NEWS
author nipkow
Thu Aug 18 17:42:18 2011 +0200 (2011-08-18)
changeset 44274 731b18266d5a
parent 44136 e63ad7d5158d
child 44282 f0de18b62d63
permissions -rw-r--r--
case_names NEWS
     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 * Attribute case_names has been refined: the assumptions in each case can
    61 be named now by following the case name with [name1 name2 ...].
    62 
    63 
    64 *** HOL ***
    65 
    66 * Classes bot and top require underlying partial order rather than preorder:
    67 uniqueness of bot and top is guaranteed.  INCOMPATIBILITY.
    68 
    69 * Class complete_lattice: generalized a couple of lemmas from sets;
    70 generalized theorems INF_cong and SUP_cong.  New type classes for complete
    71 boolean algebras and complete linear orders.  Lemmas Inf_less_iff,
    72 less_Sup_iff, INF_less_iff, less_SUP_iff now reside in class complete_linorder.
    73 Changed proposition of lemmas Inf_fun_def, Sup_fun_def, Inf_apply, Sup_apply.
    74 Redundant lemmas Inf_singleton, Sup_singleton, Inf_binary, Sup_binary,
    75 INF_eq, SUP_eq, INF_UNIV_range, SUP_UNIV_range, Int_eq_Inter,
    76 INTER_eq_Inter_image, Inter_def, INT_eq, Un_eq_Union, UNION_eq_Union_image,
    77 Union_def, UN_singleton, UN_eq have been discarded.
    78 More consistent and less misunderstandable names:
    79   INFI_def ~> INF_def
    80   SUPR_def ~> SUP_def
    81   INF_leI ~> INF_lower
    82   INF_leI2 ~> INF_lower2
    83   le_INFI ~> INF_greatest
    84   le_SUPI ~> SUP_upper
    85   le_SUPI2 ~> SUP_upper2
    86   SUP_leI ~> SUP_least
    87   INFI_bool_eq ~> INF_bool_eq
    88   SUPR_bool_eq ~> SUP_bool_eq
    89   INFI_apply ~> INF_apply
    90   SUPR_apply ~> SUP_apply
    91   INTER_def ~> INTER_eq
    92   UNION_def ~> UNION_eq
    93 
    94 INCOMPATIBILITY.
    95 
    96 * Theorem collections ball_simps and bex_simps do not contain theorems referring
    97 to UNION any longer;  these have been moved to collection UN_ball_bex_simps.
    98 INCOMPATIBILITY.
    99 
   100 * Archimedean_Field.thy:
   101     floor now is defined as parameter of a separate type class floor_ceiling.
   102  
   103 * Finite_Set.thy: more coherent development of fold_set locales:
   104 
   105     locale fun_left_comm ~> locale comp_fun_commute
   106     locale fun_left_comm_idem ~> locale comp_fun_idem
   107     
   108 Both use point-free characterisation; interpretation proofs may need adjustment.
   109 INCOMPATIBILITY.
   110 
   111 * Code generation:
   112   - theory Library/Code_Char_ord provides native ordering of characters
   113     in the target language.
   114   - commands code_module and code_library are legacy, use export_code instead. 
   115   - method evaluation is legacy, use method eval instead.
   116   - legacy evaluator "SML" is deactivated by default. To activate it, add the following
   117     line in your theory:
   118       setup {* Value.add_evaluator ("SML", Codegen.eval_term) *}
   119  
   120 * Declare ext [intro] by default.  Rare INCOMPATIBILITY.
   121 
   122 * Nitpick:
   123   - Added "need" and "total_consts" options.
   124   - Reintroduced "show_skolems" option by popular demand.
   125   - Renamed attribute: nitpick_def ~> nitpick_unfold.
   126     INCOMPATIBILITY.
   127 
   128 * Sledgehammer:
   129   - sledgehammer available_provers ~> sledgehammer supported_provers.
   130     INCOMPATIBILITY.
   131   - Added support for SNARK and ToFoF-E on SystemOnTPTP and for simply typed
   132     TPTP problems (TFF).
   133   - Added "preplay_timeout", "slicing", "type_enc", "sound", "max_mono_iters",
   134     and "max_new_mono_instances" options.
   135   - Removed "explicit_apply" and "full_types" options as well as "Full Types"
   136     Proof General menu item. INCOMPATIBILITY.
   137 
   138 * Metis:
   139   - Removed "metisF" -- use "metis" instead. INCOMPATIBILITY.
   140   - Obsoleted "metisFT" -- use "metis (full_types)" instead. INCOMPATIBILITY.
   141 
   142 * "try":
   143   - Renamed "try_methods" and added "simp:", "intro:", "dest:", and "elim:"
   144     options. INCOMPATIBILITY.
   145   - Introduced "try" that not only runs "try_methods" but also "solve_direct",
   146     "sledgehammer", "quickcheck", and "nitpick".
   147 
   148 * Quickcheck:
   149   - Added "eval" option to evaluate terms for the found counterexample
   150     (currently only supported by the default (exhaustive) tester)
   151   - Added post-processing of terms to obtain readable counterexamples
   152     (currently only supported by the default (exhaustive) tester)
   153   - New counterexample generator quickcheck[narrowing] enables
   154     narrowing-based testing.
   155     It requires that the Glasgow Haskell compiler is installed and
   156     its location is known to Isabelle with the environment variable
   157     ISABELLE_GHC.
   158   - Removed quickcheck tester "SML" based on the SML code generator
   159     from HOL-Library
   160 
   161 * Function package: discontinued option "tailrec".
   162 INCOMPATIBILITY. Use partial_function instead.
   163 
   164 * HOL-Probability:
   165   - Caratheodory's extension lemma is now proved for ring_of_sets.
   166   - Infinite products of probability measures are now available.
   167   - Use extended reals instead of positive extended reals.
   168     INCOMPATIBILITY.
   169 
   170 * Old recdef package has been moved to Library/Old_Recdef.thy, where it
   171 must be loaded explicitly.  INCOMPATIBILITY.
   172 
   173 * Well-founded recursion combinator "wfrec" has been moved to
   174 Library/Wfrec.thy. INCOMPATIBILITY.
   175 
   176 * Theory Library/Nat_Infinity has been renamed to Library/Extended_Nat.
   177 The names of the following types and constants have changed:
   178   inat (type) ~> enat
   179   Fin         ~> enat
   180   Infty       ~> infinity (overloaded)
   181   iSuc        ~> eSuc
   182   the_Fin     ~> the_enat
   183 Every theorem name containing "inat", "Fin", "Infty", or "iSuc" has
   184 been renamed accordingly.
   185 
   186 * Limits.thy: Type "'a net" has been renamed to "'a filter", in
   187 accordance with standard mathematical terminology. INCOMPATIBILITY.
   188 
   189 * Session Multivariate_Analysis: Type "('a, 'b) cart" has been renamed
   190 to "('a, 'b) vec" (the syntax "'a ^ 'b" remains unaffected). Constants
   191 "Cart_nth" and "Cart_lambda" have been respectively renamed to
   192 "vec_nth" and "vec_lambda"; theorems mentioning those names have
   193 changed to match. Definition theorems for overloaded constants now use
   194 the standard "foo_vec_def" naming scheme. A few other theorems have
   195 been renamed as follows (INCOMPATIBILITY):
   196 
   197   Cart_eq          ~> vec_eq_iff
   198   dist_nth_le_cart ~> dist_vec_nth_le
   199   tendsto_vector   ~> vec_tendstoI
   200   Cauchy_vector    ~> vec_CauchyI
   201 
   202 
   203 *** Document preparation ***
   204 
   205 * Discontinued special treatment of hard tabulators, which are better
   206 avoided in the first place.  Implicit tab-width is 1.
   207 
   208 * Antiquotation @{rail} layouts railroad syntax diagrams, see also
   209 isar-ref manual.
   210 
   211 * Antiquotation @{value} evaluates the given term and presents its result.
   212 
   213 * Localized \isabellestyle switch can be used within blocks or groups
   214 like this:
   215 
   216   \isabellestyle{it}  %preferred default
   217   {\isabellestylett @{text "typewriter stuff"}}
   218 
   219 * New term style "isub" as ad-hoc conversion of variables x1, y23 into
   220 subscripted form x\<^isub>1, y\<^isub>2\<^isub>3.
   221 
   222 * Predefined LaTeX macros for Isabelle symbols \<bind> and \<then>
   223 (e.g. see ~~/src/HOL/Library/Monad_Syntax.thy).
   224 
   225 
   226 *** ML ***
   227 
   228 * The inner syntax of sort/type/term/prop supports inlined YXML
   229 representations within quoted string tokens.  By encoding logical
   230 entities via Term_XML (in ML or Scala) concrete syntax can be
   231 bypassed, which is particularly useful for producing bits of text
   232 under external program control.
   233 
   234 * Antiquotations for ML and document preparation are managed as theory
   235 data, which requires explicit setup.
   236 
   237 * Isabelle_Process.is_active allows tools to check if the official
   238 process wrapper is running (Isabelle/Scala/jEdit) or the old TTY loop
   239 (better known as Proof General).
   240 
   241 * Structure Proof_Context follows standard naming scheme.  Old
   242 ProofContext is still available for some time as legacy alias.
   243 
   244 * Structure Timing provides various operations for timing; supersedes
   245 former start_timing/end_timing etc.
   246 
   247 * Path.print is the official way to show file-system paths to users
   248 (including quotes etc.).
   249 
   250 * Inner syntax: identifiers in parse trees of generic categories
   251 "logic", "aprop", "idt" etc. carry position information (disguised as
   252 type constraints).  Occasional INCOMPATIBILITY with non-compliant
   253 translations that choke on unexpected type constraints.  Positions can
   254 be stripped in ML translations via Syntax.strip_positions /
   255 Syntax.strip_positions_ast, or via the syntax constant
   256 "_strip_positions" within parse trees.  As last resort, positions can
   257 be disabled via the configuration option Syntax.positions, which is
   258 called "syntax_positions" in Isar attribute syntax.
   259 
   260 * Discontinued special status of various ML structures that contribute
   261 to structure Syntax (Ast, Lexicon, Mixfix, Parser, Printer etc.): less
   262 pervasive content, no inclusion in structure Syntax.  INCOMPATIBILITY,
   263 refer directly to Ast.Constant, Lexicon.is_identifier,
   264 Syntax_Trans.mk_binder_tr etc.
   265 
   266 * Typed print translation: discontinued show_sorts argument, which is
   267 already available via context of "advanced" translation.
   268 
   269 * Refined PARALLEL_GOALS tactical: degrades gracefully for schematic
   270 goal states; body tactic needs to address all subgoals uniformly.
   271 
   272 * Slightly more special eq_list/eq_set, with shortcut involving
   273 pointer equality (assumes that eq relation is reflexive).
   274 
   275 * Classical tactics use proper Proof.context instead of historic types
   276 claset/clasimpset.  Old-style declarations like addIs, addEs, addDs
   277 operate directly on Proof.context.  Raw type claset retains its use as
   278 snapshot of the classical context, which can be recovered via
   279 (put_claset HOL_cs) etc.  Type clasimpset has been discontinued.
   280 INCOMPATIBILITY, classical tactics and derived proof methods require
   281 proper Proof.context.
   282 
   283 * Scala layer provides JVM method invocation service for static
   284 methods of type (String)String, see Invoke_Scala.method in ML.
   285 For example:
   286 
   287   Invoke_Scala.method "java.lang.System.getProperty" "java.home"
   288 
   289 
   290 
   291 New in Isabelle2011 (January 2011)
   292 ----------------------------------
   293 
   294 *** General ***
   295 
   296 * Experimental Prover IDE based on Isabelle/Scala and jEdit (see
   297 src/Tools/jEdit).  This also serves as IDE for Isabelle/ML, with
   298 useful tooltips and hyperlinks produced from its static analysis.  The
   299 bundled component provides an executable Isabelle tool that can be run
   300 like this:
   301 
   302   Isabelle2011/bin/isabelle jedit
   303 
   304 * Significantly improved Isabelle/Isar implementation manual.
   305 
   306 * System settings: ISABELLE_HOME_USER now includes ISABELLE_IDENTIFIER
   307 (and thus refers to something like $HOME/.isabelle/Isabelle2011),
   308 while the default heap location within that directory lacks that extra
   309 suffix.  This isolates multiple Isabelle installations from each
   310 other, avoiding problems with old settings in new versions.
   311 INCOMPATIBILITY, need to copy/upgrade old user settings manually.
   312 
   313 * Source files are always encoded as UTF-8, instead of old-fashioned
   314 ISO-Latin-1.  INCOMPATIBILITY.  Isabelle LaTeX documents might require
   315 the following package declarations:
   316 
   317   \usepackage[utf8]{inputenc}
   318   \usepackage{textcomp}
   319 
   320 * Explicit treatment of UTF-8 sequences as Isabelle symbols, such that
   321 a Unicode character is treated as a single symbol, not a sequence of
   322 non-ASCII bytes as before.  Since Isabelle/ML string literals may
   323 contain symbols without further backslash escapes, Unicode can now be
   324 used here as well.  Recall that Symbol.explode in ML provides a
   325 consistent view on symbols, while raw explode (or String.explode)
   326 merely give a byte-oriented representation.
   327 
   328 * Theory loader: source files are primarily located via the master
   329 directory of each theory node (where the .thy file itself resides).
   330 The global load path is still partially available as legacy feature.
   331 Minor INCOMPATIBILITY due to subtle change in file lookup: use
   332 explicit paths, relatively to the theory.
   333 
   334 * Special treatment of ML file names has been discontinued.
   335 Historically, optional extensions .ML or .sml were added on demand --
   336 at the cost of clarity of file dependencies.  Recall that Isabelle/ML
   337 files exclusively use the .ML extension.  Minor INCOMPATIBILTY.
   338 
   339 * Various options that affect pretty printing etc. are now properly
   340 handled within the context via configuration options, instead of
   341 unsynchronized references or print modes.  There are both ML Config.T
   342 entities and Isar declaration attributes to access these.
   343 
   344   ML (Config.T)                 Isar (attribute)
   345 
   346   eta_contract                  eta_contract
   347   show_brackets                 show_brackets
   348   show_sorts                    show_sorts
   349   show_types                    show_types
   350   show_question_marks           show_question_marks
   351   show_consts                   show_consts
   352   show_abbrevs                  show_abbrevs
   353 
   354   Syntax.ast_trace              syntax_ast_trace
   355   Syntax.ast_stat               syntax_ast_stat
   356   Syntax.ambiguity_level        syntax_ambiguity_level
   357 
   358   Goal_Display.goals_limit      goals_limit
   359   Goal_Display.show_main_goal   show_main_goal
   360 
   361   Method.rule_trace             rule_trace
   362 
   363   Thy_Output.display            thy_output_display
   364   Thy_Output.quotes             thy_output_quotes
   365   Thy_Output.indent             thy_output_indent
   366   Thy_Output.source             thy_output_source
   367   Thy_Output.break              thy_output_break
   368 
   369 Note that corresponding "..._default" references in ML may only be
   370 changed globally at the ROOT session setup, but *not* within a theory.
   371 The option "show_abbrevs" supersedes the former print mode
   372 "no_abbrevs" with inverted meaning.
   373 
   374 * More systematic naming of some configuration options.
   375 INCOMPATIBILITY.
   376 
   377   trace_simp  ~>  simp_trace
   378   debug_simp  ~>  simp_debug
   379 
   380 * Support for real valued configuration options, using simplistic
   381 floating-point notation that coincides with the inner syntax for
   382 float_token.
   383 
   384 * Support for real valued preferences (with approximative PGIP type):
   385 front-ends need to accept "pgint" values in float notation.
   386 INCOMPATIBILITY.
   387 
   388 * The IsabelleText font now includes Cyrillic, Hebrew, Arabic from
   389 DejaVu Sans.
   390 
   391 * Discontinued support for Poly/ML 5.0 and 5.1 versions.
   392 
   393 
   394 *** Pure ***
   395 
   396 * Command 'type_synonym' (with single argument) replaces somewhat
   397 outdated 'types', which is still available as legacy feature for some
   398 time.
   399 
   400 * Command 'nonterminal' (with 'and' separated list of arguments)
   401 replaces somewhat outdated 'nonterminals'.  INCOMPATIBILITY.
   402 
   403 * Command 'notepad' replaces former 'example_proof' for
   404 experimentation in Isar without any result.  INCOMPATIBILITY.
   405 
   406 * Locale interpretation commands 'interpret' and 'sublocale' accept
   407 lists of equations to map definitions in a locale to appropriate
   408 entities in the context of the interpretation.  The 'interpretation'
   409 command already provided this functionality.
   410 
   411 * Diagnostic command 'print_dependencies' prints the locale instances
   412 that would be activated if the specified expression was interpreted in
   413 the current context.  Variant "print_dependencies!" assumes a context
   414 without interpretations.
   415 
   416 * Diagnostic command 'print_interps' prints interpretations in proofs
   417 in addition to interpretations in theories.
   418 
   419 * Discontinued obsolete 'global' and 'local' commands to manipulate
   420 the theory name space.  Rare INCOMPATIBILITY.  The ML functions
   421 Sign.root_path and Sign.local_path may be applied directly where this
   422 feature is still required for historical reasons.
   423 
   424 * Discontinued obsolete 'constdefs' command.  INCOMPATIBILITY, use
   425 'definition' instead.
   426 
   427 * The "prems" fact, which refers to the accidental collection of
   428 foundational premises in the context, is now explicitly marked as
   429 legacy feature and will be discontinued soon.  Consider using "assms"
   430 of the head statement or reference facts by explicit names.
   431 
   432 * Document antiquotations @{class} and @{type} print classes and type
   433 constructors.
   434 
   435 * Document antiquotation @{file} checks file/directory entries within
   436 the local file system.
   437 
   438 
   439 *** HOL ***
   440 
   441 * Coercive subtyping: functions can be declared as coercions and type
   442 inference will add them as necessary upon input of a term.  Theory
   443 Complex_Main declares real :: nat => real and real :: int => real as
   444 coercions. A coercion function f is declared like this:
   445 
   446   declare [[coercion f]]
   447 
   448 To lift coercions through type constructors (e.g. from nat => real to
   449 nat list => real list), map functions can be declared, e.g.
   450 
   451   declare [[coercion_map map]]
   452 
   453 Currently coercion inference is activated only in theories including
   454 real numbers, i.e. descendants of Complex_Main.  This is controlled by
   455 the configuration option "coercion_enabled", e.g. it can be enabled in
   456 other theories like this:
   457 
   458   declare [[coercion_enabled]]
   459 
   460 * Command 'partial_function' provides basic support for recursive
   461 function definitions over complete partial orders.  Concrete instances
   462 are provided for i) the option type, ii) tail recursion on arbitrary
   463 types, and iii) the heap monad of Imperative_HOL.  See
   464 src/HOL/ex/Fundefs.thy and src/HOL/Imperative_HOL/ex/Linked_Lists.thy
   465 for examples.
   466 
   467 * Function package: f.psimps rules are no longer implicitly declared
   468 as [simp].  INCOMPATIBILITY.
   469 
   470 * Datatype package: theorems generated for executable equality (class
   471 "eq") carry proper names and are treated as default code equations.
   472 
   473 * Inductive package: now offers command 'inductive_simps' to
   474 automatically derive instantiated and simplified equations for
   475 inductive predicates, similar to 'inductive_cases'.
   476 
   477 * Command 'enriched_type' allows to register properties of the
   478 functorial structure of types.
   479 
   480 * Improved infrastructure for term evaluation using code generator
   481 techniques, in particular static evaluation conversions.
   482 
   483 * Code generator: Scala (2.8 or higher) has been added to the target
   484 languages.
   485 
   486 * Code generator: globbing constant expressions "*" and "Theory.*"
   487 have been replaced by the more idiomatic "_" and "Theory._".
   488 INCOMPATIBILITY.
   489 
   490 * Code generator: export_code without explicit file declaration prints
   491 to standard output.  INCOMPATIBILITY.
   492 
   493 * Code generator: do not print function definitions for case
   494 combinators any longer.
   495 
   496 * Code generator: simplification with rules determined with
   497 src/Tools/Code/code_simp.ML and method "code_simp".
   498 
   499 * Code generator for records: more idiomatic representation of record
   500 types.  Warning: records are not covered by ancient SML code
   501 generation any longer.  INCOMPATIBILITY.  In cases of need, a suitable
   502 rep_datatype declaration helps to succeed then:
   503 
   504   record 'a foo = ...
   505   ...
   506   rep_datatype foo_ext ...
   507 
   508 * Records: logical foundation type for records does not carry a
   509 '_type' suffix any longer (obsolete due to authentic syntax).
   510 INCOMPATIBILITY.
   511 
   512 * Quickcheck now by default uses exhaustive testing instead of random
   513 testing.  Random testing can be invoked by "quickcheck [random]",
   514 exhaustive testing by "quickcheck [exhaustive]".
   515 
   516 * Quickcheck instantiates polymorphic types with small finite
   517 datatypes by default. This enables a simple execution mechanism to
   518 handle quantifiers and function equality over the finite datatypes.
   519 
   520 * Quickcheck random generator has been renamed from "code" to
   521 "random".  INCOMPATIBILITY.
   522 
   523 * Quickcheck now has a configurable time limit which is set to 30
   524 seconds by default. This can be changed by adding [timeout = n] to the
   525 quickcheck command. The time limit for Auto Quickcheck is still set
   526 independently.
   527 
   528 * Quickcheck in locales considers interpretations of that locale for
   529 counter example search.
   530 
   531 * Sledgehammer:
   532   - Added "smt" and "remote_smt" provers based on the "smt" proof
   533     method. See the Sledgehammer manual for details ("isabelle doc
   534     sledgehammer").
   535   - Renamed commands:
   536     sledgehammer atp_info ~> sledgehammer running_provers
   537     sledgehammer atp_kill ~> sledgehammer kill_provers
   538     sledgehammer available_atps ~> sledgehammer available_provers
   539     INCOMPATIBILITY.
   540   - Renamed options:
   541     sledgehammer [atps = ...] ~> sledgehammer [provers = ...]
   542     sledgehammer [atp = ...] ~> sledgehammer [prover = ...]
   543     sledgehammer [timeout = 77 s] ~> sledgehammer [timeout = 77]
   544     (and "ms" and "min" are no longer supported)
   545     INCOMPATIBILITY.
   546 
   547 * Nitpick:
   548   - Renamed options:
   549     nitpick [timeout = 77 s] ~> nitpick [timeout = 77]
   550     nitpick [tac_timeout = 777 ms] ~> nitpick [tac_timeout = 0.777]
   551     INCOMPATIBILITY.
   552   - Added support for partial quotient types.
   553   - Added local versions of the "Nitpick.register_xxx" functions.
   554   - Added "whack" option.
   555   - Allow registration of quotient types as codatatypes.
   556   - Improved "merge_type_vars" option to merge more types.
   557   - Removed unsound "fast_descrs" option.
   558   - Added custom symmetry breaking for datatypes, making it possible to reach
   559     higher cardinalities.
   560   - Prevent the expansion of too large definitions.
   561 
   562 * Proof methods "metis" and "meson" now have configuration options
   563 "meson_trace", "metis_trace", and "metis_verbose" that can be enabled
   564 to diagnose these tools. E.g.
   565 
   566     using [[metis_trace = true]]
   567 
   568 * Auto Solve: Renamed "Auto Solve Direct".  The tool is now available
   569 manually as command 'solve_direct'.
   570 
   571 * The default SMT solver Z3 must be enabled explicitly (due to
   572 licensing issues) by setting the environment variable
   573 Z3_NON_COMMERCIAL in etc/settings of the component, for example.  For
   574 commercial applications, the SMT solver CVC3 is provided as fall-back;
   575 changing the SMT solver is done via the configuration option
   576 "smt_solver".
   577 
   578 * Remote SMT solvers need to be referred to by the "remote_" prefix,
   579 i.e. "remote_cvc3" and "remote_z3".
   580 
   581 * Added basic SMT support for datatypes, records, and typedefs using
   582 the oracle mode (no proofs).  Direct support of pairs has been dropped
   583 in exchange (pass theorems fst_conv snd_conv pair_collapse to the SMT
   584 support for a similar behavior).  Minor INCOMPATIBILITY.
   585 
   586 * Changed SMT configuration options:
   587   - Renamed:
   588     z3_proofs ~> smt_oracle (with inverted meaning)
   589     z3_trace_assms ~> smt_trace_used_facts
   590     INCOMPATIBILITY.
   591   - Added:
   592     smt_verbose
   593     smt_random_seed
   594     smt_datatypes
   595     smt_infer_triggers
   596     smt_monomorph_limit
   597     cvc3_options
   598     remote_cvc3_options
   599     remote_z3_options
   600     yices_options
   601 
   602 * Boogie output files (.b2i files) need to be declared in the theory
   603 header.
   604 
   605 * Simplification procedure "list_to_set_comprehension" rewrites list
   606 comprehensions applied to List.set to set comprehensions.  Occasional
   607 INCOMPATIBILITY, may be deactivated like this:
   608 
   609   declare [[simproc del: list_to_set_comprehension]]
   610 
   611 * Removed old version of primrec package.  INCOMPATIBILITY.
   612 
   613 * Removed simplifier congruence rule of "prod_case", as has for long
   614 been the case with "split".  INCOMPATIBILITY.
   615 
   616 * String.literal is a type, but not a datatype.  INCOMPATIBILITY.
   617 
   618 * Removed [split_format ... and ... and ...] version of
   619 [split_format].  Potential INCOMPATIBILITY.
   620 
   621 * Predicate "sorted" now defined inductively, with nice induction
   622 rules.  INCOMPATIBILITY: former sorted.simps now named sorted_simps.
   623 
   624 * Constant "contents" renamed to "the_elem", to free the generic name
   625 contents for other uses.  INCOMPATIBILITY.
   626 
   627 * Renamed class eq and constant eq (for code generation) to class
   628 equal and constant equal, plus renaming of related facts and various
   629 tuning.  INCOMPATIBILITY.
   630 
   631 * Dropped type classes mult_mono and mult_mono1.  INCOMPATIBILITY.
   632 
   633 * Removed output syntax "'a ~=> 'b" for "'a => 'b option".
   634 INCOMPATIBILITY.
   635 
   636 * Renamed theory Fset to Cset, type Fset.fset to Cset.set, in order to
   637 avoid confusion with finite sets.  INCOMPATIBILITY.
   638 
   639 * Abandoned locales equiv, congruent and congruent2 for equivalence
   640 relations.  INCOMPATIBILITY: use equivI rather than equiv_intro (same
   641 for congruent(2)).
   642 
   643 * Some previously unqualified names have been qualified:
   644 
   645   types
   646     bool ~> HOL.bool
   647     nat ~> Nat.nat
   648 
   649   constants
   650     Trueprop ~> HOL.Trueprop
   651     True ~> HOL.True
   652     False ~> HOL.False
   653     op & ~> HOL.conj
   654     op | ~> HOL.disj
   655     op --> ~> HOL.implies
   656     op = ~> HOL.eq
   657     Not ~> HOL.Not
   658     The ~> HOL.The
   659     All ~> HOL.All
   660     Ex ~> HOL.Ex
   661     Ex1 ~> HOL.Ex1
   662     Let ~> HOL.Let
   663     If ~> HOL.If
   664     Ball ~> Set.Ball
   665     Bex ~> Set.Bex
   666     Suc ~> Nat.Suc
   667     Pair ~> Product_Type.Pair
   668     fst ~> Product_Type.fst
   669     snd ~> Product_Type.snd
   670     curry ~> Product_Type.curry
   671     op : ~> Set.member
   672     Collect ~> Set.Collect
   673 
   674 INCOMPATIBILITY.
   675 
   676 * More canonical naming convention for some fundamental definitions:
   677 
   678     bot_bool_eq ~> bot_bool_def
   679     top_bool_eq ~> top_bool_def
   680     inf_bool_eq ~> inf_bool_def
   681     sup_bool_eq ~> sup_bool_def
   682     bot_fun_eq  ~> bot_fun_def
   683     top_fun_eq  ~> top_fun_def
   684     inf_fun_eq  ~> inf_fun_def
   685     sup_fun_eq  ~> sup_fun_def
   686 
   687 INCOMPATIBILITY.
   688 
   689 * More stylized fact names:
   690 
   691   expand_fun_eq ~> fun_eq_iff
   692   expand_set_eq ~> set_eq_iff
   693   set_ext       ~> set_eqI
   694   nat_number    ~> eval_nat_numeral
   695 
   696 INCOMPATIBILITY.
   697 
   698 * Refactoring of code-generation specific operations in theory List:
   699 
   700   constants
   701     null ~> List.null
   702 
   703   facts
   704     mem_iff ~> member_def
   705     null_empty ~> null_def
   706 
   707 INCOMPATIBILITY.  Note that these were not supposed to be used
   708 regularly unless for striking reasons; their main purpose was code
   709 generation.
   710 
   711 Various operations from the Haskell prelude are used for generating
   712 Haskell code.
   713 
   714 * Term "bij f" is now an abbreviation of "bij_betw f UNIV UNIV".  Term
   715 "surj f" is now an abbreviation of "range f = UNIV".  The theorems
   716 bij_def and surj_def are unchanged.  INCOMPATIBILITY.
   717 
   718 * Abolished some non-alphabetic type names: "prod" and "sum" replace
   719 "*" and "+" respectively.  INCOMPATIBILITY.
   720 
   721 * Name "Plus" of disjoint sum operator "<+>" is now hidden.  Write
   722 "Sum_Type.Plus" instead.
   723 
   724 * Constant "split" has been merged with constant "prod_case"; names of
   725 ML functions, facts etc. involving split have been retained so far,
   726 though.  INCOMPATIBILITY.
   727 
   728 * Dropped old infix syntax "_ mem _" for List.member; use "_ : set _"
   729 instead.  INCOMPATIBILITY.
   730 
   731 * Removed lemma "Option.is_none_none" which duplicates "is_none_def".
   732 INCOMPATIBILITY.
   733 
   734 * Former theory Library/Enum is now part of the HOL-Main image.
   735 INCOMPATIBILITY: all constants of the Enum theory now have to be
   736 referred to by its qualified name.
   737 
   738   enum    ~>  Enum.enum
   739   nlists  ~>  Enum.nlists
   740   product ~>  Enum.product
   741 
   742 * Theory Library/Monad_Syntax provides do-syntax for monad types.
   743 Syntax in Library/State_Monad has been changed to avoid ambiguities.
   744 INCOMPATIBILITY.
   745 
   746 * Theory Library/SetsAndFunctions has been split into
   747 Library/Function_Algebras and Library/Set_Algebras; canonical names
   748 for instance definitions for functions; various improvements.
   749 INCOMPATIBILITY.
   750 
   751 * Theory Library/Multiset provides stable quicksort implementation of
   752 sort_key.
   753 
   754 * Theory Library/Multiset: renamed empty_idemp ~> empty_neutral.
   755 INCOMPATIBILITY.
   756 
   757 * Session Multivariate_Analysis: introduced a type class for euclidean
   758 space.  Most theorems are now stated in terms of euclidean spaces
   759 instead of finite cartesian products.
   760 
   761   types
   762     real ^ 'n ~>  'a::real_vector
   763               ~>  'a::euclidean_space
   764               ~>  'a::ordered_euclidean_space
   765         (depends on your needs)
   766 
   767   constants
   768      _ $ _        ~> _ $$ _
   769      \<chi> x. _  ~> \<chi>\<chi> x. _
   770      CARD('n)     ~> DIM('a)
   771 
   772 Also note that the indices are now natural numbers and not from some
   773 finite type. Finite cartesian products of euclidean spaces, products
   774 of euclidean spaces the real and complex numbers are instantiated to
   775 be euclidean_spaces.  INCOMPATIBILITY.
   776 
   777 * Session Probability: introduced pextreal as positive extended real
   778 numbers.  Use pextreal as value for measures.  Introduce the
   779 Radon-Nikodym derivative, product spaces and Fubini's theorem for
   780 arbitrary sigma finite measures.  Introduces Lebesgue measure based on
   781 the integral in Multivariate Analysis.  INCOMPATIBILITY.
   782 
   783 * Session Imperative_HOL: revamped, corrected dozens of inadequacies.
   784 INCOMPATIBILITY.
   785 
   786 * Session SPARK (with image HOL-SPARK) provides commands to load and
   787 prove verification conditions generated by the SPARK Ada program
   788 verifier.  See also src/HOL/SPARK and src/HOL/SPARK/Examples.
   789 
   790 
   791 *** HOL-Algebra ***
   792 
   793 * Theorems for additive ring operations (locale abelian_monoid and
   794 descendants) are generated by interpretation from their multiplicative
   795 counterparts.  Names (in particular theorem names) have the mandatory
   796 qualifier 'add'.  Previous theorem names are redeclared for
   797 compatibility.
   798 
   799 * Structure "int_ring" is now an abbreviation (previously a
   800 definition).  This fits more natural with advanced interpretations.
   801 
   802 
   803 *** HOLCF ***
   804 
   805 * The domain package now runs in definitional mode by default: The
   806 former command 'new_domain' is now called 'domain'.  To use the domain
   807 package in its original axiomatic mode, use 'domain (unsafe)'.
   808 INCOMPATIBILITY.
   809 
   810 * The new class "domain" is now the default sort.  Class "predomain"
   811 is an unpointed version of "domain". Theories can be updated by
   812 replacing sort annotations as shown below.  INCOMPATIBILITY.
   813 
   814   'a::type ~> 'a::countable
   815   'a::cpo  ~> 'a::predomain
   816   'a::pcpo ~> 'a::domain
   817 
   818 * The old type class "rep" has been superseded by class "domain".
   819 Accordingly, users of the definitional package must remove any
   820 "default_sort rep" declarations.  INCOMPATIBILITY.
   821 
   822 * The domain package (definitional mode) now supports unpointed
   823 predomain argument types, as long as they are marked 'lazy'. (Strict
   824 arguments must be in class "domain".) For example, the following
   825 domain definition now works:
   826 
   827   domain natlist = nil | cons (lazy "nat discr") (lazy "natlist")
   828 
   829 * Theory HOLCF/Library/HOL_Cpo provides cpo and predomain class
   830 instances for types from main HOL: bool, nat, int, char, 'a + 'b,
   831 'a option, and 'a list.  Additionally, it configures fixrec and the
   832 domain package to work with these types.  For example:
   833 
   834   fixrec isInl :: "('a + 'b) u -> tr"
   835     where "isInl$(up$(Inl x)) = TT" | "isInl$(up$(Inr y)) = FF"
   836 
   837   domain V = VFun (lazy "V -> V") | VCon (lazy "nat") (lazy "V list")
   838 
   839 * The "(permissive)" option of fixrec has been replaced with a
   840 per-equation "(unchecked)" option. See
   841 src/HOL/HOLCF/Tutorial/Fixrec_ex.thy for examples. INCOMPATIBILITY.
   842 
   843 * The "bifinite" class no longer fixes a constant "approx"; the class
   844 now just asserts that such a function exists.  INCOMPATIBILITY.
   845 
   846 * Former type "alg_defl" has been renamed to "defl".  HOLCF no longer
   847 defines an embedding of type 'a defl into udom by default; instances
   848 of "bifinite" and "domain" classes are available in
   849 src/HOL/HOLCF/Library/Defl_Bifinite.thy.
   850 
   851 * The syntax "REP('a)" has been replaced with "DEFL('a)".
   852 
   853 * The predicate "directed" has been removed.  INCOMPATIBILITY.
   854 
   855 * The type class "finite_po" has been removed.  INCOMPATIBILITY.
   856 
   857 * The function "cprod_map" has been renamed to "prod_map".
   858 INCOMPATIBILITY.
   859 
   860 * The monadic bind operator on each powerdomain has new binder syntax
   861 similar to sets, e.g. "\<Union>\<sharp>x\<in>xs. t" represents
   862 "upper_bind\<cdot>xs\<cdot>(\<Lambda> x. t)".
   863 
   864 * The infix syntax for binary union on each powerdomain has changed
   865 from e.g. "+\<sharp>" to "\<union>\<sharp>", for consistency with set
   866 syntax.  INCOMPATIBILITY.
   867 
   868 * The constant "UU" has been renamed to "bottom".  The syntax "UU" is
   869 still supported as an input translation.
   870 
   871 * Renamed some theorems (the original names are also still available).
   872 
   873   expand_fun_below   ~> fun_below_iff
   874   below_fun_ext      ~> fun_belowI
   875   expand_cfun_eq     ~> cfun_eq_iff
   876   ext_cfun           ~> cfun_eqI
   877   expand_cfun_below  ~> cfun_below_iff
   878   below_cfun_ext     ~> cfun_belowI
   879   cont2cont_Rep_CFun ~> cont2cont_APP
   880 
   881 * The Abs and Rep functions for various types have changed names.
   882 Related theorem names have also changed to match. INCOMPATIBILITY.
   883 
   884   Rep_CFun  ~> Rep_cfun
   885   Abs_CFun  ~> Abs_cfun
   886   Rep_Sprod ~> Rep_sprod
   887   Abs_Sprod ~> Abs_sprod
   888   Rep_Ssum  ~> Rep_ssum
   889   Abs_Ssum  ~> Abs_ssum
   890 
   891 * Lemmas with names of the form *_defined_iff or *_strict_iff have
   892 been renamed to *_bottom_iff.  INCOMPATIBILITY.
   893 
   894 * Various changes to bisimulation/coinduction with domain package:
   895 
   896   - Definitions of "bisim" constants no longer mention definedness.
   897   - With mutual recursion, "bisim" predicate is now curried.
   898   - With mutual recursion, each type gets a separate coind theorem.
   899   - Variable names in bisim_def and coinduct rules have changed.
   900 
   901 INCOMPATIBILITY.
   902 
   903 * Case combinators generated by the domain package for type "foo" are
   904 now named "foo_case" instead of "foo_when".  INCOMPATIBILITY.
   905 
   906 * Several theorems have been renamed to more accurately reflect the
   907 names of constants and types involved.  INCOMPATIBILITY.
   908 
   909   thelub_const    ~> lub_const
   910   lub_const       ~> is_lub_const
   911   thelubI         ~> lub_eqI
   912   is_lub_lub      ~> is_lubD2
   913   lubI            ~> is_lub_lub
   914   unique_lub      ~> is_lub_unique
   915   is_ub_lub       ~> is_lub_rangeD1
   916   lub_bin_chain   ~> is_lub_bin_chain
   917   lub_fun         ~> is_lub_fun
   918   thelub_fun      ~> lub_fun
   919   thelub_cfun     ~> lub_cfun
   920   thelub_Pair     ~> lub_Pair
   921   lub_cprod       ~> is_lub_prod
   922   thelub_cprod    ~> lub_prod
   923   minimal_cprod   ~> minimal_prod
   924   inst_cprod_pcpo ~> inst_prod_pcpo
   925   UU_I            ~> bottomI
   926   compact_UU      ~> compact_bottom
   927   deflation_UU    ~> deflation_bottom
   928   finite_deflation_UU ~> finite_deflation_bottom
   929 
   930 * Many legacy theorem names have been discontinued.  INCOMPATIBILITY.
   931 
   932   sq_ord_less_eq_trans ~> below_eq_trans
   933   sq_ord_eq_less_trans ~> eq_below_trans
   934   refl_less            ~> below_refl
   935   trans_less           ~> below_trans
   936   antisym_less         ~> below_antisym
   937   antisym_less_inverse ~> po_eq_conv [THEN iffD1]
   938   box_less             ~> box_below
   939   rev_trans_less       ~> rev_below_trans
   940   not_less2not_eq      ~> not_below2not_eq
   941   less_UU_iff          ~> below_UU_iff
   942   flat_less_iff        ~> flat_below_iff
   943   adm_less             ~> adm_below
   944   adm_not_less         ~> adm_not_below
   945   adm_compact_not_less ~> adm_compact_not_below
   946   less_fun_def         ~> below_fun_def
   947   expand_fun_less      ~> fun_below_iff
   948   less_fun_ext         ~> fun_belowI
   949   less_discr_def       ~> below_discr_def
   950   discr_less_eq        ~> discr_below_eq
   951   less_unit_def        ~> below_unit_def
   952   less_cprod_def       ~> below_prod_def
   953   prod_lessI           ~> prod_belowI
   954   Pair_less_iff        ~> Pair_below_iff
   955   fst_less_iff         ~> fst_below_iff
   956   snd_less_iff         ~> snd_below_iff
   957   expand_cfun_less     ~> cfun_below_iff
   958   less_cfun_ext        ~> cfun_belowI
   959   injection_less       ~> injection_below
   960   less_up_def          ~> below_up_def
   961   not_Iup_less         ~> not_Iup_below
   962   Iup_less             ~> Iup_below
   963   up_less              ~> up_below
   964   Def_inject_less_eq   ~> Def_below_Def
   965   Def_less_is_eq       ~> Def_below_iff
   966   spair_less_iff       ~> spair_below_iff
   967   less_sprod           ~> below_sprod
   968   spair_less           ~> spair_below
   969   sfst_less_iff        ~> sfst_below_iff
   970   ssnd_less_iff        ~> ssnd_below_iff
   971   fix_least_less       ~> fix_least_below
   972   dist_less_one        ~> dist_below_one
   973   less_ONE             ~> below_ONE
   974   ONE_less_iff         ~> ONE_below_iff
   975   less_sinlD           ~> below_sinlD
   976   less_sinrD           ~> below_sinrD
   977 
   978 
   979 *** FOL and ZF ***
   980 
   981 * All constant names are now qualified internally and use proper
   982 identifiers, e.g. "IFOL.eq" instead of "op =".  INCOMPATIBILITY.
   983 
   984 
   985 *** ML ***
   986 
   987 * Antiquotation @{assert} inlines a function bool -> unit that raises
   988 Fail if the argument is false.  Due to inlining the source position of
   989 failed assertions is included in the error output.
   990 
   991 * Discontinued antiquotation @{theory_ref}, which is obsolete since ML
   992 text is in practice always evaluated with a stable theory checkpoint.
   993 Minor INCOMPATIBILITY, use (Theory.check_thy @{theory}) instead.
   994 
   995 * Antiquotation @{theory A} refers to theory A from the ancestry of
   996 the current context, not any accidental theory loader state as before.
   997 Potential INCOMPATIBILITY, subtle change in semantics.
   998 
   999 * Syntax.pretty_priority (default 0) configures the required priority
  1000 of pretty-printed output and thus affects insertion of parentheses.
  1001 
  1002 * Syntax.default_root (default "any") configures the inner syntax
  1003 category (nonterminal symbol) for parsing of terms.
  1004 
  1005 * Former exception Library.UnequalLengths now coincides with
  1006 ListPair.UnequalLengths.
  1007 
  1008 * Renamed structure MetaSimplifier to Raw_Simplifier.  Note that the
  1009 main functionality is provided by structure Simplifier.
  1010 
  1011 * Renamed raw "explode" function to "raw_explode" to emphasize its
  1012 meaning.  Note that internally to Isabelle, Symbol.explode is used in
  1013 almost all situations.
  1014 
  1015 * Discontinued obsolete function sys_error and exception SYS_ERROR.
  1016 See implementation manual for further details on exceptions in
  1017 Isabelle/ML.
  1018 
  1019 * Renamed setmp_noncritical to Unsynchronized.setmp to emphasize its
  1020 meaning.
  1021 
  1022 * Renamed structure PureThy to Pure_Thy and moved most of its
  1023 operations to structure Global_Theory, to emphasize that this is
  1024 rarely-used global-only stuff.
  1025 
  1026 * Discontinued Output.debug.  Minor INCOMPATIBILITY, use plain writeln
  1027 instead (or tracing for high-volume output).
  1028 
  1029 * Configuration option show_question_marks only affects regular pretty
  1030 printing of types and terms, not raw Term.string_of_vname.
  1031 
  1032 * ML_Context.thm and ML_Context.thms are no longer pervasive.  Rare
  1033 INCOMPATIBILITY, superseded by static antiquotations @{thm} and
  1034 @{thms} for most purposes.
  1035 
  1036 * ML structure Unsynchronized is never opened, not even in Isar
  1037 interaction mode as before.  Old Unsynchronized.set etc. have been
  1038 discontinued -- use plain := instead.  This should be *rare* anyway,
  1039 since modern tools always work via official context data, notably
  1040 configuration options.
  1041 
  1042 * Parallel and asynchronous execution requires special care concerning
  1043 interrupts.  Structure Exn provides some convenience functions that
  1044 avoid working directly with raw Interrupt.  User code must not absorb
  1045 interrupts -- intermediate handling (for cleanup etc.) needs to be
  1046 followed by re-raising of the original exception.  Another common
  1047 source of mistakes are "handle _" patterns, which make the meaning of
  1048 the program subject to physical effects of the environment.
  1049 
  1050 
  1051 
  1052 New in Isabelle2009-2 (June 2010)
  1053 ---------------------------------
  1054 
  1055 *** General ***
  1056 
  1057 * Authentic syntax for *all* logical entities (type classes, type
  1058 constructors, term constants): provides simple and robust
  1059 correspondence between formal entities and concrete syntax.  Within
  1060 the parse tree / AST representations, "constants" are decorated by
  1061 their category (class, type, const) and spelled out explicitly with
  1062 their full internal name.
  1063 
  1064 Substantial INCOMPATIBILITY concerning low-level syntax declarations
  1065 and translations (translation rules and translation functions in ML).
  1066 Some hints on upgrading:
  1067 
  1068   - Many existing uses of 'syntax' and 'translations' can be replaced
  1069     by more modern 'type_notation', 'notation' and 'abbreviation',
  1070     which are independent of this issue.
  1071 
  1072   - 'translations' require markup within the AST; the term syntax
  1073     provides the following special forms:
  1074 
  1075       CONST c   -- produces syntax version of constant c from context
  1076       XCONST c  -- literally c, checked as constant from context
  1077       c         -- literally c, if declared by 'syntax'
  1078 
  1079     Plain identifiers are treated as AST variables -- occasionally the
  1080     system indicates accidental variables via the error "rhs contains
  1081     extra variables".
  1082 
  1083     Type classes and type constructors are marked according to their
  1084     concrete syntax.  Some old translations rules need to be written
  1085     for the "type" category, using type constructor application
  1086     instead of pseudo-term application of the default category
  1087     "logic".
  1088 
  1089   - 'parse_translation' etc. in ML may use the following
  1090     antiquotations:
  1091 
  1092       @{class_syntax c}   -- type class c within parse tree / AST
  1093       @{term_syntax c}    -- type constructor c within parse tree / AST
  1094       @{const_syntax c}   -- ML version of "CONST c" above
  1095       @{syntax_const c}   -- literally c (checked wrt. 'syntax' declarations)
  1096 
  1097   - Literal types within 'typed_print_translations', i.e. those *not*
  1098     represented as pseudo-terms are represented verbatim.  Use @{class
  1099     c} or @{type_name c} here instead of the above syntax
  1100     antiquotations.
  1101 
  1102 Note that old non-authentic syntax was based on unqualified base
  1103 names, so all of the above "constant" names would coincide.  Recall
  1104 that 'print_syntax' and ML_command "set Syntax.trace_ast" help to
  1105 diagnose syntax problems.
  1106 
  1107 * Type constructors admit general mixfix syntax, not just infix.
  1108 
  1109 * Concrete syntax may be attached to local entities without a proof
  1110 body, too.  This works via regular mixfix annotations for 'fix',
  1111 'def', 'obtain' etc. or via the explicit 'write' command, which is
  1112 similar to the 'notation' command in theory specifications.
  1113 
  1114 * Discontinued unnamed infix syntax (legacy feature for many years) --
  1115 need to specify constant name and syntax separately.  Internal ML
  1116 datatype constructors have been renamed from InfixName to Infix etc.
  1117 Minor INCOMPATIBILITY.
  1118 
  1119 * Schematic theorem statements need to be explicitly markup as such,
  1120 via commands 'schematic_lemma', 'schematic_theorem',
  1121 'schematic_corollary'.  Thus the relevance of the proof is made
  1122 syntactically clear, which impacts performance in a parallel or
  1123 asynchronous interactive environment.  Minor INCOMPATIBILITY.
  1124 
  1125 * Use of cumulative prems via "!" in some proof methods has been
  1126 discontinued (old legacy feature).
  1127 
  1128 * References 'trace_simp' and 'debug_simp' have been replaced by
  1129 configuration options stored in the context. Enabling tracing (the
  1130 case of debugging is similar) in proofs works via
  1131 
  1132   using [[trace_simp = true]]
  1133 
  1134 Tracing is then active for all invocations of the simplifier in
  1135 subsequent goal refinement steps. Tracing may also still be enabled or
  1136 disabled via the ProofGeneral settings menu.
  1137 
  1138 * Separate commands 'hide_class', 'hide_type', 'hide_const',
  1139 'hide_fact' replace the former 'hide' KIND command.  Minor
  1140 INCOMPATIBILITY.
  1141 
  1142 * Improved parallelism of proof term normalization: usedir -p2 -q0 is
  1143 more efficient than combinations with -q1 or -q2.
  1144 
  1145 
  1146 *** Pure ***
  1147 
  1148 * Proofterms record type-class reasoning explicitly, using the
  1149 "unconstrain" operation internally.  This eliminates all sort
  1150 constraints from a theorem and proof, introducing explicit
  1151 OFCLASS-premises.  On the proof term level, this operation is
  1152 automatically applied at theorem boundaries, such that closed proofs
  1153 are always free of sort constraints.  INCOMPATIBILITY for tools that
  1154 inspect proof terms.
  1155 
  1156 * Local theory specifications may depend on extra type variables that
  1157 are not present in the result type -- arguments TYPE('a) :: 'a itself
  1158 are added internally.  For example:
  1159 
  1160   definition unitary :: bool where "unitary = (ALL (x::'a) y. x = y)"
  1161 
  1162 * Predicates of locales introduced by classes carry a mandatory
  1163 "class" prefix.  INCOMPATIBILITY.
  1164 
  1165 * Vacuous class specifications observe default sort.  INCOMPATIBILITY.
  1166 
  1167 * Old 'axclass' command has been discontinued.  INCOMPATIBILITY, use
  1168 'class' instead.
  1169 
  1170 * Command 'code_reflect' allows to incorporate generated ML code into
  1171 runtime environment; replaces immature code_datatype antiquotation.
  1172 INCOMPATIBILITY.
  1173 
  1174 * Code generator: simple concept for abstract datatypes obeying
  1175 invariants.
  1176 
  1177 * Code generator: details of internal data cache have no impact on the
  1178 user space functionality any longer.
  1179 
  1180 * Methods "unfold_locales" and "intro_locales" ignore non-locale
  1181 subgoals.  This is more appropriate for interpretations with 'where'.
  1182 INCOMPATIBILITY.
  1183 
  1184 * Command 'example_proof' opens an empty proof body.  This allows to
  1185 experiment with Isar, without producing any persistent result.
  1186 
  1187 * Commands 'type_notation' and 'no_type_notation' declare type syntax
  1188 within a local theory context, with explicit checking of the
  1189 constructors involved (in contrast to the raw 'syntax' versions).
  1190 
  1191 * Commands 'types' and 'typedecl' now work within a local theory
  1192 context -- without introducing dependencies on parameters or
  1193 assumptions, which is not possible in Isabelle/Pure.
  1194 
  1195 * Command 'defaultsort' has been renamed to 'default_sort', it works
  1196 within a local theory context.  Minor INCOMPATIBILITY.
  1197 
  1198 
  1199 *** HOL ***
  1200 
  1201 * Command 'typedef' now works within a local theory context -- without
  1202 introducing dependencies on parameters or assumptions, which is not
  1203 possible in Isabelle/Pure/HOL.  Note that the logical environment may
  1204 contain multiple interpretations of local typedefs (with different
  1205 non-emptiness proofs), even in a global theory context.
  1206 
  1207 * New package for quotient types.  Commands 'quotient_type' and
  1208 'quotient_definition' may be used for defining types and constants by
  1209 quotient constructions.  An example is the type of integers created by
  1210 quotienting pairs of natural numbers:
  1211 
  1212   fun
  1213     intrel :: "(nat * nat) => (nat * nat) => bool"
  1214   where
  1215     "intrel (x, y) (u, v) = (x + v = u + y)"
  1216 
  1217   quotient_type int = "nat * nat" / intrel
  1218     by (auto simp add: equivp_def expand_fun_eq)
  1219 
  1220   quotient_definition
  1221     "0::int" is "(0::nat, 0::nat)"
  1222 
  1223 The method "lifting" can be used to lift of theorems from the
  1224 underlying "raw" type to the quotient type.  The example
  1225 src/HOL/Quotient_Examples/FSet.thy includes such a quotient
  1226 construction and provides a reasoning infrastructure for finite sets.
  1227 
  1228 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
  1229 clash with new theory Quotient in Main HOL.
  1230 
  1231 * Moved the SMT binding into the main HOL session, eliminating
  1232 separate HOL-SMT session.
  1233 
  1234 * List membership infix mem operation is only an input abbreviation.
  1235 INCOMPATIBILITY.
  1236 
  1237 * Theory Library/Word.thy has been removed.  Use library Word/Word.thy
  1238 for future developements; former Library/Word.thy is still present in
  1239 the AFP entry RSAPPS.
  1240 
  1241 * Theorem Int.int_induct renamed to Int.int_of_nat_induct and is no
  1242 longer shadowed.  INCOMPATIBILITY.
  1243 
  1244 * Dropped theorem duplicate comp_arith; use semiring_norm instead.
  1245 INCOMPATIBILITY.
  1246 
  1247 * Dropped theorem RealPow.real_sq_order; use power2_le_imp_le instead.
  1248 INCOMPATIBILITY.
  1249 
  1250 * Dropped normalizing_semiring etc; use the facts in semiring classes
  1251 instead.  INCOMPATIBILITY.
  1252 
  1253 * Dropped several real-specific versions of lemmas about floor and
  1254 ceiling; use the generic lemmas from theory "Archimedean_Field"
  1255 instead.  INCOMPATIBILITY.
  1256 
  1257   floor_number_of_eq         ~> floor_number_of
  1258   le_floor_eq_number_of      ~> number_of_le_floor
  1259   le_floor_eq_zero           ~> zero_le_floor
  1260   le_floor_eq_one            ~> one_le_floor
  1261   floor_less_eq_number_of    ~> floor_less_number_of
  1262   floor_less_eq_zero         ~> floor_less_zero
  1263   floor_less_eq_one          ~> floor_less_one
  1264   less_floor_eq_number_of    ~> number_of_less_floor
  1265   less_floor_eq_zero         ~> zero_less_floor
  1266   less_floor_eq_one          ~> one_less_floor
  1267   floor_le_eq_number_of      ~> floor_le_number_of
  1268   floor_le_eq_zero           ~> floor_le_zero
  1269   floor_le_eq_one            ~> floor_le_one
  1270   floor_subtract_number_of   ~> floor_diff_number_of
  1271   floor_subtract_one         ~> floor_diff_one
  1272   ceiling_number_of_eq       ~> ceiling_number_of
  1273   ceiling_le_eq_number_of    ~> ceiling_le_number_of
  1274   ceiling_le_zero_eq         ~> ceiling_le_zero
  1275   ceiling_le_eq_one          ~> ceiling_le_one
  1276   less_ceiling_eq_number_of  ~> number_of_less_ceiling
  1277   less_ceiling_eq_zero       ~> zero_less_ceiling
  1278   less_ceiling_eq_one        ~> one_less_ceiling
  1279   ceiling_less_eq_number_of  ~> ceiling_less_number_of
  1280   ceiling_less_eq_zero       ~> ceiling_less_zero
  1281   ceiling_less_eq_one        ~> ceiling_less_one
  1282   le_ceiling_eq_number_of    ~> number_of_le_ceiling
  1283   le_ceiling_eq_zero         ~> zero_le_ceiling
  1284   le_ceiling_eq_one          ~> one_le_ceiling
  1285   ceiling_subtract_number_of ~> ceiling_diff_number_of
  1286   ceiling_subtract_one       ~> ceiling_diff_one
  1287 
  1288 * Theory "Finite_Set": various folding_XXX locales facilitate the
  1289 application of the various fold combinators on finite sets.
  1290 
  1291 * Library theory "RBT" renamed to "RBT_Impl"; new library theory "RBT"
  1292 provides abstract red-black tree type which is backed by "RBT_Impl" as
  1293 implementation.  INCOMPATIBILTY.
  1294 
  1295 * Theory Library/Coinductive_List has been removed -- superseded by
  1296 AFP/thys/Coinductive.
  1297 
  1298 * Theory PReal, including the type "preal" and related operations, has
  1299 been removed.  INCOMPATIBILITY.
  1300 
  1301 * Real: new development using Cauchy Sequences.
  1302 
  1303 * Split off theory "Big_Operators" containing setsum, setprod,
  1304 Inf_fin, Sup_fin, Min, Max from theory Finite_Set.  INCOMPATIBILITY.
  1305 
  1306 * Theory "Rational" renamed to "Rat", for consistency with "Nat",
  1307 "Int" etc.  INCOMPATIBILITY.
  1308 
  1309 * Constant Rat.normalize needs to be qualified.  INCOMPATIBILITY.
  1310 
  1311 * New set of rules "ac_simps" provides combined assoc / commute
  1312 rewrites for all interpretations of the appropriate generic locales.
  1313 
  1314 * Renamed theory "OrderedGroup" to "Groups" and split theory
  1315 "Ring_and_Field" into theories "Rings" and "Fields"; for more
  1316 appropriate and more consistent names suitable for name prefixes
  1317 within the HOL theories.  INCOMPATIBILITY.
  1318 
  1319 * Some generic constants have been put to appropriate theories:
  1320   - less_eq, less: Orderings
  1321   - zero, one, plus, minus, uminus, times, abs, sgn: Groups
  1322   - inverse, divide: Rings
  1323 INCOMPATIBILITY.
  1324 
  1325 * More consistent naming of type classes involving orderings (and
  1326 lattices):
  1327 
  1328     lower_semilattice                   ~> semilattice_inf
  1329     upper_semilattice                   ~> semilattice_sup
  1330 
  1331     dense_linear_order                  ~> dense_linorder
  1332 
  1333     pordered_ab_group_add               ~> ordered_ab_group_add
  1334     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
  1335     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
  1336     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
  1337     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
  1338     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
  1339     pordered_cancel_semiring            ~> ordered_cancel_semiring
  1340     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
  1341     pordered_comm_ring                  ~> ordered_comm_ring
  1342     pordered_comm_semiring              ~> ordered_comm_semiring
  1343     pordered_ring                       ~> ordered_ring
  1344     pordered_ring_abs                   ~> ordered_ring_abs
  1345     pordered_semiring                   ~> ordered_semiring
  1346 
  1347     ordered_ab_group_add                ~> linordered_ab_group_add
  1348     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
  1349     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
  1350     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
  1351     ordered_field                       ~> linordered_field
  1352     ordered_field_no_lb                 ~> linordered_field_no_lb
  1353     ordered_field_no_ub                 ~> linordered_field_no_ub
  1354     ordered_field_dense_linear_order    ~> dense_linordered_field
  1355     ordered_idom                        ~> linordered_idom
  1356     ordered_ring                        ~> linordered_ring
  1357     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
  1358     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
  1359     ordered_ring_strict                 ~> linordered_ring_strict
  1360     ordered_semidom                     ~> linordered_semidom
  1361     ordered_semiring                    ~> linordered_semiring
  1362     ordered_semiring_1                  ~> linordered_semiring_1
  1363     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
  1364     ordered_semiring_strict             ~> linordered_semiring_strict
  1365 
  1366   The following slightly odd type classes have been moved to a
  1367   separate theory Library/Lattice_Algebras:
  1368 
  1369     lordered_ab_group_add               ~> lattice_ab_group_add
  1370     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
  1371     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
  1372     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
  1373     lordered_ring                       ~> lattice_ring
  1374 
  1375 INCOMPATIBILITY.
  1376 
  1377 * Refined field classes:
  1378   - classes division_ring_inverse_zero, field_inverse_zero,
  1379     linordered_field_inverse_zero include rule inverse 0 = 0 --
  1380     subsumes former division_by_zero class;
  1381   - numerous lemmas have been ported from field to division_ring.
  1382 INCOMPATIBILITY.
  1383 
  1384 * Refined algebra theorem collections:
  1385   - dropped theorem group group_simps, use algebra_simps instead;
  1386   - dropped theorem group ring_simps, use field_simps instead;
  1387   - proper theorem collection field_simps subsumes former theorem
  1388     groups field_eq_simps and field_simps;
  1389   - dropped lemma eq_minus_self_iff which is a duplicate for
  1390     equal_neg_zero.
  1391 INCOMPATIBILITY.
  1392 
  1393 * Theory Finite_Set and List: some lemmas have been generalized from
  1394 sets to lattices:
  1395 
  1396   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
  1397   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
  1398   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
  1399   union_Union_fold_union        ~> sup_Sup_fold_sup
  1400   Inter_fold_inter              ~> Inf_fold_inf
  1401   Union_fold_union              ~> Sup_fold_sup
  1402   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
  1403   union_UNION_fold_union        ~> sup_SUPR_fold_sup
  1404   INTER_fold_inter              ~> INFI_fold_inf
  1405   UNION_fold_union              ~> SUPR_fold_sup
  1406 
  1407 * Theory "Complete_Lattice": lemmas top_def and bot_def have been
  1408 replaced by the more convenient lemmas Inf_empty and Sup_empty.
  1409 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
  1410 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
  1411 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
  1412 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
  1413 
  1414 * Reorganized theory Multiset: swapped notation of pointwise and
  1415 multiset order:
  1416 
  1417   - pointwise ordering is instance of class order with standard syntax
  1418     <= and <;
  1419   - multiset ordering has syntax <=# and <#; partial order properties
  1420     are provided by means of interpretation with prefix
  1421     multiset_order;
  1422   - less duplication, less historical organization of sections,
  1423     conversion from associations lists to multisets, rudimentary code
  1424     generation;
  1425   - use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union,
  1426     if needed.
  1427 
  1428 Renamed:
  1429 
  1430   multiset_eq_conv_count_eq  ~>  multiset_ext_iff
  1431   multi_count_ext  ~>  multiset_ext
  1432   diff_union_inverse2  ~>  diff_union_cancelR
  1433 
  1434 INCOMPATIBILITY.
  1435 
  1436 * Theory Permutation: replaced local "remove" by List.remove1.
  1437 
  1438 * Code generation: ML and OCaml code is decorated with signatures.
  1439 
  1440 * Theory List: added transpose.
  1441 
  1442 * Library/Nat_Bijection.thy is a collection of bijective functions
  1443 between nat and other types, which supersedes the older libraries
  1444 Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.
  1445 
  1446   Constants:
  1447   Nat_Int_Bij.nat2_to_nat         ~> prod_encode
  1448   Nat_Int_Bij.nat_to_nat2         ~> prod_decode
  1449   Nat_Int_Bij.int_to_nat_bij      ~> int_encode
  1450   Nat_Int_Bij.nat_to_int_bij      ~> int_decode
  1451   Countable.pair_encode           ~> prod_encode
  1452   NatIso.prod2nat                 ~> prod_encode
  1453   NatIso.nat2prod                 ~> prod_decode
  1454   NatIso.sum2nat                  ~> sum_encode
  1455   NatIso.nat2sum                  ~> sum_decode
  1456   NatIso.list2nat                 ~> list_encode
  1457   NatIso.nat2list                 ~> list_decode
  1458   NatIso.set2nat                  ~> set_encode
  1459   NatIso.nat2set                  ~> set_decode
  1460 
  1461   Lemmas:
  1462   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
  1463   Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
  1464   Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
  1465   Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
  1466   Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
  1467   Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
  1468   Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
  1469   Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
  1470   Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
  1471   Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
  1472   Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
  1473   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
  1474   Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode
  1475 
  1476 * Sledgehammer:
  1477   - Renamed ATP commands:
  1478     atp_info     ~> sledgehammer running_atps
  1479     atp_kill     ~> sledgehammer kill_atps
  1480     atp_messages ~> sledgehammer messages
  1481     atp_minimize ~> sledgehammer minimize
  1482     print_atps   ~> sledgehammer available_atps
  1483     INCOMPATIBILITY.
  1484   - Added user's manual ("isabelle doc sledgehammer").
  1485   - Added option syntax and "sledgehammer_params" to customize
  1486     Sledgehammer's behavior.  See the manual for details.
  1487   - Modified the Isar proof reconstruction code so that it produces
  1488     direct proofs rather than proofs by contradiction.  (This feature
  1489     is still experimental.)
  1490   - Made Isar proof reconstruction work for SPASS, remote ATPs, and in
  1491     full-typed mode.
  1492   - Added support for TPTP syntax for SPASS via the "spass_tptp" ATP.
  1493 
  1494 * Nitpick:
  1495   - Added and implemented "binary_ints" and "bits" options.
  1496   - Added "std" option and implemented support for nonstandard models.
  1497   - Added and implemented "finitize" option to improve the precision
  1498     of infinite datatypes based on a monotonicity analysis.
  1499   - Added support for quotient types.
  1500   - Added support for "specification" and "ax_specification"
  1501     constructs.
  1502   - Added support for local definitions (for "function" and
  1503     "termination" proofs).
  1504   - Added support for term postprocessors.
  1505   - Optimized "Multiset.multiset" and "FinFun.finfun".
  1506   - Improved efficiency of "destroy_constrs" optimization.
  1507   - Fixed soundness bugs related to "destroy_constrs" optimization and
  1508     record getters.
  1509   - Fixed soundness bug related to higher-order constructors.
  1510   - Fixed soundness bug when "full_descrs" is enabled.
  1511   - Improved precision of set constructs.
  1512   - Added "atoms" option.
  1513   - Added cache to speed up repeated Kodkod invocations on the same
  1514     problems.
  1515   - Renamed "MiniSatJNI", "zChaffJNI", "BerkMinAlloy", and
  1516     "SAT4JLight" to "MiniSat_JNI", "zChaff_JNI", "BerkMin_Alloy", and
  1517     "SAT4J_Light".  INCOMPATIBILITY.
  1518   - Removed "skolemize", "uncurry", "sym_break", "flatten_prop",
  1519     "sharing_depth", and "show_skolems" options.  INCOMPATIBILITY.
  1520   - Removed "nitpick_intro" attribute.  INCOMPATIBILITY.
  1521 
  1522 * Method "induct" now takes instantiations of the form t, where t is not
  1523   a variable, as a shorthand for "x == t", where x is a fresh variable.
  1524   If this is not intended, t has to be enclosed in parentheses.
  1525   By default, the equalities generated by definitional instantiations
  1526   are pre-simplified, which may cause parameters of inductive cases
  1527   to disappear, or may even delete some of the inductive cases.
  1528   Use "induct (no_simp)" instead of "induct" to restore the old
  1529   behaviour. The (no_simp) option is also understood by the "cases"
  1530   and "nominal_induct" methods, which now perform pre-simplification, too.
  1531   INCOMPATIBILITY.
  1532 
  1533 
  1534 *** HOLCF ***
  1535 
  1536 * Variable names in lemmas generated by the domain package have
  1537 changed; the naming scheme is now consistent with the HOL datatype
  1538 package.  Some proof scripts may be affected, INCOMPATIBILITY.
  1539 
  1540 * The domain package no longer defines the function "foo_copy" for
  1541 recursive domain "foo".  The reach lemma is now stated directly in
  1542 terms of "foo_take".  Lemmas and proofs that mention "foo_copy" must
  1543 be reformulated in terms of "foo_take", INCOMPATIBILITY.
  1544 
  1545 * Most definedness lemmas generated by the domain package (previously
  1546 of the form "x ~= UU ==> foo$x ~= UU") now have an if-and-only-if form
  1547 like "foo$x = UU <-> x = UU", which works better as a simp rule.
  1548 Proofs that used definedness lemmas as intro rules may break,
  1549 potential INCOMPATIBILITY.
  1550 
  1551 * Induction and casedist rules generated by the domain package now
  1552 declare proper case_names (one called "bottom", and one named for each
  1553 constructor).  INCOMPATIBILITY.
  1554 
  1555 * For mutually-recursive domains, separate "reach" and "take_lemma"
  1556 rules are generated for each domain, INCOMPATIBILITY.
  1557 
  1558   foo_bar.reach       ~> foo.reach  bar.reach
  1559   foo_bar.take_lemmas ~> foo.take_lemma  bar.take_lemma
  1560 
  1561 * Some lemmas generated by the domain package have been renamed for
  1562 consistency with the datatype package, INCOMPATIBILITY.
  1563 
  1564   foo.ind        ~> foo.induct
  1565   foo.finite_ind ~> foo.finite_induct
  1566   foo.coind      ~> foo.coinduct
  1567   foo.casedist   ~> foo.exhaust
  1568   foo.exhaust    ~> foo.nchotomy
  1569 
  1570 * For consistency with other definition packages, the fixrec package
  1571 now generates qualified theorem names, INCOMPATIBILITY.
  1572 
  1573   foo_simps  ~> foo.simps
  1574   foo_unfold ~> foo.unfold
  1575   foo_induct ~> foo.induct
  1576 
  1577 * The "fixrec_simp" attribute has been removed.  The "fixrec_simp"
  1578 method and internal fixrec proofs now use the default simpset instead.
  1579 INCOMPATIBILITY.
  1580 
  1581 * The "contlub" predicate has been removed.  Proof scripts should use
  1582 lemma contI2 in place of monocontlub2cont, INCOMPATIBILITY.
  1583 
  1584 * The "admw" predicate has been removed, INCOMPATIBILITY.
  1585 
  1586 * The constants cpair, cfst, and csnd have been removed in favor of
  1587 Pair, fst, and snd from Isabelle/HOL, INCOMPATIBILITY.
  1588 
  1589 
  1590 *** ML ***
  1591 
  1592 * Antiquotations for basic formal entities:
  1593 
  1594     @{class NAME}         -- type class
  1595     @{class_syntax NAME}  -- syntax representation of the above
  1596 
  1597     @{type_name NAME}     -- logical type
  1598     @{type_abbrev NAME}   -- type abbreviation
  1599     @{nonterminal NAME}   -- type of concrete syntactic category
  1600     @{type_syntax NAME}   -- syntax representation of any of the above
  1601 
  1602     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
  1603     @{const_abbrev NAME}  -- abbreviated constant
  1604     @{const_syntax NAME}  -- syntax representation of any of the above
  1605 
  1606 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
  1607 syntax constant (cf. 'syntax' command).
  1608 
  1609 * Antiquotation @{make_string} inlines a function to print arbitrary
  1610 values similar to the ML toplevel.  The result is compiler dependent
  1611 and may fall back on "?" in certain situations.
  1612 
  1613 * Diagnostic commands 'ML_val' and 'ML_command' may refer to
  1614 antiquotations @{Isar.state} and @{Isar.goal}.  This replaces impure
  1615 Isar.state() and Isar.goal(), which belong to the old TTY loop and do
  1616 not work with the asynchronous Isar document model.
  1617 
  1618 * Configuration options now admit dynamic default values, depending on
  1619 the context or even global references.
  1620 
  1621 * SHA1.digest digests strings according to SHA-1 (see RFC 3174).  It
  1622 uses an efficient external library if available (for Poly/ML).
  1623 
  1624 * Renamed some important ML structures, while keeping the old names
  1625 for some time as aliases within the structure Legacy:
  1626 
  1627   OuterKeyword  ~>  Keyword
  1628   OuterLex      ~>  Token
  1629   OuterParse    ~>  Parse
  1630   OuterSyntax   ~>  Outer_Syntax
  1631   PrintMode     ~>  Print_Mode
  1632   SpecParse     ~>  Parse_Spec
  1633   ThyInfo       ~>  Thy_Info
  1634   ThyLoad       ~>  Thy_Load
  1635   ThyOutput     ~>  Thy_Output
  1636   TypeInfer     ~>  Type_Infer
  1637 
  1638 Note that "open Legacy" simplifies porting of sources, but forgetting
  1639 to remove it again will complicate porting again in the future.
  1640 
  1641 * Most operations that refer to a global context are named
  1642 accordingly, e.g. Simplifier.global_context or
  1643 ProofContext.init_global.  There are some situations where a global
  1644 context actually works, but under normal circumstances one needs to
  1645 pass the proper local context through the code!
  1646 
  1647 * Discontinued old TheoryDataFun with its copy/init operation -- data
  1648 needs to be pure.  Functor Theory_Data_PP retains the traditional
  1649 Pretty.pp argument to merge, which is absent in the standard
  1650 Theory_Data version.
  1651 
  1652 * Sorts.certify_sort and derived "cert" operations for types and terms
  1653 no longer minimize sorts.  Thus certification at the boundary of the
  1654 inference kernel becomes invariant under addition of class relations,
  1655 which is an important monotonicity principle.  Sorts are now minimized
  1656 in the syntax layer only, at the boundary between the end-user and the
  1657 system.  Subtle INCOMPATIBILITY, may have to use Sign.minimize_sort
  1658 explicitly in rare situations.
  1659 
  1660 * Renamed old-style Drule.standard to Drule.export_without_context, to
  1661 emphasize that this is in no way a standard operation.
  1662 INCOMPATIBILITY.
  1663 
  1664 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
  1665 usual for resolution.  Rare INCOMPATIBILITY.
  1666 
  1667 * Renamed varify/unvarify operations to varify_global/unvarify_global
  1668 to emphasize that these only work in a global situation (which is
  1669 quite rare).
  1670 
  1671 * Curried take and drop in library.ML; negative length is interpreted
  1672 as infinity (as in chop).  Subtle INCOMPATIBILITY.
  1673 
  1674 * Proof terms: type substitutions on proof constants now use canonical
  1675 order of type variables.  INCOMPATIBILITY for tools working with proof
  1676 terms.
  1677 
  1678 * Raw axioms/defs may no longer carry sort constraints, and raw defs
  1679 may no longer carry premises.  User-level specifications are
  1680 transformed accordingly by Thm.add_axiom/add_def.
  1681 
  1682 
  1683 *** System ***
  1684 
  1685 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
  1686 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
  1687 proof terms are enabled unconditionally in the new HOL-Proofs image.
  1688 
  1689 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
  1690 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
  1691 respectively.
  1692 
  1693 * Old lib/scripts/polyml-platform is superseded by the
  1694 ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
  1695 variant, even on a 64 bit machine.  The following example setting
  1696 prefers 64 bit if available:
  1697 
  1698   ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"
  1699 
  1700 * The preliminary Isabelle/jEdit application demonstrates the emerging
  1701 Isabelle/Scala layer for advanced prover interaction and integration.
  1702 See src/Tools/jEdit or "isabelle jedit" provided by the properly built
  1703 component.
  1704 
  1705 * "IsabelleText" is a Unicode font derived from Bitstream Vera Mono
  1706 and Bluesky TeX fonts.  It provides the usual Isabelle symbols,
  1707 similar to the default assignment of the document preparation system
  1708 (cf. isabellesym.sty).  The Isabelle/Scala class Isabelle_System
  1709 provides some operations for direct access to the font without asking
  1710 the user for manual installation.
  1711 
  1712 
  1713 
  1714 New in Isabelle2009-1 (December 2009)
  1715 -------------------------------------
  1716 
  1717 *** General ***
  1718 
  1719 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
  1720 one backslash should be used, even in ML sources.
  1721 
  1722 
  1723 *** Pure ***
  1724 
  1725 * Locale interpretation propagates mixins along the locale hierarchy.
  1726 The currently only available mixins are the equations used to map
  1727 local definitions to terms of the target domain of an interpretation.
  1728 
  1729 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
  1730 loc" to print all interpretations of locale "loc" in the theory.
  1731 Interpretations in proofs are not shown.
  1732 
  1733 * Thoroughly revised locales tutorial.  New section on conditional
  1734 interpretation.
  1735 
  1736 * On instantiation of classes, remaining undefined class parameters
  1737 are formally declared.  INCOMPATIBILITY.
  1738 
  1739 
  1740 *** Document preparation ***
  1741 
  1742 * New generalized style concept for printing terms: @{foo (style) ...}
  1743 instead of @{foo_style style ...}  (old form is still retained for
  1744 backward compatibility).  Styles can be also applied for
  1745 antiquotations prop, term_type and typeof.
  1746 
  1747 
  1748 *** HOL ***
  1749 
  1750 * New proof method "smt" for a combination of first-order logic with
  1751 equality, linear and nonlinear (natural/integer/real) arithmetic, and
  1752 fixed-size bitvectors; there is also basic support for higher-order
  1753 features (esp. lambda abstractions).  It is an incomplete decision
  1754 procedure based on external SMT solvers using the oracle mechanism;
  1755 for the SMT solver Z3, this method is proof-producing.  Certificates
  1756 are provided to avoid calling the external solvers solely for
  1757 re-checking proofs.  Due to a remote SMT service there is no need for
  1758 installing SMT solvers locally.  See src/HOL/SMT.
  1759 
  1760 * New commands to load and prove verification conditions generated by
  1761 the Boogie program verifier or derived systems (e.g. the Verifying C
  1762 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
  1763 
  1764 * New counterexample generator tool 'nitpick' based on the Kodkod
  1765 relational model finder.  See src/HOL/Tools/Nitpick and
  1766 src/HOL/Nitpick_Examples.
  1767 
  1768 * New commands 'code_pred' and 'values' to invoke the predicate
  1769 compiler and to enumerate values of inductive predicates.
  1770 
  1771 * A tabled implementation of the reflexive transitive closure.
  1772 
  1773 * New implementation of quickcheck uses generic code generator;
  1774 default generators are provided for all suitable HOL types, records
  1775 and datatypes.  Old quickcheck can be re-activated importing theory
  1776 Library/SML_Quickcheck.
  1777 
  1778 * New testing tool Mirabelle for automated proof tools.  Applies
  1779 several tools and tactics like sledgehammer, metis, or quickcheck, to
  1780 every proof step in a theory.  To be used in batch mode via the
  1781 "mirabelle" utility.
  1782 
  1783 * New proof method "sos" (sum of squares) for nonlinear real
  1784 arithmetic (originally due to John Harison). It requires theory
  1785 Library/Sum_Of_Squares.  It is not a complete decision procedure but
  1786 works well in practice on quantifier-free real arithmetic with +, -,
  1787 *, ^, =, <= and <, i.e. boolean combinations of equalities and
  1788 inequalities between polynomials.  It makes use of external
  1789 semidefinite programming solvers.  Method "sos" generates a
  1790 certificate that can be pasted into the proof thus avoiding the need
  1791 to call an external tool every time the proof is checked.  See
  1792 src/HOL/Library/Sum_Of_Squares.
  1793 
  1794 * New method "linarith" invokes existing linear arithmetic decision
  1795 procedure only.
  1796 
  1797 * New command 'atp_minimal' reduces result produced by Sledgehammer.
  1798 
  1799 * New Sledgehammer option "Full Types" in Proof General settings menu.
  1800 Causes full type information to be output to the ATPs.  This slows
  1801 ATPs down considerably but eliminates a source of unsound "proofs"
  1802 that fail later.
  1803 
  1804 * New method "metisFT": A version of metis that uses full type
  1805 information in order to avoid failures of proof reconstruction.
  1806 
  1807 * New evaluator "approximate" approximates an real valued term using
  1808 the same method as the approximation method.
  1809 
  1810 * Method "approximate" now supports arithmetic expressions as
  1811 boundaries of intervals and implements interval splitting and Taylor
  1812 series expansion.
  1813 
  1814 * ML antiquotation @{code_datatype} inserts definition of a datatype
  1815 generated by the code generator; e.g. see src/HOL/Predicate.thy.
  1816 
  1817 * New theory SupInf of the supremum and infimum operators for sets of
  1818 reals.
  1819 
  1820 * New theory Probability, which contains a development of measure
  1821 theory, eventually leading to Lebesgue integration and probability.
  1822 
  1823 * Extended Multivariate Analysis to include derivation and Brouwer's
  1824 fixpoint theorem.
  1825 
  1826 * Reorganization of number theory, INCOMPATIBILITY:
  1827   - new number theory development for nat and int, in theories Divides
  1828     and GCD as well as in new session Number_Theory
  1829   - some constants and facts now suffixed with _nat and _int
  1830     accordingly
  1831   - former session NumberTheory now named Old_Number_Theory, including
  1832     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
  1833   - moved theory Pocklington from src/HOL/Library to
  1834     src/HOL/Old_Number_Theory
  1835 
  1836 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
  1837 lcm of finite and infinite sets. It is shown that they form a complete
  1838 lattice.
  1839 
  1840 * Class semiring_div requires superclass no_zero_divisors and proof of
  1841 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
  1842 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
  1843 generalized to class semiring_div, subsuming former theorems
  1844 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
  1845 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
  1846 INCOMPATIBILITY.
  1847 
  1848 * Refinements to lattice classes and sets:
  1849   - less default intro/elim rules in locale variant, more default
  1850     intro/elim rules in class variant: more uniformity
  1851   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
  1852     le_inf_iff
  1853   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
  1854     sup_aci)
  1855   - renamed ACI to inf_sup_aci
  1856   - new class "boolean_algebra"
  1857   - class "complete_lattice" moved to separate theory
  1858     "Complete_Lattice"; corresponding constants (and abbreviations)
  1859     renamed and with authentic syntax:
  1860     Set.Inf ~>    Complete_Lattice.Inf
  1861     Set.Sup ~>    Complete_Lattice.Sup
  1862     Set.INFI ~>   Complete_Lattice.INFI
  1863     Set.SUPR ~>   Complete_Lattice.SUPR
  1864     Set.Inter ~>  Complete_Lattice.Inter
  1865     Set.Union ~>  Complete_Lattice.Union
  1866     Set.INTER ~>  Complete_Lattice.INTER
  1867     Set.UNION ~>  Complete_Lattice.UNION
  1868   - authentic syntax for
  1869     Set.Pow
  1870     Set.image
  1871   - mere abbreviations:
  1872     Set.empty               (for bot)
  1873     Set.UNIV                (for top)
  1874     Set.inter               (for inf, formerly Set.Int)
  1875     Set.union               (for sup, formerly Set.Un)
  1876     Complete_Lattice.Inter  (for Inf)
  1877     Complete_Lattice.Union  (for Sup)
  1878     Complete_Lattice.INTER  (for INFI)
  1879     Complete_Lattice.UNION  (for SUPR)
  1880   - object-logic definitions as far as appropriate
  1881 
  1882 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
  1883 Un_subset_iff are explicitly deleted as default simp rules; then also
  1884 their lattice counterparts le_inf_iff and le_sup_iff have to be
  1885 deleted to achieve the desired effect.
  1886 
  1887 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
  1888 rules by default any longer; the same applies to min_max.inf_absorb1
  1889 etc.  INCOMPATIBILITY.
  1890 
  1891 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
  1892 pred_set_conv by default.  INCOMPATIBILITY.
  1893 
  1894 * Power operations on relations and functions are now one dedicated
  1895 constant "compow" with infix syntax "^^".  Power operation on
  1896 multiplicative monoids retains syntax "^" and is now defined generic
  1897 in class power.  INCOMPATIBILITY.
  1898 
  1899 * Relation composition "R O S" now has a more standard argument order:
  1900 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
  1901 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
  1902 break, since the O_assoc rule was not rewritten like this.  Fix using
  1903 O_assoc[symmetric].  The same applies to the curried version "R OO S".
  1904 
  1905 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
  1906 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
  1907 INCOMPATIBILITY.
  1908 
  1909 * Most rules produced by inductive and datatype package have mandatory
  1910 prefixes.  INCOMPATIBILITY.
  1911 
  1912 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
  1913 the attribute of the same name.  Each of the theorems in the list
  1914 DERIV_intros assumes composition with an additional function and
  1915 matches a variable to the derivative, which has to be solved by the
  1916 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
  1917 of most elementary terms.  Former Maclauren.DERIV_tac and
  1918 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
  1919 INCOMPATIBILITY.
  1920 
  1921 * Code generator attributes follow the usual underscore convention:
  1922     code_unfold     replaces    code unfold
  1923     code_post       replaces    code post
  1924     etc.
  1925   INCOMPATIBILITY.
  1926 
  1927 * Renamed methods:
  1928     sizechange -> size_change
  1929     induct_scheme -> induction_schema
  1930   INCOMPATIBILITY.
  1931 
  1932 * Discontinued abbreviation "arbitrary" of constant "undefined".
  1933 INCOMPATIBILITY, use "undefined" directly.
  1934 
  1935 * Renamed theorems:
  1936     Suc_eq_add_numeral_1 -> Suc_eq_plus1
  1937     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
  1938     Suc_plus1 -> Suc_eq_plus1
  1939     *anti_sym -> *antisym*
  1940     vector_less_eq_def -> vector_le_def
  1941   INCOMPATIBILITY.
  1942 
  1943 * Added theorem List.map_map as [simp].  Removed List.map_compose.
  1944 INCOMPATIBILITY.
  1945 
  1946 * Removed predicate "M hassize n" (<--> card M = n & finite M).
  1947 INCOMPATIBILITY.
  1948 
  1949 
  1950 *** HOLCF ***
  1951 
  1952 * Theory Representable defines a class "rep" of domains that are
  1953 representable (via an ep-pair) in the universal domain type "udom".
  1954 Instances are provided for all type constructors defined in HOLCF.
  1955 
  1956 * The 'new_domain' command is a purely definitional version of the
  1957 domain package, for representable domains.  Syntax is identical to the
  1958 old domain package.  The 'new_domain' package also supports indirect
  1959 recursion using previously-defined type constructors.  See
  1960 src/HOLCF/ex/New_Domain.thy for examples.
  1961 
  1962 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
  1963 on the left-hand side of an equation, and then performs
  1964 simplification.  Rewriting is done using rules declared with the
  1965 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
  1966 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
  1967 
  1968 * The pattern-match compiler in 'fixrec' can now handle constructors
  1969 with HOL function types.  Pattern-match combinators for the Pair
  1970 constructor are pre-configured.
  1971 
  1972 * The 'fixrec' package now produces better fixed-point induction rules
  1973 for mutually-recursive definitions:  Induction rules have conclusions
  1974 of the form "P foo bar" instead of "P <foo, bar>".
  1975 
  1976 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
  1977 been renamed to "below".  The name "below" now replaces "less" in many
  1978 theorem names.  (Legacy theorem names using "less" are still supported
  1979 as well.)
  1980 
  1981 * The 'fixrec' package now supports "bottom patterns".  Bottom
  1982 patterns can be used to generate strictness rules, or to make
  1983 functions more strict (much like the bang-patterns supported by the
  1984 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
  1985 examples.
  1986 
  1987 
  1988 *** ML ***
  1989 
  1990 * Support for Poly/ML 5.3.0, with improved reporting of compiler
  1991 errors and run-time exceptions, including detailed source positions.
  1992 
  1993 * Structure Name_Space (formerly NameSpace) now manages uniquely
  1994 identified entries, with some additional information such as source
  1995 position, logical grouping etc.
  1996 
  1997 * Theory and context data is now introduced by the simplified and
  1998 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
  1999 to be pure, but the old TheoryDataFun for mutable data (with explicit
  2000 copy operation) is still available for some time.
  2001 
  2002 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
  2003 provides a high-level programming interface to synchronized state
  2004 variables with atomic update.  This works via pure function
  2005 application within a critical section -- its runtime should be as
  2006 short as possible; beware of deadlocks if critical code is nested,
  2007 either directly or indirectly via other synchronized variables!
  2008 
  2009 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
  2010 wraps raw ML references, explicitly indicating their non-thread-safe
  2011 behaviour.  The Isar toplevel keeps this structure open, to
  2012 accommodate Proof General as well as quick and dirty interactive
  2013 experiments with references.
  2014 
  2015 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
  2016 parallel tactical reasoning.
  2017 
  2018 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
  2019 are similar to SUBPROOF, but are slightly more flexible: only the
  2020 specified parts of the subgoal are imported into the context, and the
  2021 body tactic may introduce new subgoals and schematic variables.
  2022 
  2023 * Old tactical METAHYPS, which does not observe the proof context, has
  2024 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
  2025 or Subgoal.FOCUS etc.
  2026 
  2027 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
  2028 functors have their own ML name space there is no point to mark them
  2029 separately.)  Minor INCOMPATIBILITY.
  2030 
  2031 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
  2032 
  2033 * Renamed several structures FooBar to Foo_Bar.  Occasional,
  2034 INCOMPATIBILITY.
  2035 
  2036 * Operations of structure Skip_Proof no longer require quick_and_dirty
  2037 mode, which avoids critical setmp.
  2038 
  2039 * Eliminated old Attrib.add_attributes, Method.add_methods and related
  2040 combinators for "args".  INCOMPATIBILITY, need to use simplified
  2041 Attrib/Method.setup introduced in Isabelle2009.
  2042 
  2043 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
  2044 back on global_simpset_of, global_claset_of, global_clasimpset_of as
  2045 last resort.  INCOMPATIBILITY.
  2046 
  2047 * Display.pretty_thm now requires a proper context (cf. former
  2048 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
  2049 or even Display.pretty_thm_without_context as last resort.
  2050 INCOMPATIBILITY.
  2051 
  2052 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
  2053 Syntax.pretty_typ/term directly, preferably with proper context
  2054 instead of global theory.
  2055 
  2056 
  2057 *** System ***
  2058 
  2059 * Further fine tuning of parallel proof checking, scales up to 8 cores
  2060 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
  2061 usedir option -q.
  2062 
  2063 * Support for additional "Isabelle components" via etc/components, see
  2064 also the system manual.
  2065 
  2066 * The isabelle makeall tool now operates on all components with
  2067 IsaMakefile, not just hardwired "logics".
  2068 
  2069 * Removed "compress" option from isabelle-process and isabelle usedir;
  2070 this is always enabled.
  2071 
  2072 * Discontinued support for Poly/ML 4.x versions.
  2073 
  2074 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
  2075 on a given logic image.  This requires the lighttpd webserver and is
  2076 currently supported on Linux only.
  2077 
  2078 
  2079 
  2080 New in Isabelle2009 (April 2009)
  2081 --------------------------------
  2082 
  2083 *** General ***
  2084 
  2085 * Simplified main Isabelle executables, with less surprises on
  2086 case-insensitive file-systems (such as Mac OS).
  2087 
  2088   - The main Isabelle tool wrapper is now called "isabelle" instead of
  2089     "isatool."
  2090 
  2091   - The former "isabelle" alias for "isabelle-process" has been
  2092     removed (should rarely occur to regular users).
  2093 
  2094   - The former "isabelle-interface" and its alias "Isabelle" have been
  2095     removed (interfaces are now regular Isabelle tools).
  2096 
  2097 Within scripts and make files, the Isabelle environment variables
  2098 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
  2099 respectively.  (The latter are still available as legacy feature.)
  2100 
  2101 The old isabelle-interface wrapper could react in confusing ways if
  2102 the interface was uninstalled or changed otherwise.  Individual
  2103 interface tool configuration is now more explicit, see also the
  2104 Isabelle system manual.  In particular, Proof General is now available
  2105 via "isabelle emacs".
  2106 
  2107 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
  2108 purge installed copies of Isabelle executables and re-run "isabelle
  2109 install -p ...", or use symlinks.
  2110 
  2111 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
  2112 old ~/isabelle, which was slightly non-standard and apt to cause
  2113 surprises on case-insensitive file-systems (such as Mac OS).
  2114 
  2115 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
  2116 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
  2117 care is required when using older releases of Isabelle.  Note that
  2118 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
  2119 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
  2120 
  2121 * Proofs of fully specified statements are run in parallel on
  2122 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
  2123 a regular 4-core machine, if the initial heap space is made reasonably
  2124 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
  2125 
  2126 * The main reference manuals ("isar-ref", "implementation", and
  2127 "system") have been updated and extended.  Formally checked references
  2128 as hyperlinks are now available uniformly.
  2129 
  2130 
  2131 *** Pure ***
  2132 
  2133 * Complete re-implementation of locales.  INCOMPATIBILITY in several
  2134 respects.  The most important changes are listed below.  See the
  2135 Tutorial on Locales ("locales" manual) for details.
  2136 
  2137 - In locale expressions, instantiation replaces renaming.  Parameters
  2138 must be declared in a for clause.  To aid compatibility with previous
  2139 parameter inheritance, in locale declarations, parameters that are not
  2140 'touched' (instantiation position "_" or omitted) are implicitly added
  2141 with their syntax at the beginning of the for clause.
  2142 
  2143 - Syntax from abbreviations and definitions in locales is available in
  2144 locale expressions and context elements.  The latter is particularly
  2145 useful in locale declarations.
  2146 
  2147 - More flexible mechanisms to qualify names generated by locale
  2148 expressions.  Qualifiers (prefixes) may be specified in locale
  2149 expressions, and can be marked as mandatory (syntax: "name!:") or
  2150 optional (syntax "name?:").  The default depends for plain "name:"
  2151 depends on the situation where a locale expression is used: in
  2152 commands 'locale' and 'sublocale' prefixes are optional, in
  2153 'interpretation' and 'interpret' prefixes are mandatory.  The old
  2154 implicit qualifiers derived from the parameter names of a locale are
  2155 no longer generated.
  2156 
  2157 - Command "sublocale l < e" replaces "interpretation l < e".  The
  2158 instantiation clause in "interpretation" and "interpret" (square
  2159 brackets) is no longer available.  Use locale expressions.
  2160 
  2161 - When converting proof scripts, mandatory qualifiers in
  2162 'interpretation' and 'interpret' should be retained by default, even
  2163 if this is an INCOMPATIBILITY compared to former behavior.  In the
  2164 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
  2165 in locale expressions range over a single locale instance only.
  2166 
  2167 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
  2168 In existing theorem specifications replace the includes element by the
  2169 respective context elements of the included locale, omitting those
  2170 that are already present in the theorem specification.  Multiple
  2171 assume elements of a locale should be replaced by a single one
  2172 involving the locale predicate.  In the proof body, declarations (most
  2173 notably theorems) may be regained by interpreting the respective
  2174 locales in the proof context as required (command "interpret").
  2175 
  2176 If using "includes" in replacement of a target solely because the
  2177 parameter types in the theorem are not as general as in the target,
  2178 consider declaring a new locale with additional type constraints on
  2179 the parameters (context element "constrains").
  2180 
  2181 - Discontinued "locale (open)".  INCOMPATIBILITY.
  2182 
  2183 - Locale interpretation commands no longer attempt to simplify goal.
  2184 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
  2185 methods intro_locales and unfold_locales to clarify.
  2186 
  2187 - Locale interpretation commands no longer accept interpretation
  2188 attributes.  INCOMPATIBILITY.
  2189 
  2190 * Class declaration: so-called "base sort" must not be given in import
  2191 list any longer, but is inferred from the specification.  Particularly
  2192 in HOL, write
  2193 
  2194     class foo = ...
  2195 
  2196 instead of
  2197 
  2198     class foo = type + ...
  2199 
  2200 * Class target: global versions of theorems stemming do not carry a
  2201 parameter prefix any longer.  INCOMPATIBILITY.
  2202 
  2203 * Class 'instance' command no longer accepts attached definitions.
  2204 INCOMPATIBILITY, use proper 'instantiation' target instead.
  2205 
  2206 * Recovered hiding of consts, which was accidentally broken in
  2207 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
  2208 makes c inaccessible; consider using ``hide (open) const c'' instead.
  2209 
  2210 * Slightly more coherent Pure syntax, with updated documentation in
  2211 isar-ref manual.  Removed locales meta_term_syntax and
  2212 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
  2213 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
  2214 directly in regular applications.
  2215 
  2216 * There is a new syntactic category "float_const" for signed decimal
  2217 fractions (e.g. 123.45 or -123.45).
  2218 
  2219 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
  2220 interface with 'setup' command instead.
  2221 
  2222 * Command 'local_setup' is similar to 'setup', but operates on a local
  2223 theory context.
  2224 
  2225 * The 'axiomatization' command now only works within a global theory
  2226 context.  INCOMPATIBILITY.
  2227 
  2228 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
  2229 hypotheses.  Sorts required in the course of reasoning need to be
  2230 covered by the constraints in the initial statement, completed by the
  2231 type instance information of the background theory.  Non-trivial sort
  2232 hypotheses, which rarely occur in practice, may be specified via
  2233 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
  2234 
  2235   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
  2236 
  2237 The result contains an implicit sort hypotheses as before --
  2238 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
  2239 normalization.
  2240 
  2241 * Generalized Isar history, with support for linear undo, direct state
  2242 addressing etc.
  2243 
  2244 * Changed defaults for unify configuration options:
  2245 
  2246   unify_trace_bound = 50 (formerly 25)
  2247   unify_search_bound = 60 (formerly 30)
  2248 
  2249 * Different bookkeeping for code equations (INCOMPATIBILITY):
  2250 
  2251   a) On theory merge, the last set of code equations for a particular
  2252      constant is taken (in accordance with the policy applied by other
  2253      parts of the code generator framework).
  2254 
  2255   b) Code equations stemming from explicit declarations (e.g. code
  2256      attribute) gain priority over default code equations stemming
  2257      from definition, primrec, fun etc.
  2258 
  2259 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
  2260 
  2261 * Unified theorem tables for both code generators.  Thus [code
  2262 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
  2263 
  2264 * Command 'find_consts' searches for constants based on type and name
  2265 patterns, e.g.
  2266 
  2267     find_consts "_ => bool"
  2268 
  2269 By default, matching is against subtypes, but it may be restricted to
  2270 the whole type.  Searching by name is possible.  Multiple queries are
  2271 conjunctive and queries may be negated by prefixing them with a
  2272 hyphen:
  2273 
  2274     find_consts strict: "_ => bool" name: "Int" -"int => int"
  2275 
  2276 * New 'find_theorems' criterion "solves" matches theorems that
  2277 directly solve the current goal (modulo higher-order unification).
  2278 
  2279 * Auto solve feature for main theorem statements: whenever a new goal
  2280 is stated, "find_theorems solves" is called; any theorems that could
  2281 solve the lemma directly are listed as part of the goal state.
  2282 Cf. associated options in Proof General Isabelle settings menu,
  2283 enabled by default, with reasonable timeout for pathological cases of
  2284 higher-order unification.
  2285 
  2286 
  2287 *** Document preparation ***
  2288 
  2289 * Antiquotation @{lemma} now imitates a regular terminal proof,
  2290 demanding keyword 'by' and supporting the full method expression
  2291 syntax just like the Isar command 'by'.
  2292 
  2293 
  2294 *** HOL ***
  2295 
  2296 * Integrated main parts of former image HOL-Complex with HOL.  Entry
  2297 points Main and Complex_Main remain as before.
  2298 
  2299 * Logic image HOL-Plain provides a minimal HOL with the most important
  2300 tools available (inductive, datatype, primrec, ...).  This facilitates
  2301 experimentation and tool development.  Note that user applications
  2302 (and library theories) should never refer to anything below theory
  2303 Main, as before.
  2304 
  2305 * Logic image HOL-Main stops at theory Main, and thus facilitates
  2306 experimentation due to shorter build times.
  2307 
  2308 * Logic image HOL-NSA contains theories of nonstandard analysis which
  2309 were previously part of former HOL-Complex.  Entry point Hyperreal
  2310 remains valid, but theories formerly using Complex_Main should now use
  2311 new entry point Hypercomplex.
  2312 
  2313 * Generic ATP manager for Sledgehammer, based on ML threads instead of
  2314 Posix processes.  Avoids potentially expensive forking of the ML
  2315 process.  New thread-based implementation also works on non-Unix
  2316 platforms (Cygwin).  Provers are no longer hardwired, but defined
  2317 within the theory via plain ML wrapper functions.  Basic Sledgehammer
  2318 commands are covered in the isar-ref manual.
  2319 
  2320 * Wrapper scripts for remote SystemOnTPTP service allows to use
  2321 sledgehammer without local ATP installation (Vampire etc.). Other
  2322 provers may be included via suitable ML wrappers, see also
  2323 src/HOL/ATP_Linkup.thy.
  2324 
  2325 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
  2326 menu.
  2327 
  2328 * The metis method no longer fails because the theorem is too trivial
  2329 (contains the empty clause).
  2330 
  2331 * The metis method now fails in the usual manner, rather than raising
  2332 an exception, if it determines that it cannot prove the theorem.
  2333 
  2334 * Method "coherent" implements a prover for coherent logic (see also
  2335 src/Tools/coherent.ML).
  2336 
  2337 * Constants "undefined" and "default" replace "arbitrary".  Usually
  2338 "undefined" is the right choice to replace "arbitrary", though
  2339 logically there is no difference.  INCOMPATIBILITY.
  2340 
  2341 * Command "value" now integrates different evaluation mechanisms.  The
  2342 result of the first successful evaluation mechanism is printed.  In
  2343 square brackets a particular named evaluation mechanisms may be
  2344 specified (currently, [SML], [code] or [nbe]).  See further
  2345 src/HOL/ex/Eval_Examples.thy.
  2346 
  2347 * Normalization by evaluation now allows non-leftlinear equations.
  2348 Declare with attribute [code nbe].
  2349 
  2350 * Methods "case_tac" and "induct_tac" now refer to the very same rules
  2351 as the structured Isar versions "cases" and "induct", cf. the
  2352 corresponding "cases" and "induct" attributes.  Mutual induction rules
  2353 are now presented as a list of individual projections
  2354 (e.g. foo_bar.inducts for types foo and bar); the old format with
  2355 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
  2356 rare situations a different rule is selected --- notably nested tuple
  2357 elimination instead of former prod.exhaust: use explicit (case_tac t
  2358 rule: prod.exhaust) here.
  2359 
  2360 * Attributes "cases", "induct", "coinduct" support "del" option.
  2361 
  2362 * Removed fact "case_split_thm", which duplicates "case_split".
  2363 
  2364 * The option datatype has been moved to a new theory Option.  Renamed
  2365 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
  2366 
  2367 * New predicate "strict_mono" classifies strict functions on partial
  2368 orders.  With strict functions on linear orders, reasoning about
  2369 (in)equalities is facilitated by theorems "strict_mono_eq",
  2370 "strict_mono_less_eq" and "strict_mono_less".
  2371 
  2372 * Some set operations are now proper qualified constants with
  2373 authentic syntax.  INCOMPATIBILITY:
  2374 
  2375     op Int ~>   Set.Int
  2376     op Un ~>    Set.Un
  2377     INTER ~>    Set.INTER
  2378     UNION ~>    Set.UNION
  2379     Inter ~>    Set.Inter
  2380     Union ~>    Set.Union
  2381     {} ~>       Set.empty
  2382     UNIV ~>     Set.UNIV
  2383 
  2384 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  2385 theory Set.
  2386 
  2387 * Auxiliary class "itself" has disappeared -- classes without any
  2388 parameter are treated as expected by the 'class' command.
  2389 
  2390 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  2391 
  2392 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  2393 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  2394 
  2395 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  2396 method "approximation".  It proves formulas on real values by using
  2397 interval arithmetic.  In the formulas are also the transcendental
  2398 functions sin, cos, tan, atan, ln, exp and the constant pi are
  2399 allowed. For examples see
  2400 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  2401 
  2402 * Theory "Reflection" now resides in HOL/Library.
  2403 
  2404 * Entry point to Word library now simply named "Word".
  2405 INCOMPATIBILITY.
  2406 
  2407 * Made source layout more coherent with logical distribution
  2408 structure:
  2409 
  2410     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  2411     src/HOL/Library/Code_Message.thy ~> src/HOL/
  2412     src/HOL/Library/GCD.thy ~> src/HOL/
  2413     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  2414     src/HOL/Library/Parity.thy ~> src/HOL/
  2415     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  2416     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  2417     src/HOL/Real/Lubs.thy ~> src/HOL/
  2418     src/HOL/Real/PReal.thy ~> src/HOL/
  2419     src/HOL/Real/Rational.thy ~> src/HOL/
  2420     src/HOL/Real/RComplete.thy ~> src/HOL/
  2421     src/HOL/Real/RealDef.thy ~> src/HOL/
  2422     src/HOL/Real/RealPow.thy ~> src/HOL/
  2423     src/HOL/Real/Real.thy ~> src/HOL/
  2424     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  2425     src/HOL/Complex/Complex.thy ~> src/HOL/
  2426     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  2427     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  2428     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  2429     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  2430     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  2431     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  2432     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  2433     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  2434     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  2435     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  2436     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  2437     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  2438     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  2439     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  2440     src/HOL/Real/Float ~> src/HOL/Library/
  2441     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  2442     src/HOL/Real/RealVector.thy ~> src/HOL/
  2443 
  2444     src/HOL/arith_data.ML ~> src/HOL/Tools
  2445     src/HOL/hologic.ML ~> src/HOL/Tools
  2446     src/HOL/simpdata.ML ~> src/HOL/Tools
  2447     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  2448     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  2449     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  2450     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  2451     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  2452     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  2453     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  2454 
  2455     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  2456     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  2457     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  2458     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  2459     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  2460     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  2461 
  2462 * If methods "eval" and "evaluation" encounter a structured proof
  2463 state with !!/==>, only the conclusion is evaluated to True (if
  2464 possible), avoiding strange error messages.
  2465 
  2466 * Method "sizechange" automates termination proofs using (a
  2467 modification of) the size-change principle.  Requires SAT solver.  See
  2468 src/HOL/ex/Termination.thy for examples.
  2469 
  2470 * Simplifier: simproc for let expressions now unfolds if bound
  2471 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  2472 
  2473 * Method "arith": Linear arithmetic now ignores all inequalities when
  2474 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  2475 
  2476 * New attribute "arith" for facts that should always be used
  2477 automatically by arithmetic. It is intended to be used locally in
  2478 proofs, e.g.
  2479 
  2480   assumes [arith]: "x > 0"
  2481 
  2482 Global usage is discouraged because of possible performance impact.
  2483 
  2484 * New classes "top" and "bot" with corresponding operations "top" and
  2485 "bot" in theory Orderings; instantiation of class "complete_lattice"
  2486 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  2487 
  2488 * Changed definition lemma "less_fun_def" in order to provide an
  2489 instance for preorders on functions; use lemma "less_le" instead.
  2490 INCOMPATIBILITY.
  2491 
  2492 * Theory Orderings: class "wellorder" moved here, with explicit
  2493 induction rule "less_induct" as assumption.  For instantiation of
  2494 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  2495 INCOMPATIBILITY.
  2496 
  2497 * Theory Orderings: added class "preorder" as superclass of "order".
  2498 INCOMPATIBILITY: Instantiation proofs for order, linorder
  2499 etc. slightly changed.  Some theorems named order_class.* now named
  2500 preorder_class.*.
  2501 
  2502 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  2503 "diag" to "Id_on".
  2504 
  2505 * Theory Finite_Set: added a new fold combinator of type
  2506 
  2507   ('a => 'b => 'b) => 'b => 'a set => 'b
  2508 
  2509 Occasionally this is more convenient than the old fold combinator
  2510 which is now defined in terms of the new one and renamed to
  2511 fold_image.
  2512 
  2513 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  2514 and "ring_simps" have been replaced by "algebra_simps" (which can be
  2515 extended with further lemmas!).  At the moment both still exist but
  2516 the former will disappear at some point.
  2517 
  2518 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  2519 class recpower.  Type-specific simp rules for various recpower types
  2520 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  2521 
  2522 rat_power_0    -> power_0
  2523 rat_power_Suc  -> power_Suc
  2524 realpow_0      -> power_0
  2525 realpow_Suc    -> power_Suc
  2526 complexpow_0   -> power_0
  2527 complexpow_Suc -> power_Suc
  2528 power_poly_0   -> power_0
  2529 power_poly_Suc -> power_Suc
  2530 
  2531 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  2532 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  2533 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  2534 of lemmas from Divides has been generalized from nat to class
  2535 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  2536 renames resulting from duplicate elimination:
  2537 
  2538     dvd_def_mod ~>          dvd_eq_mod_eq_0
  2539     zero_dvd_iff ~>         dvd_0_left_iff
  2540     dvd_0 ~>                dvd_0_right
  2541     DIVISION_BY_ZERO_DIV ~> div_by_0
  2542     DIVISION_BY_ZERO_MOD ~> mod_by_0
  2543     mult_div ~>             div_mult_self2_is_id
  2544     mult_mod ~>             mod_mult_self2_is_0
  2545 
  2546 * Theory IntDiv: removed many lemmas that are instances of class-based
  2547 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  2548 rename old lemmas as follows:
  2549 
  2550 dvd_diff               -> nat_dvd_diff
  2551 dvd_zminus_iff         -> dvd_minus_iff
  2552 mod_add1_eq            -> mod_add_eq
  2553 mod_mult1_eq           -> mod_mult_right_eq
  2554 mod_mult1_eq'          -> mod_mult_left_eq
  2555 mod_mult_distrib_mod   -> mod_mult_eq
  2556 nat_mod_add_left_eq    -> mod_add_left_eq
  2557 nat_mod_add_right_eq   -> mod_add_right_eq
  2558 nat_mod_div_trivial    -> mod_div_trivial
  2559 nat_mod_mod_trivial    -> mod_mod_trivial
  2560 zdiv_zadd_self1        -> div_add_self1
  2561 zdiv_zadd_self2        -> div_add_self2
  2562 zdiv_zmult_self1       -> div_mult_self2_is_id
  2563 zdiv_zmult_self2       -> div_mult_self1_is_id
  2564 zdvd_triv_left         -> dvd_triv_left
  2565 zdvd_triv_right        -> dvd_triv_right
  2566 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  2567 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  2568 zmod_zadd_left_eq      -> mod_add_left_eq
  2569 zmod_zadd_right_eq     -> mod_add_right_eq
  2570 zmod_zadd_self1        -> mod_add_self1
  2571 zmod_zadd_self2        -> mod_add_self2
  2572 zmod_zadd1_eq          -> mod_add_eq
  2573 zmod_zdiff1_eq         -> mod_diff_eq
  2574 zmod_zdvd_zmod         -> mod_mod_cancel
  2575 zmod_zmod_cancel       -> mod_mod_cancel
  2576 zmod_zmult_self1       -> mod_mult_self2_is_0
  2577 zmod_zmult_self2       -> mod_mult_self1_is_0
  2578 zmod_1                 -> mod_by_1
  2579 zdiv_1                 -> div_by_1
  2580 zdvd_abs1              -> abs_dvd_iff
  2581 zdvd_abs2              -> dvd_abs_iff
  2582 zdvd_refl              -> dvd_refl
  2583 zdvd_trans             -> dvd_trans
  2584 zdvd_zadd              -> dvd_add
  2585 zdvd_zdiff             -> dvd_diff
  2586 zdvd_zminus_iff        -> dvd_minus_iff
  2587 zdvd_zminus2_iff       -> minus_dvd_iff
  2588 zdvd_zmultD            -> dvd_mult_right
  2589 zdvd_zmultD2           -> dvd_mult_left
  2590 zdvd_zmult_mono        -> mult_dvd_mono
  2591 zdvd_0_right           -> dvd_0_right
  2592 zdvd_0_left            -> dvd_0_left_iff
  2593 zdvd_1_left            -> one_dvd
  2594 zminus_dvd_iff         -> minus_dvd_iff
  2595 
  2596 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  2597 
  2598 * The real numbers offer decimal input syntax: 12.34 is translated
  2599 into 1234/10^2. This translation is not reversed upon output.
  2600 
  2601 * Theory Library/Polynomial defines an abstract type 'a poly of
  2602 univariate polynomials with coefficients of type 'a.  In addition to
  2603 the standard ring operations, it also supports div and mod.  Code
  2604 generation is also supported, using list-style constructors.
  2605 
  2606 * Theory Library/Inner_Product defines a class of real_inner for real
  2607 inner product spaces, with an overloaded operation inner :: 'a => 'a
  2608 => real.  Class real_inner is a subclass of real_normed_vector from
  2609 theory RealVector.
  2610 
  2611 * Theory Library/Product_Vector provides instances for the product
  2612 type 'a * 'b of several classes from RealVector and Inner_Product.
  2613 Definitions of addition, subtraction, scalar multiplication, norms,
  2614 and inner products are included.
  2615 
  2616 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  2617 addition to the field operations, numerals and case syntax are also
  2618 supported.
  2619 
  2620 * Theory Library/Diagonalize provides constructive version of Cantor's
  2621 first diagonalization argument.
  2622 
  2623 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  2624 zlcm (for int); carried together from various gcd/lcm developements in
  2625 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  2626 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  2627 may recover tupled syntax as follows:
  2628 
  2629     hide (open) const gcd
  2630     abbreviation gcd where
  2631       "gcd == (%(a, b). GCD.gcd a b)"
  2632     notation (output)
  2633       GCD.gcd ("gcd '(_, _')")
  2634 
  2635 The same works for lcm, zgcd, zlcm.
  2636 
  2637 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  2638 instantiations for algebraic structures.  Removed some duplicate
  2639 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  2640 
  2641 * ML antiquotation @{code} takes a constant as argument and generates
  2642 corresponding code in background and inserts name of the corresponding
  2643 resulting ML value/function/datatype constructor binding in place.
  2644 All occurrences of @{code} with a single ML block are generated
  2645 simultaneously.  Provides a generic and safe interface for
  2646 instrumentalizing code generation.  See
  2647 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  2648 In future you ought to refrain from ad-hoc compiling generated SML
  2649 code on the ML toplevel.  Note that (for technical reasons) @{code}
  2650 cannot refer to constants for which user-defined serializations are
  2651 set.  Refer to the corresponding ML counterpart directly in that
  2652 cases.
  2653 
  2654 * Command 'rep_datatype': instead of theorem names the command now
  2655 takes a list of terms denoting the constructors of the type to be
  2656 represented as datatype.  The characteristic theorems have to be
  2657 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  2658 have disappeared in favour of existing ones:
  2659 
  2660     unit_induct                 ~> unit.induct
  2661     prod_induct                 ~> prod.induct
  2662     sum_induct                  ~> sum.induct
  2663     Suc_Suc_eq                  ~> nat.inject
  2664     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  2665 
  2666 
  2667 *** HOL-Algebra ***
  2668 
  2669 * New locales for orders and lattices where the equivalence relation
  2670 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  2671 locales use a record structure with field eq for the equivalence.
  2672 
  2673 * New theory of factorial domains.
  2674 
  2675 * Units_l_inv and Units_r_inv are now simp rules by default.
  2676 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  2677 and/or r_inv will now also require deletion of these lemmas.
  2678 
  2679 * Renamed the following theorems, INCOMPATIBILITY:
  2680 
  2681 UpperD ~> Upper_memD
  2682 LowerD ~> Lower_memD
  2683 least_carrier ~> least_closed
  2684 greatest_carrier ~> greatest_closed
  2685 greatest_Lower_above ~> greatest_Lower_below
  2686 one_zero ~> carrier_one_zero
  2687 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  2688 
  2689 
  2690 *** HOL-Nominal ***
  2691 
  2692 * Nominal datatypes can now contain type-variables.
  2693 
  2694 * Commands 'nominal_inductive' and 'equivariance' work with local
  2695 theory targets.
  2696 
  2697 * Nominal primrec can now works with local theory targets and its
  2698 specification syntax now conforms to the general format as seen in
  2699 'inductive' etc.
  2700 
  2701 * Method "perm_simp" honours the standard simplifier attributes
  2702 (no_asm), (no_asm_use) etc.
  2703 
  2704 * The new predicate #* is defined like freshness, except that on the
  2705 left hand side can be a set or list of atoms.
  2706 
  2707 * Experimental command 'nominal_inductive2' derives strong induction
  2708 principles for inductive definitions.  In contrast to
  2709 'nominal_inductive', which can only deal with a fixed number of
  2710 binders, it can deal with arbitrary expressions standing for sets of
  2711 atoms to be avoided.  The only inductive definition we have at the
  2712 moment that needs this generalisation is the typing rule for Lets in
  2713 the algorithm W:
  2714 
  2715  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  2716  -----------------------------------------------------------------
  2717          Gamma |- Let x be t1 in t2 : T2
  2718 
  2719 In this rule one wants to avoid all the binders that are introduced by
  2720 "close Gamma T1".  We are looking for other examples where this
  2721 feature might be useful.  Please let us know.
  2722 
  2723 
  2724 *** HOLCF ***
  2725 
  2726 * Reimplemented the simplification procedure for proving continuity
  2727 subgoals.  The new simproc is extensible; users can declare additional
  2728 continuity introduction rules with the attribute [cont2cont].
  2729 
  2730 * The continuity simproc now uses a different introduction rule for
  2731 solving continuity subgoals on terms with lambda abstractions.  In
  2732 some rare cases the new simproc may fail to solve subgoals that the
  2733 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  2734 Potential INCOMPATIBILITY.
  2735 
  2736 * Command 'fixrec': specification syntax now conforms to the general
  2737 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  2738 examples.  INCOMPATIBILITY.
  2739 
  2740 
  2741 *** ZF ***
  2742 
  2743 * Proof of Zorn's Lemma for partial orders.
  2744 
  2745 
  2746 *** ML ***
  2747 
  2748 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  2749 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  2750 depends on multithreading, so timouts will not work before Poly/ML
  2751 5.2.1!
  2752 
  2753 * High-level support for concurrent ML programming, see
  2754 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  2755 particularly convenient to organize independent functional
  2756 computations.  The concept of "synchronized variables" provides a
  2757 higher-order interface for components with shared state, avoiding the
  2758 delicate details of mutexes and condition variables.  (Requires
  2759 Poly/ML 5.2.1 or later.)
  2760 
  2761 * ML bindings produced via Isar commands are stored within the Isar
  2762 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  2763 become thread-safe and work with undo as expected (concerning
  2764 top-level bindings, not side-effects on global references).
  2765 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  2766 compiler at runtime; really global bindings need to be given outside a
  2767 theory.  (Requires Poly/ML 5.2 or later.)
  2768 
  2769 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  2770 context.  Top-level ML bindings are stored within the proof context in
  2771 a purely sequential fashion, disregarding the nested proof structure.
  2772 ML bindings introduced by 'ML_prf' are discarded at the end of the
  2773 proof.  (Requires Poly/ML 5.2 or later.)
  2774 
  2775 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  2776 and Method.setup, as well as Isar commands 'attribute_setup' and
  2777 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  2778 existing code accordingly, or use plain 'setup' together with old
  2779 Method.add_method.
  2780 
  2781 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  2782 to 'a -> thm, while results are always tagged with an authentic oracle
  2783 name.  The Isar command 'oracle' is now polymorphic, no argument type
  2784 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  2785 accordingly.  Note that extra performance may be gained by producing
  2786 the cterm carefully, avoiding slow Thm.cterm_of.
  2787 
  2788 * Simplified interface for defining document antiquotations via
  2789 ThyOutput.antiquotation, ThyOutput.output, and optionally
  2790 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  2791 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  2792 examples.
  2793 
  2794 * More systematic treatment of long names, abstract name bindings, and
  2795 name space operations.  Basic operations on qualified names have been
  2796 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  2797 Long_Name.append.  Old type bstring has been mostly replaced by
  2798 abstract type binding (see structure Binding), which supports precise
  2799 qualification by packages and local theory targets, as well as proper
  2800 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  2801 bstring values into Binding.name, or better pass through abstract
  2802 bindings everywhere.  See further src/Pure/General/long_name.ML,
  2803 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  2804 
  2805 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  2806 LocalTheory.note etc.) now refer to the *full* internal name, not the
  2807 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  2808 
  2809 * Disposed old type and term read functions (Sign.read_def_typ,
  2810 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  2811 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  2812 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  2813 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  2814 resort for legacy applications.
  2815 
  2816 * Disposed old declarations, tactics, tactic combinators that refer to
  2817 the simpset or claset of an implicit theory (such as Addsimps,
  2818 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  2819 embedded ML text, or local_simpset_of with a proper context passed as
  2820 explicit runtime argument.
  2821 
  2822 * Rules and tactics that read instantiations (read_instantiate,
  2823 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  2824 context, which is required for parsing and type-checking.  Moreover,
  2825 the variables are specified as plain indexnames, not string encodings
  2826 thereof.  INCOMPATIBILITY.
  2827 
  2828 * Generic Toplevel.add_hook interface allows to analyze the result of
  2829 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  2830 for theorem dependency output of transactions resulting in a new
  2831 theory state.
  2832 
  2833 * ML antiquotations: block-structured compilation context indicated by
  2834 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  2835 
  2836   @{binding name}                         - basic name binding
  2837   @{let ?pat = term}                      - term abbreviation (HO matching)
  2838   @{note name = fact}                     - fact abbreviation
  2839   @{thm fact}                             - singleton fact (with attributes)
  2840   @{thms fact}                            - general fact (with attributes)
  2841   @{lemma prop by method}                 - singleton goal
  2842   @{lemma prop by meth1 meth2}            - singleton goal
  2843   @{lemma prop1 ... propN by method}      - general goal
  2844   @{lemma prop1 ... propN by meth1 meth2} - general goal
  2845   @{lemma (open) ...}                     - open derivation
  2846 
  2847 
  2848 *** System ***
  2849 
  2850 * The Isabelle "emacs" tool provides a specific interface to invoke
  2851 Proof General / Emacs, with more explicit failure if that is not
  2852 installed (the old isabelle-interface script silently falls back on
  2853 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  2854 installation location of the Proof General distribution.
  2855 
  2856 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  2857 the Isabelle process into a JVM/Scala application.  See
  2858 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  2859 process wrapper has been discontinued.)
  2860 
  2861 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  2862 
  2863 * Various status messages (with exact source position information) are
  2864 emitted, if proper markup print mode is enabled.  This allows
  2865 user-interface components to provide detailed feedback on internal
  2866 prover operations.
  2867 
  2868 
  2869 
  2870 New in Isabelle2008 (June 2008)
  2871 -------------------------------
  2872 
  2873 *** General ***
  2874 
  2875 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  2876 and updated, with formally checked references as hyperlinks.
  2877 
  2878 * Theory loader: use_thy (and similar operations) no longer set the
  2879 implicit ML context, which was occasionally hard to predict and in
  2880 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  2881 provides a proper context already.
  2882 
  2883 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2884 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  2885 'use' within a theory file will do the job.
  2886 
  2887 * Name space merge now observes canonical order, i.e. the second space
  2888 is inserted into the first one, while existing entries in the first
  2889 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  2890 swap theory imports.
  2891 
  2892 * Syntax: symbol \<chi> is now considered a letter.  Potential
  2893 INCOMPATIBILITY in identifier syntax etc.
  2894 
  2895 * Outer syntax: string tokens no longer admit escaped white space,
  2896 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  2897 white space without escapes.
  2898 
  2899 * Outer syntax: string tokens may contain arbitrary character codes
  2900 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  2901 "foo_bar".
  2902 
  2903 
  2904 *** Pure ***
  2905 
  2906 * Context-dependent token translations.  Default setup reverts locally
  2907 fixed variables, and adds hilite markup for undeclared frees.
  2908 
  2909 * Unused theorems can be found using the new command 'unused_thms'.
  2910 There are three ways of invoking it:
  2911 
  2912 (1) unused_thms
  2913      Only finds unused theorems in the current theory.
  2914 
  2915 (2) unused_thms thy_1 ... thy_n -
  2916      Finds unused theorems in the current theory and all of its ancestors,
  2917      excluding the theories thy_1 ... thy_n and all of their ancestors.
  2918 
  2919 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  2920      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  2921      their ancestors, excluding the theories thy_1 ... thy_n and all of
  2922      their ancestors.
  2923 
  2924 In order to increase the readability of the list produced by
  2925 unused_thms, theorems that have been created by a particular instance
  2926 of a theory command such as 'inductive' or 'function' are considered
  2927 to belong to the same "group", meaning that if at least one theorem in
  2928 this group is used, the other theorems in the same group are no longer
  2929 reported as unused.  Moreover, if all theorems in the group are
  2930 unused, only one theorem in the group is displayed.
  2931 
  2932 Note that proof objects have to be switched on in order for
  2933 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  2934 usually the case when using Proof General with the default settings).
  2935 
  2936 * Authentic naming of facts disallows ad-hoc overwriting of previous
  2937 theorems within the same name space.  INCOMPATIBILITY, need to remove
  2938 duplicate fact bindings, or even accidental fact duplications.  Note
  2939 that tools may maintain dynamically scoped facts systematically, using
  2940 PureThy.add_thms_dynamic.
  2941 
  2942 * Command 'hide' now allows to hide from "fact" name space as well.
  2943 
  2944 * Eliminated destructive theorem database, simpset, claset, and
  2945 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  2946 update of theories within ML code.
  2947 
  2948 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  2949 INCOMPATIBILITY, object-logics depending on former Pure require
  2950 additional setup PureThy.old_appl_syntax_setup; object-logics
  2951 depending on former CPure need to refer to Pure.
  2952 
  2953 * Commands 'use' and 'ML' are now purely functional, operating on
  2954 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  2955 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  2956 INCOMPATIBILITY.
  2957 
  2958 * Command 'setup': discontinued implicit version with ML reference.
  2959 
  2960 * Instantiation target allows for simultaneous specification of class
  2961 instance operations together with an instantiation proof.
  2962 Type-checking phase allows to refer to class operations uniformly.
  2963 See src/HOL/Complex/Complex.thy for an Isar example and
  2964 src/HOL/Library/Eval.thy for an ML example.
  2965 
  2966 * Indexing of literal facts: be more serious about including only
  2967 facts from the visible specification/proof context, but not the
  2968 background context (locale etc.).  Affects `prop` notation and method
  2969 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  2970 situations.
  2971 
  2972 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  2973 "(open)" option, which used to expose internal bound variables to the
  2974 proof text.
  2975 
  2976 * Isar statements: removed obsolete case "rule_context".
  2977 INCOMPATIBILITY, better use explicit fixes/assumes.
  2978 
  2979 * Locale proofs: default proof step now includes 'unfold_locales';
  2980 hence 'proof' without argument may be used to unfold locale
  2981 predicates.
  2982 
  2983 
  2984 *** Document preparation ***
  2985 
  2986 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  2987 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  2988 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  2989 spot); renamed link color from "darkblue" to "linkcolor" (default
  2990 value unchanged, can be redefined via \definecolor); no longer sets
  2991 "a4paper" option (unnecessary or even intrusive).
  2992 
  2993 * Antiquotation @{lemma A method} proves proposition A by the given
  2994 method (either a method name or a method name plus (optional) method
  2995 arguments in parentheses) and prints A just like @{prop A}.
  2996 
  2997 
  2998 *** HOL ***
  2999 
  3000 * New primrec package.  Specification syntax conforms in style to
  3001 definition/function/....  No separate induction rule is provided.  The
  3002 "primrec" command distinguishes old-style and new-style specifications
  3003 by syntax.  The former primrec package is now named OldPrimrecPackage.
  3004 When adjusting theories, beware: constants stemming from new-style
  3005 primrec specifications have authentic syntax.
  3006 
  3007 * Metis prover is now an order of magnitude faster, and also works
  3008 with multithreading.
  3009 
  3010 * Metis: the maximum number of clauses that can be produced from a
  3011 theorem is now given by the attribute max_clauses.  Theorems that
  3012 exceed this number are ignored, with a warning printed.
  3013 
  3014 * Sledgehammer no longer produces structured proofs by default. To
  3015 enable, declare [[sledgehammer_full = true]].  Attributes
  3016 reconstruction_modulus, reconstruction_sorts renamed
  3017 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  3018 
  3019 * Method "induct_scheme" derives user-specified induction rules
  3020 from well-founded induction and completeness of patterns. This factors
  3021 out some operations that are done internally by the function package
  3022 and makes them available separately.  See
  3023 src/HOL/ex/Induction_Scheme.thy for examples.
  3024 
  3025 * More flexible generation of measure functions for termination
  3026 proofs: Measure functions can be declared by proving a rule of the
  3027 form "is_measure f" and giving it the [measure_function] attribute.
  3028 The "is_measure" predicate is logically meaningless (always true), and
  3029 just guides the heuristic.  To find suitable measure functions, the
  3030 termination prover sets up the goal "is_measure ?f" of the appropriate
  3031 type and generates all solutions by prolog-style backwards proof using
  3032 the declared rules.
  3033 
  3034 This setup also deals with rules like 
  3035 
  3036   "is_measure f ==> is_measure (list_size f)"
  3037 
  3038 which accommodates nested datatypes that recurse through lists.
  3039 Similar rules are predeclared for products and option types.
  3040 
  3041 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  3042 
  3043   INCOMPATIBILITIES:
  3044 
  3045   - Definitions of overloaded constants on sets have to be replaced by
  3046     definitions on => and bool.
  3047 
  3048   - Some definitions of overloaded operators on sets can now be proved
  3049     using the definitions of the operators on => and bool.  Therefore,
  3050     the following theorems have been renamed:
  3051 
  3052       subset_def   -> subset_eq
  3053       psubset_def  -> psubset_eq
  3054       set_diff_def -> set_diff_eq
  3055       Compl_def    -> Compl_eq
  3056       Sup_set_def  -> Sup_set_eq
  3057       Inf_set_def  -> Inf_set_eq
  3058       sup_set_def  -> sup_set_eq
  3059       inf_set_def  -> inf_set_eq
  3060 
  3061   - Due to the incompleteness of the HO unification algorithm, some
  3062     rules such as subst may require manual instantiation, if some of
  3063     the unknowns in the rule is a set.
  3064 
  3065   - Higher order unification and forward proofs:
  3066     The proof pattern
  3067 
  3068       have "P (S::'a set)" <...>
  3069       then have "EX S. P S" ..
  3070 
  3071     no longer works (due to the incompleteness of the HO unification
  3072     algorithm) and must be replaced by the pattern
  3073 
  3074       have "EX S. P S"
  3075       proof
  3076         show "P S" <...>
  3077       qed
  3078 
  3079   - Calculational reasoning with subst (or similar rules):
  3080     The proof pattern
  3081 
  3082       have "P (S::'a set)" <...>
  3083       also have "S = T" <...>
  3084       finally have "P T" .
  3085 
  3086     no longer works (for similar reasons as the previous example) and
  3087     must be replaced by something like
  3088 
  3089       have "P (S::'a set)" <...>
  3090       moreover have "S = T" <...>
  3091       ultimately have "P T" by simp
  3092 
  3093   - Tactics or packages written in ML code:
  3094     Code performing pattern matching on types via
  3095 
  3096       Type ("set", [T]) => ...
  3097 
  3098     must be rewritten. Moreover, functions like strip_type or
  3099     binder_types no longer return the right value when applied to a
  3100     type of the form
  3101 
  3102       T1 => ... => Tn => U => bool
  3103 
  3104     rather than
  3105 
  3106       T1 => ... => Tn => U set
  3107 
  3108 * Merged theories Wellfounded_Recursion, Accessible_Part and
  3109 Wellfounded_Relations to theory Wellfounded.
  3110 
  3111 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  3112 
  3113 * Class finite no longer treats UNIV as class parameter.  Use class
  3114 enum from theory Library/Enum instead to achieve a similar effect.
  3115 INCOMPATIBILITY.
  3116 
  3117 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  3118 and "Cons".  INCOMPATIBILITY.
  3119 
  3120 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  3121 Potential INCOMPATIBILITY.
  3122 
  3123 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  3124 injective_fst_snd removed, use split_eta and prod_eqI instead.
  3125 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  3126 
  3127 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  3128 the same name in theory Orderings:
  3129 
  3130   less_trans
  3131   less_linear
  3132   le_imp_less_or_eq
  3133   le_less_trans
  3134   less_le_trans
  3135   less_not_sym
  3136   less_asym
  3137 
  3138 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  3139 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  3140 and different variable names.
  3141 
  3142 * Library/Option_ord.thy: Canonical order on option type.
  3143 
  3144 * Library/RBT.thy: Red-black trees, an efficient implementation of
  3145 finite maps.
  3146 
  3147 * Library/Countable.thy: Type class for countable types.
  3148 
  3149 * Theory Int: The representation of numerals has changed.  The infix
  3150 operator BIT and the bit datatype with constructors B0 and B1 have
  3151 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  3152 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  3153 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  3154 accordingly.
  3155 
  3156 * Theory Nat: definition of <= and < on natural numbers no longer
  3157 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  3158 le_def and less_def have disappeared.  Consider lemmas not_less
  3159 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  3160 
  3161 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  3162 (whose purpose mainly is for various fold_set functionals) have been
  3163 abandoned in favor of the existing algebraic classes
  3164 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  3165 lower_semilattice (resp. upper_semilattice) and linorder.
  3166 INCOMPATIBILITY.
  3167 
  3168 * Theory Transitive_Closure: induct and cases rules now declare proper
  3169 case_names ("base" and "step").  INCOMPATIBILITY.
  3170 
  3171 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  3172 lattices.  The form set-specific version is available as
  3173 Inductive.lfp_ordinal_induct_set.
  3174 
  3175 * Renamed theorems "power.simps" to "power_int.simps".
  3176 INCOMPATIBILITY.
  3177 
  3178 * Class semiring_div provides basic abstract properties of semirings
  3179 with division and modulo operations.  Subsumes former class dvd_mod.
  3180 
  3181 * Merged theories IntDef, Numeral and IntArith into unified theory
  3182 Int.  INCOMPATIBILITY.
  3183 
  3184 * Theory Library/Code_Index: type "index" now represents natural
  3185 numbers rather than integers.  INCOMPATIBILITY.
  3186 
  3187 * New class "uminus" with operation "uminus" (split of from class
  3188 "minus" which now only has operation "minus", binary).
  3189 INCOMPATIBILITY.
  3190 
  3191 * Constants "card", "internal_split", "option_map" now with authentic
  3192 syntax.  INCOMPATIBILITY.
  3193 
  3194 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  3195 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  3196 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  3197 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  3198 Sup_set_def, le_def, less_def, option_map_def now with object
  3199 equality.  INCOMPATIBILITY.
  3200 
  3201 * Records. Removed K_record, and replaced it by pure lambda term
  3202 %x. c. The simplifier setup is now more robust against eta expansion.
  3203 INCOMPATIBILITY: in cases explicitly referring to K_record.
  3204 
  3205 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  3206 
  3207 * Library/ListVector: new theory of arithmetic vector operations.
  3208 
  3209 * Library/Order_Relation: new theory of various orderings as sets of
  3210 pairs.  Defines preorders, partial orders, linear orders and
  3211 well-orders on sets and on types.
  3212 
  3213 
  3214 *** ZF ***
  3215 
  3216 * Renamed some theories to allow to loading both ZF and HOL in the
  3217 same session:
  3218 
  3219   Datatype  -> Datatype_ZF
  3220   Inductive -> Inductive_ZF
  3221   Int       -> Int_ZF
  3222   IntDiv    -> IntDiv_ZF
  3223   Nat       -> Nat_ZF
  3224   List      -> List_ZF
  3225   Main      -> Main_ZF
  3226 
  3227 INCOMPATIBILITY: ZF theories that import individual theories below
  3228 Main might need to be adapted.  Regular theory Main is still
  3229 available, as trivial extension of Main_ZF.
  3230 
  3231 
  3232 *** ML ***
  3233 
  3234 * ML within Isar: antiquotation @{const name} or @{const
  3235 name(typargs)} produces statically-checked Const term.
  3236 
  3237 * Functor NamedThmsFun: data is available to the user as dynamic fact
  3238 (of the same name).  Removed obsolete print command.
  3239 
  3240 * Removed obsolete "use_legacy_bindings" function.
  3241 
  3242 * The ``print mode'' is now a thread-local value derived from a global
  3243 template (the former print_mode reference), thus access becomes
  3244 non-critical.  The global print_mode reference is for session
  3245 management only; user-code should use print_mode_value,
  3246 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  3247 
  3248 * Functions system/system_out provide a robust way to invoke external
  3249 shell commands, with propagation of interrupts (requires Poly/ML
  3250 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  3251 
  3252 
  3253 *** System ***
  3254 
  3255 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  3256 in accordance with Proof General 3.7, which prefers GNU emacs.
  3257 
  3258 * isatool tty runs Isabelle process with plain tty interaction;
  3259 optional line editor may be specified via ISABELLE_LINE_EDITOR
  3260 setting, the default settings attempt to locate "ledit" and "rlwrap".
  3261 
  3262 * isatool browser now works with Cygwin as well, using general
  3263 "javapath" function defined in Isabelle process environment.
  3264 
  3265 * YXML notation provides a simple and efficient alternative to
  3266 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  3267 isatool yxml as described in the Isabelle system manual.
  3268 
  3269 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  3270 provides general wrapper for managing an Isabelle process in a robust
  3271 fashion, with ``cooked'' output from stdin/stderr.
  3272 
  3273 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  3274 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  3275 
  3276 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  3277 way of changing the user's settings is via
  3278 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  3279 script.
  3280 
  3281 * Multithreading.max_threads := 0 refers to the number of actual CPU
  3282 cores of the underlying machine, which is a good starting point for
  3283 optimal performance tuning.  The corresponding usedir option -M allows
  3284 "max" as an alias for "0".  WARNING: does not work on certain versions
  3285 of Mac OS (with Poly/ML 5.1).
  3286 
  3287 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  3288 adverse effect of Isabelle flooding interactive front-ends (notably
  3289 ProofGeneral / XEmacs).
  3290 
  3291 
  3292 
  3293 New in Isabelle2007 (November 2007)
  3294 -----------------------------------
  3295 
  3296 *** General ***
  3297 
  3298 * More uniform information about legacy features, notably a
  3299 warning/error of "Legacy feature: ...", depending on the state of the
  3300 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  3301 legacy features will disappear eventually.
  3302 
  3303 * Theory syntax: the header format ``theory A = B + C:'' has been
  3304 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  3305 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  3306 
  3307 * Theory syntax: the old non-Isar theory file format has been
  3308 discontinued altogether.  Note that ML proof scripts may still be used
  3309 with Isar theories; migration is usually quite simple with the ML
  3310 function use_legacy_bindings.  INCOMPATIBILITY.
  3311 
  3312 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  3313 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  3314 quotes.
  3315 
  3316 * Theory loader: be more serious about observing the static theory
  3317 header specifications (including optional directories), but not the
  3318 accidental file locations of previously successful loads.  The strict
  3319 update policy of former update_thy is now already performed by
  3320 use_thy, so the former has been removed; use_thys updates several
  3321 theories simultaneously, just as 'imports' within a theory header
  3322 specification, but without merging the results.  Potential
  3323 INCOMPATIBILITY: may need to refine theory headers and commands
  3324 ROOT.ML which depend on load order.
  3325 
  3326 * Theory loader: optional support for content-based file
  3327 identification, instead of the traditional scheme of full physical
  3328 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  3329 (cf. the system manual).  The new scheme allows to work with
  3330 non-finished theories in persistent session images, such that source
  3331 files may be moved later on without requiring reloads.
  3332 
  3333 * Theory loader: old-style ML proof scripts being *attached* to a thy
  3334 file (with the same base name as the theory) are considered a legacy
  3335 feature, which will disappear eventually. Even now, the theory loader
  3336 no longer maintains dependencies on such files.
  3337 
  3338 * Syntax: the scope for resolving ambiguities via type-inference is
  3339 now limited to individual terms, instead of whole simultaneous
  3340 specifications as before. This greatly reduces the complexity of the
  3341 syntax module and improves flexibility by separating parsing and
  3342 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  3343 'fixes' etc.) are required in rare situations.
  3344 
  3345 * Syntax: constants introduced by new-style packages ('definition',
  3346 'abbreviation' etc.) are passed through the syntax module in
  3347 ``authentic mode''. This means that associated mixfix annotations
  3348 really stick to such constants, independently of potential name space
  3349 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  3350 trees are represented slightly differently, may need to adapt syntax
  3351 translations accordingly. Use CONST marker in 'translations' and
  3352 @{const_syntax} antiquotation in 'parse_translation' etc.
  3353 
  3354 * Legacy goal package: reduced interface to the bare minimum required
  3355 to keep existing proof scripts running.  Most other user-level
  3356 functions are now part of the OldGoals structure, which is *not* open
  3357 by default (consider isatool expandshort before open OldGoals).
  3358 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  3359 these tend to cause confusion about the actual goal (!) context being
  3360 used here, which is not necessarily the same as the_context().
  3361 
  3362 * Command 'find_theorems': supports "*" wild-card in "name:"
  3363 criterion; "with_dups" option.  Certain ProofGeneral versions might
  3364 support a specific search form (see ProofGeneral/CHANGES).
  3365 
  3366 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  3367 by default, which means that "prems" (and also "fixed variables") are
  3368 suppressed from proof state output.  Note that the ProofGeneral
  3369 settings mechanism allows to change and save options persistently, but
  3370 older versions of Isabelle will fail to start up if a negative prems
  3371 limit is imposed.
  3372 
  3373 * Local theory targets may be specified by non-nested blocks of
  3374 ``context/locale/class ... begin'' followed by ``end''.  The body may
  3375 contain definitions, theorems etc., including any derived mechanism
  3376 that has been implemented on top of these primitives.  This concept
  3377 generalizes the existing ``theorem (in ...)'' towards more versatility
  3378 and scalability.
  3379 
  3380 * Proof General interface: proper undo of final 'end' command;
  3381 discontinued Isabelle/classic mode (ML proof scripts).
  3382 
  3383 
  3384 *** Document preparation ***
  3385 
  3386 * Added antiquotation @{theory name} which prints the given name,
  3387 after checking that it refers to a valid ancestor theory in the
  3388 current context.
  3389 
  3390 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  3391 check the given source text as ML type/structure, printing verbatim.
  3392 
  3393 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  3394 "c args == rhs" given in the current context.  (Any number of
  3395 arguments may be given on the LHS.)
  3396 
  3397 
  3398 *** Pure ***
  3399 
  3400 * The 'class' package offers a combination of axclass and locale to
  3401 achieve Haskell-like type classes in Isabelle.  Definitions and
  3402 theorems within a class context produce both relative results (with
  3403 implicit parameters according to the locale context), and polymorphic
  3404 constants with qualified polymorphism (according to the class
  3405 context).  Within the body context of a 'class' target, a separate
  3406 syntax layer ("user space type system") takes care of converting
  3407 between global polymorphic consts and internal locale representation.
  3408 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  3409 "isatool doc classes" provides a tutorial.
  3410 
  3411 * Generic code generator framework allows to generate executable
  3412 code for ML and Haskell (including Isabelle classes).  A short usage
  3413 sketch:
  3414 
  3415     internal compilation:
  3416         export_code <list of constants (term syntax)> in SML
  3417     writing SML code to a file:
  3418         export_code <list of constants (term syntax)> in SML <filename>
  3419     writing OCaml code to a file:
  3420         export_code <list of constants (term syntax)> in OCaml <filename>
  3421     writing Haskell code to a bunch of files:
  3422         export_code <list of constants (term syntax)> in Haskell <filename>
  3423 
  3424     evaluating closed propositions to True/False using code generation:
  3425         method ``eval''
  3426 
  3427 Reasonable default setup of framework in HOL.
  3428 
  3429 Theorem attributs for selecting and transforming function equations theorems:
  3430 
  3431     [code fun]:        select a theorem as function equation for a specific constant
  3432     [code fun del]:    deselect a theorem as function equation for a specific constant
  3433     [code inline]:     select an equation theorem for unfolding (inlining) in place
  3434     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  3435 
  3436 User-defined serializations (target in {SML, OCaml, Haskell}):
  3437 
  3438     code_const <and-list of constants (term syntax)>
  3439       {(target) <and-list of const target syntax>}+
  3440 
  3441     code_type <and-list of type constructors>
  3442       {(target) <and-list of type target syntax>}+
  3443 
  3444     code_instance <and-list of instances>
  3445       {(target)}+
  3446         where instance ::= <type constructor> :: <class>
  3447 
  3448     code_class <and_list of classes>
  3449       {(target) <and-list of class target syntax>}+
  3450         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  3451 
  3452 code_instance and code_class only are effective to target Haskell.
  3453 
  3454 For example usage see src/HOL/ex/Codegenerator.thy and
  3455 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  3456 generation from Isabelle/HOL theories is available via "isatool doc
  3457 codegen".
  3458 
  3459 * Code generator: consts in 'consts_code' Isar commands are now
  3460 referred to by usual term syntax (including optional type
  3461 annotations).
  3462 
  3463 * Command 'no_translations' removes translation rules from theory
  3464 syntax.
  3465 
  3466 * Overloaded definitions are now actually checked for acyclic
  3467 dependencies.  The overloading scheme is slightly more general than
  3468 that of Haskell98, although Isabelle does not demand an exact
  3469 correspondence to type class and instance declarations.
  3470 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  3471 exotic versions of overloading -- at the discretion of the user!
  3472 
  3473 Polymorphic constants are represented via type arguments, i.e. the
  3474 instantiation that matches an instance against the most general
  3475 declaration given in the signature.  For example, with the declaration
  3476 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  3477 as c(nat).  Overloading is essentially simultaneous structural
  3478 recursion over such type arguments.  Incomplete specification patterns
  3479 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  3480 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  3481 Command 'print_theory' outputs the normalized system of recursive
  3482 equations, see section "definitions".
  3483 
  3484 * Configuration options are maintained within the theory or proof
  3485 context (with name and type bool/int/string), providing a very simple
  3486 interface to a poor-man's version of general context data.  Tools may
  3487 declare options in ML (e.g. using Attrib.config_int) and then refer to
  3488 these values using Config.get etc.  Users may change options via an
  3489 associated attribute of the same name.  This form of context
  3490 declaration works particularly well with commands 'declare' or
  3491 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  3492 very easy to avoid global references, which would not observe Isar
  3493 toplevel undo/redo and fail to work with multithreading.
  3494 
  3495 Various global ML references of Pure and HOL have been turned into
  3496 configuration options:
  3497 
  3498   Unify.search_bound		unify_search_bound
  3499   Unify.trace_bound		unify_trace_bound
  3500   Unify.trace_simp		unify_trace_simp
  3501   Unify.trace_types		unify_trace_types
  3502   Simplifier.simp_depth_limit	simp_depth_limit
  3503   Blast.depth_limit		blast_depth_limit
  3504   DatatypeProp.dtK		datatype_distinctness_limit
  3505   fast_arith_neq_limit  	fast_arith_neq_limit
  3506   fast_arith_split_limit	fast_arith_split_limit
  3507 
  3508 * Named collections of theorems may be easily installed as context
  3509 data using the functor NamedThmsFun (see also
  3510 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  3511 attributes; there is also a toplevel print command.  This facility is
  3512 just a common case of general context data, which is the preferred way
  3513 for anything more complex than just a list of facts in canonical
  3514 order.
  3515 
  3516 * Isar: command 'declaration' augments a local theory by generic
  3517 declaration functions written in ML.  This enables arbitrary content
  3518 being added to the context, depending on a morphism that tells the
  3519 difference of the original declaration context wrt. the application
  3520 context encountered later on.
  3521 
  3522 * Isar: proper interfaces for simplification procedures.  Command
  3523 'simproc_setup' declares named simprocs (with match patterns, and body
  3524 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  3525 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  3526 
  3527 * Isar: an extra pair of brackets around attribute declarations
  3528 abbreviates a theorem reference involving an internal dummy fact,
  3529 which will be ignored later --- only the effect of the attribute on
  3530 the background context will persist.  This form of in-place
  3531 declarations is particularly useful with commands like 'declare' and
  3532 'using', for example ``have A using [[simproc a]] by simp''.
  3533 
  3534 * Isar: method "assumption" (and implicit closing of subproofs) now
  3535 takes simple non-atomic goal assumptions into account: after applying
  3536 an assumption as a rule the resulting subgoals are solved by atomic
  3537 assumption steps.  This is particularly useful to finish 'obtain'
  3538 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  3539 without referring to the original premise "!!x. P x ==> thesis" in the
  3540 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  3541 more permissive.
  3542 
  3543 * Isar: implicit use of prems from the Isar proof context is
  3544 considered a legacy feature.  Common applications like ``have A .''
  3545 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  3546 referencing facts explicitly here improves readability and
  3547 maintainability of proof texts.
  3548 
  3549 * Isar: improper proof element 'guess' is like 'obtain', but derives
  3550 the obtained context from the course of reasoning!  For example:
  3551 
  3552   assume "EX x y. A x & B y"   -- "any previous fact"
  3553   then guess x and y by clarify
  3554 
  3555 This technique is potentially adventurous, depending on the facts and
  3556 proof tools being involved here.
  3557 
  3558 * Isar: known facts from the proof context may be specified as literal
  3559 propositions, using ASCII back-quote syntax.  This works wherever
  3560 named facts used to be allowed so far, in proof commands, proof
  3561 methods, attributes etc.  Literal facts are retrieved from the context
  3562 according to unification of type and term parameters.  For example,
  3563 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  3564 theorems in the current context, then these are valid literal facts:
  3565 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  3566 
  3567 There is also a proof method "fact" which does the same composition
  3568 for explicit goal states, e.g. the following proof texts coincide with
  3569 certain special cases of literal facts:
  3570 
  3571   have "A" by fact                 ==  note `A`
  3572   have "A ==> B" by fact           ==  note `A ==> B`
  3573   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  3574   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  3575 
  3576 * Isar: ":" (colon) is no longer a symbolic identifier character in
  3577 outer syntax.  Thus symbolic identifiers may be used without
  3578 additional white space in declarations like this: ``assume *: A''.
  3579 
  3580 * Isar: 'print_facts' prints all local facts of the current context,
  3581 both named and unnamed ones.
  3582 
  3583 * Isar: 'def' now admits simultaneous definitions, e.g.:
  3584 
  3585   def x == "t" and y == "u"
  3586 
  3587 * Isar: added command 'unfolding', which is structurally similar to
  3588 'using', but affects both the goal state and facts by unfolding given
  3589 rewrite rules.  Thus many occurrences of the 'unfold' method or
  3590 'unfolded' attribute may be replaced by first-class proof text.
  3591 
  3592 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  3593 and command 'unfolding' now all support object-level equalities
  3594 (potentially conditional).  The underlying notion of rewrite rule is
  3595 analogous to the 'rule_format' attribute, but *not* that of the
  3596 Simplifier (which is usually more generous).
  3597 
  3598 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  3599 premises of a theorem by n. Useful in conjunction with drule.
  3600 
  3601 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  3602 method expression within a sandbox consisting of the first N
  3603 sub-goals, which need to exist.  For example, ``simp_all [3]''
  3604 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  3605 simplifies all new goals that emerge from applying rule foo to the
  3606 originally first one.
  3607 
  3608 * Isar: schematic goals are no longer restricted to higher-order
  3609 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  3610 expected.
  3611 
  3612 * Isar: the conclusion of a long theorem statement is now either
  3613 'shows' (a simultaneous conjunction, as before), or 'obtains'
  3614 (essentially a disjunction of cases with local parameters and
  3615 assumptions).  The latter allows to express general elimination rules
  3616 adequately; in this notation common elimination rules look like this:
  3617 
  3618   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  3619     assumes "EX x. P x"
  3620     obtains x where "P x"
  3621 
  3622   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  3623     assumes "A & B"
  3624     obtains A and B
  3625 
  3626   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  3627     assumes "A | B"
  3628     obtains
  3629       A
  3630     | B
  3631 
  3632 The subsequent classical rules even refer to the formal "thesis"
  3633 explicitly:
  3634 
  3635   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  3636     obtains "~ thesis"
  3637 
  3638   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  3639     obtains "thesis ==> something"
  3640 
  3641 The actual proof of an 'obtains' statement is analogous to that of the
  3642 Isar proof element 'obtain', only that there may be several cases.
  3643 Optional case names may be specified in parentheses; these will be
  3644 available both in the present proof and as annotations in the
  3645 resulting rule, for later use with the 'cases' method (cf. attribute
  3646 case_names).
  3647 
  3648 * Isar: the assumptions of a long theorem statement are available as
  3649 "assms" fact in the proof context.  This is more appropriate than the
  3650 (historical) "prems", which refers to all assumptions of the current
  3651 context, including those from the target locale, proof body etc.
  3652 
  3653 * Isar: 'print_statement' prints theorems from the current theory or
  3654 proof context in long statement form, according to the syntax of a
  3655 top-level lemma.
  3656 
  3657 * Isar: 'obtain' takes an optional case name for the local context
  3658 introduction rule (default "that").
  3659 
  3660 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  3661 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  3662 to occur.
  3663 
  3664 * Pure: syntax "CONST name" produces a fully internalized constant
  3665 according to the current context.  This is particularly useful for
  3666 syntax translations that should refer to internal constant
  3667 representations independently of name spaces.
  3668 
  3669 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  3670 instead of "FOO ". This allows multiple binder declarations to coexist
  3671 in the same context.  INCOMPATIBILITY.
  3672 
  3673 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  3674 primitive that also works in a locale context (both for constants and
  3675 fixed variables). Type declaration and internal syntactic representation
  3676 of given constants retrieved from the context. Likewise, the
  3677 'no_notation' command allows to remove given syntax annotations from the
  3678 current context.
  3679 
  3680 * Isar/locales: new derived specification elements 'axiomatization',
  3681 'definition', 'abbreviation', which support type-inference, admit
  3682 object-level specifications (equality, equivalence).  See also the
  3683 isar-ref manual.  Examples:
  3684 
  3685   axiomatization
  3686     eq  (infix "===" 50) where
  3687     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  3688 
  3689   definition "f x y = x + y + 1"
  3690   definition g where "g x = f x x"
  3691 
  3692   abbreviation
  3693     neq  (infix "=!=" 50) where
  3694     "x =!= y == ~ (x === y)"
  3695 
  3696 These specifications may be also used in a locale context.  Then the
  3697 constants being introduced depend on certain fixed parameters, and the
  3698 constant name is qualified by the locale base name.  An internal
  3699 abbreviation takes care for convenient input and output, making the
  3700 parameters implicit and using the original short name.  See also
  3701 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  3702 entities from a monomorphic theory.
  3703 
  3704 Presently, abbreviations are only available 'in' a target locale, but
  3705 not inherited by general import expressions.  Also note that
  3706 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  3707 'translations' in common applications.  The "no_abbrevs" print mode
  3708 prevents folding of abbreviations in term output.
  3709 
  3710 Concrete syntax is attached to specified constants in internal form,
  3711 independently of name spaces.  The parse tree representation is
  3712 slightly different -- use 'notation' instead of raw 'syntax', and
  3713 'translations' with explicit "CONST" markup to accommodate this.
  3714 
  3715 * Pure/Isar: unified syntax for new-style specification mechanisms
  3716 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  3717 full type inference and dummy patterns ("_").  For example:
  3718 
  3719   definition "K x _ = x"
  3720 
  3721   inductive conj for A B
  3722   where "A ==> B ==> conj A B"
  3723 
  3724 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  3725 the current context.  Print mode "no_abbrevs" prevents inversion of
  3726 abbreviations on output.
  3727 
  3728 * Isar/locales: improved parameter handling: use of locales "var" and
  3729 "struct" no longer necessary; - parameter renamings are no longer
  3730 required to be injective.  For example, this allows to define
  3731 endomorphisms as locale endom = homom mult mult h.
  3732 
  3733 * Isar/locales: changed the way locales with predicates are defined.
  3734 Instead of accumulating the specification, the imported expression is
  3735 now an interpretation.  INCOMPATIBILITY: different normal form of
  3736 locale expressions.  In particular, in interpretations of locales with
  3737 predicates, goals repesenting already interpreted fragments are not
  3738 removed automatically.  Use methods `intro_locales' and
  3739 `unfold_locales'; see below.
  3740 
  3741 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  3742 provide backward reasoning on locales predicates.  The methods are
  3743 aware of interpretations and discharge corresponding goals.
  3744 `intro_locales' is less aggressive then `unfold_locales' and does not
  3745 unfold predicates to assumptions.
  3746 
  3747 * Isar/locales: the order in which locale fragments are accumulated
  3748 has changed.  This enables to override declarations from fragments due
  3749 to interpretations -- for example, unwanted simp rules.
  3750 
  3751 * Isar/locales: interpretation in theories and proof contexts has been
  3752 extended.  One may now specify (and prove) equations, which are
  3753 unfolded in interpreted theorems.  This is useful for replacing
  3754 defined concepts (constants depending on locale parameters) by
  3755 concepts already existing in the target context.  Example:
  3756 
  3757   interpretation partial_order ["op <= :: [int, int] => bool"]
  3758     where "partial_order.less (op <=) (x::int) y = (x < y)"
  3759 
  3760 Typically, the constant `partial_order.less' is created by a
  3761 definition specification element in the context of locale
  3762 partial_order.
  3763 
  3764 * Method "induct": improved internal context management to support
  3765 local fixes and defines on-the-fly. Thus explicit meta-level
  3766 connectives !!  and ==> are rarely required anymore in inductive goals
  3767 (using object-logic connectives for this purpose has been long
  3768 obsolete anyway). Common proof patterns are explained in
  3769 src/HOL/Induct/Common_Patterns.thy, see also
  3770 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  3771 examples.
  3772 
  3773 * Method "induct": improved handling of simultaneous goals. Instead of
  3774 introducing object-level conjunction, the statement is now split into
  3775 several conclusions, while the corresponding symbolic cases are nested
  3776 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  3777 see src/HOL/Induct/Common_Patterns.thy, for example.
  3778 
  3779 * Method "induct": mutual induction rules are now specified as a list
  3780 of rule sharing the same induction cases. HOL packages usually provide
  3781 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  3782 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  3783 mutual induction rules differently, i.e. like this:
  3784 
  3785   (induct rule: foo_bar.inducts)
  3786   (induct set: foo bar)
  3787   (induct pred: foo bar)
  3788   (induct type: foo bar)
  3789 
  3790 The ML function ProjectRule.projections turns old-style rules into the
  3791 new format.
  3792 
  3793 * Method "coinduct": dual of induction, see
  3794 src/HOL/Library/Coinductive_List.thy for various examples.
  3795 
  3796 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  3797 considered a legacy feature.
  3798 
  3799 * Attribute "symmetric" produces result with standardized schematic
  3800 variables (index 0).  Potential INCOMPATIBILITY.
  3801 
  3802 * Simplifier: by default the simplifier trace only shows top level
  3803 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  3804 default. Thus there is less danger of being flooded by the trace. The
  3805 trace indicates where parts have been suppressed.
  3806   
  3807 * Provers/classical: removed obsolete classical version of elim_format
  3808 attribute; classical elim/dest rules are now treated uniformly when
  3809 manipulating the claset.
  3810 
  3811 * Provers/classical: stricter checks to ensure that supplied intro,
  3812 dest and elim rules are well-formed; dest and elim rules must have at
  3813 least one premise.
  3814 
  3815 * Provers/classical: attributes dest/elim/intro take an optional
  3816 weight argument for the rule (just as the Pure versions).  Weights are
  3817 ignored by automated tools, but determine the search order of single
  3818 rule steps.
  3819 
  3820 * Syntax: input syntax now supports dummy variable binding "%_. b",
  3821 where the body does not mention the bound variable.  Note that dummy
  3822 patterns implicitly depend on their context of bounds, which makes
  3823 "{_. _}" match any set comprehension as expected.  Potential
  3824 INCOMPATIBILITY -- parse translations need to cope with syntactic
  3825 constant "_idtdummy" in the binding position.
  3826 
  3827 * Syntax: removed obsolete syntactic constant "_K" and its associated
  3828 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  3829 for example "A -> B" => "Pi A (%_. B)".
  3830 
  3831 * Pure: 'class_deps' command visualizes the subclass relation, using
  3832 the graph browser tool.
  3833 
  3834 * Pure: 'print_theory' now suppresses certain internal declarations by
  3835 default; use '!' option for full details.
  3836 
  3837 
  3838 *** HOL ***
  3839 
  3840 * Method "metis" proves goals by applying the Metis general-purpose
  3841 resolution prover (see also http://gilith.com/software/metis/).
  3842 Examples are in the directory MetisExamples.  WARNING: the
  3843 Isabelle/HOL-Metis integration does not yet work properly with
  3844 multi-threading.
  3845   
  3846 * Command 'sledgehammer' invokes external automatic theorem provers as
  3847 background processes.  It generates calls to the "metis" method if
  3848 successful. These can be pasted into the proof.  Users do not have to
  3849 wait for the automatic provers to return.  WARNING: does not really
  3850 work with multi-threading.
  3851 
  3852 * New "auto_quickcheck" feature tests outermost goal statements for
  3853 potential counter-examples.  Controlled by ML references
  3854 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  3855 5000 milliseconds).  Fails silently if statements is outside of
  3856 executable fragment, or any other codgenerator problem occurs.
  3857 
  3858 * New constant "undefined" with axiom "undefined x = undefined".
  3859 
  3860 * Added class "HOL.eq", allowing for code generation with polymorphic
  3861 equality.
  3862 
  3863 * Some renaming of class constants due to canonical name prefixing in
  3864 the new 'class' package:
  3865 
  3866     HOL.abs ~> HOL.abs_class.abs
  3867     HOL.divide ~> HOL.divide_class.divide
  3868     0 ~> HOL.zero_class.zero
  3869     1 ~> HOL.one_class.one
  3870     op + ~> HOL.plus_class.plus
  3871     op - ~> HOL.minus_class.minus
  3872     uminus ~> HOL.minus_class.uminus
  3873     op * ~> HOL.times_class.times
  3874     op < ~> HOL.ord_class.less
  3875     op <= > HOL.ord_class.less_eq
  3876     Nat.power ~> Power.power_class.power
  3877     Nat.size ~> Nat.size_class.size
  3878     Numeral.number_of ~> Numeral.number_class.number_of
  3879     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  3880     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  3881     Orderings.min ~> Orderings.ord_class.min
  3882     Orderings.max ~> Orderings.ord_class.max
  3883     Divides.op div ~> Divides.div_class.div
  3884     Divides.op mod ~> Divides.div_class.mod
  3885     Divides.op dvd ~> Divides.div_class.dvd
  3886 
  3887 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  3888 
  3889 a) User-defined constants using any of the names "plus", "minus",
  3890 "times", "less" or "less_eq". The standard syntax translations for
  3891 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  3892 names.
  3893 
  3894 b) Variables named "plus", "minus", "times", "less", "less_eq"
  3895 INCOMPATIBILITY: use more specific names.
  3896 
  3897 c) Permutative equations (e.g. "a + b = b + a")
  3898 Since the change of names also changes the order of terms, permutative
  3899 rewrite rules may get applied in a different order. Experience shows
  3900 that this is rarely the case (only two adaptions in the whole Isabelle
  3901 distribution).  INCOMPATIBILITY: rewrite proofs
  3902 
  3903 d) ML code directly refering to constant names
  3904 This in general only affects hand-written proof tactics, simprocs and
  3905 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  3906 Consider using @{const_name} antiquotation.
  3907 
  3908 * New class "default" with associated constant "default".
  3909 
  3910 * Function "sgn" is now overloaded and available on int, real, complex
  3911 (and other numeric types), using class "sgn".  Two possible defs of
  3912 sgn are given as equational assumptions in the classes sgn_if and
  3913 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  3914 INCOMPATIBILITY.
  3915 
  3916 * Locale "partial_order" now unified with class "order" (cf. theory
  3917 Orderings), added parameter "less".  INCOMPATIBILITY.
  3918 
  3919 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  3920 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  3921 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  3922 
  3923 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  3924 changed order of proof goals in instance proofs.
  3925 
  3926 * The transitivity reasoner for partial and linear orders is set up
  3927 for classes "order" and "linorder".  Instances of the reasoner are available
  3928 in all contexts importing or interpreting the corresponding locales.
  3929 Method "order" invokes the reasoner separately; the reasoner
  3930 is also integrated with the Simplifier as a solver.  Diagnostic
  3931 command 'print_orders' shows the available instances of the reasoner
  3932 in the current context.
  3933 
  3934 * Localized monotonicity predicate in theory "Orderings"; integrated
  3935 lemmas max_of_mono and min_of_mono with this predicate.
  3936 INCOMPATIBILITY.
  3937 
  3938 * Formulation of theorem "dense" changed slightly due to integration
  3939 with new class dense_linear_order.
  3940 
  3941 * Uniform lattice theory development in HOL.
  3942 
  3943     constants "meet" and "join" now named "inf" and "sup"
  3944     constant "Meet" now named "Inf"
  3945 
  3946     classes "meet_semilorder" and "join_semilorder" now named
  3947       "lower_semilattice" and "upper_semilattice"
  3948     class "lorder" now named "lattice"
  3949     class "comp_lat" now named "complete_lattice"
  3950 
  3951     Instantiation of lattice classes allows explicit definitions
  3952     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  3953 
  3954   INCOMPATIBILITY.  Theorem renames:
  3955 
  3956     meet_left_le            ~> inf_le1
  3957     meet_right_le           ~> inf_le2
  3958     join_left_le            ~> sup_ge1
  3959     join_right_le           ~> sup_ge2
  3960     meet_join_le            ~> inf_sup_ord
  3961     le_meetI                ~> le_infI
  3962     join_leI                ~> le_supI
  3963     le_meet                 ~> le_inf_iff
  3964     le_join                 ~> ge_sup_conv
  3965     meet_idempotent         ~> inf_idem
  3966     join_idempotent         ~> sup_idem
  3967     meet_comm               ~> inf_commute
  3968     join_comm               ~> sup_commute
  3969     meet_leI1               ~> le_infI1
  3970     meet_leI2               ~> le_infI2
  3971     le_joinI1               ~> le_supI1
  3972     le_joinI2               ~> le_supI2
  3973     meet_assoc              ~> inf_assoc
  3974     join_assoc              ~> sup_assoc
  3975     meet_left_comm          ~> inf_left_commute
  3976     meet_left_idempotent    ~> inf_left_idem
  3977     join_left_comm          ~> sup_left_commute
  3978     join_left_idempotent    ~> sup_left_idem
  3979     meet_aci                ~> inf_aci
  3980     join_aci                ~> sup_aci
  3981     le_def_meet             ~> le_iff_inf
  3982     le_def_join             ~> le_iff_sup
  3983     join_absorp2            ~> sup_absorb2
  3984     join_absorp1            ~> sup_absorb1
  3985     meet_absorp1            ~> inf_absorb1
  3986     meet_absorp2            ~> inf_absorb2
  3987     meet_join_absorp        ~> inf_sup_absorb
  3988     join_meet_absorp        ~> sup_inf_absorb
  3989     distrib_join_le         ~> distrib_sup_le
  3990     distrib_meet_le         ~> distrib_inf_le
  3991 
  3992     add_meet_distrib_left   ~> add_inf_distrib_left
  3993     add_join_distrib_left   ~> add_sup_distrib_left
  3994     is_join_neg_meet        ~> is_join_neg_inf
  3995     is_meet_neg_join        ~> is_meet_neg_sup
  3996     add_meet_distrib_right  ~> add_inf_distrib_right
  3997     add_join_distrib_right  ~> add_sup_distrib_right
  3998     add_meet_join_distribs  ~> add_sup_inf_distribs
  3999     join_eq_neg_meet        ~> sup_eq_neg_inf
  4000     meet_eq_neg_join        ~> inf_eq_neg_sup
  4001     add_eq_meet_join        ~> add_eq_inf_sup
  4002     meet_0_imp_0            ~> inf_0_imp_0
  4003     join_0_imp_0            ~> sup_0_imp_0
  4004     meet_0_eq_0             ~> inf_0_eq_0
  4005     join_0_eq_0             ~> sup_0_eq_0
  4006     neg_meet_eq_join        ~> neg_inf_eq_sup
  4007     neg_join_eq_meet        ~> neg_sup_eq_inf
  4008     join_eq_if              ~> sup_eq_if
  4009 
  4010     mono_meet               ~> mono_inf
  4011     mono_join               ~> mono_sup
  4012     meet_bool_eq            ~> inf_bool_eq
  4013     join_bool_eq            ~> sup_bool_eq
  4014     meet_fun_eq             ~> inf_fun_eq
  4015     join_fun_eq             ~> sup_fun_eq
  4016     meet_set_eq             ~> inf_set_eq
  4017     join_set_eq             ~> sup_set_eq
  4018     meet1_iff               ~> inf1_iff
  4019     meet2_iff               ~> inf2_iff
  4020     meet1I                  ~> inf1I
  4021     meet2I                  ~> inf2I
  4022     meet1D1                 ~> inf1D1
  4023     meet2D1                 ~> inf2D1
  4024     meet1D2                 ~> inf1D2
  4025     meet2D2                 ~> inf2D2
  4026     meet1E                  ~> inf1E
  4027     meet2E                  ~> inf2E
  4028     join1_iff               ~> sup1_iff
  4029     join2_iff               ~> sup2_iff
  4030     join1I1                 ~> sup1I1
  4031     join2I1                 ~> sup2I1
  4032     join1I1                 ~> sup1I1
  4033     join2I2                 ~> sup1I2
  4034     join1CI                 ~> sup1CI
  4035     join2CI                 ~> sup2CI
  4036     join1E                  ~> sup1E
  4037     join2E                  ~> sup2E
  4038 
  4039     is_meet_Meet            ~> is_meet_Inf
  4040     Meet_bool_def           ~> Inf_bool_def
  4041     Meet_fun_def            ~> Inf_fun_def
  4042     Meet_greatest           ~> Inf_greatest
  4043     Meet_lower              ~> Inf_lower
  4044     Meet_set_def            ~> Inf_set_def
  4045 
  4046     Sup_def                 ~> Sup_Inf
  4047     Sup_bool_eq             ~> Sup_bool_def
  4048     Sup_fun_eq              ~> Sup_fun_def
  4049     Sup_set_eq              ~> Sup_set_def
  4050 
  4051     listsp_meetI            ~> listsp_infI
  4052     listsp_meet_eq          ~> listsp_inf_eq
  4053 
  4054     meet_min                ~> inf_min
  4055     join_max                ~> sup_max
  4056 
  4057 * Added syntactic class "size"; overloaded constant "size" now has
  4058 type "'a::size ==> bool"
  4059 
  4060 * Internal reorganisation of `size' of datatypes: size theorems
  4061 "foo.size" are no longer subsumed by "foo.simps" (but are still
  4062 simplification rules by default!); theorems "prod.size" now named
  4063 "*.size".
  4064 
  4065 * Class "div" now inherits from class "times" rather than "type".
  4066 INCOMPATIBILITY.
  4067 
  4068 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  4069 Linorder etc.  have disappeared; operations defined in terms of
  4070 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  4071 
  4072 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  4073 
  4074 * HOL-Word: New extensive library and type for generic, fixed size
  4075 machine words, with arithemtic, bit-wise, shifting and rotating
  4076 operations, reflection into int, nat, and bool lists, automation for
  4077 linear arithmetic (by automatic reflection into nat or int), including
  4078 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  4079 arithmetic type classes, supporting automatic simplification of
  4080 numerals on all operations.
  4081 
  4082 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  4083 
  4084 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  4085 
  4086 * Code generator library theories:
  4087   - Code_Integer represents HOL integers by big integer literals in target
  4088     languages.
  4089   - Code_Char represents HOL characters by character literals in target
  4090     languages.
  4091   - Code_Char_chr like Code_Char, but also offers treatment of character
  4092     codes; includes Code_Integer.
  4093   - Executable_Set allows to generate code for finite sets using lists.
  4094   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  4095     denominator).
  4096   - Executable_Real implements a subset of real numbers, namly those
  4097     representable by rational numbers.
  4098   - Efficient_Nat implements natural numbers by integers, which in general will
  4099     result in higher efficency; pattern matching with 0/Suc is eliminated;
  4100     includes Code_Integer.
  4101   - Code_Index provides an additional datatype index which is mapped to
  4102     target-language built-in integers.
  4103   - Code_Message provides an additional datatype message_string which is isomorphic to
  4104     strings; messages are mapped to target-language strings.
  4105 
  4106 * New package for inductive predicates
  4107 
  4108   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  4109 
  4110     inductive
  4111       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  4112       for z_1 :: U_1 and ... and z_n :: U_m
  4113     where
  4114       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  4115     | ...
  4116 
  4117   with full support for type-inference, rather than
  4118 
  4119     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4120 
  4121     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  4122     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  4123 
  4124     inductive "s z_1 ... z_m"
  4125     intros
  4126       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  4127       ...
  4128 
  4129   For backward compatibility, there is a wrapper allowing inductive
  4130   sets to be defined with the new package via
  4131 
  4132     inductive_set
  4133       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4134       for z_1 :: U_1 and ... and z_n :: U_m
  4135     where
  4136       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  4137     | ...
  4138 
  4139   or
  4140 
  4141     inductive_set
  4142       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4143       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  4144       for z_1 :: U_1 and ... and z_n :: U_m
  4145     where
  4146       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  4147     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  4148     | ...
  4149 
  4150   if the additional syntax "p ..." is required.
  4151 
  4152   Numerous examples can be found in the subdirectories src/HOL/Auth,
  4153   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  4154 
  4155   INCOMPATIBILITIES:
  4156 
  4157   - Since declaration and definition of inductive sets or predicates
  4158     is no longer separated, abbreviations involving the newly
  4159     introduced sets or predicates must be specified together with the
  4160     introduction rules after the 'where' keyword (see above), rather
  4161     than before the actual inductive definition.
  4162 
  4163   - The variables in induction and elimination rules are now
  4164     quantified in the order of their occurrence in the introduction
  4165     rules, rather than in alphabetical order. Since this may break
  4166     some proofs, these proofs either have to be repaired, e.g. by
  4167     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  4168     statements of the form
  4169 
  4170       case (rule_i a_i_1 ... a_i_{k_i})
  4171 
  4172     or the old order of quantification has to be restored by explicitly adding
  4173     meta-level quantifiers in the introduction rules, i.e.
  4174 
  4175       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  4176 
  4177   - The format of the elimination rules is now
  4178 
  4179       p z_1 ... z_m x_1 ... x_n ==>
  4180         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  4181         ==> ... ==> P
  4182 
  4183     for predicates and
  4184 
  4185       (x_1, ..., x_n) : s z_1 ... z_m ==>
  4186         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  4187         ==> ... ==> P
  4188 
  4189     for sets rather than
  4190 
  4191       x : s z_1 ... z_m ==>
  4192         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  4193         ==> ... ==> P
  4194 
  4195     This may require terms in goals to be expanded to n-tuples
  4196     (e.g. using case_tac or simplification with the split_paired_all
  4197     rule) before the above elimination rule is applicable.
  4198 
  4199   - The elimination or case analysis rules for (mutually) inductive
  4200     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  4201     list of rules "p_1_..._p_k.elims" is no longer available.
  4202 
  4203 * New package "function"/"fun" for general recursive functions,
  4204 supporting mutual and nested recursion, definitions in local contexts,
  4205 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  4206 for small examples, and the separate tutorial on the function
  4207 package. The old recdef "package" is still available as before, but
  4208 users are encouraged to use the new package.
  4209 
  4210 * Method "lexicographic_order" automatically synthesizes termination
  4211 relations as lexicographic combinations of size measures. 
  4212 
  4213 * Case-expressions allow arbitrary constructor-patterns (including
  4214 "_") and take their order into account, like in functional
  4215 programming.  Internally, this is translated into nested
  4216 case-expressions; missing cases are added and mapped to the predefined
  4217 constant "undefined". In complicated cases printing may no longer show
  4218 the original input but the internal form. Lambda-abstractions allow
  4219 the same form of pattern matching: "% pat1 => e1 | ..." is an
  4220 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  4221 variable.
  4222 
  4223 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  4224 is an abbreviation for "of_nat :: nat => int". The simplification
  4225 rules for "of_nat" have been changed to work like "int" did
  4226 previously.  Potential INCOMPATIBILITY:
  4227   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  4228   - of_nat_diff and of_nat_mult are no longer default simp rules
  4229 
  4230 * Method "algebra" solves polynomial equations over (semi)rings using
  4231 Groebner bases. The (semi)ring structure is defined by locales and the
  4232 tool setup depends on that generic context. Installing the method for
  4233 a specific type involves instantiating the locale and possibly adding
  4234 declarations for computation on the coefficients.  The method is
  4235 already instantiated for natural numbers and for the axiomatic class
  4236 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  4237 CALCULEMUS 2007 for the general principles underlying this
  4238 architecture of context-aware proof-tools.
  4239 
  4240 * Method "ferrack" implements quantifier elimination over
  4241 special-purpose dense linear orders using locales (analogous to
  4242 "algebra"). The method is already installed for class
  4243 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  4244 rat, etc.
  4245 
  4246 * Former constant "List.op @" now named "List.append".  Use ML
  4247 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  4248 circumvent possible incompatibilities when working on ML level.
  4249 
  4250 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  4251 
  4252 * New function listsum :: 'a list => 'a for arbitrary monoids.
  4253 Special syntax: "SUM x <- xs. f x" (and latex variants)
  4254 
  4255 * New syntax for Haskell-like list comprehension (input only), eg.
  4256 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  4257 
  4258 * The special syntax for function "filter" has changed from [x :
  4259 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  4260 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  4261 
  4262 * [a..b] is now defined for arbitrary linear orders.  It used to be
  4263 defined on nat only, as an abbreviation for [a..<Suc b]
  4264 INCOMPATIBILITY.
  4265 
  4266 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  4267 
  4268 * New functions "sorted" and "sort" in src/HOL/List.thy.
  4269 
  4270 * New lemma collection field_simps (an extension of ring_simps) for
  4271 manipulating (in)equations involving division. Multiplies with all
  4272 denominators that can be proved to be non-zero (in equations) or
  4273 positive/negative (in inequations).
  4274 
  4275 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  4276 have been improved and renamed to ring_simps, group_simps and
  4277 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  4278 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  4279 
  4280 * Theory Library/Commutative_Ring: switched from recdef to function
  4281 package; constants add, mul, pow now curried.  Infix syntax for
  4282 algebraic operations.
  4283 
  4284 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  4285 INCOMPATIBILITY.
  4286 
  4287 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  4288 INCOMPATIBILITY.
  4289 
  4290 * HOL/records: generalised field-update to take a function on the
  4291 field rather than the new value: r(|A := x|) is translated to A_update
  4292 (K x) r The K-combinator that is internally used is called K_record.
  4293 INCOMPATIBILITY: Usage of the plain update functions has to be
  4294 adapted.
  4295  
  4296 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  4297 * x = 0, which are required for a semiring.  Richer structures do not
  4298 inherit from semiring_0 anymore, because this property is a theorem
  4299 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  4300 there is more to prove, but this is mostly trivial.
  4301 
  4302 * Class "recpower" is generalized to arbitrary monoids, not just
  4303 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  4304 commutativity or semiring properties additionally.
  4305 
  4306 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  4307 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  4308 better use 'abbreviation'.
  4309 
  4310 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  4311 
  4312 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  4313 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  4314 significant changes for setting up numeral syntax for types:
  4315   - New constants Numeral.pred and Numeral.succ instead
  4316       of former Numeral.bin_pred and Numeral.bin_succ.
  4317   - Use integer operations instead of bin_add, bin_mult and so on.
  4318   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  4319   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  4320 
  4321 See src/HOL/Integ/IntArith.thy for an example setup.
  4322 
  4323 * Command 'normal_form' computes the normal form of a term that may
  4324 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  4325 produces ``[b, c, a]'' (without proof).  This command is suitable for
  4326 heavy-duty computations because the functions are compiled to ML
  4327 first.  Correspondingly, a method "normalization" is provided.  See
  4328 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  4329 
  4330 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  4331 25 like -->); output depends on the "iff" print_mode, the default is
  4332 "A = B" (with priority 50).
  4333 
  4334 * Relations less (<) and less_eq (<=) are also available on type bool.
  4335 Modified syntax to disallow nesting without explicit parentheses,
  4336 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  4337 INCOMPATIBILITY.
  4338 
  4339 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  4340 
  4341 * Relation composition operator "op O" now has precedence 75 and binds
  4342 stronger than union and intersection. INCOMPATIBILITY.
  4343 
  4344 * The old set interval syntax "{m..n(}" (and relatives) has been
  4345 removed.  Use "{m..<n}" (and relatives) instead.
  4346 
  4347 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  4348 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  4349 ``declare [[simproc del: neq]]''.
  4350 
  4351 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  4352 True/False.
  4353 
  4354 * Theorem Cons_eq_map_conv no longer declared as "simp".
  4355 
  4356 * Theorem setsum_mult renamed to setsum_right_distrib.
  4357 
  4358 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  4359 ``rule'' method.
  4360 
  4361 * Reimplemented methods "sat" and "satx", with several improvements:
  4362 goals no longer need to be stated as "<prems> ==> False", equivalences
  4363 (i.e. "=" on type bool) are handled, variable names of the form
  4364 "lit_<n>" are no longer reserved, significant speedup.
  4365 
  4366 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  4367 zChaff is still supported as well.
  4368 
  4369 * 'inductive' and 'datatype': provide projections of mutual rules,
  4370 bundled as foo_bar.inducts;
  4371 
  4372 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  4373 Library.
  4374 
  4375 * Library: moved theory Accessible_Part to main HOL.
  4376 
  4377 * Library: added theory Coinductive_List of potentially infinite lists
  4378 as greatest fixed-point.
  4379 
  4380 * Library: added theory AssocList which implements (finite) maps as
  4381 association lists.
  4382 
  4383 * Method "evaluation" solves goals (i.e. a boolean expression)
  4384 efficiently by compiling it to ML.  The goal is "proved" (via an
  4385 oracle) if it evaluates to True.
  4386 
  4387 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  4388 also when invoked by the simplifier.  This results in the Simplifier
  4389 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  4390 Configuration option fast_arith_split_limit=0 recovers the old
  4391 behavior.
  4392 
  4393 * Support for hex (0x20) and binary (0b1001) numerals.
  4394 
  4395 * New method: reify eqs (t), where eqs are equations for an
  4396 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  4397 parameter, computes a term s::'b and a list xs::'a list and proves the
  4398 theorem I xs s = t. This is also known as reification or quoting. The
  4399 resulting theorem is applied to the subgoal to substitute t with I xs
  4400 s.  If t is omitted, the subgoal itself is reified.
  4401 
  4402 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  4403 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  4404 where f is supposed to be a computable function (in the sense of code
  4405 generattion). The method uses reify to compute s and xs as above then
  4406 applies corr_thm and uses normalization by evaluation to "prove" f s =
  4407 r and finally gets the theorem t = r, which is again applied to the
  4408 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  4409 
  4410 * Reflection: Automatic reification now handels binding, an example is
  4411 available in src/HOL/ex/ReflectionEx.thy
  4412 
  4413 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  4414 command 'statespace' that is similar to 'record', but introduces an
  4415 abstract specification based on the locale infrastructure instead of
  4416 HOL types.  This leads to extra flexibility in composing state spaces,
  4417 in particular multiple inheritance and renaming of components.
  4418 
  4419 
  4420 *** HOL-Complex ***
  4421 
  4422 * Hyperreal: Functions root and sqrt are now defined on negative real
  4423 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  4424 Nonnegativity side conditions have been removed from many lemmas, so
  4425 that more subgoals may now be solved by simplification; potential
  4426 INCOMPATIBILITY.
  4427 
  4428 * Real: new type classes formalize real normed vector spaces and
  4429 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  4430 and norm :: 'a => real.
  4431 
  4432 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  4433 reals into other types. The overloaded constant Reals :: 'a set is now
  4434 defined as range of_real; potential INCOMPATIBILITY.
  4435 
  4436 * Real: proper support for ML code generation, including 'quickcheck'.
  4437 Reals are implemented as arbitrary precision rationals.
  4438 
  4439 * Hyperreal: Several constants that previously worked only for the
  4440 reals have been generalized, so they now work over arbitrary vector
  4441 spaces. Type annotations may need to be added in some cases; potential
  4442 INCOMPATIBILITY.
  4443 
  4444   Infinitesimal  :: ('a::real_normed_vector) star set
  4445   HFinite        :: ('a::real_normed_vector) star set
  4446   HInfinite      :: ('a::real_normed_vector) star set
  4447   approx         :: ('a::real_normed_vector) star => 'a star => bool
  4448   monad          :: ('a::real_normed_vector) star => 'a star set
  4449   galaxy         :: ('a::real_normed_vector) star => 'a star set
  4450   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  4451   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  4452   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  4453   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  4454   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  4455   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  4456   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  4457   sgn            :: 'a::real_normed_vector => 'a
  4458   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  4459 
  4460 * Complex: Some complex-specific constants are now abbreviations for
  4461 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  4462 hnorm.  Other constants have been entirely removed in favor of the
  4463 polymorphic versions (INCOMPATIBILITY):
  4464 
  4465   approx        <-- capprox
  4466   HFinite       <-- CFinite
  4467   HInfinite     <-- CInfinite
  4468   Infinitesimal <-- CInfinitesimal
  4469   monad         <-- cmonad
  4470   galaxy        <-- cgalaxy
  4471   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  4472   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  4473   (ns)deriv     <-- (ns)cderiv
  4474 
  4475 
  4476 *** HOL-Algebra ***
  4477 
  4478 * Formalisation of ideals and the quotient construction over rings.
  4479 
  4480 * Order and lattice theory no longer based on records.
  4481 INCOMPATIBILITY.
  4482 
  4483 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  4484 greatest_closed.  INCOMPATIBILITY.
  4485 
  4486 * Method algebra is now set up via an attribute.  For examples see
  4487 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  4488 of algebraic structures.
  4489 
  4490 * Renamed theory CRing to Ring.
  4491 
  4492 
  4493 *** HOL-Nominal ***
  4494 
  4495 * Substantial, yet incomplete support for nominal datatypes (binding
  4496 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  4497 src/HOL/Nominal/Examples.  Prospective users should consult
  4498 http://isabelle.in.tum.de/nominal/
  4499 
  4500 
  4501 *** ML ***
  4502 
  4503 * ML basics: just one true type int, which coincides with IntInf.int
  4504 (even on SML/NJ).
  4505 
  4506 * ML within Isar: antiquotations allow to embed statically-checked
  4507 formal entities in the source, referring to the context available at
  4508 compile-time.  For example:
  4509 
  4510 ML {* @{sort "{zero,one}"} *}
  4511 ML {* @{typ "'a => 'b"} *}
  4512 ML {* @{term "%x. x"} *}
  4513 ML {* @{prop "x == y"} *}
  4514 ML {* @{ctyp "'a => 'b"} *}
  4515 ML {* @{cterm "%x. x"} *}
  4516 ML {* @{cprop "x == y"} *}
  4517 ML {* @{thm asm_rl} *}
  4518 ML {* @{thms asm_rl} *}
  4519 ML {* @{type_name c} *}
  4520 ML {* @{type_syntax c} *}
  4521 ML {* @{const_name c} *}
  4522 ML {* @{const_syntax c} *}
  4523 ML {* @{context} *}
  4524 ML {* @{theory} *}
  4525 ML {* @{theory Pure} *}
  4526 ML {* @{theory_ref} *}
  4527 ML {* @{theory_ref Pure} *}
  4528 ML {* @{simpset} *}
  4529 ML {* @{claset} *}
  4530 ML {* @{clasimpset} *}
  4531 
  4532 The same works for sources being ``used'' within an Isar context.
  4533 
  4534 * ML in Isar: improved error reporting; extra verbosity with
  4535 ML_Context.trace enabled.
  4536 
  4537 * Pure/General/table.ML: the join operations now works via exceptions
  4538 DUP/SAME instead of type option. This is simpler in simple cases, and
  4539 admits slightly more efficient complex applications.
  4540 
  4541 * Pure: 'advanced' translation functions (parse_translation etc.) now
  4542 use Context.generic instead of just theory.
  4543 
  4544 * Pure: datatype Context.generic joins theory/Proof.context and
  4545 provides some facilities for code that works in either kind of
  4546 context, notably GenericDataFun for uniform theory and proof data.
  4547 
  4548 * Pure: simplified internal attribute type, which is now always
  4549 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  4550 local (Proof.context) attributes have been discontinued, while
  4551 minimizing code duplication. Thm.rule_attribute and
  4552 Thm.declaration_attribute build canonical attributes; see also structure
  4553 Context for further operations on Context.generic, notably
  4554 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  4555 declarations and definitions.
  4556 
  4557 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  4558 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  4559 init only required for impure data. INCOMPATIBILITY: empty really need
  4560 to be empty (no dependencies on theory content!)
  4561 
  4562 * Pure/kernel: consts certification ignores sort constraints given in
  4563 signature declarations. (This information is not relevant to the
  4564 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  4565 potential INCOMPATIBILITY.
  4566 
  4567 * Pure: axiomatic type classes are now purely definitional, with
  4568 explicit proofs of class axioms and super class relations performed
  4569 internally. See Pure/axclass.ML for the main internal interfaces --
  4570 notably AxClass.define_class supercedes AxClass.add_axclass, and
  4571 AxClass.axiomatize_class/classrel/arity supersede
  4572 Sign.add_classes/classrel/arities.
  4573 
  4574 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  4575 global/local versions on theory vs. Proof.context have been
  4576 discontinued; Attrib.syntax and Method.syntax have been adapted
  4577 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  4578 attributes, methods, etc.
  4579 
  4580 * Pure: several functions of signature "... -> theory -> theory * ..."
  4581 have been reoriented to "... -> theory -> ... * theory" in order to
  4582 allow natural usage in combination with the ||>, ||>>, |-> and
  4583 fold_map combinators.
  4584 
  4585 * Pure: official theorem names (closed derivations) and additional
  4586 comments (tags) are now strictly separate.  Name hints -- which are
  4587 maintained as tags -- may be attached any time without affecting the
  4588 derivation.
  4589 
  4590 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  4591 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  4592 achieve the old behaviour.
  4593 
  4594 * Pure: the "Goal" constant is now called "prop", supporting a
  4595 slightly more general idea of ``protecting'' meta-level rule
  4596 statements.
  4597 
  4598 * Pure: Logic.(un)varify only works in a global context, which is now
  4599 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  4600 Logic.legacy_(un)varify as temporary workaround.
  4601 
  4602 * Pure: structure Name provides scalable operations for generating
  4603 internal variable names, notably Name.variants etc.  This replaces
  4604 some popular functions from term.ML:
  4605 
  4606   Term.variant		->  Name.variant
  4607   Term.variantlist	->  Name.variant_list
  4608   Term.invent_names	->  Name.invent_list
  4609 
  4610 Note that low-level renaming rarely occurs in new code -- operations
  4611 from structure Variable are used instead (see below).
  4612 
  4613 * Pure: structure Variable provides fundamental operations for proper
  4614 treatment of fixed/schematic variables in a context.  For example,
  4615 Variable.import introduces fixes for schematics of given facts and
  4616 Variable.export reverses the effect (up to renaming) -- this replaces
  4617 various freeze_thaw operations.
  4618 
  4619 * Pure: structure Goal provides simple interfaces for
  4620 init/conclude/finish and tactical prove operations (replacing former
  4621 Tactic.prove).  Goal.prove is the canonical way to prove results
  4622 within a given context; Goal.prove_global is a degraded version for
  4623 theory level goals, including a global Drule.standard.  Note that
  4624 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  4625 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  4626 in a locale context).
  4627 
  4628 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  4629 and type checking (Syntax.check_term etc.), with common combinations
  4630 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  4631 which are considered legacy and await removal.
  4632 
  4633 * Pure/Syntax: generic interfaces for type unchecking
  4634 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  4635 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  4636 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  4637 available for convenience, but refer to the very same operations using
  4638 a mere theory instead of a full context.
  4639 
  4640 * Isar: simplified treatment of user-level errors, using exception
  4641 ERROR of string uniformly.  Function error now merely raises ERROR,
  4642 without any side effect on output channels.  The Isar toplevel takes
  4643 care of proper display of ERROR exceptions.  ML code may use plain
  4644 handle/can/try; cat_error may be used to concatenate errors like this:
  4645 
  4646   ... handle ERROR msg => cat_error msg "..."
  4647 
  4648 Toplevel ML code (run directly or through the Isar toplevel) may be
  4649 embedded into the Isar toplevel with exception display/debug like
  4650 this:
  4651 
  4652   Isar.toplevel (fn () => ...)
  4653 
  4654 INCOMPATIBILITY, removed special transform_error facilities, removed
  4655 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  4656 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  4657 -- use plain ERROR instead.
  4658 
  4659 * Isar: theory setup now has type (theory -> theory), instead of a
  4660 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  4661 
  4662 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  4663 ProofContext.debug/verbose flags.
  4664 
  4665 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  4666 theory before entering a proof state.  Transactions now always see a
  4667 quasi-functional intermediate checkpoint, both in interactive and
  4668 batch mode.
  4669 
  4670 * Isar: simplified interfaces for outer syntax.  Renamed
  4671 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  4672 OuterSyntax.add_parsers -- this functionality is now included in
  4673 OuterSyntax.command etc.  INCOMPATIBILITY.
  4674 
  4675 * Simplifier: the simpset of a running simplification process now
  4676 contains a proof context (cf. Simplifier.the_context), which is the
  4677 very context that the initial simpset has been retrieved from (by
  4678 simpset_of/local_simpset_of).  Consequently, all plug-in components
  4679 (solver, looper etc.) may depend on arbitrary proof data.
  4680 
  4681 * Simplifier.inherit_context inherits the proof context (plus the
  4682 local bounds) of the current simplification process; any simproc
  4683 etc. that calls the Simplifier recursively should do this!  Removed
  4684 former Simplifier.inherit_bounds, which is already included here --
  4685 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  4686 specify an explicit context using Simplifier.context/theory_context.
  4687 
  4688 * Simplifier/Classical Reasoner: more abstract interfaces
  4689 change_simpset/claset for modifying the simpset/claset reference of a
  4690 theory; raw versions simpset/claset_ref etc. have been discontinued --
  4691 INCOMPATIBILITY.
  4692 
  4693 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  4694 "Trueprop" etc.
  4695 
  4696 
  4697 *** System ***
  4698 
  4699 * settings: the default heap location within ISABELLE_HOME_USER now
  4700 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  4701 Isabelle installations.
  4702 
  4703 * isabelle-process: option -S (secure mode) disables some critical
  4704 operations, notably runtime compilation and evaluation of ML source
  4705 code.
  4706 
  4707 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  4708 
  4709 * Support for parallel execution, using native multicore support of
  4710 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  4711 independent theories, according to the given theory header
  4712 specifications. The maximum number of worker threads is specified via
  4713 usedir option -M or the "max-threads" setting in Proof General. A
  4714 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  4715 to 6 on a 8-core machine.  User-code needs to observe certain
  4716 guidelines for thread-safe programming, see appendix A in the Isar
  4717 Implementation manual.
  4718 
  4719 
  4720 
  4721 New in Isabelle2005 (October 2005)
  4722 ----------------------------------
  4723 
  4724 *** General ***
  4725 
  4726 * Theory headers: the new header syntax for Isar theories is
  4727 
  4728   theory <name>
  4729   imports <theory1> ... <theoryN>
  4730   uses <file1> ... <fileM>
  4731   begin
  4732 
  4733 where the 'uses' part is optional.  The previous syntax
  4734 
  4735   theory <name> = <theory1> + ... + <theoryN>:
  4736 
  4737 will disappear in the next release.  Use isatool fixheaders to convert
  4738 existing theory files.  Note that there is no change in ancient
  4739 non-Isar theories now, but these will disappear soon.
  4740 
  4741 * Theory loader: parent theories can now also be referred to via
  4742 relative and absolute paths.
  4743 
  4744 * Command 'find_theorems' searches for a list of criteria instead of a
  4745 list of constants. Known criteria are: intro, elim, dest, name:string,
  4746 simp:term, and any term. Criteria can be preceded by '-' to select
  4747 theorems that do not match. Intro, elim, dest select theorems that
  4748 match the current goal, name:s selects theorems whose fully qualified
  4749 name contain s, and simp:term selects all simplification rules whose
  4750 lhs match term.  Any other term is interpreted as pattern and selects
  4751 all theorems matching the pattern. Available in ProofGeneral under
  4752 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  4753 
  4754   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  4755 
  4756 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  4757 matching the current goal as introduction rule and not having "HOL."
  4758 in their name (i.e. not being defined in theory HOL).
  4759 
  4760 * Command 'thms_containing' has been discontinued in favour of
  4761 'find_theorems'; INCOMPATIBILITY.
  4762 
  4763 * Communication with Proof General is now 8bit clean, which means that
  4764 Unicode text in UTF-8 encoding may be used within theory texts (both
  4765 formal and informal parts).  Cf. option -U of the Isabelle Proof
  4766 General interface.  Here are some simple examples (cf. src/HOL/ex):
  4767 
  4768   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  4769   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  4770 
  4771 * Improved efficiency of the Simplifier and, to a lesser degree, the
  4772 Classical Reasoner.  Typical big applications run around 2 times
  4773 faster.
  4774 
  4775 
  4776 *** Document preparation ***
  4777 
  4778 * Commands 'display_drafts' and 'print_drafts' perform simple output
  4779 of raw sources.  Only those symbols that do not require additional
  4780 LaTeX packages (depending on comments in isabellesym.sty) are
  4781 displayed properly, everything else is left verbatim.  isatool display
  4782 and isatool print are used as front ends (these are subject to the
  4783 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  4784 
  4785 * Command tags control specific markup of certain regions of text,
  4786 notably folding and hiding.  Predefined tags include "theory" (for
  4787 theory begin and end), "proof" for proof commands, and "ML" for
  4788 commands involving ML code; the additional tags "visible" and
  4789 "invisible" are unused by default.  Users may give explicit tag
  4790 specifications in the text, e.g. ''by %invisible (auto)''.  The
  4791 interpretation of tags is determined by the LaTeX job during document
  4792 preparation: see option -V of isatool usedir, or options -n and -t of
  4793 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  4794 \isadroptag.
  4795 
  4796 Several document versions may be produced at the same time via isatool
  4797 usedir (the generated index.html will link all of them).  Typical
  4798 specifications include ''-V document=theory,proof,ML'' to present
  4799 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  4800 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  4801 these parts without any formal replacement text.  The Isabelle site
  4802 default settings produce ''document'' and ''outline'' versions as
  4803 specified above.
  4804 
  4805 * Several new antiquotations:
  4806 
  4807   @{term_type term} prints a term with its type annotated;
  4808 
  4809   @{typeof term} prints the type of a term;
  4810 
  4811   @{const const} is the same as @{term const}, but checks that the
  4812   argument is a known logical constant;
  4813 
  4814   @{term_style style term} and @{thm_style style thm} print a term or
  4815   theorem applying a "style" to it
  4816 
  4817   @{ML text}
  4818 
  4819 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  4820 definitions, equations, inequations etc., 'concl' printing only the
  4821 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  4822 to print the specified premise.  TermStyle.add_style provides an ML
  4823 interface for introducing further styles.  See also the "LaTeX Sugar"
  4824 document practical applications.  The ML antiquotation prints
  4825 type-checked ML expressions verbatim.
  4826 
  4827 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  4828 and 'text' support optional locale specification '(in loc)', which
  4829 specifies the default context for interpreting antiquotations.  For
  4830 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  4831 
  4832 * Option 'locale=NAME' of antiquotations specifies an alternative
  4833 context interpreting the subsequent argument.  For example: @{thm
  4834 [locale=lattice] inf_assoc}.
  4835 
  4836 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  4837 a proof context.
  4838 
  4839 * Proper output of antiquotations for theory commands involving a
  4840 proof context (such as 'locale' or 'theorem (in loc) ...').
  4841 
  4842 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  4843 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  4844 
  4845 * isatool usedir: new option -C (default true) controls whether option
  4846 -D should include a copy of the original document directory; -C false
  4847 prevents unwanted effects such as copying of administrative CVS data.
  4848 
  4849 
  4850 *** Pure ***
  4851 
  4852 * Considerably improved version of 'constdefs' command.  Now performs
  4853 automatic type-inference of declared constants; additional support for
  4854 local structure declarations (cf. locales and HOL records), see also
  4855 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  4856 sequential dependencies of definitions within a single 'constdefs'
  4857 section; moreover, the declared name needs to be an identifier.  If
  4858 all fails, consider to fall back on 'consts' and 'defs' separately.
  4859 
  4860 * Improved indexed syntax and implicit structures.  First of all,
  4861 indexed syntax provides a notational device for subscripted
  4862 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  4863 expressions.  Secondly, in a local context with structure
  4864 declarations, number indexes \<^sub>n or the empty index (default
  4865 number 1) refer to a certain fixed variable implicitly; option
  4866 show_structs controls printing of implicit structures.  Typical
  4867 applications of these concepts involve record types and locales.
  4868 
  4869 * New command 'no_syntax' removes grammar declarations (and
  4870 translations) resulting from the given syntax specification, which is
  4871 interpreted in the same manner as for the 'syntax' command.
  4872 
  4873 * 'Advanced' translation functions (parse_translation etc.) may depend
  4874 on the signature of the theory context being presently used for
  4875 parsing/printing, see also isar-ref manual.
  4876 
  4877 * Improved 'oracle' command provides a type-safe interface to turn an
  4878 ML expression of type theory -> T -> term into a primitive rule of
  4879 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  4880 is already included here); see also FOL/ex/IffExample.thy;
  4881 INCOMPATIBILITY.
  4882 
  4883 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  4884 before); "cI" is no longer bound, use "c.intro" instead.
  4885 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  4886 axclasses vs. locales.
  4887 
  4888 * Improved internal renaming of symbolic identifiers -- attach primes
  4889 instead of base 26 numbers.
  4890 
  4891 * New flag show_question_marks controls printing of leading question
  4892 marks in schematic variable names.
  4893 
  4894 * In schematic variable names, *any* symbol following \<^isub> or
  4895 \<^isup> is now treated as part of the base name.  For example, the
  4896 following works without printing of awkward ".0" indexes:
  4897 
  4898   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  4899     by simp
  4900 
  4901 * Inner syntax includes (*(*nested*) comments*).
  4902 
  4903 * Pretty printer now supports unbreakable blocks, specified in mixfix
  4904 annotations as "(00...)".
  4905 
  4906 * Clear separation of logical types and nonterminals, where the latter
  4907 may only occur in 'syntax' specifications or type abbreviations.
  4908 Before that distinction was only partially implemented via type class
  4909 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  4910 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  4911 exotic syntax specifications may require further adaption
  4912 (e.g. Cube/Cube.thy).
  4913 
  4914 * Removed obsolete type class "logic", use the top sort {} instead.
  4915 Note that non-logical types should be declared as 'nonterminals'
  4916 rather than 'types'.  INCOMPATIBILITY for new object-logic
  4917 specifications.
  4918 
  4919 * Attributes 'induct' and 'cases': type or set names may now be
  4920 locally fixed variables as well.
  4921 
  4922 * Simplifier: can now control the depth to which conditional rewriting
  4923 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  4924 Limit.
  4925 
  4926 * Simplifier: simplification procedures may now take the current
  4927 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  4928 interface), which is very useful for calling the Simplifier
  4929 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  4930 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  4931 low-level mk_simproc no longer applies Logic.varify internally, to
  4932 allow for use in a context of fixed variables.
  4933 
  4934 * thin_tac now works even if the assumption being deleted contains !!
  4935 or ==>.  More generally, erule now works even if the major premise of
  4936 the elimination rule contains !! or ==>.
  4937 
  4938 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  4939 
  4940 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  4941 from Pure, which contains all common declarations already.  Both
  4942 theories are defined via plain Isabelle/Isar .thy files.
  4943 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  4944 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  4945 use isatool fixcpure to adapt your theory and ML sources.
  4946 
  4947 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  4948 selections of theorems in named facts via index ranges.
  4949 
  4950 * 'print_theorems': in theory mode, really print the difference
  4951 wrt. the last state (works for interactive theory development only),
  4952 in proof mode print all local facts (cf. 'print_facts');
  4953 
  4954 * 'hide': option '(open)' hides only base names.
  4955 
  4956 * More efficient treatment of intermediate checkpoints in interactive
  4957 theory development.
  4958 
  4959 * Code generator is now invoked via code_module (incremental code
  4960 generation) and code_library (modular code generation, ML structures
  4961 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  4962 must be quoted when used as identifiers.
  4963 
  4964 * New 'value' command for reading, evaluating and printing terms using
  4965 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  4966 quoted when used as identifier.
  4967 
  4968 
  4969 *** Locales ***
  4970 
  4971 * New commands for the interpretation of locale expressions in
  4972 theories (1), locales (2) and proof contexts (3).  These generate
  4973 proof obligations from the expression specification.  After the
  4974 obligations have been discharged, theorems of the expression are added
  4975 to the theory, target locale or proof context.  The synopsis of the
  4976 commands is a follows:
  4977 
  4978   (1) interpretation expr inst
  4979   (2) interpretation target < expr
  4980   (3) interpret expr inst
  4981 
  4982 Interpretation in theories and proof contexts require a parameter
  4983 instantiation of terms from the current context.  This is applied to
  4984 specifications and theorems of the interpreted expression.
  4985 Interpretation in locales only permits parameter renaming through the
  4986 locale expression.  Interpretation is smart in that interpretations
  4987 that are active already do not occur in proof obligations, neither are
  4988 instantiated theorems stored in duplicate.  Use 'print_interps' to
  4989 inspect active interpretations of a particular locale.  For details,
  4990 see the Isar Reference manual.  Examples can be found in
  4991 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  4992 
  4993 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  4994 'interpret' instead.
  4995 
  4996 * New context element 'constrains' for adding type constraints to
  4997 parameters.
  4998 
  4999 * Context expressions: renaming of parameters with syntax
  5000 redeclaration.
  5001 
  5002 * Locale declaration: 'includes' disallowed.
  5003 
  5004 * Proper static binding of attribute syntax -- i.e. types / terms /
  5005 facts mentioned as arguments are always those of the locale definition
  5006 context, independently of the context of later invocations.  Moreover,
  5007 locale operations (renaming and type / term instantiation) are applied
  5008 to attribute arguments as expected.
  5009 
  5010 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  5011 actual attributes; rare situations may require Attrib.attribute to
  5012 embed those attributes into Attrib.src that lack concrete syntax.
  5013 Attribute implementations need to cooperate properly with the static
  5014 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  5015 Attrib.XXX_thm etc. already do the right thing without further
  5016 intervention.  Only unusual applications -- such as "where" or "of"
  5017 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  5018 on the context and the facts involved -- may have to assign parsed
  5019 values to argument tokens explicitly.
  5020 
  5021 * Changed parameter management in theorem generation for long goal
  5022 statements with 'includes'.  INCOMPATIBILITY: produces a different
  5023 theorem statement in rare situations.
  5024 
  5025 * Locale inspection command 'print_locale' omits notes elements.  Use
  5026 'print_locale!' to have them included in the output.
  5027 
  5028 
  5029 *** Provers ***
  5030 
  5031 * Provers/hypsubst.ML: improved version of the subst method, for
  5032 single-step rewriting: it now works in bound variable contexts. New is
  5033 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  5034 rewrite a different subterm than the original subst method, which is
  5035 still available as 'simplesubst'.
  5036 
  5037 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  5038 and quasi orders.
  5039 
  5040 * Provers/trancl.ML: new transitivity reasoner for transitive and
  5041 reflexive-transitive closure of relations.
  5042 
  5043 * Provers/blast.ML: new reference depth_limit to make blast's depth
  5044 limit (previously hard-coded with a value of 20) user-definable.
  5045 
  5046 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  5047 is peformed already.  Object-logics merely need to finish their
  5048 initial simpset configuration as before.  INCOMPATIBILITY.
  5049 
  5050 
  5051 *** HOL ***
  5052 
  5053 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  5054 
  5055   syntax (epsilon)
  5056     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  5057 
  5058 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  5059 and x-symbol; use option '-m epsilon' to get it actually printed.
  5060 Moreover, the mathematically important symbolic identifier \<epsilon>
  5061 becomes available as variable, constant etc.  INCOMPATIBILITY,
  5062 
  5063 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  5064 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  5065 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  5066 support corresponding Isar calculations.
  5067 
  5068 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  5069 instead of ":".
  5070 
  5071 * theory SetInterval: changed the syntax for open intervals:
  5072 
  5073   Old       New
  5074   {..n(}    {..<n}
  5075   {)n..}    {n<..}
  5076   {m..n(}   {m..<n}
  5077   {)m..n}   {m<..n}
  5078   {)m..n(}  {m<..<n}
  5079 
  5080 The old syntax is still supported but will disappear in the next
  5081 release.  For conversion use the following Emacs search and replace
  5082 patterns (these are not perfect but work quite well):
  5083 
  5084   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  5085   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  5086 
  5087 * Theory Commutative_Ring (in Library): method comm_ring for proving
  5088 equalities in commutative rings; method 'algebra' provides a generic
  5089 interface.
  5090 
  5091 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  5092 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  5093 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  5094 be a tuple pattern.
  5095 
  5096 Some new syntax forms are available:
  5097 
  5098   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  5099   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  5100   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  5101   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  5102 
  5103 The latter form "\<Sum>x < k. e" used to be based on a separate
  5104 function "Summation", which has been discontinued.
  5105 
  5106 * theory Finite_Set: in structured induction proofs, the insert case
  5107 is now 'case (insert x F)' instead of the old counterintuitive 'case
  5108 (insert F x)'.
  5109 
  5110 * The 'refute' command has been extended to support a much larger
  5111 fragment of HOL, including axiomatic type classes, constdefs and
  5112 typedefs, inductive datatypes and recursion.
  5113 
  5114 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  5115 Requires zChaff with proof generation to be installed.  See
  5116 HOL/ex/SAT_Examples.thy for examples.
  5117 
  5118 * Datatype induction via method 'induct' now preserves the name of the
  5119 induction variable. For example, when proving P(xs::'a list) by
  5120 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  5121 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  5122 in unstructured proof scripts.
  5123 
  5124 * Reworked implementation of records.  Improved scalability for
  5125 records with many fields, avoiding performance problems for type
  5126 inference. Records are no longer composed of nested field types, but
  5127 of nested extension types. Therefore the record type only grows linear
  5128 in the number of extensions and not in the number of fields.  The
  5129 top-level (users) view on records is preserved.  Potential
  5130 INCOMPATIBILITY only in strange cases, where the theory depends on the
  5131 old record representation. The type generated for a record is called
  5132 <record_name>_ext_type.
  5133 
  5134 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  5135 proofs triggered by a record definition or a simproc (if
  5136 quick_and_dirty is enabled).  Definitions of large records can take
  5137 quite long.
  5138 
  5139 New simproc record_upd_simproc for simplification of multiple record
  5140 updates enabled by default.  Moreover, trivial updates are also
  5141 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  5142 occasionally, since simplification is more powerful by default.
  5143 
  5144 * typedef: proper support for polymorphic sets, which contain extra
  5145 type-variables in the term.
  5146 
  5147 * Simplifier: automatically reasons about transitivity chains
  5148 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  5149 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  5150 old proofs break occasionally as simplification may now solve more
  5151 goals than previously.
  5152 
  5153 * Simplifier: converts x <= y into x = y if assumption y <= x is
  5154 present.  Works for all partial orders (class "order"), in particular
  5155 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  5156 just like y <= x.
  5157 
  5158 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  5159 bound variable or a constant then the let is unfolded.  Otherwise
  5160 first a is simplified to b, and then f b is simplified to g. If
  5161 possible we abstract b from g arriving at "let x = b in h x",
  5162 otherwise we unfold the let and arrive at g.  The simproc can be
  5163 enabled/disabled by the reference use_let_simproc.  Potential
  5164 INCOMPATIBILITY since simplification is more powerful by default.
  5165 
  5166 * Classical reasoning: the meson method now accepts theorems as arguments.
  5167 
  5168 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  5169 jobs to provide advice on the provability of subgoals.
  5170 
  5171 * Theory OrderedGroup and Ring_and_Field: various additions and
  5172 improvements to faciliate calculations involving equalities and
  5173 inequalities.
  5174 
  5175 The following theorems have been eliminated or modified
  5176 (INCOMPATIBILITY):
  5177 
  5178   abs_eq             now named abs_of_nonneg
  5179   abs_of_ge_0        now named abs_of_nonneg
  5180   abs_minus_eq       now named abs_of_nonpos
  5181   imp_abs_id         now named abs_of_nonneg
  5182   imp_abs_neg_id     now named abs_of_nonpos
  5183   mult_pos           now named mult_pos_pos
  5184   mult_pos_le        now named mult_nonneg_nonneg
  5185   mult_pos_neg_le    now named mult_nonneg_nonpos
  5186   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  5187   mult_neg           now named mult_neg_neg
  5188   mult_neg_le        now named mult_nonpos_nonpos
  5189 
  5190 * The following lemmas in Ring_and_Field have been added to the simplifier:
  5191      
  5192      zero_le_square
  5193      not_square_less_zero 
  5194 
  5195   The following lemmas have been deleted from Real/RealPow:
  5196   
  5197      realpow_zero_zero
  5198      realpow_two
  5199      realpow_less
  5200      zero_le_power
  5201      realpow_two_le
  5202      abs_realpow_two
  5203      realpow_two_abs     
  5204 
  5205 * Theory Parity: added rules for simplifying exponents.
  5206 
  5207 * Theory List:
  5208 
  5209 The following theorems have been eliminated or modified
  5210 (INCOMPATIBILITY):
  5211 
  5212   list_all_Nil       now named list_all.simps(1)
  5213   list_all_Cons      now named list_all.simps(2)
  5214   list_all_conv      now named list_all_iff
  5215   set_mem_eq         now named mem_iff
  5216 
  5217 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  5218 asymptotic "big O" calculations.  See the notes in BigO.thy.
  5219 
  5220 
  5221 *** HOL-Complex ***
  5222 
  5223 * Theory RealDef: better support for embedding natural numbers and
  5224 integers in the reals.
  5225 
  5226 The following theorems have been eliminated or modified
  5227 (INCOMPATIBILITY):
  5228 
  5229   exp_ge_add_one_self  now requires no hypotheses
  5230   real_of_int_add      reversed direction of equality (use [symmetric])
  5231   real_of_int_minus    reversed direction of equality (use [symmetric])
  5232   real_of_int_diff     reversed direction of equality (use [symmetric])
  5233   real_of_int_mult     reversed direction of equality (use [symmetric])
  5234 
  5235 * Theory RComplete: expanded support for floor and ceiling functions.
  5236 
  5237 * Theory Ln is new, with properties of the natural logarithm
  5238 
  5239 * Hyperreal: There is a new type constructor "star" for making
  5240 nonstandard types.  The old type names are now type synonyms:
  5241 
  5242   hypreal = real star
  5243   hypnat = nat star
  5244   hcomplex = complex star
  5245 
  5246 * Hyperreal: Many groups of similarly-defined constants have been
  5247 replaced by polymorphic versions (INCOMPATIBILITY):
  5248 
  5249   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  5250 
  5251   starset      <-- starsetNat, starsetC
  5252   *s*          <-- *sNat*, *sc*
  5253   starset_n    <-- starsetNat_n, starsetC_n
  5254   *sn*         <-- *sNatn*, *scn*
  5255   InternalSets <-- InternalNatSets, InternalCSets
  5256 
  5257   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  5258   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  5259   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  5260   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  5261   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  5262 
  5263 * Hyperreal: Many type-specific theorems have been removed in favor of
  5264 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  5265 
  5266   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  5267   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  5268   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  5269   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  5270   right_minus <-- hypreal_add_minus
  5271   left_minus <-- {hypreal,hcomplex}_add_minus_left
  5272   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  5273   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  5274   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  5275   mult_1_right <-- hcomplex_mult_one_right
  5276   mult_zero_left <-- hcomplex_mult_zero_left
  5277   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  5278   right_distrib <-- hypnat_add_mult_distrib2
  5279   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  5280   right_inverse <-- hypreal_mult_inverse
  5281   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  5282   order_refl <-- {hypreal,hypnat}_le_refl
  5283   order_trans <-- {hypreal,hypnat}_le_trans
  5284   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  5285   order_less_le <-- {hypreal,hypnat}_less_le
  5286   linorder_linear <-- {hypreal,hypnat}_le_linear
  5287   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  5288   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  5289   add_nonneg_nonneg <-- hypreal_le_add_order
  5290 
  5291 * Hyperreal: Separate theorems having to do with type-specific
  5292 versions of constants have been merged into theorems that apply to the
  5293 new polymorphic constants (INCOMPATIBILITY):
  5294 
  5295   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  5296   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  5297   STAR_Un <-- {STAR,NatStar,STARC}_Un
  5298   STAR_Int <-- {STAR,NatStar,STARC}_Int
  5299   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  5300   STAR_subset <-- {STAR,NatStar,STARC}_subset
  5301   STAR_mem <-- {STAR,NatStar,STARC}_mem
  5302   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  5303   STAR_diff <-- {STAR,STARC}_diff
  5304   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  5305     STARC_hcomplex_of_complex}_image_subset
  5306   starset_n_Un <-- starset{Nat,C}_n_Un
  5307   starset_n_Int <-- starset{Nat,C}_n_Int
  5308   starset_n_Compl <-- starset{Nat,C}_n_Compl
  5309   starset_n_diff <-- starset{Nat,C}_n_diff
  5310   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  5311   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  5312   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  5313   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  5314   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  5315   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  5316   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  5317   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  5318   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  5319   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  5320   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  5321   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  5322   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  5323   starfun_diff <-- starfun{C,RC,CR}_diff
  5324   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  5325   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  5326   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  5327   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  5328   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  5329   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  5330   starfun_Id <-- starfunC_Id
  5331   starfun_approx <-- starfun{Nat,CR}_approx
  5332   starfun_capprox <-- starfun{C,RC}_capprox
  5333   starfun_abs <-- starfunNat_rabs
  5334   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  5335   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  5336   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  5337   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  5338   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  5339   starfun_add_approx <-- starfunCR_add_approx
  5340   starfun_inverse_inverse <-- starfunC_inverse_inverse
  5341   starfun_divide <-- starfun{C,CR,RC}_divide
  5342   starfun_n <-- starfun{Nat,C}_n
  5343   starfun_n_mult <-- starfun{Nat,C}_n_mult
  5344   starfun_n_add <-- starfun{Nat,C}_n_add
  5345   starfun_n_add_minus <-- starfunNat_n_add_minus
  5346   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  5347   starfun_n_minus <-- starfun{Nat,C}_n_minus
  5348   starfun_n_eq <-- starfun{Nat,C}_n_eq
  5349 
  5350   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  5351   star_n_minus <-- {hypreal,hcomplex}_minus
  5352   star_n_diff <-- {hypreal,hcomplex}_diff
  5353   star_n_mult <-- {hypreal,hcomplex}_mult
  5354   star_n_inverse <-- {hypreal,hcomplex}_inverse
  5355   star_n_le <-- {hypreal,hypnat}_le
  5356   star_n_less <-- {hypreal,hypnat}_less
  5357   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  5358   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  5359   star_n_abs <-- hypreal_hrabs
  5360   star_n_divide <-- hcomplex_divide
  5361 
  5362   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  5363   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  5364   star_of_diff <-- hypreal_of_real_diff
  5365   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  5366   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  5367   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  5368   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  5369   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  5370   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  5371   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  5372   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  5373   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  5374   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  5375   star_of_number_of <-- {hypreal,hcomplex}_number_of
  5376   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  5377   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  5378   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  5379   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  5380   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  5381   star_of_power <-- hypreal_of_real_power
  5382   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  5383 
  5384 * Hyperreal: new method "transfer" that implements the transfer
  5385 principle of nonstandard analysis. With a subgoal that mentions
  5386 nonstandard types like "'a star", the command "apply transfer"
  5387 replaces it with an equivalent one that mentions only standard types.
  5388 To be successful, all free variables must have standard types; non-
  5389 standard variables must have explicit universal quantifiers.
  5390 
  5391 * Hyperreal: A theory of Taylor series.
  5392 
  5393 
  5394 *** HOLCF ***
  5395 
  5396 * Discontinued special version of 'constdefs' (which used to support
  5397 continuous functions) in favor of the general Pure one with full
  5398 type-inference.
  5399 
  5400 * New simplification procedure for solving continuity conditions; it
  5401 is much faster on terms with many nested lambda abstractions (cubic
  5402 instead of exponential time).
  5403 
  5404 * New syntax for domain package: selector names are now optional.
  5405 Parentheses should be omitted unless argument is lazy, for example:
  5406 
  5407   domain 'a stream = cons "'a" (lazy "'a stream")
  5408 
  5409 * New command 'fixrec' for defining recursive functions with pattern
  5410 matching; defining multiple functions with mutual recursion is also
  5411 supported.  Patterns may include the constants cpair, spair, up, sinl,
  5412 sinr, or any data constructor defined by the domain package. The given
  5413 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  5414 syntax and examples.
  5415 
  5416 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  5417 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  5418 but the proof obligation additionally includes an admissibility
  5419 requirement. The packages generate instances of class cpo or pcpo,
  5420 with continuity and strictness theorems for Rep and Abs.
  5421 
  5422 * HOLCF: Many theorems have been renamed according to a more standard naming
  5423 scheme (INCOMPATIBILITY):
  5424 
  5425   foo_inject:  "foo$x = foo$y ==> x = y"
  5426   foo_eq:      "(foo$x = foo$y) = (x = y)"
  5427   foo_less:    "(foo$x << foo$y) = (x << y)"
  5428   foo_strict:  "foo$UU = UU"
  5429   foo_defined: "... ==> foo$x ~= UU"
  5430   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  5431 
  5432 
  5433 *** ZF ***
  5434 
  5435 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  5436 including the First Isomorphism Theorem (on quotienting by the kernel
  5437 of a homomorphism).
  5438 
  5439 * ZF/Simplifier: install second copy of type solver that actually
  5440 makes use of TC rules declared to Isar proof contexts (or locales);
  5441 the old version is still required for ML proof scripts.
  5442 
  5443 
  5444 *** Cube ***
  5445 
  5446 * Converted to Isar theory format; use locales instead of axiomatic
  5447 theories.
  5448 
  5449 
  5450 *** ML ***
  5451 
  5452 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  5453 for ||>, ||>>, |>>,
  5454 
  5455 * Pure/library.ML no longer defines its own option datatype, but uses
  5456 that of the SML basis, which has constructors NONE and SOME instead of
  5457 None and Some, as well as exception Option.Option instead of OPTION.
  5458 The functions the, if_none, is_some, is_none have been adapted
  5459 accordingly, while Option.map replaces apsome.
  5460 
  5461 * Pure/library.ML: the exception LIST has been given up in favour of
  5462 the standard exceptions Empty and Subscript, as well as
  5463 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  5464 superceded by the standard hd and tl functions etc.
  5465 
  5466 A number of basic list functions are no longer exported to the ML
  5467 toplevel, as they are variants of predefined functions.  The following
  5468 suggests how one can translate existing code:
  5469 
  5470     rev_append xs ys = List.revAppend (xs, ys)
  5471     nth_elem (i, xs) = List.nth (xs, i)
  5472     last_elem xs = List.last xs
  5473     flat xss = List.concat xss
  5474     seq fs = List.app fs
  5475     partition P xs = List.partition P xs
  5476     mapfilter f xs = List.mapPartial f xs
  5477 
  5478 * Pure/library.ML: several combinators for linear functional
  5479 transformations, notably reverse application and composition:
  5480 
  5481   x |> f                f #> g
  5482   (x, y) |-> f          f #-> g
  5483 
  5484 * Pure/library.ML: introduced/changed precedence of infix operators:
  5485 
  5486   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  5487   infix 2 ?;
  5488   infix 3 o oo ooo oooo;
  5489   infix 4 ~~ upto downto;
  5490 
  5491 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  5492 infix operators.
  5493 
  5494 * Pure/library.ML: natural list combinators fold, fold_rev, and
  5495 fold_map support linear functional transformations and nesting.  For
  5496 example:
  5497 
  5498   fold f [x1, ..., xN] y =
  5499     y |> f x1 |> ... |> f xN
  5500 
  5501   (fold o fold) f [xs1, ..., xsN] y =
  5502     y |> fold f xs1 |> ... |> fold f xsN
  5503 
  5504   fold f [x1, ..., xN] =
  5505     f x1 #> ... #> f xN
  5506 
  5507   (fold o fold) f [xs1, ..., xsN] =
  5508     fold f xs1 #> ... #> fold f xsN
  5509 
  5510 * Pure/library.ML: the following selectors on type 'a option are
  5511 available:
  5512 
  5513   the:               'a option -> 'a  (*partial*)
  5514   these:             'a option -> 'a  where 'a = 'b list
  5515   the_default: 'a -> 'a option -> 'a
  5516   the_list:          'a option -> 'a list
  5517 
  5518 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5519 basic operations for association lists, following natural argument
  5520 order; moreover the explicit equality predicate passed here avoids
  5521 potentially expensive polymorphic runtime equality checks.
  5522 The old functions may be expressed as follows:
  5523 
  5524   assoc = uncurry (AList.lookup (op =))
  5525   assocs = these oo AList.lookup (op =)
  5526   overwrite = uncurry (AList.update (op =)) o swap
  5527 
  5528 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5529 
  5530   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  5531   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  5532 
  5533 replacing make_keylist and keyfilter (occassionally used)
  5534 Naive rewrites:
  5535 
  5536   make_keylist = AList.make
  5537   keyfilter = AList.find (op =)
  5538 
  5539 * eq_fst and eq_snd now take explicit equality parameter, thus
  5540   avoiding eqtypes. Naive rewrites:
  5541 
  5542     eq_fst = eq_fst (op =)
  5543     eq_snd = eq_snd (op =)
  5544 
  5545 * Removed deprecated apl and apr (rarely used).
  5546   Naive rewrites:
  5547 
  5548     apl (n, op) =>>= curry op n
  5549     apr (op, m) =>>= fn n => op (n, m)
  5550 
  5551 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  5552 provides a reasonably efficient light-weight implementation of sets as
  5553 lists.
  5554 
  5555 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  5556 few new operations; existing lookup and update are now curried to
  5557 follow natural argument order (for use with fold etc.);
  5558 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  5559 
  5560 * Pure/General: output via the Isabelle channels of
  5561 writeln/warning/error etc. is now passed through Output.output, with a
  5562 hook for arbitrary transformations depending on the print_mode
  5563 (cf. Output.add_mode -- the first active mode that provides a output
  5564 function wins).  Already formatted output may be embedded into further
  5565 text via Output.raw; the result of Pretty.string_of/str_of and derived
  5566 functions (string_of_term/cterm/thm etc.) is already marked raw to
  5567 accommodate easy composition of diagnostic messages etc.  Programmers
  5568 rarely need to care about Output.output or Output.raw at all, with
  5569 some notable exceptions: Output.output is required when bypassing the
  5570 standard channels (writeln etc.), or in token translations to produce
  5571 properly formatted results; Output.raw is required when capturing
  5572 already output material that will eventually be presented to the user
  5573 a second time.  For the default print mode, both Output.output and
  5574 Output.raw have no effect.
  5575 
  5576 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  5577 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  5578 cumulative results are displayed at the end of a batch session.
  5579 
  5580 * Pure/General: File.sysify_path and File.quote_sysify path have been
  5581 replaced by File.platform_path and File.shell_path (with appropriate
  5582 hooks).  This provides a clean interface for unusual systems where the
  5583 internal and external process view of file names are different.
  5584 
  5585 * Pure: more efficient orders for basic syntactic entities: added
  5586 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  5587 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  5588 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  5589 orders now -- potential INCOMPATIBILITY for code that depends on a
  5590 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  5591 Library.sort_strings on result).
  5592 
  5593 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  5594 fold_types traverse types/terms from left to right, observing natural
  5595 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  5596 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  5597 
  5598 * Pure: name spaces have been refined, with significant changes of the
  5599 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  5600 to extern(_table).  The plain name entry path is superceded by a
  5601 general 'naming' context, which also includes the 'policy' to produce
  5602 a fully qualified name and external accesses of a fully qualified
  5603 name; NameSpace.extend is superceded by context dependent
  5604 Sign.declare_name.  Several theory and proof context operations modify
  5605 the naming context.  Especially note Theory.restore_naming and
  5606 ProofContext.restore_naming to get back to a sane state; note that
  5607 Theory.add_path is no longer sufficient to recover from
  5608 Theory.absolute_path in particular.
  5609 
  5610 * Pure: new flags short_names (default false) and unique_names
  5611 (default true) for controlling output of qualified names.  If
  5612 short_names is set, names are printed unqualified.  If unique_names is
  5613 reset, the name prefix is reduced to the minimum required to achieve
  5614 the original result when interning again, even if there is an overlap
  5615 with earlier declarations.
  5616 
  5617 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  5618 now 'extend', and 'merge' gets an additional Pretty.pp argument
  5619 (useful for printing error messages).  INCOMPATIBILITY.
  5620 
  5621 * Pure: major reorganization of the theory context.  Type Sign.sg and
  5622 Theory.theory are now identified, referring to the universal
  5623 Context.theory (see Pure/context.ML).  Actual signature and theory
  5624 content is managed as theory data.  The old code and interfaces were
  5625 spread over many files and structures; the new arrangement introduces
  5626 considerable INCOMPATIBILITY to gain more clarity:
  5627 
  5628   Context -- theory management operations (name, identity, inclusion,
  5629     parents, ancestors, merge, etc.), plus generic theory data;
  5630 
  5631   Sign -- logical signature and syntax operations (declaring consts,
  5632     types, etc.), plus certify/read for common entities;
  5633 
  5634   Theory -- logical theory operations (stating axioms, definitions,
  5635     oracles), plus a copy of logical signature operations (consts,
  5636     types, etc.); also a few basic management operations (Theory.copy,
  5637     Theory.merge, etc.)
  5638 
  5639 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  5640 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  5641 for convenience -- they merely return the theory.
  5642 
  5643 * Pure: type Type.tsig is superceded by theory in most interfaces.
  5644 
  5645 * Pure: the Isar proof context type is already defined early in Pure
  5646 as Context.proof (note that ProofContext.context and Proof.context are
  5647 aliases, where the latter is the preferred name).  This enables other
  5648 Isabelle components to refer to that type even before Isar is present.
  5649 
  5650 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  5651 typeK, constK, axiomK, oracleK), but provide explicit operations for
  5652 any of these kinds.  For example, Sign.intern typeK is now
  5653 Sign.intern_type, Theory.hide_space Sign.typeK is now
  5654 Theory.hide_types.  Also note that former
  5655 Theory.hide_classes/types/consts are now
  5656 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  5657 internalize their arguments!  INCOMPATIBILITY.
  5658 
  5659 * Pure: get_thm interface (of PureThy and ProofContext) expects
  5660 datatype thmref (with constructors Name and NameSelection) instead of
  5661 plain string -- INCOMPATIBILITY;
  5662 
  5663 * Pure: cases produced by proof methods specify options, where NONE
  5664 means to remove case bindings -- INCOMPATIBILITY in
  5665 (RAW_)METHOD_CASES.
  5666 
  5667 * Pure: the following operations retrieve axioms or theorems from a
  5668 theory node or theory hierarchy, respectively:
  5669 
  5670   Theory.axioms_of: theory -> (string * term) list
  5671   Theory.all_axioms_of: theory -> (string * term) list
  5672   PureThy.thms_of: theory -> (string * thm) list
  5673   PureThy.all_thms_of: theory -> (string * thm) list
  5674 
  5675 * Pure: print_tac now outputs the goal through the trace channel.
  5676 
  5677 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  5678 Reference Toplevel.debug (default false) controls detailed printing
  5679 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  5680 controls execution profiling -- set to 1 for time and 2 for space
  5681 (both increase the runtime).
  5682 
  5683 * Isar session: The initial use of ROOT.ML is now always timed,
  5684 i.e. the log will show the actual process times, in contrast to the
  5685 elapsed wall-clock time that the outer shell wrapper produces.
  5686 
  5687 * Simplifier: improved handling of bound variables (nameless
  5688 representation, avoid allocating new strings).  Simprocs that invoke
  5689 the Simplifier recursively should use Simplifier.inherit_bounds to
  5690 avoid local name clashes.  Failure to do so produces warnings
  5691 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  5692 for further details.
  5693 
  5694 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  5695 bindings for all theorems stored within a given theory; this may help
  5696 in porting non-Isar theories to Isar ones, while keeping ML proof
  5697 scripts for the time being.
  5698 
  5699 * ML operator HTML.with_charset specifies the charset begin used for
  5700 generated HTML files.  For example:
  5701 
  5702   HTML.with_charset "utf-8" use_thy "Hebrew";
  5703   HTML.with_charset "utf-8" use_thy "Chinese";
  5704 
  5705 
  5706 *** System ***
  5707 
  5708 * Allow symlinks to all proper Isabelle executables (Isabelle,
  5709 isabelle, isatool etc.).
  5710 
  5711 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  5712 isatool doc, isatool mkdir, display_drafts etc.).
  5713 
  5714 * isatool usedir: option -f allows specification of the ML file to be
  5715 used by Isabelle; default is ROOT.ML.
  5716 
  5717 * New isatool version outputs the version identifier of the Isabelle
  5718 distribution being used.
  5719 
  5720 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  5721 (containing Boolean satisfiability problems) into Isabelle/HOL
  5722 theories.
  5723 
  5724 
  5725 
  5726 New in Isabelle2004 (April 2004)
  5727 --------------------------------
  5728 
  5729 *** General ***
  5730 
  5731 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  5732   Replaces linorder.ML.
  5733 
  5734 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  5735   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  5736   (\<a>...\<z>), are now considered normal letters, and can therefore
  5737   be used anywhere where an ASCII letter (a...zA...Z) has until
  5738   now. COMPATIBILITY: This obviously changes the parsing of some
  5739   terms, especially where a symbol has been used as a binder, say
  5740   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  5741   as an identifier.  Fix it by inserting a space around former
  5742   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  5743   existing theory and ML files.
  5744 
  5745 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  5746 
  5747 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  5748   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  5749   a normal (but invisible) letter. For multiple letter subscripts repeat
  5750   \<^isub> like this: x\<^isub>1\<^isub>2.
  5751 
  5752 * Pure: There are now sub-/superscripts that can span more than one
  5753   character. Text between \<^bsub> and \<^esub> is set in subscript in
  5754   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  5755   superscript. The new control characters are not identifier parts.
  5756 
  5757 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  5758   content of "..." to the latex file instead of \isacntrl... . The "..."
  5759   may consist of any printable characters excluding the end bracket >.
  5760 
  5761 * Pure: Using new Isar command "finalconsts" (or the ML functions
  5762   Theory.add_finals or Theory.add_finals_i) it is now possible to
  5763   declare constants "final", which prevents their being given a definition
  5764   later.  It is useful for constants whose behaviour is fixed axiomatically
  5765   rather than definitionally, such as the meta-logic connectives.
  5766 
  5767 * Pure: 'instance' now handles general arities with general sorts
  5768   (i.e. intersections of classes),
  5769 
  5770 * Presentation: generated HTML now uses a CSS style sheet to make layout
  5771   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  5772   It can be changed to alter the colors/layout of generated pages.
  5773 
  5774 
  5775 *** Isar ***
  5776 
  5777 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  5778   cut_tac, subgoal_tac and thin_tac:
  5779   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  5780     locales are no longer forced to write Isar proof scripts.
  5781     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  5782     emulations.
  5783   - INCOMPATIBILITY: names of variables to be instantiated may no
  5784     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  5785     This is consistent with the instantiation attribute "where".
  5786 
  5787 * Attributes "where" and "of":
  5788   - Now take type variables of instantiated theorem into account when reading
  5789     the instantiation string.  This fixes a bug that caused instantiated
  5790     theorems to have too special types in some circumstances.
  5791   - "where" permits explicit instantiations of type variables.
  5792 
  5793 * Calculation commands "moreover" and "also" no longer interfere with
  5794   current facts ("this"), admitting arbitrary combinations with "then"
  5795   and derived forms.
  5796 
  5797 * Locales:
  5798   - Goal statements involving the context element "includes" no longer
  5799     generate theorems with internal delta predicates (those ending on
  5800     "_axioms") in the premise.
  5801     Resolve particular premise with <locale>.intro to obtain old form.
  5802   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  5803     specification and "includes" elements in goal statement.
  5804   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  5805     [intro?] and [elim?] (respectively) by default.
  5806   - Experimental command for instantiation of locales in proof contexts:
  5807         instantiate <label>[<attrs>]: <loc>
  5808     Instantiates locale <loc> and adds all its theorems to the current context
  5809     taking into account their attributes.  Label and attrs are optional
  5810     modifiers, like in theorem declarations.  If present, names of
  5811     instantiated theorems are qualified with <label>, and the attributes
  5812     <attrs> are applied after any attributes these theorems might have already.
  5813       If the locale has assumptions, a chained fact of the form
  5814     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  5815     are derived.  The command does not support old-style locales declared
  5816     with "locale (open)".
  5817       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  5818 
  5819 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  5820   (Isar) contexts.
  5821 
  5822 
  5823 *** HOL ***
  5824 
  5825 * Proof import: new image HOL4 contains the imported library from
  5826   the HOL4 system with about 2500 theorems. It is imported by
  5827   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  5828   can be used like any other Isabelle image.  See
  5829   HOL/Import/HOL/README for more information.
  5830 
  5831 * Simplifier:
  5832   - Much improved handling of linear and partial orders.
  5833     Reasoners for linear and partial orders are set up for type classes
  5834     "linorder" and "order" respectively, and are added to the default simpset
  5835     as solvers.  This means that the simplifier can build transitivity chains
  5836     to solve goals from the assumptions.
  5837   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  5838     of blast or auto after simplification become unnecessary because the goal
  5839     is solved by simplification already.
  5840 
  5841 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  5842     all proved in axiomatic type classes for semirings, rings and fields.
  5843 
  5844 * Numerics:
  5845   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  5846     now formalized using the Ring_and_Field theory mentioned above.
  5847   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  5848     than before, because now they are set up once in a generic manner.
  5849   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  5850     Look for the general versions in Ring_and_Field (and Power if they concern
  5851     exponentiation).
  5852 
  5853 * Type "rat" of the rational numbers is now available in HOL-Complex.
  5854 
  5855 * Records:
  5856   - Record types are now by default printed with their type abbreviation
  5857     instead of the list of all field types. This can be configured via
  5858     the reference "print_record_type_abbr".
  5859   - Simproc "record_upd_simproc" for simplification of multiple updates added
  5860     (not enabled by default).
  5861   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  5862     EX x. x = sel r to True (not enabled by default).
  5863   - Tactic "record_split_simp_tac" to split and simplify records added.
  5864 
  5865 * 'specification' command added, allowing for definition by
  5866   specification.  There is also an 'ax_specification' command that
  5867   introduces the new constants axiomatically.
  5868 
  5869 * arith(_tac) is now able to generate counterexamples for reals as well.
  5870 
  5871 * HOL-Algebra: new locale "ring" for non-commutative rings.
  5872 
  5873 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  5874   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  5875 
  5876 * HOL-Matrix: a first theory for matrices in HOL with an application of
  5877   matrix theory to linear programming.
  5878 
  5879 * Unions and Intersections:
  5880   The latex output syntax of UN and INT has been changed
  5881   from "\Union x \in A. B" to "\Union_{x \in A} B"
  5882   i.e. the index formulae has become a subscript.
  5883   Similarly for "\Union x. B", and for \Inter instead of \Union.
  5884 
  5885 * Unions and Intersections over Intervals:
  5886   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  5887   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  5888   like in normal math, and corresponding versions for < and for intersection.
  5889 
  5890 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  5891   lexicographic dictonary ordering has been added as "lexord".
  5892 
  5893 * ML: the legacy theory structures Int and List have been removed. They had
  5894   conflicted with ML Basis Library structures having the same names.
  5895 
  5896 * 'refute' command added to search for (finite) countermodels.  Only works
  5897   for a fragment of HOL.  The installation of an external SAT solver is
  5898   highly recommended.  See "HOL/Refute.thy" for details.
  5899 
  5900 * 'quickcheck' command: Allows to find counterexamples by evaluating
  5901   formulae under an assignment of free variables to random values.
  5902   In contrast to 'refute', it can deal with inductive datatypes,
  5903   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  5904   for examples.
  5905 
  5906 
  5907 *** HOLCF ***
  5908 
  5909 * Streams now come with concatenation and are part of the HOLCF image
  5910 
  5911 
  5912 
  5913 New in Isabelle2003 (May 2003)
  5914 ------------------------------
  5915 
  5916 *** General ***
  5917 
  5918 * Provers/simplifier:
  5919 
  5920   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  5921     Assumptions are now subject to complete mutual simplification,
  5922     not just from left to right. The simplifier now preserves
  5923     the order of assumptions.
  5924 
  5925     Potential INCOMPATIBILITY:
  5926 
  5927     -- simp sometimes diverges where the old version did
  5928        not, e.g. invoking simp on the goal
  5929 
  5930         [| P (f x); y = x; f x = f y |] ==> Q
  5931 
  5932        now gives rise to the infinite reduction sequence
  5933 
  5934         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  5935 
  5936        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  5937        kind of problem.
  5938 
  5939     -- Tactics combining classical reasoner and simplification (such as auto)
  5940        are also affected by this change, because many of them rely on
  5941        simp. They may sometimes diverge as well or yield a different numbers
  5942        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  5943        in case of problems. Sometimes subsequent calls to the classical
  5944        reasoner will fail because a preceeding call to the simplifier too
  5945        eagerly simplified the goal, e.g. deleted redundant premises.
  5946 
  5947   - The simplifier trace now shows the names of the applied rewrite rules
  5948 
  5949   - You can limit the number of recursive invocations of the simplifier
  5950     during conditional rewriting (where the simplifie tries to solve the
  5951     conditions before applying the rewrite rule):
  5952     ML "simp_depth_limit := n"
  5953     where n is an integer. Thus you can force termination where previously
  5954     the simplifier would diverge.
  5955 
  5956   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  5957 
  5958   - No longer aborts on failed congruence proof.  Instead, the
  5959     congruence is ignored.
  5960 
  5961 * Pure: New generic framework for extracting programs from constructive
  5962   proofs. See HOL/Extraction.thy for an example instantiation, as well
  5963   as HOL/Extraction for some case studies.
  5964 
  5965 * Pure: The main goal of the proof state is no longer shown by default, only
  5966 the subgoals. This behaviour is controlled by a new flag.
  5967    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  5968 (ML: Proof.show_main_goal).
  5969 
  5970 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  5971 rules whose conclusion matches subgoal 1:
  5972       PG menu: Isabelle/Isar -> Show me -> matching rules
  5973 The rules are ordered by how closely they match the subgoal.
  5974 In particular, rules that solve a subgoal outright are displayed first
  5975 (or rather last, the way they are printed).
  5976 (ML: ProofGeneral.print_intros())
  5977 
  5978 * Pure: New flag trace_unify_fail causes unification to print
  5979 diagnostic information (PG: in trace buffer) when it fails. This is
  5980 useful for figuring out why single step proofs like rule, erule or
  5981 assumption failed.
  5982 
  5983 * Pure: Locale specifications now produce predicate definitions
  5984 according to the body of text (covering assumptions modulo local
  5985 definitions); predicate "loc_axioms" covers newly introduced text,
  5986 while "loc" is cumulative wrt. all included locale expressions; the
  5987 latter view is presented only on export into the global theory
  5988 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  5989 on the old view without predicates;
  5990 
  5991 * Pure: predefined locales "var" and "struct" are useful for sharing
  5992 parameters (as in CASL, for example); just specify something like
  5993 ``var x + var y + struct M'' as import;
  5994 
  5995 * Pure: improved thms_containing: proper indexing of facts instead of
  5996 raw theorems; check validity of results wrt. current name space;
  5997 include local facts of proof configuration (also covers active
  5998 locales), cover fixed variables in index; may use "_" in term
  5999 specification; an optional limit for the number of printed facts may
  6000 be given (the default is 40);
  6001 
  6002 * Pure: disallow duplicate fact bindings within new-style theory files
  6003 (batch-mode only);
  6004 
  6005 * Provers: improved induct method: assumptions introduced by case
  6006 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  6007 the goal statement); "foo" still refers to all facts collectively;
  6008 
  6009 * Provers: the function blast.overloaded has been removed: all constants
  6010 are regarded as potentially overloaded, which improves robustness in exchange
  6011 for slight decrease in efficiency;
  6012 
  6013 * Provers/linorder: New generic prover for transitivity reasoning over
  6014 linear orders.  Note: this prover is not efficient!
  6015 
  6016 * Isar: preview of problems to finish 'show' now produce an error
  6017 rather than just a warning (in interactive mode);
  6018 
  6019 
  6020 *** HOL ***
  6021 
  6022 * arith(_tac)
  6023 
  6024  - Produces a counter example if it cannot prove a goal.
  6025    Note that the counter example may be spurious if the goal is not a formula
  6026    of quantifier-free linear arithmetic.
  6027    In ProofGeneral the counter example appears in the trace buffer.
  6028 
  6029  - Knows about div k and mod k where k is a numeral of type nat or int.
  6030 
  6031  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  6032    linear arithmetic fails. This takes account of quantifiers and divisibility.
  6033    Presburger arithmetic can also be called explicitly via presburger(_tac).
  6034 
  6035 * simp's arithmetic capabilities have been enhanced a bit: it now
  6036 takes ~= in premises into account (by performing a case split);
  6037 
  6038 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  6039 are distributed over a sum of terms;
  6040 
  6041 * New tactic "trans_tac" and method "trans" instantiate
  6042 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  6043 "<=", "<" and "=").
  6044 
  6045 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  6046 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  6047 
  6048 * 'typedef' command has new option "open" to suppress the set
  6049 definition;
  6050 
  6051 * functions Min and Max on finite sets have been introduced (theory
  6052 Finite_Set);
  6053 
  6054 * attribute [symmetric] now works for relations as well; it turns
  6055 (x,y) : R^-1 into (y,x) : R, and vice versa;
  6056 
  6057 * induct over a !!-quantified statement (say !!x1..xn):
  6058   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  6059 
  6060 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  6061 %x. None. Warning: empty_def now refers to the previously hidden definition
  6062 of the empty set.
  6063 
  6064 * Algebra: formalization of classical algebra.  Intended as base for
  6065 any algebraic development in Isabelle.  Currently covers group theory
  6066 (up to Sylow's theorem) and ring theory (Universal Property of
  6067 Univariate Polynomials).  Contributions welcome;
  6068 
  6069 * GroupTheory: deleted, since its material has been moved to Algebra;
  6070 
  6071 * Complex: new directory of the complex numbers with numeric constants,
  6072 nonstandard complex numbers, and some complex analysis, standard and
  6073 nonstandard (Jacques Fleuriot);
  6074 
  6075 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  6076 
  6077 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  6078 Fleuriot);
  6079 
  6080 * Real/HahnBanach: updated and adapted to locales;
  6081 
  6082 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  6083 Gray and Kramer);
  6084 
  6085 * UNITY: added the Meier-Sanders theory of progress sets;
  6086 
  6087 * MicroJava: bytecode verifier and lightweight bytecode verifier
  6088 as abstract algorithms, instantiated to the JVM;
  6089 
  6090 * Bali: Java source language formalization. Type system, operational
  6091 semantics, axiomatic semantics. Supported language features:
  6092 classes, interfaces, objects,virtual methods, static methods,
  6093 static/instance fields, arrays, access modifiers, definite
  6094 assignment, exceptions.
  6095 
  6096 
  6097 *** ZF ***
  6098 
  6099 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  6100 universe, etc.);
  6101 
  6102 * Main ZF: virtually all theories converted to new-style format;
  6103 
  6104 
  6105 *** ML ***
  6106 
  6107 * Pure: Tactic.prove provides sane interface for internal proofs;
  6108 omits the infamous "standard" operation, so this is more appropriate
  6109 than prove_goalw_cterm in many situations (e.g. in simprocs);
  6110 
  6111 * Pure: improved error reporting of simprocs;
  6112 
  6113 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  6114 up simprocs;
  6115 
  6116 
  6117 *** Document preparation ***
  6118 
  6119 * uses \par instead of \\ for line breaks in theory text. This may
  6120 shift some page breaks in large documents. To get the old behaviour
  6121 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  6122 
  6123 * minimized dependencies of isabelle.sty and isabellesym.sty on
  6124 other packages
  6125 
  6126 * \<euro> now needs package babel/greek instead of marvosym (which
  6127 broke \Rightarrow)
  6128 
  6129 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  6130 textcomp package)
  6131 
  6132 
  6133 
  6134 New in Isabelle2002 (March 2002)
  6135 --------------------------------
  6136 
  6137 *** Document preparation ***
  6138 
  6139 * greatly simplified document preparation setup, including more
  6140 graceful interpretation of isatool usedir -i/-d/-D options, and more
  6141 instructive isatool mkdir; users should basically be able to get
  6142 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  6143 users may run a separate document processing stage manually like this:
  6144 "isatool usedir -D output HOL Test && isatool document Test/output";
  6145 
  6146 * theory dependency graph may now be incorporated into documents;
  6147 isatool usedir -g true will produce session_graph.eps/.pdf for use
  6148 with \includegraphics of LaTeX;
  6149 
  6150 * proper spacing of consecutive markup elements, especially text
  6151 blocks after section headings;
  6152 
  6153 * support bold style (for single symbols only), input syntax is like
  6154 this: "\<^bold>\<alpha>" or "\<^bold>A";
  6155 
  6156 * \<bullet> is now output as bold \cdot by default, which looks much
  6157 better in printed text;
  6158 
  6159 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  6160 note that these symbols are currently unavailable in Proof General /
  6161 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  6162 
  6163 * isatool latex no longer depends on changed TEXINPUTS, instead
  6164 isatool document copies the Isabelle style files to the target
  6165 location;
  6166 
  6167 
  6168 *** Isar ***
  6169 
  6170 * Pure/Provers: improved proof by cases and induction;
  6171   - 'case' command admits impromptu naming of parameters (such as
  6172     "case (Suc n)");
  6173   - 'induct' method divinates rule instantiation from the inductive
  6174     claim; no longer requires excessive ?P bindings for proper
  6175     instantiation of cases;
  6176   - 'induct' method properly enumerates all possibilities of set/type
  6177     rules; as a consequence facts may be also passed through *type*
  6178     rules without further ado;
  6179   - 'induct' method now derives symbolic cases from the *rulified*
  6180     rule (before it used to rulify cases stemming from the internal
  6181     atomized version); this means that the context of a non-atomic
  6182     statement becomes is included in the hypothesis, avoiding the
  6183     slightly cumbersome show "PROP ?case" form;
  6184   - 'induct' may now use elim-style induction rules without chaining
  6185     facts, using ``missing'' premises from the goal state; this allows
  6186     rules stemming from inductive sets to be applied in unstructured
  6187     scripts, while still benefitting from proper handling of non-atomic
  6188     statements; NB: major inductive premises need to be put first, all
  6189     the rest of the goal is passed through the induction;
  6190   - 'induct' proper support for mutual induction involving non-atomic
  6191     rule statements (uses the new concept of simultaneous goals, see
  6192     below);
  6193   - append all possible rule selections, but only use the first
  6194     success (no backtracking);
  6195   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  6196   - undeclared rule case names default to numbers 1, 2, 3, ...;
  6197   - added 'print_induct_rules' (covered by help item in recent Proof
  6198     General versions);
  6199   - moved induct/cases attributes to Pure, methods to Provers;
  6200   - generic method setup instantiated for FOL and HOL;
  6201 
  6202 * Pure: support multiple simultaneous goal statements, for example
  6203 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  6204 meta-level mechanism, this acts as if several individual goals had
  6205 been stated separately; in particular common proof methods need to be
  6206 repeated in order to cover all claims; note that a single elimination
  6207 step is *not* sufficient to establish the two conjunctions, so this
  6208 fails:
  6209 
  6210   assume "A & B" then have A and B ..   (*".." fails*)
  6211 
  6212 better use "obtain" in situations as above; alternative refer to
  6213 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  6214 
  6215 * Pure: proper integration with ``locales''; unlike the original
  6216 version by Florian Kammller, Isar locales package high-level proof
  6217 contexts rather than raw logical ones (e.g. we admit to include
  6218 attributes everywhere); operations on locales include merge and
  6219 rename; support for implicit arguments (``structures''); simultaneous
  6220 type-inference over imports and text; see also HOL/ex/Locales.thy for
  6221 some examples;
  6222 
  6223 * Pure: the following commands have been ``localized'', supporting a
  6224 target locale specification "(in name)": 'lemma', 'theorem',
  6225 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  6226 stored both within the locale and at the theory level (exported and
  6227 qualified by the locale name);
  6228 
  6229 * Pure: theory goals may now be specified in ``long'' form, with
  6230 ad-hoc contexts consisting of arbitrary locale elements. for example