NEWS
author huffman
Tue Aug 02 07:36:58 2011 -0700 (2011-08-02)
changeset 44018 d34f0cd62164
parent 44015 a1507f567de6
child 44019 ee784502aed5
permissions -rw-r--r--
NEWS: fix 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 * Theorem collections ball_simps and bex_simps do not contain theorems referring
    83 to UNION any longer;  these have been moved to collection UN_ball_bex_simps.
    84 INCOMPATIBILITY.
    85 
    86 * Archimedian_Field.thy:
    87     floor now is defined as parameter of a separate type class floor_ceiling.
    88  
    89 * Finite_Set.thy: more coherent development of fold_set locales:
    90 
    91     locale fun_left_comm ~> locale comp_fun_commute
    92     locale fun_left_comm_idem ~> locale comp_fun_idem
    93     
    94 Both use point-free characterisation; interpretation proofs may need adjustment.
    95 INCOMPATIBILITY.
    96 
    97 * Code generation:
    98   - theory Library/Code_Char_ord provides native ordering of characters
    99     in the target language.
   100   - commands code_module and code_library are legacy, use export_code instead. 
   101   - evaluator "SML" and method evaluation are legacy, use evaluator "code"
   102     and method eval instead.
   103   
   104 * Declare ext [intro] by default.  Rare INCOMPATIBILITY.
   105 
   106 * Nitpick:
   107   - Added "need" and "total_consts" options.
   108   - Reintroduced "show_skolems" option by popular demand.
   109   - Renamed attribute: nitpick_def ~> nitpick_unfold.
   110     INCOMPATIBILITY.
   111 
   112 * Sledgehammer:
   113   - sledgehammer available_provers ~> sledgehammer supported_provers.
   114     INCOMPATIBILITY.
   115   - Added support for SNARK and ToFoF-E on SystemOnTPTP and for simply typed
   116     TPTP problems (TFF).
   117   - Added "preplay_timeout", "slicing", "type_enc", "sound", "max_mono_iters",
   118     and "max_new_mono_instances" options.
   119   - Removed "explicit_apply" and "full_types" options as well as "Full Types"
   120     Proof General menu item. INCOMPATIBILITY.
   121 
   122 * Metis:
   123   - Removed "metisF" -- use "metis" instead. INCOMPATIBILITY.
   124   - Obsoleted "metisFT" -- use "metis (full_types)" instead. INCOMPATIBILITY.
   125 
   126 * "try":
   127   - Renamed "try_methods" and added "simp:", "intro:", "dest:", and "elim:"
   128     options. INCOMPATIBILITY.
   129   - Introduced "try" that not only runs "try_methods" but also "solve_direct",
   130     "sledgehammer", "quickcheck", and "nitpick".
   131 
   132 * Quickcheck:
   133   - Added "eval" option to evaluate terms for the found counterexample
   134     (currently only supported by the default (exhaustive) tester)
   135   - Added post-processing of terms to obtain readable counterexamples
   136     (currently only supported by the default (exhaustive) tester)
   137   - New counterexample generator quickcheck[narrowing] enables
   138     narrowing-based testing.
   139     It requires that the Glasgow Haskell compiler is installed and
   140     its location is known to Isabelle with the environment variable
   141     ISABELLE_GHC.
   142   - Removed quickcheck tester "SML" based on the SML code generator
   143     from HOL-Library
   144 
   145 * Function package: discontinued option "tailrec".
   146 INCOMPATIBILITY. Use partial_function instead.
   147 
   148 * HOL-Probability:
   149   - Caratheodory's extension lemma is now proved for ring_of_sets.
   150   - Infinite products of probability measures are now available.
   151   - Use extended reals instead of positive extended reals.
   152     INCOMPATIBILITY.
   153 
   154 * Old recdef package has been moved to Library/Old_Recdef.thy, where it
   155 must be loaded explicitly.  INCOMPATIBILITY.
   156 
   157 * Well-founded recursion combinator "wfrec" has been moved to
   158 Library/Wfrec.thy. INCOMPATIBILITY.
   159 
   160 
   161 *** Document preparation ***
   162 
   163 * Discontinued special treatment of hard tabulators, which are better
   164 avoided in the first place.  Implicit tab-width is 1.
   165 
   166 * Antiquotation @{rail} layouts railroad syntax diagrams, see also
   167 isar-ref manual.
   168 
   169 * Antiquotation @{value} evaluates the given term and presents its result.
   170 
   171 * Localized \isabellestyle switch can be used within blocks or groups
   172 like this:
   173 
   174   \isabellestyle{it}  %preferred default
   175   {\isabellestylett @{text "typewriter stuff"}}
   176 
   177 * New term style "isub" as ad-hoc conversion of variables x1, y23 into
   178 subscripted form x\<^isub>1, y\<^isub>2\<^isub>3.
   179 
   180 * Predefined LaTeX macros for Isabelle symbols \<bind> and \<then>
   181 (e.g. see ~~/src/HOL/Library/Monad_Syntax.thy).
   182 
   183 
   184 *** ML ***
   185 
   186 * The inner syntax of sort/type/term/prop supports inlined YXML
   187 representations within quoted string tokens.  By encoding logical
   188 entities via Term_XML (in ML or Scala) concrete syntax can be
   189 bypassed, which is particularly useful for producing bits of text
   190 under external program control.
   191 
   192 * Antiquotations for ML and document preparation are managed as theory
   193 data, which requires explicit setup.
   194 
   195 * Isabelle_Process.is_active allows tools to check if the official
   196 process wrapper is running (Isabelle/Scala/jEdit) or the old TTY loop
   197 (better known as Proof General).
   198 
   199 * Structure Proof_Context follows standard naming scheme.  Old
   200 ProofContext is still available for some time as legacy alias.
   201 
   202 * Structure Timing provides various operations for timing; supersedes
   203 former start_timing/end_timing etc.
   204 
   205 * Path.print is the official way to show file-system paths to users
   206 (including quotes etc.).
   207 
   208 * Inner syntax: identifiers in parse trees of generic categories
   209 "logic", "aprop", "idt" etc. carry position information (disguised as
   210 type constraints).  Occasional INCOMPATIBILITY with non-compliant
   211 translations that choke on unexpected type constraints.  Positions can
   212 be stripped in ML translations via Syntax.strip_positions /
   213 Syntax.strip_positions_ast, or via the syntax constant
   214 "_strip_positions" within parse trees.  As last resort, positions can
   215 be disabled via the configuration option Syntax.positions, which is
   216 called "syntax_positions" in Isar attribute syntax.
   217 
   218 * Discontinued special status of various ML structures that contribute
   219 to structure Syntax (Ast, Lexicon, Mixfix, Parser, Printer etc.): less
   220 pervasive content, no inclusion in structure Syntax.  INCOMPATIBILITY,
   221 refer directly to Ast.Constant, Lexicon.is_identifier,
   222 Syntax_Trans.mk_binder_tr etc.
   223 
   224 * Typed print translation: discontinued show_sorts argument, which is
   225 already available via context of "advanced" translation.
   226 
   227 * Refined PARALLEL_GOALS tactical: degrades gracefully for schematic
   228 goal states; body tactic needs to address all subgoals uniformly.
   229 
   230 * Slightly more special eq_list/eq_set, with shortcut involving
   231 pointer equality (assumes that eq relation is reflexive).
   232 
   233 * Classical tactics use proper Proof.context instead of historic types
   234 claset/clasimpset.  Old-style declarations like addIs, addEs, addDs
   235 operate directly on Proof.context.  Raw type claset retains its use as
   236 snapshot of the classical context, which can be recovered via
   237 (put_claset HOL_cs) etc.  Type clasimpset has been discontinued.
   238 INCOMPATIBILITY, classical tactics and derived proof methods require
   239 proper Proof.context.
   240 
   241 * Scala layer provides JVM method invocation service for static
   242 methods of type (String)String, see Invoke_Scala.method in ML.
   243 For example:
   244 
   245   Invoke_Scala.method "java.lang.System.getProperty" "java.home"
   246 
   247 
   248 
   249 New in Isabelle2011 (January 2011)
   250 ----------------------------------
   251 
   252 *** General ***
   253 
   254 * Experimental Prover IDE based on Isabelle/Scala and jEdit (see
   255 src/Tools/jEdit).  This also serves as IDE for Isabelle/ML, with
   256 useful tooltips and hyperlinks produced from its static analysis.  The
   257 bundled component provides an executable Isabelle tool that can be run
   258 like this:
   259 
   260   Isabelle2011/bin/isabelle jedit
   261 
   262 * Significantly improved Isabelle/Isar implementation manual.
   263 
   264 * System settings: ISABELLE_HOME_USER now includes ISABELLE_IDENTIFIER
   265 (and thus refers to something like $HOME/.isabelle/Isabelle2011),
   266 while the default heap location within that directory lacks that extra
   267 suffix.  This isolates multiple Isabelle installations from each
   268 other, avoiding problems with old settings in new versions.
   269 INCOMPATIBILITY, need to copy/upgrade old user settings manually.
   270 
   271 * Source files are always encoded as UTF-8, instead of old-fashioned
   272 ISO-Latin-1.  INCOMPATIBILITY.  Isabelle LaTeX documents might require
   273 the following package declarations:
   274 
   275   \usepackage[utf8]{inputenc}
   276   \usepackage{textcomp}
   277 
   278 * Explicit treatment of UTF-8 sequences as Isabelle symbols, such that
   279 a Unicode character is treated as a single symbol, not a sequence of
   280 non-ASCII bytes as before.  Since Isabelle/ML string literals may
   281 contain symbols without further backslash escapes, Unicode can now be
   282 used here as well.  Recall that Symbol.explode in ML provides a
   283 consistent view on symbols, while raw explode (or String.explode)
   284 merely give a byte-oriented representation.
   285 
   286 * Theory loader: source files are primarily located via the master
   287 directory of each theory node (where the .thy file itself resides).
   288 The global load path is still partially available as legacy feature.
   289 Minor INCOMPATIBILITY due to subtle change in file lookup: use
   290 explicit paths, relatively to the theory.
   291 
   292 * Special treatment of ML file names has been discontinued.
   293 Historically, optional extensions .ML or .sml were added on demand --
   294 at the cost of clarity of file dependencies.  Recall that Isabelle/ML
   295 files exclusively use the .ML extension.  Minor INCOMPATIBILTY.
   296 
   297 * Various options that affect pretty printing etc. are now properly
   298 handled within the context via configuration options, instead of
   299 unsynchronized references or print modes.  There are both ML Config.T
   300 entities and Isar declaration attributes to access these.
   301 
   302   ML (Config.T)                 Isar (attribute)
   303 
   304   eta_contract                  eta_contract
   305   show_brackets                 show_brackets
   306   show_sorts                    show_sorts
   307   show_types                    show_types
   308   show_question_marks           show_question_marks
   309   show_consts                   show_consts
   310   show_abbrevs                  show_abbrevs
   311 
   312   Syntax.ast_trace              syntax_ast_trace
   313   Syntax.ast_stat               syntax_ast_stat
   314   Syntax.ambiguity_level        syntax_ambiguity_level
   315 
   316   Goal_Display.goals_limit      goals_limit
   317   Goal_Display.show_main_goal   show_main_goal
   318 
   319   Method.rule_trace             rule_trace
   320 
   321   Thy_Output.display            thy_output_display
   322   Thy_Output.quotes             thy_output_quotes
   323   Thy_Output.indent             thy_output_indent
   324   Thy_Output.source             thy_output_source
   325   Thy_Output.break              thy_output_break
   326 
   327 Note that corresponding "..._default" references in ML may only be
   328 changed globally at the ROOT session setup, but *not* within a theory.
   329 The option "show_abbrevs" supersedes the former print mode
   330 "no_abbrevs" with inverted meaning.
   331 
   332 * More systematic naming of some configuration options.
   333 INCOMPATIBILITY.
   334 
   335   trace_simp  ~>  simp_trace
   336   debug_simp  ~>  simp_debug
   337 
   338 * Support for real valued configuration options, using simplistic
   339 floating-point notation that coincides with the inner syntax for
   340 float_token.
   341 
   342 * Support for real valued preferences (with approximative PGIP type):
   343 front-ends need to accept "pgint" values in float notation.
   344 INCOMPATIBILITY.
   345 
   346 * The IsabelleText font now includes Cyrillic, Hebrew, Arabic from
   347 DejaVu Sans.
   348 
   349 * Discontinued support for Poly/ML 5.0 and 5.1 versions.
   350 
   351 
   352 *** Pure ***
   353 
   354 * Command 'type_synonym' (with single argument) replaces somewhat
   355 outdated 'types', which is still available as legacy feature for some
   356 time.
   357 
   358 * Command 'nonterminal' (with 'and' separated list of arguments)
   359 replaces somewhat outdated 'nonterminals'.  INCOMPATIBILITY.
   360 
   361 * Command 'notepad' replaces former 'example_proof' for
   362 experimentation in Isar without any result.  INCOMPATIBILITY.
   363 
   364 * Locale interpretation commands 'interpret' and 'sublocale' accept
   365 lists of equations to map definitions in a locale to appropriate
   366 entities in the context of the interpretation.  The 'interpretation'
   367 command already provided this functionality.
   368 
   369 * Diagnostic command 'print_dependencies' prints the locale instances
   370 that would be activated if the specified expression was interpreted in
   371 the current context.  Variant "print_dependencies!" assumes a context
   372 without interpretations.
   373 
   374 * Diagnostic command 'print_interps' prints interpretations in proofs
   375 in addition to interpretations in theories.
   376 
   377 * Discontinued obsolete 'global' and 'local' commands to manipulate
   378 the theory name space.  Rare INCOMPATIBILITY.  The ML functions
   379 Sign.root_path and Sign.local_path may be applied directly where this
   380 feature is still required for historical reasons.
   381 
   382 * Discontinued obsolete 'constdefs' command.  INCOMPATIBILITY, use
   383 'definition' instead.
   384 
   385 * The "prems" fact, which refers to the accidental collection of
   386 foundational premises in the context, is now explicitly marked as
   387 legacy feature and will be discontinued soon.  Consider using "assms"
   388 of the head statement or reference facts by explicit names.
   389 
   390 * Document antiquotations @{class} and @{type} print classes and type
   391 constructors.
   392 
   393 * Document antiquotation @{file} checks file/directory entries within
   394 the local file system.
   395 
   396 
   397 *** HOL ***
   398 
   399 * Coercive subtyping: functions can be declared as coercions and type
   400 inference will add them as necessary upon input of a term.  Theory
   401 Complex_Main declares real :: nat => real and real :: int => real as
   402 coercions. A coercion function f is declared like this:
   403 
   404   declare [[coercion f]]
   405 
   406 To lift coercions through type constructors (e.g. from nat => real to
   407 nat list => real list), map functions can be declared, e.g.
   408 
   409   declare [[coercion_map map]]
   410 
   411 Currently coercion inference is activated only in theories including
   412 real numbers, i.e. descendants of Complex_Main.  This is controlled by
   413 the configuration option "coercion_enabled", e.g. it can be enabled in
   414 other theories like this:
   415 
   416   declare [[coercion_enabled]]
   417 
   418 * Command 'partial_function' provides basic support for recursive
   419 function definitions over complete partial orders.  Concrete instances
   420 are provided for i) the option type, ii) tail recursion on arbitrary
   421 types, and iii) the heap monad of Imperative_HOL.  See
   422 src/HOL/ex/Fundefs.thy and src/HOL/Imperative_HOL/ex/Linked_Lists.thy
   423 for examples.
   424 
   425 * Function package: f.psimps rules are no longer implicitly declared
   426 as [simp].  INCOMPATIBILITY.
   427 
   428 * Datatype package: theorems generated for executable equality (class
   429 "eq") carry proper names and are treated as default code equations.
   430 
   431 * Inductive package: now offers command 'inductive_simps' to
   432 automatically derive instantiated and simplified equations for
   433 inductive predicates, similar to 'inductive_cases'.
   434 
   435 * Command 'enriched_type' allows to register properties of the
   436 functorial structure of types.
   437 
   438 * Improved infrastructure for term evaluation using code generator
   439 techniques, in particular static evaluation conversions.
   440 
   441 * Code generator: Scala (2.8 or higher) has been added to the target
   442 languages.
   443 
   444 * Code generator: globbing constant expressions "*" and "Theory.*"
   445 have been replaced by the more idiomatic "_" and "Theory._".
   446 INCOMPATIBILITY.
   447 
   448 * Code generator: export_code without explicit file declaration prints
   449 to standard output.  INCOMPATIBILITY.
   450 
   451 * Code generator: do not print function definitions for case
   452 combinators any longer.
   453 
   454 * Code generator: simplification with rules determined with
   455 src/Tools/Code/code_simp.ML and method "code_simp".
   456 
   457 * Code generator for records: more idiomatic representation of record
   458 types.  Warning: records are not covered by ancient SML code
   459 generation any longer.  INCOMPATIBILITY.  In cases of need, a suitable
   460 rep_datatype declaration helps to succeed then:
   461 
   462   record 'a foo = ...
   463   ...
   464   rep_datatype foo_ext ...
   465 
   466 * Records: logical foundation type for records does not carry a
   467 '_type' suffix any longer (obsolete due to authentic syntax).
   468 INCOMPATIBILITY.
   469 
   470 * Quickcheck now by default uses exhaustive testing instead of random
   471 testing.  Random testing can be invoked by "quickcheck [random]",
   472 exhaustive testing by "quickcheck [exhaustive]".
   473 
   474 * Quickcheck instantiates polymorphic types with small finite
   475 datatypes by default. This enables a simple execution mechanism to
   476 handle quantifiers and function equality over the finite datatypes.
   477 
   478 * Quickcheck random generator has been renamed from "code" to
   479 "random".  INCOMPATIBILITY.
   480 
   481 * Quickcheck now has a configurable time limit which is set to 30
   482 seconds by default. This can be changed by adding [timeout = n] to the
   483 quickcheck command. The time limit for Auto Quickcheck is still set
   484 independently.
   485 
   486 * Quickcheck in locales considers interpretations of that locale for
   487 counter example search.
   488 
   489 * Sledgehammer:
   490   - Added "smt" and "remote_smt" provers based on the "smt" proof
   491     method. See the Sledgehammer manual for details ("isabelle doc
   492     sledgehammer").
   493   - Renamed commands:
   494     sledgehammer atp_info ~> sledgehammer running_provers
   495     sledgehammer atp_kill ~> sledgehammer kill_provers
   496     sledgehammer available_atps ~> sledgehammer available_provers
   497     INCOMPATIBILITY.
   498   - Renamed options:
   499     sledgehammer [atps = ...] ~> sledgehammer [provers = ...]
   500     sledgehammer [atp = ...] ~> sledgehammer [prover = ...]
   501     sledgehammer [timeout = 77 s] ~> sledgehammer [timeout = 77]
   502     (and "ms" and "min" are no longer supported)
   503     INCOMPATIBILITY.
   504 
   505 * Nitpick:
   506   - Renamed options:
   507     nitpick [timeout = 77 s] ~> nitpick [timeout = 77]
   508     nitpick [tac_timeout = 777 ms] ~> nitpick [tac_timeout = 0.777]
   509     INCOMPATIBILITY.
   510   - Added support for partial quotient types.
   511   - Added local versions of the "Nitpick.register_xxx" functions.
   512   - Added "whack" option.
   513   - Allow registration of quotient types as codatatypes.
   514   - Improved "merge_type_vars" option to merge more types.
   515   - Removed unsound "fast_descrs" option.
   516   - Added custom symmetry breaking for datatypes, making it possible to reach
   517     higher cardinalities.
   518   - Prevent the expansion of too large definitions.
   519 
   520 * Proof methods "metis" and "meson" now have configuration options
   521 "meson_trace", "metis_trace", and "metis_verbose" that can be enabled
   522 to diagnose these tools. E.g.
   523 
   524     using [[metis_trace = true]]
   525 
   526 * Auto Solve: Renamed "Auto Solve Direct".  The tool is now available
   527 manually as command 'solve_direct'.
   528 
   529 * The default SMT solver Z3 must be enabled explicitly (due to
   530 licensing issues) by setting the environment variable
   531 Z3_NON_COMMERCIAL in etc/settings of the component, for example.  For
   532 commercial applications, the SMT solver CVC3 is provided as fall-back;
   533 changing the SMT solver is done via the configuration option
   534 "smt_solver".
   535 
   536 * Remote SMT solvers need to be referred to by the "remote_" prefix,
   537 i.e. "remote_cvc3" and "remote_z3".
   538 
   539 * Added basic SMT support for datatypes, records, and typedefs using
   540 the oracle mode (no proofs).  Direct support of pairs has been dropped
   541 in exchange (pass theorems fst_conv snd_conv pair_collapse to the SMT
   542 support for a similar behavior).  Minor INCOMPATIBILITY.
   543 
   544 * Changed SMT configuration options:
   545   - Renamed:
   546     z3_proofs ~> smt_oracle (with inverted meaning)
   547     z3_trace_assms ~> smt_trace_used_facts
   548     INCOMPATIBILITY.
   549   - Added:
   550     smt_verbose
   551     smt_random_seed
   552     smt_datatypes
   553     smt_infer_triggers
   554     smt_monomorph_limit
   555     cvc3_options
   556     remote_cvc3_options
   557     remote_z3_options
   558     yices_options
   559 
   560 * Boogie output files (.b2i files) need to be declared in the theory
   561 header.
   562 
   563 * Simplification procedure "list_to_set_comprehension" rewrites list
   564 comprehensions applied to List.set to set comprehensions.  Occasional
   565 INCOMPATIBILITY, may be deactivated like this:
   566 
   567   declare [[simproc del: list_to_set_comprehension]]
   568 
   569 * Removed old version of primrec package.  INCOMPATIBILITY.
   570 
   571 * Removed simplifier congruence rule of "prod_case", as has for long
   572 been the case with "split".  INCOMPATIBILITY.
   573 
   574 * String.literal is a type, but not a datatype.  INCOMPATIBILITY.
   575 
   576 * Removed [split_format ... and ... and ...] version of
   577 [split_format].  Potential INCOMPATIBILITY.
   578 
   579 * Predicate "sorted" now defined inductively, with nice induction
   580 rules.  INCOMPATIBILITY: former sorted.simps now named sorted_simps.
   581 
   582 * Constant "contents" renamed to "the_elem", to free the generic name
   583 contents for other uses.  INCOMPATIBILITY.
   584 
   585 * Renamed class eq and constant eq (for code generation) to class
   586 equal and constant equal, plus renaming of related facts and various
   587 tuning.  INCOMPATIBILITY.
   588 
   589 * Dropped type classes mult_mono and mult_mono1.  INCOMPATIBILITY.
   590 
   591 * Removed output syntax "'a ~=> 'b" for "'a => 'b option".
   592 INCOMPATIBILITY.
   593 
   594 * Renamed theory Fset to Cset, type Fset.fset to Cset.set, in order to
   595 avoid confusion with finite sets.  INCOMPATIBILITY.
   596 
   597 * Abandoned locales equiv, congruent and congruent2 for equivalence
   598 relations.  INCOMPATIBILITY: use equivI rather than equiv_intro (same
   599 for congruent(2)).
   600 
   601 * Some previously unqualified names have been qualified:
   602 
   603   types
   604     bool ~> HOL.bool
   605     nat ~> Nat.nat
   606 
   607   constants
   608     Trueprop ~> HOL.Trueprop
   609     True ~> HOL.True
   610     False ~> HOL.False
   611     op & ~> HOL.conj
   612     op | ~> HOL.disj
   613     op --> ~> HOL.implies
   614     op = ~> HOL.eq
   615     Not ~> HOL.Not
   616     The ~> HOL.The
   617     All ~> HOL.All
   618     Ex ~> HOL.Ex
   619     Ex1 ~> HOL.Ex1
   620     Let ~> HOL.Let
   621     If ~> HOL.If
   622     Ball ~> Set.Ball
   623     Bex ~> Set.Bex
   624     Suc ~> Nat.Suc
   625     Pair ~> Product_Type.Pair
   626     fst ~> Product_Type.fst
   627     snd ~> Product_Type.snd
   628     curry ~> Product_Type.curry
   629     op : ~> Set.member
   630     Collect ~> Set.Collect
   631 
   632 INCOMPATIBILITY.
   633 
   634 * More canonical naming convention for some fundamental definitions:
   635 
   636     bot_bool_eq ~> bot_bool_def
   637     top_bool_eq ~> top_bool_def
   638     inf_bool_eq ~> inf_bool_def
   639     sup_bool_eq ~> sup_bool_def
   640     bot_fun_eq  ~> bot_fun_def
   641     top_fun_eq  ~> top_fun_def
   642     inf_fun_eq  ~> inf_fun_def
   643     sup_fun_eq  ~> sup_fun_def
   644 
   645 INCOMPATIBILITY.
   646 
   647 * More stylized fact names:
   648 
   649   expand_fun_eq ~> fun_eq_iff
   650   expand_set_eq ~> set_eq_iff
   651   set_ext       ~> set_eqI
   652   nat_number    ~> eval_nat_numeral
   653 
   654 INCOMPATIBILITY.
   655 
   656 * Refactoring of code-generation specific operations in theory List:
   657 
   658   constants
   659     null ~> List.null
   660 
   661   facts
   662     mem_iff ~> member_def
   663     null_empty ~> null_def
   664 
   665 INCOMPATIBILITY.  Note that these were not supposed to be used
   666 regularly unless for striking reasons; their main purpose was code
   667 generation.
   668 
   669 Various operations from the Haskell prelude are used for generating
   670 Haskell code.
   671 
   672 * Term "bij f" is now an abbreviation of "bij_betw f UNIV UNIV".  Term
   673 "surj f" is now an abbreviation of "range f = UNIV".  The theorems
   674 bij_def and surj_def are unchanged.  INCOMPATIBILITY.
   675 
   676 * Abolished some non-alphabetic type names: "prod" and "sum" replace
   677 "*" and "+" respectively.  INCOMPATIBILITY.
   678 
   679 * Name "Plus" of disjoint sum operator "<+>" is now hidden.  Write
   680 "Sum_Type.Plus" instead.
   681 
   682 * Constant "split" has been merged with constant "prod_case"; names of
   683 ML functions, facts etc. involving split have been retained so far,
   684 though.  INCOMPATIBILITY.
   685 
   686 * Dropped old infix syntax "_ mem _" for List.member; use "_ : set _"
   687 instead.  INCOMPATIBILITY.
   688 
   689 * Removed lemma "Option.is_none_none" which duplicates "is_none_def".
   690 INCOMPATIBILITY.
   691 
   692 * Former theory Library/Enum is now part of the HOL-Main image.
   693 INCOMPATIBILITY: all constants of the Enum theory now have to be
   694 referred to by its qualified name.
   695 
   696   enum    ~>  Enum.enum
   697   nlists  ~>  Enum.nlists
   698   product ~>  Enum.product
   699 
   700 * Theory Library/Monad_Syntax provides do-syntax for monad types.
   701 Syntax in Library/State_Monad has been changed to avoid ambiguities.
   702 INCOMPATIBILITY.
   703 
   704 * Theory Library/SetsAndFunctions has been split into
   705 Library/Function_Algebras and Library/Set_Algebras; canonical names
   706 for instance definitions for functions; various improvements.
   707 INCOMPATIBILITY.
   708 
   709 * Theory Library/Multiset provides stable quicksort implementation of
   710 sort_key.
   711 
   712 * Theory Library/Multiset: renamed empty_idemp ~> empty_neutral.
   713 INCOMPATIBILITY.
   714 
   715 * Session Multivariate_Analysis: introduced a type class for euclidean
   716 space.  Most theorems are now stated in terms of euclidean spaces
   717 instead of finite cartesian products.
   718 
   719   types
   720     real ^ 'n ~>  'a::real_vector
   721               ~>  'a::euclidean_space
   722               ~>  'a::ordered_euclidean_space
   723         (depends on your needs)
   724 
   725   constants
   726      _ $ _        ~> _ $$ _
   727      \<chi> x. _  ~> \<chi>\<chi> x. _
   728      CARD('n)     ~> DIM('a)
   729 
   730 Also note that the indices are now natural numbers and not from some
   731 finite type. Finite cartesian products of euclidean spaces, products
   732 of euclidean spaces the real and complex numbers are instantiated to
   733 be euclidean_spaces.  INCOMPATIBILITY.
   734 
   735 * Session Probability: introduced pextreal as positive extended real
   736 numbers.  Use pextreal as value for measures.  Introduce the
   737 Radon-Nikodym derivative, product spaces and Fubini's theorem for
   738 arbitrary sigma finite measures.  Introduces Lebesgue measure based on
   739 the integral in Multivariate Analysis.  INCOMPATIBILITY.
   740 
   741 * Session Imperative_HOL: revamped, corrected dozens of inadequacies.
   742 INCOMPATIBILITY.
   743 
   744 * Session SPARK (with image HOL-SPARK) provides commands to load and
   745 prove verification conditions generated by the SPARK Ada program
   746 verifier.  See also src/HOL/SPARK and src/HOL/SPARK/Examples.
   747 
   748 
   749 *** HOL-Algebra ***
   750 
   751 * Theorems for additive ring operations (locale abelian_monoid and
   752 descendants) are generated by interpretation from their multiplicative
   753 counterparts.  Names (in particular theorem names) have the mandatory
   754 qualifier 'add'.  Previous theorem names are redeclared for
   755 compatibility.
   756 
   757 * Structure "int_ring" is now an abbreviation (previously a
   758 definition).  This fits more natural with advanced interpretations.
   759 
   760 
   761 *** HOLCF ***
   762 
   763 * The domain package now runs in definitional mode by default: The
   764 former command 'new_domain' is now called 'domain'.  To use the domain
   765 package in its original axiomatic mode, use 'domain (unsafe)'.
   766 INCOMPATIBILITY.
   767 
   768 * The new class "domain" is now the default sort.  Class "predomain"
   769 is an unpointed version of "domain". Theories can be updated by
   770 replacing sort annotations as shown below.  INCOMPATIBILITY.
   771 
   772   'a::type ~> 'a::countable
   773   'a::cpo  ~> 'a::predomain
   774   'a::pcpo ~> 'a::domain
   775 
   776 * The old type class "rep" has been superseded by class "domain".
   777 Accordingly, users of the definitional package must remove any
   778 "default_sort rep" declarations.  INCOMPATIBILITY.
   779 
   780 * The domain package (definitional mode) now supports unpointed
   781 predomain argument types, as long as they are marked 'lazy'. (Strict
   782 arguments must be in class "domain".) For example, the following
   783 domain definition now works:
   784 
   785   domain natlist = nil | cons (lazy "nat discr") (lazy "natlist")
   786 
   787 * Theory HOLCF/Library/HOL_Cpo provides cpo and predomain class
   788 instances for types from main HOL: bool, nat, int, char, 'a + 'b,
   789 'a option, and 'a list.  Additionally, it configures fixrec and the
   790 domain package to work with these types.  For example:
   791 
   792   fixrec isInl :: "('a + 'b) u -> tr"
   793     where "isInl$(up$(Inl x)) = TT" | "isInl$(up$(Inr y)) = FF"
   794 
   795   domain V = VFun (lazy "V -> V") | VCon (lazy "nat") (lazy "V list")
   796 
   797 * The "(permissive)" option of fixrec has been replaced with a
   798 per-equation "(unchecked)" option. See
   799 src/HOL/HOLCF/Tutorial/Fixrec_ex.thy for examples. INCOMPATIBILITY.
   800 
   801 * The "bifinite" class no longer fixes a constant "approx"; the class
   802 now just asserts that such a function exists.  INCOMPATIBILITY.
   803 
   804 * Former type "alg_defl" has been renamed to "defl".  HOLCF no longer
   805 defines an embedding of type 'a defl into udom by default; instances
   806 of "bifinite" and "domain" classes are available in
   807 src/HOL/HOLCF/Library/Defl_Bifinite.thy.
   808 
   809 * The syntax "REP('a)" has been replaced with "DEFL('a)".
   810 
   811 * The predicate "directed" has been removed.  INCOMPATIBILITY.
   812 
   813 * The type class "finite_po" has been removed.  INCOMPATIBILITY.
   814 
   815 * The function "cprod_map" has been renamed to "prod_map".
   816 INCOMPATIBILITY.
   817 
   818 * The monadic bind operator on each powerdomain has new binder syntax
   819 similar to sets, e.g. "\<Union>\<sharp>x\<in>xs. t" represents
   820 "upper_bind\<cdot>xs\<cdot>(\<Lambda> x. t)".
   821 
   822 * The infix syntax for binary union on each powerdomain has changed
   823 from e.g. "+\<sharp>" to "\<union>\<sharp>", for consistency with set
   824 syntax.  INCOMPATIBILITY.
   825 
   826 * The constant "UU" has been renamed to "bottom".  The syntax "UU" is
   827 still supported as an input translation.
   828 
   829 * Renamed some theorems (the original names are also still available).
   830 
   831   expand_fun_below   ~> fun_below_iff
   832   below_fun_ext      ~> fun_belowI
   833   expand_cfun_eq     ~> cfun_eq_iff
   834   ext_cfun           ~> cfun_eqI
   835   expand_cfun_below  ~> cfun_below_iff
   836   below_cfun_ext     ~> cfun_belowI
   837   cont2cont_Rep_CFun ~> cont2cont_APP
   838 
   839 * The Abs and Rep functions for various types have changed names.
   840 Related theorem names have also changed to match. INCOMPATIBILITY.
   841 
   842   Rep_CFun  ~> Rep_cfun
   843   Abs_CFun  ~> Abs_cfun
   844   Rep_Sprod ~> Rep_sprod
   845   Abs_Sprod ~> Abs_sprod
   846   Rep_Ssum  ~> Rep_ssum
   847   Abs_Ssum  ~> Abs_ssum
   848 
   849 * Lemmas with names of the form *_defined_iff or *_strict_iff have
   850 been renamed to *_bottom_iff.  INCOMPATIBILITY.
   851 
   852 * Various changes to bisimulation/coinduction with domain package:
   853 
   854   - Definitions of "bisim" constants no longer mention definedness.
   855   - With mutual recursion, "bisim" predicate is now curried.
   856   - With mutual recursion, each type gets a separate coind theorem.
   857   - Variable names in bisim_def and coinduct rules have changed.
   858 
   859 INCOMPATIBILITY.
   860 
   861 * Case combinators generated by the domain package for type "foo" are
   862 now named "foo_case" instead of "foo_when".  INCOMPATIBILITY.
   863 
   864 * Several theorems have been renamed to more accurately reflect the
   865 names of constants and types involved.  INCOMPATIBILITY.
   866 
   867   thelub_const    ~> lub_const
   868   lub_const       ~> is_lub_const
   869   thelubI         ~> lub_eqI
   870   is_lub_lub      ~> is_lubD2
   871   lubI            ~> is_lub_lub
   872   unique_lub      ~> is_lub_unique
   873   is_ub_lub       ~> is_lub_rangeD1
   874   lub_bin_chain   ~> is_lub_bin_chain
   875   lub_fun         ~> is_lub_fun
   876   thelub_fun      ~> lub_fun
   877   thelub_cfun     ~> lub_cfun
   878   thelub_Pair     ~> lub_Pair
   879   lub_cprod       ~> is_lub_prod
   880   thelub_cprod    ~> lub_prod
   881   minimal_cprod   ~> minimal_prod
   882   inst_cprod_pcpo ~> inst_prod_pcpo
   883   UU_I            ~> bottomI
   884   compact_UU      ~> compact_bottom
   885   deflation_UU    ~> deflation_bottom
   886   finite_deflation_UU ~> finite_deflation_bottom
   887 
   888 * Many legacy theorem names have been discontinued.  INCOMPATIBILITY.
   889 
   890   sq_ord_less_eq_trans ~> below_eq_trans
   891   sq_ord_eq_less_trans ~> eq_below_trans
   892   refl_less            ~> below_refl
   893   trans_less           ~> below_trans
   894   antisym_less         ~> below_antisym
   895   antisym_less_inverse ~> po_eq_conv [THEN iffD1]
   896   box_less             ~> box_below
   897   rev_trans_less       ~> rev_below_trans
   898   not_less2not_eq      ~> not_below2not_eq
   899   less_UU_iff          ~> below_UU_iff
   900   flat_less_iff        ~> flat_below_iff
   901   adm_less             ~> adm_below
   902   adm_not_less         ~> adm_not_below
   903   adm_compact_not_less ~> adm_compact_not_below
   904   less_fun_def         ~> below_fun_def
   905   expand_fun_less      ~> fun_below_iff
   906   less_fun_ext         ~> fun_belowI
   907   less_discr_def       ~> below_discr_def
   908   discr_less_eq        ~> discr_below_eq
   909   less_unit_def        ~> below_unit_def
   910   less_cprod_def       ~> below_prod_def
   911   prod_lessI           ~> prod_belowI
   912   Pair_less_iff        ~> Pair_below_iff
   913   fst_less_iff         ~> fst_below_iff
   914   snd_less_iff         ~> snd_below_iff
   915   expand_cfun_less     ~> cfun_below_iff
   916   less_cfun_ext        ~> cfun_belowI
   917   injection_less       ~> injection_below
   918   less_up_def          ~> below_up_def
   919   not_Iup_less         ~> not_Iup_below
   920   Iup_less             ~> Iup_below
   921   up_less              ~> up_below
   922   Def_inject_less_eq   ~> Def_below_Def
   923   Def_less_is_eq       ~> Def_below_iff
   924   spair_less_iff       ~> spair_below_iff
   925   less_sprod           ~> below_sprod
   926   spair_less           ~> spair_below
   927   sfst_less_iff        ~> sfst_below_iff
   928   ssnd_less_iff        ~> ssnd_below_iff
   929   fix_least_less       ~> fix_least_below
   930   dist_less_one        ~> dist_below_one
   931   less_ONE             ~> below_ONE
   932   ONE_less_iff         ~> ONE_below_iff
   933   less_sinlD           ~> below_sinlD
   934   less_sinrD           ~> below_sinrD
   935 
   936 
   937 *** FOL and ZF ***
   938 
   939 * All constant names are now qualified internally and use proper
   940 identifiers, e.g. "IFOL.eq" instead of "op =".  INCOMPATIBILITY.
   941 
   942 
   943 *** ML ***
   944 
   945 * Antiquotation @{assert} inlines a function bool -> unit that raises
   946 Fail if the argument is false.  Due to inlining the source position of
   947 failed assertions is included in the error output.
   948 
   949 * Discontinued antiquotation @{theory_ref}, which is obsolete since ML
   950 text is in practice always evaluated with a stable theory checkpoint.
   951 Minor INCOMPATIBILITY, use (Theory.check_thy @{theory}) instead.
   952 
   953 * Antiquotation @{theory A} refers to theory A from the ancestry of
   954 the current context, not any accidental theory loader state as before.
   955 Potential INCOMPATIBILITY, subtle change in semantics.
   956 
   957 * Syntax.pretty_priority (default 0) configures the required priority
   958 of pretty-printed output and thus affects insertion of parentheses.
   959 
   960 * Syntax.default_root (default "any") configures the inner syntax
   961 category (nonterminal symbol) for parsing of terms.
   962 
   963 * Former exception Library.UnequalLengths now coincides with
   964 ListPair.UnequalLengths.
   965 
   966 * Renamed structure MetaSimplifier to Raw_Simplifier.  Note that the
   967 main functionality is provided by structure Simplifier.
   968 
   969 * Renamed raw "explode" function to "raw_explode" to emphasize its
   970 meaning.  Note that internally to Isabelle, Symbol.explode is used in
   971 almost all situations.
   972 
   973 * Discontinued obsolete function sys_error and exception SYS_ERROR.
   974 See implementation manual for further details on exceptions in
   975 Isabelle/ML.
   976 
   977 * Renamed setmp_noncritical to Unsynchronized.setmp to emphasize its
   978 meaning.
   979 
   980 * Renamed structure PureThy to Pure_Thy and moved most of its
   981 operations to structure Global_Theory, to emphasize that this is
   982 rarely-used global-only stuff.
   983 
   984 * Discontinued Output.debug.  Minor INCOMPATIBILITY, use plain writeln
   985 instead (or tracing for high-volume output).
   986 
   987 * Configuration option show_question_marks only affects regular pretty
   988 printing of types and terms, not raw Term.string_of_vname.
   989 
   990 * ML_Context.thm and ML_Context.thms are no longer pervasive.  Rare
   991 INCOMPATIBILITY, superseded by static antiquotations @{thm} and
   992 @{thms} for most purposes.
   993 
   994 * ML structure Unsynchronized is never opened, not even in Isar
   995 interaction mode as before.  Old Unsynchronized.set etc. have been
   996 discontinued -- use plain := instead.  This should be *rare* anyway,
   997 since modern tools always work via official context data, notably
   998 configuration options.
   999 
  1000 * Parallel and asynchronous execution requires special care concerning
  1001 interrupts.  Structure Exn provides some convenience functions that
  1002 avoid working directly with raw Interrupt.  User code must not absorb
  1003 interrupts -- intermediate handling (for cleanup etc.) needs to be
  1004 followed by re-raising of the original exception.  Another common
  1005 source of mistakes are "handle _" patterns, which make the meaning of
  1006 the program subject to physical effects of the environment.
  1007 
  1008 
  1009 
  1010 New in Isabelle2009-2 (June 2010)
  1011 ---------------------------------
  1012 
  1013 *** General ***
  1014 
  1015 * Authentic syntax for *all* logical entities (type classes, type
  1016 constructors, term constants): provides simple and robust
  1017 correspondence between formal entities and concrete syntax.  Within
  1018 the parse tree / AST representations, "constants" are decorated by
  1019 their category (class, type, const) and spelled out explicitly with
  1020 their full internal name.
  1021 
  1022 Substantial INCOMPATIBILITY concerning low-level syntax declarations
  1023 and translations (translation rules and translation functions in ML).
  1024 Some hints on upgrading:
  1025 
  1026   - Many existing uses of 'syntax' and 'translations' can be replaced
  1027     by more modern 'type_notation', 'notation' and 'abbreviation',
  1028     which are independent of this issue.
  1029 
  1030   - 'translations' require markup within the AST; the term syntax
  1031     provides the following special forms:
  1032 
  1033       CONST c   -- produces syntax version of constant c from context
  1034       XCONST c  -- literally c, checked as constant from context
  1035       c         -- literally c, if declared by 'syntax'
  1036 
  1037     Plain identifiers are treated as AST variables -- occasionally the
  1038     system indicates accidental variables via the error "rhs contains
  1039     extra variables".
  1040 
  1041     Type classes and type constructors are marked according to their
  1042     concrete syntax.  Some old translations rules need to be written
  1043     for the "type" category, using type constructor application
  1044     instead of pseudo-term application of the default category
  1045     "logic".
  1046 
  1047   - 'parse_translation' etc. in ML may use the following
  1048     antiquotations:
  1049 
  1050       @{class_syntax c}   -- type class c within parse tree / AST
  1051       @{term_syntax c}    -- type constructor c within parse tree / AST
  1052       @{const_syntax c}   -- ML version of "CONST c" above
  1053       @{syntax_const c}   -- literally c (checked wrt. 'syntax' declarations)
  1054 
  1055   - Literal types within 'typed_print_translations', i.e. those *not*
  1056     represented as pseudo-terms are represented verbatim.  Use @{class
  1057     c} or @{type_name c} here instead of the above syntax
  1058     antiquotations.
  1059 
  1060 Note that old non-authentic syntax was based on unqualified base
  1061 names, so all of the above "constant" names would coincide.  Recall
  1062 that 'print_syntax' and ML_command "set Syntax.trace_ast" help to
  1063 diagnose syntax problems.
  1064 
  1065 * Type constructors admit general mixfix syntax, not just infix.
  1066 
  1067 * Concrete syntax may be attached to local entities without a proof
  1068 body, too.  This works via regular mixfix annotations for 'fix',
  1069 'def', 'obtain' etc. or via the explicit 'write' command, which is
  1070 similar to the 'notation' command in theory specifications.
  1071 
  1072 * Discontinued unnamed infix syntax (legacy feature for many years) --
  1073 need to specify constant name and syntax separately.  Internal ML
  1074 datatype constructors have been renamed from InfixName to Infix etc.
  1075 Minor INCOMPATIBILITY.
  1076 
  1077 * Schematic theorem statements need to be explicitly markup as such,
  1078 via commands 'schematic_lemma', 'schematic_theorem',
  1079 'schematic_corollary'.  Thus the relevance of the proof is made
  1080 syntactically clear, which impacts performance in a parallel or
  1081 asynchronous interactive environment.  Minor INCOMPATIBILITY.
  1082 
  1083 * Use of cumulative prems via "!" in some proof methods has been
  1084 discontinued (old legacy feature).
  1085 
  1086 * References 'trace_simp' and 'debug_simp' have been replaced by
  1087 configuration options stored in the context. Enabling tracing (the
  1088 case of debugging is similar) in proofs works via
  1089 
  1090   using [[trace_simp = true]]
  1091 
  1092 Tracing is then active for all invocations of the simplifier in
  1093 subsequent goal refinement steps. Tracing may also still be enabled or
  1094 disabled via the ProofGeneral settings menu.
  1095 
  1096 * Separate commands 'hide_class', 'hide_type', 'hide_const',
  1097 'hide_fact' replace the former 'hide' KIND command.  Minor
  1098 INCOMPATIBILITY.
  1099 
  1100 * Improved parallelism of proof term normalization: usedir -p2 -q0 is
  1101 more efficient than combinations with -q1 or -q2.
  1102 
  1103 
  1104 *** Pure ***
  1105 
  1106 * Proofterms record type-class reasoning explicitly, using the
  1107 "unconstrain" operation internally.  This eliminates all sort
  1108 constraints from a theorem and proof, introducing explicit
  1109 OFCLASS-premises.  On the proof term level, this operation is
  1110 automatically applied at theorem boundaries, such that closed proofs
  1111 are always free of sort constraints.  INCOMPATIBILITY for tools that
  1112 inspect proof terms.
  1113 
  1114 * Local theory specifications may depend on extra type variables that
  1115 are not present in the result type -- arguments TYPE('a) :: 'a itself
  1116 are added internally.  For example:
  1117 
  1118   definition unitary :: bool where "unitary = (ALL (x::'a) y. x = y)"
  1119 
  1120 * Predicates of locales introduced by classes carry a mandatory
  1121 "class" prefix.  INCOMPATIBILITY.
  1122 
  1123 * Vacuous class specifications observe default sort.  INCOMPATIBILITY.
  1124 
  1125 * Old 'axclass' command has been discontinued.  INCOMPATIBILITY, use
  1126 'class' instead.
  1127 
  1128 * Command 'code_reflect' allows to incorporate generated ML code into
  1129 runtime environment; replaces immature code_datatype antiquotation.
  1130 INCOMPATIBILITY.
  1131 
  1132 * Code generator: simple concept for abstract datatypes obeying
  1133 invariants.
  1134 
  1135 * Code generator: details of internal data cache have no impact on the
  1136 user space functionality any longer.
  1137 
  1138 * Methods "unfold_locales" and "intro_locales" ignore non-locale
  1139 subgoals.  This is more appropriate for interpretations with 'where'.
  1140 INCOMPATIBILITY.
  1141 
  1142 * Command 'example_proof' opens an empty proof body.  This allows to
  1143 experiment with Isar, without producing any persistent result.
  1144 
  1145 * Commands 'type_notation' and 'no_type_notation' declare type syntax
  1146 within a local theory context, with explicit checking of the
  1147 constructors involved (in contrast to the raw 'syntax' versions).
  1148 
  1149 * Commands 'types' and 'typedecl' now work within a local theory
  1150 context -- without introducing dependencies on parameters or
  1151 assumptions, which is not possible in Isabelle/Pure.
  1152 
  1153 * Command 'defaultsort' has been renamed to 'default_sort', it works
  1154 within a local theory context.  Minor INCOMPATIBILITY.
  1155 
  1156 
  1157 *** HOL ***
  1158 
  1159 * Command 'typedef' now works within a local theory context -- without
  1160 introducing dependencies on parameters or assumptions, which is not
  1161 possible in Isabelle/Pure/HOL.  Note that the logical environment may
  1162 contain multiple interpretations of local typedefs (with different
  1163 non-emptiness proofs), even in a global theory context.
  1164 
  1165 * New package for quotient types.  Commands 'quotient_type' and
  1166 'quotient_definition' may be used for defining types and constants by
  1167 quotient constructions.  An example is the type of integers created by
  1168 quotienting pairs of natural numbers:
  1169 
  1170   fun
  1171     intrel :: "(nat * nat) => (nat * nat) => bool"
  1172   where
  1173     "intrel (x, y) (u, v) = (x + v = u + y)"
  1174 
  1175   quotient_type int = "nat * nat" / intrel
  1176     by (auto simp add: equivp_def expand_fun_eq)
  1177 
  1178   quotient_definition
  1179     "0::int" is "(0::nat, 0::nat)"
  1180 
  1181 The method "lifting" can be used to lift of theorems from the
  1182 underlying "raw" type to the quotient type.  The example
  1183 src/HOL/Quotient_Examples/FSet.thy includes such a quotient
  1184 construction and provides a reasoning infrastructure for finite sets.
  1185 
  1186 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
  1187 clash with new theory Quotient in Main HOL.
  1188 
  1189 * Moved the SMT binding into the main HOL session, eliminating
  1190 separate HOL-SMT session.
  1191 
  1192 * List membership infix mem operation is only an input abbreviation.
  1193 INCOMPATIBILITY.
  1194 
  1195 * Theory Library/Word.thy has been removed.  Use library Word/Word.thy
  1196 for future developements; former Library/Word.thy is still present in
  1197 the AFP entry RSAPPS.
  1198 
  1199 * Theorem Int.int_induct renamed to Int.int_of_nat_induct and is no
  1200 longer shadowed.  INCOMPATIBILITY.
  1201 
  1202 * Dropped theorem duplicate comp_arith; use semiring_norm instead.
  1203 INCOMPATIBILITY.
  1204 
  1205 * Dropped theorem RealPow.real_sq_order; use power2_le_imp_le instead.
  1206 INCOMPATIBILITY.
  1207 
  1208 * Dropped normalizing_semiring etc; use the facts in semiring classes
  1209 instead.  INCOMPATIBILITY.
  1210 
  1211 * Dropped several real-specific versions of lemmas about floor and
  1212 ceiling; use the generic lemmas from theory "Archimedean_Field"
  1213 instead.  INCOMPATIBILITY.
  1214 
  1215   floor_number_of_eq         ~> floor_number_of
  1216   le_floor_eq_number_of      ~> number_of_le_floor
  1217   le_floor_eq_zero           ~> zero_le_floor
  1218   le_floor_eq_one            ~> one_le_floor
  1219   floor_less_eq_number_of    ~> floor_less_number_of
  1220   floor_less_eq_zero         ~> floor_less_zero
  1221   floor_less_eq_one          ~> floor_less_one
  1222   less_floor_eq_number_of    ~> number_of_less_floor
  1223   less_floor_eq_zero         ~> zero_less_floor
  1224   less_floor_eq_one          ~> one_less_floor
  1225   floor_le_eq_number_of      ~> floor_le_number_of
  1226   floor_le_eq_zero           ~> floor_le_zero
  1227   floor_le_eq_one            ~> floor_le_one
  1228   floor_subtract_number_of   ~> floor_diff_number_of
  1229   floor_subtract_one         ~> floor_diff_one
  1230   ceiling_number_of_eq       ~> ceiling_number_of
  1231   ceiling_le_eq_number_of    ~> ceiling_le_number_of
  1232   ceiling_le_zero_eq         ~> ceiling_le_zero
  1233   ceiling_le_eq_one          ~> ceiling_le_one
  1234   less_ceiling_eq_number_of  ~> number_of_less_ceiling
  1235   less_ceiling_eq_zero       ~> zero_less_ceiling
  1236   less_ceiling_eq_one        ~> one_less_ceiling
  1237   ceiling_less_eq_number_of  ~> ceiling_less_number_of
  1238   ceiling_less_eq_zero       ~> ceiling_less_zero
  1239   ceiling_less_eq_one        ~> ceiling_less_one
  1240   le_ceiling_eq_number_of    ~> number_of_le_ceiling
  1241   le_ceiling_eq_zero         ~> zero_le_ceiling
  1242   le_ceiling_eq_one          ~> one_le_ceiling
  1243   ceiling_subtract_number_of ~> ceiling_diff_number_of
  1244   ceiling_subtract_one       ~> ceiling_diff_one
  1245 
  1246 * Theory "Finite_Set": various folding_XXX locales facilitate the
  1247 application of the various fold combinators on finite sets.
  1248 
  1249 * Library theory "RBT" renamed to "RBT_Impl"; new library theory "RBT"
  1250 provides abstract red-black tree type which is backed by "RBT_Impl" as
  1251 implementation.  INCOMPATIBILTY.
  1252 
  1253 * Theory Library/Coinductive_List has been removed -- superseded by
  1254 AFP/thys/Coinductive.
  1255 
  1256 * Theory PReal, including the type "preal" and related operations, has
  1257 been removed.  INCOMPATIBILITY.
  1258 
  1259 * Real: new development using Cauchy Sequences.
  1260 
  1261 * Split off theory "Big_Operators" containing setsum, setprod,
  1262 Inf_fin, Sup_fin, Min, Max from theory Finite_Set.  INCOMPATIBILITY.
  1263 
  1264 * Theory "Rational" renamed to "Rat", for consistency with "Nat",
  1265 "Int" etc.  INCOMPATIBILITY.
  1266 
  1267 * Constant Rat.normalize needs to be qualified.  INCOMPATIBILITY.
  1268 
  1269 * New set of rules "ac_simps" provides combined assoc / commute
  1270 rewrites for all interpretations of the appropriate generic locales.
  1271 
  1272 * Renamed theory "OrderedGroup" to "Groups" and split theory
  1273 "Ring_and_Field" into theories "Rings" and "Fields"; for more
  1274 appropriate and more consistent names suitable for name prefixes
  1275 within the HOL theories.  INCOMPATIBILITY.
  1276 
  1277 * Some generic constants have been put to appropriate theories:
  1278   - less_eq, less: Orderings
  1279   - zero, one, plus, minus, uminus, times, abs, sgn: Groups
  1280   - inverse, divide: Rings
  1281 INCOMPATIBILITY.
  1282 
  1283 * More consistent naming of type classes involving orderings (and
  1284 lattices):
  1285 
  1286     lower_semilattice                   ~> semilattice_inf
  1287     upper_semilattice                   ~> semilattice_sup
  1288 
  1289     dense_linear_order                  ~> dense_linorder
  1290 
  1291     pordered_ab_group_add               ~> ordered_ab_group_add
  1292     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
  1293     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
  1294     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
  1295     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
  1296     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
  1297     pordered_cancel_semiring            ~> ordered_cancel_semiring
  1298     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
  1299     pordered_comm_ring                  ~> ordered_comm_ring
  1300     pordered_comm_semiring              ~> ordered_comm_semiring
  1301     pordered_ring                       ~> ordered_ring
  1302     pordered_ring_abs                   ~> ordered_ring_abs
  1303     pordered_semiring                   ~> ordered_semiring
  1304 
  1305     ordered_ab_group_add                ~> linordered_ab_group_add
  1306     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
  1307     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
  1308     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
  1309     ordered_field                       ~> linordered_field
  1310     ordered_field_no_lb                 ~> linordered_field_no_lb
  1311     ordered_field_no_ub                 ~> linordered_field_no_ub
  1312     ordered_field_dense_linear_order    ~> dense_linordered_field
  1313     ordered_idom                        ~> linordered_idom
  1314     ordered_ring                        ~> linordered_ring
  1315     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
  1316     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
  1317     ordered_ring_strict                 ~> linordered_ring_strict
  1318     ordered_semidom                     ~> linordered_semidom
  1319     ordered_semiring                    ~> linordered_semiring
  1320     ordered_semiring_1                  ~> linordered_semiring_1
  1321     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
  1322     ordered_semiring_strict             ~> linordered_semiring_strict
  1323 
  1324   The following slightly odd type classes have been moved to a
  1325   separate theory Library/Lattice_Algebras:
  1326 
  1327     lordered_ab_group_add               ~> lattice_ab_group_add
  1328     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
  1329     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
  1330     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
  1331     lordered_ring                       ~> lattice_ring
  1332 
  1333 INCOMPATIBILITY.
  1334 
  1335 * Refined field classes:
  1336   - classes division_ring_inverse_zero, field_inverse_zero,
  1337     linordered_field_inverse_zero include rule inverse 0 = 0 --
  1338     subsumes former division_by_zero class;
  1339   - numerous lemmas have been ported from field to division_ring.
  1340 INCOMPATIBILITY.
  1341 
  1342 * Refined algebra theorem collections:
  1343   - dropped theorem group group_simps, use algebra_simps instead;
  1344   - dropped theorem group ring_simps, use field_simps instead;
  1345   - proper theorem collection field_simps subsumes former theorem
  1346     groups field_eq_simps and field_simps;
  1347   - dropped lemma eq_minus_self_iff which is a duplicate for
  1348     equal_neg_zero.
  1349 INCOMPATIBILITY.
  1350 
  1351 * Theory Finite_Set and List: some lemmas have been generalized from
  1352 sets to lattices:
  1353 
  1354   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
  1355   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
  1356   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
  1357   union_Union_fold_union        ~> sup_Sup_fold_sup
  1358   Inter_fold_inter              ~> Inf_fold_inf
  1359   Union_fold_union              ~> Sup_fold_sup
  1360   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
  1361   union_UNION_fold_union        ~> sup_SUPR_fold_sup
  1362   INTER_fold_inter              ~> INFI_fold_inf
  1363   UNION_fold_union              ~> SUPR_fold_sup
  1364 
  1365 * Theory "Complete_Lattice": lemmas top_def and bot_def have been
  1366 replaced by the more convenient lemmas Inf_empty and Sup_empty.
  1367 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
  1368 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
  1369 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
  1370 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
  1371 
  1372 * Reorganized theory Multiset: swapped notation of pointwise and
  1373 multiset order:
  1374 
  1375   - pointwise ordering is instance of class order with standard syntax
  1376     <= and <;
  1377   - multiset ordering has syntax <=# and <#; partial order properties
  1378     are provided by means of interpretation with prefix
  1379     multiset_order;
  1380   - less duplication, less historical organization of sections,
  1381     conversion from associations lists to multisets, rudimentary code
  1382     generation;
  1383   - use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union,
  1384     if needed.
  1385 
  1386 Renamed:
  1387 
  1388   multiset_eq_conv_count_eq  ~>  multiset_ext_iff
  1389   multi_count_ext  ~>  multiset_ext
  1390   diff_union_inverse2  ~>  diff_union_cancelR
  1391 
  1392 INCOMPATIBILITY.
  1393 
  1394 * Theory Permutation: replaced local "remove" by List.remove1.
  1395 
  1396 * Code generation: ML and OCaml code is decorated with signatures.
  1397 
  1398 * Theory List: added transpose.
  1399 
  1400 * Library/Nat_Bijection.thy is a collection of bijective functions
  1401 between nat and other types, which supersedes the older libraries
  1402 Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.
  1403 
  1404   Constants:
  1405   Nat_Int_Bij.nat2_to_nat         ~> prod_encode
  1406   Nat_Int_Bij.nat_to_nat2         ~> prod_decode
  1407   Nat_Int_Bij.int_to_nat_bij      ~> int_encode
  1408   Nat_Int_Bij.nat_to_int_bij      ~> int_decode
  1409   Countable.pair_encode           ~> prod_encode
  1410   NatIso.prod2nat                 ~> prod_encode
  1411   NatIso.nat2prod                 ~> prod_decode
  1412   NatIso.sum2nat                  ~> sum_encode
  1413   NatIso.nat2sum                  ~> sum_decode
  1414   NatIso.list2nat                 ~> list_encode
  1415   NatIso.nat2list                 ~> list_decode
  1416   NatIso.set2nat                  ~> set_encode
  1417   NatIso.nat2set                  ~> set_decode
  1418 
  1419   Lemmas:
  1420   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
  1421   Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
  1422   Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
  1423   Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
  1424   Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
  1425   Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
  1426   Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
  1427   Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
  1428   Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
  1429   Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
  1430   Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
  1431   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
  1432   Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode
  1433 
  1434 * Sledgehammer:
  1435   - Renamed ATP commands:
  1436     atp_info     ~> sledgehammer running_atps
  1437     atp_kill     ~> sledgehammer kill_atps
  1438     atp_messages ~> sledgehammer messages
  1439     atp_minimize ~> sledgehammer minimize
  1440     print_atps   ~> sledgehammer available_atps
  1441     INCOMPATIBILITY.
  1442   - Added user's manual ("isabelle doc sledgehammer").
  1443   - Added option syntax and "sledgehammer_params" to customize
  1444     Sledgehammer's behavior.  See the manual for details.
  1445   - Modified the Isar proof reconstruction code so that it produces
  1446     direct proofs rather than proofs by contradiction.  (This feature
  1447     is still experimental.)
  1448   - Made Isar proof reconstruction work for SPASS, remote ATPs, and in
  1449     full-typed mode.
  1450   - Added support for TPTP syntax for SPASS via the "spass_tptp" ATP.
  1451 
  1452 * Nitpick:
  1453   - Added and implemented "binary_ints" and "bits" options.
  1454   - Added "std" option and implemented support for nonstandard models.
  1455   - Added and implemented "finitize" option to improve the precision
  1456     of infinite datatypes based on a monotonicity analysis.
  1457   - Added support for quotient types.
  1458   - Added support for "specification" and "ax_specification"
  1459     constructs.
  1460   - Added support for local definitions (for "function" and
  1461     "termination" proofs).
  1462   - Added support for term postprocessors.
  1463   - Optimized "Multiset.multiset" and "FinFun.finfun".
  1464   - Improved efficiency of "destroy_constrs" optimization.
  1465   - Fixed soundness bugs related to "destroy_constrs" optimization and
  1466     record getters.
  1467   - Fixed soundness bug related to higher-order constructors.
  1468   - Fixed soundness bug when "full_descrs" is enabled.
  1469   - Improved precision of set constructs.
  1470   - Added "atoms" option.
  1471   - Added cache to speed up repeated Kodkod invocations on the same
  1472     problems.
  1473   - Renamed "MiniSatJNI", "zChaffJNI", "BerkMinAlloy", and
  1474     "SAT4JLight" to "MiniSat_JNI", "zChaff_JNI", "BerkMin_Alloy", and
  1475     "SAT4J_Light".  INCOMPATIBILITY.
  1476   - Removed "skolemize", "uncurry", "sym_break", "flatten_prop",
  1477     "sharing_depth", and "show_skolems" options.  INCOMPATIBILITY.
  1478   - Removed "nitpick_intro" attribute.  INCOMPATIBILITY.
  1479 
  1480 * Method "induct" now takes instantiations of the form t, where t is not
  1481   a variable, as a shorthand for "x == t", where x is a fresh variable.
  1482   If this is not intended, t has to be enclosed in parentheses.
  1483   By default, the equalities generated by definitional instantiations
  1484   are pre-simplified, which may cause parameters of inductive cases
  1485   to disappear, or may even delete some of the inductive cases.
  1486   Use "induct (no_simp)" instead of "induct" to restore the old
  1487   behaviour. The (no_simp) option is also understood by the "cases"
  1488   and "nominal_induct" methods, which now perform pre-simplification, too.
  1489   INCOMPATIBILITY.
  1490 
  1491 
  1492 *** HOLCF ***
  1493 
  1494 * Variable names in lemmas generated by the domain package have
  1495 changed; the naming scheme is now consistent with the HOL datatype
  1496 package.  Some proof scripts may be affected, INCOMPATIBILITY.
  1497 
  1498 * The domain package no longer defines the function "foo_copy" for
  1499 recursive domain "foo".  The reach lemma is now stated directly in
  1500 terms of "foo_take".  Lemmas and proofs that mention "foo_copy" must
  1501 be reformulated in terms of "foo_take", INCOMPATIBILITY.
  1502 
  1503 * Most definedness lemmas generated by the domain package (previously
  1504 of the form "x ~= UU ==> foo$x ~= UU") now have an if-and-only-if form
  1505 like "foo$x = UU <-> x = UU", which works better as a simp rule.
  1506 Proofs that used definedness lemmas as intro rules may break,
  1507 potential INCOMPATIBILITY.
  1508 
  1509 * Induction and casedist rules generated by the domain package now
  1510 declare proper case_names (one called "bottom", and one named for each
  1511 constructor).  INCOMPATIBILITY.
  1512 
  1513 * For mutually-recursive domains, separate "reach" and "take_lemma"
  1514 rules are generated for each domain, INCOMPATIBILITY.
  1515 
  1516   foo_bar.reach       ~> foo.reach  bar.reach
  1517   foo_bar.take_lemmas ~> foo.take_lemma  bar.take_lemma
  1518 
  1519 * Some lemmas generated by the domain package have been renamed for
  1520 consistency with the datatype package, INCOMPATIBILITY.
  1521 
  1522   foo.ind        ~> foo.induct
  1523   foo.finite_ind ~> foo.finite_induct
  1524   foo.coind      ~> foo.coinduct
  1525   foo.casedist   ~> foo.exhaust
  1526   foo.exhaust    ~> foo.nchotomy
  1527 
  1528 * For consistency with other definition packages, the fixrec package
  1529 now generates qualified theorem names, INCOMPATIBILITY.
  1530 
  1531   foo_simps  ~> foo.simps
  1532   foo_unfold ~> foo.unfold
  1533   foo_induct ~> foo.induct
  1534 
  1535 * The "fixrec_simp" attribute has been removed.  The "fixrec_simp"
  1536 method and internal fixrec proofs now use the default simpset instead.
  1537 INCOMPATIBILITY.
  1538 
  1539 * The "contlub" predicate has been removed.  Proof scripts should use
  1540 lemma contI2 in place of monocontlub2cont, INCOMPATIBILITY.
  1541 
  1542 * The "admw" predicate has been removed, INCOMPATIBILITY.
  1543 
  1544 * The constants cpair, cfst, and csnd have been removed in favor of
  1545 Pair, fst, and snd from Isabelle/HOL, INCOMPATIBILITY.
  1546 
  1547 
  1548 *** ML ***
  1549 
  1550 * Antiquotations for basic formal entities:
  1551 
  1552     @{class NAME}         -- type class
  1553     @{class_syntax NAME}  -- syntax representation of the above
  1554 
  1555     @{type_name NAME}     -- logical type
  1556     @{type_abbrev NAME}   -- type abbreviation
  1557     @{nonterminal NAME}   -- type of concrete syntactic category
  1558     @{type_syntax NAME}   -- syntax representation of any of the above
  1559 
  1560     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
  1561     @{const_abbrev NAME}  -- abbreviated constant
  1562     @{const_syntax NAME}  -- syntax representation of any of the above
  1563 
  1564 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
  1565 syntax constant (cf. 'syntax' command).
  1566 
  1567 * Antiquotation @{make_string} inlines a function to print arbitrary
  1568 values similar to the ML toplevel.  The result is compiler dependent
  1569 and may fall back on "?" in certain situations.
  1570 
  1571 * Diagnostic commands 'ML_val' and 'ML_command' may refer to
  1572 antiquotations @{Isar.state} and @{Isar.goal}.  This replaces impure
  1573 Isar.state() and Isar.goal(), which belong to the old TTY loop and do
  1574 not work with the asynchronous Isar document model.
  1575 
  1576 * Configuration options now admit dynamic default values, depending on
  1577 the context or even global references.
  1578 
  1579 * SHA1.digest digests strings according to SHA-1 (see RFC 3174).  It
  1580 uses an efficient external library if available (for Poly/ML).
  1581 
  1582 * Renamed some important ML structures, while keeping the old names
  1583 for some time as aliases within the structure Legacy:
  1584 
  1585   OuterKeyword  ~>  Keyword
  1586   OuterLex      ~>  Token
  1587   OuterParse    ~>  Parse
  1588   OuterSyntax   ~>  Outer_Syntax
  1589   PrintMode     ~>  Print_Mode
  1590   SpecParse     ~>  Parse_Spec
  1591   ThyInfo       ~>  Thy_Info
  1592   ThyLoad       ~>  Thy_Load
  1593   ThyOutput     ~>  Thy_Output
  1594   TypeInfer     ~>  Type_Infer
  1595 
  1596 Note that "open Legacy" simplifies porting of sources, but forgetting
  1597 to remove it again will complicate porting again in the future.
  1598 
  1599 * Most operations that refer to a global context are named
  1600 accordingly, e.g. Simplifier.global_context or
  1601 ProofContext.init_global.  There are some situations where a global
  1602 context actually works, but under normal circumstances one needs to
  1603 pass the proper local context through the code!
  1604 
  1605 * Discontinued old TheoryDataFun with its copy/init operation -- data
  1606 needs to be pure.  Functor Theory_Data_PP retains the traditional
  1607 Pretty.pp argument to merge, which is absent in the standard
  1608 Theory_Data version.
  1609 
  1610 * Sorts.certify_sort and derived "cert" operations for types and terms
  1611 no longer minimize sorts.  Thus certification at the boundary of the
  1612 inference kernel becomes invariant under addition of class relations,
  1613 which is an important monotonicity principle.  Sorts are now minimized
  1614 in the syntax layer only, at the boundary between the end-user and the
  1615 system.  Subtle INCOMPATIBILITY, may have to use Sign.minimize_sort
  1616 explicitly in rare situations.
  1617 
  1618 * Renamed old-style Drule.standard to Drule.export_without_context, to
  1619 emphasize that this is in no way a standard operation.
  1620 INCOMPATIBILITY.
  1621 
  1622 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
  1623 usual for resolution.  Rare INCOMPATIBILITY.
  1624 
  1625 * Renamed varify/unvarify operations to varify_global/unvarify_global
  1626 to emphasize that these only work in a global situation (which is
  1627 quite rare).
  1628 
  1629 * Curried take and drop in library.ML; negative length is interpreted
  1630 as infinity (as in chop).  Subtle INCOMPATIBILITY.
  1631 
  1632 * Proof terms: type substitutions on proof constants now use canonical
  1633 order of type variables.  INCOMPATIBILITY for tools working with proof
  1634 terms.
  1635 
  1636 * Raw axioms/defs may no longer carry sort constraints, and raw defs
  1637 may no longer carry premises.  User-level specifications are
  1638 transformed accordingly by Thm.add_axiom/add_def.
  1639 
  1640 
  1641 *** System ***
  1642 
  1643 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
  1644 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
  1645 proof terms are enabled unconditionally in the new HOL-Proofs image.
  1646 
  1647 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
  1648 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
  1649 respectively.
  1650 
  1651 * Old lib/scripts/polyml-platform is superseded by the
  1652 ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
  1653 variant, even on a 64 bit machine.  The following example setting
  1654 prefers 64 bit if available:
  1655 
  1656   ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"
  1657 
  1658 * The preliminary Isabelle/jEdit application demonstrates the emerging
  1659 Isabelle/Scala layer for advanced prover interaction and integration.
  1660 See src/Tools/jEdit or "isabelle jedit" provided by the properly built
  1661 component.
  1662 
  1663 * "IsabelleText" is a Unicode font derived from Bitstream Vera Mono
  1664 and Bluesky TeX fonts.  It provides the usual Isabelle symbols,
  1665 similar to the default assignment of the document preparation system
  1666 (cf. isabellesym.sty).  The Isabelle/Scala class Isabelle_System
  1667 provides some operations for direct access to the font without asking
  1668 the user for manual installation.
  1669 
  1670 
  1671 
  1672 New in Isabelle2009-1 (December 2009)
  1673 -------------------------------------
  1674 
  1675 *** General ***
  1676 
  1677 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
  1678 one backslash should be used, even in ML sources.
  1679 
  1680 
  1681 *** Pure ***
  1682 
  1683 * Locale interpretation propagates mixins along the locale hierarchy.
  1684 The currently only available mixins are the equations used to map
  1685 local definitions to terms of the target domain of an interpretation.
  1686 
  1687 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
  1688 loc" to print all interpretations of locale "loc" in the theory.
  1689 Interpretations in proofs are not shown.
  1690 
  1691 * Thoroughly revised locales tutorial.  New section on conditional
  1692 interpretation.
  1693 
  1694 * On instantiation of classes, remaining undefined class parameters
  1695 are formally declared.  INCOMPATIBILITY.
  1696 
  1697 
  1698 *** Document preparation ***
  1699 
  1700 * New generalized style concept for printing terms: @{foo (style) ...}
  1701 instead of @{foo_style style ...}  (old form is still retained for
  1702 backward compatibility).  Styles can be also applied for
  1703 antiquotations prop, term_type and typeof.
  1704 
  1705 
  1706 *** HOL ***
  1707 
  1708 * New proof method "smt" for a combination of first-order logic with
  1709 equality, linear and nonlinear (natural/integer/real) arithmetic, and
  1710 fixed-size bitvectors; there is also basic support for higher-order
  1711 features (esp. lambda abstractions).  It is an incomplete decision
  1712 procedure based on external SMT solvers using the oracle mechanism;
  1713 for the SMT solver Z3, this method is proof-producing.  Certificates
  1714 are provided to avoid calling the external solvers solely for
  1715 re-checking proofs.  Due to a remote SMT service there is no need for
  1716 installing SMT solvers locally.  See src/HOL/SMT.
  1717 
  1718 * New commands to load and prove verification conditions generated by
  1719 the Boogie program verifier or derived systems (e.g. the Verifying C
  1720 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
  1721 
  1722 * New counterexample generator tool 'nitpick' based on the Kodkod
  1723 relational model finder.  See src/HOL/Tools/Nitpick and
  1724 src/HOL/Nitpick_Examples.
  1725 
  1726 * New commands 'code_pred' and 'values' to invoke the predicate
  1727 compiler and to enumerate values of inductive predicates.
  1728 
  1729 * A tabled implementation of the reflexive transitive closure.
  1730 
  1731 * New implementation of quickcheck uses generic code generator;
  1732 default generators are provided for all suitable HOL types, records
  1733 and datatypes.  Old quickcheck can be re-activated importing theory
  1734 Library/SML_Quickcheck.
  1735 
  1736 * New testing tool Mirabelle for automated proof tools.  Applies
  1737 several tools and tactics like sledgehammer, metis, or quickcheck, to
  1738 every proof step in a theory.  To be used in batch mode via the
  1739 "mirabelle" utility.
  1740 
  1741 * New proof method "sos" (sum of squares) for nonlinear real
  1742 arithmetic (originally due to John Harison). It requires theory
  1743 Library/Sum_Of_Squares.  It is not a complete decision procedure but
  1744 works well in practice on quantifier-free real arithmetic with +, -,
  1745 *, ^, =, <= and <, i.e. boolean combinations of equalities and
  1746 inequalities between polynomials.  It makes use of external
  1747 semidefinite programming solvers.  Method "sos" generates a
  1748 certificate that can be pasted into the proof thus avoiding the need
  1749 to call an external tool every time the proof is checked.  See
  1750 src/HOL/Library/Sum_Of_Squares.
  1751 
  1752 * New method "linarith" invokes existing linear arithmetic decision
  1753 procedure only.
  1754 
  1755 * New command 'atp_minimal' reduces result produced by Sledgehammer.
  1756 
  1757 * New Sledgehammer option "Full Types" in Proof General settings menu.
  1758 Causes full type information to be output to the ATPs.  This slows
  1759 ATPs down considerably but eliminates a source of unsound "proofs"
  1760 that fail later.
  1761 
  1762 * New method "metisFT": A version of metis that uses full type
  1763 information in order to avoid failures of proof reconstruction.
  1764 
  1765 * New evaluator "approximate" approximates an real valued term using
  1766 the same method as the approximation method.
  1767 
  1768 * Method "approximate" now supports arithmetic expressions as
  1769 boundaries of intervals and implements interval splitting and Taylor
  1770 series expansion.
  1771 
  1772 * ML antiquotation @{code_datatype} inserts definition of a datatype
  1773 generated by the code generator; e.g. see src/HOL/Predicate.thy.
  1774 
  1775 * New theory SupInf of the supremum and infimum operators for sets of
  1776 reals.
  1777 
  1778 * New theory Probability, which contains a development of measure
  1779 theory, eventually leading to Lebesgue integration and probability.
  1780 
  1781 * Extended Multivariate Analysis to include derivation and Brouwer's
  1782 fixpoint theorem.
  1783 
  1784 * Reorganization of number theory, INCOMPATIBILITY:
  1785   - new number theory development for nat and int, in theories Divides
  1786     and GCD as well as in new session Number_Theory
  1787   - some constants and facts now suffixed with _nat and _int
  1788     accordingly
  1789   - former session NumberTheory now named Old_Number_Theory, including
  1790     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
  1791   - moved theory Pocklington from src/HOL/Library to
  1792     src/HOL/Old_Number_Theory
  1793 
  1794 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
  1795 lcm of finite and infinite sets. It is shown that they form a complete
  1796 lattice.
  1797 
  1798 * Class semiring_div requires superclass no_zero_divisors and proof of
  1799 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
  1800 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
  1801 generalized to class semiring_div, subsuming former theorems
  1802 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
  1803 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
  1804 INCOMPATIBILITY.
  1805 
  1806 * Refinements to lattice classes and sets:
  1807   - less default intro/elim rules in locale variant, more default
  1808     intro/elim rules in class variant: more uniformity
  1809   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
  1810     le_inf_iff
  1811   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
  1812     sup_aci)
  1813   - renamed ACI to inf_sup_aci
  1814   - new class "boolean_algebra"
  1815   - class "complete_lattice" moved to separate theory
  1816     "Complete_Lattice"; corresponding constants (and abbreviations)
  1817     renamed and with authentic syntax:
  1818     Set.Inf ~>    Complete_Lattice.Inf
  1819     Set.Sup ~>    Complete_Lattice.Sup
  1820     Set.INFI ~>   Complete_Lattice.INFI
  1821     Set.SUPR ~>   Complete_Lattice.SUPR
  1822     Set.Inter ~>  Complete_Lattice.Inter
  1823     Set.Union ~>  Complete_Lattice.Union
  1824     Set.INTER ~>  Complete_Lattice.INTER
  1825     Set.UNION ~>  Complete_Lattice.UNION
  1826   - authentic syntax for
  1827     Set.Pow
  1828     Set.image
  1829   - mere abbreviations:
  1830     Set.empty               (for bot)
  1831     Set.UNIV                (for top)
  1832     Set.inter               (for inf, formerly Set.Int)
  1833     Set.union               (for sup, formerly Set.Un)
  1834     Complete_Lattice.Inter  (for Inf)
  1835     Complete_Lattice.Union  (for Sup)
  1836     Complete_Lattice.INTER  (for INFI)
  1837     Complete_Lattice.UNION  (for SUPR)
  1838   - object-logic definitions as far as appropriate
  1839 
  1840 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
  1841 Un_subset_iff are explicitly deleted as default simp rules; then also
  1842 their lattice counterparts le_inf_iff and le_sup_iff have to be
  1843 deleted to achieve the desired effect.
  1844 
  1845 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
  1846 rules by default any longer; the same applies to min_max.inf_absorb1
  1847 etc.  INCOMPATIBILITY.
  1848 
  1849 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
  1850 pred_set_conv by default.  INCOMPATIBILITY.
  1851 
  1852 * Power operations on relations and functions are now one dedicated
  1853 constant "compow" with infix syntax "^^".  Power operation on
  1854 multiplicative monoids retains syntax "^" and is now defined generic
  1855 in class power.  INCOMPATIBILITY.
  1856 
  1857 * Relation composition "R O S" now has a more standard argument order:
  1858 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
  1859 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
  1860 break, since the O_assoc rule was not rewritten like this.  Fix using
  1861 O_assoc[symmetric].  The same applies to the curried version "R OO S".
  1862 
  1863 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
  1864 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
  1865 INCOMPATIBILITY.
  1866 
  1867 * Most rules produced by inductive and datatype package have mandatory
  1868 prefixes.  INCOMPATIBILITY.
  1869 
  1870 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
  1871 the attribute of the same name.  Each of the theorems in the list
  1872 DERIV_intros assumes composition with an additional function and
  1873 matches a variable to the derivative, which has to be solved by the
  1874 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
  1875 of most elementary terms.  Former Maclauren.DERIV_tac and
  1876 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
  1877 INCOMPATIBILITY.
  1878 
  1879 * Code generator attributes follow the usual underscore convention:
  1880     code_unfold     replaces    code unfold
  1881     code_post       replaces    code post
  1882     etc.
  1883   INCOMPATIBILITY.
  1884 
  1885 * Renamed methods:
  1886     sizechange -> size_change
  1887     induct_scheme -> induction_schema
  1888   INCOMPATIBILITY.
  1889 
  1890 * Discontinued abbreviation "arbitrary" of constant "undefined".
  1891 INCOMPATIBILITY, use "undefined" directly.
  1892 
  1893 * Renamed theorems:
  1894     Suc_eq_add_numeral_1 -> Suc_eq_plus1
  1895     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
  1896     Suc_plus1 -> Suc_eq_plus1
  1897     *anti_sym -> *antisym*
  1898     vector_less_eq_def -> vector_le_def
  1899   INCOMPATIBILITY.
  1900 
  1901 * Added theorem List.map_map as [simp].  Removed List.map_compose.
  1902 INCOMPATIBILITY.
  1903 
  1904 * Removed predicate "M hassize n" (<--> card M = n & finite M).
  1905 INCOMPATIBILITY.
  1906 
  1907 
  1908 *** HOLCF ***
  1909 
  1910 * Theory Representable defines a class "rep" of domains that are
  1911 representable (via an ep-pair) in the universal domain type "udom".
  1912 Instances are provided for all type constructors defined in HOLCF.
  1913 
  1914 * The 'new_domain' command is a purely definitional version of the
  1915 domain package, for representable domains.  Syntax is identical to the
  1916 old domain package.  The 'new_domain' package also supports indirect
  1917 recursion using previously-defined type constructors.  See
  1918 src/HOLCF/ex/New_Domain.thy for examples.
  1919 
  1920 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
  1921 on the left-hand side of an equation, and then performs
  1922 simplification.  Rewriting is done using rules declared with the
  1923 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
  1924 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
  1925 
  1926 * The pattern-match compiler in 'fixrec' can now handle constructors
  1927 with HOL function types.  Pattern-match combinators for the Pair
  1928 constructor are pre-configured.
  1929 
  1930 * The 'fixrec' package now produces better fixed-point induction rules
  1931 for mutually-recursive definitions:  Induction rules have conclusions
  1932 of the form "P foo bar" instead of "P <foo, bar>".
  1933 
  1934 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
  1935 been renamed to "below".  The name "below" now replaces "less" in many
  1936 theorem names.  (Legacy theorem names using "less" are still supported
  1937 as well.)
  1938 
  1939 * The 'fixrec' package now supports "bottom patterns".  Bottom
  1940 patterns can be used to generate strictness rules, or to make
  1941 functions more strict (much like the bang-patterns supported by the
  1942 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
  1943 examples.
  1944 
  1945 
  1946 *** ML ***
  1947 
  1948 * Support for Poly/ML 5.3.0, with improved reporting of compiler
  1949 errors and run-time exceptions, including detailed source positions.
  1950 
  1951 * Structure Name_Space (formerly NameSpace) now manages uniquely
  1952 identified entries, with some additional information such as source
  1953 position, logical grouping etc.
  1954 
  1955 * Theory and context data is now introduced by the simplified and
  1956 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
  1957 to be pure, but the old TheoryDataFun for mutable data (with explicit
  1958 copy operation) is still available for some time.
  1959 
  1960 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
  1961 provides a high-level programming interface to synchronized state
  1962 variables with atomic update.  This works via pure function
  1963 application within a critical section -- its runtime should be as
  1964 short as possible; beware of deadlocks if critical code is nested,
  1965 either directly or indirectly via other synchronized variables!
  1966 
  1967 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
  1968 wraps raw ML references, explicitly indicating their non-thread-safe
  1969 behaviour.  The Isar toplevel keeps this structure open, to
  1970 accommodate Proof General as well as quick and dirty interactive
  1971 experiments with references.
  1972 
  1973 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
  1974 parallel tactical reasoning.
  1975 
  1976 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
  1977 are similar to SUBPROOF, but are slightly more flexible: only the
  1978 specified parts of the subgoal are imported into the context, and the
  1979 body tactic may introduce new subgoals and schematic variables.
  1980 
  1981 * Old tactical METAHYPS, which does not observe the proof context, has
  1982 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
  1983 or Subgoal.FOCUS etc.
  1984 
  1985 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
  1986 functors have their own ML name space there is no point to mark them
  1987 separately.)  Minor INCOMPATIBILITY.
  1988 
  1989 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
  1990 
  1991 * Renamed several structures FooBar to Foo_Bar.  Occasional,
  1992 INCOMPATIBILITY.
  1993 
  1994 * Operations of structure Skip_Proof no longer require quick_and_dirty
  1995 mode, which avoids critical setmp.
  1996 
  1997 * Eliminated old Attrib.add_attributes, Method.add_methods and related
  1998 combinators for "args".  INCOMPATIBILITY, need to use simplified
  1999 Attrib/Method.setup introduced in Isabelle2009.
  2000 
  2001 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
  2002 back on global_simpset_of, global_claset_of, global_clasimpset_of as
  2003 last resort.  INCOMPATIBILITY.
  2004 
  2005 * Display.pretty_thm now requires a proper context (cf. former
  2006 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
  2007 or even Display.pretty_thm_without_context as last resort.
  2008 INCOMPATIBILITY.
  2009 
  2010 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
  2011 Syntax.pretty_typ/term directly, preferably with proper context
  2012 instead of global theory.
  2013 
  2014 
  2015 *** System ***
  2016 
  2017 * Further fine tuning of parallel proof checking, scales up to 8 cores
  2018 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
  2019 usedir option -q.
  2020 
  2021 * Support for additional "Isabelle components" via etc/components, see
  2022 also the system manual.
  2023 
  2024 * The isabelle makeall tool now operates on all components with
  2025 IsaMakefile, not just hardwired "logics".
  2026 
  2027 * Removed "compress" option from isabelle-process and isabelle usedir;
  2028 this is always enabled.
  2029 
  2030 * Discontinued support for Poly/ML 4.x versions.
  2031 
  2032 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
  2033 on a given logic image.  This requires the lighttpd webserver and is
  2034 currently supported on Linux only.
  2035 
  2036 
  2037 
  2038 New in Isabelle2009 (April 2009)
  2039 --------------------------------
  2040 
  2041 *** General ***
  2042 
  2043 * Simplified main Isabelle executables, with less surprises on
  2044 case-insensitive file-systems (such as Mac OS).
  2045 
  2046   - The main Isabelle tool wrapper is now called "isabelle" instead of
  2047     "isatool."
  2048 
  2049   - The former "isabelle" alias for "isabelle-process" has been
  2050     removed (should rarely occur to regular users).
  2051 
  2052   - The former "isabelle-interface" and its alias "Isabelle" have been
  2053     removed (interfaces are now regular Isabelle tools).
  2054 
  2055 Within scripts and make files, the Isabelle environment variables
  2056 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
  2057 respectively.  (The latter are still available as legacy feature.)
  2058 
  2059 The old isabelle-interface wrapper could react in confusing ways if
  2060 the interface was uninstalled or changed otherwise.  Individual
  2061 interface tool configuration is now more explicit, see also the
  2062 Isabelle system manual.  In particular, Proof General is now available
  2063 via "isabelle emacs".
  2064 
  2065 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
  2066 purge installed copies of Isabelle executables and re-run "isabelle
  2067 install -p ...", or use symlinks.
  2068 
  2069 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
  2070 old ~/isabelle, which was slightly non-standard and apt to cause
  2071 surprises on case-insensitive file-systems (such as Mac OS).
  2072 
  2073 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
  2074 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
  2075 care is required when using older releases of Isabelle.  Note that
  2076 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
  2077 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
  2078 
  2079 * Proofs of fully specified statements are run in parallel on
  2080 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
  2081 a regular 4-core machine, if the initial heap space is made reasonably
  2082 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
  2083 
  2084 * The main reference manuals ("isar-ref", "implementation", and
  2085 "system") have been updated and extended.  Formally checked references
  2086 as hyperlinks are now available uniformly.
  2087 
  2088 
  2089 *** Pure ***
  2090 
  2091 * Complete re-implementation of locales.  INCOMPATIBILITY in several
  2092 respects.  The most important changes are listed below.  See the
  2093 Tutorial on Locales ("locales" manual) for details.
  2094 
  2095 - In locale expressions, instantiation replaces renaming.  Parameters
  2096 must be declared in a for clause.  To aid compatibility with previous
  2097 parameter inheritance, in locale declarations, parameters that are not
  2098 'touched' (instantiation position "_" or omitted) are implicitly added
  2099 with their syntax at the beginning of the for clause.
  2100 
  2101 - Syntax from abbreviations and definitions in locales is available in
  2102 locale expressions and context elements.  The latter is particularly
  2103 useful in locale declarations.
  2104 
  2105 - More flexible mechanisms to qualify names generated by locale
  2106 expressions.  Qualifiers (prefixes) may be specified in locale
  2107 expressions, and can be marked as mandatory (syntax: "name!:") or
  2108 optional (syntax "name?:").  The default depends for plain "name:"
  2109 depends on the situation where a locale expression is used: in
  2110 commands 'locale' and 'sublocale' prefixes are optional, in
  2111 'interpretation' and 'interpret' prefixes are mandatory.  The old
  2112 implicit qualifiers derived from the parameter names of a locale are
  2113 no longer generated.
  2114 
  2115 - Command "sublocale l < e" replaces "interpretation l < e".  The
  2116 instantiation clause in "interpretation" and "interpret" (square
  2117 brackets) is no longer available.  Use locale expressions.
  2118 
  2119 - When converting proof scripts, mandatory qualifiers in
  2120 'interpretation' and 'interpret' should be retained by default, even
  2121 if this is an INCOMPATIBILITY compared to former behavior.  In the
  2122 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
  2123 in locale expressions range over a single locale instance only.
  2124 
  2125 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
  2126 In existing theorem specifications replace the includes element by the
  2127 respective context elements of the included locale, omitting those
  2128 that are already present in the theorem specification.  Multiple
  2129 assume elements of a locale should be replaced by a single one
  2130 involving the locale predicate.  In the proof body, declarations (most
  2131 notably theorems) may be regained by interpreting the respective
  2132 locales in the proof context as required (command "interpret").
  2133 
  2134 If using "includes" in replacement of a target solely because the
  2135 parameter types in the theorem are not as general as in the target,
  2136 consider declaring a new locale with additional type constraints on
  2137 the parameters (context element "constrains").
  2138 
  2139 - Discontinued "locale (open)".  INCOMPATIBILITY.
  2140 
  2141 - Locale interpretation commands no longer attempt to simplify goal.
  2142 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
  2143 methods intro_locales and unfold_locales to clarify.
  2144 
  2145 - Locale interpretation commands no longer accept interpretation
  2146 attributes.  INCOMPATIBILITY.
  2147 
  2148 * Class declaration: so-called "base sort" must not be given in import
  2149 list any longer, but is inferred from the specification.  Particularly
  2150 in HOL, write
  2151 
  2152     class foo = ...
  2153 
  2154 instead of
  2155 
  2156     class foo = type + ...
  2157 
  2158 * Class target: global versions of theorems stemming do not carry a
  2159 parameter prefix any longer.  INCOMPATIBILITY.
  2160 
  2161 * Class 'instance' command no longer accepts attached definitions.
  2162 INCOMPATIBILITY, use proper 'instantiation' target instead.
  2163 
  2164 * Recovered hiding of consts, which was accidentally broken in
  2165 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
  2166 makes c inaccessible; consider using ``hide (open) const c'' instead.
  2167 
  2168 * Slightly more coherent Pure syntax, with updated documentation in
  2169 isar-ref manual.  Removed locales meta_term_syntax and
  2170 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
  2171 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
  2172 directly in regular applications.
  2173 
  2174 * There is a new syntactic category "float_const" for signed decimal
  2175 fractions (e.g. 123.45 or -123.45).
  2176 
  2177 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
  2178 interface with 'setup' command instead.
  2179 
  2180 * Command 'local_setup' is similar to 'setup', but operates on a local
  2181 theory context.
  2182 
  2183 * The 'axiomatization' command now only works within a global theory
  2184 context.  INCOMPATIBILITY.
  2185 
  2186 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
  2187 hypotheses.  Sorts required in the course of reasoning need to be
  2188 covered by the constraints in the initial statement, completed by the
  2189 type instance information of the background theory.  Non-trivial sort
  2190 hypotheses, which rarely occur in practice, may be specified via
  2191 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
  2192 
  2193   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
  2194 
  2195 The result contains an implicit sort hypotheses as before --
  2196 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
  2197 normalization.
  2198 
  2199 * Generalized Isar history, with support for linear undo, direct state
  2200 addressing etc.
  2201 
  2202 * Changed defaults for unify configuration options:
  2203 
  2204   unify_trace_bound = 50 (formerly 25)
  2205   unify_search_bound = 60 (formerly 30)
  2206 
  2207 * Different bookkeeping for code equations (INCOMPATIBILITY):
  2208 
  2209   a) On theory merge, the last set of code equations for a particular
  2210      constant is taken (in accordance with the policy applied by other
  2211      parts of the code generator framework).
  2212 
  2213   b) Code equations stemming from explicit declarations (e.g. code
  2214      attribute) gain priority over default code equations stemming
  2215      from definition, primrec, fun etc.
  2216 
  2217 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
  2218 
  2219 * Unified theorem tables for both code generators.  Thus [code
  2220 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
  2221 
  2222 * Command 'find_consts' searches for constants based on type and name
  2223 patterns, e.g.
  2224 
  2225     find_consts "_ => bool"
  2226 
  2227 By default, matching is against subtypes, but it may be restricted to
  2228 the whole type.  Searching by name is possible.  Multiple queries are
  2229 conjunctive and queries may be negated by prefixing them with a
  2230 hyphen:
  2231 
  2232     find_consts strict: "_ => bool" name: "Int" -"int => int"
  2233 
  2234 * New 'find_theorems' criterion "solves" matches theorems that
  2235 directly solve the current goal (modulo higher-order unification).
  2236 
  2237 * Auto solve feature for main theorem statements: whenever a new goal
  2238 is stated, "find_theorems solves" is called; any theorems that could
  2239 solve the lemma directly are listed as part of the goal state.
  2240 Cf. associated options in Proof General Isabelle settings menu,
  2241 enabled by default, with reasonable timeout for pathological cases of
  2242 higher-order unification.
  2243 
  2244 
  2245 *** Document preparation ***
  2246 
  2247 * Antiquotation @{lemma} now imitates a regular terminal proof,
  2248 demanding keyword 'by' and supporting the full method expression
  2249 syntax just like the Isar command 'by'.
  2250 
  2251 
  2252 *** HOL ***
  2253 
  2254 * Integrated main parts of former image HOL-Complex with HOL.  Entry
  2255 points Main and Complex_Main remain as before.
  2256 
  2257 * Logic image HOL-Plain provides a minimal HOL with the most important
  2258 tools available (inductive, datatype, primrec, ...).  This facilitates
  2259 experimentation and tool development.  Note that user applications
  2260 (and library theories) should never refer to anything below theory
  2261 Main, as before.
  2262 
  2263 * Logic image HOL-Main stops at theory Main, and thus facilitates
  2264 experimentation due to shorter build times.
  2265 
  2266 * Logic image HOL-NSA contains theories of nonstandard analysis which
  2267 were previously part of former HOL-Complex.  Entry point Hyperreal
  2268 remains valid, but theories formerly using Complex_Main should now use
  2269 new entry point Hypercomplex.
  2270 
  2271 * Generic ATP manager for Sledgehammer, based on ML threads instead of
  2272 Posix processes.  Avoids potentially expensive forking of the ML
  2273 process.  New thread-based implementation also works on non-Unix
  2274 platforms (Cygwin).  Provers are no longer hardwired, but defined
  2275 within the theory via plain ML wrapper functions.  Basic Sledgehammer
  2276 commands are covered in the isar-ref manual.
  2277 
  2278 * Wrapper scripts for remote SystemOnTPTP service allows to use
  2279 sledgehammer without local ATP installation (Vampire etc.). Other
  2280 provers may be included via suitable ML wrappers, see also
  2281 src/HOL/ATP_Linkup.thy.
  2282 
  2283 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
  2284 menu.
  2285 
  2286 * The metis method no longer fails because the theorem is too trivial
  2287 (contains the empty clause).
  2288 
  2289 * The metis method now fails in the usual manner, rather than raising
  2290 an exception, if it determines that it cannot prove the theorem.
  2291 
  2292 * Method "coherent" implements a prover for coherent logic (see also
  2293 src/Tools/coherent.ML).
  2294 
  2295 * Constants "undefined" and "default" replace "arbitrary".  Usually
  2296 "undefined" is the right choice to replace "arbitrary", though
  2297 logically there is no difference.  INCOMPATIBILITY.
  2298 
  2299 * Command "value" now integrates different evaluation mechanisms.  The
  2300 result of the first successful evaluation mechanism is printed.  In
  2301 square brackets a particular named evaluation mechanisms may be
  2302 specified (currently, [SML], [code] or [nbe]).  See further
  2303 src/HOL/ex/Eval_Examples.thy.
  2304 
  2305 * Normalization by evaluation now allows non-leftlinear equations.
  2306 Declare with attribute [code nbe].
  2307 
  2308 * Methods "case_tac" and "induct_tac" now refer to the very same rules
  2309 as the structured Isar versions "cases" and "induct", cf. the
  2310 corresponding "cases" and "induct" attributes.  Mutual induction rules
  2311 are now presented as a list of individual projections
  2312 (e.g. foo_bar.inducts for types foo and bar); the old format with
  2313 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
  2314 rare situations a different rule is selected --- notably nested tuple
  2315 elimination instead of former prod.exhaust: use explicit (case_tac t
  2316 rule: prod.exhaust) here.
  2317 
  2318 * Attributes "cases", "induct", "coinduct" support "del" option.
  2319 
  2320 * Removed fact "case_split_thm", which duplicates "case_split".
  2321 
  2322 * The option datatype has been moved to a new theory Option.  Renamed
  2323 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
  2324 
  2325 * New predicate "strict_mono" classifies strict functions on partial
  2326 orders.  With strict functions on linear orders, reasoning about
  2327 (in)equalities is facilitated by theorems "strict_mono_eq",
  2328 "strict_mono_less_eq" and "strict_mono_less".
  2329 
  2330 * Some set operations are now proper qualified constants with
  2331 authentic syntax.  INCOMPATIBILITY:
  2332 
  2333     op Int ~>   Set.Int
  2334     op Un ~>    Set.Un
  2335     INTER ~>    Set.INTER
  2336     UNION ~>    Set.UNION
  2337     Inter ~>    Set.Inter
  2338     Union ~>    Set.Union
  2339     {} ~>       Set.empty
  2340     UNIV ~>     Set.UNIV
  2341 
  2342 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  2343 theory Set.
  2344 
  2345 * Auxiliary class "itself" has disappeared -- classes without any
  2346 parameter are treated as expected by the 'class' command.
  2347 
  2348 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  2349 
  2350 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  2351 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  2352 
  2353 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  2354 method "approximation".  It proves formulas on real values by using
  2355 interval arithmetic.  In the formulas are also the transcendental
  2356 functions sin, cos, tan, atan, ln, exp and the constant pi are
  2357 allowed. For examples see
  2358 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  2359 
  2360 * Theory "Reflection" now resides in HOL/Library.
  2361 
  2362 * Entry point to Word library now simply named "Word".
  2363 INCOMPATIBILITY.
  2364 
  2365 * Made source layout more coherent with logical distribution
  2366 structure:
  2367 
  2368     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  2369     src/HOL/Library/Code_Message.thy ~> src/HOL/
  2370     src/HOL/Library/GCD.thy ~> src/HOL/
  2371     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  2372     src/HOL/Library/Parity.thy ~> src/HOL/
  2373     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  2374     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  2375     src/HOL/Real/Lubs.thy ~> src/HOL/
  2376     src/HOL/Real/PReal.thy ~> src/HOL/
  2377     src/HOL/Real/Rational.thy ~> src/HOL/
  2378     src/HOL/Real/RComplete.thy ~> src/HOL/
  2379     src/HOL/Real/RealDef.thy ~> src/HOL/
  2380     src/HOL/Real/RealPow.thy ~> src/HOL/
  2381     src/HOL/Real/Real.thy ~> src/HOL/
  2382     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  2383     src/HOL/Complex/Complex.thy ~> src/HOL/
  2384     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  2385     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  2386     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  2387     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  2388     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  2389     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  2390     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  2391     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  2392     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  2393     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  2394     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  2395     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  2396     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  2397     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  2398     src/HOL/Real/Float ~> src/HOL/Library/
  2399     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  2400     src/HOL/Real/RealVector.thy ~> src/HOL/
  2401 
  2402     src/HOL/arith_data.ML ~> src/HOL/Tools
  2403     src/HOL/hologic.ML ~> src/HOL/Tools
  2404     src/HOL/simpdata.ML ~> src/HOL/Tools
  2405     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  2406     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  2407     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  2408     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  2409     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  2410     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  2411     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  2412 
  2413     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  2414     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  2415     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  2416     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  2417     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  2418     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  2419 
  2420 * If methods "eval" and "evaluation" encounter a structured proof
  2421 state with !!/==>, only the conclusion is evaluated to True (if
  2422 possible), avoiding strange error messages.
  2423 
  2424 * Method "sizechange" automates termination proofs using (a
  2425 modification of) the size-change principle.  Requires SAT solver.  See
  2426 src/HOL/ex/Termination.thy for examples.
  2427 
  2428 * Simplifier: simproc for let expressions now unfolds if bound
  2429 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  2430 
  2431 * Method "arith": Linear arithmetic now ignores all inequalities when
  2432 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  2433 
  2434 * New attribute "arith" for facts that should always be used
  2435 automatically by arithmetic. It is intended to be used locally in
  2436 proofs, e.g.
  2437 
  2438   assumes [arith]: "x > 0"
  2439 
  2440 Global usage is discouraged because of possible performance impact.
  2441 
  2442 * New classes "top" and "bot" with corresponding operations "top" and
  2443 "bot" in theory Orderings; instantiation of class "complete_lattice"
  2444 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  2445 
  2446 * Changed definition lemma "less_fun_def" in order to provide an
  2447 instance for preorders on functions; use lemma "less_le" instead.
  2448 INCOMPATIBILITY.
  2449 
  2450 * Theory Orderings: class "wellorder" moved here, with explicit
  2451 induction rule "less_induct" as assumption.  For instantiation of
  2452 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  2453 INCOMPATIBILITY.
  2454 
  2455 * Theory Orderings: added class "preorder" as superclass of "order".
  2456 INCOMPATIBILITY: Instantiation proofs for order, linorder
  2457 etc. slightly changed.  Some theorems named order_class.* now named
  2458 preorder_class.*.
  2459 
  2460 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  2461 "diag" to "Id_on".
  2462 
  2463 * Theory Finite_Set: added a new fold combinator of type
  2464 
  2465   ('a => 'b => 'b) => 'b => 'a set => 'b
  2466 
  2467 Occasionally this is more convenient than the old fold combinator
  2468 which is now defined in terms of the new one and renamed to
  2469 fold_image.
  2470 
  2471 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  2472 and "ring_simps" have been replaced by "algebra_simps" (which can be
  2473 extended with further lemmas!).  At the moment both still exist but
  2474 the former will disappear at some point.
  2475 
  2476 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  2477 class recpower.  Type-specific simp rules for various recpower types
  2478 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  2479 
  2480 rat_power_0    -> power_0
  2481 rat_power_Suc  -> power_Suc
  2482 realpow_0      -> power_0
  2483 realpow_Suc    -> power_Suc
  2484 complexpow_0   -> power_0
  2485 complexpow_Suc -> power_Suc
  2486 power_poly_0   -> power_0
  2487 power_poly_Suc -> power_Suc
  2488 
  2489 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  2490 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  2491 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  2492 of lemmas from Divides has been generalized from nat to class
  2493 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  2494 renames resulting from duplicate elimination:
  2495 
  2496     dvd_def_mod ~>          dvd_eq_mod_eq_0
  2497     zero_dvd_iff ~>         dvd_0_left_iff
  2498     dvd_0 ~>                dvd_0_right
  2499     DIVISION_BY_ZERO_DIV ~> div_by_0
  2500     DIVISION_BY_ZERO_MOD ~> mod_by_0
  2501     mult_div ~>             div_mult_self2_is_id
  2502     mult_mod ~>             mod_mult_self2_is_0
  2503 
  2504 * Theory IntDiv: removed many lemmas that are instances of class-based
  2505 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  2506 rename old lemmas as follows:
  2507 
  2508 dvd_diff               -> nat_dvd_diff
  2509 dvd_zminus_iff         -> dvd_minus_iff
  2510 mod_add1_eq            -> mod_add_eq
  2511 mod_mult1_eq           -> mod_mult_right_eq
  2512 mod_mult1_eq'          -> mod_mult_left_eq
  2513 mod_mult_distrib_mod   -> mod_mult_eq
  2514 nat_mod_add_left_eq    -> mod_add_left_eq
  2515 nat_mod_add_right_eq   -> mod_add_right_eq
  2516 nat_mod_div_trivial    -> mod_div_trivial
  2517 nat_mod_mod_trivial    -> mod_mod_trivial
  2518 zdiv_zadd_self1        -> div_add_self1
  2519 zdiv_zadd_self2        -> div_add_self2
  2520 zdiv_zmult_self1       -> div_mult_self2_is_id
  2521 zdiv_zmult_self2       -> div_mult_self1_is_id
  2522 zdvd_triv_left         -> dvd_triv_left
  2523 zdvd_triv_right        -> dvd_triv_right
  2524 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  2525 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  2526 zmod_zadd_left_eq      -> mod_add_left_eq
  2527 zmod_zadd_right_eq     -> mod_add_right_eq
  2528 zmod_zadd_self1        -> mod_add_self1
  2529 zmod_zadd_self2        -> mod_add_self2
  2530 zmod_zadd1_eq          -> mod_add_eq
  2531 zmod_zdiff1_eq         -> mod_diff_eq
  2532 zmod_zdvd_zmod         -> mod_mod_cancel
  2533 zmod_zmod_cancel       -> mod_mod_cancel
  2534 zmod_zmult_self1       -> mod_mult_self2_is_0
  2535 zmod_zmult_self2       -> mod_mult_self1_is_0
  2536 zmod_1                 -> mod_by_1
  2537 zdiv_1                 -> div_by_1
  2538 zdvd_abs1              -> abs_dvd_iff
  2539 zdvd_abs2              -> dvd_abs_iff
  2540 zdvd_refl              -> dvd_refl
  2541 zdvd_trans             -> dvd_trans
  2542 zdvd_zadd              -> dvd_add
  2543 zdvd_zdiff             -> dvd_diff
  2544 zdvd_zminus_iff        -> dvd_minus_iff
  2545 zdvd_zminus2_iff       -> minus_dvd_iff
  2546 zdvd_zmultD            -> dvd_mult_right
  2547 zdvd_zmultD2           -> dvd_mult_left
  2548 zdvd_zmult_mono        -> mult_dvd_mono
  2549 zdvd_0_right           -> dvd_0_right
  2550 zdvd_0_left            -> dvd_0_left_iff
  2551 zdvd_1_left            -> one_dvd
  2552 zminus_dvd_iff         -> minus_dvd_iff
  2553 
  2554 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  2555 
  2556 * The real numbers offer decimal input syntax: 12.34 is translated
  2557 into 1234/10^2. This translation is not reversed upon output.
  2558 
  2559 * Theory Library/Polynomial defines an abstract type 'a poly of
  2560 univariate polynomials with coefficients of type 'a.  In addition to
  2561 the standard ring operations, it also supports div and mod.  Code
  2562 generation is also supported, using list-style constructors.
  2563 
  2564 * Theory Library/Inner_Product defines a class of real_inner for real
  2565 inner product spaces, with an overloaded operation inner :: 'a => 'a
  2566 => real.  Class real_inner is a subclass of real_normed_vector from
  2567 theory RealVector.
  2568 
  2569 * Theory Library/Product_Vector provides instances for the product
  2570 type 'a * 'b of several classes from RealVector and Inner_Product.
  2571 Definitions of addition, subtraction, scalar multiplication, norms,
  2572 and inner products are included.
  2573 
  2574 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  2575 addition to the field operations, numerals and case syntax are also
  2576 supported.
  2577 
  2578 * Theory Library/Diagonalize provides constructive version of Cantor's
  2579 first diagonalization argument.
  2580 
  2581 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  2582 zlcm (for int); carried together from various gcd/lcm developements in
  2583 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  2584 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  2585 may recover tupled syntax as follows:
  2586 
  2587     hide (open) const gcd
  2588     abbreviation gcd where
  2589       "gcd == (%(a, b). GCD.gcd a b)"
  2590     notation (output)
  2591       GCD.gcd ("gcd '(_, _')")
  2592 
  2593 The same works for lcm, zgcd, zlcm.
  2594 
  2595 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  2596 instantiations for algebraic structures.  Removed some duplicate
  2597 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  2598 
  2599 * ML antiquotation @{code} takes a constant as argument and generates
  2600 corresponding code in background and inserts name of the corresponding
  2601 resulting ML value/function/datatype constructor binding in place.
  2602 All occurrences of @{code} with a single ML block are generated
  2603 simultaneously.  Provides a generic and safe interface for
  2604 instrumentalizing code generation.  See
  2605 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  2606 In future you ought to refrain from ad-hoc compiling generated SML
  2607 code on the ML toplevel.  Note that (for technical reasons) @{code}
  2608 cannot refer to constants for which user-defined serializations are
  2609 set.  Refer to the corresponding ML counterpart directly in that
  2610 cases.
  2611 
  2612 * Command 'rep_datatype': instead of theorem names the command now
  2613 takes a list of terms denoting the constructors of the type to be
  2614 represented as datatype.  The characteristic theorems have to be
  2615 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  2616 have disappeared in favour of existing ones:
  2617 
  2618     unit_induct                 ~> unit.induct
  2619     prod_induct                 ~> prod.induct
  2620     sum_induct                  ~> sum.induct
  2621     Suc_Suc_eq                  ~> nat.inject
  2622     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  2623 
  2624 
  2625 *** HOL-Algebra ***
  2626 
  2627 * New locales for orders and lattices where the equivalence relation
  2628 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  2629 locales use a record structure with field eq for the equivalence.
  2630 
  2631 * New theory of factorial domains.
  2632 
  2633 * Units_l_inv and Units_r_inv are now simp rules by default.
  2634 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  2635 and/or r_inv will now also require deletion of these lemmas.
  2636 
  2637 * Renamed the following theorems, INCOMPATIBILITY:
  2638 
  2639 UpperD ~> Upper_memD
  2640 LowerD ~> Lower_memD
  2641 least_carrier ~> least_closed
  2642 greatest_carrier ~> greatest_closed
  2643 greatest_Lower_above ~> greatest_Lower_below
  2644 one_zero ~> carrier_one_zero
  2645 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  2646 
  2647 
  2648 *** HOL-Nominal ***
  2649 
  2650 * Nominal datatypes can now contain type-variables.
  2651 
  2652 * Commands 'nominal_inductive' and 'equivariance' work with local
  2653 theory targets.
  2654 
  2655 * Nominal primrec can now works with local theory targets and its
  2656 specification syntax now conforms to the general format as seen in
  2657 'inductive' etc.
  2658 
  2659 * Method "perm_simp" honours the standard simplifier attributes
  2660 (no_asm), (no_asm_use) etc.
  2661 
  2662 * The new predicate #* is defined like freshness, except that on the
  2663 left hand side can be a set or list of atoms.
  2664 
  2665 * Experimental command 'nominal_inductive2' derives strong induction
  2666 principles for inductive definitions.  In contrast to
  2667 'nominal_inductive', which can only deal with a fixed number of
  2668 binders, it can deal with arbitrary expressions standing for sets of
  2669 atoms to be avoided.  The only inductive definition we have at the
  2670 moment that needs this generalisation is the typing rule for Lets in
  2671 the algorithm W:
  2672 
  2673  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  2674  -----------------------------------------------------------------
  2675          Gamma |- Let x be t1 in t2 : T2
  2676 
  2677 In this rule one wants to avoid all the binders that are introduced by
  2678 "close Gamma T1".  We are looking for other examples where this
  2679 feature might be useful.  Please let us know.
  2680 
  2681 
  2682 *** HOLCF ***
  2683 
  2684 * Reimplemented the simplification procedure for proving continuity
  2685 subgoals.  The new simproc is extensible; users can declare additional
  2686 continuity introduction rules with the attribute [cont2cont].
  2687 
  2688 * The continuity simproc now uses a different introduction rule for
  2689 solving continuity subgoals on terms with lambda abstractions.  In
  2690 some rare cases the new simproc may fail to solve subgoals that the
  2691 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  2692 Potential INCOMPATIBILITY.
  2693 
  2694 * Command 'fixrec': specification syntax now conforms to the general
  2695 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  2696 examples.  INCOMPATIBILITY.
  2697 
  2698 
  2699 *** ZF ***
  2700 
  2701 * Proof of Zorn's Lemma for partial orders.
  2702 
  2703 
  2704 *** ML ***
  2705 
  2706 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  2707 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  2708 depends on multithreading, so timouts will not work before Poly/ML
  2709 5.2.1!
  2710 
  2711 * High-level support for concurrent ML programming, see
  2712 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  2713 particularly convenient to organize independent functional
  2714 computations.  The concept of "synchronized variables" provides a
  2715 higher-order interface for components with shared state, avoiding the
  2716 delicate details of mutexes and condition variables.  (Requires
  2717 Poly/ML 5.2.1 or later.)
  2718 
  2719 * ML bindings produced via Isar commands are stored within the Isar
  2720 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  2721 become thread-safe and work with undo as expected (concerning
  2722 top-level bindings, not side-effects on global references).
  2723 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  2724 compiler at runtime; really global bindings need to be given outside a
  2725 theory.  (Requires Poly/ML 5.2 or later.)
  2726 
  2727 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  2728 context.  Top-level ML bindings are stored within the proof context in
  2729 a purely sequential fashion, disregarding the nested proof structure.
  2730 ML bindings introduced by 'ML_prf' are discarded at the end of the
  2731 proof.  (Requires Poly/ML 5.2 or later.)
  2732 
  2733 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  2734 and Method.setup, as well as Isar commands 'attribute_setup' and
  2735 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  2736 existing code accordingly, or use plain 'setup' together with old
  2737 Method.add_method.
  2738 
  2739 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  2740 to 'a -> thm, while results are always tagged with an authentic oracle
  2741 name.  The Isar command 'oracle' is now polymorphic, no argument type
  2742 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  2743 accordingly.  Note that extra performance may be gained by producing
  2744 the cterm carefully, avoiding slow Thm.cterm_of.
  2745 
  2746 * Simplified interface for defining document antiquotations via
  2747 ThyOutput.antiquotation, ThyOutput.output, and optionally
  2748 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  2749 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  2750 examples.
  2751 
  2752 * More systematic treatment of long names, abstract name bindings, and
  2753 name space operations.  Basic operations on qualified names have been
  2754 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  2755 Long_Name.append.  Old type bstring has been mostly replaced by
  2756 abstract type binding (see structure Binding), which supports precise
  2757 qualification by packages and local theory targets, as well as proper
  2758 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  2759 bstring values into Binding.name, or better pass through abstract
  2760 bindings everywhere.  See further src/Pure/General/long_name.ML,
  2761 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  2762 
  2763 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  2764 LocalTheory.note etc.) now refer to the *full* internal name, not the
  2765 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  2766 
  2767 * Disposed old type and term read functions (Sign.read_def_typ,
  2768 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  2769 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  2770 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  2771 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  2772 resort for legacy applications.
  2773 
  2774 * Disposed old declarations, tactics, tactic combinators that refer to
  2775 the simpset or claset of an implicit theory (such as Addsimps,
  2776 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  2777 embedded ML text, or local_simpset_of with a proper context passed as
  2778 explicit runtime argument.
  2779 
  2780 * Rules and tactics that read instantiations (read_instantiate,
  2781 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  2782 context, which is required for parsing and type-checking.  Moreover,
  2783 the variables are specified as plain indexnames, not string encodings
  2784 thereof.  INCOMPATIBILITY.
  2785 
  2786 * Generic Toplevel.add_hook interface allows to analyze the result of
  2787 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  2788 for theorem dependency output of transactions resulting in a new
  2789 theory state.
  2790 
  2791 * ML antiquotations: block-structured compilation context indicated by
  2792 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  2793 
  2794   @{binding name}                         - basic name binding
  2795   @{let ?pat = term}                      - term abbreviation (HO matching)
  2796   @{note name = fact}                     - fact abbreviation
  2797   @{thm fact}                             - singleton fact (with attributes)
  2798   @{thms fact}                            - general fact (with attributes)
  2799   @{lemma prop by method}                 - singleton goal
  2800   @{lemma prop by meth1 meth2}            - singleton goal
  2801   @{lemma prop1 ... propN by method}      - general goal
  2802   @{lemma prop1 ... propN by meth1 meth2} - general goal
  2803   @{lemma (open) ...}                     - open derivation
  2804 
  2805 
  2806 *** System ***
  2807 
  2808 * The Isabelle "emacs" tool provides a specific interface to invoke
  2809 Proof General / Emacs, with more explicit failure if that is not
  2810 installed (the old isabelle-interface script silently falls back on
  2811 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  2812 installation location of the Proof General distribution.
  2813 
  2814 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  2815 the Isabelle process into a JVM/Scala application.  See
  2816 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  2817 process wrapper has been discontinued.)
  2818 
  2819 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  2820 
  2821 * Various status messages (with exact source position information) are
  2822 emitted, if proper markup print mode is enabled.  This allows
  2823 user-interface components to provide detailed feedback on internal
  2824 prover operations.
  2825 
  2826 
  2827 
  2828 New in Isabelle2008 (June 2008)
  2829 -------------------------------
  2830 
  2831 *** General ***
  2832 
  2833 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  2834 and updated, with formally checked references as hyperlinks.
  2835 
  2836 * Theory loader: use_thy (and similar operations) no longer set the
  2837 implicit ML context, which was occasionally hard to predict and in
  2838 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  2839 provides a proper context already.
  2840 
  2841 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2842 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  2843 'use' within a theory file will do the job.
  2844 
  2845 * Name space merge now observes canonical order, i.e. the second space
  2846 is inserted into the first one, while existing entries in the first
  2847 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  2848 swap theory imports.
  2849 
  2850 * Syntax: symbol \<chi> is now considered a letter.  Potential
  2851 INCOMPATIBILITY in identifier syntax etc.
  2852 
  2853 * Outer syntax: string tokens no longer admit escaped white space,
  2854 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  2855 white space without escapes.
  2856 
  2857 * Outer syntax: string tokens may contain arbitrary character codes
  2858 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  2859 "foo_bar".
  2860 
  2861 
  2862 *** Pure ***
  2863 
  2864 * Context-dependent token translations.  Default setup reverts locally
  2865 fixed variables, and adds hilite markup for undeclared frees.
  2866 
  2867 * Unused theorems can be found using the new command 'unused_thms'.
  2868 There are three ways of invoking it:
  2869 
  2870 (1) unused_thms
  2871      Only finds unused theorems in the current theory.
  2872 
  2873 (2) unused_thms thy_1 ... thy_n -
  2874      Finds unused theorems in the current theory and all of its ancestors,
  2875      excluding the theories thy_1 ... thy_n and all of their ancestors.
  2876 
  2877 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  2878      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  2879      their ancestors, excluding the theories thy_1 ... thy_n and all of
  2880      their ancestors.
  2881 
  2882 In order to increase the readability of the list produced by
  2883 unused_thms, theorems that have been created by a particular instance
  2884 of a theory command such as 'inductive' or 'function' are considered
  2885 to belong to the same "group", meaning that if at least one theorem in
  2886 this group is used, the other theorems in the same group are no longer
  2887 reported as unused.  Moreover, if all theorems in the group are
  2888 unused, only one theorem in the group is displayed.
  2889 
  2890 Note that proof objects have to be switched on in order for
  2891 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  2892 usually the case when using Proof General with the default settings).
  2893 
  2894 * Authentic naming of facts disallows ad-hoc overwriting of previous
  2895 theorems within the same name space.  INCOMPATIBILITY, need to remove
  2896 duplicate fact bindings, or even accidental fact duplications.  Note
  2897 that tools may maintain dynamically scoped facts systematically, using
  2898 PureThy.add_thms_dynamic.
  2899 
  2900 * Command 'hide' now allows to hide from "fact" name space as well.
  2901 
  2902 * Eliminated destructive theorem database, simpset, claset, and
  2903 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  2904 update of theories within ML code.
  2905 
  2906 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  2907 INCOMPATIBILITY, object-logics depending on former Pure require
  2908 additional setup PureThy.old_appl_syntax_setup; object-logics
  2909 depending on former CPure need to refer to Pure.
  2910 
  2911 * Commands 'use' and 'ML' are now purely functional, operating on
  2912 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  2913 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  2914 INCOMPATIBILITY.
  2915 
  2916 * Command 'setup': discontinued implicit version with ML reference.
  2917 
  2918 * Instantiation target allows for simultaneous specification of class
  2919 instance operations together with an instantiation proof.
  2920 Type-checking phase allows to refer to class operations uniformly.
  2921 See src/HOL/Complex/Complex.thy for an Isar example and
  2922 src/HOL/Library/Eval.thy for an ML example.
  2923 
  2924 * Indexing of literal facts: be more serious about including only
  2925 facts from the visible specification/proof context, but not the
  2926 background context (locale etc.).  Affects `prop` notation and method
  2927 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  2928 situations.
  2929 
  2930 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  2931 "(open)" option, which used to expose internal bound variables to the
  2932 proof text.
  2933 
  2934 * Isar statements: removed obsolete case "rule_context".
  2935 INCOMPATIBILITY, better use explicit fixes/assumes.
  2936 
  2937 * Locale proofs: default proof step now includes 'unfold_locales';
  2938 hence 'proof' without argument may be used to unfold locale
  2939 predicates.
  2940 
  2941 
  2942 *** Document preparation ***
  2943 
  2944 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  2945 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  2946 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  2947 spot); renamed link color from "darkblue" to "linkcolor" (default
  2948 value unchanged, can be redefined via \definecolor); no longer sets
  2949 "a4paper" option (unnecessary or even intrusive).
  2950 
  2951 * Antiquotation @{lemma A method} proves proposition A by the given
  2952 method (either a method name or a method name plus (optional) method
  2953 arguments in parentheses) and prints A just like @{prop A}.
  2954 
  2955 
  2956 *** HOL ***
  2957 
  2958 * New primrec package.  Specification syntax conforms in style to
  2959 definition/function/....  No separate induction rule is provided.  The
  2960 "primrec" command distinguishes old-style and new-style specifications
  2961 by syntax.  The former primrec package is now named OldPrimrecPackage.
  2962 When adjusting theories, beware: constants stemming from new-style
  2963 primrec specifications have authentic syntax.
  2964 
  2965 * Metis prover is now an order of magnitude faster, and also works
  2966 with multithreading.
  2967 
  2968 * Metis: the maximum number of clauses that can be produced from a
  2969 theorem is now given by the attribute max_clauses.  Theorems that
  2970 exceed this number are ignored, with a warning printed.
  2971 
  2972 * Sledgehammer no longer produces structured proofs by default. To
  2973 enable, declare [[sledgehammer_full = true]].  Attributes
  2974 reconstruction_modulus, reconstruction_sorts renamed
  2975 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  2976 
  2977 * Method "induct_scheme" derives user-specified induction rules
  2978 from well-founded induction and completeness of patterns. This factors
  2979 out some operations that are done internally by the function package
  2980 and makes them available separately.  See
  2981 src/HOL/ex/Induction_Scheme.thy for examples.
  2982 
  2983 * More flexible generation of measure functions for termination
  2984 proofs: Measure functions can be declared by proving a rule of the
  2985 form "is_measure f" and giving it the [measure_function] attribute.
  2986 The "is_measure" predicate is logically meaningless (always true), and
  2987 just guides the heuristic.  To find suitable measure functions, the
  2988 termination prover sets up the goal "is_measure ?f" of the appropriate
  2989 type and generates all solutions by prolog-style backwards proof using
  2990 the declared rules.
  2991 
  2992 This setup also deals with rules like 
  2993 
  2994   "is_measure f ==> is_measure (list_size f)"
  2995 
  2996 which accommodates nested datatypes that recurse through lists.
  2997 Similar rules are predeclared for products and option types.
  2998 
  2999 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  3000 
  3001   INCOMPATIBILITIES:
  3002 
  3003   - Definitions of overloaded constants on sets have to be replaced by
  3004     definitions on => and bool.
  3005 
  3006   - Some definitions of overloaded operators on sets can now be proved
  3007     using the definitions of the operators on => and bool.  Therefore,
  3008     the following theorems have been renamed:
  3009 
  3010       subset_def   -> subset_eq
  3011       psubset_def  -> psubset_eq
  3012       set_diff_def -> set_diff_eq
  3013       Compl_def    -> Compl_eq
  3014       Sup_set_def  -> Sup_set_eq
  3015       Inf_set_def  -> Inf_set_eq
  3016       sup_set_def  -> sup_set_eq
  3017       inf_set_def  -> inf_set_eq
  3018 
  3019   - Due to the incompleteness of the HO unification algorithm, some
  3020     rules such as subst may require manual instantiation, if some of
  3021     the unknowns in the rule is a set.
  3022 
  3023   - Higher order unification and forward proofs:
  3024     The proof pattern
  3025 
  3026       have "P (S::'a set)" <...>
  3027       then have "EX S. P S" ..
  3028 
  3029     no longer works (due to the incompleteness of the HO unification
  3030     algorithm) and must be replaced by the pattern
  3031 
  3032       have "EX S. P S"
  3033       proof
  3034         show "P S" <...>
  3035       qed
  3036 
  3037   - Calculational reasoning with subst (or similar rules):
  3038     The proof pattern
  3039 
  3040       have "P (S::'a set)" <...>
  3041       also have "S = T" <...>
  3042       finally have "P T" .
  3043 
  3044     no longer works (for similar reasons as the previous example) and
  3045     must be replaced by something like
  3046 
  3047       have "P (S::'a set)" <...>
  3048       moreover have "S = T" <...>
  3049       ultimately have "P T" by simp
  3050 
  3051   - Tactics or packages written in ML code:
  3052     Code performing pattern matching on types via
  3053 
  3054       Type ("set", [T]) => ...
  3055 
  3056     must be rewritten. Moreover, functions like strip_type or
  3057     binder_types no longer return the right value when applied to a
  3058     type of the form
  3059 
  3060       T1 => ... => Tn => U => bool
  3061 
  3062     rather than
  3063 
  3064       T1 => ... => Tn => U set
  3065 
  3066 * Merged theories Wellfounded_Recursion, Accessible_Part and
  3067 Wellfounded_Relations to theory Wellfounded.
  3068 
  3069 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  3070 
  3071 * Class finite no longer treats UNIV as class parameter.  Use class
  3072 enum from theory Library/Enum instead to achieve a similar effect.
  3073 INCOMPATIBILITY.
  3074 
  3075 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  3076 and "Cons".  INCOMPATIBILITY.
  3077 
  3078 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  3079 Potential INCOMPATIBILITY.
  3080 
  3081 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  3082 injective_fst_snd removed, use split_eta and prod_eqI instead.
  3083 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  3084 
  3085 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  3086 the same name in theory Orderings:
  3087 
  3088   less_trans
  3089   less_linear
  3090   le_imp_less_or_eq
  3091   le_less_trans
  3092   less_le_trans
  3093   less_not_sym
  3094   less_asym
  3095 
  3096 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  3097 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  3098 and different variable names.
  3099 
  3100 * Library/Option_ord.thy: Canonical order on option type.
  3101 
  3102 * Library/RBT.thy: Red-black trees, an efficient implementation of
  3103 finite maps.
  3104 
  3105 * Library/Countable.thy: Type class for countable types.
  3106 
  3107 * Theory Int: The representation of numerals has changed.  The infix
  3108 operator BIT and the bit datatype with constructors B0 and B1 have
  3109 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  3110 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  3111 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  3112 accordingly.
  3113 
  3114 * Theory Nat: definition of <= and < on natural numbers no longer
  3115 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  3116 le_def and less_def have disappeared.  Consider lemmas not_less
  3117 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  3118 
  3119 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  3120 (whose purpose mainly is for various fold_set functionals) have been
  3121 abandoned in favor of the existing algebraic classes
  3122 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  3123 lower_semilattice (resp. upper_semilattice) and linorder.
  3124 INCOMPATIBILITY.
  3125 
  3126 * Theory Transitive_Closure: induct and cases rules now declare proper
  3127 case_names ("base" and "step").  INCOMPATIBILITY.
  3128 
  3129 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  3130 lattices.  The form set-specific version is available as
  3131 Inductive.lfp_ordinal_induct_set.
  3132 
  3133 * Renamed theorems "power.simps" to "power_int.simps".
  3134 INCOMPATIBILITY.
  3135 
  3136 * Class semiring_div provides basic abstract properties of semirings
  3137 with division and modulo operations.  Subsumes former class dvd_mod.
  3138 
  3139 * Merged theories IntDef, Numeral and IntArith into unified theory
  3140 Int.  INCOMPATIBILITY.
  3141 
  3142 * Theory Library/Code_Index: type "index" now represents natural
  3143 numbers rather than integers.  INCOMPATIBILITY.
  3144 
  3145 * New class "uminus" with operation "uminus" (split of from class
  3146 "minus" which now only has operation "minus", binary).
  3147 INCOMPATIBILITY.
  3148 
  3149 * Constants "card", "internal_split", "option_map" now with authentic
  3150 syntax.  INCOMPATIBILITY.
  3151 
  3152 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  3153 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  3154 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  3155 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  3156 Sup_set_def, le_def, less_def, option_map_def now with object
  3157 equality.  INCOMPATIBILITY.
  3158 
  3159 * Records. Removed K_record, and replaced it by pure lambda term
  3160 %x. c. The simplifier setup is now more robust against eta expansion.
  3161 INCOMPATIBILITY: in cases explicitly referring to K_record.
  3162 
  3163 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  3164 
  3165 * Library/ListVector: new theory of arithmetic vector operations.
  3166 
  3167 * Library/Order_Relation: new theory of various orderings as sets of
  3168 pairs.  Defines preorders, partial orders, linear orders and
  3169 well-orders on sets and on types.
  3170 
  3171 
  3172 *** ZF ***
  3173 
  3174 * Renamed some theories to allow to loading both ZF and HOL in the
  3175 same session:
  3176 
  3177   Datatype  -> Datatype_ZF
  3178   Inductive -> Inductive_ZF
  3179   Int       -> Int_ZF
  3180   IntDiv    -> IntDiv_ZF
  3181   Nat       -> Nat_ZF
  3182   List      -> List_ZF
  3183   Main      -> Main_ZF
  3184 
  3185 INCOMPATIBILITY: ZF theories that import individual theories below
  3186 Main might need to be adapted.  Regular theory Main is still
  3187 available, as trivial extension of Main_ZF.
  3188 
  3189 
  3190 *** ML ***
  3191 
  3192 * ML within Isar: antiquotation @{const name} or @{const
  3193 name(typargs)} produces statically-checked Const term.
  3194 
  3195 * Functor NamedThmsFun: data is available to the user as dynamic fact
  3196 (of the same name).  Removed obsolete print command.
  3197 
  3198 * Removed obsolete "use_legacy_bindings" function.
  3199 
  3200 * The ``print mode'' is now a thread-local value derived from a global
  3201 template (the former print_mode reference), thus access becomes
  3202 non-critical.  The global print_mode reference is for session
  3203 management only; user-code should use print_mode_value,
  3204 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  3205 
  3206 * Functions system/system_out provide a robust way to invoke external
  3207 shell commands, with propagation of interrupts (requires Poly/ML
  3208 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  3209 
  3210 
  3211 *** System ***
  3212 
  3213 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  3214 in accordance with Proof General 3.7, which prefers GNU emacs.
  3215 
  3216 * isatool tty runs Isabelle process with plain tty interaction;
  3217 optional line editor may be specified via ISABELLE_LINE_EDITOR
  3218 setting, the default settings attempt to locate "ledit" and "rlwrap".
  3219 
  3220 * isatool browser now works with Cygwin as well, using general
  3221 "javapath" function defined in Isabelle process environment.
  3222 
  3223 * YXML notation provides a simple and efficient alternative to
  3224 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  3225 isatool yxml as described in the Isabelle system manual.
  3226 
  3227 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  3228 provides general wrapper for managing an Isabelle process in a robust
  3229 fashion, with ``cooked'' output from stdin/stderr.
  3230 
  3231 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  3232 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  3233 
  3234 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  3235 way of changing the user's settings is via
  3236 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  3237 script.
  3238 
  3239 * Multithreading.max_threads := 0 refers to the number of actual CPU
  3240 cores of the underlying machine, which is a good starting point for
  3241 optimal performance tuning.  The corresponding usedir option -M allows
  3242 "max" as an alias for "0".  WARNING: does not work on certain versions
  3243 of Mac OS (with Poly/ML 5.1).
  3244 
  3245 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  3246 adverse effect of Isabelle flooding interactive front-ends (notably
  3247 ProofGeneral / XEmacs).
  3248 
  3249 
  3250 
  3251 New in Isabelle2007 (November 2007)
  3252 -----------------------------------
  3253 
  3254 *** General ***
  3255 
  3256 * More uniform information about legacy features, notably a
  3257 warning/error of "Legacy feature: ...", depending on the state of the
  3258 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  3259 legacy features will disappear eventually.
  3260 
  3261 * Theory syntax: the header format ``theory A = B + C:'' has been
  3262 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  3263 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  3264 
  3265 * Theory syntax: the old non-Isar theory file format has been
  3266 discontinued altogether.  Note that ML proof scripts may still be used
  3267 with Isar theories; migration is usually quite simple with the ML
  3268 function use_legacy_bindings.  INCOMPATIBILITY.
  3269 
  3270 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  3271 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  3272 quotes.
  3273 
  3274 * Theory loader: be more serious about observing the static theory
  3275 header specifications (including optional directories), but not the
  3276 accidental file locations of previously successful loads.  The strict
  3277 update policy of former update_thy is now already performed by
  3278 use_thy, so the former has been removed; use_thys updates several
  3279 theories simultaneously, just as 'imports' within a theory header
  3280 specification, but without merging the results.  Potential
  3281 INCOMPATIBILITY: may need to refine theory headers and commands
  3282 ROOT.ML which depend on load order.
  3283 
  3284 * Theory loader: optional support for content-based file
  3285 identification, instead of the traditional scheme of full physical
  3286 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  3287 (cf. the system manual).  The new scheme allows to work with
  3288 non-finished theories in persistent session images, such that source
  3289 files may be moved later on without requiring reloads.
  3290 
  3291 * Theory loader: old-style ML proof scripts being *attached* to a thy
  3292 file (with the same base name as the theory) are considered a legacy
  3293 feature, which will disappear eventually. Even now, the theory loader
  3294 no longer maintains dependencies on such files.
  3295 
  3296 * Syntax: the scope for resolving ambiguities via type-inference is
  3297 now limited to individual terms, instead of whole simultaneous
  3298 specifications as before. This greatly reduces the complexity of the
  3299 syntax module and improves flexibility by separating parsing and
  3300 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  3301 'fixes' etc.) are required in rare situations.
  3302 
  3303 * Syntax: constants introduced by new-style packages ('definition',
  3304 'abbreviation' etc.) are passed through the syntax module in
  3305 ``authentic mode''. This means that associated mixfix annotations
  3306 really stick to such constants, independently of potential name space
  3307 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  3308 trees are represented slightly differently, may need to adapt syntax
  3309 translations accordingly. Use CONST marker in 'translations' and
  3310 @{const_syntax} antiquotation in 'parse_translation' etc.
  3311 
  3312 * Legacy goal package: reduced interface to the bare minimum required
  3313 to keep existing proof scripts running.  Most other user-level
  3314 functions are now part of the OldGoals structure, which is *not* open
  3315 by default (consider isatool expandshort before open OldGoals).
  3316 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  3317 these tend to cause confusion about the actual goal (!) context being
  3318 used here, which is not necessarily the same as the_context().
  3319 
  3320 * Command 'find_theorems': supports "*" wild-card in "name:"
  3321 criterion; "with_dups" option.  Certain ProofGeneral versions might
  3322 support a specific search form (see ProofGeneral/CHANGES).
  3323 
  3324 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  3325 by default, which means that "prems" (and also "fixed variables") are
  3326 suppressed from proof state output.  Note that the ProofGeneral
  3327 settings mechanism allows to change and save options persistently, but
  3328 older versions of Isabelle will fail to start up if a negative prems
  3329 limit is imposed.
  3330 
  3331 * Local theory targets may be specified by non-nested blocks of
  3332 ``context/locale/class ... begin'' followed by ``end''.  The body may
  3333 contain definitions, theorems etc., including any derived mechanism
  3334 that has been implemented on top of these primitives.  This concept
  3335 generalizes the existing ``theorem (in ...)'' towards more versatility
  3336 and scalability.
  3337 
  3338 * Proof General interface: proper undo of final 'end' command;
  3339 discontinued Isabelle/classic mode (ML proof scripts).
  3340 
  3341 
  3342 *** Document preparation ***
  3343 
  3344 * Added antiquotation @{theory name} which prints the given name,
  3345 after checking that it refers to a valid ancestor theory in the
  3346 current context.
  3347 
  3348 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  3349 check the given source text as ML type/structure, printing verbatim.
  3350 
  3351 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  3352 "c args == rhs" given in the current context.  (Any number of
  3353 arguments may be given on the LHS.)
  3354 
  3355 
  3356 *** Pure ***
  3357 
  3358 * The 'class' package offers a combination of axclass and locale to
  3359 achieve Haskell-like type classes in Isabelle.  Definitions and
  3360 theorems within a class context produce both relative results (with
  3361 implicit parameters according to the locale context), and polymorphic
  3362 constants with qualified polymorphism (according to the class
  3363 context).  Within the body context of a 'class' target, a separate
  3364 syntax layer ("user space type system") takes care of converting
  3365 between global polymorphic consts and internal locale representation.
  3366 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  3367 "isatool doc classes" provides a tutorial.
  3368 
  3369 * Generic code generator framework allows to generate executable
  3370 code for ML and Haskell (including Isabelle classes).  A short usage
  3371 sketch:
  3372 
  3373     internal compilation:
  3374         export_code <list of constants (term syntax)> in SML
  3375     writing SML code to a file:
  3376         export_code <list of constants (term syntax)> in SML <filename>
  3377     writing OCaml code to a file:
  3378         export_code <list of constants (term syntax)> in OCaml <filename>
  3379     writing Haskell code to a bunch of files:
  3380         export_code <list of constants (term syntax)> in Haskell <filename>
  3381 
  3382     evaluating closed propositions to True/False using code generation:
  3383         method ``eval''
  3384 
  3385 Reasonable default setup of framework in HOL.
  3386 
  3387 Theorem attributs for selecting and transforming function equations theorems:
  3388 
  3389     [code fun]:        select a theorem as function equation for a specific constant
  3390     [code fun del]:    deselect a theorem as function equation for a specific constant
  3391     [code inline]:     select an equation theorem for unfolding (inlining) in place
  3392     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  3393 
  3394 User-defined serializations (target in {SML, OCaml, Haskell}):
  3395 
  3396     code_const <and-list of constants (term syntax)>
  3397       {(target) <and-list of const target syntax>}+
  3398 
  3399     code_type <and-list of type constructors>
  3400       {(target) <and-list of type target syntax>}+
  3401 
  3402     code_instance <and-list of instances>
  3403       {(target)}+
  3404         where instance ::= <type constructor> :: <class>
  3405 
  3406     code_class <and_list of classes>
  3407       {(target) <and-list of class target syntax>}+
  3408         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  3409 
  3410 code_instance and code_class only are effective to target Haskell.
  3411 
  3412 For example usage see src/HOL/ex/Codegenerator.thy and
  3413 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  3414 generation from Isabelle/HOL theories is available via "isatool doc
  3415 codegen".
  3416 
  3417 * Code generator: consts in 'consts_code' Isar commands are now
  3418 referred to by usual term syntax (including optional type
  3419 annotations).
  3420 
  3421 * Command 'no_translations' removes translation rules from theory
  3422 syntax.
  3423 
  3424 * Overloaded definitions are now actually checked for acyclic
  3425 dependencies.  The overloading scheme is slightly more general than
  3426 that of Haskell98, although Isabelle does not demand an exact
  3427 correspondence to type class and instance declarations.
  3428 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  3429 exotic versions of overloading -- at the discretion of the user!
  3430 
  3431 Polymorphic constants are represented via type arguments, i.e. the
  3432 instantiation that matches an instance against the most general
  3433 declaration given in the signature.  For example, with the declaration
  3434 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  3435 as c(nat).  Overloading is essentially simultaneous structural
  3436 recursion over such type arguments.  Incomplete specification patterns
  3437 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  3438 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  3439 Command 'print_theory' outputs the normalized system of recursive
  3440 equations, see section "definitions".
  3441 
  3442 * Configuration options are maintained within the theory or proof
  3443 context (with name and type bool/int/string), providing a very simple
  3444 interface to a poor-man's version of general context data.  Tools may
  3445 declare options in ML (e.g. using Attrib.config_int) and then refer to
  3446 these values using Config.get etc.  Users may change options via an
  3447 associated attribute of the same name.  This form of context
  3448 declaration works particularly well with commands 'declare' or
  3449 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  3450 very easy to avoid global references, which would not observe Isar
  3451 toplevel undo/redo and fail to work with multithreading.
  3452 
  3453 Various global ML references of Pure and HOL have been turned into
  3454 configuration options:
  3455 
  3456   Unify.search_bound		unify_search_bound
  3457   Unify.trace_bound		unify_trace_bound
  3458   Unify.trace_simp		unify_trace_simp
  3459   Unify.trace_types		unify_trace_types
  3460   Simplifier.simp_depth_limit	simp_depth_limit
  3461   Blast.depth_limit		blast_depth_limit
  3462   DatatypeProp.dtK		datatype_distinctness_limit
  3463   fast_arith_neq_limit  	fast_arith_neq_limit
  3464   fast_arith_split_limit	fast_arith_split_limit
  3465 
  3466 * Named collections of theorems may be easily installed as context
  3467 data using the functor NamedThmsFun (see also
  3468 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  3469 attributes; there is also a toplevel print command.  This facility is
  3470 just a common case of general context data, which is the preferred way
  3471 for anything more complex than just a list of facts in canonical
  3472 order.
  3473 
  3474 * Isar: command 'declaration' augments a local theory by generic
  3475 declaration functions written in ML.  This enables arbitrary content
  3476 being added to the context, depending on a morphism that tells the
  3477 difference of the original declaration context wrt. the application
  3478 context encountered later on.
  3479 
  3480 * Isar: proper interfaces for simplification procedures.  Command
  3481 'simproc_setup' declares named simprocs (with match patterns, and body
  3482 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  3483 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  3484 
  3485 * Isar: an extra pair of brackets around attribute declarations
  3486 abbreviates a theorem reference involving an internal dummy fact,
  3487 which will be ignored later --- only the effect of the attribute on
  3488 the background context will persist.  This form of in-place
  3489 declarations is particularly useful with commands like 'declare' and
  3490 'using', for example ``have A using [[simproc a]] by simp''.
  3491 
  3492 * Isar: method "assumption" (and implicit closing of subproofs) now
  3493 takes simple non-atomic goal assumptions into account: after applying
  3494 an assumption as a rule the resulting subgoals are solved by atomic
  3495 assumption steps.  This is particularly useful to finish 'obtain'
  3496 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  3497 without referring to the original premise "!!x. P x ==> thesis" in the
  3498 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  3499 more permissive.
  3500 
  3501 * Isar: implicit use of prems from the Isar proof context is
  3502 considered a legacy feature.  Common applications like ``have A .''
  3503 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  3504 referencing facts explicitly here improves readability and
  3505 maintainability of proof texts.
  3506 
  3507 * Isar: improper proof element 'guess' is like 'obtain', but derives
  3508 the obtained context from the course of reasoning!  For example:
  3509 
  3510   assume "EX x y. A x & B y"   -- "any previous fact"
  3511   then guess x and y by clarify
  3512 
  3513 This technique is potentially adventurous, depending on the facts and
  3514 proof tools being involved here.
  3515 
  3516 * Isar: known facts from the proof context may be specified as literal
  3517 propositions, using ASCII back-quote syntax.  This works wherever
  3518 named facts used to be allowed so far, in proof commands, proof
  3519 methods, attributes etc.  Literal facts are retrieved from the context
  3520 according to unification of type and term parameters.  For example,
  3521 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  3522 theorems in the current context, then these are valid literal facts:
  3523 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  3524 
  3525 There is also a proof method "fact" which does the same composition
  3526 for explicit goal states, e.g. the following proof texts coincide with
  3527 certain special cases of literal facts:
  3528 
  3529   have "A" by fact                 ==  note `A`
  3530   have "A ==> B" by fact           ==  note `A ==> B`
  3531   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  3532   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  3533 
  3534 * Isar: ":" (colon) is no longer a symbolic identifier character in
  3535 outer syntax.  Thus symbolic identifiers may be used without
  3536 additional white space in declarations like this: ``assume *: A''.
  3537 
  3538 * Isar: 'print_facts' prints all local facts of the current context,
  3539 both named and unnamed ones.
  3540 
  3541 * Isar: 'def' now admits simultaneous definitions, e.g.:
  3542 
  3543   def x == "t" and y == "u"
  3544 
  3545 * Isar: added command 'unfolding', which is structurally similar to
  3546 'using', but affects both the goal state and facts by unfolding given
  3547 rewrite rules.  Thus many occurrences of the 'unfold' method or
  3548 'unfolded' attribute may be replaced by first-class proof text.
  3549 
  3550 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  3551 and command 'unfolding' now all support object-level equalities
  3552 (potentially conditional).  The underlying notion of rewrite rule is
  3553 analogous to the 'rule_format' attribute, but *not* that of the
  3554 Simplifier (which is usually more generous).
  3555 
  3556 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  3557 premises of a theorem by n. Useful in conjunction with drule.
  3558 
  3559 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  3560 method expression within a sandbox consisting of the first N
  3561 sub-goals, which need to exist.  For example, ``simp_all [3]''
  3562 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  3563 simplifies all new goals that emerge from applying rule foo to the
  3564 originally first one.
  3565 
  3566 * Isar: schematic goals are no longer restricted to higher-order
  3567 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  3568 expected.
  3569 
  3570 * Isar: the conclusion of a long theorem statement is now either
  3571 'shows' (a simultaneous conjunction, as before), or 'obtains'
  3572 (essentially a disjunction of cases with local parameters and
  3573 assumptions).  The latter allows to express general elimination rules
  3574 adequately; in this notation common elimination rules look like this:
  3575 
  3576   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  3577     assumes "EX x. P x"
  3578     obtains x where "P x"
  3579 
  3580   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  3581     assumes "A & B"
  3582     obtains A and B
  3583 
  3584   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  3585     assumes "A | B"
  3586     obtains
  3587       A
  3588     | B
  3589 
  3590 The subsequent classical rules even refer to the formal "thesis"
  3591 explicitly:
  3592 
  3593   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  3594     obtains "~ thesis"
  3595 
  3596   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  3597     obtains "thesis ==> something"
  3598 
  3599 The actual proof of an 'obtains' statement is analogous to that of the
  3600 Isar proof element 'obtain', only that there may be several cases.
  3601 Optional case names may be specified in parentheses; these will be
  3602 available both in the present proof and as annotations in the
  3603 resulting rule, for later use with the 'cases' method (cf. attribute
  3604 case_names).
  3605 
  3606 * Isar: the assumptions of a long theorem statement are available as
  3607 "assms" fact in the proof context.  This is more appropriate than the
  3608 (historical) "prems", which refers to all assumptions of the current
  3609 context, including those from the target locale, proof body etc.
  3610 
  3611 * Isar: 'print_statement' prints theorems from the current theory or
  3612 proof context in long statement form, according to the syntax of a
  3613 top-level lemma.
  3614 
  3615 * Isar: 'obtain' takes an optional case name for the local context
  3616 introduction rule (default "that").
  3617 
  3618 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  3619 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  3620 to occur.
  3621 
  3622 * Pure: syntax "CONST name" produces a fully internalized constant
  3623 according to the current context.  This is particularly useful for
  3624 syntax translations that should refer to internal constant
  3625 representations independently of name spaces.
  3626 
  3627 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  3628 instead of "FOO ". This allows multiple binder declarations to coexist
  3629 in the same context.  INCOMPATIBILITY.
  3630 
  3631 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  3632 primitive that also works in a locale context (both for constants and
  3633 fixed variables). Type declaration and internal syntactic representation
  3634 of given constants retrieved from the context. Likewise, the
  3635 'no_notation' command allows to remove given syntax annotations from the
  3636 current context.
  3637 
  3638 * Isar/locales: new derived specification elements 'axiomatization',
  3639 'definition', 'abbreviation', which support type-inference, admit
  3640 object-level specifications (equality, equivalence).  See also the
  3641 isar-ref manual.  Examples:
  3642 
  3643   axiomatization
  3644     eq  (infix "===" 50) where
  3645     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  3646 
  3647   definition "f x y = x + y + 1"
  3648   definition g where "g x = f x x"
  3649 
  3650   abbreviation
  3651     neq  (infix "=!=" 50) where
  3652     "x =!= y == ~ (x === y)"
  3653 
  3654 These specifications may be also used in a locale context.  Then the
  3655 constants being introduced depend on certain fixed parameters, and the
  3656 constant name is qualified by the locale base name.  An internal
  3657 abbreviation takes care for convenient input and output, making the
  3658 parameters implicit and using the original short name.  See also
  3659 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  3660 entities from a monomorphic theory.
  3661 
  3662 Presently, abbreviations are only available 'in' a target locale, but
  3663 not inherited by general import expressions.  Also note that
  3664 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  3665 'translations' in common applications.  The "no_abbrevs" print mode
  3666 prevents folding of abbreviations in term output.
  3667 
  3668 Concrete syntax is attached to specified constants in internal form,
  3669 independently of name spaces.  The parse tree representation is
  3670 slightly different -- use 'notation' instead of raw 'syntax', and
  3671 'translations' with explicit "CONST" markup to accommodate this.
  3672 
  3673 * Pure/Isar: unified syntax for new-style specification mechanisms
  3674 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  3675 full type inference and dummy patterns ("_").  For example:
  3676 
  3677   definition "K x _ = x"
  3678 
  3679   inductive conj for A B
  3680   where "A ==> B ==> conj A B"
  3681 
  3682 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  3683 the current context.  Print mode "no_abbrevs" prevents inversion of
  3684 abbreviations on output.
  3685 
  3686 * Isar/locales: improved parameter handling: use of locales "var" and
  3687 "struct" no longer necessary; - parameter renamings are no longer
  3688 required to be injective.  For example, this allows to define
  3689 endomorphisms as locale endom = homom mult mult h.
  3690 
  3691 * Isar/locales: changed the way locales with predicates are defined.
  3692 Instead of accumulating the specification, the imported expression is
  3693 now an interpretation.  INCOMPATIBILITY: different normal form of
  3694 locale expressions.  In particular, in interpretations of locales with
  3695 predicates, goals repesenting already interpreted fragments are not
  3696 removed automatically.  Use methods `intro_locales' and
  3697 `unfold_locales'; see below.
  3698 
  3699 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  3700 provide backward reasoning on locales predicates.  The methods are
  3701 aware of interpretations and discharge corresponding goals.
  3702 `intro_locales' is less aggressive then `unfold_locales' and does not
  3703 unfold predicates to assumptions.
  3704 
  3705 * Isar/locales: the order in which locale fragments are accumulated
  3706 has changed.  This enables to override declarations from fragments due
  3707 to interpretations -- for example, unwanted simp rules.
  3708 
  3709 * Isar/locales: interpretation in theories and proof contexts has been
  3710 extended.  One may now specify (and prove) equations, which are
  3711 unfolded in interpreted theorems.  This is useful for replacing
  3712 defined concepts (constants depending on locale parameters) by
  3713 concepts already existing in the target context.  Example:
  3714 
  3715   interpretation partial_order ["op <= :: [int, int] => bool"]
  3716     where "partial_order.less (op <=) (x::int) y = (x < y)"
  3717 
  3718 Typically, the constant `partial_order.less' is created by a
  3719 definition specification element in the context of locale
  3720 partial_order.
  3721 
  3722 * Method "induct": improved internal context management to support
  3723 local fixes and defines on-the-fly. Thus explicit meta-level
  3724 connectives !!  and ==> are rarely required anymore in inductive goals
  3725 (using object-logic connectives for this purpose has been long
  3726 obsolete anyway). Common proof patterns are explained in
  3727 src/HOL/Induct/Common_Patterns.thy, see also
  3728 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  3729 examples.
  3730 
  3731 * Method "induct": improved handling of simultaneous goals. Instead of
  3732 introducing object-level conjunction, the statement is now split into
  3733 several conclusions, while the corresponding symbolic cases are nested
  3734 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  3735 see src/HOL/Induct/Common_Patterns.thy, for example.
  3736 
  3737 * Method "induct": mutual induction rules are now specified as a list
  3738 of rule sharing the same induction cases. HOL packages usually provide
  3739 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  3740 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  3741 mutual induction rules differently, i.e. like this:
  3742 
  3743   (induct rule: foo_bar.inducts)
  3744   (induct set: foo bar)
  3745   (induct pred: foo bar)
  3746   (induct type: foo bar)
  3747 
  3748 The ML function ProjectRule.projections turns old-style rules into the
  3749 new format.
  3750 
  3751 * Method "coinduct": dual of induction, see
  3752 src/HOL/Library/Coinductive_List.thy for various examples.
  3753 
  3754 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  3755 considered a legacy feature.
  3756 
  3757 * Attribute "symmetric" produces result with standardized schematic
  3758 variables (index 0).  Potential INCOMPATIBILITY.
  3759 
  3760 * Simplifier: by default the simplifier trace only shows top level
  3761 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  3762 default. Thus there is less danger of being flooded by the trace. The
  3763 trace indicates where parts have been suppressed.
  3764   
  3765 * Provers/classical: removed obsolete classical version of elim_format
  3766 attribute; classical elim/dest rules are now treated uniformly when
  3767 manipulating the claset.
  3768 
  3769 * Provers/classical: stricter checks to ensure that supplied intro,
  3770 dest and elim rules are well-formed; dest and elim rules must have at
  3771 least one premise.
  3772 
  3773 * Provers/classical: attributes dest/elim/intro take an optional
  3774 weight argument for the rule (just as the Pure versions).  Weights are
  3775 ignored by automated tools, but determine the search order of single
  3776 rule steps.
  3777 
  3778 * Syntax: input syntax now supports dummy variable binding "%_. b",
  3779 where the body does not mention the bound variable.  Note that dummy
  3780 patterns implicitly depend on their context of bounds, which makes
  3781 "{_. _}" match any set comprehension as expected.  Potential
  3782 INCOMPATIBILITY -- parse translations need to cope with syntactic
  3783 constant "_idtdummy" in the binding position.
  3784 
  3785 * Syntax: removed obsolete syntactic constant "_K" and its associated
  3786 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  3787 for example "A -> B" => "Pi A (%_. B)".
  3788 
  3789 * Pure: 'class_deps' command visualizes the subclass relation, using
  3790 the graph browser tool.
  3791 
  3792 * Pure: 'print_theory' now suppresses certain internal declarations by
  3793 default; use '!' option for full details.
  3794 
  3795 
  3796 *** HOL ***
  3797 
  3798 * Method "metis" proves goals by applying the Metis general-purpose
  3799 resolution prover (see also http://gilith.com/software/metis/).
  3800 Examples are in the directory MetisExamples.  WARNING: the
  3801 Isabelle/HOL-Metis integration does not yet work properly with
  3802 multi-threading.
  3803   
  3804 * Command 'sledgehammer' invokes external automatic theorem provers as
  3805 background processes.  It generates calls to the "metis" method if
  3806 successful. These can be pasted into the proof.  Users do not have to
  3807 wait for the automatic provers to return.  WARNING: does not really
  3808 work with multi-threading.
  3809 
  3810 * New "auto_quickcheck" feature tests outermost goal statements for
  3811 potential counter-examples.  Controlled by ML references
  3812 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  3813 5000 milliseconds).  Fails silently if statements is outside of
  3814 executable fragment, or any other codgenerator problem occurs.
  3815 
  3816 * New constant "undefined" with axiom "undefined x = undefined".
  3817 
  3818 * Added class "HOL.eq", allowing for code generation with polymorphic
  3819 equality.
  3820 
  3821 * Some renaming of class constants due to canonical name prefixing in
  3822 the new 'class' package:
  3823 
  3824     HOL.abs ~> HOL.abs_class.abs
  3825     HOL.divide ~> HOL.divide_class.divide
  3826     0 ~> HOL.zero_class.zero
  3827     1 ~> HOL.one_class.one
  3828     op + ~> HOL.plus_class.plus
  3829     op - ~> HOL.minus_class.minus
  3830     uminus ~> HOL.minus_class.uminus
  3831     op * ~> HOL.times_class.times
  3832     op < ~> HOL.ord_class.less
  3833     op <= > HOL.ord_class.less_eq
  3834     Nat.power ~> Power.power_class.power
  3835     Nat.size ~> Nat.size_class.size
  3836     Numeral.number_of ~> Numeral.number_class.number_of
  3837     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  3838     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  3839     Orderings.min ~> Orderings.ord_class.min
  3840     Orderings.max ~> Orderings.ord_class.max
  3841     Divides.op div ~> Divides.div_class.div
  3842     Divides.op mod ~> Divides.div_class.mod
  3843     Divides.op dvd ~> Divides.div_class.dvd
  3844 
  3845 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  3846 
  3847 a) User-defined constants using any of the names "plus", "minus",
  3848 "times", "less" or "less_eq". The standard syntax translations for
  3849 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  3850 names.
  3851 
  3852 b) Variables named "plus", "minus", "times", "less", "less_eq"
  3853 INCOMPATIBILITY: use more specific names.
  3854 
  3855 c) Permutative equations (e.g. "a + b = b + a")
  3856 Since the change of names also changes the order of terms, permutative
  3857 rewrite rules may get applied in a different order. Experience shows
  3858 that this is rarely the case (only two adaptions in the whole Isabelle
  3859 distribution).  INCOMPATIBILITY: rewrite proofs
  3860 
  3861 d) ML code directly refering to constant names
  3862 This in general only affects hand-written proof tactics, simprocs and
  3863 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  3864 Consider using @{const_name} antiquotation.
  3865 
  3866 * New class "default" with associated constant "default".
  3867 
  3868 * Function "sgn" is now overloaded and available on int, real, complex
  3869 (and other numeric types), using class "sgn".  Two possible defs of
  3870 sgn are given as equational assumptions in the classes sgn_if and
  3871 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  3872 INCOMPATIBILITY.
  3873 
  3874 * Locale "partial_order" now unified with class "order" (cf. theory
  3875 Orderings), added parameter "less".  INCOMPATIBILITY.
  3876 
  3877 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  3878 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  3879 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  3880 
  3881 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  3882 changed order of proof goals in instance proofs.
  3883 
  3884 * The transitivity reasoner for partial and linear orders is set up
  3885 for classes "order" and "linorder".  Instances of the reasoner are available
  3886 in all contexts importing or interpreting the corresponding locales.
  3887 Method "order" invokes the reasoner separately; the reasoner
  3888 is also integrated with the Simplifier as a solver.  Diagnostic
  3889 command 'print_orders' shows the available instances of the reasoner
  3890 in the current context.
  3891 
  3892 * Localized monotonicity predicate in theory "Orderings"; integrated
  3893 lemmas max_of_mono and min_of_mono with this predicate.
  3894 INCOMPATIBILITY.
  3895 
  3896 * Formulation of theorem "dense" changed slightly due to integration
  3897 with new class dense_linear_order.
  3898 
  3899 * Uniform lattice theory development in HOL.
  3900 
  3901     constants "meet" and "join" now named "inf" and "sup"
  3902     constant "Meet" now named "Inf"
  3903 
  3904     classes "meet_semilorder" and "join_semilorder" now named
  3905       "lower_semilattice" and "upper_semilattice"
  3906     class "lorder" now named "lattice"
  3907     class "comp_lat" now named "complete_lattice"
  3908 
  3909     Instantiation of lattice classes allows explicit definitions
  3910     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  3911 
  3912   INCOMPATIBILITY.  Theorem renames:
  3913 
  3914     meet_left_le            ~> inf_le1
  3915     meet_right_le           ~> inf_le2
  3916     join_left_le            ~> sup_ge1
  3917     join_right_le           ~> sup_ge2
  3918     meet_join_le            ~> inf_sup_ord
  3919     le_meetI                ~> le_infI
  3920     join_leI                ~> le_supI
  3921     le_meet                 ~> le_inf_iff
  3922     le_join                 ~> ge_sup_conv
  3923     meet_idempotent         ~> inf_idem
  3924     join_idempotent         ~> sup_idem
  3925     meet_comm               ~> inf_commute
  3926     join_comm               ~> sup_commute
  3927     meet_leI1               ~> le_infI1
  3928     meet_leI2               ~> le_infI2
  3929     le_joinI1               ~> le_supI1
  3930     le_joinI2               ~> le_supI2
  3931     meet_assoc              ~> inf_assoc
  3932     join_assoc              ~> sup_assoc
  3933     meet_left_comm          ~> inf_left_commute
  3934     meet_left_idempotent    ~> inf_left_idem
  3935     join_left_comm          ~> sup_left_commute
  3936     join_left_idempotent    ~> sup_left_idem
  3937     meet_aci                ~> inf_aci
  3938     join_aci                ~> sup_aci
  3939     le_def_meet             ~> le_iff_inf
  3940     le_def_join             ~> le_iff_sup
  3941     join_absorp2            ~> sup_absorb2
  3942     join_absorp1            ~> sup_absorb1
  3943     meet_absorp1            ~> inf_absorb1
  3944     meet_absorp2            ~> inf_absorb2
  3945     meet_join_absorp        ~> inf_sup_absorb
  3946     join_meet_absorp        ~> sup_inf_absorb
  3947     distrib_join_le         ~> distrib_sup_le
  3948     distrib_meet_le         ~> distrib_inf_le
  3949 
  3950     add_meet_distrib_left   ~> add_inf_distrib_left
  3951     add_join_distrib_left   ~> add_sup_distrib_left
  3952     is_join_neg_meet        ~> is_join_neg_inf
  3953     is_meet_neg_join        ~> is_meet_neg_sup
  3954     add_meet_distrib_right  ~> add_inf_distrib_right
  3955     add_join_distrib_right  ~> add_sup_distrib_right
  3956     add_meet_join_distribs  ~> add_sup_inf_distribs
  3957     join_eq_neg_meet        ~> sup_eq_neg_inf
  3958     meet_eq_neg_join        ~> inf_eq_neg_sup
  3959     add_eq_meet_join        ~> add_eq_inf_sup
  3960     meet_0_imp_0            ~> inf_0_imp_0
  3961     join_0_imp_0            ~> sup_0_imp_0
  3962     meet_0_eq_0             ~> inf_0_eq_0
  3963     join_0_eq_0             ~> sup_0_eq_0
  3964     neg_meet_eq_join        ~> neg_inf_eq_sup
  3965     neg_join_eq_meet        ~> neg_sup_eq_inf
  3966     join_eq_if              ~> sup_eq_if
  3967 
  3968     mono_meet               ~> mono_inf
  3969     mono_join               ~> mono_sup
  3970     meet_bool_eq            ~> inf_bool_eq
  3971     join_bool_eq            ~> sup_bool_eq
  3972     meet_fun_eq             ~> inf_fun_eq
  3973     join_fun_eq             ~> sup_fun_eq
  3974     meet_set_eq             ~> inf_set_eq
  3975     join_set_eq             ~> sup_set_eq
  3976     meet1_iff               ~> inf1_iff
  3977     meet2_iff               ~> inf2_iff
  3978     meet1I                  ~> inf1I
  3979     meet2I                  ~> inf2I
  3980     meet1D1                 ~> inf1D1
  3981     meet2D1                 ~> inf2D1
  3982     meet1D2                 ~> inf1D2
  3983     meet2D2                 ~> inf2D2
  3984     meet1E                  ~> inf1E
  3985     meet2E                  ~> inf2E
  3986     join1_iff               ~> sup1_iff
  3987     join2_iff               ~> sup2_iff
  3988     join1I1                 ~> sup1I1
  3989     join2I1                 ~> sup2I1
  3990     join1I1                 ~> sup1I1
  3991     join2I2                 ~> sup1I2
  3992     join1CI                 ~> sup1CI
  3993     join2CI                 ~> sup2CI
  3994     join1E                  ~> sup1E
  3995     join2E                  ~> sup2E
  3996 
  3997     is_meet_Meet            ~> is_meet_Inf
  3998     Meet_bool_def           ~> Inf_bool_def
  3999     Meet_fun_def            ~> Inf_fun_def
  4000     Meet_greatest           ~> Inf_greatest
  4001     Meet_lower              ~> Inf_lower
  4002     Meet_set_def            ~> Inf_set_def
  4003 
  4004     Sup_def                 ~> Sup_Inf
  4005     Sup_bool_eq             ~> Sup_bool_def
  4006     Sup_fun_eq              ~> Sup_fun_def
  4007     Sup_set_eq              ~> Sup_set_def
  4008 
  4009     listsp_meetI            ~> listsp_infI
  4010     listsp_meet_eq          ~> listsp_inf_eq
  4011 
  4012     meet_min                ~> inf_min
  4013     join_max                ~> sup_max
  4014 
  4015 * Added syntactic class "size"; overloaded constant "size" now has
  4016 type "'a::size ==> bool"
  4017 
  4018 * Internal reorganisation of `size' of datatypes: size theorems
  4019 "foo.size" are no longer subsumed by "foo.simps" (but are still
  4020 simplification rules by default!); theorems "prod.size" now named
  4021 "*.size".
  4022 
  4023 * Class "div" now inherits from class "times" rather than "type".
  4024 INCOMPATIBILITY.
  4025 
  4026 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  4027 Linorder etc.  have disappeared; operations defined in terms of
  4028 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  4029 
  4030 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  4031 
  4032 * HOL-Word: New extensive library and type for generic, fixed size
  4033 machine words, with arithemtic, bit-wise, shifting and rotating
  4034 operations, reflection into int, nat, and bool lists, automation for
  4035 linear arithmetic (by automatic reflection into nat or int), including
  4036 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  4037 arithmetic type classes, supporting automatic simplification of
  4038 numerals on all operations.
  4039 
  4040 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  4041 
  4042 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  4043 
  4044 * Code generator library theories:
  4045   - Code_Integer represents HOL integers by big integer literals in target
  4046     languages.
  4047   - Code_Char represents HOL characters by character literals in target
  4048     languages.
  4049   - Code_Char_chr like Code_Char, but also offers treatment of character
  4050     codes; includes Code_Integer.
  4051   - Executable_Set allows to generate code for finite sets using lists.
  4052   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  4053     denominator).
  4054   - Executable_Real implements a subset of real numbers, namly those
  4055     representable by rational numbers.
  4056   - Efficient_Nat implements natural numbers by integers, which in general will
  4057     result in higher efficency; pattern matching with 0/Suc is eliminated;
  4058     includes Code_Integer.
  4059   - Code_Index provides an additional datatype index which is mapped to
  4060     target-language built-in integers.
  4061   - Code_Message provides an additional datatype message_string which is isomorphic to
  4062     strings; messages are mapped to target-language strings.
  4063 
  4064 * New package for inductive predicates
  4065 
  4066   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  4067 
  4068     inductive
  4069       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  4070       for z_1 :: U_1 and ... and z_n :: U_m
  4071     where
  4072       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  4073     | ...
  4074 
  4075   with full support for type-inference, rather than
  4076 
  4077     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4078 
  4079     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  4080     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  4081 
  4082     inductive "s z_1 ... z_m"
  4083     intros
  4084       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  4085       ...
  4086 
  4087   For backward compatibility, there is a wrapper allowing inductive
  4088   sets to be defined with the new package via
  4089 
  4090     inductive_set
  4091       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4092       for z_1 :: U_1 and ... and z_n :: U_m
  4093     where
  4094       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  4095     | ...
  4096 
  4097   or
  4098 
  4099     inductive_set
  4100       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4101       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  4102       for z_1 :: U_1 and ... and z_n :: U_m
  4103     where
  4104       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  4105     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  4106     | ...
  4107 
  4108   if the additional syntax "p ..." is required.
  4109 
  4110   Numerous examples can be found in the subdirectories src/HOL/Auth,
  4111   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  4112 
  4113   INCOMPATIBILITIES:
  4114 
  4115   - Since declaration and definition of inductive sets or predicates
  4116     is no longer separated, abbreviations involving the newly
  4117     introduced sets or predicates must be specified together with the
  4118     introduction rules after the 'where' keyword (see above), rather
  4119     than before the actual inductive definition.
  4120 
  4121   - The variables in induction and elimination rules are now
  4122     quantified in the order of their occurrence in the introduction
  4123     rules, rather than in alphabetical order. Since this may break
  4124     some proofs, these proofs either have to be repaired, e.g. by
  4125     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  4126     statements of the form
  4127 
  4128       case (rule_i a_i_1 ... a_i_{k_i})
  4129 
  4130     or the old order of quantification has to be restored by explicitly adding
  4131     meta-level quantifiers in the introduction rules, i.e.
  4132 
  4133       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  4134 
  4135   - The format of the elimination rules is now
  4136 
  4137       p z_1 ... z_m x_1 ... x_n ==>
  4138         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  4139         ==> ... ==> P
  4140 
  4141     for predicates and
  4142 
  4143       (x_1, ..., x_n) : s z_1 ... z_m ==>
  4144         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  4145         ==> ... ==> P
  4146 
  4147     for sets rather than
  4148 
  4149       x : s z_1 ... z_m ==>
  4150         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  4151         ==> ... ==> P
  4152 
  4153     This may require terms in goals to be expanded to n-tuples
  4154     (e.g. using case_tac or simplification with the split_paired_all
  4155     rule) before the above elimination rule is applicable.
  4156 
  4157   - The elimination or case analysis rules for (mutually) inductive
  4158     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  4159     list of rules "p_1_..._p_k.elims" is no longer available.
  4160 
  4161 * New package "function"/"fun" for general recursive functions,
  4162 supporting mutual and nested recursion, definitions in local contexts,
  4163 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  4164 for small examples, and the separate tutorial on the function
  4165 package. The old recdef "package" is still available as before, but
  4166 users are encouraged to use the new package.
  4167 
  4168 * Method "lexicographic_order" automatically synthesizes termination
  4169 relations as lexicographic combinations of size measures. 
  4170 
  4171 * Case-expressions allow arbitrary constructor-patterns (including
  4172 "_") and take their order into account, like in functional
  4173 programming.  Internally, this is translated into nested
  4174 case-expressions; missing cases are added and mapped to the predefined
  4175 constant "undefined". In complicated cases printing may no longer show
  4176 the original input but the internal form. Lambda-abstractions allow
  4177 the same form of pattern matching: "% pat1 => e1 | ..." is an
  4178 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  4179 variable.
  4180 
  4181 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  4182 is an abbreviation for "of_nat :: nat => int". The simplification
  4183 rules for "of_nat" have been changed to work like "int" did
  4184 previously.  Potential INCOMPATIBILITY:
  4185   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  4186   - of_nat_diff and of_nat_mult are no longer default simp rules
  4187 
  4188 * Method "algebra" solves polynomial equations over (semi)rings using
  4189 Groebner bases. The (semi)ring structure is defined by locales and the
  4190 tool setup depends on that generic context. Installing the method for
  4191 a specific type involves instantiating the locale and possibly adding
  4192 declarations for computation on the coefficients.  The method is
  4193 already instantiated for natural numbers and for the axiomatic class
  4194 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  4195 CALCULEMUS 2007 for the general principles underlying this
  4196 architecture of context-aware proof-tools.
  4197 
  4198 * Method "ferrack" implements quantifier elimination over
  4199 special-purpose dense linear orders using locales (analogous to
  4200 "algebra"). The method is already installed for class
  4201 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  4202 rat, etc.
  4203 
  4204 * Former constant "List.op @" now named "List.append".  Use ML
  4205 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  4206 circumvent possible incompatibilities when working on ML level.
  4207 
  4208 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  4209 
  4210 * New function listsum :: 'a list => 'a for arbitrary monoids.
  4211 Special syntax: "SUM x <- xs. f x" (and latex variants)
  4212 
  4213 * New syntax for Haskell-like list comprehension (input only), eg.
  4214 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  4215 
  4216 * The special syntax for function "filter" has changed from [x :
  4217 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  4218 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  4219 
  4220 * [a..b] is now defined for arbitrary linear orders.  It used to be
  4221 defined on nat only, as an abbreviation for [a..<Suc b]
  4222 INCOMPATIBILITY.
  4223 
  4224 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  4225 
  4226 * New functions "sorted" and "sort" in src/HOL/List.thy.
  4227 
  4228 * New lemma collection field_simps (an extension of ring_simps) for
  4229 manipulating (in)equations involving division. Multiplies with all
  4230 denominators that can be proved to be non-zero (in equations) or
  4231 positive/negative (in inequations).
  4232 
  4233 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  4234 have been improved and renamed to ring_simps, group_simps and
  4235 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  4236 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  4237 
  4238 * Theory Library/Commutative_Ring: switched from recdef to function
  4239 package; constants add, mul, pow now curried.  Infix syntax for
  4240 algebraic operations.
  4241 
  4242 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  4243 INCOMPATIBILITY.
  4244 
  4245 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  4246 INCOMPATIBILITY.
  4247 
  4248 * HOL/records: generalised field-update to take a function on the
  4249 field rather than the new value: r(|A := x|) is translated to A_update
  4250 (K x) r The K-combinator that is internally used is called K_record.
  4251 INCOMPATIBILITY: Usage of the plain update functions has to be
  4252 adapted.
  4253  
  4254 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  4255 * x = 0, which are required for a semiring.  Richer structures do not
  4256 inherit from semiring_0 anymore, because this property is a theorem
  4257 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  4258 there is more to prove, but this is mostly trivial.
  4259 
  4260 * Class "recpower" is generalized to arbitrary monoids, not just
  4261 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  4262 commutativity or semiring properties additionally.
  4263 
  4264 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  4265 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  4266 better use 'abbreviation'.
  4267 
  4268 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  4269 
  4270 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  4271 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  4272 significant changes for setting up numeral syntax for types:
  4273   - New constants Numeral.pred and Numeral.succ instead
  4274       of former Numeral.bin_pred and Numeral.bin_succ.
  4275   - Use integer operations instead of bin_add, bin_mult and so on.
  4276   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  4277   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  4278 
  4279 See src/HOL/Integ/IntArith.thy for an example setup.
  4280 
  4281 * Command 'normal_form' computes the normal form of a term that may
  4282 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  4283 produces ``[b, c, a]'' (without proof).  This command is suitable for
  4284 heavy-duty computations because the functions are compiled to ML
  4285 first.  Correspondingly, a method "normalization" is provided.  See
  4286 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  4287 
  4288 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  4289 25 like -->); output depends on the "iff" print_mode, the default is
  4290 "A = B" (with priority 50).
  4291 
  4292 * Relations less (<) and less_eq (<=) are also available on type bool.
  4293 Modified syntax to disallow nesting without explicit parentheses,
  4294 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  4295 INCOMPATIBILITY.
  4296 
  4297 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  4298 
  4299 * Relation composition operator "op O" now has precedence 75 and binds
  4300 stronger than union and intersection. INCOMPATIBILITY.
  4301 
  4302 * The old set interval syntax "{m..n(}" (and relatives) has been
  4303 removed.  Use "{m..<n}" (and relatives) instead.
  4304 
  4305 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  4306 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  4307 ``declare [[simproc del: neq]]''.
  4308 
  4309 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  4310 True/False.
  4311 
  4312 * Theorem Cons_eq_map_conv no longer declared as "simp".
  4313 
  4314 * Theorem setsum_mult renamed to setsum_right_distrib.
  4315 
  4316 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  4317 ``rule'' method.
  4318 
  4319 * Reimplemented methods "sat" and "satx", with several improvements:
  4320 goals no longer need to be stated as "<prems> ==> False", equivalences
  4321 (i.e. "=" on type bool) are handled, variable names of the form
  4322 "lit_<n>" are no longer reserved, significant speedup.
  4323 
  4324 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  4325 zChaff is still supported as well.
  4326 
  4327 * 'inductive' and 'datatype': provide projections of mutual rules,
  4328 bundled as foo_bar.inducts;
  4329 
  4330 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  4331 Library.
  4332 
  4333 * Library: moved theory Accessible_Part to main HOL.
  4334 
  4335 * Library: added theory Coinductive_List of potentially infinite lists
  4336 as greatest fixed-point.
  4337 
  4338 * Library: added theory AssocList which implements (finite) maps as
  4339 association lists.
  4340 
  4341 * Method "evaluation" solves goals (i.e. a boolean expression)
  4342 efficiently by compiling it to ML.  The goal is "proved" (via an
  4343 oracle) if it evaluates to True.
  4344 
  4345 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  4346 also when invoked by the simplifier.  This results in the Simplifier
  4347 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  4348 Configuration option fast_arith_split_limit=0 recovers the old
  4349 behavior.
  4350 
  4351 * Support for hex (0x20) and binary (0b1001) numerals.
  4352 
  4353 * New method: reify eqs (t), where eqs are equations for an
  4354 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  4355 parameter, computes a term s::'b and a list xs::'a list and proves the
  4356 theorem I xs s = t. This is also known as reification or quoting. The
  4357 resulting theorem is applied to the subgoal to substitute t with I xs
  4358 s.  If t is omitted, the subgoal itself is reified.
  4359 
  4360 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  4361 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  4362 where f is supposed to be a computable function (in the sense of code
  4363 generattion). The method uses reify to compute s and xs as above then
  4364 applies corr_thm and uses normalization by evaluation to "prove" f s =
  4365 r and finally gets the theorem t = r, which is again applied to the
  4366 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  4367 
  4368 * Reflection: Automatic reification now handels binding, an example is
  4369 available in src/HOL/ex/ReflectionEx.thy
  4370 
  4371 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  4372 command 'statespace' that is similar to 'record', but introduces an
  4373 abstract specification based on the locale infrastructure instead of
  4374 HOL types.  This leads to extra flexibility in composing state spaces,
  4375 in particular multiple inheritance and renaming of components.
  4376 
  4377 
  4378 *** HOL-Complex ***
  4379 
  4380 * Hyperreal: Functions root and sqrt are now defined on negative real
  4381 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  4382 Nonnegativity side conditions have been removed from many lemmas, so
  4383 that more subgoals may now be solved by simplification; potential
  4384 INCOMPATIBILITY.
  4385 
  4386 * Real: new type classes formalize real normed vector spaces and
  4387 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  4388 and norm :: 'a => real.
  4389 
  4390 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  4391 reals into other types. The overloaded constant Reals :: 'a set is now
  4392 defined as range of_real; potential INCOMPATIBILITY.
  4393 
  4394 * Real: proper support for ML code generation, including 'quickcheck'.
  4395 Reals are implemented as arbitrary precision rationals.
  4396 
  4397 * Hyperreal: Several constants that previously worked only for the
  4398 reals have been generalized, so they now work over arbitrary vector
  4399 spaces. Type annotations may need to be added in some cases; potential
  4400 INCOMPATIBILITY.
  4401 
  4402   Infinitesimal  :: ('a::real_normed_vector) star set
  4403   HFinite        :: ('a::real_normed_vector) star set
  4404   HInfinite      :: ('a::real_normed_vector) star set
  4405   approx         :: ('a::real_normed_vector) star => 'a star => bool
  4406   monad          :: ('a::real_normed_vector) star => 'a star set
  4407   galaxy         :: ('a::real_normed_vector) star => 'a star set
  4408   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  4409   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  4410   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  4411   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  4412   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  4413   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  4414   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  4415   sgn            :: 'a::real_normed_vector => 'a
  4416   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  4417 
  4418 * Complex: Some complex-specific constants are now abbreviations for
  4419 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  4420 hnorm.  Other constants have been entirely removed in favor of the
  4421 polymorphic versions (INCOMPATIBILITY):
  4422 
  4423   approx        <-- capprox
  4424   HFinite       <-- CFinite
  4425   HInfinite     <-- CInfinite
  4426   Infinitesimal <-- CInfinitesimal
  4427   monad         <-- cmonad
  4428   galaxy        <-- cgalaxy
  4429   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  4430   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  4431   (ns)deriv     <-- (ns)cderiv
  4432 
  4433 
  4434 *** HOL-Algebra ***
  4435 
  4436 * Formalisation of ideals and the quotient construction over rings.
  4437 
  4438 * Order and lattice theory no longer based on records.
  4439 INCOMPATIBILITY.
  4440 
  4441 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  4442 greatest_closed.  INCOMPATIBILITY.
  4443 
  4444 * Method algebra is now set up via an attribute.  For examples see
  4445 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  4446 of algebraic structures.
  4447 
  4448 * Renamed theory CRing to Ring.
  4449 
  4450 
  4451 *** HOL-Nominal ***
  4452 
  4453 * Substantial, yet incomplete support for nominal datatypes (binding
  4454 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  4455 src/HOL/Nominal/Examples.  Prospective users should consult
  4456 http://isabelle.in.tum.de/nominal/
  4457 
  4458 
  4459 *** ML ***
  4460 
  4461 * ML basics: just one true type int, which coincides with IntInf.int
  4462 (even on SML/NJ).
  4463 
  4464 * ML within Isar: antiquotations allow to embed statically-checked
  4465 formal entities in the source, referring to the context available at
  4466 compile-time.  For example:
  4467 
  4468 ML {* @{sort "{zero,one}"} *}
  4469 ML {* @{typ "'a => 'b"} *}
  4470 ML {* @{term "%x. x"} *}
  4471 ML {* @{prop "x == y"} *}
  4472 ML {* @{ctyp "'a => 'b"} *}
  4473 ML {* @{cterm "%x. x"} *}
  4474 ML {* @{cprop "x == y"} *}
  4475 ML {* @{thm asm_rl} *}
  4476 ML {* @{thms asm_rl} *}
  4477 ML {* @{type_name c} *}
  4478 ML {* @{type_syntax c} *}
  4479 ML {* @{const_name c} *}
  4480 ML {* @{const_syntax c} *}
  4481 ML {* @{context} *}
  4482 ML {* @{theory} *}
  4483 ML {* @{theory Pure} *}
  4484 ML {* @{theory_ref} *}
  4485 ML {* @{theory_ref Pure} *}
  4486 ML {* @{simpset} *}
  4487 ML {* @{claset} *}
  4488 ML {* @{clasimpset} *}
  4489 
  4490 The same works for sources being ``used'' within an Isar context.
  4491 
  4492 * ML in Isar: improved error reporting; extra verbosity with
  4493 ML_Context.trace enabled.
  4494 
  4495 * Pure/General/table.ML: the join operations now works via exceptions
  4496 DUP/SAME instead of type option. This is simpler in simple cases, and
  4497 admits slightly more efficient complex applications.
  4498 
  4499 * Pure: 'advanced' translation functions (parse_translation etc.) now
  4500 use Context.generic instead of just theory.
  4501 
  4502 * Pure: datatype Context.generic joins theory/Proof.context and
  4503 provides some facilities for code that works in either kind of
  4504 context, notably GenericDataFun for uniform theory and proof data.
  4505 
  4506 * Pure: simplified internal attribute type, which is now always
  4507 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  4508 local (Proof.context) attributes have been discontinued, while
  4509 minimizing code duplication. Thm.rule_attribute and
  4510 Thm.declaration_attribute build canonical attributes; see also structure
  4511 Context for further operations on Context.generic, notably
  4512 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  4513 declarations and definitions.
  4514 
  4515 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  4516 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  4517 init only required for impure data. INCOMPATIBILITY: empty really need
  4518 to be empty (no dependencies on theory content!)
  4519 
  4520 * Pure/kernel: consts certification ignores sort constraints given in
  4521 signature declarations. (This information is not relevant to the
  4522 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  4523 potential INCOMPATIBILITY.
  4524 
  4525 * Pure: axiomatic type classes are now purely definitional, with
  4526 explicit proofs of class axioms and super class relations performed
  4527 internally. See Pure/axclass.ML for the main internal interfaces --
  4528 notably AxClass.define_class supercedes AxClass.add_axclass, and
  4529 AxClass.axiomatize_class/classrel/arity supersede
  4530 Sign.add_classes/classrel/arities.
  4531 
  4532 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  4533 global/local versions on theory vs. Proof.context have been
  4534 discontinued; Attrib.syntax and Method.syntax have been adapted
  4535 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  4536 attributes, methods, etc.
  4537 
  4538 * Pure: several functions of signature "... -> theory -> theory * ..."
  4539 have been reoriented to "... -> theory -> ... * theory" in order to
  4540 allow natural usage in combination with the ||>, ||>>, |-> and
  4541 fold_map combinators.
  4542 
  4543 * Pure: official theorem names (closed derivations) and additional
  4544 comments (tags) are now strictly separate.  Name hints -- which are
  4545 maintained as tags -- may be attached any time without affecting the
  4546 derivation.
  4547 
  4548 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  4549 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  4550 achieve the old behaviour.
  4551 
  4552 * Pure: the "Goal" constant is now called "prop", supporting a
  4553 slightly more general idea of ``protecting'' meta-level rule
  4554 statements.
  4555 
  4556 * Pure: Logic.(un)varify only works in a global context, which is now
  4557 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  4558 Logic.legacy_(un)varify as temporary workaround.
  4559 
  4560 * Pure: structure Name provides scalable operations for generating
  4561 internal variable names, notably Name.variants etc.  This replaces
  4562 some popular functions from term.ML:
  4563 
  4564   Term.variant		->  Name.variant
  4565   Term.variantlist	->  Name.variant_list
  4566   Term.invent_names	->  Name.invent_list
  4567 
  4568 Note that low-level renaming rarely occurs in new code -- operations
  4569 from structure Variable are used instead (see below).
  4570 
  4571 * Pure: structure Variable provides fundamental operations for proper
  4572 treatment of fixed/schematic variables in a context.  For example,
  4573 Variable.import introduces fixes for schematics of given facts and
  4574 Variable.export reverses the effect (up to renaming) -- this replaces
  4575 various freeze_thaw operations.
  4576 
  4577 * Pure: structure Goal provides simple interfaces for
  4578 init/conclude/finish and tactical prove operations (replacing former
  4579 Tactic.prove).  Goal.prove is the canonical way to prove results
  4580 within a given context; Goal.prove_global is a degraded version for
  4581 theory level goals, including a global Drule.standard.  Note that
  4582 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  4583 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  4584 in a locale context).
  4585 
  4586 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  4587 and type checking (Syntax.check_term etc.), with common combinations
  4588 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  4589 which are considered legacy and await removal.
  4590 
  4591 * Pure/Syntax: generic interfaces for type unchecking
  4592 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  4593 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  4594 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  4595 available for convenience, but refer to the very same operations using
  4596 a mere theory instead of a full context.
  4597 
  4598 * Isar: simplified treatment of user-level errors, using exception
  4599 ERROR of string uniformly.  Function error now merely raises ERROR,
  4600 without any side effect on output channels.  The Isar toplevel takes
  4601 care of proper display of ERROR exceptions.  ML code may use plain
  4602 handle/can/try; cat_error may be used to concatenate errors like this:
  4603 
  4604   ... handle ERROR msg => cat_error msg "..."
  4605 
  4606 Toplevel ML code (run directly or through the Isar toplevel) may be
  4607 embedded into the Isar toplevel with exception display/debug like
  4608 this:
  4609 
  4610   Isar.toplevel (fn () => ...)
  4611 
  4612 INCOMPATIBILITY, removed special transform_error facilities, removed
  4613 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  4614 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  4615 -- use plain ERROR instead.
  4616 
  4617 * Isar: theory setup now has type (theory -> theory), instead of a
  4618 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  4619 
  4620 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  4621 ProofContext.debug/verbose flags.
  4622 
  4623 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  4624 theory before entering a proof state.  Transactions now always see a
  4625 quasi-functional intermediate checkpoint, both in interactive and
  4626 batch mode.
  4627 
  4628 * Isar: simplified interfaces for outer syntax.  Renamed
  4629 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  4630 OuterSyntax.add_parsers -- this functionality is now included in
  4631 OuterSyntax.command etc.  INCOMPATIBILITY.
  4632 
  4633 * Simplifier: the simpset of a running simplification process now
  4634 contains a proof context (cf. Simplifier.the_context), which is the
  4635 very context that the initial simpset has been retrieved from (by
  4636 simpset_of/local_simpset_of).  Consequently, all plug-in components
  4637 (solver, looper etc.) may depend on arbitrary proof data.
  4638 
  4639 * Simplifier.inherit_context inherits the proof context (plus the
  4640 local bounds) of the current simplification process; any simproc
  4641 etc. that calls the Simplifier recursively should do this!  Removed
  4642 former Simplifier.inherit_bounds, which is already included here --
  4643 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  4644 specify an explicit context using Simplifier.context/theory_context.
  4645 
  4646 * Simplifier/Classical Reasoner: more abstract interfaces
  4647 change_simpset/claset for modifying the simpset/claset reference of a
  4648 theory; raw versions simpset/claset_ref etc. have been discontinued --
  4649 INCOMPATIBILITY.
  4650 
  4651 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  4652 "Trueprop" etc.
  4653 
  4654 
  4655 *** System ***
  4656 
  4657 * settings: the default heap location within ISABELLE_HOME_USER now
  4658 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  4659 Isabelle installations.
  4660 
  4661 * isabelle-process: option -S (secure mode) disables some critical
  4662 operations, notably runtime compilation and evaluation of ML source
  4663 code.
  4664 
  4665 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  4666 
  4667 * Support for parallel execution, using native multicore support of
  4668 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  4669 independent theories, according to the given theory header
  4670 specifications. The maximum number of worker threads is specified via
  4671 usedir option -M or the "max-threads" setting in Proof General. A
  4672 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  4673 to 6 on a 8-core machine.  User-code needs to observe certain
  4674 guidelines for thread-safe programming, see appendix A in the Isar
  4675 Implementation manual.
  4676 
  4677 
  4678 
  4679 New in Isabelle2005 (October 2005)
  4680 ----------------------------------
  4681 
  4682 *** General ***
  4683 
  4684 * Theory headers: the new header syntax for Isar theories is
  4685 
  4686   theory <name>
  4687   imports <theory1> ... <theoryN>
  4688   uses <file1> ... <fileM>
  4689   begin
  4690 
  4691 where the 'uses' part is optional.  The previous syntax
  4692 
  4693   theory <name> = <theory1> + ... + <theoryN>:
  4694 
  4695 will disappear in the next release.  Use isatool fixheaders to convert
  4696 existing theory files.  Note that there is no change in ancient
  4697 non-Isar theories now, but these will disappear soon.
  4698 
  4699 * Theory loader: parent theories can now also be referred to via
  4700 relative and absolute paths.
  4701 
  4702 * Command 'find_theorems' searches for a list of criteria instead of a
  4703 list of constants. Known criteria are: intro, elim, dest, name:string,
  4704 simp:term, and any term. Criteria can be preceded by '-' to select
  4705 theorems that do not match. Intro, elim, dest select theorems that
  4706 match the current goal, name:s selects theorems whose fully qualified
  4707 name contain s, and simp:term selects all simplification rules whose
  4708 lhs match term.  Any other term is interpreted as pattern and selects
  4709 all theorems matching the pattern. Available in ProofGeneral under
  4710 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  4711 
  4712   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  4713 
  4714 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  4715 matching the current goal as introduction rule and not having "HOL."
  4716 in their name (i.e. not being defined in theory HOL).
  4717 
  4718 * Command 'thms_containing' has been discontinued in favour of
  4719 'find_theorems'; INCOMPATIBILITY.
  4720 
  4721 * Communication with Proof General is now 8bit clean, which means that
  4722 Unicode text in UTF-8 encoding may be used within theory texts (both
  4723 formal and informal parts).  Cf. option -U of the Isabelle Proof
  4724 General interface.  Here are some simple examples (cf. src/HOL/ex):
  4725 
  4726   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  4727   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  4728 
  4729 * Improved efficiency of the Simplifier and, to a lesser degree, the
  4730 Classical Reasoner.  Typical big applications run around 2 times
  4731 faster.
  4732 
  4733 
  4734 *** Document preparation ***
  4735 
  4736 * Commands 'display_drafts' and 'print_drafts' perform simple output
  4737 of raw sources.  Only those symbols that do not require additional
  4738 LaTeX packages (depending on comments in isabellesym.sty) are
  4739 displayed properly, everything else is left verbatim.  isatool display
  4740 and isatool print are used as front ends (these are subject to the
  4741 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  4742 
  4743 * Command tags control specific markup of certain regions of text,
  4744 notably folding and hiding.  Predefined tags include "theory" (for
  4745 theory begin and end), "proof" for proof commands, and "ML" for
  4746 commands involving ML code; the additional tags "visible" and
  4747 "invisible" are unused by default.  Users may give explicit tag
  4748 specifications in the text, e.g. ''by %invisible (auto)''.  The
  4749 interpretation of tags is determined by the LaTeX job during document
  4750 preparation: see option -V of isatool usedir, or options -n and -t of
  4751 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  4752 \isadroptag.
  4753 
  4754 Several document versions may be produced at the same time via isatool
  4755 usedir (the generated index.html will link all of them).  Typical
  4756 specifications include ''-V document=theory,proof,ML'' to present
  4757 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  4758 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  4759 these parts without any formal replacement text.  The Isabelle site
  4760 default settings produce ''document'' and ''outline'' versions as
  4761 specified above.
  4762 
  4763 * Several new antiquotations:
  4764 
  4765   @{term_type term} prints a term with its type annotated;
  4766 
  4767   @{typeof term} prints the type of a term;
  4768 
  4769   @{const const} is the same as @{term const}, but checks that the
  4770   argument is a known logical constant;
  4771 
  4772   @{term_style style term} and @{thm_style style thm} print a term or
  4773   theorem applying a "style" to it
  4774 
  4775   @{ML text}
  4776 
  4777 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  4778 definitions, equations, inequations etc., 'concl' printing only the
  4779 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  4780 to print the specified premise.  TermStyle.add_style provides an ML
  4781 interface for introducing further styles.  See also the "LaTeX Sugar"
  4782 document practical applications.  The ML antiquotation prints
  4783 type-checked ML expressions verbatim.
  4784 
  4785 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  4786 and 'text' support optional locale specification '(in loc)', which
  4787 specifies the default context for interpreting antiquotations.  For
  4788 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  4789 
  4790 * Option 'locale=NAME' of antiquotations specifies an alternative
  4791 context interpreting the subsequent argument.  For example: @{thm
  4792 [locale=lattice] inf_assoc}.
  4793 
  4794 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  4795 a proof context.
  4796 
  4797 * Proper output of antiquotations for theory commands involving a
  4798 proof context (such as 'locale' or 'theorem (in loc) ...').
  4799 
  4800 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  4801 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  4802 
  4803 * isatool usedir: new option -C (default true) controls whether option
  4804 -D should include a copy of the original document directory; -C false
  4805 prevents unwanted effects such as copying of administrative CVS data.
  4806 
  4807 
  4808 *** Pure ***
  4809 
  4810 * Considerably improved version of 'constdefs' command.  Now performs
  4811 automatic type-inference of declared constants; additional support for
  4812 local structure declarations (cf. locales and HOL records), see also
  4813 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  4814 sequential dependencies of definitions within a single 'constdefs'
  4815 section; moreover, the declared name needs to be an identifier.  If
  4816 all fails, consider to fall back on 'consts' and 'defs' separately.
  4817 
  4818 * Improved indexed syntax and implicit structures.  First of all,
  4819 indexed syntax provides a notational device for subscripted
  4820 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  4821 expressions.  Secondly, in a local context with structure
  4822 declarations, number indexes \<^sub>n or the empty index (default
  4823 number 1) refer to a certain fixed variable implicitly; option
  4824 show_structs controls printing of implicit structures.  Typical
  4825 applications of these concepts involve record types and locales.
  4826 
  4827 * New command 'no_syntax' removes grammar declarations (and
  4828 translations) resulting from the given syntax specification, which is
  4829 interpreted in the same manner as for the 'syntax' command.
  4830 
  4831 * 'Advanced' translation functions (parse_translation etc.) may depend
  4832 on the signature of the theory context being presently used for
  4833 parsing/printing, see also isar-ref manual.
  4834 
  4835 * Improved 'oracle' command provides a type-safe interface to turn an
  4836 ML expression of type theory -> T -> term into a primitive rule of
  4837 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  4838 is already included here); see also FOL/ex/IffExample.thy;
  4839 INCOMPATIBILITY.
  4840 
  4841 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  4842 before); "cI" is no longer bound, use "c.intro" instead.
  4843 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  4844 axclasses vs. locales.
  4845 
  4846 * Improved internal renaming of symbolic identifiers -- attach primes
  4847 instead of base 26 numbers.
  4848 
  4849 * New flag show_question_marks controls printing of leading question
  4850 marks in schematic variable names.
  4851 
  4852 * In schematic variable names, *any* symbol following \<^isub> or
  4853 \<^isup> is now treated as part of the base name.  For example, the
  4854 following works without printing of awkward ".0" indexes:
  4855 
  4856   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  4857     by simp
  4858 
  4859 * Inner syntax includes (*(*nested*) comments*).
  4860 
  4861 * Pretty printer now supports unbreakable blocks, specified in mixfix
  4862 annotations as "(00...)".
  4863 
  4864 * Clear separation of logical types and nonterminals, where the latter
  4865 may only occur in 'syntax' specifications or type abbreviations.
  4866 Before that distinction was only partially implemented via type class
  4867 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  4868 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  4869 exotic syntax specifications may require further adaption
  4870 (e.g. Cube/Cube.thy).
  4871 
  4872 * Removed obsolete type class "logic", use the top sort {} instead.
  4873 Note that non-logical types should be declared as 'nonterminals'
  4874 rather than 'types'.  INCOMPATIBILITY for new object-logic
  4875 specifications.
  4876 
  4877 * Attributes 'induct' and 'cases': type or set names may now be
  4878 locally fixed variables as well.
  4879 
  4880 * Simplifier: can now control the depth to which conditional rewriting
  4881 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  4882 Limit.
  4883 
  4884 * Simplifier: simplification procedures may now take the current
  4885 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  4886 interface), which is very useful for calling the Simplifier
  4887 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  4888 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  4889 low-level mk_simproc no longer applies Logic.varify internally, to
  4890 allow for use in a context of fixed variables.
  4891 
  4892 * thin_tac now works even if the assumption being deleted contains !!
  4893 or ==>.  More generally, erule now works even if the major premise of
  4894 the elimination rule contains !! or ==>.
  4895 
  4896 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  4897 
  4898 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  4899 from Pure, which contains all common declarations already.  Both
  4900 theories are defined via plain Isabelle/Isar .thy files.
  4901 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  4902 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  4903 use isatool fixcpure to adapt your theory and ML sources.
  4904 
  4905 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  4906 selections of theorems in named facts via index ranges.
  4907 
  4908 * 'print_theorems': in theory mode, really print the difference
  4909 wrt. the last state (works for interactive theory development only),
  4910 in proof mode print all local facts (cf. 'print_facts');
  4911 
  4912 * 'hide': option '(open)' hides only base names.
  4913 
  4914 * More efficient treatment of intermediate checkpoints in interactive
  4915 theory development.
  4916 
  4917 * Code generator is now invoked via code_module (incremental code
  4918 generation) and code_library (modular code generation, ML structures
  4919 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  4920 must be quoted when used as identifiers.
  4921 
  4922 * New 'value' command for reading, evaluating and printing terms using
  4923 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  4924 quoted when used as identifier.
  4925 
  4926 
  4927 *** Locales ***
  4928 
  4929 * New commands for the interpretation of locale expressions in
  4930 theories (1), locales (2) and proof contexts (3).  These generate
  4931 proof obligations from the expression specification.  After the
  4932 obligations have been discharged, theorems of the expression are added
  4933 to the theory, target locale or proof context.  The synopsis of the
  4934 commands is a follows:
  4935 
  4936   (1) interpretation expr inst
  4937   (2) interpretation target < expr
  4938   (3) interpret expr inst
  4939 
  4940 Interpretation in theories and proof contexts require a parameter
  4941 instantiation of terms from the current context.  This is applied to
  4942 specifications and theorems of the interpreted expression.
  4943 Interpretation in locales only permits parameter renaming through the
  4944 locale expression.  Interpretation is smart in that interpretations
  4945 that are active already do not occur in proof obligations, neither are
  4946 instantiated theorems stored in duplicate.  Use 'print_interps' to
  4947 inspect active interpretations of a particular locale.  For details,
  4948 see the Isar Reference manual.  Examples can be found in
  4949 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  4950 
  4951 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  4952 'interpret' instead.
  4953 
  4954 * New context element 'constrains' for adding type constraints to
  4955 parameters.
  4956 
  4957 * Context expressions: renaming of parameters with syntax
  4958 redeclaration.
  4959 
  4960 * Locale declaration: 'includes' disallowed.
  4961 
  4962 * Proper static binding of attribute syntax -- i.e. types / terms /
  4963 facts mentioned as arguments are always those of the locale definition
  4964 context, independently of the context of later invocations.  Moreover,
  4965 locale operations (renaming and type / term instantiation) are applied
  4966 to attribute arguments as expected.
  4967 
  4968 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  4969 actual attributes; rare situations may require Attrib.attribute to
  4970 embed those attributes into Attrib.src that lack concrete syntax.
  4971 Attribute implementations need to cooperate properly with the static
  4972 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  4973 Attrib.XXX_thm etc. already do the right thing without further
  4974 intervention.  Only unusual applications -- such as "where" or "of"
  4975 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  4976 on the context and the facts involved -- may have to assign parsed
  4977 values to argument tokens explicitly.
  4978 
  4979 * Changed parameter management in theorem generation for long goal
  4980 statements with 'includes'.  INCOMPATIBILITY: produces a different
  4981 theorem statement in rare situations.
  4982 
  4983 * Locale inspection command 'print_locale' omits notes elements.  Use
  4984 'print_locale!' to have them included in the output.
  4985 
  4986 
  4987 *** Provers ***
  4988 
  4989 * Provers/hypsubst.ML: improved version of the subst method, for
  4990 single-step rewriting: it now works in bound variable contexts. New is
  4991 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  4992 rewrite a different subterm than the original subst method, which is
  4993 still available as 'simplesubst'.
  4994 
  4995 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  4996 and quasi orders.
  4997 
  4998 * Provers/trancl.ML: new transitivity reasoner for transitive and
  4999 reflexive-transitive closure of relations.
  5000 
  5001 * Provers/blast.ML: new reference depth_limit to make blast's depth
  5002 limit (previously hard-coded with a value of 20) user-definable.
  5003 
  5004 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  5005 is peformed already.  Object-logics merely need to finish their
  5006 initial simpset configuration as before.  INCOMPATIBILITY.
  5007 
  5008 
  5009 *** HOL ***
  5010 
  5011 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  5012 
  5013   syntax (epsilon)
  5014     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  5015 
  5016 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  5017 and x-symbol; use option '-m epsilon' to get it actually printed.
  5018 Moreover, the mathematically important symbolic identifier \<epsilon>
  5019 becomes available as variable, constant etc.  INCOMPATIBILITY,
  5020 
  5021 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  5022 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  5023 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  5024 support corresponding Isar calculations.
  5025 
  5026 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  5027 instead of ":".
  5028 
  5029 * theory SetInterval: changed the syntax for open intervals:
  5030 
  5031   Old       New
  5032   {..n(}    {..<n}
  5033   {)n..}    {n<..}
  5034   {m..n(}   {m..<n}
  5035   {)m..n}   {m<..n}
  5036   {)m..n(}  {m<..<n}
  5037 
  5038 The old syntax is still supported but will disappear in the next
  5039 release.  For conversion use the following Emacs search and replace
  5040 patterns (these are not perfect but work quite well):
  5041 
  5042   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  5043   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  5044 
  5045 * Theory Commutative_Ring (in Library): method comm_ring for proving
  5046 equalities in commutative rings; method 'algebra' provides a generic
  5047 interface.
  5048 
  5049 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  5050 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  5051 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  5052 be a tuple pattern.
  5053 
  5054 Some new syntax forms are available:
  5055 
  5056   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  5057   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  5058   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  5059   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  5060 
  5061 The latter form "\<Sum>x < k. e" used to be based on a separate
  5062 function "Summation", which has been discontinued.
  5063 
  5064 * theory Finite_Set: in structured induction proofs, the insert case
  5065 is now 'case (insert x F)' instead of the old counterintuitive 'case
  5066 (insert F x)'.
  5067 
  5068 * The 'refute' command has been extended to support a much larger
  5069 fragment of HOL, including axiomatic type classes, constdefs and
  5070 typedefs, inductive datatypes and recursion.
  5071 
  5072 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  5073 Requires zChaff with proof generation to be installed.  See
  5074 HOL/ex/SAT_Examples.thy for examples.
  5075 
  5076 * Datatype induction via method 'induct' now preserves the name of the
  5077 induction variable. For example, when proving P(xs::'a list) by
  5078 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  5079 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  5080 in unstructured proof scripts.
  5081 
  5082 * Reworked implementation of records.  Improved scalability for
  5083 records with many fields, avoiding performance problems for type
  5084 inference. Records are no longer composed of nested field types, but
  5085 of nested extension types. Therefore the record type only grows linear
  5086 in the number of extensions and not in the number of fields.  The
  5087 top-level (users) view on records is preserved.  Potential
  5088 INCOMPATIBILITY only in strange cases, where the theory depends on the
  5089 old record representation. The type generated for a record is called
  5090 <record_name>_ext_type.
  5091 
  5092 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  5093 proofs triggered by a record definition or a simproc (if
  5094 quick_and_dirty is enabled).  Definitions of large records can take
  5095 quite long.
  5096 
  5097 New simproc record_upd_simproc for simplification of multiple record
  5098 updates enabled by default.  Moreover, trivial updates are also
  5099 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  5100 occasionally, since simplification is more powerful by default.
  5101 
  5102 * typedef: proper support for polymorphic sets, which contain extra
  5103 type-variables in the term.
  5104 
  5105 * Simplifier: automatically reasons about transitivity chains
  5106 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  5107 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  5108 old proofs break occasionally as simplification may now solve more
  5109 goals than previously.
  5110 
  5111 * Simplifier: converts x <= y into x = y if assumption y <= x is
  5112 present.  Works for all partial orders (class "order"), in particular
  5113 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  5114 just like y <= x.
  5115 
  5116 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  5117 bound variable or a constant then the let is unfolded.  Otherwise
  5118 first a is simplified to b, and then f b is simplified to g. If
  5119 possible we abstract b from g arriving at "let x = b in h x",
  5120 otherwise we unfold the let and arrive at g.  The simproc can be
  5121 enabled/disabled by the reference use_let_simproc.  Potential
  5122 INCOMPATIBILITY since simplification is more powerful by default.
  5123 
  5124 * Classical reasoning: the meson method now accepts theorems as arguments.
  5125 
  5126 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  5127 jobs to provide advice on the provability of subgoals.
  5128 
  5129 * Theory OrderedGroup and Ring_and_Field: various additions and
  5130 improvements to faciliate calculations involving equalities and
  5131 inequalities.
  5132 
  5133 The following theorems have been eliminated or modified
  5134 (INCOMPATIBILITY):
  5135 
  5136   abs_eq             now named abs_of_nonneg
  5137   abs_of_ge_0        now named abs_of_nonneg
  5138   abs_minus_eq       now named abs_of_nonpos
  5139   imp_abs_id         now named abs_of_nonneg
  5140   imp_abs_neg_id     now named abs_of_nonpos
  5141   mult_pos           now named mult_pos_pos
  5142   mult_pos_le        now named mult_nonneg_nonneg
  5143   mult_pos_neg_le    now named mult_nonneg_nonpos
  5144   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  5145   mult_neg           now named mult_neg_neg
  5146   mult_neg_le        now named mult_nonpos_nonpos
  5147 
  5148 * The following lemmas in Ring_and_Field have been added to the simplifier:
  5149      
  5150      zero_le_square
  5151      not_square_less_zero 
  5152 
  5153   The following lemmas have been deleted from Real/RealPow:
  5154   
  5155      realpow_zero_zero
  5156      realpow_two
  5157      realpow_less
  5158      zero_le_power
  5159      realpow_two_le
  5160      abs_realpow_two
  5161      realpow_two_abs     
  5162 
  5163 * Theory Parity: added rules for simplifying exponents.
  5164 
  5165 * Theory List:
  5166 
  5167 The following theorems have been eliminated or modified
  5168 (INCOMPATIBILITY):
  5169 
  5170   list_all_Nil       now named list_all.simps(1)
  5171   list_all_Cons      now named list_all.simps(2)
  5172   list_all_conv      now named list_all_iff
  5173   set_mem_eq         now named mem_iff
  5174 
  5175 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  5176 asymptotic "big O" calculations.  See the notes in BigO.thy.
  5177 
  5178 
  5179 *** HOL-Complex ***
  5180 
  5181 * Theory RealDef: better support for embedding natural numbers and
  5182 integers in the reals.
  5183 
  5184 The following theorems have been eliminated or modified
  5185 (INCOMPATIBILITY):
  5186 
  5187   exp_ge_add_one_self  now requires no hypotheses
  5188   real_of_int_add      reversed direction of equality (use [symmetric])
  5189   real_of_int_minus    reversed direction of equality (use [symmetric])
  5190   real_of_int_diff     reversed direction of equality (use [symmetric])
  5191   real_of_int_mult     reversed direction of equality (use [symmetric])
  5192 
  5193 * Theory RComplete: expanded support for floor and ceiling functions.
  5194 
  5195 * Theory Ln is new, with properties of the natural logarithm
  5196 
  5197 * Hyperreal: There is a new type constructor "star" for making
  5198 nonstandard types.  The old type names are now type synonyms:
  5199 
  5200   hypreal = real star
  5201   hypnat = nat star
  5202   hcomplex = complex star
  5203 
  5204 * Hyperreal: Many groups of similarly-defined constants have been
  5205 replaced by polymorphic versions (INCOMPATIBILITY):
  5206 
  5207   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  5208 
  5209   starset      <-- starsetNat, starsetC
  5210   *s*          <-- *sNat*, *sc*
  5211   starset_n    <-- starsetNat_n, starsetC_n
  5212   *sn*         <-- *sNatn*, *scn*
  5213   InternalSets <-- InternalNatSets, InternalCSets
  5214 
  5215   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  5216   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  5217   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  5218   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  5219   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  5220 
  5221 * Hyperreal: Many type-specific theorems have been removed in favor of
  5222 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  5223 
  5224   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  5225   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  5226   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  5227   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  5228   right_minus <-- hypreal_add_minus
  5229   left_minus <-- {hypreal,hcomplex}_add_minus_left
  5230   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  5231   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  5232   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  5233   mult_1_right <-- hcomplex_mult_one_right
  5234   mult_zero_left <-- hcomplex_mult_zero_left
  5235   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  5236   right_distrib <-- hypnat_add_mult_distrib2
  5237   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  5238   right_inverse <-- hypreal_mult_inverse
  5239   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  5240   order_refl <-- {hypreal,hypnat}_le_refl
  5241   order_trans <-- {hypreal,hypnat}_le_trans
  5242   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  5243   order_less_le <-- {hypreal,hypnat}_less_le
  5244   linorder_linear <-- {hypreal,hypnat}_le_linear
  5245   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  5246   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  5247   add_nonneg_nonneg <-- hypreal_le_add_order
  5248 
  5249 * Hyperreal: Separate theorems having to do with type-specific
  5250 versions of constants have been merged into theorems that apply to the
  5251 new polymorphic constants (INCOMPATIBILITY):
  5252 
  5253   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  5254   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  5255   STAR_Un <-- {STAR,NatStar,STARC}_Un
  5256   STAR_Int <-- {STAR,NatStar,STARC}_Int
  5257   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  5258   STAR_subset <-- {STAR,NatStar,STARC}_subset
  5259   STAR_mem <-- {STAR,NatStar,STARC}_mem
  5260   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  5261   STAR_diff <-- {STAR,STARC}_diff
  5262   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  5263     STARC_hcomplex_of_complex}_image_subset
  5264   starset_n_Un <-- starset{Nat,C}_n_Un
  5265   starset_n_Int <-- starset{Nat,C}_n_Int
  5266   starset_n_Compl <-- starset{Nat,C}_n_Compl
  5267   starset_n_diff <-- starset{Nat,C}_n_diff
  5268   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  5269   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  5270   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  5271   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  5272   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  5273   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  5274   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  5275   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  5276   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  5277   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  5278   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  5279   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  5280   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  5281   starfun_diff <-- starfun{C,RC,CR}_diff
  5282   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  5283   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  5284   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  5285   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  5286   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  5287   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  5288   starfun_Id <-- starfunC_Id
  5289   starfun_approx <-- starfun{Nat,CR}_approx
  5290   starfun_capprox <-- starfun{C,RC}_capprox
  5291   starfun_abs <-- starfunNat_rabs
  5292   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  5293   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  5294   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  5295   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  5296   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  5297   starfun_add_approx <-- starfunCR_add_approx
  5298   starfun_inverse_inverse <-- starfunC_inverse_inverse
  5299   starfun_divide <-- starfun{C,CR,RC}_divide
  5300   starfun_n <-- starfun{Nat,C}_n
  5301   starfun_n_mult <-- starfun{Nat,C}_n_mult
  5302   starfun_n_add <-- starfun{Nat,C}_n_add
  5303   starfun_n_add_minus <-- starfunNat_n_add_minus
  5304   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  5305   starfun_n_minus <-- starfun{Nat,C}_n_minus
  5306   starfun_n_eq <-- starfun{Nat,C}_n_eq
  5307 
  5308   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  5309   star_n_minus <-- {hypreal,hcomplex}_minus
  5310   star_n_diff <-- {hypreal,hcomplex}_diff
  5311   star_n_mult <-- {hypreal,hcomplex}_mult
  5312   star_n_inverse <-- {hypreal,hcomplex}_inverse
  5313   star_n_le <-- {hypreal,hypnat}_le
  5314   star_n_less <-- {hypreal,hypnat}_less
  5315   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  5316   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  5317   star_n_abs <-- hypreal_hrabs
  5318   star_n_divide <-- hcomplex_divide
  5319 
  5320   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  5321   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  5322   star_of_diff <-- hypreal_of_real_diff
  5323   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  5324   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  5325   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  5326   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  5327   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  5328   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  5329   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  5330   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  5331   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  5332   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  5333   star_of_number_of <-- {hypreal,hcomplex}_number_of
  5334   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  5335   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  5336   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  5337   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  5338   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  5339   star_of_power <-- hypreal_of_real_power
  5340   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  5341 
  5342 * Hyperreal: new method "transfer" that implements the transfer
  5343 principle of nonstandard analysis. With a subgoal that mentions
  5344 nonstandard types like "'a star", the command "apply transfer"
  5345 replaces it with an equivalent one that mentions only standard types.
  5346 To be successful, all free variables must have standard types; non-
  5347 standard variables must have explicit universal quantifiers.
  5348 
  5349 * Hyperreal: A theory of Taylor series.
  5350 
  5351 
  5352 *** HOLCF ***
  5353 
  5354 * Discontinued special version of 'constdefs' (which used to support
  5355 continuous functions) in favor of the general Pure one with full
  5356 type-inference.
  5357 
  5358 * New simplification procedure for solving continuity conditions; it
  5359 is much faster on terms with many nested lambda abstractions (cubic
  5360 instead of exponential time).
  5361 
  5362 * New syntax for domain package: selector names are now optional.
  5363 Parentheses should be omitted unless argument is lazy, for example:
  5364 
  5365   domain 'a stream = cons "'a" (lazy "'a stream")
  5366 
  5367 * New command 'fixrec' for defining recursive functions with pattern
  5368 matching; defining multiple functions with mutual recursion is also
  5369 supported.  Patterns may include the constants cpair, spair, up, sinl,
  5370 sinr, or any data constructor defined by the domain package. The given
  5371 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  5372 syntax and examples.
  5373 
  5374 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  5375 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  5376 but the proof obligation additionally includes an admissibility
  5377 requirement. The packages generate instances of class cpo or pcpo,
  5378 with continuity and strictness theorems for Rep and Abs.
  5379 
  5380 * HOLCF: Many theorems have been renamed according to a more standard naming
  5381 scheme (INCOMPATIBILITY):
  5382 
  5383   foo_inject:  "foo$x = foo$y ==> x = y"
  5384   foo_eq:      "(foo$x = foo$y) = (x = y)"
  5385   foo_less:    "(foo$x << foo$y) = (x << y)"
  5386   foo_strict:  "foo$UU = UU"
  5387   foo_defined: "... ==> foo$x ~= UU"
  5388   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  5389 
  5390 
  5391 *** ZF ***
  5392 
  5393 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  5394 including the First Isomorphism Theorem (on quotienting by the kernel
  5395 of a homomorphism).
  5396 
  5397 * ZF/Simplifier: install second copy of type solver that actually
  5398 makes use of TC rules declared to Isar proof contexts (or locales);
  5399 the old version is still required for ML proof scripts.
  5400 
  5401 
  5402 *** Cube ***
  5403 
  5404 * Converted to Isar theory format; use locales instead of axiomatic
  5405 theories.
  5406 
  5407 
  5408 *** ML ***
  5409 
  5410 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  5411 for ||>, ||>>, |>>,
  5412 
  5413 * Pure/library.ML no longer defines its own option datatype, but uses
  5414 that of the SML basis, which has constructors NONE and SOME instead of
  5415 None and Some, as well as exception Option.Option instead of OPTION.
  5416 The functions the, if_none, is_some, is_none have been adapted
  5417 accordingly, while Option.map replaces apsome.
  5418 
  5419 * Pure/library.ML: the exception LIST has been given up in favour of
  5420 the standard exceptions Empty and Subscript, as well as
  5421 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  5422 superceded by the standard hd and tl functions etc.
  5423 
  5424 A number of basic list functions are no longer exported to the ML
  5425 toplevel, as they are variants of predefined functions.  The following
  5426 suggests how one can translate existing code:
  5427 
  5428     rev_append xs ys = List.revAppend (xs, ys)
  5429     nth_elem (i, xs) = List.nth (xs, i)
  5430     last_elem xs = List.last xs
  5431     flat xss = List.concat xss
  5432     seq fs = List.app fs
  5433     partition P xs = List.partition P xs
  5434     mapfilter f xs = List.mapPartial f xs
  5435 
  5436 * Pure/library.ML: several combinators for linear functional
  5437 transformations, notably reverse application and composition:
  5438 
  5439   x |> f                f #> g
  5440   (x, y) |-> f          f #-> g
  5441 
  5442 * Pure/library.ML: introduced/changed precedence of infix operators:
  5443 
  5444   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  5445   infix 2 ?;
  5446   infix 3 o oo ooo oooo;
  5447   infix 4 ~~ upto downto;
  5448 
  5449 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  5450 infix operators.
  5451 
  5452 * Pure/library.ML: natural list combinators fold, fold_rev, and
  5453 fold_map support linear functional transformations and nesting.  For
  5454 example:
  5455 
  5456   fold f [x1, ..., xN] y =
  5457     y |> f x1 |> ... |> f xN
  5458 
  5459   (fold o fold) f [xs1, ..., xsN] y =
  5460     y |> fold f xs1 |> ... |> fold f xsN
  5461 
  5462   fold f [x1, ..., xN] =
  5463     f x1 #> ... #> f xN
  5464 
  5465   (fold o fold) f [xs1, ..., xsN] =
  5466     fold f xs1 #> ... #> fold f xsN
  5467 
  5468 * Pure/library.ML: the following selectors on type 'a option are
  5469 available:
  5470 
  5471   the:               'a option -> 'a  (*partial*)
  5472   these:             'a option -> 'a  where 'a = 'b list
  5473   the_default: 'a -> 'a option -> 'a
  5474   the_list:          'a option -> 'a list
  5475 
  5476 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5477 basic operations for association lists, following natural argument
  5478 order; moreover the explicit equality predicate passed here avoids
  5479 potentially expensive polymorphic runtime equality checks.
  5480 The old functions may be expressed as follows:
  5481 
  5482   assoc = uncurry (AList.lookup (op =))
  5483   assocs = these oo AList.lookup (op =)
  5484   overwrite = uncurry (AList.update (op =)) o swap
  5485 
  5486 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5487 
  5488   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  5489   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  5490 
  5491 replacing make_keylist and keyfilter (occassionally used)
  5492 Naive rewrites:
  5493 
  5494   make_keylist = AList.make
  5495   keyfilter = AList.find (op =)
  5496 
  5497 * eq_fst and eq_snd now take explicit equality parameter, thus
  5498   avoiding eqtypes. Naive rewrites:
  5499 
  5500     eq_fst = eq_fst (op =)
  5501     eq_snd = eq_snd (op =)
  5502 
  5503 * Removed deprecated apl and apr (rarely used).
  5504   Naive rewrites:
  5505 
  5506     apl (n, op) =>>= curry op n
  5507     apr (op, m) =>>= fn n => op (n, m)
  5508 
  5509 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  5510 provides a reasonably efficient light-weight implementation of sets as
  5511 lists.
  5512 
  5513 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  5514 few new operations; existing lookup and update are now curried to
  5515 follow natural argument order (for use with fold etc.);
  5516 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  5517 
  5518 * Pure/General: output via the Isabelle channels of
  5519 writeln/warning/error etc. is now passed through Output.output, with a
  5520 hook for arbitrary transformations depending on the print_mode
  5521 (cf. Output.add_mode -- the first active mode that provides a output
  5522 function wins).  Already formatted output may be embedded into further
  5523 text via Output.raw; the result of Pretty.string_of/str_of and derived
  5524 functions (string_of_term/cterm/thm etc.) is already marked raw to
  5525 accommodate easy composition of diagnostic messages etc.  Programmers
  5526 rarely need to care about Output.output or Output.raw at all, with
  5527 some notable exceptions: Output.output is required when bypassing the
  5528 standard channels (writeln etc.), or in token translations to produce
  5529 properly formatted results; Output.raw is required when capturing
  5530 already output material that will eventually be presented to the user
  5531 a second time.  For the default print mode, both Output.output and
  5532 Output.raw have no effect.
  5533 
  5534 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  5535 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  5536 cumulative results are displayed at the end of a batch session.
  5537 
  5538 * Pure/General: File.sysify_path and File.quote_sysify path have been
  5539 replaced by File.platform_path and File.shell_path (with appropriate
  5540 hooks).  This provides a clean interface for unusual systems where the
  5541 internal and external process view of file names are different.
  5542 
  5543 * Pure: more efficient orders for basic syntactic entities: added
  5544 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  5545 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  5546 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  5547 orders now -- potential INCOMPATIBILITY for code that depends on a
  5548 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  5549 Library.sort_strings on result).
  5550 
  5551 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  5552 fold_types traverse types/terms from left to right, observing natural
  5553 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  5554 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  5555 
  5556 * Pure: name spaces have been refined, with significant changes of the
  5557 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  5558 to extern(_table).  The plain name entry path is superceded by a
  5559 general 'naming' context, which also includes the 'policy' to produce
  5560 a fully qualified name and external accesses of a fully qualified
  5561 name; NameSpace.extend is superceded by context dependent
  5562 Sign.declare_name.  Several theory and proof context operations modify
  5563 the naming context.  Especially note Theory.restore_naming and
  5564 ProofContext.restore_naming to get back to a sane state; note that
  5565 Theory.add_path is no longer sufficient to recover from
  5566 Theory.absolute_path in particular.
  5567 
  5568 * Pure: new flags short_names (default false) and unique_names
  5569 (default true) for controlling output of qualified names.  If
  5570 short_names is set, names are printed unqualified.  If unique_names is
  5571 reset, the name prefix is reduced to the minimum required to achieve
  5572 the original result when interning again, even if there is an overlap
  5573 with earlier declarations.
  5574 
  5575 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  5576 now 'extend', and 'merge' gets an additional Pretty.pp argument
  5577 (useful for printing error messages).  INCOMPATIBILITY.
  5578 
  5579 * Pure: major reorganization of the theory context.  Type Sign.sg and
  5580 Theory.theory are now identified, referring to the universal
  5581 Context.theory (see Pure/context.ML).  Actual signature and theory
  5582 content is managed as theory data.  The old code and interfaces were
  5583 spread over many files and structures; the new arrangement introduces
  5584 considerable INCOMPATIBILITY to gain more clarity:
  5585 
  5586   Context -- theory management operations (name, identity, inclusion,
  5587     parents, ancestors, merge, etc.), plus generic theory data;
  5588 
  5589   Sign -- logical signature and syntax operations (declaring consts,
  5590     types, etc.), plus certify/read for common entities;
  5591 
  5592   Theory -- logical theory operations (stating axioms, definitions,
  5593     oracles), plus a copy of logical signature operations (consts,
  5594     types, etc.); also a few basic management operations (Theory.copy,
  5595     Theory.merge, etc.)
  5596 
  5597 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  5598 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  5599 for convenience -- they merely return the theory.
  5600 
  5601 * Pure: type Type.tsig is superceded by theory in most interfaces.
  5602 
  5603 * Pure: the Isar proof context type is already defined early in Pure
  5604 as Context.proof (note that ProofContext.context and Proof.context are
  5605 aliases, where the latter is the preferred name).  This enables other
  5606 Isabelle components to refer to that type even before Isar is present.
  5607 
  5608 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  5609 typeK, constK, axiomK, oracleK), but provide explicit operations for
  5610 any of these kinds.  For example, Sign.intern typeK is now
  5611 Sign.intern_type, Theory.hide_space Sign.typeK is now
  5612 Theory.hide_types.  Also note that former
  5613 Theory.hide_classes/types/consts are now
  5614 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  5615 internalize their arguments!  INCOMPATIBILITY.
  5616 
  5617 * Pure: get_thm interface (of PureThy and ProofContext) expects
  5618 datatype thmref (with constructors Name and NameSelection) instead of
  5619 plain string -- INCOMPATIBILITY;
  5620 
  5621 * Pure: cases produced by proof methods specify options, where NONE
  5622 means to remove case bindings -- INCOMPATIBILITY in
  5623 (RAW_)METHOD_CASES.
  5624 
  5625 * Pure: the following operations retrieve axioms or theorems from a
  5626 theory node or theory hierarchy, respectively:
  5627 
  5628   Theory.axioms_of: theory -> (string * term) list
  5629   Theory.all_axioms_of: theory -> (string * term) list
  5630   PureThy.thms_of: theory -> (string * thm) list
  5631   PureThy.all_thms_of: theory -> (string * thm) list
  5632 
  5633 * Pure: print_tac now outputs the goal through the trace channel.
  5634 
  5635 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  5636 Reference Toplevel.debug (default false) controls detailed printing
  5637 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  5638 controls execution profiling -- set to 1 for time and 2 for space
  5639 (both increase the runtime).
  5640 
  5641 * Isar session: The initial use of ROOT.ML is now always timed,
  5642 i.e. the log will show the actual process times, in contrast to the
  5643 elapsed wall-clock time that the outer shell wrapper produces.
  5644 
  5645 * Simplifier: improved handling of bound variables (nameless
  5646 representation, avoid allocating new strings).  Simprocs that invoke
  5647 the Simplifier recursively should use Simplifier.inherit_bounds to
  5648 avoid local name clashes.  Failure to do so produces warnings
  5649 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  5650 for further details.
  5651 
  5652 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  5653 bindings for all theorems stored within a given theory; this may help
  5654 in porting non-Isar theories to Isar ones, while keeping ML proof
  5655 scripts for the time being.
  5656 
  5657 * ML operator HTML.with_charset specifies the charset begin used for
  5658 generated HTML files.  For example:
  5659 
  5660   HTML.with_charset "utf-8" use_thy "Hebrew";
  5661   HTML.with_charset "utf-8" use_thy "Chinese";
  5662 
  5663 
  5664 *** System ***
  5665 
  5666 * Allow symlinks to all proper Isabelle executables (Isabelle,
  5667 isabelle, isatool etc.).
  5668 
  5669 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  5670 isatool doc, isatool mkdir, display_drafts etc.).
  5671 
  5672 * isatool usedir: option -f allows specification of the ML file to be
  5673 used by Isabelle; default is ROOT.ML.
  5674 
  5675 * New isatool version outputs the version identifier of the Isabelle
  5676 distribution being used.
  5677 
  5678 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  5679 (containing Boolean satisfiability problems) into Isabelle/HOL
  5680 theories.
  5681 
  5682 
  5683 
  5684 New in Isabelle2004 (April 2004)
  5685 --------------------------------
  5686 
  5687 *** General ***
  5688 
  5689 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  5690   Replaces linorder.ML.
  5691 
  5692 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  5693   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  5694   (\<a>...\<z>), are now considered normal letters, and can therefore
  5695   be used anywhere where an ASCII letter (a...zA...Z) has until
  5696   now. COMPATIBILITY: This obviously changes the parsing of some
  5697   terms, especially where a symbol has been used as a binder, say
  5698   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  5699   as an identifier.  Fix it by inserting a space around former
  5700   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  5701   existing theory and ML files.
  5702 
  5703 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  5704 
  5705 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  5706   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  5707   a normal (but invisible) letter. For multiple letter subscripts repeat
  5708   \<^isub> like this: x\<^isub>1\<^isub>2.
  5709 
  5710 * Pure: There are now sub-/superscripts that can span more than one
  5711   character. Text between \<^bsub> and \<^esub> is set in subscript in
  5712   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  5713   superscript. The new control characters are not identifier parts.
  5714 
  5715 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  5716   content of "..." to the latex file instead of \isacntrl... . The "..."
  5717   may consist of any printable characters excluding the end bracket >.
  5718 
  5719 * Pure: Using new Isar command "finalconsts" (or the ML functions
  5720   Theory.add_finals or Theory.add_finals_i) it is now possible to
  5721   declare constants "final", which prevents their being given a definition
  5722   later.  It is useful for constants whose behaviour is fixed axiomatically
  5723   rather than definitionally, such as the meta-logic connectives.
  5724 
  5725 * Pure: 'instance' now handles general arities with general sorts
  5726   (i.e. intersections of classes),
  5727 
  5728 * Presentation: generated HTML now uses a CSS style sheet to make layout
  5729   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  5730   It can be changed to alter the colors/layout of generated pages.
  5731 
  5732 
  5733 *** Isar ***
  5734 
  5735 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  5736   cut_tac, subgoal_tac and thin_tac:
  5737   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  5738     locales are no longer forced to write Isar proof scripts.
  5739     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  5740     emulations.
  5741   - INCOMPATIBILITY: names of variables to be instantiated may no
  5742     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  5743     This is consistent with the instantiation attribute "where".
  5744 
  5745 * Attributes "where" and "of":
  5746   - Now take type variables of instantiated theorem into account when reading
  5747     the instantiation string.  This fixes a bug that caused instantiated
  5748     theorems to have too special types in some circumstances.
  5749   - "where" permits explicit instantiations of type variables.
  5750 
  5751 * Calculation commands "moreover" and "also" no longer interfere with
  5752   current facts ("this"), admitting arbitrary combinations with "then"
  5753   and derived forms.
  5754 
  5755 * Locales:
  5756   - Goal statements involving the context element "includes" no longer
  5757     generate theorems with internal delta predicates (those ending on
  5758     "_axioms") in the premise.
  5759     Resolve particular premise with <locale>.intro to obtain old form.
  5760   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  5761     specification and "includes" elements in goal statement.
  5762   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  5763     [intro?] and [elim?] (respectively) by default.
  5764   - Experimental command for instantiation of locales in proof contexts:
  5765         instantiate <label>[<attrs>]: <loc>
  5766     Instantiates locale <loc> and adds all its theorems to the current context
  5767     taking into account their attributes.  Label and attrs are optional
  5768     modifiers, like in theorem declarations.  If present, names of
  5769     instantiated theorems are qualified with <label>, and the attributes
  5770     <attrs> are applied after any attributes these theorems might have already.
  5771       If the locale has assumptions, a chained fact of the form
  5772     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  5773     are derived.  The command does not support old-style locales declared
  5774     with "locale (open)".
  5775       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  5776 
  5777 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  5778   (Isar) contexts.
  5779 
  5780 
  5781 *** HOL ***
  5782 
  5783 * Proof import: new image HOL4 contains the imported library from
  5784   the HOL4 system with about 2500 theorems. It is imported by
  5785   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  5786   can be used like any other Isabelle image.  See
  5787   HOL/Import/HOL/README for more information.
  5788 
  5789 * Simplifier:
  5790   - Much improved handling of linear and partial orders.
  5791     Reasoners for linear and partial orders are set up for type classes
  5792     "linorder" and "order" respectively, and are added to the default simpset
  5793     as solvers.  This means that the simplifier can build transitivity chains
  5794     to solve goals from the assumptions.
  5795   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  5796     of blast or auto after simplification become unnecessary because the goal
  5797     is solved by simplification already.
  5798 
  5799 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  5800     all proved in axiomatic type classes for semirings, rings and fields.
  5801 
  5802 * Numerics:
  5803   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  5804     now formalized using the Ring_and_Field theory mentioned above.
  5805   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  5806     than before, because now they are set up once in a generic manner.
  5807   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  5808     Look for the general versions in Ring_and_Field (and Power if they concern
  5809     exponentiation).
  5810 
  5811 * Type "rat" of the rational numbers is now available in HOL-Complex.
  5812 
  5813 * Records:
  5814   - Record types are now by default printed with their type abbreviation
  5815     instead of the list of all field types. This can be configured via
  5816     the reference "print_record_type_abbr".
  5817   - Simproc "record_upd_simproc" for simplification of multiple updates added
  5818     (not enabled by default).
  5819   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  5820     EX x. x = sel r to True (not enabled by default).
  5821   - Tactic "record_split_simp_tac" to split and simplify records added.
  5822 
  5823 * 'specification' command added, allowing for definition by
  5824   specification.  There is also an 'ax_specification' command that
  5825   introduces the new constants axiomatically.
  5826 
  5827 * arith(_tac) is now able to generate counterexamples for reals as well.
  5828 
  5829 * HOL-Algebra: new locale "ring" for non-commutative rings.
  5830 
  5831 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  5832   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  5833 
  5834 * HOL-Matrix: a first theory for matrices in HOL with an application of
  5835   matrix theory to linear programming.
  5836 
  5837 * Unions and Intersections:
  5838   The latex output syntax of UN and INT has been changed
  5839   from "\Union x \in A. B" to "\Union_{x \in A} B"
  5840   i.e. the index formulae has become a subscript.
  5841   Similarly for "\Union x. B", and for \Inter instead of \Union.
  5842 
  5843 * Unions and Intersections over Intervals:
  5844   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  5845   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  5846   like in normal math, and corresponding versions for < and for intersection.
  5847 
  5848 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  5849   lexicographic dictonary ordering has been added as "lexord".
  5850 
  5851 * ML: the legacy theory structures Int and List have been removed. They had
  5852   conflicted with ML Basis Library structures having the same names.
  5853 
  5854 * 'refute' command added to search for (finite) countermodels.  Only works
  5855   for a fragment of HOL.  The installation of an external SAT solver is
  5856   highly recommended.  See "HOL/Refute.thy" for details.
  5857 
  5858 * 'quickcheck' command: Allows to find counterexamples by evaluating
  5859   formulae under an assignment of free variables to random values.
  5860   In contrast to 'refute', it can deal with inductive datatypes,
  5861   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  5862   for examples.
  5863 
  5864 
  5865 *** HOLCF ***
  5866 
  5867 * Streams now come with concatenation and are part of the HOLCF image
  5868 
  5869 
  5870 
  5871 New in Isabelle2003 (May 2003)
  5872 ------------------------------
  5873 
  5874 *** General ***
  5875 
  5876 * Provers/simplifier:
  5877 
  5878   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  5879     Assumptions are now subject to complete mutual simplification,
  5880     not just from left to right. The simplifier now preserves
  5881     the order of assumptions.
  5882 
  5883     Potential INCOMPATIBILITY:
  5884 
  5885     -- simp sometimes diverges where the old version did
  5886        not, e.g. invoking simp on the goal
  5887 
  5888         [| P (f x); y = x; f x = f y |] ==> Q
  5889 
  5890        now gives rise to the infinite reduction sequence
  5891 
  5892         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  5893 
  5894        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  5895        kind of problem.
  5896 
  5897     -- Tactics combining classical reasoner and simplification (such as auto)
  5898        are also affected by this change, because many of them rely on
  5899        simp. They may sometimes diverge as well or yield a different numbers
  5900        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  5901        in case of problems. Sometimes subsequent calls to the classical
  5902        reasoner will fail because a preceeding call to the simplifier too
  5903        eagerly simplified the goal, e.g. deleted redundant premises.
  5904 
  5905   - The simplifier trace now shows the names of the applied rewrite rules
  5906 
  5907   - You can limit the number of recursive invocations of the simplifier
  5908     during conditional rewriting (where the simplifie tries to solve the
  5909     conditions before applying the rewrite rule):
  5910     ML "simp_depth_limit := n"
  5911     where n is an integer. Thus you can force termination where previously
  5912     the simplifier would diverge.
  5913 
  5914   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  5915 
  5916   - No longer aborts on failed congruence proof.  Instead, the
  5917     congruence is ignored.
  5918 
  5919 * Pure: New generic framework for extracting programs from constructive
  5920   proofs. See HOL/Extraction.thy for an example instantiation, as well
  5921   as HOL/Extraction for some case studies.
  5922 
  5923 * Pure: The main goal of the proof state is no longer shown by default, only
  5924 the subgoals. This behaviour is controlled by a new flag.
  5925    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  5926 (ML: Proof.show_main_goal).
  5927 
  5928 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  5929 rules whose conclusion matches subgoal 1:
  5930       PG menu: Isabelle/Isar -> Show me -> matching rules
  5931 The rules are ordered by how closely they match the subgoal.
  5932 In particular, rules that solve a subgoal outright are displayed first
  5933 (or rather last, the way they are printed).
  5934 (ML: ProofGeneral.print_intros())
  5935 
  5936 * Pure: New flag trace_unify_fail causes unification to print
  5937 diagnostic information (PG: in trace buffer) when it fails. This is
  5938 useful for figuring out why single step proofs like rule, erule or
  5939 assumption failed.
  5940 
  5941 * Pure: Locale specifications now produce predicate definitions
  5942 according to the body of text (covering assumptions modulo local
  5943 definitions); predicate "loc_axioms" covers newly introduced text,
  5944 while "loc" is cumulative wrt. all included locale expressions; the
  5945 latter view is presented only on export into the global theory
  5946 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  5947 on the old view without predicates;
  5948 
  5949 * Pure: predefined locales "var" and "struct" are useful for sharing
  5950 parameters (as in CASL, for example); just specify something like
  5951 ``var x + var y + struct M'' as import;
  5952 
  5953 * Pure: improved thms_containing: proper indexing of facts instead of
  5954 raw theorems; check validity of results wrt. current name space;
  5955 include local facts of proof configuration (also covers active
  5956 locales), cover fixed variables in index; may use "_" in term
  5957 specification; an optional limit for the number of printed facts may
  5958 be given (the default is 40);
  5959 
  5960 * Pure: disallow duplicate fact bindings within new-style theory files
  5961 (batch-mode only);
  5962 
  5963 * Provers: improved induct method: assumptions introduced by case
  5964 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  5965 the goal statement); "foo" still refers to all facts collectively;
  5966 
  5967 * Provers: the function blast.overloaded has been removed: all constants
  5968 are regarded as potentially overloaded, which improves robustness in exchange
  5969 for slight decrease in efficiency;
  5970 
  5971 * Provers/linorder: New generic prover for transitivity reasoning over
  5972 linear orders.  Note: this prover is not efficient!
  5973 
  5974 * Isar: preview of problems to finish 'show' now produce an error
  5975 rather than just a warning (in interactive mode);
  5976 
  5977 
  5978 *** HOL ***
  5979 
  5980 * arith(_tac)
  5981 
  5982  - Produces a counter example if it cannot prove a goal.
  5983    Note that the counter example may be spurious if the goal is not a formula
  5984    of quantifier-free linear arithmetic.
  5985    In ProofGeneral the counter example appears in the trace buffer.
  5986 
  5987  - Knows about div k and mod k where k is a numeral of type nat or int.
  5988 
  5989  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  5990    linear arithmetic fails. This takes account of quantifiers and divisibility.
  5991    Presburger arithmetic can also be called explicitly via presburger(_tac).
  5992 
  5993 * simp's arithmetic capabilities have been enhanced a bit: it now
  5994 takes ~= in premises into account (by performing a case split);
  5995 
  5996 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  5997 are distributed over a sum of terms;
  5998 
  5999 * New tactic "trans_tac" and method "trans" instantiate
  6000 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  6001 "<=", "<" and "=").
  6002 
  6003 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  6004 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  6005 
  6006 * 'typedef' command has new option "open" to suppress the set
  6007 definition;
  6008 
  6009 * functions Min and Max on finite sets have been introduced (theory
  6010 Finite_Set);
  6011 
  6012 * attribute [symmetric] now works for relations as well; it turns
  6013 (x,y) : R^-1 into (y,x) : R, and vice versa;
  6014 
  6015 * induct over a !!-quantified statement (say !!x1..xn):
  6016   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  6017 
  6018 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  6019 %x. None. Warning: empty_def now refers to the previously hidden definition
  6020 of the empty set.
  6021 
  6022 * Algebra: formalization of classical algebra.  Intended as base for
  6023 any algebraic development in Isabelle.  Currently covers group theory
  6024 (up to Sylow's theorem) and ring theory (Universal Property of
  6025 Univariate Polynomials).  Contributions welcome;
  6026 
  6027 * GroupTheory: deleted, since its material has been moved to Algebra;
  6028 
  6029 * Complex: new directory of the complex numbers with numeric constants,
  6030 nonstandard complex numbers, and some complex analysis, standard and
  6031 nonstandard (Jacques Fleuriot);
  6032 
  6033 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  6034 
  6035 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  6036 Fleuriot);
  6037 
  6038 * Real/HahnBanach: updated and adapted to locales;
  6039 
  6040 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  6041 Gray and Kramer);
  6042 
  6043 * UNITY: added the Meier-Sanders theory of progress sets;
  6044 
  6045 * MicroJava: bytecode verifier and lightweight bytecode verifier
  6046 as abstract algorithms, instantiated to the JVM;
  6047 
  6048 * Bali: Java source language formalization. Type system, operational
  6049 semantics, axiomatic semantics. Supported language features:
  6050 classes, interfaces, objects,virtual methods, static methods,
  6051 static/instance fields, arrays, access modifiers, definite
  6052 assignment, exceptions.
  6053 
  6054 
  6055 *** ZF ***
  6056 
  6057 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  6058 universe, etc.);
  6059 
  6060 * Main ZF: virtually all theories converted to new-style format;
  6061 
  6062 
  6063 *** ML ***
  6064 
  6065 * Pure: Tactic.prove provides sane interface for internal proofs;
  6066 omits the infamous "standard" operation, so this is more appropriate
  6067 than prove_goalw_cterm in many situations (e.g. in simprocs);
  6068 
  6069 * Pure: improved error reporting of simprocs;
  6070 
  6071 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  6072 up simprocs;
  6073 
  6074 
  6075 *** Document preparation ***
  6076 
  6077 * uses \par instead of \\ for line breaks in theory text. This may
  6078 shift some page breaks in large documents. To get the old behaviour
  6079 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  6080 
  6081 * minimized dependencies of isabelle.sty and isabellesym.sty on
  6082 other packages
  6083 
  6084 * \<euro> now needs package babel/greek instead of marvosym (which
  6085 broke \Rightarrow)
  6086 
  6087 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  6088 textcomp package)
  6089 
  6090 
  6091 
  6092 New in Isabelle2002 (March 2002)
  6093 --------------------------------
  6094 
  6095 *** Document preparation ***
  6096 
  6097 * greatly simplified document preparation setup, including more
  6098 graceful interpretation of isatool usedir -i/-d/-D options, and more
  6099 instructive isatool mkdir; users should basically be able to get
  6100 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  6101 users may run a separate document processing stage manually like this:
  6102 "isatool usedir -D output HOL Test && isatool document Test/output";
  6103 
  6104 * theory dependency graph may now be incorporated into documents;
  6105 isatool usedir -g true will produce session_graph.eps/.pdf for use
  6106 with \includegraphics of LaTeX;
  6107 
  6108 * proper spacing of consecutive markup elements, especially text
  6109 blocks after section headings;
  6110 
  6111 * support bold style (for single symbols only), input syntax is like
  6112 this: "\<^bold>\<alpha>" or "\<^bold>A";
  6113 
  6114 * \<bullet> is now output as bold \cdot by default, which looks much
  6115 better in printed text;
  6116 
  6117 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  6118 note that these symbols are currently unavailable in Proof General /
  6119 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  6120 
  6121 * isatool latex no longer depends on changed TEXINPUTS, instead
  6122 isatool document copies the Isabelle style files to the target
  6123 location;
  6124 
  6125 
  6126 *** Isar ***
  6127 
  6128 * Pure/Provers: improved proof by cases and induction;
  6129   - 'case' command admits impromptu naming of parameters (such as
  6130     "case (Suc n)");
  6131   - 'induct' method divinates rule instantiation from the inductive
  6132     claim; no longer requires excessive ?P bindings for proper
  6133     instantiation of cases;
  6134   - 'induct' method properly enumerates all possibilities of set/type
  6135     rules; as a consequence facts may be also passed through *type*
  6136     rules without further ado;
  6137   - 'induct' method now derives symbolic cases from the *rulified*
  6138     rule (before it used to rulify cases stemming from the internal
  6139     atomized version); this means that the context of a non-atomic
  6140     statement becomes is included in the hypothesis, avoiding the
  6141     slightly cumbersome show "PROP ?case" form;
  6142   - 'induct' may now use elim-style induction rules without chaining
  6143     facts, using ``missing'' premises from the goal state; this allows
  6144     rules stemming from inductive sets to be applied in unstructured
  6145     scripts, while still benefitting from proper handling of non-atomic
  6146     statements; NB: major inductive premises need to be put first, all
  6147     the rest of the goal is passed through the induction;
  6148   - 'induct' proper support for mutual induction involving non-atomic
  6149     rule statements (uses the new concept of simultaneous goals, see
  6150     below);
  6151   - append all possible rule selections, but only use the first
  6152     success (no backtracking);
  6153   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  6154   - undeclared rule case names default to numbers 1, 2, 3, ...;
  6155   - added 'print_induct_rules' (covered by help item in recent Proof
  6156     General versions);
  6157   - moved induct/cases attributes to Pure, methods to Provers;
  6158   - generic method setup instantiated for FOL and HOL;
  6159 
  6160 * Pure: support multiple simultaneous goal statements, for example
  6161 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  6162 meta-level mechanism, this acts as if several individual goals had
  6163 been stated separately; in particular common proof methods need to be
  6164 repeated in order to cover all claims; note that a single elimination
  6165 step is *not* sufficient to establish the two conjunctions, so this
  6166 fails:
  6167 
  6168   assume "A & B" then have A and B ..   (*".." fails*)
  6169 
  6170 better use "obtain" in situations as above; alternative refer to
  6171 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  6172 
  6173 * Pure: proper integration with ``locales''; unlike the original
  6174 version by Florian Kammller, Isar locales package high-level proof
  6175 contexts rather than raw logical ones (e.g. we admit to include
  6176 attributes everywhere); operations on locales include merge and
  6177 rename; support for implicit arguments (``structures''); simultaneous
  6178 type-inference over imports and text; see also HOL/ex/Locales.thy for
  6179 some examples;
  6180 
  6181 * Pure: the following commands have been ``localized'', supporting a
  6182 target locale specification "(in name)": 'lemma', 'theorem',
  6183 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  6184 stored both within the locale and at the theory level (exported and
  6185 qualified by the locale name);
  6186 
  6187 * Pure: theory goals may now be specified in ``long'' form, with
  6188 ad-hoc contexts consisting of arbitrary locale elements. for example
  6189 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  6190 definitions may be given, too); the result is a meta-level rule with
  6191 the context elements being discharged in the obvious way;
  6192 
  6193 * Pure: new proof command 'using' allows to augment currently used
  6194 facts after a goal statement ('using' is syntactically analogous to
  6195 'apply', but acts on the goal's facts only); this allows chained facts
  6196 to be separated into parts given before and after a claim, as in
  6197 ``from a and b have C using d and e <proof>'';
  6198 
  6199 * Pure: renamed "antecedent" case to "rule_context";
  6200 
  6201 * Pure: new 'judgment' command records explicit information about the
  6202 object-logic embedding (used by several tools internally); no longer
  6203 use hard-wired "Trueprop";
  6204 
  6205 * Pure: added 'corollary' command;
  6206 
  6207 * Pure: fixed 'token_translation' command;
  6208 
  6209 * Pure: removed obsolete 'exported' attribute;
  6210 
  6211 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  6212 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  6213 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  6214 
  6215 * Pure: method 'atomize' presents local goal premises as object-level
  6216 statements (atomic meta-level propositions); setup controlled via
  6217 rewrite rules declarations of 'atomize' attribute; example
  6218 application: 'induct' method with proper rule statements in improper
  6219 proof *scripts*;
  6220 
  6221 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  6222 now consider the syntactic context of assumptions, giving a better
  6223 chance to get type-inference of the arguments right (this is
  6224 especially important for locales);
  6225 
  6226 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  6227 mode;
  6228 
  6229 * Pure/obtain: the formal conclusion "thesis", being marked as
  6230 ``internal'', may no longer be reference directly in the text;