NEWS
author wenzelm
Fri Aug 12 22:10:49 2011 +0200 (2011-08-12)
changeset 44163 32e0c150c010
parent 44136 e63ad7d5158d
child 44274 731b18266d5a
permissions -rw-r--r--
normalized theory dependencies wrt. file_store;
     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 orders.  Lemmas Inf_less_iff,
    69 less_Sup_iff, INF_less_iff, less_SUP_iff now reside in class complete_linorder.
    70 Changed proposition of lemmas Inf_fun_def, Sup_fun_def, Inf_apply, Sup_apply.
    71 Redundant lemmas Inf_singleton, Sup_singleton, Inf_binary, Sup_binary,
    72 INF_eq, SUP_eq, INF_UNIV_range, SUP_UNIV_range, Int_eq_Inter,
    73 INTER_eq_Inter_image, Inter_def, INT_eq, Un_eq_Union, UNION_eq_Union_image,
    74 Union_def, UN_singleton, UN_eq have been discarded.
    75 More consistent and less misunderstandable names:
    76   INFI_def ~> INF_def
    77   SUPR_def ~> SUP_def
    78   INF_leI ~> INF_lower
    79   INF_leI2 ~> INF_lower2
    80   le_INFI ~> INF_greatest
    81   le_SUPI ~> SUP_upper
    82   le_SUPI2 ~> SUP_upper2
    83   SUP_leI ~> SUP_least
    84   INFI_bool_eq ~> INF_bool_eq
    85   SUPR_bool_eq ~> SUP_bool_eq
    86   INFI_apply ~> INF_apply
    87   SUPR_apply ~> SUP_apply
    88   INTER_def ~> INTER_eq
    89   UNION_def ~> UNION_eq
    90 
    91 INCOMPATIBILITY.
    92 
    93 * Theorem collections ball_simps and bex_simps do not contain theorems referring
    94 to UNION any longer;  these have been moved to collection UN_ball_bex_simps.
    95 INCOMPATIBILITY.
    96 
    97 * Archimedean_Field.thy:
    98     floor now is defined as parameter of a separate type class floor_ceiling.
    99  
   100 * Finite_Set.thy: more coherent development of fold_set locales:
   101 
   102     locale fun_left_comm ~> locale comp_fun_commute
   103     locale fun_left_comm_idem ~> locale comp_fun_idem
   104     
   105 Both use point-free characterisation; interpretation proofs may need adjustment.
   106 INCOMPATIBILITY.
   107 
   108 * Code generation:
   109   - theory Library/Code_Char_ord provides native ordering of characters
   110     in the target language.
   111   - commands code_module and code_library are legacy, use export_code instead. 
   112   - method evaluation is legacy, use method eval instead.
   113   - legacy evaluator "SML" is deactivated by default. To activate it, add the following
   114     line in your theory:
   115       setup {* Value.add_evaluator ("SML", Codegen.eval_term) *}
   116  
   117 * Declare ext [intro] by default.  Rare INCOMPATIBILITY.
   118 
   119 * Nitpick:
   120   - Added "need" and "total_consts" options.
   121   - Reintroduced "show_skolems" option by popular demand.
   122   - Renamed attribute: nitpick_def ~> nitpick_unfold.
   123     INCOMPATIBILITY.
   124 
   125 * Sledgehammer:
   126   - sledgehammer available_provers ~> sledgehammer supported_provers.
   127     INCOMPATIBILITY.
   128   - Added support for SNARK and ToFoF-E on SystemOnTPTP and for simply typed
   129     TPTP problems (TFF).
   130   - Added "preplay_timeout", "slicing", "type_enc", "sound", "max_mono_iters",
   131     and "max_new_mono_instances" options.
   132   - Removed "explicit_apply" and "full_types" options as well as "Full Types"
   133     Proof General menu item. INCOMPATIBILITY.
   134 
   135 * Metis:
   136   - Removed "metisF" -- use "metis" instead. INCOMPATIBILITY.
   137   - Obsoleted "metisFT" -- use "metis (full_types)" instead. INCOMPATIBILITY.
   138 
   139 * "try":
   140   - Renamed "try_methods" and added "simp:", "intro:", "dest:", and "elim:"
   141     options. INCOMPATIBILITY.
   142   - Introduced "try" that not only runs "try_methods" but also "solve_direct",
   143     "sledgehammer", "quickcheck", and "nitpick".
   144 
   145 * Quickcheck:
   146   - Added "eval" option to evaluate terms for the found counterexample
   147     (currently only supported by the default (exhaustive) tester)
   148   - Added post-processing of terms to obtain readable counterexamples
   149     (currently only supported by the default (exhaustive) tester)
   150   - New counterexample generator quickcheck[narrowing] enables
   151     narrowing-based testing.
   152     It requires that the Glasgow Haskell compiler is installed and
   153     its location is known to Isabelle with the environment variable
   154     ISABELLE_GHC.
   155   - Removed quickcheck tester "SML" based on the SML code generator
   156     from HOL-Library
   157 
   158 * Function package: discontinued option "tailrec".
   159 INCOMPATIBILITY. Use partial_function instead.
   160 
   161 * HOL-Probability:
   162   - Caratheodory's extension lemma is now proved for ring_of_sets.
   163   - Infinite products of probability measures are now available.
   164   - Use extended reals instead of positive extended reals.
   165     INCOMPATIBILITY.
   166 
   167 * Old recdef package has been moved to Library/Old_Recdef.thy, where it
   168 must be loaded explicitly.  INCOMPATIBILITY.
   169 
   170 * Well-founded recursion combinator "wfrec" has been moved to
   171 Library/Wfrec.thy. INCOMPATIBILITY.
   172 
   173 * Theory Library/Nat_Infinity has been renamed to Library/Extended_Nat.
   174 The names of the following types and constants have changed:
   175   inat (type) ~> enat
   176   Fin         ~> enat
   177   Infty       ~> infinity (overloaded)
   178   iSuc        ~> eSuc
   179   the_Fin     ~> the_enat
   180 Every theorem name containing "inat", "Fin", "Infty", or "iSuc" has
   181 been renamed accordingly.
   182 
   183 * Limits.thy: Type "'a net" has been renamed to "'a filter", in
   184 accordance with standard mathematical terminology. INCOMPATIBILITY.
   185 
   186 * Session Multivariate_Analysis: Type "('a, 'b) cart" has been renamed
   187 to "('a, 'b) vec" (the syntax "'a ^ 'b" remains unaffected). Constants
   188 "Cart_nth" and "Cart_lambda" have been respectively renamed to
   189 "vec_nth" and "vec_lambda"; theorems mentioning those names have
   190 changed to match. Definition theorems for overloaded constants now use
   191 the standard "foo_vec_def" naming scheme. A few other theorems have
   192 been renamed as follows (INCOMPATIBILITY):
   193 
   194   Cart_eq          ~> vec_eq_iff
   195   dist_nth_le_cart ~> dist_vec_nth_le
   196   tendsto_vector   ~> vec_tendstoI
   197   Cauchy_vector    ~> vec_CauchyI
   198 
   199 
   200 *** Document preparation ***
   201 
   202 * Discontinued special treatment of hard tabulators, which are better
   203 avoided in the first place.  Implicit tab-width is 1.
   204 
   205 * Antiquotation @{rail} layouts railroad syntax diagrams, see also
   206 isar-ref manual.
   207 
   208 * Antiquotation @{value} evaluates the given term and presents its result.
   209 
   210 * Localized \isabellestyle switch can be used within blocks or groups
   211 like this:
   212 
   213   \isabellestyle{it}  %preferred default
   214   {\isabellestylett @{text "typewriter stuff"}}
   215 
   216 * New term style "isub" as ad-hoc conversion of variables x1, y23 into
   217 subscripted form x\<^isub>1, y\<^isub>2\<^isub>3.
   218 
   219 * Predefined LaTeX macros for Isabelle symbols \<bind> and \<then>
   220 (e.g. see ~~/src/HOL/Library/Monad_Syntax.thy).
   221 
   222 
   223 *** ML ***
   224 
   225 * The inner syntax of sort/type/term/prop supports inlined YXML
   226 representations within quoted string tokens.  By encoding logical
   227 entities via Term_XML (in ML or Scala) concrete syntax can be
   228 bypassed, which is particularly useful for producing bits of text
   229 under external program control.
   230 
   231 * Antiquotations for ML and document preparation are managed as theory
   232 data, which requires explicit setup.
   233 
   234 * Isabelle_Process.is_active allows tools to check if the official
   235 process wrapper is running (Isabelle/Scala/jEdit) or the old TTY loop
   236 (better known as Proof General).
   237 
   238 * Structure Proof_Context follows standard naming scheme.  Old
   239 ProofContext is still available for some time as legacy alias.
   240 
   241 * Structure Timing provides various operations for timing; supersedes
   242 former start_timing/end_timing etc.
   243 
   244 * Path.print is the official way to show file-system paths to users
   245 (including quotes etc.).
   246 
   247 * Inner syntax: identifiers in parse trees of generic categories
   248 "logic", "aprop", "idt" etc. carry position information (disguised as
   249 type constraints).  Occasional INCOMPATIBILITY with non-compliant
   250 translations that choke on unexpected type constraints.  Positions can
   251 be stripped in ML translations via Syntax.strip_positions /
   252 Syntax.strip_positions_ast, or via the syntax constant
   253 "_strip_positions" within parse trees.  As last resort, positions can
   254 be disabled via the configuration option Syntax.positions, which is
   255 called "syntax_positions" in Isar attribute syntax.
   256 
   257 * Discontinued special status of various ML structures that contribute
   258 to structure Syntax (Ast, Lexicon, Mixfix, Parser, Printer etc.): less
   259 pervasive content, no inclusion in structure Syntax.  INCOMPATIBILITY,
   260 refer directly to Ast.Constant, Lexicon.is_identifier,
   261 Syntax_Trans.mk_binder_tr etc.
   262 
   263 * Typed print translation: discontinued show_sorts argument, which is
   264 already available via context of "advanced" translation.
   265 
   266 * Refined PARALLEL_GOALS tactical: degrades gracefully for schematic
   267 goal states; body tactic needs to address all subgoals uniformly.
   268 
   269 * Slightly more special eq_list/eq_set, with shortcut involving
   270 pointer equality (assumes that eq relation is reflexive).
   271 
   272 * Classical tactics use proper Proof.context instead of historic types
   273 claset/clasimpset.  Old-style declarations like addIs, addEs, addDs
   274 operate directly on Proof.context.  Raw type claset retains its use as
   275 snapshot of the classical context, which can be recovered via
   276 (put_claset HOL_cs) etc.  Type clasimpset has been discontinued.
   277 INCOMPATIBILITY, classical tactics and derived proof methods require
   278 proper Proof.context.
   279 
   280 * Scala layer provides JVM method invocation service for static
   281 methods of type (String)String, see Invoke_Scala.method in ML.
   282 For example:
   283 
   284   Invoke_Scala.method "java.lang.System.getProperty" "java.home"
   285 
   286 
   287 
   288 New in Isabelle2011 (January 2011)
   289 ----------------------------------
   290 
   291 *** General ***
   292 
   293 * Experimental Prover IDE based on Isabelle/Scala and jEdit (see
   294 src/Tools/jEdit).  This also serves as IDE for Isabelle/ML, with
   295 useful tooltips and hyperlinks produced from its static analysis.  The
   296 bundled component provides an executable Isabelle tool that can be run
   297 like this:
   298 
   299   Isabelle2011/bin/isabelle jedit
   300 
   301 * Significantly improved Isabelle/Isar implementation manual.
   302 
   303 * System settings: ISABELLE_HOME_USER now includes ISABELLE_IDENTIFIER
   304 (and thus refers to something like $HOME/.isabelle/Isabelle2011),
   305 while the default heap location within that directory lacks that extra
   306 suffix.  This isolates multiple Isabelle installations from each
   307 other, avoiding problems with old settings in new versions.
   308 INCOMPATIBILITY, need to copy/upgrade old user settings manually.
   309 
   310 * Source files are always encoded as UTF-8, instead of old-fashioned
   311 ISO-Latin-1.  INCOMPATIBILITY.  Isabelle LaTeX documents might require
   312 the following package declarations:
   313 
   314   \usepackage[utf8]{inputenc}
   315   \usepackage{textcomp}
   316 
   317 * Explicit treatment of UTF-8 sequences as Isabelle symbols, such that
   318 a Unicode character is treated as a single symbol, not a sequence of
   319 non-ASCII bytes as before.  Since Isabelle/ML string literals may
   320 contain symbols without further backslash escapes, Unicode can now be
   321 used here as well.  Recall that Symbol.explode in ML provides a
   322 consistent view on symbols, while raw explode (or String.explode)
   323 merely give a byte-oriented representation.
   324 
   325 * Theory loader: source files are primarily located via the master
   326 directory of each theory node (where the .thy file itself resides).
   327 The global load path is still partially available as legacy feature.
   328 Minor INCOMPATIBILITY due to subtle change in file lookup: use
   329 explicit paths, relatively to the theory.
   330 
   331 * Special treatment of ML file names has been discontinued.
   332 Historically, optional extensions .ML or .sml were added on demand --
   333 at the cost of clarity of file dependencies.  Recall that Isabelle/ML
   334 files exclusively use the .ML extension.  Minor INCOMPATIBILTY.
   335 
   336 * Various options that affect pretty printing etc. are now properly
   337 handled within the context via configuration options, instead of
   338 unsynchronized references or print modes.  There are both ML Config.T
   339 entities and Isar declaration attributes to access these.
   340 
   341   ML (Config.T)                 Isar (attribute)
   342 
   343   eta_contract                  eta_contract
   344   show_brackets                 show_brackets
   345   show_sorts                    show_sorts
   346   show_types                    show_types
   347   show_question_marks           show_question_marks
   348   show_consts                   show_consts
   349   show_abbrevs                  show_abbrevs
   350 
   351   Syntax.ast_trace              syntax_ast_trace
   352   Syntax.ast_stat               syntax_ast_stat
   353   Syntax.ambiguity_level        syntax_ambiguity_level
   354 
   355   Goal_Display.goals_limit      goals_limit
   356   Goal_Display.show_main_goal   show_main_goal
   357 
   358   Method.rule_trace             rule_trace
   359 
   360   Thy_Output.display            thy_output_display
   361   Thy_Output.quotes             thy_output_quotes
   362   Thy_Output.indent             thy_output_indent
   363   Thy_Output.source             thy_output_source
   364   Thy_Output.break              thy_output_break
   365 
   366 Note that corresponding "..._default" references in ML may only be
   367 changed globally at the ROOT session setup, but *not* within a theory.
   368 The option "show_abbrevs" supersedes the former print mode
   369 "no_abbrevs" with inverted meaning.
   370 
   371 * More systematic naming of some configuration options.
   372 INCOMPATIBILITY.
   373 
   374   trace_simp  ~>  simp_trace
   375   debug_simp  ~>  simp_debug
   376 
   377 * Support for real valued configuration options, using simplistic
   378 floating-point notation that coincides with the inner syntax for
   379 float_token.
   380 
   381 * Support for real valued preferences (with approximative PGIP type):
   382 front-ends need to accept "pgint" values in float notation.
   383 INCOMPATIBILITY.
   384 
   385 * The IsabelleText font now includes Cyrillic, Hebrew, Arabic from
   386 DejaVu Sans.
   387 
   388 * Discontinued support for Poly/ML 5.0 and 5.1 versions.
   389 
   390 
   391 *** Pure ***
   392 
   393 * Command 'type_synonym' (with single argument) replaces somewhat
   394 outdated 'types', which is still available as legacy feature for some
   395 time.
   396 
   397 * Command 'nonterminal' (with 'and' separated list of arguments)
   398 replaces somewhat outdated 'nonterminals'.  INCOMPATIBILITY.
   399 
   400 * Command 'notepad' replaces former 'example_proof' for
   401 experimentation in Isar without any result.  INCOMPATIBILITY.
   402 
   403 * Locale interpretation commands 'interpret' and 'sublocale' accept
   404 lists of equations to map definitions in a locale to appropriate
   405 entities in the context of the interpretation.  The 'interpretation'
   406 command already provided this functionality.
   407 
   408 * Diagnostic command 'print_dependencies' prints the locale instances
   409 that would be activated if the specified expression was interpreted in
   410 the current context.  Variant "print_dependencies!" assumes a context
   411 without interpretations.
   412 
   413 * Diagnostic command 'print_interps' prints interpretations in proofs
   414 in addition to interpretations in theories.
   415 
   416 * Discontinued obsolete 'global' and 'local' commands to manipulate
   417 the theory name space.  Rare INCOMPATIBILITY.  The ML functions
   418 Sign.root_path and Sign.local_path may be applied directly where this
   419 feature is still required for historical reasons.
   420 
   421 * Discontinued obsolete 'constdefs' command.  INCOMPATIBILITY, use
   422 'definition' instead.
   423 
   424 * The "prems" fact, which refers to the accidental collection of
   425 foundational premises in the context, is now explicitly marked as
   426 legacy feature and will be discontinued soon.  Consider using "assms"
   427 of the head statement or reference facts by explicit names.
   428 
   429 * Document antiquotations @{class} and @{type} print classes and type
   430 constructors.
   431 
   432 * Document antiquotation @{file} checks file/directory entries within
   433 the local file system.
   434 
   435 
   436 *** HOL ***
   437 
   438 * Coercive subtyping: functions can be declared as coercions and type
   439 inference will add them as necessary upon input of a term.  Theory
   440 Complex_Main declares real :: nat => real and real :: int => real as
   441 coercions. A coercion function f is declared like this:
   442 
   443   declare [[coercion f]]
   444 
   445 To lift coercions through type constructors (e.g. from nat => real to
   446 nat list => real list), map functions can be declared, e.g.
   447 
   448   declare [[coercion_map map]]
   449 
   450 Currently coercion inference is activated only in theories including
   451 real numbers, i.e. descendants of Complex_Main.  This is controlled by
   452 the configuration option "coercion_enabled", e.g. it can be enabled in
   453 other theories like this:
   454 
   455   declare [[coercion_enabled]]
   456 
   457 * Command 'partial_function' provides basic support for recursive
   458 function definitions over complete partial orders.  Concrete instances
   459 are provided for i) the option type, ii) tail recursion on arbitrary
   460 types, and iii) the heap monad of Imperative_HOL.  See
   461 src/HOL/ex/Fundefs.thy and src/HOL/Imperative_HOL/ex/Linked_Lists.thy
   462 for examples.
   463 
   464 * Function package: f.psimps rules are no longer implicitly declared
   465 as [simp].  INCOMPATIBILITY.
   466 
   467 * Datatype package: theorems generated for executable equality (class
   468 "eq") carry proper names and are treated as default code equations.
   469 
   470 * Inductive package: now offers command 'inductive_simps' to
   471 automatically derive instantiated and simplified equations for
   472 inductive predicates, similar to 'inductive_cases'.
   473 
   474 * Command 'enriched_type' allows to register properties of the
   475 functorial structure of types.
   476 
   477 * Improved infrastructure for term evaluation using code generator
   478 techniques, in particular static evaluation conversions.
   479 
   480 * Code generator: Scala (2.8 or higher) has been added to the target
   481 languages.
   482 
   483 * Code generator: globbing constant expressions "*" and "Theory.*"
   484 have been replaced by the more idiomatic "_" and "Theory._".
   485 INCOMPATIBILITY.
   486 
   487 * Code generator: export_code without explicit file declaration prints
   488 to standard output.  INCOMPATIBILITY.
   489 
   490 * Code generator: do not print function definitions for case
   491 combinators any longer.
   492 
   493 * Code generator: simplification with rules determined with
   494 src/Tools/Code/code_simp.ML and method "code_simp".
   495 
   496 * Code generator for records: more idiomatic representation of record
   497 types.  Warning: records are not covered by ancient SML code
   498 generation any longer.  INCOMPATIBILITY.  In cases of need, a suitable
   499 rep_datatype declaration helps to succeed then:
   500 
   501   record 'a foo = ...
   502   ...
   503   rep_datatype foo_ext ...
   504 
   505 * Records: logical foundation type for records does not carry a
   506 '_type' suffix any longer (obsolete due to authentic syntax).
   507 INCOMPATIBILITY.
   508 
   509 * Quickcheck now by default uses exhaustive testing instead of random
   510 testing.  Random testing can be invoked by "quickcheck [random]",
   511 exhaustive testing by "quickcheck [exhaustive]".
   512 
   513 * Quickcheck instantiates polymorphic types with small finite
   514 datatypes by default. This enables a simple execution mechanism to
   515 handle quantifiers and function equality over the finite datatypes.
   516 
   517 * Quickcheck random generator has been renamed from "code" to
   518 "random".  INCOMPATIBILITY.
   519 
   520 * Quickcheck now has a configurable time limit which is set to 30
   521 seconds by default. This can be changed by adding [timeout = n] to the
   522 quickcheck command. The time limit for Auto Quickcheck is still set
   523 independently.
   524 
   525 * Quickcheck in locales considers interpretations of that locale for
   526 counter example search.
   527 
   528 * Sledgehammer:
   529   - Added "smt" and "remote_smt" provers based on the "smt" proof
   530     method. See the Sledgehammer manual for details ("isabelle doc
   531     sledgehammer").
   532   - Renamed commands:
   533     sledgehammer atp_info ~> sledgehammer running_provers
   534     sledgehammer atp_kill ~> sledgehammer kill_provers
   535     sledgehammer available_atps ~> sledgehammer available_provers
   536     INCOMPATIBILITY.
   537   - Renamed options:
   538     sledgehammer [atps = ...] ~> sledgehammer [provers = ...]
   539     sledgehammer [atp = ...] ~> sledgehammer [prover = ...]
   540     sledgehammer [timeout = 77 s] ~> sledgehammer [timeout = 77]
   541     (and "ms" and "min" are no longer supported)
   542     INCOMPATIBILITY.
   543 
   544 * Nitpick:
   545   - Renamed options:
   546     nitpick [timeout = 77 s] ~> nitpick [timeout = 77]
   547     nitpick [tac_timeout = 777 ms] ~> nitpick [tac_timeout = 0.777]
   548     INCOMPATIBILITY.
   549   - Added support for partial quotient types.
   550   - Added local versions of the "Nitpick.register_xxx" functions.
   551   - Added "whack" option.
   552   - Allow registration of quotient types as codatatypes.
   553   - Improved "merge_type_vars" option to merge more types.
   554   - Removed unsound "fast_descrs" option.
   555   - Added custom symmetry breaking for datatypes, making it possible to reach
   556     higher cardinalities.
   557   - Prevent the expansion of too large definitions.
   558 
   559 * Proof methods "metis" and "meson" now have configuration options
   560 "meson_trace", "metis_trace", and "metis_verbose" that can be enabled
   561 to diagnose these tools. E.g.
   562 
   563     using [[metis_trace = true]]
   564 
   565 * Auto Solve: Renamed "Auto Solve Direct".  The tool is now available
   566 manually as command 'solve_direct'.
   567 
   568 * The default SMT solver Z3 must be enabled explicitly (due to
   569 licensing issues) by setting the environment variable
   570 Z3_NON_COMMERCIAL in etc/settings of the component, for example.  For
   571 commercial applications, the SMT solver CVC3 is provided as fall-back;
   572 changing the SMT solver is done via the configuration option
   573 "smt_solver".
   574 
   575 * Remote SMT solvers need to be referred to by the "remote_" prefix,
   576 i.e. "remote_cvc3" and "remote_z3".
   577 
   578 * Added basic SMT support for datatypes, records, and typedefs using
   579 the oracle mode (no proofs).  Direct support of pairs has been dropped
   580 in exchange (pass theorems fst_conv snd_conv pair_collapse to the SMT
   581 support for a similar behavior).  Minor INCOMPATIBILITY.
   582 
   583 * Changed SMT configuration options:
   584   - Renamed:
   585     z3_proofs ~> smt_oracle (with inverted meaning)
   586     z3_trace_assms ~> smt_trace_used_facts
   587     INCOMPATIBILITY.
   588   - Added:
   589     smt_verbose
   590     smt_random_seed
   591     smt_datatypes
   592     smt_infer_triggers
   593     smt_monomorph_limit
   594     cvc3_options
   595     remote_cvc3_options
   596     remote_z3_options
   597     yices_options
   598 
   599 * Boogie output files (.b2i files) need to be declared in the theory
   600 header.
   601 
   602 * Simplification procedure "list_to_set_comprehension" rewrites list
   603 comprehensions applied to List.set to set comprehensions.  Occasional
   604 INCOMPATIBILITY, may be deactivated like this:
   605 
   606   declare [[simproc del: list_to_set_comprehension]]
   607 
   608 * Removed old version of primrec package.  INCOMPATIBILITY.
   609 
   610 * Removed simplifier congruence rule of "prod_case", as has for long
   611 been the case with "split".  INCOMPATIBILITY.
   612 
   613 * String.literal is a type, but not a datatype.  INCOMPATIBILITY.
   614 
   615 * Removed [split_format ... and ... and ...] version of
   616 [split_format].  Potential INCOMPATIBILITY.
   617 
   618 * Predicate "sorted" now defined inductively, with nice induction
   619 rules.  INCOMPATIBILITY: former sorted.simps now named sorted_simps.
   620 
   621 * Constant "contents" renamed to "the_elem", to free the generic name
   622 contents for other uses.  INCOMPATIBILITY.
   623 
   624 * Renamed class eq and constant eq (for code generation) to class
   625 equal and constant equal, plus renaming of related facts and various
   626 tuning.  INCOMPATIBILITY.
   627 
   628 * Dropped type classes mult_mono and mult_mono1.  INCOMPATIBILITY.
   629 
   630 * Removed output syntax "'a ~=> 'b" for "'a => 'b option".
   631 INCOMPATIBILITY.
   632 
   633 * Renamed theory Fset to Cset, type Fset.fset to Cset.set, in order to
   634 avoid confusion with finite sets.  INCOMPATIBILITY.
   635 
   636 * Abandoned locales equiv, congruent and congruent2 for equivalence
   637 relations.  INCOMPATIBILITY: use equivI rather than equiv_intro (same
   638 for congruent(2)).
   639 
   640 * Some previously unqualified names have been qualified:
   641 
   642   types
   643     bool ~> HOL.bool
   644     nat ~> Nat.nat
   645 
   646   constants
   647     Trueprop ~> HOL.Trueprop
   648     True ~> HOL.True
   649     False ~> HOL.False
   650     op & ~> HOL.conj
   651     op | ~> HOL.disj
   652     op --> ~> HOL.implies
   653     op = ~> HOL.eq
   654     Not ~> HOL.Not
   655     The ~> HOL.The
   656     All ~> HOL.All
   657     Ex ~> HOL.Ex
   658     Ex1 ~> HOL.Ex1
   659     Let ~> HOL.Let
   660     If ~> HOL.If
   661     Ball ~> Set.Ball
   662     Bex ~> Set.Bex
   663     Suc ~> Nat.Suc
   664     Pair ~> Product_Type.Pair
   665     fst ~> Product_Type.fst
   666     snd ~> Product_Type.snd
   667     curry ~> Product_Type.curry
   668     op : ~> Set.member
   669     Collect ~> Set.Collect
   670 
   671 INCOMPATIBILITY.
   672 
   673 * More canonical naming convention for some fundamental definitions:
   674 
   675     bot_bool_eq ~> bot_bool_def
   676     top_bool_eq ~> top_bool_def
   677     inf_bool_eq ~> inf_bool_def
   678     sup_bool_eq ~> sup_bool_def
   679     bot_fun_eq  ~> bot_fun_def
   680     top_fun_eq  ~> top_fun_def
   681     inf_fun_eq  ~> inf_fun_def
   682     sup_fun_eq  ~> sup_fun_def
   683 
   684 INCOMPATIBILITY.
   685 
   686 * More stylized fact names:
   687 
   688   expand_fun_eq ~> fun_eq_iff
   689   expand_set_eq ~> set_eq_iff
   690   set_ext       ~> set_eqI
   691   nat_number    ~> eval_nat_numeral
   692 
   693 INCOMPATIBILITY.
   694 
   695 * Refactoring of code-generation specific operations in theory List:
   696 
   697   constants
   698     null ~> List.null
   699 
   700   facts
   701     mem_iff ~> member_def
   702     null_empty ~> null_def
   703 
   704 INCOMPATIBILITY.  Note that these were not supposed to be used
   705 regularly unless for striking reasons; their main purpose was code
   706 generation.
   707 
   708 Various operations from the Haskell prelude are used for generating
   709 Haskell code.
   710 
   711 * Term "bij f" is now an abbreviation of "bij_betw f UNIV UNIV".  Term
   712 "surj f" is now an abbreviation of "range f = UNIV".  The theorems
   713 bij_def and surj_def are unchanged.  INCOMPATIBILITY.
   714 
   715 * Abolished some non-alphabetic type names: "prod" and "sum" replace
   716 "*" and "+" respectively.  INCOMPATIBILITY.
   717 
   718 * Name "Plus" of disjoint sum operator "<+>" is now hidden.  Write
   719 "Sum_Type.Plus" instead.
   720 
   721 * Constant "split" has been merged with constant "prod_case"; names of
   722 ML functions, facts etc. involving split have been retained so far,
   723 though.  INCOMPATIBILITY.
   724 
   725 * Dropped old infix syntax "_ mem _" for List.member; use "_ : set _"
   726 instead.  INCOMPATIBILITY.
   727 
   728 * Removed lemma "Option.is_none_none" which duplicates "is_none_def".
   729 INCOMPATIBILITY.
   730 
   731 * Former theory Library/Enum is now part of the HOL-Main image.
   732 INCOMPATIBILITY: all constants of the Enum theory now have to be
   733 referred to by its qualified name.
   734 
   735   enum    ~>  Enum.enum
   736   nlists  ~>  Enum.nlists
   737   product ~>  Enum.product
   738 
   739 * Theory Library/Monad_Syntax provides do-syntax for monad types.
   740 Syntax in Library/State_Monad has been changed to avoid ambiguities.
   741 INCOMPATIBILITY.
   742 
   743 * Theory Library/SetsAndFunctions has been split into
   744 Library/Function_Algebras and Library/Set_Algebras; canonical names
   745 for instance definitions for functions; various improvements.
   746 INCOMPATIBILITY.
   747 
   748 * Theory Library/Multiset provides stable quicksort implementation of
   749 sort_key.
   750 
   751 * Theory Library/Multiset: renamed empty_idemp ~> empty_neutral.
   752 INCOMPATIBILITY.
   753 
   754 * Session Multivariate_Analysis: introduced a type class for euclidean
   755 space.  Most theorems are now stated in terms of euclidean spaces
   756 instead of finite cartesian products.
   757 
   758   types
   759     real ^ 'n ~>  'a::real_vector
   760               ~>  'a::euclidean_space
   761               ~>  'a::ordered_euclidean_space
   762         (depends on your needs)
   763 
   764   constants
   765      _ $ _        ~> _ $$ _
   766      \<chi> x. _  ~> \<chi>\<chi> x. _
   767      CARD('n)     ~> DIM('a)
   768 
   769 Also note that the indices are now natural numbers and not from some
   770 finite type. Finite cartesian products of euclidean spaces, products
   771 of euclidean spaces the real and complex numbers are instantiated to
   772 be euclidean_spaces.  INCOMPATIBILITY.
   773 
   774 * Session Probability: introduced pextreal as positive extended real
   775 numbers.  Use pextreal as value for measures.  Introduce the
   776 Radon-Nikodym derivative, product spaces and Fubini's theorem for
   777 arbitrary sigma finite measures.  Introduces Lebesgue measure based on
   778 the integral in Multivariate Analysis.  INCOMPATIBILITY.
   779 
   780 * Session Imperative_HOL: revamped, corrected dozens of inadequacies.
   781 INCOMPATIBILITY.
   782 
   783 * Session SPARK (with image HOL-SPARK) provides commands to load and
   784 prove verification conditions generated by the SPARK Ada program
   785 verifier.  See also src/HOL/SPARK and src/HOL/SPARK/Examples.
   786 
   787 
   788 *** HOL-Algebra ***
   789 
   790 * Theorems for additive ring operations (locale abelian_monoid and
   791 descendants) are generated by interpretation from their multiplicative
   792 counterparts.  Names (in particular theorem names) have the mandatory
   793 qualifier 'add'.  Previous theorem names are redeclared for
   794 compatibility.
   795 
   796 * Structure "int_ring" is now an abbreviation (previously a
   797 definition).  This fits more natural with advanced interpretations.
   798 
   799 
   800 *** HOLCF ***
   801 
   802 * The domain package now runs in definitional mode by default: The
   803 former command 'new_domain' is now called 'domain'.  To use the domain
   804 package in its original axiomatic mode, use 'domain (unsafe)'.
   805 INCOMPATIBILITY.
   806 
   807 * The new class "domain" is now the default sort.  Class "predomain"
   808 is an unpointed version of "domain". Theories can be updated by
   809 replacing sort annotations as shown below.  INCOMPATIBILITY.
   810 
   811   'a::type ~> 'a::countable
   812   'a::cpo  ~> 'a::predomain
   813   'a::pcpo ~> 'a::domain
   814 
   815 * The old type class "rep" has been superseded by class "domain".
   816 Accordingly, users of the definitional package must remove any
   817 "default_sort rep" declarations.  INCOMPATIBILITY.
   818 
   819 * The domain package (definitional mode) now supports unpointed
   820 predomain argument types, as long as they are marked 'lazy'. (Strict
   821 arguments must be in class "domain".) For example, the following
   822 domain definition now works:
   823 
   824   domain natlist = nil | cons (lazy "nat discr") (lazy "natlist")
   825 
   826 * Theory HOLCF/Library/HOL_Cpo provides cpo and predomain class
   827 instances for types from main HOL: bool, nat, int, char, 'a + 'b,
   828 'a option, and 'a list.  Additionally, it configures fixrec and the
   829 domain package to work with these types.  For example:
   830 
   831   fixrec isInl :: "('a + 'b) u -> tr"
   832     where "isInl$(up$(Inl x)) = TT" | "isInl$(up$(Inr y)) = FF"
   833 
   834   domain V = VFun (lazy "V -> V") | VCon (lazy "nat") (lazy "V list")
   835 
   836 * The "(permissive)" option of fixrec has been replaced with a
   837 per-equation "(unchecked)" option. See
   838 src/HOL/HOLCF/Tutorial/Fixrec_ex.thy for examples. INCOMPATIBILITY.
   839 
   840 * The "bifinite" class no longer fixes a constant "approx"; the class
   841 now just asserts that such a function exists.  INCOMPATIBILITY.
   842 
   843 * Former type "alg_defl" has been renamed to "defl".  HOLCF no longer
   844 defines an embedding of type 'a defl into udom by default; instances
   845 of "bifinite" and "domain" classes are available in
   846 src/HOL/HOLCF/Library/Defl_Bifinite.thy.
   847 
   848 * The syntax "REP('a)" has been replaced with "DEFL('a)".
   849 
   850 * The predicate "directed" has been removed.  INCOMPATIBILITY.
   851 
   852 * The type class "finite_po" has been removed.  INCOMPATIBILITY.
   853 
   854 * The function "cprod_map" has been renamed to "prod_map".
   855 INCOMPATIBILITY.
   856 
   857 * The monadic bind operator on each powerdomain has new binder syntax
   858 similar to sets, e.g. "\<Union>\<sharp>x\<in>xs. t" represents
   859 "upper_bind\<cdot>xs\<cdot>(\<Lambda> x. t)".
   860 
   861 * The infix syntax for binary union on each powerdomain has changed
   862 from e.g. "+\<sharp>" to "\<union>\<sharp>", for consistency with set
   863 syntax.  INCOMPATIBILITY.
   864 
   865 * The constant "UU" has been renamed to "bottom".  The syntax "UU" is
   866 still supported as an input translation.
   867 
   868 * Renamed some theorems (the original names are also still available).
   869 
   870   expand_fun_below   ~> fun_below_iff
   871   below_fun_ext      ~> fun_belowI
   872   expand_cfun_eq     ~> cfun_eq_iff
   873   ext_cfun           ~> cfun_eqI
   874   expand_cfun_below  ~> cfun_below_iff
   875   below_cfun_ext     ~> cfun_belowI
   876   cont2cont_Rep_CFun ~> cont2cont_APP
   877 
   878 * The Abs and Rep functions for various types have changed names.
   879 Related theorem names have also changed to match. INCOMPATIBILITY.
   880 
   881   Rep_CFun  ~> Rep_cfun
   882   Abs_CFun  ~> Abs_cfun
   883   Rep_Sprod ~> Rep_sprod
   884   Abs_Sprod ~> Abs_sprod
   885   Rep_Ssum  ~> Rep_ssum
   886   Abs_Ssum  ~> Abs_ssum
   887 
   888 * Lemmas with names of the form *_defined_iff or *_strict_iff have
   889 been renamed to *_bottom_iff.  INCOMPATIBILITY.
   890 
   891 * Various changes to bisimulation/coinduction with domain package:
   892 
   893   - Definitions of "bisim" constants no longer mention definedness.
   894   - With mutual recursion, "bisim" predicate is now curried.
   895   - With mutual recursion, each type gets a separate coind theorem.
   896   - Variable names in bisim_def and coinduct rules have changed.
   897 
   898 INCOMPATIBILITY.
   899 
   900 * Case combinators generated by the domain package for type "foo" are
   901 now named "foo_case" instead of "foo_when".  INCOMPATIBILITY.
   902 
   903 * Several theorems have been renamed to more accurately reflect the
   904 names of constants and types involved.  INCOMPATIBILITY.
   905 
   906   thelub_const    ~> lub_const
   907   lub_const       ~> is_lub_const
   908   thelubI         ~> lub_eqI
   909   is_lub_lub      ~> is_lubD2
   910   lubI            ~> is_lub_lub
   911   unique_lub      ~> is_lub_unique
   912   is_ub_lub       ~> is_lub_rangeD1
   913   lub_bin_chain   ~> is_lub_bin_chain
   914   lub_fun         ~> is_lub_fun
   915   thelub_fun      ~> lub_fun
   916   thelub_cfun     ~> lub_cfun
   917   thelub_Pair     ~> lub_Pair
   918   lub_cprod       ~> is_lub_prod
   919   thelub_cprod    ~> lub_prod
   920   minimal_cprod   ~> minimal_prod
   921   inst_cprod_pcpo ~> inst_prod_pcpo
   922   UU_I            ~> bottomI
   923   compact_UU      ~> compact_bottom
   924   deflation_UU    ~> deflation_bottom
   925   finite_deflation_UU ~> finite_deflation_bottom
   926 
   927 * Many legacy theorem names have been discontinued.  INCOMPATIBILITY.
   928 
   929   sq_ord_less_eq_trans ~> below_eq_trans
   930   sq_ord_eq_less_trans ~> eq_below_trans
   931   refl_less            ~> below_refl
   932   trans_less           ~> below_trans
   933   antisym_less         ~> below_antisym
   934   antisym_less_inverse ~> po_eq_conv [THEN iffD1]
   935   box_less             ~> box_below
   936   rev_trans_less       ~> rev_below_trans
   937   not_less2not_eq      ~> not_below2not_eq
   938   less_UU_iff          ~> below_UU_iff
   939   flat_less_iff        ~> flat_below_iff
   940   adm_less             ~> adm_below
   941   adm_not_less         ~> adm_not_below
   942   adm_compact_not_less ~> adm_compact_not_below
   943   less_fun_def         ~> below_fun_def
   944   expand_fun_less      ~> fun_below_iff
   945   less_fun_ext         ~> fun_belowI
   946   less_discr_def       ~> below_discr_def
   947   discr_less_eq        ~> discr_below_eq
   948   less_unit_def        ~> below_unit_def
   949   less_cprod_def       ~> below_prod_def
   950   prod_lessI           ~> prod_belowI
   951   Pair_less_iff        ~> Pair_below_iff
   952   fst_less_iff         ~> fst_below_iff
   953   snd_less_iff         ~> snd_below_iff
   954   expand_cfun_less     ~> cfun_below_iff
   955   less_cfun_ext        ~> cfun_belowI
   956   injection_less       ~> injection_below
   957   less_up_def          ~> below_up_def
   958   not_Iup_less         ~> not_Iup_below
   959   Iup_less             ~> Iup_below
   960   up_less              ~> up_below
   961   Def_inject_less_eq   ~> Def_below_Def
   962   Def_less_is_eq       ~> Def_below_iff
   963   spair_less_iff       ~> spair_below_iff
   964   less_sprod           ~> below_sprod
   965   spair_less           ~> spair_below
   966   sfst_less_iff        ~> sfst_below_iff
   967   ssnd_less_iff        ~> ssnd_below_iff
   968   fix_least_less       ~> fix_least_below
   969   dist_less_one        ~> dist_below_one
   970   less_ONE             ~> below_ONE
   971   ONE_less_iff         ~> ONE_below_iff
   972   less_sinlD           ~> below_sinlD
   973   less_sinrD           ~> below_sinrD
   974 
   975 
   976 *** FOL and ZF ***
   977 
   978 * All constant names are now qualified internally and use proper
   979 identifiers, e.g. "IFOL.eq" instead of "op =".  INCOMPATIBILITY.
   980 
   981 
   982 *** ML ***
   983 
   984 * Antiquotation @{assert} inlines a function bool -> unit that raises
   985 Fail if the argument is false.  Due to inlining the source position of
   986 failed assertions is included in the error output.
   987 
   988 * Discontinued antiquotation @{theory_ref}, which is obsolete since ML
   989 text is in practice always evaluated with a stable theory checkpoint.
   990 Minor INCOMPATIBILITY, use (Theory.check_thy @{theory}) instead.
   991 
   992 * Antiquotation @{theory A} refers to theory A from the ancestry of
   993 the current context, not any accidental theory loader state as before.
   994 Potential INCOMPATIBILITY, subtle change in semantics.
   995 
   996 * Syntax.pretty_priority (default 0) configures the required priority
   997 of pretty-printed output and thus affects insertion of parentheses.
   998 
   999 * Syntax.default_root (default "any") configures the inner syntax
  1000 category (nonterminal symbol) for parsing of terms.
  1001 
  1002 * Former exception Library.UnequalLengths now coincides with
  1003 ListPair.UnequalLengths.
  1004 
  1005 * Renamed structure MetaSimplifier to Raw_Simplifier.  Note that the
  1006 main functionality is provided by structure Simplifier.
  1007 
  1008 * Renamed raw "explode" function to "raw_explode" to emphasize its
  1009 meaning.  Note that internally to Isabelle, Symbol.explode is used in
  1010 almost all situations.
  1011 
  1012 * Discontinued obsolete function sys_error and exception SYS_ERROR.
  1013 See implementation manual for further details on exceptions in
  1014 Isabelle/ML.
  1015 
  1016 * Renamed setmp_noncritical to Unsynchronized.setmp to emphasize its
  1017 meaning.
  1018 
  1019 * Renamed structure PureThy to Pure_Thy and moved most of its
  1020 operations to structure Global_Theory, to emphasize that this is
  1021 rarely-used global-only stuff.
  1022 
  1023 * Discontinued Output.debug.  Minor INCOMPATIBILITY, use plain writeln
  1024 instead (or tracing for high-volume output).
  1025 
  1026 * Configuration option show_question_marks only affects regular pretty
  1027 printing of types and terms, not raw Term.string_of_vname.
  1028 
  1029 * ML_Context.thm and ML_Context.thms are no longer pervasive.  Rare
  1030 INCOMPATIBILITY, superseded by static antiquotations @{thm} and
  1031 @{thms} for most purposes.
  1032 
  1033 * ML structure Unsynchronized is never opened, not even in Isar
  1034 interaction mode as before.  Old Unsynchronized.set etc. have been
  1035 discontinued -- use plain := instead.  This should be *rare* anyway,
  1036 since modern tools always work via official context data, notably
  1037 configuration options.
  1038 
  1039 * Parallel and asynchronous execution requires special care concerning
  1040 interrupts.  Structure Exn provides some convenience functions that
  1041 avoid working directly with raw Interrupt.  User code must not absorb
  1042 interrupts -- intermediate handling (for cleanup etc.) needs to be
  1043 followed by re-raising of the original exception.  Another common
  1044 source of mistakes are "handle _" patterns, which make the meaning of
  1045 the program subject to physical effects of the environment.
  1046 
  1047 
  1048 
  1049 New in Isabelle2009-2 (June 2010)
  1050 ---------------------------------
  1051 
  1052 *** General ***
  1053 
  1054 * Authentic syntax for *all* logical entities (type classes, type
  1055 constructors, term constants): provides simple and robust
  1056 correspondence between formal entities and concrete syntax.  Within
  1057 the parse tree / AST representations, "constants" are decorated by
  1058 their category (class, type, const) and spelled out explicitly with
  1059 their full internal name.
  1060 
  1061 Substantial INCOMPATIBILITY concerning low-level syntax declarations
  1062 and translations (translation rules and translation functions in ML).
  1063 Some hints on upgrading:
  1064 
  1065   - Many existing uses of 'syntax' and 'translations' can be replaced
  1066     by more modern 'type_notation', 'notation' and 'abbreviation',
  1067     which are independent of this issue.
  1068 
  1069   - 'translations' require markup within the AST; the term syntax
  1070     provides the following special forms:
  1071 
  1072       CONST c   -- produces syntax version of constant c from context
  1073       XCONST c  -- literally c, checked as constant from context
  1074       c         -- literally c, if declared by 'syntax'
  1075 
  1076     Plain identifiers are treated as AST variables -- occasionally the
  1077     system indicates accidental variables via the error "rhs contains
  1078     extra variables".
  1079 
  1080     Type classes and type constructors are marked according to their
  1081     concrete syntax.  Some old translations rules need to be written
  1082     for the "type" category, using type constructor application
  1083     instead of pseudo-term application of the default category
  1084     "logic".
  1085 
  1086   - 'parse_translation' etc. in ML may use the following
  1087     antiquotations:
  1088 
  1089       @{class_syntax c}   -- type class c within parse tree / AST
  1090       @{term_syntax c}    -- type constructor c within parse tree / AST
  1091       @{const_syntax c}   -- ML version of "CONST c" above
  1092       @{syntax_const c}   -- literally c (checked wrt. 'syntax' declarations)
  1093 
  1094   - Literal types within 'typed_print_translations', i.e. those *not*
  1095     represented as pseudo-terms are represented verbatim.  Use @{class
  1096     c} or @{type_name c} here instead of the above syntax
  1097     antiquotations.
  1098 
  1099 Note that old non-authentic syntax was based on unqualified base
  1100 names, so all of the above "constant" names would coincide.  Recall
  1101 that 'print_syntax' and ML_command "set Syntax.trace_ast" help to
  1102 diagnose syntax problems.
  1103 
  1104 * Type constructors admit general mixfix syntax, not just infix.
  1105 
  1106 * Concrete syntax may be attached to local entities without a proof
  1107 body, too.  This works via regular mixfix annotations for 'fix',
  1108 'def', 'obtain' etc. or via the explicit 'write' command, which is
  1109 similar to the 'notation' command in theory specifications.
  1110 
  1111 * Discontinued unnamed infix syntax (legacy feature for many years) --
  1112 need to specify constant name and syntax separately.  Internal ML
  1113 datatype constructors have been renamed from InfixName to Infix etc.
  1114 Minor INCOMPATIBILITY.
  1115 
  1116 * Schematic theorem statements need to be explicitly markup as such,
  1117 via commands 'schematic_lemma', 'schematic_theorem',
  1118 'schematic_corollary'.  Thus the relevance of the proof is made
  1119 syntactically clear, which impacts performance in a parallel or
  1120 asynchronous interactive environment.  Minor INCOMPATIBILITY.
  1121 
  1122 * Use of cumulative prems via "!" in some proof methods has been
  1123 discontinued (old legacy feature).
  1124 
  1125 * References 'trace_simp' and 'debug_simp' have been replaced by
  1126 configuration options stored in the context. Enabling tracing (the
  1127 case of debugging is similar) in proofs works via
  1128 
  1129   using [[trace_simp = true]]
  1130 
  1131 Tracing is then active for all invocations of the simplifier in
  1132 subsequent goal refinement steps. Tracing may also still be enabled or
  1133 disabled via the ProofGeneral settings menu.
  1134 
  1135 * Separate commands 'hide_class', 'hide_type', 'hide_const',
  1136 'hide_fact' replace the former 'hide' KIND command.  Minor
  1137 INCOMPATIBILITY.
  1138 
  1139 * Improved parallelism of proof term normalization: usedir -p2 -q0 is
  1140 more efficient than combinations with -q1 or -q2.
  1141 
  1142 
  1143 *** Pure ***
  1144 
  1145 * Proofterms record type-class reasoning explicitly, using the
  1146 "unconstrain" operation internally.  This eliminates all sort
  1147 constraints from a theorem and proof, introducing explicit
  1148 OFCLASS-premises.  On the proof term level, this operation is
  1149 automatically applied at theorem boundaries, such that closed proofs
  1150 are always free of sort constraints.  INCOMPATIBILITY for tools that
  1151 inspect proof terms.
  1152 
  1153 * Local theory specifications may depend on extra type variables that
  1154 are not present in the result type -- arguments TYPE('a) :: 'a itself
  1155 are added internally.  For example:
  1156 
  1157   definition unitary :: bool where "unitary = (ALL (x::'a) y. x = y)"
  1158 
  1159 * Predicates of locales introduced by classes carry a mandatory
  1160 "class" prefix.  INCOMPATIBILITY.
  1161 
  1162 * Vacuous class specifications observe default sort.  INCOMPATIBILITY.
  1163 
  1164 * Old 'axclass' command has been discontinued.  INCOMPATIBILITY, use
  1165 'class' instead.
  1166 
  1167 * Command 'code_reflect' allows to incorporate generated ML code into
  1168 runtime environment; replaces immature code_datatype antiquotation.
  1169 INCOMPATIBILITY.
  1170 
  1171 * Code generator: simple concept for abstract datatypes obeying
  1172 invariants.
  1173 
  1174 * Code generator: details of internal data cache have no impact on the
  1175 user space functionality any longer.
  1176 
  1177 * Methods "unfold_locales" and "intro_locales" ignore non-locale
  1178 subgoals.  This is more appropriate for interpretations with 'where'.
  1179 INCOMPATIBILITY.
  1180 
  1181 * Command 'example_proof' opens an empty proof body.  This allows to
  1182 experiment with Isar, without producing any persistent result.
  1183 
  1184 * Commands 'type_notation' and 'no_type_notation' declare type syntax
  1185 within a local theory context, with explicit checking of the
  1186 constructors involved (in contrast to the raw 'syntax' versions).
  1187 
  1188 * Commands 'types' and 'typedecl' now work within a local theory
  1189 context -- without introducing dependencies on parameters or
  1190 assumptions, which is not possible in Isabelle/Pure.
  1191 
  1192 * Command 'defaultsort' has been renamed to 'default_sort', it works
  1193 within a local theory context.  Minor INCOMPATIBILITY.
  1194 
  1195 
  1196 *** HOL ***
  1197 
  1198 * Command 'typedef' now works within a local theory context -- without
  1199 introducing dependencies on parameters or assumptions, which is not
  1200 possible in Isabelle/Pure/HOL.  Note that the logical environment may
  1201 contain multiple interpretations of local typedefs (with different
  1202 non-emptiness proofs), even in a global theory context.
  1203 
  1204 * New package for quotient types.  Commands 'quotient_type' and
  1205 'quotient_definition' may be used for defining types and constants by
  1206 quotient constructions.  An example is the type of integers created by
  1207 quotienting pairs of natural numbers:
  1208 
  1209   fun
  1210     intrel :: "(nat * nat) => (nat * nat) => bool"
  1211   where
  1212     "intrel (x, y) (u, v) = (x + v = u + y)"
  1213 
  1214   quotient_type int = "nat * nat" / intrel
  1215     by (auto simp add: equivp_def expand_fun_eq)
  1216 
  1217   quotient_definition
  1218     "0::int" is "(0::nat, 0::nat)"
  1219 
  1220 The method "lifting" can be used to lift of theorems from the
  1221 underlying "raw" type to the quotient type.  The example
  1222 src/HOL/Quotient_Examples/FSet.thy includes such a quotient
  1223 construction and provides a reasoning infrastructure for finite sets.
  1224 
  1225 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
  1226 clash with new theory Quotient in Main HOL.
  1227 
  1228 * Moved the SMT binding into the main HOL session, eliminating
  1229 separate HOL-SMT session.
  1230 
  1231 * List membership infix mem operation is only an input abbreviation.
  1232 INCOMPATIBILITY.
  1233 
  1234 * Theory Library/Word.thy has been removed.  Use library Word/Word.thy
  1235 for future developements; former Library/Word.thy is still present in
  1236 the AFP entry RSAPPS.
  1237 
  1238 * Theorem Int.int_induct renamed to Int.int_of_nat_induct and is no
  1239 longer shadowed.  INCOMPATIBILITY.
  1240 
  1241 * Dropped theorem duplicate comp_arith; use semiring_norm instead.
  1242 INCOMPATIBILITY.
  1243 
  1244 * Dropped theorem RealPow.real_sq_order; use power2_le_imp_le instead.
  1245 INCOMPATIBILITY.
  1246 
  1247 * Dropped normalizing_semiring etc; use the facts in semiring classes
  1248 instead.  INCOMPATIBILITY.
  1249 
  1250 * Dropped several real-specific versions of lemmas about floor and
  1251 ceiling; use the generic lemmas from theory "Archimedean_Field"
  1252 instead.  INCOMPATIBILITY.
  1253 
  1254   floor_number_of_eq         ~> floor_number_of
  1255   le_floor_eq_number_of      ~> number_of_le_floor
  1256   le_floor_eq_zero           ~> zero_le_floor
  1257   le_floor_eq_one            ~> one_le_floor
  1258   floor_less_eq_number_of    ~> floor_less_number_of
  1259   floor_less_eq_zero         ~> floor_less_zero
  1260   floor_less_eq_one          ~> floor_less_one
  1261   less_floor_eq_number_of    ~> number_of_less_floor
  1262   less_floor_eq_zero         ~> zero_less_floor
  1263   less_floor_eq_one          ~> one_less_floor
  1264   floor_le_eq_number_of      ~> floor_le_number_of
  1265   floor_le_eq_zero           ~> floor_le_zero
  1266   floor_le_eq_one            ~> floor_le_one
  1267   floor_subtract_number_of   ~> floor_diff_number_of
  1268   floor_subtract_one         ~> floor_diff_one
  1269   ceiling_number_of_eq       ~> ceiling_number_of
  1270   ceiling_le_eq_number_of    ~> ceiling_le_number_of
  1271   ceiling_le_zero_eq         ~> ceiling_le_zero
  1272   ceiling_le_eq_one          ~> ceiling_le_one
  1273   less_ceiling_eq_number_of  ~> number_of_less_ceiling
  1274   less_ceiling_eq_zero       ~> zero_less_ceiling
  1275   less_ceiling_eq_one        ~> one_less_ceiling
  1276   ceiling_less_eq_number_of  ~> ceiling_less_number_of
  1277   ceiling_less_eq_zero       ~> ceiling_less_zero
  1278   ceiling_less_eq_one        ~> ceiling_less_one
  1279   le_ceiling_eq_number_of    ~> number_of_le_ceiling
  1280   le_ceiling_eq_zero         ~> zero_le_ceiling
  1281   le_ceiling_eq_one          ~> one_le_ceiling
  1282   ceiling_subtract_number_of ~> ceiling_diff_number_of
  1283   ceiling_subtract_one       ~> ceiling_diff_one
  1284 
  1285 * Theory "Finite_Set": various folding_XXX locales facilitate the
  1286 application of the various fold combinators on finite sets.
  1287 
  1288 * Library theory "RBT" renamed to "RBT_Impl"; new library theory "RBT"
  1289 provides abstract red-black tree type which is backed by "RBT_Impl" as
  1290 implementation.  INCOMPATIBILTY.
  1291 
  1292 * Theory Library/Coinductive_List has been removed -- superseded by
  1293 AFP/thys/Coinductive.
  1294 
  1295 * Theory PReal, including the type "preal" and related operations, has
  1296 been removed.  INCOMPATIBILITY.
  1297 
  1298 * Real: new development using Cauchy Sequences.
  1299 
  1300 * Split off theory "Big_Operators" containing setsum, setprod,
  1301 Inf_fin, Sup_fin, Min, Max from theory Finite_Set.  INCOMPATIBILITY.
  1302 
  1303 * Theory "Rational" renamed to "Rat", for consistency with "Nat",
  1304 "Int" etc.  INCOMPATIBILITY.
  1305 
  1306 * Constant Rat.normalize needs to be qualified.  INCOMPATIBILITY.
  1307 
  1308 * New set of rules "ac_simps" provides combined assoc / commute
  1309 rewrites for all interpretations of the appropriate generic locales.
  1310 
  1311 * Renamed theory "OrderedGroup" to "Groups" and split theory
  1312 "Ring_and_Field" into theories "Rings" and "Fields"; for more
  1313 appropriate and more consistent names suitable for name prefixes
  1314 within the HOL theories.  INCOMPATIBILITY.
  1315 
  1316 * Some generic constants have been put to appropriate theories:
  1317   - less_eq, less: Orderings
  1318   - zero, one, plus, minus, uminus, times, abs, sgn: Groups
  1319   - inverse, divide: Rings
  1320 INCOMPATIBILITY.
  1321 
  1322 * More consistent naming of type classes involving orderings (and
  1323 lattices):
  1324 
  1325     lower_semilattice                   ~> semilattice_inf
  1326     upper_semilattice                   ~> semilattice_sup
  1327 
  1328     dense_linear_order                  ~> dense_linorder
  1329 
  1330     pordered_ab_group_add               ~> ordered_ab_group_add
  1331     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
  1332     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
  1333     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
  1334     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
  1335     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
  1336     pordered_cancel_semiring            ~> ordered_cancel_semiring
  1337     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
  1338     pordered_comm_ring                  ~> ordered_comm_ring
  1339     pordered_comm_semiring              ~> ordered_comm_semiring
  1340     pordered_ring                       ~> ordered_ring
  1341     pordered_ring_abs                   ~> ordered_ring_abs
  1342     pordered_semiring                   ~> ordered_semiring
  1343 
  1344     ordered_ab_group_add                ~> linordered_ab_group_add
  1345     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
  1346     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
  1347     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
  1348     ordered_field                       ~> linordered_field
  1349     ordered_field_no_lb                 ~> linordered_field_no_lb
  1350     ordered_field_no_ub                 ~> linordered_field_no_ub
  1351     ordered_field_dense_linear_order    ~> dense_linordered_field
  1352     ordered_idom                        ~> linordered_idom
  1353     ordered_ring                        ~> linordered_ring
  1354     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
  1355     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
  1356     ordered_ring_strict                 ~> linordered_ring_strict
  1357     ordered_semidom                     ~> linordered_semidom
  1358     ordered_semiring                    ~> linordered_semiring
  1359     ordered_semiring_1                  ~> linordered_semiring_1
  1360     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
  1361     ordered_semiring_strict             ~> linordered_semiring_strict
  1362 
  1363   The following slightly odd type classes have been moved to a
  1364   separate theory Library/Lattice_Algebras:
  1365 
  1366     lordered_ab_group_add               ~> lattice_ab_group_add
  1367     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
  1368     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
  1369     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
  1370     lordered_ring                       ~> lattice_ring
  1371 
  1372 INCOMPATIBILITY.
  1373 
  1374 * Refined field classes:
  1375   - classes division_ring_inverse_zero, field_inverse_zero,
  1376     linordered_field_inverse_zero include rule inverse 0 = 0 --
  1377     subsumes former division_by_zero class;
  1378   - numerous lemmas have been ported from field to division_ring.
  1379 INCOMPATIBILITY.
  1380 
  1381 * Refined algebra theorem collections:
  1382   - dropped theorem group group_simps, use algebra_simps instead;
  1383   - dropped theorem group ring_simps, use field_simps instead;
  1384   - proper theorem collection field_simps subsumes former theorem
  1385     groups field_eq_simps and field_simps;
  1386   - dropped lemma eq_minus_self_iff which is a duplicate for
  1387     equal_neg_zero.
  1388 INCOMPATIBILITY.
  1389 
  1390 * Theory Finite_Set and List: some lemmas have been generalized from
  1391 sets to lattices:
  1392 
  1393   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
  1394   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
  1395   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
  1396   union_Union_fold_union        ~> sup_Sup_fold_sup
  1397   Inter_fold_inter              ~> Inf_fold_inf
  1398   Union_fold_union              ~> Sup_fold_sup
  1399   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
  1400   union_UNION_fold_union        ~> sup_SUPR_fold_sup
  1401   INTER_fold_inter              ~> INFI_fold_inf
  1402   UNION_fold_union              ~> SUPR_fold_sup
  1403 
  1404 * Theory "Complete_Lattice": lemmas top_def and bot_def have been
  1405 replaced by the more convenient lemmas Inf_empty and Sup_empty.
  1406 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
  1407 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
  1408 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
  1409 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
  1410 
  1411 * Reorganized theory Multiset: swapped notation of pointwise and
  1412 multiset order:
  1413 
  1414   - pointwise ordering is instance of class order with standard syntax
  1415     <= and <;
  1416   - multiset ordering has syntax <=# and <#; partial order properties
  1417     are provided by means of interpretation with prefix
  1418     multiset_order;
  1419   - less duplication, less historical organization of sections,
  1420     conversion from associations lists to multisets, rudimentary code
  1421     generation;
  1422   - use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union,
  1423     if needed.
  1424 
  1425 Renamed:
  1426 
  1427   multiset_eq_conv_count_eq  ~>  multiset_ext_iff
  1428   multi_count_ext  ~>  multiset_ext
  1429   diff_union_inverse2  ~>  diff_union_cancelR
  1430 
  1431 INCOMPATIBILITY.
  1432 
  1433 * Theory Permutation: replaced local "remove" by List.remove1.
  1434 
  1435 * Code generation: ML and OCaml code is decorated with signatures.
  1436 
  1437 * Theory List: added transpose.
  1438 
  1439 * Library/Nat_Bijection.thy is a collection of bijective functions
  1440 between nat and other types, which supersedes the older libraries
  1441 Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.
  1442 
  1443   Constants:
  1444   Nat_Int_Bij.nat2_to_nat         ~> prod_encode
  1445   Nat_Int_Bij.nat_to_nat2         ~> prod_decode
  1446   Nat_Int_Bij.int_to_nat_bij      ~> int_encode
  1447   Nat_Int_Bij.nat_to_int_bij      ~> int_decode
  1448   Countable.pair_encode           ~> prod_encode
  1449   NatIso.prod2nat                 ~> prod_encode
  1450   NatIso.nat2prod                 ~> prod_decode
  1451   NatIso.sum2nat                  ~> sum_encode
  1452   NatIso.nat2sum                  ~> sum_decode
  1453   NatIso.list2nat                 ~> list_encode
  1454   NatIso.nat2list                 ~> list_decode
  1455   NatIso.set2nat                  ~> set_encode
  1456   NatIso.nat2set                  ~> set_decode
  1457 
  1458   Lemmas:
  1459   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
  1460   Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
  1461   Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
  1462   Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
  1463   Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
  1464   Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
  1465   Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
  1466   Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
  1467   Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
  1468   Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
  1469   Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
  1470   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
  1471   Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode
  1472 
  1473 * Sledgehammer:
  1474   - Renamed ATP commands:
  1475     atp_info     ~> sledgehammer running_atps
  1476     atp_kill     ~> sledgehammer kill_atps
  1477     atp_messages ~> sledgehammer messages
  1478     atp_minimize ~> sledgehammer minimize
  1479     print_atps   ~> sledgehammer available_atps
  1480     INCOMPATIBILITY.
  1481   - Added user's manual ("isabelle doc sledgehammer").
  1482   - Added option syntax and "sledgehammer_params" to customize
  1483     Sledgehammer's behavior.  See the manual for details.
  1484   - Modified the Isar proof reconstruction code so that it produces
  1485     direct proofs rather than proofs by contradiction.  (This feature
  1486     is still experimental.)
  1487   - Made Isar proof reconstruction work for SPASS, remote ATPs, and in
  1488     full-typed mode.
  1489   - Added support for TPTP syntax for SPASS via the "spass_tptp" ATP.
  1490 
  1491 * Nitpick:
  1492   - Added and implemented "binary_ints" and "bits" options.
  1493   - Added "std" option and implemented support for nonstandard models.
  1494   - Added and implemented "finitize" option to improve the precision
  1495     of infinite datatypes based on a monotonicity analysis.
  1496   - Added support for quotient types.
  1497   - Added support for "specification" and "ax_specification"
  1498     constructs.
  1499   - Added support for local definitions (for "function" and
  1500     "termination" proofs).
  1501   - Added support for term postprocessors.
  1502   - Optimized "Multiset.multiset" and "FinFun.finfun".
  1503   - Improved efficiency of "destroy_constrs" optimization.
  1504   - Fixed soundness bugs related to "destroy_constrs" optimization and
  1505     record getters.
  1506   - Fixed soundness bug related to higher-order constructors.
  1507   - Fixed soundness bug when "full_descrs" is enabled.
  1508   - Improved precision of set constructs.
  1509   - Added "atoms" option.
  1510   - Added cache to speed up repeated Kodkod invocations on the same
  1511     problems.
  1512   - Renamed "MiniSatJNI", "zChaffJNI", "BerkMinAlloy", and
  1513     "SAT4JLight" to "MiniSat_JNI", "zChaff_JNI", "BerkMin_Alloy", and
  1514     "SAT4J_Light".  INCOMPATIBILITY.
  1515   - Removed "skolemize", "uncurry", "sym_break", "flatten_prop",
  1516     "sharing_depth", and "show_skolems" options.  INCOMPATIBILITY.
  1517   - Removed "nitpick_intro" attribute.  INCOMPATIBILITY.
  1518 
  1519 * Method "induct" now takes instantiations of the form t, where t is not
  1520   a variable, as a shorthand for "x == t", where x is a fresh variable.
  1521   If this is not intended, t has to be enclosed in parentheses.
  1522   By default, the equalities generated by definitional instantiations
  1523   are pre-simplified, which may cause parameters of inductive cases
  1524   to disappear, or may even delete some of the inductive cases.
  1525   Use "induct (no_simp)" instead of "induct" to restore the old
  1526   behaviour. The (no_simp) option is also understood by the "cases"
  1527   and "nominal_induct" methods, which now perform pre-simplification, too.
  1528   INCOMPATIBILITY.
  1529 
  1530 
  1531 *** HOLCF ***
  1532 
  1533 * Variable names in lemmas generated by the domain package have
  1534 changed; the naming scheme is now consistent with the HOL datatype
  1535 package.  Some proof scripts may be affected, INCOMPATIBILITY.
  1536 
  1537 * The domain package no longer defines the function "foo_copy" for
  1538 recursive domain "foo".  The reach lemma is now stated directly in
  1539 terms of "foo_take".  Lemmas and proofs that mention "foo_copy" must
  1540 be reformulated in terms of "foo_take", INCOMPATIBILITY.
  1541 
  1542 * Most definedness lemmas generated by the domain package (previously
  1543 of the form "x ~= UU ==> foo$x ~= UU") now have an if-and-only-if form
  1544 like "foo$x = UU <-> x = UU", which works better as a simp rule.
  1545 Proofs that used definedness lemmas as intro rules may break,
  1546 potential INCOMPATIBILITY.
  1547 
  1548 * Induction and casedist rules generated by the domain package now
  1549 declare proper case_names (one called "bottom", and one named for each
  1550 constructor).  INCOMPATIBILITY.
  1551 
  1552 * For mutually-recursive domains, separate "reach" and "take_lemma"
  1553 rules are generated for each domain, INCOMPATIBILITY.
  1554 
  1555   foo_bar.reach       ~> foo.reach  bar.reach
  1556   foo_bar.take_lemmas ~> foo.take_lemma  bar.take_lemma
  1557 
  1558 * Some lemmas generated by the domain package have been renamed for
  1559 consistency with the datatype package, INCOMPATIBILITY.
  1560 
  1561   foo.ind        ~> foo.induct
  1562   foo.finite_ind ~> foo.finite_induct
  1563   foo.coind      ~> foo.coinduct
  1564   foo.casedist   ~> foo.exhaust
  1565   foo.exhaust    ~> foo.nchotomy
  1566 
  1567 * For consistency with other definition packages, the fixrec package
  1568 now generates qualified theorem names, INCOMPATIBILITY.
  1569 
  1570   foo_simps  ~> foo.simps
  1571   foo_unfold ~> foo.unfold
  1572   foo_induct ~> foo.induct
  1573 
  1574 * The "fixrec_simp" attribute has been removed.  The "fixrec_simp"
  1575 method and internal fixrec proofs now use the default simpset instead.
  1576 INCOMPATIBILITY.
  1577 
  1578 * The "contlub" predicate has been removed.  Proof scripts should use
  1579 lemma contI2 in place of monocontlub2cont, INCOMPATIBILITY.
  1580 
  1581 * The "admw" predicate has been removed, INCOMPATIBILITY.
  1582 
  1583 * The constants cpair, cfst, and csnd have been removed in favor of
  1584 Pair, fst, and snd from Isabelle/HOL, INCOMPATIBILITY.
  1585 
  1586 
  1587 *** ML ***
  1588 
  1589 * Antiquotations for basic formal entities:
  1590 
  1591     @{class NAME}         -- type class
  1592     @{class_syntax NAME}  -- syntax representation of the above
  1593 
  1594     @{type_name NAME}     -- logical type
  1595     @{type_abbrev NAME}   -- type abbreviation
  1596     @{nonterminal NAME}   -- type of concrete syntactic category
  1597     @{type_syntax NAME}   -- syntax representation of any of the above
  1598 
  1599     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
  1600     @{const_abbrev NAME}  -- abbreviated constant
  1601     @{const_syntax NAME}  -- syntax representation of any of the above
  1602 
  1603 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
  1604 syntax constant (cf. 'syntax' command).
  1605 
  1606 * Antiquotation @{make_string} inlines a function to print arbitrary
  1607 values similar to the ML toplevel.  The result is compiler dependent
  1608 and may fall back on "?" in certain situations.
  1609 
  1610 * Diagnostic commands 'ML_val' and 'ML_command' may refer to
  1611 antiquotations @{Isar.state} and @{Isar.goal}.  This replaces impure
  1612 Isar.state() and Isar.goal(), which belong to the old TTY loop and do
  1613 not work with the asynchronous Isar document model.
  1614 
  1615 * Configuration options now admit dynamic default values, depending on
  1616 the context or even global references.
  1617 
  1618 * SHA1.digest digests strings according to SHA-1 (see RFC 3174).  It
  1619 uses an efficient external library if available (for Poly/ML).
  1620 
  1621 * Renamed some important ML structures, while keeping the old names
  1622 for some time as aliases within the structure Legacy:
  1623 
  1624   OuterKeyword  ~>  Keyword
  1625   OuterLex      ~>  Token
  1626   OuterParse    ~>  Parse
  1627   OuterSyntax   ~>  Outer_Syntax
  1628   PrintMode     ~>  Print_Mode
  1629   SpecParse     ~>  Parse_Spec
  1630   ThyInfo       ~>  Thy_Info
  1631   ThyLoad       ~>  Thy_Load
  1632   ThyOutput     ~>  Thy_Output
  1633   TypeInfer     ~>  Type_Infer
  1634 
  1635 Note that "open Legacy" simplifies porting of sources, but forgetting
  1636 to remove it again will complicate porting again in the future.
  1637 
  1638 * Most operations that refer to a global context are named
  1639 accordingly, e.g. Simplifier.global_context or
  1640 ProofContext.init_global.  There are some situations where a global
  1641 context actually works, but under normal circumstances one needs to
  1642 pass the proper local context through the code!
  1643 
  1644 * Discontinued old TheoryDataFun with its copy/init operation -- data
  1645 needs to be pure.  Functor Theory_Data_PP retains the traditional
  1646 Pretty.pp argument to merge, which is absent in the standard
  1647 Theory_Data version.
  1648 
  1649 * Sorts.certify_sort and derived "cert" operations for types and terms
  1650 no longer minimize sorts.  Thus certification at the boundary of the
  1651 inference kernel becomes invariant under addition of class relations,
  1652 which is an important monotonicity principle.  Sorts are now minimized
  1653 in the syntax layer only, at the boundary between the end-user and the
  1654 system.  Subtle INCOMPATIBILITY, may have to use Sign.minimize_sort
  1655 explicitly in rare situations.
  1656 
  1657 * Renamed old-style Drule.standard to Drule.export_without_context, to
  1658 emphasize that this is in no way a standard operation.
  1659 INCOMPATIBILITY.
  1660 
  1661 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
  1662 usual for resolution.  Rare INCOMPATIBILITY.
  1663 
  1664 * Renamed varify/unvarify operations to varify_global/unvarify_global
  1665 to emphasize that these only work in a global situation (which is
  1666 quite rare).
  1667 
  1668 * Curried take and drop in library.ML; negative length is interpreted
  1669 as infinity (as in chop).  Subtle INCOMPATIBILITY.
  1670 
  1671 * Proof terms: type substitutions on proof constants now use canonical
  1672 order of type variables.  INCOMPATIBILITY for tools working with proof
  1673 terms.
  1674 
  1675 * Raw axioms/defs may no longer carry sort constraints, and raw defs
  1676 may no longer carry premises.  User-level specifications are
  1677 transformed accordingly by Thm.add_axiom/add_def.
  1678 
  1679 
  1680 *** System ***
  1681 
  1682 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
  1683 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
  1684 proof terms are enabled unconditionally in the new HOL-Proofs image.
  1685 
  1686 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
  1687 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
  1688 respectively.
  1689 
  1690 * Old lib/scripts/polyml-platform is superseded by the
  1691 ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
  1692 variant, even on a 64 bit machine.  The following example setting
  1693 prefers 64 bit if available:
  1694 
  1695   ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"
  1696 
  1697 * The preliminary Isabelle/jEdit application demonstrates the emerging
  1698 Isabelle/Scala layer for advanced prover interaction and integration.
  1699 See src/Tools/jEdit or "isabelle jedit" provided by the properly built
  1700 component.
  1701 
  1702 * "IsabelleText" is a Unicode font derived from Bitstream Vera Mono
  1703 and Bluesky TeX fonts.  It provides the usual Isabelle symbols,
  1704 similar to the default assignment of the document preparation system
  1705 (cf. isabellesym.sty).  The Isabelle/Scala class Isabelle_System
  1706 provides some operations for direct access to the font without asking
  1707 the user for manual installation.
  1708 
  1709 
  1710 
  1711 New in Isabelle2009-1 (December 2009)
  1712 -------------------------------------
  1713 
  1714 *** General ***
  1715 
  1716 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
  1717 one backslash should be used, even in ML sources.
  1718 
  1719 
  1720 *** Pure ***
  1721 
  1722 * Locale interpretation propagates mixins along the locale hierarchy.
  1723 The currently only available mixins are the equations used to map
  1724 local definitions to terms of the target domain of an interpretation.
  1725 
  1726 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
  1727 loc" to print all interpretations of locale "loc" in the theory.
  1728 Interpretations in proofs are not shown.
  1729 
  1730 * Thoroughly revised locales tutorial.  New section on conditional
  1731 interpretation.
  1732 
  1733 * On instantiation of classes, remaining undefined class parameters
  1734 are formally declared.  INCOMPATIBILITY.
  1735 
  1736 
  1737 *** Document preparation ***
  1738 
  1739 * New generalized style concept for printing terms: @{foo (style) ...}
  1740 instead of @{foo_style style ...}  (old form is still retained for
  1741 backward compatibility).  Styles can be also applied for
  1742 antiquotations prop, term_type and typeof.
  1743 
  1744 
  1745 *** HOL ***
  1746 
  1747 * New proof method "smt" for a combination of first-order logic with
  1748 equality, linear and nonlinear (natural/integer/real) arithmetic, and
  1749 fixed-size bitvectors; there is also basic support for higher-order
  1750 features (esp. lambda abstractions).  It is an incomplete decision
  1751 procedure based on external SMT solvers using the oracle mechanism;
  1752 for the SMT solver Z3, this method is proof-producing.  Certificates
  1753 are provided to avoid calling the external solvers solely for
  1754 re-checking proofs.  Due to a remote SMT service there is no need for
  1755 installing SMT solvers locally.  See src/HOL/SMT.
  1756 
  1757 * New commands to load and prove verification conditions generated by
  1758 the Boogie program verifier or derived systems (e.g. the Verifying C
  1759 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
  1760 
  1761 * New counterexample generator tool 'nitpick' based on the Kodkod
  1762 relational model finder.  See src/HOL/Tools/Nitpick and
  1763 src/HOL/Nitpick_Examples.
  1764 
  1765 * New commands 'code_pred' and 'values' to invoke the predicate
  1766 compiler and to enumerate values of inductive predicates.
  1767 
  1768 * A tabled implementation of the reflexive transitive closure.
  1769 
  1770 * New implementation of quickcheck uses generic code generator;
  1771 default generators are provided for all suitable HOL types, records
  1772 and datatypes.  Old quickcheck can be re-activated importing theory
  1773 Library/SML_Quickcheck.
  1774 
  1775 * New testing tool Mirabelle for automated proof tools.  Applies
  1776 several tools and tactics like sledgehammer, metis, or quickcheck, to
  1777 every proof step in a theory.  To be used in batch mode via the
  1778 "mirabelle" utility.
  1779 
  1780 * New proof method "sos" (sum of squares) for nonlinear real
  1781 arithmetic (originally due to John Harison). It requires theory
  1782 Library/Sum_Of_Squares.  It is not a complete decision procedure but
  1783 works well in practice on quantifier-free real arithmetic with +, -,
  1784 *, ^, =, <= and <, i.e. boolean combinations of equalities and
  1785 inequalities between polynomials.  It makes use of external
  1786 semidefinite programming solvers.  Method "sos" generates a
  1787 certificate that can be pasted into the proof thus avoiding the need
  1788 to call an external tool every time the proof is checked.  See
  1789 src/HOL/Library/Sum_Of_Squares.
  1790 
  1791 * New method "linarith" invokes existing linear arithmetic decision
  1792 procedure only.
  1793 
  1794 * New command 'atp_minimal' reduces result produced by Sledgehammer.
  1795 
  1796 * New Sledgehammer option "Full Types" in Proof General settings menu.
  1797 Causes full type information to be output to the ATPs.  This slows
  1798 ATPs down considerably but eliminates a source of unsound "proofs"
  1799 that fail later.
  1800 
  1801 * New method "metisFT": A version of metis that uses full type
  1802 information in order to avoid failures of proof reconstruction.
  1803 
  1804 * New evaluator "approximate" approximates an real valued term using
  1805 the same method as the approximation method.
  1806 
  1807 * Method "approximate" now supports arithmetic expressions as
  1808 boundaries of intervals and implements interval splitting and Taylor
  1809 series expansion.
  1810 
  1811 * ML antiquotation @{code_datatype} inserts definition of a datatype
  1812 generated by the code generator; e.g. see src/HOL/Predicate.thy.
  1813 
  1814 * New theory SupInf of the supremum and infimum operators for sets of
  1815 reals.
  1816 
  1817 * New theory Probability, which contains a development of measure
  1818 theory, eventually leading to Lebesgue integration and probability.
  1819 
  1820 * Extended Multivariate Analysis to include derivation and Brouwer's
  1821 fixpoint theorem.
  1822 
  1823 * Reorganization of number theory, INCOMPATIBILITY:
  1824   - new number theory development for nat and int, in theories Divides
  1825     and GCD as well as in new session Number_Theory
  1826   - some constants and facts now suffixed with _nat and _int
  1827     accordingly
  1828   - former session NumberTheory now named Old_Number_Theory, including
  1829     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
  1830   - moved theory Pocklington from src/HOL/Library to
  1831     src/HOL/Old_Number_Theory
  1832 
  1833 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
  1834 lcm of finite and infinite sets. It is shown that they form a complete
  1835 lattice.
  1836 
  1837 * Class semiring_div requires superclass no_zero_divisors and proof of
  1838 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
  1839 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
  1840 generalized to class semiring_div, subsuming former theorems
  1841 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
  1842 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
  1843 INCOMPATIBILITY.
  1844 
  1845 * Refinements to lattice classes and sets:
  1846   - less default intro/elim rules in locale variant, more default
  1847     intro/elim rules in class variant: more uniformity
  1848   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
  1849     le_inf_iff
  1850   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
  1851     sup_aci)
  1852   - renamed ACI to inf_sup_aci
  1853   - new class "boolean_algebra"
  1854   - class "complete_lattice" moved to separate theory
  1855     "Complete_Lattice"; corresponding constants (and abbreviations)
  1856     renamed and with authentic syntax:
  1857     Set.Inf ~>    Complete_Lattice.Inf
  1858     Set.Sup ~>    Complete_Lattice.Sup
  1859     Set.INFI ~>   Complete_Lattice.INFI
  1860     Set.SUPR ~>   Complete_Lattice.SUPR
  1861     Set.Inter ~>  Complete_Lattice.Inter
  1862     Set.Union ~>  Complete_Lattice.Union
  1863     Set.INTER ~>  Complete_Lattice.INTER
  1864     Set.UNION ~>  Complete_Lattice.UNION
  1865   - authentic syntax for
  1866     Set.Pow
  1867     Set.image
  1868   - mere abbreviations:
  1869     Set.empty               (for bot)
  1870     Set.UNIV                (for top)
  1871     Set.inter               (for inf, formerly Set.Int)
  1872     Set.union               (for sup, formerly Set.Un)
  1873     Complete_Lattice.Inter  (for Inf)
  1874     Complete_Lattice.Union  (for Sup)
  1875     Complete_Lattice.INTER  (for INFI)
  1876     Complete_Lattice.UNION  (for SUPR)
  1877   - object-logic definitions as far as appropriate
  1878 
  1879 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
  1880 Un_subset_iff are explicitly deleted as default simp rules; then also
  1881 their lattice counterparts le_inf_iff and le_sup_iff have to be
  1882 deleted to achieve the desired effect.
  1883 
  1884 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
  1885 rules by default any longer; the same applies to min_max.inf_absorb1
  1886 etc.  INCOMPATIBILITY.
  1887 
  1888 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
  1889 pred_set_conv by default.  INCOMPATIBILITY.
  1890 
  1891 * Power operations on relations and functions are now one dedicated
  1892 constant "compow" with infix syntax "^^".  Power operation on
  1893 multiplicative monoids retains syntax "^" and is now defined generic
  1894 in class power.  INCOMPATIBILITY.
  1895 
  1896 * Relation composition "R O S" now has a more standard argument order:
  1897 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
  1898 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
  1899 break, since the O_assoc rule was not rewritten like this.  Fix using
  1900 O_assoc[symmetric].  The same applies to the curried version "R OO S".
  1901 
  1902 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
  1903 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
  1904 INCOMPATIBILITY.
  1905 
  1906 * Most rules produced by inductive and datatype package have mandatory
  1907 prefixes.  INCOMPATIBILITY.
  1908 
  1909 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
  1910 the attribute of the same name.  Each of the theorems in the list
  1911 DERIV_intros assumes composition with an additional function and
  1912 matches a variable to the derivative, which has to be solved by the
  1913 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
  1914 of most elementary terms.  Former Maclauren.DERIV_tac and
  1915 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
  1916 INCOMPATIBILITY.
  1917 
  1918 * Code generator attributes follow the usual underscore convention:
  1919     code_unfold     replaces    code unfold
  1920     code_post       replaces    code post
  1921     etc.
  1922   INCOMPATIBILITY.
  1923 
  1924 * Renamed methods:
  1925     sizechange -> size_change
  1926     induct_scheme -> induction_schema
  1927   INCOMPATIBILITY.
  1928 
  1929 * Discontinued abbreviation "arbitrary" of constant "undefined".
  1930 INCOMPATIBILITY, use "undefined" directly.
  1931 
  1932 * Renamed theorems:
  1933     Suc_eq_add_numeral_1 -> Suc_eq_plus1
  1934     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
  1935     Suc_plus1 -> Suc_eq_plus1
  1936     *anti_sym -> *antisym*
  1937     vector_less_eq_def -> vector_le_def
  1938   INCOMPATIBILITY.
  1939 
  1940 * Added theorem List.map_map as [simp].  Removed List.map_compose.
  1941 INCOMPATIBILITY.
  1942 
  1943 * Removed predicate "M hassize n" (<--> card M = n & finite M).
  1944 INCOMPATIBILITY.
  1945 
  1946 
  1947 *** HOLCF ***
  1948 
  1949 * Theory Representable defines a class "rep" of domains that are
  1950 representable (via an ep-pair) in the universal domain type "udom".
  1951 Instances are provided for all type constructors defined in HOLCF.
  1952 
  1953 * The 'new_domain' command is a purely definitional version of the
  1954 domain package, for representable domains.  Syntax is identical to the
  1955 old domain package.  The 'new_domain' package also supports indirect
  1956 recursion using previously-defined type constructors.  See
  1957 src/HOLCF/ex/New_Domain.thy for examples.
  1958 
  1959 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
  1960 on the left-hand side of an equation, and then performs
  1961 simplification.  Rewriting is done using rules declared with the
  1962 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
  1963 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
  1964 
  1965 * The pattern-match compiler in 'fixrec' can now handle constructors
  1966 with HOL function types.  Pattern-match combinators for the Pair
  1967 constructor are pre-configured.
  1968 
  1969 * The 'fixrec' package now produces better fixed-point induction rules
  1970 for mutually-recursive definitions:  Induction rules have conclusions
  1971 of the form "P foo bar" instead of "P <foo, bar>".
  1972 
  1973 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
  1974 been renamed to "below".  The name "below" now replaces "less" in many
  1975 theorem names.  (Legacy theorem names using "less" are still supported
  1976 as well.)
  1977 
  1978 * The 'fixrec' package now supports "bottom patterns".  Bottom
  1979 patterns can be used to generate strictness rules, or to make
  1980 functions more strict (much like the bang-patterns supported by the
  1981 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
  1982 examples.
  1983 
  1984 
  1985 *** ML ***
  1986 
  1987 * Support for Poly/ML 5.3.0, with improved reporting of compiler
  1988 errors and run-time exceptions, including detailed source positions.
  1989 
  1990 * Structure Name_Space (formerly NameSpace) now manages uniquely
  1991 identified entries, with some additional information such as source
  1992 position, logical grouping etc.
  1993 
  1994 * Theory and context data is now introduced by the simplified and
  1995 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
  1996 to be pure, but the old TheoryDataFun for mutable data (with explicit
  1997 copy operation) is still available for some time.
  1998 
  1999 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
  2000 provides a high-level programming interface to synchronized state
  2001 variables with atomic update.  This works via pure function
  2002 application within a critical section -- its runtime should be as
  2003 short as possible; beware of deadlocks if critical code is nested,
  2004 either directly or indirectly via other synchronized variables!
  2005 
  2006 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
  2007 wraps raw ML references, explicitly indicating their non-thread-safe
  2008 behaviour.  The Isar toplevel keeps this structure open, to
  2009 accommodate Proof General as well as quick and dirty interactive
  2010 experiments with references.
  2011 
  2012 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
  2013 parallel tactical reasoning.
  2014 
  2015 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
  2016 are similar to SUBPROOF, but are slightly more flexible: only the
  2017 specified parts of the subgoal are imported into the context, and the
  2018 body tactic may introduce new subgoals and schematic variables.
  2019 
  2020 * Old tactical METAHYPS, which does not observe the proof context, has
  2021 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
  2022 or Subgoal.FOCUS etc.
  2023 
  2024 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
  2025 functors have their own ML name space there is no point to mark them
  2026 separately.)  Minor INCOMPATIBILITY.
  2027 
  2028 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
  2029 
  2030 * Renamed several structures FooBar to Foo_Bar.  Occasional,
  2031 INCOMPATIBILITY.
  2032 
  2033 * Operations of structure Skip_Proof no longer require quick_and_dirty
  2034 mode, which avoids critical setmp.
  2035 
  2036 * Eliminated old Attrib.add_attributes, Method.add_methods and related
  2037 combinators for "args".  INCOMPATIBILITY, need to use simplified
  2038 Attrib/Method.setup introduced in Isabelle2009.
  2039 
  2040 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
  2041 back on global_simpset_of, global_claset_of, global_clasimpset_of as
  2042 last resort.  INCOMPATIBILITY.
  2043 
  2044 * Display.pretty_thm now requires a proper context (cf. former
  2045 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
  2046 or even Display.pretty_thm_without_context as last resort.
  2047 INCOMPATIBILITY.
  2048 
  2049 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
  2050 Syntax.pretty_typ/term directly, preferably with proper context
  2051 instead of global theory.
  2052 
  2053 
  2054 *** System ***
  2055 
  2056 * Further fine tuning of parallel proof checking, scales up to 8 cores
  2057 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
  2058 usedir option -q.
  2059 
  2060 * Support for additional "Isabelle components" via etc/components, see
  2061 also the system manual.
  2062 
  2063 * The isabelle makeall tool now operates on all components with
  2064 IsaMakefile, not just hardwired "logics".
  2065 
  2066 * Removed "compress" option from isabelle-process and isabelle usedir;
  2067 this is always enabled.
  2068 
  2069 * Discontinued support for Poly/ML 4.x versions.
  2070 
  2071 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
  2072 on a given logic image.  This requires the lighttpd webserver and is
  2073 currently supported on Linux only.
  2074 
  2075 
  2076 
  2077 New in Isabelle2009 (April 2009)
  2078 --------------------------------
  2079 
  2080 *** General ***
  2081 
  2082 * Simplified main Isabelle executables, with less surprises on
  2083 case-insensitive file-systems (such as Mac OS).
  2084 
  2085   - The main Isabelle tool wrapper is now called "isabelle" instead of
  2086     "isatool."
  2087 
  2088   - The former "isabelle" alias for "isabelle-process" has been
  2089     removed (should rarely occur to regular users).
  2090 
  2091   - The former "isabelle-interface" and its alias "Isabelle" have been
  2092     removed (interfaces are now regular Isabelle tools).
  2093 
  2094 Within scripts and make files, the Isabelle environment variables
  2095 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
  2096 respectively.  (The latter are still available as legacy feature.)
  2097 
  2098 The old isabelle-interface wrapper could react in confusing ways if
  2099 the interface was uninstalled or changed otherwise.  Individual
  2100 interface tool configuration is now more explicit, see also the
  2101 Isabelle system manual.  In particular, Proof General is now available
  2102 via "isabelle emacs".
  2103 
  2104 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
  2105 purge installed copies of Isabelle executables and re-run "isabelle
  2106 install -p ...", or use symlinks.
  2107 
  2108 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
  2109 old ~/isabelle, which was slightly non-standard and apt to cause
  2110 surprises on case-insensitive file-systems (such as Mac OS).
  2111 
  2112 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
  2113 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
  2114 care is required when using older releases of Isabelle.  Note that
  2115 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
  2116 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
  2117 
  2118 * Proofs of fully specified statements are run in parallel on
  2119 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
  2120 a regular 4-core machine, if the initial heap space is made reasonably
  2121 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
  2122 
  2123 * The main reference manuals ("isar-ref", "implementation", and
  2124 "system") have been updated and extended.  Formally checked references
  2125 as hyperlinks are now available uniformly.
  2126 
  2127 
  2128 *** Pure ***
  2129 
  2130 * Complete re-implementation of locales.  INCOMPATIBILITY in several
  2131 respects.  The most important changes are listed below.  See the
  2132 Tutorial on Locales ("locales" manual) for details.
  2133 
  2134 - In locale expressions, instantiation replaces renaming.  Parameters
  2135 must be declared in a for clause.  To aid compatibility with previous
  2136 parameter inheritance, in locale declarations, parameters that are not
  2137 'touched' (instantiation position "_" or omitted) are implicitly added
  2138 with their syntax at the beginning of the for clause.
  2139 
  2140 - Syntax from abbreviations and definitions in locales is available in
  2141 locale expressions and context elements.  The latter is particularly
  2142 useful in locale declarations.
  2143 
  2144 - More flexible mechanisms to qualify names generated by locale
  2145 expressions.  Qualifiers (prefixes) may be specified in locale
  2146 expressions, and can be marked as mandatory (syntax: "name!:") or
  2147 optional (syntax "name?:").  The default depends for plain "name:"
  2148 depends on the situation where a locale expression is used: in
  2149 commands 'locale' and 'sublocale' prefixes are optional, in
  2150 'interpretation' and 'interpret' prefixes are mandatory.  The old
  2151 implicit qualifiers derived from the parameter names of a locale are
  2152 no longer generated.
  2153 
  2154 - Command "sublocale l < e" replaces "interpretation l < e".  The
  2155 instantiation clause in "interpretation" and "interpret" (square
  2156 brackets) is no longer available.  Use locale expressions.
  2157 
  2158 - When converting proof scripts, mandatory qualifiers in
  2159 'interpretation' and 'interpret' should be retained by default, even
  2160 if this is an INCOMPATIBILITY compared to former behavior.  In the
  2161 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
  2162 in locale expressions range over a single locale instance only.
  2163 
  2164 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
  2165 In existing theorem specifications replace the includes element by the
  2166 respective context elements of the included locale, omitting those
  2167 that are already present in the theorem specification.  Multiple
  2168 assume elements of a locale should be replaced by a single one
  2169 involving the locale predicate.  In the proof body, declarations (most
  2170 notably theorems) may be regained by interpreting the respective
  2171 locales in the proof context as required (command "interpret").
  2172 
  2173 If using "includes" in replacement of a target solely because the
  2174 parameter types in the theorem are not as general as in the target,
  2175 consider declaring a new locale with additional type constraints on
  2176 the parameters (context element "constrains").
  2177 
  2178 - Discontinued "locale (open)".  INCOMPATIBILITY.
  2179 
  2180 - Locale interpretation commands no longer attempt to simplify goal.
  2181 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
  2182 methods intro_locales and unfold_locales to clarify.
  2183 
  2184 - Locale interpretation commands no longer accept interpretation
  2185 attributes.  INCOMPATIBILITY.
  2186 
  2187 * Class declaration: so-called "base sort" must not be given in import
  2188 list any longer, but is inferred from the specification.  Particularly
  2189 in HOL, write
  2190 
  2191     class foo = ...
  2192 
  2193 instead of
  2194 
  2195     class foo = type + ...
  2196 
  2197 * Class target: global versions of theorems stemming do not carry a
  2198 parameter prefix any longer.  INCOMPATIBILITY.
  2199 
  2200 * Class 'instance' command no longer accepts attached definitions.
  2201 INCOMPATIBILITY, use proper 'instantiation' target instead.
  2202 
  2203 * Recovered hiding of consts, which was accidentally broken in
  2204 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
  2205 makes c inaccessible; consider using ``hide (open) const c'' instead.
  2206 
  2207 * Slightly more coherent Pure syntax, with updated documentation in
  2208 isar-ref manual.  Removed locales meta_term_syntax and
  2209 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
  2210 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
  2211 directly in regular applications.
  2212 
  2213 * There is a new syntactic category "float_const" for signed decimal
  2214 fractions (e.g. 123.45 or -123.45).
  2215 
  2216 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
  2217 interface with 'setup' command instead.
  2218 
  2219 * Command 'local_setup' is similar to 'setup', but operates on a local
  2220 theory context.
  2221 
  2222 * The 'axiomatization' command now only works within a global theory
  2223 context.  INCOMPATIBILITY.
  2224 
  2225 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
  2226 hypotheses.  Sorts required in the course of reasoning need to be
  2227 covered by the constraints in the initial statement, completed by the
  2228 type instance information of the background theory.  Non-trivial sort
  2229 hypotheses, which rarely occur in practice, may be specified via
  2230 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
  2231 
  2232   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
  2233 
  2234 The result contains an implicit sort hypotheses as before --
  2235 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
  2236 normalization.
  2237 
  2238 * Generalized Isar history, with support for linear undo, direct state
  2239 addressing etc.
  2240 
  2241 * Changed defaults for unify configuration options:
  2242 
  2243   unify_trace_bound = 50 (formerly 25)
  2244   unify_search_bound = 60 (formerly 30)
  2245 
  2246 * Different bookkeeping for code equations (INCOMPATIBILITY):
  2247 
  2248   a) On theory merge, the last set of code equations for a particular
  2249      constant is taken (in accordance with the policy applied by other
  2250      parts of the code generator framework).
  2251 
  2252   b) Code equations stemming from explicit declarations (e.g. code
  2253      attribute) gain priority over default code equations stemming
  2254      from definition, primrec, fun etc.
  2255 
  2256 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
  2257 
  2258 * Unified theorem tables for both code generators.  Thus [code
  2259 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
  2260 
  2261 * Command 'find_consts' searches for constants based on type and name
  2262 patterns, e.g.
  2263 
  2264     find_consts "_ => bool"
  2265 
  2266 By default, matching is against subtypes, but it may be restricted to
  2267 the whole type.  Searching by name is possible.  Multiple queries are
  2268 conjunctive and queries may be negated by prefixing them with a
  2269 hyphen:
  2270 
  2271     find_consts strict: "_ => bool" name: "Int" -"int => int"
  2272 
  2273 * New 'find_theorems' criterion "solves" matches theorems that
  2274 directly solve the current goal (modulo higher-order unification).
  2275 
  2276 * Auto solve feature for main theorem statements: whenever a new goal
  2277 is stated, "find_theorems solves" is called; any theorems that could
  2278 solve the lemma directly are listed as part of the goal state.
  2279 Cf. associated options in Proof General Isabelle settings menu,
  2280 enabled by default, with reasonable timeout for pathological cases of
  2281 higher-order unification.
  2282 
  2283 
  2284 *** Document preparation ***
  2285 
  2286 * Antiquotation @{lemma} now imitates a regular terminal proof,
  2287 demanding keyword 'by' and supporting the full method expression
  2288 syntax just like the Isar command 'by'.
  2289 
  2290 
  2291 *** HOL ***
  2292 
  2293 * Integrated main parts of former image HOL-Complex with HOL.  Entry
  2294 points Main and Complex_Main remain as before.
  2295 
  2296 * Logic image HOL-Plain provides a minimal HOL with the most important
  2297 tools available (inductive, datatype, primrec, ...).  This facilitates
  2298 experimentation and tool development.  Note that user applications
  2299 (and library theories) should never refer to anything below theory
  2300 Main, as before.
  2301 
  2302 * Logic image HOL-Main stops at theory Main, and thus facilitates
  2303 experimentation due to shorter build times.
  2304 
  2305 * Logic image HOL-NSA contains theories of nonstandard analysis which
  2306 were previously part of former HOL-Complex.  Entry point Hyperreal
  2307 remains valid, but theories formerly using Complex_Main should now use
  2308 new entry point Hypercomplex.
  2309 
  2310 * Generic ATP manager for Sledgehammer, based on ML threads instead of
  2311 Posix processes.  Avoids potentially expensive forking of the ML
  2312 process.  New thread-based implementation also works on non-Unix
  2313 platforms (Cygwin).  Provers are no longer hardwired, but defined
  2314 within the theory via plain ML wrapper functions.  Basic Sledgehammer
  2315 commands are covered in the isar-ref manual.
  2316 
  2317 * Wrapper scripts for remote SystemOnTPTP service allows to use
  2318 sledgehammer without local ATP installation (Vampire etc.). Other
  2319 provers may be included via suitable ML wrappers, see also
  2320 src/HOL/ATP_Linkup.thy.
  2321 
  2322 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
  2323 menu.
  2324 
  2325 * The metis method no longer fails because the theorem is too trivial
  2326 (contains the empty clause).
  2327 
  2328 * The metis method now fails in the usual manner, rather than raising
  2329 an exception, if it determines that it cannot prove the theorem.
  2330 
  2331 * Method "coherent" implements a prover for coherent logic (see also
  2332 src/Tools/coherent.ML).
  2333 
  2334 * Constants "undefined" and "default" replace "arbitrary".  Usually
  2335 "undefined" is the right choice to replace "arbitrary", though
  2336 logically there is no difference.  INCOMPATIBILITY.
  2337 
  2338 * Command "value" now integrates different evaluation mechanisms.  The
  2339 result of the first successful evaluation mechanism is printed.  In
  2340 square brackets a particular named evaluation mechanisms may be
  2341 specified (currently, [SML], [code] or [nbe]).  See further
  2342 src/HOL/ex/Eval_Examples.thy.
  2343 
  2344 * Normalization by evaluation now allows non-leftlinear equations.
  2345 Declare with attribute [code nbe].
  2346 
  2347 * Methods "case_tac" and "induct_tac" now refer to the very same rules
  2348 as the structured Isar versions "cases" and "induct", cf. the
  2349 corresponding "cases" and "induct" attributes.  Mutual induction rules
  2350 are now presented as a list of individual projections
  2351 (e.g. foo_bar.inducts for types foo and bar); the old format with
  2352 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
  2353 rare situations a different rule is selected --- notably nested tuple
  2354 elimination instead of former prod.exhaust: use explicit (case_tac t
  2355 rule: prod.exhaust) here.
  2356 
  2357 * Attributes "cases", "induct", "coinduct" support "del" option.
  2358 
  2359 * Removed fact "case_split_thm", which duplicates "case_split".
  2360 
  2361 * The option datatype has been moved to a new theory Option.  Renamed
  2362 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
  2363 
  2364 * New predicate "strict_mono" classifies strict functions on partial
  2365 orders.  With strict functions on linear orders, reasoning about
  2366 (in)equalities is facilitated by theorems "strict_mono_eq",
  2367 "strict_mono_less_eq" and "strict_mono_less".
  2368 
  2369 * Some set operations are now proper qualified constants with
  2370 authentic syntax.  INCOMPATIBILITY:
  2371 
  2372     op Int ~>   Set.Int
  2373     op Un ~>    Set.Un
  2374     INTER ~>    Set.INTER
  2375     UNION ~>    Set.UNION
  2376     Inter ~>    Set.Inter
  2377     Union ~>    Set.Union
  2378     {} ~>       Set.empty
  2379     UNIV ~>     Set.UNIV
  2380 
  2381 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  2382 theory Set.
  2383 
  2384 * Auxiliary class "itself" has disappeared -- classes without any
  2385 parameter are treated as expected by the 'class' command.
  2386 
  2387 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  2388 
  2389 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  2390 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  2391 
  2392 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  2393 method "approximation".  It proves formulas on real values by using
  2394 interval arithmetic.  In the formulas are also the transcendental
  2395 functions sin, cos, tan, atan, ln, exp and the constant pi are
  2396 allowed. For examples see
  2397 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  2398 
  2399 * Theory "Reflection" now resides in HOL/Library.
  2400 
  2401 * Entry point to Word library now simply named "Word".
  2402 INCOMPATIBILITY.
  2403 
  2404 * Made source layout more coherent with logical distribution
  2405 structure:
  2406 
  2407     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  2408     src/HOL/Library/Code_Message.thy ~> src/HOL/
  2409     src/HOL/Library/GCD.thy ~> src/HOL/
  2410     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  2411     src/HOL/Library/Parity.thy ~> src/HOL/
  2412     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  2413     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  2414     src/HOL/Real/Lubs.thy ~> src/HOL/
  2415     src/HOL/Real/PReal.thy ~> src/HOL/
  2416     src/HOL/Real/Rational.thy ~> src/HOL/
  2417     src/HOL/Real/RComplete.thy ~> src/HOL/
  2418     src/HOL/Real/RealDef.thy ~> src/HOL/
  2419     src/HOL/Real/RealPow.thy ~> src/HOL/
  2420     src/HOL/Real/Real.thy ~> src/HOL/
  2421     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  2422     src/HOL/Complex/Complex.thy ~> src/HOL/
  2423     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  2424     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  2425     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  2426     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  2427     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  2428     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  2429     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  2430     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  2431     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  2432     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  2433     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  2434     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  2435     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  2436     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  2437     src/HOL/Real/Float ~> src/HOL/Library/
  2438     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  2439     src/HOL/Real/RealVector.thy ~> src/HOL/
  2440 
  2441     src/HOL/arith_data.ML ~> src/HOL/Tools
  2442     src/HOL/hologic.ML ~> src/HOL/Tools
  2443     src/HOL/simpdata.ML ~> src/HOL/Tools
  2444     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  2445     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  2446     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  2447     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  2448     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  2449     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  2450     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  2451 
  2452     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  2453     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  2454     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  2455     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  2456     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  2457     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  2458 
  2459 * If methods "eval" and "evaluation" encounter a structured proof
  2460 state with !!/==>, only the conclusion is evaluated to True (if
  2461 possible), avoiding strange error messages.
  2462 
  2463 * Method "sizechange" automates termination proofs using (a
  2464 modification of) the size-change principle.  Requires SAT solver.  See
  2465 src/HOL/ex/Termination.thy for examples.
  2466 
  2467 * Simplifier: simproc for let expressions now unfolds if bound
  2468 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  2469 
  2470 * Method "arith": Linear arithmetic now ignores all inequalities when
  2471 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  2472 
  2473 * New attribute "arith" for facts that should always be used
  2474 automatically by arithmetic. It is intended to be used locally in
  2475 proofs, e.g.
  2476 
  2477   assumes [arith]: "x > 0"
  2478 
  2479 Global usage is discouraged because of possible performance impact.
  2480 
  2481 * New classes "top" and "bot" with corresponding operations "top" and
  2482 "bot" in theory Orderings; instantiation of class "complete_lattice"
  2483 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  2484 
  2485 * Changed definition lemma "less_fun_def" in order to provide an
  2486 instance for preorders on functions; use lemma "less_le" instead.
  2487 INCOMPATIBILITY.
  2488 
  2489 * Theory Orderings: class "wellorder" moved here, with explicit
  2490 induction rule "less_induct" as assumption.  For instantiation of
  2491 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  2492 INCOMPATIBILITY.
  2493 
  2494 * Theory Orderings: added class "preorder" as superclass of "order".
  2495 INCOMPATIBILITY: Instantiation proofs for order, linorder
  2496 etc. slightly changed.  Some theorems named order_class.* now named
  2497 preorder_class.*.
  2498 
  2499 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  2500 "diag" to "Id_on".
  2501 
  2502 * Theory Finite_Set: added a new fold combinator of type
  2503 
  2504   ('a => 'b => 'b) => 'b => 'a set => 'b
  2505 
  2506 Occasionally this is more convenient than the old fold combinator
  2507 which is now defined in terms of the new one and renamed to
  2508 fold_image.
  2509 
  2510 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  2511 and "ring_simps" have been replaced by "algebra_simps" (which can be
  2512 extended with further lemmas!).  At the moment both still exist but
  2513 the former will disappear at some point.
  2514 
  2515 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  2516 class recpower.  Type-specific simp rules for various recpower types
  2517 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  2518 
  2519 rat_power_0    -> power_0
  2520 rat_power_Suc  -> power_Suc
  2521 realpow_0      -> power_0
  2522 realpow_Suc    -> power_Suc
  2523 complexpow_0   -> power_0
  2524 complexpow_Suc -> power_Suc
  2525 power_poly_0   -> power_0
  2526 power_poly_Suc -> power_Suc
  2527 
  2528 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  2529 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  2530 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  2531 of lemmas from Divides has been generalized from nat to class
  2532 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  2533 renames resulting from duplicate elimination:
  2534 
  2535     dvd_def_mod ~>          dvd_eq_mod_eq_0
  2536     zero_dvd_iff ~>         dvd_0_left_iff
  2537     dvd_0 ~>                dvd_0_right
  2538     DIVISION_BY_ZERO_DIV ~> div_by_0
  2539     DIVISION_BY_ZERO_MOD ~> mod_by_0
  2540     mult_div ~>             div_mult_self2_is_id
  2541     mult_mod ~>             mod_mult_self2_is_0
  2542 
  2543 * Theory IntDiv: removed many lemmas that are instances of class-based
  2544 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  2545 rename old lemmas as follows:
  2546 
  2547 dvd_diff               -> nat_dvd_diff
  2548 dvd_zminus_iff         -> dvd_minus_iff
  2549 mod_add1_eq            -> mod_add_eq
  2550 mod_mult1_eq           -> mod_mult_right_eq
  2551 mod_mult1_eq'          -> mod_mult_left_eq
  2552 mod_mult_distrib_mod   -> mod_mult_eq
  2553 nat_mod_add_left_eq    -> mod_add_left_eq
  2554 nat_mod_add_right_eq   -> mod_add_right_eq
  2555 nat_mod_div_trivial    -> mod_div_trivial
  2556 nat_mod_mod_trivial    -> mod_mod_trivial
  2557 zdiv_zadd_self1        -> div_add_self1
  2558 zdiv_zadd_self2        -> div_add_self2
  2559 zdiv_zmult_self1       -> div_mult_self2_is_id
  2560 zdiv_zmult_self2       -> div_mult_self1_is_id
  2561 zdvd_triv_left         -> dvd_triv_left
  2562 zdvd_triv_right        -> dvd_triv_right
  2563 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  2564 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  2565 zmod_zadd_left_eq      -> mod_add_left_eq
  2566 zmod_zadd_right_eq     -> mod_add_right_eq
  2567 zmod_zadd_self1        -> mod_add_self1
  2568 zmod_zadd_self2        -> mod_add_self2
  2569 zmod_zadd1_eq          -> mod_add_eq
  2570 zmod_zdiff1_eq         -> mod_diff_eq
  2571 zmod_zdvd_zmod         -> mod_mod_cancel
  2572 zmod_zmod_cancel       -> mod_mod_cancel
  2573 zmod_zmult_self1       -> mod_mult_self2_is_0
  2574 zmod_zmult_self2       -> mod_mult_self1_is_0
  2575 zmod_1                 -> mod_by_1
  2576 zdiv_1                 -> div_by_1
  2577 zdvd_abs1              -> abs_dvd_iff
  2578 zdvd_abs2              -> dvd_abs_iff
  2579 zdvd_refl              -> dvd_refl
  2580 zdvd_trans             -> dvd_trans
  2581 zdvd_zadd              -> dvd_add
  2582 zdvd_zdiff             -> dvd_diff
  2583 zdvd_zminus_iff        -> dvd_minus_iff
  2584 zdvd_zminus2_iff       -> minus_dvd_iff
  2585 zdvd_zmultD            -> dvd_mult_right
  2586 zdvd_zmultD2           -> dvd_mult_left
  2587 zdvd_zmult_mono        -> mult_dvd_mono
  2588 zdvd_0_right           -> dvd_0_right
  2589 zdvd_0_left            -> dvd_0_left_iff
  2590 zdvd_1_left            -> one_dvd
  2591 zminus_dvd_iff         -> minus_dvd_iff
  2592 
  2593 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  2594 
  2595 * The real numbers offer decimal input syntax: 12.34 is translated
  2596 into 1234/10^2. This translation is not reversed upon output.
  2597 
  2598 * Theory Library/Polynomial defines an abstract type 'a poly of
  2599 univariate polynomials with coefficients of type 'a.  In addition to
  2600 the standard ring operations, it also supports div and mod.  Code
  2601 generation is also supported, using list-style constructors.
  2602 
  2603 * Theory Library/Inner_Product defines a class of real_inner for real
  2604 inner product spaces, with an overloaded operation inner :: 'a => 'a
  2605 => real.  Class real_inner is a subclass of real_normed_vector from
  2606 theory RealVector.
  2607 
  2608 * Theory Library/Product_Vector provides instances for the product
  2609 type 'a * 'b of several classes from RealVector and Inner_Product.
  2610 Definitions of addition, subtraction, scalar multiplication, norms,
  2611 and inner products are included.
  2612 
  2613 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  2614 addition to the field operations, numerals and case syntax are also
  2615 supported.
  2616 
  2617 * Theory Library/Diagonalize provides constructive version of Cantor's
  2618 first diagonalization argument.
  2619 
  2620 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  2621 zlcm (for int); carried together from various gcd/lcm developements in
  2622 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  2623 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  2624 may recover tupled syntax as follows:
  2625 
  2626     hide (open) const gcd
  2627     abbreviation gcd where
  2628       "gcd == (%(a, b). GCD.gcd a b)"
  2629     notation (output)
  2630       GCD.gcd ("gcd '(_, _')")
  2631 
  2632 The same works for lcm, zgcd, zlcm.
  2633 
  2634 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  2635 instantiations for algebraic structures.  Removed some duplicate
  2636 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  2637 
  2638 * ML antiquotation @{code} takes a constant as argument and generates
  2639 corresponding code in background and inserts name of the corresponding
  2640 resulting ML value/function/datatype constructor binding in place.
  2641 All occurrences of @{code} with a single ML block are generated
  2642 simultaneously.  Provides a generic and safe interface for
  2643 instrumentalizing code generation.  See
  2644 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  2645 In future you ought to refrain from ad-hoc compiling generated SML
  2646 code on the ML toplevel.  Note that (for technical reasons) @{code}
  2647 cannot refer to constants for which user-defined serializations are
  2648 set.  Refer to the corresponding ML counterpart directly in that
  2649 cases.
  2650 
  2651 * Command 'rep_datatype': instead of theorem names the command now
  2652 takes a list of terms denoting the constructors of the type to be
  2653 represented as datatype.  The characteristic theorems have to be
  2654 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  2655 have disappeared in favour of existing ones:
  2656 
  2657     unit_induct                 ~> unit.induct
  2658     prod_induct                 ~> prod.induct
  2659     sum_induct                  ~> sum.induct
  2660     Suc_Suc_eq                  ~> nat.inject
  2661     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  2662 
  2663 
  2664 *** HOL-Algebra ***
  2665 
  2666 * New locales for orders and lattices where the equivalence relation
  2667 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  2668 locales use a record structure with field eq for the equivalence.
  2669 
  2670 * New theory of factorial domains.
  2671 
  2672 * Units_l_inv and Units_r_inv are now simp rules by default.
  2673 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  2674 and/or r_inv will now also require deletion of these lemmas.
  2675 
  2676 * Renamed the following theorems, INCOMPATIBILITY:
  2677 
  2678 UpperD ~> Upper_memD
  2679 LowerD ~> Lower_memD
  2680 least_carrier ~> least_closed
  2681 greatest_carrier ~> greatest_closed
  2682 greatest_Lower_above ~> greatest_Lower_below
  2683 one_zero ~> carrier_one_zero
  2684 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  2685 
  2686 
  2687 *** HOL-Nominal ***
  2688 
  2689 * Nominal datatypes can now contain type-variables.
  2690 
  2691 * Commands 'nominal_inductive' and 'equivariance' work with local
  2692 theory targets.
  2693 
  2694 * Nominal primrec can now works with local theory targets and its
  2695 specification syntax now conforms to the general format as seen in
  2696 'inductive' etc.
  2697 
  2698 * Method "perm_simp" honours the standard simplifier attributes
  2699 (no_asm), (no_asm_use) etc.
  2700 
  2701 * The new predicate #* is defined like freshness, except that on the
  2702 left hand side can be a set or list of atoms.
  2703 
  2704 * Experimental command 'nominal_inductive2' derives strong induction
  2705 principles for inductive definitions.  In contrast to
  2706 'nominal_inductive', which can only deal with a fixed number of
  2707 binders, it can deal with arbitrary expressions standing for sets of
  2708 atoms to be avoided.  The only inductive definition we have at the
  2709 moment that needs this generalisation is the typing rule for Lets in
  2710 the algorithm W:
  2711 
  2712  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  2713  -----------------------------------------------------------------
  2714          Gamma |- Let x be t1 in t2 : T2
  2715 
  2716 In this rule one wants to avoid all the binders that are introduced by
  2717 "close Gamma T1".  We are looking for other examples where this
  2718 feature might be useful.  Please let us know.
  2719 
  2720 
  2721 *** HOLCF ***
  2722 
  2723 * Reimplemented the simplification procedure for proving continuity
  2724 subgoals.  The new simproc is extensible; users can declare additional
  2725 continuity introduction rules with the attribute [cont2cont].
  2726 
  2727 * The continuity simproc now uses a different introduction rule for
  2728 solving continuity subgoals on terms with lambda abstractions.  In
  2729 some rare cases the new simproc may fail to solve subgoals that the
  2730 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  2731 Potential INCOMPATIBILITY.
  2732 
  2733 * Command 'fixrec': specification syntax now conforms to the general
  2734 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  2735 examples.  INCOMPATIBILITY.
  2736 
  2737 
  2738 *** ZF ***
  2739 
  2740 * Proof of Zorn's Lemma for partial orders.
  2741 
  2742 
  2743 *** ML ***
  2744 
  2745 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  2746 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  2747 depends on multithreading, so timouts will not work before Poly/ML
  2748 5.2.1!
  2749 
  2750 * High-level support for concurrent ML programming, see
  2751 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  2752 particularly convenient to organize independent functional
  2753 computations.  The concept of "synchronized variables" provides a
  2754 higher-order interface for components with shared state, avoiding the
  2755 delicate details of mutexes and condition variables.  (Requires
  2756 Poly/ML 5.2.1 or later.)
  2757 
  2758 * ML bindings produced via Isar commands are stored within the Isar
  2759 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  2760 become thread-safe and work with undo as expected (concerning
  2761 top-level bindings, not side-effects on global references).
  2762 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  2763 compiler at runtime; really global bindings need to be given outside a
  2764 theory.  (Requires Poly/ML 5.2 or later.)
  2765 
  2766 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  2767 context.  Top-level ML bindings are stored within the proof context in
  2768 a purely sequential fashion, disregarding the nested proof structure.
  2769 ML bindings introduced by 'ML_prf' are discarded at the end of the
  2770 proof.  (Requires Poly/ML 5.2 or later.)
  2771 
  2772 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  2773 and Method.setup, as well as Isar commands 'attribute_setup' and
  2774 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  2775 existing code accordingly, or use plain 'setup' together with old
  2776 Method.add_method.
  2777 
  2778 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  2779 to 'a -> thm, while results are always tagged with an authentic oracle
  2780 name.  The Isar command 'oracle' is now polymorphic, no argument type
  2781 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  2782 accordingly.  Note that extra performance may be gained by producing
  2783 the cterm carefully, avoiding slow Thm.cterm_of.
  2784 
  2785 * Simplified interface for defining document antiquotations via
  2786 ThyOutput.antiquotation, ThyOutput.output, and optionally
  2787 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  2788 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  2789 examples.
  2790 
  2791 * More systematic treatment of long names, abstract name bindings, and
  2792 name space operations.  Basic operations on qualified names have been
  2793 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  2794 Long_Name.append.  Old type bstring has been mostly replaced by
  2795 abstract type binding (see structure Binding), which supports precise
  2796 qualification by packages and local theory targets, as well as proper
  2797 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  2798 bstring values into Binding.name, or better pass through abstract
  2799 bindings everywhere.  See further src/Pure/General/long_name.ML,
  2800 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  2801 
  2802 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  2803 LocalTheory.note etc.) now refer to the *full* internal name, not the
  2804 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  2805 
  2806 * Disposed old type and term read functions (Sign.read_def_typ,
  2807 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  2808 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  2809 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  2810 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  2811 resort for legacy applications.
  2812 
  2813 * Disposed old declarations, tactics, tactic combinators that refer to
  2814 the simpset or claset of an implicit theory (such as Addsimps,
  2815 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  2816 embedded ML text, or local_simpset_of with a proper context passed as
  2817 explicit runtime argument.
  2818 
  2819 * Rules and tactics that read instantiations (read_instantiate,
  2820 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  2821 context, which is required for parsing and type-checking.  Moreover,
  2822 the variables are specified as plain indexnames, not string encodings
  2823 thereof.  INCOMPATIBILITY.
  2824 
  2825 * Generic Toplevel.add_hook interface allows to analyze the result of
  2826 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  2827 for theorem dependency output of transactions resulting in a new
  2828 theory state.
  2829 
  2830 * ML antiquotations: block-structured compilation context indicated by
  2831 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  2832 
  2833   @{binding name}                         - basic name binding
  2834   @{let ?pat = term}                      - term abbreviation (HO matching)
  2835   @{note name = fact}                     - fact abbreviation
  2836   @{thm fact}                             - singleton fact (with attributes)
  2837   @{thms fact}                            - general fact (with attributes)
  2838   @{lemma prop by method}                 - singleton goal
  2839   @{lemma prop by meth1 meth2}            - singleton goal
  2840   @{lemma prop1 ... propN by method}      - general goal
  2841   @{lemma prop1 ... propN by meth1 meth2} - general goal
  2842   @{lemma (open) ...}                     - open derivation
  2843 
  2844 
  2845 *** System ***
  2846 
  2847 * The Isabelle "emacs" tool provides a specific interface to invoke
  2848 Proof General / Emacs, with more explicit failure if that is not
  2849 installed (the old isabelle-interface script silently falls back on
  2850 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  2851 installation location of the Proof General distribution.
  2852 
  2853 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  2854 the Isabelle process into a JVM/Scala application.  See
  2855 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  2856 process wrapper has been discontinued.)
  2857 
  2858 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  2859 
  2860 * Various status messages (with exact source position information) are
  2861 emitted, if proper markup print mode is enabled.  This allows
  2862 user-interface components to provide detailed feedback on internal
  2863 prover operations.
  2864 
  2865 
  2866 
  2867 New in Isabelle2008 (June 2008)
  2868 -------------------------------
  2869 
  2870 *** General ***
  2871 
  2872 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  2873 and updated, with formally checked references as hyperlinks.
  2874 
  2875 * Theory loader: use_thy (and similar operations) no longer set the
  2876 implicit ML context, which was occasionally hard to predict and in
  2877 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  2878 provides a proper context already.
  2879 
  2880 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2881 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  2882 'use' within a theory file will do the job.
  2883 
  2884 * Name space merge now observes canonical order, i.e. the second space
  2885 is inserted into the first one, while existing entries in the first
  2886 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  2887 swap theory imports.
  2888 
  2889 * Syntax: symbol \<chi> is now considered a letter.  Potential
  2890 INCOMPATIBILITY in identifier syntax etc.
  2891 
  2892 * Outer syntax: string tokens no longer admit escaped white space,
  2893 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  2894 white space without escapes.
  2895 
  2896 * Outer syntax: string tokens may contain arbitrary character codes
  2897 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  2898 "foo_bar".
  2899 
  2900 
  2901 *** Pure ***
  2902 
  2903 * Context-dependent token translations.  Default setup reverts locally
  2904 fixed variables, and adds hilite markup for undeclared frees.
  2905 
  2906 * Unused theorems can be found using the new command 'unused_thms'.
  2907 There are three ways of invoking it:
  2908 
  2909 (1) unused_thms
  2910      Only finds unused theorems in the current theory.
  2911 
  2912 (2) unused_thms thy_1 ... thy_n -
  2913      Finds unused theorems in the current theory and all of its ancestors,
  2914      excluding the theories thy_1 ... thy_n and all of their ancestors.
  2915 
  2916 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  2917      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  2918      their ancestors, excluding the theories thy_1 ... thy_n and all of
  2919      their ancestors.
  2920 
  2921 In order to increase the readability of the list produced by
  2922 unused_thms, theorems that have been created by a particular instance
  2923 of a theory command such as 'inductive' or 'function' are considered
  2924 to belong to the same "group", meaning that if at least one theorem in
  2925 this group is used, the other theorems in the same group are no longer
  2926 reported as unused.  Moreover, if all theorems in the group are
  2927 unused, only one theorem in the group is displayed.
  2928 
  2929 Note that proof objects have to be switched on in order for
  2930 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  2931 usually the case when using Proof General with the default settings).
  2932 
  2933 * Authentic naming of facts disallows ad-hoc overwriting of previous
  2934 theorems within the same name space.  INCOMPATIBILITY, need to remove
  2935 duplicate fact bindings, or even accidental fact duplications.  Note
  2936 that tools may maintain dynamically scoped facts systematically, using
  2937 PureThy.add_thms_dynamic.
  2938 
  2939 * Command 'hide' now allows to hide from "fact" name space as well.
  2940 
  2941 * Eliminated destructive theorem database, simpset, claset, and
  2942 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  2943 update of theories within ML code.
  2944 
  2945 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  2946 INCOMPATIBILITY, object-logics depending on former Pure require
  2947 additional setup PureThy.old_appl_syntax_setup; object-logics
  2948 depending on former CPure need to refer to Pure.
  2949 
  2950 * Commands 'use' and 'ML' are now purely functional, operating on
  2951 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  2952 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  2953 INCOMPATIBILITY.
  2954 
  2955 * Command 'setup': discontinued implicit version with ML reference.
  2956 
  2957 * Instantiation target allows for simultaneous specification of class
  2958 instance operations together with an instantiation proof.
  2959 Type-checking phase allows to refer to class operations uniformly.
  2960 See src/HOL/Complex/Complex.thy for an Isar example and
  2961 src/HOL/Library/Eval.thy for an ML example.
  2962 
  2963 * Indexing of literal facts: be more serious about including only
  2964 facts from the visible specification/proof context, but not the
  2965 background context (locale etc.).  Affects `prop` notation and method
  2966 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  2967 situations.
  2968 
  2969 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  2970 "(open)" option, which used to expose internal bound variables to the
  2971 proof text.
  2972 
  2973 * Isar statements: removed obsolete case "rule_context".
  2974 INCOMPATIBILITY, better use explicit fixes/assumes.
  2975 
  2976 * Locale proofs: default proof step now includes 'unfold_locales';
  2977 hence 'proof' without argument may be used to unfold locale
  2978 predicates.
  2979 
  2980 
  2981 *** Document preparation ***
  2982 
  2983 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  2984 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  2985 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  2986 spot); renamed link color from "darkblue" to "linkcolor" (default
  2987 value unchanged, can be redefined via \definecolor); no longer sets
  2988 "a4paper" option (unnecessary or even intrusive).
  2989 
  2990 * Antiquotation @{lemma A method} proves proposition A by the given
  2991 method (either a method name or a method name plus (optional) method
  2992 arguments in parentheses) and prints A just like @{prop A}.
  2993 
  2994 
  2995 *** HOL ***
  2996 
  2997 * New primrec package.  Specification syntax conforms in style to
  2998 definition/function/....  No separate induction rule is provided.  The
  2999 "primrec" command distinguishes old-style and new-style specifications
  3000 by syntax.  The former primrec package is now named OldPrimrecPackage.
  3001 When adjusting theories, beware: constants stemming from new-style
  3002 primrec specifications have authentic syntax.
  3003 
  3004 * Metis prover is now an order of magnitude faster, and also works
  3005 with multithreading.
  3006 
  3007 * Metis: the maximum number of clauses that can be produced from a
  3008 theorem is now given by the attribute max_clauses.  Theorems that
  3009 exceed this number are ignored, with a warning printed.
  3010 
  3011 * Sledgehammer no longer produces structured proofs by default. To
  3012 enable, declare [[sledgehammer_full = true]].  Attributes
  3013 reconstruction_modulus, reconstruction_sorts renamed
  3014 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  3015 
  3016 * Method "induct_scheme" derives user-specified induction rules
  3017 from well-founded induction and completeness of patterns. This factors
  3018 out some operations that are done internally by the function package
  3019 and makes them available separately.  See
  3020 src/HOL/ex/Induction_Scheme.thy for examples.
  3021 
  3022 * More flexible generation of measure functions for termination
  3023 proofs: Measure functions can be declared by proving a rule of the
  3024 form "is_measure f" and giving it the [measure_function] attribute.
  3025 The "is_measure" predicate is logically meaningless (always true), and
  3026 just guides the heuristic.  To find suitable measure functions, the
  3027 termination prover sets up the goal "is_measure ?f" of the appropriate
  3028 type and generates all solutions by prolog-style backwards proof using
  3029 the declared rules.
  3030 
  3031 This setup also deals with rules like 
  3032 
  3033   "is_measure f ==> is_measure (list_size f)"
  3034 
  3035 which accommodates nested datatypes that recurse through lists.
  3036 Similar rules are predeclared for products and option types.
  3037 
  3038 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  3039 
  3040   INCOMPATIBILITIES:
  3041 
  3042   - Definitions of overloaded constants on sets have to be replaced by
  3043     definitions on => and bool.
  3044 
  3045   - Some definitions of overloaded operators on sets can now be proved
  3046     using the definitions of the operators on => and bool.  Therefore,
  3047     the following theorems have been renamed:
  3048 
  3049       subset_def   -> subset_eq
  3050       psubset_def  -> psubset_eq
  3051       set_diff_def -> set_diff_eq
  3052       Compl_def    -> Compl_eq
  3053       Sup_set_def  -> Sup_set_eq
  3054       Inf_set_def  -> Inf_set_eq
  3055       sup_set_def  -> sup_set_eq
  3056       inf_set_def  -> inf_set_eq
  3057 
  3058   - Due to the incompleteness of the HO unification algorithm, some
  3059     rules such as subst may require manual instantiation, if some of
  3060     the unknowns in the rule is a set.
  3061 
  3062   - Higher order unification and forward proofs:
  3063     The proof pattern
  3064 
  3065       have "P (S::'a set)" <...>
  3066       then have "EX S. P S" ..
  3067 
  3068     no longer works (due to the incompleteness of the HO unification
  3069     algorithm) and must be replaced by the pattern
  3070 
  3071       have "EX S. P S"
  3072       proof
  3073         show "P S" <...>
  3074       qed
  3075 
  3076   - Calculational reasoning with subst (or similar rules):
  3077     The proof pattern
  3078 
  3079       have "P (S::'a set)" <...>
  3080       also have "S = T" <...>
  3081       finally have "P T" .
  3082 
  3083     no longer works (for similar reasons as the previous example) and
  3084     must be replaced by something like
  3085 
  3086       have "P (S::'a set)" <...>
  3087       moreover have "S = T" <...>
  3088       ultimately have "P T" by simp
  3089 
  3090   - Tactics or packages written in ML code:
  3091     Code performing pattern matching on types via
  3092 
  3093       Type ("set", [T]) => ...
  3094 
  3095     must be rewritten. Moreover, functions like strip_type or
  3096     binder_types no longer return the right value when applied to a
  3097     type of the form
  3098 
  3099       T1 => ... => Tn => U => bool
  3100 
  3101     rather than
  3102 
  3103       T1 => ... => Tn => U set
  3104 
  3105 * Merged theories Wellfounded_Recursion, Accessible_Part and
  3106 Wellfounded_Relations to theory Wellfounded.
  3107 
  3108 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  3109 
  3110 * Class finite no longer treats UNIV as class parameter.  Use class
  3111 enum from theory Library/Enum instead to achieve a similar effect.
  3112 INCOMPATIBILITY.
  3113 
  3114 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  3115 and "Cons".  INCOMPATIBILITY.
  3116 
  3117 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  3118 Potential INCOMPATIBILITY.
  3119 
  3120 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  3121 injective_fst_snd removed, use split_eta and prod_eqI instead.
  3122 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  3123 
  3124 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  3125 the same name in theory Orderings:
  3126 
  3127   less_trans
  3128   less_linear
  3129   le_imp_less_or_eq
  3130   le_less_trans
  3131   less_le_trans
  3132   less_not_sym
  3133   less_asym
  3134 
  3135 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  3136 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  3137 and different variable names.
  3138 
  3139 * Library/Option_ord.thy: Canonical order on option type.
  3140 
  3141 * Library/RBT.thy: Red-black trees, an efficient implementation of
  3142 finite maps.
  3143 
  3144 * Library/Countable.thy: Type class for countable types.
  3145 
  3146 * Theory Int: The representation of numerals has changed.  The infix
  3147 operator BIT and the bit datatype with constructors B0 and B1 have
  3148 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  3149 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  3150 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  3151 accordingly.
  3152 
  3153 * Theory Nat: definition of <= and < on natural numbers no longer
  3154 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  3155 le_def and less_def have disappeared.  Consider lemmas not_less
  3156 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  3157 
  3158 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  3159 (whose purpose mainly is for various fold_set functionals) have been
  3160 abandoned in favor of the existing algebraic classes
  3161 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  3162 lower_semilattice (resp. upper_semilattice) and linorder.
  3163 INCOMPATIBILITY.
  3164 
  3165 * Theory Transitive_Closure: induct and cases rules now declare proper
  3166 case_names ("base" and "step").  INCOMPATIBILITY.
  3167 
  3168 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  3169 lattices.  The form set-specific version is available as
  3170 Inductive.lfp_ordinal_induct_set.
  3171 
  3172 * Renamed theorems "power.simps" to "power_int.simps".
  3173 INCOMPATIBILITY.
  3174 
  3175 * Class semiring_div provides basic abstract properties of semirings
  3176 with division and modulo operations.  Subsumes former class dvd_mod.
  3177 
  3178 * Merged theories IntDef, Numeral and IntArith into unified theory
  3179 Int.  INCOMPATIBILITY.
  3180 
  3181 * Theory Library/Code_Index: type "index" now represents natural
  3182 numbers rather than integers.  INCOMPATIBILITY.
  3183 
  3184 * New class "uminus" with operation "uminus" (split of from class
  3185 "minus" which now only has operation "minus", binary).
  3186 INCOMPATIBILITY.
  3187 
  3188 * Constants "card", "internal_split", "option_map" now with authentic
  3189 syntax.  INCOMPATIBILITY.
  3190 
  3191 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  3192 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  3193 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  3194 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  3195 Sup_set_def, le_def, less_def, option_map_def now with object
  3196 equality.  INCOMPATIBILITY.
  3197 
  3198 * Records. Removed K_record, and replaced it by pure lambda term
  3199 %x. c. The simplifier setup is now more robust against eta expansion.
  3200 INCOMPATIBILITY: in cases explicitly referring to K_record.
  3201 
  3202 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  3203 
  3204 * Library/ListVector: new theory of arithmetic vector operations.
  3205 
  3206 * Library/Order_Relation: new theory of various orderings as sets of
  3207 pairs.  Defines preorders, partial orders, linear orders and
  3208 well-orders on sets and on types.
  3209 
  3210 
  3211 *** ZF ***
  3212 
  3213 * Renamed some theories to allow to loading both ZF and HOL in the
  3214 same session:
  3215 
  3216   Datatype  -> Datatype_ZF
  3217   Inductive -> Inductive_ZF
  3218   Int       -> Int_ZF
  3219   IntDiv    -> IntDiv_ZF
  3220   Nat       -> Nat_ZF
  3221   List      -> List_ZF
  3222   Main      -> Main_ZF
  3223 
  3224 INCOMPATIBILITY: ZF theories that import individual theories below
  3225 Main might need to be adapted.  Regular theory Main is still
  3226 available, as trivial extension of Main_ZF.
  3227 
  3228 
  3229 *** ML ***
  3230 
  3231 * ML within Isar: antiquotation @{const name} or @{const
  3232 name(typargs)} produces statically-checked Const term.
  3233 
  3234 * Functor NamedThmsFun: data is available to the user as dynamic fact
  3235 (of the same name).  Removed obsolete print command.
  3236 
  3237 * Removed obsolete "use_legacy_bindings" function.
  3238 
  3239 * The ``print mode'' is now a thread-local value derived from a global
  3240 template (the former print_mode reference), thus access becomes
  3241 non-critical.  The global print_mode reference is for session
  3242 management only; user-code should use print_mode_value,
  3243 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  3244 
  3245 * Functions system/system_out provide a robust way to invoke external
  3246 shell commands, with propagation of interrupts (requires Poly/ML
  3247 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  3248 
  3249 
  3250 *** System ***
  3251 
  3252 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  3253 in accordance with Proof General 3.7, which prefers GNU emacs.
  3254 
  3255 * isatool tty runs Isabelle process with plain tty interaction;
  3256 optional line editor may be specified via ISABELLE_LINE_EDITOR
  3257 setting, the default settings attempt to locate "ledit" and "rlwrap".
  3258 
  3259 * isatool browser now works with Cygwin as well, using general
  3260 "javapath" function defined in Isabelle process environment.
  3261 
  3262 * YXML notation provides a simple and efficient alternative to
  3263 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  3264 isatool yxml as described in the Isabelle system manual.
  3265 
  3266 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  3267 provides general wrapper for managing an Isabelle process in a robust
  3268 fashion, with ``cooked'' output from stdin/stderr.
  3269 
  3270 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  3271 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  3272 
  3273 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  3274 way of changing the user's settings is via
  3275 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  3276 script.
  3277 
  3278 * Multithreading.max_threads := 0 refers to the number of actual CPU
  3279 cores of the underlying machine, which is a good starting point for
  3280 optimal performance tuning.  The corresponding usedir option -M allows
  3281 "max" as an alias for "0".  WARNING: does not work on certain versions
  3282 of Mac OS (with Poly/ML 5.1).
  3283 
  3284 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  3285 adverse effect of Isabelle flooding interactive front-ends (notably
  3286 ProofGeneral / XEmacs).
  3287 
  3288 
  3289 
  3290 New in Isabelle2007 (November 2007)
  3291 -----------------------------------
  3292 
  3293 *** General ***
  3294 
  3295 * More uniform information about legacy features, notably a
  3296 warning/error of "Legacy feature: ...", depending on the state of the
  3297 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  3298 legacy features will disappear eventually.
  3299 
  3300 * Theory syntax: the header format ``theory A = B + C:'' has been
  3301 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  3302 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  3303 
  3304 * Theory syntax: the old non-Isar theory file format has been
  3305 discontinued altogether.  Note that ML proof scripts may still be used
  3306 with Isar theories; migration is usually quite simple with the ML
  3307 function use_legacy_bindings.  INCOMPATIBILITY.
  3308 
  3309 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  3310 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  3311 quotes.
  3312 
  3313 * Theory loader: be more serious about observing the static theory
  3314 header specifications (including optional directories), but not the
  3315 accidental file locations of previously successful loads.  The strict
  3316 update policy of former update_thy is now already performed by
  3317 use_thy, so the former has been removed; use_thys updates several
  3318 theories simultaneously, just as 'imports' within a theory header
  3319 specification, but without merging the results.  Potential
  3320 INCOMPATIBILITY: may need to refine theory headers and commands
  3321 ROOT.ML which depend on load order.
  3322 
  3323 * Theory loader: optional support for content-based file
  3324 identification, instead of the traditional scheme of full physical
  3325 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  3326 (cf. the system manual).  The new scheme allows to work with
  3327 non-finished theories in persistent session images, such that source
  3328 files may be moved later on without requiring reloads.
  3329 
  3330 * Theory loader: old-style ML proof scripts being *attached* to a thy
  3331 file (with the same base name as the theory) are considered a legacy
  3332 feature, which will disappear eventually. Even now, the theory loader
  3333 no longer maintains dependencies on such files.
  3334 
  3335 * Syntax: the scope for resolving ambiguities via type-inference is
  3336 now limited to individual terms, instead of whole simultaneous
  3337 specifications as before. This greatly reduces the complexity of the
  3338 syntax module and improves flexibility by separating parsing and
  3339 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  3340 'fixes' etc.) are required in rare situations.
  3341 
  3342 * Syntax: constants introduced by new-style packages ('definition',
  3343 'abbreviation' etc.) are passed through the syntax module in
  3344 ``authentic mode''. This means that associated mixfix annotations
  3345 really stick to such constants, independently of potential name space
  3346 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  3347 trees are represented slightly differently, may need to adapt syntax
  3348 translations accordingly. Use CONST marker in 'translations' and
  3349 @{const_syntax} antiquotation in 'parse_translation' etc.
  3350 
  3351 * Legacy goal package: reduced interface to the bare minimum required
  3352 to keep existing proof scripts running.  Most other user-level
  3353 functions are now part of the OldGoals structure, which is *not* open
  3354 by default (consider isatool expandshort before open OldGoals).
  3355 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  3356 these tend to cause confusion about the actual goal (!) context being
  3357 used here, which is not necessarily the same as the_context().
  3358 
  3359 * Command 'find_theorems': supports "*" wild-card in "name:"
  3360 criterion; "with_dups" option.  Certain ProofGeneral versions might
  3361 support a specific search form (see ProofGeneral/CHANGES).
  3362 
  3363 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  3364 by default, which means that "prems" (and also "fixed variables") are
  3365 suppressed from proof state output.  Note that the ProofGeneral
  3366 settings mechanism allows to change and save options persistently, but
  3367 older versions of Isabelle will fail to start up if a negative prems
  3368 limit is imposed.
  3369 
  3370 * Local theory targets may be specified by non-nested blocks of
  3371 ``context/locale/class ... begin'' followed by ``end''.  The body may
  3372 contain definitions, theorems etc., including any derived mechanism
  3373 that has been implemented on top of these primitives.  This concept
  3374 generalizes the existing ``theorem (in ...)'' towards more versatility
  3375 and scalability.
  3376 
  3377 * Proof General interface: proper undo of final 'end' command;
  3378 discontinued Isabelle/classic mode (ML proof scripts).
  3379 
  3380 
  3381 *** Document preparation ***
  3382 
  3383 * Added antiquotation @{theory name} which prints the given name,
  3384 after checking that it refers to a valid ancestor theory in the
  3385 current context.
  3386 
  3387 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  3388 check the given source text as ML type/structure, printing verbatim.
  3389 
  3390 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  3391 "c args == rhs" given in the current context.  (Any number of
  3392 arguments may be given on the LHS.)
  3393 
  3394 
  3395 *** Pure ***
  3396 
  3397 * The 'class' package offers a combination of axclass and locale to
  3398 achieve Haskell-like type classes in Isabelle.  Definitions and
  3399 theorems within a class context produce both relative results (with
  3400 implicit parameters according to the locale context), and polymorphic
  3401 constants with qualified polymorphism (according to the class
  3402 context).  Within the body context of a 'class' target, a separate
  3403 syntax layer ("user space type system") takes care of converting
  3404 between global polymorphic consts and internal locale representation.
  3405 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  3406 "isatool doc classes" provides a tutorial.
  3407 
  3408 * Generic code generator framework allows to generate executable
  3409 code for ML and Haskell (including Isabelle classes).  A short usage
  3410 sketch:
  3411 
  3412     internal compilation:
  3413         export_code <list of constants (term syntax)> in SML
  3414     writing SML code to a file:
  3415         export_code <list of constants (term syntax)> in SML <filename>
  3416     writing OCaml code to a file:
  3417         export_code <list of constants (term syntax)> in OCaml <filename>
  3418     writing Haskell code to a bunch of files:
  3419         export_code <list of constants (term syntax)> in Haskell <filename>
  3420 
  3421     evaluating closed propositions to True/False using code generation:
  3422         method ``eval''
  3423 
  3424 Reasonable default setup of framework in HOL.
  3425 
  3426 Theorem attributs for selecting and transforming function equations theorems:
  3427 
  3428     [code fun]:        select a theorem as function equation for a specific constant
  3429     [code fun del]:    deselect a theorem as function equation for a specific constant
  3430     [code inline]:     select an equation theorem for unfolding (inlining) in place
  3431     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  3432 
  3433 User-defined serializations (target in {SML, OCaml, Haskell}):
  3434 
  3435     code_const <and-list of constants (term syntax)>
  3436       {(target) <and-list of const target syntax>}+
  3437 
  3438     code_type <and-list of type constructors>
  3439       {(target) <and-list of type target syntax>}+
  3440 
  3441     code_instance <and-list of instances>
  3442       {(target)}+
  3443         where instance ::= <type constructor> :: <class>
  3444 
  3445     code_class <and_list of classes>
  3446       {(target) <and-list of class target syntax>}+
  3447         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  3448 
  3449 code_instance and code_class only are effective to target Haskell.
  3450 
  3451 For example usage see src/HOL/ex/Codegenerator.thy and
  3452 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  3453 generation from Isabelle/HOL theories is available via "isatool doc
  3454 codegen".
  3455 
  3456 * Code generator: consts in 'consts_code' Isar commands are now
  3457 referred to by usual term syntax (including optional type
  3458 annotations).
  3459 
  3460 * Command 'no_translations' removes translation rules from theory
  3461 syntax.
  3462 
  3463 * Overloaded definitions are now actually checked for acyclic
  3464 dependencies.  The overloading scheme is slightly more general than
  3465 that of Haskell98, although Isabelle does not demand an exact
  3466 correspondence to type class and instance declarations.
  3467 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  3468 exotic versions of overloading -- at the discretion of the user!
  3469 
  3470 Polymorphic constants are represented via type arguments, i.e. the
  3471 instantiation that matches an instance against the most general
  3472 declaration given in the signature.  For example, with the declaration
  3473 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  3474 as c(nat).  Overloading is essentially simultaneous structural
  3475 recursion over such type arguments.  Incomplete specification patterns
  3476 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  3477 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  3478 Command 'print_theory' outputs the normalized system of recursive
  3479 equations, see section "definitions".
  3480 
  3481 * Configuration options are maintained within the theory or proof
  3482 context (with name and type bool/int/string), providing a very simple
  3483 interface to a poor-man's version of general context data.  Tools may
  3484 declare options in ML (e.g. using Attrib.config_int) and then refer to
  3485 these values using Config.get etc.  Users may change options via an
  3486 associated attribute of the same name.  This form of context
  3487 declaration works particularly well with commands 'declare' or
  3488 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  3489 very easy to avoid global references, which would not observe Isar
  3490 toplevel undo/redo and fail to work with multithreading.
  3491 
  3492 Various global ML references of Pure and HOL have been turned into
  3493 configuration options:
  3494 
  3495   Unify.search_bound		unify_search_bound
  3496   Unify.trace_bound		unify_trace_bound
  3497   Unify.trace_simp		unify_trace_simp
  3498   Unify.trace_types		unify_trace_types
  3499   Simplifier.simp_depth_limit	simp_depth_limit
  3500   Blast.depth_limit		blast_depth_limit
  3501   DatatypeProp.dtK		datatype_distinctness_limit
  3502   fast_arith_neq_limit  	fast_arith_neq_limit
  3503   fast_arith_split_limit	fast_arith_split_limit
  3504 
  3505 * Named collections of theorems may be easily installed as context
  3506 data using the functor NamedThmsFun (see also
  3507 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  3508 attributes; there is also a toplevel print command.  This facility is
  3509 just a common case of general context data, which is the preferred way
  3510 for anything more complex than just a list of facts in canonical
  3511 order.
  3512 
  3513 * Isar: command 'declaration' augments a local theory by generic
  3514 declaration functions written in ML.  This enables arbitrary content
  3515 being added to the context, depending on a morphism that tells the
  3516 difference of the original declaration context wrt. the application
  3517 context encountered later on.
  3518 
  3519 * Isar: proper interfaces for simplification procedures.  Command
  3520 'simproc_setup' declares named simprocs (with match patterns, and body
  3521 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  3522 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  3523 
  3524 * Isar: an extra pair of brackets around attribute declarations
  3525 abbreviates a theorem reference involving an internal dummy fact,
  3526 which will be ignored later --- only the effect of the attribute on
  3527 the background context will persist.  This form of in-place
  3528 declarations is particularly useful with commands like 'declare' and
  3529 'using', for example ``have A using [[simproc a]] by simp''.
  3530 
  3531 * Isar: method "assumption" (and implicit closing of subproofs) now
  3532 takes simple non-atomic goal assumptions into account: after applying
  3533 an assumption as a rule the resulting subgoals are solved by atomic
  3534 assumption steps.  This is particularly useful to finish 'obtain'
  3535 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  3536 without referring to the original premise "!!x. P x ==> thesis" in the
  3537 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  3538 more permissive.
  3539 
  3540 * Isar: implicit use of prems from the Isar proof context is
  3541 considered a legacy feature.  Common applications like ``have A .''
  3542 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  3543 referencing facts explicitly here improves readability and
  3544 maintainability of proof texts.
  3545 
  3546 * Isar: improper proof element 'guess' is like 'obtain', but derives
  3547 the obtained context from the course of reasoning!  For example:
  3548 
  3549   assume "EX x y. A x & B y"   -- "any previous fact"
  3550   then guess x and y by clarify
  3551 
  3552 This technique is potentially adventurous, depending on the facts and
  3553 proof tools being involved here.
  3554 
  3555 * Isar: known facts from the proof context may be specified as literal
  3556 propositions, using ASCII back-quote syntax.  This works wherever
  3557 named facts used to be allowed so far, in proof commands, proof
  3558 methods, attributes etc.  Literal facts are retrieved from the context
  3559 according to unification of type and term parameters.  For example,
  3560 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  3561 theorems in the current context, then these are valid literal facts:
  3562 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  3563 
  3564 There is also a proof method "fact" which does the same composition
  3565 for explicit goal states, e.g. the following proof texts coincide with
  3566 certain special cases of literal facts:
  3567 
  3568   have "A" by fact                 ==  note `A`
  3569   have "A ==> B" by fact           ==  note `A ==> B`
  3570   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  3571   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  3572 
  3573 * Isar: ":" (colon) is no longer a symbolic identifier character in
  3574 outer syntax.  Thus symbolic identifiers may be used without
  3575 additional white space in declarations like this: ``assume *: A''.
  3576 
  3577 * Isar: 'print_facts' prints all local facts of the current context,
  3578 both named and unnamed ones.
  3579 
  3580 * Isar: 'def' now admits simultaneous definitions, e.g.:
  3581 
  3582   def x == "t" and y == "u"
  3583 
  3584 * Isar: added command 'unfolding', which is structurally similar to
  3585 'using', but affects both the goal state and facts by unfolding given
  3586 rewrite rules.  Thus many occurrences of the 'unfold' method or
  3587 'unfolded' attribute may be replaced by first-class proof text.
  3588 
  3589 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  3590 and command 'unfolding' now all support object-level equalities
  3591 (potentially conditional).  The underlying notion of rewrite rule is
  3592 analogous to the 'rule_format' attribute, but *not* that of the
  3593 Simplifier (which is usually more generous).
  3594 
  3595 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  3596 premises of a theorem by n. Useful in conjunction with drule.
  3597 
  3598 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  3599 method expression within a sandbox consisting of the first N
  3600 sub-goals, which need to exist.  For example, ``simp_all [3]''
  3601 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  3602 simplifies all new goals that emerge from applying rule foo to the
  3603 originally first one.
  3604 
  3605 * Isar: schematic goals are no longer restricted to higher-order
  3606 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  3607 expected.
  3608 
  3609 * Isar: the conclusion of a long theorem statement is now either
  3610 'shows' (a simultaneous conjunction, as before), or 'obtains'
  3611 (essentially a disjunction of cases with local parameters and
  3612 assumptions).  The latter allows to express general elimination rules
  3613 adequately; in this notation common elimination rules look like this:
  3614 
  3615   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  3616     assumes "EX x. P x"
  3617     obtains x where "P x"
  3618 
  3619   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  3620     assumes "A & B"
  3621     obtains A and B
  3622 
  3623   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  3624     assumes "A | B"
  3625     obtains
  3626       A
  3627     | B
  3628 
  3629 The subsequent classical rules even refer to the formal "thesis"
  3630 explicitly:
  3631 
  3632   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  3633     obtains "~ thesis"
  3634 
  3635   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  3636     obtains "thesis ==> something"
  3637 
  3638 The actual proof of an 'obtains' statement is analogous to that of the
  3639 Isar proof element 'obtain', only that there may be several cases.
  3640 Optional case names may be specified in parentheses; these will be
  3641 available both in the present proof and as annotations in the
  3642 resulting rule, for later use with the 'cases' method (cf. attribute
  3643 case_names).
  3644 
  3645 * Isar: the assumptions of a long theorem statement are available as
  3646 "assms" fact in the proof context.  This is more appropriate than the
  3647 (historical) "prems", which refers to all assumptions of the current
  3648 context, including those from the target locale, proof body etc.
  3649 
  3650 * Isar: 'print_statement' prints theorems from the current theory or
  3651 proof context in long statement form, according to the syntax of a
  3652 top-level lemma.
  3653 
  3654 * Isar: 'obtain' takes an optional case name for the local context
  3655 introduction rule (default "that").
  3656 
  3657 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  3658 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  3659 to occur.
  3660 
  3661 * Pure: syntax "CONST name" produces a fully internalized constant
  3662 according to the current context.  This is particularly useful for
  3663 syntax translations that should refer to internal constant
  3664 representations independently of name spaces.
  3665 
  3666 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  3667 instead of "FOO ". This allows multiple binder declarations to coexist
  3668 in the same context.  INCOMPATIBILITY.
  3669 
  3670 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  3671 primitive that also works in a locale context (both for constants and
  3672 fixed variables). Type declaration and internal syntactic representation
  3673 of given constants retrieved from the context. Likewise, the
  3674 'no_notation' command allows to remove given syntax annotations from the
  3675 current context.
  3676 
  3677 * Isar/locales: new derived specification elements 'axiomatization',
  3678 'definition', 'abbreviation', which support type-inference, admit
  3679 object-level specifications (equality, equivalence).  See also the
  3680 isar-ref manual.  Examples:
  3681 
  3682   axiomatization
  3683     eq  (infix "===" 50) where
  3684     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  3685 
  3686   definition "f x y = x + y + 1"
  3687   definition g where "g x = f x x"
  3688 
  3689   abbreviation
  3690     neq  (infix "=!=" 50) where
  3691     "x =!= y == ~ (x === y)"
  3692 
  3693 These specifications may be also used in a locale context.  Then the
  3694 constants being introduced depend on certain fixed parameters, and the
  3695 constant name is qualified by the locale base name.  An internal
  3696 abbreviation takes care for convenient input and output, making the
  3697 parameters implicit and using the original short name.  See also
  3698 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  3699 entities from a monomorphic theory.
  3700 
  3701 Presently, abbreviations are only available 'in' a target locale, but
  3702 not inherited by general import expressions.  Also note that
  3703 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  3704 'translations' in common applications.  The "no_abbrevs" print mode
  3705 prevents folding of abbreviations in term output.
  3706 
  3707 Concrete syntax is attached to specified constants in internal form,
  3708 independently of name spaces.  The parse tree representation is
  3709 slightly different -- use 'notation' instead of raw 'syntax', and
  3710 'translations' with explicit "CONST" markup to accommodate this.
  3711 
  3712 * Pure/Isar: unified syntax for new-style specification mechanisms
  3713 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  3714 full type inference and dummy patterns ("_").  For example:
  3715 
  3716   definition "K x _ = x"
  3717 
  3718   inductive conj for A B
  3719   where "A ==> B ==> conj A B"
  3720 
  3721 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  3722 the current context.  Print mode "no_abbrevs" prevents inversion of
  3723 abbreviations on output.
  3724 
  3725 * Isar/locales: improved parameter handling: use of locales "var" and
  3726 "struct" no longer necessary; - parameter renamings are no longer
  3727 required to be injective.  For example, this allows to define
  3728 endomorphisms as locale endom = homom mult mult h.
  3729 
  3730 * Isar/locales: changed the way locales with predicates are defined.
  3731 Instead of accumulating the specification, the imported expression is
  3732 now an interpretation.  INCOMPATIBILITY: different normal form of
  3733 locale expressions.  In particular, in interpretations of locales with
  3734 predicates, goals repesenting already interpreted fragments are not
  3735 removed automatically.  Use methods `intro_locales' and
  3736 `unfold_locales'; see below.
  3737 
  3738 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  3739 provide backward reasoning on locales predicates.  The methods are
  3740 aware of interpretations and discharge corresponding goals.
  3741 `intro_locales' is less aggressive then `unfold_locales' and does not
  3742 unfold predicates to assumptions.
  3743 
  3744 * Isar/locales: the order in which locale fragments are accumulated
  3745 has changed.  This enables to override declarations from fragments due
  3746 to interpretations -- for example, unwanted simp rules.
  3747 
  3748 * Isar/locales: interpretation in theories and proof contexts has been
  3749 extended.  One may now specify (and prove) equations, which are
  3750 unfolded in interpreted theorems.  This is useful for replacing
  3751 defined concepts (constants depending on locale parameters) by
  3752 concepts already existing in the target context.  Example:
  3753 
  3754   interpretation partial_order ["op <= :: [int, int] => bool"]
  3755     where "partial_order.less (op <=) (x::int) y = (x < y)"
  3756 
  3757 Typically, the constant `partial_order.less' is created by a
  3758 definition specification element in the context of locale
  3759 partial_order.
  3760 
  3761 * Method "induct": improved internal context management to support
  3762 local fixes and defines on-the-fly. Thus explicit meta-level
  3763 connectives !!  and ==> are rarely required anymore in inductive goals
  3764 (using object-logic connectives for this purpose has been long
  3765 obsolete anyway). Common proof patterns are explained in
  3766 src/HOL/Induct/Common_Patterns.thy, see also
  3767 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  3768 examples.
  3769 
  3770 * Method "induct": improved handling of simultaneous goals. Instead of
  3771 introducing object-level conjunction, the statement is now split into
  3772 several conclusions, while the corresponding symbolic cases are nested
  3773 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  3774 see src/HOL/Induct/Common_Patterns.thy, for example.
  3775 
  3776 * Method "induct": mutual induction rules are now specified as a list
  3777 of rule sharing the same induction cases. HOL packages usually provide
  3778 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  3779 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  3780 mutual induction rules differently, i.e. like this:
  3781 
  3782   (induct rule: foo_bar.inducts)
  3783   (induct set: foo bar)
  3784   (induct pred: foo bar)
  3785   (induct type: foo bar)
  3786 
  3787 The ML function ProjectRule.projections turns old-style rules into the
  3788 new format.
  3789 
  3790 * Method "coinduct": dual of induction, see
  3791 src/HOL/Library/Coinductive_List.thy for various examples.
  3792 
  3793 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  3794 considered a legacy feature.
  3795 
  3796 * Attribute "symmetric" produces result with standardized schematic
  3797 variables (index 0).  Potential INCOMPATIBILITY.
  3798 
  3799 * Simplifier: by default the simplifier trace only shows top level
  3800 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  3801 default. Thus there is less danger of being flooded by the trace. The
  3802 trace indicates where parts have been suppressed.
  3803   
  3804 * Provers/classical: removed obsolete classical version of elim_format
  3805 attribute; classical elim/dest rules are now treated uniformly when
  3806 manipulating the claset.
  3807 
  3808 * Provers/classical: stricter checks to ensure that supplied intro,
  3809 dest and elim rules are well-formed; dest and elim rules must have at
  3810 least one premise.
  3811 
  3812 * Provers/classical: attributes dest/elim/intro take an optional
  3813 weight argument for the rule (just as the Pure versions).  Weights are
  3814 ignored by automated tools, but determine the search order of single
  3815 rule steps.
  3816 
  3817 * Syntax: input syntax now supports dummy variable binding "%_. b",
  3818 where the body does not mention the bound variable.  Note that dummy
  3819 patterns implicitly depend on their context of bounds, which makes
  3820 "{_. _}" match any set comprehension as expected.  Potential
  3821 INCOMPATIBILITY -- parse translations need to cope with syntactic
  3822 constant "_idtdummy" in the binding position.
  3823 
  3824 * Syntax: removed obsolete syntactic constant "_K" and its associated
  3825 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  3826 for example "A -> B" => "Pi A (%_. B)".
  3827 
  3828 * Pure: 'class_deps' command visualizes the subclass relation, using
  3829 the graph browser tool.
  3830 
  3831 * Pure: 'print_theory' now suppresses certain internal declarations by
  3832 default; use '!' option for full details.
  3833 
  3834 
  3835 *** HOL ***
  3836 
  3837 * Method "metis" proves goals by applying the Metis general-purpose
  3838 resolution prover (see also http://gilith.com/software/metis/).
  3839 Examples are in the directory MetisExamples.  WARNING: the
  3840 Isabelle/HOL-Metis integration does not yet work properly with
  3841 multi-threading.
  3842   
  3843 * Command 'sledgehammer' invokes external automatic theorem provers as
  3844 background processes.  It generates calls to the "metis" method if
  3845 successful. These can be pasted into the proof.  Users do not have to
  3846 wait for the automatic provers to return.  WARNING: does not really
  3847 work with multi-threading.
  3848 
  3849 * New "auto_quickcheck" feature tests outermost goal statements for
  3850 potential counter-examples.  Controlled by ML references
  3851 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  3852 5000 milliseconds).  Fails silently if statements is outside of
  3853 executable fragment, or any other codgenerator problem occurs.
  3854 
  3855 * New constant "undefined" with axiom "undefined x = undefined".
  3856 
  3857 * Added class "HOL.eq", allowing for code generation with polymorphic
  3858 equality.
  3859 
  3860 * Some renaming of class constants due to canonical name prefixing in
  3861 the new 'class' package:
  3862 
  3863     HOL.abs ~> HOL.abs_class.abs
  3864     HOL.divide ~> HOL.divide_class.divide
  3865     0 ~> HOL.zero_class.zero
  3866     1 ~> HOL.one_class.one
  3867     op + ~> HOL.plus_class.plus
  3868     op - ~> HOL.minus_class.minus
  3869     uminus ~> HOL.minus_class.uminus
  3870     op * ~> HOL.times_class.times
  3871     op < ~> HOL.ord_class.less
  3872     op <= > HOL.ord_class.less_eq
  3873     Nat.power ~> Power.power_class.power
  3874     Nat.size ~> Nat.size_class.size
  3875     Numeral.number_of ~> Numeral.number_class.number_of
  3876     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  3877     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  3878     Orderings.min ~> Orderings.ord_class.min
  3879     Orderings.max ~> Orderings.ord_class.max
  3880     Divides.op div ~> Divides.div_class.div
  3881     Divides.op mod ~> Divides.div_class.mod
  3882     Divides.op dvd ~> Divides.div_class.dvd
  3883 
  3884 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  3885 
  3886 a) User-defined constants using any of the names "plus", "minus",
  3887 "times", "less" or "less_eq". The standard syntax translations for
  3888 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  3889 names.
  3890 
  3891 b) Variables named "plus", "minus", "times", "less", "less_eq"
  3892 INCOMPATIBILITY: use more specific names.
  3893 
  3894 c) Permutative equations (e.g. "a + b = b + a")
  3895 Since the change of names also changes the order of terms, permutative
  3896 rewrite rules may get applied in a different order. Experience shows
  3897 that this is rarely the case (only two adaptions in the whole Isabelle
  3898 distribution).  INCOMPATIBILITY: rewrite proofs
  3899 
  3900 d) ML code directly refering to constant names
  3901 This in general only affects hand-written proof tactics, simprocs and
  3902 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  3903 Consider using @{const_name} antiquotation.
  3904 
  3905 * New class "default" with associated constant "default".
  3906 
  3907 * Function "sgn" is now overloaded and available on int, real, complex
  3908 (and other numeric types), using class "sgn".  Two possible defs of
  3909 sgn are given as equational assumptions in the classes sgn_if and
  3910 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  3911 INCOMPATIBILITY.
  3912 
  3913 * Locale "partial_order" now unified with class "order" (cf. theory
  3914 Orderings), added parameter "less".  INCOMPATIBILITY.
  3915 
  3916 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  3917 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  3918 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  3919 
  3920 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  3921 changed order of proof goals in instance proofs.
  3922 
  3923 * The transitivity reasoner for partial and linear orders is set up
  3924 for classes "order" and "linorder".  Instances of the reasoner are available
  3925 in all contexts importing or interpreting the corresponding locales.
  3926 Method "order" invokes the reasoner separately; the reasoner
  3927 is also integrated with the Simplifier as a solver.  Diagnostic
  3928 command 'print_orders' shows the available instances of the reasoner
  3929 in the current context.
  3930 
  3931 * Localized monotonicity predicate in theory "Orderings"; integrated
  3932 lemmas max_of_mono and min_of_mono with this predicate.
  3933 INCOMPATIBILITY.
  3934 
  3935 * Formulation of theorem "dense" changed slightly due to integration
  3936 with new class dense_linear_order.
  3937 
  3938 * Uniform lattice theory development in HOL.
  3939 
  3940     constants "meet" and "join" now named "inf" and "sup"
  3941     constant "Meet" now named "Inf"
  3942 
  3943     classes "meet_semilorder" and "join_semilorder" now named
  3944       "lower_semilattice" and "upper_semilattice"
  3945     class "lorder" now named "lattice"
  3946     class "comp_lat" now named "complete_lattice"
  3947 
  3948     Instantiation of lattice classes allows explicit definitions
  3949     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  3950 
  3951   INCOMPATIBILITY.  Theorem renames:
  3952 
  3953     meet_left_le            ~> inf_le1
  3954     meet_right_le           ~> inf_le2
  3955     join_left_le            ~> sup_ge1
  3956     join_right_le           ~> sup_ge2
  3957     meet_join_le            ~> inf_sup_ord
  3958     le_meetI                ~> le_infI
  3959     join_leI                ~> le_supI
  3960     le_meet                 ~> le_inf_iff
  3961     le_join                 ~> ge_sup_conv
  3962     meet_idempotent         ~> inf_idem
  3963     join_idempotent         ~> sup_idem
  3964     meet_comm               ~> inf_commute
  3965     join_comm               ~> sup_commute
  3966     meet_leI1               ~> le_infI1
  3967     meet_leI2               ~> le_infI2
  3968     le_joinI1               ~> le_supI1
  3969     le_joinI2               ~> le_supI2
  3970     meet_assoc              ~> inf_assoc
  3971     join_assoc              ~> sup_assoc
  3972     meet_left_comm          ~> inf_left_commute
  3973     meet_left_idempotent    ~> inf_left_idem
  3974     join_left_comm          ~> sup_left_commute
  3975     join_left_idempotent    ~> sup_left_idem
  3976     meet_aci                ~> inf_aci
  3977     join_aci                ~> sup_aci
  3978     le_def_meet             ~> le_iff_inf
  3979     le_def_join             ~> le_iff_sup
  3980     join_absorp2            ~> sup_absorb2
  3981     join_absorp1            ~> sup_absorb1
  3982     meet_absorp1            ~> inf_absorb1
  3983     meet_absorp2            ~> inf_absorb2
  3984     meet_join_absorp        ~> inf_sup_absorb
  3985     join_meet_absorp        ~> sup_inf_absorb
  3986     distrib_join_le         ~> distrib_sup_le
  3987     distrib_meet_le         ~> distrib_inf_le
  3988 
  3989     add_meet_distrib_left   ~> add_inf_distrib_left
  3990     add_join_distrib_left   ~> add_sup_distrib_left
  3991     is_join_neg_meet        ~> is_join_neg_inf
  3992     is_meet_neg_join        ~> is_meet_neg_sup
  3993     add_meet_distrib_right  ~> add_inf_distrib_right
  3994     add_join_distrib_right  ~> add_sup_distrib_right
  3995     add_meet_join_distribs  ~> add_sup_inf_distribs
  3996     join_eq_neg_meet        ~> sup_eq_neg_inf
  3997     meet_eq_neg_join        ~> inf_eq_neg_sup
  3998     add_eq_meet_join        ~> add_eq_inf_sup
  3999     meet_0_imp_0            ~> inf_0_imp_0
  4000     join_0_imp_0            ~> sup_0_imp_0
  4001     meet_0_eq_0             ~> inf_0_eq_0
  4002     join_0_eq_0             ~> sup_0_eq_0
  4003     neg_meet_eq_join        ~> neg_inf_eq_sup
  4004     neg_join_eq_meet        ~> neg_sup_eq_inf
  4005     join_eq_if              ~> sup_eq_if
  4006 
  4007     mono_meet               ~> mono_inf
  4008     mono_join               ~> mono_sup
  4009     meet_bool_eq            ~> inf_bool_eq
  4010     join_bool_eq            ~> sup_bool_eq
  4011     meet_fun_eq             ~> inf_fun_eq
  4012     join_fun_eq             ~> sup_fun_eq
  4013     meet_set_eq             ~> inf_set_eq
  4014     join_set_eq             ~> sup_set_eq
  4015     meet1_iff               ~> inf1_iff
  4016     meet2_iff               ~> inf2_iff
  4017     meet1I                  ~> inf1I
  4018     meet2I                  ~> inf2I
  4019     meet1D1                 ~> inf1D1
  4020     meet2D1                 ~> inf2D1
  4021     meet1D2                 ~> inf1D2
  4022     meet2D2                 ~> inf2D2
  4023     meet1E                  ~> inf1E
  4024     meet2E                  ~> inf2E
  4025     join1_iff               ~> sup1_iff
  4026     join2_iff               ~> sup2_iff
  4027     join1I1                 ~> sup1I1
  4028     join2I1                 ~> sup2I1
  4029     join1I1                 ~> sup1I1
  4030     join2I2                 ~> sup1I2
  4031     join1CI                 ~> sup1CI
  4032     join2CI                 ~> sup2CI
  4033     join1E                  ~> sup1E
  4034     join2E                  ~> sup2E
  4035 
  4036     is_meet_Meet            ~> is_meet_Inf
  4037     Meet_bool_def           ~> Inf_bool_def
  4038     Meet_fun_def            ~> Inf_fun_def
  4039     Meet_greatest           ~> Inf_greatest
  4040     Meet_lower              ~> Inf_lower
  4041     Meet_set_def            ~> Inf_set_def
  4042 
  4043     Sup_def                 ~> Sup_Inf
  4044     Sup_bool_eq             ~> Sup_bool_def
  4045     Sup_fun_eq              ~> Sup_fun_def
  4046     Sup_set_eq              ~> Sup_set_def
  4047 
  4048     listsp_meetI            ~> listsp_infI
  4049     listsp_meet_eq          ~> listsp_inf_eq
  4050 
  4051     meet_min                ~> inf_min
  4052     join_max                ~> sup_max
  4053 
  4054 * Added syntactic class "size"; overloaded constant "size" now has
  4055 type "'a::size ==> bool"
  4056 
  4057 * Internal reorganisation of `size' of datatypes: size theorems
  4058 "foo.size" are no longer subsumed by "foo.simps" (but are still
  4059 simplification rules by default!); theorems "prod.size" now named
  4060 "*.size".
  4061 
  4062 * Class "div" now inherits from class "times" rather than "type".
  4063 INCOMPATIBILITY.
  4064 
  4065 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  4066 Linorder etc.  have disappeared; operations defined in terms of
  4067 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  4068 
  4069 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  4070 
  4071 * HOL-Word: New extensive library and type for generic, fixed size
  4072 machine words, with arithemtic, bit-wise, shifting and rotating
  4073 operations, reflection into int, nat, and bool lists, automation for
  4074 linear arithmetic (by automatic reflection into nat or int), including
  4075 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  4076 arithmetic type classes, supporting automatic simplification of
  4077 numerals on all operations.
  4078 
  4079 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  4080 
  4081 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  4082 
  4083 * Code generator library theories:
  4084   - Code_Integer represents HOL integers by big integer literals in target
  4085     languages.
  4086   - Code_Char represents HOL characters by character literals in target
  4087     languages.
  4088   - Code_Char_chr like Code_Char, but also offers treatment of character
  4089     codes; includes Code_Integer.
  4090   - Executable_Set allows to generate code for finite sets using lists.
  4091   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  4092     denominator).
  4093   - Executable_Real implements a subset of real numbers, namly those
  4094     representable by rational numbers.
  4095   - Efficient_Nat implements natural numbers by integers, which in general will
  4096     result in higher efficency; pattern matching with 0/Suc is eliminated;
  4097     includes Code_Integer.
  4098   - Code_Index provides an additional datatype index which is mapped to
  4099     target-language built-in integers.
  4100   - Code_Message provides an additional datatype message_string which is isomorphic to
  4101     strings; messages are mapped to target-language strings.
  4102 
  4103 * New package for inductive predicates
  4104 
  4105   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  4106 
  4107     inductive
  4108       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  4109       for z_1 :: U_1 and ... and z_n :: U_m
  4110     where
  4111       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  4112     | ...
  4113 
  4114   with full support for type-inference, rather than
  4115 
  4116     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4117 
  4118     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  4119     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  4120 
  4121     inductive "s z_1 ... z_m"
  4122     intros
  4123       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  4124       ...
  4125 
  4126   For backward compatibility, there is a wrapper allowing inductive
  4127   sets to be defined with the new package via
  4128 
  4129     inductive_set
  4130       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4131       for z_1 :: U_1 and ... and z_n :: U_m
  4132     where
  4133       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  4134     | ...
  4135 
  4136   or
  4137 
  4138     inductive_set
  4139       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4140       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  4141       for z_1 :: U_1 and ... and z_n :: U_m
  4142     where
  4143       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  4144     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  4145     | ...
  4146 
  4147   if the additional syntax "p ..." is required.
  4148 
  4149   Numerous examples can be found in the subdirectories src/HOL/Auth,
  4150   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  4151 
  4152   INCOMPATIBILITIES:
  4153 
  4154   - Since declaration and definition of inductive sets or predicates
  4155     is no longer separated, abbreviations involving the newly
  4156     introduced sets or predicates must be specified together with the
  4157     introduction rules after the 'where' keyword (see above), rather
  4158     than before the actual inductive definition.
  4159 
  4160   - The variables in induction and elimination rules are now
  4161     quantified in the order of their occurrence in the introduction
  4162     rules, rather than in alphabetical order. Since this may break
  4163     some proofs, these proofs either have to be repaired, e.g. by
  4164     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  4165     statements of the form
  4166 
  4167       case (rule_i a_i_1 ... a_i_{k_i})
  4168 
  4169     or the old order of quantification has to be restored by explicitly adding
  4170     meta-level quantifiers in the introduction rules, i.e.
  4171 
  4172       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  4173 
  4174   - The format of the elimination rules is now
  4175 
  4176       p z_1 ... z_m x_1 ... x_n ==>
  4177         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  4178         ==> ... ==> P
  4179 
  4180     for predicates and
  4181 
  4182       (x_1, ..., x_n) : s z_1 ... z_m ==>
  4183         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  4184         ==> ... ==> P
  4185 
  4186     for sets rather than
  4187 
  4188       x : s z_1 ... z_m ==>
  4189         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  4190         ==> ... ==> P
  4191 
  4192     This may require terms in goals to be expanded to n-tuples
  4193     (e.g. using case_tac or simplification with the split_paired_all
  4194     rule) before the above elimination rule is applicable.
  4195 
  4196   - The elimination or case analysis rules for (mutually) inductive
  4197     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  4198     list of rules "p_1_..._p_k.elims" is no longer available.
  4199 
  4200 * New package "function"/"fun" for general recursive functions,
  4201 supporting mutual and nested recursion, definitions in local contexts,
  4202 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  4203 for small examples, and the separate tutorial on the function
  4204 package. The old recdef "package" is still available as before, but
  4205 users are encouraged to use the new package.
  4206 
  4207 * Method "lexicographic_order" automatically synthesizes termination
  4208 relations as lexicographic combinations of size measures. 
  4209 
  4210 * Case-expressions allow arbitrary constructor-patterns (including
  4211 "_") and take their order into account, like in functional
  4212 programming.  Internally, this is translated into nested
  4213 case-expressions; missing cases are added and mapped to the predefined
  4214 constant "undefined". In complicated cases printing may no longer show
  4215 the original input but the internal form. Lambda-abstractions allow
  4216 the same form of pattern matching: "% pat1 => e1 | ..." is an
  4217 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  4218 variable.
  4219 
  4220 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  4221 is an abbreviation for "of_nat :: nat => int". The simplification
  4222 rules for "of_nat" have been changed to work like "int" did
  4223 previously.  Potential INCOMPATIBILITY:
  4224   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  4225   - of_nat_diff and of_nat_mult are no longer default simp rules
  4226 
  4227 * Method "algebra" solves polynomial equations over (semi)rings using
  4228 Groebner bases. The (semi)ring structure is defined by locales and the
  4229 tool setup depends on that generic context. Installing the method for
  4230 a specific type involves instantiating the locale and possibly adding
  4231 declarations for computation on the coefficients.  The method is
  4232 already instantiated for natural numbers and for the axiomatic class
  4233 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  4234 CALCULEMUS 2007 for the general principles underlying this
  4235 architecture of context-aware proof-tools.
  4236 
  4237 * Method "ferrack" implements quantifier elimination over
  4238 special-purpose dense linear orders using locales (analogous to
  4239 "algebra"). The method is already installed for class
  4240 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  4241 rat, etc.
  4242 
  4243 * Former constant "List.op @" now named "List.append".  Use ML
  4244 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  4245 circumvent possible incompatibilities when working on ML level.
  4246 
  4247 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  4248 
  4249 * New function listsum :: 'a list => 'a for arbitrary monoids.
  4250 Special syntax: "SUM x <- xs. f x" (and latex variants)
  4251 
  4252 * New syntax for Haskell-like list comprehension (input only), eg.
  4253 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  4254 
  4255 * The special syntax for function "filter" has changed from [x :
  4256 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  4257 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  4258 
  4259 * [a..b] is now defined for arbitrary linear orders.  It used to be
  4260 defined on nat only, as an abbreviation for [a..<Suc b]
  4261 INCOMPATIBILITY.
  4262 
  4263 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  4264 
  4265 * New functions "sorted" and "sort" in src/HOL/List.thy.
  4266 
  4267 * New lemma collection field_simps (an extension of ring_simps) for
  4268 manipulating (in)equations involving division. Multiplies with all
  4269 denominators that can be proved to be non-zero (in equations) or
  4270 positive/negative (in inequations).
  4271 
  4272 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  4273 have been improved and renamed to ring_simps, group_simps and
  4274 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  4275 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  4276 
  4277 * Theory Library/Commutative_Ring: switched from recdef to function
  4278 package; constants add, mul, pow now curried.  Infix syntax for
  4279 algebraic operations.
  4280 
  4281 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  4282 INCOMPATIBILITY.
  4283 
  4284 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  4285 INCOMPATIBILITY.
  4286 
  4287 * HOL/records: generalised field-update to take a function on the
  4288 field rather than the new value: r(|A := x|) is translated to A_update
  4289 (K x) r The K-combinator that is internally used is called K_record.
  4290 INCOMPATIBILITY: Usage of the plain update functions has to be
  4291 adapted.
  4292  
  4293 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  4294 * x = 0, which are required for a semiring.  Richer structures do not
  4295 inherit from semiring_0 anymore, because this property is a theorem
  4296 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  4297 there is more to prove, but this is mostly trivial.
  4298 
  4299 * Class "recpower" is generalized to arbitrary monoids, not just
  4300 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  4301 commutativity or semiring properties additionally.
  4302 
  4303 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  4304 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  4305 better use 'abbreviation'.
  4306 
  4307 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  4308 
  4309 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  4310 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  4311 significant changes for setting up numeral syntax for types:
  4312   - New constants Numeral.pred and Numeral.succ instead
  4313       of former Numeral.bin_pred and Numeral.bin_succ.
  4314   - Use integer operations instead of bin_add, bin_mult and so on.
  4315   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  4316   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  4317 
  4318 See src/HOL/Integ/IntArith.thy for an example setup.
  4319 
  4320 * Command 'normal_form' computes the normal form of a term that may
  4321 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  4322 produces ``[b, c, a]'' (without proof).  This command is suitable for
  4323 heavy-duty computations because the functions are compiled to ML
  4324 first.  Correspondingly, a method "normalization" is provided.  See
  4325 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  4326 
  4327 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  4328 25 like -->); output depends on the "iff" print_mode, the default is
  4329 "A = B" (with priority 50).
  4330 
  4331 * Relations less (<) and less_eq (<=) are also available on type bool.
  4332 Modified syntax to disallow nesting without explicit parentheses,
  4333 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  4334 INCOMPATIBILITY.
  4335 
  4336 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  4337 
  4338 * Relation composition operator "op O" now has precedence 75 and binds
  4339 stronger than union and intersection. INCOMPATIBILITY.
  4340 
  4341 * The old set interval syntax "{m..n(}" (and relatives) has been
  4342 removed.  Use "{m..<n}" (and relatives) instead.
  4343 
  4344 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  4345 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  4346 ``declare [[simproc del: neq]]''.
  4347 
  4348 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  4349 True/False.
  4350 
  4351 * Theorem Cons_eq_map_conv no longer declared as "simp".
  4352 
  4353 * Theorem setsum_mult renamed to setsum_right_distrib.
  4354 
  4355 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  4356 ``rule'' method.
  4357 
  4358 * Reimplemented methods "sat" and "satx", with several improvements:
  4359 goals no longer need to be stated as "<prems> ==> False", equivalences
  4360 (i.e. "=" on type bool) are handled, variable names of the form
  4361 "lit_<n>" are no longer reserved, significant speedup.
  4362 
  4363 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  4364 zChaff is still supported as well.
  4365 
  4366 * 'inductive' and 'datatype': provide projections of mutual rules,
  4367 bundled as foo_bar.inducts;
  4368 
  4369 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  4370 Library.
  4371 
  4372 * Library: moved theory Accessible_Part to main HOL.
  4373 
  4374 * Library: added theory Coinductive_List of potentially infinite lists
  4375 as greatest fixed-point.
  4376 
  4377 * Library: added theory AssocList which implements (finite) maps as
  4378 association lists.
  4379 
  4380 * Method "evaluation" solves goals (i.e. a boolean expression)
  4381 efficiently by compiling it to ML.  The goal is "proved" (via an
  4382 oracle) if it evaluates to True.
  4383 
  4384 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  4385 also when invoked by the simplifier.  This results in the Simplifier
  4386 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  4387 Configuration option fast_arith_split_limit=0 recovers the old
  4388 behavior.
  4389 
  4390 * Support for hex (0x20) and binary (0b1001) numerals.
  4391 
  4392 * New method: reify eqs (t), where eqs are equations for an
  4393 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  4394 parameter, computes a term s::'b and a list xs::'a list and proves the
  4395 theorem I xs s = t. This is also known as reification or quoting. The
  4396 resulting theorem is applied to the subgoal to substitute t with I xs
  4397 s.  If t is omitted, the subgoal itself is reified.
  4398 
  4399 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  4400 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  4401 where f is supposed to be a computable function (in the sense of code
  4402 generattion). The method uses reify to compute s and xs as above then
  4403 applies corr_thm and uses normalization by evaluation to "prove" f s =
  4404 r and finally gets the theorem t = r, which is again applied to the
  4405 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  4406 
  4407 * Reflection: Automatic reification now handels binding, an example is
  4408 available in src/HOL/ex/ReflectionEx.thy
  4409 
  4410 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  4411 command 'statespace' that is similar to 'record', but introduces an
  4412 abstract specification based on the locale infrastructure instead of
  4413 HOL types.  This leads to extra flexibility in composing state spaces,
  4414 in particular multiple inheritance and renaming of components.
  4415 
  4416 
  4417 *** HOL-Complex ***
  4418 
  4419 * Hyperreal: Functions root and sqrt are now defined on negative real
  4420 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  4421 Nonnegativity side conditions have been removed from many lemmas, so
  4422 that more subgoals may now be solved by simplification; potential
  4423 INCOMPATIBILITY.
  4424 
  4425 * Real: new type classes formalize real normed vector spaces and
  4426 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  4427 and norm :: 'a => real.
  4428 
  4429 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  4430 reals into other types. The overloaded constant Reals :: 'a set is now
  4431 defined as range of_real; potential INCOMPATIBILITY.
  4432 
  4433 * Real: proper support for ML code generation, including 'quickcheck'.
  4434 Reals are implemented as arbitrary precision rationals.
  4435 
  4436 * Hyperreal: Several constants that previously worked only for the
  4437 reals have been generalized, so they now work over arbitrary vector
  4438 spaces. Type annotations may need to be added in some cases; potential
  4439 INCOMPATIBILITY.
  4440 
  4441   Infinitesimal  :: ('a::real_normed_vector) star set
  4442   HFinite        :: ('a::real_normed_vector) star set
  4443   HInfinite      :: ('a::real_normed_vector) star set
  4444   approx         :: ('a::real_normed_vector) star => 'a star => bool
  4445   monad          :: ('a::real_normed_vector) star => 'a star set
  4446   galaxy         :: ('a::real_normed_vector) star => 'a star set
  4447   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  4448   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  4449   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  4450   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  4451   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  4452   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  4453   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  4454   sgn            :: 'a::real_normed_vector => 'a
  4455   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  4456 
  4457 * Complex: Some complex-specific constants are now abbreviations for
  4458 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  4459 hnorm.  Other constants have been entirely removed in favor of the
  4460 polymorphic versions (INCOMPATIBILITY):
  4461 
  4462   approx        <-- capprox
  4463   HFinite       <-- CFinite
  4464   HInfinite     <-- CInfinite
  4465   Infinitesimal <-- CInfinitesimal
  4466   monad         <-- cmonad
  4467   galaxy        <-- cgalaxy
  4468   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  4469   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  4470   (ns)deriv     <-- (ns)cderiv
  4471 
  4472 
  4473 *** HOL-Algebra ***
  4474 
  4475 * Formalisation of ideals and the quotient construction over rings.
  4476 
  4477 * Order and lattice theory no longer based on records.
  4478 INCOMPATIBILITY.
  4479 
  4480 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  4481 greatest_closed.  INCOMPATIBILITY.
  4482 
  4483 * Method algebra is now set up via an attribute.  For examples see
  4484 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  4485 of algebraic structures.
  4486 
  4487 * Renamed theory CRing to Ring.
  4488 
  4489 
  4490 *** HOL-Nominal ***
  4491 
  4492 * Substantial, yet incomplete support for nominal datatypes (binding
  4493 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  4494 src/HOL/Nominal/Examples.  Prospective users should consult
  4495 http://isabelle.in.tum.de/nominal/
  4496 
  4497 
  4498 *** ML ***
  4499 
  4500 * ML basics: just one true type int, which coincides with IntInf.int
  4501 (even on SML/NJ).
  4502 
  4503 * ML within Isar: antiquotations allow to embed statically-checked
  4504 formal entities in the source, referring to the context available at
  4505 compile-time.  For example:
  4506 
  4507 ML {* @{sort "{zero,one}"} *}
  4508 ML {* @{typ "'a => 'b"} *}
  4509 ML {* @{term "%x. x"} *}
  4510 ML {* @{prop "x == y"} *}
  4511 ML {* @{ctyp "'a => 'b"} *}
  4512 ML {* @{cterm "%x. x"} *}
  4513 ML {* @{cprop "x == y"} *}
  4514 ML {* @{thm asm_rl} *}
  4515 ML {* @{thms asm_rl} *}
  4516 ML {* @{type_name c} *}
  4517 ML {* @{type_syntax c} *}
  4518 ML {* @{const_name c} *}
  4519 ML {* @{const_syntax c} *}
  4520 ML {* @{context} *}
  4521 ML {* @{theory} *}
  4522 ML {* @{theory Pure} *}
  4523 ML {* @{theory_ref} *}
  4524 ML {* @{theory_ref Pure} *}
  4525 ML {* @{simpset} *}
  4526 ML {* @{claset} *}
  4527 ML {* @{clasimpset} *}
  4528 
  4529 The same works for sources being ``used'' within an Isar context.
  4530 
  4531 * ML in Isar: improved error reporting; extra verbosity with
  4532 ML_Context.trace enabled.
  4533 
  4534 * Pure/General/table.ML: the join operations now works via exceptions
  4535 DUP/SAME instead of type option. This is simpler in simple cases, and
  4536 admits slightly more efficient complex applications.
  4537 
  4538 * Pure: 'advanced' translation functions (parse_translation etc.) now
  4539 use Context.generic instead of just theory.
  4540 
  4541 * Pure: datatype Context.generic joins theory/Proof.context and
  4542 provides some facilities for code that works in either kind of
  4543 context, notably GenericDataFun for uniform theory and proof data.
  4544 
  4545 * Pure: simplified internal attribute type, which is now always
  4546 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  4547 local (Proof.context) attributes have been discontinued, while
  4548 minimizing code duplication. Thm.rule_attribute and
  4549 Thm.declaration_attribute build canonical attributes; see also structure
  4550 Context for further operations on Context.generic, notably
  4551 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  4552 declarations and definitions.
  4553 
  4554 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  4555 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  4556 init only required for impure data. INCOMPATIBILITY: empty really need
  4557 to be empty (no dependencies on theory content!)
  4558 
  4559 * Pure/kernel: consts certification ignores sort constraints given in
  4560 signature declarations. (This information is not relevant to the
  4561 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  4562 potential INCOMPATIBILITY.
  4563 
  4564 * Pure: axiomatic type classes are now purely definitional, with
  4565 explicit proofs of class axioms and super class relations performed
  4566 internally. See Pure/axclass.ML for the main internal interfaces --
  4567 notably AxClass.define_class supercedes AxClass.add_axclass, and
  4568 AxClass.axiomatize_class/classrel/arity supersede
  4569 Sign.add_classes/classrel/arities.
  4570 
  4571 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  4572 global/local versions on theory vs. Proof.context have been
  4573 discontinued; Attrib.syntax and Method.syntax have been adapted
  4574 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  4575 attributes, methods, etc.
  4576 
  4577 * Pure: several functions of signature "... -> theory -> theory * ..."
  4578 have been reoriented to "... -> theory -> ... * theory" in order to
  4579 allow natural usage in combination with the ||>, ||>>, |-> and
  4580 fold_map combinators.
  4581 
  4582 * Pure: official theorem names (closed derivations) and additional
  4583 comments (tags) are now strictly separate.  Name hints -- which are
  4584 maintained as tags -- may be attached any time without affecting the
  4585 derivation.
  4586 
  4587 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  4588 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  4589 achieve the old behaviour.
  4590 
  4591 * Pure: the "Goal" constant is now called "prop", supporting a
  4592 slightly more general idea of ``protecting'' meta-level rule
  4593 statements.
  4594 
  4595 * Pure: Logic.(un)varify only works in a global context, which is now
  4596 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  4597 Logic.legacy_(un)varify as temporary workaround.
  4598 
  4599 * Pure: structure Name provides scalable operations for generating
  4600 internal variable names, notably Name.variants etc.  This replaces
  4601 some popular functions from term.ML:
  4602 
  4603   Term.variant		->  Name.variant
  4604   Term.variantlist	->  Name.variant_list
  4605   Term.invent_names	->  Name.invent_list
  4606 
  4607 Note that low-level renaming rarely occurs in new code -- operations
  4608 from structure Variable are used instead (see below).
  4609 
  4610 * Pure: structure Variable provides fundamental operations for proper
  4611 treatment of fixed/schematic variables in a context.  For example,
  4612 Variable.import introduces fixes for schematics of given facts and
  4613 Variable.export reverses the effect (up to renaming) -- this replaces
  4614 various freeze_thaw operations.
  4615 
  4616 * Pure: structure Goal provides simple interfaces for
  4617 init/conclude/finish and tactical prove operations (replacing former
  4618 Tactic.prove).  Goal.prove is the canonical way to prove results
  4619 within a given context; Goal.prove_global is a degraded version for
  4620 theory level goals, including a global Drule.standard.  Note that
  4621 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  4622 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  4623 in a locale context).
  4624 
  4625 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  4626 and type checking (Syntax.check_term etc.), with common combinations
  4627 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  4628 which are considered legacy and await removal.
  4629 
  4630 * Pure/Syntax: generic interfaces for type unchecking
  4631 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  4632 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  4633 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  4634 available for convenience, but refer to the very same operations using
  4635 a mere theory instead of a full context.
  4636 
  4637 * Isar: simplified treatment of user-level errors, using exception
  4638 ERROR of string uniformly.  Function error now merely raises ERROR,
  4639 without any side effect on output channels.  The Isar toplevel takes
  4640 care of proper display of ERROR exceptions.  ML code may use plain
  4641 handle/can/try; cat_error may be used to concatenate errors like this:
  4642 
  4643   ... handle ERROR msg => cat_error msg "..."
  4644 
  4645 Toplevel ML code (run directly or through the Isar toplevel) may be
  4646 embedded into the Isar toplevel with exception display/debug like
  4647 this:
  4648 
  4649   Isar.toplevel (fn () => ...)
  4650 
  4651 INCOMPATIBILITY, removed special transform_error facilities, removed
  4652 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  4653 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  4654 -- use plain ERROR instead.
  4655 
  4656 * Isar: theory setup now has type (theory -> theory), instead of a
  4657 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  4658 
  4659 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  4660 ProofContext.debug/verbose flags.
  4661 
  4662 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  4663 theory before entering a proof state.  Transactions now always see a
  4664 quasi-functional intermediate checkpoint, both in interactive and
  4665 batch mode.
  4666 
  4667 * Isar: simplified interfaces for outer syntax.  Renamed
  4668 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  4669 OuterSyntax.add_parsers -- this functionality is now included in
  4670 OuterSyntax.command etc.  INCOMPATIBILITY.
  4671 
  4672 * Simplifier: the simpset of a running simplification process now
  4673 contains a proof context (cf. Simplifier.the_context), which is the
  4674 very context that the initial simpset has been retrieved from (by
  4675 simpset_of/local_simpset_of).  Consequently, all plug-in components
  4676 (solver, looper etc.) may depend on arbitrary proof data.
  4677 
  4678 * Simplifier.inherit_context inherits the proof context (plus the
  4679 local bounds) of the current simplification process; any simproc
  4680 etc. that calls the Simplifier recursively should do this!  Removed
  4681 former Simplifier.inherit_bounds, which is already included here --
  4682 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  4683 specify an explicit context using Simplifier.context/theory_context.
  4684 
  4685 * Simplifier/Classical Reasoner: more abstract interfaces
  4686 change_simpset/claset for modifying the simpset/claset reference of a
  4687 theory; raw versions simpset/claset_ref etc. have been discontinued --
  4688 INCOMPATIBILITY.
  4689 
  4690 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  4691 "Trueprop" etc.
  4692 
  4693 
  4694 *** System ***
  4695 
  4696 * settings: the default heap location within ISABELLE_HOME_USER now
  4697 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  4698 Isabelle installations.
  4699 
  4700 * isabelle-process: option -S (secure mode) disables some critical
  4701 operations, notably runtime compilation and evaluation of ML source
  4702 code.
  4703 
  4704 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  4705 
  4706 * Support for parallel execution, using native multicore support of
  4707 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  4708 independent theories, according to the given theory header
  4709 specifications. The maximum number of worker threads is specified via
  4710 usedir option -M or the "max-threads" setting in Proof General. A
  4711 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  4712 to 6 on a 8-core machine.  User-code needs to observe certain
  4713 guidelines for thread-safe programming, see appendix A in the Isar
  4714 Implementation manual.
  4715 
  4716 
  4717 
  4718 New in Isabelle2005 (October 2005)
  4719 ----------------------------------
  4720 
  4721 *** General ***
  4722 
  4723 * Theory headers: the new header syntax for Isar theories is
  4724 
  4725   theory <name>
  4726   imports <theory1> ... <theoryN>
  4727   uses <file1> ... <fileM>
  4728   begin
  4729 
  4730 where the 'uses' part is optional.  The previous syntax
  4731 
  4732   theory <name> = <theory1> + ... + <theoryN>:
  4733 
  4734 will disappear in the next release.  Use isatool fixheaders to convert
  4735 existing theory files.  Note that there is no change in ancient
  4736 non-Isar theories now, but these will disappear soon.
  4737 
  4738 * Theory loader: parent theories can now also be referred to via
  4739 relative and absolute paths.
  4740 
  4741 * Command 'find_theorems' searches for a list of criteria instead of a
  4742 list of constants. Known criteria are: intro, elim, dest, name:string,
  4743 simp:term, and any term. Criteria can be preceded by '-' to select
  4744 theorems that do not match. Intro, elim, dest select theorems that
  4745 match the current goal, name:s selects theorems whose fully qualified
  4746 name contain s, and simp:term selects all simplification rules whose
  4747 lhs match term.  Any other term is interpreted as pattern and selects
  4748 all theorems matching the pattern. Available in ProofGeneral under
  4749 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  4750 
  4751   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  4752 
  4753 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  4754 matching the current goal as introduction rule and not having "HOL."
  4755 in their name (i.e. not being defined in theory HOL).
  4756 
  4757 * Command 'thms_containing' has been discontinued in favour of
  4758 'find_theorems'; INCOMPATIBILITY.
  4759 
  4760 * Communication with Proof General is now 8bit clean, which means that
  4761 Unicode text in UTF-8 encoding may be used within theory texts (both
  4762 formal and informal parts).  Cf. option -U of the Isabelle Proof
  4763 General interface.  Here are some simple examples (cf. src/HOL/ex):
  4764 
  4765   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  4766   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  4767 
  4768 * Improved efficiency of the Simplifier and, to a lesser degree, the
  4769 Classical Reasoner.  Typical big applications run around 2 times
  4770 faster.
  4771 
  4772 
  4773 *** Document preparation ***
  4774 
  4775 * Commands 'display_drafts' and 'print_drafts' perform simple output
  4776 of raw sources.  Only those symbols that do not require additional
  4777 LaTeX packages (depending on comments in isabellesym.sty) are
  4778 displayed properly, everything else is left verbatim.  isatool display
  4779 and isatool print are used as front ends (these are subject to the
  4780 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  4781 
  4782 * Command tags control specific markup of certain regions of text,
  4783 notably folding and hiding.  Predefined tags include "theory" (for
  4784 theory begin and end), "proof" for proof commands, and "ML" for
  4785 commands involving ML code; the additional tags "visible" and
  4786 "invisible" are unused by default.  Users may give explicit tag
  4787 specifications in the text, e.g. ''by %invisible (auto)''.  The
  4788 interpretation of tags is determined by the LaTeX job during document
  4789 preparation: see option -V of isatool usedir, or options -n and -t of
  4790 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  4791 \isadroptag.
  4792 
  4793 Several document versions may be produced at the same time via isatool
  4794 usedir (the generated index.html will link all of them).  Typical
  4795 specifications include ''-V document=theory,proof,ML'' to present
  4796 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  4797 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  4798 these parts without any formal replacement text.  The Isabelle site
  4799 default settings produce ''document'' and ''outline'' versions as
  4800 specified above.
  4801 
  4802 * Several new antiquotations:
  4803 
  4804   @{term_type term} prints a term with its type annotated;
  4805 
  4806   @{typeof term} prints the type of a term;
  4807 
  4808   @{const const} is the same as @{term const}, but checks that the
  4809   argument is a known logical constant;
  4810 
  4811   @{term_style style term} and @{thm_style style thm} print a term or
  4812   theorem applying a "style" to it
  4813 
  4814   @{ML text}
  4815 
  4816 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  4817 definitions, equations, inequations etc., 'concl' printing only the
  4818 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  4819 to print the specified premise.  TermStyle.add_style provides an ML
  4820 interface for introducing further styles.  See also the "LaTeX Sugar"
  4821 document practical applications.  The ML antiquotation prints
  4822 type-checked ML expressions verbatim.
  4823 
  4824 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  4825 and 'text' support optional locale specification '(in loc)', which
  4826 specifies the default context for interpreting antiquotations.  For
  4827 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  4828 
  4829 * Option 'locale=NAME' of antiquotations specifies an alternative
  4830 context interpreting the subsequent argument.  For example: @{thm
  4831 [locale=lattice] inf_assoc}.
  4832 
  4833 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  4834 a proof context.
  4835 
  4836 * Proper output of antiquotations for theory commands involving a
  4837 proof context (such as 'locale' or 'theorem (in loc) ...').
  4838 
  4839 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  4840 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  4841 
  4842 * isatool usedir: new option -C (default true) controls whether option
  4843 -D should include a copy of the original document directory; -C false
  4844 prevents unwanted effects such as copying of administrative CVS data.
  4845 
  4846 
  4847 *** Pure ***
  4848 
  4849 * Considerably improved version of 'constdefs' command.  Now performs
  4850 automatic type-inference of declared constants; additional support for
  4851 local structure declarations (cf. locales and HOL records), see also
  4852 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  4853 sequential dependencies of definitions within a single 'constdefs'
  4854 section; moreover, the declared name needs to be an identifier.  If
  4855 all fails, consider to fall back on 'consts' and 'defs' separately.
  4856 
  4857 * Improved indexed syntax and implicit structures.  First of all,
  4858 indexed syntax provides a notational device for subscripted
  4859 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  4860 expressions.  Secondly, in a local context with structure
  4861 declarations, number indexes \<^sub>n or the empty index (default
  4862 number 1) refer to a certain fixed variable implicitly; option
  4863 show_structs controls printing of implicit structures.  Typical
  4864 applications of these concepts involve record types and locales.
  4865 
  4866 * New command 'no_syntax' removes grammar declarations (and
  4867 translations) resulting from the given syntax specification, which is
  4868 interpreted in the same manner as for the 'syntax' command.
  4869 
  4870 * 'Advanced' translation functions (parse_translation etc.) may depend
  4871 on the signature of the theory context being presently used for
  4872 parsing/printing, see also isar-ref manual.
  4873 
  4874 * Improved 'oracle' command provides a type-safe interface to turn an
  4875 ML expression of type theory -> T -> term into a primitive rule of
  4876 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  4877 is already included here); see also FOL/ex/IffExample.thy;
  4878 INCOMPATIBILITY.
  4879 
  4880 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  4881 before); "cI" is no longer bound, use "c.intro" instead.
  4882 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  4883 axclasses vs. locales.
  4884 
  4885 * Improved internal renaming of symbolic identifiers -- attach primes
  4886 instead of base 26 numbers.
  4887 
  4888 * New flag show_question_marks controls printing of leading question
  4889 marks in schematic variable names.
  4890 
  4891 * In schematic variable names, *any* symbol following \<^isub> or
  4892 \<^isup> is now treated as part of the base name.  For example, the
  4893 following works without printing of awkward ".0" indexes:
  4894 
  4895   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  4896     by simp
  4897 
  4898 * Inner syntax includes (*(*nested*) comments*).
  4899 
  4900 * Pretty printer now supports unbreakable blocks, specified in mixfix
  4901 annotations as "(00...)".
  4902 
  4903 * Clear separation of logical types and nonterminals, where the latter
  4904 may only occur in 'syntax' specifications or type abbreviations.
  4905 Before that distinction was only partially implemented via type class
  4906 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  4907 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  4908 exotic syntax specifications may require further adaption
  4909 (e.g. Cube/Cube.thy).
  4910 
  4911 * Removed obsolete type class "logic", use the top sort {} instead.
  4912 Note that non-logical types should be declared as 'nonterminals'
  4913 rather than 'types'.  INCOMPATIBILITY for new object-logic
  4914 specifications.
  4915 
  4916 * Attributes 'induct' and 'cases': type or set names may now be
  4917 locally fixed variables as well.
  4918 
  4919 * Simplifier: can now control the depth to which conditional rewriting
  4920 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  4921 Limit.
  4922 
  4923 * Simplifier: simplification procedures may now take the current
  4924 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  4925 interface), which is very useful for calling the Simplifier
  4926 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  4927 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  4928 low-level mk_simproc no longer applies Logic.varify internally, to
  4929 allow for use in a context of fixed variables.
  4930 
  4931 * thin_tac now works even if the assumption being deleted contains !!
  4932 or ==>.  More generally, erule now works even if the major premise of
  4933 the elimination rule contains !! or ==>.
  4934 
  4935 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  4936 
  4937 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  4938 from Pure, which contains all common declarations already.  Both
  4939 theories are defined via plain Isabelle/Isar .thy files.
  4940 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  4941 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  4942 use isatool fixcpure to adapt your theory and ML sources.
  4943 
  4944 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  4945 selections of theorems in named facts via index ranges.
  4946 
  4947 * 'print_theorems': in theory mode, really print the difference
  4948 wrt. the last state (works for interactive theory development only),
  4949 in proof mode print all local facts (cf. 'print_facts');
  4950 
  4951 * 'hide': option '(open)' hides only base names.
  4952 
  4953 * More efficient treatment of intermediate checkpoints in interactive
  4954 theory development.
  4955 
  4956 * Code generator is now invoked via code_module (incremental code
  4957 generation) and code_library (modular code generation, ML structures
  4958 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  4959 must be quoted when used as identifiers.
  4960 
  4961 * New 'value' command for reading, evaluating and printing terms using
  4962 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  4963 quoted when used as identifier.
  4964 
  4965 
  4966 *** Locales ***
  4967 
  4968 * New commands for the interpretation of locale expressions in
  4969 theories (1), locales (2) and proof contexts (3).  These generate
  4970 proof obligations from the expression specification.  After the
  4971 obligations have been discharged, theorems of the expression are added
  4972 to the theory, target locale or proof context.  The synopsis of the
  4973 commands is a follows:
  4974 
  4975   (1) interpretation expr inst
  4976   (2) interpretation target < expr
  4977   (3) interpret expr inst
  4978 
  4979 Interpretation in theories and proof contexts require a parameter
  4980 instantiation of terms from the current context.  This is applied to
  4981 specifications and theorems of the interpreted expression.
  4982 Interpretation in locales only permits parameter renaming through the
  4983 locale expression.  Interpretation is smart in that interpretations
  4984 that are active already do not occur in proof obligations, neither are
  4985 instantiated theorems stored in duplicate.  Use 'print_interps' to
  4986 inspect active interpretations of a particular locale.  For details,
  4987 see the Isar Reference manual.  Examples can be found in
  4988 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  4989 
  4990 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  4991 'interpret' instead.
  4992 
  4993 * New context element 'constrains' for adding type constraints to
  4994 parameters.
  4995 
  4996 * Context expressions: renaming of parameters with syntax
  4997 redeclaration.
  4998 
  4999 * Locale declaration: 'includes' disallowed.
  5000 
  5001 * Proper static binding of attribute syntax -- i.e. types / terms /
  5002 facts mentioned as arguments are always those of the locale definition
  5003 context, independently of the context of later invocations.  Moreover,
  5004 locale operations (renaming and type / term instantiation) are applied
  5005 to attribute arguments as expected.
  5006 
  5007 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  5008 actual attributes; rare situations may require Attrib.attribute to
  5009 embed those attributes into Attrib.src that lack concrete syntax.
  5010 Attribute implementations need to cooperate properly with the static
  5011 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  5012 Attrib.XXX_thm etc. already do the right thing without further
  5013 intervention.  Only unusual applications -- such as "where" or "of"
  5014 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  5015 on the context and the facts involved -- may have to assign parsed
  5016 values to argument tokens explicitly.
  5017 
  5018 * Changed parameter management in theorem generation for long goal
  5019 statements with 'includes'.  INCOMPATIBILITY: produces a different
  5020 theorem statement in rare situations.
  5021 
  5022 * Locale inspection command 'print_locale' omits notes elements.  Use
  5023 'print_locale!' to have them included in the output.
  5024 
  5025 
  5026 *** Provers ***
  5027 
  5028 * Provers/hypsubst.ML: improved version of the subst method, for
  5029 single-step rewriting: it now works in bound variable contexts. New is
  5030 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  5031 rewrite a different subterm than the original subst method, which is
  5032 still available as 'simplesubst'.
  5033 
  5034 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  5035 and quasi orders.
  5036 
  5037 * Provers/trancl.ML: new transitivity reasoner for transitive and
  5038 reflexive-transitive closure of relations.
  5039 
  5040 * Provers/blast.ML: new reference depth_limit to make blast's depth
  5041 limit (previously hard-coded with a value of 20) user-definable.
  5042 
  5043 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  5044 is peformed already.  Object-logics merely need to finish their
  5045 initial simpset configuration as before.  INCOMPATIBILITY.
  5046 
  5047 
  5048 *** HOL ***
  5049 
  5050 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  5051 
  5052   syntax (epsilon)
  5053     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  5054 
  5055 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  5056 and x-symbol; use option '-m epsilon' to get it actually printed.
  5057 Moreover, the mathematically important symbolic identifier \<epsilon>
  5058 becomes available as variable, constant etc.  INCOMPATIBILITY,
  5059 
  5060 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  5061 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  5062 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  5063 support corresponding Isar calculations.
  5064 
  5065 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  5066 instead of ":".
  5067 
  5068 * theory SetInterval: changed the syntax for open intervals:
  5069 
  5070   Old       New
  5071   {..n(}    {..<n}
  5072   {)n..}    {n<..}
  5073   {m..n(}   {m..<n}
  5074   {)m..n}   {m<..n}
  5075   {)m..n(}  {m<..<n}
  5076 
  5077 The old syntax is still supported but will disappear in the next
  5078 release.  For conversion use the following Emacs search and replace
  5079 patterns (these are not perfect but work quite well):
  5080 
  5081   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  5082   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  5083 
  5084 * Theory Commutative_Ring (in Library): method comm_ring for proving
  5085 equalities in commutative rings; method 'algebra' provides a generic
  5086 interface.
  5087 
  5088 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  5089 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  5090 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  5091 be a tuple pattern.
  5092 
  5093 Some new syntax forms are available:
  5094 
  5095   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  5096   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  5097   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  5098   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  5099 
  5100 The latter form "\<Sum>x < k. e" used to be based on a separate
  5101 function "Summation", which has been discontinued.
  5102 
  5103 * theory Finite_Set: in structured induction proofs, the insert case
  5104 is now 'case (insert x F)' instead of the old counterintuitive 'case
  5105 (insert F x)'.
  5106 
  5107 * The 'refute' command has been extended to support a much larger
  5108 fragment of HOL, including axiomatic type classes, constdefs and
  5109 typedefs, inductive datatypes and recursion.
  5110 
  5111 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  5112 Requires zChaff with proof generation to be installed.  See
  5113 HOL/ex/SAT_Examples.thy for examples.
  5114 
  5115 * Datatype induction via method 'induct' now preserves the name of the
  5116 induction variable. For example, when proving P(xs::'a list) by
  5117 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  5118 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  5119 in unstructured proof scripts.
  5120 
  5121 * Reworked implementation of records.  Improved scalability for
  5122 records with many fields, avoiding performance problems for type
  5123 inference. Records are no longer composed of nested field types, but
  5124 of nested extension types. Therefore the record type only grows linear
  5125 in the number of extensions and not in the number of fields.  The
  5126 top-level (users) view on records is preserved.  Potential
  5127 INCOMPATIBILITY only in strange cases, where the theory depends on the
  5128 old record representation. The type generated for a record is called
  5129 <record_name>_ext_type.
  5130 
  5131 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  5132 proofs triggered by a record definition or a simproc (if
  5133 quick_and_dirty is enabled).  Definitions of large records can take
  5134 quite long.
  5135 
  5136 New simproc record_upd_simproc for simplification of multiple record
  5137 updates enabled by default.  Moreover, trivial updates are also
  5138 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  5139 occasionally, since simplification is more powerful by default.
  5140 
  5141 * typedef: proper support for polymorphic sets, which contain extra
  5142 type-variables in the term.
  5143 
  5144 * Simplifier: automatically reasons about transitivity chains
  5145 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  5146 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  5147 old proofs break occasionally as simplification may now solve more
  5148 goals than previously.
  5149 
  5150 * Simplifier: converts x <= y into x = y if assumption y <= x is
  5151 present.  Works for all partial orders (class "order"), in particular
  5152 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  5153 just like y <= x.
  5154 
  5155 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  5156 bound variable or a constant then the let is unfolded.  Otherwise
  5157 first a is simplified to b, and then f b is simplified to g. If
  5158 possible we abstract b from g arriving at "let x = b in h x",
  5159 otherwise we unfold the let and arrive at g.  The simproc can be
  5160 enabled/disabled by the reference use_let_simproc.  Potential
  5161 INCOMPATIBILITY since simplification is more powerful by default.
  5162 
  5163 * Classical reasoning: the meson method now accepts theorems as arguments.
  5164 
  5165 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  5166 jobs to provide advice on the provability of subgoals.
  5167 
  5168 * Theory OrderedGroup and Ring_and_Field: various additions and
  5169 improvements to faciliate calculations involving equalities and
  5170 inequalities.
  5171 
  5172 The following theorems have been eliminated or modified
  5173 (INCOMPATIBILITY):
  5174 
  5175   abs_eq             now named abs_of_nonneg
  5176   abs_of_ge_0        now named abs_of_nonneg
  5177   abs_minus_eq       now named abs_of_nonpos
  5178   imp_abs_id         now named abs_of_nonneg
  5179   imp_abs_neg_id     now named abs_of_nonpos
  5180   mult_pos           now named mult_pos_pos
  5181   mult_pos_le        now named mult_nonneg_nonneg
  5182   mult_pos_neg_le    now named mult_nonneg_nonpos
  5183   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  5184   mult_neg           now named mult_neg_neg
  5185   mult_neg_le        now named mult_nonpos_nonpos
  5186 
  5187 * The following lemmas in Ring_and_Field have been added to the simplifier:
  5188      
  5189      zero_le_square
  5190      not_square_less_zero 
  5191 
  5192   The following lemmas have been deleted from Real/RealPow:
  5193   
  5194      realpow_zero_zero
  5195      realpow_two
  5196      realpow_less
  5197      zero_le_power
  5198      realpow_two_le
  5199      abs_realpow_two
  5200      realpow_two_abs     
  5201 
  5202 * Theory Parity: added rules for simplifying exponents.
  5203 
  5204 * Theory List:
  5205 
  5206 The following theorems have been eliminated or modified
  5207 (INCOMPATIBILITY):
  5208 
  5209   list_all_Nil       now named list_all.simps(1)
  5210   list_all_Cons      now named list_all.simps(2)
  5211   list_all_conv      now named list_all_iff
  5212   set_mem_eq         now named mem_iff
  5213 
  5214 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  5215 asymptotic "big O" calculations.  See the notes in BigO.thy.
  5216 
  5217 
  5218 *** HOL-Complex ***
  5219 
  5220 * Theory RealDef: better support for embedding natural numbers and
  5221 integers in the reals.
  5222 
  5223 The following theorems have been eliminated or modified
  5224 (INCOMPATIBILITY):
  5225 
  5226   exp_ge_add_one_self  now requires no hypotheses
  5227   real_of_int_add      reversed direction of equality (use [symmetric])
  5228   real_of_int_minus    reversed direction of equality (use [symmetric])
  5229   real_of_int_diff     reversed direction of equality (use [symmetric])
  5230   real_of_int_mult     reversed direction of equality (use [symmetric])
  5231 
  5232 * Theory RComplete: expanded support for floor and ceiling functions.
  5233 
  5234 * Theory Ln is new, with properties of the natural logarithm
  5235 
  5236 * Hyperreal: There is a new type constructor "star" for making
  5237 nonstandard types.  The old type names are now type synonyms:
  5238 
  5239   hypreal = real star
  5240   hypnat = nat star
  5241   hcomplex = complex star
  5242 
  5243 * Hyperreal: Many groups of similarly-defined constants have been
  5244 replaced by polymorphic versions (INCOMPATIBILITY):
  5245 
  5246   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  5247 
  5248   starset      <-- starsetNat, starsetC
  5249   *s*          <-- *sNat*, *sc*
  5250   starset_n    <-- starsetNat_n, starsetC_n
  5251   *sn*         <-- *sNatn*, *scn*
  5252   InternalSets <-- InternalNatSets, InternalCSets
  5253 
  5254   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  5255   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  5256   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  5257   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  5258   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  5259 
  5260 * Hyperreal: Many type-specific theorems have been removed in favor of
  5261 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  5262 
  5263   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  5264   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  5265   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  5266   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  5267   right_minus <-- hypreal_add_minus
  5268   left_minus <-- {hypreal,hcomplex}_add_minus_left
  5269   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  5270   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  5271   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  5272   mult_1_right <-- hcomplex_mult_one_right
  5273   mult_zero_left <-- hcomplex_mult_zero_left
  5274   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  5275   right_distrib <-- hypnat_add_mult_distrib2
  5276   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  5277   right_inverse <-- hypreal_mult_inverse
  5278   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  5279   order_refl <-- {hypreal,hypnat}_le_refl
  5280   order_trans <-- {hypreal,hypnat}_le_trans
  5281   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  5282   order_less_le <-- {hypreal,hypnat}_less_le
  5283   linorder_linear <-- {hypreal,hypnat}_le_linear
  5284   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  5285   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  5286   add_nonneg_nonneg <-- hypreal_le_add_order
  5287 
  5288 * Hyperreal: Separate theorems having to do with type-specific
  5289 versions of constants have been merged into theorems that apply to the
  5290 new polymorphic constants (INCOMPATIBILITY):
  5291 
  5292   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  5293   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  5294   STAR_Un <-- {STAR,NatStar,STARC}_Un
  5295   STAR_Int <-- {STAR,NatStar,STARC}_Int
  5296   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  5297   STAR_subset <-- {STAR,NatStar,STARC}_subset
  5298   STAR_mem <-- {STAR,NatStar,STARC}_mem
  5299   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  5300   STAR_diff <-- {STAR,STARC}_diff
  5301   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  5302     STARC_hcomplex_of_complex}_image_subset
  5303   starset_n_Un <-- starset{Nat,C}_n_Un
  5304   starset_n_Int <-- starset{Nat,C}_n_Int
  5305   starset_n_Compl <-- starset{Nat,C}_n_Compl
  5306   starset_n_diff <-- starset{Nat,C}_n_diff
  5307   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  5308   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  5309   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  5310   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  5311   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  5312   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  5313   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  5314   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  5315   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  5316   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  5317   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  5318   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  5319   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  5320   starfun_diff <-- starfun{C,RC,CR}_diff
  5321   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  5322   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  5323   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  5324   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  5325   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  5326   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  5327   starfun_Id <-- starfunC_Id
  5328   starfun_approx <-- starfun{Nat,CR}_approx
  5329   starfun_capprox <-- starfun{C,RC}_capprox
  5330   starfun_abs <-- starfunNat_rabs
  5331   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  5332   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  5333   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  5334   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  5335   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  5336   starfun_add_approx <-- starfunCR_add_approx
  5337   starfun_inverse_inverse <-- starfunC_inverse_inverse
  5338   starfun_divide <-- starfun{C,CR,RC}_divide
  5339   starfun_n <-- starfun{Nat,C}_n
  5340   starfun_n_mult <-- starfun{Nat,C}_n_mult
  5341   starfun_n_add <-- starfun{Nat,C}_n_add
  5342   starfun_n_add_minus <-- starfunNat_n_add_minus
  5343   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  5344   starfun_n_minus <-- starfun{Nat,C}_n_minus
  5345   starfun_n_eq <-- starfun{Nat,C}_n_eq
  5346 
  5347   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  5348   star_n_minus <-- {hypreal,hcomplex}_minus
  5349   star_n_diff <-- {hypreal,hcomplex}_diff
  5350   star_n_mult <-- {hypreal,hcomplex}_mult
  5351   star_n_inverse <-- {hypreal,hcomplex}_inverse
  5352   star_n_le <-- {hypreal,hypnat}_le
  5353   star_n_less <-- {hypreal,hypnat}_less
  5354   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  5355   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  5356   star_n_abs <-- hypreal_hrabs
  5357   star_n_divide <-- hcomplex_divide
  5358 
  5359   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  5360   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  5361   star_of_diff <-- hypreal_of_real_diff
  5362   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  5363   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  5364   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  5365   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  5366   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  5367   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  5368   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  5369   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  5370   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  5371   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  5372   star_of_number_of <-- {hypreal,hcomplex}_number_of
  5373   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  5374   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  5375   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  5376   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  5377   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  5378   star_of_power <-- hypreal_of_real_power
  5379   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  5380 
  5381 * Hyperreal: new method "transfer" that implements the transfer
  5382 principle of nonstandard analysis. With a subgoal that mentions
  5383 nonstandard types like "'a star", the command "apply transfer"
  5384 replaces it with an equivalent one that mentions only standard types.
  5385 To be successful, all free variables must have standard types; non-
  5386 standard variables must have explicit universal quantifiers.
  5387 
  5388 * Hyperreal: A theory of Taylor series.
  5389 
  5390 
  5391 *** HOLCF ***
  5392 
  5393 * Discontinued special version of 'constdefs' (which used to support
  5394 continuous functions) in favor of the general Pure one with full
  5395 type-inference.
  5396 
  5397 * New simplification procedure for solving continuity conditions; it
  5398 is much faster on terms with many nested lambda abstractions (cubic
  5399 instead of exponential time).
  5400 
  5401 * New syntax for domain package: selector names are now optional.
  5402 Parentheses should be omitted unless argument is lazy, for example:
  5403 
  5404   domain 'a stream = cons "'a" (lazy "'a stream")
  5405 
  5406 * New command 'fixrec' for defining recursive functions with pattern
  5407 matching; defining multiple functions with mutual recursion is also
  5408 supported.  Patterns may include the constants cpair, spair, up, sinl,
  5409 sinr, or any data constructor defined by the domain package. The given
  5410 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  5411 syntax and examples.
  5412 
  5413 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  5414 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  5415 but the proof obligation additionally includes an admissibility
  5416 requirement. The packages generate instances of class cpo or pcpo,
  5417 with continuity and strictness theorems for Rep and Abs.
  5418 
  5419 * HOLCF: Many theorems have been renamed according to a more standard naming
  5420 scheme (INCOMPATIBILITY):
  5421 
  5422   foo_inject:  "foo$x = foo$y ==> x = y"
  5423   foo_eq:      "(foo$x = foo$y) = (x = y)"
  5424   foo_less:    "(foo$x << foo$y) = (x << y)"
  5425   foo_strict:  "foo$UU = UU"
  5426   foo_defined: "... ==> foo$x ~= UU"
  5427   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  5428 
  5429 
  5430 *** ZF ***
  5431 
  5432 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  5433 including the First Isomorphism Theorem (on quotienting by the kernel
  5434 of a homomorphism).
  5435 
  5436 * ZF/Simplifier: install second copy of type solver that actually
  5437 makes use of TC rules declared to Isar proof contexts (or locales);
  5438 the old version is still required for ML proof scripts.
  5439 
  5440 
  5441 *** Cube ***
  5442 
  5443 * Converted to Isar theory format; use locales instead of axiomatic
  5444 theories.
  5445 
  5446 
  5447 *** ML ***
  5448 
  5449 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  5450 for ||>, ||>>, |>>,
  5451 
  5452 * Pure/library.ML no longer defines its own option datatype, but uses
  5453 that of the SML basis, which has constructors NONE and SOME instead of
  5454 None and Some, as well as exception Option.Option instead of OPTION.
  5455 The functions the, if_none, is_some, is_none have been adapted
  5456 accordingly, while Option.map replaces apsome.
  5457 
  5458 * Pure/library.ML: the exception LIST has been given up in favour of
  5459 the standard exceptions Empty and Subscript, as well as
  5460 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  5461 superceded by the standard hd and tl functions etc.
  5462 
  5463 A number of basic list functions are no longer exported to the ML
  5464 toplevel, as they are variants of predefined functions.  The following
  5465 suggests how one can translate existing code:
  5466 
  5467     rev_append xs ys = List.revAppend (xs, ys)
  5468     nth_elem (i, xs) = List.nth (xs, i)
  5469     last_elem xs = List.last xs
  5470     flat xss = List.concat xss
  5471     seq fs = List.app fs
  5472     partition P xs = List.partition P xs
  5473     mapfilter f xs = List.mapPartial f xs
  5474 
  5475 * Pure/library.ML: several combinators for linear functional
  5476 transformations, notably reverse application and composition:
  5477 
  5478   x |> f                f #> g
  5479   (x, y) |-> f          f #-> g
  5480 
  5481 * Pure/library.ML: introduced/changed precedence of infix operators:
  5482 
  5483   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  5484   infix 2 ?;
  5485   infix 3 o oo ooo oooo;
  5486   infix 4 ~~ upto downto;
  5487 
  5488 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  5489 infix operators.
  5490 
  5491 * Pure/library.ML: natural list combinators fold, fold_rev, and
  5492 fold_map support linear functional transformations and nesting.  For
  5493 example:
  5494 
  5495   fold f [x1, ..., xN] y =
  5496     y |> f x1 |> ... |> f xN
  5497 
  5498   (fold o fold) f [xs1, ..., xsN] y =
  5499     y |> fold f xs1 |> ... |> fold f xsN
  5500 
  5501   fold f [x1, ..., xN] =
  5502     f x1 #> ... #> f xN
  5503 
  5504   (fold o fold) f [xs1, ..., xsN] =
  5505     fold f xs1 #> ... #> fold f xsN
  5506 
  5507 * Pure/library.ML: the following selectors on type 'a option are
  5508 available:
  5509 
  5510   the:               'a option -> 'a  (*partial*)
  5511   these:             'a option -> 'a  where 'a = 'b list
  5512   the_default: 'a -> 'a option -> 'a
  5513   the_list:          'a option -> 'a list
  5514 
  5515 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5516 basic operations for association lists, following natural argument
  5517 order; moreover the explicit equality predicate passed here avoids
  5518 potentially expensive polymorphic runtime equality checks.
  5519 The old functions may be expressed as follows:
  5520 
  5521   assoc = uncurry (AList.lookup (op =))
  5522   assocs = these oo AList.lookup (op =)
  5523   overwrite = uncurry (AList.update (op =)) o swap
  5524 
  5525 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5526 
  5527   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  5528   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  5529 
  5530 replacing make_keylist and keyfilter (occassionally used)
  5531 Naive rewrites:
  5532 
  5533   make_keylist = AList.make
  5534   keyfilter = AList.find (op =)
  5535 
  5536 * eq_fst and eq_snd now take explicit equality parameter, thus
  5537   avoiding eqtypes. Naive rewrites:
  5538 
  5539     eq_fst = eq_fst (op =)
  5540     eq_snd = eq_snd (op =)
  5541 
  5542 * Removed deprecated apl and apr (rarely used).
  5543   Naive rewrites:
  5544 
  5545     apl (n, op) =>>= curry op n
  5546     apr (op, m) =>>= fn n => op (n, m)
  5547 
  5548 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  5549 provides a reasonably efficient light-weight implementation of sets as
  5550 lists.
  5551 
  5552 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  5553 few new operations; existing lookup and update are now curried to
  5554 follow natural argument order (for use with fold etc.);
  5555 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  5556 
  5557 * Pure/General: output via the Isabelle channels of
  5558 writeln/warning/error etc. is now passed through Output.output, with a
  5559 hook for arbitrary transformations depending on the print_mode
  5560 (cf. Output.add_mode -- the first active mode that provides a output
  5561 function wins).  Already formatted output may be embedded into further
  5562 text via Output.raw; the result of Pretty.string_of/str_of and derived
  5563 functions (string_of_term/cterm/thm etc.) is already marked raw to
  5564 accommodate easy composition of diagnostic messages etc.  Programmers
  5565 rarely need to care about Output.output or Output.raw at all, with
  5566 some notable exceptions: Output.output is required when bypassing the
  5567 standard channels (writeln etc.), or in token translations to produce
  5568 properly formatted results; Output.raw is required when capturing
  5569 already output material that will eventually be presented to the user
  5570 a second time.  For the default print mode, both Output.output and
  5571 Output.raw have no effect.
  5572 
  5573 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  5574 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  5575 cumulative results are displayed at the end of a batch session.
  5576 
  5577 * Pure/General: File.sysify_path and File.quote_sysify path have been
  5578 replaced by File.platform_path and File.shell_path (with appropriate
  5579 hooks).  This provides a clean interface for unusual systems where the
  5580 internal and external process view of file names are different.
  5581 
  5582 * Pure: more efficient orders for basic syntactic entities: added
  5583 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  5584 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  5585 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  5586 orders now -- potential INCOMPATIBILITY for code that depends on a
  5587 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  5588 Library.sort_strings on result).
  5589 
  5590 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  5591 fold_types traverse types/terms from left to right, observing natural
  5592 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  5593 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  5594 
  5595 * Pure: name spaces have been refined, with significant changes of the
  5596 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  5597 to extern(_table).  The plain name entry path is superceded by a
  5598 general 'naming' context, which also includes the 'policy' to produce
  5599 a fully qualified name and external accesses of a fully qualified
  5600 name; NameSpace.extend is superceded by context dependent
  5601 Sign.declare_name.  Several theory and proof context operations modify
  5602 the naming context.  Especially note Theory.restore_naming and
  5603 ProofContext.restore_naming to get back to a sane state; note that
  5604 Theory.add_path is no longer sufficient to recover from
  5605 Theory.absolute_path in particular.
  5606 
  5607 * Pure: new flags short_names (default false) and unique_names
  5608 (default true) for controlling output of qualified names.  If
  5609 short_names is set, names are printed unqualified.  If unique_names is
  5610 reset, the name prefix is reduced to the minimum required to achieve
  5611 the original result when interning again, even if there is an overlap
  5612 with earlier declarations.
  5613 
  5614 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  5615 now 'extend', and 'merge' gets an additional Pretty.pp argument
  5616 (useful for printing error messages).  INCOMPATIBILITY.
  5617 
  5618 * Pure: major reorganization of the theory context.  Type Sign.sg and
  5619 Theory.theory are now identified, referring to the universal
  5620 Context.theory (see Pure/context.ML).  Actual signature and theory
  5621 content is managed as theory data.  The old code and interfaces were
  5622 spread over many files and structures; the new arrangement introduces
  5623 considerable INCOMPATIBILITY to gain more clarity:
  5624 
  5625   Context -- theory management operations (name, identity, inclusion,
  5626     parents, ancestors, merge, etc.), plus generic theory data;
  5627 
  5628   Sign -- logical signature and syntax operations (declaring consts,
  5629     types, etc.), plus certify/read for common entities;
  5630 
  5631   Theory -- logical theory operations (stating axioms, definitions,
  5632     oracles), plus a copy of logical signature operations (consts,
  5633     types, etc.); also a few basic management operations (Theory.copy,
  5634     Theory.merge, etc.)
  5635 
  5636 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  5637 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  5638 for convenience -- they merely return the theory.
  5639 
  5640 * Pure: type Type.tsig is superceded by theory in most interfaces.
  5641 
  5642 * Pure: the Isar proof context type is already defined early in Pure
  5643 as Context.proof (note that ProofContext.context and Proof.context are
  5644 aliases, where the latter is the preferred name).  This enables other
  5645 Isabelle components to refer to that type even before Isar is present.
  5646 
  5647 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  5648 typeK, constK, axiomK, oracleK), but provide explicit operations for
  5649 any of these kinds.  For example, Sign.intern typeK is now
  5650 Sign.intern_type, Theory.hide_space Sign.typeK is now
  5651 Theory.hide_types.  Also note that former
  5652 Theory.hide_classes/types/consts are now
  5653 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  5654 internalize their arguments!  INCOMPATIBILITY.
  5655 
  5656 * Pure: get_thm interface (of PureThy and ProofContext) expects
  5657 datatype thmref (with constructors Name and NameSelection) instead of
  5658 plain string -- INCOMPATIBILITY;
  5659 
  5660 * Pure: cases produced by proof methods specify options, where NONE
  5661 means to remove case bindings -- INCOMPATIBILITY in
  5662 (RAW_)METHOD_CASES.
  5663 
  5664 * Pure: the following operations retrieve axioms or theorems from a
  5665 theory node or theory hierarchy, respectively:
  5666 
  5667   Theory.axioms_of: theory -> (string * term) list
  5668   Theory.all_axioms_of: theory -> (string * term) list
  5669   PureThy.thms_of: theory -> (string * thm) list
  5670   PureThy.all_thms_of: theory -> (string * thm) list
  5671 
  5672 * Pure: print_tac now outputs the goal through the trace channel.
  5673 
  5674 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  5675 Reference Toplevel.debug (default false) controls detailed printing
  5676 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  5677 controls execution profiling -- set to 1 for time and 2 for space
  5678 (both increase the runtime).
  5679 
  5680 * Isar session: The initial use of ROOT.ML is now always timed,
  5681 i.e. the log will show the actual process times, in contrast to the
  5682 elapsed wall-clock time that the outer shell wrapper produces.
  5683 
  5684 * Simplifier: improved handling of bound variables (nameless
  5685 representation, avoid allocating new strings).  Simprocs that invoke
  5686 the Simplifier recursively should use Simplifier.inherit_bounds to
  5687 avoid local name clashes.  Failure to do so produces warnings
  5688 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  5689 for further details.
  5690 
  5691 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  5692 bindings for all theorems stored within a given theory; this may help
  5693 in porting non-Isar theories to Isar ones, while keeping ML proof
  5694 scripts for the time being.
  5695 
  5696 * ML operator HTML.with_charset specifies the charset begin used for
  5697 generated HTML files.  For example:
  5698 
  5699   HTML.with_charset "utf-8" use_thy "Hebrew";
  5700   HTML.with_charset "utf-8" use_thy "Chinese";
  5701 
  5702 
  5703 *** System ***
  5704 
  5705 * Allow symlinks to all proper Isabelle executables (Isabelle,
  5706 isabelle, isatool etc.).
  5707 
  5708 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  5709 isatool doc, isatool mkdir, display_drafts etc.).
  5710 
  5711 * isatool usedir: option -f allows specification of the ML file to be
  5712 used by Isabelle; default is ROOT.ML.
  5713 
  5714 * New isatool version outputs the version identifier of the Isabelle
  5715 distribution being used.
  5716 
  5717 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  5718 (containing Boolean satisfiability problems) into Isabelle/HOL
  5719 theories.
  5720 
  5721 
  5722 
  5723 New in Isabelle2004 (April 2004)
  5724 --------------------------------
  5725 
  5726 *** General ***
  5727 
  5728 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  5729   Replaces linorder.ML.
  5730 
  5731 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  5732   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  5733   (\<a>...\<z>), are now considered normal letters, and can therefore
  5734   be used anywhere where an ASCII letter (a...zA...Z) has until
  5735   now. COMPATIBILITY: This obviously changes the parsing of some
  5736   terms, especially where a symbol has been used as a binder, say
  5737   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  5738   as an identifier.  Fix it by inserting a space around former
  5739   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  5740   existing theory and ML files.
  5741 
  5742 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  5743 
  5744 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  5745   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  5746   a normal (but invisible) letter. For multiple letter subscripts repeat
  5747   \<^isub> like this: x\<^isub>1\<^isub>2.
  5748 
  5749 * Pure: There are now sub-/superscripts that can span more than one
  5750   character. Text between \<^bsub> and \<^esub> is set in subscript in
  5751   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  5752   superscript. The new control characters are not identifier parts.
  5753 
  5754 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  5755   content of "..." to the latex file instead of \isacntrl... . The "..."
  5756   may consist of any printable characters excluding the end bracket >.
  5757 
  5758 * Pure: Using new Isar command "finalconsts" (or the ML functions
  5759   Theory.add_finals or Theory.add_finals_i) it is now possible to
  5760   declare constants "final", which prevents their being given a definition
  5761   later.  It is useful for constants whose behaviour is fixed axiomatically
  5762   rather than definitionally, such as the meta-logic connectives.
  5763 
  5764 * Pure: 'instance' now handles general arities with general sorts
  5765   (i.e. intersections of classes),
  5766 
  5767 * Presentation: generated HTML now uses a CSS style sheet to make layout
  5768   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  5769   It can be changed to alter the colors/layout of generated pages.
  5770 
  5771 
  5772 *** Isar ***
  5773 
  5774 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  5775   cut_tac, subgoal_tac and thin_tac:
  5776   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  5777     locales are no longer forced to write Isar proof scripts.
  5778     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  5779     emulations.
  5780   - INCOMPATIBILITY: names of variables to be instantiated may no
  5781     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  5782     This is consistent with the instantiation attribute "where".
  5783 
  5784 * Attributes "where" and "of":
  5785   - Now take type variables of instantiated theorem into account when reading
  5786     the instantiation string.  This fixes a bug that caused instantiated
  5787     theorems to have too special types in some circumstances.
  5788   - "where" permits explicit instantiations of type variables.
  5789 
  5790 * Calculation commands "moreover" and "also" no longer interfere with
  5791   current facts ("this"), admitting arbitrary combinations with "then"
  5792   and derived forms.
  5793 
  5794 * Locales:
  5795   - Goal statements involving the context element "includes" no longer
  5796     generate theorems with internal delta predicates (those ending on
  5797     "_axioms") in the premise.
  5798     Resolve particular premise with <locale>.intro to obtain old form.
  5799   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  5800     specification and "includes" elements in goal statement.
  5801   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  5802     [intro?] and [elim?] (respectively) by default.
  5803   - Experimental command for instantiation of locales in proof contexts:
  5804         instantiate <label>[<attrs>]: <loc>
  5805     Instantiates locale <loc> and adds all its theorems to the current context
  5806     taking into account their attributes.  Label and attrs are optional
  5807     modifiers, like in theorem declarations.  If present, names of
  5808     instantiated theorems are qualified with <label>, and the attributes
  5809     <attrs> are applied after any attributes these theorems might have already.
  5810       If the locale has assumptions, a chained fact of the form
  5811     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  5812     are derived.  The command does not support old-style locales declared
  5813     with "locale (open)".
  5814       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  5815 
  5816 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  5817   (Isar) contexts.
  5818 
  5819 
  5820 *** HOL ***
  5821 
  5822 * Proof import: new image HOL4 contains the imported library from
  5823   the HOL4 system with about 2500 theorems. It is imported by
  5824   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  5825   can be used like any other Isabelle image.  See
  5826   HOL/Import/HOL/README for more information.
  5827 
  5828 * Simplifier:
  5829   - Much improved handling of linear and partial orders.
  5830     Reasoners for linear and partial orders are set up for type classes
  5831     "linorder" and "order" respectively, and are added to the default simpset
  5832     as solvers.  This means that the simplifier can build transitivity chains
  5833     to solve goals from the assumptions.
  5834   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  5835     of blast or auto after simplification become unnecessary because the goal
  5836     is solved by simplification already.
  5837 
  5838 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  5839     all proved in axiomatic type classes for semirings, rings and fields.
  5840 
  5841 * Numerics:
  5842   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  5843     now formalized using the Ring_and_Field theory mentioned above.
  5844   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  5845     than before, because now they are set up once in a generic manner.
  5846   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  5847     Look for the general versions in Ring_and_Field (and Power if they concern
  5848     exponentiation).
  5849 
  5850 * Type "rat" of the rational numbers is now available in HOL-Complex.
  5851 
  5852 * Records:
  5853   - Record types are now by default printed with their type abbreviation
  5854     instead of the list of all field types. This can be configured via
  5855     the reference "print_record_type_abbr".
  5856   - Simproc "record_upd_simproc" for simplification of multiple updates added
  5857     (not enabled by default).
  5858   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  5859     EX x. x = sel r to True (not enabled by default).
  5860   - Tactic "record_split_simp_tac" to split and simplify records added.
  5861 
  5862 * 'specification' command added, allowing for definition by
  5863   specification.  There is also an 'ax_specification' command that
  5864   introduces the new constants axiomatically.
  5865 
  5866 * arith(_tac) is now able to generate counterexamples for reals as well.
  5867 
  5868 * HOL-Algebra: new locale "ring" for non-commutative rings.
  5869 
  5870 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  5871   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  5872 
  5873 * HOL-Matrix: a first theory for matrices in HOL with an application of
  5874   matrix theory to linear programming.
  5875 
  5876 * Unions and Intersections:
  5877   The latex output syntax of UN and INT has been changed
  5878   from "\Union x \in A. B" to "\Union_{x \in A} B"
  5879   i.e. the index formulae has become a subscript.
  5880   Similarly for "\Union x. B", and for \Inter instead of \Union.
  5881 
  5882 * Unions and Intersections over Intervals:
  5883   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  5884   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  5885   like in normal math, and corresponding versions for < and for intersection.
  5886 
  5887 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  5888   lexicographic dictonary ordering has been added as "lexord".
  5889 
  5890 * ML: the legacy theory structures Int and List have been removed. They had
  5891   conflicted with ML Basis Library structures having the same names.
  5892 
  5893 * 'refute' command added to search for (finite) countermodels.  Only works
  5894   for a fragment of HOL.  The installation of an external SAT solver is
  5895   highly recommended.  See "HOL/Refute.thy" for details.
  5896 
  5897 * 'quickcheck' command: Allows to find counterexamples by evaluating
  5898   formulae under an assignment of free variables to random values.
  5899   In contrast to 'refute', it can deal with inductive datatypes,
  5900   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  5901   for examples.
  5902 
  5903 
  5904 *** HOLCF ***
  5905 
  5906 * Streams now come with concatenation and are part of the HOLCF image
  5907 
  5908 
  5909 
  5910 New in Isabelle2003 (May 2003)
  5911 ------------------------------
  5912 
  5913 *** General ***
  5914 
  5915 * Provers/simplifier:
  5916 
  5917   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  5918     Assumptions are now subject to complete mutual simplification,
  5919     not just from left to right. The simplifier now preserves
  5920     the order of assumptions.
  5921 
  5922     Potential INCOMPATIBILITY:
  5923 
  5924     -- simp sometimes diverges where the old version did
  5925        not, e.g. invoking simp on the goal
  5926 
  5927         [| P (f x); y = x; f x = f y |] ==> Q
  5928 
  5929        now gives rise to the infinite reduction sequence
  5930 
  5931         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  5932 
  5933        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  5934        kind of problem.
  5935 
  5936     -- Tactics combining classical reasoner and simplification (such as auto)
  5937        are also affected by this change, because many of them rely on
  5938        simp. They may sometimes diverge as well or yield a different numbers
  5939        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  5940        in case of problems. Sometimes subsequent calls to the classical
  5941        reasoner will fail because a preceeding call to the simplifier too
  5942        eagerly simplified the goal, e.g. deleted redundant premises.
  5943 
  5944   - The simplifier trace now shows the names of the applied rewrite rules
  5945 
  5946   - You can limit the number of recursive invocations of the simplifier
  5947     during conditional rewriting (where the simplifie tries to solve the
  5948     conditions before applying the rewrite rule):
  5949     ML "simp_depth_limit := n"
  5950     where n is an integer. Thus you can force termination where previously
  5951     the simplifier would diverge.
  5952 
  5953   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  5954 
  5955   - No longer aborts on failed congruence proof.  Instead, the
  5956     congruence is ignored.
  5957 
  5958 * Pure: New generic framework for extracting programs from constructive
  5959   proofs. See HOL/Extraction.thy for an example instantiation, as well
  5960   as HOL/Extraction for some case studies.
  5961 
  5962 * Pure: The main goal of the proof state is no longer shown by default, only
  5963 the subgoals. This behaviour is controlled by a new flag.
  5964    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  5965 (ML: Proof.show_main_goal).
  5966 
  5967 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  5968 rules whose conclusion matches subgoal 1:
  5969       PG menu: Isabelle/Isar -> Show me -> matching rules
  5970 The rules are ordered by how closely they match the subgoal.
  5971 In particular, rules that solve a subgoal outright are displayed first
  5972 (or rather last, the way they are printed).
  5973 (ML: ProofGeneral.print_intros())
  5974 
  5975 * Pure: New flag trace_unify_fail causes unification to print
  5976 diagnostic information (PG: in trace buffer) when it fails. This is
  5977 useful for figuring out why single step proofs like rule, erule or
  5978 assumption failed.
  5979 
  5980 * Pure: Locale specifications now produce predicate definitions
  5981 according to the body of text (covering assumptions modulo local
  5982 definitions); predicate "loc_axioms" covers newly introduced text,
  5983 while "loc" is cumulative wrt. all included locale expressions; the
  5984 latter view is presented only on export into the global theory
  5985 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  5986 on the old view without predicates;
  5987 
  5988 * Pure: predefined locales "var" and "struct" are useful for sharing
  5989 parameters (as in CASL, for example); just specify something like
  5990 ``var x + var y + struct M'' as import;
  5991 
  5992 * Pure: improved thms_containing: proper indexing of facts instead of
  5993 raw theorems; check validity of results wrt. current name space;
  5994 include local facts of proof configuration (also covers active
  5995 locales), cover fixed variables in index; may use "_" in term
  5996 specification; an optional limit for the number of printed facts may
  5997 be given (the default is 40);
  5998 
  5999 * Pure: disallow duplicate fact bindings within new-style theory files
  6000 (batch-mode only);
  6001 
  6002 * Provers: improved induct method: assumptions introduced by case
  6003 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  6004 the goal statement); "foo" still refers to all facts collectively;
  6005 
  6006 * Provers: the function blast.overloaded has been removed: all constants
  6007 are regarded as potentially overloaded, which improves robustness in exchange
  6008 for slight decrease in efficiency;
  6009 
  6010 * Provers/linorder: New generic prover for transitivity reasoning over
  6011 linear orders.  Note: this prover is not efficient!
  6012 
  6013 * Isar: preview of problems to finish 'show' now produce an error
  6014 rather than just a warning (in interactive mode);
  6015 
  6016 
  6017 *** HOL ***
  6018 
  6019 * arith(_tac)
  6020 
  6021  - Produces a counter example if it cannot prove a goal.
  6022    Note that the counter example may be spurious if the goal is not a formula
  6023    of quantifier-free linear arithmetic.
  6024    In ProofGeneral the counter example appears in the trace buffer.
  6025 
  6026  - Knows about div k and mod k where k is a numeral of type nat or int.
  6027 
  6028  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  6029    linear arithmetic fails. This takes account of quantifiers and divisibility.
  6030    Presburger arithmetic can also be called explicitly via presburger(_tac).
  6031 
  6032 * simp's arithmetic capabilities have been enhanced a bit: it now
  6033 takes ~= in premises into account (by performing a case split);
  6034 
  6035 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  6036 are distributed over a sum of terms;
  6037 
  6038 * New tactic "trans_tac" and method "trans" instantiate
  6039 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  6040 "<=", "<" and "=").
  6041 
  6042 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  6043 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  6044 
  6045 * 'typedef' command has new option "open" to suppress the set
  6046 definition;
  6047 
  6048 * functions Min and Max on finite sets have been introduced (theory
  6049 Finite_Set);
  6050 
  6051 * attribute [symmetric] now works for relations as well; it turns
  6052 (x,y) : R^-1 into (y,x) : R, and vice versa;
  6053 
  6054 * induct over a !!-quantified statement (say !!x1..xn):
  6055   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  6056 
  6057 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  6058 %x. None. Warning: empty_def now refers to the previously hidden definition
  6059 of the empty set.
  6060 
  6061 * Algebra: formalization of classical algebra.  Intended as base for
  6062 any algebraic development in Isabelle.  Currently covers group theory
  6063 (up to Sylow's theorem) and ring theory (Universal Property of
  6064 Univariate Polynomials).  Contributions welcome;
  6065 
  6066 * GroupTheory: deleted, since its material has been moved to Algebra;
  6067 
  6068 * Complex: new directory of the complex numbers with numeric constants,
  6069 nonstandard complex numbers, and some complex analysis, standard and
  6070 nonstandard (Jacques Fleuriot);
  6071 
  6072 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  6073 
  6074 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  6075 Fleuriot);
  6076 
  6077 * Real/HahnBanach: updated and adapted to locales;
  6078 
  6079 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  6080 Gray and Kramer);
  6081 
  6082 * UNITY: added the Meier-Sanders theory of progress sets;
  6083 
  6084 * MicroJava: bytecode verifier and lightweight bytecode verifier
  6085 as abstract algorithms, instantiated to the JVM;
  6086 
  6087 * Bali: Java source language formalization. Type system, operational
  6088 semantics, axiomatic semantics. Supported language features:
  6089 classes, interfaces, objects,virtual methods, static methods,
  6090 static/instance fields, arrays, access modifiers, definite
  6091 assignment, exceptions.
  6092 
  6093 
  6094 *** ZF ***
  6095 
  6096 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  6097 universe, etc.);
  6098 
  6099 * Main ZF: virtually all theories converted to new-style format;
  6100 
  6101 
  6102 *** ML ***
  6103 
  6104 * Pure: Tactic.prove provides sane interface for internal proofs;
  6105 omits the infamous "standard" operation, so this is more appropriate
  6106 than prove_goalw_cterm in many situations (e.g. in simprocs);
  6107 
  6108 * Pure: improved error reporting of simprocs;
  6109 
  6110 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  6111 up simprocs;
  6112 
  6113 
  6114 *** Document preparation ***
  6115 
  6116 * uses \par instead of \\ for line breaks in theory text. This may
  6117 shift some page breaks in large documents. To get the old behaviour
  6118 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  6119 
  6120 * minimized dependencies of isabelle.sty and isabellesym.sty on
  6121 other packages
  6122 
  6123 * \<euro> now needs package babel/greek instead of marvosym (which
  6124 broke \Rightarrow)
  6125 
  6126 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  6127 textcomp package)
  6128 
  6129 
  6130 
  6131 New in Isabelle2002 (March 2002)
  6132 --------------------------------
  6133 
  6134 *** Document preparation ***
  6135 
  6136 * greatly simplified document preparation setup, including more
  6137 graceful interpretation of isatool usedir -i/-d/-D options, and more
  6138 instructive isatool mkdir; users should basically be able to get
  6139 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  6140 users may run a separate document processing stage manually like this:
  6141 "isatool usedir -D output HOL Test && isatool document Test/output";
  6142 
  6143 * theory dependency graph may now be incorporated into documents;
  6144 isatool usedir -g true will produce session_graph.eps/.pdf for use
  6145 with \includegraphics of LaTeX;
  6146 
  6147 * proper spacing of consecutive markup elements, especially text
  6148 blocks after section headings;
  6149 
  6150 * support bold style (for single symbols only), input syntax is like
  6151 this: "\<^bold>\<alpha>" or "\<^bold>A";
  6152 
  6153 * \<bullet> is now output as bold \cdot by default, which looks much
  6154 better in printed text;
  6155 
  6156 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  6157 note that these symbols are currently unavailable in Proof General /
  6158 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  6159 
  6160 * isatool latex no longer depends on changed TEXINPUTS, instead
  6161 isatool document copies the Isabelle style files to the target
  6162 location;
  6163 
  6164 
  6165 *** Isar ***
  6166 
  6167 * Pure/Provers: improved proof by cases and induction;
  6168   - 'case' command admits impromptu naming of parameters (such as
  6169     "case (Suc n)");
  6170   - 'induct' method divinates rule instantiation from the inductive
  6171     claim; no longer requires excessive ?P bindings for proper
  6172     instantiation of cases;
  6173   - 'induct' method properly enumerates all possibilities of set/type
  6174     rules; as a consequence facts may be also passed through *type*
  6175     rules without further ado;
  6176   - 'induct' method now derives symbolic cases from the *rulified*
  6177     rule (before it used to rulify cases stemming from the internal
  6178     atomized version); this means that the context of a non-atomic
  6179     statement becomes is included in the hypothesis, avoiding the
  6180     slightly cumbersome show "PROP ?case" form;
  6181   - 'induct' may now use elim-style induction rules without chaining
  6182     facts, using ``missing'' premises from the goal state; this allows
  6183     rules stemming from inductive sets to be applied in unstructured
  6184     scripts, while still benefitting from proper handling of non-atomic
  6185     statements; NB: major inductive premises need to be put first, all
  6186     the rest of the goal is passed through the induction;
  6187   - 'induct' proper support for mutual induction involving non-atomic
  6188     rule statements (uses the new concept of simultaneous goals, see
  6189     below);
  6190   - append all possible rule selections, but only use the first
  6191     success (no backtracking);
  6192   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  6193   - undeclared rule case names default to numbers 1, 2, 3, ...;
  6194   - added 'print_induct_rules' (covered by help item in recent Proof
  6195     General versions);
  6196   - moved induct/cases attributes to Pure, methods to Provers;
  6197   - generic method setup instantiated for FOL and HOL;
  6198 
  6199 * Pure: support multiple simultaneous goal statements, for example
  6200 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  6201 meta-level mechanism, this acts as if several individual goals had
  6202 been stated separately; in particular common proof methods need to be
  6203 repeated in order to cover all claims; note that a single elimination
  6204 step is *not* sufficient to establish the two conjunctions, so this
  6205 fails:
  6206 
  6207   assume "A & B" then have A and B ..   (*".." fails*)
  6208 
  6209 better use "obtain" in situations as above; alternative refer to
  6210 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  6211 
  6212 * Pure: proper integration with ``locales''; unlike the original
  6213 version by Florian Kammller, Isar locales package high-level proof
  6214 contexts rather than raw logical ones (e.g. we admit to include
  6215 attributes everywhere); operations on locales include merge and
  6216 rename; support for implicit arguments (``structures''); simultaneous
  6217 type-inference over imports and text; see also HOL/ex/Locales.thy for
  6218 some examples;
  6219 
  6220 * Pure: the following commands have been ``localized'', supporting a
  6221 target locale specification "(in name)": 'lemma', 'theorem',
  6222 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  6223 stored both within the locale and at the theory level (exported and
  6224 qualified by the locale name);
  6225 
  6226 * Pure: theory goals may now be specified in ``long'' form, with
  6227 ad-hoc contexts consisting of arbitrary locale elements. for example
  6228 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  6229 definitions may be given, too); the result is a meta-level rule with