removed global_names compatibility flag -- all theory declarations
  7764 are qualified by default;
  7765 
  7766 * module Pure/Syntax now offers quote / antiquote translation
  7767 functions (useful for Hoare logic etc. with implicit dependencies);
  7768 see HOL/ex/Antiquote for an example use;
  7769 
  7770 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  7771 cterm -> thm;
  7772 
  7773 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  7774 subgoal;
  7775 
  7776 * Display.print_goals function moved to Locale.print_goals;
  7777 
  7778 * standard print function for goals supports current_goals_markers
  7779 variable for marking begin of proof, end of proof, start of goal; the
  7780 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  7781 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  7782 for example;
  7783 
  7784 
  7785 
  7786 New in Isabelle98 (January 1998)
  7787 --------------------------------
  7788 
  7789 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  7790 
  7791 * changed lexical syntax of terms / types: dots made part of long
  7792 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  7793 
  7794 * simpset (and claset) reference variable replaced by functions
  7795 simpset / simpset_ref;
  7796 
  7797 * no longer supports theory aliases (via merge) and non-trivial
  7798 implicit merge of thms' signatures;
  7799 
  7800 * most internal names of constants changed due to qualified names;
  7801 
  7802 * changed Pure/Sequence interface (see Pure/seq.ML);
  7803 
  7804 
  7805 *** General Changes ***
  7806 
  7807 * hierachically structured name spaces (for consts, types, axms, thms
  7808 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  7809 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  7810 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  7811 long_names for fully qualified output names; NOTE: ML programs
  7812 (special tactics, packages etc.) referring to internal names may have
  7813 to be adapted to cope with fully qualified names; in case of severe
  7814 backward campatibility problems try setting 'global_names' at compile
  7815 time to have enrything declared within a flat name space; one may also
  7816 fine tune name declarations in theories via the 'global' and 'local'
  7817 section;
  7818 
  7819 * reimplemented the implicit simpset and claset using the new anytype
  7820 data filed in signatures; references simpset:simpset ref etc. are
  7821 replaced by functions simpset:unit->simpset and
  7822 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  7823 to patch your ML files accordingly;
  7824 
  7825 * HTML output now includes theory graph data for display with Java
  7826 applet or isatool browser; data generated automatically via isatool
  7827 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  7828 
  7829 * defs may now be conditional; improved rewrite_goals_tac to handle
  7830 conditional equations;
  7831 
  7832 * defs now admits additional type arguments, using TYPE('a) syntax;
  7833 
  7834 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  7835 creates a new theory node; implicit merge of thms' signatures is
  7836 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  7837 transfer:theory->thm->thm in (rare) cases;
  7838 
  7839 * improved handling of draft signatures / theories; draft thms (and
  7840 ctyps, cterms) are automatically promoted to real ones;
  7841 
  7842 * slightly changed interfaces for oracles: admit many per theory, named
  7843 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  7844 
  7845 * print_goals: optional output of const types (set show_consts and
  7846 show_types);
  7847 
  7848 * improved output of warnings (###) and errors (***);
  7849 
  7850 * subgoal_tac displays a warning if the new subgoal has type variables;
  7851 
  7852 * removed old README and Makefiles;
  7853 
  7854 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  7855 
  7856 * removed obsolete init_pps and init_database;
  7857 
  7858 * deleted the obsolete tactical STATE, which was declared by
  7859     fun STATE tacfun st = tacfun st st;
  7860 
  7861 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  7862 (which abbreviates $HOME);
  7863 
  7864 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  7865 use isatool fixseq to adapt your ML programs (this works for fully
  7866 qualified references to the Sequence structure only!);
  7867 
  7868 * use_thy no longer requires writable current directory; it always
  7869 reloads .ML *and* .thy file, if either one is out of date;
  7870 
  7871 
  7872 *** Classical Reasoner ***
  7873 
  7874 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  7875 tactics that use classical reasoning to simplify a subgoal without
  7876 splitting it into several subgoals;
  7877 
  7878 * Safe_tac: like safe_tac but uses the default claset;
  7879 
  7880 
  7881 *** Simplifier ***
  7882 
  7883 * added simplification meta rules:
  7884     (asm_)(full_)simplify: simpset -> thm -> thm;
  7885 
  7886 * simplifier.ML no longer part of Pure -- has to be loaded by object
  7887 logics (again);
  7888 
  7889 * added prems argument to simplification procedures;
  7890 
  7891 * HOL, FOL, ZF: added infix function `addsplits':
  7892   instead of `<simpset> setloop (split_tac <thms>)'
  7893   you can simply write `<simpset> addsplits <thms>'
  7894 
  7895 
  7896 *** Syntax ***
  7897 
  7898 * TYPE('a) syntax for type reflection terms;
  7899 
  7900 * no longer handles consts with name "" -- declare as 'syntax' instead;
  7901 
  7902 * pretty printer: changed order of mixfix annotation preference (again!);
  7903 
  7904 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  7905 
  7906 
  7907 *** HOL ***
  7908 
  7909 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  7910   with `addloop' of the simplifier to faciliate case splitting in premises.
  7911 
  7912 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  7913 
  7914 * HOL/Auth: new protocol proofs including some for the Internet
  7915   protocol TLS;
  7916 
  7917 * HOL/Map: new theory of `maps' a la VDM;
  7918 
  7919 * HOL/simplifier: simplification procedures nat_cancel_sums for
  7920 cancelling out common nat summands from =, <, <= (in)equalities, or
  7921 differences; simplification procedures nat_cancel_factor for
  7922 cancelling common factor from =, <, <= (in)equalities over natural
  7923 sums; nat_cancel contains both kinds of procedures, it is installed by
  7924 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  7925 
  7926 * HOL/simplifier: terms of the form
  7927   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  7928   are rewritten to
  7929   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  7930   and those of the form
  7931   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  7932   are rewritten to
  7933   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  7934 
  7935 * HOL/datatype
  7936   Each datatype `t' now comes with a theorem `split_t_case' of the form
  7937 
  7938   P(t_case f1 ... fn x) =
  7939      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  7940         ...
  7941        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  7942      )
  7943 
  7944   and a theorem `split_t_case_asm' of the form
  7945 
  7946   P(t_case f1 ... fn x) =
  7947     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  7948         ...
  7949        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  7950      )
  7951   which can be added to a simpset via `addsplits'. The existing theorems
  7952   expand_list_case and expand_option_case have been renamed to
  7953   split_list_case and split_option_case.
  7954 
  7955 * HOL/Arithmetic:
  7956   - `pred n' is automatically converted to `n-1'.
  7957     Users are strongly encouraged not to use `pred' any longer,
  7958     because it will disappear altogether at some point.
  7959   - Users are strongly encouraged to write "0 < n" rather than
  7960     "n ~= 0". Theorems and proof tools have been modified towards this
  7961     `standard'.
  7962 
  7963 * HOL/Lists:
  7964   the function "set_of_list" has been renamed "set" (and its theorems too);
  7965   the function "nth" now takes its arguments in the reverse order and
  7966   has acquired the infix notation "!" as in "xs!n".
  7967 
  7968 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  7969 
  7970 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  7971   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  7972 
  7973 * HOL/record: extensible records with schematic structural subtyping
  7974 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  7975 still lacks various theorems and concrete record syntax;
  7976 
  7977 
  7978 *** HOLCF ***
  7979 
  7980 * removed "axioms" and "generated by" sections;
  7981 
  7982 * replaced "ops" section by extended "consts" section, which is capable of
  7983   handling the continuous function space "->" directly;
  7984 
  7985 * domain package:
  7986   . proves theorems immediately and stores them in the theory,
  7987   . creates hierachical name space,
  7988   . now uses normal mixfix annotations (instead of cinfix...),
  7989   . minor changes to some names and values (for consistency),
  7990   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  7991   . separator between mutual domain defs: changed "," to "and",
  7992   . improved handling of sort constraints;  now they have to
  7993     appear on the left-hand side of the equations only;
  7994 
  7995 * fixed LAM <x,y,zs>.b syntax;
  7996 
  7997 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  7998 adm (%x. P (t x)), where P is chainfinite and t continuous;
  7999 
  8000 
  8001 *** FOL and ZF ***
  8002 
  8003 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  8004   with `addloop' of the simplifier to faciliate case splitting in premises.
  8005 
  8006 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  8007 in HOL, they strip ALL and --> from proved theorems;
  8008 
  8009 
  8010 
  8011 New in Isabelle94-8 (May 1997)
  8012 ------------------------------
  8013 
  8014 *** General Changes ***
  8015 
  8016 * new utilities to build / run / maintain Isabelle etc. (in parts
  8017 still somewhat experimental); old Makefiles etc. still functional;
  8018 
  8019 * new 'Isabelle System Manual';
  8020 
  8021 * INSTALL text, together with ./configure and ./build scripts;
  8022 
  8023 * reimplemented type inference for greater efficiency, better error
  8024 messages and clean internal interface;
  8025 
  8026 * prlim command for dealing with lots of subgoals (an easier way of
  8027 setting goals_limit);
  8028 
  8029 
  8030 *** Syntax ***
  8031 
  8032 * supports alternative (named) syntax tables (parser and pretty
  8033 printer); internal interface is provided by add_modesyntax(_i);
  8034 
  8035 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  8036 be used in conjunction with the Isabelle symbol font; uses the
  8037 "symbols" syntax table;
  8038 
  8039 * added token_translation interface (may translate name tokens in
  8040 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  8041 the current print_mode); IMPORTANT: user print translation functions
  8042 are responsible for marking newly introduced bounds
  8043 (Syntax.mark_boundT);
  8044 
  8045 * token translations for modes "xterm" and "xterm_color" that display
  8046 names in bold, underline etc. or colors (which requires a color
  8047 version of xterm);
  8048 
  8049 * infixes may now be declared with names independent of their syntax;
  8050 
  8051 * added typed_print_translation (like print_translation, but may
  8052 access type of constant);
  8053 
  8054 
  8055 *** Classical Reasoner ***
  8056 
  8057 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  8058 some limitations.  Blast_tac...
  8059   + ignores addss, addbefore, addafter; this restriction is intrinsic
  8060   + ignores elimination rules that don't have the correct format
  8061         (the conclusion MUST be a formula variable)
  8062   + ignores types, which can make HOL proofs fail
  8063   + rules must not require higher-order unification, e.g. apply_type in ZF
  8064     [message "Function Var's argument not a bound variable" relates to this]
  8065   + its proof strategy is more general but can actually be slower
  8066 
  8067 * substitution with equality assumptions no longer permutes other
  8068 assumptions;
  8069 
  8070 * minor changes in semantics of addafter (now called addaltern); renamed
  8071 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  8072 (and access functions for it);
  8073 
  8074 * improved combination of classical reasoner and simplifier:
  8075   + functions for handling clasimpsets
  8076   + improvement of addss: now the simplifier is called _after_ the
  8077     safe steps.
  8078   + safe variant of addss called addSss: uses safe simplifications
  8079     _during_ the safe steps. It is more complete as it allows multiple
  8080     instantiations of unknowns (e.g. with slow_tac).
  8081 
  8082 *** Simplifier ***
  8083 
  8084 * added interface for simplification procedures (functions that
  8085 produce *proven* rewrite rules on the fly, depending on current
  8086 redex);
  8087 
  8088 * ordering on terms as parameter (used for ordered rewriting);
  8089 
  8090 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  8091 
  8092 * the solver is now split into a safe and an unsafe part.
  8093 This should be invisible for the normal user, except that the
  8094 functions setsolver and addsolver have been renamed to setSolver and
  8095 addSolver; added safe_asm_full_simp_tac;
  8096 
  8097 
  8098 *** HOL ***
  8099 
  8100 * a generic induction tactic `induct_tac' which works for all datatypes and
  8101 also for type `nat';
  8102 
  8103 * a generic case distinction tactic `exhaust_tac' which works for all
  8104 datatypes and also for type `nat';
  8105 
  8106 * each datatype comes with a function `size';
  8107 
  8108 * patterns in case expressions allow tuple patterns as arguments to
  8109 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  8110 
  8111 * primrec now also works with type nat;
  8112 
  8113 * recdef: a new declaration form, allows general recursive functions to be
  8114 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  8115 
  8116 * the constant for negation has been renamed from "not" to "Not" to
  8117 harmonize with FOL, ZF, LK, etc.;
  8118 
  8119 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  8120 infinite lists;
  8121 
  8122 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  8123 
  8124 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  8125 problems in commutative rings, using axiomatic type classes for + and *;
  8126 
  8127 * more examples in HOL/MiniML and HOL/Auth;
  8128 
  8129 * more default rewrite rules for quantifiers, union/intersection;
  8130 
  8131 * a new constant `arbitrary == @x.False';
  8132 
  8133 * HOLCF/IOA replaces old HOL/IOA;
  8134 
  8135 * HOLCF changes: derived all rules and arities
  8136   + axiomatic type classes instead of classes
  8137   + typedef instead of faking type definitions
  8138   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  8139   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  8140   + eliminated the types void, one, tr
  8141   + use unit lift and bool lift (with translations) instead of one and tr
  8142   + eliminated blift from Lift3.thy (use Def instead of blift)
  8143   all eliminated rules are derived as theorems --> no visible changes ;
  8144 
  8145 
  8146 *** ZF ***
  8147 
  8148 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  8149 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  8150 as ZF_cs addSIs [equalityI];
  8151 
  8152 
  8153 
  8154 New in Isabelle94-7 (November 96)
  8155 ---------------------------------
  8156 
  8157 * allowing negative levels (as offsets) in prlev and choplev;
  8158 
  8159 * super-linear speedup for large simplifications;
  8160 
  8161 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  8162 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  8163 FAIL); can suppress it using the command Delsimps (ex_simps @
  8164 all_simps); De Morgan laws are also now included, by default;
  8165 
  8166 * improved printing of ==>  :  ~:
  8167 
  8168 * new object-logic "Sequents" adds linear logic, while replacing LK
  8169 and Modal (thanks to Sara Kalvala);
  8170 
  8171 * HOL/Auth: correctness proofs for authentication protocols;
  8172 
  8173 * HOL: new auto_tac combines rewriting and classical reasoning (many
  8174 examples on HOL/Auth);
  8175 
  8176 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  8177 the rewriter and classical reasoner simultaneously;
  8178 
  8179 * function uresult no longer returns theorems in "standard" format;
  8180 regain previous version by: val uresult = standard o uresult;
  8181 
  8182 
  8183 
  8184 New in Isabelle94-6
  8185 -------------------
  8186 
  8187 * oracles -- these establish an interface between Isabelle and trusted
  8188 external reasoners, which may deliver results as theorems;
  8189 
  8190 * proof objects (in particular record all uses of oracles);
  8191 
  8192 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  8193 
  8194 * "constdefs" section in theory files;
  8195 
  8196 * "primrec" section (HOL) no longer requires names;
  8197 
  8198 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  8199 
  8200 
  8201 
  8202 New in Isabelle94-5
  8203 -------------------
  8204 
  8205 * reduced space requirements;
  8206 
  8207 * automatic HTML generation from theories;
  8208 
  8209 * theory files no longer require "..." (quotes) around most types;
  8210 
  8211 * new examples, including two proofs of the Church-Rosser theorem;
  8212 
  8213 * non-curried (1994) version of HOL is no longer distributed;
  8214 
  8215 
  8216 
  8217 New in Isabelle94-4
  8218 -------------------
  8219 
  8220 * greatly reduced space requirements;
  8221 
  8222 * theory files (.thy) no longer require \...\ escapes at line breaks;
  8223 
  8224 * searchable theorem database (see the section "Retrieving theorems" on
  8225 page 8 of the Reference Manual);
  8226 
  8227 * new examples, including Grabczewski's monumental case study of the
  8228 Axiom of Choice;
  8229 
  8230 * The previous version of HOL renamed to Old_HOL;
  8231 
  8232 * The new version of HOL (previously called CHOL) uses a curried syntax
  8233 for functions.  Application looks like f a b instead of f(a,b);
  8234 
  8235 * Mutually recursive inductive definitions finally work in HOL;
  8236 
  8237 * In ZF, pattern-matching on tuples is now available in all abstractions and
  8238 translates to the operator "split";
  8239 
  8240 
  8241 
  8242 New in Isabelle94-3
  8243 -------------------
  8244 
  8245 * new infix operator, addss, allowing the classical reasoner to
  8246 perform simplification at each step of its search.  Example:
  8247         fast_tac (cs addss ss)
  8248 
  8249 * a new logic, CHOL, the same as HOL, but with a curried syntax
  8250 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  8251 look like (a,b) instead of <a,b>;
  8252 
  8253 * PLEASE NOTE: CHOL will eventually replace HOL!
  8254 
  8255 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  8256 It translates to the operator "split".  A new theory of integers is available;
  8257 
  8258 * In ZF, integer numerals now denote two's-complement binary integers.
  8259 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  8260 
  8261 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  8262 of the Axiom of Choice;
  8263 
  8264 
  8265 
  8266 New in Isabelle94-2
  8267 -------------------
  8268 
  8269 * Significantly faster resolution;
  8270 
  8271 * the different sections in a .thy file can now be mixed and repeated
  8272 freely;
  8273 
  8274 * Database of theorems for FOL, HOL and ZF.  New
  8275 commands including qed, qed_goal and bind_thm store theorems in the database.
  8276 
  8277 * Simple database queries: return a named theorem (get_thm) or all theorems of
  8278 a given theory (thms_of), or find out what theory a theorem was proved in
  8279 (theory_of_thm);
  8280 
  8281 * Bugs fixed in the inductive definition and datatype packages;
  8282 
  8283 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  8284 and HOL_dup_cs obsolete;
  8285 
  8286 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  8287 have been removed;
  8288 
  8289 * Simpler definition of function space in ZF;
  8290 
  8291 * new results about cardinal and ordinal arithmetic in ZF;
  8292 
  8293 * 'subtype' facility in HOL for introducing new types as subsets of existing
  8294 types;
  8295 
  8296 :mode=text:wrap=hard:maxLineLen=72: