NEWS
author blanchet
Sun May 01 18:37:25 2011 +0200 (2011-05-01)
changeset 42582 6321d0dc3d72
parent 42514 f32500b4bc23
child 42633 f86467c5a72c
permissions -rw-r--r--
document new type system syntax
     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) is has been
    26 discontinued.  INCOMPATIBILITY.
    27 
    28 * Various optional external tools are referenced more robustly and
    29 uniformly by explicit Isabelle settings as follows:
    30 
    31   ISABELLE_CSDP   (formerly CSDP_EXE)
    32   ISABELLE_GHC    (formerly EXEC_GHC or GHC_PATH)
    33   ISABELLE_OCAML  (formerly EXEC_OCAML)
    34   ISABELLE_SWIPL  (formerly EXEC_SWIPL)
    35   ISABELLE_YAP    (formerly EXEC_YAP)
    36 
    37 Note that automated detection from the file-system or search path has
    38 been discontinued.  INCOMPATIBILITY.
    39 
    40 * Name space: proper configuration options "long_names",
    41 "short_names", "unique_names" instead of former unsynchronized
    42 references.  Minor INCOMPATIBILITY, need to declare options in context
    43 like this:
    44 
    45   declare [[unique_names = false]]
    46 
    47 * Literal facts `prop` may contain dummy patterns, e.g. `_ = _`.  Note
    48 that the result needs to be unique, which means fact specifications
    49 may have to be refined after enriching a proof context.
    50 
    51 
    52 *** HOL ***
    53 
    54 * Nitpick:
    55   - Added "need" and "total_consts" options.
    56   - Reintroduced "show_skolems" option by popular demand.
    57   - Renamed attribute: nitpick_def ~> nitpick_unfold.
    58     INCOMPATIBILITY.
    59 
    60 * Sledgehammer:
    61   - sledgehammer available_provers ~> sledgehammer supported_provers
    62     INCOMPATIBILITY.
    63   - Added support for SNARK and ToFoF-E on SystemOnTPTP and for simply typed
    64     TPTP problems (TFF).
    65   - Added "type_sys" and "monomorphize_limit" options.
    66 
    67 * "try":
    68   - Added "simp:", "intro:", and "elim:" options.
    69 
    70 * Quickcheck:
    71   - Added "eval" option to evaluate terms for the found counterexample
    72     (currently only supported by the default (exhaustive) tester)
    73   - Added post-processing of terms to obtain readable counterexamples
    74     (currently only supported by the default (exhaustive) tester)
    75 
    76 * Function package: discontinued option "tailrec".
    77 INCOMPATIBILITY. Use partial_function instead.
    78 
    79 * HOL-Probability:
    80   - Caratheodory's extension lemma is now proved for ring_of_sets.
    81   - Infinite products of probability measures are now available.
    82   - Use extended reals instead of positive extended reals.
    83     INCOMPATIBILITY.
    84 
    85 
    86 *** Document preparation ***
    87 
    88 * Localized \isabellestyle switch can be used within blocks or groups
    89 like this:
    90 
    91   \isabellestyle{it}  %preferred default
    92   {\isabellestylett @{text "typewriter stuff"}}
    93 
    94 * New term style "isub" as ad-hoc conversion of variables x1, y23 into
    95 subscripted form x\<^isub>1, y\<^isub>2\<^isub>3.
    96 
    97 * Predefined LaTeX macros for Isabelle symbols \<bind> and \<then>
    98 (e.g. see ~~/src/HOL/Library/Monad_Syntax.thy).
    99 
   100 
   101 *** ML ***
   102 
   103 * Structure Proof_Context follows standard naming scheme.  Old
   104 ProofContext is still available for some time as legacy alias.
   105 
   106 * Structure Timing provides various operations for timing; supersedes
   107 former start_timing/end_timing etc.
   108 
   109 * Path.print is the official way to show file-system paths to users
   110 (including quotes etc.).
   111 
   112 * Inner syntax: identifiers in parse trees of generic categories
   113 "logic", "aprop", "idt" etc. carry position information (disguised as
   114 type constraints).  Occasional INCOMPATIBILITY with non-compliant
   115 translations that choke on unexpected type constraints.  Positions can
   116 be stripped in ML translations via Syntax.strip_positions /
   117 Syntax.strip_positions_ast, or via the syntax constant
   118 "_strip_positions" within parse trees.  As last resort, positions can
   119 be disabled via the configuration option Syntax.positions, which is
   120 called "syntax_positions" in Isar attribute syntax.
   121 
   122 * Discontinued special status of various ML structures that contribute
   123 to structure Syntax (Ast, Lexicon, Mixfix, Parser, Printer etc.): less
   124 pervasive content, no inclusion in structure Syntax.  INCOMPATIBILITY,
   125 refer directly to Ast.Constant, Lexicon.is_identifier,
   126 Syntax_Trans.mk_binder_tr etc.
   127 
   128 * Typed print translation: discontinued show_sorts argument, which is
   129 already available via context of "advanced" translation.
   130 
   131 * Refined PARALLEL_GOALS tactical: degrades gracefully for schematic
   132 goal states; body tactic needs to address all subgoals uniformly.
   133 
   134 * Slightly more special eq_list/eq_set, with shortcut involving
   135 pointer equality (assumes that eq relation is reflexive).
   136 
   137 
   138 
   139 New in Isabelle2011 (January 2011)
   140 ----------------------------------
   141 
   142 *** General ***
   143 
   144 * Experimental Prover IDE based on Isabelle/Scala and jEdit (see
   145 src/Tools/jEdit).  This also serves as IDE for Isabelle/ML, with
   146 useful tooltips and hyperlinks produced from its static analysis.  The
   147 bundled component provides an executable Isabelle tool that can be run
   148 like this:
   149 
   150   Isabelle2011/bin/isabelle jedit
   151 
   152 * Significantly improved Isabelle/Isar implementation manual.
   153 
   154 * System settings: ISABELLE_HOME_USER now includes ISABELLE_IDENTIFIER
   155 (and thus refers to something like $HOME/.isabelle/Isabelle2011),
   156 while the default heap location within that directory lacks that extra
   157 suffix.  This isolates multiple Isabelle installations from each
   158 other, avoiding problems with old settings in new versions.
   159 INCOMPATIBILITY, need to copy/upgrade old user settings manually.
   160 
   161 * Source files are always encoded as UTF-8, instead of old-fashioned
   162 ISO-Latin-1.  INCOMPATIBILITY.  Isabelle LaTeX documents might require
   163 the following package declarations:
   164 
   165   \usepackage[utf8]{inputenc}
   166   \usepackage{textcomp}
   167 
   168 * Explicit treatment of UTF-8 sequences as Isabelle symbols, such that
   169 a Unicode character is treated as a single symbol, not a sequence of
   170 non-ASCII bytes as before.  Since Isabelle/ML string literals may
   171 contain symbols without further backslash escapes, Unicode can now be
   172 used here as well.  Recall that Symbol.explode in ML provides a
   173 consistent view on symbols, while raw explode (or String.explode)
   174 merely give a byte-oriented representation.
   175 
   176 * Theory loader: source files are primarily located via the master
   177 directory of each theory node (where the .thy file itself resides).
   178 The global load path is still partially available as legacy feature.
   179 Minor INCOMPATIBILITY due to subtle change in file lookup: use
   180 explicit paths, relatively to the theory.
   181 
   182 * Special treatment of ML file names has been discontinued.
   183 Historically, optional extensions .ML or .sml were added on demand --
   184 at the cost of clarity of file dependencies.  Recall that Isabelle/ML
   185 files exclusively use the .ML extension.  Minor INCOMPATIBILTY.
   186 
   187 * Various options that affect pretty printing etc. are now properly
   188 handled within the context via configuration options, instead of
   189 unsynchronized references or print modes.  There are both ML Config.T
   190 entities and Isar declaration attributes to access these.
   191 
   192   ML (Config.T)                 Isar (attribute)
   193 
   194   eta_contract                  eta_contract
   195   show_brackets                 show_brackets
   196   show_sorts                    show_sorts
   197   show_types                    show_types
   198   show_question_marks           show_question_marks
   199   show_consts                   show_consts
   200   show_abbrevs                  show_abbrevs
   201 
   202   Syntax.ast_trace              syntax_ast_trace
   203   Syntax.ast_stat               syntax_ast_stat
   204   Syntax.ambiguity_level        syntax_ambiguity_level
   205 
   206   Goal_Display.goals_limit      goals_limit
   207   Goal_Display.show_main_goal   show_main_goal
   208 
   209   Method.rule_trace             rule_trace
   210 
   211   Thy_Output.display            thy_output_display
   212   Thy_Output.quotes             thy_output_quotes
   213   Thy_Output.indent             thy_output_indent
   214   Thy_Output.source             thy_output_source
   215   Thy_Output.break              thy_output_break
   216 
   217 Note that corresponding "..._default" references in ML may only be
   218 changed globally at the ROOT session setup, but *not* within a theory.
   219 The option "show_abbrevs" supersedes the former print mode
   220 "no_abbrevs" with inverted meaning.
   221 
   222 * More systematic naming of some configuration options.
   223 INCOMPATIBILITY.
   224 
   225   trace_simp  ~>  simp_trace
   226   debug_simp  ~>  simp_debug
   227 
   228 * Support for real valued configuration options, using simplistic
   229 floating-point notation that coincides with the inner syntax for
   230 float_token.
   231 
   232 * Support for real valued preferences (with approximative PGIP type):
   233 front-ends need to accept "pgint" values in float notation.
   234 INCOMPATIBILITY.
   235 
   236 * The IsabelleText font now includes Cyrillic, Hebrew, Arabic from
   237 DejaVu Sans.
   238 
   239 * Discontinued support for Poly/ML 5.0 and 5.1 versions.
   240 
   241 
   242 *** Pure ***
   243 
   244 * Command 'type_synonym' (with single argument) replaces somewhat
   245 outdated 'types', which is still available as legacy feature for some
   246 time.
   247 
   248 * Command 'nonterminal' (with 'and' separated list of arguments)
   249 replaces somewhat outdated 'nonterminals'.  INCOMPATIBILITY.
   250 
   251 * Command 'notepad' replaces former 'example_proof' for
   252 experimentation in Isar without any result.  INCOMPATIBILITY.
   253 
   254 * Locale interpretation commands 'interpret' and 'sublocale' accept
   255 lists of equations to map definitions in a locale to appropriate
   256 entities in the context of the interpretation.  The 'interpretation'
   257 command already provided this functionality.
   258 
   259 * Diagnostic command 'print_dependencies' prints the locale instances
   260 that would be activated if the specified expression was interpreted in
   261 the current context.  Variant "print_dependencies!" assumes a context
   262 without interpretations.
   263 
   264 * Diagnostic command 'print_interps' prints interpretations in proofs
   265 in addition to interpretations in theories.
   266 
   267 * Discontinued obsolete 'global' and 'local' commands to manipulate
   268 the theory name space.  Rare INCOMPATIBILITY.  The ML functions
   269 Sign.root_path and Sign.local_path may be applied directly where this
   270 feature is still required for historical reasons.
   271 
   272 * Discontinued obsolete 'constdefs' command.  INCOMPATIBILITY, use
   273 'definition' instead.
   274 
   275 * The "prems" fact, which refers to the accidental collection of
   276 foundational premises in the context, is now explicitly marked as
   277 legacy feature and will be discontinued soon.  Consider using "assms"
   278 of the head statement or reference facts by explicit names.
   279 
   280 * Document antiquotations @{class} and @{type} print classes and type
   281 constructors.
   282 
   283 * Document antiquotation @{file} checks file/directory entries within
   284 the local file system.
   285 
   286 
   287 *** HOL ***
   288 
   289 * Coercive subtyping: functions can be declared as coercions and type
   290 inference will add them as necessary upon input of a term.  Theory
   291 Complex_Main declares real :: nat => real and real :: int => real as
   292 coercions. A coercion function f is declared like this:
   293 
   294   declare [[coercion f]]
   295 
   296 To lift coercions through type constructors (e.g. from nat => real to
   297 nat list => real list), map functions can be declared, e.g.
   298 
   299   declare [[coercion_map map]]
   300 
   301 Currently coercion inference is activated only in theories including
   302 real numbers, i.e. descendants of Complex_Main.  This is controlled by
   303 the configuration option "coercion_enabled", e.g. it can be enabled in
   304 other theories like this:
   305 
   306   declare [[coercion_enabled]]
   307 
   308 * Command 'partial_function' provides basic support for recursive
   309 function definitions over complete partial orders.  Concrete instances
   310 are provided for i) the option type, ii) tail recursion on arbitrary
   311 types, and iii) the heap monad of Imperative_HOL.  See
   312 src/HOL/ex/Fundefs.thy and src/HOL/Imperative_HOL/ex/Linked_Lists.thy
   313 for examples.
   314 
   315 * Function package: f.psimps rules are no longer implicitly declared
   316 as [simp].  INCOMPATIBILITY.
   317 
   318 * Datatype package: theorems generated for executable equality (class
   319 "eq") carry proper names and are treated as default code equations.
   320 
   321 * Inductive package: now offers command 'inductive_simps' to
   322 automatically derive instantiated and simplified equations for
   323 inductive predicates, similar to 'inductive_cases'.
   324 
   325 * Command 'enriched_type' allows to register properties of the
   326 functorial structure of types.
   327 
   328 * Improved infrastructure for term evaluation using code generator
   329 techniques, in particular static evaluation conversions.
   330 
   331 * Code generator: Scala (2.8 or higher) has been added to the target
   332 languages.
   333 
   334 * Code generator: globbing constant expressions "*" and "Theory.*"
   335 have been replaced by the more idiomatic "_" and "Theory._".
   336 INCOMPATIBILITY.
   337 
   338 * Code generator: export_code without explicit file declaration prints
   339 to standard output.  INCOMPATIBILITY.
   340 
   341 * Code generator: do not print function definitions for case
   342 combinators any longer.
   343 
   344 * Code generator: simplification with rules determined with
   345 src/Tools/Code/code_simp.ML and method "code_simp".
   346 
   347 * Code generator for records: more idiomatic representation of record
   348 types.  Warning: records are not covered by ancient SML code
   349 generation any longer.  INCOMPATIBILITY.  In cases of need, a suitable
   350 rep_datatype declaration helps to succeed then:
   351 
   352   record 'a foo = ...
   353   ...
   354   rep_datatype foo_ext ...
   355 
   356 * Records: logical foundation type for records does not carry a
   357 '_type' suffix any longer (obsolete due to authentic syntax).
   358 INCOMPATIBILITY.
   359 
   360 * Quickcheck now by default uses exhaustive testing instead of random
   361 testing.  Random testing can be invoked by "quickcheck [random]",
   362 exhaustive testing by "quickcheck [exhaustive]".
   363 
   364 * Quickcheck instantiates polymorphic types with small finite
   365 datatypes by default. This enables a simple execution mechanism to
   366 handle quantifiers and function equality over the finite datatypes.
   367 
   368 * Quickcheck random generator has been renamed from "code" to
   369 "random".  INCOMPATIBILITY.
   370 
   371 * Quickcheck now has a configurable time limit which is set to 30
   372 seconds by default. This can be changed by adding [timeout = n] to the
   373 quickcheck command. The time limit for Auto Quickcheck is still set
   374 independently.
   375 
   376 * Quickcheck in locales considers interpretations of that locale for
   377 counter example search.
   378 
   379 * Sledgehammer:
   380   - Added "smt" and "remote_smt" provers based on the "smt" proof
   381     method. See the Sledgehammer manual for details ("isabelle doc
   382     sledgehammer").
   383   - Renamed commands:
   384     sledgehammer atp_info ~> sledgehammer running_provers
   385     sledgehammer atp_kill ~> sledgehammer kill_provers
   386     sledgehammer available_atps ~> sledgehammer available_provers
   387     INCOMPATIBILITY.
   388   - Renamed options:
   389     sledgehammer [atps = ...] ~> sledgehammer [provers = ...]
   390     sledgehammer [atp = ...] ~> sledgehammer [prover = ...]
   391     sledgehammer [timeout = 77 s] ~> sledgehammer [timeout = 77]
   392     (and "ms" and "min" are no longer supported)
   393     INCOMPATIBILITY.
   394 
   395 * Nitpick:
   396   - Renamed options:
   397     nitpick [timeout = 77 s] ~> nitpick [timeout = 77]
   398     nitpick [tac_timeout = 777 ms] ~> nitpick [tac_timeout = 0.777]
   399     INCOMPATIBILITY.
   400   - Added support for partial quotient types.
   401   - Added local versions of the "Nitpick.register_xxx" functions.
   402   - Added "whack" option.
   403   - Allow registration of quotient types as codatatypes.
   404   - Improved "merge_type_vars" option to merge more types.
   405   - Removed unsound "fast_descrs" option.
   406   - Added custom symmetry breaking for datatypes, making it possible to reach
   407     higher cardinalities.
   408   - Prevent the expansion of too large definitions.
   409 
   410 * Proof methods "metis" and "meson" now have configuration options
   411 "meson_trace", "metis_trace", and "metis_verbose" that can be enabled
   412 to diagnose these tools. E.g.
   413 
   414     using [[metis_trace = true]]
   415 
   416 * Auto Solve: Renamed "Auto Solve Direct".  The tool is now available
   417 manually as command 'solve_direct'.
   418 
   419 * The default SMT solver Z3 must be enabled explicitly (due to
   420 licensing issues) by setting the environment variable
   421 Z3_NON_COMMERCIAL in etc/settings of the component, for example.  For
   422 commercial applications, the SMT solver CVC3 is provided as fall-back;
   423 changing the SMT solver is done via the configuration option
   424 "smt_solver".
   425 
   426 * Remote SMT solvers need to be referred to by the "remote_" prefix,
   427 i.e. "remote_cvc3" and "remote_z3".
   428 
   429 * Added basic SMT support for datatypes, records, and typedefs using
   430 the oracle mode (no proofs).  Direct support of pairs has been dropped
   431 in exchange (pass theorems fst_conv snd_conv pair_collapse to the SMT
   432 support for a similar behavior).  Minor INCOMPATIBILITY.
   433 
   434 * Changed SMT configuration options:
   435   - Renamed:
   436     z3_proofs ~> smt_oracle (with inverted meaning)
   437     z3_trace_assms ~> smt_trace_used_facts
   438     INCOMPATIBILITY.
   439   - Added:
   440     smt_verbose
   441     smt_random_seed
   442     smt_datatypes
   443     smt_infer_triggers
   444     smt_monomorph_limit
   445     cvc3_options
   446     remote_cvc3_options
   447     remote_z3_options
   448     yices_options
   449 
   450 * Boogie output files (.b2i files) need to be declared in the theory
   451 header.
   452 
   453 * Simplification procedure "list_to_set_comprehension" rewrites list
   454 comprehensions applied to List.set to set comprehensions.  Occasional
   455 INCOMPATIBILITY, may be deactivated like this:
   456 
   457   declare [[simproc del: list_to_set_comprehension]]
   458 
   459 * Removed old version of primrec package.  INCOMPATIBILITY.
   460 
   461 * Removed simplifier congruence rule of "prod_case", as has for long
   462 been the case with "split".  INCOMPATIBILITY.
   463 
   464 * String.literal is a type, but not a datatype.  INCOMPATIBILITY.
   465 
   466 * Removed [split_format ... and ... and ...] version of
   467 [split_format].  Potential INCOMPATIBILITY.
   468 
   469 * Predicate "sorted" now defined inductively, with nice induction
   470 rules.  INCOMPATIBILITY: former sorted.simps now named sorted_simps.
   471 
   472 * Constant "contents" renamed to "the_elem", to free the generic name
   473 contents for other uses.  INCOMPATIBILITY.
   474 
   475 * Renamed class eq and constant eq (for code generation) to class
   476 equal and constant equal, plus renaming of related facts and various
   477 tuning.  INCOMPATIBILITY.
   478 
   479 * Dropped type classes mult_mono and mult_mono1.  INCOMPATIBILITY.
   480 
   481 * Removed output syntax "'a ~=> 'b" for "'a => 'b option".
   482 INCOMPATIBILITY.
   483 
   484 * Renamed theory Fset to Cset, type Fset.fset to Cset.set, in order to
   485 avoid confusion with finite sets.  INCOMPATIBILITY.
   486 
   487 * Abandoned locales equiv, congruent and congruent2 for equivalence
   488 relations.  INCOMPATIBILITY: use equivI rather than equiv_intro (same
   489 for congruent(2)).
   490 
   491 * Some previously unqualified names have been qualified:
   492 
   493   types
   494     bool ~> HOL.bool
   495     nat ~> Nat.nat
   496 
   497   constants
   498     Trueprop ~> HOL.Trueprop
   499     True ~> HOL.True
   500     False ~> HOL.False
   501     op & ~> HOL.conj
   502     op | ~> HOL.disj
   503     op --> ~> HOL.implies
   504     op = ~> HOL.eq
   505     Not ~> HOL.Not
   506     The ~> HOL.The
   507     All ~> HOL.All
   508     Ex ~> HOL.Ex
   509     Ex1 ~> HOL.Ex1
   510     Let ~> HOL.Let
   511     If ~> HOL.If
   512     Ball ~> Set.Ball
   513     Bex ~> Set.Bex
   514     Suc ~> Nat.Suc
   515     Pair ~> Product_Type.Pair
   516     fst ~> Product_Type.fst
   517     snd ~> Product_Type.snd
   518     curry ~> Product_Type.curry
   519     op : ~> Set.member
   520     Collect ~> Set.Collect
   521 
   522 INCOMPATIBILITY.
   523 
   524 * More canonical naming convention for some fundamental definitions:
   525 
   526     bot_bool_eq ~> bot_bool_def
   527     top_bool_eq ~> top_bool_def
   528     inf_bool_eq ~> inf_bool_def
   529     sup_bool_eq ~> sup_bool_def
   530     bot_fun_eq  ~> bot_fun_def
   531     top_fun_eq  ~> top_fun_def
   532     inf_fun_eq  ~> inf_fun_def
   533     sup_fun_eq  ~> sup_fun_def
   534 
   535 INCOMPATIBILITY.
   536 
   537 * More stylized fact names:
   538 
   539   expand_fun_eq ~> fun_eq_iff
   540   expand_set_eq ~> set_eq_iff
   541   set_ext       ~> set_eqI
   542   nat_number    ~> eval_nat_numeral
   543 
   544 INCOMPATIBILITY.
   545 
   546 * Refactoring of code-generation specific operations in theory List:
   547 
   548   constants
   549     null ~> List.null
   550 
   551   facts
   552     mem_iff ~> member_def
   553     null_empty ~> null_def
   554 
   555 INCOMPATIBILITY.  Note that these were not supposed to be used
   556 regularly unless for striking reasons; their main purpose was code
   557 generation.
   558 
   559 Various operations from the Haskell prelude are used for generating
   560 Haskell code.
   561 
   562 * Term "bij f" is now an abbreviation of "bij_betw f UNIV UNIV".  Term
   563 "surj f" is now an abbreviation of "range f = UNIV".  The theorems
   564 bij_def and surj_def are unchanged.  INCOMPATIBILITY.
   565 
   566 * Abolished some non-alphabetic type names: "prod" and "sum" replace
   567 "*" and "+" respectively.  INCOMPATIBILITY.
   568 
   569 * Name "Plus" of disjoint sum operator "<+>" is now hidden.  Write
   570 "Sum_Type.Plus" instead.
   571 
   572 * Constant "split" has been merged with constant "prod_case"; names of
   573 ML functions, facts etc. involving split have been retained so far,
   574 though.  INCOMPATIBILITY.
   575 
   576 * Dropped old infix syntax "_ mem _" for List.member; use "_ : set _"
   577 instead.  INCOMPATIBILITY.
   578 
   579 * Removed lemma "Option.is_none_none" which duplicates "is_none_def".
   580 INCOMPATIBILITY.
   581 
   582 * Former theory Library/Enum is now part of the HOL-Main image.
   583 INCOMPATIBILITY: all constants of the Enum theory now have to be
   584 referred to by its qualified name.
   585 
   586   enum    ~>  Enum.enum
   587   nlists  ~>  Enum.nlists
   588   product ~>  Enum.product
   589 
   590 * Theory Library/Monad_Syntax provides do-syntax for monad types.
   591 Syntax in Library/State_Monad has been changed to avoid ambiguities.
   592 INCOMPATIBILITY.
   593 
   594 * Theory Library/SetsAndFunctions has been split into
   595 Library/Function_Algebras and Library/Set_Algebras; canonical names
   596 for instance definitions for functions; various improvements.
   597 INCOMPATIBILITY.
   598 
   599 * Theory Library/Multiset provides stable quicksort implementation of
   600 sort_key.
   601 
   602 * Theory Library/Multiset: renamed empty_idemp ~> empty_neutral.
   603 INCOMPATIBILITY.
   604 
   605 * Session Multivariate_Analysis: introduced a type class for euclidean
   606 space.  Most theorems are now stated in terms of euclidean spaces
   607 instead of finite cartesian products.
   608 
   609   types
   610     real ^ 'n ~>  'a::real_vector
   611               ~>  'a::euclidean_space
   612               ~>  'a::ordered_euclidean_space
   613         (depends on your needs)
   614 
   615   constants
   616      _ $ _        ~> _ $$ _
   617      \<chi> x. _  ~> \<chi>\<chi> x. _
   618      CARD('n)     ~> DIM('a)
   619 
   620 Also note that the indices are now natural numbers and not from some
   621 finite type. Finite cartesian products of euclidean spaces, products
   622 of euclidean spaces the real and complex numbers are instantiated to
   623 be euclidean_spaces.  INCOMPATIBILITY.
   624 
   625 * Session Probability: introduced pextreal as positive extended real
   626 numbers.  Use pextreal as value for measures.  Introduce the
   627 Radon-Nikodym derivative, product spaces and Fubini's theorem for
   628 arbitrary sigma finite measures.  Introduces Lebesgue measure based on
   629 the integral in Multivariate Analysis.  INCOMPATIBILITY.
   630 
   631 * Session Imperative_HOL: revamped, corrected dozens of inadequacies.
   632 INCOMPATIBILITY.
   633 
   634 * Session SPARK (with image HOL-SPARK) provides commands to load and
   635 prove verification conditions generated by the SPARK Ada program
   636 verifier.  See also src/HOL/SPARK and src/HOL/SPARK/Examples.
   637 
   638 
   639 *** HOL-Algebra ***
   640 
   641 * Theorems for additive ring operations (locale abelian_monoid and
   642 descendants) are generated by interpretation from their multiplicative
   643 counterparts.  Names (in particular theorem names) have the mandatory
   644 qualifier 'add'.  Previous theorem names are redeclared for
   645 compatibility.
   646 
   647 * Structure "int_ring" is now an abbreviation (previously a
   648 definition).  This fits more natural with advanced interpretations.
   649 
   650 
   651 *** HOLCF ***
   652 
   653 * The domain package now runs in definitional mode by default: The
   654 former command 'new_domain' is now called 'domain'.  To use the domain
   655 package in its original axiomatic mode, use 'domain (unsafe)'.
   656 INCOMPATIBILITY.
   657 
   658 * The new class "domain" is now the default sort.  Class "predomain"
   659 is an unpointed version of "domain". Theories can be updated by
   660 replacing sort annotations as shown below.  INCOMPATIBILITY.
   661 
   662   'a::type ~> 'a::countable
   663   'a::cpo  ~> 'a::predomain
   664   'a::pcpo ~> 'a::domain
   665 
   666 * The old type class "rep" has been superseded by class "domain".
   667 Accordingly, users of the definitional package must remove any
   668 "default_sort rep" declarations.  INCOMPATIBILITY.
   669 
   670 * The domain package (definitional mode) now supports unpointed
   671 predomain argument types, as long as they are marked 'lazy'. (Strict
   672 arguments must be in class "domain".) For example, the following
   673 domain definition now works:
   674 
   675   domain natlist = nil | cons (lazy "nat discr") (lazy "natlist")
   676 
   677 * Theory HOLCF/Library/HOL_Cpo provides cpo and predomain class
   678 instances for types from main HOL: bool, nat, int, char, 'a + 'b,
   679 'a option, and 'a list.  Additionally, it configures fixrec and the
   680 domain package to work with these types.  For example:
   681 
   682   fixrec isInl :: "('a + 'b) u -> tr"
   683     where "isInl$(up$(Inl x)) = TT" | "isInl$(up$(Inr y)) = FF"
   684 
   685   domain V = VFun (lazy "V -> V") | VCon (lazy "nat") (lazy "V list")
   686 
   687 * The "(permissive)" option of fixrec has been replaced with a
   688 per-equation "(unchecked)" option. See
   689 src/HOL/HOLCF/Tutorial/Fixrec_ex.thy for examples. INCOMPATIBILITY.
   690 
   691 * The "bifinite" class no longer fixes a constant "approx"; the class
   692 now just asserts that such a function exists.  INCOMPATIBILITY.
   693 
   694 * Former type "alg_defl" has been renamed to "defl".  HOLCF no longer
   695 defines an embedding of type 'a defl into udom by default; instances
   696 of "bifinite" and "domain" classes are available in
   697 src/HOL/HOLCF/Library/Defl_Bifinite.thy.
   698 
   699 * The syntax "REP('a)" has been replaced with "DEFL('a)".
   700 
   701 * The predicate "directed" has been removed.  INCOMPATIBILITY.
   702 
   703 * The type class "finite_po" has been removed.  INCOMPATIBILITY.
   704 
   705 * The function "cprod_map" has been renamed to "prod_map".
   706 INCOMPATIBILITY.
   707 
   708 * The monadic bind operator on each powerdomain has new binder syntax
   709 similar to sets, e.g. "\<Union>\<sharp>x\<in>xs. t" represents
   710 "upper_bind\<cdot>xs\<cdot>(\<Lambda> x. t)".
   711 
   712 * The infix syntax for binary union on each powerdomain has changed
   713 from e.g. "+\<sharp>" to "\<union>\<sharp>", for consistency with set
   714 syntax.  INCOMPATIBILITY.
   715 
   716 * The constant "UU" has been renamed to "bottom".  The syntax "UU" is
   717 still supported as an input translation.
   718 
   719 * Renamed some theorems (the original names are also still available).
   720 
   721   expand_fun_below   ~> fun_below_iff
   722   below_fun_ext      ~> fun_belowI
   723   expand_cfun_eq     ~> cfun_eq_iff
   724   ext_cfun           ~> cfun_eqI
   725   expand_cfun_below  ~> cfun_below_iff
   726   below_cfun_ext     ~> cfun_belowI
   727   cont2cont_Rep_CFun ~> cont2cont_APP
   728 
   729 * The Abs and Rep functions for various types have changed names.
   730 Related theorem names have also changed to match. INCOMPATIBILITY.
   731 
   732   Rep_CFun  ~> Rep_cfun
   733   Abs_CFun  ~> Abs_cfun
   734   Rep_Sprod ~> Rep_sprod
   735   Abs_Sprod ~> Abs_sprod
   736   Rep_Ssum  ~> Rep_ssum
   737   Abs_Ssum  ~> Abs_ssum
   738 
   739 * Lemmas with names of the form *_defined_iff or *_strict_iff have
   740 been renamed to *_bottom_iff.  INCOMPATIBILITY.
   741 
   742 * Various changes to bisimulation/coinduction with domain package:
   743 
   744   - Definitions of "bisim" constants no longer mention definedness.
   745   - With mutual recursion, "bisim" predicate is now curried.
   746   - With mutual recursion, each type gets a separate coind theorem.
   747   - Variable names in bisim_def and coinduct rules have changed.
   748 
   749 INCOMPATIBILITY.
   750 
   751 * Case combinators generated by the domain package for type "foo" are
   752 now named "foo_case" instead of "foo_when".  INCOMPATIBILITY.
   753 
   754 * Several theorems have been renamed to more accurately reflect the
   755 names of constants and types involved.  INCOMPATIBILITY.
   756 
   757   thelub_const    ~> lub_const
   758   lub_const       ~> is_lub_const
   759   thelubI         ~> lub_eqI
   760   is_lub_lub      ~> is_lubD2
   761   lubI            ~> is_lub_lub
   762   unique_lub      ~> is_lub_unique
   763   is_ub_lub       ~> is_lub_rangeD1
   764   lub_bin_chain   ~> is_lub_bin_chain
   765   lub_fun         ~> is_lub_fun
   766   thelub_fun      ~> lub_fun
   767   thelub_cfun     ~> lub_cfun
   768   thelub_Pair     ~> lub_Pair
   769   lub_cprod       ~> is_lub_prod
   770   thelub_cprod    ~> lub_prod
   771   minimal_cprod   ~> minimal_prod
   772   inst_cprod_pcpo ~> inst_prod_pcpo
   773   UU_I            ~> bottomI
   774   compact_UU      ~> compact_bottom
   775   deflation_UU    ~> deflation_bottom
   776   finite_deflation_UU ~> finite_deflation_bottom
   777 
   778 * Many legacy theorem names have been discontinued.  INCOMPATIBILITY.
   779 
   780   sq_ord_less_eq_trans ~> below_eq_trans
   781   sq_ord_eq_less_trans ~> eq_below_trans
   782   refl_less            ~> below_refl
   783   trans_less           ~> below_trans
   784   antisym_less         ~> below_antisym
   785   antisym_less_inverse ~> po_eq_conv [THEN iffD1]
   786   box_less             ~> box_below
   787   rev_trans_less       ~> rev_below_trans
   788   not_less2not_eq      ~> not_below2not_eq
   789   less_UU_iff          ~> below_UU_iff
   790   flat_less_iff        ~> flat_below_iff
   791   adm_less             ~> adm_below
   792   adm_not_less         ~> adm_not_below
   793   adm_compact_not_less ~> adm_compact_not_below
   794   less_fun_def         ~> below_fun_def
   795   expand_fun_less      ~> fun_below_iff
   796   less_fun_ext         ~> fun_belowI
   797   less_discr_def       ~> below_discr_def
   798   discr_less_eq        ~> discr_below_eq
   799   less_unit_def        ~> below_unit_def
   800   less_cprod_def       ~> below_prod_def
   801   prod_lessI           ~> prod_belowI
   802   Pair_less_iff        ~> Pair_below_iff
   803   fst_less_iff         ~> fst_below_iff
   804   snd_less_iff         ~> snd_below_iff
   805   expand_cfun_less     ~> cfun_below_iff
   806   less_cfun_ext        ~> cfun_belowI
   807   injection_less       ~> injection_below
   808   less_up_def          ~> below_up_def
   809   not_Iup_less         ~> not_Iup_below
   810   Iup_less             ~> Iup_below
   811   up_less              ~> up_below
   812   Def_inject_less_eq   ~> Def_below_Def
   813   Def_less_is_eq       ~> Def_below_iff
   814   spair_less_iff       ~> spair_below_iff
   815   less_sprod           ~> below_sprod
   816   spair_less           ~> spair_below
   817   sfst_less_iff        ~> sfst_below_iff
   818   ssnd_less_iff        ~> ssnd_below_iff
   819   fix_least_less       ~> fix_least_below
   820   dist_less_one        ~> dist_below_one
   821   less_ONE             ~> below_ONE
   822   ONE_less_iff         ~> ONE_below_iff
   823   less_sinlD           ~> below_sinlD
   824   less_sinrD           ~> below_sinrD
   825 
   826 
   827 *** FOL and ZF ***
   828 
   829 * All constant names are now qualified internally and use proper
   830 identifiers, e.g. "IFOL.eq" instead of "op =".  INCOMPATIBILITY.
   831 
   832 
   833 *** ML ***
   834 
   835 * Antiquotation @{assert} inlines a function bool -> unit that raises
   836 Fail if the argument is false.  Due to inlining the source position of
   837 failed assertions is included in the error output.
   838 
   839 * Discontinued antiquotation @{theory_ref}, which is obsolete since ML
   840 text is in practice always evaluated with a stable theory checkpoint.
   841 Minor INCOMPATIBILITY, use (Theory.check_thy @{theory}) instead.
   842 
   843 * Antiquotation @{theory A} refers to theory A from the ancestry of
   844 the current context, not any accidental theory loader state as before.
   845 Potential INCOMPATIBILITY, subtle change in semantics.
   846 
   847 * Syntax.pretty_priority (default 0) configures the required priority
   848 of pretty-printed output and thus affects insertion of parentheses.
   849 
   850 * Syntax.default_root (default "any") configures the inner syntax
   851 category (nonterminal symbol) for parsing of terms.
   852 
   853 * Former exception Library.UnequalLengths now coincides with
   854 ListPair.UnequalLengths.
   855 
   856 * Renamed structure MetaSimplifier to Raw_Simplifier.  Note that the
   857 main functionality is provided by structure Simplifier.
   858 
   859 * Renamed raw "explode" function to "raw_explode" to emphasize its
   860 meaning.  Note that internally to Isabelle, Symbol.explode is used in
   861 almost all situations.
   862 
   863 * Discontinued obsolete function sys_error and exception SYS_ERROR.
   864 See implementation manual for further details on exceptions in
   865 Isabelle/ML.
   866 
   867 * Renamed setmp_noncritical to Unsynchronized.setmp to emphasize its
   868 meaning.
   869 
   870 * Renamed structure PureThy to Pure_Thy and moved most of its
   871 operations to structure Global_Theory, to emphasize that this is
   872 rarely-used global-only stuff.
   873 
   874 * Discontinued Output.debug.  Minor INCOMPATIBILITY, use plain writeln
   875 instead (or tracing for high-volume output).
   876 
   877 * Configuration option show_question_marks only affects regular pretty
   878 printing of types and terms, not raw Term.string_of_vname.
   879 
   880 * ML_Context.thm and ML_Context.thms are no longer pervasive.  Rare
   881 INCOMPATIBILITY, superseded by static antiquotations @{thm} and
   882 @{thms} for most purposes.
   883 
   884 * ML structure Unsynchronized is never opened, not even in Isar
   885 interaction mode as before.  Old Unsynchronized.set etc. have been
   886 discontinued -- use plain := instead.  This should be *rare* anyway,
   887 since modern tools always work via official context data, notably
   888 configuration options.
   889 
   890 * Parallel and asynchronous execution requires special care concerning
   891 interrupts.  Structure Exn provides some convenience functions that
   892 avoid working directly with raw Interrupt.  User code must not absorb
   893 interrupts -- intermediate handling (for cleanup etc.) needs to be
   894 followed by re-raising of the original exception.  Another common
   895 source of mistakes are "handle _" patterns, which make the meaning of
   896 the program subject to physical effects of the environment.
   897 
   898 
   899 
   900 New in Isabelle2009-2 (June 2010)
   901 ---------------------------------
   902 
   903 *** General ***
   904 
   905 * Authentic syntax for *all* logical entities (type classes, type
   906 constructors, term constants): provides simple and robust
   907 correspondence between formal entities and concrete syntax.  Within
   908 the parse tree / AST representations, "constants" are decorated by
   909 their category (class, type, const) and spelled out explicitly with
   910 their full internal name.
   911 
   912 Substantial INCOMPATIBILITY concerning low-level syntax declarations
   913 and translations (translation rules and translation functions in ML).
   914 Some hints on upgrading:
   915 
   916   - Many existing uses of 'syntax' and 'translations' can be replaced
   917     by more modern 'type_notation', 'notation' and 'abbreviation',
   918     which are independent of this issue.
   919 
   920   - 'translations' require markup within the AST; the term syntax
   921     provides the following special forms:
   922 
   923       CONST c   -- produces syntax version of constant c from context
   924       XCONST c  -- literally c, checked as constant from context
   925       c         -- literally c, if declared by 'syntax'
   926 
   927     Plain identifiers are treated as AST variables -- occasionally the
   928     system indicates accidental variables via the error "rhs contains
   929     extra variables".
   930 
   931     Type classes and type constructors are marked according to their
   932     concrete syntax.  Some old translations rules need to be written
   933     for the "type" category, using type constructor application
   934     instead of pseudo-term application of the default category
   935     "logic".
   936 
   937   - 'parse_translation' etc. in ML may use the following
   938     antiquotations:
   939 
   940       @{class_syntax c}   -- type class c within parse tree / AST
   941       @{term_syntax c}    -- type constructor c within parse tree / AST
   942       @{const_syntax c}   -- ML version of "CONST c" above
   943       @{syntax_const c}   -- literally c (checked wrt. 'syntax' declarations)
   944 
   945   - Literal types within 'typed_print_translations', i.e. those *not*
   946     represented as pseudo-terms are represented verbatim.  Use @{class
   947     c} or @{type_name c} here instead of the above syntax
   948     antiquotations.
   949 
   950 Note that old non-authentic syntax was based on unqualified base
   951 names, so all of the above "constant" names would coincide.  Recall
   952 that 'print_syntax' and ML_command "set Syntax.trace_ast" help to
   953 diagnose syntax problems.
   954 
   955 * Type constructors admit general mixfix syntax, not just infix.
   956 
   957 * Concrete syntax may be attached to local entities without a proof
   958 body, too.  This works via regular mixfix annotations for 'fix',
   959 'def', 'obtain' etc. or via the explicit 'write' command, which is
   960 similar to the 'notation' command in theory specifications.
   961 
   962 * Discontinued unnamed infix syntax (legacy feature for many years) --
   963 need to specify constant name and syntax separately.  Internal ML
   964 datatype constructors have been renamed from InfixName to Infix etc.
   965 Minor INCOMPATIBILITY.
   966 
   967 * Schematic theorem statements need to be explicitly markup as such,
   968 via commands 'schematic_lemma', 'schematic_theorem',
   969 'schematic_corollary'.  Thus the relevance of the proof is made
   970 syntactically clear, which impacts performance in a parallel or
   971 asynchronous interactive environment.  Minor INCOMPATIBILITY.
   972 
   973 * Use of cumulative prems via "!" in some proof methods has been
   974 discontinued (old legacy feature).
   975 
   976 * References 'trace_simp' and 'debug_simp' have been replaced by
   977 configuration options stored in the context. Enabling tracing (the
   978 case of debugging is similar) in proofs works via
   979 
   980   using [[trace_simp = true]]
   981 
   982 Tracing is then active for all invocations of the simplifier in
   983 subsequent goal refinement steps. Tracing may also still be enabled or
   984 disabled via the ProofGeneral settings menu.
   985 
   986 * Separate commands 'hide_class', 'hide_type', 'hide_const',
   987 'hide_fact' replace the former 'hide' KIND command.  Minor
   988 INCOMPATIBILITY.
   989 
   990 * Improved parallelism of proof term normalization: usedir -p2 -q0 is
   991 more efficient than combinations with -q1 or -q2.
   992 
   993 
   994 *** Pure ***
   995 
   996 * Proofterms record type-class reasoning explicitly, using the
   997 "unconstrain" operation internally.  This eliminates all sort
   998 constraints from a theorem and proof, introducing explicit
   999 OFCLASS-premises.  On the proof term level, this operation is
  1000 automatically applied at theorem boundaries, such that closed proofs
  1001 are always free of sort constraints.  INCOMPATIBILITY for tools that
  1002 inspect proof terms.
  1003 
  1004 * Local theory specifications may depend on extra type variables that
  1005 are not present in the result type -- arguments TYPE('a) :: 'a itself
  1006 are added internally.  For example:
  1007 
  1008   definition unitary :: bool where "unitary = (ALL (x::'a) y. x = y)"
  1009 
  1010 * Predicates of locales introduced by classes carry a mandatory
  1011 "class" prefix.  INCOMPATIBILITY.
  1012 
  1013 * Vacuous class specifications observe default sort.  INCOMPATIBILITY.
  1014 
  1015 * Old 'axclass' command has been discontinued.  INCOMPATIBILITY, use
  1016 'class' instead.
  1017 
  1018 * Command 'code_reflect' allows to incorporate generated ML code into
  1019 runtime environment; replaces immature code_datatype antiquotation.
  1020 INCOMPATIBILITY.
  1021 
  1022 * Code generator: simple concept for abstract datatypes obeying
  1023 invariants.
  1024 
  1025 * Code generator: details of internal data cache have no impact on the
  1026 user space functionality any longer.
  1027 
  1028 * Methods "unfold_locales" and "intro_locales" ignore non-locale
  1029 subgoals.  This is more appropriate for interpretations with 'where'.
  1030 INCOMPATIBILITY.
  1031 
  1032 * Command 'example_proof' opens an empty proof body.  This allows to
  1033 experiment with Isar, without producing any persistent result.
  1034 
  1035 * Commands 'type_notation' and 'no_type_notation' declare type syntax
  1036 within a local theory context, with explicit checking of the
  1037 constructors involved (in contrast to the raw 'syntax' versions).
  1038 
  1039 * Commands 'types' and 'typedecl' now work within a local theory
  1040 context -- without introducing dependencies on parameters or
  1041 assumptions, which is not possible in Isabelle/Pure.
  1042 
  1043 * Command 'defaultsort' has been renamed to 'default_sort', it works
  1044 within a local theory context.  Minor INCOMPATIBILITY.
  1045 
  1046 
  1047 *** HOL ***
  1048 
  1049 * Command 'typedef' now works within a local theory context -- without
  1050 introducing dependencies on parameters or assumptions, which is not
  1051 possible in Isabelle/Pure/HOL.  Note that the logical environment may
  1052 contain multiple interpretations of local typedefs (with different
  1053 non-emptiness proofs), even in a global theory context.
  1054 
  1055 * New package for quotient types.  Commands 'quotient_type' and
  1056 'quotient_definition' may be used for defining types and constants by
  1057 quotient constructions.  An example is the type of integers created by
  1058 quotienting pairs of natural numbers:
  1059 
  1060   fun
  1061     intrel :: "(nat * nat) => (nat * nat) => bool"
  1062   where
  1063     "intrel (x, y) (u, v) = (x + v = u + y)"
  1064 
  1065   quotient_type int = "nat * nat" / intrel
  1066     by (auto simp add: equivp_def expand_fun_eq)
  1067 
  1068   quotient_definition
  1069     "0::int" is "(0::nat, 0::nat)"
  1070 
  1071 The method "lifting" can be used to lift of theorems from the
  1072 underlying "raw" type to the quotient type.  The example
  1073 src/HOL/Quotient_Examples/FSet.thy includes such a quotient
  1074 construction and provides a reasoning infrastructure for finite sets.
  1075 
  1076 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
  1077 clash with new theory Quotient in Main HOL.
  1078 
  1079 * Moved the SMT binding into the main HOL session, eliminating
  1080 separate HOL-SMT session.
  1081 
  1082 * List membership infix mem operation is only an input abbreviation.
  1083 INCOMPATIBILITY.
  1084 
  1085 * Theory Library/Word.thy has been removed.  Use library Word/Word.thy
  1086 for future developements; former Library/Word.thy is still present in
  1087 the AFP entry RSAPPS.
  1088 
  1089 * Theorem Int.int_induct renamed to Int.int_of_nat_induct and is no
  1090 longer shadowed.  INCOMPATIBILITY.
  1091 
  1092 * Dropped theorem duplicate comp_arith; use semiring_norm instead.
  1093 INCOMPATIBILITY.
  1094 
  1095 * Dropped theorem RealPow.real_sq_order; use power2_le_imp_le instead.
  1096 INCOMPATIBILITY.
  1097 
  1098 * Dropped normalizing_semiring etc; use the facts in semiring classes
  1099 instead.  INCOMPATIBILITY.
  1100 
  1101 * Dropped several real-specific versions of lemmas about floor and
  1102 ceiling; use the generic lemmas from theory "Archimedean_Field"
  1103 instead.  INCOMPATIBILITY.
  1104 
  1105   floor_number_of_eq         ~> floor_number_of
  1106   le_floor_eq_number_of      ~> number_of_le_floor
  1107   le_floor_eq_zero           ~> zero_le_floor
  1108   le_floor_eq_one            ~> one_le_floor
  1109   floor_less_eq_number_of    ~> floor_less_number_of
  1110   floor_less_eq_zero         ~> floor_less_zero
  1111   floor_less_eq_one          ~> floor_less_one
  1112   less_floor_eq_number_of    ~> number_of_less_floor
  1113   less_floor_eq_zero         ~> zero_less_floor
  1114   less_floor_eq_one          ~> one_less_floor
  1115   floor_le_eq_number_of      ~> floor_le_number_of
  1116   floor_le_eq_zero           ~> floor_le_zero
  1117   floor_le_eq_one            ~> floor_le_one
  1118   floor_subtract_number_of   ~> floor_diff_number_of
  1119   floor_subtract_one         ~> floor_diff_one
  1120   ceiling_number_of_eq       ~> ceiling_number_of
  1121   ceiling_le_eq_number_of    ~> ceiling_le_number_of
  1122   ceiling_le_zero_eq         ~> ceiling_le_zero
  1123   ceiling_le_eq_one          ~> ceiling_le_one
  1124   less_ceiling_eq_number_of  ~> number_of_less_ceiling
  1125   less_ceiling_eq_zero       ~> zero_less_ceiling
  1126   less_ceiling_eq_one        ~> one_less_ceiling
  1127   ceiling_less_eq_number_of  ~> ceiling_less_number_of
  1128   ceiling_less_eq_zero       ~> ceiling_less_zero
  1129   ceiling_less_eq_one        ~> ceiling_less_one
  1130   le_ceiling_eq_number_of    ~> number_of_le_ceiling
  1131   le_ceiling_eq_zero         ~> zero_le_ceiling
  1132   le_ceiling_eq_one          ~> one_le_ceiling
  1133   ceiling_subtract_number_of ~> ceiling_diff_number_of
  1134   ceiling_subtract_one       ~> ceiling_diff_one
  1135 
  1136 * Theory "Finite_Set": various folding_XXX locales facilitate the
  1137 application of the various fold combinators on finite sets.
  1138 
  1139 * Library theory "RBT" renamed to "RBT_Impl"; new library theory "RBT"
  1140 provides abstract red-black tree type which is backed by "RBT_Impl" as
  1141 implementation.  INCOMPATIBILTY.
  1142 
  1143 * Theory Library/Coinductive_List has been removed -- superseded by
  1144 AFP/thys/Coinductive.
  1145 
  1146 * Theory PReal, including the type "preal" and related operations, has
  1147 been removed.  INCOMPATIBILITY.
  1148 
  1149 * Real: new development using Cauchy Sequences.
  1150 
  1151 * Split off theory "Big_Operators" containing setsum, setprod,
  1152 Inf_fin, Sup_fin, Min, Max from theory Finite_Set.  INCOMPATIBILITY.
  1153 
  1154 * Theory "Rational" renamed to "Rat", for consistency with "Nat",
  1155 "Int" etc.  INCOMPATIBILITY.
  1156 
  1157 * Constant Rat.normalize needs to be qualified.  INCOMPATIBILITY.
  1158 
  1159 * New set of rules "ac_simps" provides combined assoc / commute
  1160 rewrites for all interpretations of the appropriate generic locales.
  1161 
  1162 * Renamed theory "OrderedGroup" to "Groups" and split theory
  1163 "Ring_and_Field" into theories "Rings" and "Fields"; for more
  1164 appropriate and more consistent names suitable for name prefixes
  1165 within the HOL theories.  INCOMPATIBILITY.
  1166 
  1167 * Some generic constants have been put to appropriate theories:
  1168   - less_eq, less: Orderings
  1169   - zero, one, plus, minus, uminus, times, abs, sgn: Groups
  1170   - inverse, divide: Rings
  1171 INCOMPATIBILITY.
  1172 
  1173 * More consistent naming of type classes involving orderings (and
  1174 lattices):
  1175 
  1176     lower_semilattice                   ~> semilattice_inf
  1177     upper_semilattice                   ~> semilattice_sup
  1178 
  1179     dense_linear_order                  ~> dense_linorder
  1180 
  1181     pordered_ab_group_add               ~> ordered_ab_group_add
  1182     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
  1183     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
  1184     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
  1185     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
  1186     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
  1187     pordered_cancel_semiring            ~> ordered_cancel_semiring
  1188     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
  1189     pordered_comm_ring                  ~> ordered_comm_ring
  1190     pordered_comm_semiring              ~> ordered_comm_semiring
  1191     pordered_ring                       ~> ordered_ring
  1192     pordered_ring_abs                   ~> ordered_ring_abs
  1193     pordered_semiring                   ~> ordered_semiring
  1194 
  1195     ordered_ab_group_add                ~> linordered_ab_group_add
  1196     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
  1197     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
  1198     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
  1199     ordered_field                       ~> linordered_field
  1200     ordered_field_no_lb                 ~> linordered_field_no_lb
  1201     ordered_field_no_ub                 ~> linordered_field_no_ub
  1202     ordered_field_dense_linear_order    ~> dense_linordered_field
  1203     ordered_idom                        ~> linordered_idom
  1204     ordered_ring                        ~> linordered_ring
  1205     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
  1206     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
  1207     ordered_ring_strict                 ~> linordered_ring_strict
  1208     ordered_semidom                     ~> linordered_semidom
  1209     ordered_semiring                    ~> linordered_semiring
  1210     ordered_semiring_1                  ~> linordered_semiring_1
  1211     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
  1212     ordered_semiring_strict             ~> linordered_semiring_strict
  1213 
  1214   The following slightly odd type classes have been moved to a
  1215   separate theory Library/Lattice_Algebras:
  1216 
  1217     lordered_ab_group_add               ~> lattice_ab_group_add
  1218     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
  1219     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
  1220     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
  1221     lordered_ring                       ~> lattice_ring
  1222 
  1223 INCOMPATIBILITY.
  1224 
  1225 * Refined field classes:
  1226   - classes division_ring_inverse_zero, field_inverse_zero,
  1227     linordered_field_inverse_zero include rule inverse 0 = 0 --
  1228     subsumes former division_by_zero class;
  1229   - numerous lemmas have been ported from field to division_ring.
  1230 INCOMPATIBILITY.
  1231 
  1232 * Refined algebra theorem collections:
  1233   - dropped theorem group group_simps, use algebra_simps instead;
  1234   - dropped theorem group ring_simps, use field_simps instead;
  1235   - proper theorem collection field_simps subsumes former theorem
  1236     groups field_eq_simps and field_simps;
  1237   - dropped lemma eq_minus_self_iff which is a duplicate for
  1238     equal_neg_zero.
  1239 INCOMPATIBILITY.
  1240 
  1241 * Theory Finite_Set and List: some lemmas have been generalized from
  1242 sets to lattices:
  1243 
  1244   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
  1245   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
  1246   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
  1247   union_Union_fold_union        ~> sup_Sup_fold_sup
  1248   Inter_fold_inter              ~> Inf_fold_inf
  1249   Union_fold_union              ~> Sup_fold_sup
  1250   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
  1251   union_UNION_fold_union        ~> sup_SUPR_fold_sup
  1252   INTER_fold_inter              ~> INFI_fold_inf
  1253   UNION_fold_union              ~> SUPR_fold_sup
  1254 
  1255 * Theory "Complete_Lattice": lemmas top_def and bot_def have been
  1256 replaced by the more convenient lemmas Inf_empty and Sup_empty.
  1257 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
  1258 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
  1259 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
  1260 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
  1261 
  1262 * Reorganized theory Multiset: swapped notation of pointwise and
  1263 multiset order:
  1264 
  1265   - pointwise ordering is instance of class order with standard syntax
  1266     <= and <;
  1267   - multiset ordering has syntax <=# and <#; partial order properties
  1268     are provided by means of interpretation with prefix
  1269     multiset_order;
  1270   - less duplication, less historical organization of sections,
  1271     conversion from associations lists to multisets, rudimentary code
  1272     generation;
  1273   - use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union,
  1274     if needed.
  1275 
  1276 Renamed:
  1277 
  1278   multiset_eq_conv_count_eq  ~>  multiset_ext_iff
  1279   multi_count_ext  ~>  multiset_ext
  1280   diff_union_inverse2  ~>  diff_union_cancelR
  1281 
  1282 INCOMPATIBILITY.
  1283 
  1284 * Theory Permutation: replaced local "remove" by List.remove1.
  1285 
  1286 * Code generation: ML and OCaml code is decorated with signatures.
  1287 
  1288 * Theory List: added transpose.
  1289 
  1290 * Library/Nat_Bijection.thy is a collection of bijective functions
  1291 between nat and other types, which supersedes the older libraries
  1292 Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.
  1293 
  1294   Constants:
  1295   Nat_Int_Bij.nat2_to_nat         ~> prod_encode
  1296   Nat_Int_Bij.nat_to_nat2         ~> prod_decode
  1297   Nat_Int_Bij.int_to_nat_bij      ~> int_encode
  1298   Nat_Int_Bij.nat_to_int_bij      ~> int_decode
  1299   Countable.pair_encode           ~> prod_encode
  1300   NatIso.prod2nat                 ~> prod_encode
  1301   NatIso.nat2prod                 ~> prod_decode
  1302   NatIso.sum2nat                  ~> sum_encode
  1303   NatIso.nat2sum                  ~> sum_decode
  1304   NatIso.list2nat                 ~> list_encode
  1305   NatIso.nat2list                 ~> list_decode
  1306   NatIso.set2nat                  ~> set_encode
  1307   NatIso.nat2set                  ~> set_decode
  1308 
  1309   Lemmas:
  1310   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
  1311   Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
  1312   Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
  1313   Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
  1314   Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
  1315   Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
  1316   Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
  1317   Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
  1318   Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
  1319   Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
  1320   Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
  1321   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
  1322   Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode
  1323 
  1324 * Sledgehammer:
  1325   - Renamed ATP commands:
  1326     atp_info     ~> sledgehammer running_atps
  1327     atp_kill     ~> sledgehammer kill_atps
  1328     atp_messages ~> sledgehammer messages
  1329     atp_minimize ~> sledgehammer minimize
  1330     print_atps   ~> sledgehammer available_atps
  1331     INCOMPATIBILITY.
  1332   - Added user's manual ("isabelle doc sledgehammer").
  1333   - Added option syntax and "sledgehammer_params" to customize
  1334     Sledgehammer's behavior.  See the manual for details.
  1335   - Modified the Isar proof reconstruction code so that it produces
  1336     direct proofs rather than proofs by contradiction.  (This feature
  1337     is still experimental.)
  1338   - Made Isar proof reconstruction work for SPASS, remote ATPs, and in
  1339     full-typed mode.
  1340   - Added support for TPTP syntax for SPASS via the "spass_tptp" ATP.
  1341 
  1342 * Nitpick:
  1343   - Added and implemented "binary_ints" and "bits" options.
  1344   - Added "std" option and implemented support for nonstandard models.
  1345   - Added and implemented "finitize" option to improve the precision
  1346     of infinite datatypes based on a monotonicity analysis.
  1347   - Added support for quotient types.
  1348   - Added support for "specification" and "ax_specification"
  1349     constructs.
  1350   - Added support for local definitions (for "function" and
  1351     "termination" proofs).
  1352   - Added support for term postprocessors.
  1353   - Optimized "Multiset.multiset" and "FinFun.finfun".
  1354   - Improved efficiency of "destroy_constrs" optimization.
  1355   - Fixed soundness bugs related to "destroy_constrs" optimization and
  1356     record getters.
  1357   - Fixed soundness bug related to higher-order constructors.
  1358   - Fixed soundness bug when "full_descrs" is enabled.
  1359   - Improved precision of set constructs.
  1360   - Added "atoms" option.
  1361   - Added cache to speed up repeated Kodkod invocations on the same
  1362     problems.
  1363   - Renamed "MiniSatJNI", "zChaffJNI", "BerkMinAlloy", and
  1364     "SAT4JLight" to "MiniSat_JNI", "zChaff_JNI", "BerkMin_Alloy", and
  1365     "SAT4J_Light".  INCOMPATIBILITY.
  1366   - Removed "skolemize", "uncurry", "sym_break", "flatten_prop",
  1367     "sharing_depth", and "show_skolems" options.  INCOMPATIBILITY.
  1368   - Removed "nitpick_intro" attribute.  INCOMPATIBILITY.
  1369 
  1370 * Method "induct" now takes instantiations of the form t, where t is not
  1371   a variable, as a shorthand for "x == t", where x is a fresh variable.
  1372   If this is not intended, t has to be enclosed in parentheses.
  1373   By default, the equalities generated by definitional instantiations
  1374   are pre-simplified, which may cause parameters of inductive cases
  1375   to disappear, or may even delete some of the inductive cases.
  1376   Use "induct (no_simp)" instead of "induct" to restore the old
  1377   behaviour. The (no_simp) option is also understood by the "cases"
  1378   and "nominal_induct" methods, which now perform pre-simplification, too.
  1379   INCOMPATIBILITY.
  1380 
  1381 
  1382 *** HOLCF ***
  1383 
  1384 * Variable names in lemmas generated by the domain package have
  1385 changed; the naming scheme is now consistent with the HOL datatype
  1386 package.  Some proof scripts may be affected, INCOMPATIBILITY.
  1387 
  1388 * The domain package no longer defines the function "foo_copy" for
  1389 recursive domain "foo".  The reach lemma is now stated directly in
  1390 terms of "foo_take".  Lemmas and proofs that mention "foo_copy" must
  1391 be reformulated in terms of "foo_take", INCOMPATIBILITY.
  1392 
  1393 * Most definedness lemmas generated by the domain package (previously
  1394 of the form "x ~= UU ==> foo$x ~= UU") now have an if-and-only-if form
  1395 like "foo$x = UU <-> x = UU", which works better as a simp rule.
  1396 Proofs that used definedness lemmas as intro rules may break,
  1397 potential INCOMPATIBILITY.
  1398 
  1399 * Induction and casedist rules generated by the domain package now
  1400 declare proper case_names (one called "bottom", and one named for each
  1401 constructor).  INCOMPATIBILITY.
  1402 
  1403 * For mutually-recursive domains, separate "reach" and "take_lemma"
  1404 rules are generated for each domain, INCOMPATIBILITY.
  1405 
  1406   foo_bar.reach       ~> foo.reach  bar.reach
  1407   foo_bar.take_lemmas ~> foo.take_lemma  bar.take_lemma
  1408 
  1409 * Some lemmas generated by the domain package have been renamed for
  1410 consistency with the datatype package, INCOMPATIBILITY.
  1411 
  1412   foo.ind        ~> foo.induct
  1413   foo.finite_ind ~> foo.finite_induct
  1414   foo.coind      ~> foo.coinduct
  1415   foo.casedist   ~> foo.exhaust
  1416   foo.exhaust    ~> foo.nchotomy
  1417 
  1418 * For consistency with other definition packages, the fixrec package
  1419 now generates qualified theorem names, INCOMPATIBILITY.
  1420 
  1421   foo_simps  ~> foo.simps
  1422   foo_unfold ~> foo.unfold
  1423   foo_induct ~> foo.induct
  1424 
  1425 * The "fixrec_simp" attribute has been removed.  The "fixrec_simp"
  1426 method and internal fixrec proofs now use the default simpset instead.
  1427 INCOMPATIBILITY.
  1428 
  1429 * The "contlub" predicate has been removed.  Proof scripts should use
  1430 lemma contI2 in place of monocontlub2cont, INCOMPATIBILITY.
  1431 
  1432 * The "admw" predicate has been removed, INCOMPATIBILITY.
  1433 
  1434 * The constants cpair, cfst, and csnd have been removed in favor of
  1435 Pair, fst, and snd from Isabelle/HOL, INCOMPATIBILITY.
  1436 
  1437 
  1438 *** ML ***
  1439 
  1440 * Antiquotations for basic formal entities:
  1441 
  1442     @{class NAME}         -- type class
  1443     @{class_syntax NAME}  -- syntax representation of the above
  1444 
  1445     @{type_name NAME}     -- logical type
  1446     @{type_abbrev NAME}   -- type abbreviation
  1447     @{nonterminal NAME}   -- type of concrete syntactic category
  1448     @{type_syntax NAME}   -- syntax representation of any of the above
  1449 
  1450     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
  1451     @{const_abbrev NAME}  -- abbreviated constant
  1452     @{const_syntax NAME}  -- syntax representation of any of the above
  1453 
  1454 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
  1455 syntax constant (cf. 'syntax' command).
  1456 
  1457 * Antiquotation @{make_string} inlines a function to print arbitrary
  1458 values similar to the ML toplevel.  The result is compiler dependent
  1459 and may fall back on "?" in certain situations.
  1460 
  1461 * Diagnostic commands 'ML_val' and 'ML_command' may refer to
  1462 antiquotations @{Isar.state} and @{Isar.goal}.  This replaces impure
  1463 Isar.state() and Isar.goal(), which belong to the old TTY loop and do
  1464 not work with the asynchronous Isar document model.
  1465 
  1466 * Configuration options now admit dynamic default values, depending on
  1467 the context or even global references.
  1468 
  1469 * SHA1.digest digests strings according to SHA-1 (see RFC 3174).  It
  1470 uses an efficient external library if available (for Poly/ML).
  1471 
  1472 * Renamed some important ML structures, while keeping the old names
  1473 for some time as aliases within the structure Legacy:
  1474 
  1475   OuterKeyword  ~>  Keyword
  1476   OuterLex      ~>  Token
  1477   OuterParse    ~>  Parse
  1478   OuterSyntax   ~>  Outer_Syntax
  1479   PrintMode     ~>  Print_Mode
  1480   SpecParse     ~>  Parse_Spec
  1481   ThyInfo       ~>  Thy_Info
  1482   ThyLoad       ~>  Thy_Load
  1483   ThyOutput     ~>  Thy_Output
  1484   TypeInfer     ~>  Type_Infer
  1485 
  1486 Note that "open Legacy" simplifies porting of sources, but forgetting
  1487 to remove it again will complicate porting again in the future.
  1488 
  1489 * Most operations that refer to a global context are named
  1490 accordingly, e.g. Simplifier.global_context or
  1491 ProofContext.init_global.  There are some situations where a global
  1492 context actually works, but under normal circumstances one needs to
  1493 pass the proper local context through the code!
  1494 
  1495 * Discontinued old TheoryDataFun with its copy/init operation -- data
  1496 needs to be pure.  Functor Theory_Data_PP retains the traditional
  1497 Pretty.pp argument to merge, which is absent in the standard
  1498 Theory_Data version.
  1499 
  1500 * Sorts.certify_sort and derived "cert" operations for types and terms
  1501 no longer minimize sorts.  Thus certification at the boundary of the
  1502 inference kernel becomes invariant under addition of class relations,
  1503 which is an important monotonicity principle.  Sorts are now minimized
  1504 in the syntax layer only, at the boundary between the end-user and the
  1505 system.  Subtle INCOMPATIBILITY, may have to use Sign.minimize_sort
  1506 explicitly in rare situations.
  1507 
  1508 * Renamed old-style Drule.standard to Drule.export_without_context, to
  1509 emphasize that this is in no way a standard operation.
  1510 INCOMPATIBILITY.
  1511 
  1512 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
  1513 usual for resolution.  Rare INCOMPATIBILITY.
  1514 
  1515 * Renamed varify/unvarify operations to varify_global/unvarify_global
  1516 to emphasize that these only work in a global situation (which is
  1517 quite rare).
  1518 
  1519 * Curried take and drop in library.ML; negative length is interpreted
  1520 as infinity (as in chop).  Subtle INCOMPATIBILITY.
  1521 
  1522 * Proof terms: type substitutions on proof constants now use canonical
  1523 order of type variables.  INCOMPATIBILITY for tools working with proof
  1524 terms.
  1525 
  1526 * Raw axioms/defs may no longer carry sort constraints, and raw defs
  1527 may no longer carry premises.  User-level specifications are
  1528 transformed accordingly by Thm.add_axiom/add_def.
  1529 
  1530 
  1531 *** System ***
  1532 
  1533 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
  1534 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
  1535 proof terms are enabled unconditionally in the new HOL-Proofs image.
  1536 
  1537 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
  1538 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
  1539 respectively.
  1540 
  1541 * Old lib/scripts/polyml-platform is superseded by the
  1542 ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
  1543 variant, even on a 64 bit machine.  The following example setting
  1544 prefers 64 bit if available:
  1545 
  1546   ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"
  1547 
  1548 * The preliminary Isabelle/jEdit application demonstrates the emerging
  1549 Isabelle/Scala layer for advanced prover interaction and integration.
  1550 See src/Tools/jEdit or "isabelle jedit" provided by the properly built
  1551 component.
  1552 
  1553 * "IsabelleText" is a Unicode font derived from Bitstream Vera Mono
  1554 and Bluesky TeX fonts.  It provides the usual Isabelle symbols,
  1555 similar to the default assignment of the document preparation system
  1556 (cf. isabellesym.sty).  The Isabelle/Scala class Isabelle_System
  1557 provides some operations for direct access to the font without asking
  1558 the user for manual installation.
  1559 
  1560 
  1561 
  1562 New in Isabelle2009-1 (December 2009)
  1563 -------------------------------------
  1564 
  1565 *** General ***
  1566 
  1567 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
  1568 one backslash should be used, even in ML sources.
  1569 
  1570 
  1571 *** Pure ***
  1572 
  1573 * Locale interpretation propagates mixins along the locale hierarchy.
  1574 The currently only available mixins are the equations used to map
  1575 local definitions to terms of the target domain of an interpretation.
  1576 
  1577 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
  1578 loc" to print all interpretations of locale "loc" in the theory.
  1579 Interpretations in proofs are not shown.
  1580 
  1581 * Thoroughly revised locales tutorial.  New section on conditional
  1582 interpretation.
  1583 
  1584 * On instantiation of classes, remaining undefined class parameters
  1585 are formally declared.  INCOMPATIBILITY.
  1586 
  1587 
  1588 *** Document preparation ***
  1589 
  1590 * New generalized style concept for printing terms: @{foo (style) ...}
  1591 instead of @{foo_style style ...}  (old form is still retained for
  1592 backward compatibility).  Styles can be also applied for
  1593 antiquotations prop, term_type and typeof.
  1594 
  1595 
  1596 *** HOL ***
  1597 
  1598 * New proof method "smt" for a combination of first-order logic with
  1599 equality, linear and nonlinear (natural/integer/real) arithmetic, and
  1600 fixed-size bitvectors; there is also basic support for higher-order
  1601 features (esp. lambda abstractions).  It is an incomplete decision
  1602 procedure based on external SMT solvers using the oracle mechanism;
  1603 for the SMT solver Z3, this method is proof-producing.  Certificates
  1604 are provided to avoid calling the external solvers solely for
  1605 re-checking proofs.  Due to a remote SMT service there is no need for
  1606 installing SMT solvers locally.  See src/HOL/SMT.
  1607 
  1608 * New commands to load and prove verification conditions generated by
  1609 the Boogie program verifier or derived systems (e.g. the Verifying C
  1610 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
  1611 
  1612 * New counterexample generator tool 'nitpick' based on the Kodkod
  1613 relational model finder.  See src/HOL/Tools/Nitpick and
  1614 src/HOL/Nitpick_Examples.
  1615 
  1616 * New commands 'code_pred' and 'values' to invoke the predicate
  1617 compiler and to enumerate values of inductive predicates.
  1618 
  1619 * A tabled implementation of the reflexive transitive closure.
  1620 
  1621 * New implementation of quickcheck uses generic code generator;
  1622 default generators are provided for all suitable HOL types, records
  1623 and datatypes.  Old quickcheck can be re-activated importing theory
  1624 Library/SML_Quickcheck.
  1625 
  1626 * New testing tool Mirabelle for automated proof tools.  Applies
  1627 several tools and tactics like sledgehammer, metis, or quickcheck, to
  1628 every proof step in a theory.  To be used in batch mode via the
  1629 "mirabelle" utility.
  1630 
  1631 * New proof method "sos" (sum of squares) for nonlinear real
  1632 arithmetic (originally due to John Harison). It requires theory
  1633 Library/Sum_Of_Squares.  It is not a complete decision procedure but
  1634 works well in practice on quantifier-free real arithmetic with +, -,
  1635 *, ^, =, <= and <, i.e. boolean combinations of equalities and
  1636 inequalities between polynomials.  It makes use of external
  1637 semidefinite programming solvers.  Method "sos" generates a
  1638 certificate that can be pasted into the proof thus avoiding the need
  1639 to call an external tool every time the proof is checked.  See
  1640 src/HOL/Library/Sum_Of_Squares.
  1641 
  1642 * New method "linarith" invokes existing linear arithmetic decision
  1643 procedure only.
  1644 
  1645 * New command 'atp_minimal' reduces result produced by Sledgehammer.
  1646 
  1647 * New Sledgehammer option "Full Types" in Proof General settings menu.
  1648 Causes full type information to be output to the ATPs.  This slows
  1649 ATPs down considerably but eliminates a source of unsound "proofs"
  1650 that fail later.
  1651 
  1652 * New method "metisFT": A version of metis that uses full type
  1653 information in order to avoid failures of proof reconstruction.
  1654 
  1655 * New evaluator "approximate" approximates an real valued term using
  1656 the same method as the approximation method.
  1657 
  1658 * Method "approximate" now supports arithmetic expressions as
  1659 boundaries of intervals and implements interval splitting and Taylor
  1660 series expansion.
  1661 
  1662 * ML antiquotation @{code_datatype} inserts definition of a datatype
  1663 generated by the code generator; e.g. see src/HOL/Predicate.thy.
  1664 
  1665 * New theory SupInf of the supremum and infimum operators for sets of
  1666 reals.
  1667 
  1668 * New theory Probability, which contains a development of measure
  1669 theory, eventually leading to Lebesgue integration and probability.
  1670 
  1671 * Extended Multivariate Analysis to include derivation and Brouwer's
  1672 fixpoint theorem.
  1673 
  1674 * Reorganization of number theory, INCOMPATIBILITY:
  1675   - new number theory development for nat and int, in theories Divides
  1676     and GCD as well as in new session Number_Theory
  1677   - some constants and facts now suffixed with _nat and _int
  1678     accordingly
  1679   - former session NumberTheory now named Old_Number_Theory, including
  1680     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
  1681   - moved theory Pocklington from src/HOL/Library to
  1682     src/HOL/Old_Number_Theory
  1683 
  1684 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
  1685 lcm of finite and infinite sets. It is shown that they form a complete
  1686 lattice.
  1687 
  1688 * Class semiring_div requires superclass no_zero_divisors and proof of
  1689 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
  1690 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
  1691 generalized to class semiring_div, subsuming former theorems
  1692 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
  1693 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
  1694 INCOMPATIBILITY.
  1695 
  1696 * Refinements to lattice classes and sets:
  1697   - less default intro/elim rules in locale variant, more default
  1698     intro/elim rules in class variant: more uniformity
  1699   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
  1700     le_inf_iff
  1701   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
  1702     sup_aci)
  1703   - renamed ACI to inf_sup_aci
  1704   - new class "boolean_algebra"
  1705   - class "complete_lattice" moved to separate theory
  1706     "Complete_Lattice"; corresponding constants (and abbreviations)
  1707     renamed and with authentic syntax:
  1708     Set.Inf ~>    Complete_Lattice.Inf
  1709     Set.Sup ~>    Complete_Lattice.Sup
  1710     Set.INFI ~>   Complete_Lattice.INFI
  1711     Set.SUPR ~>   Complete_Lattice.SUPR
  1712     Set.Inter ~>  Complete_Lattice.Inter
  1713     Set.Union ~>  Complete_Lattice.Union
  1714     Set.INTER ~>  Complete_Lattice.INTER
  1715     Set.UNION ~>  Complete_Lattice.UNION
  1716   - authentic syntax for
  1717     Set.Pow
  1718     Set.image
  1719   - mere abbreviations:
  1720     Set.empty               (for bot)
  1721     Set.UNIV                (for top)
  1722     Set.inter               (for inf, formerly Set.Int)
  1723     Set.union               (for sup, formerly Set.Un)
  1724     Complete_Lattice.Inter  (for Inf)
  1725     Complete_Lattice.Union  (for Sup)
  1726     Complete_Lattice.INTER  (for INFI)
  1727     Complete_Lattice.UNION  (for SUPR)
  1728   - object-logic definitions as far as appropriate
  1729 
  1730 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
  1731 Un_subset_iff are explicitly deleted as default simp rules; then also
  1732 their lattice counterparts le_inf_iff and le_sup_iff have to be
  1733 deleted to achieve the desired effect.
  1734 
  1735 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
  1736 rules by default any longer; the same applies to min_max.inf_absorb1
  1737 etc.  INCOMPATIBILITY.
  1738 
  1739 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
  1740 pred_set_conv by default.  INCOMPATIBILITY.
  1741 
  1742 * Power operations on relations and functions are now one dedicated
  1743 constant "compow" with infix syntax "^^".  Power operation on
  1744 multiplicative monoids retains syntax "^" and is now defined generic
  1745 in class power.  INCOMPATIBILITY.
  1746 
  1747 * Relation composition "R O S" now has a more standard argument order:
  1748 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
  1749 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
  1750 break, since the O_assoc rule was not rewritten like this.  Fix using
  1751 O_assoc[symmetric].  The same applies to the curried version "R OO S".
  1752 
  1753 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
  1754 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
  1755 INCOMPATIBILITY.
  1756 
  1757 * Most rules produced by inductive and datatype package have mandatory
  1758 prefixes.  INCOMPATIBILITY.
  1759 
  1760 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
  1761 the attribute of the same name.  Each of the theorems in the list
  1762 DERIV_intros assumes composition with an additional function and
  1763 matches a variable to the derivative, which has to be solved by the
  1764 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
  1765 of most elementary terms.  Former Maclauren.DERIV_tac and
  1766 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
  1767 INCOMPATIBILITY.
  1768 
  1769 * Code generator attributes follow the usual underscore convention:
  1770     code_unfold     replaces    code unfold
  1771     code_post       replaces    code post
  1772     etc.
  1773   INCOMPATIBILITY.
  1774 
  1775 * Renamed methods:
  1776     sizechange -> size_change
  1777     induct_scheme -> induction_schema
  1778   INCOMPATIBILITY.
  1779 
  1780 * Discontinued abbreviation "arbitrary" of constant "undefined".
  1781 INCOMPATIBILITY, use "undefined" directly.
  1782 
  1783 * Renamed theorems:
  1784     Suc_eq_add_numeral_1 -> Suc_eq_plus1
  1785     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
  1786     Suc_plus1 -> Suc_eq_plus1
  1787     *anti_sym -> *antisym*
  1788     vector_less_eq_def -> vector_le_def
  1789   INCOMPATIBILITY.
  1790 
  1791 * Added theorem List.map_map as [simp].  Removed List.map_compose.
  1792 INCOMPATIBILITY.
  1793 
  1794 * Removed predicate "M hassize n" (<--> card M = n & finite M).
  1795 INCOMPATIBILITY.
  1796 
  1797 
  1798 *** HOLCF ***
  1799 
  1800 * Theory Representable defines a class "rep" of domains that are
  1801 representable (via an ep-pair) in the universal domain type "udom".
  1802 Instances are provided for all type constructors defined in HOLCF.
  1803 
  1804 * The 'new_domain' command is a purely definitional version of the
  1805 domain package, for representable domains.  Syntax is identical to the
  1806 old domain package.  The 'new_domain' package also supports indirect
  1807 recursion using previously-defined type constructors.  See
  1808 src/HOLCF/ex/New_Domain.thy for examples.
  1809 
  1810 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
  1811 on the left-hand side of an equation, and then performs
  1812 simplification.  Rewriting is done using rules declared with the
  1813 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
  1814 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
  1815 
  1816 * The pattern-match compiler in 'fixrec' can now handle constructors
  1817 with HOL function types.  Pattern-match combinators for the Pair
  1818 constructor are pre-configured.
  1819 
  1820 * The 'fixrec' package now produces better fixed-point induction rules
  1821 for mutually-recursive definitions:  Induction rules have conclusions
  1822 of the form "P foo bar" instead of "P <foo, bar>".
  1823 
  1824 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
  1825 been renamed to "below".  The name "below" now replaces "less" in many
  1826 theorem names.  (Legacy theorem names using "less" are still supported
  1827 as well.)
  1828 
  1829 * The 'fixrec' package now supports "bottom patterns".  Bottom
  1830 patterns can be used to generate strictness rules, or to make
  1831 functions more strict (much like the bang-patterns supported by the
  1832 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
  1833 examples.
  1834 
  1835 
  1836 *** ML ***
  1837 
  1838 * Support for Poly/ML 5.3.0, with improved reporting of compiler
  1839 errors and run-time exceptions, including detailed source positions.
  1840 
  1841 * Structure Name_Space (formerly NameSpace) now manages uniquely
  1842 identified entries, with some additional information such as source
  1843 position, logical grouping etc.
  1844 
  1845 * Theory and context data is now introduced by the simplified and
  1846 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
  1847 to be pure, but the old TheoryDataFun for mutable data (with explicit
  1848 copy operation) is still available for some time.
  1849 
  1850 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
  1851 provides a high-level programming interface to synchronized state
  1852 variables with atomic update.  This works via pure function
  1853 application within a critical section -- its runtime should be as
  1854 short as possible; beware of deadlocks if critical code is nested,
  1855 either directly or indirectly via other synchronized variables!
  1856 
  1857 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
  1858 wraps raw ML references, explicitly indicating their non-thread-safe
  1859 behaviour.  The Isar toplevel keeps this structure open, to
  1860 accommodate Proof General as well as quick and dirty interactive
  1861 experiments with references.
  1862 
  1863 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
  1864 parallel tactical reasoning.
  1865 
  1866 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
  1867 are similar to SUBPROOF, but are slightly more flexible: only the
  1868 specified parts of the subgoal are imported into the context, and the
  1869 body tactic may introduce new subgoals and schematic variables.
  1870 
  1871 * Old tactical METAHYPS, which does not observe the proof context, has
  1872 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
  1873 or Subgoal.FOCUS etc.
  1874 
  1875 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
  1876 functors have their own ML name space there is no point to mark them
  1877 separately.)  Minor INCOMPATIBILITY.
  1878 
  1879 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
  1880 
  1881 * Renamed several structures FooBar to Foo_Bar.  Occasional,
  1882 INCOMPATIBILITY.
  1883 
  1884 * Operations of structure Skip_Proof no longer require quick_and_dirty
  1885 mode, which avoids critical setmp.
  1886 
  1887 * Eliminated old Attrib.add_attributes, Method.add_methods and related
  1888 combinators for "args".  INCOMPATIBILITY, need to use simplified
  1889 Attrib/Method.setup introduced in Isabelle2009.
  1890 
  1891 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
  1892 back on global_simpset_of, global_claset_of, global_clasimpset_of as
  1893 last resort.  INCOMPATIBILITY.
  1894 
  1895 * Display.pretty_thm now requires a proper context (cf. former
  1896 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
  1897 or even Display.pretty_thm_without_context as last resort.
  1898 INCOMPATIBILITY.
  1899 
  1900 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
  1901 Syntax.pretty_typ/term directly, preferably with proper context
  1902 instead of global theory.
  1903 
  1904 
  1905 *** System ***
  1906 
  1907 * Further fine tuning of parallel proof checking, scales up to 8 cores
  1908 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
  1909 usedir option -q.
  1910 
  1911 * Support for additional "Isabelle components" via etc/components, see
  1912 also the system manual.
  1913 
  1914 * The isabelle makeall tool now operates on all components with
  1915 IsaMakefile, not just hardwired "logics".
  1916 
  1917 * Removed "compress" option from isabelle-process and isabelle usedir;
  1918 this is always enabled.
  1919 
  1920 * Discontinued support for Poly/ML 4.x versions.
  1921 
  1922 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
  1923 on a given logic image.  This requires the lighttpd webserver and is
  1924 currently supported on Linux only.
  1925 
  1926 
  1927 
  1928 New in Isabelle2009 (April 2009)
  1929 --------------------------------
  1930 
  1931 *** General ***
  1932 
  1933 * Simplified main Isabelle executables, with less surprises on
  1934 case-insensitive file-systems (such as Mac OS).
  1935 
  1936   - The main Isabelle tool wrapper is now called "isabelle" instead of
  1937     "isatool."
  1938 
  1939   - The former "isabelle" alias for "isabelle-process" has been
  1940     removed (should rarely occur to regular users).
  1941 
  1942   - The former "isabelle-interface" and its alias "Isabelle" have been
  1943     removed (interfaces are now regular Isabelle tools).
  1944 
  1945 Within scripts and make files, the Isabelle environment variables
  1946 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
  1947 respectively.  (The latter are still available as legacy feature.)
  1948 
  1949 The old isabelle-interface wrapper could react in confusing ways if
  1950 the interface was uninstalled or changed otherwise.  Individual
  1951 interface tool configuration is now more explicit, see also the
  1952 Isabelle system manual.  In particular, Proof General is now available
  1953 via "isabelle emacs".
  1954 
  1955 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
  1956 purge installed copies of Isabelle executables and re-run "isabelle
  1957 install -p ...", or use symlinks.
  1958 
  1959 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
  1960 old ~/isabelle, which was slightly non-standard and apt to cause
  1961 surprises on case-insensitive file-systems (such as Mac OS).
  1962 
  1963 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
  1964 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
  1965 care is required when using older releases of Isabelle.  Note that
  1966 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
  1967 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
  1968 
  1969 * Proofs of fully specified statements are run in parallel on
  1970 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
  1971 a regular 4-core machine, if the initial heap space is made reasonably
  1972 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
  1973 
  1974 * The main reference manuals ("isar-ref", "implementation", and
  1975 "system") have been updated and extended.  Formally checked references
  1976 as hyperlinks are now available uniformly.
  1977 
  1978 
  1979 *** Pure ***
  1980 
  1981 * Complete re-implementation of locales.  INCOMPATIBILITY in several
  1982 respects.  The most important changes are listed below.  See the
  1983 Tutorial on Locales ("locales" manual) for details.
  1984 
  1985 - In locale expressions, instantiation replaces renaming.  Parameters
  1986 must be declared in a for clause.  To aid compatibility with previous
  1987 parameter inheritance, in locale declarations, parameters that are not
  1988 'touched' (instantiation position "_" or omitted) are implicitly added
  1989 with their syntax at the beginning of the for clause.
  1990 
  1991 - Syntax from abbreviations and definitions in locales is available in
  1992 locale expressions and context elements.  The latter is particularly
  1993 useful in locale declarations.
  1994 
  1995 - More flexible mechanisms to qualify names generated by locale
  1996 expressions.  Qualifiers (prefixes) may be specified in locale
  1997 expressions, and can be marked as mandatory (syntax: "name!:") or
  1998 optional (syntax "name?:").  The default depends for plain "name:"
  1999 depends on the situation where a locale expression is used: in
  2000 commands 'locale' and 'sublocale' prefixes are optional, in
  2001 'interpretation' and 'interpret' prefixes are mandatory.  The old
  2002 implicit qualifiers derived from the parameter names of a locale are
  2003 no longer generated.
  2004 
  2005 - Command "sublocale l < e" replaces "interpretation l < e".  The
  2006 instantiation clause in "interpretation" and "interpret" (square
  2007 brackets) is no longer available.  Use locale expressions.
  2008 
  2009 - When converting proof scripts, mandatory qualifiers in
  2010 'interpretation' and 'interpret' should be retained by default, even
  2011 if this is an INCOMPATIBILITY compared to former behavior.  In the
  2012 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
  2013 in locale expressions range over a single locale instance only.
  2014 
  2015 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
  2016 In existing theorem specifications replace the includes element by the
  2017 respective context elements of the included locale, omitting those
  2018 that are already present in the theorem specification.  Multiple
  2019 assume elements of a locale should be replaced by a single one
  2020 involving the locale predicate.  In the proof body, declarations (most
  2021 notably theorems) may be regained by interpreting the respective
  2022 locales in the proof context as required (command "interpret").
  2023 
  2024 If using "includes" in replacement of a target solely because the
  2025 parameter types in the theorem are not as general as in the target,
  2026 consider declaring a new locale with additional type constraints on
  2027 the parameters (context element "constrains").
  2028 
  2029 - Discontinued "locale (open)".  INCOMPATIBILITY.
  2030 
  2031 - Locale interpretation commands no longer attempt to simplify goal.
  2032 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
  2033 methods intro_locales and unfold_locales to clarify.
  2034 
  2035 - Locale interpretation commands no longer accept interpretation
  2036 attributes.  INCOMPATIBILITY.
  2037 
  2038 * Class declaration: so-called "base sort" must not be given in import
  2039 list any longer, but is inferred from the specification.  Particularly
  2040 in HOL, write
  2041 
  2042     class foo = ...
  2043 
  2044 instead of
  2045 
  2046     class foo = type + ...
  2047 
  2048 * Class target: global versions of theorems stemming do not carry a
  2049 parameter prefix any longer.  INCOMPATIBILITY.
  2050 
  2051 * Class 'instance' command no longer accepts attached definitions.
  2052 INCOMPATIBILITY, use proper 'instantiation' target instead.
  2053 
  2054 * Recovered hiding of consts, which was accidentally broken in
  2055 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
  2056 makes c inaccessible; consider using ``hide (open) const c'' instead.
  2057 
  2058 * Slightly more coherent Pure syntax, with updated documentation in
  2059 isar-ref manual.  Removed locales meta_term_syntax and
  2060 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
  2061 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
  2062 directly in regular applications.
  2063 
  2064 * There is a new syntactic category "float_const" for signed decimal
  2065 fractions (e.g. 123.45 or -123.45).
  2066 
  2067 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
  2068 interface with 'setup' command instead.
  2069 
  2070 * Command 'local_setup' is similar to 'setup', but operates on a local
  2071 theory context.
  2072 
  2073 * The 'axiomatization' command now only works within a global theory
  2074 context.  INCOMPATIBILITY.
  2075 
  2076 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
  2077 hypotheses.  Sorts required in the course of reasoning need to be
  2078 covered by the constraints in the initial statement, completed by the
  2079 type instance information of the background theory.  Non-trivial sort
  2080 hypotheses, which rarely occur in practice, may be specified via
  2081 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
  2082 
  2083   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
  2084 
  2085 The result contains an implicit sort hypotheses as before --
  2086 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
  2087 normalization.
  2088 
  2089 * Generalized Isar history, with support for linear undo, direct state
  2090 addressing etc.
  2091 
  2092 * Changed defaults for unify configuration options:
  2093 
  2094   unify_trace_bound = 50 (formerly 25)
  2095   unify_search_bound = 60 (formerly 30)
  2096 
  2097 * Different bookkeeping for code equations (INCOMPATIBILITY):
  2098 
  2099   a) On theory merge, the last set of code equations for a particular
  2100      constant is taken (in accordance with the policy applied by other
  2101      parts of the code generator framework).
  2102 
  2103   b) Code equations stemming from explicit declarations (e.g. code
  2104      attribute) gain priority over default code equations stemming
  2105      from definition, primrec, fun etc.
  2106 
  2107 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
  2108 
  2109 * Unified theorem tables for both code generators.  Thus [code
  2110 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
  2111 
  2112 * Command 'find_consts' searches for constants based on type and name
  2113 patterns, e.g.
  2114 
  2115     find_consts "_ => bool"
  2116 
  2117 By default, matching is against subtypes, but it may be restricted to
  2118 the whole type.  Searching by name is possible.  Multiple queries are
  2119 conjunctive and queries may be negated by prefixing them with a
  2120 hyphen:
  2121 
  2122     find_consts strict: "_ => bool" name: "Int" -"int => int"
  2123 
  2124 * New 'find_theorems' criterion "solves" matches theorems that
  2125 directly solve the current goal (modulo higher-order unification).
  2126 
  2127 * Auto solve feature for main theorem statements: whenever a new goal
  2128 is stated, "find_theorems solves" is called; any theorems that could
  2129 solve the lemma directly are listed as part of the goal state.
  2130 Cf. associated options in Proof General Isabelle settings menu,
  2131 enabled by default, with reasonable timeout for pathological cases of
  2132 higher-order unification.
  2133 
  2134 
  2135 *** Document preparation ***
  2136 
  2137 * Antiquotation @{lemma} now imitates a regular terminal proof,
  2138 demanding keyword 'by' and supporting the full method expression
  2139 syntax just like the Isar command 'by'.
  2140 
  2141 
  2142 *** HOL ***
  2143 
  2144 * Integrated main parts of former image HOL-Complex with HOL.  Entry
  2145 points Main and Complex_Main remain as before.
  2146 
  2147 * Logic image HOL-Plain provides a minimal HOL with the most important
  2148 tools available (inductive, datatype, primrec, ...).  This facilitates
  2149 experimentation and tool development.  Note that user applications
  2150 (and library theories) should never refer to anything below theory
  2151 Main, as before.
  2152 
  2153 * Logic image HOL-Main stops at theory Main, and thus facilitates
  2154 experimentation due to shorter build times.
  2155 
  2156 * Logic image HOL-NSA contains theories of nonstandard analysis which
  2157 were previously part of former HOL-Complex.  Entry point Hyperreal
  2158 remains valid, but theories formerly using Complex_Main should now use
  2159 new entry point Hypercomplex.
  2160 
  2161 * Generic ATP manager for Sledgehammer, based on ML threads instead of
  2162 Posix processes.  Avoids potentially expensive forking of the ML
  2163 process.  New thread-based implementation also works on non-Unix
  2164 platforms (Cygwin).  Provers are no longer hardwired, but defined
  2165 within the theory via plain ML wrapper functions.  Basic Sledgehammer
  2166 commands are covered in the isar-ref manual.
  2167 
  2168 * Wrapper scripts for remote SystemOnTPTP service allows to use
  2169 sledgehammer without local ATP installation (Vampire etc.). Other
  2170 provers may be included via suitable ML wrappers, see also
  2171 src/HOL/ATP_Linkup.thy.
  2172 
  2173 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
  2174 menu.
  2175 
  2176 * The metis method no longer fails because the theorem is too trivial
  2177 (contains the empty clause).
  2178 
  2179 * The metis method now fails in the usual manner, rather than raising
  2180 an exception, if it determines that it cannot prove the theorem.
  2181 
  2182 * Method "coherent" implements a prover for coherent logic (see also
  2183 src/Tools/coherent.ML).
  2184 
  2185 * Constants "undefined" and "default" replace "arbitrary".  Usually
  2186 "undefined" is the right choice to replace "arbitrary", though
  2187 logically there is no difference.  INCOMPATIBILITY.
  2188 
  2189 * Command "value" now integrates different evaluation mechanisms.  The
  2190 result of the first successful evaluation mechanism is printed.  In
  2191 square brackets a particular named evaluation mechanisms may be
  2192 specified (currently, [SML], [code] or [nbe]).  See further
  2193 src/HOL/ex/Eval_Examples.thy.
  2194 
  2195 * Normalization by evaluation now allows non-leftlinear equations.
  2196 Declare with attribute [code nbe].
  2197 
  2198 * Methods "case_tac" and "induct_tac" now refer to the very same rules
  2199 as the structured Isar versions "cases" and "induct", cf. the
  2200 corresponding "cases" and "induct" attributes.  Mutual induction rules
  2201 are now presented as a list of individual projections
  2202 (e.g. foo_bar.inducts for types foo and bar); the old format with
  2203 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
  2204 rare situations a different rule is selected --- notably nested tuple
  2205 elimination instead of former prod.exhaust: use explicit (case_tac t
  2206 rule: prod.exhaust) here.
  2207 
  2208 * Attributes "cases", "induct", "coinduct" support "del" option.
  2209 
  2210 * Removed fact "case_split_thm", which duplicates "case_split".
  2211 
  2212 * The option datatype has been moved to a new theory Option.  Renamed
  2213 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
  2214 
  2215 * New predicate "strict_mono" classifies strict functions on partial
  2216 orders.  With strict functions on linear orders, reasoning about
  2217 (in)equalities is facilitated by theorems "strict_mono_eq",
  2218 "strict_mono_less_eq" and "strict_mono_less".
  2219 
  2220 * Some set operations are now proper qualified constants with
  2221 authentic syntax.  INCOMPATIBILITY:
  2222 
  2223     op Int ~>   Set.Int
  2224     op Un ~>    Set.Un
  2225     INTER ~>    Set.INTER
  2226     UNION ~>    Set.UNION
  2227     Inter ~>    Set.Inter
  2228     Union ~>    Set.Union
  2229     {} ~>       Set.empty
  2230     UNIV ~>     Set.UNIV
  2231 
  2232 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  2233 theory Set.
  2234 
  2235 * Auxiliary class "itself" has disappeared -- classes without any
  2236 parameter are treated as expected by the 'class' command.
  2237 
  2238 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  2239 
  2240 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  2241 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  2242 
  2243 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  2244 method "approximation".  It proves formulas on real values by using
  2245 interval arithmetic.  In the formulas are also the transcendental
  2246 functions sin, cos, tan, atan, ln, exp and the constant pi are
  2247 allowed. For examples see
  2248 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  2249 
  2250 * Theory "Reflection" now resides in HOL/Library.
  2251 
  2252 * Entry point to Word library now simply named "Word".
  2253 INCOMPATIBILITY.
  2254 
  2255 * Made source layout more coherent with logical distribution
  2256 structure:
  2257 
  2258     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  2259     src/HOL/Library/Code_Message.thy ~> src/HOL/
  2260     src/HOL/Library/GCD.thy ~> src/HOL/
  2261     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  2262     src/HOL/Library/Parity.thy ~> src/HOL/
  2263     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  2264     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  2265     src/HOL/Real/Lubs.thy ~> src/HOL/
  2266     src/HOL/Real/PReal.thy ~> src/HOL/
  2267     src/HOL/Real/Rational.thy ~> src/HOL/
  2268     src/HOL/Real/RComplete.thy ~> src/HOL/
  2269     src/HOL/Real/RealDef.thy ~> src/HOL/
  2270     src/HOL/Real/RealPow.thy ~> src/HOL/
  2271     src/HOL/Real/Real.thy ~> src/HOL/
  2272     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  2273     src/HOL/Complex/Complex.thy ~> src/HOL/
  2274     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  2275     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  2276     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  2277     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  2278     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  2279     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  2280     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  2281     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  2282     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  2283     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  2284     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  2285     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  2286     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  2287     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  2288     src/HOL/Real/Float ~> src/HOL/Library/
  2289     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  2290     src/HOL/Real/RealVector.thy ~> src/HOL/
  2291 
  2292     src/HOL/arith_data.ML ~> src/HOL/Tools
  2293     src/HOL/hologic.ML ~> src/HOL/Tools
  2294     src/HOL/simpdata.ML ~> src/HOL/Tools
  2295     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  2296     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  2297     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  2298     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  2299     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  2300     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  2301     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  2302 
  2303     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  2304     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  2305     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  2306     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  2307     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  2308     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  2309 
  2310 * If methods "eval" and "evaluation" encounter a structured proof
  2311 state with !!/==>, only the conclusion is evaluated to True (if
  2312 possible), avoiding strange error messages.
  2313 
  2314 * Method "sizechange" automates termination proofs using (a
  2315 modification of) the size-change principle.  Requires SAT solver.  See
  2316 src/HOL/ex/Termination.thy for examples.
  2317 
  2318 * Simplifier: simproc for let expressions now unfolds if bound
  2319 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  2320 
  2321 * Method "arith": Linear arithmetic now ignores all inequalities when
  2322 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  2323 
  2324 * New attribute "arith" for facts that should always be used
  2325 automatically by arithmetic. It is intended to be used locally in
  2326 proofs, e.g.
  2327 
  2328   assumes [arith]: "x > 0"
  2329 
  2330 Global usage is discouraged because of possible performance impact.
  2331 
  2332 * New classes "top" and "bot" with corresponding operations "top" and
  2333 "bot" in theory Orderings; instantiation of class "complete_lattice"
  2334 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  2335 
  2336 * Changed definition lemma "less_fun_def" in order to provide an
  2337 instance for preorders on functions; use lemma "less_le" instead.
  2338 INCOMPATIBILITY.
  2339 
  2340 * Theory Orderings: class "wellorder" moved here, with explicit
  2341 induction rule "less_induct" as assumption.  For instantiation of
  2342 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  2343 INCOMPATIBILITY.
  2344 
  2345 * Theory Orderings: added class "preorder" as superclass of "order".
  2346 INCOMPATIBILITY: Instantiation proofs for order, linorder
  2347 etc. slightly changed.  Some theorems named order_class.* now named
  2348 preorder_class.*.
  2349 
  2350 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  2351 "diag" to "Id_on".
  2352 
  2353 * Theory Finite_Set: added a new fold combinator of type
  2354 
  2355   ('a => 'b => 'b) => 'b => 'a set => 'b
  2356 
  2357 Occasionally this is more convenient than the old fold combinator
  2358 which is now defined in terms of the new one and renamed to
  2359 fold_image.
  2360 
  2361 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  2362 and "ring_simps" have been replaced by "algebra_simps" (which can be
  2363 extended with further lemmas!).  At the moment both still exist but
  2364 the former will disappear at some point.
  2365 
  2366 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  2367 class recpower.  Type-specific simp rules for various recpower types
  2368 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  2369 
  2370 rat_power_0    -> power_0
  2371 rat_power_Suc  -> power_Suc
  2372 realpow_0      -> power_0
  2373 realpow_Suc    -> power_Suc
  2374 complexpow_0   -> power_0
  2375 complexpow_Suc -> power_Suc
  2376 power_poly_0   -> power_0
  2377 power_poly_Suc -> power_Suc
  2378 
  2379 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  2380 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  2381 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  2382 of lemmas from Divides has been generalized from nat to class
  2383 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  2384 renames resulting from duplicate elimination:
  2385 
  2386     dvd_def_mod ~>          dvd_eq_mod_eq_0
  2387     zero_dvd_iff ~>         dvd_0_left_iff
  2388     dvd_0 ~>                dvd_0_right
  2389     DIVISION_BY_ZERO_DIV ~> div_by_0
  2390     DIVISION_BY_ZERO_MOD ~> mod_by_0
  2391     mult_div ~>             div_mult_self2_is_id
  2392     mult_mod ~>             mod_mult_self2_is_0
  2393 
  2394 * Theory IntDiv: removed many lemmas that are instances of class-based
  2395 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  2396 rename old lemmas as follows:
  2397 
  2398 dvd_diff               -> nat_dvd_diff
  2399 dvd_zminus_iff         -> dvd_minus_iff
  2400 mod_add1_eq            -> mod_add_eq
  2401 mod_mult1_eq           -> mod_mult_right_eq
  2402 mod_mult1_eq'          -> mod_mult_left_eq
  2403 mod_mult_distrib_mod   -> mod_mult_eq
  2404 nat_mod_add_left_eq    -> mod_add_left_eq
  2405 nat_mod_add_right_eq   -> mod_add_right_eq
  2406 nat_mod_div_trivial    -> mod_div_trivial
  2407 nat_mod_mod_trivial    -> mod_mod_trivial
  2408 zdiv_zadd_self1        -> div_add_self1
  2409 zdiv_zadd_self2        -> div_add_self2
  2410 zdiv_zmult_self1       -> div_mult_self2_is_id
  2411 zdiv_zmult_self2       -> div_mult_self1_is_id
  2412 zdvd_triv_left         -> dvd_triv_left
  2413 zdvd_triv_right        -> dvd_triv_right
  2414 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  2415 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  2416 zmod_zadd_left_eq      -> mod_add_left_eq
  2417 zmod_zadd_right_eq     -> mod_add_right_eq
  2418 zmod_zadd_self1        -> mod_add_self1
  2419 zmod_zadd_self2        -> mod_add_self2
  2420 zmod_zadd1_eq          -> mod_add_eq
  2421 zmod_zdiff1_eq         -> mod_diff_eq
  2422 zmod_zdvd_zmod         -> mod_mod_cancel
  2423 zmod_zmod_cancel       -> mod_mod_cancel
  2424 zmod_zmult_self1       -> mod_mult_self2_is_0
  2425 zmod_zmult_self2       -> mod_mult_self1_is_0
  2426 zmod_1                 -> mod_by_1
  2427 zdiv_1                 -> div_by_1
  2428 zdvd_abs1              -> abs_dvd_iff
  2429 zdvd_abs2              -> dvd_abs_iff
  2430 zdvd_refl              -> dvd_refl
  2431 zdvd_trans             -> dvd_trans
  2432 zdvd_zadd              -> dvd_add
  2433 zdvd_zdiff             -> dvd_diff
  2434 zdvd_zminus_iff        -> dvd_minus_iff
  2435 zdvd_zminus2_iff       -> minus_dvd_iff
  2436 zdvd_zmultD            -> dvd_mult_right
  2437 zdvd_zmultD2           -> dvd_mult_left
  2438 zdvd_zmult_mono        -> mult_dvd_mono
  2439 zdvd_0_right           -> dvd_0_right
  2440 zdvd_0_left            -> dvd_0_left_iff
  2441 zdvd_1_left            -> one_dvd
  2442 zminus_dvd_iff         -> minus_dvd_iff
  2443 
  2444 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  2445 
  2446 * The real numbers offer decimal input syntax: 12.34 is translated
  2447 into 1234/10^2. This translation is not reversed upon output.
  2448 
  2449 * Theory Library/Polynomial defines an abstract type 'a poly of
  2450 univariate polynomials with coefficients of type 'a.  In addition to
  2451 the standard ring operations, it also supports div and mod.  Code
  2452 generation is also supported, using list-style constructors.
  2453 
  2454 * Theory Library/Inner_Product defines a class of real_inner for real
  2455 inner product spaces, with an overloaded operation inner :: 'a => 'a
  2456 => real.  Class real_inner is a subclass of real_normed_vector from
  2457 theory RealVector.
  2458 
  2459 * Theory Library/Product_Vector provides instances for the product
  2460 type 'a * 'b of several classes from RealVector and Inner_Product.
  2461 Definitions of addition, subtraction, scalar multiplication, norms,
  2462 and inner products are included.
  2463 
  2464 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  2465 addition to the field operations, numerals and case syntax are also
  2466 supported.
  2467 
  2468 * Theory Library/Diagonalize provides constructive version of Cantor's
  2469 first diagonalization argument.
  2470 
  2471 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  2472 zlcm (for int); carried together from various gcd/lcm developements in
  2473 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  2474 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  2475 may recover tupled syntax as follows:
  2476 
  2477     hide (open) const gcd
  2478     abbreviation gcd where
  2479       "gcd == (%(a, b). GCD.gcd a b)"
  2480     notation (output)
  2481       GCD.gcd ("gcd '(_, _')")
  2482 
  2483 The same works for lcm, zgcd, zlcm.
  2484 
  2485 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  2486 instantiations for algebraic structures.  Removed some duplicate
  2487 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  2488 
  2489 * ML antiquotation @{code} takes a constant as argument and generates
  2490 corresponding code in background and inserts name of the corresponding
  2491 resulting ML value/function/datatype constructor binding in place.
  2492 All occurrences of @{code} with a single ML block are generated
  2493 simultaneously.  Provides a generic and safe interface for
  2494 instrumentalizing code generation.  See
  2495 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  2496 In future you ought to refrain from ad-hoc compiling generated SML
  2497 code on the ML toplevel.  Note that (for technical reasons) @{code}
  2498 cannot refer to constants for which user-defined serializations are
  2499 set.  Refer to the corresponding ML counterpart directly in that
  2500 cases.
  2501 
  2502 * Command 'rep_datatype': instead of theorem names the command now
  2503 takes a list of terms denoting the constructors of the type to be
  2504 represented as datatype.  The characteristic theorems have to be
  2505 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  2506 have disappeared in favour of existing ones:
  2507 
  2508     unit_induct                 ~> unit.induct
  2509     prod_induct                 ~> prod.induct
  2510     sum_induct                  ~> sum.induct
  2511     Suc_Suc_eq                  ~> nat.inject
  2512     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  2513 
  2514 
  2515 *** HOL-Algebra ***
  2516 
  2517 * New locales for orders and lattices where the equivalence relation
  2518 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  2519 locales use a record structure with field eq for the equivalence.
  2520 
  2521 * New theory of factorial domains.
  2522 
  2523 * Units_l_inv and Units_r_inv are now simp rules by default.
  2524 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  2525 and/or r_inv will now also require deletion of these lemmas.
  2526 
  2527 * Renamed the following theorems, INCOMPATIBILITY:
  2528 
  2529 UpperD ~> Upper_memD
  2530 LowerD ~> Lower_memD
  2531 least_carrier ~> least_closed
  2532 greatest_carrier ~> greatest_closed
  2533 greatest_Lower_above ~> greatest_Lower_below
  2534 one_zero ~> carrier_one_zero
  2535 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  2536 
  2537 
  2538 *** HOL-Nominal ***
  2539 
  2540 * Nominal datatypes can now contain type-variables.
  2541 
  2542 * Commands 'nominal_inductive' and 'equivariance' work with local
  2543 theory targets.
  2544 
  2545 * Nominal primrec can now works with local theory targets and its
  2546 specification syntax now conforms to the general format as seen in
  2547 'inductive' etc.
  2548 
  2549 * Method "perm_simp" honours the standard simplifier attributes
  2550 (no_asm), (no_asm_use) etc.
  2551 
  2552 * The new predicate #* is defined like freshness, except that on the
  2553 left hand side can be a set or list of atoms.
  2554 
  2555 * Experimental command 'nominal_inductive2' derives strong induction
  2556 principles for inductive definitions.  In contrast to
  2557 'nominal_inductive', which can only deal with a fixed number of
  2558 binders, it can deal with arbitrary expressions standing for sets of
  2559 atoms to be avoided.  The only inductive definition we have at the
  2560 moment that needs this generalisation is the typing rule for Lets in
  2561 the algorithm W:
  2562 
  2563  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  2564  -----------------------------------------------------------------
  2565          Gamma |- Let x be t1 in t2 : T2
  2566 
  2567 In this rule one wants to avoid all the binders that are introduced by
  2568 "close Gamma T1".  We are looking for other examples where this
  2569 feature might be useful.  Please let us know.
  2570 
  2571 
  2572 *** HOLCF ***
  2573 
  2574 * Reimplemented the simplification procedure for proving continuity
  2575 subgoals.  The new simproc is extensible; users can declare additional
  2576 continuity introduction rules with the attribute [cont2cont].
  2577 
  2578 * The continuity simproc now uses a different introduction rule for
  2579 solving continuity subgoals on terms with lambda abstractions.  In
  2580 some rare cases the new simproc may fail to solve subgoals that the
  2581 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  2582 Potential INCOMPATIBILITY.
  2583 
  2584 * Command 'fixrec': specification syntax now conforms to the general
  2585 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  2586 examples.  INCOMPATIBILITY.
  2587 
  2588 
  2589 *** ZF ***
  2590 
  2591 * Proof of Zorn's Lemma for partial orders.
  2592 
  2593 
  2594 *** ML ***
  2595 
  2596 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  2597 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  2598 depends on multithreading, so timouts will not work before Poly/ML
  2599 5.2.1!
  2600 
  2601 * High-level support for concurrent ML programming, see
  2602 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  2603 particularly convenient to organize independent functional
  2604 computations.  The concept of "synchronized variables" provides a
  2605 higher-order interface for components with shared state, avoiding the
  2606 delicate details of mutexes and condition variables.  (Requires
  2607 Poly/ML 5.2.1 or later.)
  2608 
  2609 * ML bindings produced via Isar commands are stored within the Isar
  2610 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  2611 become thread-safe and work with undo as expected (concerning
  2612 top-level bindings, not side-effects on global references).
  2613 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  2614 compiler at runtime; really global bindings need to be given outside a
  2615 theory.  (Requires Poly/ML 5.2 or later.)
  2616 
  2617 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  2618 context.  Top-level ML bindings are stored within the proof context in
  2619 a purely sequential fashion, disregarding the nested proof structure.
  2620 ML bindings introduced by 'ML_prf' are discarded at the end of the
  2621 proof.  (Requires Poly/ML 5.2 or later.)
  2622 
  2623 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  2624 and Method.setup, as well as Isar commands 'attribute_setup' and
  2625 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  2626 existing code accordingly, or use plain 'setup' together with old
  2627 Method.add_method.
  2628 
  2629 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  2630 to 'a -> thm, while results are always tagged with an authentic oracle
  2631 name.  The Isar command 'oracle' is now polymorphic, no argument type
  2632 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  2633 accordingly.  Note that extra performance may be gained by producing
  2634 the cterm carefully, avoiding slow Thm.cterm_of.
  2635 
  2636 * Simplified interface for defining document antiquotations via
  2637 ThyOutput.antiquotation, ThyOutput.output, and optionally
  2638 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  2639 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  2640 examples.
  2641 
  2642 * More systematic treatment of long names, abstract name bindings, and
  2643 name space operations.  Basic operations on qualified names have been
  2644 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  2645 Long_Name.append.  Old type bstring has been mostly replaced by
  2646 abstract type binding (see structure Binding), which supports precise
  2647 qualification by packages and local theory targets, as well as proper
  2648 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  2649 bstring values into Binding.name, or better pass through abstract
  2650 bindings everywhere.  See further src/Pure/General/long_name.ML,
  2651 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  2652 
  2653 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  2654 LocalTheory.note etc.) now refer to the *full* internal name, not the
  2655 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  2656 
  2657 * Disposed old type and term read functions (Sign.read_def_typ,
  2658 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  2659 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  2660 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  2661 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  2662 resort for legacy applications.
  2663 
  2664 * Disposed old declarations, tactics, tactic combinators that refer to
  2665 the simpset or claset of an implicit theory (such as Addsimps,
  2666 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  2667 embedded ML text, or local_simpset_of with a proper context passed as
  2668 explicit runtime argument.
  2669 
  2670 * Rules and tactics that read instantiations (read_instantiate,
  2671 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  2672 context, which is required for parsing and type-checking.  Moreover,
  2673 the variables are specified as plain indexnames, not string encodings
  2674 thereof.  INCOMPATIBILITY.
  2675 
  2676 * Generic Toplevel.add_hook interface allows to analyze the result of
  2677 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  2678 for theorem dependency output of transactions resulting in a new
  2679 theory state.
  2680 
  2681 * ML antiquotations: block-structured compilation context indicated by
  2682 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  2683 
  2684   @{binding name}                         - basic name binding
  2685   @{let ?pat = term}                      - term abbreviation (HO matching)
  2686   @{note name = fact}                     - fact abbreviation
  2687   @{thm fact}                             - singleton fact (with attributes)
  2688   @{thms fact}                            - general fact (with attributes)
  2689   @{lemma prop by method}                 - singleton goal
  2690   @{lemma prop by meth1 meth2}            - singleton goal
  2691   @{lemma prop1 ... propN by method}      - general goal
  2692   @{lemma prop1 ... propN by meth1 meth2} - general goal
  2693   @{lemma (open) ...}                     - open derivation
  2694 
  2695 
  2696 *** System ***
  2697 
  2698 * The Isabelle "emacs" tool provides a specific interface to invoke
  2699 Proof General / Emacs, with more explicit failure if that is not
  2700 installed (the old isabelle-interface script silently falls back on
  2701 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  2702 installation location of the Proof General distribution.
  2703 
  2704 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  2705 the Isabelle process into a JVM/Scala application.  See
  2706 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  2707 process wrapper has been discontinued.)
  2708 
  2709 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  2710 
  2711 * Various status messages (with exact source position information) are
  2712 emitted, if proper markup print mode is enabled.  This allows
  2713 user-interface components to provide detailed feedback on internal
  2714 prover operations.
  2715 
  2716 
  2717 
  2718 New in Isabelle2008 (June 2008)
  2719 -------------------------------
  2720 
  2721 *** General ***
  2722 
  2723 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  2724 and updated, with formally checked references as hyperlinks.
  2725 
  2726 * Theory loader: use_thy (and similar operations) no longer set the
  2727 implicit ML context, which was occasionally hard to predict and in
  2728 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  2729 provides a proper context already.
  2730 
  2731 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2732 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  2733 'use' within a theory file will do the job.
  2734 
  2735 * Name space merge now observes canonical order, i.e. the second space
  2736 is inserted into the first one, while existing entries in the first
  2737 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  2738 swap theory imports.
  2739 
  2740 * Syntax: symbol \<chi> is now considered a letter.  Potential
  2741 INCOMPATIBILITY in identifier syntax etc.
  2742 
  2743 * Outer syntax: string tokens no longer admit escaped white space,
  2744 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  2745 white space without escapes.
  2746 
  2747 * Outer syntax: string tokens may contain arbitrary character codes
  2748 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  2749 "foo_bar".
  2750 
  2751 
  2752 *** Pure ***
  2753 
  2754 * Context-dependent token translations.  Default setup reverts locally
  2755 fixed variables, and adds hilite markup for undeclared frees.
  2756 
  2757 * Unused theorems can be found using the new command 'unused_thms'.
  2758 There are three ways of invoking it:
  2759 
  2760 (1) unused_thms
  2761      Only finds unused theorems in the current theory.
  2762 
  2763 (2) unused_thms thy_1 ... thy_n -
  2764      Finds unused theorems in the current theory and all of its ancestors,
  2765      excluding the theories thy_1 ... thy_n and all of their ancestors.
  2766 
  2767 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  2768      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  2769      their ancestors, excluding the theories thy_1 ... thy_n and all of
  2770      their ancestors.
  2771 
  2772 In order to increase the readability of the list produced by
  2773 unused_thms, theorems that have been created by a particular instance
  2774 of a theory command such as 'inductive' or 'function' are considered
  2775 to belong to the same "group", meaning that if at least one theorem in
  2776 this group is used, the other theorems in the same group are no longer
  2777 reported as unused.  Moreover, if all theorems in the group are
  2778 unused, only one theorem in the group is displayed.
  2779 
  2780 Note that proof objects have to be switched on in order for
  2781 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  2782 usually the case when using Proof General with the default settings).
  2783 
  2784 * Authentic naming of facts disallows ad-hoc overwriting of previous
  2785 theorems within the same name space.  INCOMPATIBILITY, need to remove
  2786 duplicate fact bindings, or even accidental fact duplications.  Note
  2787 that tools may maintain dynamically scoped facts systematically, using
  2788 PureThy.add_thms_dynamic.
  2789 
  2790 * Command 'hide' now allows to hide from "fact" name space as well.
  2791 
  2792 * Eliminated destructive theorem database, simpset, claset, and
  2793 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  2794 update of theories within ML code.
  2795 
  2796 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  2797 INCOMPATIBILITY, object-logics depending on former Pure require
  2798 additional setup PureThy.old_appl_syntax_setup; object-logics
  2799 depending on former CPure need to refer to Pure.
  2800 
  2801 * Commands 'use' and 'ML' are now purely functional, operating on
  2802 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  2803 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  2804 INCOMPATIBILITY.
  2805 
  2806 * Command 'setup': discontinued implicit version with ML reference.
  2807 
  2808 * Instantiation target allows for simultaneous specification of class
  2809 instance operations together with an instantiation proof.
  2810 Type-checking phase allows to refer to class operations uniformly.
  2811 See src/HOL/Complex/Complex.thy for an Isar example and
  2812 src/HOL/Library/Eval.thy for an ML example.
  2813 
  2814 * Indexing of literal facts: be more serious about including only
  2815 facts from the visible specification/proof context, but not the
  2816 background context (locale etc.).  Affects `prop` notation and method
  2817 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  2818 situations.
  2819 
  2820 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  2821 "(open)" option, which used to expose internal bound variables to the
  2822 proof text.
  2823 
  2824 * Isar statements: removed obsolete case "rule_context".
  2825 INCOMPATIBILITY, better use explicit fixes/assumes.
  2826 
  2827 * Locale proofs: default proof step now includes 'unfold_locales';
  2828 hence 'proof' without argument may be used to unfold locale
  2829 predicates.
  2830 
  2831 
  2832 *** Document preparation ***
  2833 
  2834 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  2835 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  2836 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  2837 spot); renamed link color from "darkblue" to "linkcolor" (default
  2838 value unchanged, can be redefined via \definecolor); no longer sets
  2839 "a4paper" option (unnecessary or even intrusive).
  2840 
  2841 * Antiquotation @{lemma A method} proves proposition A by the given
  2842 method (either a method name or a method name plus (optional) method
  2843 arguments in parentheses) and prints A just like @{prop A}.
  2844 
  2845 
  2846 *** HOL ***
  2847 
  2848 * New primrec package.  Specification syntax conforms in style to
  2849 definition/function/....  No separate induction rule is provided.  The
  2850 "primrec" command distinguishes old-style and new-style specifications
  2851 by syntax.  The former primrec package is now named OldPrimrecPackage.
  2852 When adjusting theories, beware: constants stemming from new-style
  2853 primrec specifications have authentic syntax.
  2854 
  2855 * Metis prover is now an order of magnitude faster, and also works
  2856 with multithreading.
  2857 
  2858 * Metis: the maximum number of clauses that can be produced from a
  2859 theorem is now given by the attribute max_clauses.  Theorems that
  2860 exceed this number are ignored, with a warning printed.
  2861 
  2862 * Sledgehammer no longer produces structured proofs by default. To
  2863 enable, declare [[sledgehammer_full = true]].  Attributes
  2864 reconstruction_modulus, reconstruction_sorts renamed
  2865 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  2866 
  2867 * Method "induct_scheme" derives user-specified induction rules
  2868 from well-founded induction and completeness of patterns. This factors
  2869 out some operations that are done internally by the function package
  2870 and makes them available separately.  See
  2871 src/HOL/ex/Induction_Scheme.thy for examples.
  2872 
  2873 * More flexible generation of measure functions for termination
  2874 proofs: Measure functions can be declared by proving a rule of the
  2875 form "is_measure f" and giving it the [measure_function] attribute.
  2876 The "is_measure" predicate is logically meaningless (always true), and
  2877 just guides the heuristic.  To find suitable measure functions, the
  2878 termination prover sets up the goal "is_measure ?f" of the appropriate
  2879 type and generates all solutions by prolog-style backwards proof using
  2880 the declared rules.
  2881 
  2882 This setup also deals with rules like 
  2883 
  2884   "is_measure f ==> is_measure (list_size f)"
  2885 
  2886 which accommodates nested datatypes that recurse through lists.
  2887 Similar rules are predeclared for products and option types.
  2888 
  2889 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  2890 
  2891   INCOMPATIBILITIES:
  2892 
  2893   - Definitions of overloaded constants on sets have to be replaced by
  2894     definitions on => and bool.
  2895 
  2896   - Some definitions of overloaded operators on sets can now be proved
  2897     using the definitions of the operators on => and bool.  Therefore,
  2898     the following theorems have been renamed:
  2899 
  2900       subset_def   -> subset_eq
  2901       psubset_def  -> psubset_eq
  2902       set_diff_def -> set_diff_eq
  2903       Compl_def    -> Compl_eq
  2904       Sup_set_def  -> Sup_set_eq
  2905       Inf_set_def  -> Inf_set_eq
  2906       sup_set_def  -> sup_set_eq
  2907       inf_set_def  -> inf_set_eq
  2908 
  2909   - Due to the incompleteness of the HO unification algorithm, some
  2910     rules such as subst may require manual instantiation, if some of
  2911     the unknowns in the rule is a set.
  2912 
  2913   - Higher order unification and forward proofs:
  2914     The proof pattern
  2915 
  2916       have "P (S::'a set)" <...>
  2917       then have "EX S. P S" ..
  2918 
  2919     no longer works (due to the incompleteness of the HO unification
  2920     algorithm) and must be replaced by the pattern
  2921 
  2922       have "EX S. P S"
  2923       proof
  2924         show "P S" <...>
  2925       qed
  2926 
  2927   - Calculational reasoning with subst (or similar rules):
  2928     The proof pattern
  2929 
  2930       have "P (S::'a set)" <...>
  2931       also have "S = T" <...>
  2932       finally have "P T" .
  2933 
  2934     no longer works (for similar reasons as the previous example) and
  2935     must be replaced by something like
  2936 
  2937       have "P (S::'a set)" <...>
  2938       moreover have "S = T" <...>
  2939       ultimately have "P T" by simp
  2940 
  2941   - Tactics or packages written in ML code:
  2942     Code performing pattern matching on types via
  2943 
  2944       Type ("set", [T]) => ...
  2945 
  2946     must be rewritten. Moreover, functions like strip_type or
  2947     binder_types no longer return the right value when applied to a
  2948     type of the form
  2949 
  2950       T1 => ... => Tn => U => bool
  2951 
  2952     rather than
  2953 
  2954       T1 => ... => Tn => U set
  2955 
  2956 * Merged theories Wellfounded_Recursion, Accessible_Part and
  2957 Wellfounded_Relations to theory Wellfounded.
  2958 
  2959 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  2960 
  2961 * Class finite no longer treats UNIV as class parameter.  Use class
  2962 enum from theory Library/Enum instead to achieve a similar effect.
  2963 INCOMPATIBILITY.
  2964 
  2965 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  2966 and "Cons".  INCOMPATIBILITY.
  2967 
  2968 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  2969 Potential INCOMPATIBILITY.
  2970 
  2971 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  2972 injective_fst_snd removed, use split_eta and prod_eqI instead.
  2973 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  2974 
  2975 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  2976 the same name in theory Orderings:
  2977 
  2978   less_trans
  2979   less_linear
  2980   le_imp_less_or_eq
  2981   le_less_trans
  2982   less_le_trans
  2983   less_not_sym
  2984   less_asym
  2985 
  2986 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  2987 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  2988 and different variable names.
  2989 
  2990 * Library/Option_ord.thy: Canonical order on option type.
  2991 
  2992 * Library/RBT.thy: Red-black trees, an efficient implementation of
  2993 finite maps.
  2994 
  2995 * Library/Countable.thy: Type class for countable types.
  2996 
  2997 * Theory Int: The representation of numerals has changed.  The infix
  2998 operator BIT and the bit datatype with constructors B0 and B1 have
  2999 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  3000 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  3001 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  3002 accordingly.
  3003 
  3004 * Theory Nat: definition of <= and < on natural numbers no longer
  3005 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  3006 le_def and less_def have disappeared.  Consider lemmas not_less
  3007 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  3008 
  3009 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  3010 (whose purpose mainly is for various fold_set functionals) have been
  3011 abandoned in favor of the existing algebraic classes
  3012 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  3013 lower_semilattice (resp. upper_semilattice) and linorder.
  3014 INCOMPATIBILITY.
  3015 
  3016 * Theory Transitive_Closure: induct and cases rules now declare proper
  3017 case_names ("base" and "step").  INCOMPATIBILITY.
  3018 
  3019 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  3020 lattices.  The form set-specific version is available as
  3021 Inductive.lfp_ordinal_induct_set.
  3022 
  3023 * Renamed theorems "power.simps" to "power_int.simps".
  3024 INCOMPATIBILITY.
  3025 
  3026 * Class semiring_div provides basic abstract properties of semirings
  3027 with division and modulo operations.  Subsumes former class dvd_mod.
  3028 
  3029 * Merged theories IntDef, Numeral and IntArith into unified theory
  3030 Int.  INCOMPATIBILITY.
  3031 
  3032 * Theory Library/Code_Index: type "index" now represents natural
  3033 numbers rather than integers.  INCOMPATIBILITY.
  3034 
  3035 * New class "uminus" with operation "uminus" (split of from class
  3036 "minus" which now only has operation "minus", binary).
  3037 INCOMPATIBILITY.
  3038 
  3039 * Constants "card", "internal_split", "option_map" now with authentic
  3040 syntax.  INCOMPATIBILITY.
  3041 
  3042 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  3043 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  3044 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  3045 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  3046 Sup_set_def, le_def, less_def, option_map_def now with object
  3047 equality.  INCOMPATIBILITY.
  3048 
  3049 * Records. Removed K_record, and replaced it by pure lambda term
  3050 %x. c. The simplifier setup is now more robust against eta expansion.
  3051 INCOMPATIBILITY: in cases explicitly referring to K_record.
  3052 
  3053 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  3054 
  3055 * Library/ListVector: new theory of arithmetic vector operations.
  3056 
  3057 * Library/Order_Relation: new theory of various orderings as sets of
  3058 pairs.  Defines preorders, partial orders, linear orders and
  3059 well-orders on sets and on types.
  3060 
  3061 
  3062 *** ZF ***
  3063 
  3064 * Renamed some theories to allow to loading both ZF and HOL in the
  3065 same session:
  3066 
  3067   Datatype  -> Datatype_ZF
  3068   Inductive -> Inductive_ZF
  3069   Int       -> Int_ZF
  3070   IntDiv    -> IntDiv_ZF
  3071   Nat       -> Nat_ZF
  3072   List      -> List_ZF
  3073   Main      -> Main_ZF
  3074 
  3075 INCOMPATIBILITY: ZF theories that import individual theories below
  3076 Main might need to be adapted.  Regular theory Main is still
  3077 available, as trivial extension of Main_ZF.
  3078 
  3079 
  3080 *** ML ***
  3081 
  3082 * ML within Isar: antiquotation @{const name} or @{const
  3083 name(typargs)} produces statically-checked Const term.
  3084 
  3085 * Functor NamedThmsFun: data is available to the user as dynamic fact
  3086 (of the same name).  Removed obsolete print command.
  3087 
  3088 * Removed obsolete "use_legacy_bindings" function.
  3089 
  3090 * The ``print mode'' is now a thread-local value derived from a global
  3091 template (the former print_mode reference), thus access becomes
  3092 non-critical.  The global print_mode reference is for session
  3093 management only; user-code should use print_mode_value,
  3094 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  3095 
  3096 * Functions system/system_out provide a robust way to invoke external
  3097 shell commands, with propagation of interrupts (requires Poly/ML
  3098 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  3099 
  3100 
  3101 *** System ***
  3102 
  3103 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  3104 in accordance with Proof General 3.7, which prefers GNU emacs.
  3105 
  3106 * isatool tty runs Isabelle process with plain tty interaction;
  3107 optional line editor may be specified via ISABELLE_LINE_EDITOR
  3108 setting, the default settings attempt to locate "ledit" and "rlwrap".
  3109 
  3110 * isatool browser now works with Cygwin as well, using general
  3111 "javapath" function defined in Isabelle process environment.
  3112 
  3113 * YXML notation provides a simple and efficient alternative to
  3114 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  3115 isatool yxml as described in the Isabelle system manual.
  3116 
  3117 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  3118 provides general wrapper for managing an Isabelle process in a robust
  3119 fashion, with ``cooked'' output from stdin/stderr.
  3120 
  3121 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  3122 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  3123 
  3124 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  3125 way of changing the user's settings is via
  3126 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  3127 script.
  3128 
  3129 * Multithreading.max_threads := 0 refers to the number of actual CPU
  3130 cores of the underlying machine, which is a good starting point for
  3131 optimal performance tuning.  The corresponding usedir option -M allows
  3132 "max" as an alias for "0".  WARNING: does not work on certain versions
  3133 of Mac OS (with Poly/ML 5.1).
  3134 
  3135 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  3136 adverse effect of Isabelle flooding interactive front-ends (notably
  3137 ProofGeneral / XEmacs).
  3138 
  3139 
  3140 
  3141 New in Isabelle2007 (November 2007)
  3142 -----------------------------------
  3143 
  3144 *** General ***
  3145 
  3146 * More uniform information about legacy features, notably a
  3147 warning/error of "Legacy feature: ...", depending on the state of the
  3148 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  3149 legacy features will disappear eventually.
  3150 
  3151 * Theory syntax: the header format ``theory A = B + C:'' has been
  3152 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  3153 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  3154 
  3155 * Theory syntax: the old non-Isar theory file format has been
  3156 discontinued altogether.  Note that ML proof scripts may still be used
  3157 with Isar theories; migration is usually quite simple with the ML
  3158 function use_legacy_bindings.  INCOMPATIBILITY.
  3159 
  3160 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  3161 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  3162 quotes.
  3163 
  3164 * Theory loader: be more serious about observing the static theory
  3165 header specifications (including optional directories), but not the
  3166 accidental file locations of previously successful loads.  The strict
  3167 update policy of former update_thy is now already performed by
  3168 use_thy, so the former has been removed; use_thys updates several
  3169 theories simultaneously, just as 'imports' within a theory header
  3170 specification, but without merging the results.  Potential
  3171 INCOMPATIBILITY: may need to refine theory headers and commands
  3172 ROOT.ML which depend on load order.
  3173 
  3174 * Theory loader: optional support for content-based file
  3175 identification, instead of the traditional scheme of full physical
  3176 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  3177 (cf. the system manual).  The new scheme allows to work with
  3178 non-finished theories in persistent session images, such that source
  3179 files may be moved later on without requiring reloads.
  3180 
  3181 * Theory loader: old-style ML proof scripts being *attached* to a thy
  3182 file (with the same base name as the theory) are considered a legacy
  3183 feature, which will disappear eventually. Even now, the theory loader
  3184 no longer maintains dependencies on such files.
  3185 
  3186 * Syntax: the scope for resolving ambiguities via type-inference is
  3187 now limited to individual terms, instead of whole simultaneous
  3188 specifications as before. This greatly reduces the complexity of the
  3189 syntax module and improves flexibility by separating parsing and
  3190 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  3191 'fixes' etc.) are required in rare situations.
  3192 
  3193 * Syntax: constants introduced by new-style packages ('definition',
  3194 'abbreviation' etc.) are passed through the syntax module in
  3195 ``authentic mode''. This means that associated mixfix annotations
  3196 really stick to such constants, independently of potential name space
  3197 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  3198 trees are represented slightly differently, may need to adapt syntax
  3199 translations accordingly. Use CONST marker in 'translations' and
  3200 @{const_syntax} antiquotation in 'parse_translation' etc.
  3201 
  3202 * Legacy goal package: reduced interface to the bare minimum required
  3203 to keep existing proof scripts running.  Most other user-level
  3204 functions are now part of the OldGoals structure, which is *not* open
  3205 by default (consider isatool expandshort before open OldGoals).
  3206 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  3207 these tend to cause confusion about the actual goal (!) context being
  3208 used here, which is not necessarily the same as the_context().
  3209 
  3210 * Command 'find_theorems': supports "*" wild-card in "name:"
  3211 criterion; "with_dups" option.  Certain ProofGeneral versions might
  3212 support a specific search form (see ProofGeneral/CHANGES).
  3213 
  3214 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  3215 by default, which means that "prems" (and also "fixed variables") are
  3216 suppressed from proof state output.  Note that the ProofGeneral
  3217 settings mechanism allows to change and save options persistently, but
  3218 older versions of Isabelle will fail to start up if a negative prems
  3219 limit is imposed.
  3220 
  3221 * Local theory targets may be specified by non-nested blocks of
  3222 ``context/locale/class ... begin'' followed by ``end''.  The body may
  3223 contain definitions, theorems etc., including any derived mechanism
  3224 that has been implemented on top of these primitives.  This concept
  3225 generalizes the existing ``theorem (in ...)'' towards more versatility
  3226 and scalability.
  3227 
  3228 * Proof General interface: proper undo of final 'end' command;
  3229 discontinued Isabelle/classic mode (ML proof scripts).
  3230 
  3231 
  3232 *** Document preparation ***
  3233 
  3234 * Added antiquotation @{theory name} which prints the given name,
  3235 after checking that it refers to a valid ancestor theory in the
  3236 current context.
  3237 
  3238 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  3239 check the given source text as ML type/structure, printing verbatim.
  3240 
  3241 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  3242 "c args == rhs" given in the current context.  (Any number of
  3243 arguments may be given on the LHS.)
  3244 
  3245 
  3246 *** Pure ***
  3247 
  3248 * The 'class' package offers a combination of axclass and locale to
  3249 achieve Haskell-like type classes in Isabelle.  Definitions and
  3250 theorems within a class context produce both relative results (with
  3251 implicit parameters according to the locale context), and polymorphic
  3252 constants with qualified polymorphism (according to the class
  3253 context).  Within the body context of a 'class' target, a separate
  3254 syntax layer ("user space type system") takes care of converting
  3255 between global polymorphic consts and internal locale representation.
  3256 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  3257 "isatool doc classes" provides a tutorial.
  3258 
  3259 * Generic code generator framework allows to generate executable
  3260 code for ML and Haskell (including Isabelle classes).  A short usage
  3261 sketch:
  3262 
  3263     internal compilation:
  3264         export_code <list of constants (term syntax)> in SML
  3265     writing SML code to a file:
  3266         export_code <list of constants (term syntax)> in SML <filename>
  3267     writing OCaml code to a file:
  3268         export_code <list of constants (term syntax)> in OCaml <filename>
  3269     writing Haskell code to a bunch of files:
  3270         export_code <list of constants (term syntax)> in Haskell <filename>
  3271 
  3272     evaluating closed propositions to True/False using code generation:
  3273         method ``eval''
  3274 
  3275 Reasonable default setup of framework in HOL.
  3276 
  3277 Theorem attributs for selecting and transforming function equations theorems:
  3278 
  3279     [code fun]:        select a theorem as function equation for a specific constant
  3280     [code fun del]:    deselect a theorem as function equation for a specific constant
  3281     [code inline]:     select an equation theorem for unfolding (inlining) in place
  3282     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  3283 
  3284 User-defined serializations (target in {SML, OCaml, Haskell}):
  3285 
  3286     code_const <and-list of constants (term syntax)>
  3287       {(target) <and-list of const target syntax>}+
  3288 
  3289     code_type <and-list of type constructors>
  3290       {(target) <and-list of type target syntax>}+
  3291 
  3292     code_instance <and-list of instances>
  3293       {(target)}+
  3294         where instance ::= <type constructor> :: <class>
  3295 
  3296     code_class <and_list of classes>
  3297       {(target) <and-list of class target syntax>}+
  3298         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  3299 
  3300 code_instance and code_class only are effective to target Haskell.
  3301 
  3302 For example usage see src/HOL/ex/Codegenerator.thy and
  3303 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  3304 generation from Isabelle/HOL theories is available via "isatool doc
  3305 codegen".
  3306 
  3307 * Code generator: consts in 'consts_code' Isar commands are now
  3308 referred to by usual term syntax (including optional type
  3309 annotations).
  3310 
  3311 * Command 'no_translations' removes translation rules from theory
  3312 syntax.
  3313 
  3314 * Overloaded definitions are now actually checked for acyclic
  3315 dependencies.  The overloading scheme is slightly more general than
  3316 that of Haskell98, although Isabelle does not demand an exact
  3317 correspondence to type class and instance declarations.
  3318 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  3319 exotic versions of overloading -- at the discretion of the user!
  3320 
  3321 Polymorphic constants are represented via type arguments, i.e. the
  3322 instantiation that matches an instance against the most general
  3323 declaration given in the signature.  For example, with the declaration
  3324 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  3325 as c(nat).  Overloading is essentially simultaneous structural
  3326 recursion over such type arguments.  Incomplete specification patterns
  3327 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  3328 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  3329 Command 'print_theory' outputs the normalized system of recursive
  3330 equations, see section "definitions".
  3331 
  3332 * Configuration options are maintained within the theory or proof
  3333 context (with name and type bool/int/string), providing a very simple
  3334 interface to a poor-man's version of general context data.  Tools may
  3335 declare options in ML (e.g. using Attrib.config_int) and then refer to
  3336 these values using Config.get etc.  Users may change options via an
  3337 associated attribute of the same name.  This form of context
  3338 declaration works particularly well with commands 'declare' or
  3339 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  3340 very easy to avoid global references, which would not observe Isar
  3341 toplevel undo/redo and fail to work with multithreading.
  3342 
  3343 Various global ML references of Pure and HOL have been turned into
  3344 configuration options:
  3345 
  3346   Unify.search_bound		unify_search_bound
  3347   Unify.trace_bound		unify_trace_bound
  3348   Unify.trace_simp		unify_trace_simp
  3349   Unify.trace_types		unify_trace_types
  3350   Simplifier.simp_depth_limit	simp_depth_limit
  3351   Blast.depth_limit		blast_depth_limit
  3352   DatatypeProp.dtK		datatype_distinctness_limit
  3353   fast_arith_neq_limit  	fast_arith_neq_limit
  3354   fast_arith_split_limit	fast_arith_split_limit
  3355 
  3356 * Named collections of theorems may be easily installed as context
  3357 data using the functor NamedThmsFun (see also
  3358 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  3359 attributes; there is also a toplevel print command.  This facility is
  3360 just a common case of general context data, which is the preferred way
  3361 for anything more complex than just a list of facts in canonical
  3362 order.
  3363 
  3364 * Isar: command 'declaration' augments a local theory by generic
  3365 declaration functions written in ML.  This enables arbitrary content
  3366 being added to the context, depending on a morphism that tells the
  3367 difference of the original declaration context wrt. the application
  3368 context encountered later on.
  3369 
  3370 * Isar: proper interfaces for simplification procedures.  Command
  3371 'simproc_setup' declares named simprocs (with match patterns, and body
  3372 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  3373 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  3374 
  3375 * Isar: an extra pair of brackets around attribute declarations
  3376 abbreviates a theorem reference involving an internal dummy fact,
  3377 which will be ignored later --- only the effect of the attribute on
  3378 the background context will persist.  This form of in-place
  3379 declarations is particularly useful with commands like 'declare' and
  3380 'using', for example ``have A using [[simproc a]] by simp''.
  3381 
  3382 * Isar: method "assumption" (and implicit closing of subproofs) now
  3383 takes simple non-atomic goal assumptions into account: after applying
  3384 an assumption as a rule the resulting subgoals are solved by atomic
  3385 assumption steps.  This is particularly useful to finish 'obtain'
  3386 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  3387 without referring to the original premise "!!x. P x ==> thesis" in the
  3388 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  3389 more permissive.
  3390 
  3391 * Isar: implicit use of prems from the Isar proof context is
  3392 considered a legacy feature.  Common applications like ``have A .''
  3393 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  3394 referencing facts explicitly here improves readability and
  3395 maintainability of proof texts.
  3396 
  3397 * Isar: improper proof element 'guess' is like 'obtain', but derives
  3398 the obtained context from the course of reasoning!  For example:
  3399 
  3400   assume "EX x y. A x & B y"   -- "any previous fact"
  3401   then guess x and y by clarify
  3402 
  3403 This technique is potentially adventurous, depending on the facts and
  3404 proof tools being involved here.
  3405 
  3406 * Isar: known facts from the proof context may be specified as literal
  3407 propositions, using ASCII back-quote syntax.  This works wherever
  3408 named facts used to be allowed so far, in proof commands, proof
  3409 methods, attributes etc.  Literal facts are retrieved from the context
  3410 according to unification of type and term parameters.  For example,
  3411 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  3412 theorems in the current context, then these are valid literal facts:
  3413 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  3414 
  3415 There is also a proof method "fact" which does the same composition
  3416 for explicit goal states, e.g. the following proof texts coincide with
  3417 certain special cases of literal facts:
  3418 
  3419   have "A" by fact                 ==  note `A`
  3420   have "A ==> B" by fact           ==  note `A ==> B`
  3421   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  3422   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  3423 
  3424 * Isar: ":" (colon) is no longer a symbolic identifier character in
  3425 outer syntax.  Thus symbolic identifiers may be used without
  3426 additional white space in declarations like this: ``assume *: A''.
  3427 
  3428 * Isar: 'print_facts' prints all local facts of the current context,
  3429 both named and unnamed ones.
  3430 
  3431 * Isar: 'def' now admits simultaneous definitions, e.g.:
  3432 
  3433   def x == "t" and y == "u"
  3434 
  3435 * Isar: added command 'unfolding', which is structurally similar to
  3436 'using', but affects both the goal state and facts by unfolding given
  3437 rewrite rules.  Thus many occurrences of the 'unfold' method or
  3438 'unfolded' attribute may be replaced by first-class proof text.
  3439 
  3440 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  3441 and command 'unfolding' now all support object-level equalities
  3442 (potentially conditional).  The underlying notion of rewrite rule is
  3443 analogous to the 'rule_format' attribute, but *not* that of the
  3444 Simplifier (which is usually more generous).
  3445 
  3446 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  3447 premises of a theorem by n. Useful in conjunction with drule.
  3448 
  3449 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  3450 method expression within a sandbox consisting of the first N
  3451 sub-goals, which need to exist.  For example, ``simp_all [3]''
  3452 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  3453 simplifies all new goals that emerge from applying rule foo to the
  3454 originally first one.
  3455 
  3456 * Isar: schematic goals are no longer restricted to higher-order
  3457 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  3458 expected.
  3459 
  3460 * Isar: the conclusion of a long theorem statement is now either
  3461 'shows' (a simultaneous conjunction, as before), or 'obtains'
  3462 (essentially a disjunction of cases with local parameters and
  3463 assumptions).  The latter allows to express general elimination rules
  3464 adequately; in this notation common elimination rules look like this:
  3465 
  3466   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  3467     assumes "EX x. P x"
  3468     obtains x where "P x"
  3469 
  3470   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  3471     assumes "A & B"
  3472     obtains A and B
  3473 
  3474   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  3475     assumes "A | B"
  3476     obtains
  3477       A
  3478     | B
  3479 
  3480 The subsequent classical rules even refer to the formal "thesis"
  3481 explicitly:
  3482 
  3483   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  3484     obtains "~ thesis"
  3485 
  3486   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  3487     obtains "thesis ==> something"
  3488 
  3489 The actual proof of an 'obtains' statement is analogous to that of the
  3490 Isar proof element 'obtain', only that there may be several cases.
  3491 Optional case names may be specified in parentheses; these will be
  3492 available both in the present proof and as annotations in the
  3493 resulting rule, for later use with the 'cases' method (cf. attribute
  3494 case_names).
  3495 
  3496 * Isar: the assumptions of a long theorem statement are available as
  3497 "assms" fact in the proof context.  This is more appropriate than the
  3498 (historical) "prems", which refers to all assumptions of the current
  3499 context, including those from the target locale, proof body etc.
  3500 
  3501 * Isar: 'print_statement' prints theorems from the current theory or
  3502 proof context in long statement form, according to the syntax of a
  3503 top-level lemma.
  3504 
  3505 * Isar: 'obtain' takes an optional case name for the local context
  3506 introduction rule (default "that").
  3507 
  3508 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  3509 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  3510 to occur.
  3511 
  3512 * Pure: syntax "CONST name" produces a fully internalized constant
  3513 according to the current context.  This is particularly useful for
  3514 syntax translations that should refer to internal constant
  3515 representations independently of name spaces.
  3516 
  3517 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  3518 instead of "FOO ". This allows multiple binder declarations to coexist
  3519 in the same context.  INCOMPATIBILITY.
  3520 
  3521 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  3522 primitive that also works in a locale context (both for constants and
  3523 fixed variables). Type declaration and internal syntactic representation
  3524 of given constants retrieved from the context. Likewise, the
  3525 'no_notation' command allows to remove given syntax annotations from the
  3526 current context.
  3527 
  3528 * Isar/locales: new derived specification elements 'axiomatization',
  3529 'definition', 'abbreviation', which support type-inference, admit
  3530 object-level specifications (equality, equivalence).  See also the
  3531 isar-ref manual.  Examples:
  3532 
  3533   axiomatization
  3534     eq  (infix "===" 50) where
  3535     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  3536 
  3537   definition "f x y = x + y + 1"
  3538   definition g where "g x = f x x"
  3539 
  3540   abbreviation
  3541     neq  (infix "=!=" 50) where
  3542     "x =!= y == ~ (x === y)"
  3543 
  3544 These specifications may be also used in a locale context.  Then the
  3545 constants being introduced depend on certain fixed parameters, and the
  3546 constant name is qualified by the locale base name.  An internal
  3547 abbreviation takes care for convenient input and output, making the
  3548 parameters implicit and using the original short name.  See also
  3549 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  3550 entities from a monomorphic theory.
  3551 
  3552 Presently, abbreviations are only available 'in' a target locale, but
  3553 not inherited by general import expressions.  Also note that
  3554 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  3555 'translations' in common applications.  The "no_abbrevs" print mode
  3556 prevents folding of abbreviations in term output.
  3557 
  3558 Concrete syntax is attached to specified constants in internal form,
  3559 independently of name spaces.  The parse tree representation is
  3560 slightly different -- use 'notation' instead of raw 'syntax', and
  3561 'translations' with explicit "CONST" markup to accommodate this.
  3562 
  3563 * Pure/Isar: unified syntax for new-style specification mechanisms
  3564 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  3565 full type inference and dummy patterns ("_").  For example:
  3566 
  3567   definition "K x _ = x"
  3568 
  3569   inductive conj for A B
  3570   where "A ==> B ==> conj A B"
  3571 
  3572 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  3573 the current context.  Print mode "no_abbrevs" prevents inversion of
  3574 abbreviations on output.
  3575 
  3576 * Isar/locales: improved parameter handling: use of locales "var" and
  3577 "struct" no longer necessary; - parameter renamings are no longer
  3578 required to be injective.  For example, this allows to define
  3579 endomorphisms as locale endom = homom mult mult h.
  3580 
  3581 * Isar/locales: changed the way locales with predicates are defined.
  3582 Instead of accumulating the specification, the imported expression is
  3583 now an interpretation.  INCOMPATIBILITY: different normal form of
  3584 locale expressions.  In particular, in interpretations of locales with
  3585 predicates, goals repesenting already interpreted fragments are not
  3586 removed automatically.  Use methods `intro_locales' and
  3587 `unfold_locales'; see below.
  3588 
  3589 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  3590 provide backward reasoning on locales predicates.  The methods are
  3591 aware of interpretations and discharge corresponding goals.
  3592 `intro_locales' is less aggressive then `unfold_locales' and does not
  3593 unfold predicates to assumptions.
  3594 
  3595 * Isar/locales: the order in which locale fragments are accumulated
  3596 has changed.  This enables to override declarations from fragments due
  3597 to interpretations -- for example, unwanted simp rules.
  3598 
  3599 * Isar/locales: interpretation in theories and proof contexts has been
  3600 extended.  One may now specify (and prove) equations, which are
  3601 unfolded in interpreted theorems.  This is useful for replacing
  3602 defined concepts (constants depending on locale parameters) by
  3603 concepts already existing in the target context.  Example:
  3604 
  3605   interpretation partial_order ["op <= :: [int, int] => bool"]
  3606     where "partial_order.less (op <=) (x::int) y = (x < y)"
  3607 
  3608 Typically, the constant `partial_order.less' is created by a
  3609 definition specification element in the context of locale
  3610 partial_order.
  3611 
  3612 * Method "induct": improved internal context management to support
  3613 local fixes and defines on-the-fly. Thus explicit meta-level
  3614 connectives !!  and ==> are rarely required anymore in inductive goals
  3615 (using object-logic connectives for this purpose has been long
  3616 obsolete anyway). Common proof patterns are explained in
  3617 src/HOL/Induct/Common_Patterns.thy, see also
  3618 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  3619 examples.
  3620 
  3621 * Method "induct": improved handling of simultaneous goals. Instead of
  3622 introducing object-level conjunction, the statement is now split into
  3623 several conclusions, while the corresponding symbolic cases are nested
  3624 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  3625 see src/HOL/Induct/Common_Patterns.thy, for example.
  3626 
  3627 * Method "induct": mutual induction rules are now specified as a list
  3628 of rule sharing the same induction cases. HOL packages usually provide
  3629 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  3630 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  3631 mutual induction rules differently, i.e. like this:
  3632 
  3633   (induct rule: foo_bar.inducts)
  3634   (induct set: foo bar)
  3635   (induct pred: foo bar)
  3636   (induct type: foo bar)
  3637 
  3638 The ML function ProjectRule.projections turns old-style rules into the
  3639 new format.
  3640 
  3641 * Method "coinduct": dual of induction, see
  3642 src/HOL/Library/Coinductive_List.thy for various examples.
  3643 
  3644 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  3645 considered a legacy feature.
  3646 
  3647 * Attribute "symmetric" produces result with standardized schematic
  3648 variables (index 0).  Potential INCOMPATIBILITY.
  3649 
  3650 * Simplifier: by default the simplifier trace only shows top level
  3651 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  3652 default. Thus there is less danger of being flooded by the trace. The
  3653 trace indicates where parts have been suppressed.
  3654   
  3655 * Provers/classical: removed obsolete classical version of elim_format
  3656 attribute; classical elim/dest rules are now treated uniformly when
  3657 manipulating the claset.
  3658 
  3659 * Provers/classical: stricter checks to ensure that supplied intro,
  3660 dest and elim rules are well-formed; dest and elim rules must have at
  3661 least one premise.
  3662 
  3663 * Provers/classical: attributes dest/elim/intro take an optional
  3664 weight argument for the rule (just as the Pure versions).  Weights are
  3665 ignored by automated tools, but determine the search order of single
  3666 rule steps.
  3667 
  3668 * Syntax: input syntax now supports dummy variable binding "%_. b",
  3669 where the body does not mention the bound variable.  Note that dummy
  3670 patterns implicitly depend on their context of bounds, which makes
  3671 "{_. _}" match any set comprehension as expected.  Potential
  3672 INCOMPATIBILITY -- parse translations need to cope with syntactic
  3673 constant "_idtdummy" in the binding position.
  3674 
  3675 * Syntax: removed obsolete syntactic constant "_K" and its associated
  3676 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  3677 for example "A -> B" => "Pi A (%_. B)".
  3678 
  3679 * Pure: 'class_deps' command visualizes the subclass relation, using
  3680 the graph browser tool.
  3681 
  3682 * Pure: 'print_theory' now suppresses certain internal declarations by
  3683 default; use '!' option for full details.
  3684 
  3685 
  3686 *** HOL ***
  3687 
  3688 * Method "metis" proves goals by applying the Metis general-purpose
  3689 resolution prover (see also http://gilith.com/software/metis/).
  3690 Examples are in the directory MetisExamples.  WARNING: the
  3691 Isabelle/HOL-Metis integration does not yet work properly with
  3692 multi-threading.
  3693   
  3694 * Command 'sledgehammer' invokes external automatic theorem provers as
  3695 background processes.  It generates calls to the "metis" method if
  3696 successful. These can be pasted into the proof.  Users do not have to
  3697 wait for the automatic provers to return.  WARNING: does not really
  3698 work with multi-threading.
  3699 
  3700 * New "auto_quickcheck" feature tests outermost goal statements for
  3701 potential counter-examples.  Controlled by ML references
  3702 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  3703 5000 milliseconds).  Fails silently if statements is outside of
  3704 executable fragment, or any other codgenerator problem occurs.
  3705 
  3706 * New constant "undefined" with axiom "undefined x = undefined".
  3707 
  3708 * Added class "HOL.eq", allowing for code generation with polymorphic
  3709 equality.
  3710 
  3711 * Some renaming of class constants due to canonical name prefixing in
  3712 the new 'class' package:
  3713 
  3714     HOL.abs ~> HOL.abs_class.abs
  3715     HOL.divide ~> HOL.divide_class.divide
  3716     0 ~> HOL.zero_class.zero
  3717     1 ~> HOL.one_class.one
  3718     op + ~> HOL.plus_class.plus
  3719     op - ~> HOL.minus_class.minus
  3720     uminus ~> HOL.minus_class.uminus
  3721     op * ~> HOL.times_class.times
  3722     op < ~> HOL.ord_class.less
  3723     op <= > HOL.ord_class.less_eq
  3724     Nat.power ~> Power.power_class.power
  3725     Nat.size ~> Nat.size_class.size
  3726     Numeral.number_of ~> Numeral.number_class.number_of
  3727     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  3728     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  3729     Orderings.min ~> Orderings.ord_class.min
  3730     Orderings.max ~> Orderings.ord_class.max
  3731     Divides.op div ~> Divides.div_class.div
  3732     Divides.op mod ~> Divides.div_class.mod
  3733     Divides.op dvd ~> Divides.div_class.dvd
  3734 
  3735 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  3736 
  3737 a) User-defined constants using any of the names "plus", "minus",
  3738 "times", "less" or "less_eq". The standard syntax translations for
  3739 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  3740 names.
  3741 
  3742 b) Variables named "plus", "minus", "times", "less", "less_eq"
  3743 INCOMPATIBILITY: use more specific names.
  3744 
  3745 c) Permutative equations (e.g. "a + b = b + a")
  3746 Since the change of names also changes the order of terms, permutative
  3747 rewrite rules may get applied in a different order. Experience shows
  3748 that this is rarely the case (only two adaptions in the whole Isabelle
  3749 distribution).  INCOMPATIBILITY: rewrite proofs
  3750 
  3751 d) ML code directly refering to constant names
  3752 This in general only affects hand-written proof tactics, simprocs and
  3753 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  3754 Consider using @{const_name} antiquotation.
  3755 
  3756 * New class "default" with associated constant "default".
  3757 
  3758 * Function "sgn" is now overloaded and available on int, real, complex
  3759 (and other numeric types), using class "sgn".  Two possible defs of
  3760 sgn are given as equational assumptions in the classes sgn_if and
  3761 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  3762 INCOMPATIBILITY.
  3763 
  3764 * Locale "partial_order" now unified with class "order" (cf. theory
  3765 Orderings), added parameter "less".  INCOMPATIBILITY.
  3766 
  3767 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  3768 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  3769 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  3770 
  3771 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  3772 changed order of proof goals in instance proofs.
  3773 
  3774 * The transitivity reasoner for partial and linear orders is set up
  3775 for classes "order" and "linorder".  Instances of the reasoner are available
  3776 in all contexts importing or interpreting the corresponding locales.
  3777 Method "order" invokes the reasoner separately; the reasoner
  3778 is also integrated with the Simplifier as a solver.  Diagnostic
  3779 command 'print_orders' shows the available instances of the reasoner
  3780 in the current context.
  3781 
  3782 * Localized monotonicity predicate in theory "Orderings"; integrated
  3783 lemmas max_of_mono and min_of_mono with this predicate.
  3784 INCOMPATIBILITY.
  3785 
  3786 * Formulation of theorem "dense" changed slightly due to integration
  3787 with new class dense_linear_order.
  3788 
  3789 * Uniform lattice theory development in HOL.
  3790 
  3791     constants "meet" and "join" now named "inf" and "sup"
  3792     constant "Meet" now named "Inf"
  3793 
  3794     classes "meet_semilorder" and "join_semilorder" now named
  3795       "lower_semilattice" and "upper_semilattice"
  3796     class "lorder" now named "lattice"
  3797     class "comp_lat" now named "complete_lattice"
  3798 
  3799     Instantiation of lattice classes allows explicit definitions
  3800     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  3801 
  3802   INCOMPATIBILITY.  Theorem renames:
  3803 
  3804     meet_left_le            ~> inf_le1
  3805     meet_right_le           ~> inf_le2
  3806     join_left_le            ~> sup_ge1
  3807     join_right_le           ~> sup_ge2
  3808     meet_join_le            ~> inf_sup_ord
  3809     le_meetI                ~> le_infI
  3810     join_leI                ~> le_supI
  3811     le_meet                 ~> le_inf_iff
  3812     le_join                 ~> ge_sup_conv
  3813     meet_idempotent         ~> inf_idem
  3814     join_idempotent         ~> sup_idem
  3815     meet_comm               ~> inf_commute
  3816     join_comm               ~> sup_commute
  3817     meet_leI1               ~> le_infI1
  3818     meet_leI2               ~> le_infI2
  3819     le_joinI1               ~> le_supI1
  3820     le_joinI2               ~> le_supI2
  3821     meet_assoc              ~> inf_assoc
  3822     join_assoc              ~> sup_assoc
  3823     meet_left_comm          ~> inf_left_commute
  3824     meet_left_idempotent    ~> inf_left_idem
  3825     join_left_comm          ~> sup_left_commute
  3826     join_left_idempotent    ~> sup_left_idem
  3827     meet_aci                ~> inf_aci
  3828     join_aci                ~> sup_aci
  3829     le_def_meet             ~> le_iff_inf
  3830     le_def_join             ~> le_iff_sup
  3831     join_absorp2            ~> sup_absorb2
  3832     join_absorp1            ~> sup_absorb1
  3833     meet_absorp1            ~> inf_absorb1
  3834     meet_absorp2            ~> inf_absorb2
  3835     meet_join_absorp        ~> inf_sup_absorb
  3836     join_meet_absorp        ~> sup_inf_absorb
  3837     distrib_join_le         ~> distrib_sup_le
  3838     distrib_meet_le         ~> distrib_inf_le
  3839 
  3840     add_meet_distrib_left   ~> add_inf_distrib_left
  3841     add_join_distrib_left   ~> add_sup_distrib_left
  3842     is_join_neg_meet        ~> is_join_neg_inf
  3843     is_meet_neg_join        ~> is_meet_neg_sup
  3844     add_meet_distrib_right  ~> add_inf_distrib_right
  3845     add_join_distrib_right  ~> add_sup_distrib_right
  3846     add_meet_join_distribs  ~> add_sup_inf_distribs
  3847     join_eq_neg_meet        ~> sup_eq_neg_inf
  3848     meet_eq_neg_join        ~> inf_eq_neg_sup
  3849     add_eq_meet_join        ~> add_eq_inf_sup
  3850     meet_0_imp_0            ~> inf_0_imp_0
  3851     join_0_imp_0            ~> sup_0_imp_0
  3852     meet_0_eq_0             ~> inf_0_eq_0
  3853     join_0_eq_0             ~> sup_0_eq_0
  3854     neg_meet_eq_join        ~> neg_inf_eq_sup
  3855     neg_join_eq_meet        ~> neg_sup_eq_inf
  3856     join_eq_if              ~> sup_eq_if
  3857 
  3858     mono_meet               ~> mono_inf
  3859     mono_join               ~> mono_sup
  3860     meet_bool_eq            ~> inf_bool_eq
  3861     join_bool_eq            ~> sup_bool_eq
  3862     meet_fun_eq             ~> inf_fun_eq
  3863     join_fun_eq             ~> sup_fun_eq
  3864     meet_set_eq             ~> inf_set_eq
  3865     join_set_eq             ~> sup_set_eq
  3866     meet1_iff               ~> inf1_iff
  3867     meet2_iff               ~> inf2_iff
  3868     meet1I                  ~> inf1I
  3869     meet2I                  ~> inf2I
  3870     meet1D1                 ~> inf1D1
  3871     meet2D1                 ~> inf2D1
  3872     meet1D2                 ~> inf1D2
  3873     meet2D2                 ~> inf2D2
  3874     meet1E                  ~> inf1E
  3875     meet2E                  ~> inf2E
  3876     join1_iff               ~> sup1_iff
  3877     join2_iff               ~> sup2_iff
  3878     join1I1                 ~> sup1I1
  3879     join2I1                 ~> sup2I1
  3880     join1I1                 ~> sup1I1
  3881     join2I2                 ~> sup1I2
  3882     join1CI                 ~> sup1CI
  3883     join2CI                 ~> sup2CI
  3884     join1E                  ~> sup1E
  3885     join2E                  ~> sup2E
  3886 
  3887     is_meet_Meet            ~> is_meet_Inf
  3888     Meet_bool_def           ~> Inf_bool_def
  3889     Meet_fun_def            ~> Inf_fun_def
  3890     Meet_greatest           ~> Inf_greatest
  3891     Meet_lower              ~> Inf_lower
  3892     Meet_set_def            ~> Inf_set_def
  3893 
  3894     Sup_def                 ~> Sup_Inf
  3895     Sup_bool_eq             ~> Sup_bool_def
  3896     Sup_fun_eq              ~> Sup_fun_def
  3897     Sup_set_eq              ~> Sup_set_def
  3898 
  3899     listsp_meetI            ~> listsp_infI
  3900     listsp_meet_eq          ~> listsp_inf_eq
  3901 
  3902     meet_min                ~> inf_min
  3903     join_max                ~> sup_max
  3904 
  3905 * Added syntactic class "size"; overloaded constant "size" now has
  3906 type "'a::size ==> bool"
  3907 
  3908 * Internal reorganisation of `size' of datatypes: size theorems
  3909 "foo.size" are no longer subsumed by "foo.simps" (but are still
  3910 simplification rules by default!); theorems "prod.size" now named
  3911 "*.size".
  3912 
  3913 * Class "div" now inherits from class "times" rather than "type".
  3914 INCOMPATIBILITY.
  3915 
  3916 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  3917 Linorder etc.  have disappeared; operations defined in terms of
  3918 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  3919 
  3920 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  3921 
  3922 * HOL-Word: New extensive library and type for generic, fixed size
  3923 machine words, with arithemtic, bit-wise, shifting and rotating
  3924 operations, reflection into int, nat, and bool lists, automation for
  3925 linear arithmetic (by automatic reflection into nat or int), including
  3926 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  3927 arithmetic type classes, supporting automatic simplification of
  3928 numerals on all operations.
  3929 
  3930 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  3931 
  3932 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  3933 
  3934 * Code generator library theories:
  3935   - Code_Integer represents HOL integers by big integer literals in target
  3936     languages.
  3937   - Code_Char represents HOL characters by character literals in target
  3938     languages.
  3939   - Code_Char_chr like Code_Char, but also offers treatment of character
  3940     codes; includes Code_Integer.
  3941   - Executable_Set allows to generate code for finite sets using lists.
  3942   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  3943     denominator).
  3944   - Executable_Real implements a subset of real numbers, namly those
  3945     representable by rational numbers.
  3946   - Efficient_Nat implements natural numbers by integers, which in general will
  3947     result in higher efficency; pattern matching with 0/Suc is eliminated;
  3948     includes Code_Integer.
  3949   - Code_Index provides an additional datatype index which is mapped to
  3950     target-language built-in integers.
  3951   - Code_Message provides an additional datatype message_string which is isomorphic to
  3952     strings; messages are mapped to target-language strings.
  3953 
  3954 * New package for inductive predicates
  3955 
  3956   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  3957 
  3958     inductive
  3959       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3960       for z_1 :: U_1 and ... and z_n :: U_m
  3961     where
  3962       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3963     | ...
  3964 
  3965   with full support for type-inference, rather than
  3966 
  3967     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3968 
  3969     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3970     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3971 
  3972     inductive "s z_1 ... z_m"
  3973     intros
  3974       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3975       ...
  3976 
  3977   For backward compatibility, there is a wrapper allowing inductive
  3978   sets to be defined with the new package via
  3979 
  3980     inductive_set
  3981       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3982       for z_1 :: U_1 and ... and z_n :: U_m
  3983     where
  3984       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3985     | ...
  3986 
  3987   or
  3988 
  3989     inductive_set
  3990       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3991       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3992       for z_1 :: U_1 and ... and z_n :: U_m
  3993     where
  3994       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3995     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3996     | ...
  3997 
  3998   if the additional syntax "p ..." is required.
  3999 
  4000   Numerous examples can be found in the subdirectories src/HOL/Auth,
  4001   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  4002 
  4003   INCOMPATIBILITIES:
  4004 
  4005   - Since declaration and definition of inductive sets or predicates
  4006     is no longer separated, abbreviations involving the newly
  4007     introduced sets or predicates must be specified together with the
  4008     introduction rules after the 'where' keyword (see above), rather
  4009     than before the actual inductive definition.
  4010 
  4011   - The variables in induction and elimination rules are now
  4012     quantified in the order of their occurrence in the introduction
  4013     rules, rather than in alphabetical order. Since this may break
  4014     some proofs, these proofs either have to be repaired, e.g. by
  4015     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  4016     statements of the form
  4017 
  4018       case (rule_i a_i_1 ... a_i_{k_i})
  4019 
  4020     or the old order of quantification has to be restored by explicitly adding
  4021     meta-level quantifiers in the introduction rules, i.e.
  4022 
  4023       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  4024 
  4025   - The format of the elimination rules is now
  4026 
  4027       p z_1 ... z_m x_1 ... x_n ==>
  4028         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  4029         ==> ... ==> P
  4030 
  4031     for predicates and
  4032 
  4033       (x_1, ..., x_n) : s z_1 ... z_m ==>
  4034         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  4035         ==> ... ==> P
  4036 
  4037     for sets rather than
  4038 
  4039       x : s z_1 ... z_m ==>
  4040         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  4041         ==> ... ==> P
  4042 
  4043     This may require terms in goals to be expanded to n-tuples
  4044     (e.g. using case_tac or simplification with the split_paired_all
  4045     rule) before the above elimination rule is applicable.
  4046 
  4047   - The elimination or case analysis rules for (mutually) inductive
  4048     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  4049     list of rules "p_1_..._p_k.elims" is no longer available.
  4050 
  4051 * New package "function"/"fun" for general recursive functions,
  4052 supporting mutual and nested recursion, definitions in local contexts,
  4053 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  4054 for small examples, and the separate tutorial on the function
  4055 package. The old recdef "package" is still available as before, but
  4056 users are encouraged to use the new package.
  4057 
  4058 * Method "lexicographic_order" automatically synthesizes termination
  4059 relations as lexicographic combinations of size measures. 
  4060 
  4061 * Case-expressions allow arbitrary constructor-patterns (including
  4062 "_") and take their order into account, like in functional
  4063 programming.  Internally, this is translated into nested
  4064 case-expressions; missing cases are added and mapped to the predefined
  4065 constant "undefined". In complicated cases printing may no longer show
  4066 the original input but the internal form. Lambda-abstractions allow
  4067 the same form of pattern matching: "% pat1 => e1 | ..." is an
  4068 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  4069 variable.
  4070 
  4071 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  4072 is an abbreviation for "of_nat :: nat => int". The simplification
  4073 rules for "of_nat" have been changed to work like "int" did
  4074 previously.  Potential INCOMPATIBILITY:
  4075   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  4076   - of_nat_diff and of_nat_mult are no longer default simp rules
  4077 
  4078 * Method "algebra" solves polynomial equations over (semi)rings using
  4079 Groebner bases. The (semi)ring structure is defined by locales and the
  4080 tool setup depends on that generic context. Installing the method for
  4081 a specific type involves instantiating the locale and possibly adding
  4082 declarations for computation on the coefficients.  The method is
  4083 already instantiated for natural numbers and for the axiomatic class
  4084 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  4085 CALCULEMUS 2007 for the general principles underlying this
  4086 architecture of context-aware proof-tools.
  4087 
  4088 * Method "ferrack" implements quantifier elimination over
  4089 special-purpose dense linear orders using locales (analogous to
  4090 "algebra"). The method is already installed for class
  4091 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  4092 rat, etc.
  4093 
  4094 * Former constant "List.op @" now named "List.append".  Use ML
  4095 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  4096 circumvent possible incompatibilities when working on ML level.
  4097 
  4098 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  4099 
  4100 * New function listsum :: 'a list => 'a for arbitrary monoids.
  4101 Special syntax: "SUM x <- xs. f x" (and latex variants)
  4102 
  4103 * New syntax for Haskell-like list comprehension (input only), eg.
  4104 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  4105 
  4106 * The special syntax for function "filter" has changed from [x :
  4107 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  4108 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  4109 
  4110 * [a..b] is now defined for arbitrary linear orders.  It used to be
  4111 defined on nat only, as an abbreviation for [a..<Suc b]
  4112 INCOMPATIBILITY.
  4113 
  4114 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  4115 
  4116 * New functions "sorted" and "sort" in src/HOL/List.thy.
  4117 
  4118 * New lemma collection field_simps (an extension of ring_simps) for
  4119 manipulating (in)equations involving division. Multiplies with all
  4120 denominators that can be proved to be non-zero (in equations) or
  4121 positive/negative (in inequations).
  4122 
  4123 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  4124 have been improved and renamed to ring_simps, group_simps and
  4125 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  4126 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  4127 
  4128 * Theory Library/Commutative_Ring: switched from recdef to function
  4129 package; constants add, mul, pow now curried.  Infix syntax for
  4130 algebraic operations.
  4131 
  4132 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  4133 INCOMPATIBILITY.
  4134 
  4135 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  4136 INCOMPATIBILITY.
  4137 
  4138 * HOL/records: generalised field-update to take a function on the
  4139 field rather than the new value: r(|A := x|) is translated to A_update
  4140 (K x) r The K-combinator that is internally used is called K_record.
  4141 INCOMPATIBILITY: Usage of the plain update functions has to be
  4142 adapted.
  4143  
  4144 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  4145 * x = 0, which are required for a semiring.  Richer structures do not
  4146 inherit from semiring_0 anymore, because this property is a theorem
  4147 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  4148 there is more to prove, but this is mostly trivial.
  4149 
  4150 * Class "recpower" is generalized to arbitrary monoids, not just
  4151 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  4152 commutativity or semiring properties additionally.
  4153 
  4154 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  4155 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  4156 better use 'abbreviation'.
  4157 
  4158 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  4159 
  4160 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  4161 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  4162 significant changes for setting up numeral syntax for types:
  4163   - New constants Numeral.pred and Numeral.succ instead
  4164       of former Numeral.bin_pred and Numeral.bin_succ.
  4165   - Use integer operations instead of bin_add, bin_mult and so on.
  4166   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  4167   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  4168 
  4169 See src/HOL/Integ/IntArith.thy for an example setup.
  4170 
  4171 * Command 'normal_form' computes the normal form of a term that may
  4172 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  4173 produces ``[b, c, a]'' (without proof).  This command is suitable for
  4174 heavy-duty computations because the functions are compiled to ML
  4175 first.  Correspondingly, a method "normalization" is provided.  See
  4176 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  4177 
  4178 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  4179 25 like -->); output depends on the "iff" print_mode, the default is
  4180 "A = B" (with priority 50).
  4181 
  4182 * Relations less (<) and less_eq (<=) are also available on type bool.
  4183 Modified syntax to disallow nesting without explicit parentheses,
  4184 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  4185 INCOMPATIBILITY.
  4186 
  4187 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  4188 
  4189 * Relation composition operator "op O" now has precedence 75 and binds
  4190 stronger than union and intersection. INCOMPATIBILITY.
  4191 
  4192 * The old set interval syntax "{m..n(}" (and relatives) has been
  4193 removed.  Use "{m..<n}" (and relatives) instead.
  4194 
  4195 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  4196 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  4197 ``declare [[simproc del: neq]]''.
  4198 
  4199 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  4200 True/False.
  4201 
  4202 * Theorem Cons_eq_map_conv no longer declared as "simp".
  4203 
  4204 * Theorem setsum_mult renamed to setsum_right_distrib.
  4205 
  4206 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  4207 ``rule'' method.
  4208 
  4209 * Reimplemented methods "sat" and "satx", with several improvements:
  4210 goals no longer need to be stated as "<prems> ==> False", equivalences
  4211 (i.e. "=" on type bool) are handled, variable names of the form
  4212 "lit_<n>" are no longer reserved, significant speedup.
  4213 
  4214 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  4215 zChaff is still supported as well.
  4216 
  4217 * 'inductive' and 'datatype': provide projections of mutual rules,
  4218 bundled as foo_bar.inducts;
  4219 
  4220 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  4221 Library.
  4222 
  4223 * Library: moved theory Accessible_Part to main HOL.
  4224 
  4225 * Library: added theory Coinductive_List of potentially infinite lists
  4226 as greatest fixed-point.
  4227 
  4228 * Library: added theory AssocList which implements (finite) maps as
  4229 association lists.
  4230 
  4231 * Method "evaluation" solves goals (i.e. a boolean expression)
  4232 efficiently by compiling it to ML.  The goal is "proved" (via an
  4233 oracle) if it evaluates to True.
  4234 
  4235 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  4236 also when invoked by the simplifier.  This results in the Simplifier
  4237 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  4238 Configuration option fast_arith_split_limit=0 recovers the old
  4239 behavior.
  4240 
  4241 * Support for hex (0x20) and binary (0b1001) numerals.
  4242 
  4243 * New method: reify eqs (t), where eqs are equations for an
  4244 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  4245 parameter, computes a term s::'b and a list xs::'a list and proves the
  4246 theorem I xs s = t. This is also known as reification or quoting. The
  4247 resulting theorem is applied to the subgoal to substitute t with I xs
  4248 s.  If t is omitted, the subgoal itself is reified.
  4249 
  4250 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  4251 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  4252 where f is supposed to be a computable function (in the sense of code
  4253 generattion). The method uses reify to compute s and xs as above then
  4254 applies corr_thm and uses normalization by evaluation to "prove" f s =
  4255 r and finally gets the theorem t = r, which is again applied to the
  4256 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  4257 
  4258 * Reflection: Automatic reification now handels binding, an example is
  4259 available in src/HOL/ex/ReflectionEx.thy
  4260 
  4261 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  4262 command 'statespace' that is similar to 'record', but introduces an
  4263 abstract specification based on the locale infrastructure instead of
  4264 HOL types.  This leads to extra flexibility in composing state spaces,
  4265 in particular multiple inheritance and renaming of components.
  4266 
  4267 
  4268 *** HOL-Complex ***
  4269 
  4270 * Hyperreal: Functions root and sqrt are now defined on negative real
  4271 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  4272 Nonnegativity side conditions have been removed from many lemmas, so
  4273 that more subgoals may now be solved by simplification; potential
  4274 INCOMPATIBILITY.
  4275 
  4276 * Real: new type classes formalize real normed vector spaces and
  4277 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  4278 and norm :: 'a => real.
  4279 
  4280 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  4281 reals into other types. The overloaded constant Reals :: 'a set is now
  4282 defined as range of_real; potential INCOMPATIBILITY.
  4283 
  4284 * Real: proper support for ML code generation, including 'quickcheck'.
  4285 Reals are implemented as arbitrary precision rationals.
  4286 
  4287 * Hyperreal: Several constants that previously worked only for the
  4288 reals have been generalized, so they now work over arbitrary vector
  4289 spaces. Type annotations may need to be added in some cases; potential
  4290 INCOMPATIBILITY.
  4291 
  4292   Infinitesimal  :: ('a::real_normed_vector) star set
  4293   HFinite        :: ('a::real_normed_vector) star set
  4294   HInfinite      :: ('a::real_normed_vector) star set
  4295   approx         :: ('a::real_normed_vector) star => 'a star => bool
  4296   monad          :: ('a::real_normed_vector) star => 'a star set
  4297   galaxy         :: ('a::real_normed_vector) star => 'a star set
  4298   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  4299   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  4300   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  4301   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  4302   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  4303   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  4304   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  4305   sgn            :: 'a::real_normed_vector => 'a
  4306   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  4307 
  4308 * Complex: Some complex-specific constants are now abbreviations for
  4309 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  4310 hnorm.  Other constants have been entirely removed in favor of the
  4311 polymorphic versions (INCOMPATIBILITY):
  4312 
  4313   approx        <-- capprox
  4314   HFinite       <-- CFinite
  4315   HInfinite     <-- CInfinite
  4316   Infinitesimal <-- CInfinitesimal
  4317   monad         <-- cmonad
  4318   galaxy        <-- cgalaxy
  4319   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  4320   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  4321   (ns)deriv     <-- (ns)cderiv
  4322 
  4323 
  4324 *** HOL-Algebra ***
  4325 
  4326 * Formalisation of ideals and the quotient construction over rings.
  4327 
  4328 * Order and lattice theory no longer based on records.
  4329 INCOMPATIBILITY.
  4330 
  4331 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  4332 greatest_closed.  INCOMPATIBILITY.
  4333 
  4334 * Method algebra is now set up via an attribute.  For examples see
  4335 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  4336 of algebraic structures.
  4337 
  4338 * Renamed theory CRing to Ring.
  4339 
  4340 
  4341 *** HOL-Nominal ***
  4342 
  4343 * Substantial, yet incomplete support for nominal datatypes (binding
  4344 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  4345 src/HOL/Nominal/Examples.  Prospective users should consult
  4346 http://isabelle.in.tum.de/nominal/
  4347 
  4348 
  4349 *** ML ***
  4350 
  4351 * ML basics: just one true type int, which coincides with IntInf.int
  4352 (even on SML/NJ).
  4353 
  4354 * ML within Isar: antiquotations allow to embed statically-checked
  4355 formal entities in the source, referring to the context available at
  4356 compile-time.  For example:
  4357 
  4358 ML {* @{sort "{zero,one}"} *}
  4359 ML {* @{typ "'a => 'b"} *}
  4360 ML {* @{term "%x. x"} *}
  4361 ML {* @{prop "x == y"} *}
  4362 ML {* @{ctyp "'a => 'b"} *}
  4363 ML {* @{cterm "%x. x"} *}
  4364 ML {* @{cprop "x == y"} *}
  4365 ML {* @{thm asm_rl} *}
  4366 ML {* @{thms asm_rl} *}
  4367 ML {* @{type_name c} *}
  4368 ML {* @{type_syntax c} *}
  4369 ML {* @{const_name c} *}
  4370 ML {* @{const_syntax c} *}
  4371 ML {* @{context} *}
  4372 ML {* @{theory} *}
  4373 ML {* @{theory Pure} *}
  4374 ML {* @{theory_ref} *}
  4375 ML {* @{theory_ref Pure} *}
  4376 ML {* @{simpset} *}
  4377 ML {* @{claset} *}
  4378 ML {* @{clasimpset} *}
  4379 
  4380 The same works for sources being ``used'' within an Isar context.
  4381 
  4382 * ML in Isar: improved error reporting; extra verbosity with
  4383 ML_Context.trace enabled.
  4384 
  4385 * Pure/General/table.ML: the join operations now works via exceptions
  4386 DUP/SAME instead of type option. This is simpler in simple cases, and
  4387 admits slightly more efficient complex applications.
  4388 
  4389 * Pure: 'advanced' translation functions (parse_translation etc.) now
  4390 use Context.generic instead of just theory.
  4391 
  4392 * Pure: datatype Context.generic joins theory/Proof.context and
  4393 provides some facilities for code that works in either kind of
  4394 context, notably GenericDataFun for uniform theory and proof data.
  4395 
  4396 * Pure: simplified internal attribute type, which is now always
  4397 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  4398 local (Proof.context) attributes have been discontinued, while
  4399 minimizing code duplication. Thm.rule_attribute and
  4400 Thm.declaration_attribute build canonical attributes; see also structure
  4401 Context for further operations on Context.generic, notably
  4402 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  4403 declarations and definitions.
  4404 
  4405 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  4406 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  4407 init only required for impure data. INCOMPATIBILITY: empty really need
  4408 to be empty (no dependencies on theory content!)
  4409 
  4410 * Pure/kernel: consts certification ignores sort constraints given in
  4411 signature declarations. (This information is not relevant to the
  4412 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  4413 potential INCOMPATIBILITY.
  4414 
  4415 * Pure: axiomatic type classes are now purely definitional, with
  4416 explicit proofs of class axioms and super class relations performed
  4417 internally. See Pure/axclass.ML for the main internal interfaces --
  4418 notably AxClass.define_class supercedes AxClass.add_axclass, and
  4419 AxClass.axiomatize_class/classrel/arity supersede
  4420 Sign.add_classes/classrel/arities.
  4421 
  4422 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  4423 global/local versions on theory vs. Proof.context have been
  4424 discontinued; Attrib.syntax and Method.syntax have been adapted
  4425 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  4426 attributes, methods, etc.
  4427 
  4428 * Pure: several functions of signature "... -> theory -> theory * ..."
  4429 have been reoriented to "... -> theory -> ... * theory" in order to
  4430 allow natural usage in combination with the ||>, ||>>, |-> and
  4431 fold_map combinators.
  4432 
  4433 * Pure: official theorem names (closed derivations) and additional
  4434 comments (tags) are now strictly separate.  Name hints -- which are
  4435 maintained as tags -- may be attached any time without affecting the
  4436 derivation.
  4437 
  4438 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  4439 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  4440 achieve the old behaviour.
  4441 
  4442 * Pure: the "Goal" constant is now called "prop", supporting a
  4443 slightly more general idea of ``protecting'' meta-level rule
  4444 statements.
  4445 
  4446 * Pure: Logic.(un)varify only works in a global context, which is now
  4447 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  4448 Logic.legacy_(un)varify as temporary workaround.
  4449 
  4450 * Pure: structure Name provides scalable operations for generating
  4451 internal variable names, notably Name.variants etc.  This replaces
  4452 some popular functions from term.ML:
  4453 
  4454   Term.variant		->  Name.variant
  4455   Term.variantlist	->  Name.variant_list
  4456   Term.invent_names	->  Name.invent_list
  4457 
  4458 Note that low-level renaming rarely occurs in new code -- operations
  4459 from structure Variable are used instead (see below).
  4460 
  4461 * Pure: structure Variable provides fundamental operations for proper
  4462 treatment of fixed/schematic variables in a context.  For example,
  4463 Variable.import introduces fixes for schematics of given facts and
  4464 Variable.export reverses the effect (up to renaming) -- this replaces
  4465 various freeze_thaw operations.
  4466 
  4467 * Pure: structure Goal provides simple interfaces for
  4468 init/conclude/finish and tactical prove operations (replacing former
  4469 Tactic.prove).  Goal.prove is the canonical way to prove results
  4470 within a given context; Goal.prove_global is a degraded version for
  4471 theory level goals, including a global Drule.standard.  Note that
  4472 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  4473 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  4474 in a locale context).
  4475 
  4476 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  4477 and type checking (Syntax.check_term etc.), with common combinations
  4478 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  4479 which are considered legacy and await removal.
  4480 
  4481 * Pure/Syntax: generic interfaces for type unchecking
  4482 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  4483 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  4484 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  4485 available for convenience, but refer to the very same operations using
  4486 a mere theory instead of a full context.
  4487 
  4488 * Isar: simplified treatment of user-level errors, using exception
  4489 ERROR of string uniformly.  Function error now merely raises ERROR,
  4490 without any side effect on output channels.  The Isar toplevel takes
  4491 care of proper display of ERROR exceptions.  ML code may use plain
  4492 handle/can/try; cat_error may be used to concatenate errors like this:
  4493 
  4494   ... handle ERROR msg => cat_error msg "..."
  4495 
  4496 Toplevel ML code (run directly or through the Isar toplevel) may be
  4497 embedded into the Isar toplevel with exception display/debug like
  4498 this:
  4499 
  4500   Isar.toplevel (fn () => ...)
  4501 
  4502 INCOMPATIBILITY, removed special transform_error facilities, removed
  4503 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  4504 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  4505 -- use plain ERROR instead.
  4506 
  4507 * Isar: theory setup now has type (theory -> theory), instead of a
  4508 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  4509 
  4510 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  4511 ProofContext.debug/verbose flags.
  4512 
  4513 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  4514 theory before entering a proof state.  Transactions now always see a
  4515 quasi-functional intermediate checkpoint, both in interactive and
  4516 batch mode.
  4517 
  4518 * Isar: simplified interfaces for outer syntax.  Renamed
  4519 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  4520 OuterSyntax.add_parsers -- this functionality is now included in
  4521 OuterSyntax.command etc.  INCOMPATIBILITY.
  4522 
  4523 * Simplifier: the simpset of a running simplification process now
  4524 contains a proof context (cf. Simplifier.the_context), which is the
  4525 very context that the initial simpset has been retrieved from (by
  4526 simpset_of/local_simpset_of).  Consequently, all plug-in components
  4527 (solver, looper etc.) may depend on arbitrary proof data.
  4528 
  4529 * Simplifier.inherit_context inherits the proof context (plus the
  4530 local bounds) of the current simplification process; any simproc
  4531 etc. that calls the Simplifier recursively should do this!  Removed
  4532 former Simplifier.inherit_bounds, which is already included here --
  4533 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  4534 specify an explicit context using Simplifier.context/theory_context.
  4535 
  4536 * Simplifier/Classical Reasoner: more abstract interfaces
  4537 change_simpset/claset for modifying the simpset/claset reference of a
  4538 theory; raw versions simpset/claset_ref etc. have been discontinued --
  4539 INCOMPATIBILITY.
  4540 
  4541 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  4542 "Trueprop" etc.
  4543 
  4544 
  4545 *** System ***
  4546 
  4547 * settings: the default heap location within ISABELLE_HOME_USER now
  4548 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  4549 Isabelle installations.
  4550 
  4551 * isabelle-process: option -S (secure mode) disables some critical
  4552 operations, notably runtime compilation and evaluation of ML source
  4553 code.
  4554 
  4555 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  4556 
  4557 * Support for parallel execution, using native multicore support of
  4558 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  4559 independent theories, according to the given theory header
  4560 specifications. The maximum number of worker threads is specified via
  4561 usedir option -M or the "max-threads" setting in Proof General. A
  4562 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  4563 to 6 on a 8-core machine.  User-code needs to observe certain
  4564 guidelines for thread-safe programming, see appendix A in the Isar
  4565 Implementation manual.
  4566 
  4567 
  4568 
  4569 New in Isabelle2005 (October 2005)
  4570 ----------------------------------
  4571 
  4572 *** General ***
  4573 
  4574 * Theory headers: the new header syntax for Isar theories is
  4575 
  4576   theory <name>
  4577   imports <theory1> ... <theoryN>
  4578   uses <file1> ... <fileM>
  4579   begin
  4580 
  4581 where the 'uses' part is optional.  The previous syntax
  4582 
  4583   theory <name> = <theory1> + ... + <theoryN>:
  4584 
  4585 will disappear in the next release.  Use isatool fixheaders to convert
  4586 existing theory files.  Note that there is no change in ancient
  4587 non-Isar theories now, but these will disappear soon.
  4588 
  4589 * Theory loader: parent theories can now also be referred to via
  4590 relative and absolute paths.
  4591 
  4592 * Command 'find_theorems' searches for a list of criteria instead of a
  4593 list of constants. Known criteria are: intro, elim, dest, name:string,
  4594 simp:term, and any term. Criteria can be preceded by '-' to select
  4595 theorems that do not match. Intro, elim, dest select theorems that
  4596 match the current goal, name:s selects theorems whose fully qualified
  4597 name contain s, and simp:term selects all simplification rules whose
  4598 lhs match term.  Any other term is interpreted as pattern and selects
  4599 all theorems matching the pattern. Available in ProofGeneral under
  4600 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  4601 
  4602   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  4603 
  4604 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  4605 matching the current goal as introduction rule and not having "HOL."
  4606 in their name (i.e. not being defined in theory HOL).
  4607 
  4608 * Command 'thms_containing' has been discontinued in favour of
  4609 'find_theorems'; INCOMPATIBILITY.
  4610 
  4611 * Communication with Proof General is now 8bit clean, which means that
  4612 Unicode text in UTF-8 encoding may be used within theory texts (both
  4613 formal and informal parts).  Cf. option -U of the Isabelle Proof
  4614 General interface.  Here are some simple examples (cf. src/HOL/ex):
  4615 
  4616   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  4617   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  4618 
  4619 * Improved efficiency of the Simplifier and, to a lesser degree, the
  4620 Classical Reasoner.  Typical big applications run around 2 times
  4621 faster.
  4622 
  4623 
  4624 *** Document preparation ***
  4625 
  4626 * Commands 'display_drafts' and 'print_drafts' perform simple output
  4627 of raw sources.  Only those symbols that do not require additional
  4628 LaTeX packages (depending on comments in isabellesym.sty) are
  4629 displayed properly, everything else is left verbatim.  isatool display
  4630 and isatool print are used as front ends (these are subject to the
  4631 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  4632 
  4633 * Command tags control specific markup of certain regions of text,
  4634 notably folding and hiding.  Predefined tags include "theory" (for
  4635 theory begin and end), "proof" for proof commands, and "ML" for
  4636 commands involving ML code; the additional tags "visible" and
  4637 "invisible" are unused by default.  Users may give explicit tag
  4638 specifications in the text, e.g. ''by %invisible (auto)''.  The
  4639 interpretation of tags is determined by the LaTeX job during document
  4640 preparation: see option -V of isatool usedir, or options -n and -t of
  4641 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  4642 \isadroptag.
  4643 
  4644 Several document versions may be produced at the same time via isatool
  4645 usedir (the generated index.html will link all of them).  Typical
  4646 specifications include ''-V document=theory,proof,ML'' to present
  4647 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  4648 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  4649 these parts without any formal replacement text.  The Isabelle site
  4650 default settings produce ''document'' and ''outline'' versions as
  4651 specified above.
  4652 
  4653 * Several new antiquotations:
  4654 
  4655   @{term_type term} prints a term with its type annotated;
  4656 
  4657   @{typeof term} prints the type of a term;
  4658 
  4659   @{const const} is the same as @{term const}, but checks that the
  4660   argument is a known logical constant;
  4661 
  4662   @{term_style style term} and @{thm_style style thm} print a term or
  4663   theorem applying a "style" to it
  4664 
  4665   @{ML text}
  4666 
  4667 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  4668 definitions, equations, inequations etc., 'concl' printing only the
  4669 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  4670 to print the specified premise.  TermStyle.add_style provides an ML
  4671 interface for introducing further styles.  See also the "LaTeX Sugar"
  4672 document practical applications.  The ML antiquotation prints
  4673 type-checked ML expressions verbatim.
  4674 
  4675 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  4676 and 'text' support optional locale specification '(in loc)', which
  4677 specifies the default context for interpreting antiquotations.  For
  4678 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  4679 
  4680 * Option 'locale=NAME' of antiquotations specifies an alternative
  4681 context interpreting the subsequent argument.  For example: @{thm
  4682 [locale=lattice] inf_assoc}.
  4683 
  4684 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  4685 a proof context.
  4686 
  4687 * Proper output of antiquotations for theory commands involving a
  4688 proof context (such as 'locale' or 'theorem (in loc) ...').
  4689 
  4690 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  4691 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  4692 
  4693 * isatool usedir: new option -C (default true) controls whether option
  4694 -D should include a copy of the original document directory; -C false
  4695 prevents unwanted effects such as copying of administrative CVS data.
  4696 
  4697 
  4698 *** Pure ***
  4699 
  4700 * Considerably improved version of 'constdefs' command.  Now performs
  4701 automatic type-inference of declared constants; additional support for
  4702 local structure declarations (cf. locales and HOL records), see also
  4703 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  4704 sequential dependencies of definitions within a single 'constdefs'
  4705 section; moreover, the declared name needs to be an identifier.  If
  4706 all fails, consider to fall back on 'consts' and 'defs' separately.
  4707 
  4708 * Improved indexed syntax and implicit structures.  First of all,
  4709 indexed syntax provides a notational device for subscripted
  4710 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  4711 expressions.  Secondly, in a local context with structure
  4712 declarations, number indexes \<^sub>n or the empty index (default
  4713 number 1) refer to a certain fixed variable implicitly; option
  4714 show_structs controls printing of implicit structures.  Typical
  4715 applications of these concepts involve record types and locales.
  4716 
  4717 * New command 'no_syntax' removes grammar declarations (and
  4718 translations) resulting from the given syntax specification, which is
  4719 interpreted in the same manner as for the 'syntax' command.
  4720 
  4721 * 'Advanced' translation functions (parse_translation etc.) may depend
  4722 on the signature of the theory context being presently used for
  4723 parsing/printing, see also isar-ref manual.
  4724 
  4725 * Improved 'oracle' command provides a type-safe interface to turn an
  4726 ML expression of type theory -> T -> term into a primitive rule of
  4727 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  4728 is already included here); see also FOL/ex/IffExample.thy;
  4729 INCOMPATIBILITY.
  4730 
  4731 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  4732 before); "cI" is no longer bound, use "c.intro" instead.
  4733 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  4734 axclasses vs. locales.
  4735 
  4736 * Improved internal renaming of symbolic identifiers -- attach primes
  4737 instead of base 26 numbers.
  4738 
  4739 * New flag show_question_marks controls printing of leading question
  4740 marks in schematic variable names.
  4741 
  4742 * In schematic variable names, *any* symbol following \<^isub> or
  4743 \<^isup> is now treated as part of the base name.  For example, the
  4744 following works without printing of awkward ".0" indexes:
  4745 
  4746   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  4747     by simp
  4748 
  4749 * Inner syntax includes (*(*nested*) comments*).
  4750 
  4751 * Pretty printer now supports unbreakable blocks, specified in mixfix
  4752 annotations as "(00...)".
  4753 
  4754 * Clear separation of logical types and nonterminals, where the latter
  4755 may only occur in 'syntax' specifications or type abbreviations.
  4756 Before that distinction was only partially implemented via type class
  4757 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  4758 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  4759 exotic syntax specifications may require further adaption
  4760 (e.g. Cube/Cube.thy).
  4761 
  4762 * Removed obsolete type class "logic", use the top sort {} instead.
  4763 Note that non-logical types should be declared as 'nonterminals'
  4764 rather than 'types'.  INCOMPATIBILITY for new object-logic
  4765 specifications.
  4766 
  4767 * Attributes 'induct' and 'cases': type or set names may now be
  4768 locally fixed variables as well.
  4769 
  4770 * Simplifier: can now control the depth to which conditional rewriting
  4771 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  4772 Limit.
  4773 
  4774 * Simplifier: simplification procedures may now take the current
  4775 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  4776 interface), which is very useful for calling the Simplifier
  4777 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  4778 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  4779 low-level mk_simproc no longer applies Logic.varify internally, to
  4780 allow for use in a context of fixed variables.
  4781 
  4782 * thin_tac now works even if the assumption being deleted contains !!
  4783 or ==>.  More generally, erule now works even if the major premise of
  4784 the elimination rule contains !! or ==>.
  4785 
  4786 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  4787 
  4788 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  4789 from Pure, which contains all common declarations already.  Both
  4790 theories are defined via plain Isabelle/Isar .thy files.
  4791 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  4792 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  4793 use isatool fixcpure to adapt your theory and ML sources.
  4794 
  4795 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  4796 selections of theorems in named facts via index ranges.
  4797 
  4798 * 'print_theorems': in theory mode, really print the difference
  4799 wrt. the last state (works for interactive theory development only),
  4800 in proof mode print all local facts (cf. 'print_facts');
  4801 
  4802 * 'hide': option '(open)' hides only base names.
  4803 
  4804 * More efficient treatment of intermediate checkpoints in interactive
  4805 theory development.
  4806 
  4807 * Code generator is now invoked via code_module (incremental code
  4808 generation) and code_library (modular code generation, ML structures
  4809 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  4810 must be quoted when used as identifiers.
  4811 
  4812 * New 'value' command for reading, evaluating and printing terms using
  4813 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  4814 quoted when used as identifier.
  4815 
  4816 
  4817 *** Locales ***
  4818 
  4819 * New commands for the interpretation of locale expressions in
  4820 theories (1), locales (2) and proof contexts (3).  These generate
  4821 proof obligations from the expression specification.  After the
  4822 obligations have been discharged, theorems of the expression are added
  4823 to the theory, target locale or proof context.  The synopsis of the
  4824 commands is a follows:
  4825 
  4826   (1) interpretation expr inst
  4827   (2) interpretation target < expr
  4828   (3) interpret expr inst
  4829 
  4830 Interpretation in theories and proof contexts require a parameter
  4831 instantiation of terms from the current context.  This is applied to
  4832 specifications and theorems of the interpreted expression.
  4833 Interpretation in locales only permits parameter renaming through the
  4834 locale expression.  Interpretation is smart in that interpretations
  4835 that are active already do not occur in proof obligations, neither are
  4836 instantiated theorems stored in duplicate.  Use 'print_interps' to
  4837 inspect active interpretations of a particular locale.  For details,
  4838 see the Isar Reference manual.  Examples can be found in
  4839 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  4840 
  4841 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  4842 'interpret' instead.
  4843 
  4844 * New context element 'constrains' for adding type constraints to
  4845 parameters.
  4846 
  4847 * Context expressions: renaming of parameters with syntax
  4848 redeclaration.
  4849 
  4850 * Locale declaration: 'includes' disallowed.
  4851 
  4852 * Proper static binding of attribute syntax -- i.e. types / terms /
  4853 facts mentioned as arguments are always those of the locale definition
  4854 context, independently of the context of later invocations.  Moreover,
  4855 locale operations (renaming and type / term instantiation) are applied
  4856 to attribute arguments as expected.
  4857 
  4858 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  4859 actual attributes; rare situations may require Attrib.attribute to
  4860 embed those attributes into Attrib.src that lack concrete syntax.
  4861 Attribute implementations need to cooperate properly with the static
  4862 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  4863 Attrib.XXX_thm etc. already do the right thing without further
  4864 intervention.  Only unusual applications -- such as "where" or "of"
  4865 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  4866 on the context and the facts involved -- may have to assign parsed
  4867 values to argument tokens explicitly.
  4868 
  4869 * Changed parameter management in theorem generation for long goal
  4870 statements with 'includes'.  INCOMPATIBILITY: produces a different
  4871 theorem statement in rare situations.
  4872 
  4873 * Locale inspection command 'print_locale' omits notes elements.  Use
  4874 'print_locale!' to have them included in the output.
  4875 
  4876 
  4877 *** Provers ***
  4878 
  4879 * Provers/hypsubst.ML: improved version of the subst method, for
  4880 single-step rewriting: it now works in bound variable contexts. New is
  4881 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  4882 rewrite a different subterm than the original subst method, which is
  4883 still available as 'simplesubst'.
  4884 
  4885 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  4886 and quasi orders.
  4887 
  4888 * Provers/trancl.ML: new transitivity reasoner for transitive and
  4889 reflexive-transitive closure of relations.
  4890 
  4891 * Provers/blast.ML: new reference depth_limit to make blast's depth
  4892 limit (previously hard-coded with a value of 20) user-definable.
  4893 
  4894 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  4895 is peformed already.  Object-logics merely need to finish their
  4896 initial simpset configuration as before.  INCOMPATIBILITY.
  4897 
  4898 
  4899 *** HOL ***
  4900 
  4901 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  4902 
  4903   syntax (epsilon)
  4904     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  4905 
  4906 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  4907 and x-symbol; use option '-m epsilon' to get it actually printed.
  4908 Moreover, the mathematically important symbolic identifier \<epsilon>
  4909 becomes available as variable, constant etc.  INCOMPATIBILITY,
  4910 
  4911 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  4912 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  4913 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  4914 support corresponding Isar calculations.
  4915 
  4916 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  4917 instead of ":".
  4918 
  4919 * theory SetInterval: changed the syntax for open intervals:
  4920 
  4921   Old       New
  4922   {..n(}    {..<n}
  4923   {)n..}    {n<..}
  4924   {m..n(}   {m..<n}
  4925   {)m..n}   {m<..n}
  4926   {)m..n(}  {m<..<n}
  4927 
  4928 The old syntax is still supported but will disappear in the next
  4929 release.  For conversion use the following Emacs search and replace
  4930 patterns (these are not perfect but work quite well):
  4931 
  4932   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  4933   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  4934 
  4935 * Theory Commutative_Ring (in Library): method comm_ring for proving
  4936 equalities in commutative rings; method 'algebra' provides a generic
  4937 interface.
  4938 
  4939 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  4940 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  4941 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  4942 be a tuple pattern.
  4943 
  4944 Some new syntax forms are available:
  4945 
  4946   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  4947   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  4948   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  4949   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  4950 
  4951 The latter form "\<Sum>x < k. e" used to be based on a separate
  4952 function "Summation", which has been discontinued.
  4953 
  4954 * theory Finite_Set: in structured induction proofs, the insert case
  4955 is now 'case (insert x F)' instead of the old counterintuitive 'case
  4956 (insert F x)'.
  4957 
  4958 * The 'refute' command has been extended to support a much larger
  4959 fragment of HOL, including axiomatic type classes, constdefs and
  4960 typedefs, inductive datatypes and recursion.
  4961 
  4962 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  4963 Requires zChaff with proof generation to be installed.  See
  4964 HOL/ex/SAT_Examples.thy for examples.
  4965 
  4966 * Datatype induction via method 'induct' now preserves the name of the
  4967 induction variable. For example, when proving P(xs::'a list) by
  4968 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  4969 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  4970 in unstructured proof scripts.
  4971 
  4972 * Reworked implementation of records.  Improved scalability for
  4973 records with many fields, avoiding performance problems for type
  4974 inference. Records are no longer composed of nested field types, but
  4975 of nested extension types. Therefore the record type only grows linear
  4976 in the number of extensions and not in the number of fields.  The
  4977 top-level (users) view on records is preserved.  Potential
  4978 INCOMPATIBILITY only in strange cases, where the theory depends on the
  4979 old record representation. The type generated for a record is called
  4980 <record_name>_ext_type.
  4981 
  4982 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  4983 proofs triggered by a record definition or a simproc (if
  4984 quick_and_dirty is enabled).  Definitions of large records can take
  4985 quite long.
  4986 
  4987 New simproc record_upd_simproc for simplification of multiple record
  4988 updates enabled by default.  Moreover, trivial updates are also
  4989 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  4990 occasionally, since simplification is more powerful by default.
  4991 
  4992 * typedef: proper support for polymorphic sets, which contain extra
  4993 type-variables in the term.
  4994 
  4995 * Simplifier: automatically reasons about transitivity chains
  4996 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  4997 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  4998 old proofs break occasionally as simplification may now solve more
  4999 goals than previously.
  5000 
  5001 * Simplifier: converts x <= y into x = y if assumption y <= x is
  5002 present.  Works for all partial orders (class "order"), in particular
  5003 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  5004 just like y <= x.
  5005 
  5006 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  5007 bound variable or a constant then the let is unfolded.  Otherwise
  5008 first a is simplified to b, and then f b is simplified to g. If
  5009 possible we abstract b from g arriving at "let x = b in h x",
  5010 otherwise we unfold the let and arrive at g.  The simproc can be
  5011 enabled/disabled by the reference use_let_simproc.  Potential
  5012 INCOMPATIBILITY since simplification is more powerful by default.
  5013 
  5014 * Classical reasoning: the meson method now accepts theorems as arguments.
  5015 
  5016 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  5017 jobs to provide advice on the provability of subgoals.
  5018 
  5019 * Theory OrderedGroup and Ring_and_Field: various additions and
  5020 improvements to faciliate calculations involving equalities and
  5021 inequalities.
  5022 
  5023 The following theorems have been eliminated or modified
  5024 (INCOMPATIBILITY):
  5025 
  5026   abs_eq             now named abs_of_nonneg
  5027   abs_of_ge_0        now named abs_of_nonneg
  5028   abs_minus_eq       now named abs_of_nonpos
  5029   imp_abs_id         now named abs_of_nonneg
  5030   imp_abs_neg_id     now named abs_of_nonpos
  5031   mult_pos           now named mult_pos_pos
  5032   mult_pos_le        now named mult_nonneg_nonneg
  5033   mult_pos_neg_le    now named mult_nonneg_nonpos
  5034   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  5035   mult_neg           now named mult_neg_neg
  5036   mult_neg_le        now named mult_nonpos_nonpos
  5037 
  5038 * The following lemmas in Ring_and_Field have been added to the simplifier:
  5039      
  5040      zero_le_square
  5041      not_square_less_zero 
  5042 
  5043   The following lemmas have been deleted from Real/RealPow:
  5044   
  5045      realpow_zero_zero
  5046      realpow_two
  5047      realpow_less
  5048      zero_le_power
  5049      realpow_two_le
  5050      abs_realpow_two
  5051      realpow_two_abs     
  5052 
  5053 * Theory Parity: added rules for simplifying exponents.
  5054 
  5055 * Theory List:
  5056 
  5057 The following theorems have been eliminated or modified
  5058 (INCOMPATIBILITY):
  5059 
  5060   list_all_Nil       now named list_all.simps(1)
  5061   list_all_Cons      now named list_all.simps(2)
  5062   list_all_conv      now named list_all_iff
  5063   set_mem_eq         now named mem_iff
  5064 
  5065 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  5066 asymptotic "big O" calculations.  See the notes in BigO.thy.
  5067 
  5068 
  5069 *** HOL-Complex ***
  5070 
  5071 * Theory RealDef: better support for embedding natural numbers and
  5072 integers in the reals.
  5073 
  5074 The following theorems have been eliminated or modified
  5075 (INCOMPATIBILITY):
  5076 
  5077   exp_ge_add_one_self  now requires no hypotheses
  5078   real_of_int_add      reversed direction of equality (use [symmetric])
  5079   real_of_int_minus    reversed direction of equality (use [symmetric])
  5080   real_of_int_diff     reversed direction of equality (use [symmetric])
  5081   real_of_int_mult     reversed direction of equality (use [symmetric])
  5082 
  5083 * Theory RComplete: expanded support for floor and ceiling functions.
  5084 
  5085 * Theory Ln is new, with properties of the natural logarithm
  5086 
  5087 * Hyperreal: There is a new type constructor "star" for making
  5088 nonstandard types.  The old type names are now type synonyms:
  5089 
  5090   hypreal = real star
  5091   hypnat = nat star
  5092   hcomplex = complex star
  5093 
  5094 * Hyperreal: Many groups of similarly-defined constants have been
  5095 replaced by polymorphic versions (INCOMPATIBILITY):
  5096 
  5097   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  5098 
  5099   starset      <-- starsetNat, starsetC
  5100   *s*          <-- *sNat*, *sc*
  5101   starset_n    <-- starsetNat_n, starsetC_n
  5102   *sn*         <-- *sNatn*, *scn*
  5103   InternalSets <-- InternalNatSets, InternalCSets
  5104 
  5105   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  5106   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  5107   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  5108   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  5109   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  5110 
  5111 * Hyperreal: Many type-specific theorems have been removed in favor of
  5112 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  5113 
  5114   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  5115   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  5116   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  5117   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  5118   right_minus <-- hypreal_add_minus
  5119   left_minus <-- {hypreal,hcomplex}_add_minus_left
  5120   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  5121   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  5122   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  5123   mult_1_right <-- hcomplex_mult_one_right
  5124   mult_zero_left <-- hcomplex_mult_zero_left
  5125   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  5126   right_distrib <-- hypnat_add_mult_distrib2
  5127   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  5128   right_inverse <-- hypreal_mult_inverse
  5129   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  5130   order_refl <-- {hypreal,hypnat}_le_refl
  5131   order_trans <-- {hypreal,hypnat}_le_trans
  5132   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  5133   order_less_le <-- {hypreal,hypnat}_less_le
  5134   linorder_linear <-- {hypreal,hypnat}_le_linear
  5135   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  5136   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  5137   add_nonneg_nonneg <-- hypreal_le_add_order
  5138 
  5139 * Hyperreal: Separate theorems having to do with type-specific
  5140 versions of constants have been merged into theorems that apply to the
  5141 new polymorphic constants (INCOMPATIBILITY):
  5142 
  5143   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  5144   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  5145   STAR_Un <-- {STAR,NatStar,STARC}_Un
  5146   STAR_Int <-- {STAR,NatStar,STARC}_Int
  5147   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  5148   STAR_subset <-- {STAR,NatStar,STARC}_subset
  5149   STAR_mem <-- {STAR,NatStar,STARC}_mem
  5150   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  5151   STAR_diff <-- {STAR,STARC}_diff
  5152   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  5153     STARC_hcomplex_of_complex}_image_subset
  5154   starset_n_Un <-- starset{Nat,C}_n_Un
  5155   starset_n_Int <-- starset{Nat,C}_n_Int
  5156   starset_n_Compl <-- starset{Nat,C}_n_Compl
  5157   starset_n_diff <-- starset{Nat,C}_n_diff
  5158   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  5159   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  5160   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  5161   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  5162   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  5163   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  5164   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  5165   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  5166   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  5167   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  5168   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  5169   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  5170   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  5171   starfun_diff <-- starfun{C,RC,CR}_diff
  5172   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  5173   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  5174   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  5175   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  5176   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  5177   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  5178   starfun_Id <-- starfunC_Id
  5179   starfun_approx <-- starfun{Nat,CR}_approx
  5180   starfun_capprox <-- starfun{C,RC}_capprox
  5181   starfun_abs <-- starfunNat_rabs
  5182   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  5183   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  5184   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  5185   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  5186   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  5187   starfun_add_approx <-- starfunCR_add_approx
  5188   starfun_inverse_inverse <-- starfunC_inverse_inverse
  5189   starfun_divide <-- starfun{C,CR,RC}_divide
  5190   starfun_n <-- starfun{Nat,C}_n
  5191   starfun_n_mult <-- starfun{Nat,C}_n_mult
  5192   starfun_n_add <-- starfun{Nat,C}_n_add
  5193   starfun_n_add_minus <-- starfunNat_n_add_minus
  5194   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  5195   starfun_n_minus <-- starfun{Nat,C}_n_minus
  5196   starfun_n_eq <-- starfun{Nat,C}_n_eq
  5197 
  5198   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  5199   star_n_minus <-- {hypreal,hcomplex}_minus
  5200   star_n_diff <-- {hypreal,hcomplex}_diff
  5201   star_n_mult <-- {hypreal,hcomplex}_mult
  5202   star_n_inverse <-- {hypreal,hcomplex}_inverse
  5203   star_n_le <-- {hypreal,hypnat}_le
  5204   star_n_less <-- {hypreal,hypnat}_less
  5205   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  5206   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  5207   star_n_abs <-- hypreal_hrabs
  5208   star_n_divide <-- hcomplex_divide
  5209 
  5210   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  5211   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  5212   star_of_diff <-- hypreal_of_real_diff
  5213   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  5214   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  5215   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  5216   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  5217   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  5218   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  5219   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  5220   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  5221   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  5222   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  5223   star_of_number_of <-- {hypreal,hcomplex}_number_of
  5224   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  5225   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  5226   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  5227   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  5228   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  5229   star_of_power <-- hypreal_of_real_power
  5230   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  5231 
  5232 * Hyperreal: new method "transfer" that implements the transfer
  5233 principle of nonstandard analysis. With a subgoal that mentions
  5234 nonstandard types like "'a star", the command "apply transfer"
  5235 replaces it with an equivalent one that mentions only standard types.
  5236 To be successful, all free variables must have standard types; non-
  5237 standard variables must have explicit universal quantifiers.
  5238 
  5239 * Hyperreal: A theory of Taylor series.
  5240 
  5241 
  5242 *** HOLCF ***
  5243 
  5244 * Discontinued special version of 'constdefs' (which used to support
  5245 continuous functions) in favor of the general Pure one with full
  5246 type-inference.
  5247 
  5248 * New simplification procedure for solving continuity conditions; it
  5249 is much faster on terms with many nested lambda abstractions (cubic
  5250 instead of exponential time).
  5251 
  5252 * New syntax for domain package: selector names are now optional.
  5253 Parentheses should be omitted unless argument is lazy, for example:
  5254 
  5255   domain 'a stream = cons "'a" (lazy "'a stream")
  5256 
  5257 * New command 'fixrec' for defining recursive functions with pattern
  5258 matching; defining multiple functions with mutual recursion is also
  5259 supported.  Patterns may include the constants cpair, spair, up, sinl,
  5260 sinr, or any data constructor defined by the domain package. The given
  5261 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  5262 syntax and examples.
  5263 
  5264 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  5265 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  5266 but the proof obligation additionally includes an admissibility
  5267 requirement. The packages generate instances of class cpo or pcpo,
  5268 with continuity and strictness theorems for Rep and Abs.
  5269 
  5270 * HOLCF: Many theorems have been renamed according to a more standard naming
  5271 scheme (INCOMPATIBILITY):
  5272 
  5273   foo_inject:  "foo$x = foo$y ==> x = y"
  5274   foo_eq:      "(foo$x = foo$y) = (x = y)"
  5275   foo_less:    "(foo$x << foo$y) = (x << y)"
  5276   foo_strict:  "foo$UU = UU"
  5277   foo_defined: "... ==> foo$x ~= UU"
  5278   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  5279 
  5280 
  5281 *** ZF ***
  5282 
  5283 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  5284 including the First Isomorphism Theorem (on quotienting by the kernel
  5285 of a homomorphism).
  5286 
  5287 * ZF/Simplifier: install second copy of type solver that actually
  5288 makes use of TC rules declared to Isar proof contexts (or locales);
  5289 the old version is still required for ML proof scripts.
  5290 
  5291 
  5292 *** Cube ***
  5293 
  5294 * Converted to Isar theory format; use locales instead of axiomatic
  5295 theories.
  5296 
  5297 
  5298 *** ML ***
  5299 
  5300 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  5301 for ||>, ||>>, |>>,
  5302 
  5303 * Pure/library.ML no longer defines its own option datatype, but uses
  5304 that of the SML basis, which has constructors NONE and SOME instead of
  5305 None and Some, as well as exception Option.Option instead of OPTION.
  5306 The functions the, if_none, is_some, is_none have been adapted
  5307 accordingly, while Option.map replaces apsome.
  5308 
  5309 * Pure/library.ML: the exception LIST has been given up in favour of
  5310 the standard exceptions Empty and Subscript, as well as
  5311 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  5312 superceded by the standard hd and tl functions etc.
  5313 
  5314 A number of basic list functions are no longer exported to the ML
  5315 toplevel, as they are variants of predefined functions.  The following
  5316 suggests how one can translate existing code:
  5317 
  5318     rev_append xs ys = List.revAppend (xs, ys)
  5319     nth_elem (i, xs) = List.nth (xs, i)
  5320     last_elem xs = List.last xs
  5321     flat xss = List.concat xss
  5322     seq fs = List.app fs
  5323     partition P xs = List.partition P xs
  5324     mapfilter f xs = List.mapPartial f xs
  5325 
  5326 * Pure/library.ML: several combinators for linear functional
  5327 transformations, notably reverse application and composition:
  5328 
  5329   x |> f                f #> g
  5330   (x, y) |-> f          f #-> g
  5331 
  5332 * Pure/library.ML: introduced/changed precedence of infix operators:
  5333 
  5334   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  5335   infix 2 ?;
  5336   infix 3 o oo ooo oooo;
  5337   infix 4 ~~ upto downto;
  5338 
  5339 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  5340 infix operators.
  5341 
  5342 * Pure/library.ML: natural list combinators fold, fold_rev, and
  5343 fold_map support linear functional transformations and nesting.  For
  5344 example:
  5345 
  5346   fold f [x1, ..., xN] y =
  5347     y |> f x1 |> ... |> f xN
  5348 
  5349   (fold o fold) f [xs1, ..., xsN] y =
  5350     y |> fold f xs1 |> ... |> fold f xsN
  5351 
  5352   fold f [x1, ..., xN] =
  5353     f x1 #> ... #> f xN
  5354 
  5355   (fold o fold) f [xs1, ..., xsN] =
  5356     fold f xs1 #> ... #> fold f xsN
  5357 
  5358 * Pure/library.ML: the following selectors on type 'a option are
  5359 available:
  5360 
  5361   the:               'a option -> 'a  (*partial*)
  5362   these:             'a option -> 'a  where 'a = 'b list
  5363   the_default: 'a -> 'a option -> 'a
  5364   the_list:          'a option -> 'a list
  5365 
  5366 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5367 basic operations for association lists, following natural argument
  5368 order; moreover the explicit equality predicate passed here avoids
  5369 potentially expensive polymorphic runtime equality checks.
  5370 The old functions may be expressed as follows:
  5371 
  5372   assoc = uncurry (AList.lookup (op =))
  5373   assocs = these oo AList.lookup (op =)
  5374   overwrite = uncurry (AList.update (op =)) o swap
  5375 
  5376 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5377 
  5378   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  5379   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  5380 
  5381 replacing make_keylist and keyfilter (occassionally used)
  5382 Naive rewrites:
  5383 
  5384   make_keylist = AList.make
  5385   keyfilter = AList.find (op =)
  5386 
  5387 * eq_fst and eq_snd now take explicit equality parameter, thus
  5388   avoiding eqtypes. Naive rewrites:
  5389 
  5390     eq_fst = eq_fst (op =)
  5391     eq_snd = eq_snd (op =)
  5392 
  5393 * Removed deprecated apl and apr (rarely used).
  5394   Naive rewrites:
  5395 
  5396     apl (n, op) =>>= curry op n
  5397     apr (op, m) =>>= fn n => op (n, m)
  5398 
  5399 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  5400 provides a reasonably efficient light-weight implementation of sets as
  5401 lists.
  5402 
  5403 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  5404 few new operations; existing lookup and update are now curried to
  5405 follow natural argument order (for use with fold etc.);
  5406 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  5407 
  5408 * Pure/General: output via the Isabelle channels of
  5409 writeln/warning/error etc. is now passed through Output.output, with a
  5410 hook for arbitrary transformations depending on the print_mode
  5411 (cf. Output.add_mode -- the first active mode that provides a output
  5412 function wins).  Already formatted output may be embedded into further
  5413 text via Output.raw; the result of Pretty.string_of/str_of and derived
  5414 functions (string_of_term/cterm/thm etc.) is already marked raw to
  5415 accommodate easy composition of diagnostic messages etc.  Programmers
  5416 rarely need to care about Output.output or Output.raw at all, with
  5417 some notable exceptions: Output.output is required when bypassing the
  5418 standard channels (writeln etc.), or in token translations to produce
  5419 properly formatted results; Output.raw is required when capturing
  5420 already output material that will eventually be presented to the user
  5421 a second time.  For the default print mode, both Output.output and
  5422 Output.raw have no effect.
  5423 
  5424 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  5425 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  5426 cumulative results are displayed at the end of a batch session.
  5427 
  5428 * Pure/General: File.sysify_path and File.quote_sysify path have been
  5429 replaced by File.platform_path and File.shell_path (with appropriate
  5430 hooks).  This provides a clean interface for unusual systems where the
  5431 internal and external process view of file names are different.
  5432 
  5433 * Pure: more efficient orders for basic syntactic entities: added
  5434 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  5435 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  5436 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  5437 orders now -- potential INCOMPATIBILITY for code that depends on a
  5438 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  5439 Library.sort_strings on result).
  5440 
  5441 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  5442 fold_types traverse types/terms from left to right, observing natural
  5443 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  5444 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  5445 
  5446 * Pure: name spaces have been refined, with significant changes of the
  5447 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  5448 to extern(_table).  The plain name entry path is superceded by a
  5449 general 'naming' context, which also includes the 'policy' to produce
  5450 a fully qualified name and external accesses of a fully qualified
  5451 name; NameSpace.extend is superceded by context dependent
  5452 Sign.declare_name.  Several theory and proof context operations modify
  5453 the naming context.  Especially note Theory.restore_naming and
  5454 ProofContext.restore_naming to get back to a sane state; note that
  5455 Theory.add_path is no longer sufficient to recover from
  5456 Theory.absolute_path in particular.
  5457 
  5458 * Pure: new flags short_names (default false) and unique_names
  5459 (default true) for controlling output of qualified names.  If
  5460 short_names is set, names are printed unqualified.  If unique_names is
  5461 reset, the name prefix is reduced to the minimum required to achieve
  5462 the original result when interning again, even if there is an overlap
  5463 with earlier declarations.
  5464 
  5465 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  5466 now 'extend', and 'merge' gets an additional Pretty.pp argument
  5467 (useful for printing error messages).  INCOMPATIBILITY.
  5468 
  5469 * Pure: major reorganization of the theory context.  Type Sign.sg and
  5470 Theory.theory are now identified, referring to the universal
  5471 Context.theory (see Pure/context.ML).  Actual signature and theory
  5472 content is managed as theory data.  The old code and interfaces were
  5473 spread over many files and structures; the new arrangement introduces
  5474 considerable INCOMPATIBILITY to gain more clarity:
  5475 
  5476   Context -- theory management operations (name, identity, inclusion,
  5477     parents, ancestors, merge, etc.), plus generic theory data;
  5478 
  5479   Sign -- logical signature and syntax operations (declaring consts,
  5480     types, etc.), plus certify/read for common entities;
  5481 
  5482   Theory -- logical theory operations (stating axioms, definitions,
  5483     oracles), plus a copy of logical signature operations (consts,
  5484     types, etc.); also a few basic management operations (Theory.copy,
  5485     Theory.merge, etc.)
  5486 
  5487 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  5488 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  5489 for convenience -- they merely return the theory.
  5490 
  5491 * Pure: type Type.tsig is superceded by theory in most interfaces.
  5492 
  5493 * Pure: the Isar proof context type is already defined early in Pure
  5494 as Context.proof (note that ProofContext.context and Proof.context are
  5495 aliases, where the latter is the preferred name).  This enables other
  5496 Isabelle components to refer to that type even before Isar is present.
  5497 
  5498 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  5499 typeK, constK, axiomK, oracleK), but provide explicit operations for
  5500 any of these kinds.  For example, Sign.intern typeK is now
  5501 Sign.intern_type, Theory.hide_space Sign.typeK is now
  5502 Theory.hide_types.  Also note that former
  5503 Theory.hide_classes/types/consts are now
  5504 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  5505 internalize their arguments!  INCOMPATIBILITY.
  5506 
  5507 * Pure: get_thm interface (of PureThy and ProofContext) expects
  5508 datatype thmref (with constructors Name and NameSelection) instead of
  5509 plain string -- INCOMPATIBILITY;
  5510 
  5511 * Pure: cases produced by proof methods specify options, where NONE
  5512 means to remove case bindings -- INCOMPATIBILITY in
  5513 (RAW_)METHOD_CASES.
  5514 
  5515 * Pure: the following operations retrieve axioms or theorems from a
  5516 theory node or theory hierarchy, respectively:
  5517 
  5518   Theory.axioms_of: theory -> (string * term) list
  5519   Theory.all_axioms_of: theory -> (string * term) list
  5520   PureThy.thms_of: theory -> (string * thm) list
  5521   PureThy.all_thms_of: theory -> (string * thm) list
  5522 
  5523 * Pure: print_tac now outputs the goal through the trace channel.
  5524 
  5525 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  5526 Reference Toplevel.debug (default false) controls detailed printing
  5527 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  5528 controls execution profiling -- set to 1 for time and 2 for space
  5529 (both increase the runtime).
  5530 
  5531 * Isar session: The initial use of ROOT.ML is now always timed,
  5532 i.e. the log will show the actual process times, in contrast to the
  5533 elapsed wall-clock time that the outer shell wrapper produces.
  5534 
  5535 * Simplifier: improved handling of bound variables (nameless
  5536 representation, avoid allocating new strings).  Simprocs that invoke
  5537 the Simplifier recursively should use Simplifier.inherit_bounds to
  5538 avoid local name clashes.  Failure to do so produces warnings
  5539 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  5540 for further details.
  5541 
  5542 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  5543 bindings for all theorems stored within a given theory; this may help
  5544 in porting non-Isar theories to Isar ones, while keeping ML proof
  5545 scripts for the time being.
  5546 
  5547 * ML operator HTML.with_charset specifies the charset begin used for
  5548 generated HTML files.  For example:
  5549 
  5550   HTML.with_charset "utf-8" use_thy "Hebrew";
  5551   HTML.with_charset "utf-8" use_thy "Chinese";
  5552 
  5553 
  5554 *** System ***
  5555 
  5556 * Allow symlinks to all proper Isabelle executables (Isabelle,
  5557 isabelle, isatool etc.).
  5558 
  5559 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  5560 isatool doc, isatool mkdir, display_drafts etc.).
  5561 
  5562 * isatool usedir: option -f allows specification of the ML file to be
  5563 used by Isabelle; default is ROOT.ML.
  5564 
  5565 * New isatool version outputs the version identifier of the Isabelle
  5566 distribution being used.
  5567 
  5568 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  5569 (containing Boolean satisfiability problems) into Isabelle/HOL
  5570 theories.
  5571 
  5572 
  5573 
  5574 New in Isabelle2004 (April 2004)
  5575 --------------------------------
  5576 
  5577 *** General ***
  5578 
  5579 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  5580   Replaces linorder.ML.
  5581 
  5582 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  5583   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  5584   (\<a>...\<z>), are now considered normal letters, and can therefore
  5585   be used anywhere where an ASCII letter (a...zA...Z) has until
  5586   now. COMPATIBILITY: This obviously changes the parsing of some
  5587   terms, especially where a symbol has been used as a binder, say
  5588   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  5589   as an identifier.  Fix it by inserting a space around former
  5590   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  5591   existing theory and ML files.
  5592 
  5593 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  5594 
  5595 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  5596   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  5597   a normal (but invisible) letter. For multiple letter subscripts repeat
  5598   \<^isub> like this: x\<^isub>1\<^isub>2.
  5599 
  5600 * Pure: There are now sub-/superscripts that can span more than one
  5601   character. Text between \<^bsub> and \<^esub> is set in subscript in
  5602   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  5603   superscript. The new control characters are not identifier parts.
  5604 
  5605 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  5606   content of "..." to the latex file instead of \isacntrl... . The "..."
  5607   may consist of any printable characters excluding the end bracket >.
  5608 
  5609 * Pure: Using new Isar command "finalconsts" (or the ML functions
  5610   Theory.add_finals or Theory.add_finals_i) it is now possible to
  5611   declare constants "final", which prevents their being given a definition
  5612   later.  It is useful for constants whose behaviour is fixed axiomatically
  5613   rather than definitionally, such as the meta-logic connectives.
  5614 
  5615 * Pure: 'instance' now handles general arities with general sorts
  5616   (i.e. intersections of classes),
  5617 
  5618 * Presentation: generated HTML now uses a CSS style sheet to make layout
  5619   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  5620   It can be changed to alter the colors/layout of generated pages.
  5621 
  5622 
  5623 *** Isar ***
  5624 
  5625 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  5626   cut_tac, subgoal_tac and thin_tac:
  5627   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  5628     locales are no longer forced to write Isar proof scripts.
  5629     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  5630     emulations.
  5631   - INCOMPATIBILITY: names of variables to be instantiated may no
  5632     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  5633     This is consistent with the instantiation attribute "where".
  5634 
  5635 * Attributes "where" and "of":
  5636   - Now take type variables of instantiated theorem into account when reading
  5637     the instantiation string.  This fixes a bug that caused instantiated
  5638     theorems to have too special types in some circumstances.
  5639   - "where" permits explicit instantiations of type variables.
  5640 
  5641 * Calculation commands "moreover" and "also" no longer interfere with
  5642   current facts ("this"), admitting arbitrary combinations with "then"
  5643   and derived forms.
  5644 
  5645 * Locales:
  5646   - Goal statements involving the context element "includes" no longer
  5647     generate theorems with internal delta predicates (those ending on
  5648     "_axioms") in the premise.
  5649     Resolve particular premise with <locale>.intro to obtain old form.
  5650   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  5651     specification and "includes" elements in goal statement.
  5652   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  5653     [intro?] and [elim?] (respectively) by default.
  5654   - Experimental command for instantiation of locales in proof contexts:
  5655         instantiate <label>[<attrs>]: <loc>
  5656     Instantiates locale <loc> and adds all its theorems to the current context
  5657     taking into account their attributes.  Label and attrs are optional
  5658     modifiers, like in theorem declarations.  If present, names of
  5659     instantiated theorems are qualified with <label>, and the attributes
  5660     <attrs> are applied after any attributes these theorems might have already.
  5661       If the locale has assumptions, a chained fact of the form
  5662     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  5663     are derived.  The command does not support old-style locales declared
  5664     with "locale (open)".
  5665       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  5666 
  5667 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  5668   (Isar) contexts.
  5669 
  5670 
  5671 *** HOL ***
  5672 
  5673 * Proof import: new image HOL4 contains the imported library from
  5674   the HOL4 system with about 2500 theorems. It is imported by
  5675   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  5676   can be used like any other Isabelle image.  See
  5677   HOL/Import/HOL/README for more information.
  5678 
  5679 * Simplifier:
  5680   - Much improved handling of linear and partial orders.
  5681     Reasoners for linear and partial orders are set up for type classes
  5682     "linorder" and "order" respectively, and are added to the default simpset
  5683     as solvers.  This means that the simplifier can build transitivity chains
  5684     to solve goals from the assumptions.
  5685   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  5686     of blast or auto after simplification become unnecessary because the goal
  5687     is solved by simplification already.
  5688 
  5689 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  5690     all proved in axiomatic type classes for semirings, rings and fields.
  5691 
  5692 * Numerics:
  5693   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  5694     now formalized using the Ring_and_Field theory mentioned above.
  5695   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  5696     than before, because now they are set up once in a generic manner.
  5697   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  5698     Look for the general versions in Ring_and_Field (and Power if they concern
  5699     exponentiation).
  5700 
  5701 * Type "rat" of the rational numbers is now available in HOL-Complex.
  5702 
  5703 * Records:
  5704   - Record types are now by default printed with their type abbreviation
  5705     instead of the list of all field types. This can be configured via
  5706     the reference "print_record_type_abbr".
  5707   - Simproc "record_upd_simproc" for simplification of multiple updates added
  5708     (not enabled by default).
  5709   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  5710     EX x. x = sel r to True (not enabled by default).
  5711   - Tactic "record_split_simp_tac" to split and simplify records added.
  5712 
  5713 * 'specification' command added, allowing for definition by
  5714   specification.  There is also an 'ax_specification' command that
  5715   introduces the new constants axiomatically.
  5716 
  5717 * arith(_tac) is now able to generate counterexamples for reals as well.
  5718 
  5719 * HOL-Algebra: new locale "ring" for non-commutative rings.
  5720 
  5721 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  5722   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  5723 
  5724 * HOL-Matrix: a first theory for matrices in HOL with an application of
  5725   matrix theory to linear programming.
  5726 
  5727 * Unions and Intersections:
  5728   The latex output syntax of UN and INT has been changed
  5729   from "\Union x \in A. B" to "\Union_{x \in A} B"
  5730   i.e. the index formulae has become a subscript.
  5731   Similarly for "\Union x. B", and for \Inter instead of \Union.
  5732 
  5733 * Unions and Intersections over Intervals:
  5734   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  5735   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  5736   like in normal math, and corresponding versions for < and for intersection.
  5737 
  5738 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  5739   lexicographic dictonary ordering has been added as "lexord".
  5740 
  5741 * ML: the legacy theory structures Int and List have been removed. They had
  5742   conflicted with ML Basis Library structures having the same names.
  5743 
  5744 * 'refute' command added to search for (finite) countermodels.  Only works
  5745   for a fragment of HOL.  The installation of an external SAT solver is
  5746   highly recommended.  See "HOL/Refute.thy" for details.
  5747 
  5748 * 'quickcheck' command: Allows to find counterexamples by evaluating
  5749   formulae under an assignment of free variables to random values.
  5750   In contrast to 'refute', it can deal with inductive datatypes,
  5751   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  5752   for examples.
  5753 
  5754 
  5755 *** HOLCF ***
  5756 
  5757 * Streams now come with concatenation and are part of the HOLCF image
  5758 
  5759 
  5760 
  5761 New in Isabelle2003 (May 2003)
  5762 ------------------------------
  5763 
  5764 *** General ***
  5765 
  5766 * Provers/simplifier:
  5767 
  5768   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  5769     Assumptions are now subject to complete mutual simplification,
  5770     not just from left to right. The simplifier now preserves
  5771     the order of assumptions.
  5772 
  5773     Potential INCOMPATIBILITY:
  5774 
  5775     -- simp sometimes diverges where the old version did
  5776        not, e.g. invoking simp on the goal
  5777 
  5778         [| P (f x); y = x; f x = f y |] ==> Q
  5779 
  5780        now gives rise to the infinite reduction sequence
  5781 
  5782         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  5783 
  5784        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  5785        kind of problem.
  5786 
  5787     -- Tactics combining classical reasoner and simplification (such as auto)
  5788        are also affected by this change, because many of them rely on
  5789        simp. They may sometimes diverge as well or yield a different numbers
  5790        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  5791        in case of problems. Sometimes subsequent calls to the classical
  5792        reasoner will fail because a preceeding call to the simplifier too
  5793        eagerly simplified the goal, e.g. deleted redundant premises.
  5794 
  5795   - The simplifier trace now shows the names of the applied rewrite rules
  5796 
  5797   - You can limit the number of recursive invocations of the simplifier
  5798     during conditional rewriting (where the simplifie tries to solve the
  5799     conditions before applying the rewrite rule):
  5800     ML "simp_depth_limit := n"
  5801     where n is an integer. Thus you can force termination where previously
  5802     the simplifier would diverge.
  5803 
  5804   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  5805 
  5806   - No longer aborts on failed congruence proof.  Instead, the
  5807     congruence is ignored.
  5808 
  5809 * Pure: New generic framework for extracting programs from constructive
  5810   proofs. See HOL/Extraction.thy for an example instantiation, as well
  5811   as HOL/Extraction for some case studies.
  5812 
  5813 * Pure: The main goal of the proof state is no longer shown by default, only
  5814 the subgoals. This behaviour is controlled by a new flag.
  5815    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  5816 (ML: Proof.show_main_goal).
  5817 
  5818 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  5819 rules whose conclusion matches subgoal 1:
  5820       PG menu: Isabelle/Isar -> Show me -> matching rules
  5821 The rules are ordered by how closely they match the subgoal.
  5822 In particular, rules that solve a subgoal outright are displayed first
  5823 (or rather last, the way they are printed).
  5824 (ML: ProofGeneral.print_intros())
  5825 
  5826 * Pure: New flag trace_unify_fail causes unification to print
  5827 diagnostic information (PG: in trace buffer) when it fails. This is
  5828 useful for figuring out why single step proofs like rule, erule or
  5829 assumption failed.
  5830 
  5831 * Pure: Locale specifications now produce predicate definitions
  5832 according to the body of text (covering assumptions modulo local
  5833 definitions); predicate "loc_axioms" covers newly introduced text,
  5834 while "loc" is cumulative wrt. all included locale expressions; the
  5835 latter view is presented only on export into the global theory
  5836 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  5837 on the old view without predicates;
  5838 
  5839 * Pure: predefined locales "var" and "struct" are useful for sharing
  5840 parameters (as in CASL, for example); just specify something like
  5841 ``var x + var y + struct M'' as import;
  5842 
  5843 * Pure: improved thms_containing: proper indexing of facts instead of
  5844 raw theorems; check validity of results wrt. current name space;
  5845 include local facts of proof configuration (also covers active
  5846 locales), cover fixed variables in index; may use "_" in term
  5847 specification; an optional limit for the number of printed facts may
  5848 be given (the default is 40);
  5849 
  5850 * Pure: disallow duplicate fact bindings within new-style theory files
  5851 (batch-mode only);
  5852 
  5853 * Provers: improved induct method: assumptions introduced by case
  5854 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  5855 the goal statement); "foo" still refers to all facts collectively;
  5856 
  5857 * Provers: the function blast.overloaded has been removed: all constants
  5858 are regarded as potentially overloaded, which improves robustness in exchange
  5859 for slight decrease in efficiency;
  5860 
  5861 * Provers/linorder: New generic prover for transitivity reasoning over
  5862 linear orders.  Note: this prover is not efficient!
  5863 
  5864 * Isar: preview of problems to finish 'show' now produce an error
  5865 rather than just a warning (in interactive mode);
  5866 
  5867 
  5868 *** HOL ***
  5869 
  5870 * arith(_tac)
  5871 
  5872  - Produces a counter example if it cannot prove a goal.
  5873    Note that the counter example may be spurious if the goal is not a formula
  5874    of quantifier-free linear arithmetic.
  5875    In ProofGeneral the counter example appears in the trace buffer.
  5876 
  5877  - Knows about div k and mod k where k is a numeral of type nat or int.
  5878 
  5879  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  5880    linear arithmetic fails. This takes account of quantifiers and divisibility.
  5881    Presburger arithmetic can also be called explicitly via presburger(_tac).
  5882 
  5883 * simp's arithmetic capabilities have been enhanced a bit: it now
  5884 takes ~= in premises into account (by performing a case split);
  5885 
  5886 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  5887 are distributed over a sum of terms;
  5888 
  5889 * New tactic "trans_tac" and method "trans" instantiate
  5890 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  5891 "<=", "<" and "=").
  5892 
  5893 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  5894 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  5895 
  5896 * 'typedef' command has new option "open" to suppress the set
  5897 definition;
  5898 
  5899 * functions Min and Max on finite sets have been introduced (theory
  5900 Finite_Set);
  5901 
  5902 * attribute [symmetric] now works for relations as well; it turns
  5903 (x,y) : R^-1 into (y,x) : R, and vice versa;
  5904 
  5905 * induct over a !!-quantified statement (say !!x1..xn):
  5906   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  5907 
  5908 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  5909 %x. None. Warning: empty_def now refers to the previously hidden definition
  5910 of the empty set.
  5911 
  5912 * Algebra: formalization of classical algebra.  Intended as base for
  5913 any algebraic development in Isabelle.  Currently covers group theory
  5914 (up to Sylow's theorem) and ring theory (Universal Property of
  5915 Univariate Polynomials).  Contributions welcome;
  5916 
  5917 * GroupTheory: deleted, since its material has been moved to Algebra;
  5918 
  5919 * Complex: new directory of the complex numbers with numeric constants,
  5920 nonstandard complex numbers, and some complex analysis, standard and
  5921 nonstandard (Jacques Fleuriot);
  5922 
  5923 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  5924 
  5925 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  5926 Fleuriot);
  5927 
  5928 * Real/HahnBanach: updated and adapted to locales;
  5929 
  5930 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  5931 Gray and Kramer);
  5932 
  5933 * UNITY: added the Meier-Sanders theory of progress sets;
  5934 
  5935 * MicroJava: bytecode verifier and lightweight bytecode verifier
  5936 as abstract algorithms, instantiated to the JVM;
  5937 
  5938 * Bali: Java source language formalization. Type system, operational
  5939 semantics, axiomatic semantics. Supported language features:
  5940 classes, interfaces, objects,virtual methods, static methods,
  5941 static/instance fields, arrays, access modifiers, definite
  5942 assignment, exceptions.
  5943 
  5944 
  5945 *** ZF ***
  5946 
  5947 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  5948 universe, etc.);
  5949 
  5950 * Main ZF: virtually all theories converted to new-style format;
  5951 
  5952 
  5953 *** ML ***
  5954 
  5955 * Pure: Tactic.prove provides sane interface for internal proofs;
  5956 omits the infamous "standard" operation, so this is more appropriate
  5957 than prove_goalw_cterm in many situations (e.g. in simprocs);
  5958 
  5959 * Pure: improved error reporting of simprocs;
  5960 
  5961 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  5962 up simprocs;
  5963 
  5964 
  5965 *** Document preparation ***
  5966 
  5967 * uses \par instead of \\ for line breaks in theory text. This may
  5968 shift some page breaks in large documents. To get the old behaviour
  5969 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  5970 
  5971 * minimized dependencies of isabelle.sty and isabellesym.sty on
  5972 other packages
  5973 
  5974 * \<euro> now needs package babel/greek instead of marvosym (which
  5975 broke \Rightarrow)
  5976 
  5977 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  5978 textcomp package)
  5979 
  5980 
  5981 
  5982 New in Isabelle2002 (March 2002)
  5983 --------------------------------
  5984 
  5985 *** Document preparation ***
  5986 
  5987 * greatly simplified document preparation setup, including more
  5988 graceful interpretation of isatool usedir -i/-d/-D options, and more
  5989 instructive isatool mkdir; users should basically be able to get
  5990 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  5991 users may run a separate document processing stage manually like this:
  5992 "isatool usedir -D output HOL Test && isatool document Test/output";
  5993 
  5994 * theory dependency graph may now be incorporated into documents;
  5995 isatool usedir -g true will produce session_graph.eps/.pdf for use
  5996 with \includegraphics of LaTeX;
  5997 
  5998 * proper spacing of consecutive markup elements, especially text
  5999 blocks after section headings;
  6000 
  6001 * support bold style (for single symbols only), input syntax is like
  6002 this: "\<^bold>\<alpha>" or "\<^bold>A";
  6003 
  6004 * \<bullet> is now output as bold \cdot by default, which looks much
  6005 better in printed text;
  6006 
  6007 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  6008 note that these symbols are currently unavailable in Proof General /
  6009 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  6010 
  6011 * isatool latex no longer depends on changed TEXINPUTS, instead
  6012 isatool document copies the Isabelle style files to the target
  6013 location;
  6014 
  6015 
  6016 *** Isar ***
  6017 
  6018 * Pure/Provers: improved proof by cases and induction;
  6019   - 'case' command admits impromptu naming of parameters (such as
  6020     "case (Suc n)");
  6021   - 'induct' method divinates rule instantiation from the inductive
  6022     claim; no longer requires excessive ?P bindings for proper
  6023     instantiation of cases;
  6024   - 'induct' method properly enumerates all possibilities of set/type
  6025     rules; as a consequence facts may be also passed through *type*
  6026     rules without further ado;
  6027   - 'induct' method now derives symbolic cases from the *rulified*
  6028     rule (before it used to rulify cases stemming from the internal
  6029     atomized version); this means that the context of a non-atomic
  6030     statement becomes is included in the hypothesis, avoiding the
  6031     slightly cumbersome show "PROP ?case" form;
  6032   - 'induct' may now use elim-style induction rules without chaining
  6033     facts, using ``missing'' premises from the goal state; this allows
  6034     rules stemming from inductive sets to be applied in unstructured
  6035     scripts, while still benefitting from proper handling of non-atomic
  6036     statements; NB: major inductive premises need to be put first, all
  6037     the rest of the goal is passed through the induction;
  6038   - 'induct' proper support for mutual induction involving non-atomic
  6039     rule statements (uses the new concept of simultaneous goals, see
  6040     below);
  6041   - append all possible rule selections, but only use the first
  6042     success (no backtracking);
  6043   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  6044   - undeclared rule case names default to numbers 1, 2, 3, ...;
  6045   - added 'print_induct_rules' (covered by help item in recent Proof
  6046     General versions);
  6047   - moved induct/cases attributes to Pure, methods to Provers;
  6048   - generic method setup instantiated for FOL and HOL;
  6049 
  6050 * Pure: support multiple simultaneous goal statements, for example
  6051 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  6052 meta-level mechanism, this acts as if several individual goals had
  6053 been stated separately; in particular common proof methods need to be
  6054 repeated in order to cover all claims; note that a single elimination
  6055 step is *not* sufficient to establish the two conjunctions, so this
  6056 fails:
  6057 
  6058   assume "A & B" then have A and B ..   (*".." fails*)
  6059 
  6060 better use "obtain" in situations as above; alternative refer to
  6061 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  6062 
  6063 * Pure: proper integration with ``locales''; unlike the original
  6064 version by Florian Kammller, Isar locales package high-level proof
  6065 contexts rather than raw logical ones (e.g. we admit to include
  6066 attributes everywhere); operations on locales include merge and
  6067 rename; support for implicit arguments (``structures''); simultaneous
  6068 type-inference over imports and text; see also HOL/ex/Locales.thy for
  6069 some examples;
  6070 
  6071 * Pure: the following commands have been ``localized'', supporting a
  6072 target locale specification "(in name)": 'lemma', 'theorem',
  6073 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  6074 stored both within the locale and at the theory level (exported and
  6075 qualified by the locale name);
  6076 
  6077 * Pure: theory goals may now be specified in ``long'' form, with
  6078 ad-hoc contexts consisting of arbitrary locale elements. for example
  6079 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  6080 definitions may be given, too); the result is a meta-level rule with
  6081 the context elements being discharged in the obvious way;
  6082 
  6083 * Pure: new proof command 'using' allows to augment currently used
  6084 facts after a goal statement ('using' is syntactically analogous to
  6085 'apply', but acts on the goal's facts only); this allows chained facts
  6086 to be separated into parts given before and after a claim, as in
  6087 ``from a and b have C using d and e <proof>'';
  6088 
  6089 * Pure: renamed "antecedent" case to "rule_context";
  6090 
  6091 * Pure: new 'judgment' command records explicit information about the
  6092 object-logic embedding (used by several tools internally); no longer
  6093 use hard-wired "Trueprop";
  6094 
  6095 * Pure: added 'corollary' command;
  6096 
  6097 * Pure: fixed 'token_translation' command;
  6098 
  6099 * Pure: removed obsolete 'exported' attribute;
  6100 
  6101 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  6102 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  6103 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  6104 
  6105 * Pure: method 'atomize' presents local goal premises as object-level
  6106 statements (atomic meta-level propositions); setup controlled via
  6107 rewrite rules declarations of 'atomize' attribute; example
  6108 application: 'induct' method with proper rule statements in improper
  6109 proof *scripts*;
  6110 
  6111 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  6112 now consider the syntactic context of assumptions, giving a better
  6113 chance to get type-inference of the arguments right (this is
  6114 especially important for locales);
  6115 
  6116 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  6117 mode;
  6118 
  6119 * Pure/obtain: the formal conclusion "thesis", being marked as
  6120 ``internal'', may no longer be reference directly in the text;
  6121 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  6122 situations;
  6123 
  6124 * Pure: generic 'sym' attribute which declares a rule both as pure
  6125 'elim?' and for the 'symmetric' operation;
  6126 
  6127 * Pure: marginal comments ``--'' may now occur just anywhere in the
  6128 text; the fixed correlation with particular command syntax has been
  6129 discontinued;
  6130 
  6131 * Pure: new method 'rules' is particularly well-suited for proof
  6132 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  6133 but often produces more compact proof terms with less detours;
  6134 
  6135 * Pure/Provers/classical: simplified integration with pure rule
  6136 attributes and methods; the classical "intro?/elim?/dest?"
  6137 declarations coincide with the pure ones; the "rule" method no longer
  6138 includes classically swapped intros; "intro" and "elim" methods no
  6139 longer pick rules from the context; also got rid of ML declarations
  6140 AddXIs/AddXEs/AddXDs; all of this has some potential for
  6141 INCOMPATIBILITY;
  6142 
  6143 * Provers/classical: attribute 'swapped' produces classical inversions
  6144 of introduction rules;
  6145 
  6146 * Provers/simplifier: 'simplified' attribute may refer to explicit
  6147 rules instead of full simplifier context; 'iff' attribute handles
  6148 conditional rules;
  6149 
  6150 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  6151 
  6152 * HOL: 'recdef' now fails on unfinished automated proofs, use
  6153 "(permissive)" option to recover old behavior;
  6154 
  6155 * HOL: 'inductive' no longer features separate (collective) attributes
  6156 for 'intros' (was found too confusing);
  6157 
  6158 * HOL: properly declared induction rules less_induct and
  6159 wf_induct_rule;
  6160 
  6161 
  6162 *** HOL ***
  6163 
  6164 * HOL: moved over to sane numeral syntax; the new policy is as
  6165 follows:
  6166 
  6167   - 0 and 1 are polymorphic constants, which are defined on any
  6168   numeric type (nat, int, real etc.);
  6169 
  6170   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  6171   binary representation internally;
  6172 
  6173   - type nat has special constructor Suc, and generally prefers Suc 0
  6174   over 1::nat and Suc (Suc 0) over 2::nat;
  6175 
  6176 This change may cause significant problems of INCOMPATIBILITY; here
  6177 are some hints on converting existing sources:
  6178 
  6179   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  6180   entities, so expressions involving "-" (unary or binary minus) need
  6181   to be spaced properly;
  6182 
  6183   - existing occurrences of "1" may need to be constraint "1::nat" or
  6184   even replaced by Suc 0; similar for old "2";
  6185 
  6186   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  6187 
  6188   - remove all special provisions on numerals in proofs;
  6189 
  6190 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  6191 representation (depends on bin_arith_simps in the default context);
  6192 
  6193 * HOL: symbolic syntax for x^2 (numeral 2);
  6194 
  6195 * HOL: the class of all HOL types is now called "type" rather than
  6196 "term"; INCOMPATIBILITY, need to adapt references to this type class
  6197 in axclass/classes, instance/arities, and (usually rare) occurrences
  6198 in typings (of consts etc.); internally the class is called
  6199 "HOL.type", ML programs should refer to HOLogic.typeS;
  6200 
  6201 * HOL/record package improvements:
  6202   - new derived operations "fields" to build a partial record section,
  6203     "extend" to promote a fixed record to a record scheme, and
  6204     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  6205     declared as simp by default;
  6206   - shared operations ("more", "fields", etc.) now need to be always
  6207     qualified) --- potential INCOMPATIBILITY;
  6208   - removed "make_scheme" operations (use "make" with "extend") --
  6209     INCOMPATIBILITY;
  6210   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  6211   - provides cases/induct rules for use with corresponding Isar
  6212     methods (for concrete records, record schemes, concrete more
  6213     parts, and schematic more parts -- in that order);
  6214   - internal definitions directly based on a light-weight abstract
  6215     theory of product types over typedef rather than datatype;
  6216 
  6217 * HOL: generic code generator for generating executable ML code from
  6218 specifications; specific support for HOL constructs such as inductive
  6219 datatypes and sets, as well as recursive functions; can be invoked
  6220 via 'generate_code' theory section;
  6221 
  6222 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  6223 
  6224 * HOL: consolidated and renamed several theories.  In particular:
  6225         Ord.thy has been absorbed into HOL.thy
  6226         String.thy has been absorbed into List.thy
  6227 
  6228 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  6229 (beware of argument permutation!);
  6230 
  6231 * HOL: lino