NEWS
author bulwahn
Mon, 25 Jul 2011 11:21:44 +0200
changeset 44830 285ffb18da30
parent 44828 64f88ef1835e
child 44841 3d204d261903
permissions -rw-r--r--
fixed typo
     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 * Archimedian_Field.thy:
    83     floor now is defined as parameter of a separate type class floor_ceiling.
    84  
    85 * Finite_Set.thy: more coherent development of fold_set locales:
    86 
    87     locale fun_left_comm ~> locale comp_fun_commute
    88     locale fun_left_comm_idem ~> locale comp_fun_idem
    89     
    90 Both use point-free characterisation; interpretation proofs may need adjustment.
    91 INCOMPATIBILITY.
    92 
    93 * Code generation:
    94   - theory Library/Code_Char_ord provides native ordering of characters
    95     in the target language.
    96   - commands code_module and code_library are legacy, use export_code instead. 
    97   - evaluator "SML" and method evaluation are legacy, use evaluator "code"
    98     and method eval instead.
    99   
   100 * Declare ext [intro] by default.  Rare INCOMPATIBILITY.
   101 
   102 * Nitpick:
   103   - Added "need" and "total_consts" options.
   104   - Reintroduced "show_skolems" option by popular demand.
   105   - Renamed attribute: nitpick_def ~> nitpick_unfold.
   106     INCOMPATIBILITY.
   107 
   108 * Sledgehammer:
   109   - sledgehammer available_provers ~> sledgehammer supported_provers.
   110     INCOMPATIBILITY.
   111   - Added support for SNARK and ToFoF-E on SystemOnTPTP and for simply typed
   112     TPTP problems (TFF).
   113   - Added "preplay_timeout", "slicing", "type_enc", "sound", "max_mono_iters",
   114     and "max_new_mono_instances" options.
   115   - Removed "explicit_apply" and "full_types" options as well as "Full Types"
   116     Proof General menu item. INCOMPATIBILITY.
   117 
   118 * Metis:
   119   - Removed "metisF" -- use "metis" instead. INCOMPATIBILITY.
   120   - Obsoleted "metisFT" -- use "metis (full_types)" instead. INCOMPATIBILITY.
   121 
   122 * "try":
   123   - Renamed "try_methods" and added "simp:", "intro:", "dest:", and "elim:"
   124     options. INCOMPATIBILITY.
   125   - Introduced "try" that not only runs "try_methods" but also "solve_direct",
   126     "sledgehammer", "quickcheck", and "nitpick".
   127 
   128 * Quickcheck:
   129   - Added "eval" option to evaluate terms for the found counterexample
   130     (currently only supported by the default (exhaustive) tester)
   131   - Added post-processing of terms to obtain readable counterexamples
   132     (currently only supported by the default (exhaustive) tester)
   133   - New counterexample generator quickcheck[narrowing] enables
   134     narrowing-based testing.
   135     It requires that the Glasgow Haskell compiler is installed and
   136     its location is known to Isabelle with the environment variable
   137     ISABELLE_GHC.
   138   - Removed quickcheck tester "SML" based on the SML code generator
   139     from HOL-Library
   140 
   141 * Function package: discontinued option "tailrec".
   142 INCOMPATIBILITY. Use partial_function instead.
   143 
   144 * HOL-Probability:
   145   - Caratheodory's extension lemma is now proved for ring_of_sets.
   146   - Infinite products of probability measures are now available.
   147   - Use extended reals instead of positive extended reals.
   148     INCOMPATIBILITY.
   149 
   150 
   151 *** Document preparation ***
   152 
   153 * Discontinued special treatment of hard tabulators, which are better
   154 avoided in the first place.  Implicit tab-width is 1.
   155 
   156 * Antiquotation @{rail} layouts railroad syntax diagrams, see also
   157 isar-ref manual.
   158 
   159 * Antiquotation @{value} evaluates the given term and presents its result.
   160 
   161 * Localized \isabellestyle switch can be used within blocks or groups
   162 like this:
   163 
   164   \isabellestyle{it}  %preferred default
   165   {\isabellestylett @{text "typewriter stuff"}}
   166 
   167 * New term style "isub" as ad-hoc conversion of variables x1, y23 into
   168 subscripted form x\<^isub>1, y\<^isub>2\<^isub>3.
   169 
   170 * Predefined LaTeX macros for Isabelle symbols \<bind> and \<then>
   171 (e.g. see ~~/src/HOL/Library/Monad_Syntax.thy).
   172 
   173 
   174 *** ML ***
   175 
   176 * The inner syntax of sort/type/term/prop supports inlined YXML
   177 representations within quoted string tokens.  By encoding logical
   178 entities via Term_XML (in ML or Scala) concrete syntax can be
   179 bypassed, which is particularly useful for producing bits of text
   180 under external program control.
   181 
   182 * Antiquotations for ML and document preparation are managed as theory
   183 data, which requires explicit setup.
   184 
   185 * Isabelle_Process.is_active allows tools to check if the official
   186 process wrapper is running (Isabelle/Scala/jEdit) or the old TTY loop
   187 (better known as Proof General).
   188 
   189 * Structure Proof_Context follows standard naming scheme.  Old
   190 ProofContext is still available for some time as legacy alias.
   191 
   192 * Structure Timing provides various operations for timing; supersedes
   193 former start_timing/end_timing etc.
   194 
   195 * Path.print is the official way to show file-system paths to users
   196 (including quotes etc.).
   197 
   198 * Inner syntax: identifiers in parse trees of generic categories
   199 "logic", "aprop", "idt" etc. carry position information (disguised as
   200 type constraints).  Occasional INCOMPATIBILITY with non-compliant
   201 translations that choke on unexpected type constraints.  Positions can
   202 be stripped in ML translations via Syntax.strip_positions /
   203 Syntax.strip_positions_ast, or via the syntax constant
   204 "_strip_positions" within parse trees.  As last resort, positions can
   205 be disabled via the configuration option Syntax.positions, which is
   206 called "syntax_positions" in Isar attribute syntax.
   207 
   208 * Discontinued special status of various ML structures that contribute
   209 to structure Syntax (Ast, Lexicon, Mixfix, Parser, Printer etc.): less
   210 pervasive content, no inclusion in structure Syntax.  INCOMPATIBILITY,
   211 refer directly to Ast.Constant, Lexicon.is_identifier,
   212 Syntax_Trans.mk_binder_tr etc.
   213 
   214 * Typed print translation: discontinued show_sorts argument, which is
   215 already available via context of "advanced" translation.
   216 
   217 * Refined PARALLEL_GOALS tactical: degrades gracefully for schematic
   218 goal states; body tactic needs to address all subgoals uniformly.
   219 
   220 * Slightly more special eq_list/eq_set, with shortcut involving
   221 pointer equality (assumes that eq relation is reflexive).
   222 
   223 * Classical tactics use proper Proof.context instead of historic types
   224 claset/clasimpset.  Old-style declarations like addIs, addEs, addDs
   225 operate directly on Proof.context.  Raw type claset retains its use as
   226 snapshot of the classical context, which can be recovered via
   227 (put_claset HOL_cs) etc.  Type clasimpset has been discontinued.
   228 INCOMPATIBILITY, classical tactics and derived proof methods require
   229 proper Proof.context.
   230 
   231 * Scala layer provides JVM method invocation service for static
   232 methods of type (String)String, see Invoke_Scala.method in ML.
   233 For example:
   234 
   235   Invoke_Scala.method "java.lang.System.getProperty" "java.home"
   236 
   237 
   238 
   239 New in Isabelle2011 (January 2011)
   240 ----------------------------------
   241 
   242 *** General ***
   243 
   244 * Experimental Prover IDE based on Isabelle/Scala and jEdit (see
   245 src/Tools/jEdit).  This also serves as IDE for Isabelle/ML, with
   246 useful tooltips and hyperlinks produced from its static analysis.  The
   247 bundled component provides an executable Isabelle tool that can be run
   248 like this:
   249 
   250   Isabelle2011/bin/isabelle jedit
   251 
   252 * Significantly improved Isabelle/Isar implementation manual.
   253 
   254 * System settings: ISABELLE_HOME_USER now includes ISABELLE_IDENTIFIER
   255 (and thus refers to something like $HOME/.isabelle/Isabelle2011),
   256 while the default heap location within that directory lacks that extra
   257 suffix.  This isolates multiple Isabelle installations from each
   258 other, avoiding problems with old settings in new versions.
   259 INCOMPATIBILITY, need to copy/upgrade old user settings manually.
   260 
   261 * Source files are always encoded as UTF-8, instead of old-fashioned
   262 ISO-Latin-1.  INCOMPATIBILITY.  Isabelle LaTeX documents might require
   263 the following package declarations:
   264 
   265   \usepackage[utf8]{inputenc}
   266   \usepackage{textcomp}
   267 
   268 * Explicit treatment of UTF-8 sequences as Isabelle symbols, such that
   269 a Unicode character is treated as a single symbol, not a sequence of
   270 non-ASCII bytes as before.  Since Isabelle/ML string literals may
   271 contain symbols without further backslash escapes, Unicode can now be
   272 used here as well.  Recall that Symbol.explode in ML provides a
   273 consistent view on symbols, while raw explode (or String.explode)
   274 merely give a byte-oriented representation.
   275 
   276 * Theory loader: source files are primarily located via the master
   277 directory of each theory node (where the .thy file itself resides).
   278 The global load path is still partially available as legacy feature.
   279 Minor INCOMPATIBILITY due to subtle change in file lookup: use
   280 explicit paths, relatively to the theory.
   281 
   282 * Special treatment of ML file names has been discontinued.
   283 Historically, optional extensions .ML or .sml were added on demand --
   284 at the cost of clarity of file dependencies.  Recall that Isabelle/ML
   285 files exclusively use the .ML extension.  Minor INCOMPATIBILTY.
   286 
   287 * Various options that affect pretty printing etc. are now properly
   288 handled within the context via configuration options, instead of
   289 unsynchronized references or print modes.  There are both ML Config.T
   290 entities and Isar declaration attributes to access these.
   291 
   292   ML (Config.T)                 Isar (attribute)
   293 
   294   eta_contract                  eta_contract
   295   show_brackets                 show_brackets
   296   show_sorts                    show_sorts
   297   show_types                    show_types
   298   show_question_marks           show_question_marks
   299   show_consts                   show_consts
   300   show_abbrevs                  show_abbrevs
   301 
   302   Syntax.ast_trace              syntax_ast_trace
   303   Syntax.ast_stat               syntax_ast_stat
   304   Syntax.ambiguity_level        syntax_ambiguity_level
   305 
   306   Goal_Display.goals_limit      goals_limit
   307   Goal_Display.show_main_goal   show_main_goal
   308 
   309   Method.rule_trace             rule_trace
   310 
   311   Thy_Output.display            thy_output_display
   312   Thy_Output.quotes             thy_output_quotes
   313   Thy_Output.indent             thy_output_indent
   314   Thy_Output.source             thy_output_source
   315   Thy_Output.break              thy_output_break
   316 
   317 Note that corresponding "..._default" references in ML may only be
   318 changed globally at the ROOT session setup, but *not* within a theory.
   319 The option "show_abbrevs" supersedes the former print mode
   320 "no_abbrevs" with inverted meaning.
   321 
   322 * More systematic naming of some configuration options.
   323 INCOMPATIBILITY.
   324 
   325   trace_simp  ~>  simp_trace
   326   debug_simp  ~>  simp_debug
   327 
   328 * Support for real valued configuration options, using simplistic
   329 floating-point notation that coincides with the inner syntax for
   330 float_token.
   331 
   332 * Support for real valued preferences (with approximative PGIP type):
   333 front-ends need to accept "pgint" values in float notation.
   334 INCOMPATIBILITY.
   335 
   336 * The IsabelleText font now includes Cyrillic, Hebrew, Arabic from
   337 DejaVu Sans.
   338 
   339 * Discontinued support for Poly/ML 5.0 and 5.1 versions.
   340 
   341 
   342 *** Pure ***
   343 
   344 * Command 'type_synonym' (with single argument) replaces somewhat
   345 outdated 'types', which is still available as legacy feature for some
   346 time.
   347 
   348 * Command 'nonterminal' (with 'and' separated list of arguments)
   349 replaces somewhat outdated 'nonterminals'.  INCOMPATIBILITY.
   350 
   351 * Command 'notepad' replaces former 'example_proof' for
   352 experimentation in Isar without any result.  INCOMPATIBILITY.
   353 
   354 * Locale interpretation commands 'interpret' and 'sublocale' accept
   355 lists of equations to map definitions in a locale to appropriate
   356 entities in the context of the interpretation.  The 'interpretation'
   357 command already provided this functionality.
   358 
   359 * Diagnostic command 'print_dependencies' prints the locale instances
   360 that would be activated if the specified expression was interpreted in
   361 the current context.  Variant "print_dependencies!" assumes a context
   362 without interpretations.
   363 
   364 * Diagnostic command 'print_interps' prints interpretations in proofs
   365 in addition to interpretations in theories.
   366 
   367 * Discontinued obsolete 'global' and 'local' commands to manipulate
   368 the theory name space.  Rare INCOMPATIBILITY.  The ML functions
   369 Sign.root_path and Sign.local_path may be applied directly where this
   370 feature is still required for historical reasons.
   371 
   372 * Discontinued obsolete 'constdefs' command.  INCOMPATIBILITY, use
   373 'definition' instead.
   374 
   375 * The "prems" fact, which refers to the accidental collection of
   376 foundational premises in the context, is now explicitly marked as
   377 legacy feature and will be discontinued soon.  Consider using "assms"
   378 of the head statement or reference facts by explicit names.
   379 
   380 * Document antiquotations @{class} and @{type} print classes and type
   381 constructors.
   382 
   383 * Document antiquotation @{file} checks file/directory entries within
   384 the local file system.
   385 
   386 
   387 *** HOL ***
   388 
   389 * Coercive subtyping: functions can be declared as coercions and type
   390 inference will add them as necessary upon input of a term.  Theory
   391 Complex_Main declares real :: nat => real and real :: int => real as
   392 coercions. A coercion function f is declared like this:
   393 
   394   declare [[coercion f]]
   395 
   396 To lift coercions through type constructors (e.g. from nat => real to
   397 nat list => real list), map functions can be declared, e.g.
   398 
   399   declare [[coercion_map map]]
   400 
   401 Currently coercion inference is activated only in theories including
   402 real numbers, i.e. descendants of Complex_Main.  This is controlled by
   403 the configuration option "coercion_enabled", e.g. it can be enabled in
   404 other theories like this:
   405 
   406   declare [[coercion_enabled]]
   407 
   408 * Command 'partial_function' provides basic support for recursive
   409 function definitions over complete partial orders.  Concrete instances
   410 are provided for i) the option type, ii) tail recursion on arbitrary
   411 types, and iii) the heap monad of Imperative_HOL.  See
   412 src/HOL/ex/Fundefs.thy and src/HOL/Imperative_HOL/ex/Linked_Lists.thy
   413 for examples.
   414 
   415 * Function package: f.psimps rules are no longer implicitly declared
   416 as [simp].  INCOMPATIBILITY.
   417 
   418 * Datatype package: theorems generated for executable equality (class
   419 "eq") carry proper names and are treated as default code equations.
   420 
   421 * Inductive package: now offers command 'inductive_simps' to
   422 automatically derive instantiated and simplified equations for
   423 inductive predicates, similar to 'inductive_cases'.
   424 
   425 * Command 'enriched_type' allows to register properties of the
   426 functorial structure of types.
   427 
   428 * Improved infrastructure for term evaluation using code generator
   429 techniques, in particular static evaluation conversions.
   430 
   431 * Code generator: Scala (2.8 or higher) has been added to the target
   432 languages.
   433 
   434 * Code generator: globbing constant expressions "*" and "Theory.*"
   435 have been replaced by the more idiomatic "_" and "Theory._".
   436 INCOMPATIBILITY.
   437 
   438 * Code generator: export_code without explicit file declaration prints
   439 to standard output.  INCOMPATIBILITY.
   440 
   441 * Code generator: do not print function definitions for case
   442 combinators any longer.
   443 
   444 * Code generator: simplification with rules determined with
   445 src/Tools/Code/code_simp.ML and method "code_simp".
   446 
   447 * Code generator for records: more idiomatic representation of record
   448 types.  Warning: records are not covered by ancient SML code
   449 generation any longer.  INCOMPATIBILITY.  In cases of need, a suitable
   450 rep_datatype declaration helps to succeed then:
   451 
   452   record 'a foo = ...
   453   ...
   454   rep_datatype foo_ext ...
   455 
   456 * Records: logical foundation type for records does not carry a
   457 '_type' suffix any longer (obsolete due to authentic syntax).
   458 INCOMPATIBILITY.
   459 
   460 * Quickcheck now by default uses exhaustive testing instead of random
   461 testing.  Random testing can be invoked by "quickcheck [random]",
   462 exhaustive testing by "quickcheck [exhaustive]".
   463 
   464 * Quickcheck instantiates polymorphic types with small finite
   465 datatypes by default. This enables a simple execution mechanism to
   466 handle quantifiers and function equality over the finite datatypes.
   467 
   468 * Quickcheck random generator has been renamed from "code" to
   469 "random".  INCOMPATIBILITY.
   470 
   471 * Quickcheck now has a configurable time limit which is set to 30
   472 seconds by default. This can be changed by adding [timeout = n] to the
   473 quickcheck command. The time limit for Auto Quickcheck is still set
   474 independently.
   475 
   476 * Quickcheck in locales considers interpretations of that locale for
   477 counter example search.
   478 
   479 * Sledgehammer:
   480   - Added "smt" and "remote_smt" provers based on the "smt" proof
   481     method. See the Sledgehammer manual for details ("isabelle doc
   482     sledgehammer").
   483   - Renamed commands:
   484     sledgehammer atp_info ~> sledgehammer running_provers
   485     sledgehammer atp_kill ~> sledgehammer kill_provers
   486     sledgehammer available_atps ~> sledgehammer available_provers
   487     INCOMPATIBILITY.
   488   - Renamed options:
   489     sledgehammer [atps = ...] ~> sledgehammer [provers = ...]
   490     sledgehammer [atp = ...] ~> sledgehammer [prover = ...]
   491     sledgehammer [timeout = 77 s] ~> sledgehammer [timeout = 77]
   492     (and "ms" and "min" are no longer supported)
   493     INCOMPATIBILITY.
   494 
   495 * Nitpick:
   496   - Renamed options:
   497     nitpick [timeout = 77 s] ~> nitpick [timeout = 77]
   498     nitpick [tac_timeout = 777 ms] ~> nitpick [tac_timeout = 0.777]
   499     INCOMPATIBILITY.
   500   - Added support for partial quotient types.
   501   - Added local versions of the "Nitpick.register_xxx" functions.
   502   - Added "whack" option.
   503   - Allow registration of quotient types as codatatypes.
   504   - Improved "merge_type_vars" option to merge more types.
   505   - Removed unsound "fast_descrs" option.
   506   - Added custom symmetry breaking for datatypes, making it possible to reach
   507     higher cardinalities.
   508   - Prevent the expansion of too large definitions.
   509 
   510 * Proof methods "metis" and "meson" now have configuration options
   511 "meson_trace", "metis_trace", and "metis_verbose" that can be enabled
   512 to diagnose these tools. E.g.
   513 
   514     using [[metis_trace = true]]
   515 
   516 * Auto Solve: Renamed "Auto Solve Direct".  The tool is now available
   517 manually as command 'solve_direct'.
   518 
   519 * The default SMT solver Z3 must be enabled explicitly (due to
   520 licensing issues) by setting the environment variable
   521 Z3_NON_COMMERCIAL in etc/settings of the component, for example.  For
   522 commercial applications, the SMT solver CVC3 is provided as fall-back;
   523 changing the SMT solver is done via the configuration option
   524 "smt_solver".
   525 
   526 * Remote SMT solvers need to be referred to by the "remote_" prefix,
   527 i.e. "remote_cvc3" and "remote_z3".
   528 
   529 * Added basic SMT support for datatypes, records, and typedefs using
   530 the oracle mode (no proofs).  Direct support of pairs has been dropped
   531 in exchange (pass theorems fst_conv snd_conv pair_collapse to the SMT
   532 support for a similar behavior).  Minor INCOMPATIBILITY.
   533 
   534 * Changed SMT configuration options:
   535   - Renamed:
   536     z3_proofs ~> smt_oracle (with inverted meaning)
   537     z3_trace_assms ~> smt_trace_used_facts
   538     INCOMPATIBILITY.
   539   - Added:
   540     smt_verbose
   541     smt_random_seed
   542     smt_datatypes
   543     smt_infer_triggers
   544     smt_monomorph_limit
   545     cvc3_options
   546     remote_cvc3_options
   547     remote_z3_options
   548     yices_options
   549 
   550 * Boogie output files (.b2i files) need to be declared in the theory
   551 header.
   552 
   553 * Simplification procedure "list_to_set_comprehension" rewrites list
   554 comprehensions applied to List.set to set comprehensions.  Occasional
   555 INCOMPATIBILITY, may be deactivated like this:
   556 
   557   declare [[simproc del: list_to_set_comprehension]]
   558 
   559 * Removed old version of primrec package.  INCOMPATIBILITY.
   560 
   561 * Removed simplifier congruence rule of "prod_case", as has for long
   562 been the case with "split".  INCOMPATIBILITY.
   563 
   564 * String.literal is a type, but not a datatype.  INCOMPATIBILITY.
   565 
   566 * Removed [split_format ... and ... and ...] version of
   567 [split_format].  Potential INCOMPATIBILITY.
   568 
   569 * Predicate "sorted" now defined inductively, with nice induction
   570 rules.  INCOMPATIBILITY: former sorted.simps now named sorted_simps.
   571 
   572 * Constant "contents" renamed to "the_elem", to free the generic name
   573 contents for other uses.  INCOMPATIBILITY.
   574 
   575 * Renamed class eq and constant eq (for code generation) to class
   576 equal and constant equal, plus renaming of related facts and various
   577 tuning.  INCOMPATIBILITY.
   578 
   579 * Dropped type classes mult_mono and mult_mono1.  INCOMPATIBILITY.
   580 
   581 * Removed output syntax "'a ~=> 'b" for "'a => 'b option".
   582 INCOMPATIBILITY.
   583 
   584 * Renamed theory Fset to Cset, type Fset.fset to Cset.set, in order to
   585 avoid confusion with finite sets.  INCOMPATIBILITY.
   586 
   587 * Abandoned locales equiv, congruent and congruent2 for equivalence
   588 relations.  INCOMPATIBILITY: use equivI rather than equiv_intro (same
   589 for congruent(2)).
   590 
   591 * Some previously unqualified names have been qualified:
   592 
   593   types
   594     bool ~> HOL.bool
   595     nat ~> Nat.nat
   596 
   597   constants
   598     Trueprop ~> HOL.Trueprop
   599     True ~> HOL.True
   600     False ~> HOL.False
   601     op & ~> HOL.conj
   602     op | ~> HOL.disj
   603     op --> ~> HOL.implies
   604     op = ~> HOL.eq
   605     Not ~> HOL.Not
   606     The ~> HOL.The
   607     All ~> HOL.All
   608     Ex ~> HOL.Ex
   609     Ex1 ~> HOL.Ex1
   610     Let ~> HOL.Let
   611     If ~> HOL.If
   612     Ball ~> Set.Ball
   613     Bex ~> Set.Bex
   614     Suc ~> Nat.Suc
   615     Pair ~> Product_Type.Pair
   616     fst ~> Product_Type.fst
   617     snd ~> Product_Type.snd
   618     curry ~> Product_Type.curry
   619     op : ~> Set.member
   620     Collect ~> Set.Collect
   621 
   622 INCOMPATIBILITY.
   623 
   624 * More canonical naming convention for some fundamental definitions:
   625 
   626     bot_bool_eq ~> bot_bool_def
   627     top_bool_eq ~> top_bool_def
   628     inf_bool_eq ~> inf_bool_def
   629     sup_bool_eq ~> sup_bool_def
   630     bot_fun_eq  ~> bot_fun_def
   631     top_fun_eq  ~> top_fun_def
   632     inf_fun_eq  ~> inf_fun_def
   633     sup_fun_eq  ~> sup_fun_def
   634 
   635 INCOMPATIBILITY.
   636 
   637 * More stylized fact names:
   638 
   639   expand_fun_eq ~> fun_eq_iff
   640   expand_set_eq ~> set_eq_iff
   641   set_ext       ~> set_eqI
   642   nat_number    ~> eval_nat_numeral
   643 
   644 INCOMPATIBILITY.
   645 
   646 * Refactoring of code-generation specific operations in theory List:
   647 
   648   constants
   649     null ~> List.null
   650 
   651   facts
   652     mem_iff ~> member_def
   653     null_empty ~> null_def
   654 
   655 INCOMPATIBILITY.  Note that these were not supposed to be used
   656 regularly unless for striking reasons; their main purpose was code
   657 generation.
   658 
   659 Various operations from the Haskell prelude are used for generating
   660 Haskell code.
   661 
   662 * Term "bij f" is now an abbreviation of "bij_betw f UNIV UNIV".  Term
   663 "surj f" is now an abbreviation of "range f = UNIV".  The theorems
   664 bij_def and surj_def are unchanged.  INCOMPATIBILITY.
   665 
   666 * Abolished some non-alphabetic type names: "prod" and "sum" replace
   667 "*" and "+" respectively.  INCOMPATIBILITY.
   668 
   669 * Name "Plus" of disjoint sum operator "<+>" is now hidden.  Write
   670 "Sum_Type.Plus" instead.
   671 
   672 * Constant "split" has been merged with constant "prod_case"; names of
   673 ML functions, facts etc. involving split have been retained so far,
   674 though.  INCOMPATIBILITY.
   675 
   676 * Dropped old infix syntax "_ mem _" for List.member; use "_ : set _"
   677 instead.  INCOMPATIBILITY.
   678 
   679 * Removed lemma "Option.is_none_none" which duplicates "is_none_def".
   680 INCOMPATIBILITY.
   681 
   682 * Former theory Library/Enum is now part of the HOL-Main image.
   683 INCOMPATIBILITY: all constants of the Enum theory now have to be
   684 referred to by its qualified name.
   685 
   686   enum    ~>  Enum.enum
   687   nlists  ~>  Enum.nlists
   688   product ~>  Enum.product
   689 
   690 * Theory Library/Monad_Syntax provides do-syntax for monad types.
   691 Syntax in Library/State_Monad has been changed to avoid ambiguities.
   692 INCOMPATIBILITY.
   693 
   694 * Theory Library/SetsAndFunctions has been split into
   695 Library/Function_Algebras and Library/Set_Algebras; canonical names
   696 for instance definitions for functions; various improvements.
   697 INCOMPATIBILITY.
   698 
   699 * Theory Library/Multiset provides stable quicksort implementation of
   700 sort_key.
   701 
   702 * Theory Library/Multiset: renamed empty_idemp ~> empty_neutral.
   703 INCOMPATIBILITY.
   704 
   705 * Session Multivariate_Analysis: introduced a type class for euclidean
   706 space.  Most theorems are now stated in terms of euclidean spaces
   707 instead of finite cartesian products.
   708 
   709   types
   710     real ^ 'n ~>  'a::real_vector
   711               ~>  'a::euclidean_space
   712               ~>  'a::ordered_euclidean_space
   713         (depends on your needs)
   714 
   715   constants
   716      _ $ _        ~> _ $$ _
   717      \<chi> x. _  ~> \<chi>\<chi> x. _
   718      CARD('n)     ~> DIM('a)
   719 
   720 Also note that the indices are now natural numbers and not from some
   721 finite type. Finite cartesian products of euclidean spaces, products
   722 of euclidean spaces the real and complex numbers are instantiated to
   723 be euclidean_spaces.  INCOMPATIBILITY.
   724 
   725 * Session Probability: introduced pextreal as positive extended real
   726 numbers.  Use pextreal as value for measures.  Introduce the
   727 Radon-Nikodym derivative, product spaces and Fubini's theorem for
   728 arbitrary sigma finite measures.  Introduces Lebesgue measure based on
   729 the integral in Multivariate Analysis.  INCOMPATIBILITY.
   730 
   731 * Session Imperative_HOL: revamped, corrected dozens of inadequacies.
   732 INCOMPATIBILITY.
   733 
   734 * Session SPARK (with image HOL-SPARK) provides commands to load and
   735 prove verification conditions generated by the SPARK Ada program
   736 verifier.  See also src/HOL/SPARK and src/HOL/SPARK/Examples.
   737 
   738 
   739 *** HOL-Algebra ***
   740 
   741 * Theorems for additive ring operations (locale abelian_monoid and
   742 descendants) are generated by interpretation from their multiplicative
   743 counterparts.  Names (in particular theorem names) have the mandatory
   744 qualifier 'add'.  Previous theorem names are redeclared for
   745 compatibility.
   746 
   747 * Structure "int_ring" is now an abbreviation (previously a
   748 definition).  This fits more natural with advanced interpretations.
   749 
   750 
   751 *** HOLCF ***
   752 
   753 * The domain package now runs in definitional mode by default: The
   754 former command 'new_domain' is now called 'domain'.  To use the domain
   755 package in its original axiomatic mode, use 'domain (unsafe)'.
   756 INCOMPATIBILITY.
   757 
   758 * The new class "domain" is now the default sort.  Class "predomain"
   759 is an unpointed version of "domain". Theories can be updated by
   760 replacing sort annotations as shown below.  INCOMPATIBILITY.
   761 
   762   'a::type ~> 'a::countable
   763   'a::cpo  ~> 'a::predomain
   764   'a::pcpo ~> 'a::domain
   765 
   766 * The old type class "rep" has been superseded by class "domain".
   767 Accordingly, users of the definitional package must remove any
   768 "default_sort rep" declarations.  INCOMPATIBILITY.
   769 
   770 * The domain package (definitional mode) now supports unpointed
   771 predomain argument types, as long as they are marked 'lazy'. (Strict
   772 arguments must be in class "domain".) For example, the following
   773 domain definition now works:
   774 
   775   domain natlist = nil | cons (lazy "nat discr") (lazy "natlist")
   776 
   777 * Theory HOLCF/Library/HOL_Cpo provides cpo and predomain class
   778 instances for types from main HOL: bool, nat, int, char, 'a + 'b,
   779 'a option, and 'a list.  Additionally, it configures fixrec and the
   780 domain package to work with these types.  For example:
   781 
   782   fixrec isInl :: "('a + 'b) u -> tr"
   783     where "isInl$(up$(Inl x)) = TT" | "isInl$(up$(Inr y)) = FF"
   784 
   785   domain V = VFun (lazy "V -> V") | VCon (lazy "nat") (lazy "V list")
   786 
   787 * The "(permissive)" option of fixrec has been replaced with a
   788 per-equation "(unchecked)" option. See
   789 src/HOL/HOLCF/Tutorial/Fixrec_ex.thy for examples. INCOMPATIBILITY.
   790 
   791 * The "bifinite" class no longer fixes a constant "approx"; the class
   792 now just asserts that such a function exists.  INCOMPATIBILITY.
   793 
   794 * Former type "alg_defl" has been renamed to "defl".  HOLCF no longer
   795 defines an embedding of type 'a defl into udom by default; instances
   796 of "bifinite" and "domain" classes are available in
   797 src/HOL/HOLCF/Library/Defl_Bifinite.thy.
   798 
   799 * The syntax "REP('a)" has been replaced with "DEFL('a)".
   800 
   801 * The predicate "directed" has been removed.  INCOMPATIBILITY.
   802 
   803 * The type class "finite_po" has been removed.  INCOMPATIBILITY.
   804 
   805 * The function "cprod_map" has been renamed to "prod_map".
   806 INCOMPATIBILITY.
   807 
   808 * The monadic bind operator on each powerdomain has new binder syntax
   809 similar to sets, e.g. "\<Union>\<sharp>x\<in>xs. t" represents
   810 "upper_bind\<cdot>xs\<cdot>(\<Lambda> x. t)".
   811 
   812 * The infix syntax for binary union on each powerdomain has changed
   813 from e.g. "+\<sharp>" to "\<union>\<sharp>", for consistency with set
   814 syntax.  INCOMPATIBILITY.
   815 
   816 * The constant "UU" has been renamed to "bottom".  The syntax "UU" is
   817 still supported as an input translation.
   818 
   819 * Renamed some theorems (the original names are also still available).
   820 
   821   expand_fun_below   ~> fun_below_iff
   822   below_fun_ext      ~> fun_belowI
   823   expand_cfun_eq     ~> cfun_eq_iff
   824   ext_cfun           ~> cfun_eqI
   825   expand_cfun_below  ~> cfun_below_iff
   826   below_cfun_ext     ~> cfun_belowI
   827   cont2cont_Rep_CFun ~> cont2cont_APP
   828 
   829 * The Abs and Rep functions for various types have changed names.
   830 Related theorem names have also changed to match. INCOMPATIBILITY.
   831 
   832   Rep_CFun  ~> Rep_cfun
   833   Abs_CFun  ~> Abs_cfun
   834   Rep_Sprod ~> Rep_sprod
   835   Abs_Sprod ~> Abs_sprod
   836   Rep_Ssum  ~> Rep_ssum
   837   Abs_Ssum  ~> Abs_ssum
   838 
   839 * Lemmas with names of the form *_defined_iff or *_strict_iff have
   840 been renamed to *_bottom_iff.  INCOMPATIBILITY.
   841 
   842 * Various changes to bisimulation/coinduction with domain package:
   843 
   844   - Definitions of "bisim" constants no longer mention definedness.
   845   - With mutual recursion, "bisim" predicate is now curried.
   846   - With mutual recursion, each type gets a separate coind theorem.
   847   - Variable names in bisim_def and coinduct rules have changed.
   848 
   849 INCOMPATIBILITY.
   850 
   851 * Case combinators generated by the domain package for type "foo" are
   852 now named "foo_case" instead of "foo_when".  INCOMPATIBILITY.
   853 
   854 * Several theorems have been renamed to more accurately reflect the
   855 names of constants and types involved.  INCOMPATIBILITY.
   856 
   857   thelub_const    ~> lub_const
   858   lub_const       ~> is_lub_const
   859   thelubI         ~> lub_eqI
   860   is_lub_lub      ~> is_lubD2
   861   lubI            ~> is_lub_lub
   862   unique_lub      ~> is_lub_unique
   863   is_ub_lub       ~> is_lub_rangeD1
   864   lub_bin_chain   ~> is_lub_bin_chain
   865   lub_fun         ~> is_lub_fun
   866   thelub_fun      ~> lub_fun
   867   thelub_cfun     ~> lub_cfun
   868   thelub_Pair     ~> lub_Pair
   869   lub_cprod       ~> is_lub_prod
   870   thelub_cprod    ~> lub_prod
   871   minimal_cprod   ~> minimal_prod
   872   inst_cprod_pcpo ~> inst_prod_pcpo
   873   UU_I            ~> bottomI
   874   compact_UU      ~> compact_bottom
   875   deflation_UU    ~> deflation_bottom
   876   finite_deflation_UU ~> finite_deflation_bottom
   877 
   878 * Many legacy theorem names have been discontinued.  INCOMPATIBILITY.
   879 
   880   sq_ord_less_eq_trans ~> below_eq_trans
   881   sq_ord_eq_less_trans ~> eq_below_trans
   882   refl_less            ~> below_refl
   883   trans_less           ~> below_trans
   884   antisym_less         ~> below_antisym
   885   antisym_less_inverse ~> po_eq_conv [THEN iffD1]
   886   box_less             ~> box_below
   887   rev_trans_less       ~> rev_below_trans
   888   not_less2not_eq      ~> not_below2not_eq
   889   less_UU_iff          ~> below_UU_iff
   890   flat_less_iff        ~> flat_below_iff
   891   adm_less             ~> adm_below
   892   adm_not_less         ~> adm_not_below
   893   adm_compact_not_less ~> adm_compact_not_below
   894   less_fun_def         ~> below_fun_def
   895   expand_fun_less      ~> fun_below_iff
   896   less_fun_ext         ~> fun_belowI
   897   less_discr_def       ~> below_discr_def
   898   discr_less_eq        ~> discr_below_eq
   899   less_unit_def        ~> below_unit_def
   900   less_cprod_def       ~> below_prod_def
   901   prod_lessI           ~> prod_belowI
   902   Pair_less_iff        ~> Pair_below_iff
   903   fst_less_iff         ~> fst_below_iff
   904   snd_less_iff         ~> snd_below_iff
   905   expand_cfun_less     ~> cfun_below_iff
   906   less_cfun_ext        ~> cfun_belowI
   907   injection_less       ~> injection_below
   908   less_up_def          ~> below_up_def
   909   not_Iup_less         ~> not_Iup_below
   910   Iup_less             ~> Iup_below
   911   up_less              ~> up_below
   912   Def_inject_less_eq   ~> Def_below_Def
   913   Def_less_is_eq       ~> Def_below_iff
   914   spair_less_iff       ~> spair_below_iff
   915   less_sprod           ~> below_sprod
   916   spair_less           ~> spair_below
   917   sfst_less_iff        ~> sfst_below_iff
   918   ssnd_less_iff        ~> ssnd_below_iff
   919   fix_least_less       ~> fix_least_below
   920   dist_less_one        ~> dist_below_one
   921   less_ONE             ~> below_ONE
   922   ONE_less_iff         ~> ONE_below_iff
   923   less_sinlD           ~> below_sinlD
   924   less_sinrD           ~> below_sinrD
   925 
   926 
   927 *** FOL and ZF ***
   928 
   929 * All constant names are now qualified internally and use proper
   930 identifiers, e.g. "IFOL.eq" instead of "op =".  INCOMPATIBILITY.
   931 
   932 
   933 *** ML ***
   934 
   935 * Antiquotation @{assert} inlines a function bool -> unit that raises
   936 Fail if the argument is false.  Due to inlining the source position of
   937 failed assertions is included in the error output.
   938 
   939 * Discontinued antiquotation @{theory_ref}, which is obsolete since ML
   940 text is in practice always evaluated with a stable theory checkpoint.
   941 Minor INCOMPATIBILITY, use (Theory.check_thy @{theory}) instead.
   942 
   943 * Antiquotation @{theory A} refers to theory A from the ancestry of
   944 the current context, not any accidental theory loader state as before.
   945 Potential INCOMPATIBILITY, subtle change in semantics.
   946 
   947 * Syntax.pretty_priority (default 0) configures the required priority
   948 of pretty-printed output and thus affects insertion of parentheses.
   949 
   950 * Syntax.default_root (default "any") configures the inner syntax
   951 category (nonterminal symbol) for parsing of terms.
   952 
   953 * Former exception Library.UnequalLengths now coincides with
   954 ListPair.UnequalLengths.
   955 
   956 * Renamed structure MetaSimplifier to Raw_Simplifier.  Note that the
   957 main functionality is provided by structure Simplifier.
   958 
   959 * Renamed raw "explode" function to "raw_explode" to emphasize its
   960 meaning.  Note that internally to Isabelle, Symbol.explode is used in
   961 almost all situations.
   962 
   963 * Discontinued obsolete function sys_error and exception SYS_ERROR.
   964 See implementation manual for further details on exceptions in
   965 Isabelle/ML.
   966 
   967 * Renamed setmp_noncritical to Unsynchronized.setmp to emphasize its
   968 meaning.
   969 
   970 * Renamed structure PureThy to Pure_Thy and moved most of its
   971 operations to structure Global_Theory, to emphasize that this is
   972 rarely-used global-only stuff.
   973 
   974 * Discontinued Output.debug.  Minor INCOMPATIBILITY, use plain writeln
   975 instead (or tracing for high-volume output).
   976 
   977 * Configuration option show_question_marks only affects regular pretty
   978 printing of types and terms, not raw Term.string_of_vname.
   979 
   980 * ML_Context.thm and ML_Context.thms are no longer pervasive.  Rare
   981 INCOMPATIBILITY, superseded by static antiquotations @{thm} and
   982 @{thms} for most purposes.
   983 
   984 * ML structure Unsynchronized is never opened, not even in Isar
   985 interaction mode as before.  Old Unsynchronized.set etc. have been
   986 discontinued -- use plain := instead.  This should be *rare* anyway,
   987 since modern tools always work via official context data, notably
   988 configuration options.
   989 
   990 * Parallel and asynchronous execution requires special care concerning
   991 interrupts.  Structure Exn provides some convenience functions that
   992 avoid working directly with raw Interrupt.  User code must not absorb
   993 interrupts -- intermediate handling (for cleanup etc.) needs to be
   994 followed by re-raising of the original exception.  Another common
   995 source of mistakes are "handle _" patterns, which make the meaning of
   996 the program subject to physical effects of the environment.
   997 
   998 
   999 
  1000 New in Isabelle2009-2 (June 2010)
  1001 ---------------------------------
  1002 
  1003 *** General ***
  1004 
  1005 * Authentic syntax for *all* logical entities (type classes, type
  1006 constructors, term constants): provides simple and robust
  1007 correspondence between formal entities and concrete syntax.  Within
  1008 the parse tree / AST representations, "constants" are decorated by
  1009 their category (class, type, const) and spelled out explicitly with
  1010 their full internal name.
  1011 
  1012 Substantial INCOMPATIBILITY concerning low-level syntax declarations
  1013 and translations (translation rules and translation functions in ML).
  1014 Some hints on upgrading:
  1015 
  1016   - Many existing uses of 'syntax' and 'translations' can be replaced
  1017     by more modern 'type_notation', 'notation' and 'abbreviation',
  1018     which are independent of this issue.
  1019 
  1020   - 'translations' require markup within the AST; the term syntax
  1021     provides the following special forms:
  1022 
  1023       CONST c   -- produces syntax version of constant c from context
  1024       XCONST c  -- literally c, checked as constant from context
  1025       c         -- literally c, if declared by 'syntax'
  1026 
  1027     Plain identifiers are treated as AST variables -- occasionally the
  1028     system indicates accidental variables via the error "rhs contains
  1029     extra variables".
  1030 
  1031     Type classes and type constructors are marked according to their
  1032     concrete syntax.  Some old translations rules need to be written
  1033     for the "type" category, using type constructor application
  1034     instead of pseudo-term application of the default category
  1035     "logic".
  1036 
  1037   - 'parse_translation' etc. in ML may use the following
  1038     antiquotations:
  1039 
  1040       @{class_syntax c}   -- type class c within parse tree / AST
  1041       @{term_syntax c}    -- type constructor c within parse tree / AST
  1042       @{const_syntax c}   -- ML version of "CONST c" above
  1043       @{syntax_const c}   -- literally c (checked wrt. 'syntax' declarations)
  1044 
  1045   - Literal types within 'typed_print_translations', i.e. those *not*
  1046     represented as pseudo-terms are represented verbatim.  Use @{class
  1047     c} or @{type_name c} here instead of the above syntax
  1048     antiquotations.
  1049 
  1050 Note that old non-authentic syntax was based on unqualified base
  1051 names, so all of the above "constant" names would coincide.  Recall
  1052 that 'print_syntax' and ML_command "set Syntax.trace_ast" help to
  1053 diagnose syntax problems.
  1054 
  1055 * Type constructors admit general mixfix syntax, not just infix.
  1056 
  1057 * Concrete syntax may be attached to local entities without a proof
  1058 body, too.  This works via regular mixfix annotations for 'fix',
  1059 'def', 'obtain' etc. or via the explicit 'write' command, which is
  1060 similar to the 'notation' command in theory specifications.
  1061 
  1062 * Discontinued unnamed infix syntax (legacy feature for many years) --
  1063 need to specify constant name and syntax separately.  Internal ML
  1064 datatype constructors have been renamed from InfixName to Infix etc.
  1065 Minor INCOMPATIBILITY.
  1066 
  1067 * Schematic theorem statements need to be explicitly markup as such,
  1068 via commands 'schematic_lemma', 'schematic_theorem',
  1069 'schematic_corollary'.  Thus the relevance of the proof is made
  1070 syntactically clear, which impacts performance in a parallel or
  1071 asynchronous interactive environment.  Minor INCOMPATIBILITY.
  1072 
  1073 * Use of cumulative prems via "!" in some proof methods has been
  1074 discontinued (old legacy feature).
  1075 
  1076 * References 'trace_simp' and 'debug_simp' have been replaced by
  1077 configuration options stored in the context. Enabling tracing (the
  1078 case of debugging is similar) in proofs works via
  1079 
  1080   using [[trace_simp = true]]
  1081 
  1082 Tracing is then active for all invocations of the simplifier in
  1083 subsequent goal refinement steps. Tracing may also still be enabled or
  1084 disabled via the ProofGeneral settings menu.
  1085 
  1086 * Separate commands 'hide_class', 'hide_type', 'hide_const',
  1087 'hide_fact' replace the former 'hide' KIND command.  Minor
  1088 INCOMPATIBILITY.
  1089 
  1090 * Improved parallelism of proof term normalization: usedir -p2 -q0 is
  1091 more efficient than combinations with -q1 or -q2.
  1092 
  1093 
  1094 *** Pure ***
  1095 
  1096 * Proofterms record type-class reasoning explicitly, using the
  1097 "unconstrain" operation internally.  This eliminates all sort
  1098 constraints from a theorem and proof, introducing explicit
  1099 OFCLASS-premises.  On the proof term level, this operation is
  1100 automatically applied at theorem boundaries, such that closed proofs
  1101 are always free of sort constraints.  INCOMPATIBILITY for tools that
  1102 inspect proof terms.
  1103 
  1104 * Local theory specifications may depend on extra type variables that
  1105 are not present in the result type -- arguments TYPE('a) :: 'a itself
  1106 are added internally.  For example:
  1107 
  1108   definition unitary :: bool where "unitary = (ALL (x::'a) y. x = y)"
  1109 
  1110 * Predicates of locales introduced by classes carry a mandatory
  1111 "class" prefix.  INCOMPATIBILITY.
  1112 
  1113 * Vacuous class specifications observe default sort.  INCOMPATIBILITY.
  1114 
  1115 * Old 'axclass' command has been discontinued.  INCOMPATIBILITY, use
  1116 'class' instead.
  1117 
  1118 * Command 'code_reflect' allows to incorporate generated ML code into
  1119 runtime environment; replaces immature code_datatype antiquotation.
  1120 INCOMPATIBILITY.
  1121 
  1122 * Code generator: simple concept for abstract datatypes obeying
  1123 invariants.
  1124 
  1125 * Code generator: details of internal data cache have no impact on the
  1126 user space functionality any longer.
  1127 
  1128 * Methods "unfold_locales" and "intro_locales" ignore non-locale
  1129 subgoals.  This is more appropriate for interpretations with 'where'.
  1130 INCOMPATIBILITY.
  1131 
  1132 * Command 'example_proof' opens an empty proof body.  This allows to
  1133 experiment with Isar, without producing any persistent result.
  1134 
  1135 * Commands 'type_notation' and 'no_type_notation' declare type syntax
  1136 within a local theory context, with explicit checking of the
  1137 constructors involved (in contrast to the raw 'syntax' versions).
  1138 
  1139 * Commands 'types' and 'typedecl' now work within a local theory
  1140 context -- without introducing dependencies on parameters or
  1141 assumptions, which is not possible in Isabelle/Pure.
  1142 
  1143 * Command 'defaultsort' has been renamed to 'default_sort', it works
  1144 within a local theory context.  Minor INCOMPATIBILITY.
  1145 
  1146 
  1147 *** HOL ***
  1148 
  1149 * Command 'typedef' now works within a local theory context -- without
  1150 introducing dependencies on parameters or assumptions, which is not
  1151 possible in Isabelle/Pure/HOL.  Note that the logical environment may
  1152 contain multiple interpretations of local typedefs (with different
  1153 non-emptiness proofs), even in a global theory context.
  1154 
  1155 * New package for quotient types.  Commands 'quotient_type' and
  1156 'quotient_definition' may be used for defining types and constants by
  1157 quotient constructions.  An example is the type of integers created by
  1158 quotienting pairs of natural numbers:
  1159 
  1160   fun
  1161     intrel :: "(nat * nat) => (nat * nat) => bool"
  1162   where
  1163     "intrel (x, y) (u, v) = (x + v = u + y)"
  1164 
  1165   quotient_type int = "nat * nat" / intrel
  1166     by (auto simp add: equivp_def expand_fun_eq)
  1167 
  1168   quotient_definition
  1169     "0::int" is "(0::nat, 0::nat)"
  1170 
  1171 The method "lifting" can be used to lift of theorems from the
  1172 underlying "raw" type to the quotient type.  The example
  1173 src/HOL/Quotient_Examples/FSet.thy includes such a quotient
  1174 construction and provides a reasoning infrastructure for finite sets.
  1175 
  1176 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
  1177 clash with new theory Quotient in Main HOL.
  1178 
  1179 * Moved the SMT binding into the main HOL session, eliminating
  1180 separate HOL-SMT session.
  1181 
  1182 * List membership infix mem operation is only an input abbreviation.
  1183 INCOMPATIBILITY.
  1184 
  1185 * Theory Library/Word.thy has been removed.  Use library Word/Word.thy
  1186 for future developements; former Library/Word.thy is still present in
  1187 the AFP entry RSAPPS.
  1188 
  1189 * Theorem Int.int_induct renamed to Int.int_of_nat_induct and is no
  1190 longer shadowed.  INCOMPATIBILITY.
  1191 
  1192 * Dropped theorem duplicate comp_arith; use semiring_norm instead.
  1193 INCOMPATIBILITY.
  1194 
  1195 * Dropped theorem RealPow.real_sq_order; use power2_le_imp_le instead.
  1196 INCOMPATIBILITY.
  1197 
  1198 * Dropped normalizing_semiring etc; use the facts in semiring classes
  1199 instead.  INCOMPATIBILITY.
  1200 
  1201 * Dropped several real-specific versions of lemmas about floor and
  1202 ceiling; use the generic lemmas from theory "Archimedean_Field"
  1203 instead.  INCOMPATIBILITY.
  1204 
  1205   floor_number_of_eq         ~> floor_number_of
  1206   le_floor_eq_number_of      ~> number_of_le_floor
  1207   le_floor_eq_zero           ~> zero_le_floor
  1208   le_floor_eq_one            ~> one_le_floor
  1209   floor_less_eq_number_of    ~> floor_less_number_of
  1210   floor_less_eq_zero         ~> floor_less_zero
  1211   floor_less_eq_one          ~> floor_less_one
  1212   less_floor_eq_number_of    ~> number_of_less_floor
  1213   less_floor_eq_zero         ~> zero_less_floor
  1214   less_floor_eq_one          ~> one_less_floor
  1215   floor_le_eq_number_of      ~> floor_le_number_of
  1216   floor_le_eq_zero           ~> floor_le_zero
  1217   floor_le_eq_one            ~> floor_le_one
  1218   floor_subtract_number_of   ~> floor_diff_number_of
  1219   floor_subtract_one         ~> floor_diff_one
  1220   ceiling_number_of_eq       ~> ceiling_number_of
  1221   ceiling_le_eq_number_of    ~> ceiling_le_number_of
  1222   ceiling_le_zero_eq         ~> ceiling_le_zero
  1223   ceiling_le_eq_one          ~> ceiling_le_one
  1224   less_ceiling_eq_number_of  ~> number_of_less_ceiling
  1225   less_ceiling_eq_zero       ~> zero_less_ceiling
  1226   less_ceiling_eq_one        ~> one_less_ceiling
  1227   ceiling_less_eq_number_of  ~> ceiling_less_number_of
  1228   ceiling_less_eq_zero       ~> ceiling_less_zero
  1229   ceiling_less_eq_one        ~> ceiling_less_one
  1230   le_ceiling_eq_number_of    ~> number_of_le_ceiling
  1231   le_ceiling_eq_zero         ~> zero_le_ceiling
  1232   le_ceiling_eq_one          ~> one_le_ceiling
  1233   ceiling_subtract_number_of ~> ceiling_diff_number_of
  1234   ceiling_subtract_one       ~> ceiling_diff_one
  1235 
  1236 * Theory "Finite_Set": various folding_XXX locales facilitate the
  1237 application of the various fold combinators on finite sets.
  1238 
  1239 * Library theory "RBT" renamed to "RBT_Impl"; new library theory "RBT"
  1240 provides abstract red-black tree type which is backed by "RBT_Impl" as
  1241 implementation.  INCOMPATIBILTY.
  1242 
  1243 * Theory Library/Coinductive_List has been removed -- superseded by
  1244 AFP/thys/Coinductive.
  1245 
  1246 * Theory PReal, including the type "preal" and related operations, has
  1247 been removed.  INCOMPATIBILITY.
  1248 
  1249 * Real: new development using Cauchy Sequences.
  1250 
  1251 * Split off theory "Big_Operators" containing setsum, setprod,
  1252 Inf_fin, Sup_fin, Min, Max from theory Finite_Set.  INCOMPATIBILITY.
  1253 
  1254 * Theory "Rational" renamed to "Rat", for consistency with "Nat",
  1255 "Int" etc.  INCOMPATIBILITY.
  1256 
  1257 * Constant Rat.normalize needs to be qualified.  INCOMPATIBILITY.
  1258 
  1259 * New set of rules "ac_simps" provides combined assoc / commute
  1260 rewrites for all interpretations of the appropriate generic locales.
  1261 
  1262 * Renamed theory "OrderedGroup" to "Groups" and split theory
  1263 "Ring_and_Field" into theories "Rings" and "Fields"; for more
  1264 appropriate and more consistent names suitable for name prefixes
  1265 within the HOL theories.  INCOMPATIBILITY.
  1266 
  1267 * Some generic constants have been put to appropriate theories:
  1268   - less_eq, less: Orderings
  1269   - zero, one, plus, minus, uminus, times, abs, sgn: Groups
  1270   - inverse, divide: Rings
  1271 INCOMPATIBILITY.
  1272 
  1273 * More consistent naming of type classes involving orderings (and
  1274 lattices):
  1275 
  1276     lower_semilattice                   ~> semilattice_inf
  1277     upper_semilattice                   ~> semilattice_sup
  1278 
  1279     dense_linear_order                  ~> dense_linorder
  1280 
  1281     pordered_ab_group_add               ~> ordered_ab_group_add
  1282     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
  1283     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
  1284     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
  1285     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
  1286     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
  1287     pordered_cancel_semiring            ~> ordered_cancel_semiring
  1288     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
  1289     pordered_comm_ring                  ~> ordered_comm_ring
  1290     pordered_comm_semiring              ~> ordered_comm_semiring
  1291     pordered_ring                       ~> ordered_ring
  1292     pordered_ring_abs                   ~> ordered_ring_abs
  1293     pordered_semiring                   ~> ordered_semiring
  1294 
  1295     ordered_ab_group_add                ~> linordered_ab_group_add
  1296     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
  1297     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
  1298     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
  1299     ordered_field                       ~> linordered_field
  1300     ordered_field_no_lb                 ~> linordered_field_no_lb
  1301     ordered_field_no_ub                 ~> linordered_field_no_ub
  1302     ordered_field_dense_linear_order    ~> dense_linordered_field
  1303     ordered_idom                        ~> linordered_idom
  1304     ordered_ring                        ~> linordered_ring
  1305     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
  1306     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
  1307     ordered_ring_strict                 ~> linordered_ring_strict
  1308     ordered_semidom                     ~> linordered_semidom
  1309     ordered_semiring                    ~> linordered_semiring
  1310     ordered_semiring_1                  ~> linordered_semiring_1
  1311     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
  1312     ordered_semiring_strict             ~> linordered_semiring_strict
  1313 
  1314   The following slightly odd type classes have been moved to a
  1315   separate theory Library/Lattice_Algebras:
  1316 
  1317     lordered_ab_group_add               ~> lattice_ab_group_add
  1318     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
  1319     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
  1320     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
  1321     lordered_ring                       ~> lattice_ring
  1322 
  1323 INCOMPATIBILITY.
  1324 
  1325 * Refined field classes:
  1326   - classes division_ring_inverse_zero, field_inverse_zero,
  1327     linordered_field_inverse_zero include rule inverse 0 = 0 --
  1328     subsumes former division_by_zero class;
  1329   - numerous lemmas have been ported from field to division_ring.
  1330 INCOMPATIBILITY.
  1331 
  1332 * Refined algebra theorem collections:
  1333   - dropped theorem group group_simps, use algebra_simps instead;
  1334   - dropped theorem group ring_simps, use field_simps instead;
  1335   - proper theorem collection field_simps subsumes former theorem
  1336     groups field_eq_simps and field_simps;
  1337   - dropped lemma eq_minus_self_iff which is a duplicate for
  1338     equal_neg_zero.
  1339 INCOMPATIBILITY.
  1340 
  1341 * Theory Finite_Set and List: some lemmas have been generalized from
  1342 sets to lattices:
  1343 
  1344   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
  1345   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
  1346   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
  1347   union_Union_fold_union        ~> sup_Sup_fold_sup
  1348   Inter_fold_inter              ~> Inf_fold_inf
  1349   Union_fold_union              ~> Sup_fold_sup
  1350   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
  1351   union_UNION_fold_union        ~> sup_SUPR_fold_sup
  1352   INTER_fold_inter              ~> INFI_fold_inf
  1353   UNION_fold_union              ~> SUPR_fold_sup
  1354 
  1355 * Theory "Complete_Lattice": lemmas top_def and bot_def have been
  1356 replaced by the more convenient lemmas Inf_empty and Sup_empty.
  1357 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
  1358 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
  1359 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
  1360 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
  1361 
  1362 * Reorganized theory Multiset: swapped notation of pointwise and
  1363 multiset order:
  1364 
  1365   - pointwise ordering is instance of class order with standard syntax
  1366     <= and <;
  1367   - multiset ordering has syntax <=# and <#; partial order properties
  1368     are provided by means of interpretation with prefix
  1369     multiset_order;
  1370   - less duplication, less historical organization of sections,
  1371     conversion from associations lists to multisets, rudimentary code
  1372     generation;
  1373   - use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union,
  1374     if needed.
  1375 
  1376 Renamed:
  1377 
  1378   multiset_eq_conv_count_eq  ~>  multiset_ext_iff
  1379   multi_count_ext  ~>  multiset_ext
  1380   diff_union_inverse2  ~>  diff_union_cancelR
  1381 
  1382 INCOMPATIBILITY.
  1383 
  1384 * Theory Permutation: replaced local "remove" by List.remove1.
  1385 
  1386 * Code generation: ML and OCaml code is decorated with signatures.
  1387 
  1388 * Theory List: added transpose.
  1389 
  1390 * Library/Nat_Bijection.thy is a collection of bijective functions
  1391 between nat and other types, which supersedes the older libraries
  1392 Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.
  1393 
  1394   Constants:
  1395   Nat_Int_Bij.nat2_to_nat         ~> prod_encode
  1396   Nat_Int_Bij.nat_to_nat2         ~> prod_decode
  1397   Nat_Int_Bij.int_to_nat_bij      ~> int_encode
  1398   Nat_Int_Bij.nat_to_int_bij      ~> int_decode
  1399   Countable.pair_encode           ~> prod_encode
  1400   NatIso.prod2nat                 ~> prod_encode
  1401   NatIso.nat2prod                 ~> prod_decode
  1402   NatIso.sum2nat                  ~> sum_encode
  1403   NatIso.nat2sum                  ~> sum_decode
  1404   NatIso.list2nat                 ~> list_encode
  1405   NatIso.nat2list                 ~> list_decode
  1406   NatIso.set2nat                  ~> set_encode
  1407   NatIso.nat2set                  ~> set_decode
  1408 
  1409   Lemmas:
  1410   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
  1411   Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
  1412   Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
  1413   Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
  1414   Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
  1415   Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
  1416   Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
  1417   Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
  1418   Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
  1419   Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
  1420   Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
  1421   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
  1422   Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode
  1423 
  1424 * Sledgehammer:
  1425   - Renamed ATP commands:
  1426     atp_info     ~> sledgehammer running_atps
  1427     atp_kill     ~> sledgehammer kill_atps
  1428     atp_messages ~> sledgehammer messages
  1429     atp_minimize ~> sledgehammer minimize
  1430     print_atps   ~> sledgehammer available_atps
  1431     INCOMPATIBILITY.
  1432   - Added user's manual ("isabelle doc sledgehammer").
  1433   - Added option syntax and "sledgehammer_params" to customize
  1434     Sledgehammer's behavior.  See the manual for details.
  1435   - Modified the Isar proof reconstruction code so that it produces
  1436     direct proofs rather than proofs by contradiction.  (This feature
  1437     is still experimental.)
  1438   - Made Isar proof reconstruction work for SPASS, remote ATPs, and in
  1439     full-typed mode.
  1440   - Added support for TPTP syntax for SPASS via the "spass_tptp" ATP.
  1441 
  1442 * Nitpick:
  1443   - Added and implemented "binary_ints" and "bits" options.
  1444   - Added "std" option and implemented support for nonstandard models.
  1445   - Added and implemented "finitize" option to improve the precision
  1446     of infinite datatypes based on a monotonicity analysis.
  1447   - Added support for quotient types.
  1448   - Added support for "specification" and "ax_specification"
  1449     constructs.
  1450   - Added support for local definitions (for "function" and
  1451     "termination" proofs).
  1452   - Added support for term postprocessors.
  1453   - Optimized "Multiset.multiset" and "FinFun.finfun".
  1454   - Improved efficiency of "destroy_constrs" optimization.
  1455   - Fixed soundness bugs related to "destroy_constrs" optimization and
  1456     record getters.
  1457   - Fixed soundness bug related to higher-order constructors.
  1458   - Fixed soundness bug when "full_descrs" is enabled.
  1459   - Improved precision of set constructs.
  1460   - Added "atoms" option.
  1461   - Added cache to speed up repeated Kodkod invocations on the same
  1462     problems.
  1463   - Renamed "MiniSatJNI", "zChaffJNI", "BerkMinAlloy", and
  1464     "SAT4JLight" to "MiniSat_JNI", "zChaff_JNI", "BerkMin_Alloy", and
  1465     "SAT4J_Light".  INCOMPATIBILITY.
  1466   - Removed "skolemize", "uncurry", "sym_break", "flatten_prop",
  1467     "sharing_depth", and "show_skolems" options.  INCOMPATIBILITY.
  1468   - Removed "nitpick_intro" attribute.  INCOMPATIBILITY.
  1469 
  1470 * Method "induct" now takes instantiations of the form t, where t is not
  1471   a variable, as a shorthand for "x == t", where x is a fresh variable.
  1472   If this is not intended, t has to be enclosed in parentheses.
  1473   By default, the equalities generated by definitional instantiations
  1474   are pre-simplified, which may cause parameters of inductive cases
  1475   to disappear, or may even delete some of the inductive cases.
  1476   Use "induct (no_simp)" instead of "induct" to restore the old
  1477   behaviour. The (no_simp) option is also understood by the "cases"
  1478   and "nominal_induct" methods, which now perform pre-simplification, too.
  1479   INCOMPATIBILITY.
  1480 
  1481 
  1482 *** HOLCF ***
  1483 
  1484 * Variable names in lemmas generated by the domain package have
  1485 changed; the naming scheme is now consistent with the HOL datatype
  1486 package.  Some proof scripts may be affected, INCOMPATIBILITY.
  1487 
  1488 * The domain package no longer defines the function "foo_copy" for
  1489 recursive domain "foo".  The reach lemma is now stated directly in
  1490 terms of "foo_take".  Lemmas and proofs that mention "foo_copy" must
  1491 be reformulated in terms of "foo_take", INCOMPATIBILITY.
  1492 
  1493 * Most definedness lemmas generated by the domain package (previously
  1494 of the form "x ~= UU ==> foo$x ~= UU") now have an if-and-only-if form
  1495 like "foo$x = UU <-> x = UU", which works better as a simp rule.
  1496 Proofs that used definedness lemmas as intro rules may break,
  1497 potential INCOMPATIBILITY.
  1498 
  1499 * Induction and casedist rules generated by the domain package now
  1500 declare proper case_names (one called "bottom", and one named for each
  1501 constructor).  INCOMPATIBILITY.
  1502 
  1503 * For mutually-recursive domains, separate "reach" and "take_lemma"
  1504 rules are generated for each domain, INCOMPATIBILITY.
  1505 
  1506   foo_bar.reach       ~> foo.reach  bar.reach
  1507   foo_bar.take_lemmas ~> foo.take_lemma  bar.take_lemma
  1508 
  1509 * Some lemmas generated by the domain package have been renamed for
  1510 consistency with the datatype package, INCOMPATIBILITY.
  1511 
  1512   foo.ind        ~> foo.induct
  1513   foo.finite_ind ~> foo.finite_induct
  1514   foo.coind      ~> foo.coinduct
  1515   foo.casedist   ~> foo.exhaust
  1516   foo.exhaust    ~> foo.nchotomy
  1517 
  1518 * For consistency with other definition packages, the fixrec package
  1519 now generates qualified theorem names, INCOMPATIBILITY.
  1520 
  1521   foo_simps  ~> foo.simps
  1522   foo_unfold ~> foo.unfold
  1523   foo_induct ~> foo.induct
  1524 
  1525 * The "fixrec_simp" attribute has been removed.  The "fixrec_simp"
  1526 method and internal fixrec proofs now use the default simpset instead.
  1527 INCOMPATIBILITY.
  1528 
  1529 * The "contlub" predicate has been removed.  Proof scripts should use
  1530 lemma contI2 in place of monocontlub2cont, INCOMPATIBILITY.
  1531 
  1532 * The "admw" predicate has been removed, INCOMPATIBILITY.
  1533 
  1534 * The constants cpair, cfst, and csnd have been removed in favor of
  1535 Pair, fst, and snd from Isabelle/HOL, INCOMPATIBILITY.
  1536 
  1537 
  1538 *** ML ***
  1539 
  1540 * Antiquotations for basic formal entities:
  1541 
  1542     @{class NAME}         -- type class
  1543     @{class_syntax NAME}  -- syntax representation of the above
  1544 
  1545     @{type_name NAME}     -- logical type
  1546     @{type_abbrev NAME}   -- type abbreviation
  1547     @{nonterminal NAME}   -- type of concrete syntactic category
  1548     @{type_syntax NAME}   -- syntax representation of any of the above
  1549 
  1550     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
  1551     @{const_abbrev NAME}  -- abbreviated constant
  1552     @{const_syntax NAME}  -- syntax representation of any of the above
  1553 
  1554 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
  1555 syntax constant (cf. 'syntax' command).
  1556 
  1557 * Antiquotation @{make_string} inlines a function to print arbitrary
  1558 values similar to the ML toplevel.  The result is compiler dependent
  1559 and may fall back on "?" in certain situations.
  1560 
  1561 * Diagnostic commands 'ML_val' and 'ML_command' may refer to
  1562 antiquotations @{Isar.state} and @{Isar.goal}.  This replaces impure
  1563 Isar.state() and Isar.goal(), which belong to the old TTY loop and do
  1564 not work with the asynchronous Isar document model.
  1565 
  1566 * Configuration options now admit dynamic default values, depending on
  1567 the context or even global references.
  1568 
  1569 * SHA1.digest digests strings according to SHA-1 (see RFC 3174).  It
  1570 uses an efficient external library if available (for Poly/ML).
  1571 
  1572 * Renamed some important ML structures, while keeping the old names
  1573 for some time as aliases within the structure Legacy:
  1574 
  1575   OuterKeyword  ~>  Keyword
  1576   OuterLex      ~>  Token
  1577   OuterParse    ~>  Parse
  1578   OuterSyntax   ~>  Outer_Syntax
  1579   PrintMode     ~>  Print_Mode
  1580   SpecParse     ~>  Parse_Spec
  1581   ThyInfo       ~>  Thy_Info
  1582   ThyLoad       ~>  Thy_Load
  1583   ThyOutput     ~>  Thy_Output
  1584   TypeInfer     ~>  Type_Infer
  1585 
  1586 Note that "open Legacy" simplifies porting of sources, but forgetting
  1587 to remove it again will complicate porting again in the future.
  1588 
  1589 * Most operations that refer to a global context are named
  1590 accordingly, e.g. Simplifier.global_context or
  1591 ProofContext.init_global.  There are some situations where a global
  1592 context actually works, but under normal circumstances one needs to
  1593 pass the proper local context through the code!
  1594 
  1595 * Discontinued old TheoryDataFun with its copy/init operation -- data
  1596 needs to be pure.  Functor Theory_Data_PP retains the traditional
  1597 Pretty.pp argument to merge, which is absent in the standard
  1598 Theory_Data version.
  1599 
  1600 * Sorts.certify_sort and derived "cert" operations for types and terms
  1601 no longer minimize sorts.  Thus certification at the boundary of the
  1602 inference kernel becomes invariant under addition of class relations,
  1603 which is an important monotonicity principle.  Sorts are now minimized
  1604 in the syntax layer only, at the boundary between the end-user and the
  1605 system.  Subtle INCOMPATIBILITY, may have to use Sign.minimize_sort
  1606 explicitly in rare situations.
  1607 
  1608 * Renamed old-style Drule.standard to Drule.export_without_context, to
  1609 emphasize that this is in no way a standard operation.
  1610 INCOMPATIBILITY.
  1611 
  1612 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
  1613 usual for resolution.  Rare INCOMPATIBILITY.
  1614 
  1615 * Renamed varify/unvarify operations to varify_global/unvarify_global
  1616 to emphasize that these only work in a global situation (which is
  1617 quite rare).
  1618 
  1619 * Curried take and drop in library.ML; negative length is interpreted
  1620 as infinity (as in chop).  Subtle INCOMPATIBILITY.
  1621 
  1622 * Proof terms: type substitutions on proof constants now use canonical
  1623 order of type variables.  INCOMPATIBILITY for tools working with proof
  1624 terms.
  1625 
  1626 * Raw axioms/defs may no longer carry sort constraints, and raw defs
  1627 may no longer carry premises.  User-level specifications are
  1628 transformed accordingly by Thm.add_axiom/add_def.
  1629 
  1630 
  1631 *** System ***
  1632 
  1633 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
  1634 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
  1635 proof terms are enabled unconditionally in the new HOL-Proofs image.
  1636 
  1637 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
  1638 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
  1639 respectively.
  1640 
  1641 * Old lib/scripts/polyml-platform is superseded by the
  1642 ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
  1643 variant, even on a 64 bit machine.  The following example setting
  1644 prefers 64 bit if available:
  1645 
  1646   ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"
  1647 
  1648 * The preliminary Isabelle/jEdit application demonstrates the emerging
  1649 Isabelle/Scala layer for advanced prover interaction and integration.
  1650 See src/Tools/jEdit or "isabelle jedit" provided by the properly built
  1651 component.
  1652 
  1653 * "IsabelleText" is a Unicode font derived from Bitstream Vera Mono
  1654 and Bluesky TeX fonts.  It provides the usual Isabelle symbols,
  1655 similar to the default assignment of the document preparation system
  1656 (cf. isabellesym.sty).  The Isabelle/Scala class Isabelle_System
  1657 provides some operations for direct access to the font without asking
  1658 the user for manual installation.
  1659 
  1660 
  1661 
  1662 New in Isabelle2009-1 (December 2009)
  1663 -------------------------------------
  1664 
  1665 *** General ***
  1666 
  1667 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
  1668 one backslash should be used, even in ML sources.
  1669 
  1670 
  1671 *** Pure ***
  1672 
  1673 * Locale interpretation propagates mixins along the locale hierarchy.
  1674 The currently only available mixins are the equations used to map
  1675 local definitions to terms of the target domain of an interpretation.
  1676 
  1677 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
  1678 loc" to print all interpretations of locale "loc" in the theory.
  1679 Interpretations in proofs are not shown.
  1680 
  1681 * Thoroughly revised locales tutorial.  New section on conditional
  1682 interpretation.
  1683 
  1684 * On instantiation of classes, remaining undefined class parameters
  1685 are formally declared.  INCOMPATIBILITY.
  1686 
  1687 
  1688 *** Document preparation ***
  1689 
  1690 * New generalized style concept for printing terms: @{foo (style) ...}
  1691 instead of @{foo_style style ...}  (old form is still retained for
  1692 backward compatibility).  Styles can be also applied for
  1693 antiquotations prop, term_type and typeof.
  1694 
  1695 
  1696 *** HOL ***
  1697 
  1698 * New proof method "smt" for a combination of first-order logic with
  1699 equality, linear and nonlinear (natural/integer/real) arithmetic, and
  1700 fixed-size bitvectors; there is also basic support for higher-order
  1701 features (esp. lambda abstractions).  It is an incomplete decision
  1702 procedure based on external SMT solvers using the oracle mechanism;
  1703 for the SMT solver Z3, this method is proof-producing.  Certificates
  1704 are provided to avoid calling the external solvers solely for
  1705 re-checking proofs.  Due to a remote SMT service there is no need for
  1706 installing SMT solvers locally.  See src/HOL/SMT.
  1707 
  1708 * New commands to load and prove verification conditions generated by
  1709 the Boogie program verifier or derived systems (e.g. the Verifying C
  1710 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
  1711 
  1712 * New counterexample generator tool 'nitpick' based on the Kodkod
  1713 relational model finder.  See src/HOL/Tools/Nitpick and
  1714 src/HOL/Nitpick_Examples.
  1715 
  1716 * New commands 'code_pred' and 'values' to invoke the predicate
  1717 compiler and to enumerate values of inductive predicates.
  1718 
  1719 * A tabled implementation of the reflexive transitive closure.
  1720 
  1721 * New implementation of quickcheck uses generic code generator;
  1722 default generators are provided for all suitable HOL types, records
  1723 and datatypes.  Old quickcheck can be re-activated importing theory
  1724 Library/SML_Quickcheck.
  1725 
  1726 * New testing tool Mirabelle for automated proof tools.  Applies
  1727 several tools and tactics like sledgehammer, metis, or quickcheck, to
  1728 every proof step in a theory.  To be used in batch mode via the
  1729 "mirabelle" utility.
  1730 
  1731 * New proof method "sos" (sum of squares) for nonlinear real
  1732 arithmetic (originally due to John Harison). It requires theory
  1733 Library/Sum_Of_Squares.  It is not a complete decision procedure but
  1734 works well in practice on quantifier-free real arithmetic with +, -,
  1735 *, ^, =, <= and <, i.e. boolean combinations of equalities and
  1736 inequalities between polynomials.  It makes use of external
  1737 semidefinite programming solvers.  Method "sos" generates a
  1738 certificate that can be pasted into the proof thus avoiding the need
  1739 to call an external tool every time the proof is checked.  See
  1740 src/HOL/Library/Sum_Of_Squares.
  1741 
  1742 * New method "linarith" invokes existing linear arithmetic decision
  1743 procedure only.
  1744 
  1745 * New command 'atp_minimal' reduces result produced by Sledgehammer.
  1746 
  1747 * New Sledgehammer option "Full Types" in Proof General settings menu.
  1748 Causes full type information to be output to the ATPs.  This slows
  1749 ATPs down considerably but eliminates a source of unsound "proofs"
  1750 that fail later.
  1751 
  1752 * New method "metisFT": A version of metis that uses full type
  1753 information in order to avoid failures of proof reconstruction.
  1754 
  1755 * New evaluator "approximate" approximates an real valued term using
  1756 the same method as the approximation method.
  1757 
  1758 * Method "approximate" now supports arithmetic expressions as
  1759 boundaries of intervals and implements interval splitting and Taylor
  1760 series expansion.
  1761 
  1762 * ML antiquotation @{code_datatype} inserts definition of a datatype
  1763 generated by the code generator; e.g. see src/HOL/Predicate.thy.
  1764 
  1765 * New theory SupInf of the supremum and infimum operators for sets of
  1766 reals.
  1767 
  1768 * New theory Probability, which contains a development of measure
  1769 theory, eventually leading to Lebesgue integration and probability.
  1770 
  1771 * Extended Multivariate Analysis to include derivation and Brouwer's
  1772 fixpoint theorem.
  1773 
  1774 * Reorganization of number theory, INCOMPATIBILITY:
  1775   - new number theory development for nat and int, in theories Divides
  1776     and GCD as well as in new session Number_Theory
  1777   - some constants and facts now suffixed with _nat and _int
  1778     accordingly
  1779   - former session NumberTheory now named Old_Number_Theory, including
  1780     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
  1781   - moved theory Pocklington from src/HOL/Library to
  1782     src/HOL/Old_Number_Theory
  1783 
  1784 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
  1785 lcm of finite and infinite sets. It is shown that they form a complete
  1786 lattice.
  1787 
  1788 * Class semiring_div requires superclass no_zero_divisors and proof of
  1789 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
  1790 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
  1791 generalized to class semiring_div, subsuming former theorems
  1792 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
  1793 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
  1794 INCOMPATIBILITY.
  1795 
  1796 * Refinements to lattice classes and sets:
  1797   - less default intro/elim rules in locale variant, more default
  1798     intro/elim rules in class variant: more uniformity
  1799   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
  1800     le_inf_iff
  1801   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
  1802     sup_aci)
  1803   - renamed ACI to inf_sup_aci
  1804   - new class "boolean_algebra"
  1805   - class "complete_lattice" moved to separate theory
  1806     "Complete_Lattice"; corresponding constants (and abbreviations)
  1807     renamed and with authentic syntax:
  1808     Set.Inf ~>    Complete_Lattice.Inf
  1809     Set.Sup ~>    Complete_Lattice.Sup
  1810     Set.INFI ~>   Complete_Lattice.INFI
  1811     Set.SUPR ~>   Complete_Lattice.SUPR
  1812     Set.Inter ~>  Complete_Lattice.Inter
  1813     Set.Union ~>  Complete_Lattice.Union
  1814     Set.INTER ~>  Complete_Lattice.INTER
  1815     Set.UNION ~>  Complete_Lattice.UNION
  1816   - authentic syntax for
  1817     Set.Pow
  1818     Set.image
  1819   - mere abbreviations:
  1820     Set.empty               (for bot)
  1821     Set.UNIV                (for top)
  1822     Set.inter               (for inf, formerly Set.Int)
  1823     Set.union               (for sup, formerly Set.Un)
  1824     Complete_Lattice.Inter  (for Inf)
  1825     Complete_Lattice.Union  (for Sup)
  1826     Complete_Lattice.INTER  (for INFI)
  1827     Complete_Lattice.UNION  (for SUPR)
  1828   - object-logic definitions as far as appropriate
  1829 
  1830 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
  1831 Un_subset_iff are explicitly deleted as default simp rules; then also
  1832 their lattice counterparts le_inf_iff and le_sup_iff have to be
  1833 deleted to achieve the desired effect.
  1834 
  1835 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
  1836 rules by default any longer; the same applies to min_max.inf_absorb1
  1837 etc.  INCOMPATIBILITY.
  1838 
  1839 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
  1840 pred_set_conv by default.  INCOMPATIBILITY.
  1841 
  1842 * Power operations on relations and functions are now one dedicated
  1843 constant "compow" with infix syntax "^^".  Power operation on
  1844 multiplicative monoids retains syntax "^" and is now defined generic
  1845 in class power.  INCOMPATIBILITY.
  1846 
  1847 * Relation composition "R O S" now has a more standard argument order:
  1848 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
  1849 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
  1850 break, since the O_assoc rule was not rewritten like this.  Fix using
  1851 O_assoc[symmetric].  The same applies to the curried version "R OO S".
  1852 
  1853 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
  1854 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
  1855 INCOMPATIBILITY.
  1856 
  1857 * Most rules produced by inductive and datatype package have mandatory
  1858 prefixes.  INCOMPATIBILITY.
  1859 
  1860 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
  1861 the attribute of the same name.  Each of the theorems in the list
  1862 DERIV_intros assumes composition with an additional function and
  1863 matches a variable to the derivative, which has to be solved by the
  1864 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
  1865 of most elementary terms.  Former Maclauren.DERIV_tac and
  1866 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
  1867 INCOMPATIBILITY.
  1868 
  1869 * Code generator attributes follow the usual underscore convention:
  1870     code_unfold     replaces    code unfold
  1871     code_post       replaces    code post
  1872     etc.
  1873   INCOMPATIBILITY.
  1874 
  1875 * Renamed methods:
  1876     sizechange -> size_change
  1877     induct_scheme -> induction_schema
  1878   INCOMPATIBILITY.
  1879 
  1880 * Discontinued abbreviation "arbitrary" of constant "undefined".
  1881 INCOMPATIBILITY, use "undefined" directly.
  1882 
  1883 * Renamed theorems:
  1884     Suc_eq_add_numeral_1 -> Suc_eq_plus1
  1885     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
  1886     Suc_plus1 -> Suc_eq_plus1
  1887     *anti_sym -> *antisym*
  1888     vector_less_eq_def -> vector_le_def
  1889   INCOMPATIBILITY.
  1890 
  1891 * Added theorem List.map_map as [simp].  Removed List.map_compose.
  1892 INCOMPATIBILITY.
  1893 
  1894 * Removed predicate "M hassize n" (<--> card M = n & finite M).
  1895 INCOMPATIBILITY.
  1896 
  1897 
  1898 *** HOLCF ***
  1899 
  1900 * Theory Representable defines a class "rep" of domains that are
  1901 representable (via an ep-pair) in the universal domain type "udom".
  1902 Instances are provided for all type constructors defined in HOLCF.
  1903 
  1904 * The 'new_domain' command is a purely definitional version of the
  1905 domain package, for representable domains.  Syntax is identical to the
  1906 old domain package.  The 'new_domain' package also supports indirect
  1907 recursion using previously-defined type constructors.  See
  1908 src/HOLCF/ex/New_Domain.thy for examples.
  1909 
  1910 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
  1911 on the left-hand side of an equation, and then performs
  1912 simplification.  Rewriting is done using rules declared with the
  1913 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
  1914 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
  1915 
  1916 * The pattern-match compiler in 'fixrec' can now handle constructors
  1917 with HOL function types.  Pattern-match combinators for the Pair
  1918 constructor are pre-configured.
  1919 
  1920 * The 'fixrec' package now produces better fixed-point induction rules
  1921 for mutually-recursive definitions:  Induction rules have conclusions
  1922 of the form "P foo bar" instead of "P <foo, bar>".
  1923 
  1924 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
  1925 been renamed to "below".  The name "below" now replaces "less" in many
  1926 theorem names.  (Legacy theorem names using "less" are still supported
  1927 as well.)
  1928 
  1929 * The 'fixrec' package now supports "bottom patterns".  Bottom
  1930 patterns can be used to generate strictness rules, or to make
  1931 functions more strict (much like the bang-patterns supported by the
  1932 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
  1933 examples.
  1934 
  1935 
  1936 *** ML ***
  1937 
  1938 * Support for Poly/ML 5.3.0, with improved reporting of compiler
  1939 errors and run-time exceptions, including detailed source positions.
  1940 
  1941 * Structure Name_Space (formerly NameSpace) now manages uniquely
  1942 identified entries, with some additional information such as source
  1943 position, logical grouping etc.
  1944 
  1945 * Theory and context data is now introduced by the simplified and
  1946 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
  1947 to be pure, but the old TheoryDataFun for mutable data (with explicit
  1948 copy operation) is still available for some time.
  1949 
  1950 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
  1951 provides a high-level programming interface to synchronized state
  1952 variables with atomic update.  This works via pure function
  1953 application within a critical section -- its runtime should be as
  1954 short as possible; beware of deadlocks if critical code is nested,
  1955 either directly or indirectly via other synchronized variables!
  1956 
  1957 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
  1958 wraps raw ML references, explicitly indicating their non-thread-safe
  1959 behaviour.  The Isar toplevel keeps this structure open, to
  1960 accommodate Proof General as well as quick and dirty interactive
  1961 experiments with references.
  1962 
  1963 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
  1964 parallel tactical reasoning.
  1965 
  1966 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
  1967 are similar to SUBPROOF, but are slightly more flexible: only the
  1968 specified parts of the subgoal are imported into the context, and the
  1969 body tactic may introduce new subgoals and schematic variables.
  1970 
  1971 * Old tactical METAHYPS, which does not observe the proof context, has
  1972 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
  1973 or Subgoal.FOCUS etc.
  1974 
  1975 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
  1976 functors have their own ML name space there is no point to mark them
  1977 separately.)  Minor INCOMPATIBILITY.
  1978 
  1979 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
  1980 
  1981 * Renamed several structures FooBar to Foo_Bar.  Occasional,
  1982 INCOMPATIBILITY.
  1983 
  1984 * Operations of structure Skip_Proof no longer require quick_and_dirty
  1985 mode, which avoids critical setmp.
  1986 
  1987 * Eliminated old Attrib.add_attributes, Method.add_methods and related
  1988 combinators for "args".  INCOMPATIBILITY, need to use simplified
  1989 Attrib/Method.setup introduced in Isabelle2009.
  1990 
  1991 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
  1992 back on global_simpset_of, global_claset_of, global_clasimpset_of as
  1993 last resort.  INCOMPATIBILITY.
  1994 
  1995 * Display.pretty_thm now requires a proper context (cf. former
  1996 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
  1997 or even Display.pretty_thm_without_context as last resort.
  1998 INCOMPATIBILITY.
  1999 
  2000 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
  2001 Syntax.pretty_typ/term directly, preferably with proper context
  2002 instead of global theory.
  2003 
  2004 
  2005 *** System ***
  2006 
  2007 * Further fine tuning of parallel proof checking, scales up to 8 cores
  2008 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
  2009 usedir option -q.
  2010 
  2011 * Support for additional "Isabelle components" via etc/components, see
  2012 also the system manual.
  2013 
  2014 * The isabelle makeall tool now operates on all components with
  2015 IsaMakefile, not just hardwired "logics".
  2016 
  2017 * Removed "compress" option from isabelle-process and isabelle usedir;
  2018 this is always enabled.
  2019 
  2020 * Discontinued support for Poly/ML 4.x versions.
  2021 
  2022 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
  2023 on a given logic image.  This requires the lighttpd webserver and is
  2024 currently supported on Linux only.
  2025 
  2026 
  2027 
  2028 New in Isabelle2009 (April 2009)
  2029 --------------------------------
  2030 
  2031 *** General ***
  2032 
  2033 * Simplified main Isabelle executables, with less surprises on
  2034 case-insensitive file-systems (such as Mac OS).
  2035 
  2036   - The main Isabelle tool wrapper is now called "isabelle" instead of
  2037     "isatool."
  2038 
  2039   - The former "isabelle" alias for "isabelle-process" has been
  2040     removed (should rarely occur to regular users).
  2041 
  2042   - The former "isabelle-interface" and its alias "Isabelle" have been
  2043     removed (interfaces are now regular Isabelle tools).
  2044 
  2045 Within scripts and make files, the Isabelle environment variables
  2046 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
  2047 respectively.  (The latter are still available as legacy feature.)
  2048 
  2049 The old isabelle-interface wrapper could react in confusing ways if
  2050 the interface was uninstalled or changed otherwise.  Individual
  2051 interface tool configuration is now more explicit, see also the
  2052 Isabelle system manual.  In particular, Proof General is now available
  2053 via "isabelle emacs".
  2054 
  2055 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
  2056 purge installed copies of Isabelle executables and re-run "isabelle
  2057 install -p ...", or use symlinks.
  2058 
  2059 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
  2060 old ~/isabelle, which was slightly non-standard and apt to cause
  2061 surprises on case-insensitive file-systems (such as Mac OS).
  2062 
  2063 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
  2064 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
  2065 care is required when using older releases of Isabelle.  Note that
  2066 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
  2067 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
  2068 
  2069 * Proofs of fully specified statements are run in parallel on
  2070 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
  2071 a regular 4-core machine, if the initial heap space is made reasonably
  2072 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
  2073 
  2074 * The main reference manuals ("isar-ref", "implementation", and
  2075 "system") have been updated and extended.  Formally checked references
  2076 as hyperlinks are now available uniformly.
  2077 
  2078 
  2079 *** Pure ***
  2080 
  2081 * Complete re-implementation of locales.  INCOMPATIBILITY in several
  2082 respects.  The most important changes are listed below.  See the
  2083 Tutorial on Locales ("locales" manual) for details.
  2084 
  2085 - In locale expressions, instantiation replaces renaming.  Parameters
  2086 must be declared in a for clause.  To aid compatibility with previous
  2087 parameter inheritance, in locale declarations, parameters that are not
  2088 'touched' (instantiation position "_" or omitted) are implicitly added
  2089 with their syntax at the beginning of the for clause.
  2090 
  2091 - Syntax from abbreviations and definitions in locales is available in
  2092 locale expressions and context elements.  The latter is particularly
  2093 useful in locale declarations.
  2094 
  2095 - More flexible mechanisms to qualify names generated by locale
  2096 expressions.  Qualifiers (prefixes) may be specified in locale
  2097 expressions, and can be marked as mandatory (syntax: "name!:") or
  2098 optional (syntax "name?:").  The default depends for plain "name:"
  2099 depends on the situation where a locale expression is used: in
  2100 commands 'locale' and 'sublocale' prefixes are optional, in
  2101 'interpretation' and 'interpret' prefixes are mandatory.  The old
  2102 implicit qualifiers derived from the parameter names of a locale are
  2103 no longer generated.
  2104 
  2105 - Command "sublocale l < e" replaces "interpretation l < e".  The
  2106 instantiation clause in "interpretation" and "interpret" (square
  2107 brackets) is no longer available.  Use locale expressions.
  2108 
  2109 - When converting proof scripts, mandatory qualifiers in
  2110 'interpretation' and 'interpret' should be retained by default, even
  2111 if this is an INCOMPATIBILITY compared to former behavior.  In the
  2112 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
  2113 in locale expressions range over a single locale instance only.
  2114 
  2115 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
  2116 In existing theorem specifications replace the includes element by the
  2117 respective context elements of the included locale, omitting those
  2118 that are already present in the theorem specification.  Multiple
  2119 assume elements of a locale should be replaced by a single one
  2120 involving the locale predicate.  In the proof body, declarations (most
  2121 notably theorems) may be regained by interpreting the respective
  2122 locales in the proof context as required (command "interpret").
  2123 
  2124 If using "includes" in replacement of a target solely because the
  2125 parameter types in the theorem are not as general as in the target,
  2126 consider declaring a new locale with additional type constraints on
  2127 the parameters (context element "constrains").
  2128 
  2129 - Discontinued "locale (open)".  INCOMPATIBILITY.
  2130 
  2131 - Locale interpretation commands no longer attempt to simplify goal.
  2132 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
  2133 methods intro_locales and unfold_locales to clarify.
  2134 
  2135 - Locale interpretation commands no longer accept interpretation
  2136 attributes.  INCOMPATIBILITY.
  2137 
  2138 * Class declaration: so-called "base sort" must not be given in import
  2139 list any longer, but is inferred from the specification.  Particularly
  2140 in HOL, write
  2141 
  2142     class foo = ...
  2143 
  2144 instead of
  2145 
  2146     class foo = type + ...
  2147 
  2148 * Class target: global versions of theorems stemming do not carry a
  2149 parameter prefix any longer.  INCOMPATIBILITY.
  2150 
  2151 * Class 'instance' command no longer accepts attached definitions.
  2152 INCOMPATIBILITY, use proper 'instantiation' target instead.
  2153 
  2154 * Recovered hiding of consts, which was accidentally broken in
  2155 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
  2156 makes c inaccessible; consider using ``hide (open) const c'' instead.
  2157 
  2158 * Slightly more coherent Pure syntax, with updated documentation in
  2159 isar-ref manual.  Removed locales meta_term_syntax and
  2160 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
  2161 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
  2162 directly in regular applications.
  2163 
  2164 * There is a new syntactic category "float_const" for signed decimal
  2165 fractions (e.g. 123.45 or -123.45).
  2166 
  2167 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
  2168 interface with 'setup' command instead.
  2169 
  2170 * Command 'local_setup' is similar to 'setup', but operates on a local
  2171 theory context.
  2172 
  2173 * The 'axiomatization' command now only works within a global theory
  2174 context.  INCOMPATIBILITY.
  2175 
  2176 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
  2177 hypotheses.  Sorts required in the course of reasoning need to be
  2178 covered by the constraints in the initial statement, completed by the
  2179 type instance information of the background theory.  Non-trivial sort
  2180 hypotheses, which rarely occur in practice, may be specified via
  2181 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
  2182 
  2183   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
  2184 
  2185 The result contains an implicit sort hypotheses as before --
  2186 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
  2187 normalization.
  2188 
  2189 * Generalized Isar history, with support for linear undo, direct state
  2190 addressing etc.
  2191 
  2192 * Changed defaults for unify configuration options:
  2193 
  2194   unify_trace_bound = 50 (formerly 25)
  2195   unify_search_bound = 60 (formerly 30)
  2196 
  2197 * Different bookkeeping for code equations (INCOMPATIBILITY):
  2198 
  2199   a) On theory merge, the last set of code equations for a particular
  2200      constant is taken (in accordance with the policy applied by other
  2201      parts of the code generator framework).
  2202 
  2203   b) Code equations stemming from explicit declarations (e.g. code
  2204      attribute) gain priority over default code equations stemming
  2205      from definition, primrec, fun etc.
  2206 
  2207 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
  2208 
  2209 * Unified theorem tables for both code generators.  Thus [code
  2210 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
  2211 
  2212 * Command 'find_consts' searches for constants based on type and name
  2213 patterns, e.g.
  2214 
  2215     find_consts "_ => bool"
  2216 
  2217 By default, matching is against subtypes, but it may be restricted to
  2218 the whole type.  Searching by name is possible.  Multiple queries are
  2219 conjunctive and queries may be negated by prefixing them with a
  2220 hyphen:
  2221 
  2222     find_consts strict: "_ => bool" name: "Int" -"int => int"
  2223 
  2224 * New 'find_theorems' criterion "solves" matches theorems that
  2225 directly solve the current goal (modulo higher-order unification).
  2226 
  2227 * Auto solve feature for main theorem statements: whenever a new goal
  2228 is stated, "find_theorems solves" is called; any theorems that could
  2229 solve the lemma directly are listed as part of the goal state.
  2230 Cf. associated options in Proof General Isabelle settings menu,
  2231 enabled by default, with reasonable timeout for pathological cases of
  2232 higher-order unification.
  2233 
  2234 
  2235 *** Document preparation ***
  2236 
  2237 * Antiquotation @{lemma} now imitates a regular terminal proof,
  2238 demanding keyword 'by' and supporting the full method expression
  2239 syntax just like the Isar command 'by'.
  2240 
  2241 
  2242 *** HOL ***
  2243 
  2244 * Integrated main parts of former image HOL-Complex with HOL.  Entry
  2245 points Main and Complex_Main remain as before.
  2246 
  2247 * Logic image HOL-Plain provides a minimal HOL with the most important
  2248 tools available (inductive, datatype, primrec, ...).  This facilitates
  2249 experimentation and tool development.  Note that user applications
  2250 (and library theories) should never refer to anything below theory
  2251 Main, as before.
  2252 
  2253 * Logic image HOL-Main stops at theory Main, and thus facilitates
  2254 experimentation due to shorter build times.
  2255 
  2256 * Logic image HOL-NSA contains theories of nonstandard analysis which
  2257 were previously part of former HOL-Complex.  Entry point Hyperreal
  2258 remains valid, but theories formerly using Complex_Main should now use
  2259 new entry point Hypercomplex.
  2260 
  2261 * Generic ATP manager for Sledgehammer, based on ML threads instead of
  2262 Posix processes.  Avoids potentially expensive forking of the ML
  2263 process.  New thread-based implementation also works on non-Unix
  2264 platforms (Cygwin).  Provers are no longer hardwired, but defined
  2265 within the theory via plain ML wrapper functions.  Basic Sledgehammer
  2266 commands are covered in the isar-ref manual.
  2267 
  2268 * Wrapper scripts for remote SystemOnTPTP service allows to use
  2269 sledgehammer without local ATP installation (Vampire etc.). Other
  2270 provers may be included via suitable ML wrappers, see also
  2271 src/HOL/ATP_Linkup.thy.
  2272 
  2273 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
  2274 menu.
  2275 
  2276 * The metis method no longer fails because the theorem is too trivial
  2277 (contains the empty clause).
  2278 
  2279 * The metis method now fails in the usual manner, rather than raising
  2280 an exception, if it determines that it cannot prove the theorem.
  2281 
  2282 * Method "coherent" implements a prover for coherent logic (see also
  2283 src/Tools/coherent.ML).
  2284 
  2285 * Constants "undefined" and "default" replace "arbitrary".  Usually
  2286 "undefined" is the right choice to replace "arbitrary", though
  2287 logically there is no difference.  INCOMPATIBILITY.
  2288 
  2289 * Command "value" now integrates different evaluation mechanisms.  The
  2290 result of the first successful evaluation mechanism is printed.  In
  2291 square brackets a particular named evaluation mechanisms may be
  2292 specified (currently, [SML], [code] or [nbe]).  See further
  2293 src/HOL/ex/Eval_Examples.thy.
  2294 
  2295 * Normalization by evaluation now allows non-leftlinear equations.
  2296 Declare with attribute [code nbe].
  2297 
  2298 * Methods "case_tac" and "induct_tac" now refer to the very same rules
  2299 as the structured Isar versions "cases" and "induct", cf. the
  2300 corresponding "cases" and "induct" attributes.  Mutual induction rules
  2301 are now presented as a list of individual projections
  2302 (e.g. foo_bar.inducts for types foo and bar); the old format with
  2303 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
  2304 rare situations a different rule is selected --- notably nested tuple
  2305 elimination instead of former prod.exhaust: use explicit (case_tac t
  2306 rule: prod.exhaust) here.
  2307 
  2308 * Attributes "cases", "induct", "coinduct" support "del" option.
  2309 
  2310 * Removed fact "case_split_thm", which duplicates "case_split".
  2311 
  2312 * The option datatype has been moved to a new theory Option.  Renamed
  2313 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
  2314 
  2315 * New predicate "strict_mono" classifies strict functions on partial
  2316 orders.  With strict functions on linear orders, reasoning about
  2317 (in)equalities is facilitated by theorems "strict_mono_eq",
  2318 "strict_mono_less_eq" and "strict_mono_less".
  2319 
  2320 * Some set operations are now proper qualified constants with
  2321 authentic syntax.  INCOMPATIBILITY:
  2322 
  2323     op Int ~>   Set.Int
  2324     op Un ~>    Set.Un
  2325     INTER ~>    Set.INTER
  2326     UNION ~>    Set.UNION
  2327     Inter ~>    Set.Inter
  2328     Union ~>    Set.Union
  2329     {} ~>       Set.empty
  2330     UNIV ~>     Set.UNIV
  2331 
  2332 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  2333 theory Set.
  2334 
  2335 * Auxiliary class "itself" has disappeared -- classes without any
  2336 parameter are treated as expected by the 'class' command.
  2337 
  2338 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  2339 
  2340 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  2341 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  2342 
  2343 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  2344 method "approximation".  It proves formulas on real values by using
  2345 interval arithmetic.  In the formulas are also the transcendental
  2346 functions sin, cos, tan, atan, ln, exp and the constant pi are
  2347 allowed. For examples see
  2348 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  2349 
  2350 * Theory "Reflection" now resides in HOL/Library.
  2351 
  2352 * Entry point to Word library now simply named "Word".
  2353 INCOMPATIBILITY.
  2354 
  2355 * Made source layout more coherent with logical distribution
  2356 structure:
  2357 
  2358     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  2359     src/HOL/Library/Code_Message.thy ~> src/HOL/
  2360     src/HOL/Library/GCD.thy ~> src/HOL/
  2361     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  2362     src/HOL/Library/Parity.thy ~> src/HOL/
  2363     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  2364     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  2365     src/HOL/Real/Lubs.thy ~> src/HOL/
  2366     src/HOL/Real/PReal.thy ~> src/HOL/
  2367     src/HOL/Real/Rational.thy ~> src/HOL/
  2368     src/HOL/Real/RComplete.thy ~> src/HOL/
  2369     src/HOL/Real/RealDef.thy ~> src/HOL/
  2370     src/HOL/Real/RealPow.thy ~> src/HOL/
  2371     src/HOL/Real/Real.thy ~> src/HOL/
  2372     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  2373     src/HOL/Complex/Complex.thy ~> src/HOL/
  2374     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  2375     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  2376     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  2377     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  2378     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  2379     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  2380     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  2381     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  2382     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  2383     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  2384     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  2385     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  2386     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  2387     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  2388     src/HOL/Real/Float ~> src/HOL/Library/
  2389     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  2390     src/HOL/Real/RealVector.thy ~> src/HOL/
  2391 
  2392     src/HOL/arith_data.ML ~> src/HOL/Tools
  2393     src/HOL/hologic.ML ~> src/HOL/Tools
  2394     src/HOL/simpdata.ML ~> src/HOL/Tools
  2395     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  2396     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  2397     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  2398     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  2399     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  2400     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  2401     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  2402 
  2403     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  2404     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  2405     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  2406     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  2407     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  2408     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  2409 
  2410 * If methods "eval" and "evaluation" encounter a structured proof
  2411 state with !!/==>, only the conclusion is evaluated to True (if
  2412 possible), avoiding strange error messages.
  2413 
  2414 * Method "sizechange" automates termination proofs using (a
  2415 modification of) the size-change principle.  Requires SAT solver.  See
  2416 src/HOL/ex/Termination.thy for examples.
  2417 
  2418 * Simplifier: simproc for let expressions now unfolds if bound
  2419 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  2420 
  2421 * Method "arith": Linear arithmetic now ignores all inequalities when
  2422 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  2423 
  2424 * New attribute "arith" for facts that should always be used
  2425 automatically by arithmetic. It is intended to be used locally in
  2426 proofs, e.g.
  2427 
  2428   assumes [arith]: "x > 0"
  2429 
  2430 Global usage is discouraged because of possible performance impact.
  2431 
  2432 * New classes "top" and "bot" with corresponding operations "top" and
  2433 "bot" in theory Orderings; instantiation of class "complete_lattice"
  2434 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  2435 
  2436 * Changed definition lemma "less_fun_def" in order to provide an
  2437 instance for preorders on functions; use lemma "less_le" instead.
  2438 INCOMPATIBILITY.
  2439 
  2440 * Theory Orderings: class "wellorder" moved here, with explicit
  2441 induction rule "less_induct" as assumption.  For instantiation of
  2442 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  2443 INCOMPATIBILITY.
  2444 
  2445 * Theory Orderings: added class "preorder" as superclass of "order".
  2446 INCOMPATIBILITY: Instantiation proofs for order, linorder
  2447 etc. slightly changed.  Some theorems named order_class.* now named
  2448 preorder_class.*.
  2449 
  2450 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  2451 "diag" to "Id_on".
  2452 
  2453 * Theory Finite_Set: added a new fold combinator of type
  2454 
  2455   ('a => 'b => 'b) => 'b => 'a set => 'b
  2456 
  2457 Occasionally this is more convenient than the old fold combinator
  2458 which is now defined in terms of the new one and renamed to
  2459 fold_image.
  2460 
  2461 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  2462 and "ring_simps" have been replaced by "algebra_simps" (which can be
  2463 extended with further lemmas!).  At the moment both still exist but
  2464 the former will disappear at some point.
  2465 
  2466 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  2467 class recpower.  Type-specific simp rules for various recpower types
  2468 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  2469 
  2470 rat_power_0    -> power_0
  2471 rat_power_Suc  -> power_Suc
  2472 realpow_0      -> power_0
  2473 realpow_Suc    -> power_Suc
  2474 complexpow_0   -> power_0
  2475 complexpow_Suc -> power_Suc
  2476 power_poly_0   -> power_0
  2477 power_poly_Suc -> power_Suc
  2478 
  2479 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  2480 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  2481 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  2482 of lemmas from Divides has been generalized from nat to class
  2483 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  2484 renames resulting from duplicate elimination:
  2485 
  2486     dvd_def_mod ~>          dvd_eq_mod_eq_0
  2487     zero_dvd_iff ~>         dvd_0_left_iff
  2488     dvd_0 ~>                dvd_0_right
  2489     DIVISION_BY_ZERO_DIV ~> div_by_0
  2490     DIVISION_BY_ZERO_MOD ~> mod_by_0
  2491     mult_div ~>             div_mult_self2_is_id
  2492     mult_mod ~>             mod_mult_self2_is_0
  2493 
  2494 * Theory IntDiv: removed many lemmas that are instances of class-based
  2495 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  2496 rename old lemmas as follows:
  2497 
  2498 dvd_diff               -> nat_dvd_diff
  2499 dvd_zminus_iff         -> dvd_minus_iff
  2500 mod_add1_eq            -> mod_add_eq
  2501 mod_mult1_eq           -> mod_mult_right_eq
  2502 mod_mult1_eq'          -> mod_mult_left_eq
  2503 mod_mult_distrib_mod   -> mod_mult_eq
  2504 nat_mod_add_left_eq    -> mod_add_left_eq
  2505 nat_mod_add_right_eq   -> mod_add_right_eq
  2506 nat_mod_div_trivial    -> mod_div_trivial
  2507 nat_mod_mod_trivial    -> mod_mod_trivial
  2508 zdiv_zadd_self1        -> div_add_self1
  2509 zdiv_zadd_self2        -> div_add_self2
  2510 zdiv_zmult_self1       -> div_mult_self2_is_id
  2511 zdiv_zmult_self2       -> div_mult_self1_is_id
  2512 zdvd_triv_left         -> dvd_triv_left
  2513 zdvd_triv_right        -> dvd_triv_right
  2514 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  2515 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  2516 zmod_zadd_left_eq      -> mod_add_left_eq
  2517 zmod_zadd_right_eq     -> mod_add_right_eq
  2518 zmod_zadd_self1        -> mod_add_self1
  2519 zmod_zadd_self2        -> mod_add_self2
  2520 zmod_zadd1_eq          -> mod_add_eq
  2521 zmod_zdiff1_eq         -> mod_diff_eq
  2522 zmod_zdvd_zmod         -> mod_mod_cancel
  2523 zmod_zmod_cancel       -> mod_mod_cancel
  2524 zmod_zmult_self1       -> mod_mult_self2_is_0
  2525 zmod_zmult_self2       -> mod_mult_self1_is_0
  2526 zmod_1                 -> mod_by_1
  2527 zdiv_1                 -> div_by_1
  2528 zdvd_abs1              -> abs_dvd_iff
  2529 zdvd_abs2              -> dvd_abs_iff
  2530 zdvd_refl              -> dvd_refl
  2531 zdvd_trans             -> dvd_trans
  2532 zdvd_zadd              -> dvd_add
  2533 zdvd_zdiff             -> dvd_diff
  2534 zdvd_zminus_iff        -> dvd_minus_iff
  2535 zdvd_zminus2_iff       -> minus_dvd_iff
  2536 zdvd_zmultD            -> dvd_mult_right
  2537 zdvd_zmultD2           -> dvd_mult_left
  2538 zdvd_zmult_mono        -> mult_dvd_mono
  2539 zdvd_0_right           -> dvd_0_right
  2540 zdvd_0_left            -> dvd_0_left_iff
  2541 zdvd_1_left            -> one_dvd
  2542 zminus_dvd_iff         -> minus_dvd_iff
  2543 
  2544 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  2545 
  2546 * The real numbers offer decimal input syntax: 12.34 is translated
  2547 into 1234/10^2. This translation is not reversed upon output.
  2548 
  2549 * Theory Library/Polynomial defines an abstract type 'a poly of
  2550 univariate polynomials with coefficients of type 'a.  In addition to
  2551 the standard ring operations, it also supports div and mod.  Code
  2552 generation is also supported, using list-style constructors.
  2553 
  2554 * Theory Library/Inner_Product defines a class of real_inner for real
  2555 inner product spaces, with an overloaded operation inner :: 'a => 'a
  2556 => real.  Class real_inner is a subclass of real_normed_vector from
  2557 theory RealVector.
  2558 
  2559 * Theory Library/Product_Vector provides instances for the product
  2560 type 'a * 'b of several classes from RealVector and Inner_Product.
  2561 Definitions of addition, subtraction, scalar multiplication, norms,
  2562 and inner products are included.
  2563 
  2564 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  2565 addition to the field operations, numerals and case syntax are also
  2566 supported.
  2567 
  2568 * Theory Library/Diagonalize provides constructive version of Cantor's
  2569 first diagonalization argument.
  2570 
  2571 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  2572 zlcm (for int); carried together from various gcd/lcm developements in
  2573 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  2574 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  2575 may recover tupled syntax as follows:
  2576 
  2577     hide (open) const gcd
  2578     abbreviation gcd where
  2579       "gcd == (%(a, b). GCD.gcd a b)"
  2580     notation (output)
  2581       GCD.gcd ("gcd '(_, _')")
  2582 
  2583 The same works for lcm, zgcd, zlcm.
  2584 
  2585 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  2586 instantiations for algebraic structures.  Removed some duplicate
  2587 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  2588 
  2589 * ML antiquotation @{code} takes a constant as argument and generates
  2590 corresponding code in background and inserts name of the corresponding
  2591 resulting ML value/function/datatype constructor binding in place.
  2592 All occurrences of @{code} with a single ML block are generated
  2593 simultaneously.  Provides a generic and safe interface for
  2594 instrumentalizing code generation.  See
  2595 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  2596 In future you ought to refrain from ad-hoc compiling generated SML
  2597 code on the ML toplevel.  Note that (for technical reasons) @{code}
  2598 cannot refer to constants for which user-defined serializations are
  2599 set.  Refer to the corresponding ML counterpart directly in that
  2600 cases.
  2601 
  2602 * Command 'rep_datatype': instead of theorem names the command now
  2603 takes a list of terms denoting the constructors of the type to be
  2604 represented as datatype.  The characteristic theorems have to be
  2605 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  2606 have disappeared in favour of existing ones:
  2607 
  2608     unit_induct                 ~> unit.induct
  2609     prod_induct                 ~> prod.induct
  2610     sum_induct                  ~> sum.induct
  2611     Suc_Suc_eq                  ~> nat.inject
  2612     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  2613 
  2614 
  2615 *** HOL-Algebra ***
  2616 
  2617 * New locales for orders and lattices where the equivalence relation
  2618 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  2619 locales use a record structure with field eq for the equivalence.
  2620 
  2621 * New theory of factorial domains.
  2622 
  2623 * Units_l_inv and Units_r_inv are now simp rules by default.
  2624 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  2625 and/or r_inv will now also require deletion of these lemmas.
  2626 
  2627 * Renamed the following theorems, INCOMPATIBILITY:
  2628 
  2629 UpperD ~> Upper_memD
  2630 LowerD ~> Lower_memD
  2631 least_carrier ~> least_closed
  2632 greatest_carrier ~> greatest_closed
  2633 greatest_Lower_above ~> greatest_Lower_below
  2634 one_zero ~> carrier_one_zero
  2635 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  2636 
  2637 
  2638 *** HOL-Nominal ***
  2639 
  2640 * Nominal datatypes can now contain type-variables.
  2641 
  2642 * Commands 'nominal_inductive' and 'equivariance' work with local
  2643 theory targets.
  2644 
  2645 * Nominal primrec can now works with local theory targets and its
  2646 specification syntax now conforms to the general format as seen in
  2647 'inductive' etc.
  2648 
  2649 * Method "perm_simp" honours the standard simplifier attributes
  2650 (no_asm), (no_asm_use) etc.
  2651 
  2652 * The new predicate #* is defined like freshness, except that on the
  2653 left hand side can be a set or list of atoms.
  2654 
  2655 * Experimental command 'nominal_inductive2' derives strong induction
  2656 principles for inductive definitions.  In contrast to
  2657 'nominal_inductive', which can only deal with a fixed number of
  2658 binders, it can deal with arbitrary expressions standing for sets of
  2659 atoms to be avoided.  The only inductive definition we have at the
  2660 moment that needs this generalisation is the typing rule for Lets in
  2661 the algorithm W:
  2662 
  2663  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  2664  -----------------------------------------------------------------
  2665          Gamma |- Let x be t1 in t2 : T2
  2666 
  2667 In this rule one wants to avoid all the binders that are introduced by
  2668 "close Gamma T1".  We are looking for other examples where this
  2669 feature might be useful.  Please let us know.
  2670 
  2671 
  2672 *** HOLCF ***
  2673 
  2674 * Reimplemented the simplification procedure for proving continuity
  2675 subgoals.  The new simproc is extensible; users can declare additional
  2676 continuity introduction rules with the attribute [cont2cont].
  2677 
  2678 * The continuity simproc now uses a different introduction rule for
  2679 solving continuity subgoals on terms with lambda abstractions.  In
  2680 some rare cases the new simproc may fail to solve subgoals that the
  2681 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  2682 Potential INCOMPATIBILITY.
  2683 
  2684 * Command 'fixrec': specification syntax now conforms to the general
  2685 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  2686 examples.  INCOMPATIBILITY.
  2687 
  2688 
  2689 *** ZF ***
  2690 
  2691 * Proof of Zorn's Lemma for partial orders.
  2692 
  2693 
  2694 *** ML ***
  2695 
  2696 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  2697 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  2698 depends on multithreading, so timouts will not work before Poly/ML
  2699 5.2.1!
  2700 
  2701 * High-level support for concurrent ML programming, see
  2702 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  2703 particularly convenient to organize independent functional
  2704 computations.  The concept of "synchronized variables" provides a
  2705 higher-order interface for components with shared state, avoiding the
  2706 delicate details of mutexes and condition variables.  (Requires
  2707 Poly/ML 5.2.1 or later.)
  2708 
  2709 * ML bindings produced via Isar commands are stored within the Isar
  2710 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  2711 become thread-safe and work with undo as expected (concerning
  2712 top-level bindings, not side-effects on global references).
  2713 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  2714 compiler at runtime; really global bindings need to be given outside a
  2715 theory.  (Requires Poly/ML 5.2 or later.)
  2716 
  2717 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  2718 context.  Top-level ML bindings are stored within the proof context in
  2719 a purely sequential fashion, disregarding the nested proof structure.
  2720 ML bindings introduced by 'ML_prf' are discarded at the end of the
  2721 proof.  (Requires Poly/ML 5.2 or later.)
  2722 
  2723 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  2724 and Method.setup, as well as Isar commands 'attribute_setup' and
  2725 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  2726 existing code accordingly, or use plain 'setup' together with old
  2727 Method.add_method.
  2728 
  2729 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  2730 to 'a -> thm, while results are always tagged with an authentic oracle
  2731 name.  The Isar command 'oracle' is now polymorphic, no argument type
  2732 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  2733 accordingly.  Note that extra performance may be gained by producing
  2734 the cterm carefully, avoiding slow Thm.cterm_of.
  2735 
  2736 * Simplified interface for defining document antiquotations via
  2737 ThyOutput.antiquotation, ThyOutput.output, and optionally
  2738 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  2739 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  2740 examples.
  2741 
  2742 * More systematic treatment of long names, abstract name bindings, and
  2743 name space operations.  Basic operations on qualified names have been
  2744 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  2745 Long_Name.append.  Old type bstring has been mostly replaced by
  2746 abstract type binding (see structure Binding), which supports precise
  2747 qualification by packages and local theory targets, as well as proper
  2748 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  2749 bstring values into Binding.name, or better pass through abstract
  2750 bindings everywhere.  See further src/Pure/General/long_name.ML,
  2751 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  2752 
  2753 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  2754 LocalTheory.note etc.) now refer to the *full* internal name, not the
  2755 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  2756 
  2757 * Disposed old type and term read functions (Sign.read_def_typ,
  2758 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  2759 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  2760 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  2761 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  2762 resort for legacy applications.
  2763 
  2764 * Disposed old declarations, tactics, tactic combinators that refer to
  2765 the simpset or claset of an implicit theory (such as Addsimps,
  2766 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  2767 embedded ML text, or local_simpset_of with a proper context passed as
  2768 explicit runtime argument.
  2769 
  2770 * Rules and tactics that read instantiations (read_instantiate,
  2771 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  2772 context, which is required for parsing and type-checking.  Moreover,
  2773 the variables are specified as plain indexnames, not string encodings
  2774 thereof.  INCOMPATIBILITY.
  2775 
  2776 * Generic Toplevel.add_hook interface allows to analyze the result of
  2777 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  2778 for theorem dependency output of transactions resulting in a new
  2779 theory state.
  2780 
  2781 * ML antiquotations: block-structured compilation context indicated by
  2782 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  2783 
  2784   @{binding name}                         - basic name binding
  2785   @{let ?pat = term}                      - term abbreviation (HO matching)
  2786   @{note name = fact}                     - fact abbreviation
  2787   @{thm fact}                             - singleton fact (with attributes)
  2788   @{thms fact}                            - general fact (with attributes)
  2789   @{lemma prop by method}                 - singleton goal
  2790   @{lemma prop by meth1 meth2}            - singleton goal
  2791   @{lemma prop1 ... propN by method}      - general goal
  2792   @{lemma prop1 ... propN by meth1 meth2} - general goal
  2793   @{lemma (open) ...}                     - open derivation
  2794 
  2795 
  2796 *** System ***
  2797 
  2798 * The Isabelle "emacs" tool provides a specific interface to invoke
  2799 Proof General / Emacs, with more explicit failure if that is not
  2800 installed (the old isabelle-interface script silently falls back on
  2801 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  2802 installation location of the Proof General distribution.
  2803 
  2804 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  2805 the Isabelle process into a JVM/Scala application.  See
  2806 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  2807 process wrapper has been discontinued.)
  2808 
  2809 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  2810 
  2811 * Various status messages (with exact source position information) are
  2812 emitted, if proper markup print mode is enabled.  This allows
  2813 user-interface components to provide detailed feedback on internal
  2814 prover operations.
  2815 
  2816 
  2817 
  2818 New in Isabelle2008 (June 2008)
  2819 -------------------------------
  2820 
  2821 *** General ***
  2822 
  2823 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  2824 and updated, with formally checked references as hyperlinks.
  2825 
  2826 * Theory loader: use_thy (and similar operations) no longer set the
  2827 implicit ML context, which was occasionally hard to predict and in
  2828 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  2829 provides a proper context already.
  2830 
  2831 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2832 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  2833 'use' within a theory file will do the job.
  2834 
  2835 * Name space merge now observes canonical order, i.e. the second space
  2836 is inserted into the first one, while existing entries in the first
  2837 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  2838 swap theory imports.
  2839 
  2840 * Syntax: symbol \<chi> is now considered a letter.  Potential
  2841 INCOMPATIBILITY in identifier syntax etc.
  2842 
  2843 * Outer syntax: string tokens no longer admit escaped white space,
  2844 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  2845 white space without escapes.
  2846 
  2847 * Outer syntax: string tokens may contain arbitrary character codes
  2848 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  2849 "foo_bar".
  2850 
  2851 
  2852 *** Pure ***
  2853 
  2854 * Context-dependent token translations.  Default setup reverts locally
  2855 fixed variables, and adds hilite markup for undeclared frees.
  2856 
  2857 * Unused theorems can be found using the new command 'unused_thms'.
  2858 There are three ways of invoking it:
  2859 
  2860 (1) unused_thms
  2861      Only finds unused theorems in the current theory.
  2862 
  2863 (2) unused_thms thy_1 ... thy_n -
  2864      Finds unused theorems in the current theory and all of its ancestors,
  2865      excluding the theories thy_1 ... thy_n and all of their ancestors.
  2866 
  2867 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  2868      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  2869      their ancestors, excluding the theories thy_1 ... thy_n and all of
  2870      their ancestors.
  2871 
  2872 In order to increase the readability of the list produced by
  2873 unused_thms, theorems that have been created by a particular instance
  2874 of a theory command such as 'inductive' or 'function' are considered
  2875 to belong to the same "group", meaning that if at least one theorem in
  2876 this group is used, the other theorems in the same group are no longer
  2877 reported as unused.  Moreover, if all theorems in the group are
  2878 unused, only one theorem in the group is displayed.
  2879 
  2880 Note that proof objects have to be switched on in order for
  2881 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  2882 usually the case when using Proof General with the default settings).
  2883 
  2884 * Authentic naming of facts disallows ad-hoc overwriting of previous
  2885 theorems within the same name space.  INCOMPATIBILITY, need to remove
  2886 duplicate fact bindings, or even accidental fact duplications.  Note
  2887 that tools may maintain dynamically scoped facts systematically, using
  2888 PureThy.add_thms_dynamic.
  2889 
  2890 * Command 'hide' now allows to hide from "fact" name space as well.
  2891 
  2892 * Eliminated destructive theorem database, simpset, claset, and
  2893 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  2894 update of theories within ML code.
  2895 
  2896 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  2897 INCOMPATIBILITY, object-logics depending on former Pure require
  2898 additional setup PureThy.old_appl_syntax_setup; object-logics
  2899 depending on former CPure need to refer to Pure.
  2900 
  2901 * Commands 'use' and 'ML' are now purely functional, operating on
  2902 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  2903 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  2904 INCOMPATIBILITY.
  2905 
  2906 * Command 'setup': discontinued implicit version with ML reference.
  2907 
  2908 * Instantiation target allows for simultaneous specification of class
  2909 instance operations together with an instantiation proof.
  2910 Type-checking phase allows to refer to class operations uniformly.
  2911 See src/HOL/Complex/Complex.thy for an Isar example and
  2912 src/HOL/Library/Eval.thy for an ML example.
  2913 
  2914 * Indexing of literal facts: be more serious about including only
  2915 facts from the visible specification/proof context, but not the
  2916 background context (locale etc.).  Affects `prop` notation and method
  2917 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  2918 situations.
  2919 
  2920 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  2921 "(open)" option, which used to expose internal bound variables to the
  2922 proof text.
  2923 
  2924 * Isar statements: removed obsolete case "rule_context".
  2925 INCOMPATIBILITY, better use explicit fixes/assumes.
  2926 
  2927 * Locale proofs: default proof step now includes 'unfold_locales';
  2928 hence 'proof' without argument may be used to unfold locale
  2929 predicates.
  2930 
  2931 
  2932 *** Document preparation ***
  2933 
  2934 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  2935 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  2936 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  2937 spot); renamed link color from "darkblue" to "linkcolor" (default
  2938 value unchanged, can be redefined via \definecolor); no longer sets
  2939 "a4paper" option (unnecessary or even intrusive).
  2940 
  2941 * Antiquotation @{lemma A method} proves proposition A by the given
  2942 method (either a method name or a method name plus (optional) method
  2943 arguments in parentheses) and prints A just like @{prop A}.
  2944 
  2945 
  2946 *** HOL ***
  2947 
  2948 * New primrec package.  Specification syntax conforms in style to
  2949 definition/function/....  No separate induction rule is provided.  The
  2950 "primrec" command distinguishes old-style and new-style specifications
  2951 by syntax.  The former primrec package is now named OldPrimrecPackage.
  2952 When adjusting theories, beware: constants stemming from new-style
  2953 primrec specifications have authentic syntax.
  2954 
  2955 * Metis prover is now an order of magnitude faster, and also works
  2956 with multithreading.
  2957 
  2958 * Metis: the maximum number of clauses that can be produced from a
  2959 theorem is now given by the attribute max_clauses.  Theorems that
  2960 exceed this number are ignored, with a warning printed.
  2961 
  2962 * Sledgehammer no longer produces structured proofs by default. To
  2963 enable, declare [[sledgehammer_full = true]].  Attributes
  2964 reconstruction_modulus, reconstruction_sorts renamed
  2965 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  2966 
  2967 * Method "induct_scheme" derives user-specified induction rules
  2968 from well-founded induction and completeness of patterns. This factors
  2969 out some operations that are done internally by the function package
  2970 and makes them available separately.  See
  2971 src/HOL/ex/Induction_Scheme.thy for examples.
  2972 
  2973 * More flexible generation of measure functions for termination
  2974 proofs: Measure functions can be declared by proving a rule of the
  2975 form "is_measure f" and giving it the [measure_function] attribute.
  2976 The "is_measure" predicate is logically meaningless (always true), and
  2977 just guides the heuristic.  To find suitable measure functions, the
  2978 termination prover sets up the goal "is_measure ?f" of the appropriate
  2979 type and generates all solutions by prolog-style backwards proof using
  2980 the declared rules.
  2981 
  2982 This setup also deals with rules like 
  2983 
  2984   "is_measure f ==> is_measure (list_size f)"
  2985 
  2986 which accommodates nested datatypes that recurse through lists.
  2987 Similar rules are predeclared for products and option types.
  2988 
  2989 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  2990 
  2991   INCOMPATIBILITIES:
  2992 
  2993   - Definitions of overloaded constants on sets have to be replaced by
  2994     definitions on => and bool.
  2995 
  2996   - Some definitions of overloaded operators on sets can now be proved
  2997     using the definitions of the operators on => and bool.  Therefore,
  2998     the following theorems have been renamed:
  2999 
  3000       subset_def   -> subset_eq
  3001       psubset_def  -> psubset_eq
  3002       set_diff_def -> set_diff_eq
  3003       Compl_def    -> Compl_eq
  3004       Sup_set_def  -> Sup_set_eq
  3005       Inf_set_def  -> Inf_set_eq
  3006       sup_set_def  -> sup_set_eq
  3007       inf_set_def  -> inf_set_eq
  3008 
  3009   - Due to the incompleteness of the HO unification algorithm, some
  3010     rules such as subst may require manual instantiation, if some of
  3011     the unknowns in the rule is a set.
  3012 
  3013   - Higher order unification and forward proofs:
  3014     The proof pattern
  3015 
  3016       have "P (S::'a set)" <...>
  3017       then have "EX S. P S" ..
  3018 
  3019     no longer works (due to the incompleteness of the HO unification
  3020     algorithm) and must be replaced by the pattern
  3021 
  3022       have "EX S. P S"
  3023       proof
  3024         show "P S" <...>
  3025       qed
  3026 
  3027   - Calculational reasoning with subst (or similar rules):
  3028     The proof pattern
  3029 
  3030       have "P (S::'a set)" <...>
  3031       also have "S = T" <...>
  3032       finally have "P T" .
  3033 
  3034     no longer works (for similar reasons as the previous example) and
  3035     must be replaced by something like
  3036 
  3037       have "P (S::'a set)" <...>
  3038       moreover have "S = T" <...>
  3039       ultimately have "P T" by simp
  3040 
  3041   - Tactics or packages written in ML code:
  3042     Code performing pattern matching on types via
  3043 
  3044       Type ("set", [T]) => ...
  3045 
  3046     must be rewritten. Moreover, functions like strip_type or
  3047     binder_types no longer return the right value when applied to a
  3048     type of the form
  3049 
  3050       T1 => ... => Tn => U => bool
  3051 
  3052     rather than
  3053 
  3054       T1 => ... => Tn => U set
  3055 
  3056 * Merged theories Wellfounded_Recursion, Accessible_Part and
  3057 Wellfounded_Relations to theory Wellfounded.
  3058 
  3059 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  3060 
  3061 * Class finite no longer treats UNIV as class parameter.  Use class
  3062 enum from theory Library/Enum instead to achieve a similar effect.
  3063 INCOMPATIBILITY.
  3064 
  3065 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  3066 and "Cons".  INCOMPATIBILITY.
  3067 
  3068 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  3069 Potential INCOMPATIBILITY.
  3070 
  3071 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  3072 injective_fst_snd removed, use split_eta and prod_eqI instead.
  3073 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  3074 
  3075 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  3076 the same name in theory Orderings:
  3077 
  3078   less_trans
  3079   less_linear
  3080   le_imp_less_or_eq
  3081   le_less_trans
  3082   less_le_trans
  3083   less_not_sym
  3084   less_asym
  3085 
  3086 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  3087 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  3088 and different variable names.
  3089 
  3090 * Library/Option_ord.thy: Canonical order on option type.
  3091 
  3092 * Library/RBT.thy: Red-black trees, an efficient implementation of
  3093 finite maps.
  3094 
  3095 * Library/Countable.thy: Type class for countable types.
  3096 
  3097 * Theory Int: The representation of numerals has changed.  The infix
  3098 operator BIT and the bit datatype with constructors B0 and B1 have
  3099 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  3100 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  3101 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  3102 accordingly.
  3103 
  3104 * Theory Nat: definition of <= and < on natural numbers no longer
  3105 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  3106 le_def and less_def have disappeared.  Consider lemmas not_less
  3107 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  3108 
  3109 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  3110 (whose purpose mainly is for various fold_set functionals) have been
  3111 abandoned in favor of the existing algebraic classes
  3112 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  3113 lower_semilattice (resp. upper_semilattice) and linorder.
  3114 INCOMPATIBILITY.
  3115 
  3116 * Theory Transitive_Closure: induct and cases rules now declare proper
  3117 case_names ("base" and "step").  INCOMPATIBILITY.
  3118 
  3119 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  3120 lattices.  The form set-specific version is available as
  3121 Inductive.lfp_ordinal_induct_set.
  3122 
  3123 * Renamed theorems "power.simps" to "power_int.simps".
  3124 INCOMPATIBILITY.
  3125 
  3126 * Class semiring_div provides basic abstract properties of semirings
  3127 with division and modulo operations.  Subsumes former class dvd_mod.
  3128 
  3129 * Merged theories IntDef, Numeral and IntArith into unified theory
  3130 Int.  INCOMPATIBILITY.
  3131 
  3132 * Theory Library/Code_Index: type "index" now represents natural
  3133 numbers rather than integers.  INCOMPATIBILITY.
  3134 
  3135 * New class "uminus" with operation "uminus" (split of from class
  3136 "minus" which now only has operation "minus", binary).
  3137 INCOMPATIBILITY.
  3138 
  3139 * Constants "card", "internal_split", "option_map" now with authentic
  3140 syntax.  INCOMPATIBILITY.
  3141 
  3142 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  3143 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  3144 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  3145 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  3146 Sup_set_def, le_def, less_def, option_map_def now with object
  3147 equality.  INCOMPATIBILITY.
  3148 
  3149 * Records. Removed K_record, and replaced it by pure lambda term
  3150 %x. c. The simplifier setup is now more robust against eta expansion.
  3151 INCOMPATIBILITY: in cases explicitly referring to K_record.
  3152 
  3153 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  3154 
  3155 * Library/ListVector: new theory of arithmetic vector operations.
  3156 
  3157 * Library/Order_Relation: new theory of various orderings as sets of
  3158 pairs.  Defines preorders, partial orders, linear orders and
  3159 well-orders on sets and on types.
  3160 
  3161 
  3162 *** ZF ***
  3163 
  3164 * Renamed some theories to allow to loading both ZF and HOL in the
  3165 same session:
  3166 
  3167   Datatype  -> Datatype_ZF
  3168   Inductive -> Inductive_ZF
  3169   Int       -> Int_ZF
  3170   IntDiv    -> IntDiv_ZF
  3171   Nat       -> Nat_ZF
  3172   List      -> List_ZF
  3173   Main      -> Main_ZF
  3174 
  3175 INCOMPATIBILITY: ZF theories that import individual theories below
  3176 Main might need to be adapted.  Regular theory Main is still
  3177 available, as trivial extension of Main_ZF.
  3178 
  3179 
  3180 *** ML ***
  3181 
  3182 * ML within Isar: antiquotation @{const name} or @{const
  3183 name(typargs)} produces statically-checked Const term.
  3184 
  3185 * Functor NamedThmsFun: data is available to the user as dynamic fact
  3186 (of the same name).  Removed obsolete print command.
  3187 
  3188 * Removed obsolete "use_legacy_bindings" function.
  3189 
  3190 * The ``print mode'' is now a thread-local value derived from a global
  3191 template (the former print_mode reference), thus access becomes
  3192 non-critical.  The global print_mode reference is for session
  3193 management only; user-code should use print_mode_value,
  3194 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  3195 
  3196 * Functions system/system_out provide a robust way to invoke external
  3197 shell commands, with propagation of interrupts (requires Poly/ML
  3198 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  3199 
  3200 
  3201 *** System ***
  3202 
  3203 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  3204 in accordance with Proof General 3.7, which prefers GNU emacs.
  3205 
  3206 * isatool tty runs Isabelle process with plain tty interaction;
  3207 optional line editor may be specified via ISABELLE_LINE_EDITOR
  3208 setting, the default settings attempt to locate "ledit" and "rlwrap".
  3209 
  3210 * isatool browser now works with Cygwin as well, using general
  3211 "javapath" function defined in Isabelle process environment.
  3212 
  3213 * YXML notation provides a simple and efficient alternative to
  3214 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  3215 isatool yxml as described in the Isabelle system manual.
  3216 
  3217 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  3218 provides general wrapper for managing an Isabelle process in a robust
  3219 fashion, with ``cooked'' output from stdin/stderr.
  3220 
  3221 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  3222 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  3223 
  3224 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  3225 way of changing the user's settings is via
  3226 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  3227 script.
  3228 
  3229 * Multithreading.max_threads := 0 refers to the number of actual CPU
  3230 cores of the underlying machine, which is a good starting point for
  3231 optimal performance tuning.  The corresponding usedir option -M allows
  3232 "max" as an alias for "0".  WARNING: does not work on certain versions
  3233 of Mac OS (with Poly/ML 5.1).
  3234 
  3235 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  3236 adverse effect of Isabelle flooding interactive front-ends (notably
  3237 ProofGeneral / XEmacs).
  3238 
  3239 
  3240 
  3241 New in Isabelle2007 (November 2007)
  3242 -----------------------------------
  3243 
  3244 *** General ***
  3245 
  3246 * More uniform information about legacy features, notably a
  3247 warning/error of "Legacy feature: ...", depending on the state of the
  3248 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  3249 legacy features will disappear eventually.
  3250 
  3251 * Theory syntax: the header format ``theory A = B + C:'' has been
  3252 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  3253 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  3254 
  3255 * Theory syntax: the old non-Isar theory file format has been
  3256 discontinued altogether.  Note that ML proof scripts may still be used
  3257 with Isar theories; migration is usually quite simple with the ML
  3258 function use_legacy_bindings.  INCOMPATIBILITY.
  3259 
  3260 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  3261 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  3262 quotes.
  3263 
  3264 * Theory loader: be more serious about observing the static theory
  3265 header specifications (including optional directories), but not the
  3266 accidental file locations of previously successful loads.  The strict
  3267 update policy of former update_thy is now already performed by
  3268 use_thy, so the former has been removed; use_thys updates several
  3269 theories simultaneously, just as 'imports' within a theory header
  3270 specification, but without merging the results.  Potential
  3271 INCOMPATIBILITY: may need to refine theory headers and commands
  3272 ROOT.ML which depend on load order.
  3273 
  3274 * Theory loader: optional support for content-based file
  3275 identification, instead of the traditional scheme of full physical
  3276 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  3277 (cf. the system manual).  The new scheme allows to work with
  3278 non-finished theories in persistent session images, such that source
  3279 files may be moved later on without requiring reloads.
  3280 
  3281 * Theory loader: old-style ML proof scripts being *attached* to a thy
  3282 file (with the same base name as the theory) are considered a legacy
  3283 feature, which will disappear eventually. Even now, the theory loader
  3284 no longer maintains dependencies on such files.
  3285 
  3286 * Syntax: the scope for resolving ambiguities via type-inference is
  3287 now limited to individual terms, instead of whole simultaneous
  3288 specifications as before. This greatly reduces the complexity of the
  3289 syntax module and improves flexibility by separating parsing and
  3290 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  3291 'fixes' etc.) are required in rare situations.
  3292 
  3293 * Syntax: constants introduced by new-style packages ('definition',
  3294 'abbreviation' etc.) are passed through the syntax module in
  3295 ``authentic mode''. This means that associated mixfix annotations
  3296 really stick to such constants, independently of potential name space
  3297 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  3298 trees are represented slightly differently, may need to adapt syntax
  3299 translations accordingly. Use CONST marker in 'translations' and
  3300 @{const_syntax} antiquotation in 'parse_translation' etc.
  3301 
  3302 * Legacy goal package: reduced interface to the bare minimum required
  3303 to keep existing proof scripts running.  Most other user-level
  3304 functions are now part of the OldGoals structure, which is *not* open
  3305 by default (consider isatool expandshort before open OldGoals).
  3306 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  3307 these tend to cause confusion about the actual goal (!) context being
  3308 used here, which is not necessarily the same as the_context().
  3309 
  3310 * Command 'find_theorems': supports "*" wild-card in "name:"
  3311 criterion; "with_dups" option.  Certain ProofGeneral versions might
  3312 support a specific search form (see ProofGeneral/CHANGES).
  3313 
  3314 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  3315 by default, which means that "prems" (and also "fixed variables") are
  3316 suppressed from proof state output.  Note that the ProofGeneral
  3317 settings mechanism allows to change and save options persistently, but
  3318 older versions of Isabelle will fail to start up if a negative prems
  3319 limit is imposed.
  3320 
  3321 * Local theory targets may be specified by non-nested blocks of
  3322 ``context/locale/class ... begin'' followed by ``end''.  The body may
  3323 contain definitions, theorems etc., including any derived mechanism
  3324 that has been implemented on top of these primitives.  This concept
  3325 generalizes the existing ``theorem (in ...)'' towards more versatility
  3326 and scalability.
  3327 
  3328 * Proof General interface: proper undo of final 'end' command;
  3329 discontinued Isabelle/classic mode (ML proof scripts).
  3330 
  3331 
  3332 *** Document preparation ***
  3333 
  3334 * Added antiquotation @{theory name} which prints the given name,
  3335 after checking that it refers to a valid ancestor theory in the
  3336 current context.
  3337 
  3338 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  3339 check the given source text as ML type/structure, printing verbatim.
  3340 
  3341 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  3342 "c args == rhs" given in the current context.  (Any number of
  3343 arguments may be given on the LHS.)
  3344 
  3345 
  3346 *** Pure ***
  3347 
  3348 * The 'class' package offers a combination of axclass and locale to
  3349 achieve Haskell-like type classes in Isabelle.  Definitions and
  3350 theorems within a class context produce both relative results (with
  3351 implicit parameters according to the locale context), and polymorphic
  3352 constants with qualified polymorphism (according to the class
  3353 context).  Within the body context of a 'class' target, a separate
  3354 syntax layer ("user space type system") takes care of converting
  3355 between global polymorphic consts and internal locale representation.
  3356 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  3357 "isatool doc classes" provides a tutorial.
  3358 
  3359 * Generic code generator framework allows to generate executable
  3360 code for ML and Haskell (including Isabelle classes).  A short usage
  3361 sketch:
  3362 
  3363     internal compilation:
  3364         export_code <list of constants (term syntax)> in SML
  3365     writing SML code to a file:
  3366         export_code <list of constants (term syntax)> in SML <filename>
  3367     writing OCaml code to a file:
  3368         export_code <list of constants (term syntax)> in OCaml <filename>
  3369     writing Haskell code to a bunch of files:
  3370         export_code <list of constants (term syntax)> in Haskell <filename>
  3371 
  3372     evaluating closed propositions to True/False using code generation:
  3373         method ``eval''
  3374 
  3375 Reasonable default setup of framework in HOL.
  3376 
  3377 Theorem attributs for selecting and transforming function equations theorems:
  3378 
  3379     [code fun]:        select a theorem as function equation for a specific constant
  3380     [code fun del]:    deselect a theorem as function equation for a specific constant
  3381     [code inline]:     select an equation theorem for unfolding (inlining) in place
  3382     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  3383 
  3384 User-defined serializations (target in {SML, OCaml, Haskell}):
  3385 
  3386     code_const <and-list of constants (term syntax)>
  3387       {(target) <and-list of const target syntax>}+
  3388 
  3389     code_type <and-list of type constructors>
  3390       {(target) <and-list of type target syntax>}+
  3391 
  3392     code_instance <and-list of instances>
  3393       {(target)}+
  3394         where instance ::= <type constructor> :: <class>
  3395 
  3396     code_class <and_list of classes>
  3397       {(target) <and-list of class target syntax>}+
  3398         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  3399 
  3400 code_instance and code_class only are effective to target Haskell.
  3401 
  3402 For example usage see src/HOL/ex/Codegenerator.thy and
  3403 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  3404 generation from Isabelle/HOL theories is available via "isatool doc
  3405 codegen".
  3406 
  3407 * Code generator: consts in 'consts_code' Isar commands are now
  3408 referred to by usual term syntax (including optional type
  3409 annotations).
  3410 
  3411 * Command 'no_translations' removes translation rules from theory
  3412 syntax.
  3413 
  3414 * Overloaded definitions are now actually checked for acyclic
  3415 dependencies.  The overloading scheme is slightly more general than
  3416 that of Haskell98, although Isabelle does not demand an exact
  3417 correspondence to type class and instance declarations.
  3418 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  3419 exotic versions of overloading -- at the discretion of the user!
  3420 
  3421 Polymorphic constants are represented via type arguments, i.e. the
  3422 instantiation that matches an instance against the most general
  3423 declaration given in the signature.  For example, with the declaration
  3424 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  3425 as c(nat).  Overloading is essentially simultaneous structural
  3426 recursion over such type arguments.  Incomplete specification patterns
  3427 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  3428 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  3429 Command 'print_theory' outputs the normalized system of recursive
  3430 equations, see section "definitions".
  3431 
  3432 * Configuration options are maintained within the theory or proof
  3433 context (with name and type bool/int/string), providing a very simple
  3434 interface to a poor-man's version of general context data.  Tools may
  3435 declare options in ML (e.g. using Attrib.config_int) and then refer to
  3436 these values using Config.get etc.  Users may change options via an
  3437 associated attribute of the same name.  This form of context
  3438 declaration works particularly well with commands 'declare' or
  3439 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  3440 very easy to avoid global references, which would not observe Isar
  3441 toplevel undo/redo and fail to work with multithreading.
  3442 
  3443 Various global ML references of Pure and HOL have been turned into
  3444 configuration options:
  3445 
  3446   Unify.search_bound		unify_search_bound
  3447   Unify.trace_bound		unify_trace_bound
  3448   Unify.trace_simp		unify_trace_simp
  3449   Unify.trace_types		unify_trace_types
  3450   Simplifier.simp_depth_limit	simp_depth_limit
  3451   Blast.depth_limit		blast_depth_limit
  3452   DatatypeProp.dtK		datatype_distinctness_limit
  3453   fast_arith_neq_limit  	fast_arith_neq_limit
  3454   fast_arith_split_limit	fast_arith_split_limit
  3455 
  3456 * Named collections of theorems may be easily installed as context
  3457 data using the functor NamedThmsFun (see also
  3458 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  3459 attributes; there is also a toplevel print command.  This facility is
  3460 just a common case of general context data, which is the preferred way
  3461 for anything more complex than just a list of facts in canonical
  3462 order.
  3463 
  3464 * Isar: command 'declaration' augments a local theory by generic
  3465 declaration functions written in ML.  This enables arbitrary content
  3466 being added to the context, depending on a morphism that tells the
  3467 difference of the original declaration context wrt. the application
  3468 context encountered later on.
  3469 
  3470 * Isar: proper interfaces for simplification procedures.  Command
  3471 'simproc_setup' declares named simprocs (with match patterns, and body
  3472 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  3473 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  3474 
  3475 * Isar: an extra pair of brackets around attribute declarations
  3476 abbreviates a theorem reference involving an internal dummy fact,
  3477 which will be ignored later --- only the effect of the attribute on
  3478 the background context will persist.  This form of in-place
  3479 declarations is particularly useful with commands like 'declare' and
  3480 'using', for example ``have A using [[simproc a]] by simp''.
  3481 
  3482 * Isar: method "assumption" (and implicit closing of subproofs) now
  3483 takes simple non-atomic goal assumptions into account: after applying
  3484 an assumption as a rule the resulting subgoals are solved by atomic
  3485 assumption steps.  This is particularly useful to finish 'obtain'
  3486 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  3487 without referring to the original premise "!!x. P x ==> thesis" in the
  3488 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  3489 more permissive.
  3490 
  3491 * Isar: implicit use of prems from the Isar proof context is
  3492 considered a legacy feature.  Common applications like ``have A .''
  3493 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  3494 referencing facts explicitly here improves readability and
  3495 maintainability of proof texts.
  3496 
  3497 * Isar: improper proof element 'guess' is like 'obtain', but derives
  3498 the obtained context from the course of reasoning!  For example:
  3499 
  3500   assume "EX x y. A x & B y"   -- "any previous fact"
  3501   then guess x and y by clarify
  3502 
  3503 This technique is potentially adventurous, depending on the facts and
  3504 proof tools being involved here.
  3505 
  3506 * Isar: known facts from the proof context may be specified as literal
  3507 propositions, using ASCII back-quote syntax.  This works wherever
  3508 named facts used to be allowed so far, in proof commands, proof
  3509 methods, attributes etc.  Literal facts are retrieved from the context
  3510 according to unification of type and term parameters.  For example,
  3511 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  3512 theorems in the current context, then these are valid literal facts:
  3513 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  3514 
  3515 There is also a proof method "fact" which does the same composition
  3516 for explicit goal states, e.g. the following proof texts coincide with
  3517 certain special cases of literal facts:
  3518 
  3519   have "A" by fact                 ==  note `A`
  3520   have "A ==> B" by fact           ==  note `A ==> B`
  3521   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  3522   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  3523 
  3524 * Isar: ":" (colon) is no longer a symbolic identifier character in
  3525 outer syntax.  Thus symbolic identifiers may be used without
  3526 additional white space in declarations like this: ``assume *: A''.
  3527 
  3528 * Isar: 'print_facts' prints all local facts of the current context,
  3529 both named and unnamed ones.
  3530 
  3531 * Isar: 'def' now admits simultaneous definitions, e.g.:
  3532 
  3533   def x == "t" and y == "u"
  3534 
  3535 * Isar: added command 'unfolding', which is structurally similar to
  3536 'using', but affects both the goal state and facts by unfolding given
  3537 rewrite rules.  Thus many occurrences of the 'unfold' method or
  3538 'unfolded' attribute may be replaced by first-class proof text.
  3539 
  3540 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  3541 and command 'unfolding' now all support object-level equalities
  3542 (potentially conditional).  The underlying notion of rewrite rule is
  3543 analogous to the 'rule_format' attribute, but *not* that of the
  3544 Simplifier (which is usually more generous).
  3545 
  3546 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  3547 premises of a theorem by n. Useful in conjunction with drule.
  3548 
  3549 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  3550 method expression within a sandbox consisting of the first N
  3551 sub-goals, which need to exist.  For example, ``simp_all [3]''
  3552 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  3553 simplifies all new goals that emerge from applying rule foo to the
  3554 originally first one.
  3555 
  3556 * Isar: schematic goals are no longer restricted to higher-order
  3557 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  3558 expected.
  3559 
  3560 * Isar: the conclusion of a long theorem statement is now either
  3561 'shows' (a simultaneous conjunction, as before), or 'obtains'
  3562 (essentially a disjunction of cases with local parameters and
  3563 assumptions).  The latter allows to express general elimination rules
  3564 adequately; in this notation common elimination rules look like this:
  3565 
  3566   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  3567     assumes "EX x. P x"
  3568     obtains x where "P x"
  3569 
  3570   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  3571     assumes "A & B"
  3572     obtains A and B
  3573 
  3574   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  3575     assumes "A | B"
  3576     obtains
  3577       A
  3578     | B
  3579 
  3580 The subsequent classical rules even refer to the formal "thesis"
  3581 explicitly:
  3582 
  3583   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  3584     obtains "~ thesis"
  3585 
  3586   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  3587     obtains "thesis ==> something"
  3588 
  3589 The actual proof of an 'obtains' statement is analogous to that of the
  3590 Isar proof element 'obtain', only that there may be several cases.
  3591 Optional case names may be specified in parentheses; these will be
  3592 available both in the present proof and as annotations in the
  3593 resulting rule, for later use with the 'cases' method (cf. attribute
  3594 case_names).
  3595 
  3596 * Isar: the assumptions of a long theorem statement are available as
  3597 "assms" fact in the proof context.  This is more appropriate than the
  3598 (historical) "prems", which refers to all assumptions of the current
  3599 context, including those from the target locale, proof body etc.
  3600 
  3601 * Isar: 'print_statement' prints theorems from the current theory or
  3602 proof context in long statement form, according to the syntax of a
  3603 top-level lemma.
  3604 
  3605 * Isar: 'obtain' takes an optional case name for the local context
  3606 introduction rule (default "that").
  3607 
  3608 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  3609 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  3610 to occur.
  3611 
  3612 * Pure: syntax "CONST name" produces a fully internalized constant
  3613 according to the current context.  This is particularly useful for
  3614 syntax translations that should refer to internal constant
  3615 representations independently of name spaces.
  3616 
  3617 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  3618 instead of "FOO ". This allows multiple binder declarations to coexist
  3619 in the same context.  INCOMPATIBILITY.
  3620 
  3621 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  3622 primitive that also works in a locale context (both for constants and
  3623 fixed variables). Type declaration and internal syntactic representation
  3624 of given constants retrieved from the context. Likewise, the
  3625 'no_notation' command allows to remove given syntax annotations from the
  3626 current context.
  3627 
  3628 * Isar/locales: new derived specification elements 'axiomatization',
  3629 'definition', 'abbreviation', which support type-inference, admit
  3630 object-level specifications (equality, equivalence).  See also the
  3631 isar-ref manual.  Examples:
  3632 
  3633   axiomatization
  3634     eq  (infix "===" 50) where
  3635     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  3636 
  3637   definition "f x y = x + y + 1"
  3638   definition g where "g x = f x x"
  3639 
  3640   abbreviation
  3641     neq  (infix "=!=" 50) where
  3642     "x =!= y == ~ (x === y)"
  3643 
  3644 These specifications may be also used in a locale context.  Then the
  3645 constants being introduced depend on certain fixed parameters, and the
  3646 constant name is qualified by the locale base name.  An internal
  3647 abbreviation takes care for convenient input and output, making the
  3648 parameters implicit and using the original short name.  See also
  3649 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  3650 entities from a monomorphic theory.
  3651 
  3652 Presently, abbreviations are only available 'in' a target locale, but
  3653 not inherited by general import expressions.  Also note that
  3654 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  3655 'translations' in common applications.  The "no_abbrevs" print mode
  3656 prevents folding of abbreviations in term output.
  3657 
  3658 Concrete syntax is attached to specified constants in internal form,
  3659 independently of name spaces.  The parse tree representation is
  3660 slightly different -- use 'notation' instead of raw 'syntax', and
  3661 'translations' with explicit "CONST" markup to accommodate this.
  3662 
  3663 * Pure/Isar: unified syntax for new-style specification mechanisms
  3664 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  3665 full type inference and dummy patterns ("_").  For example:
  3666 
  3667   definition "K x _ = x"
  3668 
  3669   inductive conj for A B
  3670   where "A ==> B ==> conj A B"
  3671 
  3672 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  3673 the current context.  Print mode "no_abbrevs" prevents inversion of
  3674 abbreviations on output.
  3675 
  3676 * Isar/locales: improved parameter handling: use of locales "var" and
  3677 "struct" no longer necessary; - parameter renamings are no longer
  3678 required to be injective.  For example, this allows to define
  3679 endomorphisms as locale endom = homom mult mult h.
  3680 
  3681 * Isar/locales: changed the way locales with predicates are defined.
  3682 Instead of accumulating the specification, the imported expression is
  3683 now an interpretation.  INCOMPATIBILITY: different normal form of
  3684 locale expressions.  In particular, in interpretations of locales with
  3685 predicates, goals repesenting already interpreted fragments are not
  3686 removed automatically.  Use methods `intro_locales' and
  3687 `unfold_locales'; see below.
  3688 
  3689 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  3690 provide backward reasoning on locales predicates.  The methods are
  3691 aware of interpretations and discharge corresponding goals.
  3692 `intro_locales' is less aggressive then `unfold_locales' and does not
  3693 unfold predicates to assumptions.
  3694 
  3695 * Isar/locales: the order in which locale fragments are accumulated
  3696 has changed.  This enables to override declarations from fragments due
  3697 to interpretations -- for example, unwanted simp rules.
  3698 
  3699 * Isar/locales: interpretation in theories and proof contexts has been
  3700 extended.  One may now specify (and prove) equations, which are
  3701 unfolded in interpreted theorems.  This is useful for replacing
  3702 defined concepts (constants depending on locale parameters) by
  3703 concepts already existing in the target context.  Example:
  3704 
  3705   interpretation partial_order ["op <= :: [int, int] => bool"]
  3706     where "partial_order.less (op <=) (x::int) y = (x < y)"
  3707 
  3708 Typically, the constant `partial_order.less' is created by a
  3709 definition specification element in the context of locale
  3710 partial_order.
  3711 
  3712 * Method "induct": improved internal context management to support
  3713 local fixes and defines on-the-fly. Thus explicit meta-level
  3714 connectives !!  and ==> are rarely required anymore in inductive goals
  3715 (using object-logic connectives for this purpose has been long
  3716 obsolete anyway). Common proof patterns are explained in
  3717 src/HOL/Induct/Common_Patterns.thy, see also
  3718 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  3719 examples.
  3720 
  3721 * Method "induct": improved handling of simultaneous goals. Instead of
  3722 introducing object-level conjunction, the statement is now split into
  3723 several conclusions, while the corresponding symbolic cases are nested
  3724 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  3725 see src/HOL/Induct/Common_Patterns.thy, for example.
  3726 
  3727 * Method "induct": mutual induction rules are now specified as a list
  3728 of rule sharing the same induction cases. HOL packages usually provide
  3729 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  3730 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  3731 mutual induction rules differently, i.e. like this:
  3732 
  3733   (induct rule: foo_bar.inducts)
  3734   (induct set: foo bar)
  3735   (induct pred: foo bar)
  3736   (induct type: foo bar)
  3737 
  3738 The ML function ProjectRule.projections turns old-style rules into the
  3739 new format.
  3740 
  3741 * Method "coinduct": dual of induction, see
  3742 src/HOL/Library/Coinductive_List.thy for various examples.
  3743 
  3744 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  3745 considered a legacy feature.
  3746 
  3747 * Attribute "symmetric" produces result with standardized schematic
  3748 variables (index 0).  Potential INCOMPATIBILITY.
  3749 
  3750 * Simplifier: by default the simplifier trace only shows top level
  3751 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  3752 default. Thus there is less danger of being flooded by the trace. The
  3753 trace indicates where parts have been suppressed.
  3754   
  3755 * Provers/classical: removed obsolete classical version of elim_format
  3756 attribute; classical elim/dest rules are now treated uniformly when
  3757 manipulating the claset.
  3758 
  3759 * Provers/classical: stricter checks to ensure that supplied intro,
  3760 dest and elim rules are well-formed; dest and elim rules must have at
  3761 least one premise.
  3762 
  3763 * Provers/classical: attributes dest/elim/intro take an optional
  3764 weight argument for the rule (just as the Pure versions).  Weights are
  3765 ignored by automated tools, but determine the search order of single
  3766 rule steps.
  3767 
  3768 * Syntax: input syntax now supports dummy variable binding "%_. b",
  3769 where the body does not mention the bound variable.  Note that dummy
  3770 patterns implicitly depend on their context of bounds, which makes
  3771 "{_. _}" match any set comprehension as expected.  Potential
  3772 INCOMPATIBILITY -- parse translations need to cope with syntactic
  3773 constant "_idtdummy" in the binding position.
  3774 
  3775 * Syntax: removed obsolete syntactic constant "_K" and its associated
  3776 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  3777 for example "A -> B" => "Pi A (%_. B)".
  3778 
  3779 * Pure: 'class_deps' command visualizes the subclass relation, using
  3780 the graph browser tool.
  3781 
  3782 * Pure: 'print_theory' now suppresses certain internal declarations by
  3783 default; use '!' option for full details.
  3784 
  3785 
  3786 *** HOL ***
  3787 
  3788 * Method "metis" proves goals by applying the Metis general-purpose
  3789 resolution prover (see also http://gilith.com/software/metis/).
  3790 Examples are in the directory MetisExamples.  WARNING: the
  3791 Isabelle/HOL-Metis integration does not yet work properly with
  3792 multi-threading.
  3793   
  3794 * Command 'sledgehammer' invokes external automatic theorem provers as
  3795 background processes.  It generates calls to the "metis" method if
  3796 successful. These can be pasted into the proof.  Users do not have to
  3797 wait for the automatic provers to return.  WARNING: does not really
  3798 work with multi-threading.
  3799 
  3800 * New "auto_quickcheck" feature tests outermost goal statements for
  3801 potential counter-examples.  Controlled by ML references
  3802 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  3803 5000 milliseconds).  Fails silently if statements is outside of
  3804 executable fragment, or any other codgenerator problem occurs.
  3805 
  3806 * New constant "undefined" with axiom "undefined x = undefined".
  3807 
  3808 * Added class "HOL.eq", allowing for code generation with polymorphic
  3809 equality.
  3810 
  3811 * Some renaming of class constants due to canonical name prefixing in
  3812 the new 'class' package:
  3813 
  3814     HOL.abs ~> HOL.abs_class.abs
  3815     HOL.divide ~> HOL.divide_class.divide
  3816     0 ~> HOL.zero_class.zero
  3817     1 ~> HOL.one_class.one
  3818     op + ~> HOL.plus_class.plus
  3819     op - ~> HOL.minus_class.minus
  3820     uminus ~> HOL.minus_class.uminus
  3821     op * ~> HOL.times_class.times
  3822     op < ~> HOL.ord_class.less
  3823     op <= > HOL.ord_class.less_eq
  3824     Nat.power ~> Power.power_class.power
  3825     Nat.size ~> Nat.size_class.size
  3826     Numeral.number_of ~> Numeral.number_class.number_of
  3827     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  3828     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  3829     Orderings.min ~> Orderings.ord_class.min
  3830     Orderings.max ~> Orderings.ord_class.max
  3831     Divides.op div ~> Divides.div_class.div
  3832     Divides.op mod ~> Divides.div_class.mod
  3833     Divides.op dvd ~> Divides.div_class.dvd
  3834 
  3835 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  3836 
  3837 a) User-defined constants using any of the names "plus", "minus",
  3838 "times", "less" or "less_eq". The standard syntax translations for
  3839 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  3840 names.
  3841 
  3842 b) Variables named "plus", "minus", "times", "less", "less_eq"
  3843 INCOMPATIBILITY: use more specific names.
  3844 
  3845 c) Permutative equations (e.g. "a + b = b + a")
  3846 Since the change of names also changes the order of terms, permutative
  3847 rewrite rules may get applied in a different order. Experience shows
  3848 that this is rarely the case (only two adaptions in the whole Isabelle
  3849 distribution).  INCOMPATIBILITY: rewrite proofs
  3850 
  3851 d) ML code directly refering to constant names
  3852 This in general only affects hand-written proof tactics, simprocs and
  3853 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  3854 Consider using @{const_name} antiquotation.
  3855 
  3856 * New class "default" with associated constant "default".
  3857 
  3858 * Function "sgn" is now overloaded and available on int, real, complex
  3859 (and other numeric types), using class "sgn".  Two possible defs of
  3860 sgn are given as equational assumptions in the classes sgn_if and
  3861 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  3862 INCOMPATIBILITY.
  3863 
  3864 * Locale "partial_order" now unified with class "order" (cf. theory
  3865 Orderings), added parameter "less".  INCOMPATIBILITY.
  3866 
  3867 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  3868 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  3869 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  3870 
  3871 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  3872 changed order of proof goals in instance proofs.
  3873 
  3874 * The transitivity reasoner for partial and linear orders is set up
  3875 for classes "order" and "linorder".  Instances of the reasoner are available
  3876 in all contexts importing or interpreting the corresponding locales.
  3877 Method "order" invokes the reasoner separately; the reasoner
  3878 is also integrated with the Simplifier as a solver.  Diagnostic
  3879 command 'print_orders' shows the available instances of the reasoner
  3880 in the current context.
  3881 
  3882 * Localized monotonicity predicate in theory "Orderings"; integrated
  3883 lemmas max_of_mono and min_of_mono with this predicate.
  3884 INCOMPATIBILITY.
  3885 
  3886 * Formulation of theorem "dense" changed slightly due to integration
  3887 with new class dense_linear_order.
  3888 
  3889 * Uniform lattice theory development in HOL.
  3890 
  3891     constants "meet" and "join" now named "inf" and "sup"
  3892     constant "Meet" now named "Inf"
  3893 
  3894     classes "meet_semilorder" and "join_semilorder" now named
  3895       "lower_semilattice" and "upper_semilattice"
  3896     class "lorder" now named "lattice"
  3897     class "comp_lat" now named "complete_lattice"
  3898 
  3899     Instantiation of lattice classes allows explicit definitions
  3900     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  3901 
  3902   INCOMPATIBILITY.  Theorem renames:
  3903 
  3904     meet_left_le            ~> inf_le1
  3905     meet_right_le           ~> inf_le2
  3906     join_left_le            ~> sup_ge1
  3907     join_right_le           ~> sup_ge2
  3908     meet_join_le            ~> inf_sup_ord
  3909     le_meetI                ~> le_infI
  3910     join_leI                ~> le_supI
  3911     le_meet                 ~> le_inf_iff
  3912     le_join                 ~> ge_sup_conv
  3913     meet_idempotent         ~> inf_idem
  3914     join_idempotent         ~> sup_idem
  3915     meet_comm               ~> inf_commute
  3916     join_comm               ~> sup_commute
  3917     meet_leI1               ~> le_infI1
  3918     meet_leI2               ~> le_infI2
  3919     le_joinI1               ~> le_supI1
  3920     le_joinI2               ~> le_supI2
  3921     meet_assoc              ~> inf_assoc
  3922     join_assoc              ~> sup_assoc
  3923     meet_left_comm          ~> inf_left_commute
  3924     meet_left_idempotent    ~> inf_left_idem
  3925     join_left_comm          ~> sup_left_commute
  3926     join_left_idempotent    ~> sup_left_idem
  3927     meet_aci                ~> inf_aci
  3928     join_aci                ~> sup_aci
  3929     le_def_meet             ~> le_iff_inf
  3930     le_def_join             ~> le_iff_sup
  3931     join_absorp2            ~> sup_absorb2
  3932     join_absorp1            ~> sup_absorb1
  3933     meet_absorp1            ~> inf_absorb1
  3934     meet_absorp2            ~> inf_absorb2
  3935     meet_join_absorp        ~> inf_sup_absorb
  3936     join_meet_absorp        ~> sup_inf_absorb
  3937     distrib_join_le         ~> distrib_sup_le
  3938     distrib_meet_le         ~> distrib_inf_le
  3939 
  3940     add_meet_distrib_left   ~> add_inf_distrib_left
  3941     add_join_distrib_left   ~> add_sup_distrib_left
  3942     is_join_neg_meet        ~> is_join_neg_inf
  3943     is_meet_neg_join        ~> is_meet_neg_sup
  3944     add_meet_distrib_right  ~> add_inf_distrib_right
  3945     add_join_distrib_right  ~> add_sup_distrib_right
  3946     add_meet_join_distribs  ~> add_sup_inf_distribs
  3947     join_eq_neg_meet        ~> sup_eq_neg_inf
  3948     meet_eq_neg_join        ~> inf_eq_neg_sup
  3949     add_eq_meet_join        ~> add_eq_inf_sup
  3950     meet_0_imp_0            ~> inf_0_imp_0
  3951     join_0_imp_0            ~> sup_0_imp_0
  3952     meet_0_eq_0             ~> inf_0_eq_0
  3953     join_0_eq_0             ~> sup_0_eq_0
  3954     neg_meet_eq_join        ~> neg_inf_eq_sup
  3955     neg_join_eq_meet        ~> neg_sup_eq_inf
  3956     join_eq_if              ~> sup_eq_if
  3957 
  3958     mono_meet               ~> mono_inf
  3959     mono_join               ~> mono_sup
  3960     meet_bool_eq            ~> inf_bool_eq
  3961     join_bool_eq            ~> sup_bool_eq
  3962     meet_fun_eq             ~> inf_fun_eq
  3963     join_fun_eq             ~> sup_fun_eq
  3964     meet_set_eq             ~> inf_set_eq
  3965     join_set_eq             ~> sup_set_eq
  3966     meet1_iff               ~> inf1_iff
  3967     meet2_iff               ~> inf2_iff
  3968     meet1I                  ~> inf1I
  3969     meet2I                  ~> inf2I
  3970     meet1D1                 ~> inf1D1
  3971     meet2D1                 ~> inf2D1
  3972     meet1D2                 ~> inf1D2
  3973     meet2D2                 ~> inf2D2
  3974     meet1E                  ~> inf1E
  3975     meet2E                  ~> inf2E
  3976     join1_iff               ~> sup1_iff
  3977     join2_iff               ~> sup2_iff
  3978     join1I1                 ~> sup1I1
  3979     join2I1                 ~> sup2I1
  3980     join1I1                 ~> sup1I1
  3981     join2I2                 ~> sup1I2
  3982     join1CI                 ~> sup1CI
  3983     join2CI                 ~> sup2CI
  3984     join1E                  ~> sup1E
  3985     join2E                  ~> sup2E
  3986 
  3987     is_meet_Meet            ~> is_meet_Inf
  3988     Meet_bool_def           ~> Inf_bool_def
  3989     Meet_fun_def            ~> Inf_fun_def
  3990     Meet_greatest           ~> Inf_greatest
  3991     Meet_lower              ~> Inf_lower
  3992     Meet_set_def            ~> Inf_set_def
  3993 
  3994     Sup_def                 ~> Sup_Inf
  3995     Sup_bool_eq             ~> Sup_bool_def
  3996     Sup_fun_eq              ~> Sup_fun_def
  3997     Sup_set_eq              ~> Sup_set_def
  3998 
  3999     listsp_meetI            ~> listsp_infI
  4000     listsp_meet_eq          ~> listsp_inf_eq
  4001 
  4002     meet_min                ~> inf_min
  4003     join_max                ~> sup_max
  4004 
  4005 * Added syntactic class "size"; overloaded constant "size" now has
  4006 type "'a::size ==> bool"
  4007 
  4008 * Internal reorganisation of `size' of datatypes: size theorems
  4009 "foo.size" are no longer subsumed by "foo.simps" (but are still
  4010 simplification rules by default!); theorems "prod.size" now named
  4011 "*.size".
  4012 
  4013 * Class "div" now inherits from class "times" rather than "type".
  4014 INCOMPATIBILITY.
  4015 
  4016 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  4017 Linorder etc.  have disappeared; operations defined in terms of
  4018 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  4019 
  4020 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  4021 
  4022 * HOL-Word: New extensive library and type for generic, fixed size
  4023 machine words, with arithemtic, bit-wise, shifting and rotating
  4024 operations, reflection into int, nat, and bool lists, automation for
  4025 linear arithmetic (by automatic reflection into nat or int), including
  4026 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  4027 arithmetic type classes, supporting automatic simplification of
  4028 numerals on all operations.
  4029 
  4030 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  4031 
  4032 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  4033 
  4034 * Code generator library theories:
  4035   - Code_Integer represents HOL integers by big integer literals in target
  4036     languages.
  4037   - Code_Char represents HOL characters by character literals in target
  4038     languages.
  4039   - Code_Char_chr like Code_Char, but also offers treatment of character
  4040     codes; includes Code_Integer.
  4041   - Executable_Set allows to generate code for finite sets using lists.
  4042   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  4043     denominator).
  4044   - Executable_Real implements a subset of real numbers, namly those
  4045     representable by rational numbers.
  4046   - Efficient_Nat implements natural numbers by integers, which in general will
  4047     result in higher efficency; pattern matching with 0/Suc is eliminated;
  4048     includes Code_Integer.
  4049   - Code_Index provides an additional datatype index which is mapped to
  4050     target-language built-in integers.
  4051   - Code_Message provides an additional datatype message_string which is isomorphic to
  4052     strings; messages are mapped to target-language strings.
  4053 
  4054 * New package for inductive predicates
  4055 
  4056   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  4057 
  4058     inductive
  4059       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  4060       for z_1 :: U_1 and ... and z_n :: U_m
  4061     where
  4062       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  4063     | ...
  4064 
  4065   with full support for type-inference, rather than
  4066 
  4067     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4068 
  4069     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  4070     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  4071 
  4072     inductive "s z_1 ... z_m"
  4073     intros
  4074       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  4075       ...
  4076 
  4077   For backward compatibility, there is a wrapper allowing inductive
  4078   sets to be defined with the new package via
  4079 
  4080     inductive_set
  4081       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4082       for z_1 :: U_1 and ... and z_n :: U_m
  4083     where
  4084       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  4085     | ...
  4086 
  4087   or
  4088 
  4089     inductive_set
  4090       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4091       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  4092       for z_1 :: U_1 and ... and z_n :: U_m
  4093     where
  4094       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  4095     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  4096     | ...
  4097 
  4098   if the additional syntax "p ..." is required.
  4099 
  4100   Numerous examples can be found in the subdirectories src/HOL/Auth,
  4101   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  4102 
  4103   INCOMPATIBILITIES:
  4104 
  4105   - Since declaration and definition of inductive sets or predicates
  4106     is no longer separated, abbreviations involving the newly
  4107     introduced sets or predicates must be specified together with the
  4108     introduction rules after the 'where' keyword (see above), rather
  4109     than before the actual inductive definition.
  4110 
  4111   - The variables in induction and elimination rules are now
  4112     quantified in the order of their occurrence in the introduction
  4113     rules, rather than in alphabetical order. Since this may break
  4114     some proofs, these proofs either have to be repaired, e.g. by
  4115     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  4116     statements of the form
  4117 
  4118       case (rule_i a_i_1 ... a_i_{k_i})
  4119 
  4120     or the old order of quantification has to be restored by explicitly adding
  4121     meta-level quantifiers in the introduction rules, i.e.
  4122 
  4123       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  4124 
  4125   - The format of the elimination rules is now
  4126 
  4127       p z_1 ... z_m x_1 ... x_n ==>
  4128         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  4129         ==> ... ==> P
  4130 
  4131     for predicates and
  4132 
  4133       (x_1, ..., x_n) : s z_1 ... z_m ==>
  4134         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  4135         ==> ... ==> P
  4136 
  4137     for sets rather than
  4138 
  4139       x : s z_1 ... z_m ==>
  4140         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  4141         ==> ... ==> P
  4142 
  4143     This may require terms in goals to be expanded to n-tuples
  4144     (e.g. using case_tac or simplification with the split_paired_all
  4145     rule) before the above elimination rule is applicable.
  4146 
  4147   - The elimination or case analysis rules for (mutually) inductive
  4148     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  4149     list of rules "p_1_..._p_k.elims" is no longer available.
  4150 
  4151 * New package "function"/"fun" for general recursive functions,
  4152 supporting mutual and nested recursion, definitions in local contexts,
  4153 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  4154 for small examples, and the separate tutorial on the function
  4155 package. The old recdef "package" is still available as before, but
  4156 users are encouraged to use the new package.
  4157 
  4158 * Method "lexicographic_order" automatically synthesizes termination
  4159 relations as lexicographic combinations of size measures. 
  4160 
  4161 * Case-expressions allow arbitrary constructor-patterns (including
  4162 "_") and take their order into account, like in functional
  4163 programming.  Internally, this is translated into nested
  4164 case-expressions; missing cases are added and mapped to the predefined
  4165 constant "undefined". In complicated cases printing may no longer show
  4166 the original input but the internal form. Lambda-abstractions allow
  4167 the same form of pattern matching: "% pat1 => e1 | ..." is an
  4168 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  4169 variable.
  4170 
  4171 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  4172 is an abbreviation for "of_nat :: nat => int". The simplification
  4173 rules for "of_nat" have been changed to work like "int" did
  4174 previously.  Potential INCOMPATIBILITY:
  4175   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  4176   - of_nat_diff and of_nat_mult are no longer default simp rules
  4177 
  4178 * Method "algebra" solves polynomial equations over (semi)rings using
  4179 Groebner bases. The (semi)ring structure is defined by locales and the
  4180 tool setup depends on that generic context. Installing the method for
  4181 a specific type involves instantiating the locale and possibly adding
  4182 declarations for computation on the coefficients.  The method is
  4183 already instantiated for natural numbers and for the axiomatic class
  4184 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  4185 CALCULEMUS 2007 for the general principles underlying this
  4186 architecture of context-aware proof-tools.
  4187 
  4188 * Method "ferrack" implements quantifier elimination over
  4189 special-purpose dense linear orders using locales (analogous to
  4190 "algebra"). The method is already installed for class
  4191 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  4192 rat, etc.
  4193 
  4194 * Former constant "List.op @" now named "List.append".  Use ML
  4195 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  4196 circumvent possible incompatibilities when working on ML level.
  4197 
  4198 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  4199 
  4200 * New function listsum :: 'a list => 'a for arbitrary monoids.
  4201 Special syntax: "SUM x <- xs. f x" (and latex variants)
  4202 
  4203 * New syntax for Haskell-like list comprehension (input only), eg.
  4204 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  4205 
  4206 * The special syntax for function "filter" has changed from [x :
  4207 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  4208 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  4209 
  4210 * [a..b] is now defined for arbitrary linear orders.  It used to be
  4211 defined on nat only, as an abbreviation for [a..<Suc b]
  4212 INCOMPATIBILITY.
  4213 
  4214 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  4215 
  4216 * New functions "sorted" and "sort" in src/HOL/List.thy.
  4217 
  4218 * New lemma collection field_simps (an extension of ring_simps) for
  4219 manipulating (in)equations involving division. Multiplies with all
  4220 denominators that can be proved to be non-zero (in equations) or
  4221 positive/negative (in inequations).
  4222 
  4223 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  4224 have been improved and renamed to ring_simps, group_simps and
  4225 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  4226 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  4227 
  4228 * Theory Library/Commutative_Ring: switched from recdef to function
  4229 package; constants add, mul, pow now curried.  Infix syntax for
  4230 algebraic operations.
  4231 
  4232 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  4233 INCOMPATIBILITY.
  4234 
  4235 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  4236 INCOMPATIBILITY.
  4237 
  4238 * HOL/records: generalised field-update to take a function on the
  4239 field rather than the new value: r(|A := x|) is translated to A_update
  4240 (K x) r The K-combinator that is internally used is called K_record.
  4241 INCOMPATIBILITY: Usage of the plain update functions has to be
  4242 adapted.
  4243  
  4244 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  4245 * x = 0, which are required for a semiring.  Richer structures do not
  4246 inherit from semiring_0 anymore, because this property is a theorem
  4247 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  4248 there is more to prove, but this is mostly trivial.
  4249 
  4250 * Class "recpower" is generalized to arbitrary monoids, not just
  4251 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  4252 commutativity or semiring properties additionally.
  4253 
  4254 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  4255 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  4256 better use 'abbreviation'.
  4257 
  4258 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  4259 
  4260 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  4261 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  4262 significant changes for setting up numeral syntax for types:
  4263   - New constants Numeral.pred and Numeral.succ instead
  4264       of former Numeral.bin_pred and Numeral.bin_succ.
  4265   - Use integer operations instead of bin_add, bin_mult and so on.
  4266   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  4267   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  4268 
  4269 See src/HOL/Integ/IntArith.thy for an example setup.
  4270 
  4271 * Command 'normal_form' computes the normal form of a term that may
  4272 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  4273 produces ``[b, c, a]'' (without proof).  This command is suitable for
  4274 heavy-duty computations because the functions are compiled to ML
  4275 first.  Correspondingly, a method "normalization" is provided.  See
  4276 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  4277 
  4278 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  4279 25 like -->); output depends on the "iff" print_mode, the default is
  4280 "A = B" (with priority 50).
  4281 
  4282 * Relations less (<) and less_eq (<=) are also available on type bool.
  4283 Modified syntax to disallow nesting without explicit parentheses,
  4284 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  4285 INCOMPATIBILITY.
  4286 
  4287 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  4288 
  4289 * Relation composition operator "op O" now has precedence 75 and binds
  4290 stronger than union and intersection. INCOMPATIBILITY.
  4291 
  4292 * The old set interval syntax "{m..n(}" (and relatives) has been
  4293 removed.  Use "{m..<n}" (and relatives) instead.
  4294 
  4295 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  4296 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  4297 ``declare [[simproc del: neq]]''.
  4298 
  4299 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  4300 True/False.
  4301 
  4302 * Theorem Cons_eq_map_conv no longer declared as "simp".
  4303 
  4304 * Theorem setsum_mult renamed to setsum_right_distrib.
  4305 
  4306 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  4307 ``rule'' method.
  4308 
  4309 * Reimplemented methods "sat" and "satx", with several improvements:
  4310 goals no longer need to be stated as "<prems> ==> False", equivalences
  4311 (i.e. "=" on type bool) are handled, variable names of the form
  4312 "lit_<n>" are no longer reserved, significant speedup.
  4313 
  4314 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  4315 zChaff is still supported as well.
  4316 
  4317 * 'inductive' and 'datatype': provide projections of mutual rules,
  4318 bundled as foo_bar.inducts;
  4319 
  4320 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  4321 Library.
  4322 
  4323 * Library: moved theory Accessible_Part to main HOL.
  4324 
  4325 * Library: added theory Coinductive_List of potentially infinite lists
  4326 as greatest fixed-point.
  4327 
  4328 * Library: added theory AssocList which implements (finite) maps as
  4329 association lists.
  4330 
  4331 * Method "evaluation" solves goals (i.e. a boolean expression)
  4332 efficiently by compiling it to ML.  The goal is "proved" (via an
  4333 oracle) if it evaluates to True.
  4334 
  4335 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  4336 also when invoked by the simplifier.  This results in the Simplifier
  4337 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  4338 Configuration option fast_arith_split_limit=0 recovers the old
  4339 behavior.
  4340 
  4341 * Support for hex (0x20) and binary (0b1001) numerals.
  4342 
  4343 * New method: reify eqs (t), where eqs are equations for an
  4344 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  4345 parameter, computes a term s::'b and a list xs::'a list and proves the
  4346 theorem I xs s = t. This is also known as reification or quoting. The
  4347 resulting theorem is applied to the subgoal to substitute t with I xs
  4348 s.  If t is omitted, the subgoal itself is reified.
  4349 
  4350 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  4351 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  4352 where f is supposed to be a computable function (in the sense of code
  4353 generattion). The method uses reify to compute s and xs as above then
  4354 applies corr_thm and uses normalization by evaluation to "prove" f s =
  4355 r and finally gets the theorem t = r, which is again applied to the
  4356 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  4357 
  4358 * Reflection: Automatic reification now handels binding, an example is
  4359 available in src/HOL/ex/ReflectionEx.thy
  4360 
  4361 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  4362 command 'statespace' that is similar to 'record', but introduces an
  4363 abstract specification based on the locale infrastructure instead of
  4364 HOL types.  This leads to extra flexibility in composing state spaces,
  4365 in particular multiple inheritance and renaming of components.
  4366 
  4367 
  4368 *** HOL-Complex ***
  4369 
  4370 * Hyperreal: Functions root and sqrt are now defined on negative real
  4371 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  4372 Nonnegativity side conditions have been removed from many lemmas, so
  4373 that more subgoals may now be solved by simplification; potential
  4374 INCOMPATIBILITY.
  4375 
  4376 * Real: new type classes formalize real normed vector spaces and
  4377 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  4378 and norm :: 'a => real.
  4379 
  4380 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  4381 reals into other types. The overloaded constant Reals :: 'a set is now
  4382 defined as range of_real; potential INCOMPATIBILITY.
  4383 
  4384 * Real: proper support for ML code generation, including 'quickcheck'.
  4385 Reals are implemented as arbitrary precision rationals.
  4386 
  4387 * Hyperreal: Several constants that previously worked only for the
  4388 reals have been generalized, so they now work over arbitrary vector
  4389 spaces. Type annotations may need to be added in some cases; potential
  4390 INCOMPATIBILITY.
  4391 
  4392   Infinitesimal  :: ('a::real_normed_vector) star set
  4393   HFinite        :: ('a::real_normed_vector) star set
  4394   HInfinite      :: ('a::real_normed_vector) star set
  4395   approx         :: ('a::real_normed_vector) star => 'a star => bool
  4396   monad          :: ('a::real_normed_vector) star => 'a star set
  4397   galaxy         :: ('a::real_normed_vector) star => 'a star set
  4398   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  4399   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  4400   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  4401   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  4402   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  4403   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  4404   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  4405   sgn            :: 'a::real_normed_vector => 'a
  4406   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  4407 
  4408 * Complex: Some complex-specific constants are now abbreviations for
  4409 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  4410 hnorm.  Other constants have been entirely removed in favor of the
  4411 polymorphic versions (INCOMPATIBILITY):
  4412 
  4413   approx        <-- capprox
  4414   HFinite       <-- CFinite
  4415   HInfinite     <-- CInfinite
  4416   Infinitesimal <-- CInfinitesimal
  4417   monad         <-- cmonad
  4418   galaxy        <-- cgalaxy
  4419   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  4420   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  4421   (ns)deriv     <-- (ns)cderiv
  4422 
  4423 
  4424 *** HOL-Algebra ***
  4425 
  4426 * Formalisation of ideals and the quotient construction over rings.
  4427 
  4428 * Order and lattice theory no longer based on records.
  4429 INCOMPATIBILITY.
  4430 
  4431 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  4432 greatest_closed.  INCOMPATIBILITY.
  4433 
  4434 * Method algebra is now set up via an attribute.  For examples see
  4435 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  4436 of algebraic structures.
  4437 
  4438 * Renamed theory CRing to Ring.
  4439 
  4440 
  4441 *** HOL-Nominal ***
  4442 
  4443 * Substantial, yet incomplete support for nominal datatypes (binding
  4444 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  4445 src/HOL/Nominal/Examples.  Prospective users should consult
  4446 http://isabelle.in.tum.de/nominal/
  4447 
  4448 
  4449 *** ML ***
  4450 
  4451 * ML basics: just one true type int, which coincides with IntInf.int
  4452 (even on SML/NJ).
  4453 
  4454 * ML within Isar: antiquotations allow to embed statically-checked
  4455 formal entities in the source, referring to the context available at
  4456 compile-time.  For example:
  4457 
  4458 ML {* @{sort "{zero,one}"} *}
  4459 ML {* @{typ "'a => 'b"} *}
  4460 ML {* @{term "%x. x"} *}
  4461 ML {* @{prop "x == y"} *}
  4462 ML {* @{ctyp "'a => 'b"} *}
  4463 ML {* @{cterm "%x. x"} *}
  4464 ML {* @{cprop "x == y"} *}
  4465 ML {* @{thm asm_rl} *}
  4466 ML {* @{thms asm_rl} *}
  4467 ML {* @{type_name c} *}
  4468 ML {* @{type_syntax c} *}
  4469 ML {* @{const_name c} *}
  4470 ML {* @{const_syntax c} *}
  4471 ML {* @{context} *}
  4472 ML {* @{theory} *}
  4473 ML {* @{theory Pure} *}
  4474 ML {* @{theory_ref} *}
  4475 ML {* @{theory_ref Pure} *}
  4476 ML {* @{simpset} *}
  4477 ML {* @{claset} *}
  4478 ML {* @{clasimpset} *}
  4479 
  4480 The same works for sources being ``used'' within an Isar context.
  4481 
  4482 * ML in Isar: improved error reporting; extra verbosity with
  4483 ML_Context.trace enabled.
  4484 
  4485 * Pure/General/table.ML: the join operations now works via exceptions
  4486 DUP/SAME instead of type option. This is simpler in simple cases, and
  4487 admits slightly more efficient complex applications.
  4488 
  4489 * Pure: 'advanced' translation functions (parse_translation etc.) now
  4490 use Context.generic instead of just theory.
  4491 
  4492 * Pure: datatype Context.generic joins theory/Proof.context and
  4493 provides some facilities for code that works in either kind of
  4494 context, notably GenericDataFun for uniform theory and proof data.
  4495 
  4496 * Pure: simplified internal attribute type, which is now always
  4497 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  4498 local (Proof.context) attributes have been discontinued, while
  4499 minimizing code duplication. Thm.rule_attribute and
  4500 Thm.declaration_attribute build canonical attributes; see also structure
  4501 Context for further operations on Context.generic, notably
  4502 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  4503 declarations and definitions.
  4504 
  4505 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  4506 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  4507 init only required for impure data. INCOMPATIBILITY: empty really need
  4508 to be empty (no dependencies on theory content!)
  4509 
  4510 * Pure/kernel: consts certification ignores sort constraints given in
  4511 signature declarations. (This information is not relevant to the
  4512 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  4513 potential INCOMPATIBILITY.
  4514 
  4515 * Pure: axiomatic type classes are now purely definitional, with
  4516 explicit proofs of class axioms and super class relations performed
  4517 internally. See Pure/axclass.ML for the main internal interfaces --
  4518 notably AxClass.define_class supercedes AxClass.add_axclass, and
  4519 AxClass.axiomatize_class/classrel/arity supersede
  4520 Sign.add_classes/classrel/arities.
  4521 
  4522 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  4523 global/local versions on theory vs. Proof.context have been
  4524 discontinued; Attrib.syntax and Method.syntax have been adapted
  4525 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  4526 attributes, methods, etc.
  4527 
  4528 * Pure: several functions of signature "... -> theory -> theory * ..."
  4529 have been reoriented to "... -> theory -> ... * theory" in order to
  4530 allow natural usage in combination with the ||>, ||>>, |-> and
  4531 fold_map combinators.
  4532 
  4533 * Pure: official theorem names (closed derivations) and additional
  4534 comments (tags) are now strictly separate.  Name hints -- which are
  4535 maintained as tags -- may be attached any time without affecting the
  4536 derivation.
  4537 
  4538 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  4539 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  4540 achieve the old behaviour.
  4541 
  4542 * Pure: the "Goal" constant is now called "prop", supporting a
  4543 slightly more general idea of ``protecting'' meta-level rule
  4544 statements.
  4545 
  4546 * Pure: Logic.(un)varify only works in a global context, which is now
  4547 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  4548 Logic.legacy_(un)varify as temporary workaround.
  4549 
  4550 * Pure: structure Name provides scalable operations for generating
  4551 internal variable names, notably Name.variants etc.  This replaces
  4552 some popular functions from term.ML:
  4553 
  4554   Term.variant		->  Name.variant
  4555   Term.variantlist	->  Name.variant_list
  4556   Term.invent_names	->  Name.invent_list
  4557 
  4558 Note that low-level renaming rarely occurs in new code -- operations
  4559 from structure Variable are used instead (see below).
  4560 
  4561 * Pure: structure Variable provides fundamental operations for proper
  4562 treatment of fixed/schematic variables in a context.  For example,
  4563 Variable.import introduces fixes for schematics of given facts and
  4564 Variable.export reverses the effect (up to renaming) -- this replaces
  4565 various freeze_thaw operations.
  4566 
  4567 * Pure: structure Goal provides simple interfaces for
  4568 init/conclude/finish and tactical prove operations (replacing former
  4569 Tactic.prove).  Goal.prove is the canonical way to prove results
  4570 within a given context; Goal.prove_global is a degraded version for
  4571 theory level goals, including a global Drule.standard.  Note that
  4572 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  4573 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  4574 in a locale context).
  4575 
  4576 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  4577 and type checking (Syntax.check_term etc.), with common combinations
  4578 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  4579 which are considered legacy and await removal.
  4580 
  4581 * Pure/Syntax: generic interfaces for type unchecking
  4582 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  4583 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  4584 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  4585 available for convenience, but refer to the very same operations using
  4586 a mere theory instead of a full context.
  4587 
  4588 * Isar: simplified treatment of user-level errors, using exception
  4589 ERROR of string uniformly.  Function error now merely raises ERROR,
  4590 without any side effect on output channels.  The Isar toplevel takes
  4591 care of proper display of ERROR exceptions.  ML code may use plain
  4592 handle/can/try; cat_error may be used to concatenate errors like this:
  4593 
  4594   ... handle ERROR msg => cat_error msg "..."
  4595 
  4596 Toplevel ML code (run directly or through the Isar toplevel) may be
  4597 embedded into the Isar toplevel with exception display/debug like
  4598 this:
  4599 
  4600   Isar.toplevel (fn () => ...)
  4601 
  4602 INCOMPATIBILITY, removed special transform_error facilities, removed
  4603 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  4604 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  4605 -- use plain ERROR instead.
  4606 
  4607 * Isar: theory setup now has type (theory -> theory), instead of a
  4608 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  4609 
  4610 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  4611 ProofContext.debug/verbose flags.
  4612 
  4613 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  4614 theory before entering a proof state.  Transactions now always see a
  4615 quasi-functional intermediate checkpoint, both in interactive and
  4616 batch mode.
  4617 
  4618 * Isar: simplified interfaces for outer syntax.  Renamed
  4619 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  4620 OuterSyntax.add_parsers -- this functionality is now included in
  4621 OuterSyntax.command etc.  INCOMPATIBILITY.
  4622 
  4623 * Simplifier: the simpset of a running simplification process now
  4624 contains a proof context (cf. Simplifier.the_context), which is the
  4625 very context that the initial simpset has been retrieved from (by
  4626 simpset_of/local_simpset_of).  Consequently, all plug-in components
  4627 (solver, looper etc.) may depend on arbitrary proof data.
  4628 
  4629 * Simplifier.inherit_context inherits the proof context (plus the
  4630 local bounds) of the current simplification process; any simproc
  4631 etc. that calls the Simplifier recursively should do this!  Removed
  4632 former Simplifier.inherit_bounds, which is already included here --
  4633 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  4634 specify an explicit context using Simplifier.context/theory_context.
  4635 
  4636 * Simplifier/Classical Reasoner: more abstract interfaces
  4637 change_simpset/claset for modifying the simpset/claset reference of a
  4638 theory; raw versions simpset/claset_ref etc. have been discontinued --
  4639 INCOMPATIBILITY.
  4640 
  4641 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  4642 "Trueprop" etc.
  4643 
  4644 
  4645 *** System ***
  4646 
  4647 * settings: the default heap location within ISABELLE_HOME_USER now
  4648 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  4649 Isabelle installations.
  4650 
  4651 * isabelle-process: option -S (secure mode) disables some critical
  4652 operations, notably runtime compilation and evaluation of ML source
  4653 code.
  4654 
  4655 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  4656 
  4657 * Support for parallel execution, using native multicore support of
  4658 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  4659 independent theories, according to the given theory header
  4660 specifications. The maximum number of worker threads is specified via
  4661 usedir option -M or the "max-threads" setting in Proof General. A
  4662 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  4663 to 6 on a 8-core machine.  User-code needs to observe certain
  4664 guidelines for thread-safe programming, see appendix A in the Isar
  4665 Implementation manual.
  4666 
  4667 
  4668 
  4669 New in Isabelle2005 (October 2005)
  4670 ----------------------------------
  4671 
  4672 *** General ***
  4673 
  4674 * Theory headers: the new header syntax for Isar theories is
  4675 
  4676   theory <name>
  4677   imports <theory1> ... <theoryN>
  4678   uses <file1> ... <fileM>
  4679   begin
  4680 
  4681 where the 'uses' part is optional.  The previous syntax
  4682 
  4683   theory <name> = <theory1> + ... + <theoryN>:
  4684 
  4685 will disappear in the next release.  Use isatool fixheaders to convert
  4686 existing theory files.  Note that there is no change in ancient
  4687 non-Isar theories now, but these will disappear soon.
  4688 
  4689 * Theory loader: parent theories can now also be referred to via
  4690 relative and absolute paths.
  4691 
  4692 * Command 'find_theorems' searches for a list of criteria instead of a
  4693 list of constants. Known criteria are: intro, elim, dest, name:string,
  4694 simp:term, and any term. Criteria can be preceded by '-' to select
  4695 theorems that do not match. Intro, elim, dest select theorems that
  4696 match the current goal, name:s selects theorems whose fully qualified
  4697 name contain s, and simp:term selects all simplification rules whose
  4698 lhs match term.  Any other term is interpreted as pattern and selects
  4699 all theorems matching the pattern. Available in ProofGeneral under
  4700 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  4701 
  4702   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  4703 
  4704 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  4705 matching the current goal as introduction rule and not having "HOL."
  4706 in their name (i.e. not being defined in theory HOL).
  4707 
  4708 * Command 'thms_containing' has been discontinued in favour of
  4709 'find_theorems'; INCOMPATIBILITY.
  4710 
  4711 * Communication with Proof General is now 8bit clean, which means that
  4712 Unicode text in UTF-8 encoding may be used within theory texts (both
  4713 formal and informal parts).  Cf. option -U of the Isabelle Proof
  4714 General interface.  Here are some simple examples (cf. src/HOL/ex):
  4715 
  4716   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  4717   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  4718 
  4719 * Improved efficiency of the Simplifier and, to a lesser degree, the
  4720 Classical Reasoner.  Typical big applications run around 2 times
  4721 faster.
  4722 
  4723 
  4724 *** Document preparation ***
  4725 
  4726 * Commands 'display_drafts' and 'print_drafts' perform simple output
  4727 of raw sources.  Only those symbols that do not require additional
  4728 LaTeX packages (depending on comments in isabellesym.sty) are
  4729 displayed properly, everything else is left verbatim.  isatool display
  4730 and isatool print are used as front ends (these are subject to the
  4731 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  4732 
  4733 * Command tags control specific markup of certain regions of text,
  4734 notably folding and hiding.  Predefined tags include "theory" (for
  4735 theory begin and end), "proof" for proof commands, and "ML" for
  4736 commands involving ML code; the additional tags "visible" and
  4737 "invisible" are unused by default.  Users may give explicit tag
  4738 specifications in the text, e.g. ''by %invisible (auto)''.  The
  4739 interpretation of tags is determined by the LaTeX job during document
  4740 preparation: see option -V of isatool usedir, or options -n and -t of
  4741 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  4742 \isadroptag.
  4743 
  4744 Several document versions may be produced at the same time via isatool
  4745 usedir (the generated index.html will link all of them).  Typical
  4746 specifications include ''-V document=theory,proof,ML'' to present
  4747 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  4748 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  4749 these parts without any formal replacement text.  The Isabelle site
  4750 default settings produce ''document'' and ''outline'' versions as
  4751 specified above.
  4752 
  4753 * Several new antiquotations:
  4754 
  4755   @{term_type term} prints a term with its type annotated;
  4756 
  4757   @{typeof term} prints the type of a term;
  4758 
  4759   @{const const} is the same as @{term const}, but checks that the
  4760   argument is a known logical constant;
  4761 
  4762   @{term_style style term} and @{thm_style style thm} print a term or
  4763   theorem applying a "style" to it
  4764 
  4765   @{ML text}
  4766 
  4767 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  4768 definitions, equations, inequations etc., 'concl' printing only the
  4769 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  4770 to print the specified premise.  TermStyle.add_style provides an ML
  4771 interface for introducing further styles.  See also the "LaTeX Sugar"
  4772 document practical applications.  The ML antiquotation prints
  4773 type-checked ML expressions verbatim.
  4774 
  4775 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  4776 and 'text' support optional locale specification '(in loc)', which
  4777 specifies the default context for interpreting antiquotations.  For
  4778 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  4779 
  4780 * Option 'locale=NAME' of antiquotations specifies an alternative
  4781 context interpreting the subsequent argument.  For example: @{thm
  4782 [locale=lattice] inf_assoc}.
  4783 
  4784 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  4785 a proof context.
  4786 
  4787 * Proper output of antiquotations for theory commands involving a
  4788 proof context (such as 'locale' or 'theorem (in loc) ...').
  4789 
  4790 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  4791 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  4792 
  4793 * isatool usedir: new option -C (default true) controls whether option
  4794 -D should include a copy of the original document directory; -C false
  4795 prevents unwanted effects such as copying of administrative CVS data.
  4796 
  4797 
  4798 *** Pure ***
  4799 
  4800 * Considerably improved version of 'constdefs' command.  Now performs
  4801 automatic type-inference of declared constants; additional support for
  4802 local structure declarations (cf. locales and HOL records), see also
  4803 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  4804 sequential dependencies of definitions within a single 'constdefs'
  4805 section; moreover, the declared name needs to be an identifier.  If
  4806 all fails, consider to fall back on 'consts' and 'defs' separately.
  4807 
  4808 * Improved indexed syntax and implicit structures.  First of all,
  4809 indexed syntax provides a notational device for subscripted
  4810 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  4811 expressions.  Secondly, in a local context with structure
  4812 declarations, number indexes \<^sub>n or the empty index (default
  4813 number 1) refer to a certain fixed variable implicitly; option
  4814 show_structs controls printing of implicit structures.  Typical
  4815 applications of these concepts involve record types and locales.
  4816 
  4817 * New command 'no_syntax' removes grammar declarations (and
  4818 translations) resulting from the given syntax specification, which is
  4819 interpreted in the same manner as for the 'syntax' command.
  4820 
  4821 * 'Advanced' translation functions (parse_translation etc.) may depend
  4822 on the signature of the theory context being presently used for
  4823 parsing/printing, see also isar-ref manual.
  4824 
  4825 * Improved 'oracle' command provides a type-safe interface to turn an
  4826 ML expression of type theory -> T -> term into a primitive rule of
  4827 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  4828 is already included here); see also FOL/ex/IffExample.thy;
  4829 INCOMPATIBILITY.
  4830 
  4831 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  4832 before); "cI" is no longer bound, use "c.intro" instead.
  4833 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  4834 axclasses vs. locales.
  4835 
  4836 * Improved internal renaming of symbolic identifiers -- attach primes
  4837 instead of base 26 numbers.
  4838 
  4839 * New flag show_question_marks controls printing of leading question
  4840 marks in schematic variable names.
  4841 
  4842 * In schematic variable names, *any* symbol following \<^isub> or
  4843 \<^isup> is now treated as part of the base name.  For example, the
  4844 following works without printing of awkward ".0" indexes:
  4845 
  4846   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  4847     by simp
  4848 
  4849 * Inner syntax includes (*(*nested*) comments*).
  4850 
  4851 * Pretty printer now supports unbreakable blocks, specified in mixfix
  4852 annotations as "(00...)".
  4853 
  4854 * Clear separation of logical types and nonterminals, where the latter
  4855 may only occur in 'syntax' specifications or type abbreviations.
  4856 Before that distinction was only partially implemented via type class
  4857 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  4858 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  4859 exotic syntax specifications may require further adaption
  4860 (e.g. Cube/Cube.thy).
  4861 
  4862 * Removed obsolete type class "logic", use the top sort {} instead.
  4863 Note that non-logical types should be declared as 'nonterminals'
  4864 rather than 'types'.  INCOMPATIBILITY for new object-logic
  4865 specifications.
  4866 
  4867 * Attributes 'induct' and 'cases': type or set names may now be
  4868 locally fixed variables as well.
  4869 
  4870 * Simplifier: can now control the depth to which conditional rewriting
  4871 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  4872 Limit.
  4873 
  4874 * Simplifier: simplification procedures may now take the current
  4875 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  4876 interface), which is very useful for calling the Simplifier
  4877 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  4878 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  4879 low-level mk_simproc no longer applies Logic.varify internally, to
  4880 allow for use in a context of fixed variables.
  4881 
  4882 * thin_tac now works even if the assumption being deleted contains !!
  4883 or ==>.  More generally, erule now works even if the major premise of
  4884 the elimination rule contains !! or ==>.
  4885 
  4886 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  4887 
  4888 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  4889 from Pure, which contains all common declarations already.  Both
  4890 theories are defined via plain Isabelle/Isar .thy files.
  4891 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  4892 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  4893 use isatool fixcpure to adapt your theory and ML sources.
  4894 
  4895 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  4896 selections of theorems in named facts via index ranges.
  4897 
  4898 * 'print_theorems': in theory mode, really print the difference
  4899 wrt. the last state (works for interactive theory development only),
  4900 in proof mode print all local facts (cf. 'print_facts');
  4901 
  4902 * 'hide': option '(open)' hides only base names.
  4903 
  4904 * More efficient treatment of intermediate checkpoints in interactive
  4905 theory development.
  4906 
  4907 * Code generator is now invoked via code_module (incremental code
  4908 generation) and code_library (modular code generation, ML structures
  4909 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  4910 must be quoted when used as identifiers.
  4911 
  4912 * New 'value' command for reading, evaluating and printing terms using
  4913 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  4914 quoted when used as identifier.
  4915 
  4916 
  4917 *** Locales ***
  4918 
  4919 * New commands for the interpretation of locale expressions in
  4920 theories (1), locales (2) and proof contexts (3).  These generate
  4921 proof obligations from the expression specification.  After the
  4922 obligations have been discharged, theorems of the expression are added
  4923 to the theory, target locale or proof context.  The synopsis of the
  4924 commands is a follows:
  4925 
  4926   (1) interpretation expr inst
  4927   (2) interpretation target < expr
  4928   (3) interpret expr inst
  4929 
  4930 Interpretation in theories and proof contexts require a parameter
  4931 instantiation of terms from the current context.  This is applied to
  4932 specifications and theorems of the interpreted expression.
  4933 Interpretation in locales only permits parameter renaming through the
  4934 locale expression.  Interpretation is smart in that interpretations
  4935 that are active already do not occur in proof obligations, neither are
  4936 instantiated theorems stored in duplicate.  Use 'print_interps' to
  4937 inspect active interpretations of a particular locale.  For details,
  4938 see the Isar Reference manual.  Examples can be found in
  4939 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  4940 
  4941 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  4942 'interpret' instead.
  4943 
  4944 * New context element 'constrains' for adding type constraints to
  4945 parameters.
  4946 
  4947 * Context expressions: renaming of parameters with syntax
  4948 redeclaration.
  4949 
  4950 * Locale declaration: 'includes' disallowed.
  4951 
  4952 * Proper static binding of attribute syntax -- i.e. types / terms /
  4953 facts mentioned as arguments are always those of the locale definition
  4954 context, independently of the context of later invocations.  Moreover,
  4955 locale operations (renaming and type / term instantiation) are applied
  4956 to attribute arguments as expected.
  4957 
  4958 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  4959 actual attributes; rare situations may require Attrib.attribute to
  4960 embed those attributes into Attrib.src that lack concrete syntax.
  4961 Attribute implementations need to cooperate properly with the static
  4962 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  4963 Attrib.XXX_thm etc. already do the right thing without further
  4964 intervention.  Only unusual applications -- such as "where" or "of"
  4965 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  4966 on the context and the facts involved -- may have to assign parsed
  4967 values to argument tokens explicitly.
  4968 
  4969 * Changed parameter management in theorem generation for long goal
  4970 statements with 'includes'.  INCOMPATIBILITY: produces a different
  4971 theorem statement in rare situations.
  4972 
  4973 * Locale inspection command 'print_locale' omits notes elements.  Use
  4974 'print_locale!' to have them included in the output.
  4975 
  4976 
  4977 *** Provers ***
  4978 
  4979 * Provers/hypsubst.ML: improved version of the subst method, for
  4980 single-step rewriting: it now works in bound variable contexts. New is
  4981 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  4982 rewrite a different subterm than the original subst method, which is
  4983 still available as 'simplesubst'.
  4984 
  4985 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  4986 and quasi orders.
  4987 
  4988 * Provers/trancl.ML: new transitivity reasoner for transitive and
  4989 reflexive-transitive closure of relations.
  4990 
  4991 * Provers/blast.ML: new reference depth_limit to make blast's depth
  4992 limit (previously hard-coded with a value of 20) user-definable.
  4993 
  4994 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  4995 is peformed already.  Object-logics merely need to finish their
  4996 initial simpset configuration as before.  INCOMPATIBILITY.
  4997 
  4998 
  4999 *** HOL ***
  5000 
  5001 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  5002 
  5003   syntax (epsilon)
  5004     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  5005 
  5006 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  5007 and x-symbol; use option '-m epsilon' to get it actually printed.
  5008 Moreover, the mathematically important symbolic identifier \<epsilon>
  5009 becomes available as variable, constant etc.  INCOMPATIBILITY,
  5010 
  5011 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  5012 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  5013 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  5014 support corresponding Isar calculations.
  5015 
  5016 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  5017 instead of ":".
  5018 
  5019 * theory SetInterval: changed the syntax for open intervals:
  5020 
  5021   Old       New
  5022   {..n(}    {..<n}
  5023   {)n..}    {n<..}
  5024   {m..n(}   {m..<n}
  5025   {)m..n}   {m<..n}
  5026   {)m..n(}  {m<..<n}
  5027 
  5028 The old syntax is still supported but will disappear in the next
  5029 release.  For conversion use the following Emacs search and replace
  5030 patterns (these are not perfect but work quite well):
  5031 
  5032   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  5033   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  5034 
  5035 * Theory Commutative_Ring (in Library): method comm_ring for proving
  5036 equalities in commutative rings; method 'algebra' provides a generic
  5037 interface.
  5038 
  5039 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  5040 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  5041 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  5042 be a tuple pattern.
  5043 
  5044 Some new syntax forms are available:
  5045 
  5046   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  5047   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  5048   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  5049   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  5050 
  5051 The latter form "\<Sum>x < k. e" used to be based on a separate
  5052 function "Summation", which has been discontinued.
  5053 
  5054 * theory Finite_Set: in structured induction proofs, the insert case
  5055 is now 'case (insert x F)' instead of the old counterintuitive 'case
  5056 (insert F x)'.
  5057 
  5058 * The 'refute' command has been extended to support a much larger
  5059 fragment of HOL, including axiomatic type classes, constdefs and
  5060 typedefs, inductive datatypes and recursion.
  5061 
  5062 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  5063 Requires zChaff with proof generation to be installed.  See
  5064 HOL/ex/SAT_Examples.thy for examples.
  5065 
  5066 * Datatype induction via method 'induct' now preserves the name of the
  5067 induction variable. For example, when proving P(xs::'a list) by
  5068 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  5069 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  5070 in unstructured proof scripts.
  5071 
  5072 * Reworked implementation of records.  Improved scalability for
  5073 records with many fields, avoiding performance problems for type
  5074 inference. Records are no longer composed of nested field types, but
  5075 of nested extension types. Therefore the record type only grows linear
  5076 in the number of extensions and not in the number of fields.  The
  5077 top-level (users) view on records is preserved.  Potential
  5078 INCOMPATIBILITY only in strange cases, where the theory depends on the
  5079 old record representation. The type generated for a record is called
  5080 <record_name>_ext_type.
  5081 
  5082 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  5083 proofs triggered by a record definition or a simproc (if
  5084 quick_and_dirty is enabled).  Definitions of large records can take
  5085 quite long.
  5086 
  5087 New simproc record_upd_simproc for simplification of multiple record
  5088 updates enabled by default.  Moreover, trivial updates are also
  5089 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  5090 occasionally, since simplification is more powerful by default.
  5091 
  5092 * typedef: proper support for polymorphic sets, which contain extra
  5093 type-variables in the term.
  5094 
  5095 * Simplifier: automatically reasons about transitivity chains
  5096 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  5097 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  5098 old proofs break occasionally as simplification may now solve more
  5099 goals than previously.
  5100 
  5101 * Simplifier: converts x <= y into x = y if assumption y <= x is
  5102 present.  Works for all partial orders (class "order"), in particular
  5103 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  5104 just like y <= x.
  5105 
  5106 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  5107 bound variable or a constant then the let is unfolded.  Otherwise
  5108 first a is simplified to b, and then f b is simplified to g. If
  5109 possible we abstract b from g arriving at "let x = b in h x",
  5110 otherwise we unfold the let and arrive at g.  The simproc can be
  5111 enabled/disabled by the reference use_let_simproc.  Potential
  5112 INCOMPATIBILITY since simplification is more powerful by default.
  5113 
  5114 * Classical reasoning: the meson method now accepts theorems as arguments.
  5115 
  5116 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  5117 jobs to provide advice on the provability of subgoals.
  5118 
  5119 * Theory OrderedGroup and Ring_and_Field: various additions and
  5120 improvements to faciliate calculations involving equalities and
  5121 inequalities.
  5122 
  5123 The following theorems have been eliminated or modified
  5124 (INCOMPATIBILITY):
  5125 
  5126   abs_eq             now named abs_of_nonneg
  5127   abs_of_ge_0        now named abs_of_nonneg
  5128   abs_minus_eq       now named abs_of_nonpos
  5129   imp_abs_id         now named abs_of_nonneg
  5130   imp_abs_neg_id     now named abs_of_nonpos
  5131   mult_pos           now named mult_pos_pos
  5132   mult_pos_le        now named mult_nonneg_nonneg
  5133   mult_pos_neg_le    now named mult_nonneg_nonpos
  5134   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  5135   mult_neg           now named mult_neg_neg
  5136   mult_neg_le        now named mult_nonpos_nonpos
  5137 
  5138 * The following lemmas in Ring_and_Field have been added to the simplifier:
  5139      
  5140      zero_le_square
  5141      not_square_less_zero 
  5142 
  5143   The following lemmas have been deleted from Real/RealPow:
  5144   
  5145      realpow_zero_zero
  5146      realpow_two
  5147      realpow_less
  5148      zero_le_power
  5149      realpow_two_le
  5150      abs_realpow_two
  5151      realpow_two_abs     
  5152 
  5153 * Theory Parity: added rules for simplifying exponents.
  5154 
  5155 * Theory List:
  5156 
  5157 The following theorems have been eliminated or modified
  5158 (INCOMPATIBILITY):
  5159 
  5160   list_all_Nil       now named list_all.simps(1)
  5161   list_all_Cons      now named list_all.simps(2)
  5162   list_all_conv      now named list_all_iff
  5163   set_mem_eq         now named mem_iff
  5164 
  5165 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  5166 asymptotic "big O" calculations.  See the notes in BigO.thy.
  5167 
  5168 
  5169 *** HOL-Complex ***
  5170 
  5171 * Theory RealDef: better support for embedding natural numbers and
  5172 integers in the reals.
  5173 
  5174 The following theorems have been eliminated or modified
  5175 (INCOMPATIBILITY):
  5176 
  5177   exp_ge_add_one_self  now requires no hypotheses
  5178   real_of_int_add      reversed direction of equality (use [symmetric])
  5179   real_of_int_minus    reversed direction of equality (use [symmetric])
  5180   real_of_int_diff     reversed direction of equality (use [symmetric])
  5181   real_of_int_mult     reversed direction of equality (use [symmetric])
  5182 
  5183 * Theory RComplete: expanded support for floor and ceiling functions.
  5184 
  5185 * Theory Ln is new, with properties of the natural logarithm
  5186 
  5187 * Hyperreal: There is a new type constructor "star" for making
  5188 nonstandard types.  The old type names are now type synonyms:
  5189 
  5190   hypreal = real star
  5191   hypnat = nat star
  5192   hcomplex = complex star
  5193 
  5194 * Hyperreal: Many groups of similarly-defined constants have been
  5195 replaced by polymorphic versions (INCOMPATIBILITY):
  5196 
  5197   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  5198 
  5199   starset      <-- starsetNat, starsetC
  5200   *s*          <-- *sNat*, *sc*
  5201   starset_n    <-- starsetNat_n, starsetC_n
  5202   *sn*         <-- *sNatn*, *scn*
  5203   InternalSets <-- InternalNatSets, InternalCSets
  5204 
  5205   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  5206   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  5207   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  5208   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  5209   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  5210 
  5211 * Hyperreal: Many type-specific theorems have been removed in favor of
  5212 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  5213 
  5214   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  5215   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  5216   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  5217   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  5218   right_minus <-- hypreal_add_minus
  5219   left_minus <-- {hypreal,hcomplex}_add_minus_left
  5220   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  5221   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  5222   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  5223   mult_1_right <-- hcomplex_mult_one_right
  5224   mult_zero_left <-- hcomplex_mult_zero_left
  5225   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  5226   right_distrib <-- hypnat_add_mult_distrib2
  5227   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  5228   right_inverse <-- hypreal_mult_inverse
  5229   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  5230   order_refl <-- {hypreal,hypnat}_le_refl
  5231   order_trans <-- {hypreal,hypnat}_le_trans
  5232   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  5233   order_less_le <-- {hypreal,hypnat}_less_le
  5234   linorder_linear <-- {hypreal,hypnat}_le_linear
  5235   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  5236   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  5237   add_nonneg_nonneg <-- hypreal_le_add_order
  5238 
  5239 * Hyperreal: Separate theorems having to do with type-specific
  5240 versions of constants have been merged into theorems that apply to the
  5241 new polymorphic constants (INCOMPATIBILITY):
  5242 
  5243   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  5244   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  5245   STAR_Un <-- {STAR,NatStar,STARC}_Un
  5246   STAR_Int <-- {STAR,NatStar,STARC}_Int
  5247   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  5248   STAR_subset <-- {STAR,NatStar,STARC}_subset
  5249   STAR_mem <-- {STAR,NatStar,STARC}_mem
  5250   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  5251   STAR_diff <-- {STAR,STARC}_diff
  5252   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  5253     STARC_hcomplex_of_complex}_image_subset
  5254   starset_n_Un <-- starset{Nat,C}_n_Un
  5255   starset_n_Int <-- starset{Nat,C}_n_Int
  5256   starset_n_Compl <-- starset{Nat,C}_n_Compl
  5257   starset_n_diff <-- starset{Nat,C}_n_diff
  5258   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  5259   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  5260   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  5261   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  5262   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  5263   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  5264   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  5265   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  5266   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  5267   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  5268   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  5269   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  5270   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  5271   starfun_diff <-- starfun{C,RC,CR}_diff
  5272   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  5273   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  5274   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  5275   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  5276   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  5277   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  5278   starfun_Id <-- starfunC_Id
  5279   starfun_approx <-- starfun{Nat,CR}_approx
  5280   starfun_capprox <-- starfun{C,RC}_capprox
  5281   starfun_abs <-- starfunNat_rabs
  5282   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  5283   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  5284   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  5285   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  5286   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  5287   starfun_add_approx <-- starfunCR_add_approx
  5288   starfun_inverse_inverse <-- starfunC_inverse_inverse
  5289   starfun_divide <-- starfun{C,CR,RC}_divide
  5290   starfun_n <-- starfun{Nat,C}_n
  5291   starfun_n_mult <-- starfun{Nat,C}_n_mult
  5292   starfun_n_add <-- starfun{Nat,C}_n_add
  5293   starfun_n_add_minus <-- starfunNat_n_add_minus
  5294   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  5295   starfun_n_minus <-- starfun{Nat,C}_n_minus
  5296   starfun_n_eq <-- starfun{Nat,C}_n_eq
  5297 
  5298   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  5299   star_n_minus <-- {hypreal,hcomplex}_minus
  5300   star_n_diff <-- {hypreal,hcomplex}_diff
  5301   star_n_mult <-- {hypreal,hcomplex}_mult
  5302   star_n_inverse <-- {hypreal,hcomplex}_inverse
  5303   star_n_le <-- {hypreal,hypnat}_le
  5304   star_n_less <-- {hypreal,hypnat}_less
  5305   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  5306   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  5307   star_n_abs <-- hypreal_hrabs
  5308   star_n_divide <-- hcomplex_divide
  5309 
  5310   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  5311   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  5312   star_of_diff <-- hypreal_of_real_diff
  5313   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  5314   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  5315   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  5316   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  5317   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  5318   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  5319   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  5320   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  5321   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  5322   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  5323   star_of_number_of <-- {hypreal,hcomplex}_number_of
  5324   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  5325   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  5326   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  5327   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  5328   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  5329   star_of_power <-- hypreal_of_real_power
  5330   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  5331 
  5332 * Hyperreal: new method "transfer" that implements the transfer
  5333 principle of nonstandard analysis. With a subgoal that mentions
  5334 nonstandard types like "'a star", the command "apply transfer"
  5335 replaces it with an equivalent one that mentions only standard types.
  5336 To be successful, all free variables must have standard types; non-
  5337 standard variables must have explicit universal quantifiers.
  5338 
  5339 * Hyperreal: A theory of Taylor series.
  5340 
  5341 
  5342 *** HOLCF ***
  5343 
  5344 * Discontinued special version of 'constdefs' (which used to support
  5345 continuous functions) in favor of the general Pure one with full
  5346 type-inference.
  5347 
  5348 * New simplification procedure for solving continuity conditions; it
  5349 is much faster on terms with many nested lambda abstractions (cubic
  5350 instead of exponential time).
  5351 
  5352 * New syntax for domain package: selector names are now optional.
  5353 Parentheses should be omitted unless argument is lazy, for example:
  5354 
  5355   domain 'a stream = cons "'a" (lazy "'a stream")
  5356 
  5357 * New command 'fixrec' for defining recursive functions with pattern
  5358 matching; defining multiple functions with mutual recursion is also
  5359 supported.  Patterns may include the constants cpair, spair, up, sinl,
  5360 sinr, or any data constructor defined by the domain package. The given
  5361 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  5362 syntax and examples.
  5363 
  5364 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  5365 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  5366 but the proof obligation additionally includes an admissibility
  5367 requirement. The packages generate instances of class cpo or pcpo,
  5368 with continuity and strictness theorems for Rep and Abs.
  5369 
  5370 * HOLCF: Many theorems have been renamed according to a more standard naming
  5371 scheme (INCOMPATIBILITY):
  5372 
  5373   foo_inject:  "foo$x = foo$y ==> x = y"
  5374   foo_eq:      "(foo$x = foo$y) = (x = y)"
  5375   foo_less:    "(foo$x << foo$y) = (x << y)"
  5376   foo_strict:  "foo$UU = UU"
  5377   foo_defined: "... ==> foo$x ~= UU"
  5378   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  5379 
  5380 
  5381 *** ZF ***
  5382 
  5383 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  5384 including the First Isomorphism Theorem (on quotienting by the kernel
  5385 of a homomorphism).
  5386 
  5387 * ZF/Simplifier: install second copy of type solver that actually
  5388 makes use of TC rules declared to Isar proof contexts (or locales);
  5389 the old version is still required for ML proof scripts.
  5390 
  5391 
  5392 *** Cube ***
  5393 
  5394 * Converted to Isar theory format; use locales instead of axiomatic
  5395 theories.
  5396 
  5397 
  5398 *** ML ***
  5399 
  5400 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  5401 for ||>, ||>>, |>>,
  5402 
  5403 * Pure/library.ML no longer defines its own option datatype, but uses
  5404 that of the SML basis, which has constructors NONE and SOME instead of
  5405 None and Some, as well as exception Option.Option instead of OPTION.
  5406 The functions the, if_none, is_some, is_none have been adapted
  5407 accordingly, while Option.map replaces apsome.
  5408 
  5409 * Pure/library.ML: the exception LIST has been given up in favour of
  5410 the standard exceptions Empty and Subscript, as well as
  5411 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  5412 superceded by the standard hd and tl functions etc.
  5413 
  5414 A number of basic list functions are no longer exported to the ML
  5415 toplevel, as they are variants of predefined functions.  The following
  5416 suggests how one can translate existing code:
  5417 
  5418     rev_append xs ys = List.revAppend (xs, ys)
  5419     nth_elem (i, xs) = List.nth (xs, i)
  5420     last_elem xs = List.last xs
  5421     flat xss = List.concat xss
  5422     seq fs = List.app fs
  5423     partition P xs = List.partition P xs
  5424     mapfilter f xs = List.mapPartial f xs
  5425 
  5426 * Pure/library.ML: several combinators for linear functional
  5427 transformations, notably reverse application and composition:
  5428 
  5429   x |> f                f #> g
  5430   (x, y) |-> f          f #-> g
  5431 
  5432 * Pure/library.ML: introduced/changed precedence of infix operators:
  5433 
  5434   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  5435   infix 2 ?;
  5436   infix 3 o oo ooo oooo;
  5437   infix 4 ~~ upto downto;
  5438 
  5439 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  5440 infix operators.
  5441 
  5442 * Pure/library.ML: natural list combinators fold, fold_rev, and
  5443 fold_map support linear functional transformations and nesting.  For
  5444 example:
  5445 
  5446   fold f [x1, ..., xN] y =
  5447     y |> f x1 |> ... |> f xN
  5448 
  5449   (fold o fold) f [xs1, ..., xsN] y =
  5450     y |> fold f xs1 |> ... |> fold f xsN
  5451 
  5452   fold f [x1, ..., xN] =
  5453     f x1 #> ... #> f xN
  5454 
  5455   (fold o fold) f [xs1, ..., xsN] =
  5456     fold f xs1 #> ... #> fold f xsN
  5457 
  5458 * Pure/library.ML: the following selectors on type 'a option are
  5459 available:
  5460 
  5461   the:               'a option -> 'a  (*partial*)
  5462   these:             'a option -> 'a  where 'a = 'b list
  5463   the_default: 'a -> 'a option -> 'a
  5464   the_list:          'a option -> 'a list
  5465 
  5466 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5467 basic operations for association lists, following natural argument
  5468 order; moreover the explicit equality predicate passed here avoids
  5469 potentially expensive polymorphic runtime equality checks.
  5470 The old functions may be expressed as follows:
  5471 
  5472   assoc = uncurry (AList.lookup (op =))
  5473   assocs = these oo AList.lookup (op =)
  5474   overwrite = uncurry (AList.update (op =)) o swap
  5475 
  5476 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5477 
  5478   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  5479   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  5480 
  5481 replacing make_keylist and keyfilter (occassionally used)
  5482 Naive rewrites:
  5483 
  5484   make_keylist = AList.make
  5485   keyfilter = AList.find (op =)
  5486 
  5487 * eq_fst and eq_snd now take explicit equality parameter, thus
  5488   avoiding eqtypes. Naive rewrites:
  5489 
  5490     eq_fst = eq_fst (op =)
  5491     eq_snd = eq_snd (op =)
  5492 
  5493 * Removed deprecated apl and apr (rarely used).
  5494   Naive rewrites:
  5495 
  5496     apl (n, op) =>>= curry op n
  5497     apr (op, m) =>>= fn n => op (n, m)
  5498 
  5499 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  5500 provides a reasonably efficient light-weight implementation of sets as
  5501 lists.
  5502 
  5503 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  5504 few new operations; existing lookup and update are now curried to
  5505 follow natural argument order (for use with fold etc.);
  5506 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  5507 
  5508 * Pure/General: output via the Isabelle channels of
  5509 writeln/warning/error etc. is now passed through Output.output, with a
  5510 hook for arbitrary transformations depending on the print_mode
  5511 (cf. Output.add_mode -- the first active mode that provides a output
  5512 function wins).  Already formatted output may be embedded into further
  5513 text via Output.raw; the result of Pretty.string_of/str_of and derived
  5514 functions (string_of_term/cterm/thm etc.) is already marked raw to
  5515 accommodate easy composition of diagnostic messages etc.  Programmers
  5516 rarely need to care about Output.output or Output.raw at all, with
  5517 some notable exceptions: Output.output is required when bypassing the
  5518 standard channels (writeln etc.), or in token translations to produce
  5519 properly formatted results; Output.raw is required when capturing
  5520 already output material that will eventually be presented to the user
  5521 a second time.  For the default print mode, both Output.output and
  5522 Output.raw have no effect.
  5523 
  5524 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  5525 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  5526 cumulative results are displayed at the end of a batch session.
  5527 
  5528 * Pure/General: File.sysify_path and File.quote_sysify path have been
  5529 replaced by File.platform_path and File.shell_path (with appropriate
  5530 hooks).  This provides a clean interface for unusual systems where the
  5531 internal and external process view of file names are different.
  5532 
  5533 * Pure: more efficient orders for basic syntactic entities: added
  5534 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  5535 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  5536 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  5537 orders now -- potential INCOMPATIBILITY for code that depends on a
  5538 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  5539 Library.sort_strings on result).
  5540 
  5541 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  5542 fold_types traverse types/terms from left to right, observing natural
  5543 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  5544 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  5545 
  5546 * Pure: name spaces have been refined, with significant changes of the
  5547 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  5548 to extern(_table).  The plain name entry path is superceded by a
  5549 general 'naming' context, which also includes the 'policy' to produce
  5550 a fully qualified name and external accesses of a fully qualified
  5551 name; NameSpace.extend is superceded by context dependent
  5552 Sign.declare_name.  Several theory and proof context operations modify
  5553 the naming context.  Especially note Theory.restore_naming and
  5554 ProofContext.restore_naming to get back to a sane state; note that
  5555 Theory.add_path is no longer sufficient to recover from
  5556 Theory.absolute_path in particular.
  5557 
  5558 * Pure: new flags short_names (default false) and unique_names
  5559 (default true) for controlling output of qualified names.  If
  5560 short_names is set, names are printed unqualified.  If unique_names is
  5561 reset, the name prefix is reduced to the minimum required to achieve
  5562 the original result when interning again, even if there is an overlap
  5563 with earlier declarations.
  5564 
  5565 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  5566 now 'extend', and 'merge' gets an additional Pretty.pp argument
  5567 (useful for printing error messages).  INCOMPATIBILITY.
  5568 
  5569 * Pure: major reorganization of the theory context.  Type Sign.sg and
  5570 Theory.theory are now identified, referring to the universal
  5571 Context.theory (see Pure/context.ML).  Actual signature and theory
  5572 content is managed as theory data.  The old code and interfaces were
  5573 spread over many files and structures; the new arrangement introduces
  5574 considerable INCOMPATIBILITY to gain more clarity:
  5575 
  5576   Context -- theory management operations (name, identity, inclusion,
  5577     parents, ancestors, merge, etc.), plus generic theory data;
  5578 
  5579   Sign -- logical signature and syntax operations (declaring consts,
  5580     types, etc.), plus certify/read for common entities;
  5581 
  5582   Theory -- logical theory operations (stating axioms, definitions,
  5583     oracles), plus a copy of logical signature operations (consts,
  5584     types, etc.); also a few basic management operations (Theory.copy,
  5585     Theory.merge, etc.)
  5586 
  5587 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  5588 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  5589 for convenience -- they merely return the theory.
  5590 
  5591 * Pure: type Type.tsig is superceded by theory in most interfaces.
  5592 
  5593 * Pure: the Isar proof context type is already defined early in Pure
  5594 as Context.proof (note that ProofContext.context and Proof.context are
  5595 aliases, where the latter is the preferred name).  This enables other
  5596 Isabelle components to refer to that type even before Isar is present.
  5597 
  5598 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  5599 typeK, constK, axiomK, oracleK), but provide explicit operations for
  5600 any of these kinds.  For example, Sign.intern typeK is now
  5601 Sign.intern_type, Theory.hide_space Sign.typeK is now
  5602 Theory.hide_types.  Also note that former
  5603 Theory.hide_classes/types/consts are now
  5604 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  5605 internalize their arguments!  INCOMPATIBILITY.
  5606 
  5607 * Pure: get_thm interface (of PureThy and ProofContext) expects
  5608 datatype thmref (with constructors Name and NameSelection) instead of
  5609 plain string -- INCOMPATIBILITY;
  5610 
  5611 * Pure: cases produced by proof methods specify options, where NONE
  5612 means to remove case bindings -- INCOMPATIBILITY in
  5613 (RAW_)METHOD_CASES.
  5614 
  5615 * Pure: the following operations retrieve axioms or theorems from a
  5616 theory node or theory hierarchy, respectively:
  5617 
  5618   Theory.axioms_of: theory -> (string * term) list
  5619   Theory.all_axioms_of: theory -> (string * term) list
  5620   PureThy.thms_of: theory -> (string * thm) list
  5621   PureThy.all_thms_of: theory -> (string * thm) list
  5622 
  5623 * Pure: print_tac now outputs the goal through the trace channel.
  5624 
  5625 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  5626 Reference Toplevel.debug (default false) controls detailed printing
  5627 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  5628 controls execution profiling -- set to 1 for time and 2 for space
  5629 (both increase the runtime).
  5630 
  5631 * Isar session: The initial use of ROOT.ML is now always timed,
  5632 i.e. the log will show the actual process times, in contrast to the
  5633 elapsed wall-clock time that the outer shell wrapper produces.
  5634 
  5635 * Simplifier: improved handling of bound variables (nameless
  5636 representation, avoid allocating new strings).  Simprocs that invoke
  5637 the Simplifier recursively should use Simplifier.inherit_bounds to
  5638 avoid local name clashes.  Failure to do so produces warnings
  5639 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  5640 for further details.
  5641 
  5642 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  5643 bindings for all theorems stored within a given theory; this may help
  5644 in porting non-Isar theories to Isar ones, while keeping ML proof
  5645 scripts for the time being.
  5646 
  5647 * ML operator HTML.with_charset specifies the charset begin used for
  5648 generated HTML files.  For example:
  5649 
  5650   HTML.with_charset "utf-8" use_thy "Hebrew";
  5651   HTML.with_charset "utf-8" use_thy "Chinese";
  5652 
  5653 
  5654 *** System ***
  5655 
  5656 * Allow symlinks to all proper Isabelle executables (Isabelle,
  5657 isabelle, isatool etc.).
  5658 
  5659 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  5660 isatool doc, isatool mkdir, display_drafts etc.).
  5661 
  5662 * isatool usedir: option -f allows specification of the ML file to be
  5663 used by Isabelle; default is ROOT.ML.
  5664 
  5665 * New isatool version outputs the version identifier of the Isabelle
  5666 distribution being used.
  5667 
  5668 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  5669 (containing Boolean satisfiability problems) into Isabelle/HOL
  5670 theories.
  5671 
  5672 
  5673 
  5674 New in Isabelle2004 (April 2004)
  5675 --------------------------------
  5676 
  5677 *** General ***
  5678 
  5679 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  5680   Replaces linorder.ML.
  5681 
  5682 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  5683   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  5684   (\<a>...\<z>), are now considered normal letters, and can therefore
  5685   be used anywhere where an ASCII letter (a...zA...Z) has until
  5686   now. COMPATIBILITY: This obviously changes the parsing of some
  5687   terms, especially where a symbol has been used as a binder, say
  5688   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  5689   as an identifier.  Fix it by inserting a space around former
  5690   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  5691   existing theory and ML files.
  5692 
  5693 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  5694 
  5695 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  5696   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  5697   a normal (but invisible) letter. For multiple letter subscripts repeat
  5698   \<^isub> like this: x\<^isub>1\<^isub>2.
  5699 
  5700 * Pure: There are now sub-/superscripts that can span more than one
  5701   character. Text between \<^bsub> and \<^esub> is set in subscript in
  5702   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  5703   superscript. The new control characters are not identifier parts.
  5704 
  5705 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  5706   content of "..." to the latex file instead of \isacntrl... . The "..."
  5707   may consist of any printable characters excluding the end bracket >.
  5708 
  5709 * Pure: Using new Isar command "finalconsts" (or the ML functions
  5710   Theory.add_finals or Theory.add_finals_i) it is now possible to
  5711   declare constants "final", which prevents their being given a definition
  5712   later.  It is useful for constants whose behaviour is fixed axiomatically
  5713   rather than definitionally, such as the meta-logic connectives.
  5714 
  5715 * Pure: 'instance' now handles general arities with general sorts
  5716   (i.e. intersections of classes),
  5717 
  5718 * Presentation: generated HTML now uses a CSS style sheet to make layout
  5719   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  5720   It can be changed to alter the colors/layout of generated pages.
  5721 
  5722 
  5723 *** Isar ***
  5724 
  5725 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  5726   cut_tac, subgoal_tac and thin_tac:
  5727   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  5728     locales are no longer forced to write Isar proof scripts.
  5729     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  5730     emulations.
  5731   - INCOMPATIBILITY: names of variables to be instantiated may no
  5732     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  5733     This is consistent with the instantiation attribute "where".
  5734 
  5735 * Attributes "where" and "of":
  5736   - Now take type variables of instantiated theorem into account when reading
  5737     the instantiation string.  This fixes a bug that caused instantiated
  5738     theorems to have too special types in some circumstances.
  5739   - "where" permits explicit instantiations of type variables.
  5740 
  5741 * Calculation commands "moreover" and "also" no longer interfere with
  5742   current facts ("this"), admitting arbitrary combinations with "then"
  5743   and derived forms.
  5744 
  5745 * Locales:
  5746   - Goal statements involving the context element "includes" no longer
  5747     generate theorems with internal delta predicates (those ending on
  5748     "_axioms") in the premise.
  5749     Resolve particular premise with <locale>.intro to obtain old form.
  5750   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  5751     specification and "includes" elements in goal statement.
  5752   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  5753     [intro?] and [elim?] (respectively) by default.
  5754   - Experimental command for instantiation of locales in proof contexts:
  5755         instantiate <label>[<attrs>]: <loc>
  5756     Instantiates locale <loc> and adds all its theorems to the current context
  5757     taking into account their attributes.  Label and attrs are optional
  5758     modifiers, like in theorem declarations.  If present, names of
  5759     instantiated theorems are qualified with <label>, and the attributes
  5760     <attrs> are applied after any attributes these theorems might have already.
  5761       If the locale has assumptions, a chained fact of the form
  5762     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  5763     are derived.  The command does not support old-style locales declared
  5764     with "locale (open)".
  5765       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  5766 
  5767 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  5768   (Isar) contexts.
  5769 
  5770 
  5771 *** HOL ***
  5772 
  5773 * Proof import: new image HOL4 contains the imported library from
  5774   the HOL4 system with about 2500 theorems. It is imported by
  5775   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  5776   can be used like any other Isabelle image.  See
  5777   HOL/Import/HOL/README for more information.
  5778 
  5779 * Simplifier:
  5780   - Much improved handling of linear and partial orders.
  5781     Reasoners for linear and partial orders are set up for type classes
  5782     "linorder" and "order" respectively, and are added to the default simpset
  5783     as solvers.  This means that the simplifier can build transitivity chains
  5784     to solve goals from the assumptions.
  5785   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  5786     of blast or auto after simplification become unnecessary because the goal
  5787     is solved by simplification already.
  5788 
  5789 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  5790     all proved in axiomatic type classes for semirings, rings and fields.
  5791 
  5792 * Numerics:
  5793   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  5794     now formalized using the Ring_and_Field theory mentioned above.
  5795   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  5796     than before, because now they are set up once in a generic manner.
  5797   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  5798     Look for the general versions in Ring_and_Field (and Power if they concern
  5799     exponentiation).
  5800 
  5801 * Type "rat" of the rational numbers is now available in HOL-Complex.
  5802 
  5803 * Records:
  5804   - Record types are now by default printed with their type abbreviation
  5805     instead of the list of all field types. This can be configured via
  5806     the reference "print_record_type_abbr".
  5807   - Simproc "record_upd_simproc" for simplification of multiple updates added
  5808     (not enabled by default).
  5809   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  5810     EX x. x = sel r to True (not enabled by default).
  5811   - Tactic "record_split_simp_tac" to split and simplify records added.
  5812 
  5813 * 'specification' command added, allowing for definition by
  5814   specification.  There is also an 'ax_specification' command that
  5815   introduces the new constants axiomatically.
  5816 
  5817 * arith(_tac) is now able to generate counterexamples for reals as well.
  5818 
  5819 * HOL-Algebra: new locale "ring" for non-commutative rings.
  5820 
  5821 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  5822   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  5823 
  5824 * HOL-Matrix: a first theory for matrices in HOL with an application of
  5825   matrix theory to linear programming.
  5826 
  5827 * Unions and Intersections:
  5828   The latex output syntax of UN and INT has been changed
  5829   from "\Union x \in A. B" to "\Union_{x \in A} B"
  5830   i.e. the index formulae has become a subscript.
  5831   Similarly for "\Union x. B", and for \Inter instead of \Union.
  5832 
  5833 * Unions and Intersections over Intervals:
  5834   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  5835   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  5836   like in normal math, and corresponding versions for < and for intersection.
  5837 
  5838 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  5839   lexicographic dictonary ordering has been added as "lexord".
  5840 
  5841 * ML: the legacy theory structures Int and List have been removed. They had
  5842   conflicted with ML Basis Library structures having the same names.
  5843 
  5844 * 'refute' command added to search for (finite) countermodels.  Only works
  5845   for a fragment of HOL.  The installation of an external SAT solver is
  5846   highly recommended.  See "HOL/Refute.thy" for details.
  5847 
  5848 * 'quickcheck' command: Allows to find counterexamples by evaluating
  5849   formulae under an assignment of free variables to random values.
  5850   In contrast to 'refute', it can deal with inductive datatypes,
  5851   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  5852   for examples.
  5853 
  5854 
  5855 *** HOLCF ***
  5856 
  5857 * Streams now come with concatenation and are part of the HOLCF image
  5858 
  5859 
  5860 
  5861 New in Isabelle2003 (May 2003)
  5862 ------------------------------
  5863 
  5864 *** General ***
  5865 
  5866 * Provers/simplifier:
  5867 
  5868   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  5869     Assumptions are now subject to complete mutual simplification,
  5870     not just from left to right. The simplifier now preserves
  5871     the order of assumptions.
  5872 
  5873     Potential INCOMPATIBILITY:
  5874 
  5875     -- simp sometimes diverges where the old version did
  5876        not, e.g. invoking simp on the goal
  5877 
  5878         [| P (f x); y = x; f x = f y |] ==> Q
  5879 
  5880        now gives rise to the infinite reduction sequence
  5881 
  5882         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  5883 
  5884        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  5885        kind of problem.
  5886 
  5887     -- Tactics combining classical reasoner and simplification (such as auto)
  5888        are also affected by this change, because many of them rely on
  5889        simp. They may sometimes diverge as well or yield a different numbers
  5890        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  5891        in case of problems. Sometimes subsequent calls to the classical
  5892        reasoner will fail because a preceeding call to the simplifier too
  5893        eagerly simplified the goal, e.g. deleted redundant premises.
  5894 
  5895   - The simplifier trace now shows the names of the applied rewrite rules
  5896 
  5897   - You can limit the number of recursive invocations of the simplifier
  5898     during conditional rewriting (where the simplifie tries to solve the
  5899     conditions before applying the rewrite rule):
  5900     ML "simp_depth_limit := n"
  5901     where n is an integer. Thus you can force termination where previously
  5902     the simplifier would diverge.
  5903 
  5904   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  5905 
  5906   - No longer aborts on failed congruence proof.  Instead, the
  5907     congruence is ignored.
  5908 
  5909 * Pure: New generic framework for extracting programs from constructive
  5910   proofs. See HOL/Extraction.thy for an example instantiation, as well
  5911   as HOL/Extraction for some case studies.
  5912 
  5913 * Pure: The main goal of the proof state is no longer shown by default, only
  5914 the subgoals. This behaviour is controlled by a new flag.
  5915    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  5916 (ML: Proof.show_main_goal).
  5917 
  5918 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  5919 rules whose conclusion matches subgoal 1:
  5920       PG menu: Isabelle/Isar -> Show me -> matching rules
  5921 The rules are ordered by how closely they match the subgoal.
  5922 In particular, rules that solve a subgoal outright are displayed first
  5923 (or rather last, the way they are printed).
  5924 (ML: ProofGeneral.print_intros())
  5925 
  5926 * Pure: New flag trace_unify_fail causes unification to print
  5927 diagnostic information (PG: in trace buffer) when it fails. This is
  5928 useful for figuring out why single step proofs like rule, erule or
  5929 assumption failed.
  5930 
  5931 * Pure: Locale specifications now produce predicate definitions
  5932 according to the body of text (covering assumptions modulo local
  5933 definitions); predicate "loc_axioms" covers newly introduced text,
  5934 while "loc" is cumulative wrt. all included locale expressions; the
  5935 latter view is presented only on export into the global theory
  5936 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  5937 on the old view without predicates;
  5938 
  5939 * Pure: predefined locales "var" and "struct" are useful for sharing
  5940 parameters (as in CASL, for example); just specify something like
  5941 ``var x + var y + struct M'' as import;
  5942 
  5943 * Pure: improved thms_containing: proper indexing of facts instead of
  5944 raw theorems; check validity of results wrt. current name space;
  5945 include local facts of proof configuration (also covers active
  5946 locales), cover fixed variables in index; may use "_" in term
  5947 specification; an optional limit for the number of printed facts may
  5948 be given (the default is 40);
  5949 
  5950 * Pure: disallow duplicate fact bindings within new-style theory files
  5951 (batch-mode only);
  5952 
  5953 * Provers: improved induct method: assumptions introduced by case
  5954 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  5955 the goal statement); "foo" still refers to all facts collectively;
  5956 
  5957 * Provers: the function blast.overloaded has been removed: all constants
  5958 are regarded as potentially overloaded, which improves robustness in exchange
  5959 for slight decrease in efficiency;
  5960 
  5961 * Provers/linorder: New generic prover for transitivity reasoning over
  5962 linear orders.  Note: this prover is not efficient!
  5963 
  5964 * Isar: preview of problems to finish 'show' now produce an error
  5965 rather than just a warning (in interactive mode);
  5966 
  5967 
  5968 *** HOL ***
  5969 
  5970 * arith(_tac)
  5971 
  5972  - Produces a counter example if it cannot prove a goal.
  5973    Note that the counter example may be spurious if the goal is not a formula
  5974    of quantifier-free linear arithmetic.
  5975    In ProofGeneral the counter example appears in the trace buffer.
  5976 
  5977  - Knows about div k and mod k where k is a numeral of type nat or int.
  5978 
  5979  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  5980    linear arithmetic fails. This takes account of quantifiers and divisibility.
  5981    Presburger arithmetic can also be called explicitly via presburger(_tac).
  5982 
  5983 * simp's arithmetic capabilities have been enhanced a bit: it now
  5984 takes ~= in premises into account (by performing a case split);
  5985 
  5986 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  5987 are distributed over a sum of terms;
  5988 
  5989 * New tactic "trans_tac" and method "trans" instantiate
  5990 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  5991 "<=", "<" and "=").
  5992 
  5993 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  5994 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  5995 
  5996 * 'typedef' command has new option "open" to suppress the set
  5997 definition;
  5998 
  5999 * functions Min and Max on finite sets have been introduced (theory
  6000 Finite_Set);
  6001 
  6002 * attribute [symmetric] now works for relations as well; it turns
  6003 (x,y) : R^-1 into (y,x) : R, and vice versa;
  6004 
  6005 * induct over a !!-quantified statement (say !!x1..xn):
  6006   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  6007 
  6008 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  6009 %x. None. Warning: empty_def now refers to the previously hidden definition
  6010 of the empty set.
  6011 
  6012 * Algebra: formalization of classical algebra.  Intended as base for
  6013 any algebraic development in Isabelle.  Currently covers group theory
  6014 (up to Sylow's theorem) and ring theory (Universal Property of
  6015 Univariate Polynomials).  Contributions welcome;
  6016 
  6017 * GroupTheory: deleted, since its material has been moved to Algebra;
  6018 
  6019 * Complex: new directory of the complex numbers with numeric constants,
  6020 nonstandard complex numbers, and some complex analysis, standard and
  6021 nonstandard (Jacques Fleuriot);
  6022 
  6023 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  6024 
  6025 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  6026 Fleuriot);
  6027 
  6028 * Real/HahnBanach: updated and adapted to locales;
  6029 
  6030 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  6031 Gray and Kramer);
  6032 
  6033 * UNITY: added the Meier-Sanders theory of progress sets;
  6034 
  6035 * MicroJava: bytecode verifier and lightweight bytecode verifier
  6036 as abstract algorithms, instantiated to the JVM;
  6037 
  6038 * Bali: Java source language formalization. Type system, operational
  6039 semantics, axiomatic semantics. Supported language features:
  6040 classes, interfaces, objects,virtual methods, static methods,
  6041 static/instance fields, arrays, access modifiers, definite
  6042 assignment, exceptions.
  6043 
  6044 
  6045 *** ZF ***
  6046 
  6047 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  6048 universe, etc.);
  6049 
  6050 * Main ZF: virtually all theories converted to new-style format;
  6051 
  6052 
  6053 *** ML ***
  6054 
  6055 * Pure: Tactic.prove provides sane interface for internal proofs;
  6056 omits the infamous "standard" operation, so this is more appropriate
  6057 than prove_goalw_cterm in many situations (e.g. in simprocs);
  6058 
  6059 * Pure: improved error reporting of simprocs;
  6060 
  6061 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  6062 up simprocs;
  6063 
  6064 
  6065 *** Document preparation ***
  6066 
  6067 * uses \par instead of \\ for line breaks in theory text. This may
  6068 shift some page breaks in large documents. To get the old behaviour
  6069 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  6070 
  6071 * minimized dependencies of isabelle.sty and isabellesym.sty on
  6072 other packages
  6073 
  6074 * \<euro> now needs package babel/greek instead of marvosym (which
  6075 broke \Rightarrow)
  6076 
  6077 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  6078 textcomp package)
  6079 
  6080 
  6081 
  6082 New in Isabelle2002 (March 2002)
  6083 --------------------------------
  6084 
  6085 *** Document preparation ***
  6086 
  6087 * greatly simplified document preparation setup, including more
  6088 graceful interpretation of isatool usedir -i/-d/-D options, and more
  6089 instructive isatool mkdir; users should basically be able to get
  6090 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  6091 users may run a separate document processing stage manually like this:
  6092 "isatool usedir -D output HOL Test && isatool document Test/output";
  6093 
  6094 * theory dependency graph may now be incorporated into documents;
  6095 isatool usedir -g true will produce session_graph.eps/.pdf for use
  6096 with \includegraphics of LaTeX;
  6097 
  6098 * proper spacing of consecutive markup elements, especially text
  6099 blocks after section headings;
  6100 
  6101 * support bold style (for single symbols only), input syntax is like
  6102 this: "\<^bold>\<alpha>" or "\<^bold>A";
  6103 
  6104 * \<bullet> is now output as bold \cdot by default, which looks much
  6105 better in printed text;
  6106 
  6107 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  6108 note that these symbols are currently unavailable in Proof General /
  6109 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  6110 
  6111 * isatool latex no longer depends on changed TEXINPUTS, instead
  6112 isatool document copies the Isabelle style files to the target
  6113 location;
  6114 
  6115 
  6116 *** Isar ***
  6117 
  6118 * Pure/Provers: improved proof by cases and induction;
  6119   - 'case' command admits impromptu naming of parameters (such as
  6120     "case (Suc n)");
  6121   - 'induct' method divinates rule instantiation from the inductive
  6122     claim; no longer requires excessive ?P bindings for proper
  6123     instantiation of cases;
  6124   - 'induct' method properly enumerates all possibilities of set/type
  6125     rules; as a consequence facts may be also passed through *type*
  6126     rules without further ado;
  6127   - 'induct' method now derives symbolic cases from the *rulified*
  6128     rule (before it used to rulify cases stemming from the internal
  6129     atomized version); this means that the context of a non-atomic
  6130     statement becomes is included in the hypothesis, avoiding the
  6131     slightly cumbersome show "PROP ?case" form;
  6132   - 'induct' may now use elim-style induction rules without chaining
  6133     facts, using ``missing'' premises from the goal state; this allows
  6134     rules stemming from inductive sets to be applied in unstructured
  6135     scripts, while still benefitting from proper handling of non-atomic
  6136     statements; NB: major inductive premises need to be put first, all
  6137     the rest of the goal is passed through the induction;
  6138   - 'induct' proper support for mutual induction involving non-atomic
  6139     rule statements (uses the new concept of simultaneous goals, see
  6140     below);
  6141   - append all possible rule selections, but only use the first
  6142     success (no backtracking);
  6143   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  6144   - undeclared rule case names default to numbers 1, 2, 3, ...;
  6145   - added 'print_induct_rules' (covered by help item in recent Proof
  6146     General versions);
  6147   - moved induct/cases attributes to Pure, methods to Provers;
  6148   - generic method setup instantiated for FOL and HOL;
  6149 
  6150 * Pure: support multiple simultaneous goal statements, for example
  6151 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  6152 meta-level mechanism, this acts as if several individual goals had
  6153 been stated separately; in particular common proof methods need to be
  6154 repeated in order to cover all claims; note that a single elimination
  6155 step is *not* sufficient to establish the two conjunctions, so this
  6156 fails:
  6157 
  6158   assume "A & B" then have A and B ..   (*".." fails*)
  6159 
  6160 better use "obtain" in situations as above; alternative refer to
  6161 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  6162 
  6163 * Pure: proper integration with ``locales''; unlike the original
  6164 version by Florian Kammller, Isar locales package high-level proof
  6165 contexts rather than raw logical ones (e.g. we admit to include
  6166 attributes everywhere); operations on locales include merge and
  6167 rename; support for implicit arguments (``structures''); simultaneous
  6168 type-inference over imports and text; see also HOL/ex/Locales.thy for
  6169 some examples;
  6170 
  6171 * Pure: the following commands have been ``localized'', supporting a
  6172 target locale specification "(in name)": 'lemma', 'theorem',
  6173 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  6174 stored both within the locale and at the theory level (exported and
  6175 qualified by the locale name);
  6176 
  6177 * Pure: theory goals may now be specified in ``long'' form, with
  6178 ad-hoc contexts consisting of arbitrary locale elements. for example
  6179 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  6180 definitions may be given, too); the result is a meta-level rule with
  6181 the context elements being discharged in the obvious way;
  6182 
  6183 * Pure: new proof command 'using' allows to augment currently used
  6184 facts after a goal statement ('using' is syntactically analogous to
  6185 'apply', but acts on the goal's facts only); this allows chained facts
  6186 to be separated into parts given before and after a claim, as in
  6187 ``from a and b have C using d and e <proof>'';
  6188 
  6189 * Pure: renamed "antecedent" case to "rule_context";
  6190 
  6191 * Pure: new 'judgment' command records explicit information about the
  6192 object-logic embedding (used by several tools internally); no longer
  6193 use hard-wired "Trueprop";
  6194 
  6195 * Pure: added 'corollary' command;
  6196 
  6197 * Pure: fixed 'token_translation' command;
  6198 
  6199 * Pure: removed obsolete 'exported' attribute;
  6200 
  6201 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  6202 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  6203 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  6204 
  6205 * Pure: method 'atomize' presents local goal premises as object-level
  6206 statements (atomic meta-level propositions); setup controlled via
  6207 rewrite rules declarations of 'atomize' attribute; example
  6208 application: 'induct' method with proper rule statements in improper
  6209 proof *scripts*;
  6210 
  6211 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  6212 now consider the syntactic context of assumptions, giving a better
  6213 chance to get type-inference of the arguments right (this is
  6214 especially important for locales);
  6215 
  6216 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  6217 mode;
  6218 
  6219 * Pure/obtain: the formal conclusion "thesis", being marked as
  6220 ``internal'', may no longer be reference directly in the text;
  6221 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  6222 situations;
  6223 
  6224 * Pure: generic 'sym' attribute which declares a rule both as pure
  6225 'elim?' and for the 'symmetric' operation;
  6226 
  6227 * Pure: marginal comments ``--'' may now occur just anywhere in the
  6228 text; the fixed correlation with particular command syntax has been
  6229 discontinued;
  6230 
  6231 * Pure: new method 'rules' is particularly well-suited for proof
  6232 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  6233 but often produces more compact proof terms with less detours;
  6234 
  6235 * Pure/Provers/classical: simplified integration with pure rule
  6236 attributes and methods; the classical "intro?/elim?/dest?"
  6237 declarations coincide with the pure ones; the "rule" method no longer
  6238 includes classically swapped intros; "intro" and "elim" methods no
  6239 longer pick rules from the context; also got rid of ML declarations
  6240 AddXIs/AddXEs/AddXDs; all of this has some potential for
  6241 INCOMPATIBILITY;
  6242 
  6243 * Provers/classical: attribute 'swapped' produces classical inversions
  6244 of introduction rules;
  6245 
  6246 * Provers/simplifier: 'simplified' attribute may refer to explicit
  6247 rules instead of full simplifier context; 'iff' attribute handles
  6248 conditional rules;
  6249 
  6250 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  6251 
  6252 * HOL: 'recdef' now fails on unfinished automated proofs, use
  6253 "(permissive)" option to recover old behavior;
  6254 
  6255 * HOL: 'inductive' no longer features separate (collective) attributes
  6256 for 'intros' (was found too confusing);
  6257 
  6258 * HOL: properly declared induction rules less_induct and
  6259 wf_induct_rule;
  6260 
  6261 
  6262 *** HOL ***
  6263 
  6264 * HOL: moved over to sane numeral syntax; the new policy is as
  6265 follows:
  6266 
  6267   - 0 and 1 are polymorphic constants, which are defined on any
  6268   numeric type (nat, int, real etc.);
  6269 
  6270   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  6271   binary representation internally;
  6272 
  6273   - type nat has special constructor Suc, and generally prefers Suc 0
  6274   over 1::nat and Suc (Suc 0) over 2::nat;
  6275 
  6276 This change may cause significant problems of INCOMPATIBILITY; here
  6277 are some hints on converting existing sources:
  6278 
  6279   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  6280   entities, so expressions involving "-" (unary or binary minus) need
  6281   to be spaced properly;
  6282 
  6283   - existing occurrences of "1" may need to be constraint "1::nat" or
  6284   even replaced by Suc 0; similar for old "2";
  6285 
  6286   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  6287 
  6288   - remove all special provisions on numerals in proofs;
  6289 
  6290 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  6291 representation (depends on bin_arith_simps in the default context);
  6292 
  6293 * HOL: symbolic syntax for x^2 (numeral 2);
  6294 
  6295 * HOL: the class of all HOL types is now called "type" rather than
  6296 "term"; INCOMPATIBILITY, need to adapt references to this type class
  6297 in axclass/classes, instance/arities, and (usually rare) occurrences
  6298 in typings (of consts etc.); internally the class is called
  6299 "HOL.type", ML programs should refer to HOLogic.typeS;
  6300 
  6301 * HOL/record package improvements:
  6302   - new derived operations "fields" to build a partial record section,
  6303     "extend" to promote a fixed record to a record scheme, and
  6304     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  6305     declared as simp by default;
  6306   - shared operations ("more", "fields", etc.) now need to be always
  6307     qualified) --- potential INCOMPATIBILITY;
  6308   - removed "make_scheme" operations (use "make" with "extend") --
  6309     INCOMPATIBILITY;
  6310   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  6311   - provides cases/induct rules for use with corresponding Isar
  6312     methods (for concrete records, record schemes, concrete more
  6313     parts, and schematic more parts -- in that order);
  6314   - internal definitions directly based on a light-weight abstract
  6315     theory of product types over typedef rather than datatype;
  6316 
  6317 * HOL: generic code generator for generating executable ML code from
  6318 specifications; specific support for HOL constructs such as inductive
  6319 datatypes and sets, as well as recursive functions; can be invoked
  6320 via 'generate_code' theory section;
  6321 
  6322 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  6323 
  6324 * HOL: consolidated and renamed several theories.  In particular:
  6325         Ord.thy has been absorbed into HOL.thy
  6326         String.thy has been absorbed into List.thy
  6327 
  6328 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  6329 (beware of argument permutation!);
  6330 
  6331 * HOL: linorder_less_split superseded by linorder_cases;
  6332 
  6333 * HOL/List: "nodups" renamed to "distinct";
  6334 
  6335 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  6336 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  6337   - Ex_def has changed, now need to use some_eq_ex
  6338 
  6339 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  6340 in this (rare) case use:
  6341 
  6342   delSWrapper "split_all_tac"
  6343   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  6344 
  6345 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  6346 MAY FAIL;
  6347 
  6348 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  6349 Isabelle's type classes, ^ on functions and relations has too general
  6350 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  6351 necessary to attach explicit type constraints;
  6352 
  6353 * HOL/Relation: the prefix name of the infix "O" has been changed from
  6354 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  6355 renamed accordingly (eg "compI" -> "rel_compI").
  6356 
  6357 * HOL: syntax translations now work properly with numerals and records
  6358 expressions;
  6359 
  6360 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  6361 of "lam" -- INCOMPATIBILITY;
  6362 
  6363 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  6364 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  6365 renamed "Product_Type.unit";
  6366 
  6367 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  6368 
  6369 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  6370 the "cases" method);
  6371 
  6372 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  6373 Florian Kammller);
  6374 
  6375 * HOL/IMP: updated and converted to new-style theory format; several
  6376 parts turned into readable document, with proper Isar proof texts and
  6377 some explanations (by Gerwin Klein);
  6378 
  6379 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  6380 
  6381 * HOL-Hyperreal is now a logic image;
  6382 
  6383 
  6384 *** HOLCF ***
  6385 
  6386 * Isar: consts/constdefs supports mixfix syntax for continuous
  6387 operations;
  6388 
  6389 * Isar: domain package adapted to new-style theory format, e.g. see
  6390 HOLCF/ex/Dnat.thy;
  6391 
  6392 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  6393 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  6394 lift.induct_tac, always use UU instead of Undef;
  6395 
  6396 * HOLCF/IMP: updated and converted to new-style theory;
  6397 
  6398 
  6399 *** ZF ***
  6400 
  6401 * Isar: proper integration of logic-specific tools and packages,
  6402 including theory commands '(co)inductive', '(co)datatype',
  6403 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  6404 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  6405 
  6406 * theory Main no longer includes AC; for the Axiom of Choice, base
  6407 your theory on Main_ZFC;
  6408 
  6409 * the integer library now covers quotients and remainders, with many
  6410 laws relating division to addition, multiplication, etc.;
  6411 
  6412 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  6413 typeless version of the formalism;
  6414 
  6415 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  6416 format;
  6417 
  6418 * ZF/Induct: new directory for examples of inductive definitions,
  6419 including theory Multiset for multiset orderings; converted to
  6420 new-style theory format;
  6421 
  6422 * ZF: many new theorems about lists, ordinals, etc.;
  6423 
  6424 
  6425 *** General ***
  6426 
  6427 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  6428 variable proof controls level of detail: 0 = no proofs (only oracle
  6429 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  6430 also ref manual for further ML interfaces;
  6431 
  6432 * Pure/axclass: removed obsolete ML interface
  6433 goal_subclass/goal_arity;
  6434 
  6435 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  6436 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  6437 separate tokens, so expressions involving minus need to be spaced
  6438 properly;
  6439 
  6440 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  6441 rather than "infixl" or "infixr";
  6442 
  6443 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  6444 sort constraint specifications in type inference; e.g. "x::_::foo"
  6445 ensures that the type of "x" is of sort "foo" (but not necessarily a
  6446 type variable);
  6447 
  6448 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  6449 control output of nested => (types); the default behavior is
  6450 "type_brackets";
  6451 
  6452 * Pure/syntax: builtin parse translation for "_constify" turns valued
  6453 tokens into AST constants;
  6454 
  6455 * Pure/syntax: prefer later declarations of translations and print
  6456 translation functions; potential INCOMPATIBILITY: need to reverse
  6457 multiple declarations for same syntax element constant;
  6458 
  6459 * Pure/show_hyps reset by default (in accordance to existing Isar
  6460 practice);
  6461 
  6462 * Provers/classical: renamed addaltern to addafter, addSaltern to
  6463 addSafter;
  6464 
  6465 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  6466 as well;
  6467 
  6468 * system: tested support for MacOS X; should be able to get Isabelle +
  6469 Proof General to work in a plain Terminal after installing Poly/ML
  6470 (e.g. from the Isabelle distribution area) and GNU bash alone
  6471 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  6472 support requires further installations, e.g. from
  6473 http://fink.sourceforge.net/);
  6474 
  6475 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  6476 
  6477 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  6478 of 40 MB), cf. ML_OPTIONS;
  6479 
  6480 * system: Proof General keywords specification is now part of the
  6481 Isabelle distribution (see etc/isar-keywords.el);
  6482 
  6483 * system: support for persistent Proof General sessions (refrain from
  6484 outdating all loaded theories on startup); user may create writable
  6485 logic images like this: ``isabelle -q HOL Test'';
  6486 
  6487 * system: smart selection of Isabelle process versus Isabelle
  6488 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  6489 run both "isabelle" and "Isabelle" even if file names are badly
  6490 damaged (executable inspects the case of the first letter of its own
  6491 name); added separate "isabelle-process" and "isabelle-interface";
  6492 
  6493 * system: refrain from any attempt at filtering input streams; no
  6494 longer support ``8bit'' encoding of old isabelle font, instead proper
  6495 iso-latin characters may now be used; the related isatools
  6496 "symbolinput" and "nonascii" have disappeared as well;
  6497 
  6498 * system: removed old "xterm" interface (the print modes "xterm" and
  6499 "xterm_color" are still available for direct use in a suitable
  6500 terminal);
  6501 
  6502 
  6503 
  6504 New in Isabelle99-2 (February 2001)
  6505 -----------------------------------
  6506 
  6507 *** Overview of INCOMPATIBILITIES ***
  6508 
  6509 * HOL: please note that theories in the Library and elsewhere often use the
  6510 new-style (Isar) format; to refer to their theorems in an ML script you must
  6511 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  6512 
  6513 * HOL: inductive package no longer splits induction rule aggressively,
  6514 but only as far as specified by the introductions given; the old
  6515 format may be recovered via ML function complete_split_rule or attribute
  6516 'split_rule (complete)';
  6517 
  6518 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  6519 gfp_Tarski to gfp_unfold;
  6520 
  6521 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  6522 
  6523 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  6524 relation); infix "^^" has been renamed "``"; infix "``" has been
  6525 renamed "`"; "univalent" has been renamed "single_valued";
  6526 
  6527 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  6528 operation;
  6529 
  6530 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  6531 
  6532 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  6533 
  6534 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  6535 consequence, it is no longer monotonic wrt. the local goal context
  6536 (which is now passed through the inductive cases);
  6537 
  6538 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  6539 \<gg> to \<ggreater>;
  6540 
  6541 
  6542 *** Document preparation ***
  6543 
  6544 * \isabellestyle{NAME} selects version of Isabelle output (currently
  6545 available: are "it" for near math-mode best-style output, "sl" for
  6546 slanted text style, and "tt" for plain type-writer; if no
  6547 \isabellestyle command is given, output is according to slanted
  6548 type-writer);
  6549 
  6550 * support sub/super scripts (for single symbols only), input syntax is
  6551 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  6552 
  6553 * some more standard symbols; see Appendix A of the system manual for
  6554 the complete list of symbols defined in isabellesym.sty;
  6555 
  6556 * improved isabelle style files; more abstract symbol implementation
  6557 (should now use \isamath{...} and \isatext{...} in custom symbol
  6558 definitions);
  6559 
  6560 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  6561 state; Note that presentation of goal states does not conform to
  6562 actual human-readable proof documents.  Please do not include goal
  6563 states into document output unless you really know what you are doing!
  6564 
  6565 * proper indentation of antiquoted output with proportional LaTeX
  6566 fonts;
  6567 
  6568 * no_document ML operator temporarily disables LaTeX document
  6569 generation;
  6570 
  6571 * isatool unsymbolize tunes sources for plain ASCII communication;
  6572 
  6573 
  6574 *** Isar ***
  6575 
  6576 * Pure: Isar now suffers initial goal statements to contain unbound
  6577 schematic variables (this does not conform to actual readable proof
  6578 documents, due to unpredictable outcome and non-compositional proof
  6579 checking); users who know what they are doing may use schematic goals
  6580 for Prolog-style synthesis of proven results;
  6581 
  6582 * Pure: assumption method (an implicit finishing) now handles actual
  6583 rules as well;
  6584 
  6585 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  6586 initial goal, declare "that" only as Pure intro (only for single
  6587 steps); the "that" rule assumption may now be involved in implicit
  6588 finishing, thus ".." becomes a feasible for trivial obtains;
  6589 
  6590 * Pure: default proof step now includes 'intro_classes'; thus trivial
  6591 instance proofs may be performed by "..";
  6592 
  6593 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  6594 statements as well;
  6595 
  6596 * Pure: more robust selection of calculational rules;
  6597 
  6598 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  6599 rule (as well as the assumption rule);
  6600 
  6601 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  6602 lemmas, using the graph browser tool;
  6603 
  6604 * Pure: predict failure of "show" in interactive mode;
  6605 
  6606 * Pure: 'thms_containing' now takes actual terms as arguments;
  6607 
  6608 * HOL: improved method 'induct' --- now handles non-atomic goals
  6609 (potential INCOMPATIBILITY); tuned error handling;
  6610 
  6611 * HOL: cases and induct rules now provide explicit hints about the
  6612 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  6613 any remaining facts are inserted into the goal verbatim;
  6614 
  6615 * HOL: local contexts (aka cases) may now contain term bindings as
  6616 well; the 'cases' and 'induct' methods new provide a ?case binding for
  6617 the result to be shown in each case;
  6618 
  6619 * HOL: added 'recdef_tc' command;
  6620 
  6621 * isatool convert assists in eliminating legacy ML scripts;
  6622 
  6623 
  6624 *** HOL ***
  6625 
  6626 * HOL/Library: a collection of generic theories to be used together
  6627 with main HOL; the theory loader path already includes this directory
  6628 by default; the following existing theories have been moved here:
  6629 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  6630 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  6631 
  6632 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  6633 modelling and verification task performed in Isabelle/HOL +
  6634 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  6635 
  6636 * HOL/Algebra: special summation operator SUM no longer exists, it has
  6637 been replaced by setsum; infix 'assoc' now has priority 50 (like
  6638 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  6639 'domain', this makes the theory consistent with mathematical
  6640 literature;
  6641 
  6642 * HOL basics: added overloaded operations "inverse" and "divide"
  6643 (infix "/"), syntax for generic "abs" operation, generic summation
  6644 operator \<Sum>;
  6645 
  6646 * HOL/typedef: simplified package, provide more useful rules (see also
  6647 HOL/subset.thy);
  6648 
  6649 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  6650 now expressed as a proper nested rule (old-style tactic scripts may
  6651 require atomize_strip_tac to cope with non-atomic premises);
  6652 
  6653 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  6654 to "split_conv" (old name still available for compatibility);
  6655 
  6656 * HOL: improved concrete syntax for strings (e.g. allows translation
  6657 rules with string literals);
  6658 
  6659 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  6660  and Fleuriot's mechanization of analysis, including the transcendental
  6661  functions for the reals;
  6662 
  6663 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  6664 
  6665 
  6666 *** CTT ***
  6667 
  6668 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  6669 "lam" is displayed as TWO lambda-symbols
  6670 
  6671 * CTT: theory Main now available, containing everything (that is, Bool
  6672 and Arith);
  6673 
  6674 
  6675 *** General ***
  6676 
  6677 * Pure: the Simplifier has been implemented properly as a derived rule
  6678 outside of the actual kernel (at last!); the overall performance
  6679 penalty in practical applications is about 50%, while reliability of
  6680 the Isabelle inference kernel has been greatly improved;
  6681 
  6682 * print modes "brackets" and "no_brackets" control output of nested =>
  6683 (types) and ==> (props); the default behaviour is "brackets";
  6684 
  6685 * Provers: fast_tac (and friends) now handle actual object-logic rules
  6686 as assumptions as well;
  6687 
  6688 * system: support Poly/ML 4.0;
  6689 
  6690 * system: isatool install handles KDE version 1 or 2;
  6691 
  6692 
  6693 
  6694 New in Isabelle99-1 (October 2000)
  6695 ----------------------------------
  6696 
  6697 *** Overview of INCOMPATIBILITIES ***
  6698 
  6699 * HOL: simplification of natural numbers is much changed; to partly
  6700 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  6701 issue the following ML commands:
  6702 
  6703   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  6704   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  6705 
  6706 * HOL: simplification no longer dives into case-expressions; this is
  6707 controlled by "t.weak_case_cong" for each datatype t;
  6708 
  6709 * HOL: nat_less_induct renamed to less_induct;
  6710 
  6711 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  6712 fixsome to patch .thy and .ML sources automatically;
  6713 
  6714   select_equality  -> some_equality
  6715   select_eq_Ex     -> some_eq_ex
  6716   selectI2EX       -> someI2_ex
  6717   selectI2         -> someI2
  6718   selectI          -> someI
  6719   select1_equality -> some1_equality
  6720   Eps_sym_eq       -> some_sym_eq_trivial
  6721   Eps_eq           -> some_eq_trivial
  6722 
  6723 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  6724 
  6725 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  6726 instead);
  6727 
  6728 * HOL: the recursion equations generated by 'recdef' are now called
  6729 f.simps instead of f.rules;
  6730 
  6731 * HOL: qed_spec_mp now also handles bounded ALL as well;
  6732 
  6733 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  6734 sometimes be needed;
  6735 
  6736 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  6737 
  6738 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  6739 
  6740 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  6741 product is now "<*>" instead of "Times"; the lexicographic product is
  6742 now "<*lex*>" instead of "**";
  6743 
  6744 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  6745 of main HOL, but was unused); better use HOL's datatype package;
  6746 
  6747 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  6748 the old syntax may be recovered as follows:
  6749 
  6750   syntax (symbols)
  6751     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  6752       (infixl "\\<oplus>" 100)
  6753 
  6754 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  6755 
  6756 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  6757 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  6758 internally;
  6759 
  6760 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  6761 changed from A/r to A//r;
  6762 
  6763 * ZF: new treatment of arithmetic (nat & int) may break some old
  6764 proofs;
  6765 
  6766 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  6767 rulify -> rule_format, elimify -> elim_format, ...);
  6768 
  6769 * Isar/Provers: intro/elim/dest attributes changed; renamed
  6770 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  6771 should have to change intro!! to intro? only); replaced "delrule" by
  6772 "rule del";
  6773 
  6774 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  6775 
  6776 * Provers: strengthened force_tac by using new first_best_tac;
  6777 
  6778 * LaTeX document preparation: several changes of isabelle.sty (see
  6779 lib/texinputs);
  6780 
  6781 
  6782 *** Document preparation ***
  6783 
  6784 * formal comments (text blocks etc.) in new-style theories may now
  6785 contain antiquotations of thm/prop/term/typ/text to be presented
  6786 according to latex print mode; concrete syntax is like this:
  6787 @{term[show_types] "f(x) = a + x"};
  6788 
  6789 * isatool mkdir provides easy setup of Isabelle session directories,
  6790 including proper document sources;
  6791 
  6792 * generated LaTeX sources are now deleted after successful run
  6793 (isatool document -c); may retain a copy somewhere else via -D option
  6794 of isatool usedir;
  6795 
  6796 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  6797 style files, achieving self-contained LaTeX sources and simplifying
  6798 LaTeX debugging;
  6799 
  6800 * old-style theories now produce (crude) LaTeX output as well;
  6801 
  6802 * browser info session directories are now self-contained (may be put
  6803 on WWW server seperately); improved graphs of nested sessions; removed
  6804 graph for 'all sessions';
  6805 
  6806 * several improvements in isabelle style files; \isabellestyle{it}
  6807 produces fake math mode output; \isamarkupheader is now \section by
  6808 default; see lib/texinputs/isabelle.sty etc.;
  6809 
  6810 
  6811 *** Isar ***
  6812 
  6813 * Isar/Pure: local results and corresponding term bindings are now
  6814 subject to Hindley-Milner polymorphism (similar to ML); this
  6815 accommodates incremental type-inference very nicely;
  6816 
  6817 * Isar/Pure: new derived language element 'obtain' supports
  6818 generalized existence reasoning;
  6819 
  6820 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  6821 support accumulation of results, without applying any rules yet;
  6822 useful to collect intermediate results without explicit name
  6823 references, and for use with transitivity rules with more than 2
  6824 premises;
  6825 
  6826 * Isar/Pure: scalable support for case-analysis type proofs: new
  6827 'case' language element refers to local contexts symbolically, as
  6828 produced by certain proof methods; internally, case names are attached
  6829 to theorems as "tags";
  6830 
  6831 * Isar/Pure: theory command 'hide' removes declarations from
  6832 class/type/const name spaces;
  6833 
  6834 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  6835 indicate potential overloading;
  6836 
  6837 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  6838 
  6839 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  6840 "{a,b,c}" instead of {a,b,c};
  6841 
  6842 * Isar/Pure now provides its own version of intro/elim/dest
  6843 attributes; useful for building new logics, but beware of confusion
  6844 with the version in Provers/classical;
  6845 
  6846 * Isar/Pure: the local context of (non-atomic) goals is provided via
  6847 case name 'antecedent';
  6848 
  6849 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  6850 to the current context is now done automatically);
  6851 
  6852 * Isar/Pure: theory command 'method_setup' provides a simple interface
  6853 for definining proof methods in ML;
  6854 
  6855 * Isar/Provers: intro/elim/dest attributes changed; renamed
  6856 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  6857 most cases, one should have to change intro!! to intro? only);
  6858 replaced "delrule" by "rule del";
  6859 
  6860 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  6861 'symmetric' attribute (the latter supercedes [RS sym]);
  6862 
  6863 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  6864 method modifier); 'simp' method: 'only:' modifier removes loopers as
  6865 well (including splits);
  6866 
  6867 * Isar/Provers: Simplifier and Classical methods now support all kind
  6868 of modifiers used in the past, including 'cong', 'iff', etc.
  6869 
  6870 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  6871 of Simplifier and Classical reasoner);
  6872 
  6873 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  6874 now support named cases; major packages (inductive, datatype, primrec,
  6875 recdef) support case names and properly name parameters;
  6876 
  6877 * Isar/HOL: new transitivity rules for substitution in inequalities --
  6878 monotonicity conditions are extracted to be proven at end of
  6879 calculations;
  6880 
  6881 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  6882 method anyway;
  6883 
  6884 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  6885 split_if split_if_asm; datatype package provides theorems foo.splits =
  6886 foo.split foo.split_asm for each datatype;
  6887 
  6888 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  6889 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  6890 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  6891 use "(cases (simplified))" method in proper proof texts);
  6892 
  6893 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  6894 
  6895 * Isar: names of theorems etc. may be natural numbers as well;
  6896 
  6897 * Isar: 'pr' command: optional arguments for goals_limit and
  6898 ProofContext.prems_limit; no longer prints theory contexts, but only
  6899 proof states;
  6900 
  6901 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  6902 additional print modes to be specified; e.g. "pr(latex)" will print
  6903 proof state according to the Isabelle LaTeX style;
  6904 
  6905 * Isar: improved support for emulating tactic scripts, including proof
  6906 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  6907 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  6908 (for HOL datatypes);
  6909 
  6910 * Isar: simplified (more robust) goal selection of proof methods: 1st
  6911 goal, all goals, or explicit goal specifier (tactic emulation); thus
  6912 'proof method scripts' have to be in depth-first order;
  6913 
  6914 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  6915 
  6916 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  6917 should instead use individual commands for printing items
  6918 (print_commands, print_methods etc.);
  6919 
  6920 * Isar: added 'nothing' --- the empty list of theorems;
  6921 
  6922 
  6923 *** HOL ***
  6924 
  6925 * HOL/MicroJava: formalization of a fragment of Java, together with a
  6926 corresponding virtual machine and a specification of its bytecode
  6927 verifier and a lightweight bytecode verifier, including proofs of
  6928 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  6929 Cornelia Pusch (see also the homepage of project Bali at
  6930 http://isabelle.in.tum.de/Bali/);
  6931 
  6932 * HOL/Algebra: new theory of rings and univariate polynomials, by
  6933 Clemens Ballarin;
  6934 
  6935 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  6936 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  6937 Rasmussen;
  6938 
  6939 * HOL/Lattice: fundamental concepts of lattice theory and order
  6940 structures, including duals, properties of bounds versus algebraic
  6941 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  6942 Theorem for complete lattices etc.; may also serve as a demonstration
  6943 for abstract algebraic reasoning using axiomatic type classes, and
  6944 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  6945 
  6946 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  6947 von Oheimb;
  6948 
  6949 * HOL/IMPP: extension of IMP with local variables and mutually
  6950 recursive procedures, by David von Oheimb;
  6951 
  6952 * HOL/Lambda: converted into new-style theory and document;
  6953 
  6954 * HOL/ex/Multiquote: example of multiple nested quotations and
  6955 anti-quotations -- basically a generalized version of de-Bruijn
  6956 representation; very useful in avoiding lifting of operations;
  6957 
  6958 * HOL/record: added general record equality rule to simpset; fixed
  6959 select-update simplification procedure to handle extended records as
  6960 well; admit "r" as field name;
  6961 
  6962 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  6963 other numeric types and also as the identity of groups, rings, etc.;
  6964 
  6965 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  6966 Types nat and int belong to this axclass;
  6967 
  6968 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  6969    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  6970    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  6971   two terms #m*u and #n*u are replaced by #(m+n)*u
  6972     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  6973   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  6974     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  6975 
  6976 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  6977 powerful prover for predicate logic but knows nothing of clasets; see
  6978 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  6979 
  6980 * HOL: new version of "case_tac" subsumes both boolean case split and
  6981 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  6982 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  6983 
  6984 * HOL: simplification no longer dives into case-expressions: only the
  6985 selector expression is simplified, but not the remaining arms; to
  6986 enable full simplification of case-expressions for datatype t, you may
  6987 remove t.weak_case_cong from the simpset, either globally (Delcongs
  6988 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  6989 
  6990 * HOL/recdef: the recursion equations generated by 'recdef' for
  6991 function 'f' are now called f.simps instead of f.rules; if all
  6992 termination conditions are proved automatically, these simplification
  6993 rules are added to the simpset, as in primrec; rules may be named
  6994 individually as well, resulting in a separate list of theorems for
  6995 each equation;
  6996 
  6997 * HOL/While is a new theory that provides a while-combinator. It
  6998 permits the definition of tail-recursive functions without the
  6999 provision of a termination measure. The latter is necessary once the
  7000 invariant proof rule for while is applied.
  7001 
  7002 * HOL: new (overloaded) notation for the set of elements below/above
  7003 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  7004 
  7005 * HOL: theorems impI, allI, ballI bound as "strip";
  7006 
  7007 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  7008 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  7009 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  7010 
  7011 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  7012 
  7013 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  7014 main HOL, but was unused);
  7015 
  7016 * HOL: fewer consts declared as global (e.g. have to refer to
  7017 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  7018 
  7019 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  7020 in case of overlap with user translations (e.g. judgements over
  7021 tuples); (note that the underlying logical represenation is still
  7022 bogus);
  7023 
  7024 
  7025 *** ZF ***
  7026 
  7027 * ZF: simplification automatically cancels common terms in arithmetic
  7028 expressions over nat and int;
  7029 
  7030 * ZF: new treatment of nat to minimize type-checking: all operators
  7031 coerce their operands to a natural number using the function natify,
  7032 making the algebraic laws unconditional;
  7033 
  7034 * ZF: as above, for int: operators coerce their operands to an integer
  7035 using the function intify;
  7036 
  7037 * ZF: the integer library now contains many of the usual laws for the
  7038 orderings, including $<=, and monotonicity laws for $+ and $*;
  7039 
  7040 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  7041 simplification;
  7042 
  7043 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  7044 to the simplifier and classical reasoner simultaneously;
  7045 
  7046 
  7047 *** General ***
  7048 
  7049 * Provers: blast_tac now handles actual object-logic rules as
  7050 assumptions; note that auto_tac uses blast_tac internally as well;
  7051 
  7052 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  7053 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  7054 
  7055 * Provers: delrules now handles destruct rules as well (no longer need
  7056 explicit make_elim);
  7057 
  7058 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  7059   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  7060 use instead the strong form,
  7061   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  7062 in HOL, FOL and ZF the function cla_make_elim will create such rules
  7063 from destruct-rules;
  7064 
  7065 * Provers: Simplifier.easy_setup provides a fast path to basic
  7066 Simplifier setup for new object-logics;
  7067 
  7068 * Pure: AST translation rules no longer require constant head on LHS;
  7069 
  7070 * Pure: improved name spaces: ambiguous output is qualified; support
  7071 for hiding of names;
  7072 
  7073 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  7074 XSYMBOL_HOME; no longer need to do manual configuration in most
  7075 situations;
  7076 
  7077 * system: compression of ML heaps images may now be controlled via -c
  7078 option of isabelle and isatool usedir (currently only observed by
  7079 Poly/ML);
  7080 
  7081 * system: isatool installfonts may handle X-Symbol fonts as well (very
  7082 useful for remote X11);
  7083 
  7084 * system: provide TAGS file for Isabelle sources;
  7085 
  7086 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  7087 order;
  7088 
  7089 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  7090 timing flag supersedes proof_timing and Toplevel.trace;
  7091 
  7092 * ML: new combinators |>> and |>>> for incremental transformations
  7093 with secondary results (e.g. certain theory extensions):
  7094 
  7095 * ML: PureThy.add_defs gets additional argument to indicate potential
  7096 overloading (usually false);
  7097 
  7098 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  7099 results;
  7100 
  7101 
  7102 
  7103 New in Isabelle99 (October 1999)
  7104 --------------------------------
  7105 
  7106 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  7107 
  7108 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  7109 are no longer simplified.  (This allows the simplifier to unfold recursive
  7110 functional programs.)  To restore the old behaviour, declare
  7111 
  7112     Delcongs [if_weak_cong];
  7113 
  7114 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  7115 complement;
  7116 
  7117 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  7118 
  7119 * HOL/datatype: mutual_induct_tac no longer exists --
  7120   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  7121 
  7122 * HOL/typedef: fixed type inference for representing set; type
  7123 arguments now have to occur explicitly on the rhs as type constraints;
  7124 
  7125 * ZF: The con_defs part of an inductive definition may no longer refer
  7126 to constants declared in the same theory;
  7127 
  7128 * HOL, ZF: the function mk_cases, generated by the inductive
  7129 definition package, has lost an argument.  To simplify its result, it
  7130 uses the default simpset instead of a supplied list of theorems.
  7131 
  7132 * HOL/List: the constructors of type list are now Nil and Cons;
  7133 
  7134 * Simplifier: the type of the infix ML functions
  7135         setSSolver addSSolver setSolver addSolver
  7136 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  7137 for packaging solvers. A solver is created via
  7138         mk_solver: string -> (thm list -> int -> tactic) -> solver
  7139 where the string argument is only a comment.
  7140 
  7141 
  7142 *** Proof tools ***
  7143 
  7144 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  7145 decision procedure for linear arithmetic. Currently it is used for
  7146 types `nat', `int', and `real' in HOL (see below); it can, should and
  7147 will be instantiated for other types and logics as well.
  7148 
  7149 * The simplifier now accepts rewrite rules with flexible heads, eg
  7150      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  7151   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  7152   matching.
  7153 
  7154 
  7155 *** General ***
  7156 
  7157 * New Isabelle/Isar subsystem provides an alternative to traditional
  7158 tactical theorem proving; together with the ProofGeneral/isar user
  7159 interface it offers an interactive environment for developing human
  7160 readable proof documents (Isar == Intelligible semi-automated
  7161 reasoning); for further information see isatool doc isar-ref,
  7162 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  7163 
  7164 * improved and simplified presentation of theories: better HTML markup
  7165 (including colors), graph views in several sizes; isatool usedir now
  7166 provides a proper interface for user theories (via -P option); actual
  7167 document preparation based on (PDF)LaTeX is available as well (for
  7168 new-style theories only); see isatool doc system for more information;
  7169 
  7170 * native support for Proof General, both for classic Isabelle and
  7171 Isabelle/Isar;
  7172 
  7173 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  7174 using the graph browser tool;
  7175 
  7176 * Isabelle manuals now also available as PDF;
  7177 
  7178 * theory loader rewritten from scratch (may not be fully
  7179 bug-compatible); old loadpath variable has been replaced by show_path,
  7180 add_path, del_path, reset_path functions; new operations such as
  7181 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  7182 isatool doc ref);
  7183 
  7184 * improved isatool install: option -k creates KDE application icon,
  7185 option -p DIR installs standalone binaries;
  7186 
  7187 * added ML_PLATFORM setting (useful for cross-platform installations);
  7188 more robust handling of platform specific ML images for SML/NJ;
  7189 
  7190 * the settings environment is now statically scoped, i.e. it is never
  7191 created again in sub-processes invoked from isabelle, isatool, or
  7192 Isabelle;
  7193 
  7194 * path element specification '~~' refers to '$ISABELLE_HOME';
  7195 
  7196 * in locales, the "assumes" and "defines" parts may be omitted if
  7197 empty;
  7198 
  7199 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  7200 long arrows);
  7201 
  7202 * new print_mode "HTML";
  7203 
  7204 * new flag show_tags controls display of tags of theorems (which are
  7205 basically just comments that may be attached by some tools);
  7206 
  7207 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  7208 mode and goal output format:
  7209 
  7210 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  7211 244c244
  7212 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  7213 ---
  7214 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  7215 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  7216 181c181
  7217 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  7218 ---
  7219 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  7220 
  7221 * function bind_thms stores lists of theorems (cf. bind_thm);
  7222 
  7223 * new shorthand tactics ftac, eatac, datac, fatac;
  7224 
  7225 * qed (and friends) now accept "" as result name; in that case the
  7226 theorem is not stored, but proper checks and presentation of the
  7227 result still apply;
  7228 
  7229 * theorem database now also indexes constants "Trueprop", "all",
  7230 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  7231 
  7232 
  7233 *** HOL ***
  7234 
  7235 ** HOL arithmetic **
  7236 
  7237 * There are now decision procedures for linear arithmetic over nat and
  7238 int:
  7239 
  7240 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  7241 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  7242 are treated as atomic; subformulae not involving type `nat' or `int'
  7243 are ignored; quantified subformulae are ignored unless they are
  7244 positive universal or negative existential. The tactic has to be
  7245 invoked by hand and can be a little bit slow. In particular, the
  7246 running time is exponential in the number of occurrences of `min' and
  7247 `max', and `-' on `nat'.
  7248 
  7249 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  7250 (negated) (in)equalities among the premises and the conclusion into
  7251 account (i.e. no compound formulae) and does not know about `min' and
  7252 `max', and `-' on `nat'. It is fast and is used automatically by the
  7253 simplifier.
  7254 
  7255 NB: At the moment, these decision procedures do not cope with mixed
  7256 nat/int formulae where the two parts interact, such as `m < n ==>
  7257 int(m) < int(n)'.
  7258 
  7259 * HOL/Numeral provides a generic theory of numerals (encoded
  7260 efficiently as bit strings); setup for types nat/int/real is in place;
  7261 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  7262 int, existing theories and proof scripts may require a few additional
  7263 type constraints;
  7264 
  7265 * integer division and remainder can now be performed on constant
  7266 arguments;
  7267 
  7268 * many properties of integer multiplication, division and remainder
  7269 are now available;
  7270 
  7271 * An interface to the Stanford Validity Checker (SVC) is available through the
  7272 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  7273 are proved automatically.  SVC must be installed separately, and its results
  7274 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  7275 invocation of the underlying oracle).  For SVC see
  7276   http://verify.stanford.edu/SVC
  7277 
  7278 * IsaMakefile: the HOL-Real target now builds an actual image;
  7279 
  7280 
  7281 ** HOL misc **
  7282 
  7283 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  7284 (in Isabelle/Isar) -- by Gertrud Bauer;
  7285 
  7286 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  7287 analysis for assembly languages with subtypes;
  7288 
  7289 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  7290 -- avoids syntactic ambiguities and treats state, transition, and
  7291 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  7292 changed syntax and (many) tactics;
  7293 
  7294 * HOL/inductive: Now also handles more general introduction rules such
  7295   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  7296   theorems are now maintained within the theory (maintained via the
  7297   "mono" attribute);
  7298 
  7299 * HOL/datatype: Now also handles arbitrarily branching datatypes
  7300   (using function types) such as
  7301 
  7302   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  7303 
  7304 * HOL/record: record_simproc (part of the default simpset) takes care
  7305 of selectors applied to updated records; record_split_tac is no longer
  7306 part of the default claset; update_defs may now be removed from the
  7307 simpset in many cases; COMPATIBILITY: old behavior achieved by
  7308 
  7309   claset_ref () := claset() addSWrapper record_split_wrapper;
  7310   Delsimprocs [record_simproc]
  7311 
  7312 * HOL/typedef: fixed type inference for representing set; type
  7313 arguments now have to occur explicitly on the rhs as type constraints;
  7314 
  7315 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  7316 names rather than an ML expression;
  7317 
  7318 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  7319 supplied later.  Program schemes can be defined, such as
  7320     "While B C s = (if B s then While B C (C s) else s)"
  7321 where the well-founded relation can be chosen after B and C have been given.
  7322 
  7323 * HOL/List: the constructors of type list are now Nil and Cons;
  7324 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  7325 course, ML tools referring to List.list.op # etc. have to be adapted;
  7326 
  7327 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  7328 disabled by default; run isabelle with option -m HOL to get back to
  7329 the original Gordon/HOL-style output;
  7330 
  7331 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  7332 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  7333 
  7334 * HOL basic syntax simplified (more orthogonal): all variants of
  7335 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  7336 Eps operator is provided as well: "SOME x. P[x]";
  7337 
  7338 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  7339 
  7340 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  7341 thus available for user theories;
  7342 
  7343 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  7344 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  7345 time;
  7346 
  7347 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  7348 several times and then mp;
  7349 
  7350 
  7351 *** LK ***
  7352 
  7353 * the notation <<...>> is now available as a notation for sequences of
  7354 formulas;
  7355 
  7356 * the simplifier is now installed
  7357 
  7358 * the axiom system has been generalized (thanks to Soren Heilmann)
  7359 
  7360 * the classical reasoner now has a default rule database
  7361 
  7362 
  7363 *** ZF ***
  7364 
  7365 * new primrec section allows primitive recursive functions to be given
  7366 directly (as in HOL) over datatypes and the natural numbers;
  7367 
  7368 * new tactics induct_tac and exhaust_tac for induction (or case
  7369 analysis) over datatypes and the natural numbers;
  7370 
  7371 * the datatype declaration of type T now defines the recursor T_rec;
  7372 
  7373 * simplification automatically does freeness reasoning for datatype
  7374 constructors;
  7375 
  7376 * automatic type-inference, with AddTCs command to insert new
  7377 type-checking rules;
  7378 
  7379 * datatype introduction rules are now added as Safe Introduction rules
  7380 to the claset;
  7381 
  7382 * the syntax "if P then x else y" is now available in addition to
  7383 if(P,x,y);
  7384 
  7385 
  7386 *** Internal programming interfaces ***
  7387 
  7388 * tuned simplifier trace output; new flag debug_simp;
  7389 
  7390 * structures Vartab / Termtab (instances of TableFun) offer efficient
  7391 tables indexed by indexname_ord / term_ord (compatible with aconv);
  7392 
  7393 * AxClass.axclass_tac lost the theory argument;
  7394 
  7395 * tuned current_goals_markers semantics: begin / end goal avoids
  7396 printing empty lines;
  7397 
  7398 * removed prs and prs_fn hook, which was broken because it did not
  7399 include \n in its semantics, forcing writeln to add one
  7400 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  7401 string -> unit if you really want to output text without newline;
  7402 
  7403 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  7404 plain output, interface builders may have to enable 'isabelle_font'
  7405 mode to get Isabelle font glyphs as before;
  7406 
  7407 * refined token_translation interface; INCOMPATIBILITY: output length
  7408 now of type real instead of int;
  7409 
  7410 * theory loader actions may be traced via new ThyInfo.add_hook
  7411 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  7412 your own database of information attached to *whole* theories -- as
  7413 opposed to intra-theory data slots offered via TheoryDataFun;
  7414 
  7415 * proper handling of dangling sort hypotheses (at last!);
  7416 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  7417 extra sort hypotheses that can be witnessed from the type signature;
  7418 the force_strip_shyps flag is gone, any remaining shyps are simply
  7419 left in the theorem (with a warning issued by strip_shyps_warning);
  7420 
  7421 
  7422 
  7423 New in Isabelle98-1 (October 1998)
  7424 ----------------------------------
  7425 
  7426 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  7427 
  7428 * several changes of automated proof tools;
  7429 
  7430 * HOL: major changes to the inductive and datatype packages, including
  7431 some minor incompatibilities of theory syntax;
  7432 
  7433 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  7434 called `inj_on';
  7435 
  7436 * HOL: removed duplicate thms in Arith:
  7437   less_imp_add_less  should be replaced by  trans_less_add1
  7438   le_imp_add_le      should be replaced by  trans_le_add1
  7439 
  7440 * HOL: unary minus is now overloaded (new type constraints may be
  7441 required);
  7442 
  7443 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  7444 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  7445 now taken as an integer constant.
  7446 
  7447 * Pure: ML function 'theory_of' renamed to 'theory';
  7448 
  7449 
  7450 *** Proof tools ***
  7451 
  7452 * Simplifier:
  7453   1. Asm_full_simp_tac is now more aggressive.
  7454      1. It will sometimes reorient premises if that increases their power to
  7455         simplify.
  7456      2. It does no longer proceed strictly from left to right but may also
  7457         rotate premises to achieve further simplification.
  7458      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  7459      old Asm_full_simp_tac in that it does not rotate premises.
  7460   2. The simplifier now knows a little bit about nat-arithmetic.
  7461 
  7462 * Classical reasoner: wrapper mechanism for the classical reasoner now
  7463 allows for selected deletion of wrappers, by introduction of names for
  7464 wrapper functionals.  This implies that addbefore, addSbefore,
  7465 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  7466 and that adding two tactics with the same name overwrites the first
  7467 one (emitting a warning).
  7468   type wrapper = (int -> tactic) -> (int -> tactic)
  7469   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  7470   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  7471   delWrapper, delSWrapper: claset *  string            -> claset
  7472   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  7473 
  7474 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  7475 semantics; addbefore now affects only the unsafe part of step_tac
  7476 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  7477 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  7478 by Force_tac;
  7479 
  7480 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  7481 compWrapper; added safe wrapper (and access functions for it);
  7482 
  7483 * HOL/split_all_tac is now much faster and fails if there is nothing
  7484 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  7485 and the names of the automatically generated variables have changed.
  7486 split_all_tac has moved within claset() from unsafe wrappers to safe
  7487 wrappers, which means that !!-bound variables are split much more
  7488 aggressively, and safe_tac and clarify_tac now split such variables.
  7489 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  7490 Note: the same holds for record_split_tac, which does the job of
  7491 split_all_tac for record fields.
  7492 
  7493 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  7494 permanently to the default simpset using Addsplits just like
  7495 Addsimps. They can be removed via Delsplits just like
  7496 Delsimps. Lower-case versions are also available.
  7497 
  7498 * HOL/Simplifier: The rule split_if is now part of the default
  7499 simpset. This means that the simplifier will eliminate all occurrences
  7500 of if-then-else in the conclusion of a goal. To prevent this, you can
  7501 either remove split_if completely from the default simpset by
  7502 `Delsplits [split_if]' or remove it in a specific call of the
  7503 simplifier using `... delsplits [split_if]'.  You can also add/delete
  7504 other case splitting rules to/from the default simpset: every datatype
  7505 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  7506 t is the name of the datatype).
  7507 
  7508 * Classical reasoner / Simplifier combination: new force_tac (and
  7509 derivatives Force_tac, force) combines rewriting and classical
  7510 reasoning (and whatever other tools) similarly to auto_tac, but is
  7511 aimed to solve the given subgoal completely.
  7512 
  7513 
  7514 *** General ***
  7515 
  7516 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  7517 and `goalw': the theory is no longer needed as an explicit argument -
  7518 the current theory context is used; assumptions are no longer returned
  7519 at the ML-level unless one of them starts with ==> or !!; it is
  7520 recommended to convert to these new commands using isatool fixgoal
  7521 (backup your sources first!);
  7522 
  7523 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  7524 the current theory context, and 'theory' to lookup stored theories;
  7525 
  7526 * new theory section 'locale' for declaring constants, assumptions and
  7527 definitions that have local scope;
  7528 
  7529 * new theory section 'nonterminals' for purely syntactic types;
  7530 
  7531 * new theory section 'setup' for generic ML setup functions
  7532 (e.g. package initialization);
  7533 
  7534 * the distribution now includes Isabelle icons: see
  7535 lib/logo/isabelle-{small,tiny}.xpm;
  7536 
  7537 * isatool install - install binaries with absolute references to
  7538 ISABELLE_HOME/bin;
  7539 
  7540 * isatool logo -- create instances of the Isabelle logo (as EPS);
  7541 
  7542 * print mode 'emacs' reserved for Isamode;
  7543 
  7544 * support multiple print (ast) translations per constant name;
  7545 
  7546 * theorems involving oracles are now printed with a suffixed [!];
  7547 
  7548 
  7549 *** HOL ***
  7550 
  7551 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  7552 
  7553 * HOL/inductive package reorganized and improved: now supports mutual
  7554 definitions such as
  7555 
  7556   inductive EVEN ODD
  7557     intrs
  7558       null "0 : EVEN"
  7559       oddI "n : EVEN ==> Suc n : ODD"
  7560       evenI "n : ODD ==> Suc n : EVEN"
  7561 
  7562 new theorem list "elims" contains an elimination rule for each of the
  7563 recursive sets; inductive definitions now handle disjunctive premises
  7564 correctly (also ZF);
  7565 
  7566 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  7567 "mutual_induct" no longer exists - the induction rule is always
  7568 contained in "induct";
  7569 
  7570 
  7571 * HOL/datatype package re-implemented and greatly improved: now
  7572 supports mutually recursive datatypes such as
  7573 
  7574   datatype
  7575     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  7576             | SUM ('a aexp) ('a aexp)
  7577             | DIFF ('a aexp) ('a aexp)
  7578             | NUM 'a
  7579   and
  7580     'a bexp = LESS ('a aexp) ('a aexp)
  7581             | AND ('a bexp) ('a bexp)
  7582             | OR ('a bexp) ('a bexp)
  7583 
  7584 as well as indirectly recursive datatypes such as
  7585 
  7586   datatype
  7587     ('a, 'b) term = Var 'a
  7588                   | App 'b ((('a, 'b) term) list)
  7589 
  7590 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  7591 induction on mutually / indirectly recursive datatypes.
  7592 
  7593 Primrec equations are now stored in theory and can be accessed via
  7594 <function_name>.simps.
  7595 
  7596 INCOMPATIBILITIES:
  7597 
  7598   - Theories using datatypes must now have theory Datatype as an
  7599     ancestor.
  7600   - The specific <typename>.induct_tac no longer exists - use the
  7601     generic induct_tac instead.
  7602   - natE has been renamed to nat.exhaust - use exhaust_tac
  7603     instead of res_inst_tac ... natE. Note that the variable
  7604     names in nat.exhaust differ from the names in natE, this
  7605     may cause some "fragile" proofs to fail.
  7606   - The theorems split_<typename>_case and split_<typename>_case_asm
  7607     have been renamed to <typename>.split and <typename>.split_asm.
  7608   - Since default sorts of type variables are now handled correctly,
  7609     some datatype definitions may have to be annotated with explicit
  7610     sort constraints.
  7611   - Primrec definitions no longer require function name and type
  7612     of recursive argument.
  7613 
  7614 Consider using isatool fixdatatype to adapt your theories and proof
  7615 scripts to the new package (backup your sources first!).
  7616 
  7617 
  7618 * HOL/record package: considerably improved implementation; now
  7619 includes concrete syntax for record types, terms, updates; theorems
  7620 for surjective pairing and splitting !!-bound record variables; proof
  7621 support is as follows:
  7622 
  7623   1) standard conversions (selectors or updates applied to record
  7624 constructor terms) are part of the standard simpset;
  7625 
  7626   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  7627 made part of standard simpset and claset via addIffs;
  7628 
  7629   3) a tactic for record field splitting (record_split_tac) is part of
  7630 the standard claset (addSWrapper);
  7631 
  7632 To get a better idea about these rules you may retrieve them via
  7633 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  7634 the name of your record type.
  7635 
  7636 The split tactic 3) conceptually simplifies by the following rule:
  7637 
  7638   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  7639 
  7640 Thus any record variable that is bound by meta-all will automatically
  7641 blow up into some record constructor term, consequently the
  7642 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  7643 solve record problems automatically.
  7644 
  7645 
  7646 * reorganized the main HOL image: HOL/Integ and String loaded by
  7647 default; theory Main includes everything;
  7648 
  7649 * automatic simplification of integer sums and comparisons, using cancellation;
  7650 
  7651 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  7652 
  7653 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  7654 
  7655 * many new identities for unions, intersections, set difference, etc.;
  7656 
  7657 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  7658 called split_if, split_split, split_sum_case and split_nat_case (to go
  7659 with add/delsplits);
  7660 
  7661 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  7662 (?x::unit) = (); this is made part of the default simpset, which COULD
  7663 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  7664 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  7665 unit_abs_eta_conv is added in order to counter the effect of
  7666 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  7667 %u.f();
  7668 
  7669 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  7670 makes more sense);
  7671 
  7672 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  7673   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  7674   disjointness reasoning but breaking a few old proofs.
  7675 
  7676 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  7677 to 'converse' from 'inverse' (for compatibility with ZF and some
  7678 literature);
  7679 
  7680 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  7681 the well-founded relation;
  7682 
  7683 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  7684     Compl A.  The "Compl" syntax remains available as input syntax for this
  7685     release ONLY.
  7686 
  7687 * HOL/Update: new theory of function updates:
  7688     f(a:=b) == %x. if x=a then b else f x
  7689 may also be iterated as in f(a:=b,c:=d,...);
  7690 
  7691 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  7692 
  7693 * HOL/List:
  7694   - new function list_update written xs[i:=v] that updates the i-th
  7695     list position. May also be iterated as in xs[i:=a,j:=b,...].
  7696   - new function `upt' written [i..j(] which generates the list
  7697     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  7698     bound write [i..j], which is a shorthand for [i..j+1(].
  7699   - new lexicographic orderings and corresponding wellfoundedness theorems.
  7700 
  7701 * HOL/Arith:
  7702   - removed 'pred' (predecessor) function;
  7703   - generalized some theorems about n-1;
  7704   - many new laws about "div" and "mod";
  7705   - new laws about greatest common divisors (see theory ex/Primes);
  7706 
  7707 * HOL/Relation: renamed the relational operator r^-1 "converse"
  7708 instead of "inverse";
  7709 
  7710 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  7711   of the multiset ordering;
  7712 
  7713 * directory HOL/Real: a construction of the reals using Dedekind cuts
  7714   (not included by default);
  7715 
  7716 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  7717 
  7718 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  7719   programs, i.e. different program variables may have different types.
  7720 
  7721 * calling (stac rew i) now fails if "rew" has no effect on the goal
  7722   [previously, this check worked only if the rewrite rule was unconditional]
  7723   Now rew can involve either definitions or equalities (either == or =).
  7724 
  7725 
  7726 *** ZF ***
  7727 
  7728 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  7729   only the theorems proved on ZF.ML;
  7730 
  7731 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  7732   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  7733   disjointness reasoning but breaking a few old proofs.
  7734 
  7735 * ZF/Update: new theory of function updates
  7736     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  7737   may also be iterated as in f(a:=b,c:=d,...);
  7738 
  7739 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  7740 
  7741 * calling (stac rew i) now fails if "rew" has no effect on the goal
  7742   [previously, this check worked only if the rewrite rule was unconditional]
  7743   Now rew can involve either definitions or equalities (either == or =).
  7744 
  7745 * case_tac provided for compatibility with HOL
  7746     (like the old excluded_middle_tac, but with subgoals swapped)
  7747 
  7748 
  7749 *** Internal programming interfaces ***
  7750 
  7751 * Pure: several new basic modules made available for general use, see
  7752 also src/Pure/README;
  7753 
  7754 * improved the theory data mechanism to support encapsulation (data
  7755 kind name replaced by private Object.kind, acting as authorization
  7756 key); new type-safe user interface via functor TheoryDataFun; generic
  7757 print_data function becomes basically useless;
  7758 
  7759 * removed global_names compatibility flag -- all theory declarations
  7760 are qualified by default;
  7761 
  7762 * module Pure/Syntax now offers quote / antiquote translation
  7763 functions (useful for Hoare logic etc. with implicit dependencies);
  7764 see HOL/ex/Antiquote for an example use;
  7765 
  7766 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  7767 cterm -> thm;
  7768 
  7769 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  7770 subgoal;
  7771 
  7772 * Display.print_goals function moved to Locale.print_goals;
  7773 
  7774 * standard print function for goals supports current_goals_markers
  7775 variable for marking begin of proof, end of proof, start of goal; the
  7776 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  7777 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  7778 for example;
  7779 
  7780 
  7781 
  7782 New in Isabelle98 (January 1998)
  7783 --------------------------------
  7784 
  7785 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  7786 
  7787 * changed lexical syntax of terms / types: dots made part of long
  7788 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  7789 
  7790 * simpset (and claset) reference variable replaced by functions
  7791 simpset / simpset_ref;
  7792 
  7793 * no longer supports theory aliases (via merge) and non-trivial
  7794 implicit merge of thms' signatures;
  7795 
  7796 * most internal names of constants changed due to qualified names;
  7797 
  7798 * changed Pure/Sequence interface (see Pure/seq.ML);
  7799 
  7800 
  7801 *** General Changes ***
  7802 
  7803 * hierachically structured name spaces (for consts, types, axms, thms
  7804 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  7805 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  7806 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  7807 long_names for fully qualified output names; NOTE: ML programs
  7808 (special tactics, packages etc.) referring to internal names may have
  7809 to be adapted to cope with fully qualified names; in case of severe
  7810 backward campatibility problems try setting 'global_names' at compile
  7811 time to have enrything declared within a flat name space; one may also
  7812 fine tune name declarations in theories via the 'global' and 'local'
  7813 section;
  7814 
  7815 * reimplemented the implicit simpset and claset using the new anytype
  7816 data filed in signatures; references simpset:simpset ref etc. are
  7817 replaced by functions simpset:unit->simpset and
  7818 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  7819 to patch your ML files accordingly;
  7820 
  7821 * HTML output now includes theory graph data for display with Java
  7822 applet or isatool browser; data generated automatically via isatool
  7823 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  7824 
  7825 * defs may now be conditional; improved rewrite_goals_tac to handle
  7826 conditional equations;
  7827 
  7828 * defs now admits additional type arguments, using TYPE('a) syntax;
  7829 
  7830 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  7831 creates a new theory node; implicit merge of thms' signatures is
  7832 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  7833 transfer:theory->thm->thm in (rare) cases;
  7834 
  7835 * improved handling of draft signatures / theories; draft thms (and
  7836 ctyps, cterms) are automatically promoted to real ones;
  7837 
  7838 * slightly changed interfaces for oracles: admit many per theory, named
  7839 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  7840 
  7841 * print_goals: optional output of const types (set show_consts and
  7842 show_types);
  7843 
  7844 * improved output of warnings (###) and errors (***);
  7845 
  7846 * subgoal_tac displays a warning if the new subgoal has type variables;
  7847 
  7848 * removed old README and Makefiles;
  7849 
  7850 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  7851 
  7852 * removed obsolete init_pps and init_database;
  7853 
  7854 * deleted the obsolete tactical STATE, which was declared by
  7855     fun STATE tacfun st = tacfun st st;
  7856 
  7857 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  7858 (which abbreviates $HOME);
  7859 
  7860 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  7861 use isatool fixseq to adapt your ML programs (this works for fully
  7862 qualified references to the Sequence structure only!);
  7863 
  7864 * use_thy no longer requires writable current directory; it always
  7865 reloads .ML *and* .thy file, if either one is out of date;
  7866 
  7867 
  7868 *** Classical Reasoner ***
  7869 
  7870 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  7871 tactics that use classical reasoning to simplify a subgoal without
  7872 splitting it into several subgoals;
  7873 
  7874 * Safe_tac: like safe_tac but uses the default claset;
  7875 
  7876 
  7877 *** Simplifier ***
  7878 
  7879 * added simplification meta rules:
  7880     (asm_)(full_)simplify: simpset -> thm -> thm;
  7881 
  7882 * simplifier.ML no longer part of Pure -- has to be loaded by object
  7883 logics (again);
  7884 
  7885 * added prems argument to simplification procedures;
  7886 
  7887 * HOL, FOL, ZF: added infix function `addsplits':
  7888   instead of `<simpset> setloop (split_tac <thms>)'
  7889   you can simply write `<simpset> addsplits <thms>'
  7890 
  7891 
  7892 *** Syntax ***
  7893 
  7894 * TYPE('a) syntax for type reflection terms;
  7895 
  7896 * no longer handles consts with name "" -- declare as 'syntax' instead;
  7897 
  7898 * pretty printer: changed order of mixfix annotation preference (again!);
  7899 
  7900 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  7901 
  7902 
  7903 *** HOL ***
  7904 
  7905 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  7906   with `addloop' of the simplifier to faciliate case splitting in premises.
  7907 
  7908 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  7909 
  7910 * HOL/Auth: new protocol proofs including some for the Internet
  7911   protocol TLS;
  7912 
  7913 * HOL/Map: new theory of `maps' a la VDM;
  7914 
  7915 * HOL/simplifier: simplification procedures nat_cancel_sums for
  7916 cancelling out common nat summands from =, <, <= (in)equalities, or
  7917 differences; simplification procedures nat_cancel_factor for
  7918 cancelling common factor from =, <, <= (in)equalities over natural
  7919 sums; nat_cancel contains both kinds of procedures, it is installed by
  7920 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  7921 
  7922 * HOL/simplifier: terms of the form
  7923   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  7924   are rewritten to
  7925   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  7926   and those of the form
  7927   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  7928   are rewritten to
  7929   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  7930 
  7931 * HOL/datatype
  7932   Each datatype `t' now comes with a theorem `split_t_case' of the form
  7933 
  7934   P(t_case f1 ... fn x) =
  7935      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  7936         ...
  7937        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  7938      )
  7939 
  7940   and a theorem `split_t_case_asm' of the form
  7941 
  7942   P(t_case f1 ... fn x) =
  7943     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  7944         ...
  7945        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  7946      )
  7947   which can be added to a simpset via `addsplits'. The existing theorems
  7948   expand_list_case and expand_option_case have been renamed to
  7949   split_list_case and split_option_case.
  7950 
  7951 * HOL/Arithmetic:
  7952   - `pred n' is automatically converted to `n-1'.
  7953     Users are strongly encouraged not to use `pred' any longer,
  7954     because it will disappear altogether at some point.
  7955   - Users are strongly encouraged to write "0 < n" rather than
  7956     "n ~= 0". Theorems and proof tools have been modified towards this
  7957     `standard'.
  7958 
  7959 * HOL/Lists:
  7960   the function "set_of_list" has been renamed "set" (and its theorems too);
  7961   the function "nth" now takes its arguments in the reverse order and
  7962   has acquired the infix notation "!" as in "xs!n".
  7963 
  7964 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  7965 
  7966 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  7967   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  7968 
  7969 * HOL/record: extensible records with schematic structural subtyping
  7970 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  7971 still lacks various theorems and concrete record syntax;
  7972 
  7973 
  7974 *** HOLCF ***
  7975 
  7976 * removed "axioms" and "generated by" sections;
  7977 
  7978 * replaced "ops" section by extended "consts" section, which is capable of
  7979   handling the continuous function space "->" directly;
  7980 
  7981 * domain package:
  7982   . proves theorems immediately and stores them in the theory,
  7983   . creates hierachical name space,
  7984   . now uses normal mixfix annotations (instead of cinfix...),
  7985   . minor changes to some names and values (for consistency),
  7986   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  7987   . separator between mutual domain defs: changed "," to "and",
  7988   . improved handling of sort constraints;  now they have to
  7989     appear on the left-hand side of the equations only;
  7990 
  7991 * fixed LAM <x,y,zs>.b syntax;
  7992 
  7993 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  7994 adm (%x. P (t x)), where P is chainfinite and t continuous;
  7995 
  7996 
  7997 *** FOL and ZF ***
  7998 
  7999 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  8000   with `addloop' of the simplifier to faciliate case splitting in premises.
  8001 
  8002 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  8003 in HOL, they strip ALL and --> from proved theorems;
  8004 
  8005 
  8006 
  8007 New in Isabelle94-8 (May 1997)
  8008 ------------------------------
  8009 
  8010 *** General Changes ***
  8011 
  8012 * new utilities to build / run / maintain Isabelle etc. (in parts
  8013 still somewhat experimental); old Makefiles etc. still functional;
  8014 
  8015 * new 'Isabelle System Manual';
  8016 
  8017 * INSTALL text, together with ./configure and ./build scripts;
  8018 
  8019 * reimplemented type inference for greater efficiency, better error
  8020 messages and clean internal interface;
  8021 
  8022 * prlim command for dealing with lots of subgoals (an easier way of
  8023 setting goals_limit);
  8024 
  8025 
  8026 *** Syntax ***
  8027 
  8028 * supports alternative (named) syntax tables (parser and pretty
  8029 printer); internal interface is provided by add_modesyntax(_i);
  8030 
  8031 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  8032 be used in conjunction with the Isabelle symbol font; uses the
  8033 "symbols" syntax table;
  8034 
  8035 * added token_translation interface (may translate name tokens in
  8036 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  8037 the current print_mode); IMPORTANT: user print translation functions
  8038 are responsible for marking newly introduced bounds
  8039 (Syntax.mark_boundT);
  8040 
  8041 * token translations for modes "xterm" and "xterm_color" that display
  8042 names in bold, underline etc. or colors (which requires a color
  8043 version of xterm);
  8044 
  8045 * infixes may now be declared with names independent of their syntax;
  8046 
  8047 * added typed_print_translation (like print_translation, but may
  8048 access type of constant);
  8049 
  8050 
  8051 *** Classical Reasoner ***
  8052 
  8053 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  8054 some limitations.  Blast_tac...
  8055   + ignores addss, addbefore, addafter; this restriction is intrinsic
  8056   + ignores elimination rules that don't have the correct format
  8057         (the conclusion MUST be a formula variable)
  8058   + ignores types, which can make HOL proofs fail
  8059   + rules must not require higher-order unification, e.g. apply_type in ZF
  8060     [message "Function Var's argument not a bound variable" relates to this]
  8061   + its proof strategy is more general but can actually be slower
  8062 
  8063 * substitution with equality assumptions no longer permutes other
  8064 assumptions;
  8065 
  8066 * minor changes in semantics of addafter (now called addaltern); renamed
  8067 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  8068 (and access functions for it);
  8069 
  8070 * improved combination of classical reasoner and simplifier:
  8071   + functions for handling clasimpsets
  8072   + improvement of addss: now the simplifier is called _after_ the
  8073     safe steps.
  8074   + safe variant of addss called addSss: uses safe simplifications
  8075     _during_ the safe steps. It is more complete as it allows multiple
  8076     instantiations of unknowns (e.g. with slow_tac).
  8077 
  8078 *** Simplifier ***
  8079 
  8080 * added interface for simplification procedures (functions that
  8081 produce *proven* rewrite rules on the fly, depending on current
  8082 redex);
  8083 
  8084 * ordering on terms as parameter (used for ordered rewriting);
  8085 
  8086 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  8087 
  8088 * the solver is now split into a safe and an unsafe part.
  8089 This should be invisible for the normal user, except that the
  8090 functions setsolver and addsolver have been renamed to setSolver and
  8091 addSolver; added safe_asm_full_simp_tac;
  8092 
  8093 
  8094 *** HOL ***
  8095 
  8096 * a generic induction tactic `induct_tac' which works for all datatypes and
  8097 also for type `nat';
  8098 
  8099 * a generic case distinction tactic `exhaust_tac' which works for all
  8100 datatypes and also for type `nat';
  8101 
  8102 * each datatype comes with a function `size';
  8103 
  8104 * patterns in case expressions allow tuple patterns as arguments to
  8105 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  8106 
  8107 * primrec now also works with type nat;
  8108 
  8109 * recdef: a new declaration form, allows general recursive functions to be
  8110 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  8111 
  8112 * the constant for negation has been renamed from "not" to "Not" to
  8113 harmonize with FOL, ZF, LK, etc.;
  8114 
  8115 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  8116 infinite lists;
  8117 
  8118 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  8119 
  8120 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  8121 problems in commutative rings, using axiomatic type classes for + and *;
  8122 
  8123 * more examples in HOL/MiniML and HOL/Auth;
  8124 
  8125 * more default rewrite rules for quantifiers, union/intersection;
  8126 
  8127 * a new constant `arbitrary == @x.False';
  8128 
  8129 * HOLCF/IOA replaces old HOL/IOA;
  8130 
  8131 * HOLCF changes: derived all rules and arities
  8132   + axiomatic type classes instead of classes
  8133   + typedef instead of faking type definitions
  8134   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  8135   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  8136   + eliminated the types void, one, tr
  8137   + use unit lift and bool lift (with translations) instead of one and tr
  8138   + eliminated blift from Lift3.thy (use Def instead of blift)
  8139   all eliminated rules are derived as theorems --> no visible changes ;
  8140 
  8141 
  8142 *** ZF ***
  8143 
  8144 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  8145 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  8146 as ZF_cs addSIs [equalityI];
  8147 
  8148 
  8149 
  8150 New in Isabelle94-7 (November 96)
  8151 ---------------------------------
  8152 
  8153 * allowing negative levels (as offsets) in prlev and choplev;
  8154 
  8155 * super-linear speedup for large simplifications;
  8156 
  8157 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  8158 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  8159 FAIL); can suppress it using the command Delsimps (ex_simps @
  8160 all_simps); De Morgan laws are also now included, by default;
  8161 
  8162 * improved printing of ==>  :  ~:
  8163 
  8164 * new object-logic "Sequents" adds linear logic, while replacing LK
  8165 and Modal (thanks to Sara Kalvala);
  8166 
  8167 * HOL/Auth: correctness proofs for authentication protocols;
  8168 
  8169 * HOL: new auto_tac combines rewriting and classical reasoning (many
  8170 examples on HOL/Auth);
  8171 
  8172 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  8173 the rewriter and classical reasoner simultaneously;
  8174 
  8175 * function uresult no longer returns theorems in "standard" format;
  8176 regain previous version by: val uresult = standard o uresult;
  8177 
  8178 
  8179 
  8180 New in Isabelle94-6
  8181 -------------------
  8182 
  8183 * oracles -- these establish an interface between Isabelle and trusted
  8184 external reasoners, which may deliver results as theorems;
  8185 
  8186 * proof objects (in particular record all uses of oracles);
  8187 
  8188 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  8189 
  8190 * "constdefs" section in theory files;
  8191 
  8192 * "primrec" section (HOL) no longer requires names;
  8193 
  8194 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  8195 
  8196 
  8197 
  8198 New in Isabelle94-5
  8199 -------------------
  8200 
  8201 * reduced space requirements;
  8202 
  8203 * automatic HTML generation from theories;
  8204 
  8205 * theory files no longer require "..." (quotes) around most types;
  8206 
  8207 * new examples, including two proofs of the Church-Rosser theorem;
  8208 
  8209 * non-curried (1994) version of HOL is no longer distributed;
  8210 
  8211 
  8212 
  8213 New in Isabelle94-4
  8214 -------------------
  8215 
  8216 * greatly reduced space requirements;
  8217 
  8218 * theory files (.thy) no longer require \...\ escapes at line breaks;
  8219 
  8220 * searchable theorem database (see the section "Retrieving theorems" on
  8221 page 8 of the Reference Manual);
  8222 
  8223 * new examples, including Grabczewski's monumental case study of the
  8224 Axiom of Choice;
  8225 
  8226 * The previous version of HOL renamed to Old_HOL;
  8227 
  8228 * The new version of HOL (previously called CHOL) uses a curried syntax
  8229 for functions.  Application looks like f a b instead of f(a,b);
  8230 
  8231 * Mutually recursive inductive definitions finally work in HOL;
  8232 
  8233 * In ZF, pattern-matching on tuples is now available in all abstractions and
  8234 translates to the operator "split";
  8235 
  8236 
  8237 
  8238 New in Isabelle94-3
  8239 -------------------
  8240 
  8241 * new infix operator, addss, allowing the classical reasoner to
  8242 perform simplification at each step of its search.  Example:
  8243         fast_tac (cs addss ss)
  8244 
  8245 * a new logic, CHOL, the same as HOL, but with a curried syntax
  8246 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  8247 look like (a,b) instead of <a,b>;
  8248 
  8249 * PLEASE NOTE: CHOL will eventually replace HOL!
  8250 
  8251 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  8252 It translates to the operator "split".  A new theory of integers is available;
  8253 
  8254 * In ZF, integer numerals now denote two's-complement binary integers.
  8255 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  8256 
  8257 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  8258 of the Axiom of Choice;
  8259 
  8260 
  8261 
  8262 New in Isabelle94-2
  8263 -------------------
  8264 
  8265 * Significantly faster resolution;
  8266 
  8267 * the different sections in a .thy file can now be mixed and repeated
  8268 freely;
  8269 
  8270 * Database of theorems for FOL, HOL and ZF.  New
  8271 commands including qed, qed_goal and bind_thm store theorems in the database.
  8272 
  8273 * Simple database queries: return a named theorem (get_thm) or all theorems of
  8274 a given theory (thms_of), or find out what theory a theorem was proved in
  8275 (theory_of_thm);
  8276 
  8277 * Bugs fixed in the inductive definition and datatype packages;
  8278 
  8279 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  8280 and HOL_dup_cs obsolete;
  8281 
  8282 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  8283 have been removed;
  8284 
  8285 * Simpler definition of function space in ZF;
  8286 
  8287 * new results about cardinal and ordinal arithmetic in ZF;
  8288 
  8289 * 'subtype' facility in HOL for introducing new types as subsets of existing
  8290 types;
  8291 
  8292 :mode=text:wrap=hard:maxLineLen=72: