NEWS
author haftmann
Sun Jul 17 15:15:58 2011 +0200 (2011-07-17)
changeset 43865 db18f4d0cc7d
parent 43816 05ab37be94ed
child 43872 6b917e5877d2
permissions -rw-r--r--
further generalization from sets to complete lattices
     1 Isabelle NEWS -- history user-relevant changes
     2 ==============================================
     3 
     4 New in this Isabelle version
     5 ----------------------------
     6 
     7 *** General ***
     8 
     9 * Theory loader: source files are identified by content via SHA1
    10 digests.  Discontinued former path/modtime identification and optional
    11 ISABELLE_FILE_IDENT plugin scripts.
    12 
    13 * Parallelization of nested Isar proofs is subject to
    14 Goal.parallel_proofs_threshold (default 100).  See also isabelle
    15 usedir option -Q.
    16 
    17 * Discontinued support for Poly/ML 5.2, which was the last version
    18 without proper multithreading and TimeLimit implementation.
    19 
    20 * Discontinued old lib/scripts/polyml-platform, which has been
    21 obsolete since Isabelle2009-2.
    22 
    23 * Theory loader: source files are exclusively located via the master
    24 directory of each theory node (where the .thy file itself resides).
    25 The global load path (such as src/HOL/Library) has been discontinued.
    26 Note that the path element ~~ may be used to reference theories in the
    27 Isabelle home folder -- for instance, "~~/src/HOL/Library/FuncSet".
    28 INCOMPATIBILITY.
    29 
    30 * Various optional external tools are referenced more robustly and
    31 uniformly by explicit Isabelle settings as follows:
    32 
    33   ISABELLE_CSDP   (formerly CSDP_EXE)
    34   ISABELLE_GHC    (formerly EXEC_GHC or GHC_PATH)
    35   ISABELLE_OCAML  (formerly EXEC_OCAML)
    36   ISABELLE_SWIPL  (formerly EXEC_SWIPL)
    37   ISABELLE_YAP    (formerly EXEC_YAP)
    38 
    39 Note that automated detection from the file-system or search path has
    40 been discontinued.  INCOMPATIBILITY.
    41 
    42 * Name space: former unsynchronized references are now proper
    43 configuration options, with more conventional names:
    44 
    45   long_names   ~> names_long
    46   short_names  ~> names_short
    47   unique_names ~> names_unique
    48 
    49 Minor INCOMPATIBILITY, need to declare options in context like this:
    50 
    51   declare [[names_unique = false]]
    52 
    53 * Literal facts `prop` may contain dummy patterns, e.g. `_ = _`.  Note
    54 that the result needs to be unique, which means fact specifications
    55 may have to be refined after enriching a proof context.
    56 
    57 * Isabelle/Isar reference manual provides more formal references in
    58 syntax diagrams.
    59 
    60 
    61 *** HOL ***
    62 
    63 * Classes bot and top require underlying partial order rather than preorder:
    64 uniqueness of bot and top is guaranteed.  INCOMPATIBILITY.
    65 
    66 * Class 'complete_lattice': generalized a couple of lemmas from sets;
    67 generalized theorems INF_cong and SUP_cong.  More consistent names: TBD.
    68 
    69 INCOMPATIBILITY.
    70 
    71 * Archimedian_Field.thy:
    72     floor now is defined as parameter of a separate type class floor_ceiling.
    73  
    74 * Finite_Set.thy: more coherent development of fold_set locales:
    75 
    76     locale fun_left_comm ~> locale comp_fun_commute
    77     locale fun_left_comm_idem ~> locale comp_fun_idem
    78     
    79 Both use point-free characterisation; interpretation proofs may need adjustment.
    80 INCOMPATIBILITY.
    81 
    82 * Code generation:
    83   - theory Library/Code_Char_ord provides native ordering of characters
    84     in the target language.
    85     
    86 * Declare ext [intro] by default.  Rare INCOMPATIBILITY.
    87 
    88 * Nitpick:
    89   - Added "need" and "total_consts" options.
    90   - Reintroduced "show_skolems" option by popular demand.
    91   - Renamed attribute: nitpick_def ~> nitpick_unfold.
    92     INCOMPATIBILITY.
    93 
    94 * Sledgehammer:
    95   - sledgehammer available_provers ~> sledgehammer supported_provers.
    96     INCOMPATIBILITY.
    97   - Added support for SNARK and ToFoF-E on SystemOnTPTP and for simply typed
    98     TPTP problems (TFF).
    99   - Added "preplay_timeout", "slicing", "type_enc", "sound", "max_mono_iters",
   100     and "max_new_mono_instances" options.
   101   - Removed "explicit_apply" and "full_types" options as well as "Full Types"
   102     Proof General menu item. INCOMPATIBILITY.
   103 
   104 * Metis:
   105   - Removed "metisF" -- use "metis" instead. INCOMPATIBILITY.
   106   - Obsoleted "metisFT" -- use "metis (full_types)" instead. INCOMPATIBILITY.
   107 
   108 * "try":
   109   - Renamed "try_methods" and added "simp:", "intro:", "dest:", and "elim:"
   110     options. INCOMPATIBILITY.
   111   - Introduced "try" that not only runs "try_methods" but also "solve_direct",
   112     "sledgehammer", "quickcheck", and "nitpick".
   113 
   114 * Quickcheck:
   115   - Added "eval" option to evaluate terms for the found counterexample
   116     (currently only supported by the default (exhaustive) tester)
   117   - Added post-processing of terms to obtain readable counterexamples
   118     (currently only supported by the default (exhaustive) tester)
   119   - New counterexample generator quickcheck[narrowing] enables
   120     narrowing-based testing.
   121     It requires that the Glasgow Haskell compiler is installed and
   122     its location is known to Isabelle with the environment variable
   123     ISABELLE_GHC.
   124 
   125 * Function package: discontinued option "tailrec".
   126 INCOMPATIBILITY. Use partial_function instead.
   127 
   128 * HOL-Probability:
   129   - Caratheodory's extension lemma is now proved for ring_of_sets.
   130   - Infinite products of probability measures are now available.
   131   - Use extended reals instead of positive extended reals.
   132     INCOMPATIBILITY.
   133 
   134 
   135 *** Document preparation ***
   136 
   137 * Discontinued special treatment of hard tabulators, which are better
   138 avoided in the first place.  Implicit tab-width is 1.
   139 
   140 * Antiquotation @{rail} layouts railroad syntax diagrams, see also
   141 isar-ref manual.
   142 
   143 * Antiquotation @{value} evaluates the given term and presents its result.
   144 
   145 * Localized \isabellestyle switch can be used within blocks or groups
   146 like this:
   147 
   148   \isabellestyle{it}  %preferred default
   149   {\isabellestylett @{text "typewriter stuff"}}
   150 
   151 * New term style "isub" as ad-hoc conversion of variables x1, y23 into
   152 subscripted form x\<^isub>1, y\<^isub>2\<^isub>3.
   153 
   154 * Predefined LaTeX macros for Isabelle symbols \<bind> and \<then>
   155 (e.g. see ~~/src/HOL/Library/Monad_Syntax.thy).
   156 
   157 
   158 *** ML ***
   159 
   160 * The inner syntax of sort/type/term/prop supports inlined YXML
   161 representations within quoted string tokens.  By encoding logical
   162 entities via Term_XML (in ML or Scala) concrete syntax can be
   163 bypassed, which is particularly useful for producing bits of text
   164 under external program control.
   165 
   166 * Antiquotations for ML and document preparation are managed as theory
   167 data, which requires explicit setup.
   168 
   169 * Isabelle_Process.is_active allows tools to check if the official
   170 process wrapper is running (Isabelle/Scala/jEdit) or the old TTY loop
   171 (better known as Proof General).
   172 
   173 * Structure Proof_Context follows standard naming scheme.  Old
   174 ProofContext is still available for some time as legacy alias.
   175 
   176 * Structure Timing provides various operations for timing; supersedes
   177 former start_timing/end_timing etc.
   178 
   179 * Path.print is the official way to show file-system paths to users
   180 (including quotes etc.).
   181 
   182 * Inner syntax: identifiers in parse trees of generic categories
   183 "logic", "aprop", "idt" etc. carry position information (disguised as
   184 type constraints).  Occasional INCOMPATIBILITY with non-compliant
   185 translations that choke on unexpected type constraints.  Positions can
   186 be stripped in ML translations via Syntax.strip_positions /
   187 Syntax.strip_positions_ast, or via the syntax constant
   188 "_strip_positions" within parse trees.  As last resort, positions can
   189 be disabled via the configuration option Syntax.positions, which is
   190 called "syntax_positions" in Isar attribute syntax.
   191 
   192 * Discontinued special status of various ML structures that contribute
   193 to structure Syntax (Ast, Lexicon, Mixfix, Parser, Printer etc.): less
   194 pervasive content, no inclusion in structure Syntax.  INCOMPATIBILITY,
   195 refer directly to Ast.Constant, Lexicon.is_identifier,
   196 Syntax_Trans.mk_binder_tr etc.
   197 
   198 * Typed print translation: discontinued show_sorts argument, which is
   199 already available via context of "advanced" translation.
   200 
   201 * Refined PARALLEL_GOALS tactical: degrades gracefully for schematic
   202 goal states; body tactic needs to address all subgoals uniformly.
   203 
   204 * Slightly more special eq_list/eq_set, with shortcut involving
   205 pointer equality (assumes that eq relation is reflexive).
   206 
   207 * Classical tactics use proper Proof.context instead of historic types
   208 claset/clasimpset.  Old-style declarations like addIs, addEs, addDs
   209 operate directly on Proof.context.  Raw type claset retains its use as
   210 snapshot of the classical context, which can be recovered via
   211 (put_claset HOL_cs) etc.  Type clasimpset has been discontinued.
   212 INCOMPATIBILITY, classical tactics and derived proof methods require
   213 proper Proof.context.
   214 
   215 * Scala layer provides JVM method invocation service for static
   216 methods of type (String)String, see Invoke_Scala.method in ML.
   217 For example:
   218 
   219   Invoke_Scala.method "java.lang.System.getProperty" "java.home"
   220 
   221 
   222 
   223 New in Isabelle2011 (January 2011)
   224 ----------------------------------
   225 
   226 *** General ***
   227 
   228 * Experimental Prover IDE based on Isabelle/Scala and jEdit (see
   229 src/Tools/jEdit).  This also serves as IDE for Isabelle/ML, with
   230 useful tooltips and hyperlinks produced from its static analysis.  The
   231 bundled component provides an executable Isabelle tool that can be run
   232 like this:
   233 
   234   Isabelle2011/bin/isabelle jedit
   235 
   236 * Significantly improved Isabelle/Isar implementation manual.
   237 
   238 * System settings: ISABELLE_HOME_USER now includes ISABELLE_IDENTIFIER
   239 (and thus refers to something like $HOME/.isabelle/Isabelle2011),
   240 while the default heap location within that directory lacks that extra
   241 suffix.  This isolates multiple Isabelle installations from each
   242 other, avoiding problems with old settings in new versions.
   243 INCOMPATIBILITY, need to copy/upgrade old user settings manually.
   244 
   245 * Source files are always encoded as UTF-8, instead of old-fashioned
   246 ISO-Latin-1.  INCOMPATIBILITY.  Isabelle LaTeX documents might require
   247 the following package declarations:
   248 
   249   \usepackage[utf8]{inputenc}
   250   \usepackage{textcomp}
   251 
   252 * Explicit treatment of UTF-8 sequences as Isabelle symbols, such that
   253 a Unicode character is treated as a single symbol, not a sequence of
   254 non-ASCII bytes as before.  Since Isabelle/ML string literals may
   255 contain symbols without further backslash escapes, Unicode can now be
   256 used here as well.  Recall that Symbol.explode in ML provides a
   257 consistent view on symbols, while raw explode (or String.explode)
   258 merely give a byte-oriented representation.
   259 
   260 * Theory loader: source files are primarily located via the master
   261 directory of each theory node (where the .thy file itself resides).
   262 The global load path is still partially available as legacy feature.
   263 Minor INCOMPATIBILITY due to subtle change in file lookup: use
   264 explicit paths, relatively to the theory.
   265 
   266 * Special treatment of ML file names has been discontinued.
   267 Historically, optional extensions .ML or .sml were added on demand --
   268 at the cost of clarity of file dependencies.  Recall that Isabelle/ML
   269 files exclusively use the .ML extension.  Minor INCOMPATIBILTY.
   270 
   271 * Various options that affect pretty printing etc. are now properly
   272 handled within the context via configuration options, instead of
   273 unsynchronized references or print modes.  There are both ML Config.T
   274 entities and Isar declaration attributes to access these.
   275 
   276   ML (Config.T)                 Isar (attribute)
   277 
   278   eta_contract                  eta_contract
   279   show_brackets                 show_brackets
   280   show_sorts                    show_sorts
   281   show_types                    show_types
   282   show_question_marks           show_question_marks
   283   show_consts                   show_consts
   284   show_abbrevs                  show_abbrevs
   285 
   286   Syntax.ast_trace              syntax_ast_trace
   287   Syntax.ast_stat               syntax_ast_stat
   288   Syntax.ambiguity_level        syntax_ambiguity_level
   289 
   290   Goal_Display.goals_limit      goals_limit
   291   Goal_Display.show_main_goal   show_main_goal
   292 
   293   Method.rule_trace             rule_trace
   294 
   295   Thy_Output.display            thy_output_display
   296   Thy_Output.quotes             thy_output_quotes
   297   Thy_Output.indent             thy_output_indent
   298   Thy_Output.source             thy_output_source
   299   Thy_Output.break              thy_output_break
   300 
   301 Note that corresponding "..._default" references in ML may only be
   302 changed globally at the ROOT session setup, but *not* within a theory.
   303 The option "show_abbrevs" supersedes the former print mode
   304 "no_abbrevs" with inverted meaning.
   305 
   306 * More systematic naming of some configuration options.
   307 INCOMPATIBILITY.
   308 
   309   trace_simp  ~>  simp_trace
   310   debug_simp  ~>  simp_debug
   311 
   312 * Support for real valued configuration options, using simplistic
   313 floating-point notation that coincides with the inner syntax for
   314 float_token.
   315 
   316 * Support for real valued preferences (with approximative PGIP type):
   317 front-ends need to accept "pgint" values in float notation.
   318 INCOMPATIBILITY.
   319 
   320 * The IsabelleText font now includes Cyrillic, Hebrew, Arabic from
   321 DejaVu Sans.
   322 
   323 * Discontinued support for Poly/ML 5.0 and 5.1 versions.
   324 
   325 
   326 *** Pure ***
   327 
   328 * Command 'type_synonym' (with single argument) replaces somewhat
   329 outdated 'types', which is still available as legacy feature for some
   330 time.
   331 
   332 * Command 'nonterminal' (with 'and' separated list of arguments)
   333 replaces somewhat outdated 'nonterminals'.  INCOMPATIBILITY.
   334 
   335 * Command 'notepad' replaces former 'example_proof' for
   336 experimentation in Isar without any result.  INCOMPATIBILITY.
   337 
   338 * Locale interpretation commands 'interpret' and 'sublocale' accept
   339 lists of equations to map definitions in a locale to appropriate
   340 entities in the context of the interpretation.  The 'interpretation'
   341 command already provided this functionality.
   342 
   343 * Diagnostic command 'print_dependencies' prints the locale instances
   344 that would be activated if the specified expression was interpreted in
   345 the current context.  Variant "print_dependencies!" assumes a context
   346 without interpretations.
   347 
   348 * Diagnostic command 'print_interps' prints interpretations in proofs
   349 in addition to interpretations in theories.
   350 
   351 * Discontinued obsolete 'global' and 'local' commands to manipulate
   352 the theory name space.  Rare INCOMPATIBILITY.  The ML functions
   353 Sign.root_path and Sign.local_path may be applied directly where this
   354 feature is still required for historical reasons.
   355 
   356 * Discontinued obsolete 'constdefs' command.  INCOMPATIBILITY, use
   357 'definition' instead.
   358 
   359 * The "prems" fact, which refers to the accidental collection of
   360 foundational premises in the context, is now explicitly marked as
   361 legacy feature and will be discontinued soon.  Consider using "assms"
   362 of the head statement or reference facts by explicit names.
   363 
   364 * Document antiquotations @{class} and @{type} print classes and type
   365 constructors.
   366 
   367 * Document antiquotation @{file} checks file/directory entries within
   368 the local file system.
   369 
   370 
   371 *** HOL ***
   372 
   373 * Coercive subtyping: functions can be declared as coercions and type
   374 inference will add them as necessary upon input of a term.  Theory
   375 Complex_Main declares real :: nat => real and real :: int => real as
   376 coercions. A coercion function f is declared like this:
   377 
   378   declare [[coercion f]]
   379 
   380 To lift coercions through type constructors (e.g. from nat => real to
   381 nat list => real list), map functions can be declared, e.g.
   382 
   383   declare [[coercion_map map]]
   384 
   385 Currently coercion inference is activated only in theories including
   386 real numbers, i.e. descendants of Complex_Main.  This is controlled by
   387 the configuration option "coercion_enabled", e.g. it can be enabled in
   388 other theories like this:
   389 
   390   declare [[coercion_enabled]]
   391 
   392 * Command 'partial_function' provides basic support for recursive
   393 function definitions over complete partial orders.  Concrete instances
   394 are provided for i) the option type, ii) tail recursion on arbitrary
   395 types, and iii) the heap monad of Imperative_HOL.  See
   396 src/HOL/ex/Fundefs.thy and src/HOL/Imperative_HOL/ex/Linked_Lists.thy
   397 for examples.
   398 
   399 * Function package: f.psimps rules are no longer implicitly declared
   400 as [simp].  INCOMPATIBILITY.
   401 
   402 * Datatype package: theorems generated for executable equality (class
   403 "eq") carry proper names and are treated as default code equations.
   404 
   405 * Inductive package: now offers command 'inductive_simps' to
   406 automatically derive instantiated and simplified equations for
   407 inductive predicates, similar to 'inductive_cases'.
   408 
   409 * Command 'enriched_type' allows to register properties of the
   410 functorial structure of types.
   411 
   412 * Improved infrastructure for term evaluation using code generator
   413 techniques, in particular static evaluation conversions.
   414 
   415 * Code generator: Scala (2.8 or higher) has been added to the target
   416 languages.
   417 
   418 * Code generator: globbing constant expressions "*" and "Theory.*"
   419 have been replaced by the more idiomatic "_" and "Theory._".
   420 INCOMPATIBILITY.
   421 
   422 * Code generator: export_code without explicit file declaration prints
   423 to standard output.  INCOMPATIBILITY.
   424 
   425 * Code generator: do not print function definitions for case
   426 combinators any longer.
   427 
   428 * Code generator: simplification with rules determined with
   429 src/Tools/Code/code_simp.ML and method "code_simp".
   430 
   431 * Code generator for records: more idiomatic representation of record
   432 types.  Warning: records are not covered by ancient SML code
   433 generation any longer.  INCOMPATIBILITY.  In cases of need, a suitable
   434 rep_datatype declaration helps to succeed then:
   435 
   436   record 'a foo = ...
   437   ...
   438   rep_datatype foo_ext ...
   439 
   440 * Records: logical foundation type for records does not carry a
   441 '_type' suffix any longer (obsolete due to authentic syntax).
   442 INCOMPATIBILITY.
   443 
   444 * Quickcheck now by default uses exhaustive testing instead of random
   445 testing.  Random testing can be invoked by "quickcheck [random]",
   446 exhaustive testing by "quickcheck [exhaustive]".
   447 
   448 * Quickcheck instantiates polymorphic types with small finite
   449 datatypes by default. This enables a simple execution mechanism to
   450 handle quantifiers and function equality over the finite datatypes.
   451 
   452 * Quickcheck random generator has been renamed from "code" to
   453 "random".  INCOMPATIBILITY.
   454 
   455 * Quickcheck now has a configurable time limit which is set to 30
   456 seconds by default. This can be changed by adding [timeout = n] to the
   457 quickcheck command. The time limit for Auto Quickcheck is still set
   458 independently.
   459 
   460 * Quickcheck in locales considers interpretations of that locale for
   461 counter example search.
   462 
   463 * Sledgehammer:
   464   - Added "smt" and "remote_smt" provers based on the "smt" proof
   465     method. See the Sledgehammer manual for details ("isabelle doc
   466     sledgehammer").
   467   - Renamed commands:
   468     sledgehammer atp_info ~> sledgehammer running_provers
   469     sledgehammer atp_kill ~> sledgehammer kill_provers
   470     sledgehammer available_atps ~> sledgehammer available_provers
   471     INCOMPATIBILITY.
   472   - Renamed options:
   473     sledgehammer [atps = ...] ~> sledgehammer [provers = ...]
   474     sledgehammer [atp = ...] ~> sledgehammer [prover = ...]
   475     sledgehammer [timeout = 77 s] ~> sledgehammer [timeout = 77]
   476     (and "ms" and "min" are no longer supported)
   477     INCOMPATIBILITY.
   478 
   479 * Nitpick:
   480   - Renamed options:
   481     nitpick [timeout = 77 s] ~> nitpick [timeout = 77]
   482     nitpick [tac_timeout = 777 ms] ~> nitpick [tac_timeout = 0.777]
   483     INCOMPATIBILITY.
   484   - Added support for partial quotient types.
   485   - Added local versions of the "Nitpick.register_xxx" functions.
   486   - Added "whack" option.
   487   - Allow registration of quotient types as codatatypes.
   488   - Improved "merge_type_vars" option to merge more types.
   489   - Removed unsound "fast_descrs" option.
   490   - Added custom symmetry breaking for datatypes, making it possible to reach
   491     higher cardinalities.
   492   - Prevent the expansion of too large definitions.
   493 
   494 * Proof methods "metis" and "meson" now have configuration options
   495 "meson_trace", "metis_trace", and "metis_verbose" that can be enabled
   496 to diagnose these tools. E.g.
   497 
   498     using [[metis_trace = true]]
   499 
   500 * Auto Solve: Renamed "Auto Solve Direct".  The tool is now available
   501 manually as command 'solve_direct'.
   502 
   503 * The default SMT solver Z3 must be enabled explicitly (due to
   504 licensing issues) by setting the environment variable
   505 Z3_NON_COMMERCIAL in etc/settings of the component, for example.  For
   506 commercial applications, the SMT solver CVC3 is provided as fall-back;
   507 changing the SMT solver is done via the configuration option
   508 "smt_solver".
   509 
   510 * Remote SMT solvers need to be referred to by the "remote_" prefix,
   511 i.e. "remote_cvc3" and "remote_z3".
   512 
   513 * Added basic SMT support for datatypes, records, and typedefs using
   514 the oracle mode (no proofs).  Direct support of pairs has been dropped
   515 in exchange (pass theorems fst_conv snd_conv pair_collapse to the SMT
   516 support for a similar behavior).  Minor INCOMPATIBILITY.
   517 
   518 * Changed SMT configuration options:
   519   - Renamed:
   520     z3_proofs ~> smt_oracle (with inverted meaning)
   521     z3_trace_assms ~> smt_trace_used_facts
   522     INCOMPATIBILITY.
   523   - Added:
   524     smt_verbose
   525     smt_random_seed
   526     smt_datatypes
   527     smt_infer_triggers
   528     smt_monomorph_limit
   529     cvc3_options
   530     remote_cvc3_options
   531     remote_z3_options
   532     yices_options
   533 
   534 * Boogie output files (.b2i files) need to be declared in the theory
   535 header.
   536 
   537 * Simplification procedure "list_to_set_comprehension" rewrites list
   538 comprehensions applied to List.set to set comprehensions.  Occasional
   539 INCOMPATIBILITY, may be deactivated like this:
   540 
   541   declare [[simproc del: list_to_set_comprehension]]
   542 
   543 * Removed old version of primrec package.  INCOMPATIBILITY.
   544 
   545 * Removed simplifier congruence rule of "prod_case", as has for long
   546 been the case with "split".  INCOMPATIBILITY.
   547 
   548 * String.literal is a type, but not a datatype.  INCOMPATIBILITY.
   549 
   550 * Removed [split_format ... and ... and ...] version of
   551 [split_format].  Potential INCOMPATIBILITY.
   552 
   553 * Predicate "sorted" now defined inductively, with nice induction
   554 rules.  INCOMPATIBILITY: former sorted.simps now named sorted_simps.
   555 
   556 * Constant "contents" renamed to "the_elem", to free the generic name
   557 contents for other uses.  INCOMPATIBILITY.
   558 
   559 * Renamed class eq and constant eq (for code generation) to class
   560 equal and constant equal, plus renaming of related facts and various
   561 tuning.  INCOMPATIBILITY.
   562 
   563 * Dropped type classes mult_mono and mult_mono1.  INCOMPATIBILITY.
   564 
   565 * Removed output syntax "'a ~=> 'b" for "'a => 'b option".
   566 INCOMPATIBILITY.
   567 
   568 * Renamed theory Fset to Cset, type Fset.fset to Cset.set, in order to
   569 avoid confusion with finite sets.  INCOMPATIBILITY.
   570 
   571 * Abandoned locales equiv, congruent and congruent2 for equivalence
   572 relations.  INCOMPATIBILITY: use equivI rather than equiv_intro (same
   573 for congruent(2)).
   574 
   575 * Some previously unqualified names have been qualified:
   576 
   577   types
   578     bool ~> HOL.bool
   579     nat ~> Nat.nat
   580 
   581   constants
   582     Trueprop ~> HOL.Trueprop
   583     True ~> HOL.True
   584     False ~> HOL.False
   585     op & ~> HOL.conj
   586     op | ~> HOL.disj
   587     op --> ~> HOL.implies
   588     op = ~> HOL.eq
   589     Not ~> HOL.Not
   590     The ~> HOL.The
   591     All ~> HOL.All
   592     Ex ~> HOL.Ex
   593     Ex1 ~> HOL.Ex1
   594     Let ~> HOL.Let
   595     If ~> HOL.If
   596     Ball ~> Set.Ball
   597     Bex ~> Set.Bex
   598     Suc ~> Nat.Suc
   599     Pair ~> Product_Type.Pair
   600     fst ~> Product_Type.fst
   601     snd ~> Product_Type.snd
   602     curry ~> Product_Type.curry
   603     op : ~> Set.member
   604     Collect ~> Set.Collect
   605 
   606 INCOMPATIBILITY.
   607 
   608 * More canonical naming convention for some fundamental definitions:
   609 
   610     bot_bool_eq ~> bot_bool_def
   611     top_bool_eq ~> top_bool_def
   612     inf_bool_eq ~> inf_bool_def
   613     sup_bool_eq ~> sup_bool_def
   614     bot_fun_eq  ~> bot_fun_def
   615     top_fun_eq  ~> top_fun_def
   616     inf_fun_eq  ~> inf_fun_def
   617     sup_fun_eq  ~> sup_fun_def
   618 
   619 INCOMPATIBILITY.
   620 
   621 * More stylized fact names:
   622 
   623   expand_fun_eq ~> fun_eq_iff
   624   expand_set_eq ~> set_eq_iff
   625   set_ext       ~> set_eqI
   626   nat_number    ~> eval_nat_numeral
   627 
   628 INCOMPATIBILITY.
   629 
   630 * Refactoring of code-generation specific operations in theory List:
   631 
   632   constants
   633     null ~> List.null
   634 
   635   facts
   636     mem_iff ~> member_def
   637     null_empty ~> null_def
   638 
   639 INCOMPATIBILITY.  Note that these were not supposed to be used
   640 regularly unless for striking reasons; their main purpose was code
   641 generation.
   642 
   643 Various operations from the Haskell prelude are used for generating
   644 Haskell code.
   645 
   646 * Term "bij f" is now an abbreviation of "bij_betw f UNIV UNIV".  Term
   647 "surj f" is now an abbreviation of "range f = UNIV".  The theorems
   648 bij_def and surj_def are unchanged.  INCOMPATIBILITY.
   649 
   650 * Abolished some non-alphabetic type names: "prod" and "sum" replace
   651 "*" and "+" respectively.  INCOMPATIBILITY.
   652 
   653 * Name "Plus" of disjoint sum operator "<+>" is now hidden.  Write
   654 "Sum_Type.Plus" instead.
   655 
   656 * Constant "split" has been merged with constant "prod_case"; names of
   657 ML functions, facts etc. involving split have been retained so far,
   658 though.  INCOMPATIBILITY.
   659 
   660 * Dropped old infix syntax "_ mem _" for List.member; use "_ : set _"
   661 instead.  INCOMPATIBILITY.
   662 
   663 * Removed lemma "Option.is_none_none" which duplicates "is_none_def".
   664 INCOMPATIBILITY.
   665 
   666 * Former theory Library/Enum is now part of the HOL-Main image.
   667 INCOMPATIBILITY: all constants of the Enum theory now have to be
   668 referred to by its qualified name.
   669 
   670   enum    ~>  Enum.enum
   671   nlists  ~>  Enum.nlists
   672   product ~>  Enum.product
   673 
   674 * Theory Library/Monad_Syntax provides do-syntax for monad types.
   675 Syntax in Library/State_Monad has been changed to avoid ambiguities.
   676 INCOMPATIBILITY.
   677 
   678 * Theory Library/SetsAndFunctions has been split into
   679 Library/Function_Algebras and Library/Set_Algebras; canonical names
   680 for instance definitions for functions; various improvements.
   681 INCOMPATIBILITY.
   682 
   683 * Theory Library/Multiset provides stable quicksort implementation of
   684 sort_key.
   685 
   686 * Theory Library/Multiset: renamed empty_idemp ~> empty_neutral.
   687 INCOMPATIBILITY.
   688 
   689 * Session Multivariate_Analysis: introduced a type class for euclidean
   690 space.  Most theorems are now stated in terms of euclidean spaces
   691 instead of finite cartesian products.
   692 
   693   types
   694     real ^ 'n ~>  'a::real_vector
   695               ~>  'a::euclidean_space
   696               ~>  'a::ordered_euclidean_space
   697         (depends on your needs)
   698 
   699   constants
   700      _ $ _        ~> _ $$ _
   701      \<chi> x. _  ~> \<chi>\<chi> x. _
   702      CARD('n)     ~> DIM('a)
   703 
   704 Also note that the indices are now natural numbers and not from some
   705 finite type. Finite cartesian products of euclidean spaces, products
   706 of euclidean spaces the real and complex numbers are instantiated to
   707 be euclidean_spaces.  INCOMPATIBILITY.
   708 
   709 * Session Probability: introduced pextreal as positive extended real
   710 numbers.  Use pextreal as value for measures.  Introduce the
   711 Radon-Nikodym derivative, product spaces and Fubini's theorem for
   712 arbitrary sigma finite measures.  Introduces Lebesgue measure based on
   713 the integral in Multivariate Analysis.  INCOMPATIBILITY.
   714 
   715 * Session Imperative_HOL: revamped, corrected dozens of inadequacies.
   716 INCOMPATIBILITY.
   717 
   718 * Session SPARK (with image HOL-SPARK) provides commands to load and
   719 prove verification conditions generated by the SPARK Ada program
   720 verifier.  See also src/HOL/SPARK and src/HOL/SPARK/Examples.
   721 
   722 
   723 *** HOL-Algebra ***
   724 
   725 * Theorems for additive ring operations (locale abelian_monoid and
   726 descendants) are generated by interpretation from their multiplicative
   727 counterparts.  Names (in particular theorem names) have the mandatory
   728 qualifier 'add'.  Previous theorem names are redeclared for
   729 compatibility.
   730 
   731 * Structure "int_ring" is now an abbreviation (previously a
   732 definition).  This fits more natural with advanced interpretations.
   733 
   734 
   735 *** HOLCF ***
   736 
   737 * The domain package now runs in definitional mode by default: The
   738 former command 'new_domain' is now called 'domain'.  To use the domain
   739 package in its original axiomatic mode, use 'domain (unsafe)'.
   740 INCOMPATIBILITY.
   741 
   742 * The new class "domain" is now the default sort.  Class "predomain"
   743 is an unpointed version of "domain". Theories can be updated by
   744 replacing sort annotations as shown below.  INCOMPATIBILITY.
   745 
   746   'a::type ~> 'a::countable
   747   'a::cpo  ~> 'a::predomain
   748   'a::pcpo ~> 'a::domain
   749 
   750 * The old type class "rep" has been superseded by class "domain".
   751 Accordingly, users of the definitional package must remove any
   752 "default_sort rep" declarations.  INCOMPATIBILITY.
   753 
   754 * The domain package (definitional mode) now supports unpointed
   755 predomain argument types, as long as they are marked 'lazy'. (Strict
   756 arguments must be in class "domain".) For example, the following
   757 domain definition now works:
   758 
   759   domain natlist = nil | cons (lazy "nat discr") (lazy "natlist")
   760 
   761 * Theory HOLCF/Library/HOL_Cpo provides cpo and predomain class
   762 instances for types from main HOL: bool, nat, int, char, 'a + 'b,
   763 'a option, and 'a list.  Additionally, it configures fixrec and the
   764 domain package to work with these types.  For example:
   765 
   766   fixrec isInl :: "('a + 'b) u -> tr"
   767     where "isInl$(up$(Inl x)) = TT" | "isInl$(up$(Inr y)) = FF"
   768 
   769   domain V = VFun (lazy "V -> V") | VCon (lazy "nat") (lazy "V list")
   770 
   771 * The "(permissive)" option of fixrec has been replaced with a
   772 per-equation "(unchecked)" option. See
   773 src/HOL/HOLCF/Tutorial/Fixrec_ex.thy for examples. INCOMPATIBILITY.
   774 
   775 * The "bifinite" class no longer fixes a constant "approx"; the class
   776 now just asserts that such a function exists.  INCOMPATIBILITY.
   777 
   778 * Former type "alg_defl" has been renamed to "defl".  HOLCF no longer
   779 defines an embedding of type 'a defl into udom by default; instances
   780 of "bifinite" and "domain" classes are available in
   781 src/HOL/HOLCF/Library/Defl_Bifinite.thy.
   782 
   783 * The syntax "REP('a)" has been replaced with "DEFL('a)".
   784 
   785 * The predicate "directed" has been removed.  INCOMPATIBILITY.
   786 
   787 * The type class "finite_po" has been removed.  INCOMPATIBILITY.
   788 
   789 * The function "cprod_map" has been renamed to "prod_map".
   790 INCOMPATIBILITY.
   791 
   792 * The monadic bind operator on each powerdomain has new binder syntax
   793 similar to sets, e.g. "\<Union>\<sharp>x\<in>xs. t" represents
   794 "upper_bind\<cdot>xs\<cdot>(\<Lambda> x. t)".
   795 
   796 * The infix syntax for binary union on each powerdomain has changed
   797 from e.g. "+\<sharp>" to "\<union>\<sharp>", for consistency with set
   798 syntax.  INCOMPATIBILITY.
   799 
   800 * The constant "UU" has been renamed to "bottom".  The syntax "UU" is
   801 still supported as an input translation.
   802 
   803 * Renamed some theorems (the original names are also still available).
   804 
   805   expand_fun_below   ~> fun_below_iff
   806   below_fun_ext      ~> fun_belowI
   807   expand_cfun_eq     ~> cfun_eq_iff
   808   ext_cfun           ~> cfun_eqI
   809   expand_cfun_below  ~> cfun_below_iff
   810   below_cfun_ext     ~> cfun_belowI
   811   cont2cont_Rep_CFun ~> cont2cont_APP
   812 
   813 * The Abs and Rep functions for various types have changed names.
   814 Related theorem names have also changed to match. INCOMPATIBILITY.
   815 
   816   Rep_CFun  ~> Rep_cfun
   817   Abs_CFun  ~> Abs_cfun
   818   Rep_Sprod ~> Rep_sprod
   819   Abs_Sprod ~> Abs_sprod
   820   Rep_Ssum  ~> Rep_ssum
   821   Abs_Ssum  ~> Abs_ssum
   822 
   823 * Lemmas with names of the form *_defined_iff or *_strict_iff have
   824 been renamed to *_bottom_iff.  INCOMPATIBILITY.
   825 
   826 * Various changes to bisimulation/coinduction with domain package:
   827 
   828   - Definitions of "bisim" constants no longer mention definedness.
   829   - With mutual recursion, "bisim" predicate is now curried.
   830   - With mutual recursion, each type gets a separate coind theorem.
   831   - Variable names in bisim_def and coinduct rules have changed.
   832 
   833 INCOMPATIBILITY.
   834 
   835 * Case combinators generated by the domain package for type "foo" are
   836 now named "foo_case" instead of "foo_when".  INCOMPATIBILITY.
   837 
   838 * Several theorems have been renamed to more accurately reflect the
   839 names of constants and types involved.  INCOMPATIBILITY.
   840 
   841   thelub_const    ~> lub_const
   842   lub_const       ~> is_lub_const
   843   thelubI         ~> lub_eqI
   844   is_lub_lub      ~> is_lubD2
   845   lubI            ~> is_lub_lub
   846   unique_lub      ~> is_lub_unique
   847   is_ub_lub       ~> is_lub_rangeD1
   848   lub_bin_chain   ~> is_lub_bin_chain
   849   lub_fun         ~> is_lub_fun
   850   thelub_fun      ~> lub_fun
   851   thelub_cfun     ~> lub_cfun
   852   thelub_Pair     ~> lub_Pair
   853   lub_cprod       ~> is_lub_prod
   854   thelub_cprod    ~> lub_prod
   855   minimal_cprod   ~> minimal_prod
   856   inst_cprod_pcpo ~> inst_prod_pcpo
   857   UU_I            ~> bottomI
   858   compact_UU      ~> compact_bottom
   859   deflation_UU    ~> deflation_bottom
   860   finite_deflation_UU ~> finite_deflation_bottom
   861 
   862 * Many legacy theorem names have been discontinued.  INCOMPATIBILITY.
   863 
   864   sq_ord_less_eq_trans ~> below_eq_trans
   865   sq_ord_eq_less_trans ~> eq_below_trans
   866   refl_less            ~> below_refl
   867   trans_less           ~> below_trans
   868   antisym_less         ~> below_antisym
   869   antisym_less_inverse ~> po_eq_conv [THEN iffD1]
   870   box_less             ~> box_below
   871   rev_trans_less       ~> rev_below_trans
   872   not_less2not_eq      ~> not_below2not_eq
   873   less_UU_iff          ~> below_UU_iff
   874   flat_less_iff        ~> flat_below_iff
   875   adm_less             ~> adm_below
   876   adm_not_less         ~> adm_not_below
   877   adm_compact_not_less ~> adm_compact_not_below
   878   less_fun_def         ~> below_fun_def
   879   expand_fun_less      ~> fun_below_iff
   880   less_fun_ext         ~> fun_belowI
   881   less_discr_def       ~> below_discr_def
   882   discr_less_eq        ~> discr_below_eq
   883   less_unit_def        ~> below_unit_def
   884   less_cprod_def       ~> below_prod_def
   885   prod_lessI           ~> prod_belowI
   886   Pair_less_iff        ~> Pair_below_iff
   887   fst_less_iff         ~> fst_below_iff
   888   snd_less_iff         ~> snd_below_iff
   889   expand_cfun_less     ~> cfun_below_iff
   890   less_cfun_ext        ~> cfun_belowI
   891   injection_less       ~> injection_below
   892   less_up_def          ~> below_up_def
   893   not_Iup_less         ~> not_Iup_below
   894   Iup_less             ~> Iup_below
   895   up_less              ~> up_below
   896   Def_inject_less_eq   ~> Def_below_Def
   897   Def_less_is_eq       ~> Def_below_iff
   898   spair_less_iff       ~> spair_below_iff
   899   less_sprod           ~> below_sprod
   900   spair_less           ~> spair_below
   901   sfst_less_iff        ~> sfst_below_iff
   902   ssnd_less_iff        ~> ssnd_below_iff
   903   fix_least_less       ~> fix_least_below
   904   dist_less_one        ~> dist_below_one
   905   less_ONE             ~> below_ONE
   906   ONE_less_iff         ~> ONE_below_iff
   907   less_sinlD           ~> below_sinlD
   908   less_sinrD           ~> below_sinrD
   909 
   910 
   911 *** FOL and ZF ***
   912 
   913 * All constant names are now qualified internally and use proper
   914 identifiers, e.g. "IFOL.eq" instead of "op =".  INCOMPATIBILITY.
   915 
   916 
   917 *** ML ***
   918 
   919 * Antiquotation @{assert} inlines a function bool -> unit that raises
   920 Fail if the argument is false.  Due to inlining the source position of
   921 failed assertions is included in the error output.
   922 
   923 * Discontinued antiquotation @{theory_ref}, which is obsolete since ML
   924 text is in practice always evaluated with a stable theory checkpoint.
   925 Minor INCOMPATIBILITY, use (Theory.check_thy @{theory}) instead.
   926 
   927 * Antiquotation @{theory A} refers to theory A from the ancestry of
   928 the current context, not any accidental theory loader state as before.
   929 Potential INCOMPATIBILITY, subtle change in semantics.
   930 
   931 * Syntax.pretty_priority (default 0) configures the required priority
   932 of pretty-printed output and thus affects insertion of parentheses.
   933 
   934 * Syntax.default_root (default "any") configures the inner syntax
   935 category (nonterminal symbol) for parsing of terms.
   936 
   937 * Former exception Library.UnequalLengths now coincides with
   938 ListPair.UnequalLengths.
   939 
   940 * Renamed structure MetaSimplifier to Raw_Simplifier.  Note that the
   941 main functionality is provided by structure Simplifier.
   942 
   943 * Renamed raw "explode" function to "raw_explode" to emphasize its
   944 meaning.  Note that internally to Isabelle, Symbol.explode is used in
   945 almost all situations.
   946 
   947 * Discontinued obsolete function sys_error and exception SYS_ERROR.
   948 See implementation manual for further details on exceptions in
   949 Isabelle/ML.
   950 
   951 * Renamed setmp_noncritical to Unsynchronized.setmp to emphasize its
   952 meaning.
   953 
   954 * Renamed structure PureThy to Pure_Thy and moved most of its
   955 operations to structure Global_Theory, to emphasize that this is
   956 rarely-used global-only stuff.
   957 
   958 * Discontinued Output.debug.  Minor INCOMPATIBILITY, use plain writeln
   959 instead (or tracing for high-volume output).
   960 
   961 * Configuration option show_question_marks only affects regular pretty
   962 printing of types and terms, not raw Term.string_of_vname.
   963 
   964 * ML_Context.thm and ML_Context.thms are no longer pervasive.  Rare
   965 INCOMPATIBILITY, superseded by static antiquotations @{thm} and
   966 @{thms} for most purposes.
   967 
   968 * ML structure Unsynchronized is never opened, not even in Isar
   969 interaction mode as before.  Old Unsynchronized.set etc. have been
   970 discontinued -- use plain := instead.  This should be *rare* anyway,
   971 since modern tools always work via official context data, notably
   972 configuration options.
   973 
   974 * Parallel and asynchronous execution requires special care concerning
   975 interrupts.  Structure Exn provides some convenience functions that
   976 avoid working directly with raw Interrupt.  User code must not absorb
   977 interrupts -- intermediate handling (for cleanup etc.) needs to be
   978 followed by re-raising of the original exception.  Another common
   979 source of mistakes are "handle _" patterns, which make the meaning of
   980 the program subject to physical effects of the environment.
   981 
   982 
   983 
   984 New in Isabelle2009-2 (June 2010)
   985 ---------------------------------
   986 
   987 *** General ***
   988 
   989 * Authentic syntax for *all* logical entities (type classes, type
   990 constructors, term constants): provides simple and robust
   991 correspondence between formal entities and concrete syntax.  Within
   992 the parse tree / AST representations, "constants" are decorated by
   993 their category (class, type, const) and spelled out explicitly with
   994 their full internal name.
   995 
   996 Substantial INCOMPATIBILITY concerning low-level syntax declarations
   997 and translations (translation rules and translation functions in ML).
   998 Some hints on upgrading:
   999 
  1000   - Many existing uses of 'syntax' and 'translations' can be replaced
  1001     by more modern 'type_notation', 'notation' and 'abbreviation',
  1002     which are independent of this issue.
  1003 
  1004   - 'translations' require markup within the AST; the term syntax
  1005     provides the following special forms:
  1006 
  1007       CONST c   -- produces syntax version of constant c from context
  1008       XCONST c  -- literally c, checked as constant from context
  1009       c         -- literally c, if declared by 'syntax'
  1010 
  1011     Plain identifiers are treated as AST variables -- occasionally the
  1012     system indicates accidental variables via the error "rhs contains
  1013     extra variables".
  1014 
  1015     Type classes and type constructors are marked according to their
  1016     concrete syntax.  Some old translations rules need to be written
  1017     for the "type" category, using type constructor application
  1018     instead of pseudo-term application of the default category
  1019     "logic".
  1020 
  1021   - 'parse_translation' etc. in ML may use the following
  1022     antiquotations:
  1023 
  1024       @{class_syntax c}   -- type class c within parse tree / AST
  1025       @{term_syntax c}    -- type constructor c within parse tree / AST
  1026       @{const_syntax c}   -- ML version of "CONST c" above
  1027       @{syntax_const c}   -- literally c (checked wrt. 'syntax' declarations)
  1028 
  1029   - Literal types within 'typed_print_translations', i.e. those *not*
  1030     represented as pseudo-terms are represented verbatim.  Use @{class
  1031     c} or @{type_name c} here instead of the above syntax
  1032     antiquotations.
  1033 
  1034 Note that old non-authentic syntax was based on unqualified base
  1035 names, so all of the above "constant" names would coincide.  Recall
  1036 that 'print_syntax' and ML_command "set Syntax.trace_ast" help to
  1037 diagnose syntax problems.
  1038 
  1039 * Type constructors admit general mixfix syntax, not just infix.
  1040 
  1041 * Concrete syntax may be attached to local entities without a proof
  1042 body, too.  This works via regular mixfix annotations for 'fix',
  1043 'def', 'obtain' etc. or via the explicit 'write' command, which is
  1044 similar to the 'notation' command in theory specifications.
  1045 
  1046 * Discontinued unnamed infix syntax (legacy feature for many years) --
  1047 need to specify constant name and syntax separately.  Internal ML
  1048 datatype constructors have been renamed from InfixName to Infix etc.
  1049 Minor INCOMPATIBILITY.
  1050 
  1051 * Schematic theorem statements need to be explicitly markup as such,
  1052 via commands 'schematic_lemma', 'schematic_theorem',
  1053 'schematic_corollary'.  Thus the relevance of the proof is made
  1054 syntactically clear, which impacts performance in a parallel or
  1055 asynchronous interactive environment.  Minor INCOMPATIBILITY.
  1056 
  1057 * Use of cumulative prems via "!" in some proof methods has been
  1058 discontinued (old legacy feature).
  1059 
  1060 * References 'trace_simp' and 'debug_simp' have been replaced by
  1061 configuration options stored in the context. Enabling tracing (the
  1062 case of debugging is similar) in proofs works via
  1063 
  1064   using [[trace_simp = true]]
  1065 
  1066 Tracing is then active for all invocations of the simplifier in
  1067 subsequent goal refinement steps. Tracing may also still be enabled or
  1068 disabled via the ProofGeneral settings menu.
  1069 
  1070 * Separate commands 'hide_class', 'hide_type', 'hide_const',
  1071 'hide_fact' replace the former 'hide' KIND command.  Minor
  1072 INCOMPATIBILITY.
  1073 
  1074 * Improved parallelism of proof term normalization: usedir -p2 -q0 is
  1075 more efficient than combinations with -q1 or -q2.
  1076 
  1077 
  1078 *** Pure ***
  1079 
  1080 * Proofterms record type-class reasoning explicitly, using the
  1081 "unconstrain" operation internally.  This eliminates all sort
  1082 constraints from a theorem and proof, introducing explicit
  1083 OFCLASS-premises.  On the proof term level, this operation is
  1084 automatically applied at theorem boundaries, such that closed proofs
  1085 are always free of sort constraints.  INCOMPATIBILITY for tools that
  1086 inspect proof terms.
  1087 
  1088 * Local theory specifications may depend on extra type variables that
  1089 are not present in the result type -- arguments TYPE('a) :: 'a itself
  1090 are added internally.  For example:
  1091 
  1092   definition unitary :: bool where "unitary = (ALL (x::'a) y. x = y)"
  1093 
  1094 * Predicates of locales introduced by classes carry a mandatory
  1095 "class" prefix.  INCOMPATIBILITY.
  1096 
  1097 * Vacuous class specifications observe default sort.  INCOMPATIBILITY.
  1098 
  1099 * Old 'axclass' command has been discontinued.  INCOMPATIBILITY, use
  1100 'class' instead.
  1101 
  1102 * Command 'code_reflect' allows to incorporate generated ML code into
  1103 runtime environment; replaces immature code_datatype antiquotation.
  1104 INCOMPATIBILITY.
  1105 
  1106 * Code generator: simple concept for abstract datatypes obeying
  1107 invariants.
  1108 
  1109 * Code generator: details of internal data cache have no impact on the
  1110 user space functionality any longer.
  1111 
  1112 * Methods "unfold_locales" and "intro_locales" ignore non-locale
  1113 subgoals.  This is more appropriate for interpretations with 'where'.
  1114 INCOMPATIBILITY.
  1115 
  1116 * Command 'example_proof' opens an empty proof body.  This allows to
  1117 experiment with Isar, without producing any persistent result.
  1118 
  1119 * Commands 'type_notation' and 'no_type_notation' declare type syntax
  1120 within a local theory context, with explicit checking of the
  1121 constructors involved (in contrast to the raw 'syntax' versions).
  1122 
  1123 * Commands 'types' and 'typedecl' now work within a local theory
  1124 context -- without introducing dependencies on parameters or
  1125 assumptions, which is not possible in Isabelle/Pure.
  1126 
  1127 * Command 'defaultsort' has been renamed to 'default_sort', it works
  1128 within a local theory context.  Minor INCOMPATIBILITY.
  1129 
  1130 
  1131 *** HOL ***
  1132 
  1133 * Command 'typedef' now works within a local theory context -- without
  1134 introducing dependencies on parameters or assumptions, which is not
  1135 possible in Isabelle/Pure/HOL.  Note that the logical environment may
  1136 contain multiple interpretations of local typedefs (with different
  1137 non-emptiness proofs), even in a global theory context.
  1138 
  1139 * New package for quotient types.  Commands 'quotient_type' and
  1140 'quotient_definition' may be used for defining types and constants by
  1141 quotient constructions.  An example is the type of integers created by
  1142 quotienting pairs of natural numbers:
  1143 
  1144   fun
  1145     intrel :: "(nat * nat) => (nat * nat) => bool"
  1146   where
  1147     "intrel (x, y) (u, v) = (x + v = u + y)"
  1148 
  1149   quotient_type int = "nat * nat" / intrel
  1150     by (auto simp add: equivp_def expand_fun_eq)
  1151 
  1152   quotient_definition
  1153     "0::int" is "(0::nat, 0::nat)"
  1154 
  1155 The method "lifting" can be used to lift of theorems from the
  1156 underlying "raw" type to the quotient type.  The example
  1157 src/HOL/Quotient_Examples/FSet.thy includes such a quotient
  1158 construction and provides a reasoning infrastructure for finite sets.
  1159 
  1160 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
  1161 clash with new theory Quotient in Main HOL.
  1162 
  1163 * Moved the SMT binding into the main HOL session, eliminating
  1164 separate HOL-SMT session.
  1165 
  1166 * List membership infix mem operation is only an input abbreviation.
  1167 INCOMPATIBILITY.
  1168 
  1169 * Theory Library/Word.thy has been removed.  Use library Word/Word.thy
  1170 for future developements; former Library/Word.thy is still present in
  1171 the AFP entry RSAPPS.
  1172 
  1173 * Theorem Int.int_induct renamed to Int.int_of_nat_induct and is no
  1174 longer shadowed.  INCOMPATIBILITY.
  1175 
  1176 * Dropped theorem duplicate comp_arith; use semiring_norm instead.
  1177 INCOMPATIBILITY.
  1178 
  1179 * Dropped theorem RealPow.real_sq_order; use power2_le_imp_le instead.
  1180 INCOMPATIBILITY.
  1181 
  1182 * Dropped normalizing_semiring etc; use the facts in semiring classes
  1183 instead.  INCOMPATIBILITY.
  1184 
  1185 * Dropped several real-specific versions of lemmas about floor and
  1186 ceiling; use the generic lemmas from theory "Archimedean_Field"
  1187 instead.  INCOMPATIBILITY.
  1188 
  1189   floor_number_of_eq         ~> floor_number_of
  1190   le_floor_eq_number_of      ~> number_of_le_floor
  1191   le_floor_eq_zero           ~> zero_le_floor
  1192   le_floor_eq_one            ~> one_le_floor
  1193   floor_less_eq_number_of    ~> floor_less_number_of
  1194   floor_less_eq_zero         ~> floor_less_zero
  1195   floor_less_eq_one          ~> floor_less_one
  1196   less_floor_eq_number_of    ~> number_of_less_floor
  1197   less_floor_eq_zero         ~> zero_less_floor
  1198   less_floor_eq_one          ~> one_less_floor
  1199   floor_le_eq_number_of      ~> floor_le_number_of
  1200   floor_le_eq_zero           ~> floor_le_zero
  1201   floor_le_eq_one            ~> floor_le_one
  1202   floor_subtract_number_of   ~> floor_diff_number_of
  1203   floor_subtract_one         ~> floor_diff_one
  1204   ceiling_number_of_eq       ~> ceiling_number_of
  1205   ceiling_le_eq_number_of    ~> ceiling_le_number_of
  1206   ceiling_le_zero_eq         ~> ceiling_le_zero
  1207   ceiling_le_eq_one          ~> ceiling_le_one
  1208   less_ceiling_eq_number_of  ~> number_of_less_ceiling
  1209   less_ceiling_eq_zero       ~> zero_less_ceiling
  1210   less_ceiling_eq_one        ~> one_less_ceiling
  1211   ceiling_less_eq_number_of  ~> ceiling_less_number_of
  1212   ceiling_less_eq_zero       ~> ceiling_less_zero
  1213   ceiling_less_eq_one        ~> ceiling_less_one
  1214   le_ceiling_eq_number_of    ~> number_of_le_ceiling
  1215   le_ceiling_eq_zero         ~> zero_le_ceiling
  1216   le_ceiling_eq_one          ~> one_le_ceiling
  1217   ceiling_subtract_number_of ~> ceiling_diff_number_of
  1218   ceiling_subtract_one       ~> ceiling_diff_one
  1219 
  1220 * Theory "Finite_Set": various folding_XXX locales facilitate the
  1221 application of the various fold combinators on finite sets.
  1222 
  1223 * Library theory "RBT" renamed to "RBT_Impl"; new library theory "RBT"
  1224 provides abstract red-black tree type which is backed by "RBT_Impl" as
  1225 implementation.  INCOMPATIBILTY.
  1226 
  1227 * Theory Library/Coinductive_List has been removed -- superseded by
  1228 AFP/thys/Coinductive.
  1229 
  1230 * Theory PReal, including the type "preal" and related operations, has
  1231 been removed.  INCOMPATIBILITY.
  1232 
  1233 * Real: new development using Cauchy Sequences.
  1234 
  1235 * Split off theory "Big_Operators" containing setsum, setprod,
  1236 Inf_fin, Sup_fin, Min, Max from theory Finite_Set.  INCOMPATIBILITY.
  1237 
  1238 * Theory "Rational" renamed to "Rat", for consistency with "Nat",
  1239 "Int" etc.  INCOMPATIBILITY.
  1240 
  1241 * Constant Rat.normalize needs to be qualified.  INCOMPATIBILITY.
  1242 
  1243 * New set of rules "ac_simps" provides combined assoc / commute
  1244 rewrites for all interpretations of the appropriate generic locales.
  1245 
  1246 * Renamed theory "OrderedGroup" to "Groups" and split theory
  1247 "Ring_and_Field" into theories "Rings" and "Fields"; for more
  1248 appropriate and more consistent names suitable for name prefixes
  1249 within the HOL theories.  INCOMPATIBILITY.
  1250 
  1251 * Some generic constants have been put to appropriate theories:
  1252   - less_eq, less: Orderings
  1253   - zero, one, plus, minus, uminus, times, abs, sgn: Groups
  1254   - inverse, divide: Rings
  1255 INCOMPATIBILITY.
  1256 
  1257 * More consistent naming of type classes involving orderings (and
  1258 lattices):
  1259 
  1260     lower_semilattice                   ~> semilattice_inf
  1261     upper_semilattice                   ~> semilattice_sup
  1262 
  1263     dense_linear_order                  ~> dense_linorder
  1264 
  1265     pordered_ab_group_add               ~> ordered_ab_group_add
  1266     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
  1267     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
  1268     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
  1269     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
  1270     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
  1271     pordered_cancel_semiring            ~> ordered_cancel_semiring
  1272     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
  1273     pordered_comm_ring                  ~> ordered_comm_ring
  1274     pordered_comm_semiring              ~> ordered_comm_semiring
  1275     pordered_ring                       ~> ordered_ring
  1276     pordered_ring_abs                   ~> ordered_ring_abs
  1277     pordered_semiring                   ~> ordered_semiring
  1278 
  1279     ordered_ab_group_add                ~> linordered_ab_group_add
  1280     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
  1281     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
  1282     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
  1283     ordered_field                       ~> linordered_field
  1284     ordered_field_no_lb                 ~> linordered_field_no_lb
  1285     ordered_field_no_ub                 ~> linordered_field_no_ub
  1286     ordered_field_dense_linear_order    ~> dense_linordered_field
  1287     ordered_idom                        ~> linordered_idom
  1288     ordered_ring                        ~> linordered_ring
  1289     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
  1290     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
  1291     ordered_ring_strict                 ~> linordered_ring_strict
  1292     ordered_semidom                     ~> linordered_semidom
  1293     ordered_semiring                    ~> linordered_semiring
  1294     ordered_semiring_1                  ~> linordered_semiring_1
  1295     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
  1296     ordered_semiring_strict             ~> linordered_semiring_strict
  1297 
  1298   The following slightly odd type classes have been moved to a
  1299   separate theory Library/Lattice_Algebras:
  1300 
  1301     lordered_ab_group_add               ~> lattice_ab_group_add
  1302     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
  1303     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
  1304     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
  1305     lordered_ring                       ~> lattice_ring
  1306 
  1307 INCOMPATIBILITY.
  1308 
  1309 * Refined field classes:
  1310   - classes division_ring_inverse_zero, field_inverse_zero,
  1311     linordered_field_inverse_zero include rule inverse 0 = 0 --
  1312     subsumes former division_by_zero class;
  1313   - numerous lemmas have been ported from field to division_ring.
  1314 INCOMPATIBILITY.
  1315 
  1316 * Refined algebra theorem collections:
  1317   - dropped theorem group group_simps, use algebra_simps instead;
  1318   - dropped theorem group ring_simps, use field_simps instead;
  1319   - proper theorem collection field_simps subsumes former theorem
  1320     groups field_eq_simps and field_simps;
  1321   - dropped lemma eq_minus_self_iff which is a duplicate for
  1322     equal_neg_zero.
  1323 INCOMPATIBILITY.
  1324 
  1325 * Theory Finite_Set and List: some lemmas have been generalized from
  1326 sets to lattices:
  1327 
  1328   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
  1329   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
  1330   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
  1331   union_Union_fold_union        ~> sup_Sup_fold_sup
  1332   Inter_fold_inter              ~> Inf_fold_inf
  1333   Union_fold_union              ~> Sup_fold_sup
  1334   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
  1335   union_UNION_fold_union        ~> sup_SUPR_fold_sup
  1336   INTER_fold_inter              ~> INFI_fold_inf
  1337   UNION_fold_union              ~> SUPR_fold_sup
  1338 
  1339 * Theory "Complete_Lattice": lemmas top_def and bot_def have been
  1340 replaced by the more convenient lemmas Inf_empty and Sup_empty.
  1341 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
  1342 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
  1343 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
  1344 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
  1345 
  1346 * Reorganized theory Multiset: swapped notation of pointwise and
  1347 multiset order:
  1348 
  1349   - pointwise ordering is instance of class order with standard syntax
  1350     <= and <;
  1351   - multiset ordering has syntax <=# and <#; partial order properties
  1352     are provided by means of interpretation with prefix
  1353     multiset_order;
  1354   - less duplication, less historical organization of sections,
  1355     conversion from associations lists to multisets, rudimentary code
  1356     generation;
  1357   - use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union,
  1358     if needed.
  1359 
  1360 Renamed:
  1361 
  1362   multiset_eq_conv_count_eq  ~>  multiset_ext_iff
  1363   multi_count_ext  ~>  multiset_ext
  1364   diff_union_inverse2  ~>  diff_union_cancelR
  1365 
  1366 INCOMPATIBILITY.
  1367 
  1368 * Theory Permutation: replaced local "remove" by List.remove1.
  1369 
  1370 * Code generation: ML and OCaml code is decorated with signatures.
  1371 
  1372 * Theory List: added transpose.
  1373 
  1374 * Library/Nat_Bijection.thy is a collection of bijective functions
  1375 between nat and other types, which supersedes the older libraries
  1376 Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.
  1377 
  1378   Constants:
  1379   Nat_Int_Bij.nat2_to_nat         ~> prod_encode
  1380   Nat_Int_Bij.nat_to_nat2         ~> prod_decode
  1381   Nat_Int_Bij.int_to_nat_bij      ~> int_encode
  1382   Nat_Int_Bij.nat_to_int_bij      ~> int_decode
  1383   Countable.pair_encode           ~> prod_encode
  1384   NatIso.prod2nat                 ~> prod_encode
  1385   NatIso.nat2prod                 ~> prod_decode
  1386   NatIso.sum2nat                  ~> sum_encode
  1387   NatIso.nat2sum                  ~> sum_decode
  1388   NatIso.list2nat                 ~> list_encode
  1389   NatIso.nat2list                 ~> list_decode
  1390   NatIso.set2nat                  ~> set_encode
  1391   NatIso.nat2set                  ~> set_decode
  1392 
  1393   Lemmas:
  1394   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
  1395   Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
  1396   Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
  1397   Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
  1398   Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
  1399   Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
  1400   Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
  1401   Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
  1402   Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
  1403   Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
  1404   Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
  1405   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
  1406   Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode
  1407 
  1408 * Sledgehammer:
  1409   - Renamed ATP commands:
  1410     atp_info     ~> sledgehammer running_atps
  1411     atp_kill     ~> sledgehammer kill_atps
  1412     atp_messages ~> sledgehammer messages
  1413     atp_minimize ~> sledgehammer minimize
  1414     print_atps   ~> sledgehammer available_atps
  1415     INCOMPATIBILITY.
  1416   - Added user's manual ("isabelle doc sledgehammer").
  1417   - Added option syntax and "sledgehammer_params" to customize
  1418     Sledgehammer's behavior.  See the manual for details.
  1419   - Modified the Isar proof reconstruction code so that it produces
  1420     direct proofs rather than proofs by contradiction.  (This feature
  1421     is still experimental.)
  1422   - Made Isar proof reconstruction work for SPASS, remote ATPs, and in
  1423     full-typed mode.
  1424   - Added support for TPTP syntax for SPASS via the "spass_tptp" ATP.
  1425 
  1426 * Nitpick:
  1427   - Added and implemented "binary_ints" and "bits" options.
  1428   - Added "std" option and implemented support for nonstandard models.
  1429   - Added and implemented "finitize" option to improve the precision
  1430     of infinite datatypes based on a monotonicity analysis.
  1431   - Added support for quotient types.
  1432   - Added support for "specification" and "ax_specification"
  1433     constructs.
  1434   - Added support for local definitions (for "function" and
  1435     "termination" proofs).
  1436   - Added support for term postprocessors.
  1437   - Optimized "Multiset.multiset" and "FinFun.finfun".
  1438   - Improved efficiency of "destroy_constrs" optimization.
  1439   - Fixed soundness bugs related to "destroy_constrs" optimization and
  1440     record getters.
  1441   - Fixed soundness bug related to higher-order constructors.
  1442   - Fixed soundness bug when "full_descrs" is enabled.
  1443   - Improved precision of set constructs.
  1444   - Added "atoms" option.
  1445   - Added cache to speed up repeated Kodkod invocations on the same
  1446     problems.
  1447   - Renamed "MiniSatJNI", "zChaffJNI", "BerkMinAlloy", and
  1448     "SAT4JLight" to "MiniSat_JNI", "zChaff_JNI", "BerkMin_Alloy", and
  1449     "SAT4J_Light".  INCOMPATIBILITY.
  1450   - Removed "skolemize", "uncurry", "sym_break", "flatten_prop",
  1451     "sharing_depth", and "show_skolems" options.  INCOMPATIBILITY.
  1452   - Removed "nitpick_intro" attribute.  INCOMPATIBILITY.
  1453 
  1454 * Method "induct" now takes instantiations of the form t, where t is not
  1455   a variable, as a shorthand for "x == t", where x is a fresh variable.
  1456   If this is not intended, t has to be enclosed in parentheses.
  1457   By default, the equalities generated by definitional instantiations
  1458   are pre-simplified, which may cause parameters of inductive cases
  1459   to disappear, or may even delete some of the inductive cases.
  1460   Use "induct (no_simp)" instead of "induct" to restore the old
  1461   behaviour. The (no_simp) option is also understood by the "cases"
  1462   and "nominal_induct" methods, which now perform pre-simplification, too.
  1463   INCOMPATIBILITY.
  1464 
  1465 
  1466 *** HOLCF ***
  1467 
  1468 * Variable names in lemmas generated by the domain package have
  1469 changed; the naming scheme is now consistent with the HOL datatype
  1470 package.  Some proof scripts may be affected, INCOMPATIBILITY.
  1471 
  1472 * The domain package no longer defines the function "foo_copy" for
  1473 recursive domain "foo".  The reach lemma is now stated directly in
  1474 terms of "foo_take".  Lemmas and proofs that mention "foo_copy" must
  1475 be reformulated in terms of "foo_take", INCOMPATIBILITY.
  1476 
  1477 * Most definedness lemmas generated by the domain package (previously
  1478 of the form "x ~= UU ==> foo$x ~= UU") now have an if-and-only-if form
  1479 like "foo$x = UU <-> x = UU", which works better as a simp rule.
  1480 Proofs that used definedness lemmas as intro rules may break,
  1481 potential INCOMPATIBILITY.
  1482 
  1483 * Induction and casedist rules generated by the domain package now
  1484 declare proper case_names (one called "bottom", and one named for each
  1485 constructor).  INCOMPATIBILITY.
  1486 
  1487 * For mutually-recursive domains, separate "reach" and "take_lemma"
  1488 rules are generated for each domain, INCOMPATIBILITY.
  1489 
  1490   foo_bar.reach       ~> foo.reach  bar.reach
  1491   foo_bar.take_lemmas ~> foo.take_lemma  bar.take_lemma
  1492 
  1493 * Some lemmas generated by the domain package have been renamed for
  1494 consistency with the datatype package, INCOMPATIBILITY.
  1495 
  1496   foo.ind        ~> foo.induct
  1497   foo.finite_ind ~> foo.finite_induct
  1498   foo.coind      ~> foo.coinduct
  1499   foo.casedist   ~> foo.exhaust
  1500   foo.exhaust    ~> foo.nchotomy
  1501 
  1502 * For consistency with other definition packages, the fixrec package
  1503 now generates qualified theorem names, INCOMPATIBILITY.
  1504 
  1505   foo_simps  ~> foo.simps
  1506   foo_unfold ~> foo.unfold
  1507   foo_induct ~> foo.induct
  1508 
  1509 * The "fixrec_simp" attribute has been removed.  The "fixrec_simp"
  1510 method and internal fixrec proofs now use the default simpset instead.
  1511 INCOMPATIBILITY.
  1512 
  1513 * The "contlub" predicate has been removed.  Proof scripts should use
  1514 lemma contI2 in place of monocontlub2cont, INCOMPATIBILITY.
  1515 
  1516 * The "admw" predicate has been removed, INCOMPATIBILITY.
  1517 
  1518 * The constants cpair, cfst, and csnd have been removed in favor of
  1519 Pair, fst, and snd from Isabelle/HOL, INCOMPATIBILITY.
  1520 
  1521 
  1522 *** ML ***
  1523 
  1524 * Antiquotations for basic formal entities:
  1525 
  1526     @{class NAME}         -- type class
  1527     @{class_syntax NAME}  -- syntax representation of the above
  1528 
  1529     @{type_name NAME}     -- logical type
  1530     @{type_abbrev NAME}   -- type abbreviation
  1531     @{nonterminal NAME}   -- type of concrete syntactic category
  1532     @{type_syntax NAME}   -- syntax representation of any of the above
  1533 
  1534     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
  1535     @{const_abbrev NAME}  -- abbreviated constant
  1536     @{const_syntax NAME}  -- syntax representation of any of the above
  1537 
  1538 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
  1539 syntax constant (cf. 'syntax' command).
  1540 
  1541 * Antiquotation @{make_string} inlines a function to print arbitrary
  1542 values similar to the ML toplevel.  The result is compiler dependent
  1543 and may fall back on "?" in certain situations.
  1544 
  1545 * Diagnostic commands 'ML_val' and 'ML_command' may refer to
  1546 antiquotations @{Isar.state} and @{Isar.goal}.  This replaces impure
  1547 Isar.state() and Isar.goal(), which belong to the old TTY loop and do
  1548 not work with the asynchronous Isar document model.
  1549 
  1550 * Configuration options now admit dynamic default values, depending on
  1551 the context or even global references.
  1552 
  1553 * SHA1.digest digests strings according to SHA-1 (see RFC 3174).  It
  1554 uses an efficient external library if available (for Poly/ML).
  1555 
  1556 * Renamed some important ML structures, while keeping the old names
  1557 for some time as aliases within the structure Legacy:
  1558 
  1559   OuterKeyword  ~>  Keyword
  1560   OuterLex      ~>  Token
  1561   OuterParse    ~>  Parse
  1562   OuterSyntax   ~>  Outer_Syntax
  1563   PrintMode     ~>  Print_Mode
  1564   SpecParse     ~>  Parse_Spec
  1565   ThyInfo       ~>  Thy_Info
  1566   ThyLoad       ~>  Thy_Load
  1567   ThyOutput     ~>  Thy_Output
  1568   TypeInfer     ~>  Type_Infer
  1569 
  1570 Note that "open Legacy" simplifies porting of sources, but forgetting
  1571 to remove it again will complicate porting again in the future.
  1572 
  1573 * Most operations that refer to a global context are named
  1574 accordingly, e.g. Simplifier.global_context or
  1575 ProofContext.init_global.  There are some situations where a global
  1576 context actually works, but under normal circumstances one needs to
  1577 pass the proper local context through the code!
  1578 
  1579 * Discontinued old TheoryDataFun with its copy/init operation -- data
  1580 needs to be pure.  Functor Theory_Data_PP retains the traditional
  1581 Pretty.pp argument to merge, which is absent in the standard
  1582 Theory_Data version.
  1583 
  1584 * Sorts.certify_sort and derived "cert" operations for types and terms
  1585 no longer minimize sorts.  Thus certification at the boundary of the
  1586 inference kernel becomes invariant under addition of class relations,
  1587 which is an important monotonicity principle.  Sorts are now minimized
  1588 in the syntax layer only, at the boundary between the end-user and the
  1589 system.  Subtle INCOMPATIBILITY, may have to use Sign.minimize_sort
  1590 explicitly in rare situations.
  1591 
  1592 * Renamed old-style Drule.standard to Drule.export_without_context, to
  1593 emphasize that this is in no way a standard operation.
  1594 INCOMPATIBILITY.
  1595 
  1596 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
  1597 usual for resolution.  Rare INCOMPATIBILITY.
  1598 
  1599 * Renamed varify/unvarify operations to varify_global/unvarify_global
  1600 to emphasize that these only work in a global situation (which is
  1601 quite rare).
  1602 
  1603 * Curried take and drop in library.ML; negative length is interpreted
  1604 as infinity (as in chop).  Subtle INCOMPATIBILITY.
  1605 
  1606 * Proof terms: type substitutions on proof constants now use canonical
  1607 order of type variables.  INCOMPATIBILITY for tools working with proof
  1608 terms.
  1609 
  1610 * Raw axioms/defs may no longer carry sort constraints, and raw defs
  1611 may no longer carry premises.  User-level specifications are
  1612 transformed accordingly by Thm.add_axiom/add_def.
  1613 
  1614 
  1615 *** System ***
  1616 
  1617 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
  1618 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
  1619 proof terms are enabled unconditionally in the new HOL-Proofs image.
  1620 
  1621 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
  1622 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
  1623 respectively.
  1624 
  1625 * Old lib/scripts/polyml-platform is superseded by the
  1626 ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
  1627 variant, even on a 64 bit machine.  The following example setting
  1628 prefers 64 bit if available:
  1629 
  1630   ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"
  1631 
  1632 * The preliminary Isabelle/jEdit application demonstrates the emerging
  1633 Isabelle/Scala layer for advanced prover interaction and integration.
  1634 See src/Tools/jEdit or "isabelle jedit" provided by the properly built
  1635 component.
  1636 
  1637 * "IsabelleText" is a Unicode font derived from Bitstream Vera Mono
  1638 and Bluesky TeX fonts.  It provides the usual Isabelle symbols,
  1639 similar to the default assignment of the document preparation system
  1640 (cf. isabellesym.sty).  The Isabelle/Scala class Isabelle_System
  1641 provides some operations for direct access to the font without asking
  1642 the user for manual installation.
  1643 
  1644 
  1645 
  1646 New in Isabelle2009-1 (December 2009)
  1647 -------------------------------------
  1648 
  1649 *** General ***
  1650 
  1651 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
  1652 one backslash should be used, even in ML sources.
  1653 
  1654 
  1655 *** Pure ***
  1656 
  1657 * Locale interpretation propagates mixins along the locale hierarchy.
  1658 The currently only available mixins are the equations used to map
  1659 local definitions to terms of the target domain of an interpretation.
  1660 
  1661 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
  1662 loc" to print all interpretations of locale "loc" in the theory.
  1663 Interpretations in proofs are not shown.
  1664 
  1665 * Thoroughly revised locales tutorial.  New section on conditional
  1666 interpretation.
  1667 
  1668 * On instantiation of classes, remaining undefined class parameters
  1669 are formally declared.  INCOMPATIBILITY.
  1670 
  1671 
  1672 *** Document preparation ***
  1673 
  1674 * New generalized style concept for printing terms: @{foo (style) ...}
  1675 instead of @{foo_style style ...}  (old form is still retained for
  1676 backward compatibility).  Styles can be also applied for
  1677 antiquotations prop, term_type and typeof.
  1678 
  1679 
  1680 *** HOL ***
  1681 
  1682 * New proof method "smt" for a combination of first-order logic with
  1683 equality, linear and nonlinear (natural/integer/real) arithmetic, and
  1684 fixed-size bitvectors; there is also basic support for higher-order
  1685 features (esp. lambda abstractions).  It is an incomplete decision
  1686 procedure based on external SMT solvers using the oracle mechanism;
  1687 for the SMT solver Z3, this method is proof-producing.  Certificates
  1688 are provided to avoid calling the external solvers solely for
  1689 re-checking proofs.  Due to a remote SMT service there is no need for
  1690 installing SMT solvers locally.  See src/HOL/SMT.
  1691 
  1692 * New commands to load and prove verification conditions generated by
  1693 the Boogie program verifier or derived systems (e.g. the Verifying C
  1694 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
  1695 
  1696 * New counterexample generator tool 'nitpick' based on the Kodkod
  1697 relational model finder.  See src/HOL/Tools/Nitpick and
  1698 src/HOL/Nitpick_Examples.
  1699 
  1700 * New commands 'code_pred' and 'values' to invoke the predicate
  1701 compiler and to enumerate values of inductive predicates.
  1702 
  1703 * A tabled implementation of the reflexive transitive closure.
  1704 
  1705 * New implementation of quickcheck uses generic code generator;
  1706 default generators are provided for all suitable HOL types, records
  1707 and datatypes.  Old quickcheck can be re-activated importing theory
  1708 Library/SML_Quickcheck.
  1709 
  1710 * New testing tool Mirabelle for automated proof tools.  Applies
  1711 several tools and tactics like sledgehammer, metis, or quickcheck, to
  1712 every proof step in a theory.  To be used in batch mode via the
  1713 "mirabelle" utility.
  1714 
  1715 * New proof method "sos" (sum of squares) for nonlinear real
  1716 arithmetic (originally due to John Harison). It requires theory
  1717 Library/Sum_Of_Squares.  It is not a complete decision procedure but
  1718 works well in practice on quantifier-free real arithmetic with +, -,
  1719 *, ^, =, <= and <, i.e. boolean combinations of equalities and
  1720 inequalities between polynomials.  It makes use of external
  1721 semidefinite programming solvers.  Method "sos" generates a
  1722 certificate that can be pasted into the proof thus avoiding the need
  1723 to call an external tool every time the proof is checked.  See
  1724 src/HOL/Library/Sum_Of_Squares.
  1725 
  1726 * New method "linarith" invokes existing linear arithmetic decision
  1727 procedure only.
  1728 
  1729 * New command 'atp_minimal' reduces result produced by Sledgehammer.
  1730 
  1731 * New Sledgehammer option "Full Types" in Proof General settings menu.
  1732 Causes full type information to be output to the ATPs.  This slows
  1733 ATPs down considerably but eliminates a source of unsound "proofs"
  1734 that fail later.
  1735 
  1736 * New method "metisFT": A version of metis that uses full type
  1737 information in order to avoid failures of proof reconstruction.
  1738 
  1739 * New evaluator "approximate" approximates an real valued term using
  1740 the same method as the approximation method.
  1741 
  1742 * Method "approximate" now supports arithmetic expressions as
  1743 boundaries of intervals and implements interval splitting and Taylor
  1744 series expansion.
  1745 
  1746 * ML antiquotation @{code_datatype} inserts definition of a datatype
  1747 generated by the code generator; e.g. see src/HOL/Predicate.thy.
  1748 
  1749 * New theory SupInf of the supremum and infimum operators for sets of
  1750 reals.
  1751 
  1752 * New theory Probability, which contains a development of measure
  1753 theory, eventually leading to Lebesgue integration and probability.
  1754 
  1755 * Extended Multivariate Analysis to include derivation and Brouwer's
  1756 fixpoint theorem.
  1757 
  1758 * Reorganization of number theory, INCOMPATIBILITY:
  1759   - new number theory development for nat and int, in theories Divides
  1760     and GCD as well as in new session Number_Theory
  1761   - some constants and facts now suffixed with _nat and _int
  1762     accordingly
  1763   - former session NumberTheory now named Old_Number_Theory, including
  1764     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
  1765   - moved theory Pocklington from src/HOL/Library to
  1766     src/HOL/Old_Number_Theory
  1767 
  1768 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
  1769 lcm of finite and infinite sets. It is shown that they form a complete
  1770 lattice.
  1771 
  1772 * Class semiring_div requires superclass no_zero_divisors and proof of
  1773 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
  1774 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
  1775 generalized to class semiring_div, subsuming former theorems
  1776 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
  1777 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
  1778 INCOMPATIBILITY.
  1779 
  1780 * Refinements to lattice classes and sets:
  1781   - less default intro/elim rules in locale variant, more default
  1782     intro/elim rules in class variant: more uniformity
  1783   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
  1784     le_inf_iff
  1785   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
  1786     sup_aci)
  1787   - renamed ACI to inf_sup_aci
  1788   - new class "boolean_algebra"
  1789   - class "complete_lattice" moved to separate theory
  1790     "Complete_Lattice"; corresponding constants (and abbreviations)
  1791     renamed and with authentic syntax:
  1792     Set.Inf ~>    Complete_Lattice.Inf
  1793     Set.Sup ~>    Complete_Lattice.Sup
  1794     Set.INFI ~>   Complete_Lattice.INFI
  1795     Set.SUPR ~>   Complete_Lattice.SUPR
  1796     Set.Inter ~>  Complete_Lattice.Inter
  1797     Set.Union ~>  Complete_Lattice.Union
  1798     Set.INTER ~>  Complete_Lattice.INTER
  1799     Set.UNION ~>  Complete_Lattice.UNION
  1800   - authentic syntax for
  1801     Set.Pow
  1802     Set.image
  1803   - mere abbreviations:
  1804     Set.empty               (for bot)
  1805     Set.UNIV                (for top)
  1806     Set.inter               (for inf, formerly Set.Int)
  1807     Set.union               (for sup, formerly Set.Un)
  1808     Complete_Lattice.Inter  (for Inf)
  1809     Complete_Lattice.Union  (for Sup)
  1810     Complete_Lattice.INTER  (for INFI)
  1811     Complete_Lattice.UNION  (for SUPR)
  1812   - object-logic definitions as far as appropriate
  1813 
  1814 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
  1815 Un_subset_iff are explicitly deleted as default simp rules; then also
  1816 their lattice counterparts le_inf_iff and le_sup_iff have to be
  1817 deleted to achieve the desired effect.
  1818 
  1819 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
  1820 rules by default any longer; the same applies to min_max.inf_absorb1
  1821 etc.  INCOMPATIBILITY.
  1822 
  1823 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
  1824 pred_set_conv by default.  INCOMPATIBILITY.
  1825 
  1826 * Power operations on relations and functions are now one dedicated
  1827 constant "compow" with infix syntax "^^".  Power operation on
  1828 multiplicative monoids retains syntax "^" and is now defined generic
  1829 in class power.  INCOMPATIBILITY.
  1830 
  1831 * Relation composition "R O S" now has a more standard argument order:
  1832 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
  1833 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
  1834 break, since the O_assoc rule was not rewritten like this.  Fix using
  1835 O_assoc[symmetric].  The same applies to the curried version "R OO S".
  1836 
  1837 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
  1838 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
  1839 INCOMPATIBILITY.
  1840 
  1841 * Most rules produced by inductive and datatype package have mandatory
  1842 prefixes.  INCOMPATIBILITY.
  1843 
  1844 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
  1845 the attribute of the same name.  Each of the theorems in the list
  1846 DERIV_intros assumes composition with an additional function and
  1847 matches a variable to the derivative, which has to be solved by the
  1848 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
  1849 of most elementary terms.  Former Maclauren.DERIV_tac and
  1850 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
  1851 INCOMPATIBILITY.
  1852 
  1853 * Code generator attributes follow the usual underscore convention:
  1854     code_unfold     replaces    code unfold
  1855     code_post       replaces    code post
  1856     etc.
  1857   INCOMPATIBILITY.
  1858 
  1859 * Renamed methods:
  1860     sizechange -> size_change
  1861     induct_scheme -> induction_schema
  1862   INCOMPATIBILITY.
  1863 
  1864 * Discontinued abbreviation "arbitrary" of constant "undefined".
  1865 INCOMPATIBILITY, use "undefined" directly.
  1866 
  1867 * Renamed theorems:
  1868     Suc_eq_add_numeral_1 -> Suc_eq_plus1
  1869     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
  1870     Suc_plus1 -> Suc_eq_plus1
  1871     *anti_sym -> *antisym*
  1872     vector_less_eq_def -> vector_le_def
  1873   INCOMPATIBILITY.
  1874 
  1875 * Added theorem List.map_map as [simp].  Removed List.map_compose.
  1876 INCOMPATIBILITY.
  1877 
  1878 * Removed predicate "M hassize n" (<--> card M = n & finite M).
  1879 INCOMPATIBILITY.
  1880 
  1881 
  1882 *** HOLCF ***
  1883 
  1884 * Theory Representable defines a class "rep" of domains that are
  1885 representable (via an ep-pair) in the universal domain type "udom".
  1886 Instances are provided for all type constructors defined in HOLCF.
  1887 
  1888 * The 'new_domain' command is a purely definitional version of the
  1889 domain package, for representable domains.  Syntax is identical to the
  1890 old domain package.  The 'new_domain' package also supports indirect
  1891 recursion using previously-defined type constructors.  See
  1892 src/HOLCF/ex/New_Domain.thy for examples.
  1893 
  1894 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
  1895 on the left-hand side of an equation, and then performs
  1896 simplification.  Rewriting is done using rules declared with the
  1897 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
  1898 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
  1899 
  1900 * The pattern-match compiler in 'fixrec' can now handle constructors
  1901 with HOL function types.  Pattern-match combinators for the Pair
  1902 constructor are pre-configured.
  1903 
  1904 * The 'fixrec' package now produces better fixed-point induction rules
  1905 for mutually-recursive definitions:  Induction rules have conclusions
  1906 of the form "P foo bar" instead of "P <foo, bar>".
  1907 
  1908 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
  1909 been renamed to "below".  The name "below" now replaces "less" in many
  1910 theorem names.  (Legacy theorem names using "less" are still supported
  1911 as well.)
  1912 
  1913 * The 'fixrec' package now supports "bottom patterns".  Bottom
  1914 patterns can be used to generate strictness rules, or to make
  1915 functions more strict (much like the bang-patterns supported by the
  1916 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
  1917 examples.
  1918 
  1919 
  1920 *** ML ***
  1921 
  1922 * Support for Poly/ML 5.3.0, with improved reporting of compiler
  1923 errors and run-time exceptions, including detailed source positions.
  1924 
  1925 * Structure Name_Space (formerly NameSpace) now manages uniquely
  1926 identified entries, with some additional information such as source
  1927 position, logical grouping etc.
  1928 
  1929 * Theory and context data is now introduced by the simplified and
  1930 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
  1931 to be pure, but the old TheoryDataFun for mutable data (with explicit
  1932 copy operation) is still available for some time.
  1933 
  1934 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
  1935 provides a high-level programming interface to synchronized state
  1936 variables with atomic update.  This works via pure function
  1937 application within a critical section -- its runtime should be as
  1938 short as possible; beware of deadlocks if critical code is nested,
  1939 either directly or indirectly via other synchronized variables!
  1940 
  1941 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
  1942 wraps raw ML references, explicitly indicating their non-thread-safe
  1943 behaviour.  The Isar toplevel keeps this structure open, to
  1944 accommodate Proof General as well as quick and dirty interactive
  1945 experiments with references.
  1946 
  1947 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
  1948 parallel tactical reasoning.
  1949 
  1950 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
  1951 are similar to SUBPROOF, but are slightly more flexible: only the
  1952 specified parts of the subgoal are imported into the context, and the
  1953 body tactic may introduce new subgoals and schematic variables.
  1954 
  1955 * Old tactical METAHYPS, which does not observe the proof context, has
  1956 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
  1957 or Subgoal.FOCUS etc.
  1958 
  1959 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
  1960 functors have their own ML name space there is no point to mark them
  1961 separately.)  Minor INCOMPATIBILITY.
  1962 
  1963 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
  1964 
  1965 * Renamed several structures FooBar to Foo_Bar.  Occasional,
  1966 INCOMPATIBILITY.
  1967 
  1968 * Operations of structure Skip_Proof no longer require quick_and_dirty
  1969 mode, which avoids critical setmp.
  1970 
  1971 * Eliminated old Attrib.add_attributes, Method.add_methods and related
  1972 combinators for "args".  INCOMPATIBILITY, need to use simplified
  1973 Attrib/Method.setup introduced in Isabelle2009.
  1974 
  1975 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
  1976 back on global_simpset_of, global_claset_of, global_clasimpset_of as
  1977 last resort.  INCOMPATIBILITY.
  1978 
  1979 * Display.pretty_thm now requires a proper context (cf. former
  1980 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
  1981 or even Display.pretty_thm_without_context as last resort.
  1982 INCOMPATIBILITY.
  1983 
  1984 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
  1985 Syntax.pretty_typ/term directly, preferably with proper context
  1986 instead of global theory.
  1987 
  1988 
  1989 *** System ***
  1990 
  1991 * Further fine tuning of parallel proof checking, scales up to 8 cores
  1992 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
  1993 usedir option -q.
  1994 
  1995 * Support for additional "Isabelle components" via etc/components, see
  1996 also the system manual.
  1997 
  1998 * The isabelle makeall tool now operates on all components with
  1999 IsaMakefile, not just hardwired "logics".
  2000 
  2001 * Removed "compress" option from isabelle-process and isabelle usedir;
  2002 this is always enabled.
  2003 
  2004 * Discontinued support for Poly/ML 4.x versions.
  2005 
  2006 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
  2007 on a given logic image.  This requires the lighttpd webserver and is
  2008 currently supported on Linux only.
  2009 
  2010 
  2011 
  2012 New in Isabelle2009 (April 2009)
  2013 --------------------------------
  2014 
  2015 *** General ***
  2016 
  2017 * Simplified main Isabelle executables, with less surprises on
  2018 case-insensitive file-systems (such as Mac OS).
  2019 
  2020   - The main Isabelle tool wrapper is now called "isabelle" instead of
  2021     "isatool."
  2022 
  2023   - The former "isabelle" alias for "isabelle-process" has been
  2024     removed (should rarely occur to regular users).
  2025 
  2026   - The former "isabelle-interface" and its alias "Isabelle" have been
  2027     removed (interfaces are now regular Isabelle tools).
  2028 
  2029 Within scripts and make files, the Isabelle environment variables
  2030 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
  2031 respectively.  (The latter are still available as legacy feature.)
  2032 
  2033 The old isabelle-interface wrapper could react in confusing ways if
  2034 the interface was uninstalled or changed otherwise.  Individual
  2035 interface tool configuration is now more explicit, see also the
  2036 Isabelle system manual.  In particular, Proof General is now available
  2037 via "isabelle emacs".
  2038 
  2039 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
  2040 purge installed copies of Isabelle executables and re-run "isabelle
  2041 install -p ...", or use symlinks.
  2042 
  2043 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
  2044 old ~/isabelle, which was slightly non-standard and apt to cause
  2045 surprises on case-insensitive file-systems (such as Mac OS).
  2046 
  2047 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
  2048 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
  2049 care is required when using older releases of Isabelle.  Note that
  2050 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
  2051 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
  2052 
  2053 * Proofs of fully specified statements are run in parallel on
  2054 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
  2055 a regular 4-core machine, if the initial heap space is made reasonably
  2056 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
  2057 
  2058 * The main reference manuals ("isar-ref", "implementation", and
  2059 "system") have been updated and extended.  Formally checked references
  2060 as hyperlinks are now available uniformly.
  2061 
  2062 
  2063 *** Pure ***
  2064 
  2065 * Complete re-implementation of locales.  INCOMPATIBILITY in several
  2066 respects.  The most important changes are listed below.  See the
  2067 Tutorial on Locales ("locales" manual) for details.
  2068 
  2069 - In locale expressions, instantiation replaces renaming.  Parameters
  2070 must be declared in a for clause.  To aid compatibility with previous
  2071 parameter inheritance, in locale declarations, parameters that are not
  2072 'touched' (instantiation position "_" or omitted) are implicitly added
  2073 with their syntax at the beginning of the for clause.
  2074 
  2075 - Syntax from abbreviations and definitions in locales is available in
  2076 locale expressions and context elements.  The latter is particularly
  2077 useful in locale declarations.
  2078 
  2079 - More flexible mechanisms to qualify names generated by locale
  2080 expressions.  Qualifiers (prefixes) may be specified in locale
  2081 expressions, and can be marked as mandatory (syntax: "name!:") or
  2082 optional (syntax "name?:").  The default depends for plain "name:"
  2083 depends on the situation where a locale expression is used: in
  2084 commands 'locale' and 'sublocale' prefixes are optional, in
  2085 'interpretation' and 'interpret' prefixes are mandatory.  The old
  2086 implicit qualifiers derived from the parameter names of a locale are
  2087 no longer generated.
  2088 
  2089 - Command "sublocale l < e" replaces "interpretation l < e".  The
  2090 instantiation clause in "interpretation" and "interpret" (square
  2091 brackets) is no longer available.  Use locale expressions.
  2092 
  2093 - When converting proof scripts, mandatory qualifiers in
  2094 'interpretation' and 'interpret' should be retained by default, even
  2095 if this is an INCOMPATIBILITY compared to former behavior.  In the
  2096 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
  2097 in locale expressions range over a single locale instance only.
  2098 
  2099 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
  2100 In existing theorem specifications replace the includes element by the
  2101 respective context elements of the included locale, omitting those
  2102 that are already present in the theorem specification.  Multiple
  2103 assume elements of a locale should be replaced by a single one
  2104 involving the locale predicate.  In the proof body, declarations (most
  2105 notably theorems) may be regained by interpreting the respective
  2106 locales in the proof context as required (command "interpret").
  2107 
  2108 If using "includes" in replacement of a target solely because the
  2109 parameter types in the theorem are not as general as in the target,
  2110 consider declaring a new locale with additional type constraints on
  2111 the parameters (context element "constrains").
  2112 
  2113 - Discontinued "locale (open)".  INCOMPATIBILITY.
  2114 
  2115 - Locale interpretation commands no longer attempt to simplify goal.
  2116 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
  2117 methods intro_locales and unfold_locales to clarify.
  2118 
  2119 - Locale interpretation commands no longer accept interpretation
  2120 attributes.  INCOMPATIBILITY.
  2121 
  2122 * Class declaration: so-called "base sort" must not be given in import
  2123 list any longer, but is inferred from the specification.  Particularly
  2124 in HOL, write
  2125 
  2126     class foo = ...
  2127 
  2128 instead of
  2129 
  2130     class foo = type + ...
  2131 
  2132 * Class target: global versions of theorems stemming do not carry a
  2133 parameter prefix any longer.  INCOMPATIBILITY.
  2134 
  2135 * Class 'instance' command no longer accepts attached definitions.
  2136 INCOMPATIBILITY, use proper 'instantiation' target instead.
  2137 
  2138 * Recovered hiding of consts, which was accidentally broken in
  2139 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
  2140 makes c inaccessible; consider using ``hide (open) const c'' instead.
  2141 
  2142 * Slightly more coherent Pure syntax, with updated documentation in
  2143 isar-ref manual.  Removed locales meta_term_syntax and
  2144 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
  2145 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
  2146 directly in regular applications.
  2147 
  2148 * There is a new syntactic category "float_const" for signed decimal
  2149 fractions (e.g. 123.45 or -123.45).
  2150 
  2151 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
  2152 interface with 'setup' command instead.
  2153 
  2154 * Command 'local_setup' is similar to 'setup', but operates on a local
  2155 theory context.
  2156 
  2157 * The 'axiomatization' command now only works within a global theory
  2158 context.  INCOMPATIBILITY.
  2159 
  2160 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
  2161 hypotheses.  Sorts required in the course of reasoning need to be
  2162 covered by the constraints in the initial statement, completed by the
  2163 type instance information of the background theory.  Non-trivial sort
  2164 hypotheses, which rarely occur in practice, may be specified via
  2165 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
  2166 
  2167   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
  2168 
  2169 The result contains an implicit sort hypotheses as before --
  2170 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
  2171 normalization.
  2172 
  2173 * Generalized Isar history, with support for linear undo, direct state
  2174 addressing etc.
  2175 
  2176 * Changed defaults for unify configuration options:
  2177 
  2178   unify_trace_bound = 50 (formerly 25)
  2179   unify_search_bound = 60 (formerly 30)
  2180 
  2181 * Different bookkeeping for code equations (INCOMPATIBILITY):
  2182 
  2183   a) On theory merge, the last set of code equations for a particular
  2184      constant is taken (in accordance with the policy applied by other
  2185      parts of the code generator framework).
  2186 
  2187   b) Code equations stemming from explicit declarations (e.g. code
  2188      attribute) gain priority over default code equations stemming
  2189      from definition, primrec, fun etc.
  2190 
  2191 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
  2192 
  2193 * Unified theorem tables for both code generators.  Thus [code
  2194 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
  2195 
  2196 * Command 'find_consts' searches for constants based on type and name
  2197 patterns, e.g.
  2198 
  2199     find_consts "_ => bool"
  2200 
  2201 By default, matching is against subtypes, but it may be restricted to
  2202 the whole type.  Searching by name is possible.  Multiple queries are
  2203 conjunctive and queries may be negated by prefixing them with a
  2204 hyphen:
  2205 
  2206     find_consts strict: "_ => bool" name: "Int" -"int => int"
  2207 
  2208 * New 'find_theorems' criterion "solves" matches theorems that
  2209 directly solve the current goal (modulo higher-order unification).
  2210 
  2211 * Auto solve feature for main theorem statements: whenever a new goal
  2212 is stated, "find_theorems solves" is called; any theorems that could
  2213 solve the lemma directly are listed as part of the goal state.
  2214 Cf. associated options in Proof General Isabelle settings menu,
  2215 enabled by default, with reasonable timeout for pathological cases of
  2216 higher-order unification.
  2217 
  2218 
  2219 *** Document preparation ***
  2220 
  2221 * Antiquotation @{lemma} now imitates a regular terminal proof,
  2222 demanding keyword 'by' and supporting the full method expression
  2223 syntax just like the Isar command 'by'.
  2224 
  2225 
  2226 *** HOL ***
  2227 
  2228 * Integrated main parts of former image HOL-Complex with HOL.  Entry
  2229 points Main and Complex_Main remain as before.
  2230 
  2231 * Logic image HOL-Plain provides a minimal HOL with the most important
  2232 tools available (inductive, datatype, primrec, ...).  This facilitates
  2233 experimentation and tool development.  Note that user applications
  2234 (and library theories) should never refer to anything below theory
  2235 Main, as before.
  2236 
  2237 * Logic image HOL-Main stops at theory Main, and thus facilitates
  2238 experimentation due to shorter build times.
  2239 
  2240 * Logic image HOL-NSA contains theories of nonstandard analysis which
  2241 were previously part of former HOL-Complex.  Entry point Hyperreal
  2242 remains valid, but theories formerly using Complex_Main should now use
  2243 new entry point Hypercomplex.
  2244 
  2245 * Generic ATP manager for Sledgehammer, based on ML threads instead of
  2246 Posix processes.  Avoids potentially expensive forking of the ML
  2247 process.  New thread-based implementation also works on non-Unix
  2248 platforms (Cygwin).  Provers are no longer hardwired, but defined
  2249 within the theory via plain ML wrapper functions.  Basic Sledgehammer
  2250 commands are covered in the isar-ref manual.
  2251 
  2252 * Wrapper scripts for remote SystemOnTPTP service allows to use
  2253 sledgehammer without local ATP installation (Vampire etc.). Other
  2254 provers may be included via suitable ML wrappers, see also
  2255 src/HOL/ATP_Linkup.thy.
  2256 
  2257 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
  2258 menu.
  2259 
  2260 * The metis method no longer fails because the theorem is too trivial
  2261 (contains the empty clause).
  2262 
  2263 * The metis method now fails in the usual manner, rather than raising
  2264 an exception, if it determines that it cannot prove the theorem.
  2265 
  2266 * Method "coherent" implements a prover for coherent logic (see also
  2267 src/Tools/coherent.ML).
  2268 
  2269 * Constants "undefined" and "default" replace "arbitrary".  Usually
  2270 "undefined" is the right choice to replace "arbitrary", though
  2271 logically there is no difference.  INCOMPATIBILITY.
  2272 
  2273 * Command "value" now integrates different evaluation mechanisms.  The
  2274 result of the first successful evaluation mechanism is printed.  In
  2275 square brackets a particular named evaluation mechanisms may be
  2276 specified (currently, [SML], [code] or [nbe]).  See further
  2277 src/HOL/ex/Eval_Examples.thy.
  2278 
  2279 * Normalization by evaluation now allows non-leftlinear equations.
  2280 Declare with attribute [code nbe].
  2281 
  2282 * Methods "case_tac" and "induct_tac" now refer to the very same rules
  2283 as the structured Isar versions "cases" and "induct", cf. the
  2284 corresponding "cases" and "induct" attributes.  Mutual induction rules
  2285 are now presented as a list of individual projections
  2286 (e.g. foo_bar.inducts for types foo and bar); the old format with
  2287 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
  2288 rare situations a different rule is selected --- notably nested tuple
  2289 elimination instead of former prod.exhaust: use explicit (case_tac t
  2290 rule: prod.exhaust) here.
  2291 
  2292 * Attributes "cases", "induct", "coinduct" support "del" option.
  2293 
  2294 * Removed fact "case_split_thm", which duplicates "case_split".
  2295 
  2296 * The option datatype has been moved to a new theory Option.  Renamed
  2297 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
  2298 
  2299 * New predicate "strict_mono" classifies strict functions on partial
  2300 orders.  With strict functions on linear orders, reasoning about
  2301 (in)equalities is facilitated by theorems "strict_mono_eq",
  2302 "strict_mono_less_eq" and "strict_mono_less".
  2303 
  2304 * Some set operations are now proper qualified constants with
  2305 authentic syntax.  INCOMPATIBILITY:
  2306 
  2307     op Int ~>   Set.Int
  2308     op Un ~>    Set.Un
  2309     INTER ~>    Set.INTER
  2310     UNION ~>    Set.UNION
  2311     Inter ~>    Set.Inter
  2312     Union ~>    Set.Union
  2313     {} ~>       Set.empty
  2314     UNIV ~>     Set.UNIV
  2315 
  2316 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  2317 theory Set.
  2318 
  2319 * Auxiliary class "itself" has disappeared -- classes without any
  2320 parameter are treated as expected by the 'class' command.
  2321 
  2322 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  2323 
  2324 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  2325 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  2326 
  2327 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  2328 method "approximation".  It proves formulas on real values by using
  2329 interval arithmetic.  In the formulas are also the transcendental
  2330 functions sin, cos, tan, atan, ln, exp and the constant pi are
  2331 allowed. For examples see
  2332 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  2333 
  2334 * Theory "Reflection" now resides in HOL/Library.
  2335 
  2336 * Entry point to Word library now simply named "Word".
  2337 INCOMPATIBILITY.
  2338 
  2339 * Made source layout more coherent with logical distribution
  2340 structure:
  2341 
  2342     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  2343     src/HOL/Library/Code_Message.thy ~> src/HOL/
  2344     src/HOL/Library/GCD.thy ~> src/HOL/
  2345     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  2346     src/HOL/Library/Parity.thy ~> src/HOL/
  2347     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  2348     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  2349     src/HOL/Real/Lubs.thy ~> src/HOL/
  2350     src/HOL/Real/PReal.thy ~> src/HOL/
  2351     src/HOL/Real/Rational.thy ~> src/HOL/
  2352     src/HOL/Real/RComplete.thy ~> src/HOL/
  2353     src/HOL/Real/RealDef.thy ~> src/HOL/
  2354     src/HOL/Real/RealPow.thy ~> src/HOL/
  2355     src/HOL/Real/Real.thy ~> src/HOL/
  2356     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  2357     src/HOL/Complex/Complex.thy ~> src/HOL/
  2358     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  2359     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  2360     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  2361     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  2362     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  2363     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  2364     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  2365     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  2366     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  2367     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  2368     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  2369     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  2370     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  2371     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  2372     src/HOL/Real/Float ~> src/HOL/Library/
  2373     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  2374     src/HOL/Real/RealVector.thy ~> src/HOL/
  2375 
  2376     src/HOL/arith_data.ML ~> src/HOL/Tools
  2377     src/HOL/hologic.ML ~> src/HOL/Tools
  2378     src/HOL/simpdata.ML ~> src/HOL/Tools
  2379     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  2380     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  2381     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  2382     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  2383     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  2384     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  2385     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  2386 
  2387     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  2388     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  2389     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  2390     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  2391     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  2392     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  2393 
  2394 * If methods "eval" and "evaluation" encounter a structured proof
  2395 state with !!/==>, only the conclusion is evaluated to True (if
  2396 possible), avoiding strange error messages.
  2397 
  2398 * Method "sizechange" automates termination proofs using (a
  2399 modification of) the size-change principle.  Requires SAT solver.  See
  2400 src/HOL/ex/Termination.thy for examples.
  2401 
  2402 * Simplifier: simproc for let expressions now unfolds if bound
  2403 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  2404 
  2405 * Method "arith": Linear arithmetic now ignores all inequalities when
  2406 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  2407 
  2408 * New attribute "arith" for facts that should always be used
  2409 automatically by arithmetic. It is intended to be used locally in
  2410 proofs, e.g.
  2411 
  2412   assumes [arith]: "x > 0"
  2413 
  2414 Global usage is discouraged because of possible performance impact.
  2415 
  2416 * New classes "top" and "bot" with corresponding operations "top" and
  2417 "bot" in theory Orderings; instantiation of class "complete_lattice"
  2418 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  2419 
  2420 * Changed definition lemma "less_fun_def" in order to provide an
  2421 instance for preorders on functions; use lemma "less_le" instead.
  2422 INCOMPATIBILITY.
  2423 
  2424 * Theory Orderings: class "wellorder" moved here, with explicit
  2425 induction rule "less_induct" as assumption.  For instantiation of
  2426 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  2427 INCOMPATIBILITY.
  2428 
  2429 * Theory Orderings: added class "preorder" as superclass of "order".
  2430 INCOMPATIBILITY: Instantiation proofs for order, linorder
  2431 etc. slightly changed.  Some theorems named order_class.* now named
  2432 preorder_class.*.
  2433 
  2434 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  2435 "diag" to "Id_on".
  2436 
  2437 * Theory Finite_Set: added a new fold combinator of type
  2438 
  2439   ('a => 'b => 'b) => 'b => 'a set => 'b
  2440 
  2441 Occasionally this is more convenient than the old fold combinator
  2442 which is now defined in terms of the new one and renamed to
  2443 fold_image.
  2444 
  2445 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  2446 and "ring_simps" have been replaced by "algebra_simps" (which can be
  2447 extended with further lemmas!).  At the moment both still exist but
  2448 the former will disappear at some point.
  2449 
  2450 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  2451 class recpower.  Type-specific simp rules for various recpower types
  2452 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  2453 
  2454 rat_power_0    -> power_0
  2455 rat_power_Suc  -> power_Suc
  2456 realpow_0      -> power_0
  2457 realpow_Suc    -> power_Suc
  2458 complexpow_0   -> power_0
  2459 complexpow_Suc -> power_Suc
  2460 power_poly_0   -> power_0
  2461 power_poly_Suc -> power_Suc
  2462 
  2463 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  2464 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  2465 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  2466 of lemmas from Divides has been generalized from nat to class
  2467 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  2468 renames resulting from duplicate elimination:
  2469 
  2470     dvd_def_mod ~>          dvd_eq_mod_eq_0
  2471     zero_dvd_iff ~>         dvd_0_left_iff
  2472     dvd_0 ~>                dvd_0_right
  2473     DIVISION_BY_ZERO_DIV ~> div_by_0
  2474     DIVISION_BY_ZERO_MOD ~> mod_by_0
  2475     mult_div ~>             div_mult_self2_is_id
  2476     mult_mod ~>             mod_mult_self2_is_0
  2477 
  2478 * Theory IntDiv: removed many lemmas that are instances of class-based
  2479 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  2480 rename old lemmas as follows:
  2481 
  2482 dvd_diff               -> nat_dvd_diff
  2483 dvd_zminus_iff         -> dvd_minus_iff
  2484 mod_add1_eq            -> mod_add_eq
  2485 mod_mult1_eq           -> mod_mult_right_eq
  2486 mod_mult1_eq'          -> mod_mult_left_eq
  2487 mod_mult_distrib_mod   -> mod_mult_eq
  2488 nat_mod_add_left_eq    -> mod_add_left_eq
  2489 nat_mod_add_right_eq   -> mod_add_right_eq
  2490 nat_mod_div_trivial    -> mod_div_trivial
  2491 nat_mod_mod_trivial    -> mod_mod_trivial
  2492 zdiv_zadd_self1        -> div_add_self1
  2493 zdiv_zadd_self2        -> div_add_self2
  2494 zdiv_zmult_self1       -> div_mult_self2_is_id
  2495 zdiv_zmult_self2       -> div_mult_self1_is_id
  2496 zdvd_triv_left         -> dvd_triv_left
  2497 zdvd_triv_right        -> dvd_triv_right
  2498 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  2499 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  2500 zmod_zadd_left_eq      -> mod_add_left_eq
  2501 zmod_zadd_right_eq     -> mod_add_right_eq
  2502 zmod_zadd_self1        -> mod_add_self1
  2503 zmod_zadd_self2        -> mod_add_self2
  2504 zmod_zadd1_eq          -> mod_add_eq
  2505 zmod_zdiff1_eq         -> mod_diff_eq
  2506 zmod_zdvd_zmod         -> mod_mod_cancel
  2507 zmod_zmod_cancel       -> mod_mod_cancel
  2508 zmod_zmult_self1       -> mod_mult_self2_is_0
  2509 zmod_zmult_self2       -> mod_mult_self1_is_0
  2510 zmod_1                 -> mod_by_1
  2511 zdiv_1                 -> div_by_1
  2512 zdvd_abs1              -> abs_dvd_iff
  2513 zdvd_abs2              -> dvd_abs_iff
  2514 zdvd_refl              -> dvd_refl
  2515 zdvd_trans             -> dvd_trans
  2516 zdvd_zadd              -> dvd_add
  2517 zdvd_zdiff             -> dvd_diff
  2518 zdvd_zminus_iff        -> dvd_minus_iff
  2519 zdvd_zminus2_iff       -> minus_dvd_iff
  2520 zdvd_zmultD            -> dvd_mult_right
  2521 zdvd_zmultD2           -> dvd_mult_left
  2522 zdvd_zmult_mono        -> mult_dvd_mono
  2523 zdvd_0_right           -> dvd_0_right
  2524 zdvd_0_left            -> dvd_0_left_iff
  2525 zdvd_1_left            -> one_dvd
  2526 zminus_dvd_iff         -> minus_dvd_iff
  2527 
  2528 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  2529 
  2530 * The real numbers offer decimal input syntax: 12.34 is translated
  2531 into 1234/10^2. This translation is not reversed upon output.
  2532 
  2533 * Theory Library/Polynomial defines an abstract type 'a poly of
  2534 univariate polynomials with coefficients of type 'a.  In addition to
  2535 the standard ring operations, it also supports div and mod.  Code
  2536 generation is also supported, using list-style constructors.
  2537 
  2538 * Theory Library/Inner_Product defines a class of real_inner for real
  2539 inner product spaces, with an overloaded operation inner :: 'a => 'a
  2540 => real.  Class real_inner is a subclass of real_normed_vector from
  2541 theory RealVector.
  2542 
  2543 * Theory Library/Product_Vector provides instances for the product
  2544 type 'a * 'b of several classes from RealVector and Inner_Product.
  2545 Definitions of addition, subtraction, scalar multiplication, norms,
  2546 and inner products are included.
  2547 
  2548 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  2549 addition to the field operations, numerals and case syntax are also
  2550 supported.
  2551 
  2552 * Theory Library/Diagonalize provides constructive version of Cantor's
  2553 first diagonalization argument.
  2554 
  2555 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  2556 zlcm (for int); carried together from various gcd/lcm developements in
  2557 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  2558 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  2559 may recover tupled syntax as follows:
  2560 
  2561     hide (open) const gcd
  2562     abbreviation gcd where
  2563       "gcd == (%(a, b). GCD.gcd a b)"
  2564     notation (output)
  2565       GCD.gcd ("gcd '(_, _')")
  2566 
  2567 The same works for lcm, zgcd, zlcm.
  2568 
  2569 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  2570 instantiations for algebraic structures.  Removed some duplicate
  2571 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  2572 
  2573 * ML antiquotation @{code} takes a constant as argument and generates
  2574 corresponding code in background and inserts name of the corresponding
  2575 resulting ML value/function/datatype constructor binding in place.
  2576 All occurrences of @{code} with a single ML block are generated
  2577 simultaneously.  Provides a generic and safe interface for
  2578 instrumentalizing code generation.  See
  2579 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  2580 In future you ought to refrain from ad-hoc compiling generated SML
  2581 code on the ML toplevel.  Note that (for technical reasons) @{code}
  2582 cannot refer to constants for which user-defined serializations are
  2583 set.  Refer to the corresponding ML counterpart directly in that
  2584 cases.
  2585 
  2586 * Command 'rep_datatype': instead of theorem names the command now
  2587 takes a list of terms denoting the constructors of the type to be
  2588 represented as datatype.  The characteristic theorems have to be
  2589 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  2590 have disappeared in favour of existing ones:
  2591 
  2592     unit_induct                 ~> unit.induct
  2593     prod_induct                 ~> prod.induct
  2594     sum_induct                  ~> sum.induct
  2595     Suc_Suc_eq                  ~> nat.inject
  2596     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  2597 
  2598 
  2599 *** HOL-Algebra ***
  2600 
  2601 * New locales for orders and lattices where the equivalence relation
  2602 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  2603 locales use a record structure with field eq for the equivalence.
  2604 
  2605 * New theory of factorial domains.
  2606 
  2607 * Units_l_inv and Units_r_inv are now simp rules by default.
  2608 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  2609 and/or r_inv will now also require deletion of these lemmas.
  2610 
  2611 * Renamed the following theorems, INCOMPATIBILITY:
  2612 
  2613 UpperD ~> Upper_memD
  2614 LowerD ~> Lower_memD
  2615 least_carrier ~> least_closed
  2616 greatest_carrier ~> greatest_closed
  2617 greatest_Lower_above ~> greatest_Lower_below
  2618 one_zero ~> carrier_one_zero
  2619 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  2620 
  2621 
  2622 *** HOL-Nominal ***
  2623 
  2624 * Nominal datatypes can now contain type-variables.
  2625 
  2626 * Commands 'nominal_inductive' and 'equivariance' work with local
  2627 theory targets.
  2628 
  2629 * Nominal primrec can now works with local theory targets and its
  2630 specification syntax now conforms to the general format as seen in
  2631 'inductive' etc.
  2632 
  2633 * Method "perm_simp" honours the standard simplifier attributes
  2634 (no_asm), (no_asm_use) etc.
  2635 
  2636 * The new predicate #* is defined like freshness, except that on the
  2637 left hand side can be a set or list of atoms.
  2638 
  2639 * Experimental command 'nominal_inductive2' derives strong induction
  2640 principles for inductive definitions.  In contrast to
  2641 'nominal_inductive', which can only deal with a fixed number of
  2642 binders, it can deal with arbitrary expressions standing for sets of
  2643 atoms to be avoided.  The only inductive definition we have at the
  2644 moment that needs this generalisation is the typing rule for Lets in
  2645 the algorithm W:
  2646 
  2647  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  2648  -----------------------------------------------------------------
  2649          Gamma |- Let x be t1 in t2 : T2
  2650 
  2651 In this rule one wants to avoid all the binders that are introduced by
  2652 "close Gamma T1".  We are looking for other examples where this
  2653 feature might be useful.  Please let us know.
  2654 
  2655 
  2656 *** HOLCF ***
  2657 
  2658 * Reimplemented the simplification procedure for proving continuity
  2659 subgoals.  The new simproc is extensible; users can declare additional
  2660 continuity introduction rules with the attribute [cont2cont].
  2661 
  2662 * The continuity simproc now uses a different introduction rule for
  2663 solving continuity subgoals on terms with lambda abstractions.  In
  2664 some rare cases the new simproc may fail to solve subgoals that the
  2665 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  2666 Potential INCOMPATIBILITY.
  2667 
  2668 * Command 'fixrec': specification syntax now conforms to the general
  2669 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  2670 examples.  INCOMPATIBILITY.
  2671 
  2672 
  2673 *** ZF ***
  2674 
  2675 * Proof of Zorn's Lemma for partial orders.
  2676 
  2677 
  2678 *** ML ***
  2679 
  2680 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  2681 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  2682 depends on multithreading, so timouts will not work before Poly/ML
  2683 5.2.1!
  2684 
  2685 * High-level support for concurrent ML programming, see
  2686 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  2687 particularly convenient to organize independent functional
  2688 computations.  The concept of "synchronized variables" provides a
  2689 higher-order interface for components with shared state, avoiding the
  2690 delicate details of mutexes and condition variables.  (Requires
  2691 Poly/ML 5.2.1 or later.)
  2692 
  2693 * ML bindings produced via Isar commands are stored within the Isar
  2694 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  2695 become thread-safe and work with undo as expected (concerning
  2696 top-level bindings, not side-effects on global references).
  2697 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  2698 compiler at runtime; really global bindings need to be given outside a
  2699 theory.  (Requires Poly/ML 5.2 or later.)
  2700 
  2701 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  2702 context.  Top-level ML bindings are stored within the proof context in
  2703 a purely sequential fashion, disregarding the nested proof structure.
  2704 ML bindings introduced by 'ML_prf' are discarded at the end of the
  2705 proof.  (Requires Poly/ML 5.2 or later.)
  2706 
  2707 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  2708 and Method.setup, as well as Isar commands 'attribute_setup' and
  2709 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  2710 existing code accordingly, or use plain 'setup' together with old
  2711 Method.add_method.
  2712 
  2713 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  2714 to 'a -> thm, while results are always tagged with an authentic oracle
  2715 name.  The Isar command 'oracle' is now polymorphic, no argument type
  2716 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  2717 accordingly.  Note that extra performance may be gained by producing
  2718 the cterm carefully, avoiding slow Thm.cterm_of.
  2719 
  2720 * Simplified interface for defining document antiquotations via
  2721 ThyOutput.antiquotation, ThyOutput.output, and optionally
  2722 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  2723 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  2724 examples.
  2725 
  2726 * More systematic treatment of long names, abstract name bindings, and
  2727 name space operations.  Basic operations on qualified names have been
  2728 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  2729 Long_Name.append.  Old type bstring has been mostly replaced by
  2730 abstract type binding (see structure Binding), which supports precise
  2731 qualification by packages and local theory targets, as well as proper
  2732 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  2733 bstring values into Binding.name, or better pass through abstract
  2734 bindings everywhere.  See further src/Pure/General/long_name.ML,
  2735 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  2736 
  2737 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  2738 LocalTheory.note etc.) now refer to the *full* internal name, not the
  2739 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  2740 
  2741 * Disposed old type and term read functions (Sign.read_def_typ,
  2742 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  2743 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  2744 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  2745 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  2746 resort for legacy applications.
  2747 
  2748 * Disposed old declarations, tactics, tactic combinators that refer to
  2749 the simpset or claset of an implicit theory (such as Addsimps,
  2750 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  2751 embedded ML text, or local_simpset_of with a proper context passed as
  2752 explicit runtime argument.
  2753 
  2754 * Rules and tactics that read instantiations (read_instantiate,
  2755 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  2756 context, which is required for parsing and type-checking.  Moreover,
  2757 the variables are specified as plain indexnames, not string encodings
  2758 thereof.  INCOMPATIBILITY.
  2759 
  2760 * Generic Toplevel.add_hook interface allows to analyze the result of
  2761 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  2762 for theorem dependency output of transactions resulting in a new
  2763 theory state.
  2764 
  2765 * ML antiquotations: block-structured compilation context indicated by
  2766 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  2767 
  2768   @{binding name}                         - basic name binding
  2769   @{let ?pat = term}                      - term abbreviation (HO matching)
  2770   @{note name = fact}                     - fact abbreviation
  2771   @{thm fact}                             - singleton fact (with attributes)
  2772   @{thms fact}                            - general fact (with attributes)
  2773   @{lemma prop by method}                 - singleton goal
  2774   @{lemma prop by meth1 meth2}            - singleton goal
  2775   @{lemma prop1 ... propN by method}      - general goal
  2776   @{lemma prop1 ... propN by meth1 meth2} - general goal
  2777   @{lemma (open) ...}                     - open derivation
  2778 
  2779 
  2780 *** System ***
  2781 
  2782 * The Isabelle "emacs" tool provides a specific interface to invoke
  2783 Proof General / Emacs, with more explicit failure if that is not
  2784 installed (the old isabelle-interface script silently falls back on
  2785 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  2786 installation location of the Proof General distribution.
  2787 
  2788 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  2789 the Isabelle process into a JVM/Scala application.  See
  2790 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  2791 process wrapper has been discontinued.)
  2792 
  2793 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  2794 
  2795 * Various status messages (with exact source position information) are
  2796 emitted, if proper markup print mode is enabled.  This allows
  2797 user-interface components to provide detailed feedback on internal
  2798 prover operations.
  2799 
  2800 
  2801 
  2802 New in Isabelle2008 (June 2008)
  2803 -------------------------------
  2804 
  2805 *** General ***
  2806 
  2807 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  2808 and updated, with formally checked references as hyperlinks.
  2809 
  2810 * Theory loader: use_thy (and similar operations) no longer set the
  2811 implicit ML context, which was occasionally hard to predict and in
  2812 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  2813 provides a proper context already.
  2814 
  2815 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2816 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  2817 'use' within a theory file will do the job.
  2818 
  2819 * Name space merge now observes canonical order, i.e. the second space
  2820 is inserted into the first one, while existing entries in the first
  2821 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  2822 swap theory imports.
  2823 
  2824 * Syntax: symbol \<chi> is now considered a letter.  Potential
  2825 INCOMPATIBILITY in identifier syntax etc.
  2826 
  2827 * Outer syntax: string tokens no longer admit escaped white space,
  2828 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  2829 white space without escapes.
  2830 
  2831 * Outer syntax: string tokens may contain arbitrary character codes
  2832 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  2833 "foo_bar".
  2834 
  2835 
  2836 *** Pure ***
  2837 
  2838 * Context-dependent token translations.  Default setup reverts locally
  2839 fixed variables, and adds hilite markup for undeclared frees.
  2840 
  2841 * Unused theorems can be found using the new command 'unused_thms'.
  2842 There are three ways of invoking it:
  2843 
  2844 (1) unused_thms
  2845      Only finds unused theorems in the current theory.
  2846 
  2847 (2) unused_thms thy_1 ... thy_n -
  2848      Finds unused theorems in the current theory and all of its ancestors,
  2849      excluding the theories thy_1 ... thy_n and all of their ancestors.
  2850 
  2851 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  2852      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  2853      their ancestors, excluding the theories thy_1 ... thy_n and all of
  2854      their ancestors.
  2855 
  2856 In order to increase the readability of the list produced by
  2857 unused_thms, theorems that have been created by a particular instance
  2858 of a theory command such as 'inductive' or 'function' are considered
  2859 to belong to the same "group", meaning that if at least one theorem in
  2860 this group is used, the other theorems in the same group are no longer
  2861 reported as unused.  Moreover, if all theorems in the group are
  2862 unused, only one theorem in the group is displayed.
  2863 
  2864 Note that proof objects have to be switched on in order for
  2865 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  2866 usually the case when using Proof General with the default settings).
  2867 
  2868 * Authentic naming of facts disallows ad-hoc overwriting of previous
  2869 theorems within the same name space.  INCOMPATIBILITY, need to remove
  2870 duplicate fact bindings, or even accidental fact duplications.  Note
  2871 that tools may maintain dynamically scoped facts systematically, using
  2872 PureThy.add_thms_dynamic.
  2873 
  2874 * Command 'hide' now allows to hide from "fact" name space as well.
  2875 
  2876 * Eliminated destructive theorem database, simpset, claset, and
  2877 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  2878 update of theories within ML code.
  2879 
  2880 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  2881 INCOMPATIBILITY, object-logics depending on former Pure require
  2882 additional setup PureThy.old_appl_syntax_setup; object-logics
  2883 depending on former CPure need to refer to Pure.
  2884 
  2885 * Commands 'use' and 'ML' are now purely functional, operating on
  2886 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  2887 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  2888 INCOMPATIBILITY.
  2889 
  2890 * Command 'setup': discontinued implicit version with ML reference.
  2891 
  2892 * Instantiation target allows for simultaneous specification of class
  2893 instance operations together with an instantiation proof.
  2894 Type-checking phase allows to refer to class operations uniformly.
  2895 See src/HOL/Complex/Complex.thy for an Isar example and
  2896 src/HOL/Library/Eval.thy for an ML example.
  2897 
  2898 * Indexing of literal facts: be more serious about including only
  2899 facts from the visible specification/proof context, but not the
  2900 background context (locale etc.).  Affects `prop` notation and method
  2901 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  2902 situations.
  2903 
  2904 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  2905 "(open)" option, which used to expose internal bound variables to the
  2906 proof text.
  2907 
  2908 * Isar statements: removed obsolete case "rule_context".
  2909 INCOMPATIBILITY, better use explicit fixes/assumes.
  2910 
  2911 * Locale proofs: default proof step now includes 'unfold_locales';
  2912 hence 'proof' without argument may be used to unfold locale
  2913 predicates.
  2914 
  2915 
  2916 *** Document preparation ***
  2917 
  2918 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  2919 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  2920 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  2921 spot); renamed link color from "darkblue" to "linkcolor" (default
  2922 value unchanged, can be redefined via \definecolor); no longer sets
  2923 "a4paper" option (unnecessary or even intrusive).
  2924 
  2925 * Antiquotation @{lemma A method} proves proposition A by the given
  2926 method (either a method name or a method name plus (optional) method
  2927 arguments in parentheses) and prints A just like @{prop A}.
  2928 
  2929 
  2930 *** HOL ***
  2931 
  2932 * New primrec package.  Specification syntax conforms in style to
  2933 definition/function/....  No separate induction rule is provided.  The
  2934 "primrec" command distinguishes old-style and new-style specifications
  2935 by syntax.  The former primrec package is now named OldPrimrecPackage.
  2936 When adjusting theories, beware: constants stemming from new-style
  2937 primrec specifications have authentic syntax.
  2938 
  2939 * Metis prover is now an order of magnitude faster, and also works
  2940 with multithreading.
  2941 
  2942 * Metis: the maximum number of clauses that can be produced from a
  2943 theorem is now given by the attribute max_clauses.  Theorems that
  2944 exceed this number are ignored, with a warning printed.
  2945 
  2946 * Sledgehammer no longer produces structured proofs by default. To
  2947 enable, declare [[sledgehammer_full = true]].  Attributes
  2948 reconstruction_modulus, reconstruction_sorts renamed
  2949 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  2950 
  2951 * Method "induct_scheme" derives user-specified induction rules
  2952 from well-founded induction and completeness of patterns. This factors
  2953 out some operations that are done internally by the function package
  2954 and makes them available separately.  See
  2955 src/HOL/ex/Induction_Scheme.thy for examples.
  2956 
  2957 * More flexible generation of measure functions for termination
  2958 proofs: Measure functions can be declared by proving a rule of the
  2959 form "is_measure f" and giving it the [measure_function] attribute.
  2960 The "is_measure" predicate is logically meaningless (always true), and
  2961 just guides the heuristic.  To find suitable measure functions, the
  2962 termination prover sets up the goal "is_measure ?f" of the appropriate
  2963 type and generates all solutions by prolog-style backwards proof using
  2964 the declared rules.
  2965 
  2966 This setup also deals with rules like 
  2967 
  2968   "is_measure f ==> is_measure (list_size f)"
  2969 
  2970 which accommodates nested datatypes that recurse through lists.
  2971 Similar rules are predeclared for products and option types.
  2972 
  2973 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  2974 
  2975   INCOMPATIBILITIES:
  2976 
  2977   - Definitions of overloaded constants on sets have to be replaced by
  2978     definitions on => and bool.
  2979 
  2980   - Some definitions of overloaded operators on sets can now be proved
  2981     using the definitions of the operators on => and bool.  Therefore,
  2982     the following theorems have been renamed:
  2983 
  2984       subset_def   -> subset_eq
  2985       psubset_def  -> psubset_eq
  2986       set_diff_def -> set_diff_eq
  2987       Compl_def    -> Compl_eq
  2988       Sup_set_def  -> Sup_set_eq
  2989       Inf_set_def  -> Inf_set_eq
  2990       sup_set_def  -> sup_set_eq
  2991       inf_set_def  -> inf_set_eq
  2992 
  2993   - Due to the incompleteness of the HO unification algorithm, some
  2994     rules such as subst may require manual instantiation, if some of
  2995     the unknowns in the rule is a set.
  2996 
  2997   - Higher order unification and forward proofs:
  2998     The proof pattern
  2999 
  3000       have "P (S::'a set)" <...>
  3001       then have "EX S. P S" ..
  3002 
  3003     no longer works (due to the incompleteness of the HO unification
  3004     algorithm) and must be replaced by the pattern
  3005 
  3006       have "EX S. P S"
  3007       proof
  3008         show "P S" <...>
  3009       qed
  3010 
  3011   - Calculational reasoning with subst (or similar rules):
  3012     The proof pattern
  3013 
  3014       have "P (S::'a set)" <...>
  3015       also have "S = T" <...>
  3016       finally have "P T" .
  3017 
  3018     no longer works (for similar reasons as the previous example) and
  3019     must be replaced by something like
  3020 
  3021       have "P (S::'a set)" <...>
  3022       moreover have "S = T" <...>
  3023       ultimately have "P T" by simp
  3024 
  3025   - Tactics or packages written in ML code:
  3026     Code performing pattern matching on types via
  3027 
  3028       Type ("set", [T]) => ...
  3029 
  3030     must be rewritten. Moreover, functions like strip_type or
  3031     binder_types no longer return the right value when applied to a
  3032     type of the form
  3033 
  3034       T1 => ... => Tn => U => bool
  3035 
  3036     rather than
  3037 
  3038       T1 => ... => Tn => U set
  3039 
  3040 * Merged theories Wellfounded_Recursion, Accessible_Part and
  3041 Wellfounded_Relations to theory Wellfounded.
  3042 
  3043 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  3044 
  3045 * Class finite no longer treats UNIV as class parameter.  Use class
  3046 enum from theory Library/Enum instead to achieve a similar effect.
  3047 INCOMPATIBILITY.
  3048 
  3049 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  3050 and "Cons".  INCOMPATIBILITY.
  3051 
  3052 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  3053 Potential INCOMPATIBILITY.
  3054 
  3055 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  3056 injective_fst_snd removed, use split_eta and prod_eqI instead.
  3057 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  3058 
  3059 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  3060 the same name in theory Orderings:
  3061 
  3062   less_trans
  3063   less_linear
  3064   le_imp_less_or_eq
  3065   le_less_trans
  3066   less_le_trans
  3067   less_not_sym
  3068   less_asym
  3069 
  3070 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  3071 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  3072 and different variable names.
  3073 
  3074 * Library/Option_ord.thy: Canonical order on option type.
  3075 
  3076 * Library/RBT.thy: Red-black trees, an efficient implementation of
  3077 finite maps.
  3078 
  3079 * Library/Countable.thy: Type class for countable types.
  3080 
  3081 * Theory Int: The representation of numerals has changed.  The infix
  3082 operator BIT and the bit datatype with constructors B0 and B1 have
  3083 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  3084 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  3085 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  3086 accordingly.
  3087 
  3088 * Theory Nat: definition of <= and < on natural numbers no longer
  3089 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  3090 le_def and less_def have disappeared.  Consider lemmas not_less
  3091 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  3092 
  3093 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  3094 (whose purpose mainly is for various fold_set functionals) have been
  3095 abandoned in favor of the existing algebraic classes
  3096 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  3097 lower_semilattice (resp. upper_semilattice) and linorder.
  3098 INCOMPATIBILITY.
  3099 
  3100 * Theory Transitive_Closure: induct and cases rules now declare proper
  3101 case_names ("base" and "step").  INCOMPATIBILITY.
  3102 
  3103 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  3104 lattices.  The form set-specific version is available as
  3105 Inductive.lfp_ordinal_induct_set.
  3106 
  3107 * Renamed theorems "power.simps" to "power_int.simps".
  3108 INCOMPATIBILITY.
  3109 
  3110 * Class semiring_div provides basic abstract properties of semirings
  3111 with division and modulo operations.  Subsumes former class dvd_mod.
  3112 
  3113 * Merged theories IntDef, Numeral and IntArith into unified theory
  3114 Int.  INCOMPATIBILITY.
  3115 
  3116 * Theory Library/Code_Index: type "index" now represents natural
  3117 numbers rather than integers.  INCOMPATIBILITY.
  3118 
  3119 * New class "uminus" with operation "uminus" (split of from class
  3120 "minus" which now only has operation "minus", binary).
  3121 INCOMPATIBILITY.
  3122 
  3123 * Constants "card", "internal_split", "option_map" now with authentic
  3124 syntax.  INCOMPATIBILITY.
  3125 
  3126 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  3127 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  3128 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  3129 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  3130 Sup_set_def, le_def, less_def, option_map_def now with object
  3131 equality.  INCOMPATIBILITY.
  3132 
  3133 * Records. Removed K_record, and replaced it by pure lambda term
  3134 %x. c. The simplifier setup is now more robust against eta expansion.
  3135 INCOMPATIBILITY: in cases explicitly referring to K_record.
  3136 
  3137 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  3138 
  3139 * Library/ListVector: new theory of arithmetic vector operations.
  3140 
  3141 * Library/Order_Relation: new theory of various orderings as sets of
  3142 pairs.  Defines preorders, partial orders, linear orders and
  3143 well-orders on sets and on types.
  3144 
  3145 
  3146 *** ZF ***
  3147 
  3148 * Renamed some theories to allow to loading both ZF and HOL in the
  3149 same session:
  3150 
  3151   Datatype  -> Datatype_ZF
  3152   Inductive -> Inductive_ZF
  3153   Int       -> Int_ZF
  3154   IntDiv    -> IntDiv_ZF
  3155   Nat       -> Nat_ZF
  3156   List      -> List_ZF
  3157   Main      -> Main_ZF
  3158 
  3159 INCOMPATIBILITY: ZF theories that import individual theories below
  3160 Main might need to be adapted.  Regular theory Main is still
  3161 available, as trivial extension of Main_ZF.
  3162 
  3163 
  3164 *** ML ***
  3165 
  3166 * ML within Isar: antiquotation @{const name} or @{const
  3167 name(typargs)} produces statically-checked Const term.
  3168 
  3169 * Functor NamedThmsFun: data is available to the user as dynamic fact
  3170 (of the same name).  Removed obsolete print command.
  3171 
  3172 * Removed obsolete "use_legacy_bindings" function.
  3173 
  3174 * The ``print mode'' is now a thread-local value derived from a global
  3175 template (the former print_mode reference), thus access becomes
  3176 non-critical.  The global print_mode reference is for session
  3177 management only; user-code should use print_mode_value,
  3178 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  3179 
  3180 * Functions system/system_out provide a robust way to invoke external
  3181 shell commands, with propagation of interrupts (requires Poly/ML
  3182 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  3183 
  3184 
  3185 *** System ***
  3186 
  3187 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  3188 in accordance with Proof General 3.7, which prefers GNU emacs.
  3189 
  3190 * isatool tty runs Isabelle process with plain tty interaction;
  3191 optional line editor may be specified via ISABELLE_LINE_EDITOR
  3192 setting, the default settings attempt to locate "ledit" and "rlwrap".
  3193 
  3194 * isatool browser now works with Cygwin as well, using general
  3195 "javapath" function defined in Isabelle process environment.
  3196 
  3197 * YXML notation provides a simple and efficient alternative to
  3198 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  3199 isatool yxml as described in the Isabelle system manual.
  3200 
  3201 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  3202 provides general wrapper for managing an Isabelle process in a robust
  3203 fashion, with ``cooked'' output from stdin/stderr.
  3204 
  3205 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  3206 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  3207 
  3208 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  3209 way of changing the user's settings is via
  3210 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  3211 script.
  3212 
  3213 * Multithreading.max_threads := 0 refers to the number of actual CPU
  3214 cores of the underlying machine, which is a good starting point for
  3215 optimal performance tuning.  The corresponding usedir option -M allows
  3216 "max" as an alias for "0".  WARNING: does not work on certain versions
  3217 of Mac OS (with Poly/ML 5.1).
  3218 
  3219 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  3220 adverse effect of Isabelle flooding interactive front-ends (notably
  3221 ProofGeneral / XEmacs).
  3222 
  3223 
  3224 
  3225 New in Isabelle2007 (November 2007)
  3226 -----------------------------------
  3227 
  3228 *** General ***
  3229 
  3230 * More uniform information about legacy features, notably a
  3231 warning/error of "Legacy feature: ...", depending on the state of the
  3232 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  3233 legacy features will disappear eventually.
  3234 
  3235 * Theory syntax: the header format ``theory A = B + C:'' has been
  3236 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  3237 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  3238 
  3239 * Theory syntax: the old non-Isar theory file format has been
  3240 discontinued altogether.  Note that ML proof scripts may still be used
  3241 with Isar theories; migration is usually quite simple with the ML
  3242 function use_legacy_bindings.  INCOMPATIBILITY.
  3243 
  3244 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  3245 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  3246 quotes.
  3247 
  3248 * Theory loader: be more serious about observing the static theory
  3249 header specifications (including optional directories), but not the
  3250 accidental file locations of previously successful loads.  The strict
  3251 update policy of former update_thy is now already performed by
  3252 use_thy, so the former has been removed; use_thys updates several
  3253 theories simultaneously, just as 'imports' within a theory header
  3254 specification, but without merging the results.  Potential
  3255 INCOMPATIBILITY: may need to refine theory headers and commands
  3256 ROOT.ML which depend on load order.
  3257 
  3258 * Theory loader: optional support for content-based file
  3259 identification, instead of the traditional scheme of full physical
  3260 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  3261 (cf. the system manual).  The new scheme allows to work with
  3262 non-finished theories in persistent session images, such that source
  3263 files may be moved later on without requiring reloads.
  3264 
  3265 * Theory loader: old-style ML proof scripts being *attached* to a thy
  3266 file (with the same base name as the theory) are considered a legacy
  3267 feature, which will disappear eventually. Even now, the theory loader
  3268 no longer maintains dependencies on such files.
  3269 
  3270 * Syntax: the scope for resolving ambiguities via type-inference is
  3271 now limited to individual terms, instead of whole simultaneous
  3272 specifications as before. This greatly reduces the complexity of the
  3273 syntax module and improves flexibility by separating parsing and
  3274 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  3275 'fixes' etc.) are required in rare situations.
  3276 
  3277 * Syntax: constants introduced by new-style packages ('definition',
  3278 'abbreviation' etc.) are passed through the syntax module in
  3279 ``authentic mode''. This means that associated mixfix annotations
  3280 really stick to such constants, independently of potential name space
  3281 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  3282 trees are represented slightly differently, may need to adapt syntax
  3283 translations accordingly. Use CONST marker in 'translations' and
  3284 @{const_syntax} antiquotation in 'parse_translation' etc.
  3285 
  3286 * Legacy goal package: reduced interface to the bare minimum required
  3287 to keep existing proof scripts running.  Most other user-level
  3288 functions are now part of the OldGoals structure, which is *not* open
  3289 by default (consider isatool expandshort before open OldGoals).
  3290 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  3291 these tend to cause confusion about the actual goal (!) context being
  3292 used here, which is not necessarily the same as the_context().
  3293 
  3294 * Command 'find_theorems': supports "*" wild-card in "name:"
  3295 criterion; "with_dups" option.  Certain ProofGeneral versions might
  3296 support a specific search form (see ProofGeneral/CHANGES).
  3297 
  3298 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  3299 by default, which means that "prems" (and also "fixed variables") are
  3300 suppressed from proof state output.  Note that the ProofGeneral
  3301 settings mechanism allows to change and save options persistently, but
  3302 older versions of Isabelle will fail to start up if a negative prems
  3303 limit is imposed.
  3304 
  3305 * Local theory targets may be specified by non-nested blocks of
  3306 ``context/locale/class ... begin'' followed by ``end''.  The body may
  3307 contain definitions, theorems etc., including any derived mechanism
  3308 that has been implemented on top of these primitives.  This concept
  3309 generalizes the existing ``theorem (in ...)'' towards more versatility
  3310 and scalability.
  3311 
  3312 * Proof General interface: proper undo of final 'end' command;
  3313 discontinued Isabelle/classic mode (ML proof scripts).
  3314 
  3315 
  3316 *** Document preparation ***
  3317 
  3318 * Added antiquotation @{theory name} which prints the given name,
  3319 after checking that it refers to a valid ancestor theory in the
  3320 current context.
  3321 
  3322 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  3323 check the given source text as ML type/structure, printing verbatim.
  3324 
  3325 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  3326 "c args == rhs" given in the current context.  (Any number of
  3327 arguments may be given on the LHS.)
  3328 
  3329 
  3330 *** Pure ***
  3331 
  3332 * The 'class' package offers a combination of axclass and locale to
  3333 achieve Haskell-like type classes in Isabelle.  Definitions and
  3334 theorems within a class context produce both relative results (with
  3335 implicit parameters according to the locale context), and polymorphic
  3336 constants with qualified polymorphism (according to the class
  3337 context).  Within the body context of a 'class' target, a separate
  3338 syntax layer ("user space type system") takes care of converting
  3339 between global polymorphic consts and internal locale representation.
  3340 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  3341 "isatool doc classes" provides a tutorial.
  3342 
  3343 * Generic code generator framework allows to generate executable
  3344 code for ML and Haskell (including Isabelle classes).  A short usage
  3345 sketch:
  3346 
  3347     internal compilation:
  3348         export_code <list of constants (term syntax)> in SML
  3349     writing SML code to a file:
  3350         export_code <list of constants (term syntax)> in SML <filename>
  3351     writing OCaml code to a file:
  3352         export_code <list of constants (term syntax)> in OCaml <filename>
  3353     writing Haskell code to a bunch of files:
  3354         export_code <list of constants (term syntax)> in Haskell <filename>
  3355 
  3356     evaluating closed propositions to True/False using code generation:
  3357         method ``eval''
  3358 
  3359 Reasonable default setup of framework in HOL.
  3360 
  3361 Theorem attributs for selecting and transforming function equations theorems:
  3362 
  3363     [code fun]:        select a theorem as function equation for a specific constant
  3364     [code fun del]:    deselect a theorem as function equation for a specific constant
  3365     [code inline]:     select an equation theorem for unfolding (inlining) in place
  3366     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  3367 
  3368 User-defined serializations (target in {SML, OCaml, Haskell}):
  3369 
  3370     code_const <and-list of constants (term syntax)>
  3371       {(target) <and-list of const target syntax>}+
  3372 
  3373     code_type <and-list of type constructors>
  3374       {(target) <and-list of type target syntax>}+
  3375 
  3376     code_instance <and-list of instances>
  3377       {(target)}+
  3378         where instance ::= <type constructor> :: <class>
  3379 
  3380     code_class <and_list of classes>
  3381       {(target) <and-list of class target syntax>}+
  3382         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  3383 
  3384 code_instance and code_class only are effective to target Haskell.
  3385 
  3386 For example usage see src/HOL/ex/Codegenerator.thy and
  3387 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  3388 generation from Isabelle/HOL theories is available via "isatool doc
  3389 codegen".
  3390 
  3391 * Code generator: consts in 'consts_code' Isar commands are now
  3392 referred to by usual term syntax (including optional type
  3393 annotations).
  3394 
  3395 * Command 'no_translations' removes translation rules from theory
  3396 syntax.
  3397 
  3398 * Overloaded definitions are now actually checked for acyclic
  3399 dependencies.  The overloading scheme is slightly more general than
  3400 that of Haskell98, although Isabelle does not demand an exact
  3401 correspondence to type class and instance declarations.
  3402 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  3403 exotic versions of overloading -- at the discretion of the user!
  3404 
  3405 Polymorphic constants are represented via type arguments, i.e. the
  3406 instantiation that matches an instance against the most general
  3407 declaration given in the signature.  For example, with the declaration
  3408 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  3409 as c(nat).  Overloading is essentially simultaneous structural
  3410 recursion over such type arguments.  Incomplete specification patterns
  3411 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  3412 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  3413 Command 'print_theory' outputs the normalized system of recursive
  3414 equations, see section "definitions".
  3415 
  3416 * Configuration options are maintained within the theory or proof
  3417 context (with name and type bool/int/string), providing a very simple
  3418 interface to a poor-man's version of general context data.  Tools may
  3419 declare options in ML (e.g. using Attrib.config_int) and then refer to
  3420 these values using Config.get etc.  Users may change options via an
  3421 associated attribute of the same name.  This form of context
  3422 declaration works particularly well with commands 'declare' or
  3423 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  3424 very easy to avoid global references, which would not observe Isar
  3425 toplevel undo/redo and fail to work with multithreading.
  3426 
  3427 Various global ML references of Pure and HOL have been turned into
  3428 configuration options:
  3429 
  3430   Unify.search_bound		unify_search_bound
  3431   Unify.trace_bound		unify_trace_bound
  3432   Unify.trace_simp		unify_trace_simp
  3433   Unify.trace_types		unify_trace_types
  3434   Simplifier.simp_depth_limit	simp_depth_limit
  3435   Blast.depth_limit		blast_depth_limit
  3436   DatatypeProp.dtK		datatype_distinctness_limit
  3437   fast_arith_neq_limit  	fast_arith_neq_limit
  3438   fast_arith_split_limit	fast_arith_split_limit
  3439 
  3440 * Named collections of theorems may be easily installed as context
  3441 data using the functor NamedThmsFun (see also
  3442 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  3443 attributes; there is also a toplevel print command.  This facility is
  3444 just a common case of general context data, which is the preferred way
  3445 for anything more complex than just a list of facts in canonical
  3446 order.
  3447 
  3448 * Isar: command 'declaration' augments a local theory by generic
  3449 declaration functions written in ML.  This enables arbitrary content
  3450 being added to the context, depending on a morphism that tells the
  3451 difference of the original declaration context wrt. the application
  3452 context encountered later on.
  3453 
  3454 * Isar: proper interfaces for simplification procedures.  Command
  3455 'simproc_setup' declares named simprocs (with match patterns, and body
  3456 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  3457 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  3458 
  3459 * Isar: an extra pair of brackets around attribute declarations
  3460 abbreviates a theorem reference involving an internal dummy fact,
  3461 which will be ignored later --- only the effect of the attribute on
  3462 the background context will persist.  This form of in-place
  3463 declarations is particularly useful with commands like 'declare' and
  3464 'using', for example ``have A using [[simproc a]] by simp''.
  3465 
  3466 * Isar: method "assumption" (and implicit closing of subproofs) now
  3467 takes simple non-atomic goal assumptions into account: after applying
  3468 an assumption as a rule the resulting subgoals are solved by atomic
  3469 assumption steps.  This is particularly useful to finish 'obtain'
  3470 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  3471 without referring to the original premise "!!x. P x ==> thesis" in the
  3472 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  3473 more permissive.
  3474 
  3475 * Isar: implicit use of prems from the Isar proof context is
  3476 considered a legacy feature.  Common applications like ``have A .''
  3477 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  3478 referencing facts explicitly here improves readability and
  3479 maintainability of proof texts.
  3480 
  3481 * Isar: improper proof element 'guess' is like 'obtain', but derives
  3482 the obtained context from the course of reasoning!  For example:
  3483 
  3484   assume "EX x y. A x & B y"   -- "any previous fact"
  3485   then guess x and y by clarify
  3486 
  3487 This technique is potentially adventurous, depending on the facts and
  3488 proof tools being involved here.
  3489 
  3490 * Isar: known facts from the proof context may be specified as literal
  3491 propositions, using ASCII back-quote syntax.  This works wherever
  3492 named facts used to be allowed so far, in proof commands, proof
  3493 methods, attributes etc.  Literal facts are retrieved from the context
  3494 according to unification of type and term parameters.  For example,
  3495 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  3496 theorems in the current context, then these are valid literal facts:
  3497 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  3498 
  3499 There is also a proof method "fact" which does the same composition
  3500 for explicit goal states, e.g. the following proof texts coincide with
  3501 certain special cases of literal facts:
  3502 
  3503   have "A" by fact                 ==  note `A`
  3504   have "A ==> B" by fact           ==  note `A ==> B`
  3505   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  3506   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  3507 
  3508 * Isar: ":" (colon) is no longer a symbolic identifier character in
  3509 outer syntax.  Thus symbolic identifiers may be used without
  3510 additional white space in declarations like this: ``assume *: A''.
  3511 
  3512 * Isar: 'print_facts' prints all local facts of the current context,
  3513 both named and unnamed ones.
  3514 
  3515 * Isar: 'def' now admits simultaneous definitions, e.g.:
  3516 
  3517   def x == "t" and y == "u"
  3518 
  3519 * Isar: added command 'unfolding', which is structurally similar to
  3520 'using', but affects both the goal state and facts by unfolding given
  3521 rewrite rules.  Thus many occurrences of the 'unfold' method or
  3522 'unfolded' attribute may be replaced by first-class proof text.
  3523 
  3524 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  3525 and command 'unfolding' now all support object-level equalities
  3526 (potentially conditional).  The underlying notion of rewrite rule is
  3527 analogous to the 'rule_format' attribute, but *not* that of the
  3528 Simplifier (which is usually more generous).
  3529 
  3530 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  3531 premises of a theorem by n. Useful in conjunction with drule.
  3532 
  3533 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  3534 method expression within a sandbox consisting of the first N
  3535 sub-goals, which need to exist.  For example, ``simp_all [3]''
  3536 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  3537 simplifies all new goals that emerge from applying rule foo to the
  3538 originally first one.
  3539 
  3540 * Isar: schematic goals are no longer restricted to higher-order
  3541 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  3542 expected.
  3543 
  3544 * Isar: the conclusion of a long theorem statement is now either
  3545 'shows' (a simultaneous conjunction, as before), or 'obtains'
  3546 (essentially a disjunction of cases with local parameters and
  3547 assumptions).  The latter allows to express general elimination rules
  3548 adequately; in this notation common elimination rules look like this:
  3549 
  3550   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  3551     assumes "EX x. P x"
  3552     obtains x where "P x"
  3553 
  3554   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  3555     assumes "A & B"
  3556     obtains A and B
  3557 
  3558   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  3559     assumes "A | B"
  3560     obtains
  3561       A
  3562     | B
  3563 
  3564 The subsequent classical rules even refer to the formal "thesis"
  3565 explicitly:
  3566 
  3567   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  3568     obtains "~ thesis"
  3569 
  3570   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  3571     obtains "thesis ==> something"
  3572 
  3573 The actual proof of an 'obtains' statement is analogous to that of the
  3574 Isar proof element 'obtain', only that there may be several cases.
  3575 Optional case names may be specified in parentheses; these will be
  3576 available both in the present proof and as annotations in the
  3577 resulting rule, for later use with the 'cases' method (cf. attribute
  3578 case_names).
  3579 
  3580 * Isar: the assumptions of a long theorem statement are available as
  3581 "assms" fact in the proof context.  This is more appropriate than the
  3582 (historical) "prems", which refers to all assumptions of the current
  3583 context, including those from the target locale, proof body etc.
  3584 
  3585 * Isar: 'print_statement' prints theorems from the current theory or
  3586 proof context in long statement form, according to the syntax of a
  3587 top-level lemma.
  3588 
  3589 * Isar: 'obtain' takes an optional case name for the local context
  3590 introduction rule (default "that").
  3591 
  3592 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  3593 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  3594 to occur.
  3595 
  3596 * Pure: syntax "CONST name" produces a fully internalized constant
  3597 according to the current context.  This is particularly useful for
  3598 syntax translations that should refer to internal constant
  3599 representations independently of name spaces.
  3600 
  3601 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  3602 instead of "FOO ". This allows multiple binder declarations to coexist
  3603 in the same context.  INCOMPATIBILITY.
  3604 
  3605 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  3606 primitive that also works in a locale context (both for constants and
  3607 fixed variables). Type declaration and internal syntactic representation
  3608 of given constants retrieved from the context. Likewise, the
  3609 'no_notation' command allows to remove given syntax annotations from the
  3610 current context.
  3611 
  3612 * Isar/locales: new derived specification elements 'axiomatization',
  3613 'definition', 'abbreviation', which support type-inference, admit
  3614 object-level specifications (equality, equivalence).  See also the
  3615 isar-ref manual.  Examples:
  3616 
  3617   axiomatization
  3618     eq  (infix "===" 50) where
  3619     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  3620 
  3621   definition "f x y = x + y + 1"
  3622   definition g where "g x = f x x"
  3623 
  3624   abbreviation
  3625     neq  (infix "=!=" 50) where
  3626     "x =!= y == ~ (x === y)"
  3627 
  3628 These specifications may be also used in a locale context.  Then the
  3629 constants being introduced depend on certain fixed parameters, and the
  3630 constant name is qualified by the locale base name.  An internal
  3631 abbreviation takes care for convenient input and output, making the
  3632 parameters implicit and using the original short name.  See also
  3633 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  3634 entities from a monomorphic theory.
  3635 
  3636 Presently, abbreviations are only available 'in' a target locale, but
  3637 not inherited by general import expressions.  Also note that
  3638 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  3639 'translations' in common applications.  The "no_abbrevs" print mode
  3640 prevents folding of abbreviations in term output.
  3641 
  3642 Concrete syntax is attached to specified constants in internal form,
  3643 independently of name spaces.  The parse tree representation is
  3644 slightly different -- use 'notation' instead of raw 'syntax', and
  3645 'translations' with explicit "CONST" markup to accommodate this.
  3646 
  3647 * Pure/Isar: unified syntax for new-style specification mechanisms
  3648 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  3649 full type inference and dummy patterns ("_").  For example:
  3650 
  3651   definition "K x _ = x"
  3652 
  3653   inductive conj for A B
  3654   where "A ==> B ==> conj A B"
  3655 
  3656 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  3657 the current context.  Print mode "no_abbrevs" prevents inversion of
  3658 abbreviations on output.
  3659 
  3660 * Isar/locales: improved parameter handling: use of locales "var" and
  3661 "struct" no longer necessary; - parameter renamings are no longer
  3662 required to be injective.  For example, this allows to define
  3663 endomorphisms as locale endom = homom mult mult h.
  3664 
  3665 * Isar/locales: changed the way locales with predicates are defined.
  3666 Instead of accumulating the specification, the imported expression is
  3667 now an interpretation.  INCOMPATIBILITY: different normal form of
  3668 locale expressions.  In particular, in interpretations of locales with
  3669 predicates, goals repesenting already interpreted fragments are not
  3670 removed automatically.  Use methods `intro_locales' and
  3671 `unfold_locales'; see below.
  3672 
  3673 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  3674 provide backward reasoning on locales predicates.  The methods are
  3675 aware of interpretations and discharge corresponding goals.
  3676 `intro_locales' is less aggressive then `unfold_locales' and does not
  3677 unfold predicates to assumptions.
  3678 
  3679 * Isar/locales: the order in which locale fragments are accumulated
  3680 has changed.  This enables to override declarations from fragments due
  3681 to interpretations -- for example, unwanted simp rules.
  3682 
  3683 * Isar/locales: interpretation in theories and proof contexts has been
  3684 extended.  One may now specify (and prove) equations, which are
  3685 unfolded in interpreted theorems.  This is useful for replacing
  3686 defined concepts (constants depending on locale parameters) by
  3687 concepts already existing in the target context.  Example:
  3688 
  3689   interpretation partial_order ["op <= :: [int, int] => bool"]
  3690     where "partial_order.less (op <=) (x::int) y = (x < y)"
  3691 
  3692 Typically, the constant `partial_order.less' is created by a
  3693 definition specification element in the context of locale
  3694 partial_order.
  3695 
  3696 * Method "induct": improved internal context management to support
  3697 local fixes and defines on-the-fly. Thus explicit meta-level
  3698 connectives !!  and ==> are rarely required anymore in inductive goals
  3699 (using object-logic connectives for this purpose has been long
  3700 obsolete anyway). Common proof patterns are explained in
  3701 src/HOL/Induct/Common_Patterns.thy, see also
  3702 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  3703 examples.
  3704 
  3705 * Method "induct": improved handling of simultaneous goals. Instead of
  3706 introducing object-level conjunction, the statement is now split into
  3707 several conclusions, while the corresponding symbolic cases are nested
  3708 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  3709 see src/HOL/Induct/Common_Patterns.thy, for example.
  3710 
  3711 * Method "induct": mutual induction rules are now specified as a list
  3712 of rule sharing the same induction cases. HOL packages usually provide
  3713 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  3714 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  3715 mutual induction rules differently, i.e. like this:
  3716 
  3717   (induct rule: foo_bar.inducts)
  3718   (induct set: foo bar)
  3719   (induct pred: foo bar)
  3720   (induct type: foo bar)
  3721 
  3722 The ML function ProjectRule.projections turns old-style rules into the
  3723 new format.
  3724 
  3725 * Method "coinduct": dual of induction, see
  3726 src/HOL/Library/Coinductive_List.thy for various examples.
  3727 
  3728 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  3729 considered a legacy feature.
  3730 
  3731 * Attribute "symmetric" produces result with standardized schematic
  3732 variables (index 0).  Potential INCOMPATIBILITY.
  3733 
  3734 * Simplifier: by default the simplifier trace only shows top level
  3735 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  3736 default. Thus there is less danger of being flooded by the trace. The
  3737 trace indicates where parts have been suppressed.
  3738   
  3739 * Provers/classical: removed obsolete classical version of elim_format
  3740 attribute; classical elim/dest rules are now treated uniformly when
  3741 manipulating the claset.
  3742 
  3743 * Provers/classical: stricter checks to ensure that supplied intro,
  3744 dest and elim rules are well-formed; dest and elim rules must have at
  3745 least one premise.
  3746 
  3747 * Provers/classical: attributes dest/elim/intro take an optional
  3748 weight argument for the rule (just as the Pure versions).  Weights are
  3749 ignored by automated tools, but determine the search order of single
  3750 rule steps.
  3751 
  3752 * Syntax: input syntax now supports dummy variable binding "%_. b",
  3753 where the body does not mention the bound variable.  Note that dummy
  3754 patterns implicitly depend on their context of bounds, which makes
  3755 "{_. _}" match any set comprehension as expected.  Potential
  3756 INCOMPATIBILITY -- parse translations need to cope with syntactic
  3757 constant "_idtdummy" in the binding position.
  3758 
  3759 * Syntax: removed obsolete syntactic constant "_K" and its associated
  3760 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  3761 for example "A -> B" => "Pi A (%_. B)".
  3762 
  3763 * Pure: 'class_deps' command visualizes the subclass relation, using
  3764 the graph browser tool.
  3765 
  3766 * Pure: 'print_theory' now suppresses certain internal declarations by
  3767 default; use '!' option for full details.
  3768 
  3769 
  3770 *** HOL ***
  3771 
  3772 * Method "metis" proves goals by applying the Metis general-purpose
  3773 resolution prover (see also http://gilith.com/software/metis/).
  3774 Examples are in the directory MetisExamples.  WARNING: the
  3775 Isabelle/HOL-Metis integration does not yet work properly with
  3776 multi-threading.
  3777   
  3778 * Command 'sledgehammer' invokes external automatic theorem provers as
  3779 background processes.  It generates calls to the "metis" method if
  3780 successful. These can be pasted into the proof.  Users do not have to
  3781 wait for the automatic provers to return.  WARNING: does not really
  3782 work with multi-threading.
  3783 
  3784 * New "auto_quickcheck" feature tests outermost goal statements for
  3785 potential counter-examples.  Controlled by ML references
  3786 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  3787 5000 milliseconds).  Fails silently if statements is outside of
  3788 executable fragment, or any other codgenerator problem occurs.
  3789 
  3790 * New constant "undefined" with axiom "undefined x = undefined".
  3791 
  3792 * Added class "HOL.eq", allowing for code generation with polymorphic
  3793 equality.
  3794 
  3795 * Some renaming of class constants due to canonical name prefixing in
  3796 the new 'class' package:
  3797 
  3798     HOL.abs ~> HOL.abs_class.abs
  3799     HOL.divide ~> HOL.divide_class.divide
  3800     0 ~> HOL.zero_class.zero
  3801     1 ~> HOL.one_class.one
  3802     op + ~> HOL.plus_class.plus
  3803     op - ~> HOL.minus_class.minus
  3804     uminus ~> HOL.minus_class.uminus
  3805     op * ~> HOL.times_class.times
  3806     op < ~> HOL.ord_class.less
  3807     op <= > HOL.ord_class.less_eq
  3808     Nat.power ~> Power.power_class.power
  3809     Nat.size ~> Nat.size_class.size
  3810     Numeral.number_of ~> Numeral.number_class.number_of
  3811     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  3812     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  3813     Orderings.min ~> Orderings.ord_class.min
  3814     Orderings.max ~> Orderings.ord_class.max
  3815     Divides.op div ~> Divides.div_class.div
  3816     Divides.op mod ~> Divides.div_class.mod
  3817     Divides.op dvd ~> Divides.div_class.dvd
  3818 
  3819 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  3820 
  3821 a) User-defined constants using any of the names "plus", "minus",
  3822 "times", "less" or "less_eq". The standard syntax translations for
  3823 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  3824 names.
  3825 
  3826 b) Variables named "plus", "minus", "times", "less", "less_eq"
  3827 INCOMPATIBILITY: use more specific names.
  3828 
  3829 c) Permutative equations (e.g. "a + b = b + a")
  3830 Since the change of names also changes the order of terms, permutative
  3831 rewrite rules may get applied in a different order. Experience shows
  3832 that this is rarely the case (only two adaptions in the whole Isabelle
  3833 distribution).  INCOMPATIBILITY: rewrite proofs
  3834 
  3835 d) ML code directly refering to constant names
  3836 This in general only affects hand-written proof tactics, simprocs and
  3837 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  3838 Consider using @{const_name} antiquotation.
  3839 
  3840 * New class "default" with associated constant "default".
  3841 
  3842 * Function "sgn" is now overloaded and available on int, real, complex
  3843 (and other numeric types), using class "sgn".  Two possible defs of
  3844 sgn are given as equational assumptions in the classes sgn_if and
  3845 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  3846 INCOMPATIBILITY.
  3847 
  3848 * Locale "partial_order" now unified with class "order" (cf. theory
  3849 Orderings), added parameter "less".  INCOMPATIBILITY.
  3850 
  3851 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  3852 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  3853 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  3854 
  3855 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  3856 changed order of proof goals in instance proofs.
  3857 
  3858 * The transitivity reasoner for partial and linear orders is set up
  3859 for classes "order" and "linorder".  Instances of the reasoner are available
  3860 in all contexts importing or interpreting the corresponding locales.
  3861 Method "order" invokes the reasoner separately; the reasoner
  3862 is also integrated with the Simplifier as a solver.  Diagnostic
  3863 command 'print_orders' shows the available instances of the reasoner
  3864 in the current context.
  3865 
  3866 * Localized monotonicity predicate in theory "Orderings"; integrated
  3867 lemmas max_of_mono and min_of_mono with this predicate.
  3868 INCOMPATIBILITY.
  3869 
  3870 * Formulation of theorem "dense" changed slightly due to integration
  3871 with new class dense_linear_order.
  3872 
  3873 * Uniform lattice theory development in HOL.
  3874 
  3875     constants "meet" and "join" now named "inf" and "sup"
  3876     constant "Meet" now named "Inf"
  3877 
  3878     classes "meet_semilorder" and "join_semilorder" now named
  3879       "lower_semilattice" and "upper_semilattice"
  3880     class "lorder" now named "lattice"
  3881     class "comp_lat" now named "complete_lattice"
  3882 
  3883     Instantiation of lattice classes allows explicit definitions
  3884     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  3885 
  3886   INCOMPATIBILITY.  Theorem renames:
  3887 
  3888     meet_left_le            ~> inf_le1
  3889     meet_right_le           ~> inf_le2
  3890     join_left_le            ~> sup_ge1
  3891     join_right_le           ~> sup_ge2
  3892     meet_join_le            ~> inf_sup_ord
  3893     le_meetI                ~> le_infI
  3894     join_leI                ~> le_supI
  3895     le_meet                 ~> le_inf_iff
  3896     le_join                 ~> ge_sup_conv
  3897     meet_idempotent         ~> inf_idem
  3898     join_idempotent         ~> sup_idem
  3899     meet_comm               ~> inf_commute
  3900     join_comm               ~> sup_commute
  3901     meet_leI1               ~> le_infI1
  3902     meet_leI2               ~> le_infI2
  3903     le_joinI1               ~> le_supI1
  3904     le_joinI2               ~> le_supI2
  3905     meet_assoc              ~> inf_assoc
  3906     join_assoc              ~> sup_assoc
  3907     meet_left_comm          ~> inf_left_commute
  3908     meet_left_idempotent    ~> inf_left_idem
  3909     join_left_comm          ~> sup_left_commute
  3910     join_left_idempotent    ~> sup_left_idem
  3911     meet_aci                ~> inf_aci
  3912     join_aci                ~> sup_aci
  3913     le_def_meet             ~> le_iff_inf
  3914     le_def_join             ~> le_iff_sup
  3915     join_absorp2            ~> sup_absorb2
  3916     join_absorp1            ~> sup_absorb1
  3917     meet_absorp1            ~> inf_absorb1
  3918     meet_absorp2            ~> inf_absorb2
  3919     meet_join_absorp        ~> inf_sup_absorb
  3920     join_meet_absorp        ~> sup_inf_absorb
  3921     distrib_join_le         ~> distrib_sup_le
  3922     distrib_meet_le         ~> distrib_inf_le
  3923 
  3924     add_meet_distrib_left   ~> add_inf_distrib_left
  3925     add_join_distrib_left   ~> add_sup_distrib_left
  3926     is_join_neg_meet        ~> is_join_neg_inf
  3927     is_meet_neg_join        ~> is_meet_neg_sup
  3928     add_meet_distrib_right  ~> add_inf_distrib_right
  3929     add_join_distrib_right  ~> add_sup_distrib_right
  3930     add_meet_join_distribs  ~> add_sup_inf_distribs
  3931     join_eq_neg_meet        ~> sup_eq_neg_inf
  3932     meet_eq_neg_join        ~> inf_eq_neg_sup
  3933     add_eq_meet_join        ~> add_eq_inf_sup
  3934     meet_0_imp_0            ~> inf_0_imp_0
  3935     join_0_imp_0            ~> sup_0_imp_0
  3936     meet_0_eq_0             ~> inf_0_eq_0
  3937     join_0_eq_0             ~> sup_0_eq_0
  3938     neg_meet_eq_join        ~> neg_inf_eq_sup
  3939     neg_join_eq_meet        ~> neg_sup_eq_inf
  3940     join_eq_if              ~> sup_eq_if
  3941 
  3942     mono_meet               ~> mono_inf
  3943     mono_join               ~> mono_sup
  3944     meet_bool_eq            ~> inf_bool_eq
  3945     join_bool_eq            ~> sup_bool_eq
  3946     meet_fun_eq             ~> inf_fun_eq
  3947     join_fun_eq             ~> sup_fun_eq
  3948     meet_set_eq             ~> inf_set_eq
  3949     join_set_eq             ~> sup_set_eq
  3950     meet1_iff               ~> inf1_iff
  3951     meet2_iff               ~> inf2_iff
  3952     meet1I                  ~> inf1I
  3953     meet2I                  ~> inf2I
  3954     meet1D1                 ~> inf1D1
  3955     meet2D1                 ~> inf2D1
  3956     meet1D2                 ~> inf1D2
  3957     meet2D2                 ~> inf2D2
  3958     meet1E                  ~> inf1E
  3959     meet2E                  ~> inf2E
  3960     join1_iff               ~> sup1_iff
  3961     join2_iff               ~> sup2_iff
  3962     join1I1                 ~> sup1I1
  3963     join2I1                 ~> sup2I1
  3964     join1I1                 ~> sup1I1
  3965     join2I2                 ~> sup1I2
  3966     join1CI                 ~> sup1CI
  3967     join2CI                 ~> sup2CI
  3968     join1E                  ~> sup1E
  3969     join2E                  ~> sup2E
  3970 
  3971     is_meet_Meet            ~> is_meet_Inf
  3972     Meet_bool_def           ~> Inf_bool_def
  3973     Meet_fun_def            ~> Inf_fun_def
  3974     Meet_greatest           ~> Inf_greatest
  3975     Meet_lower              ~> Inf_lower
  3976     Meet_set_def            ~> Inf_set_def
  3977 
  3978     Sup_def                 ~> Sup_Inf
  3979     Sup_bool_eq             ~> Sup_bool_def
  3980     Sup_fun_eq              ~> Sup_fun_def
  3981     Sup_set_eq              ~> Sup_set_def
  3982 
  3983     listsp_meetI            ~> listsp_infI
  3984     listsp_meet_eq          ~> listsp_inf_eq
  3985 
  3986     meet_min                ~> inf_min
  3987     join_max                ~> sup_max
  3988 
  3989 * Added syntactic class "size"; overloaded constant "size" now has
  3990 type "'a::size ==> bool"
  3991 
  3992 * Internal reorganisation of `size' of datatypes: size theorems
  3993 "foo.size" are no longer subsumed by "foo.simps" (but are still
  3994 simplification rules by default!); theorems "prod.size" now named
  3995 "*.size".
  3996 
  3997 * Class "div" now inherits from class "times" rather than "type".
  3998 INCOMPATIBILITY.
  3999 
  4000 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  4001 Linorder etc.  have disappeared; operations defined in terms of
  4002 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  4003 
  4004 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  4005 
  4006 * HOL-Word: New extensive library and type for generic, fixed size
  4007 machine words, with arithemtic, bit-wise, shifting and rotating
  4008 operations, reflection into int, nat, and bool lists, automation for
  4009 linear arithmetic (by automatic reflection into nat or int), including
  4010 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  4011 arithmetic type classes, supporting automatic simplification of
  4012 numerals on all operations.
  4013 
  4014 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  4015 
  4016 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  4017 
  4018 * Code generator library theories:
  4019   - Code_Integer represents HOL integers by big integer literals in target
  4020     languages.
  4021   - Code_Char represents HOL characters by character literals in target
  4022     languages.
  4023   - Code_Char_chr like Code_Char, but also offers treatment of character
  4024     codes; includes Code_Integer.
  4025   - Executable_Set allows to generate code for finite sets using lists.
  4026   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  4027     denominator).
  4028   - Executable_Real implements a subset of real numbers, namly those
  4029     representable by rational numbers.
  4030   - Efficient_Nat implements natural numbers by integers, which in general will
  4031     result in higher efficency; pattern matching with 0/Suc is eliminated;
  4032     includes Code_Integer.
  4033   - Code_Index provides an additional datatype index which is mapped to
  4034     target-language built-in integers.
  4035   - Code_Message provides an additional datatype message_string which is isomorphic to
  4036     strings; messages are mapped to target-language strings.
  4037 
  4038 * New package for inductive predicates
  4039 
  4040   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  4041 
  4042     inductive
  4043       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  4044       for z_1 :: U_1 and ... and z_n :: U_m
  4045     where
  4046       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  4047     | ...
  4048 
  4049   with full support for type-inference, rather than
  4050 
  4051     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4052 
  4053     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  4054     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  4055 
  4056     inductive "s z_1 ... z_m"
  4057     intros
  4058       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  4059       ...
  4060 
  4061   For backward compatibility, there is a wrapper allowing inductive
  4062   sets to be defined with the new package via
  4063 
  4064     inductive_set
  4065       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4066       for z_1 :: U_1 and ... and z_n :: U_m
  4067     where
  4068       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  4069     | ...
  4070 
  4071   or
  4072 
  4073     inductive_set
  4074       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4075       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  4076       for z_1 :: U_1 and ... and z_n :: U_m
  4077     where
  4078       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  4079     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  4080     | ...
  4081 
  4082   if the additional syntax "p ..." is required.
  4083 
  4084   Numerous examples can be found in the subdirectories src/HOL/Auth,
  4085   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  4086 
  4087   INCOMPATIBILITIES:
  4088 
  4089   - Since declaration and definition of inductive sets or predicates
  4090     is no longer separated, abbreviations involving the newly
  4091     introduced sets or predicates must be specified together with the
  4092     introduction rules after the 'where' keyword (see above), rather
  4093     than before the actual inductive definition.
  4094 
  4095   - The variables in induction and elimination rules are now
  4096     quantified in the order of their occurrence in the introduction
  4097     rules, rather than in alphabetical order. Since this may break
  4098     some proofs, these proofs either have to be repaired, e.g. by
  4099     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  4100     statements of the form
  4101 
  4102       case (rule_i a_i_1 ... a_i_{k_i})
  4103 
  4104     or the old order of quantification has to be restored by explicitly adding
  4105     meta-level quantifiers in the introduction rules, i.e.
  4106 
  4107       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  4108 
  4109   - The format of the elimination rules is now
  4110 
  4111       p z_1 ... z_m x_1 ... x_n ==>
  4112         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  4113         ==> ... ==> P
  4114 
  4115     for predicates and
  4116 
  4117       (x_1, ..., x_n) : s z_1 ... z_m ==>
  4118         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  4119         ==> ... ==> P
  4120 
  4121     for sets rather than
  4122 
  4123       x : s z_1 ... z_m ==>
  4124         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  4125         ==> ... ==> P
  4126 
  4127     This may require terms in goals to be expanded to n-tuples
  4128     (e.g. using case_tac or simplification with the split_paired_all
  4129     rule) before the above elimination rule is applicable.
  4130 
  4131   - The elimination or case analysis rules for (mutually) inductive
  4132     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  4133     list of rules "p_1_..._p_k.elims" is no longer available.
  4134 
  4135 * New package "function"/"fun" for general recursive functions,
  4136 supporting mutual and nested recursion, definitions in local contexts,
  4137 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  4138 for small examples, and the separate tutorial on the function
  4139 package. The old recdef "package" is still available as before, but
  4140 users are encouraged to use the new package.
  4141 
  4142 * Method "lexicographic_order" automatically synthesizes termination
  4143 relations as lexicographic combinations of size measures. 
  4144 
  4145 * Case-expressions allow arbitrary constructor-patterns (including
  4146 "_") and take their order into account, like in functional
  4147 programming.  Internally, this is translated into nested
  4148 case-expressions; missing cases are added and mapped to the predefined
  4149 constant "undefined". In complicated cases printing may no longer show
  4150 the original input but the internal form. Lambda-abstractions allow
  4151 the same form of pattern matching: "% pat1 => e1 | ..." is an
  4152 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  4153 variable.
  4154 
  4155 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  4156 is an abbreviation for "of_nat :: nat => int". The simplification
  4157 rules for "of_nat" have been changed to work like "int" did
  4158 previously.  Potential INCOMPATIBILITY:
  4159   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  4160   - of_nat_diff and of_nat_mult are no longer default simp rules
  4161 
  4162 * Method "algebra" solves polynomial equations over (semi)rings using
  4163 Groebner bases. The (semi)ring structure is defined by locales and the
  4164 tool setup depends on that generic context. Installing the method for
  4165 a specific type involves instantiating the locale and possibly adding
  4166 declarations for computation on the coefficients.  The method is
  4167 already instantiated for natural numbers and for the axiomatic class
  4168 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  4169 CALCULEMUS 2007 for the general principles underlying this
  4170 architecture of context-aware proof-tools.
  4171 
  4172 * Method "ferrack" implements quantifier elimination over
  4173 special-purpose dense linear orders using locales (analogous to
  4174 "algebra"). The method is already installed for class
  4175 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  4176 rat, etc.
  4177 
  4178 * Former constant "List.op @" now named "List.append".  Use ML
  4179 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  4180 circumvent possible incompatibilities when working on ML level.
  4181 
  4182 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  4183 
  4184 * New function listsum :: 'a list => 'a for arbitrary monoids.
  4185 Special syntax: "SUM x <- xs. f x" (and latex variants)
  4186 
  4187 * New syntax for Haskell-like list comprehension (input only), eg.
  4188 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  4189 
  4190 * The special syntax for function "filter" has changed from [x :
  4191 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  4192 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  4193 
  4194 * [a..b] is now defined for arbitrary linear orders.  It used to be
  4195 defined on nat only, as an abbreviation for [a..<Suc b]
  4196 INCOMPATIBILITY.
  4197 
  4198 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  4199 
  4200 * New functions "sorted" and "sort" in src/HOL/List.thy.
  4201 
  4202 * New lemma collection field_simps (an extension of ring_simps) for
  4203 manipulating (in)equations involving division. Multiplies with all
  4204 denominators that can be proved to be non-zero (in equations) or
  4205 positive/negative (in inequations).
  4206 
  4207 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  4208 have been improved and renamed to ring_simps, group_simps and
  4209 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  4210 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  4211 
  4212 * Theory Library/Commutative_Ring: switched from recdef to function
  4213 package; constants add, mul, pow now curried.  Infix syntax for
  4214 algebraic operations.
  4215 
  4216 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  4217 INCOMPATIBILITY.
  4218 
  4219 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  4220 INCOMPATIBILITY.
  4221 
  4222 * HOL/records: generalised field-update to take a function on the
  4223 field rather than the new value: r(|A := x|) is translated to A_update
  4224 (K x) r The K-combinator that is internally used is called K_record.
  4225 INCOMPATIBILITY: Usage of the plain update functions has to be
  4226 adapted.
  4227  
  4228 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  4229 * x = 0, which are required for a semiring.  Richer structures do not
  4230 inherit from semiring_0 anymore, because this property is a theorem
  4231 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  4232 there is more to prove, but this is mostly trivial.
  4233 
  4234 * Class "recpower" is generalized to arbitrary monoids, not just
  4235 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  4236 commutativity or semiring properties additionally.
  4237 
  4238 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  4239 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  4240 better use 'abbreviation'.
  4241 
  4242 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  4243 
  4244 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  4245 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  4246 significant changes for setting up numeral syntax for types:
  4247   - New constants Numeral.pred and Numeral.succ instead
  4248       of former Numeral.bin_pred and Numeral.bin_succ.
  4249   - Use integer operations instead of bin_add, bin_mult and so on.
  4250   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  4251   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  4252 
  4253 See src/HOL/Integ/IntArith.thy for an example setup.
  4254 
  4255 * Command 'normal_form' computes the normal form of a term that may
  4256 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  4257 produces ``[b, c, a]'' (without proof).  This command is suitable for
  4258 heavy-duty computations because the functions are compiled to ML
  4259 first.  Correspondingly, a method "normalization" is provided.  See
  4260 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  4261 
  4262 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  4263 25 like -->); output depends on the "iff" print_mode, the default is
  4264 "A = B" (with priority 50).
  4265 
  4266 * Relations less (<) and less_eq (<=) are also available on type bool.
  4267 Modified syntax to disallow nesting without explicit parentheses,
  4268 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  4269 INCOMPATIBILITY.
  4270 
  4271 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  4272 
  4273 * Relation composition operator "op O" now has precedence 75 and binds
  4274 stronger than union and intersection. INCOMPATIBILITY.
  4275 
  4276 * The old set interval syntax "{m..n(}" (and relatives) has been
  4277 removed.  Use "{m..<n}" (and relatives) instead.
  4278 
  4279 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  4280 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  4281 ``declare [[simproc del: neq]]''.
  4282 
  4283 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  4284 True/False.
  4285 
  4286 * Theorem Cons_eq_map_conv no longer declared as "simp".
  4287 
  4288 * Theorem setsum_mult renamed to setsum_right_distrib.
  4289 
  4290 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  4291 ``rule'' method.
  4292 
  4293 * Reimplemented methods "sat" and "satx", with several improvements:
  4294 goals no longer need to be stated as "<prems> ==> False", equivalences
  4295 (i.e. "=" on type bool) are handled, variable names of the form
  4296 "lit_<n>" are no longer reserved, significant speedup.
  4297 
  4298 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  4299 zChaff is still supported as well.
  4300 
  4301 * 'inductive' and 'datatype': provide projections of mutual rules,
  4302 bundled as foo_bar.inducts;
  4303 
  4304 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  4305 Library.
  4306 
  4307 * Library: moved theory Accessible_Part to main HOL.
  4308 
  4309 * Library: added theory Coinductive_List of potentially infinite lists
  4310 as greatest fixed-point.
  4311 
  4312 * Library: added theory AssocList which implements (finite) maps as
  4313 association lists.
  4314 
  4315 * Method "evaluation" solves goals (i.e. a boolean expression)
  4316 efficiently by compiling it to ML.  The goal is "proved" (via an
  4317 oracle) if it evaluates to True.
  4318 
  4319 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  4320 also when invoked by the simplifier.  This results in the Simplifier
  4321 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  4322 Configuration option fast_arith_split_limit=0 recovers the old
  4323 behavior.
  4324 
  4325 * Support for hex (0x20) and binary (0b1001) numerals.
  4326 
  4327 * New method: reify eqs (t), where eqs are equations for an
  4328 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  4329 parameter, computes a term s::'b and a list xs::'a list and proves the
  4330 theorem I xs s = t. This is also known as reification or quoting. The
  4331 resulting theorem is applied to the subgoal to substitute t with I xs
  4332 s.  If t is omitted, the subgoal itself is reified.
  4333 
  4334 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  4335 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  4336 where f is supposed to be a computable function (in the sense of code
  4337 generattion). The method uses reify to compute s and xs as above then
  4338 applies corr_thm and uses normalization by evaluation to "prove" f s =
  4339 r and finally gets the theorem t = r, which is again applied to the
  4340 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  4341 
  4342 * Reflection: Automatic reification now handels binding, an example is
  4343 available in src/HOL/ex/ReflectionEx.thy
  4344 
  4345 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  4346 command 'statespace' that is similar to 'record', but introduces an
  4347 abstract specification based on the locale infrastructure instead of
  4348 HOL types.  This leads to extra flexibility in composing state spaces,
  4349 in particular multiple inheritance and renaming of components.
  4350 
  4351 
  4352 *** HOL-Complex ***
  4353 
  4354 * Hyperreal: Functions root and sqrt are now defined on negative real
  4355 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  4356 Nonnegativity side conditions have been removed from many lemmas, so
  4357 that more subgoals may now be solved by simplification; potential
  4358 INCOMPATIBILITY.
  4359 
  4360 * Real: new type classes formalize real normed vector spaces and
  4361 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  4362 and norm :: 'a => real.
  4363 
  4364 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  4365 reals into other types. The overloaded constant Reals :: 'a set is now
  4366 defined as range of_real; potential INCOMPATIBILITY.
  4367 
  4368 * Real: proper support for ML code generation, including 'quickcheck'.
  4369 Reals are implemented as arbitrary precision rationals.
  4370 
  4371 * Hyperreal: Several constants that previously worked only for the
  4372 reals have been generalized, so they now work over arbitrary vector
  4373 spaces. Type annotations may need to be added in some cases; potential
  4374 INCOMPATIBILITY.
  4375 
  4376   Infinitesimal  :: ('a::real_normed_vector) star set
  4377   HFinite        :: ('a::real_normed_vector) star set
  4378   HInfinite      :: ('a::real_normed_vector) star set
  4379   approx         :: ('a::real_normed_vector) star => 'a star => bool
  4380   monad          :: ('a::real_normed_vector) star => 'a star set
  4381   galaxy         :: ('a::real_normed_vector) star => 'a star set
  4382   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  4383   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  4384   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  4385   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  4386   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  4387   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  4388   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  4389   sgn            :: 'a::real_normed_vector => 'a
  4390   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  4391 
  4392 * Complex: Some complex-specific constants are now abbreviations for
  4393 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  4394 hnorm.  Other constants have been entirely removed in favor of the
  4395 polymorphic versions (INCOMPATIBILITY):
  4396 
  4397   approx        <-- capprox
  4398   HFinite       <-- CFinite
  4399   HInfinite     <-- CInfinite
  4400   Infinitesimal <-- CInfinitesimal
  4401   monad         <-- cmonad
  4402   galaxy        <-- cgalaxy
  4403   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  4404   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  4405   (ns)deriv     <-- (ns)cderiv
  4406 
  4407 
  4408 *** HOL-Algebra ***
  4409 
  4410 * Formalisation of ideals and the quotient construction over rings.
  4411 
  4412 * Order and lattice theory no longer based on records.
  4413 INCOMPATIBILITY.
  4414 
  4415 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  4416 greatest_closed.  INCOMPATIBILITY.
  4417 
  4418 * Method algebra is now set up via an attribute.  For examples see
  4419 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  4420 of algebraic structures.
  4421 
  4422 * Renamed theory CRing to Ring.
  4423 
  4424 
  4425 *** HOL-Nominal ***
  4426 
  4427 * Substantial, yet incomplete support for nominal datatypes (binding
  4428 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  4429 src/HOL/Nominal/Examples.  Prospective users should consult
  4430 http://isabelle.in.tum.de/nominal/
  4431 
  4432 
  4433 *** ML ***
  4434 
  4435 * ML basics: just one true type int, which coincides with IntInf.int
  4436 (even on SML/NJ).
  4437 
  4438 * ML within Isar: antiquotations allow to embed statically-checked
  4439 formal entities in the source, referring to the context available at
  4440 compile-time.  For example:
  4441 
  4442 ML {* @{sort "{zero,one}"} *}
  4443 ML {* @{typ "'a => 'b"} *}
  4444 ML {* @{term "%x. x"} *}
  4445 ML {* @{prop "x == y"} *}
  4446 ML {* @{ctyp "'a => 'b"} *}
  4447 ML {* @{cterm "%x. x"} *}
  4448 ML {* @{cprop "x == y"} *}
  4449 ML {* @{thm asm_rl} *}
  4450 ML {* @{thms asm_rl} *}
  4451 ML {* @{type_name c} *}
  4452 ML {* @{type_syntax c} *}
  4453 ML {* @{const_name c} *}
  4454 ML {* @{const_syntax c} *}
  4455 ML {* @{context} *}
  4456 ML {* @{theory} *}
  4457 ML {* @{theory Pure} *}
  4458 ML {* @{theory_ref} *}
  4459 ML {* @{theory_ref Pure} *}
  4460 ML {* @{simpset} *}
  4461 ML {* @{claset} *}
  4462 ML {* @{clasimpset} *}
  4463 
  4464 The same works for sources being ``used'' within an Isar context.
  4465 
  4466 * ML in Isar: improved error reporting; extra verbosity with
  4467 ML_Context.trace enabled.
  4468 
  4469 * Pure/General/table.ML: the join operations now works via exceptions
  4470 DUP/SAME instead of type option. This is simpler in simple cases, and
  4471 admits slightly more efficient complex applications.
  4472 
  4473 * Pure: 'advanced' translation functions (parse_translation etc.) now
  4474 use Context.generic instead of just theory.
  4475 
  4476 * Pure: datatype Context.generic joins theory/Proof.context and
  4477 provides some facilities for code that works in either kind of
  4478 context, notably GenericDataFun for uniform theory and proof data.
  4479 
  4480 * Pure: simplified internal attribute type, which is now always
  4481 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  4482 local (Proof.context) attributes have been discontinued, while
  4483 minimizing code duplication. Thm.rule_attribute and
  4484 Thm.declaration_attribute build canonical attributes; see also structure
  4485 Context for further operations on Context.generic, notably
  4486 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  4487 declarations and definitions.
  4488 
  4489 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  4490 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  4491 init only required for impure data. INCOMPATIBILITY: empty really need
  4492 to be empty (no dependencies on theory content!)
  4493 
  4494 * Pure/kernel: consts certification ignores sort constraints given in
  4495 signature declarations. (This information is not relevant to the
  4496 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  4497 potential INCOMPATIBILITY.
  4498 
  4499 * Pure: axiomatic type classes are now purely definitional, with
  4500 explicit proofs of class axioms and super class relations performed
  4501 internally. See Pure/axclass.ML for the main internal interfaces --
  4502 notably AxClass.define_class supercedes AxClass.add_axclass, and
  4503 AxClass.axiomatize_class/classrel/arity supersede
  4504 Sign.add_classes/classrel/arities.
  4505 
  4506 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  4507 global/local versions on theory vs. Proof.context have been
  4508 discontinued; Attrib.syntax and Method.syntax have been adapted
  4509 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  4510 attributes, methods, etc.
  4511 
  4512 * Pure: several functions of signature "... -> theory -> theory * ..."
  4513 have been reoriented to "... -> theory -> ... * theory" in order to
  4514 allow natural usage in combination with the ||>, ||>>, |-> and
  4515 fold_map combinators.
  4516 
  4517 * Pure: official theorem names (closed derivations) and additional
  4518 comments (tags) are now strictly separate.  Name hints -- which are
  4519 maintained as tags -- may be attached any time without affecting the
  4520 derivation.
  4521 
  4522 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  4523 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  4524 achieve the old behaviour.
  4525 
  4526 * Pure: the "Goal" constant is now called "prop", supporting a
  4527 slightly more general idea of ``protecting'' meta-level rule
  4528 statements.
  4529 
  4530 * Pure: Logic.(un)varify only works in a global context, which is now
  4531 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  4532 Logic.legacy_(un)varify as temporary workaround.
  4533 
  4534 * Pure: structure Name provides scalable operations for generating
  4535 internal variable names, notably Name.variants etc.  This replaces
  4536 some popular functions from term.ML:
  4537 
  4538   Term.variant		->  Name.variant
  4539   Term.variantlist	->  Name.variant_list
  4540   Term.invent_names	->  Name.invent_list
  4541 
  4542 Note that low-level renaming rarely occurs in new code -- operations
  4543 from structure Variable are used instead (see below).
  4544 
  4545 * Pure: structure Variable provides fundamental operations for proper
  4546 treatment of fixed/schematic variables in a context.  For example,
  4547 Variable.import introduces fixes for schematics of given facts and
  4548 Variable.export reverses the effect (up to renaming) -- this replaces
  4549 various freeze_thaw operations.
  4550 
  4551 * Pure: structure Goal provides simple interfaces for
  4552 init/conclude/finish and tactical prove operations (replacing former
  4553 Tactic.prove).  Goal.prove is the canonical way to prove results
  4554 within a given context; Goal.prove_global is a degraded version for
  4555 theory level goals, including a global Drule.standard.  Note that
  4556 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  4557 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  4558 in a locale context).
  4559 
  4560 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  4561 and type checking (Syntax.check_term etc.), with common combinations
  4562 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  4563 which are considered legacy and await removal.
  4564 
  4565 * Pure/Syntax: generic interfaces for type unchecking
  4566 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  4567 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  4568 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  4569 available for convenience, but refer to the very same operations using
  4570 a mere theory instead of a full context.
  4571 
  4572 * Isar: simplified treatment of user-level errors, using exception
  4573 ERROR of string uniformly.  Function error now merely raises ERROR,
  4574 without any side effect on output channels.  The Isar toplevel takes
  4575 care of proper display of ERROR exceptions.  ML code may use plain
  4576 handle/can/try; cat_error may be used to concatenate errors like this:
  4577 
  4578   ... handle ERROR msg => cat_error msg "..."
  4579 
  4580 Toplevel ML code (run directly or through the Isar toplevel) may be
  4581 embedded into the Isar toplevel with exception display/debug like
  4582 this:
  4583 
  4584   Isar.toplevel (fn () => ...)
  4585 
  4586 INCOMPATIBILITY, removed special transform_error facilities, removed
  4587 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  4588 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  4589 -- use plain ERROR instead.
  4590 
  4591 * Isar: theory setup now has type (theory -> theory), instead of a
  4592 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  4593 
  4594 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  4595 ProofContext.debug/verbose flags.
  4596 
  4597 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  4598 theory before entering a proof state.  Transactions now always see a
  4599 quasi-functional intermediate checkpoint, both in interactive and
  4600 batch mode.
  4601 
  4602 * Isar: simplified interfaces for outer syntax.  Renamed
  4603 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  4604 OuterSyntax.add_parsers -- this functionality is now included in
  4605 OuterSyntax.command etc.  INCOMPATIBILITY.
  4606 
  4607 * Simplifier: the simpset of a running simplification process now
  4608 contains a proof context (cf. Simplifier.the_context), which is the
  4609 very context that the initial simpset has been retrieved from (by
  4610 simpset_of/local_simpset_of).  Consequently, all plug-in components
  4611 (solver, looper etc.) may depend on arbitrary proof data.
  4612 
  4613 * Simplifier.inherit_context inherits the proof context (plus the
  4614 local bounds) of the current simplification process; any simproc
  4615 etc. that calls the Simplifier recursively should do this!  Removed
  4616 former Simplifier.inherit_bounds, which is already included here --
  4617 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  4618 specify an explicit context using Simplifier.context/theory_context.
  4619 
  4620 * Simplifier/Classical Reasoner: more abstract interfaces
  4621 change_simpset/claset for modifying the simpset/claset reference of a
  4622 theory; raw versions simpset/claset_ref etc. have been discontinued --
  4623 INCOMPATIBILITY.
  4624 
  4625 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  4626 "Trueprop" etc.
  4627 
  4628 
  4629 *** System ***
  4630 
  4631 * settings: the default heap location within ISABELLE_HOME_USER now
  4632 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  4633 Isabelle installations.
  4634 
  4635 * isabelle-process: option -S (secure mode) disables some critical
  4636 operations, notably runtime compilation and evaluation of ML source
  4637 code.
  4638 
  4639 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  4640 
  4641 * Support for parallel execution, using native multicore support of
  4642 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  4643 independent theories, according to the given theory header
  4644 specifications. The maximum number of worker threads is specified via
  4645 usedir option -M or the "max-threads" setting in Proof General. A
  4646 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  4647 to 6 on a 8-core machine.  User-code needs to observe certain
  4648 guidelines for thread-safe programming, see appendix A in the Isar
  4649 Implementation manual.
  4650 
  4651 
  4652 
  4653 New in Isabelle2005 (October 2005)
  4654 ----------------------------------
  4655 
  4656 *** General ***
  4657 
  4658 * Theory headers: the new header syntax for Isar theories is
  4659 
  4660   theory <name>
  4661   imports <theory1> ... <theoryN>
  4662   uses <file1> ... <fileM>
  4663   begin
  4664 
  4665 where the 'uses' part is optional.  The previous syntax
  4666 
  4667   theory <name> = <theory1> + ... + <theoryN>:
  4668 
  4669 will disappear in the next release.  Use isatool fixheaders to convert
  4670 existing theory files.  Note that there is no change in ancient
  4671 non-Isar theories now, but these will disappear soon.
  4672 
  4673 * Theory loader: parent theories can now also be referred to via
  4674 relative and absolute paths.
  4675 
  4676 * Command 'find_theorems' searches for a list of criteria instead of a
  4677 list of constants. Known criteria are: intro, elim, dest, name:string,
  4678 simp:term, and any term. Criteria can be preceded by '-' to select
  4679 theorems that do not match. Intro, elim, dest select theorems that
  4680 match the current goal, name:s selects theorems whose fully qualified
  4681 name contain s, and simp:term selects all simplification rules whose
  4682 lhs match term.  Any other term is interpreted as pattern and selects
  4683 all theorems matching the pattern. Available in ProofGeneral under
  4684 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  4685 
  4686   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  4687 
  4688 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  4689 matching the current goal as introduction rule and not having "HOL."
  4690 in their name (i.e. not being defined in theory HOL).
  4691 
  4692 * Command 'thms_containing' has been discontinued in favour of
  4693 'find_theorems'; INCOMPATIBILITY.
  4694 
  4695 * Communication with Proof General is now 8bit clean, which means that
  4696 Unicode text in UTF-8 encoding may be used within theory texts (both
  4697 formal and informal parts).  Cf. option -U of the Isabelle Proof
  4698 General interface.  Here are some simple examples (cf. src/HOL/ex):
  4699 
  4700   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  4701   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  4702 
  4703 * Improved efficiency of the Simplifier and, to a lesser degree, the
  4704 Classical Reasoner.  Typical big applications run around 2 times
  4705 faster.
  4706 
  4707 
  4708 *** Document preparation ***
  4709 
  4710 * Commands 'display_drafts' and 'print_drafts' perform simple output
  4711 of raw sources.  Only those symbols that do not require additional
  4712 LaTeX packages (depending on comments in isabellesym.sty) are
  4713 displayed properly, everything else is left verbatim.  isatool display
  4714 and isatool print are used as front ends (these are subject to the
  4715 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  4716 
  4717 * Command tags control specific markup of certain regions of text,
  4718 notably folding and hiding.  Predefined tags include "theory" (for
  4719 theory begin and end), "proof" for proof commands, and "ML" for
  4720 commands involving ML code; the additional tags "visible" and
  4721 "invisible" are unused by default.  Users may give explicit tag
  4722 specifications in the text, e.g. ''by %invisible (auto)''.  The
  4723 interpretation of tags is determined by the LaTeX job during document
  4724 preparation: see option -V of isatool usedir, or options -n and -t of
  4725 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  4726 \isadroptag.
  4727 
  4728 Several document versions may be produced at the same time via isatool
  4729 usedir (the generated index.html will link all of them).  Typical
  4730 specifications include ''-V document=theory,proof,ML'' to present
  4731 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  4732 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  4733 these parts without any formal replacement text.  The Isabelle site
  4734 default settings produce ''document'' and ''outline'' versions as
  4735 specified above.
  4736 
  4737 * Several new antiquotations:
  4738 
  4739   @{term_type term} prints a term with its type annotated;
  4740 
  4741   @{typeof term} prints the type of a term;
  4742 
  4743   @{const const} is the same as @{term const}, but checks that the
  4744   argument is a known logical constant;
  4745 
  4746   @{term_style style term} and @{thm_style style thm} print a term or
  4747   theorem applying a "style" to it
  4748 
  4749   @{ML text}
  4750 
  4751 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  4752 definitions, equations, inequations etc., 'concl' printing only the
  4753 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  4754 to print the specified premise.  TermStyle.add_style provides an ML
  4755 interface for introducing further styles.  See also the "LaTeX Sugar"
  4756 document practical applications.  The ML antiquotation prints
  4757 type-checked ML expressions verbatim.
  4758 
  4759 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  4760 and 'text' support optional locale specification '(in loc)', which
  4761 specifies the default context for interpreting antiquotations.  For
  4762 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  4763 
  4764 * Option 'locale=NAME' of antiquotations specifies an alternative
  4765 context interpreting the subsequent argument.  For example: @{thm
  4766 [locale=lattice] inf_assoc}.
  4767 
  4768 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  4769 a proof context.
  4770 
  4771 * Proper output of antiquotations for theory commands involving a
  4772 proof context (such as 'locale' or 'theorem (in loc) ...').
  4773 
  4774 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  4775 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  4776 
  4777 * isatool usedir: new option -C (default true) controls whether option
  4778 -D should include a copy of the original document directory; -C false
  4779 prevents unwanted effects such as copying of administrative CVS data.
  4780 
  4781 
  4782 *** Pure ***
  4783 
  4784 * Considerably improved version of 'constdefs' command.  Now performs
  4785 automatic type-inference of declared constants; additional support for
  4786 local structure declarations (cf. locales and HOL records), see also
  4787 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  4788 sequential dependencies of definitions within a single 'constdefs'
  4789 section; moreover, the declared name needs to be an identifier.  If
  4790 all fails, consider to fall back on 'consts' and 'defs' separately.
  4791 
  4792 * Improved indexed syntax and implicit structures.  First of all,
  4793 indexed syntax provides a notational device for subscripted
  4794 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  4795 expressions.  Secondly, in a local context with structure
  4796 declarations, number indexes \<^sub>n or the empty index (default
  4797 number 1) refer to a certain fixed variable implicitly; option
  4798 show_structs controls printing of implicit structures.  Typical
  4799 applications of these concepts involve record types and locales.
  4800 
  4801 * New command 'no_syntax' removes grammar declarations (and
  4802 translations) resulting from the given syntax specification, which is
  4803 interpreted in the same manner as for the 'syntax' command.
  4804 
  4805 * 'Advanced' translation functions (parse_translation etc.) may depend
  4806 on the signature of the theory context being presently used for
  4807 parsing/printing, see also isar-ref manual.
  4808 
  4809 * Improved 'oracle' command provides a type-safe interface to turn an
  4810 ML expression of type theory -> T -> term into a primitive rule of
  4811 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  4812 is already included here); see also FOL/ex/IffExample.thy;
  4813 INCOMPATIBILITY.
  4814 
  4815 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  4816 before); "cI" is no longer bound, use "c.intro" instead.
  4817 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  4818 axclasses vs. locales.
  4819 
  4820 * Improved internal renaming of symbolic identifiers -- attach primes
  4821 instead of base 26 numbers.
  4822 
  4823 * New flag show_question_marks controls printing of leading question
  4824 marks in schematic variable names.
  4825 
  4826 * In schematic variable names, *any* symbol following \<^isub> or
  4827 \<^isup> is now treated as part of the base name.  For example, the
  4828 following works without printing of awkward ".0" indexes:
  4829 
  4830   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  4831     by simp
  4832 
  4833 * Inner syntax includes (*(*nested*) comments*).
  4834 
  4835 * Pretty printer now supports unbreakable blocks, specified in mixfix
  4836 annotations as "(00...)".
  4837 
  4838 * Clear separation of logical types and nonterminals, where the latter
  4839 may only occur in 'syntax' specifications or type abbreviations.
  4840 Before that distinction was only partially implemented via type class
  4841 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  4842 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  4843 exotic syntax specifications may require further adaption
  4844 (e.g. Cube/Cube.thy).
  4845 
  4846 * Removed obsolete type class "logic", use the top sort {} instead.
  4847 Note that non-logical types should be declared as 'nonterminals'
  4848 rather than 'types'.  INCOMPATIBILITY for new object-logic
  4849 specifications.
  4850 
  4851 * Attributes 'induct' and 'cases': type or set names may now be
  4852 locally fixed variables as well.
  4853 
  4854 * Simplifier: can now control the depth to which conditional rewriting
  4855 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  4856 Limit.
  4857 
  4858 * Simplifier: simplification procedures may now take the current
  4859 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  4860 interface), which is very useful for calling the Simplifier
  4861 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  4862 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  4863 low-level mk_simproc no longer applies Logic.varify internally, to
  4864 allow for use in a context of fixed variables.
  4865 
  4866 * thin_tac now works even if the assumption being deleted contains !!
  4867 or ==>.  More generally, erule now works even if the major premise of
  4868 the elimination rule contains !! or ==>.
  4869 
  4870 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  4871 
  4872 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  4873 from Pure, which contains all common declarations already.  Both
  4874 theories are defined via plain Isabelle/Isar .thy files.
  4875 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  4876 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  4877 use isatool fixcpure to adapt your theory and ML sources.
  4878 
  4879 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  4880 selections of theorems in named facts via index ranges.
  4881 
  4882 * 'print_theorems': in theory mode, really print the difference
  4883 wrt. the last state (works for interactive theory development only),
  4884 in proof mode print all local facts (cf. 'print_facts');
  4885 
  4886 * 'hide': option '(open)' hides only base names.
  4887 
  4888 * More efficient treatment of intermediate checkpoints in interactive
  4889 theory development.
  4890 
  4891 * Code generator is now invoked via code_module (incremental code
  4892 generation) and code_library (modular code generation, ML structures
  4893 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  4894 must be quoted when used as identifiers.
  4895 
  4896 * New 'value' command for reading, evaluating and printing terms using
  4897 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  4898 quoted when used as identifier.
  4899 
  4900 
  4901 *** Locales ***
  4902 
  4903 * New commands for the interpretation of locale expressions in
  4904 theories (1), locales (2) and proof contexts (3).  These generate
  4905 proof obligations from the expression specification.  After the
  4906 obligations have been discharged, theorems of the expression are added
  4907 to the theory, target locale or proof context.  The synopsis of the
  4908 commands is a follows:
  4909 
  4910   (1) interpretation expr inst
  4911   (2) interpretation target < expr
  4912   (3) interpret expr inst
  4913 
  4914 Interpretation in theories and proof contexts require a parameter
  4915 instantiation of terms from the current context.  This is applied to
  4916 specifications and theorems of the interpreted expression.
  4917 Interpretation in locales only permits parameter renaming through the
  4918 locale expression.  Interpretation is smart in that interpretations
  4919 that are active already do not occur in proof obligations, neither are
  4920 instantiated theorems stored in duplicate.  Use 'print_interps' to
  4921 inspect active interpretations of a particular locale.  For details,
  4922 see the Isar Reference manual.  Examples can be found in
  4923 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  4924 
  4925 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  4926 'interpret' instead.
  4927 
  4928 * New context element 'constrains' for adding type constraints to
  4929 parameters.
  4930 
  4931 * Context expressions: renaming of parameters with syntax
  4932 redeclaration.
  4933 
  4934 * Locale declaration: 'includes' disallowed.
  4935 
  4936 * Proper static binding of attribute syntax -- i.e. types / terms /
  4937 facts mentioned as arguments are always those of the locale definition
  4938 context, independently of the context of later invocations.  Moreover,
  4939 locale operations (renaming and type / term instantiation) are applied
  4940 to attribute arguments as expected.
  4941 
  4942 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  4943 actual attributes; rare situations may require Attrib.attribute to
  4944 embed those attributes into Attrib.src that lack concrete syntax.
  4945 Attribute implementations need to cooperate properly with the static
  4946 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  4947 Attrib.XXX_thm etc. already do the right thing without further
  4948 intervention.  Only unusual applications -- such as "where" or "of"
  4949 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  4950 on the context and the facts involved -- may have to assign parsed
  4951 values to argument tokens explicitly.
  4952 
  4953 * Changed parameter management in theorem generation for long goal
  4954 statements with 'includes'.  INCOMPATIBILITY: produces a different
  4955 theorem statement in rare situations.
  4956 
  4957 * Locale inspection command 'print_locale' omits notes elements.  Use
  4958 'print_locale!' to have them included in the output.
  4959 
  4960 
  4961 *** Provers ***
  4962 
  4963 * Provers/hypsubst.ML: improved version of the subst method, for
  4964 single-step rewriting: it now works in bound variable contexts. New is
  4965 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  4966 rewrite a different subterm than the original subst method, which is
  4967 still available as 'simplesubst'.
  4968 
  4969 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  4970 and quasi orders.
  4971 
  4972 * Provers/trancl.ML: new transitivity reasoner for transitive and
  4973 reflexive-transitive closure of relations.
  4974 
  4975 * Provers/blast.ML: new reference depth_limit to make blast's depth
  4976 limit (previously hard-coded with a value of 20) user-definable.
  4977 
  4978 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  4979 is peformed already.  Object-logics merely need to finish their
  4980 initial simpset configuration as before.  INCOMPATIBILITY.
  4981 
  4982 
  4983 *** HOL ***
  4984 
  4985 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  4986 
  4987   syntax (epsilon)
  4988     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  4989 
  4990 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  4991 and x-symbol; use option '-m epsilon' to get it actually printed.
  4992 Moreover, the mathematically important symbolic identifier \<epsilon>
  4993 becomes available as variable, constant etc.  INCOMPATIBILITY,
  4994 
  4995 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  4996 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  4997 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  4998 support corresponding Isar calculations.
  4999 
  5000 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  5001 instead of ":".
  5002 
  5003 * theory SetInterval: changed the syntax for open intervals:
  5004 
  5005   Old       New
  5006   {..n(}    {..<n}
  5007   {)n..}    {n<..}
  5008   {m..n(}   {m..<n}
  5009   {)m..n}   {m<..n}
  5010   {)m..n(}  {m<..<n}
  5011 
  5012 The old syntax is still supported but will disappear in the next
  5013 release.  For conversion use the following Emacs search and replace
  5014 patterns (these are not perfect but work quite well):
  5015 
  5016   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  5017   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  5018 
  5019 * Theory Commutative_Ring (in Library): method comm_ring for proving
  5020 equalities in commutative rings; method 'algebra' provides a generic
  5021 interface.
  5022 
  5023 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  5024 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  5025 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  5026 be a tuple pattern.
  5027 
  5028 Some new syntax forms are available:
  5029 
  5030   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  5031   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  5032   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  5033   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  5034 
  5035 The latter form "\<Sum>x < k. e" used to be based on a separate
  5036 function "Summation", which has been discontinued.
  5037 
  5038 * theory Finite_Set: in structured induction proofs, the insert case
  5039 is now 'case (insert x F)' instead of the old counterintuitive 'case
  5040 (insert F x)'.
  5041 
  5042 * The 'refute' command has been extended to support a much larger
  5043 fragment of HOL, including axiomatic type classes, constdefs and
  5044 typedefs, inductive datatypes and recursion.
  5045 
  5046 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  5047 Requires zChaff with proof generation to be installed.  See
  5048 HOL/ex/SAT_Examples.thy for examples.
  5049 
  5050 * Datatype induction via method 'induct' now preserves the name of the
  5051 induction variable. For example, when proving P(xs::'a list) by
  5052 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  5053 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  5054 in unstructured proof scripts.
  5055 
  5056 * Reworked implementation of records.  Improved scalability for
  5057 records with many fields, avoiding performance problems for type
  5058 inference. Records are no longer composed of nested field types, but
  5059 of nested extension types. Therefore the record type only grows linear
  5060 in the number of extensions and not in the number of fields.  The
  5061 top-level (users) view on records is preserved.  Potential
  5062 INCOMPATIBILITY only in strange cases, where the theory depends on the
  5063 old record representation. The type generated for a record is called
  5064 <record_name>_ext_type.
  5065 
  5066 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  5067 proofs triggered by a record definition or a simproc (if
  5068 quick_and_dirty is enabled).  Definitions of large records can take
  5069 quite long.
  5070 
  5071 New simproc record_upd_simproc for simplification of multiple record
  5072 updates enabled by default.  Moreover, trivial updates are also
  5073 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  5074 occasionally, since simplification is more powerful by default.
  5075 
  5076 * typedef: proper support for polymorphic sets, which contain extra
  5077 type-variables in the term.
  5078 
  5079 * Simplifier: automatically reasons about transitivity chains
  5080 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  5081 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  5082 old proofs break occasionally as simplification may now solve more
  5083 goals than previously.
  5084 
  5085 * Simplifier: converts x <= y into x = y if assumption y <= x is
  5086 present.  Works for all partial orders (class "order"), in particular
  5087 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  5088 just like y <= x.
  5089 
  5090 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  5091 bound variable or a constant then the let is unfolded.  Otherwise
  5092 first a is simplified to b, and then f b is simplified to g. If
  5093 possible we abstract b from g arriving at "let x = b in h x",
  5094 otherwise we unfold the let and arrive at g.  The simproc can be
  5095 enabled/disabled by the reference use_let_simproc.  Potential
  5096 INCOMPATIBILITY since simplification is more powerful by default.
  5097 
  5098 * Classical reasoning: the meson method now accepts theorems as arguments.
  5099 
  5100 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  5101 jobs to provide advice on the provability of subgoals.
  5102 
  5103 * Theory OrderedGroup and Ring_and_Field: various additions and
  5104 improvements to faciliate calculations involving equalities and
  5105 inequalities.
  5106 
  5107 The following theorems have been eliminated or modified
  5108 (INCOMPATIBILITY):
  5109 
  5110   abs_eq             now named abs_of_nonneg
  5111   abs_of_ge_0        now named abs_of_nonneg
  5112   abs_minus_eq       now named abs_of_nonpos
  5113   imp_abs_id         now named abs_of_nonneg
  5114   imp_abs_neg_id     now named abs_of_nonpos
  5115   mult_pos           now named mult_pos_pos
  5116   mult_pos_le        now named mult_nonneg_nonneg
  5117   mult_pos_neg_le    now named mult_nonneg_nonpos
  5118   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  5119   mult_neg           now named mult_neg_neg
  5120   mult_neg_le        now named mult_nonpos_nonpos
  5121 
  5122 * The following lemmas in Ring_and_Field have been added to the simplifier:
  5123      
  5124      zero_le_square
  5125      not_square_less_zero 
  5126 
  5127   The following lemmas have been deleted from Real/RealPow:
  5128   
  5129      realpow_zero_zero
  5130      realpow_two
  5131      realpow_less
  5132      zero_le_power
  5133      realpow_two_le
  5134      abs_realpow_two
  5135      realpow_two_abs     
  5136 
  5137 * Theory Parity: added rules for simplifying exponents.
  5138 
  5139 * Theory List:
  5140 
  5141 The following theorems have been eliminated or modified
  5142 (INCOMPATIBILITY):
  5143 
  5144   list_all_Nil       now named list_all.simps(1)
  5145   list_all_Cons      now named list_all.simps(2)
  5146   list_all_conv      now named list_all_iff
  5147   set_mem_eq         now named mem_iff
  5148 
  5149 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  5150 asymptotic "big O" calculations.  See the notes in BigO.thy.
  5151 
  5152 
  5153 *** HOL-Complex ***
  5154 
  5155 * Theory RealDef: better support for embedding natural numbers and
  5156 integers in the reals.
  5157 
  5158 The following theorems have been eliminated or modified
  5159 (INCOMPATIBILITY):
  5160 
  5161   exp_ge_add_one_self  now requires no hypotheses
  5162   real_of_int_add      reversed direction of equality (use [symmetric])
  5163   real_of_int_minus    reversed direction of equality (use [symmetric])
  5164   real_of_int_diff     reversed direction of equality (use [symmetric])
  5165   real_of_int_mult     reversed direction of equality (use [symmetric])
  5166 
  5167 * Theory RComplete: expanded support for floor and ceiling functions.
  5168 
  5169 * Theory Ln is new, with properties of the natural logarithm
  5170 
  5171 * Hyperreal: There is a new type constructor "star" for making
  5172 nonstandard types.  The old type names are now type synonyms:
  5173 
  5174   hypreal = real star
  5175   hypnat = nat star
  5176   hcomplex = complex star
  5177 
  5178 * Hyperreal: Many groups of similarly-defined constants have been
  5179 replaced by polymorphic versions (INCOMPATIBILITY):
  5180 
  5181   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  5182 
  5183   starset      <-- starsetNat, starsetC
  5184   *s*          <-- *sNat*, *sc*
  5185   starset_n    <-- starsetNat_n, starsetC_n
  5186   *sn*         <-- *sNatn*, *scn*
  5187   InternalSets <-- InternalNatSets, InternalCSets
  5188 
  5189   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  5190   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  5191   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  5192   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  5193   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  5194 
  5195 * Hyperreal: Many type-specific theorems have been removed in favor of
  5196 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  5197 
  5198   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  5199   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  5200   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  5201   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  5202   right_minus <-- hypreal_add_minus
  5203   left_minus <-- {hypreal,hcomplex}_add_minus_left
  5204   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  5205   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  5206   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  5207   mult_1_right <-- hcomplex_mult_one_right
  5208   mult_zero_left <-- hcomplex_mult_zero_left
  5209   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  5210   right_distrib <-- hypnat_add_mult_distrib2
  5211   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  5212   right_inverse <-- hypreal_mult_inverse
  5213   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  5214   order_refl <-- {hypreal,hypnat}_le_refl
  5215   order_trans <-- {hypreal,hypnat}_le_trans
  5216   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  5217   order_less_le <-- {hypreal,hypnat}_less_le
  5218   linorder_linear <-- {hypreal,hypnat}_le_linear
  5219   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  5220   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  5221   add_nonneg_nonneg <-- hypreal_le_add_order
  5222 
  5223 * Hyperreal: Separate theorems having to do with type-specific
  5224 versions of constants have been merged into theorems that apply to the
  5225 new polymorphic constants (INCOMPATIBILITY):
  5226 
  5227   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  5228   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  5229   STAR_Un <-- {STAR,NatStar,STARC}_Un
  5230   STAR_Int <-- {STAR,NatStar,STARC}_Int
  5231   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  5232   STAR_subset <-- {STAR,NatStar,STARC}_subset
  5233   STAR_mem <-- {STAR,NatStar,STARC}_mem
  5234   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  5235   STAR_diff <-- {STAR,STARC}_diff
  5236   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  5237     STARC_hcomplex_of_complex}_image_subset
  5238   starset_n_Un <-- starset{Nat,C}_n_Un
  5239   starset_n_Int <-- starset{Nat,C}_n_Int
  5240   starset_n_Compl <-- starset{Nat,C}_n_Compl
  5241   starset_n_diff <-- starset{Nat,C}_n_diff
  5242   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  5243   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  5244   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  5245   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  5246   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  5247   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  5248   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  5249   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  5250   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  5251   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  5252   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  5253   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  5254   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  5255   starfun_diff <-- starfun{C,RC,CR}_diff
  5256   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  5257   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  5258   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  5259   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  5260   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  5261   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  5262   starfun_Id <-- starfunC_Id
  5263   starfun_approx <-- starfun{Nat,CR}_approx
  5264   starfun_capprox <-- starfun{C,RC}_capprox
  5265   starfun_abs <-- starfunNat_rabs
  5266   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  5267   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  5268   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  5269   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  5270   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  5271   starfun_add_approx <-- starfunCR_add_approx
  5272   starfun_inverse_inverse <-- starfunC_inverse_inverse
  5273   starfun_divide <-- starfun{C,CR,RC}_divide
  5274   starfun_n <-- starfun{Nat,C}_n
  5275   starfun_n_mult <-- starfun{Nat,C}_n_mult
  5276   starfun_n_add <-- starfun{Nat,C}_n_add
  5277   starfun_n_add_minus <-- starfunNat_n_add_minus
  5278   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  5279   starfun_n_minus <-- starfun{Nat,C}_n_minus
  5280   starfun_n_eq <-- starfun{Nat,C}_n_eq
  5281 
  5282   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  5283   star_n_minus <-- {hypreal,hcomplex}_minus
  5284   star_n_diff <-- {hypreal,hcomplex}_diff
  5285   star_n_mult <-- {hypreal,hcomplex}_mult
  5286   star_n_inverse <-- {hypreal,hcomplex}_inverse
  5287   star_n_le <-- {hypreal,hypnat}_le
  5288   star_n_less <-- {hypreal,hypnat}_less
  5289   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  5290   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  5291   star_n_abs <-- hypreal_hrabs
  5292   star_n_divide <-- hcomplex_divide
  5293 
  5294   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  5295   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  5296   star_of_diff <-- hypreal_of_real_diff
  5297   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  5298   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  5299   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  5300   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  5301   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  5302   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  5303   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  5304   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  5305   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  5306   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  5307   star_of_number_of <-- {hypreal,hcomplex}_number_of
  5308   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  5309   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  5310   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  5311   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  5312   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  5313   star_of_power <-- hypreal_of_real_power
  5314   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  5315 
  5316 * Hyperreal: new method "transfer" that implements the transfer
  5317 principle of nonstandard analysis. With a subgoal that mentions
  5318 nonstandard types like "'a star", the command "apply transfer"
  5319 replaces it with an equivalent one that mentions only standard types.
  5320 To be successful, all free variables must have standard types; non-
  5321 standard variables must have explicit universal quantifiers.
  5322 
  5323 * Hyperreal: A theory of Taylor series.
  5324 
  5325 
  5326 *** HOLCF ***
  5327 
  5328 * Discontinued special version of 'constdefs' (which used to support
  5329 continuous functions) in favor of the general Pure one with full
  5330 type-inference.
  5331 
  5332 * New simplification procedure for solving continuity conditions; it
  5333 is much faster on terms with many nested lambda abstractions (cubic
  5334 instead of exponential time).
  5335 
  5336 * New syntax for domain package: selector names are now optional.
  5337 Parentheses should be omitted unless argument is lazy, for example:
  5338 
  5339   domain 'a stream = cons "'a" (lazy "'a stream")
  5340 
  5341 * New command 'fixrec' for defining recursive functions with pattern
  5342 matching; defining multiple functions with mutual recursion is also
  5343 supported.  Patterns may include the constants cpair, spair, up, sinl,
  5344 sinr, or any data constructor defined by the domain package. The given
  5345 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  5346 syntax and examples.
  5347 
  5348 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  5349 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  5350 but the proof obligation additionally includes an admissibility
  5351 requirement. The packages generate instances of class cpo or pcpo,
  5352 with continuity and strictness theorems for Rep and Abs.
  5353 
  5354 * HOLCF: Many theorems have been renamed according to a more standard naming
  5355 scheme (INCOMPATIBILITY):
  5356 
  5357   foo_inject:  "foo$x = foo$y ==> x = y"
  5358   foo_eq:      "(foo$x = foo$y) = (x = y)"
  5359   foo_less:    "(foo$x << foo$y) = (x << y)"
  5360   foo_strict:  "foo$UU = UU"
  5361   foo_defined: "... ==> foo$x ~= UU"
  5362   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  5363 
  5364 
  5365 *** ZF ***
  5366 
  5367 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  5368 including the First Isomorphism Theorem (on quotienting by the kernel
  5369 of a homomorphism).
  5370 
  5371 * ZF/Simplifier: install second copy of type solver that actually
  5372 makes use of TC rules declared to Isar proof contexts (or locales);
  5373 the old version is still required for ML proof scripts.
  5374 
  5375 
  5376 *** Cube ***
  5377 
  5378 * Converted to Isar theory format; use locales instead of axiomatic
  5379 theories.
  5380 
  5381 
  5382 *** ML ***
  5383 
  5384 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  5385 for ||>, ||>>, |>>,
  5386 
  5387 * Pure/library.ML no longer defines its own option datatype, but uses
  5388 that of the SML basis, which has constructors NONE and SOME instead of
  5389 None and Some, as well as exception Option.Option instead of OPTION.
  5390 The functions the, if_none, is_some, is_none have been adapted
  5391 accordingly, while Option.map replaces apsome.
  5392 
  5393 * Pure/library.ML: the exception LIST has been given up in favour of
  5394 the standard exceptions Empty and Subscript, as well as
  5395 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  5396 superceded by the standard hd and tl functions etc.
  5397 
  5398 A number of basic list functions are no longer exported to the ML
  5399 toplevel, as they are variants of predefined functions.  The following
  5400 suggests how one can translate existing code:
  5401 
  5402     rev_append xs ys = List.revAppend (xs, ys)
  5403     nth_elem (i, xs) = List.nth (xs, i)
  5404     last_elem xs = List.last xs
  5405     flat xss = List.concat xss
  5406     seq fs = List.app fs
  5407     partition P xs = List.partition P xs
  5408     mapfilter f xs = List.mapPartial f xs
  5409 
  5410 * Pure/library.ML: several combinators for linear functional
  5411 transformations, notably reverse application and composition:
  5412 
  5413   x |> f                f #> g
  5414   (x, y) |-> f          f #-> g
  5415 
  5416 * Pure/library.ML: introduced/changed precedence of infix operators:
  5417 
  5418   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  5419   infix 2 ?;
  5420   infix 3 o oo ooo oooo;
  5421   infix 4 ~~ upto downto;
  5422 
  5423 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  5424 infix operators.
  5425 
  5426 * Pure/library.ML: natural list combinators fold, fold_rev, and
  5427 fold_map support linear functional transformations and nesting.  For
  5428 example:
  5429 
  5430   fold f [x1, ..., xN] y =
  5431     y |> f x1 |> ... |> f xN
  5432 
  5433   (fold o fold) f [xs1, ..., xsN] y =
  5434     y |> fold f xs1 |> ... |> fold f xsN
  5435 
  5436   fold f [x1, ..., xN] =
  5437     f x1 #> ... #> f xN
  5438 
  5439   (fold o fold) f [xs1, ..., xsN] =
  5440     fold f xs1 #> ... #> fold f xsN
  5441 
  5442 * Pure/library.ML: the following selectors on type 'a option are
  5443 available:
  5444 
  5445   the:               'a option -> 'a  (*partial*)
  5446   these:             'a option -> 'a  where 'a = 'b list
  5447   the_default: 'a -> 'a option -> 'a
  5448   the_list:          'a option -> 'a list
  5449 
  5450 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5451 basic operations for association lists, following natural argument
  5452 order; moreover the explicit equality predicate passed here avoids
  5453 potentially expensive polymorphic runtime equality checks.
  5454 The old functions may be expressed as follows:
  5455 
  5456   assoc = uncurry (AList.lookup (op =))
  5457   assocs = these oo AList.lookup (op =)
  5458   overwrite = uncurry (AList.update (op =)) o swap
  5459 
  5460 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5461 
  5462   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  5463   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  5464 
  5465 replacing make_keylist and keyfilter (occassionally used)
  5466 Naive rewrites:
  5467 
  5468   make_keylist = AList.make
  5469   keyfilter = AList.find (op =)
  5470 
  5471 * eq_fst and eq_snd now take explicit equality parameter, thus
  5472   avoiding eqtypes. Naive rewrites:
  5473 
  5474     eq_fst = eq_fst (op =)
  5475     eq_snd = eq_snd (op =)
  5476 
  5477 * Removed deprecated apl and apr (rarely used).
  5478   Naive rewrites:
  5479 
  5480     apl (n, op) =>>= curry op n
  5481     apr (op, m) =>>= fn n => op (n, m)
  5482 
  5483 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  5484 provides a reasonably efficient light-weight implementation of sets as
  5485 lists.
  5486 
  5487 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  5488 few new operations; existing lookup and update are now curried to
  5489 follow natural argument order (for use with fold etc.);
  5490 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  5491 
  5492 * Pure/General: output via the Isabelle channels of
  5493 writeln/warning/error etc. is now passed through Output.output, with a
  5494 hook for arbitrary transformations depending on the print_mode
  5495 (cf. Output.add_mode -- the first active mode that provides a output
  5496 function wins).  Already formatted output may be embedded into further
  5497 text via Output.raw; the result of Pretty.string_of/str_of and derived
  5498 functions (string_of_term/cterm/thm etc.) is already marked raw to
  5499 accommodate easy composition of diagnostic messages etc.  Programmers
  5500 rarely need to care about Output.output or Output.raw at all, with
  5501 some notable exceptions: Output.output is required when bypassing the
  5502 standard channels (writeln etc.), or in token translations to produce
  5503 properly formatted results; Output.raw is required when capturing
  5504 already output material that will eventually be presented to the user
  5505 a second time.  For the default print mode, both Output.output and
  5506 Output.raw have no effect.
  5507 
  5508 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  5509 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  5510 cumulative results are displayed at the end of a batch session.
  5511 
  5512 * Pure/General: File.sysify_path and File.quote_sysify path have been
  5513 replaced by File.platform_path and File.shell_path (with appropriate
  5514 hooks).  This provides a clean interface for unusual systems where the
  5515 internal and external process view of file names are different.
  5516 
  5517 * Pure: more efficient orders for basic syntactic entities: added
  5518 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  5519 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  5520 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  5521 orders now -- potential INCOMPATIBILITY for code that depends on a
  5522 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  5523 Library.sort_strings on result).
  5524 
  5525 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  5526 fold_types traverse types/terms from left to right, observing natural
  5527 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  5528 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  5529 
  5530 * Pure: name spaces have been refined, with significant changes of the
  5531 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  5532 to extern(_table).  The plain name entry path is superceded by a
  5533 general 'naming' context, which also includes the 'policy' to produce
  5534 a fully qualified name and external accesses of a fully qualified
  5535 name; NameSpace.extend is superceded by context dependent
  5536 Sign.declare_name.  Several theory and proof context operations modify
  5537 the naming context.  Especially note Theory.restore_naming and
  5538 ProofContext.restore_naming to get back to a sane state; note that
  5539 Theory.add_path is no longer sufficient to recover from
  5540 Theory.absolute_path in particular.
  5541 
  5542 * Pure: new flags short_names (default false) and unique_names
  5543 (default true) for controlling output of qualified names.  If
  5544 short_names is set, names are printed unqualified.  If unique_names is
  5545 reset, the name prefix is reduced to the minimum required to achieve
  5546 the original result when interning again, even if there is an overlap
  5547 with earlier declarations.
  5548 
  5549 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  5550 now 'extend', and 'merge' gets an additional Pretty.pp argument
  5551 (useful for printing error messages).  INCOMPATIBILITY.
  5552 
  5553 * Pure: major reorganization of the theory context.  Type Sign.sg and
  5554 Theory.theory are now identified, referring to the universal
  5555 Context.theory (see Pure/context.ML).  Actual signature and theory
  5556 content is managed as theory data.  The old code and interfaces were
  5557 spread over many files and structures; the new arrangement introduces
  5558 considerable INCOMPATIBILITY to gain more clarity:
  5559 
  5560   Context -- theory management operations (name, identity, inclusion,
  5561     parents, ancestors, merge, etc.), plus generic theory data;
  5562 
  5563   Sign -- logical signature and syntax operations (declaring consts,
  5564     types, etc.), plus certify/read for common entities;
  5565 
  5566   Theory -- logical theory operations (stating axioms, definitions,
  5567     oracles), plus a copy of logical signature operations (consts,
  5568     types, etc.); also a few basic management operations (Theory.copy,
  5569     Theory.merge, etc.)
  5570 
  5571 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  5572 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  5573 for convenience -- they merely return the theory.
  5574 
  5575 * Pure: type Type.tsig is superceded by theory in most interfaces.
  5576 
  5577 * Pure: the Isar proof context type is already defined early in Pure
  5578 as Context.proof (note that ProofContext.context and Proof.context are
  5579 aliases, where the latter is the preferred name).  This enables other
  5580 Isabelle components to refer to that type even before Isar is present.
  5581 
  5582 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  5583 typeK, constK, axiomK, oracleK), but provide explicit operations for
  5584 any of these kinds.  For example, Sign.intern typeK is now
  5585 Sign.intern_type, Theory.hide_space Sign.typeK is now
  5586 Theory.hide_types.  Also note that former
  5587 Theory.hide_classes/types/consts are now
  5588 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  5589 internalize their arguments!  INCOMPATIBILITY.
  5590 
  5591 * Pure: get_thm interface (of PureThy and ProofContext) expects
  5592 datatype thmref (with constructors Name and NameSelection) instead of
  5593 plain string -- INCOMPATIBILITY;
  5594 
  5595 * Pure: cases produced by proof methods specify options, where NONE
  5596 means to remove case bindings -- INCOMPATIBILITY in
  5597 (RAW_)METHOD_CASES.
  5598 
  5599 * Pure: the following operations retrieve axioms or theorems from a
  5600 theory node or theory hierarchy, respectively:
  5601 
  5602   Theory.axioms_of: theory -> (string * term) list
  5603   Theory.all_axioms_of: theory -> (string * term) list
  5604   PureThy.thms_of: theory -> (string * thm) list
  5605   PureThy.all_thms_of: theory -> (string * thm) list
  5606 
  5607 * Pure: print_tac now outputs the goal through the trace channel.
  5608 
  5609 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  5610 Reference Toplevel.debug (default false) controls detailed printing
  5611 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  5612 controls execution profiling -- set to 1 for time and 2 for space
  5613 (both increase the runtime).
  5614 
  5615 * Isar session: The initial use of ROOT.ML is now always timed,
  5616 i.e. the log will show the actual process times, in contrast to the
  5617 elapsed wall-clock time that the outer shell wrapper produces.
  5618 
  5619 * Simplifier: improved handling of bound variables (nameless
  5620 representation, avoid allocating new strings).  Simprocs that invoke
  5621 the Simplifier recursively should use Simplifier.inherit_bounds to
  5622 avoid local name clashes.  Failure to do so produces warnings
  5623 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  5624 for further details.
  5625 
  5626 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  5627 bindings for all theorems stored within a given theory; this may help
  5628 in porting non-Isar theories to Isar ones, while keeping ML proof
  5629 scripts for the time being.
  5630 
  5631 * ML operator HTML.with_charset specifies the charset begin used for
  5632 generated HTML files.  For example:
  5633 
  5634   HTML.with_charset "utf-8" use_thy "Hebrew";
  5635   HTML.with_charset "utf-8" use_thy "Chinese";
  5636 
  5637 
  5638 *** System ***
  5639 
  5640 * Allow symlinks to all proper Isabelle executables (Isabelle,
  5641 isabelle, isatool etc.).
  5642 
  5643 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  5644 isatool doc, isatool mkdir, display_drafts etc.).
  5645 
  5646 * isatool usedir: option -f allows specification of the ML file to be
  5647 used by Isabelle; default is ROOT.ML.
  5648 
  5649 * New isatool version outputs the version identifier of the Isabelle
  5650 distribution being used.
  5651 
  5652 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  5653 (containing Boolean satisfiability problems) into Isabelle/HOL
  5654 theories.
  5655 
  5656 
  5657 
  5658 New in Isabelle2004 (April 2004)
  5659 --------------------------------
  5660 
  5661 *** General ***
  5662 
  5663 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  5664   Replaces linorder.ML.
  5665 
  5666 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  5667   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  5668   (\<a>...\<z>), are now considered normal letters, and can therefore
  5669   be used anywhere where an ASCII letter (a...zA...Z) has until
  5670   now. COMPATIBILITY: This obviously changes the parsing of some
  5671   terms, especially where a symbol has been used as a binder, say
  5672   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  5673   as an identifier.  Fix it by inserting a space around former
  5674   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  5675   existing theory and ML files.
  5676 
  5677 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  5678 
  5679 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  5680   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  5681   a normal (but invisible) letter. For multiple letter subscripts repeat
  5682   \<^isub> like this: x\<^isub>1\<^isub>2.
  5683 
  5684 * Pure: There are now sub-/superscripts that can span more than one
  5685   character. Text between \<^bsub> and \<^esub> is set in subscript in
  5686   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  5687   superscript. The new control characters are not identifier parts.
  5688 
  5689 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  5690   content of "..." to the latex file instead of \isacntrl... . The "..."
  5691   may consist of any printable characters excluding the end bracket >.
  5692 
  5693 * Pure: Using new Isar command "finalconsts" (or the ML functions
  5694   Theory.add_finals or Theory.add_finals_i) it is now possible to
  5695   declare constants "final", which prevents their being given a definition
  5696   later.  It is useful for constants whose behaviour is fixed axiomatically
  5697   rather than definitionally, such as the meta-logic connectives.
  5698 
  5699 * Pure: 'instance' now handles general arities with general sorts
  5700   (i.e. intersections of classes),
  5701 
  5702 * Presentation: generated HTML now uses a CSS style sheet to make layout
  5703   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  5704   It can be changed to alter the colors/layout of generated pages.
  5705 
  5706 
  5707 *** Isar ***
  5708 
  5709 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  5710   cut_tac, subgoal_tac and thin_tac:
  5711   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  5712     locales are no longer forced to write Isar proof scripts.
  5713     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  5714     emulations.
  5715   - INCOMPATIBILITY: names of variables to be instantiated may no
  5716     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  5717     This is consistent with the instantiation attribute "where".
  5718 
  5719 * Attributes "where" and "of":
  5720   - Now take type variables of instantiated theorem into account when reading
  5721     the instantiation string.  This fixes a bug that caused instantiated
  5722     theorems to have too special types in some circumstances.
  5723   - "where" permits explicit instantiations of type variables.
  5724 
  5725 * Calculation commands "moreover" and "also" no longer interfere with
  5726   current facts ("this"), admitting arbitrary combinations with "then"
  5727   and derived forms.
  5728 
  5729 * Locales:
  5730   - Goal statements involving the context element "includes" no longer
  5731     generate theorems with internal delta predicates (those ending on
  5732     "_axioms") in the premise.
  5733     Resolve particular premise with <locale>.intro to obtain old form.
  5734   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  5735     specification and "includes" elements in goal statement.
  5736   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  5737     [intro?] and [elim?] (respectively) by default.
  5738   - Experimental command for instantiation of locales in proof contexts:
  5739         instantiate <label>[<attrs>]: <loc>
  5740     Instantiates locale <loc> and adds all its theorems to the current context
  5741     taking into account their attributes.  Label and attrs are optional
  5742     modifiers, like in theorem declarations.  If present, names of
  5743     instantiated theorems are qualified with <label>, and the attributes
  5744     <attrs> are applied after any attributes these theorems might have already.
  5745       If the locale has assumptions, a chained fact of the form
  5746     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  5747     are derived.  The command does not support old-style locales declared
  5748     with "locale (open)".
  5749       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  5750 
  5751 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  5752   (Isar) contexts.
  5753 
  5754 
  5755 *** HOL ***
  5756 
  5757 * Proof import: new image HOL4 contains the imported library from
  5758   the HOL4 system with about 2500 theorems. It is imported by
  5759   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  5760   can be used like any other Isabelle image.  See
  5761   HOL/Import/HOL/README for more information.
  5762 
  5763 * Simplifier:
  5764   - Much improved handling of linear and partial orders.
  5765     Reasoners for linear and partial orders are set up for type classes
  5766     "linorder" and "order" respectively, and are added to the default simpset
  5767     as solvers.  This means that the simplifier can build transitivity chains
  5768     to solve goals from the assumptions.
  5769   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  5770     of blast or auto after simplification become unnecessary because the goal
  5771     is solved by simplification already.
  5772 
  5773 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  5774     all proved in axiomatic type classes for semirings, rings and fields.
  5775 
  5776 * Numerics:
  5777   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  5778     now formalized using the Ring_and_Field theory mentioned above.
  5779   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  5780     than before, because now they are set up once in a generic manner.
  5781   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  5782     Look for the general versions in Ring_and_Field (and Power if they concern
  5783     exponentiation).
  5784 
  5785 * Type "rat" of the rational numbers is now available in HOL-Complex.
  5786 
  5787 * Records:
  5788   - Record types are now by default printed with their type abbreviation
  5789     instead of the list of all field types. This can be configured via
  5790     the reference "print_record_type_abbr".
  5791   - Simproc "record_upd_simproc" for simplification of multiple updates added
  5792     (not enabled by default).
  5793   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  5794     EX x. x = sel r to True (not enabled by default).
  5795   - Tactic "record_split_simp_tac" to split and simplify records added.
  5796 
  5797 * 'specification' command added, allowing for definition by
  5798   specification.  There is also an 'ax_specification' command that
  5799   introduces the new constants axiomatically.
  5800 
  5801 * arith(_tac) is now able to generate counterexamples for reals as well.
  5802 
  5803 * HOL-Algebra: new locale "ring" for non-commutative rings.
  5804 
  5805 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  5806   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  5807 
  5808 * HOL-Matrix: a first theory for matrices in HOL with an application of
  5809   matrix theory to linear programming.
  5810 
  5811 * Unions and Intersections:
  5812   The latex output syntax of UN and INT has been changed
  5813   from "\Union x \in A. B" to "\Union_{x \in A} B"
  5814   i.e. the index formulae has become a subscript.
  5815   Similarly for "\Union x. B", and for \Inter instead of \Union.
  5816 
  5817 * Unions and Intersections over Intervals:
  5818   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  5819   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  5820   like in normal math, and corresponding versions for < and for intersection.
  5821 
  5822 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  5823   lexicographic dictonary ordering has been added as "lexord".
  5824 
  5825 * ML: the legacy theory structures Int and List have been removed. They had
  5826   conflicted with ML Basis Library structures having the same names.
  5827 
  5828 * 'refute' command added to search for (finite) countermodels.  Only works
  5829   for a fragment of HOL.  The installation of an external SAT solver is
  5830   highly recommended.  See "HOL/Refute.thy" for details.
  5831 
  5832 * 'quickcheck' command: Allows to find counterexamples by evaluating
  5833   formulae under an assignment of free variables to random values.
  5834   In contrast to 'refute', it can deal with inductive datatypes,
  5835   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  5836   for examples.
  5837 
  5838 
  5839 *** HOLCF ***
  5840 
  5841 * Streams now come with concatenation and are part of the HOLCF image
  5842 
  5843 
  5844 
  5845 New in Isabelle2003 (May 2003)
  5846 ------------------------------
  5847 
  5848 *** General ***
  5849 
  5850 * Provers/simplifier:
  5851 
  5852   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  5853     Assumptions are now subject to complete mutual simplification,
  5854     not just from left to right. The simplifier now preserves
  5855     the order of assumptions.
  5856 
  5857     Potential INCOMPATIBILITY:
  5858 
  5859     -- simp sometimes diverges where the old version did
  5860        not, e.g. invoking simp on the goal
  5861 
  5862         [| P (f x); y = x; f x = f y |] ==> Q
  5863 
  5864        now gives rise to the infinite reduction sequence
  5865 
  5866         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  5867 
  5868        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  5869        kind of problem.
  5870 
  5871     -- Tactics combining classical reasoner and simplification (such as auto)
  5872        are also affected by this change, because many of them rely on
  5873        simp. They may sometimes diverge as well or yield a different numbers
  5874        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  5875        in case of problems. Sometimes subsequent calls to the classical
  5876        reasoner will fail because a preceeding call to the simplifier too
  5877        eagerly simplified the goal, e.g. deleted redundant premises.
  5878 
  5879   - The simplifier trace now shows the names of the applied rewrite rules
  5880 
  5881   - You can limit the number of recursive invocations of the simplifier
  5882     during conditional rewriting (where the simplifie tries to solve the
  5883     conditions before applying the rewrite rule):
  5884     ML "simp_depth_limit := n"
  5885     where n is an integer. Thus you can force termination where previously
  5886     the simplifier would diverge.
  5887 
  5888   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  5889 
  5890   - No longer aborts on failed congruence proof.  Instead, the
  5891     congruence is ignored.
  5892 
  5893 * Pure: New generic framework for extracting programs from constructive
  5894   proofs. See HOL/Extraction.thy for an example instantiation, as well
  5895   as HOL/Extraction for some case studies.
  5896 
  5897 * Pure: The main goal of the proof state is no longer shown by default, only
  5898 the subgoals. This behaviour is controlled by a new flag.
  5899    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  5900 (ML: Proof.show_main_goal).
  5901 
  5902 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  5903 rules whose conclusion matches subgoal 1:
  5904       PG menu: Isabelle/Isar -> Show me -> matching rules
  5905 The rules are ordered by how closely they match the subgoal.
  5906 In particular, rules that solve a subgoal outright are displayed first
  5907 (or rather last, the way they are printed).
  5908 (ML: ProofGeneral.print_intros())
  5909 
  5910 * Pure: New flag trace_unify_fail causes unification to print
  5911 diagnostic information (PG: in trace buffer) when it fails. This is
  5912 useful for figuring out why single step proofs like rule, erule or
  5913 assumption failed.
  5914 
  5915 * Pure: Locale specifications now produce predicate definitions
  5916 according to the body of text (covering assumptions modulo local
  5917 definitions); predicate "loc_axioms" covers newly introduced text,
  5918 while "loc" is cumulative wrt. all included locale expressions; the
  5919 latter view is presented only on export into the global theory
  5920 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  5921 on the old view without predicates;
  5922 
  5923 * Pure: predefined locales "var" and "struct" are useful for sharing
  5924 parameters (as in CASL, for example); just specify something like
  5925 ``var x + var y + struct M'' as import;
  5926 
  5927 * Pure: improved thms_containing: proper indexing of facts instead of
  5928 raw theorems; check validity of results wrt. current name space;
  5929 include local facts of proof configuration (also covers active
  5930 locales), cover fixed variables in index; may use "_" in term
  5931 specification; an optional limit for the number of printed facts may
  5932 be given (the default is 40);
  5933 
  5934 * Pure: disallow duplicate fact bindings within new-style theory files
  5935 (batch-mode only);
  5936 
  5937 * Provers: improved induct method: assumptions introduced by case
  5938 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  5939 the goal statement); "foo" still refers to all facts collectively;
  5940 
  5941 * Provers: the function blast.overloaded has been removed: all constants
  5942 are regarded as potentially overloaded, which improves robustness in exchange
  5943 for slight decrease in efficiency;
  5944 
  5945 * Provers/linorder: New generic prover for transitivity reasoning over
  5946 linear orders.  Note: this prover is not efficient!
  5947 
  5948 * Isar: preview of problems to finish 'show' now produce an error
  5949 rather than just a warning (in interactive mode);
  5950 
  5951 
  5952 *** HOL ***
  5953 
  5954 * arith(_tac)
  5955 
  5956  - Produces a counter example if it cannot prove a goal.
  5957    Note that the counter example may be spurious if the goal is not a formula
  5958    of quantifier-free linear arithmetic.
  5959    In ProofGeneral the counter example appears in the trace buffer.
  5960 
  5961  - Knows about div k and mod k where k is a numeral of type nat or int.
  5962 
  5963  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  5964    linear arithmetic fails. This takes account of quantifiers and divisibility.
  5965    Presburger arithmetic can also be called explicitly via presburger(_tac).
  5966 
  5967 * simp's arithmetic capabilities have been enhanced a bit: it now
  5968 takes ~= in premises into account (by performing a case split);
  5969 
  5970 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  5971 are distributed over a sum of terms;
  5972 
  5973 * New tactic "trans_tac" and method "trans" instantiate
  5974 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  5975 "<=", "<" and "=").
  5976 
  5977 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  5978 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  5979 
  5980 * 'typedef' command has new option "open" to suppress the set
  5981 definition;
  5982 
  5983 * functions Min and Max on finite sets have been introduced (theory
  5984 Finite_Set);
  5985 
  5986 * attribute [symmetric] now works for relations as well; it turns
  5987 (x,y) : R^-1 into (y,x) : R, and vice versa;
  5988 
  5989 * induct over a !!-quantified statement (say !!x1..xn):
  5990   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  5991 
  5992 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  5993 %x. None. Warning: empty_def now refers to the previously hidden definition
  5994 of the empty set.
  5995 
  5996 * Algebra: formalization of classical algebra.  Intended as base for
  5997 any algebraic development in Isabelle.  Currently covers group theory
  5998 (up to Sylow's theorem) and ring theory (Universal Property of
  5999 Univariate Polynomials).  Contributions welcome;
  6000 
  6001 * GroupTheory: deleted, since its material has been moved to Algebra;
  6002 
  6003 * Complex: new directory of the complex numbers with numeric constants,
  6004 nonstandard complex numbers, and some complex analysis, standard and
  6005 nonstandard (Jacques Fleuriot);
  6006 
  6007 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  6008 
  6009 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  6010 Fleuriot);
  6011 
  6012 * Real/HahnBanach: updated and adapted to locales;
  6013 
  6014 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  6015 Gray and Kramer);
  6016 
  6017 * UNITY: added the Meier-Sanders theory of progress sets;
  6018 
  6019 * MicroJava: bytecode verifier and lightweight bytecode verifier
  6020 as abstract algorithms, instantiated to the JVM;
  6021 
  6022 * Bali: Java source language formalization. Type system, operational
  6023 semantics, axiomatic semantics. Supported language features:
  6024 classes, interfaces, objects,virtual methods, static methods,
  6025 static/instance fields, arrays, access modifiers, definite
  6026 assignment, exceptions.
  6027 
  6028 
  6029 *** ZF ***
  6030 
  6031 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  6032 universe, etc.);
  6033 
  6034 * Main ZF: virtually all theories converted to new-style format;
  6035 
  6036 
  6037 *** ML ***
  6038 
  6039 * Pure: Tactic.prove provides sane interface for internal proofs;
  6040 omits the infamous "standard" operation, so this is more appropriate
  6041 than prove_goalw_cterm in many situations (e.g. in simprocs);
  6042 
  6043 * Pure: improved error reporting of simprocs;
  6044 
  6045 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  6046 up simprocs;
  6047 
  6048 
  6049 *** Document preparation ***
  6050 
  6051 * uses \par instead of \\ for line breaks in theory text. This may
  6052 shift some page breaks in large documents. To get the old behaviour
  6053 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  6054 
  6055 * minimized dependencies of isabelle.sty and isabellesym.sty on
  6056 other packages
  6057 
  6058 * \<euro> now needs package babel/greek instead of marvosym (which
  6059 broke \Rightarrow)
  6060 
  6061 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  6062 textcomp package)
  6063 
  6064 
  6065 
  6066 New in Isabelle2002 (March 2002)
  6067 --------------------------------
  6068 
  6069 *** Document preparation ***
  6070 
  6071 * greatly simplified document preparation setup, including more
  6072 graceful interpretation of isatool usedir -i/-d/-D options, and more
  6073 instructive isatool mkdir; users should basically be able to get
  6074 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  6075 users may run a separate document processing stage manually like this:
  6076 "isatool usedir -D output HOL Test && isatool document Test/output";
  6077 
  6078 * theory dependency graph may now be incorporated into documents;
  6079 isatool usedir -g true will produce session_graph.eps/.pdf for use
  6080 with \includegraphics of LaTeX;
  6081 
  6082 * proper spacing of consecutive markup elements, especially text
  6083 blocks after section headings;
  6084 
  6085 * support bold style (for single symbols only), input syntax is like
  6086 this: "\<^bold>\<alpha>" or "\<^bold>A";
  6087 
  6088 * \<bullet> is now output as bold \cdot by default, which looks much
  6089 better in printed text;
  6090 
  6091 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  6092 note that these symbols are currently unavailable in Proof General /
  6093 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  6094 
  6095 * isatool latex no longer depends on changed TEXINPUTS, instead
  6096 isatool document copies the Isabelle style files to the target
  6097 location;
  6098 
  6099 
  6100 *** Isar ***
  6101 
  6102 * Pure/Provers: improved proof by cases and induction;
  6103   - 'case' command admits impromptu naming of parameters (such as
  6104     "case (Suc n)");
  6105   - 'induct' method divinates rule instantiation from the inductive
  6106     claim; no longer requires excessive ?P bindings for proper
  6107     instantiation of cases;
  6108   - 'induct' method properly enumerates all possibilities of set/type
  6109     rules; as a consequence facts may be also passed through *type*
  6110     rules without further ado;
  6111   - 'induct' method now derives symbolic cases from the *rulified*
  6112     rule (before it used to rulify cases stemming from the internal
  6113     atomized version); this means that the context of a non-atomic
  6114     statement becomes is included in the hypothesis, avoiding the
  6115     slightly cumbersome show "PROP ?case" form;
  6116   - 'induct' may now use elim-style induction rules without chaining
  6117     facts, using ``missing'' premises from the goal state; this allows
  6118     rules stemming from inductive sets to be applied in unstructured
  6119     scripts, while still benefitting from proper handling of non-atomic
  6120     statements; NB: major inductive premises need to be put first, all
  6121     the rest of the goal is passed through the induction;
  6122   - 'induct' proper support for mutual induction involving non-atomic
  6123     rule statements (uses the new concept of simultaneous goals, see
  6124     below);
  6125   - append all possible rule selections, but only use the first
  6126     success (no backtracking);
  6127   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  6128   - undeclared rule case names default to numbers 1, 2, 3, ...;
  6129   - added 'print_induct_rules' (covered by help item in recent Proof
  6130     General versions);
  6131   - moved induct/cases attributes to Pure, methods to Provers;
  6132   - generic method setup instantiated for FOL and HOL;
  6133 
  6134 * Pure: support multiple simultaneous goal statements, for example
  6135 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  6136 meta-level mechanism, this acts as if several individual goals had
  6137 been stated separately; in particular common proof methods need to be
  6138 repeated in order to cover all claims; note that a single elimination
  6139 step is *not* sufficient to establish the two conjunctions, so this
  6140 fails:
  6141 
  6142   assume "A & B" then have A and B ..   (*".." fails*)
  6143 
  6144 better use "obtain" in situations as above; alternative refer to
  6145 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  6146 
  6147 * Pure: proper integration with ``locales''; unlike the original
  6148 version by Florian Kammller, Isar locales package high-level proof
  6149 contexts rather than raw logical ones (e.g. we admit to include
  6150 attributes everywhere); operations on locales include merge and
  6151 rename; support for implicit arguments (``structures''); simultaneous
  6152 type-inference over imports and text; see also HOL/ex/Locales.thy for
  6153 some examples;
  6154 
  6155 * Pure: the following commands have been ``localized'', supporting a
  6156 target locale specification "(in name)": 'lemma', 'theorem',
  6157 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  6158 stored both within the locale and at the theory level (exported and
  6159 qualified by the locale name);
  6160 
  6161 * Pure: theory goals may now be specified in ``long'' form, with
  6162 ad-hoc contexts consisting of arbitrary locale elements. for example
  6163 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  6164 definitions may be given, too); the result is a meta-level rule with
  6165 the context elements being discharged in the obvious way;
  6166 
  6167 * Pure: new proof command 'using' allows to augment currently used
  6168 facts after a goal statement ('using' is syntactically analogous to
  6169 'apply', but acts on the goal's facts only); this allows chained facts
  6170 to be separated into parts given before and after a claim, as in
  6171 ``from a and b have C using d and e <proof>'';
  6172 
  6173 * Pure: renamed "antecedent" case to "rule_context";
  6174 
  6175 * Pure: new 'judgment' command records explicit information about the
  6176 object-logic embedding (used by several tools internally); no longer
  6177 use hard-wired "Trueprop";
  6178 
  6179 * Pure: added 'corollary' command;
  6180 
  6181 * Pure: fixed 'token_translation' command;
  6182 
  6183 * Pure: removed obsolete 'exported' attribute;
  6184 
  6185 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  6186 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  6187 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  6188 
  6189 * Pure: method 'atomize' presents local goal premises as object-level
  6190 statements (atomic meta-level propositions); setup controlled via
  6191 rewrite rules declarations of 'atomize' attribute; example
  6192 application: 'induct' method with proper rule statements in improper
  6193 proof *scripts*;
  6194 
  6195 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  6196 now consider the syntactic context of assumptions, giving a better
  6197 chance to get type-inference of the arguments right (this is
  6198 especially important for locales);
  6199 
  6200 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  6201 mode;
  6202 
  6203 * Pure/obtain: the formal conclusion "thesis", being marked as
  6204 ``internal'', may no longer be reference directly in the text;
  6205 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  6206 situations;
  6207 
  6208 * Pure: generic 'sym' attribute which declares a rule both as pure
  6209 'elim?' and for the 'symmetric' operation;
  6210 
  6211 * Pure: marginal comments ``--'' may now occur just anywhere in the
  6212 text; the fixed correlation with particular command syntax has been
  6213 discontinued;
  6214 
  6215 * Pure: new method 'rules' is particularly well-suited for proof
  6216 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  6217 but often produces more compact proof terms with less detours;
  6218 
  6219 * Pure/Provers/classical: simplified integration with pure rule
  6220 attributes and methods; the classical "intro?/elim?/dest?"
  6221 declarations coincide with the pure ones; the "rule" method no longer
  6222 includes classically swapped intros; "intro" and "elim" methods no
  6223 longer pick rules from the context; also got rid of ML declarations
  6224 AddXIs/AddXEs/AddXDs; all of this has some potential for
  6225 INCOMPATIBILITY;
  6226 
  6227 * Provers/classical: attribute 'swapped' produces classical inversions
  6228 of introduction rules;
  6229 
  6230 * Provers/simplifier: 'simplified' attribute may refer to explicit