NEWS
author blanchet
Thu, 03 Mar 2011 11:20:48 +0100
changeset 42748 3f9adc372e0a
parent 42717 b368a7aee46a
child 42759 aa8dce9ab8a9
permissions -rw-r--r--
mention new Nitpick options
     1 Isabelle NEWS -- history user-relevant changes
     2 ==============================================
     3 
     4 New in this Isabelle version
     5 ----------------------------
     6 
     7 *** General ***
     8 
     9 * Parallelization of nested Isar proofs is subject to
    10 Goal.parallel_proofs_threshold (default 100).  See also isabelle
    11 usedir option -Q.
    12 
    13 * Discontinued support for Poly/ML 5.2, which was the last version
    14 without proper multithreading and TimeLimit implementation.
    15 
    16 * Discontinued old lib/scripts/polyml-platform, which has been
    17 obsolete since Isabelle2009-2.
    18 
    19 
    20 *** HOL ***
    21 
    22 * Nitpick:
    23   - Added "need" and "total_consts" options.
    24   - Renamed attribute: nitpick_def ~> nitpick_unfold.
    25     INCOMPATIBILITY.
    26 
    27 * Sledgehammer:
    28   - sledgehammer available_provers ~> sledgehammer supported_provers
    29     INCOMPATIBILITY.
    30 
    31 * Function package: discontinued option "tailrec".
    32 INCOMPATIBILITY. Use partial_function instead.
    33 
    34 
    35 *** Document preparation ***
    36 
    37 * New term style "isub" as ad-hoc conversion of variables x1, y23 into
    38 subscripted form x\<^isub>1, y\<^isub>2\<^isub>3.
    39 
    40 
    41 
    42 New in Isabelle2011 (January 2011)
    43 ----------------------------------
    44 
    45 *** General ***
    46 
    47 * Experimental Prover IDE based on Isabelle/Scala and jEdit (see
    48 src/Tools/jEdit).  This also serves as IDE for Isabelle/ML, with
    49 useful tooltips and hyperlinks produced from its static analysis.  The
    50 bundled component provides an executable Isabelle tool that can be run
    51 like this:
    52 
    53   Isabelle2011/bin/isabelle jedit
    54 
    55 * Significantly improved Isabelle/Isar implementation manual.
    56 
    57 * System settings: ISABELLE_HOME_USER now includes ISABELLE_IDENTIFIER
    58 (and thus refers to something like $HOME/.isabelle/Isabelle2011),
    59 while the default heap location within that directory lacks that extra
    60 suffix.  This isolates multiple Isabelle installations from each
    61 other, avoiding problems with old settings in new versions.
    62 INCOMPATIBILITY, need to copy/upgrade old user settings manually.
    63 
    64 * Source files are always encoded as UTF-8, instead of old-fashioned
    65 ISO-Latin-1.  INCOMPATIBILITY.  Isabelle LaTeX documents might require
    66 the following package declarations:
    67 
    68   \usepackage[utf8]{inputenc}
    69   \usepackage{textcomp}
    70 
    71 * Explicit treatment of UTF-8 sequences as Isabelle symbols, such that
    72 a Unicode character is treated as a single symbol, not a sequence of
    73 non-ASCII bytes as before.  Since Isabelle/ML string literals may
    74 contain symbols without further backslash escapes, Unicode can now be
    75 used here as well.  Recall that Symbol.explode in ML provides a
    76 consistent view on symbols, while raw explode (or String.explode)
    77 merely give a byte-oriented representation.
    78 
    79 * Theory loader: source files are primarily located via the master
    80 directory of each theory node (where the .thy file itself resides).
    81 The global load path is still partially available as legacy feature.
    82 Minor INCOMPATIBILITY due to subtle change in file lookup: use
    83 explicit paths, relatively to the theory.
    84 
    85 * Special treatment of ML file names has been discontinued.
    86 Historically, optional extensions .ML or .sml were added on demand --
    87 at the cost of clarity of file dependencies.  Recall that Isabelle/ML
    88 files exclusively use the .ML extension.  Minor INCOMPATIBILTY.
    89 
    90 * Various options that affect pretty printing etc. are now properly
    91 handled within the context via configuration options, instead of
    92 unsynchronized references or print modes.  There are both ML Config.T
    93 entities and Isar declaration attributes to access these.
    94 
    95   ML (Config.T)                 Isar (attribute)
    96 
    97   eta_contract                  eta_contract
    98   show_brackets                 show_brackets
    99   show_sorts                    show_sorts
   100   show_types                    show_types
   101   show_question_marks           show_question_marks
   102   show_consts                   show_consts
   103   show_abbrevs                  show_abbrevs
   104 
   105   Syntax.ast_trace              syntax_ast_trace
   106   Syntax.ast_stat               syntax_ast_stat
   107   Syntax.ambiguity_level        syntax_ambiguity_level
   108 
   109   Goal_Display.goals_limit      goals_limit
   110   Goal_Display.show_main_goal   show_main_goal
   111 
   112   Method.rule_trace             rule_trace
   113 
   114   Thy_Output.display            thy_output_display
   115   Thy_Output.quotes             thy_output_quotes
   116   Thy_Output.indent             thy_output_indent
   117   Thy_Output.source             thy_output_source
   118   Thy_Output.break              thy_output_break
   119 
   120 Note that corresponding "..._default" references in ML may only be
   121 changed globally at the ROOT session setup, but *not* within a theory.
   122 The option "show_abbrevs" supersedes the former print mode
   123 "no_abbrevs" with inverted meaning.
   124 
   125 * More systematic naming of some configuration options.
   126 INCOMPATIBILITY.
   127 
   128   trace_simp  ~>  simp_trace
   129   debug_simp  ~>  simp_debug
   130 
   131 * Support for real valued configuration options, using simplistic
   132 floating-point notation that coincides with the inner syntax for
   133 float_token.
   134 
   135 * Support for real valued preferences (with approximative PGIP type):
   136 front-ends need to accept "pgint" values in float notation.
   137 INCOMPATIBILITY.
   138 
   139 * The IsabelleText font now includes Cyrillic, Hebrew, Arabic from
   140 DejaVu Sans.
   141 
   142 * Discontinued support for Poly/ML 5.0 and 5.1 versions.
   143 
   144 
   145 *** Pure ***
   146 
   147 * Command 'type_synonym' (with single argument) replaces somewhat
   148 outdated 'types', which is still available as legacy feature for some
   149 time.
   150 
   151 * Command 'nonterminal' (with 'and' separated list of arguments)
   152 replaces somewhat outdated 'nonterminals'.  INCOMPATIBILITY.
   153 
   154 * Command 'notepad' replaces former 'example_proof' for
   155 experimentation in Isar without any result.  INCOMPATIBILITY.
   156 
   157 * Locale interpretation commands 'interpret' and 'sublocale' accept
   158 lists of equations to map definitions in a locale to appropriate
   159 entities in the context of the interpretation.  The 'interpretation'
   160 command already provided this functionality.
   161 
   162 * Diagnostic command 'print_dependencies' prints the locale instances
   163 that would be activated if the specified expression was interpreted in
   164 the current context.  Variant "print_dependencies!" assumes a context
   165 without interpretations.
   166 
   167 * Diagnostic command 'print_interps' prints interpretations in proofs
   168 in addition to interpretations in theories.
   169 
   170 * Discontinued obsolete 'global' and 'local' commands to manipulate
   171 the theory name space.  Rare INCOMPATIBILITY.  The ML functions
   172 Sign.root_path and Sign.local_path may be applied directly where this
   173 feature is still required for historical reasons.
   174 
   175 * Discontinued obsolete 'constdefs' command.  INCOMPATIBILITY, use
   176 'definition' instead.
   177 
   178 * The "prems" fact, which refers to the accidental collection of
   179 foundational premises in the context, is now explicitly marked as
   180 legacy feature and will be discontinued soon.  Consider using "assms"
   181 of the head statement or reference facts by explicit names.
   182 
   183 * Document antiquotations @{class} and @{type} print classes and type
   184 constructors.
   185 
   186 * Document antiquotation @{file} checks file/directory entries within
   187 the local file system.
   188 
   189 
   190 *** HOL ***
   191 
   192 * Coercive subtyping: functions can be declared as coercions and type
   193 inference will add them as necessary upon input of a term.  Theory
   194 Complex_Main declares real :: nat => real and real :: int => real as
   195 coercions. A coercion function f is declared like this:
   196 
   197   declare [[coercion f]]
   198 
   199 To lift coercions through type constructors (e.g. from nat => real to
   200 nat list => real list), map functions can be declared, e.g.
   201 
   202   declare [[coercion_map map]]
   203 
   204 Currently coercion inference is activated only in theories including
   205 real numbers, i.e. descendants of Complex_Main.  This is controlled by
   206 the configuration option "coercion_enabled", e.g. it can be enabled in
   207 other theories like this:
   208 
   209   declare [[coercion_enabled]]
   210 
   211 * Command 'partial_function' provides basic support for recursive
   212 function definitions over complete partial orders.  Concrete instances
   213 are provided for i) the option type, ii) tail recursion on arbitrary
   214 types, and iii) the heap monad of Imperative_HOL.  See
   215 src/HOL/ex/Fundefs.thy and src/HOL/Imperative_HOL/ex/Linked_Lists.thy
   216 for examples.
   217 
   218 * Function package: f.psimps rules are no longer implicitly declared
   219 as [simp].  INCOMPATIBILITY.
   220 
   221 * Datatype package: theorems generated for executable equality (class
   222 "eq") carry proper names and are treated as default code equations.
   223 
   224 * Inductive package: now offers command 'inductive_simps' to
   225 automatically derive instantiated and simplified equations for
   226 inductive predicates, similar to 'inductive_cases'.
   227 
   228 * Command 'enriched_type' allows to register properties of the
   229 functorial structure of types.
   230 
   231 * Improved infrastructure for term evaluation using code generator
   232 techniques, in particular static evaluation conversions.
   233 
   234 * Code generator: Scala (2.8 or higher) has been added to the target
   235 languages.
   236 
   237 * Code generator: globbing constant expressions "*" and "Theory.*"
   238 have been replaced by the more idiomatic "_" and "Theory._".
   239 INCOMPATIBILITY.
   240 
   241 * Code generator: export_code without explicit file declaration prints
   242 to standard output.  INCOMPATIBILITY.
   243 
   244 * Code generator: do not print function definitions for case
   245 combinators any longer.
   246 
   247 * Code generator: simplification with rules determined with
   248 src/Tools/Code/code_simp.ML and method "code_simp".
   249 
   250 * Code generator for records: more idiomatic representation of record
   251 types.  Warning: records are not covered by ancient SML code
   252 generation any longer.  INCOMPATIBILITY.  In cases of need, a suitable
   253 rep_datatype declaration helps to succeed then:
   254 
   255   record 'a foo = ...
   256   ...
   257   rep_datatype foo_ext ...
   258 
   259 * Records: logical foundation type for records does not carry a
   260 '_type' suffix any longer (obsolete due to authentic syntax).
   261 INCOMPATIBILITY.
   262 
   263 * Quickcheck now by default uses exhaustive testing instead of random
   264 testing.  Random testing can be invoked by "quickcheck [random]",
   265 exhaustive testing by "quickcheck [exhaustive]".
   266 
   267 * Quickcheck instantiates polymorphic types with small finite
   268 datatypes by default. This enables a simple execution mechanism to
   269 handle quantifiers and function equality over the finite datatypes.
   270 
   271 * Quickcheck random generator has been renamed from "code" to
   272 "random".  INCOMPATIBILITY.
   273 
   274 * Quickcheck now has a configurable time limit which is set to 30
   275 seconds by default. This can be changed by adding [timeout = n] to the
   276 quickcheck command. The time limit for Auto Quickcheck is still set
   277 independently.
   278 
   279 * Quickcheck in locales considers interpretations of that locale for
   280 counter example search.
   281 
   282 * Sledgehammer:
   283   - Added "smt" and "remote_smt" provers based on the "smt" proof
   284     method. See the Sledgehammer manual for details ("isabelle doc
   285     sledgehammer").
   286   - Renamed commands:
   287     sledgehammer atp_info ~> sledgehammer running_provers
   288     sledgehammer atp_kill ~> sledgehammer kill_provers
   289     sledgehammer available_atps ~> sledgehammer available_provers
   290     INCOMPATIBILITY.
   291   - Renamed options:
   292     sledgehammer [atps = ...] ~> sledgehammer [provers = ...]
   293     sledgehammer [atp = ...] ~> sledgehammer [prover = ...]
   294     sledgehammer [timeout = 77 s] ~> sledgehammer [timeout = 77]
   295     (and "ms" and "min" are no longer supported)
   296     INCOMPATIBILITY.
   297 
   298 * Nitpick:
   299   - Renamed options:
   300     nitpick [timeout = 77 s] ~> nitpick [timeout = 77]
   301     nitpick [tac_timeout = 777 ms] ~> nitpick [tac_timeout = 0.777]
   302     INCOMPATIBILITY.
   303   - Added support for partial quotient types.
   304   - Added local versions of the "Nitpick.register_xxx" functions.
   305   - Added "whack" option.
   306   - Allow registration of quotient types as codatatypes.
   307   - Improved "merge_type_vars" option to merge more types.
   308   - Removed unsound "fast_descrs" option.
   309   - Added custom symmetry breaking for datatypes, making it possible to reach
   310     higher cardinalities.
   311   - Prevent the expansion of too large definitions.
   312 
   313 * Proof methods "metis" and "meson" now have configuration options
   314 "meson_trace", "metis_trace", and "metis_verbose" that can be enabled
   315 to diagnose these tools. E.g.
   316 
   317     using [[metis_trace = true]]
   318 
   319 * Auto Solve: Renamed "Auto Solve Direct".  The tool is now available
   320 manually as command 'solve_direct'.
   321 
   322 * The default SMT solver Z3 must be enabled explicitly (due to
   323 licensing issues) by setting the environment variable
   324 Z3_NON_COMMERCIAL in etc/settings of the component, for example.  For
   325 commercial applications, the SMT solver CVC3 is provided as fall-back;
   326 changing the SMT solver is done via the configuration option
   327 "smt_solver".
   328 
   329 * Remote SMT solvers need to be referred to by the "remote_" prefix,
   330 i.e. "remote_cvc3" and "remote_z3".
   331 
   332 * Added basic SMT support for datatypes, records, and typedefs using
   333 the oracle mode (no proofs).  Direct support of pairs has been dropped
   334 in exchange (pass theorems fst_conv snd_conv pair_collapse to the SMT
   335 support for a similar behavior).  Minor INCOMPATIBILITY.
   336 
   337 * Changed SMT configuration options:
   338   - Renamed:
   339     z3_proofs ~> smt_oracle (with inverted meaning)
   340     z3_trace_assms ~> smt_trace_used_facts
   341     INCOMPATIBILITY.
   342   - Added:
   343     smt_verbose
   344     smt_random_seed
   345     smt_datatypes
   346     smt_infer_triggers
   347     smt_monomorph_limit
   348     cvc3_options
   349     remote_cvc3_options
   350     remote_z3_options
   351     yices_options
   352 
   353 * Boogie output files (.b2i files) need to be declared in the theory
   354 header.
   355 
   356 * Simplification procedure "list_to_set_comprehension" rewrites list
   357 comprehensions applied to List.set to set comprehensions.  Occasional
   358 INCOMPATIBILITY, may be deactivated like this:
   359 
   360   declare [[simproc del: list_to_set_comprehension]]
   361 
   362 * Removed old version of primrec package.  INCOMPATIBILITY.
   363 
   364 * Removed simplifier congruence rule of "prod_case", as has for long
   365 been the case with "split".  INCOMPATIBILITY.
   366 
   367 * String.literal is a type, but not a datatype.  INCOMPATIBILITY.
   368 
   369 * Removed [split_format ... and ... and ...] version of
   370 [split_format].  Potential INCOMPATIBILITY.
   371 
   372 * Predicate "sorted" now defined inductively, with nice induction
   373 rules.  INCOMPATIBILITY: former sorted.simps now named sorted_simps.
   374 
   375 * Constant "contents" renamed to "the_elem", to free the generic name
   376 contents for other uses.  INCOMPATIBILITY.
   377 
   378 * Renamed class eq and constant eq (for code generation) to class
   379 equal and constant equal, plus renaming of related facts and various
   380 tuning.  INCOMPATIBILITY.
   381 
   382 * Dropped type classes mult_mono and mult_mono1.  INCOMPATIBILITY.
   383 
   384 * Removed output syntax "'a ~=> 'b" for "'a => 'b option".
   385 INCOMPATIBILITY.
   386 
   387 * Renamed theory Fset to Cset, type Fset.fset to Cset.set, in order to
   388 avoid confusion with finite sets.  INCOMPATIBILITY.
   389 
   390 * Abandoned locales equiv, congruent and congruent2 for equivalence
   391 relations.  INCOMPATIBILITY: use equivI rather than equiv_intro (same
   392 for congruent(2)).
   393 
   394 * Some previously unqualified names have been qualified:
   395 
   396   types
   397     bool ~> HOL.bool
   398     nat ~> Nat.nat
   399 
   400   constants
   401     Trueprop ~> HOL.Trueprop
   402     True ~> HOL.True
   403     False ~> HOL.False
   404     op & ~> HOL.conj
   405     op | ~> HOL.disj
   406     op --> ~> HOL.implies
   407     op = ~> HOL.eq
   408     Not ~> HOL.Not
   409     The ~> HOL.The
   410     All ~> HOL.All
   411     Ex ~> HOL.Ex
   412     Ex1 ~> HOL.Ex1
   413     Let ~> HOL.Let
   414     If ~> HOL.If
   415     Ball ~> Set.Ball
   416     Bex ~> Set.Bex
   417     Suc ~> Nat.Suc
   418     Pair ~> Product_Type.Pair
   419     fst ~> Product_Type.fst
   420     snd ~> Product_Type.snd
   421     curry ~> Product_Type.curry
   422     op : ~> Set.member
   423     Collect ~> Set.Collect
   424 
   425 INCOMPATIBILITY.
   426 
   427 * More canonical naming convention for some fundamental definitions:
   428 
   429     bot_bool_eq ~> bot_bool_def
   430     top_bool_eq ~> top_bool_def
   431     inf_bool_eq ~> inf_bool_def
   432     sup_bool_eq ~> sup_bool_def
   433     bot_fun_eq  ~> bot_fun_def
   434     top_fun_eq  ~> top_fun_def
   435     inf_fun_eq  ~> inf_fun_def
   436     sup_fun_eq  ~> sup_fun_def
   437 
   438 INCOMPATIBILITY.
   439 
   440 * More stylized fact names:
   441 
   442   expand_fun_eq ~> fun_eq_iff
   443   expand_set_eq ~> set_eq_iff
   444   set_ext       ~> set_eqI
   445   nat_number    ~> eval_nat_numeral
   446 
   447 INCOMPATIBILITY.
   448 
   449 * Refactoring of code-generation specific operations in theory List:
   450 
   451   constants
   452     null ~> List.null
   453 
   454   facts
   455     mem_iff ~> member_def
   456     null_empty ~> null_def
   457 
   458 INCOMPATIBILITY.  Note that these were not supposed to be used
   459 regularly unless for striking reasons; their main purpose was code
   460 generation.
   461 
   462 Various operations from the Haskell prelude are used for generating
   463 Haskell code.
   464 
   465 * Term "bij f" is now an abbreviation of "bij_betw f UNIV UNIV".  Term
   466 "surj f" is now an abbreviation of "range f = UNIV".  The theorems
   467 bij_def and surj_def are unchanged.  INCOMPATIBILITY.
   468 
   469 * Abolished some non-alphabetic type names: "prod" and "sum" replace
   470 "*" and "+" respectively.  INCOMPATIBILITY.
   471 
   472 * Name "Plus" of disjoint sum operator "<+>" is now hidden.  Write
   473 "Sum_Type.Plus" instead.
   474 
   475 * Constant "split" has been merged with constant "prod_case"; names of
   476 ML functions, facts etc. involving split have been retained so far,
   477 though.  INCOMPATIBILITY.
   478 
   479 * Dropped old infix syntax "_ mem _" for List.member; use "_ : set _"
   480 instead.  INCOMPATIBILITY.
   481 
   482 * Removed lemma "Option.is_none_none" which duplicates "is_none_def".
   483 INCOMPATIBILITY.
   484 
   485 * Former theory Library/Enum is now part of the HOL-Main image.
   486 INCOMPATIBILITY: all constants of the Enum theory now have to be
   487 referred to by its qualified name.
   488 
   489   enum    ~>  Enum.enum
   490   nlists  ~>  Enum.nlists
   491   product ~>  Enum.product
   492 
   493 * Theory Library/Monad_Syntax provides do-syntax for monad types.
   494 Syntax in Library/State_Monad has been changed to avoid ambiguities.
   495 INCOMPATIBILITY.
   496 
   497 * Theory Library/SetsAndFunctions has been split into
   498 Library/Function_Algebras and Library/Set_Algebras; canonical names
   499 for instance definitions for functions; various improvements.
   500 INCOMPATIBILITY.
   501 
   502 * Theory Library/Multiset provides stable quicksort implementation of
   503 sort_key.
   504 
   505 * Theory Library/Multiset: renamed empty_idemp ~> empty_neutral.
   506 INCOMPATIBILITY.
   507 
   508 * Session Multivariate_Analysis: introduced a type class for euclidean
   509 space.  Most theorems are now stated in terms of euclidean spaces
   510 instead of finite cartesian products.
   511 
   512   types
   513     real ^ 'n ~>  'a::real_vector
   514               ~>  'a::euclidean_space
   515               ~>  'a::ordered_euclidean_space
   516         (depends on your needs)
   517 
   518   constants
   519      _ $ _        ~> _ $$ _
   520      \<chi> x. _  ~> \<chi>\<chi> x. _
   521      CARD('n)     ~> DIM('a)
   522 
   523 Also note that the indices are now natural numbers and not from some
   524 finite type. Finite cartesian products of euclidean spaces, products
   525 of euclidean spaces the real and complex numbers are instantiated to
   526 be euclidean_spaces.  INCOMPATIBILITY.
   527 
   528 * Session Probability: introduced pextreal as positive extended real
   529 numbers.  Use pextreal as value for measures.  Introduce the
   530 Radon-Nikodym derivative, product spaces and Fubini's theorem for
   531 arbitrary sigma finite measures.  Introduces Lebesgue measure based on
   532 the integral in Multivariate Analysis.  INCOMPATIBILITY.
   533 
   534 * Session Imperative_HOL: revamped, corrected dozens of inadequacies.
   535 INCOMPATIBILITY.
   536 
   537 * Session SPARK (with image HOL-SPARK) provides commands to load and
   538 prove verification conditions generated by the SPARK Ada program
   539 verifier.  See also src/HOL/SPARK and src/HOL/SPARK/Examples.
   540 
   541 
   542 *** HOL-Algebra ***
   543 
   544 * Theorems for additive ring operations (locale abelian_monoid and
   545 descendants) are generated by interpretation from their multiplicative
   546 counterparts.  Names (in particular theorem names) have the mandatory
   547 qualifier 'add'.  Previous theorem names are redeclared for
   548 compatibility.
   549 
   550 * Structure "int_ring" is now an abbreviation (previously a
   551 definition).  This fits more natural with advanced interpretations.
   552 
   553 
   554 *** HOLCF ***
   555 
   556 * The domain package now runs in definitional mode by default: The
   557 former command 'new_domain' is now called 'domain'.  To use the domain
   558 package in its original axiomatic mode, use 'domain (unsafe)'.
   559 INCOMPATIBILITY.
   560 
   561 * The new class "domain" is now the default sort.  Class "predomain"
   562 is an unpointed version of "domain". Theories can be updated by
   563 replacing sort annotations as shown below.  INCOMPATIBILITY.
   564 
   565   'a::type ~> 'a::countable
   566   'a::cpo  ~> 'a::predomain
   567   'a::pcpo ~> 'a::domain
   568 
   569 * The old type class "rep" has been superseded by class "domain".
   570 Accordingly, users of the definitional package must remove any
   571 "default_sort rep" declarations.  INCOMPATIBILITY.
   572 
   573 * The domain package (definitional mode) now supports unpointed
   574 predomain argument types, as long as they are marked 'lazy'. (Strict
   575 arguments must be in class "domain".) For example, the following
   576 domain definition now works:
   577 
   578   domain natlist = nil | cons (lazy "nat discr") (lazy "natlist")
   579 
   580 * Theory HOLCF/Library/HOL_Cpo provides cpo and predomain class
   581 instances for types from main HOL: bool, nat, int, char, 'a + 'b,
   582 'a option, and 'a list.  Additionally, it configures fixrec and the
   583 domain package to work with these types.  For example:
   584 
   585   fixrec isInl :: "('a + 'b) u -> tr"
   586     where "isInl$(up$(Inl x)) = TT" | "isInl$(up$(Inr y)) = FF"
   587 
   588   domain V = VFun (lazy "V -> V") | VCon (lazy "nat") (lazy "V list")
   589 
   590 * The "(permissive)" option of fixrec has been replaced with a
   591 per-equation "(unchecked)" option. See
   592 src/HOL/HOLCF/Tutorial/Fixrec_ex.thy for examples. INCOMPATIBILITY.
   593 
   594 * The "bifinite" class no longer fixes a constant "approx"; the class
   595 now just asserts that such a function exists.  INCOMPATIBILITY.
   596 
   597 * Former type "alg_defl" has been renamed to "defl".  HOLCF no longer
   598 defines an embedding of type 'a defl into udom by default; instances
   599 of "bifinite" and "domain" classes are available in
   600 src/HOL/HOLCF/Library/Defl_Bifinite.thy.
   601 
   602 * The syntax "REP('a)" has been replaced with "DEFL('a)".
   603 
   604 * The predicate "directed" has been removed.  INCOMPATIBILITY.
   605 
   606 * The type class "finite_po" has been removed.  INCOMPATIBILITY.
   607 
   608 * The function "cprod_map" has been renamed to "prod_map".
   609 INCOMPATIBILITY.
   610 
   611 * The monadic bind operator on each powerdomain has new binder syntax
   612 similar to sets, e.g. "\<Union>\<sharp>x\<in>xs. t" represents
   613 "upper_bind\<cdot>xs\<cdot>(\<Lambda> x. t)".
   614 
   615 * The infix syntax for binary union on each powerdomain has changed
   616 from e.g. "+\<sharp>" to "\<union>\<sharp>", for consistency with set
   617 syntax.  INCOMPATIBILITY.
   618 
   619 * The constant "UU" has been renamed to "bottom".  The syntax "UU" is
   620 still supported as an input translation.
   621 
   622 * Renamed some theorems (the original names are also still available).
   623 
   624   expand_fun_below   ~> fun_below_iff
   625   below_fun_ext      ~> fun_belowI
   626   expand_cfun_eq     ~> cfun_eq_iff
   627   ext_cfun           ~> cfun_eqI
   628   expand_cfun_below  ~> cfun_below_iff
   629   below_cfun_ext     ~> cfun_belowI
   630   cont2cont_Rep_CFun ~> cont2cont_APP
   631 
   632 * The Abs and Rep functions for various types have changed names.
   633 Related theorem names have also changed to match. INCOMPATIBILITY.
   634 
   635   Rep_CFun  ~> Rep_cfun
   636   Abs_CFun  ~> Abs_cfun
   637   Rep_Sprod ~> Rep_sprod
   638   Abs_Sprod ~> Abs_sprod
   639   Rep_Ssum  ~> Rep_ssum
   640   Abs_Ssum  ~> Abs_ssum
   641 
   642 * Lemmas with names of the form *_defined_iff or *_strict_iff have
   643 been renamed to *_bottom_iff.  INCOMPATIBILITY.
   644 
   645 * Various changes to bisimulation/coinduction with domain package:
   646 
   647   - Definitions of "bisim" constants no longer mention definedness.
   648   - With mutual recursion, "bisim" predicate is now curried.
   649   - With mutual recursion, each type gets a separate coind theorem.
   650   - Variable names in bisim_def and coinduct rules have changed.
   651 
   652 INCOMPATIBILITY.
   653 
   654 * Case combinators generated by the domain package for type "foo" are
   655 now named "foo_case" instead of "foo_when".  INCOMPATIBILITY.
   656 
   657 * Several theorems have been renamed to more accurately reflect the
   658 names of constants and types involved.  INCOMPATIBILITY.
   659 
   660   thelub_const    ~> lub_const
   661   lub_const       ~> is_lub_const
   662   thelubI         ~> lub_eqI
   663   is_lub_lub      ~> is_lubD2
   664   lubI            ~> is_lub_lub
   665   unique_lub      ~> is_lub_unique
   666   is_ub_lub       ~> is_lub_rangeD1
   667   lub_bin_chain   ~> is_lub_bin_chain
   668   lub_fun         ~> is_lub_fun
   669   thelub_fun      ~> lub_fun
   670   thelub_cfun     ~> lub_cfun
   671   thelub_Pair     ~> lub_Pair
   672   lub_cprod       ~> is_lub_prod
   673   thelub_cprod    ~> lub_prod
   674   minimal_cprod   ~> minimal_prod
   675   inst_cprod_pcpo ~> inst_prod_pcpo
   676   UU_I            ~> bottomI
   677   compact_UU      ~> compact_bottom
   678   deflation_UU    ~> deflation_bottom
   679   finite_deflation_UU ~> finite_deflation_bottom
   680 
   681 * Many legacy theorem names have been discontinued.  INCOMPATIBILITY.
   682 
   683   sq_ord_less_eq_trans ~> below_eq_trans
   684   sq_ord_eq_less_trans ~> eq_below_trans
   685   refl_less            ~> below_refl
   686   trans_less           ~> below_trans
   687   antisym_less         ~> below_antisym
   688   antisym_less_inverse ~> po_eq_conv [THEN iffD1]
   689   box_less             ~> box_below
   690   rev_trans_less       ~> rev_below_trans
   691   not_less2not_eq      ~> not_below2not_eq
   692   less_UU_iff          ~> below_UU_iff
   693   flat_less_iff        ~> flat_below_iff
   694   adm_less             ~> adm_below
   695   adm_not_less         ~> adm_not_below
   696   adm_compact_not_less ~> adm_compact_not_below
   697   less_fun_def         ~> below_fun_def
   698   expand_fun_less      ~> fun_below_iff
   699   less_fun_ext         ~> fun_belowI
   700   less_discr_def       ~> below_discr_def
   701   discr_less_eq        ~> discr_below_eq
   702   less_unit_def        ~> below_unit_def
   703   less_cprod_def       ~> below_prod_def
   704   prod_lessI           ~> prod_belowI
   705   Pair_less_iff        ~> Pair_below_iff
   706   fst_less_iff         ~> fst_below_iff
   707   snd_less_iff         ~> snd_below_iff
   708   expand_cfun_less     ~> cfun_below_iff
   709   less_cfun_ext        ~> cfun_belowI
   710   injection_less       ~> injection_below
   711   less_up_def          ~> below_up_def
   712   not_Iup_less         ~> not_Iup_below
   713   Iup_less             ~> Iup_below
   714   up_less              ~> up_below
   715   Def_inject_less_eq   ~> Def_below_Def
   716   Def_less_is_eq       ~> Def_below_iff
   717   spair_less_iff       ~> spair_below_iff
   718   less_sprod           ~> below_sprod
   719   spair_less           ~> spair_below
   720   sfst_less_iff        ~> sfst_below_iff
   721   ssnd_less_iff        ~> ssnd_below_iff
   722   fix_least_less       ~> fix_least_below
   723   dist_less_one        ~> dist_below_one
   724   less_ONE             ~> below_ONE
   725   ONE_less_iff         ~> ONE_below_iff
   726   less_sinlD           ~> below_sinlD
   727   less_sinrD           ~> below_sinrD
   728 
   729 
   730 *** FOL and ZF ***
   731 
   732 * All constant names are now qualified internally and use proper
   733 identifiers, e.g. "IFOL.eq" instead of "op =".  INCOMPATIBILITY.
   734 
   735 
   736 *** ML ***
   737 
   738 * Antiquotation @{assert} inlines a function bool -> unit that raises
   739 Fail if the argument is false.  Due to inlining the source position of
   740 failed assertions is included in the error output.
   741 
   742 * Discontinued antiquotation @{theory_ref}, which is obsolete since ML
   743 text is in practice always evaluated with a stable theory checkpoint.
   744 Minor INCOMPATIBILITY, use (Theory.check_thy @{theory}) instead.
   745 
   746 * Antiquotation @{theory A} refers to theory A from the ancestry of
   747 the current context, not any accidental theory loader state as before.
   748 Potential INCOMPATIBILITY, subtle change in semantics.
   749 
   750 * Syntax.pretty_priority (default 0) configures the required priority
   751 of pretty-printed output and thus affects insertion of parentheses.
   752 
   753 * Syntax.default_root (default "any") configures the inner syntax
   754 category (nonterminal symbol) for parsing of terms.
   755 
   756 * Former exception Library.UnequalLengths now coincides with
   757 ListPair.UnequalLengths.
   758 
   759 * Renamed structure MetaSimplifier to Raw_Simplifier.  Note that the
   760 main functionality is provided by structure Simplifier.
   761 
   762 * Renamed raw "explode" function to "raw_explode" to emphasize its
   763 meaning.  Note that internally to Isabelle, Symbol.explode is used in
   764 almost all situations.
   765 
   766 * Discontinued obsolete function sys_error and exception SYS_ERROR.
   767 See implementation manual for further details on exceptions in
   768 Isabelle/ML.
   769 
   770 * Renamed setmp_noncritical to Unsynchronized.setmp to emphasize its
   771 meaning.
   772 
   773 * Renamed structure PureThy to Pure_Thy and moved most of its
   774 operations to structure Global_Theory, to emphasize that this is
   775 rarely-used global-only stuff.
   776 
   777 * Discontinued Output.debug.  Minor INCOMPATIBILITY, use plain writeln
   778 instead (or tracing for high-volume output).
   779 
   780 * Configuration option show_question_marks only affects regular pretty
   781 printing of types and terms, not raw Term.string_of_vname.
   782 
   783 * ML_Context.thm and ML_Context.thms are no longer pervasive.  Rare
   784 INCOMPATIBILITY, superseded by static antiquotations @{thm} and
   785 @{thms} for most purposes.
   786 
   787 * ML structure Unsynchronized is never opened, not even in Isar
   788 interaction mode as before.  Old Unsynchronized.set etc. have been
   789 discontinued -- use plain := instead.  This should be *rare* anyway,
   790 since modern tools always work via official context data, notably
   791 configuration options.
   792 
   793 * Parallel and asynchronous execution requires special care concerning
   794 interrupts.  Structure Exn provides some convenience functions that
   795 avoid working directly with raw Interrupt.  User code must not absorb
   796 interrupts -- intermediate handling (for cleanup etc.) needs to be
   797 followed by re-raising of the original exception.  Another common
   798 source of mistakes are "handle _" patterns, which make the meaning of
   799 the program subject to physical effects of the environment.
   800 
   801 
   802 
   803 New in Isabelle2009-2 (June 2010)
   804 ---------------------------------
   805 
   806 *** General ***
   807 
   808 * Authentic syntax for *all* logical entities (type classes, type
   809 constructors, term constants): provides simple and robust
   810 correspondence between formal entities and concrete syntax.  Within
   811 the parse tree / AST representations, "constants" are decorated by
   812 their category (class, type, const) and spelled out explicitly with
   813 their full internal name.
   814 
   815 Substantial INCOMPATIBILITY concerning low-level syntax declarations
   816 and translations (translation rules and translation functions in ML).
   817 Some hints on upgrading:
   818 
   819   - Many existing uses of 'syntax' and 'translations' can be replaced
   820     by more modern 'type_notation', 'notation' and 'abbreviation',
   821     which are independent of this issue.
   822 
   823   - 'translations' require markup within the AST; the term syntax
   824     provides the following special forms:
   825 
   826       CONST c   -- produces syntax version of constant c from context
   827       XCONST c  -- literally c, checked as constant from context
   828       c         -- literally c, if declared by 'syntax'
   829 
   830     Plain identifiers are treated as AST variables -- occasionally the
   831     system indicates accidental variables via the error "rhs contains
   832     extra variables".
   833 
   834     Type classes and type constructors are marked according to their
   835     concrete syntax.  Some old translations rules need to be written
   836     for the "type" category, using type constructor application
   837     instead of pseudo-term application of the default category
   838     "logic".
   839 
   840   - 'parse_translation' etc. in ML may use the following
   841     antiquotations:
   842 
   843       @{class_syntax c}   -- type class c within parse tree / AST
   844       @{term_syntax c}    -- type constructor c within parse tree / AST
   845       @{const_syntax c}   -- ML version of "CONST c" above
   846       @{syntax_const c}   -- literally c (checked wrt. 'syntax' declarations)
   847 
   848   - Literal types within 'typed_print_translations', i.e. those *not*
   849     represented as pseudo-terms are represented verbatim.  Use @{class
   850     c} or @{type_name c} here instead of the above syntax
   851     antiquotations.
   852 
   853 Note that old non-authentic syntax was based on unqualified base
   854 names, so all of the above "constant" names would coincide.  Recall
   855 that 'print_syntax' and ML_command "set Syntax.trace_ast" help to
   856 diagnose syntax problems.
   857 
   858 * Type constructors admit general mixfix syntax, not just infix.
   859 
   860 * Concrete syntax may be attached to local entities without a proof
   861 body, too.  This works via regular mixfix annotations for 'fix',
   862 'def', 'obtain' etc. or via the explicit 'write' command, which is
   863 similar to the 'notation' command in theory specifications.
   864 
   865 * Discontinued unnamed infix syntax (legacy feature for many years) --
   866 need to specify constant name and syntax separately.  Internal ML
   867 datatype constructors have been renamed from InfixName to Infix etc.
   868 Minor INCOMPATIBILITY.
   869 
   870 * Schematic theorem statements need to be explicitly markup as such,
   871 via commands 'schematic_lemma', 'schematic_theorem',
   872 'schematic_corollary'.  Thus the relevance of the proof is made
   873 syntactically clear, which impacts performance in a parallel or
   874 asynchronous interactive environment.  Minor INCOMPATIBILITY.
   875 
   876 * Use of cumulative prems via "!" in some proof methods has been
   877 discontinued (old legacy feature).
   878 
   879 * References 'trace_simp' and 'debug_simp' have been replaced by
   880 configuration options stored in the context. Enabling tracing (the
   881 case of debugging is similar) in proofs works via
   882 
   883   using [[trace_simp = true]]
   884 
   885 Tracing is then active for all invocations of the simplifier in
   886 subsequent goal refinement steps. Tracing may also still be enabled or
   887 disabled via the ProofGeneral settings menu.
   888 
   889 * Separate commands 'hide_class', 'hide_type', 'hide_const',
   890 'hide_fact' replace the former 'hide' KIND command.  Minor
   891 INCOMPATIBILITY.
   892 
   893 * Improved parallelism of proof term normalization: usedir -p2 -q0 is
   894 more efficient than combinations with -q1 or -q2.
   895 
   896 
   897 *** Pure ***
   898 
   899 * Proofterms record type-class reasoning explicitly, using the
   900 "unconstrain" operation internally.  This eliminates all sort
   901 constraints from a theorem and proof, introducing explicit
   902 OFCLASS-premises.  On the proof term level, this operation is
   903 automatically applied at theorem boundaries, such that closed proofs
   904 are always free of sort constraints.  INCOMPATIBILITY for tools that
   905 inspect proof terms.
   906 
   907 * Local theory specifications may depend on extra type variables that
   908 are not present in the result type -- arguments TYPE('a) :: 'a itself
   909 are added internally.  For example:
   910 
   911   definition unitary :: bool where "unitary = (ALL (x::'a) y. x = y)"
   912 
   913 * Predicates of locales introduced by classes carry a mandatory
   914 "class" prefix.  INCOMPATIBILITY.
   915 
   916 * Vacuous class specifications observe default sort.  INCOMPATIBILITY.
   917 
   918 * Old 'axclass' command has been discontinued.  INCOMPATIBILITY, use
   919 'class' instead.
   920 
   921 * Command 'code_reflect' allows to incorporate generated ML code into
   922 runtime environment; replaces immature code_datatype antiquotation.
   923 INCOMPATIBILITY.
   924 
   925 * Code generator: simple concept for abstract datatypes obeying
   926 invariants.
   927 
   928 * Code generator: details of internal data cache have no impact on the
   929 user space functionality any longer.
   930 
   931 * Methods "unfold_locales" and "intro_locales" ignore non-locale
   932 subgoals.  This is more appropriate for interpretations with 'where'.
   933 INCOMPATIBILITY.
   934 
   935 * Command 'example_proof' opens an empty proof body.  This allows to
   936 experiment with Isar, without producing any persistent result.
   937 
   938 * Commands 'type_notation' and 'no_type_notation' declare type syntax
   939 within a local theory context, with explicit checking of the
   940 constructors involved (in contrast to the raw 'syntax' versions).
   941 
   942 * Commands 'types' and 'typedecl' now work within a local theory
   943 context -- without introducing dependencies on parameters or
   944 assumptions, which is not possible in Isabelle/Pure.
   945 
   946 * Command 'defaultsort' has been renamed to 'default_sort', it works
   947 within a local theory context.  Minor INCOMPATIBILITY.
   948 
   949 
   950 *** HOL ***
   951 
   952 * Command 'typedef' now works within a local theory context -- without
   953 introducing dependencies on parameters or assumptions, which is not
   954 possible in Isabelle/Pure/HOL.  Note that the logical environment may
   955 contain multiple interpretations of local typedefs (with different
   956 non-emptiness proofs), even in a global theory context.
   957 
   958 * New package for quotient types.  Commands 'quotient_type' and
   959 'quotient_definition' may be used for defining types and constants by
   960 quotient constructions.  An example is the type of integers created by
   961 quotienting pairs of natural numbers:
   962 
   963   fun
   964     intrel :: "(nat * nat) => (nat * nat) => bool"
   965   where
   966     "intrel (x, y) (u, v) = (x + v = u + y)"
   967 
   968   quotient_type int = "nat * nat" / intrel
   969     by (auto simp add: equivp_def expand_fun_eq)
   970 
   971   quotient_definition
   972     "0::int" is "(0::nat, 0::nat)"
   973 
   974 The method "lifting" can be used to lift of theorems from the
   975 underlying "raw" type to the quotient type.  The example
   976 src/HOL/Quotient_Examples/FSet.thy includes such a quotient
   977 construction and provides a reasoning infrastructure for finite sets.
   978 
   979 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
   980 clash with new theory Quotient in Main HOL.
   981 
   982 * Moved the SMT binding into the main HOL session, eliminating
   983 separate HOL-SMT session.
   984 
   985 * List membership infix mem operation is only an input abbreviation.
   986 INCOMPATIBILITY.
   987 
   988 * Theory Library/Word.thy has been removed.  Use library Word/Word.thy
   989 for future developements; former Library/Word.thy is still present in
   990 the AFP entry RSAPPS.
   991 
   992 * Theorem Int.int_induct renamed to Int.int_of_nat_induct and is no
   993 longer shadowed.  INCOMPATIBILITY.
   994 
   995 * Dropped theorem duplicate comp_arith; use semiring_norm instead.
   996 INCOMPATIBILITY.
   997 
   998 * Dropped theorem RealPow.real_sq_order; use power2_le_imp_le instead.
   999 INCOMPATIBILITY.
  1000 
  1001 * Dropped normalizing_semiring etc; use the facts in semiring classes
  1002 instead.  INCOMPATIBILITY.
  1003 
  1004 * Dropped several real-specific versions of lemmas about floor and
  1005 ceiling; use the generic lemmas from theory "Archimedean_Field"
  1006 instead.  INCOMPATIBILITY.
  1007 
  1008   floor_number_of_eq         ~> floor_number_of
  1009   le_floor_eq_number_of      ~> number_of_le_floor
  1010   le_floor_eq_zero           ~> zero_le_floor
  1011   le_floor_eq_one            ~> one_le_floor
  1012   floor_less_eq_number_of    ~> floor_less_number_of
  1013   floor_less_eq_zero         ~> floor_less_zero
  1014   floor_less_eq_one          ~> floor_less_one
  1015   less_floor_eq_number_of    ~> number_of_less_floor
  1016   less_floor_eq_zero         ~> zero_less_floor
  1017   less_floor_eq_one          ~> one_less_floor
  1018   floor_le_eq_number_of      ~> floor_le_number_of
  1019   floor_le_eq_zero           ~> floor_le_zero
  1020   floor_le_eq_one            ~> floor_le_one
  1021   floor_subtract_number_of   ~> floor_diff_number_of
  1022   floor_subtract_one         ~> floor_diff_one
  1023   ceiling_number_of_eq       ~> ceiling_number_of
  1024   ceiling_le_eq_number_of    ~> ceiling_le_number_of
  1025   ceiling_le_zero_eq         ~> ceiling_le_zero
  1026   ceiling_le_eq_one          ~> ceiling_le_one
  1027   less_ceiling_eq_number_of  ~> number_of_less_ceiling
  1028   less_ceiling_eq_zero       ~> zero_less_ceiling
  1029   less_ceiling_eq_one        ~> one_less_ceiling
  1030   ceiling_less_eq_number_of  ~> ceiling_less_number_of
  1031   ceiling_less_eq_zero       ~> ceiling_less_zero
  1032   ceiling_less_eq_one        ~> ceiling_less_one
  1033   le_ceiling_eq_number_of    ~> number_of_le_ceiling
  1034   le_ceiling_eq_zero         ~> zero_le_ceiling
  1035   le_ceiling_eq_one          ~> one_le_ceiling
  1036   ceiling_subtract_number_of ~> ceiling_diff_number_of
  1037   ceiling_subtract_one       ~> ceiling_diff_one
  1038 
  1039 * Theory "Finite_Set": various folding_XXX locales facilitate the
  1040 application of the various fold combinators on finite sets.
  1041 
  1042 * Library theory "RBT" renamed to "RBT_Impl"; new library theory "RBT"
  1043 provides abstract red-black tree type which is backed by "RBT_Impl" as
  1044 implementation.  INCOMPATIBILTY.
  1045 
  1046 * Theory Library/Coinductive_List has been removed -- superseded by
  1047 AFP/thys/Coinductive.
  1048 
  1049 * Theory PReal, including the type "preal" and related operations, has
  1050 been removed.  INCOMPATIBILITY.
  1051 
  1052 * Real: new development using Cauchy Sequences.
  1053 
  1054 * Split off theory "Big_Operators" containing setsum, setprod,
  1055 Inf_fin, Sup_fin, Min, Max from theory Finite_Set.  INCOMPATIBILITY.
  1056 
  1057 * Theory "Rational" renamed to "Rat", for consistency with "Nat",
  1058 "Int" etc.  INCOMPATIBILITY.
  1059 
  1060 * Constant Rat.normalize needs to be qualified.  INCOMPATIBILITY.
  1061 
  1062 * New set of rules "ac_simps" provides combined assoc / commute
  1063 rewrites for all interpretations of the appropriate generic locales.
  1064 
  1065 * Renamed theory "OrderedGroup" to "Groups" and split theory
  1066 "Ring_and_Field" into theories "Rings" and "Fields"; for more
  1067 appropriate and more consistent names suitable for name prefixes
  1068 within the HOL theories.  INCOMPATIBILITY.
  1069 
  1070 * Some generic constants have been put to appropriate theories:
  1071   - less_eq, less: Orderings
  1072   - zero, one, plus, minus, uminus, times, abs, sgn: Groups
  1073   - inverse, divide: Rings
  1074 INCOMPATIBILITY.
  1075 
  1076 * More consistent naming of type classes involving orderings (and
  1077 lattices):
  1078 
  1079     lower_semilattice                   ~> semilattice_inf
  1080     upper_semilattice                   ~> semilattice_sup
  1081 
  1082     dense_linear_order                  ~> dense_linorder
  1083 
  1084     pordered_ab_group_add               ~> ordered_ab_group_add
  1085     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
  1086     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
  1087     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
  1088     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
  1089     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
  1090     pordered_cancel_semiring            ~> ordered_cancel_semiring
  1091     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
  1092     pordered_comm_ring                  ~> ordered_comm_ring
  1093     pordered_comm_semiring              ~> ordered_comm_semiring
  1094     pordered_ring                       ~> ordered_ring
  1095     pordered_ring_abs                   ~> ordered_ring_abs
  1096     pordered_semiring                   ~> ordered_semiring
  1097 
  1098     ordered_ab_group_add                ~> linordered_ab_group_add
  1099     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
  1100     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
  1101     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
  1102     ordered_field                       ~> linordered_field
  1103     ordered_field_no_lb                 ~> linordered_field_no_lb
  1104     ordered_field_no_ub                 ~> linordered_field_no_ub
  1105     ordered_field_dense_linear_order    ~> dense_linordered_field
  1106     ordered_idom                        ~> linordered_idom
  1107     ordered_ring                        ~> linordered_ring
  1108     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
  1109     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
  1110     ordered_ring_strict                 ~> linordered_ring_strict
  1111     ordered_semidom                     ~> linordered_semidom
  1112     ordered_semiring                    ~> linordered_semiring
  1113     ordered_semiring_1                  ~> linordered_semiring_1
  1114     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
  1115     ordered_semiring_strict             ~> linordered_semiring_strict
  1116 
  1117   The following slightly odd type classes have been moved to a
  1118   separate theory Library/Lattice_Algebras:
  1119 
  1120     lordered_ab_group_add               ~> lattice_ab_group_add
  1121     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
  1122     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
  1123     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
  1124     lordered_ring                       ~> lattice_ring
  1125 
  1126 INCOMPATIBILITY.
  1127 
  1128 * Refined field classes:
  1129   - classes division_ring_inverse_zero, field_inverse_zero,
  1130     linordered_field_inverse_zero include rule inverse 0 = 0 --
  1131     subsumes former division_by_zero class;
  1132   - numerous lemmas have been ported from field to division_ring.
  1133 INCOMPATIBILITY.
  1134 
  1135 * Refined algebra theorem collections:
  1136   - dropped theorem group group_simps, use algebra_simps instead;
  1137   - dropped theorem group ring_simps, use field_simps instead;
  1138   - proper theorem collection field_simps subsumes former theorem
  1139     groups field_eq_simps and field_simps;
  1140   - dropped lemma eq_minus_self_iff which is a duplicate for
  1141     equal_neg_zero.
  1142 INCOMPATIBILITY.
  1143 
  1144 * Theory Finite_Set and List: some lemmas have been generalized from
  1145 sets to lattices:
  1146 
  1147   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
  1148   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
  1149   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
  1150   union_Union_fold_union        ~> sup_Sup_fold_sup
  1151   Inter_fold_inter              ~> Inf_fold_inf
  1152   Union_fold_union              ~> Sup_fold_sup
  1153   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
  1154   union_UNION_fold_union        ~> sup_SUPR_fold_sup
  1155   INTER_fold_inter              ~> INFI_fold_inf
  1156   UNION_fold_union              ~> SUPR_fold_sup
  1157 
  1158 * Theory "Complete_Lattice": lemmas top_def and bot_def have been
  1159 replaced by the more convenient lemmas Inf_empty and Sup_empty.
  1160 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
  1161 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
  1162 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
  1163 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
  1164 
  1165 * Reorganized theory Multiset: swapped notation of pointwise and
  1166 multiset order:
  1167 
  1168   - pointwise ordering is instance of class order with standard syntax
  1169     <= and <;
  1170   - multiset ordering has syntax <=# and <#; partial order properties
  1171     are provided by means of interpretation with prefix
  1172     multiset_order;
  1173   - less duplication, less historical organization of sections,
  1174     conversion from associations lists to multisets, rudimentary code
  1175     generation;
  1176   - use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union,
  1177     if needed.
  1178 
  1179 Renamed:
  1180 
  1181   multiset_eq_conv_count_eq  ~>  multiset_ext_iff
  1182   multi_count_ext  ~>  multiset_ext
  1183   diff_union_inverse2  ~>  diff_union_cancelR
  1184 
  1185 INCOMPATIBILITY.
  1186 
  1187 * Theory Permutation: replaced local "remove" by List.remove1.
  1188 
  1189 * Code generation: ML and OCaml code is decorated with signatures.
  1190 
  1191 * Theory List: added transpose.
  1192 
  1193 * Library/Nat_Bijection.thy is a collection of bijective functions
  1194 between nat and other types, which supersedes the older libraries
  1195 Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.
  1196 
  1197   Constants:
  1198   Nat_Int_Bij.nat2_to_nat         ~> prod_encode
  1199   Nat_Int_Bij.nat_to_nat2         ~> prod_decode
  1200   Nat_Int_Bij.int_to_nat_bij      ~> int_encode
  1201   Nat_Int_Bij.nat_to_int_bij      ~> int_decode
  1202   Countable.pair_encode           ~> prod_encode
  1203   NatIso.prod2nat                 ~> prod_encode
  1204   NatIso.nat2prod                 ~> prod_decode
  1205   NatIso.sum2nat                  ~> sum_encode
  1206   NatIso.nat2sum                  ~> sum_decode
  1207   NatIso.list2nat                 ~> list_encode
  1208   NatIso.nat2list                 ~> list_decode
  1209   NatIso.set2nat                  ~> set_encode
  1210   NatIso.nat2set                  ~> set_decode
  1211 
  1212   Lemmas:
  1213   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
  1214   Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
  1215   Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
  1216   Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
  1217   Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
  1218   Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
  1219   Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
  1220   Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
  1221   Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
  1222   Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
  1223   Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
  1224   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
  1225   Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode
  1226 
  1227 * Sledgehammer:
  1228   - Renamed ATP commands:
  1229     atp_info     ~> sledgehammer running_atps
  1230     atp_kill     ~> sledgehammer kill_atps
  1231     atp_messages ~> sledgehammer messages
  1232     atp_minimize ~> sledgehammer minimize
  1233     print_atps   ~> sledgehammer available_atps
  1234     INCOMPATIBILITY.
  1235   - Added user's manual ("isabelle doc sledgehammer").
  1236   - Added option syntax and "sledgehammer_params" to customize
  1237     Sledgehammer's behavior.  See the manual for details.
  1238   - Modified the Isar proof reconstruction code so that it produces
  1239     direct proofs rather than proofs by contradiction.  (This feature
  1240     is still experimental.)
  1241   - Made Isar proof reconstruction work for SPASS, remote ATPs, and in
  1242     full-typed mode.
  1243   - Added support for TPTP syntax for SPASS via the "spass_tptp" ATP.
  1244 
  1245 * Nitpick:
  1246   - Added and implemented "binary_ints" and "bits" options.
  1247   - Added "std" option and implemented support for nonstandard models.
  1248   - Added and implemented "finitize" option to improve the precision
  1249     of infinite datatypes based on a monotonicity analysis.
  1250   - Added support for quotient types.
  1251   - Added support for "specification" and "ax_specification"
  1252     constructs.
  1253   - Added support for local definitions (for "function" and
  1254     "termination" proofs).
  1255   - Added support for term postprocessors.
  1256   - Optimized "Multiset.multiset" and "FinFun.finfun".
  1257   - Improved efficiency of "destroy_constrs" optimization.
  1258   - Fixed soundness bugs related to "destroy_constrs" optimization and
  1259     record getters.
  1260   - Fixed soundness bug related to higher-order constructors.
  1261   - Fixed soundness bug when "full_descrs" is enabled.
  1262   - Improved precision of set constructs.
  1263   - Added "atoms" option.
  1264   - Added cache to speed up repeated Kodkod invocations on the same
  1265     problems.
  1266   - Renamed "MiniSatJNI", "zChaffJNI", "BerkMinAlloy", and
  1267     "SAT4JLight" to "MiniSat_JNI", "zChaff_JNI", "BerkMin_Alloy", and
  1268     "SAT4J_Light".  INCOMPATIBILITY.
  1269   - Removed "skolemize", "uncurry", "sym_break", "flatten_prop",
  1270     "sharing_depth", and "show_skolems" options.  INCOMPATIBILITY.
  1271   - Removed "nitpick_intro" attribute.  INCOMPATIBILITY.
  1272 
  1273 * Method "induct" now takes instantiations of the form t, where t is not
  1274   a variable, as a shorthand for "x == t", where x is a fresh variable.
  1275   If this is not intended, t has to be enclosed in parentheses.
  1276   By default, the equalities generated by definitional instantiations
  1277   are pre-simplified, which may cause parameters of inductive cases
  1278   to disappear, or may even delete some of the inductive cases.
  1279   Use "induct (no_simp)" instead of "induct" to restore the old
  1280   behaviour. The (no_simp) option is also understood by the "cases"
  1281   and "nominal_induct" methods, which now perform pre-simplification, too.
  1282   INCOMPATIBILITY.
  1283 
  1284 
  1285 *** HOLCF ***
  1286 
  1287 * Variable names in lemmas generated by the domain package have
  1288 changed; the naming scheme is now consistent with the HOL datatype
  1289 package.  Some proof scripts may be affected, INCOMPATIBILITY.
  1290 
  1291 * The domain package no longer defines the function "foo_copy" for
  1292 recursive domain "foo".  The reach lemma is now stated directly in
  1293 terms of "foo_take".  Lemmas and proofs that mention "foo_copy" must
  1294 be reformulated in terms of "foo_take", INCOMPATIBILITY.
  1295 
  1296 * Most definedness lemmas generated by the domain package (previously
  1297 of the form "x ~= UU ==> foo$x ~= UU") now have an if-and-only-if form
  1298 like "foo$x = UU <-> x = UU", which works better as a simp rule.
  1299 Proofs that used definedness lemmas as intro rules may break,
  1300 potential INCOMPATIBILITY.
  1301 
  1302 * Induction and casedist rules generated by the domain package now
  1303 declare proper case_names (one called "bottom", and one named for each
  1304 constructor).  INCOMPATIBILITY.
  1305 
  1306 * For mutually-recursive domains, separate "reach" and "take_lemma"
  1307 rules are generated for each domain, INCOMPATIBILITY.
  1308 
  1309   foo_bar.reach       ~> foo.reach  bar.reach
  1310   foo_bar.take_lemmas ~> foo.take_lemma  bar.take_lemma
  1311 
  1312 * Some lemmas generated by the domain package have been renamed for
  1313 consistency with the datatype package, INCOMPATIBILITY.
  1314 
  1315   foo.ind        ~> foo.induct
  1316   foo.finite_ind ~> foo.finite_induct
  1317   foo.coind      ~> foo.coinduct
  1318   foo.casedist   ~> foo.exhaust
  1319   foo.exhaust    ~> foo.nchotomy
  1320 
  1321 * For consistency with other definition packages, the fixrec package
  1322 now generates qualified theorem names, INCOMPATIBILITY.
  1323 
  1324   foo_simps  ~> foo.simps
  1325   foo_unfold ~> foo.unfold
  1326   foo_induct ~> foo.induct
  1327 
  1328 * The "fixrec_simp" attribute has been removed.  The "fixrec_simp"
  1329 method and internal fixrec proofs now use the default simpset instead.
  1330 INCOMPATIBILITY.
  1331 
  1332 * The "contlub" predicate has been removed.  Proof scripts should use
  1333 lemma contI2 in place of monocontlub2cont, INCOMPATIBILITY.
  1334 
  1335 * The "admw" predicate has been removed, INCOMPATIBILITY.
  1336 
  1337 * The constants cpair, cfst, and csnd have been removed in favor of
  1338 Pair, fst, and snd from Isabelle/HOL, INCOMPATIBILITY.
  1339 
  1340 
  1341 *** ML ***
  1342 
  1343 * Antiquotations for basic formal entities:
  1344 
  1345     @{class NAME}         -- type class
  1346     @{class_syntax NAME}  -- syntax representation of the above
  1347 
  1348     @{type_name NAME}     -- logical type
  1349     @{type_abbrev NAME}   -- type abbreviation
  1350     @{nonterminal NAME}   -- type of concrete syntactic category
  1351     @{type_syntax NAME}   -- syntax representation of any of the above
  1352 
  1353     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
  1354     @{const_abbrev NAME}  -- abbreviated constant
  1355     @{const_syntax NAME}  -- syntax representation of any of the above
  1356 
  1357 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
  1358 syntax constant (cf. 'syntax' command).
  1359 
  1360 * Antiquotation @{make_string} inlines a function to print arbitrary
  1361 values similar to the ML toplevel.  The result is compiler dependent
  1362 and may fall back on "?" in certain situations.
  1363 
  1364 * Diagnostic commands 'ML_val' and 'ML_command' may refer to
  1365 antiquotations @{Isar.state} and @{Isar.goal}.  This replaces impure
  1366 Isar.state() and Isar.goal(), which belong to the old TTY loop and do
  1367 not work with the asynchronous Isar document model.
  1368 
  1369 * Configuration options now admit dynamic default values, depending on
  1370 the context or even global references.
  1371 
  1372 * SHA1.digest digests strings according to SHA-1 (see RFC 3174).  It
  1373 uses an efficient external library if available (for Poly/ML).
  1374 
  1375 * Renamed some important ML structures, while keeping the old names
  1376 for some time as aliases within the structure Legacy:
  1377 
  1378   OuterKeyword  ~>  Keyword
  1379   OuterLex      ~>  Token
  1380   OuterParse    ~>  Parse
  1381   OuterSyntax   ~>  Outer_Syntax
  1382   PrintMode     ~>  Print_Mode
  1383   SpecParse     ~>  Parse_Spec
  1384   ThyInfo       ~>  Thy_Info
  1385   ThyLoad       ~>  Thy_Load
  1386   ThyOutput     ~>  Thy_Output
  1387   TypeInfer     ~>  Type_Infer
  1388 
  1389 Note that "open Legacy" simplifies porting of sources, but forgetting
  1390 to remove it again will complicate porting again in the future.
  1391 
  1392 * Most operations that refer to a global context are named
  1393 accordingly, e.g. Simplifier.global_context or
  1394 ProofContext.init_global.  There are some situations where a global
  1395 context actually works, but under normal circumstances one needs to
  1396 pass the proper local context through the code!
  1397 
  1398 * Discontinued old TheoryDataFun with its copy/init operation -- data
  1399 needs to be pure.  Functor Theory_Data_PP retains the traditional
  1400 Pretty.pp argument to merge, which is absent in the standard
  1401 Theory_Data version.
  1402 
  1403 * Sorts.certify_sort and derived "cert" operations for types and terms
  1404 no longer minimize sorts.  Thus certification at the boundary of the
  1405 inference kernel becomes invariant under addition of class relations,
  1406 which is an important monotonicity principle.  Sorts are now minimized
  1407 in the syntax layer only, at the boundary between the end-user and the
  1408 system.  Subtle INCOMPATIBILITY, may have to use Sign.minimize_sort
  1409 explicitly in rare situations.
  1410 
  1411 * Renamed old-style Drule.standard to Drule.export_without_context, to
  1412 emphasize that this is in no way a standard operation.
  1413 INCOMPATIBILITY.
  1414 
  1415 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
  1416 usual for resolution.  Rare INCOMPATIBILITY.
  1417 
  1418 * Renamed varify/unvarify operations to varify_global/unvarify_global
  1419 to emphasize that these only work in a global situation (which is
  1420 quite rare).
  1421 
  1422 * Curried take and drop in library.ML; negative length is interpreted
  1423 as infinity (as in chop).  Subtle INCOMPATIBILITY.
  1424 
  1425 * Proof terms: type substitutions on proof constants now use canonical
  1426 order of type variables.  INCOMPATIBILITY for tools working with proof
  1427 terms.
  1428 
  1429 * Raw axioms/defs may no longer carry sort constraints, and raw defs
  1430 may no longer carry premises.  User-level specifications are
  1431 transformed accordingly by Thm.add_axiom/add_def.
  1432 
  1433 
  1434 *** System ***
  1435 
  1436 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
  1437 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
  1438 proof terms are enabled unconditionally in the new HOL-Proofs image.
  1439 
  1440 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
  1441 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
  1442 respectively.
  1443 
  1444 * Old lib/scripts/polyml-platform is superseded by the
  1445 ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
  1446 variant, even on a 64 bit machine.  The following example setting
  1447 prefers 64 bit if available:
  1448 
  1449   ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"
  1450 
  1451 * The preliminary Isabelle/jEdit application demonstrates the emerging
  1452 Isabelle/Scala layer for advanced prover interaction and integration.
  1453 See src/Tools/jEdit or "isabelle jedit" provided by the properly built
  1454 component.
  1455 
  1456 * "IsabelleText" is a Unicode font derived from Bitstream Vera Mono
  1457 and Bluesky TeX fonts.  It provides the usual Isabelle symbols,
  1458 similar to the default assignment of the document preparation system
  1459 (cf. isabellesym.sty).  The Isabelle/Scala class Isabelle_System
  1460 provides some operations for direct access to the font without asking
  1461 the user for manual installation.
  1462 
  1463 
  1464 
  1465 New in Isabelle2009-1 (December 2009)
  1466 -------------------------------------
  1467 
  1468 *** General ***
  1469 
  1470 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
  1471 one backslash should be used, even in ML sources.
  1472 
  1473 
  1474 *** Pure ***
  1475 
  1476 * Locale interpretation propagates mixins along the locale hierarchy.
  1477 The currently only available mixins are the equations used to map
  1478 local definitions to terms of the target domain of an interpretation.
  1479 
  1480 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
  1481 loc" to print all interpretations of locale "loc" in the theory.
  1482 Interpretations in proofs are not shown.
  1483 
  1484 * Thoroughly revised locales tutorial.  New section on conditional
  1485 interpretation.
  1486 
  1487 * On instantiation of classes, remaining undefined class parameters
  1488 are formally declared.  INCOMPATIBILITY.
  1489 
  1490 
  1491 *** Document preparation ***
  1492 
  1493 * New generalized style concept for printing terms: @{foo (style) ...}
  1494 instead of @{foo_style style ...}  (old form is still retained for
  1495 backward compatibility).  Styles can be also applied for
  1496 antiquotations prop, term_type and typeof.
  1497 
  1498 
  1499 *** HOL ***
  1500 
  1501 * New proof method "smt" for a combination of first-order logic with
  1502 equality, linear and nonlinear (natural/integer/real) arithmetic, and
  1503 fixed-size bitvectors; there is also basic support for higher-order
  1504 features (esp. lambda abstractions).  It is an incomplete decision
  1505 procedure based on external SMT solvers using the oracle mechanism;
  1506 for the SMT solver Z3, this method is proof-producing.  Certificates
  1507 are provided to avoid calling the external solvers solely for
  1508 re-checking proofs.  Due to a remote SMT service there is no need for
  1509 installing SMT solvers locally.  See src/HOL/SMT.
  1510 
  1511 * New commands to load and prove verification conditions generated by
  1512 the Boogie program verifier or derived systems (e.g. the Verifying C
  1513 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
  1514 
  1515 * New counterexample generator tool 'nitpick' based on the Kodkod
  1516 relational model finder.  See src/HOL/Tools/Nitpick and
  1517 src/HOL/Nitpick_Examples.
  1518 
  1519 * New commands 'code_pred' and 'values' to invoke the predicate
  1520 compiler and to enumerate values of inductive predicates.
  1521 
  1522 * A tabled implementation of the reflexive transitive closure.
  1523 
  1524 * New implementation of quickcheck uses generic code generator;
  1525 default generators are provided for all suitable HOL types, records
  1526 and datatypes.  Old quickcheck can be re-activated importing theory
  1527 Library/SML_Quickcheck.
  1528 
  1529 * New testing tool Mirabelle for automated proof tools.  Applies
  1530 several tools and tactics like sledgehammer, metis, or quickcheck, to
  1531 every proof step in a theory.  To be used in batch mode via the
  1532 "mirabelle" utility.
  1533 
  1534 * New proof method "sos" (sum of squares) for nonlinear real
  1535 arithmetic (originally due to John Harison). It requires theory
  1536 Library/Sum_Of_Squares.  It is not a complete decision procedure but
  1537 works well in practice on quantifier-free real arithmetic with +, -,
  1538 *, ^, =, <= and <, i.e. boolean combinations of equalities and
  1539 inequalities between polynomials.  It makes use of external
  1540 semidefinite programming solvers.  Method "sos" generates a
  1541 certificate that can be pasted into the proof thus avoiding the need
  1542 to call an external tool every time the proof is checked.  See
  1543 src/HOL/Library/Sum_Of_Squares.
  1544 
  1545 * New method "linarith" invokes existing linear arithmetic decision
  1546 procedure only.
  1547 
  1548 * New command 'atp_minimal' reduces result produced by Sledgehammer.
  1549 
  1550 * New Sledgehammer option "Full Types" in Proof General settings menu.
  1551 Causes full type information to be output to the ATPs.  This slows
  1552 ATPs down considerably but eliminates a source of unsound "proofs"
  1553 that fail later.
  1554 
  1555 * New method "metisFT": A version of metis that uses full type
  1556 information in order to avoid failures of proof reconstruction.
  1557 
  1558 * New evaluator "approximate" approximates an real valued term using
  1559 the same method as the approximation method.
  1560 
  1561 * Method "approximate" now supports arithmetic expressions as
  1562 boundaries of intervals and implements interval splitting and Taylor
  1563 series expansion.
  1564 
  1565 * ML antiquotation @{code_datatype} inserts definition of a datatype
  1566 generated by the code generator; e.g. see src/HOL/Predicate.thy.
  1567 
  1568 * New theory SupInf of the supremum and infimum operators for sets of
  1569 reals.
  1570 
  1571 * New theory Probability, which contains a development of measure
  1572 theory, eventually leading to Lebesgue integration and probability.
  1573 
  1574 * Extended Multivariate Analysis to include derivation and Brouwer's
  1575 fixpoint theorem.
  1576 
  1577 * Reorganization of number theory, INCOMPATIBILITY:
  1578   - new number theory development for nat and int, in theories Divides
  1579     and GCD as well as in new session Number_Theory
  1580   - some constants and facts now suffixed with _nat and _int
  1581     accordingly
  1582   - former session NumberTheory now named Old_Number_Theory, including
  1583     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
  1584   - moved theory Pocklington from src/HOL/Library to
  1585     src/HOL/Old_Number_Theory
  1586 
  1587 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
  1588 lcm of finite and infinite sets. It is shown that they form a complete
  1589 lattice.
  1590 
  1591 * Class semiring_div requires superclass no_zero_divisors and proof of
  1592 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
  1593 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
  1594 generalized to class semiring_div, subsuming former theorems
  1595 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
  1596 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
  1597 INCOMPATIBILITY.
  1598 
  1599 * Refinements to lattice classes and sets:
  1600   - less default intro/elim rules in locale variant, more default
  1601     intro/elim rules in class variant: more uniformity
  1602   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
  1603     le_inf_iff
  1604   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
  1605     sup_aci)
  1606   - renamed ACI to inf_sup_aci
  1607   - new class "boolean_algebra"
  1608   - class "complete_lattice" moved to separate theory
  1609     "Complete_Lattice"; corresponding constants (and abbreviations)
  1610     renamed and with authentic syntax:
  1611     Set.Inf ~>    Complete_Lattice.Inf
  1612     Set.Sup ~>    Complete_Lattice.Sup
  1613     Set.INFI ~>   Complete_Lattice.INFI
  1614     Set.SUPR ~>   Complete_Lattice.SUPR
  1615     Set.Inter ~>  Complete_Lattice.Inter
  1616     Set.Union ~>  Complete_Lattice.Union
  1617     Set.INTER ~>  Complete_Lattice.INTER
  1618     Set.UNION ~>  Complete_Lattice.UNION
  1619   - authentic syntax for
  1620     Set.Pow
  1621     Set.image
  1622   - mere abbreviations:
  1623     Set.empty               (for bot)
  1624     Set.UNIV                (for top)
  1625     Set.inter               (for inf, formerly Set.Int)
  1626     Set.union               (for sup, formerly Set.Un)
  1627     Complete_Lattice.Inter  (for Inf)
  1628     Complete_Lattice.Union  (for Sup)
  1629     Complete_Lattice.INTER  (for INFI)
  1630     Complete_Lattice.UNION  (for SUPR)
  1631   - object-logic definitions as far as appropriate
  1632 
  1633 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
  1634 Un_subset_iff are explicitly deleted as default simp rules; then also
  1635 their lattice counterparts le_inf_iff and le_sup_iff have to be
  1636 deleted to achieve the desired effect.
  1637 
  1638 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
  1639 rules by default any longer; the same applies to min_max.inf_absorb1
  1640 etc.  INCOMPATIBILITY.
  1641 
  1642 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
  1643 pred_set_conv by default.  INCOMPATIBILITY.
  1644 
  1645 * Power operations on relations and functions are now one dedicated
  1646 constant "compow" with infix syntax "^^".  Power operation on
  1647 multiplicative monoids retains syntax "^" and is now defined generic
  1648 in class power.  INCOMPATIBILITY.
  1649 
  1650 * Relation composition "R O S" now has a more standard argument order:
  1651 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
  1652 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
  1653 break, since the O_assoc rule was not rewritten like this.  Fix using
  1654 O_assoc[symmetric].  The same applies to the curried version "R OO S".
  1655 
  1656 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
  1657 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
  1658 INCOMPATIBILITY.
  1659 
  1660 * Most rules produced by inductive and datatype package have mandatory
  1661 prefixes.  INCOMPATIBILITY.
  1662 
  1663 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
  1664 the attribute of the same name.  Each of the theorems in the list
  1665 DERIV_intros assumes composition with an additional function and
  1666 matches a variable to the derivative, which has to be solved by the
  1667 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
  1668 of most elementary terms.  Former Maclauren.DERIV_tac and
  1669 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
  1670 INCOMPATIBILITY.
  1671 
  1672 * Code generator attributes follow the usual underscore convention:
  1673     code_unfold     replaces    code unfold
  1674     code_post       replaces    code post
  1675     etc.
  1676   INCOMPATIBILITY.
  1677 
  1678 * Renamed methods:
  1679     sizechange -> size_change
  1680     induct_scheme -> induction_schema
  1681   INCOMPATIBILITY.
  1682 
  1683 * Discontinued abbreviation "arbitrary" of constant "undefined".
  1684 INCOMPATIBILITY, use "undefined" directly.
  1685 
  1686 * Renamed theorems:
  1687     Suc_eq_add_numeral_1 -> Suc_eq_plus1
  1688     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
  1689     Suc_plus1 -> Suc_eq_plus1
  1690     *anti_sym -> *antisym*
  1691     vector_less_eq_def -> vector_le_def
  1692   INCOMPATIBILITY.
  1693 
  1694 * Added theorem List.map_map as [simp].  Removed List.map_compose.
  1695 INCOMPATIBILITY.
  1696 
  1697 * Removed predicate "M hassize n" (<--> card M = n & finite M).
  1698 INCOMPATIBILITY.
  1699 
  1700 
  1701 *** HOLCF ***
  1702 
  1703 * Theory Representable defines a class "rep" of domains that are
  1704 representable (via an ep-pair) in the universal domain type "udom".
  1705 Instances are provided for all type constructors defined in HOLCF.
  1706 
  1707 * The 'new_domain' command is a purely definitional version of the
  1708 domain package, for representable domains.  Syntax is identical to the
  1709 old domain package.  The 'new_domain' package also supports indirect
  1710 recursion using previously-defined type constructors.  See
  1711 src/HOLCF/ex/New_Domain.thy for examples.
  1712 
  1713 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
  1714 on the left-hand side of an equation, and then performs
  1715 simplification.  Rewriting is done using rules declared with the
  1716 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
  1717 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
  1718 
  1719 * The pattern-match compiler in 'fixrec' can now handle constructors
  1720 with HOL function types.  Pattern-match combinators for the Pair
  1721 constructor are pre-configured.
  1722 
  1723 * The 'fixrec' package now produces better fixed-point induction rules
  1724 for mutually-recursive definitions:  Induction rules have conclusions
  1725 of the form "P foo bar" instead of "P <foo, bar>".
  1726 
  1727 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
  1728 been renamed to "below".  The name "below" now replaces "less" in many
  1729 theorem names.  (Legacy theorem names using "less" are still supported
  1730 as well.)
  1731 
  1732 * The 'fixrec' package now supports "bottom patterns".  Bottom
  1733 patterns can be used to generate strictness rules, or to make
  1734 functions more strict (much like the bang-patterns supported by the
  1735 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
  1736 examples.
  1737 
  1738 
  1739 *** ML ***
  1740 
  1741 * Support for Poly/ML 5.3.0, with improved reporting of compiler
  1742 errors and run-time exceptions, including detailed source positions.
  1743 
  1744 * Structure Name_Space (formerly NameSpace) now manages uniquely
  1745 identified entries, with some additional information such as source
  1746 position, logical grouping etc.
  1747 
  1748 * Theory and context data is now introduced by the simplified and
  1749 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
  1750 to be pure, but the old TheoryDataFun for mutable data (with explicit
  1751 copy operation) is still available for some time.
  1752 
  1753 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
  1754 provides a high-level programming interface to synchronized state
  1755 variables with atomic update.  This works via pure function
  1756 application within a critical section -- its runtime should be as
  1757 short as possible; beware of deadlocks if critical code is nested,
  1758 either directly or indirectly via other synchronized variables!
  1759 
  1760 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
  1761 wraps raw ML references, explicitly indicating their non-thread-safe
  1762 behaviour.  The Isar toplevel keeps this structure open, to
  1763 accommodate Proof General as well as quick and dirty interactive
  1764 experiments with references.
  1765 
  1766 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
  1767 parallel tactical reasoning.
  1768 
  1769 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
  1770 are similar to SUBPROOF, but are slightly more flexible: only the
  1771 specified parts of the subgoal are imported into the context, and the
  1772 body tactic may introduce new subgoals and schematic variables.
  1773 
  1774 * Old tactical METAHYPS, which does not observe the proof context, has
  1775 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
  1776 or Subgoal.FOCUS etc.
  1777 
  1778 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
  1779 functors have their own ML name space there is no point to mark them
  1780 separately.)  Minor INCOMPATIBILITY.
  1781 
  1782 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
  1783 
  1784 * Renamed several structures FooBar to Foo_Bar.  Occasional,
  1785 INCOMPATIBILITY.
  1786 
  1787 * Operations of structure Skip_Proof no longer require quick_and_dirty
  1788 mode, which avoids critical setmp.
  1789 
  1790 * Eliminated old Attrib.add_attributes, Method.add_methods and related
  1791 combinators for "args".  INCOMPATIBILITY, need to use simplified
  1792 Attrib/Method.setup introduced in Isabelle2009.
  1793 
  1794 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
  1795 back on global_simpset_of, global_claset_of, global_clasimpset_of as
  1796 last resort.  INCOMPATIBILITY.
  1797 
  1798 * Display.pretty_thm now requires a proper context (cf. former
  1799 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
  1800 or even Display.pretty_thm_without_context as last resort.
  1801 INCOMPATIBILITY.
  1802 
  1803 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
  1804 Syntax.pretty_typ/term directly, preferably with proper context
  1805 instead of global theory.
  1806 
  1807 
  1808 *** System ***
  1809 
  1810 * Further fine tuning of parallel proof checking, scales up to 8 cores
  1811 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
  1812 usedir option -q.
  1813 
  1814 * Support for additional "Isabelle components" via etc/components, see
  1815 also the system manual.
  1816 
  1817 * The isabelle makeall tool now operates on all components with
  1818 IsaMakefile, not just hardwired "logics".
  1819 
  1820 * Removed "compress" option from isabelle-process and isabelle usedir;
  1821 this is always enabled.
  1822 
  1823 * Discontinued support for Poly/ML 4.x versions.
  1824 
  1825 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
  1826 on a given logic image.  This requires the lighttpd webserver and is
  1827 currently supported on Linux only.
  1828 
  1829 
  1830 
  1831 New in Isabelle2009 (April 2009)
  1832 --------------------------------
  1833 
  1834 *** General ***
  1835 
  1836 * Simplified main Isabelle executables, with less surprises on
  1837 case-insensitive file-systems (such as Mac OS).
  1838 
  1839   - The main Isabelle tool wrapper is now called "isabelle" instead of
  1840     "isatool."
  1841 
  1842   - The former "isabelle" alias for "isabelle-process" has been
  1843     removed (should rarely occur to regular users).
  1844 
  1845   - The former "isabelle-interface" and its alias "Isabelle" have been
  1846     removed (interfaces are now regular Isabelle tools).
  1847 
  1848 Within scripts and make files, the Isabelle environment variables
  1849 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
  1850 respectively.  (The latter are still available as legacy feature.)
  1851 
  1852 The old isabelle-interface wrapper could react in confusing ways if
  1853 the interface was uninstalled or changed otherwise.  Individual
  1854 interface tool configuration is now more explicit, see also the
  1855 Isabelle system manual.  In particular, Proof General is now available
  1856 via "isabelle emacs".
  1857 
  1858 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
  1859 purge installed copies of Isabelle executables and re-run "isabelle
  1860 install -p ...", or use symlinks.
  1861 
  1862 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
  1863 old ~/isabelle, which was slightly non-standard and apt to cause
  1864 surprises on case-insensitive file-systems (such as Mac OS).
  1865 
  1866 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
  1867 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
  1868 care is required when using older releases of Isabelle.  Note that
  1869 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
  1870 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
  1871 
  1872 * Proofs of fully specified statements are run in parallel on
  1873 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
  1874 a regular 4-core machine, if the initial heap space is made reasonably
  1875 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
  1876 
  1877 * The main reference manuals ("isar-ref", "implementation", and
  1878 "system") have been updated and extended.  Formally checked references
  1879 as hyperlinks are now available uniformly.
  1880 
  1881 
  1882 *** Pure ***
  1883 
  1884 * Complete re-implementation of locales.  INCOMPATIBILITY in several
  1885 respects.  The most important changes are listed below.  See the
  1886 Tutorial on Locales ("locales" manual) for details.
  1887 
  1888 - In locale expressions, instantiation replaces renaming.  Parameters
  1889 must be declared in a for clause.  To aid compatibility with previous
  1890 parameter inheritance, in locale declarations, parameters that are not
  1891 'touched' (instantiation position "_" or omitted) are implicitly added
  1892 with their syntax at the beginning of the for clause.
  1893 
  1894 - Syntax from abbreviations and definitions in locales is available in
  1895 locale expressions and context elements.  The latter is particularly
  1896 useful in locale declarations.
  1897 
  1898 - More flexible mechanisms to qualify names generated by locale
  1899 expressions.  Qualifiers (prefixes) may be specified in locale
  1900 expressions, and can be marked as mandatory (syntax: "name!:") or
  1901 optional (syntax "name?:").  The default depends for plain "name:"
  1902 depends on the situation where a locale expression is used: in
  1903 commands 'locale' and 'sublocale' prefixes are optional, in
  1904 'interpretation' and 'interpret' prefixes are mandatory.  The old
  1905 implicit qualifiers derived from the parameter names of a locale are
  1906 no longer generated.
  1907 
  1908 - Command "sublocale l < e" replaces "interpretation l < e".  The
  1909 instantiation clause in "interpretation" and "interpret" (square
  1910 brackets) is no longer available.  Use locale expressions.
  1911 
  1912 - When converting proof scripts, mandatory qualifiers in
  1913 'interpretation' and 'interpret' should be retained by default, even
  1914 if this is an INCOMPATIBILITY compared to former behavior.  In the
  1915 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
  1916 in locale expressions range over a single locale instance only.
  1917 
  1918 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
  1919 In existing theorem specifications replace the includes element by the
  1920 respective context elements of the included locale, omitting those
  1921 that are already present in the theorem specification.  Multiple
  1922 assume elements of a locale should be replaced by a single one
  1923 involving the locale predicate.  In the proof body, declarations (most
  1924 notably theorems) may be regained by interpreting the respective
  1925 locales in the proof context as required (command "interpret").
  1926 
  1927 If using "includes" in replacement of a target solely because the
  1928 parameter types in the theorem are not as general as in the target,
  1929 consider declaring a new locale with additional type constraints on
  1930 the parameters (context element "constrains").
  1931 
  1932 - Discontinued "locale (open)".  INCOMPATIBILITY.
  1933 
  1934 - Locale interpretation commands no longer attempt to simplify goal.
  1935 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
  1936 methods intro_locales and unfold_locales to clarify.
  1937 
  1938 - Locale interpretation commands no longer accept interpretation
  1939 attributes.  INCOMPATIBILITY.
  1940 
  1941 * Class declaration: so-called "base sort" must not be given in import
  1942 list any longer, but is inferred from the specification.  Particularly
  1943 in HOL, write
  1944 
  1945     class foo = ...
  1946 
  1947 instead of
  1948 
  1949     class foo = type + ...
  1950 
  1951 * Class target: global versions of theorems stemming do not carry a
  1952 parameter prefix any longer.  INCOMPATIBILITY.
  1953 
  1954 * Class 'instance' command no longer accepts attached definitions.
  1955 INCOMPATIBILITY, use proper 'instantiation' target instead.
  1956 
  1957 * Recovered hiding of consts, which was accidentally broken in
  1958 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
  1959 makes c inaccessible; consider using ``hide (open) const c'' instead.
  1960 
  1961 * Slightly more coherent Pure syntax, with updated documentation in
  1962 isar-ref manual.  Removed locales meta_term_syntax and
  1963 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
  1964 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
  1965 directly in regular applications.
  1966 
  1967 * There is a new syntactic category "float_const" for signed decimal
  1968 fractions (e.g. 123.45 or -123.45).
  1969 
  1970 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
  1971 interface with 'setup' command instead.
  1972 
  1973 * Command 'local_setup' is similar to 'setup', but operates on a local
  1974 theory context.
  1975 
  1976 * The 'axiomatization' command now only works within a global theory
  1977 context.  INCOMPATIBILITY.
  1978 
  1979 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
  1980 hypotheses.  Sorts required in the course of reasoning need to be
  1981 covered by the constraints in the initial statement, completed by the
  1982 type instance information of the background theory.  Non-trivial sort
  1983 hypotheses, which rarely occur in practice, may be specified via
  1984 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
  1985 
  1986   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
  1987 
  1988 The result contains an implicit sort hypotheses as before --
  1989 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
  1990 normalization.
  1991 
  1992 * Generalized Isar history, with support for linear undo, direct state
  1993 addressing etc.
  1994 
  1995 * Changed defaults for unify configuration options:
  1996 
  1997   unify_trace_bound = 50 (formerly 25)
  1998   unify_search_bound = 60 (formerly 30)
  1999 
  2000 * Different bookkeeping for code equations (INCOMPATIBILITY):
  2001 
  2002   a) On theory merge, the last set of code equations for a particular
  2003      constant is taken (in accordance with the policy applied by other
  2004      parts of the code generator framework).
  2005 
  2006   b) Code equations stemming from explicit declarations (e.g. code
  2007      attribute) gain priority over default code equations stemming
  2008      from definition, primrec, fun etc.
  2009 
  2010 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
  2011 
  2012 * Unified theorem tables for both code generators.  Thus [code
  2013 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
  2014 
  2015 * Command 'find_consts' searches for constants based on type and name
  2016 patterns, e.g.
  2017 
  2018     find_consts "_ => bool"
  2019 
  2020 By default, matching is against subtypes, but it may be restricted to
  2021 the whole type.  Searching by name is possible.  Multiple queries are
  2022 conjunctive and queries may be negated by prefixing them with a
  2023 hyphen:
  2024 
  2025     find_consts strict: "_ => bool" name: "Int" -"int => int"
  2026 
  2027 * New 'find_theorems' criterion "solves" matches theorems that
  2028 directly solve the current goal (modulo higher-order unification).
  2029 
  2030 * Auto solve feature for main theorem statements: whenever a new goal
  2031 is stated, "find_theorems solves" is called; any theorems that could
  2032 solve the lemma directly are listed as part of the goal state.
  2033 Cf. associated options in Proof General Isabelle settings menu,
  2034 enabled by default, with reasonable timeout for pathological cases of
  2035 higher-order unification.
  2036 
  2037 
  2038 *** Document preparation ***
  2039 
  2040 * Antiquotation @{lemma} now imitates a regular terminal proof,
  2041 demanding keyword 'by' and supporting the full method expression
  2042 syntax just like the Isar command 'by'.
  2043 
  2044 
  2045 *** HOL ***
  2046 
  2047 * Integrated main parts of former image HOL-Complex with HOL.  Entry
  2048 points Main and Complex_Main remain as before.
  2049 
  2050 * Logic image HOL-Plain provides a minimal HOL with the most important
  2051 tools available (inductive, datatype, primrec, ...).  This facilitates
  2052 experimentation and tool development.  Note that user applications
  2053 (and library theories) should never refer to anything below theory
  2054 Main, as before.
  2055 
  2056 * Logic image HOL-Main stops at theory Main, and thus facilitates
  2057 experimentation due to shorter build times.
  2058 
  2059 * Logic image HOL-NSA contains theories of nonstandard analysis which
  2060 were previously part of former HOL-Complex.  Entry point Hyperreal
  2061 remains valid, but theories formerly using Complex_Main should now use
  2062 new entry point Hypercomplex.
  2063 
  2064 * Generic ATP manager for Sledgehammer, based on ML threads instead of
  2065 Posix processes.  Avoids potentially expensive forking of the ML
  2066 process.  New thread-based implementation also works on non-Unix
  2067 platforms (Cygwin).  Provers are no longer hardwired, but defined
  2068 within the theory via plain ML wrapper functions.  Basic Sledgehammer
  2069 commands are covered in the isar-ref manual.
  2070 
  2071 * Wrapper scripts for remote SystemOnTPTP service allows to use
  2072 sledgehammer without local ATP installation (Vampire etc.). Other
  2073 provers may be included via suitable ML wrappers, see also
  2074 src/HOL/ATP_Linkup.thy.
  2075 
  2076 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
  2077 menu.
  2078 
  2079 * The metis method no longer fails because the theorem is too trivial
  2080 (contains the empty clause).
  2081 
  2082 * The metis method now fails in the usual manner, rather than raising
  2083 an exception, if it determines that it cannot prove the theorem.
  2084 
  2085 * Method "coherent" implements a prover for coherent logic (see also
  2086 src/Tools/coherent.ML).
  2087 
  2088 * Constants "undefined" and "default" replace "arbitrary".  Usually
  2089 "undefined" is the right choice to replace "arbitrary", though
  2090 logically there is no difference.  INCOMPATIBILITY.
  2091 
  2092 * Command "value" now integrates different evaluation mechanisms.  The
  2093 result of the first successful evaluation mechanism is printed.  In
  2094 square brackets a particular named evaluation mechanisms may be
  2095 specified (currently, [SML], [code] or [nbe]).  See further
  2096 src/HOL/ex/Eval_Examples.thy.
  2097 
  2098 * Normalization by evaluation now allows non-leftlinear equations.
  2099 Declare with attribute [code nbe].
  2100 
  2101 * Methods "case_tac" and "induct_tac" now refer to the very same rules
  2102 as the structured Isar versions "cases" and "induct", cf. the
  2103 corresponding "cases" and "induct" attributes.  Mutual induction rules
  2104 are now presented as a list of individual projections
  2105 (e.g. foo_bar.inducts for types foo and bar); the old format with
  2106 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
  2107 rare situations a different rule is selected --- notably nested tuple
  2108 elimination instead of former prod.exhaust: use explicit (case_tac t
  2109 rule: prod.exhaust) here.
  2110 
  2111 * Attributes "cases", "induct", "coinduct" support "del" option.
  2112 
  2113 * Removed fact "case_split_thm", which duplicates "case_split".
  2114 
  2115 * The option datatype has been moved to a new theory Option.  Renamed
  2116 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
  2117 
  2118 * New predicate "strict_mono" classifies strict functions on partial
  2119 orders.  With strict functions on linear orders, reasoning about
  2120 (in)equalities is facilitated by theorems "strict_mono_eq",
  2121 "strict_mono_less_eq" and "strict_mono_less".
  2122 
  2123 * Some set operations are now proper qualified constants with
  2124 authentic syntax.  INCOMPATIBILITY:
  2125 
  2126     op Int ~>   Set.Int
  2127     op Un ~>    Set.Un
  2128     INTER ~>    Set.INTER
  2129     UNION ~>    Set.UNION
  2130     Inter ~>    Set.Inter
  2131     Union ~>    Set.Union
  2132     {} ~>       Set.empty
  2133     UNIV ~>     Set.UNIV
  2134 
  2135 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  2136 theory Set.
  2137 
  2138 * Auxiliary class "itself" has disappeared -- classes without any
  2139 parameter are treated as expected by the 'class' command.
  2140 
  2141 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  2142 
  2143 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  2144 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  2145 
  2146 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  2147 method "approximation".  It proves formulas on real values by using
  2148 interval arithmetic.  In the formulas are also the transcendental
  2149 functions sin, cos, tan, atan, ln, exp and the constant pi are
  2150 allowed. For examples see
  2151 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  2152 
  2153 * Theory "Reflection" now resides in HOL/Library.
  2154 
  2155 * Entry point to Word library now simply named "Word".
  2156 INCOMPATIBILITY.
  2157 
  2158 * Made source layout more coherent with logical distribution
  2159 structure:
  2160 
  2161     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  2162     src/HOL/Library/Code_Message.thy ~> src/HOL/
  2163     src/HOL/Library/GCD.thy ~> src/HOL/
  2164     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  2165     src/HOL/Library/Parity.thy ~> src/HOL/
  2166     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  2167     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  2168     src/HOL/Real/Lubs.thy ~> src/HOL/
  2169     src/HOL/Real/PReal.thy ~> src/HOL/
  2170     src/HOL/Real/Rational.thy ~> src/HOL/
  2171     src/HOL/Real/RComplete.thy ~> src/HOL/
  2172     src/HOL/Real/RealDef.thy ~> src/HOL/
  2173     src/HOL/Real/RealPow.thy ~> src/HOL/
  2174     src/HOL/Real/Real.thy ~> src/HOL/
  2175     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  2176     src/HOL/Complex/Complex.thy ~> src/HOL/
  2177     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  2178     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  2179     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  2180     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  2181     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  2182     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  2183     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  2184     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  2185     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  2186     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  2187     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  2188     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  2189     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  2190     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  2191     src/HOL/Real/Float ~> src/HOL/Library/
  2192     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  2193     src/HOL/Real/RealVector.thy ~> src/HOL/
  2194 
  2195     src/HOL/arith_data.ML ~> src/HOL/Tools
  2196     src/HOL/hologic.ML ~> src/HOL/Tools
  2197     src/HOL/simpdata.ML ~> src/HOL/Tools
  2198     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  2199     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  2200     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  2201     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  2202     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  2203     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  2204     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  2205 
  2206     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  2207     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  2208     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  2209     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  2210     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  2211     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  2212 
  2213 * If methods "eval" and "evaluation" encounter a structured proof
  2214 state with !!/==>, only the conclusion is evaluated to True (if
  2215 possible), avoiding strange error messages.
  2216 
  2217 * Method "sizechange" automates termination proofs using (a
  2218 modification of) the size-change principle.  Requires SAT solver.  See
  2219 src/HOL/ex/Termination.thy for examples.
  2220 
  2221 * Simplifier: simproc for let expressions now unfolds if bound
  2222 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  2223 
  2224 * Method "arith": Linear arithmetic now ignores all inequalities when
  2225 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  2226 
  2227 * New attribute "arith" for facts that should always be used
  2228 automatically by arithmetic. It is intended to be used locally in
  2229 proofs, e.g.
  2230 
  2231   assumes [arith]: "x > 0"
  2232 
  2233 Global usage is discouraged because of possible performance impact.
  2234 
  2235 * New classes "top" and "bot" with corresponding operations "top" and
  2236 "bot" in theory Orderings; instantiation of class "complete_lattice"
  2237 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  2238 
  2239 * Changed definition lemma "less_fun_def" in order to provide an
  2240 instance for preorders on functions; use lemma "less_le" instead.
  2241 INCOMPATIBILITY.
  2242 
  2243 * Theory Orderings: class "wellorder" moved here, with explicit
  2244 induction rule "less_induct" as assumption.  For instantiation of
  2245 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  2246 INCOMPATIBILITY.
  2247 
  2248 * Theory Orderings: added class "preorder" as superclass of "order".
  2249 INCOMPATIBILITY: Instantiation proofs for order, linorder
  2250 etc. slightly changed.  Some theorems named order_class.* now named
  2251 preorder_class.*.
  2252 
  2253 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  2254 "diag" to "Id_on".
  2255 
  2256 * Theory Finite_Set: added a new fold combinator of type
  2257 
  2258   ('a => 'b => 'b) => 'b => 'a set => 'b
  2259 
  2260 Occasionally this is more convenient than the old fold combinator
  2261 which is now defined in terms of the new one and renamed to
  2262 fold_image.
  2263 
  2264 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  2265 and "ring_simps" have been replaced by "algebra_simps" (which can be
  2266 extended with further lemmas!).  At the moment both still exist but
  2267 the former will disappear at some point.
  2268 
  2269 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  2270 class recpower.  Type-specific simp rules for various recpower types
  2271 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  2272 
  2273 rat_power_0    -> power_0
  2274 rat_power_Suc  -> power_Suc
  2275 realpow_0      -> power_0
  2276 realpow_Suc    -> power_Suc
  2277 complexpow_0   -> power_0
  2278 complexpow_Suc -> power_Suc
  2279 power_poly_0   -> power_0
  2280 power_poly_Suc -> power_Suc
  2281 
  2282 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  2283 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  2284 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  2285 of lemmas from Divides has been generalized from nat to class
  2286 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  2287 renames resulting from duplicate elimination:
  2288 
  2289     dvd_def_mod ~>          dvd_eq_mod_eq_0
  2290     zero_dvd_iff ~>         dvd_0_left_iff
  2291     dvd_0 ~>                dvd_0_right
  2292     DIVISION_BY_ZERO_DIV ~> div_by_0
  2293     DIVISION_BY_ZERO_MOD ~> mod_by_0
  2294     mult_div ~>             div_mult_self2_is_id
  2295     mult_mod ~>             mod_mult_self2_is_0
  2296 
  2297 * Theory IntDiv: removed many lemmas that are instances of class-based
  2298 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  2299 rename old lemmas as follows:
  2300 
  2301 dvd_diff               -> nat_dvd_diff
  2302 dvd_zminus_iff         -> dvd_minus_iff
  2303 mod_add1_eq            -> mod_add_eq
  2304 mod_mult1_eq           -> mod_mult_right_eq
  2305 mod_mult1_eq'          -> mod_mult_left_eq
  2306 mod_mult_distrib_mod   -> mod_mult_eq
  2307 nat_mod_add_left_eq    -> mod_add_left_eq
  2308 nat_mod_add_right_eq   -> mod_add_right_eq
  2309 nat_mod_div_trivial    -> mod_div_trivial
  2310 nat_mod_mod_trivial    -> mod_mod_trivial
  2311 zdiv_zadd_self1        -> div_add_self1
  2312 zdiv_zadd_self2        -> div_add_self2
  2313 zdiv_zmult_self1       -> div_mult_self2_is_id
  2314 zdiv_zmult_self2       -> div_mult_self1_is_id
  2315 zdvd_triv_left         -> dvd_triv_left
  2316 zdvd_triv_right        -> dvd_triv_right
  2317 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  2318 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  2319 zmod_zadd_left_eq      -> mod_add_left_eq
  2320 zmod_zadd_right_eq     -> mod_add_right_eq
  2321 zmod_zadd_self1        -> mod_add_self1
  2322 zmod_zadd_self2        -> mod_add_self2
  2323 zmod_zadd1_eq          -> mod_add_eq
  2324 zmod_zdiff1_eq         -> mod_diff_eq
  2325 zmod_zdvd_zmod         -> mod_mod_cancel
  2326 zmod_zmod_cancel       -> mod_mod_cancel
  2327 zmod_zmult_self1       -> mod_mult_self2_is_0
  2328 zmod_zmult_self2       -> mod_mult_self1_is_0
  2329 zmod_1                 -> mod_by_1
  2330 zdiv_1                 -> div_by_1
  2331 zdvd_abs1              -> abs_dvd_iff
  2332 zdvd_abs2              -> dvd_abs_iff
  2333 zdvd_refl              -> dvd_refl
  2334 zdvd_trans             -> dvd_trans
  2335 zdvd_zadd              -> dvd_add
  2336 zdvd_zdiff             -> dvd_diff
  2337 zdvd_zminus_iff        -> dvd_minus_iff
  2338 zdvd_zminus2_iff       -> minus_dvd_iff
  2339 zdvd_zmultD            -> dvd_mult_right
  2340 zdvd_zmultD2           -> dvd_mult_left
  2341 zdvd_zmult_mono        -> mult_dvd_mono
  2342 zdvd_0_right           -> dvd_0_right
  2343 zdvd_0_left            -> dvd_0_left_iff
  2344 zdvd_1_left            -> one_dvd
  2345 zminus_dvd_iff         -> minus_dvd_iff
  2346 
  2347 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  2348 
  2349 * The real numbers offer decimal input syntax: 12.34 is translated
  2350 into 1234/10^2. This translation is not reversed upon output.
  2351 
  2352 * Theory Library/Polynomial defines an abstract type 'a poly of
  2353 univariate polynomials with coefficients of type 'a.  In addition to
  2354 the standard ring operations, it also supports div and mod.  Code
  2355 generation is also supported, using list-style constructors.
  2356 
  2357 * Theory Library/Inner_Product defines a class of real_inner for real
  2358 inner product spaces, with an overloaded operation inner :: 'a => 'a
  2359 => real.  Class real_inner is a subclass of real_normed_vector from
  2360 theory RealVector.
  2361 
  2362 * Theory Library/Product_Vector provides instances for the product
  2363 type 'a * 'b of several classes from RealVector and Inner_Product.
  2364 Definitions of addition, subtraction, scalar multiplication, norms,
  2365 and inner products are included.
  2366 
  2367 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  2368 addition to the field operations, numerals and case syntax are also
  2369 supported.
  2370 
  2371 * Theory Library/Diagonalize provides constructive version of Cantor's
  2372 first diagonalization argument.
  2373 
  2374 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  2375 zlcm (for int); carried together from various gcd/lcm developements in
  2376 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  2377 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  2378 may recover tupled syntax as follows:
  2379 
  2380     hide (open) const gcd
  2381     abbreviation gcd where
  2382       "gcd == (%(a, b). GCD.gcd a b)"
  2383     notation (output)
  2384       GCD.gcd ("gcd '(_, _')")
  2385 
  2386 The same works for lcm, zgcd, zlcm.
  2387 
  2388 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  2389 instantiations for algebraic structures.  Removed some duplicate
  2390 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  2391 
  2392 * ML antiquotation @{code} takes a constant as argument and generates
  2393 corresponding code in background and inserts name of the corresponding
  2394 resulting ML value/function/datatype constructor binding in place.
  2395 All occurrences of @{code} with a single ML block are generated
  2396 simultaneously.  Provides a generic and safe interface for
  2397 instrumentalizing code generation.  See
  2398 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  2399 In future you ought to refrain from ad-hoc compiling generated SML
  2400 code on the ML toplevel.  Note that (for technical reasons) @{code}
  2401 cannot refer to constants for which user-defined serializations are
  2402 set.  Refer to the corresponding ML counterpart directly in that
  2403 cases.
  2404 
  2405 * Command 'rep_datatype': instead of theorem names the command now
  2406 takes a list of terms denoting the constructors of the type to be
  2407 represented as datatype.  The characteristic theorems have to be
  2408 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  2409 have disappeared in favour of existing ones:
  2410 
  2411     unit_induct                 ~> unit.induct
  2412     prod_induct                 ~> prod.induct
  2413     sum_induct                  ~> sum.induct
  2414     Suc_Suc_eq                  ~> nat.inject
  2415     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  2416 
  2417 
  2418 *** HOL-Algebra ***
  2419 
  2420 * New locales for orders and lattices where the equivalence relation
  2421 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  2422 locales use a record structure with field eq for the equivalence.
  2423 
  2424 * New theory of factorial domains.
  2425 
  2426 * Units_l_inv and Units_r_inv are now simp rules by default.
  2427 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  2428 and/or r_inv will now also require deletion of these lemmas.
  2429 
  2430 * Renamed the following theorems, INCOMPATIBILITY:
  2431 
  2432 UpperD ~> Upper_memD
  2433 LowerD ~> Lower_memD
  2434 least_carrier ~> least_closed
  2435 greatest_carrier ~> greatest_closed
  2436 greatest_Lower_above ~> greatest_Lower_below
  2437 one_zero ~> carrier_one_zero
  2438 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  2439 
  2440 
  2441 *** HOL-Nominal ***
  2442 
  2443 * Nominal datatypes can now contain type-variables.
  2444 
  2445 * Commands 'nominal_inductive' and 'equivariance' work with local
  2446 theory targets.
  2447 
  2448 * Nominal primrec can now works with local theory targets and its
  2449 specification syntax now conforms to the general format as seen in
  2450 'inductive' etc.
  2451 
  2452 * Method "perm_simp" honours the standard simplifier attributes
  2453 (no_asm), (no_asm_use) etc.
  2454 
  2455 * The new predicate #* is defined like freshness, except that on the
  2456 left hand side can be a set or list of atoms.
  2457 
  2458 * Experimental command 'nominal_inductive2' derives strong induction
  2459 principles for inductive definitions.  In contrast to
  2460 'nominal_inductive', which can only deal with a fixed number of
  2461 binders, it can deal with arbitrary expressions standing for sets of
  2462 atoms to be avoided.  The only inductive definition we have at the
  2463 moment that needs this generalisation is the typing rule for Lets in
  2464 the algorithm W:
  2465 
  2466  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  2467  -----------------------------------------------------------------
  2468          Gamma |- Let x be t1 in t2 : T2
  2469 
  2470 In this rule one wants to avoid all the binders that are introduced by
  2471 "close Gamma T1".  We are looking for other examples where this
  2472 feature might be useful.  Please let us know.
  2473 
  2474 
  2475 *** HOLCF ***
  2476 
  2477 * Reimplemented the simplification procedure for proving continuity
  2478 subgoals.  The new simproc is extensible; users can declare additional
  2479 continuity introduction rules with the attribute [cont2cont].
  2480 
  2481 * The continuity simproc now uses a different introduction rule for
  2482 solving continuity subgoals on terms with lambda abstractions.  In
  2483 some rare cases the new simproc may fail to solve subgoals that the
  2484 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  2485 Potential INCOMPATIBILITY.
  2486 
  2487 * Command 'fixrec': specification syntax now conforms to the general
  2488 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  2489 examples.  INCOMPATIBILITY.
  2490 
  2491 
  2492 *** ZF ***
  2493 
  2494 * Proof of Zorn's Lemma for partial orders.
  2495 
  2496 
  2497 *** ML ***
  2498 
  2499 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  2500 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  2501 depends on multithreading, so timouts will not work before Poly/ML
  2502 5.2.1!
  2503 
  2504 * High-level support for concurrent ML programming, see
  2505 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  2506 particularly convenient to organize independent functional
  2507 computations.  The concept of "synchronized variables" provides a
  2508 higher-order interface for components with shared state, avoiding the
  2509 delicate details of mutexes and condition variables.  (Requires
  2510 Poly/ML 5.2.1 or later.)
  2511 
  2512 * ML bindings produced via Isar commands are stored within the Isar
  2513 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  2514 become thread-safe and work with undo as expected (concerning
  2515 top-level bindings, not side-effects on global references).
  2516 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  2517 compiler at runtime; really global bindings need to be given outside a
  2518 theory.  (Requires Poly/ML 5.2 or later.)
  2519 
  2520 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  2521 context.  Top-level ML bindings are stored within the proof context in
  2522 a purely sequential fashion, disregarding the nested proof structure.
  2523 ML bindings introduced by 'ML_prf' are discarded at the end of the
  2524 proof.  (Requires Poly/ML 5.2 or later.)
  2525 
  2526 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  2527 and Method.setup, as well as Isar commands 'attribute_setup' and
  2528 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  2529 existing code accordingly, or use plain 'setup' together with old
  2530 Method.add_method.
  2531 
  2532 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  2533 to 'a -> thm, while results are always tagged with an authentic oracle
  2534 name.  The Isar command 'oracle' is now polymorphic, no argument type
  2535 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  2536 accordingly.  Note that extra performance may be gained by producing
  2537 the cterm carefully, avoiding slow Thm.cterm_of.
  2538 
  2539 * Simplified interface for defining document antiquotations via
  2540 ThyOutput.antiquotation, ThyOutput.output, and optionally
  2541 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  2542 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  2543 examples.
  2544 
  2545 * More systematic treatment of long names, abstract name bindings, and
  2546 name space operations.  Basic operations on qualified names have been
  2547 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  2548 Long_Name.append.  Old type bstring has been mostly replaced by
  2549 abstract type binding (see structure Binding), which supports precise
  2550 qualification by packages and local theory targets, as well as proper
  2551 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  2552 bstring values into Binding.name, or better pass through abstract
  2553 bindings everywhere.  See further src/Pure/General/long_name.ML,
  2554 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  2555 
  2556 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  2557 LocalTheory.note etc.) now refer to the *full* internal name, not the
  2558 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  2559 
  2560 * Disposed old type and term read functions (Sign.read_def_typ,
  2561 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  2562 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  2563 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  2564 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  2565 resort for legacy applications.
  2566 
  2567 * Disposed old declarations, tactics, tactic combinators that refer to
  2568 the simpset or claset of an implicit theory (such as Addsimps,
  2569 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  2570 embedded ML text, or local_simpset_of with a proper context passed as
  2571 explicit runtime argument.
  2572 
  2573 * Rules and tactics that read instantiations (read_instantiate,
  2574 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  2575 context, which is required for parsing and type-checking.  Moreover,
  2576 the variables are specified as plain indexnames, not string encodings
  2577 thereof.  INCOMPATIBILITY.
  2578 
  2579 * Generic Toplevel.add_hook interface allows to analyze the result of
  2580 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  2581 for theorem dependency output of transactions resulting in a new
  2582 theory state.
  2583 
  2584 * ML antiquotations: block-structured compilation context indicated by
  2585 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  2586 
  2587   @{binding name}                         - basic name binding
  2588   @{let ?pat = term}                      - term abbreviation (HO matching)
  2589   @{note name = fact}                     - fact abbreviation
  2590   @{thm fact}                             - singleton fact (with attributes)
  2591   @{thms fact}                            - general fact (with attributes)
  2592   @{lemma prop by method}                 - singleton goal
  2593   @{lemma prop by meth1 meth2}            - singleton goal
  2594   @{lemma prop1 ... propN by method}      - general goal
  2595   @{lemma prop1 ... propN by meth1 meth2} - general goal
  2596   @{lemma (open) ...}                     - open derivation
  2597 
  2598 
  2599 *** System ***
  2600 
  2601 * The Isabelle "emacs" tool provides a specific interface to invoke
  2602 Proof General / Emacs, with more explicit failure if that is not
  2603 installed (the old isabelle-interface script silently falls back on
  2604 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  2605 installation location of the Proof General distribution.
  2606 
  2607 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  2608 the Isabelle process into a JVM/Scala application.  See
  2609 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  2610 process wrapper has been discontinued.)
  2611 
  2612 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  2613 
  2614 * Various status messages (with exact source position information) are
  2615 emitted, if proper markup print mode is enabled.  This allows
  2616 user-interface components to provide detailed feedback on internal
  2617 prover operations.
  2618 
  2619 
  2620 
  2621 New in Isabelle2008 (June 2008)
  2622 -------------------------------
  2623 
  2624 *** General ***
  2625 
  2626 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  2627 and updated, with formally checked references as hyperlinks.
  2628 
  2629 * Theory loader: use_thy (and similar operations) no longer set the
  2630 implicit ML context, which was occasionally hard to predict and in
  2631 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  2632 provides a proper context already.
  2633 
  2634 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2635 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  2636 'use' within a theory file will do the job.
  2637 
  2638 * Name space merge now observes canonical order, i.e. the second space
  2639 is inserted into the first one, while existing entries in the first
  2640 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  2641 swap theory imports.
  2642 
  2643 * Syntax: symbol \<chi> is now considered a letter.  Potential
  2644 INCOMPATIBILITY in identifier syntax etc.
  2645 
  2646 * Outer syntax: string tokens no longer admit escaped white space,
  2647 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  2648 white space without escapes.
  2649 
  2650 * Outer syntax: string tokens may contain arbitrary character codes
  2651 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  2652 "foo_bar".
  2653 
  2654 
  2655 *** Pure ***
  2656 
  2657 * Context-dependent token translations.  Default setup reverts locally
  2658 fixed variables, and adds hilite markup for undeclared frees.
  2659 
  2660 * Unused theorems can be found using the new command 'unused_thms'.
  2661 There are three ways of invoking it:
  2662 
  2663 (1) unused_thms
  2664      Only finds unused theorems in the current theory.
  2665 
  2666 (2) unused_thms thy_1 ... thy_n -
  2667      Finds unused theorems in the current theory and all of its ancestors,
  2668      excluding the theories thy_1 ... thy_n and all of their ancestors.
  2669 
  2670 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  2671      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  2672      their ancestors, excluding the theories thy_1 ... thy_n and all of
  2673      their ancestors.
  2674 
  2675 In order to increase the readability of the list produced by
  2676 unused_thms, theorems that have been created by a particular instance
  2677 of a theory command such as 'inductive' or 'function' are considered
  2678 to belong to the same "group", meaning that if at least one theorem in
  2679 this group is used, the other theorems in the same group are no longer
  2680 reported as unused.  Moreover, if all theorems in the group are
  2681 unused, only one theorem in the group is displayed.
  2682 
  2683 Note that proof objects have to be switched on in order for
  2684 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  2685 usually the case when using Proof General with the default settings).
  2686 
  2687 * Authentic naming of facts disallows ad-hoc overwriting of previous
  2688 theorems within the same name space.  INCOMPATIBILITY, need to remove
  2689 duplicate fact bindings, or even accidental fact duplications.  Note
  2690 that tools may maintain dynamically scoped facts systematically, using
  2691 PureThy.add_thms_dynamic.
  2692 
  2693 * Command 'hide' now allows to hide from "fact" name space as well.
  2694 
  2695 * Eliminated destructive theorem database, simpset, claset, and
  2696 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  2697 update of theories within ML code.
  2698 
  2699 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  2700 INCOMPATIBILITY, object-logics depending on former Pure require
  2701 additional setup PureThy.old_appl_syntax_setup; object-logics
  2702 depending on former CPure need to refer to Pure.
  2703 
  2704 * Commands 'use' and 'ML' are now purely functional, operating on
  2705 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  2706 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  2707 INCOMPATIBILITY.
  2708 
  2709 * Command 'setup': discontinued implicit version with ML reference.
  2710 
  2711 * Instantiation target allows for simultaneous specification of class
  2712 instance operations together with an instantiation proof.
  2713 Type-checking phase allows to refer to class operations uniformly.
  2714 See src/HOL/Complex/Complex.thy for an Isar example and
  2715 src/HOL/Library/Eval.thy for an ML example.
  2716 
  2717 * Indexing of literal facts: be more serious about including only
  2718 facts from the visible specification/proof context, but not the
  2719 background context (locale etc.).  Affects `prop` notation and method
  2720 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  2721 situations.
  2722 
  2723 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  2724 "(open)" option, which used to expose internal bound variables to the
  2725 proof text.
  2726 
  2727 * Isar statements: removed obsolete case "rule_context".
  2728 INCOMPATIBILITY, better use explicit fixes/assumes.
  2729 
  2730 * Locale proofs: default proof step now includes 'unfold_locales';
  2731 hence 'proof' without argument may be used to unfold locale
  2732 predicates.
  2733 
  2734 
  2735 *** Document preparation ***
  2736 
  2737 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  2738 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  2739 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  2740 spot); renamed link color from "darkblue" to "linkcolor" (default
  2741 value unchanged, can be redefined via \definecolor); no longer sets
  2742 "a4paper" option (unnecessary or even intrusive).
  2743 
  2744 * Antiquotation @{lemma A method} proves proposition A by the given
  2745 method (either a method name or a method name plus (optional) method
  2746 arguments in parentheses) and prints A just like @{prop A}.
  2747 
  2748 
  2749 *** HOL ***
  2750 
  2751 * New primrec package.  Specification syntax conforms in style to
  2752 definition/function/....  No separate induction rule is provided.  The
  2753 "primrec" command distinguishes old-style and new-style specifications
  2754 by syntax.  The former primrec package is now named OldPrimrecPackage.
  2755 When adjusting theories, beware: constants stemming from new-style
  2756 primrec specifications have authentic syntax.
  2757 
  2758 * Metis prover is now an order of magnitude faster, and also works
  2759 with multithreading.
  2760 
  2761 * Metis: the maximum number of clauses that can be produced from a
  2762 theorem is now given by the attribute max_clauses.  Theorems that
  2763 exceed this number are ignored, with a warning printed.
  2764 
  2765 * Sledgehammer no longer produces structured proofs by default. To
  2766 enable, declare [[sledgehammer_full = true]].  Attributes
  2767 reconstruction_modulus, reconstruction_sorts renamed
  2768 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  2769 
  2770 * Method "induct_scheme" derives user-specified induction rules
  2771 from well-founded induction and completeness of patterns. This factors
  2772 out some operations that are done internally by the function package
  2773 and makes them available separately.  See
  2774 src/HOL/ex/Induction_Scheme.thy for examples.
  2775 
  2776 * More flexible generation of measure functions for termination
  2777 proofs: Measure functions can be declared by proving a rule of the
  2778 form "is_measure f" and giving it the [measure_function] attribute.
  2779 The "is_measure" predicate is logically meaningless (always true), and
  2780 just guides the heuristic.  To find suitable measure functions, the
  2781 termination prover sets up the goal "is_measure ?f" of the appropriate
  2782 type and generates all solutions by prolog-style backwards proof using
  2783 the declared rules.
  2784 
  2785 This setup also deals with rules like 
  2786 
  2787   "is_measure f ==> is_measure (list_size f)"
  2788 
  2789 which accommodates nested datatypes that recurse through lists.
  2790 Similar rules are predeclared for products and option types.
  2791 
  2792 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  2793 
  2794   INCOMPATIBILITIES:
  2795 
  2796   - Definitions of overloaded constants on sets have to be replaced by
  2797     definitions on => and bool.
  2798 
  2799   - Some definitions of overloaded operators on sets can now be proved
  2800     using the definitions of the operators on => and bool.  Therefore,
  2801     the following theorems have been renamed:
  2802 
  2803       subset_def   -> subset_eq
  2804       psubset_def  -> psubset_eq
  2805       set_diff_def -> set_diff_eq
  2806       Compl_def    -> Compl_eq
  2807       Sup_set_def  -> Sup_set_eq
  2808       Inf_set_def  -> Inf_set_eq
  2809       sup_set_def  -> sup_set_eq
  2810       inf_set_def  -> inf_set_eq
  2811 
  2812   - Due to the incompleteness of the HO unification algorithm, some
  2813     rules such as subst may require manual instantiation, if some of
  2814     the unknowns in the rule is a set.
  2815 
  2816   - Higher order unification and forward proofs:
  2817     The proof pattern
  2818 
  2819       have "P (S::'a set)" <...>
  2820       then have "EX S. P S" ..
  2821 
  2822     no longer works (due to the incompleteness of the HO unification
  2823     algorithm) and must be replaced by the pattern
  2824 
  2825       have "EX S. P S"
  2826       proof
  2827         show "P S" <...>
  2828       qed
  2829 
  2830   - Calculational reasoning with subst (or similar rules):
  2831     The proof pattern
  2832 
  2833       have "P (S::'a set)" <...>
  2834       also have "S = T" <...>
  2835       finally have "P T" .
  2836 
  2837     no longer works (for similar reasons as the previous example) and
  2838     must be replaced by something like
  2839 
  2840       have "P (S::'a set)" <...>
  2841       moreover have "S = T" <...>
  2842       ultimately have "P T" by simp
  2843 
  2844   - Tactics or packages written in ML code:
  2845     Code performing pattern matching on types via
  2846 
  2847       Type ("set", [T]) => ...
  2848 
  2849     must be rewritten. Moreover, functions like strip_type or
  2850     binder_types no longer return the right value when applied to a
  2851     type of the form
  2852 
  2853       T1 => ... => Tn => U => bool
  2854 
  2855     rather than
  2856 
  2857       T1 => ... => Tn => U set
  2858 
  2859 * Merged theories Wellfounded_Recursion, Accessible_Part and
  2860 Wellfounded_Relations to theory Wellfounded.
  2861 
  2862 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  2863 
  2864 * Class finite no longer treats UNIV as class parameter.  Use class
  2865 enum from theory Library/Enum instead to achieve a similar effect.
  2866 INCOMPATIBILITY.
  2867 
  2868 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  2869 and "Cons".  INCOMPATIBILITY.
  2870 
  2871 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  2872 Potential INCOMPATIBILITY.
  2873 
  2874 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  2875 injective_fst_snd removed, use split_eta and prod_eqI instead.
  2876 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  2877 
  2878 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  2879 the same name in theory Orderings:
  2880 
  2881   less_trans
  2882   less_linear
  2883   le_imp_less_or_eq
  2884   le_less_trans
  2885   less_le_trans
  2886   less_not_sym
  2887   less_asym
  2888 
  2889 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  2890 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  2891 and different variable names.
  2892 
  2893 * Library/Option_ord.thy: Canonical order on option type.
  2894 
  2895 * Library/RBT.thy: Red-black trees, an efficient implementation of
  2896 finite maps.
  2897 
  2898 * Library/Countable.thy: Type class for countable types.
  2899 
  2900 * Theory Int: The representation of numerals has changed.  The infix
  2901 operator BIT and the bit datatype with constructors B0 and B1 have
  2902 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  2903 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  2904 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  2905 accordingly.
  2906 
  2907 * Theory Nat: definition of <= and < on natural numbers no longer
  2908 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  2909 le_def and less_def have disappeared.  Consider lemmas not_less
  2910 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  2911 
  2912 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  2913 (whose purpose mainly is for various fold_set functionals) have been
  2914 abandoned in favor of the existing algebraic classes
  2915 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  2916 lower_semilattice (resp. upper_semilattice) and linorder.
  2917 INCOMPATIBILITY.
  2918 
  2919 * Theory Transitive_Closure: induct and cases rules now declare proper
  2920 case_names ("base" and "step").  INCOMPATIBILITY.
  2921 
  2922 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  2923 lattices.  The form set-specific version is available as
  2924 Inductive.lfp_ordinal_induct_set.
  2925 
  2926 * Renamed theorems "power.simps" to "power_int.simps".
  2927 INCOMPATIBILITY.
  2928 
  2929 * Class semiring_div provides basic abstract properties of semirings
  2930 with division and modulo operations.  Subsumes former class dvd_mod.
  2931 
  2932 * Merged theories IntDef, Numeral and IntArith into unified theory
  2933 Int.  INCOMPATIBILITY.
  2934 
  2935 * Theory Library/Code_Index: type "index" now represents natural
  2936 numbers rather than integers.  INCOMPATIBILITY.
  2937 
  2938 * New class "uminus" with operation "uminus" (split of from class
  2939 "minus" which now only has operation "minus", binary).
  2940 INCOMPATIBILITY.
  2941 
  2942 * Constants "card", "internal_split", "option_map" now with authentic
  2943 syntax.  INCOMPATIBILITY.
  2944 
  2945 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  2946 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  2947 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  2948 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  2949 Sup_set_def, le_def, less_def, option_map_def now with object
  2950 equality.  INCOMPATIBILITY.
  2951 
  2952 * Records. Removed K_record, and replaced it by pure lambda term
  2953 %x. c. The simplifier setup is now more robust against eta expansion.
  2954 INCOMPATIBILITY: in cases explicitly referring to K_record.
  2955 
  2956 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  2957 
  2958 * Library/ListVector: new theory of arithmetic vector operations.
  2959 
  2960 * Library/Order_Relation: new theory of various orderings as sets of
  2961 pairs.  Defines preorders, partial orders, linear orders and
  2962 well-orders on sets and on types.
  2963 
  2964 
  2965 *** ZF ***
  2966 
  2967 * Renamed some theories to allow to loading both ZF and HOL in the
  2968 same session:
  2969 
  2970   Datatype  -> Datatype_ZF
  2971   Inductive -> Inductive_ZF
  2972   Int       -> Int_ZF
  2973   IntDiv    -> IntDiv_ZF
  2974   Nat       -> Nat_ZF
  2975   List      -> List_ZF
  2976   Main      -> Main_ZF
  2977 
  2978 INCOMPATIBILITY: ZF theories that import individual theories below
  2979 Main might need to be adapted.  Regular theory Main is still
  2980 available, as trivial extension of Main_ZF.
  2981 
  2982 
  2983 *** ML ***
  2984 
  2985 * ML within Isar: antiquotation @{const name} or @{const
  2986 name(typargs)} produces statically-checked Const term.
  2987 
  2988 * Functor NamedThmsFun: data is available to the user as dynamic fact
  2989 (of the same name).  Removed obsolete print command.
  2990 
  2991 * Removed obsolete "use_legacy_bindings" function.
  2992 
  2993 * The ``print mode'' is now a thread-local value derived from a global
  2994 template (the former print_mode reference), thus access becomes
  2995 non-critical.  The global print_mode reference is for session
  2996 management only; user-code should use print_mode_value,
  2997 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  2998 
  2999 * Functions system/system_out provide a robust way to invoke external
  3000 shell commands, with propagation of interrupts (requires Poly/ML
  3001 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  3002 
  3003 
  3004 *** System ***
  3005 
  3006 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  3007 in accordance with Proof General 3.7, which prefers GNU emacs.
  3008 
  3009 * isatool tty runs Isabelle process with plain tty interaction;
  3010 optional line editor may be specified via ISABELLE_LINE_EDITOR
  3011 setting, the default settings attempt to locate "ledit" and "rlwrap".
  3012 
  3013 * isatool browser now works with Cygwin as well, using general
  3014 "javapath" function defined in Isabelle process environment.
  3015 
  3016 * YXML notation provides a simple and efficient alternative to
  3017 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  3018 isatool yxml as described in the Isabelle system manual.
  3019 
  3020 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  3021 provides general wrapper for managing an Isabelle process in a robust
  3022 fashion, with ``cooked'' output from stdin/stderr.
  3023 
  3024 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  3025 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  3026 
  3027 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  3028 way of changing the user's settings is via
  3029 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  3030 script.
  3031 
  3032 * Multithreading.max_threads := 0 refers to the number of actual CPU
  3033 cores of the underlying machine, which is a good starting point for
  3034 optimal performance tuning.  The corresponding usedir option -M allows
  3035 "max" as an alias for "0".  WARNING: does not work on certain versions
  3036 of Mac OS (with Poly/ML 5.1).
  3037 
  3038 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  3039 adverse effect of Isabelle flooding interactive front-ends (notably
  3040 ProofGeneral / XEmacs).
  3041 
  3042 
  3043 
  3044 New in Isabelle2007 (November 2007)
  3045 -----------------------------------
  3046 
  3047 *** General ***
  3048 
  3049 * More uniform information about legacy features, notably a
  3050 warning/error of "Legacy feature: ...", depending on the state of the
  3051 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  3052 legacy features will disappear eventually.
  3053 
  3054 * Theory syntax: the header format ``theory A = B + C:'' has been
  3055 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  3056 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  3057 
  3058 * Theory syntax: the old non-Isar theory file format has been
  3059 discontinued altogether.  Note that ML proof scripts may still be used
  3060 with Isar theories; migration is usually quite simple with the ML
  3061 function use_legacy_bindings.  INCOMPATIBILITY.
  3062 
  3063 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  3064 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  3065 quotes.
  3066 
  3067 * Theory loader: be more serious about observing the static theory
  3068 header specifications (including optional directories), but not the
  3069 accidental file locations of previously successful loads.  The strict
  3070 update policy of former update_thy is now already performed by
  3071 use_thy, so the former has been removed; use_thys updates several
  3072 theories simultaneously, just as 'imports' within a theory header
  3073 specification, but without merging the results.  Potential
  3074 INCOMPATIBILITY: may need to refine theory headers and commands
  3075 ROOT.ML which depend on load order.
  3076 
  3077 * Theory loader: optional support for content-based file
  3078 identification, instead of the traditional scheme of full physical
  3079 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  3080 (cf. the system manual).  The new scheme allows to work with
  3081 non-finished theories in persistent session images, such that source
  3082 files may be moved later on without requiring reloads.
  3083 
  3084 * Theory loader: old-style ML proof scripts being *attached* to a thy
  3085 file (with the same base name as the theory) are considered a legacy
  3086 feature, which will disappear eventually. Even now, the theory loader
  3087 no longer maintains dependencies on such files.
  3088 
  3089 * Syntax: the scope for resolving ambiguities via type-inference is
  3090 now limited to individual terms, instead of whole simultaneous
  3091 specifications as before. This greatly reduces the complexity of the
  3092 syntax module and improves flexibility by separating parsing and
  3093 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  3094 'fixes' etc.) are required in rare situations.
  3095 
  3096 * Syntax: constants introduced by new-style packages ('definition',
  3097 'abbreviation' etc.) are passed through the syntax module in
  3098 ``authentic mode''. This means that associated mixfix annotations
  3099 really stick to such constants, independently of potential name space
  3100 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  3101 trees are represented slightly differently, may need to adapt syntax
  3102 translations accordingly. Use CONST marker in 'translations' and
  3103 @{const_syntax} antiquotation in 'parse_translation' etc.
  3104 
  3105 * Legacy goal package: reduced interface to the bare minimum required
  3106 to keep existing proof scripts running.  Most other user-level
  3107 functions are now part of the OldGoals structure, which is *not* open
  3108 by default (consider isatool expandshort before open OldGoals).
  3109 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  3110 these tend to cause confusion about the actual goal (!) context being
  3111 used here, which is not necessarily the same as the_context().
  3112 
  3113 * Command 'find_theorems': supports "*" wild-card in "name:"
  3114 criterion; "with_dups" option.  Certain ProofGeneral versions might
  3115 support a specific search form (see ProofGeneral/CHANGES).
  3116 
  3117 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  3118 by default, which means that "prems" (and also "fixed variables") are
  3119 suppressed from proof state output.  Note that the ProofGeneral
  3120 settings mechanism allows to change and save options persistently, but
  3121 older versions of Isabelle will fail to start up if a negative prems
  3122 limit is imposed.
  3123 
  3124 * Local theory targets may be specified by non-nested blocks of
  3125 ``context/locale/class ... begin'' followed by ``end''.  The body may
  3126 contain definitions, theorems etc., including any derived mechanism
  3127 that has been implemented on top of these primitives.  This concept
  3128 generalizes the existing ``theorem (in ...)'' towards more versatility
  3129 and scalability.
  3130 
  3131 * Proof General interface: proper undo of final 'end' command;
  3132 discontinued Isabelle/classic mode (ML proof scripts).
  3133 
  3134 
  3135 *** Document preparation ***
  3136 
  3137 * Added antiquotation @{theory name} which prints the given name,
  3138 after checking that it refers to a valid ancestor theory in the
  3139 current context.
  3140 
  3141 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  3142 check the given source text as ML type/structure, printing verbatim.
  3143 
  3144 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  3145 "c args == rhs" given in the current context.  (Any number of
  3146 arguments may be given on the LHS.)
  3147 
  3148 
  3149 *** Pure ***
  3150 
  3151 * The 'class' package offers a combination of axclass and locale to
  3152 achieve Haskell-like type classes in Isabelle.  Definitions and
  3153 theorems within a class context produce both relative results (with
  3154 implicit parameters according to the locale context), and polymorphic
  3155 constants with qualified polymorphism (according to the class
  3156 context).  Within the body context of a 'class' target, a separate
  3157 syntax layer ("user space type system") takes care of converting
  3158 between global polymorphic consts and internal locale representation.
  3159 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  3160 "isatool doc classes" provides a tutorial.
  3161 
  3162 * Generic code generator framework allows to generate executable
  3163 code for ML and Haskell (including Isabelle classes).  A short usage
  3164 sketch:
  3165 
  3166     internal compilation:
  3167         export_code <list of constants (term syntax)> in SML
  3168     writing SML code to a file:
  3169         export_code <list of constants (term syntax)> in SML <filename>
  3170     writing OCaml code to a file:
  3171         export_code <list of constants (term syntax)> in OCaml <filename>
  3172     writing Haskell code to a bunch of files:
  3173         export_code <list of constants (term syntax)> in Haskell <filename>
  3174 
  3175     evaluating closed propositions to True/False using code generation:
  3176         method ``eval''
  3177 
  3178 Reasonable default setup of framework in HOL.
  3179 
  3180 Theorem attributs for selecting and transforming function equations theorems:
  3181 
  3182     [code fun]:        select a theorem as function equation for a specific constant
  3183     [code fun del]:    deselect a theorem as function equation for a specific constant
  3184     [code inline]:     select an equation theorem for unfolding (inlining) in place
  3185     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  3186 
  3187 User-defined serializations (target in {SML, OCaml, Haskell}):
  3188 
  3189     code_const <and-list of constants (term syntax)>
  3190       {(target) <and-list of const target syntax>}+
  3191 
  3192     code_type <and-list of type constructors>
  3193       {(target) <and-list of type target syntax>}+
  3194 
  3195     code_instance <and-list of instances>
  3196       {(target)}+
  3197         where instance ::= <type constructor> :: <class>
  3198 
  3199     code_class <and_list of classes>
  3200       {(target) <and-list of class target syntax>}+
  3201         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  3202 
  3203 code_instance and code_class only are effective to target Haskell.
  3204 
  3205 For example usage see src/HOL/ex/Codegenerator.thy and
  3206 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  3207 generation from Isabelle/HOL theories is available via "isatool doc
  3208 codegen".
  3209 
  3210 * Code generator: consts in 'consts_code' Isar commands are now
  3211 referred to by usual term syntax (including optional type
  3212 annotations).
  3213 
  3214 * Command 'no_translations' removes translation rules from theory
  3215 syntax.
  3216 
  3217 * Overloaded definitions are now actually checked for acyclic
  3218 dependencies.  The overloading scheme is slightly more general than
  3219 that of Haskell98, although Isabelle does not demand an exact
  3220 correspondence to type class and instance declarations.
  3221 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  3222 exotic versions of overloading -- at the discretion of the user!
  3223 
  3224 Polymorphic constants are represented via type arguments, i.e. the
  3225 instantiation that matches an instance against the most general
  3226 declaration given in the signature.  For example, with the declaration
  3227 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  3228 as c(nat).  Overloading is essentially simultaneous structural
  3229 recursion over such type arguments.  Incomplete specification patterns
  3230 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  3231 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  3232 Command 'print_theory' outputs the normalized system of recursive
  3233 equations, see section "definitions".
  3234 
  3235 * Configuration options are maintained within the theory or proof
  3236 context (with name and type bool/int/string), providing a very simple
  3237 interface to a poor-man's version of general context data.  Tools may
  3238 declare options in ML (e.g. using Attrib.config_int) and then refer to
  3239 these values using Config.get etc.  Users may change options via an
  3240 associated attribute of the same name.  This form of context
  3241 declaration works particularly well with commands 'declare' or
  3242 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  3243 very easy to avoid global references, which would not observe Isar
  3244 toplevel undo/redo and fail to work with multithreading.
  3245 
  3246 Various global ML references of Pure and HOL have been turned into
  3247 configuration options:
  3248 
  3249   Unify.search_bound		unify_search_bound
  3250   Unify.trace_bound		unify_trace_bound
  3251   Unify.trace_simp		unify_trace_simp
  3252   Unify.trace_types		unify_trace_types
  3253   Simplifier.simp_depth_limit	simp_depth_limit
  3254   Blast.depth_limit		blast_depth_limit
  3255   DatatypeProp.dtK		datatype_distinctness_limit
  3256   fast_arith_neq_limit  	fast_arith_neq_limit
  3257   fast_arith_split_limit	fast_arith_split_limit
  3258 
  3259 * Named collections of theorems may be easily installed as context
  3260 data using the functor NamedThmsFun (see also
  3261 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  3262 attributes; there is also a toplevel print command.  This facility is
  3263 just a common case of general context data, which is the preferred way
  3264 for anything more complex than just a list of facts in canonical
  3265 order.
  3266 
  3267 * Isar: command 'declaration' augments a local theory by generic
  3268 declaration functions written in ML.  This enables arbitrary content
  3269 being added to the context, depending on a morphism that tells the
  3270 difference of the original declaration context wrt. the application
  3271 context encountered later on.
  3272 
  3273 * Isar: proper interfaces for simplification procedures.  Command
  3274 'simproc_setup' declares named simprocs (with match patterns, and body
  3275 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  3276 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  3277 
  3278 * Isar: an extra pair of brackets around attribute declarations
  3279 abbreviates a theorem reference involving an internal dummy fact,
  3280 which will be ignored later --- only the effect of the attribute on
  3281 the background context will persist.  This form of in-place
  3282 declarations is particularly useful with commands like 'declare' and
  3283 'using', for example ``have A using [[simproc a]] by simp''.
  3284 
  3285 * Isar: method "assumption" (and implicit closing of subproofs) now
  3286 takes simple non-atomic goal assumptions into account: after applying
  3287 an assumption as a rule the resulting subgoals are solved by atomic
  3288 assumption steps.  This is particularly useful to finish 'obtain'
  3289 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  3290 without referring to the original premise "!!x. P x ==> thesis" in the
  3291 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  3292 more permissive.
  3293 
  3294 * Isar: implicit use of prems from the Isar proof context is
  3295 considered a legacy feature.  Common applications like ``have A .''
  3296 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  3297 referencing facts explicitly here improves readability and
  3298 maintainability of proof texts.
  3299 
  3300 * Isar: improper proof element 'guess' is like 'obtain', but derives
  3301 the obtained context from the course of reasoning!  For example:
  3302 
  3303   assume "EX x y. A x & B y"   -- "any previous fact"
  3304   then guess x and y by clarify
  3305 
  3306 This technique is potentially adventurous, depending on the facts and
  3307 proof tools being involved here.
  3308 
  3309 * Isar: known facts from the proof context may be specified as literal
  3310 propositions, using ASCII back-quote syntax.  This works wherever
  3311 named facts used to be allowed so far, in proof commands, proof
  3312 methods, attributes etc.  Literal facts are retrieved from the context
  3313 according to unification of type and term parameters.  For example,
  3314 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  3315 theorems in the current context, then these are valid literal facts:
  3316 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  3317 
  3318 There is also a proof method "fact" which does the same composition
  3319 for explicit goal states, e.g. the following proof texts coincide with
  3320 certain special cases of literal facts:
  3321 
  3322   have "A" by fact                 ==  note `A`
  3323   have "A ==> B" by fact           ==  note `A ==> B`
  3324   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  3325   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  3326 
  3327 * Isar: ":" (colon) is no longer a symbolic identifier character in
  3328 outer syntax.  Thus symbolic identifiers may be used without
  3329 additional white space in declarations like this: ``assume *: A''.
  3330 
  3331 * Isar: 'print_facts' prints all local facts of the current context,
  3332 both named and unnamed ones.
  3333 
  3334 * Isar: 'def' now admits simultaneous definitions, e.g.:
  3335 
  3336   def x == "t" and y == "u"
  3337 
  3338 * Isar: added command 'unfolding', which is structurally similar to
  3339 'using', but affects both the goal state and facts by unfolding given
  3340 rewrite rules.  Thus many occurrences of the 'unfold' method or
  3341 'unfolded' attribute may be replaced by first-class proof text.
  3342 
  3343 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  3344 and command 'unfolding' now all support object-level equalities
  3345 (potentially conditional).  The underlying notion of rewrite rule is
  3346 analogous to the 'rule_format' attribute, but *not* that of the
  3347 Simplifier (which is usually more generous).
  3348 
  3349 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  3350 premises of a theorem by n. Useful in conjunction with drule.
  3351 
  3352 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  3353 method expression within a sandbox consisting of the first N
  3354 sub-goals, which need to exist.  For example, ``simp_all [3]''
  3355 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  3356 simplifies all new goals that emerge from applying rule foo to the
  3357 originally first one.
  3358 
  3359 * Isar: schematic goals are no longer restricted to higher-order
  3360 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  3361 expected.
  3362 
  3363 * Isar: the conclusion of a long theorem statement is now either
  3364 'shows' (a simultaneous conjunction, as before), or 'obtains'
  3365 (essentially a disjunction of cases with local parameters and
  3366 assumptions).  The latter allows to express general elimination rules
  3367 adequately; in this notation common elimination rules look like this:
  3368 
  3369   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  3370     assumes "EX x. P x"
  3371     obtains x where "P x"
  3372 
  3373   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  3374     assumes "A & B"
  3375     obtains A and B
  3376 
  3377   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  3378     assumes "A | B"
  3379     obtains
  3380       A
  3381     | B
  3382 
  3383 The subsequent classical rules even refer to the formal "thesis"
  3384 explicitly:
  3385 
  3386   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  3387     obtains "~ thesis"
  3388 
  3389   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  3390     obtains "thesis ==> something"
  3391 
  3392 The actual proof of an 'obtains' statement is analogous to that of the
  3393 Isar proof element 'obtain', only that there may be several cases.
  3394 Optional case names may be specified in parentheses; these will be
  3395 available both in the present proof and as annotations in the
  3396 resulting rule, for later use with the 'cases' method (cf. attribute
  3397 case_names).
  3398 
  3399 * Isar: the assumptions of a long theorem statement are available as
  3400 "assms" fact in the proof context.  This is more appropriate than the
  3401 (historical) "prems", which refers to all assumptions of the current
  3402 context, including those from the target locale, proof body etc.
  3403 
  3404 * Isar: 'print_statement' prints theorems from the current theory or
  3405 proof context in long statement form, according to the syntax of a
  3406 top-level lemma.
  3407 
  3408 * Isar: 'obtain' takes an optional case name for the local context
  3409 introduction rule (default "that").
  3410 
  3411 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  3412 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  3413 to occur.
  3414 
  3415 * Pure: syntax "CONST name" produces a fully internalized constant
  3416 according to the current context.  This is particularly useful for
  3417 syntax translations that should refer to internal constant
  3418 representations independently of name spaces.
  3419 
  3420 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  3421 instead of "FOO ". This allows multiple binder declarations to coexist
  3422 in the same context.  INCOMPATIBILITY.
  3423 
  3424 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  3425 primitive that also works in a locale context (both for constants and
  3426 fixed variables). Type declaration and internal syntactic representation
  3427 of given constants retrieved from the context. Likewise, the
  3428 'no_notation' command allows to remove given syntax annotations from the
  3429 current context.
  3430 
  3431 * Isar/locales: new derived specification elements 'axiomatization',
  3432 'definition', 'abbreviation', which support type-inference, admit
  3433 object-level specifications (equality, equivalence).  See also the
  3434 isar-ref manual.  Examples:
  3435 
  3436   axiomatization
  3437     eq  (infix "===" 50) where
  3438     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  3439 
  3440   definition "f x y = x + y + 1"
  3441   definition g where "g x = f x x"
  3442 
  3443   abbreviation
  3444     neq  (infix "=!=" 50) where
  3445     "x =!= y == ~ (x === y)"
  3446 
  3447 These specifications may be also used in a locale context.  Then the
  3448 constants being introduced depend on certain fixed parameters, and the
  3449 constant name is qualified by the locale base name.  An internal
  3450 abbreviation takes care for convenient input and output, making the
  3451 parameters implicit and using the original short name.  See also
  3452 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  3453 entities from a monomorphic theory.
  3454 
  3455 Presently, abbreviations are only available 'in' a target locale, but
  3456 not inherited by general import expressions.  Also note that
  3457 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  3458 'translations' in common applications.  The "no_abbrevs" print mode
  3459 prevents folding of abbreviations in term output.
  3460 
  3461 Concrete syntax is attached to specified constants in internal form,
  3462 independently of name spaces.  The parse tree representation is
  3463 slightly different -- use 'notation' instead of raw 'syntax', and
  3464 'translations' with explicit "CONST" markup to accommodate this.
  3465 
  3466 * Pure/Isar: unified syntax for new-style specification mechanisms
  3467 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  3468 full type inference and dummy patterns ("_").  For example:
  3469 
  3470   definition "K x _ = x"
  3471 
  3472   inductive conj for A B
  3473   where "A ==> B ==> conj A B"
  3474 
  3475 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  3476 the current context.  Print mode "no_abbrevs" prevents inversion of
  3477 abbreviations on output.
  3478 
  3479 * Isar/locales: improved parameter handling: use of locales "var" and
  3480 "struct" no longer necessary; - parameter renamings are no longer
  3481 required to be injective.  For example, this allows to define
  3482 endomorphisms as locale endom = homom mult mult h.
  3483 
  3484 * Isar/locales: changed the way locales with predicates are defined.
  3485 Instead of accumulating the specification, the imported expression is
  3486 now an interpretation.  INCOMPATIBILITY: different normal form of
  3487 locale expressions.  In particular, in interpretations of locales with
  3488 predicates, goals repesenting already interpreted fragments are not
  3489 removed automatically.  Use methods `intro_locales' and
  3490 `unfold_locales'; see below.
  3491 
  3492 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  3493 provide backward reasoning on locales predicates.  The methods are
  3494 aware of interpretations and discharge corresponding goals.
  3495 `intro_locales' is less aggressive then `unfold_locales' and does not
  3496 unfold predicates to assumptions.
  3497 
  3498 * Isar/locales: the order in which locale fragments are accumulated
  3499 has changed.  This enables to override declarations from fragments due
  3500 to interpretations -- for example, unwanted simp rules.
  3501 
  3502 * Isar/locales: interpretation in theories and proof contexts has been
  3503 extended.  One may now specify (and prove) equations, which are
  3504 unfolded in interpreted theorems.  This is useful for replacing
  3505 defined concepts (constants depending on locale parameters) by
  3506 concepts already existing in the target context.  Example:
  3507 
  3508   interpretation partial_order ["op <= :: [int, int] => bool"]
  3509     where "partial_order.less (op <=) (x::int) y = (x < y)"
  3510 
  3511 Typically, the constant `partial_order.less' is created by a
  3512 definition specification element in the context of locale
  3513 partial_order.
  3514 
  3515 * Method "induct": improved internal context management to support
  3516 local fixes and defines on-the-fly. Thus explicit meta-level
  3517 connectives !!  and ==> are rarely required anymore in inductive goals
  3518 (using object-logic connectives for this purpose has been long
  3519 obsolete anyway). Common proof patterns are explained in
  3520 src/HOL/Induct/Common_Patterns.thy, see also
  3521 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  3522 examples.
  3523 
  3524 * Method "induct": improved handling of simultaneous goals. Instead of
  3525 introducing object-level conjunction, the statement is now split into
  3526 several conclusions, while the corresponding symbolic cases are nested
  3527 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  3528 see src/HOL/Induct/Common_Patterns.thy, for example.
  3529 
  3530 * Method "induct": mutual induction rules are now specified as a list
  3531 of rule sharing the same induction cases. HOL packages usually provide
  3532 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  3533 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  3534 mutual induction rules differently, i.e. like this:
  3535 
  3536   (induct rule: foo_bar.inducts)
  3537   (induct set: foo bar)
  3538   (induct pred: foo bar)
  3539   (induct type: foo bar)
  3540 
  3541 The ML function ProjectRule.projections turns old-style rules into the
  3542 new format.
  3543 
  3544 * Method "coinduct": dual of induction, see
  3545 src/HOL/Library/Coinductive_List.thy for various examples.
  3546 
  3547 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  3548 considered a legacy feature.
  3549 
  3550 * Attribute "symmetric" produces result with standardized schematic
  3551 variables (index 0).  Potential INCOMPATIBILITY.
  3552 
  3553 * Simplifier: by default the simplifier trace only shows top level
  3554 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  3555 default. Thus there is less danger of being flooded by the trace. The
  3556 trace indicates where parts have been suppressed.
  3557   
  3558 * Provers/classical: removed obsolete classical version of elim_format
  3559 attribute; classical elim/dest rules are now treated uniformly when
  3560 manipulating the claset.
  3561 
  3562 * Provers/classical: stricter checks to ensure that supplied intro,
  3563 dest and elim rules are well-formed; dest and elim rules must have at
  3564 least one premise.
  3565 
  3566 * Provers/classical: attributes dest/elim/intro take an optional
  3567 weight argument for the rule (just as the Pure versions).  Weights are
  3568 ignored by automated tools, but determine the search order of single
  3569 rule steps.
  3570 
  3571 * Syntax: input syntax now supports dummy variable binding "%_. b",
  3572 where the body does not mention the bound variable.  Note that dummy
  3573 patterns implicitly depend on their context of bounds, which makes
  3574 "{_. _}" match any set comprehension as expected.  Potential
  3575 INCOMPATIBILITY -- parse translations need to cope with syntactic
  3576 constant "_idtdummy" in the binding position.
  3577 
  3578 * Syntax: removed obsolete syntactic constant "_K" and its associated
  3579 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  3580 for example "A -> B" => "Pi A (%_. B)".
  3581 
  3582 * Pure: 'class_deps' command visualizes the subclass relation, using
  3583 the graph browser tool.
  3584 
  3585 * Pure: 'print_theory' now suppresses certain internal declarations by
  3586 default; use '!' option for full details.
  3587 
  3588 
  3589 *** HOL ***
  3590 
  3591 * Method "metis" proves goals by applying the Metis general-purpose
  3592 resolution prover (see also http://gilith.com/software/metis/).
  3593 Examples are in the directory MetisExamples.  WARNING: the
  3594 Isabelle/HOL-Metis integration does not yet work properly with
  3595 multi-threading.
  3596   
  3597 * Command 'sledgehammer' invokes external automatic theorem provers as
  3598 background processes.  It generates calls to the "metis" method if
  3599 successful. These can be pasted into the proof.  Users do not have to
  3600 wait for the automatic provers to return.  WARNING: does not really
  3601 work with multi-threading.
  3602 
  3603 * New "auto_quickcheck" feature tests outermost goal statements for
  3604 potential counter-examples.  Controlled by ML references
  3605 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  3606 5000 milliseconds).  Fails silently if statements is outside of
  3607 executable fragment, or any other codgenerator problem occurs.
  3608 
  3609 * New constant "undefined" with axiom "undefined x = undefined".
  3610 
  3611 * Added class "HOL.eq", allowing for code generation with polymorphic
  3612 equality.
  3613 
  3614 * Some renaming of class constants due to canonical name prefixing in
  3615 the new 'class' package:
  3616 
  3617     HOL.abs ~> HOL.abs_class.abs
  3618     HOL.divide ~> HOL.divide_class.divide
  3619     0 ~> HOL.zero_class.zero
  3620     1 ~> HOL.one_class.one
  3621     op + ~> HOL.plus_class.plus
  3622     op - ~> HOL.minus_class.minus
  3623     uminus ~> HOL.minus_class.uminus
  3624     op * ~> HOL.times_class.times
  3625     op < ~> HOL.ord_class.less
  3626     op <= > HOL.ord_class.less_eq
  3627     Nat.power ~> Power.power_class.power
  3628     Nat.size ~> Nat.size_class.size
  3629     Numeral.number_of ~> Numeral.number_class.number_of
  3630     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  3631     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  3632     Orderings.min ~> Orderings.ord_class.min
  3633     Orderings.max ~> Orderings.ord_class.max
  3634     Divides.op div ~> Divides.div_class.div
  3635     Divides.op mod ~> Divides.div_class.mod
  3636     Divides.op dvd ~> Divides.div_class.dvd
  3637 
  3638 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  3639 
  3640 a) User-defined constants using any of the names "plus", "minus",
  3641 "times", "less" or "less_eq". The standard syntax translations for
  3642 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  3643 names.
  3644 
  3645 b) Variables named "plus", "minus", "times", "less", "less_eq"
  3646 INCOMPATIBILITY: use more specific names.
  3647 
  3648 c) Permutative equations (e.g. "a + b = b + a")
  3649 Since the change of names also changes the order of terms, permutative
  3650 rewrite rules may get applied in a different order. Experience shows
  3651 that this is rarely the case (only two adaptions in the whole Isabelle
  3652 distribution).  INCOMPATIBILITY: rewrite proofs
  3653 
  3654 d) ML code directly refering to constant names
  3655 This in general only affects hand-written proof tactics, simprocs and
  3656 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  3657 Consider using @{const_name} antiquotation.
  3658 
  3659 * New class "default" with associated constant "default".
  3660 
  3661 * Function "sgn" is now overloaded and available on int, real, complex
  3662 (and other numeric types), using class "sgn".  Two possible defs of
  3663 sgn are given as equational assumptions in the classes sgn_if and
  3664 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  3665 INCOMPATIBILITY.
  3666 
  3667 * Locale "partial_order" now unified with class "order" (cf. theory
  3668 Orderings), added parameter "less".  INCOMPATIBILITY.
  3669 
  3670 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  3671 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  3672 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  3673 
  3674 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  3675 changed order of proof goals in instance proofs.
  3676 
  3677 * The transitivity reasoner for partial and linear orders is set up
  3678 for classes "order" and "linorder".  Instances of the reasoner are available
  3679 in all contexts importing or interpreting the corresponding locales.
  3680 Method "order" invokes the reasoner separately; the reasoner
  3681 is also integrated with the Simplifier as a solver.  Diagnostic
  3682 command 'print_orders' shows the available instances of the reasoner
  3683 in the current context.
  3684 
  3685 * Localized monotonicity predicate in theory "Orderings"; integrated
  3686 lemmas max_of_mono and min_of_mono with this predicate.
  3687 INCOMPATIBILITY.
  3688 
  3689 * Formulation of theorem "dense" changed slightly due to integration
  3690 with new class dense_linear_order.
  3691 
  3692 * Uniform lattice theory development in HOL.
  3693 
  3694     constants "meet" and "join" now named "inf" and "sup"
  3695     constant "Meet" now named "Inf"
  3696 
  3697     classes "meet_semilorder" and "join_semilorder" now named
  3698       "lower_semilattice" and "upper_semilattice"
  3699     class "lorder" now named "lattice"
  3700     class "comp_lat" now named "complete_lattice"
  3701 
  3702     Instantiation of lattice classes allows explicit definitions
  3703     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  3704 
  3705   INCOMPATIBILITY.  Theorem renames:
  3706 
  3707     meet_left_le            ~> inf_le1
  3708     meet_right_le           ~> inf_le2
  3709     join_left_le            ~> sup_ge1
  3710     join_right_le           ~> sup_ge2
  3711     meet_join_le            ~> inf_sup_ord
  3712     le_meetI                ~> le_infI
  3713     join_leI                ~> le_supI
  3714     le_meet                 ~> le_inf_iff
  3715     le_join                 ~> ge_sup_conv
  3716     meet_idempotent         ~> inf_idem
  3717     join_idempotent         ~> sup_idem
  3718     meet_comm               ~> inf_commute
  3719     join_comm               ~> sup_commute
  3720     meet_leI1               ~> le_infI1
  3721     meet_leI2               ~> le_infI2
  3722     le_joinI1               ~> le_supI1
  3723     le_joinI2               ~> le_supI2
  3724     meet_assoc              ~> inf_assoc
  3725     join_assoc              ~> sup_assoc
  3726     meet_left_comm          ~> inf_left_commute
  3727     meet_left_idempotent    ~> inf_left_idem
  3728     join_left_comm          ~> sup_left_commute
  3729     join_left_idempotent    ~> sup_left_idem
  3730     meet_aci                ~> inf_aci
  3731     join_aci                ~> sup_aci
  3732     le_def_meet             ~> le_iff_inf
  3733     le_def_join             ~> le_iff_sup
  3734     join_absorp2            ~> sup_absorb2
  3735     join_absorp1            ~> sup_absorb1
  3736     meet_absorp1            ~> inf_absorb1
  3737     meet_absorp2            ~> inf_absorb2
  3738     meet_join_absorp        ~> inf_sup_absorb
  3739     join_meet_absorp        ~> sup_inf_absorb
  3740     distrib_join_le         ~> distrib_sup_le
  3741     distrib_meet_le         ~> distrib_inf_le
  3742 
  3743     add_meet_distrib_left   ~> add_inf_distrib_left
  3744     add_join_distrib_left   ~> add_sup_distrib_left
  3745     is_join_neg_meet        ~> is_join_neg_inf
  3746     is_meet_neg_join        ~> is_meet_neg_sup
  3747     add_meet_distrib_right  ~> add_inf_distrib_right
  3748     add_join_distrib_right  ~> add_sup_distrib_right
  3749     add_meet_join_distribs  ~> add_sup_inf_distribs
  3750     join_eq_neg_meet        ~> sup_eq_neg_inf
  3751     meet_eq_neg_join        ~> inf_eq_neg_sup
  3752     add_eq_meet_join        ~> add_eq_inf_sup
  3753     meet_0_imp_0            ~> inf_0_imp_0
  3754     join_0_imp_0            ~> sup_0_imp_0
  3755     meet_0_eq_0             ~> inf_0_eq_0
  3756     join_0_eq_0             ~> sup_0_eq_0
  3757     neg_meet_eq_join        ~> neg_inf_eq_sup
  3758     neg_join_eq_meet        ~> neg_sup_eq_inf
  3759     join_eq_if              ~> sup_eq_if
  3760 
  3761     mono_meet               ~> mono_inf
  3762     mono_join               ~> mono_sup
  3763     meet_bool_eq            ~> inf_bool_eq
  3764     join_bool_eq            ~> sup_bool_eq
  3765     meet_fun_eq             ~> inf_fun_eq
  3766     join_fun_eq             ~> sup_fun_eq
  3767     meet_set_eq             ~> inf_set_eq
  3768     join_set_eq             ~> sup_set_eq
  3769     meet1_iff               ~> inf1_iff
  3770     meet2_iff               ~> inf2_iff
  3771     meet1I                  ~> inf1I
  3772     meet2I                  ~> inf2I
  3773     meet1D1                 ~> inf1D1
  3774     meet2D1                 ~> inf2D1
  3775     meet1D2                 ~> inf1D2
  3776     meet2D2                 ~> inf2D2
  3777     meet1E                  ~> inf1E
  3778     meet2E                  ~> inf2E
  3779     join1_iff               ~> sup1_iff
  3780     join2_iff               ~> sup2_iff
  3781     join1I1                 ~> sup1I1
  3782     join2I1                 ~> sup2I1
  3783     join1I1                 ~> sup1I1
  3784     join2I2                 ~> sup1I2
  3785     join1CI                 ~> sup1CI
  3786     join2CI                 ~> sup2CI
  3787     join1E                  ~> sup1E
  3788     join2E                  ~> sup2E
  3789 
  3790     is_meet_Meet            ~> is_meet_Inf
  3791     Meet_bool_def           ~> Inf_bool_def
  3792     Meet_fun_def            ~> Inf_fun_def
  3793     Meet_greatest           ~> Inf_greatest
  3794     Meet_lower              ~> Inf_lower
  3795     Meet_set_def            ~> Inf_set_def
  3796 
  3797     Sup_def                 ~> Sup_Inf
  3798     Sup_bool_eq             ~> Sup_bool_def
  3799     Sup_fun_eq              ~> Sup_fun_def
  3800     Sup_set_eq              ~> Sup_set_def
  3801 
  3802     listsp_meetI            ~> listsp_infI
  3803     listsp_meet_eq          ~> listsp_inf_eq
  3804 
  3805     meet_min                ~> inf_min
  3806     join_max                ~> sup_max
  3807 
  3808 * Added syntactic class "size"; overloaded constant "size" now has
  3809 type "'a::size ==> bool"
  3810 
  3811 * Internal reorganisation of `size' of datatypes: size theorems
  3812 "foo.size" are no longer subsumed by "foo.simps" (but are still
  3813 simplification rules by default!); theorems "prod.size" now named
  3814 "*.size".
  3815 
  3816 * Class "div" now inherits from class "times" rather than "type".
  3817 INCOMPATIBILITY.
  3818 
  3819 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  3820 Linorder etc.  have disappeared; operations defined in terms of
  3821 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  3822 
  3823 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  3824 
  3825 * HOL-Word: New extensive library and type for generic, fixed size
  3826 machine words, with arithemtic, bit-wise, shifting and rotating
  3827 operations, reflection into int, nat, and bool lists, automation for
  3828 linear arithmetic (by automatic reflection into nat or int), including
  3829 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  3830 arithmetic type classes, supporting automatic simplification of
  3831 numerals on all operations.
  3832 
  3833 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  3834 
  3835 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  3836 
  3837 * Code generator library theories:
  3838   - Code_Integer represents HOL integers by big integer literals in target
  3839     languages.
  3840   - Code_Char represents HOL characters by character literals in target
  3841     languages.
  3842   - Code_Char_chr like Code_Char, but also offers treatment of character
  3843     codes; includes Code_Integer.
  3844   - Executable_Set allows to generate code for finite sets using lists.
  3845   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  3846     denominator).
  3847   - Executable_Real implements a subset of real numbers, namly those
  3848     representable by rational numbers.
  3849   - Efficient_Nat implements natural numbers by integers, which in general will
  3850     result in higher efficency; pattern matching with 0/Suc is eliminated;
  3851     includes Code_Integer.
  3852   - Code_Index provides an additional datatype index which is mapped to
  3853     target-language built-in integers.
  3854   - Code_Message provides an additional datatype message_string which is isomorphic to
  3855     strings; messages are mapped to target-language strings.
  3856 
  3857 * New package for inductive predicates
  3858 
  3859   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  3860 
  3861     inductive
  3862       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3863       for z_1 :: U_1 and ... and z_n :: U_m
  3864     where
  3865       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3866     | ...
  3867 
  3868   with full support for type-inference, rather than
  3869 
  3870     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3871 
  3872     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3873     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3874 
  3875     inductive "s z_1 ... z_m"
  3876     intros
  3877       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3878       ...
  3879 
  3880   For backward compatibility, there is a wrapper allowing inductive
  3881   sets to be defined with the new package via
  3882 
  3883     inductive_set
  3884       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3885       for z_1 :: U_1 and ... and z_n :: U_m
  3886     where
  3887       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3888     | ...
  3889 
  3890   or
  3891 
  3892     inductive_set
  3893       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3894       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3895       for z_1 :: U_1 and ... and z_n :: U_m
  3896     where
  3897       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3898     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3899     | ...
  3900 
  3901   if the additional syntax "p ..." is required.
  3902 
  3903   Numerous examples can be found in the subdirectories src/HOL/Auth,
  3904   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  3905 
  3906   INCOMPATIBILITIES:
  3907 
  3908   - Since declaration and definition of inductive sets or predicates
  3909     is no longer separated, abbreviations involving the newly
  3910     introduced sets or predicates must be specified together with the
  3911     introduction rules after the 'where' keyword (see above), rather
  3912     than before the actual inductive definition.
  3913 
  3914   - The variables in induction and elimination rules are now
  3915     quantified in the order of their occurrence in the introduction
  3916     rules, rather than in alphabetical order. Since this may break
  3917     some proofs, these proofs either have to be repaired, e.g. by
  3918     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  3919     statements of the form
  3920 
  3921       case (rule_i a_i_1 ... a_i_{k_i})
  3922 
  3923     or the old order of quantification has to be restored by explicitly adding
  3924     meta-level quantifiers in the introduction rules, i.e.
  3925 
  3926       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  3927 
  3928   - The format of the elimination rules is now
  3929 
  3930       p z_1 ... z_m x_1 ... x_n ==>
  3931         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  3932         ==> ... ==> P
  3933 
  3934     for predicates and
  3935 
  3936       (x_1, ..., x_n) : s z_1 ... z_m ==>
  3937         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  3938         ==> ... ==> P
  3939 
  3940     for sets rather than
  3941 
  3942       x : s z_1 ... z_m ==>
  3943         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  3944         ==> ... ==> P
  3945 
  3946     This may require terms in goals to be expanded to n-tuples
  3947     (e.g. using case_tac or simplification with the split_paired_all
  3948     rule) before the above elimination rule is applicable.
  3949 
  3950   - The elimination or case analysis rules for (mutually) inductive
  3951     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  3952     list of rules "p_1_..._p_k.elims" is no longer available.
  3953 
  3954 * New package "function"/"fun" for general recursive functions,
  3955 supporting mutual and nested recursion, definitions in local contexts,
  3956 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  3957 for small examples, and the separate tutorial on the function
  3958 package. The old recdef "package" is still available as before, but
  3959 users are encouraged to use the new package.
  3960 
  3961 * Method "lexicographic_order" automatically synthesizes termination
  3962 relations as lexicographic combinations of size measures. 
  3963 
  3964 * Case-expressions allow arbitrary constructor-patterns (including
  3965 "_") and take their order into account, like in functional
  3966 programming.  Internally, this is translated into nested
  3967 case-expressions; missing cases are added and mapped to the predefined
  3968 constant "undefined". In complicated cases printing may no longer show
  3969 the original input but the internal form. Lambda-abstractions allow
  3970 the same form of pattern matching: "% pat1 => e1 | ..." is an
  3971 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  3972 variable.
  3973 
  3974 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  3975 is an abbreviation for "of_nat :: nat => int". The simplification
  3976 rules for "of_nat" have been changed to work like "int" did
  3977 previously.  Potential INCOMPATIBILITY:
  3978   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  3979   - of_nat_diff and of_nat_mult are no longer default simp rules
  3980 
  3981 * Method "algebra" solves polynomial equations over (semi)rings using
  3982 Groebner bases. The (semi)ring structure is defined by locales and the
  3983 tool setup depends on that generic context. Installing the method for
  3984 a specific type involves instantiating the locale and possibly adding
  3985 declarations for computation on the coefficients.  The method is
  3986 already instantiated for natural numbers and for the axiomatic class
  3987 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  3988 CALCULEMUS 2007 for the general principles underlying this
  3989 architecture of context-aware proof-tools.
  3990 
  3991 * Method "ferrack" implements quantifier elimination over
  3992 special-purpose dense linear orders using locales (analogous to
  3993 "algebra"). The method is already installed for class
  3994 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  3995 rat, etc.
  3996 
  3997 * Former constant "List.op @" now named "List.append".  Use ML
  3998 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  3999 circumvent possible incompatibilities when working on ML level.
  4000 
  4001 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  4002 
  4003 * New function listsum :: 'a list => 'a for arbitrary monoids.
  4004 Special syntax: "SUM x <- xs. f x" (and latex variants)
  4005 
  4006 * New syntax for Haskell-like list comprehension (input only), eg.
  4007 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  4008 
  4009 * The special syntax for function "filter" has changed from [x :
  4010 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  4011 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  4012 
  4013 * [a..b] is now defined for arbitrary linear orders.  It used to be
  4014 defined on nat only, as an abbreviation for [a..<Suc b]
  4015 INCOMPATIBILITY.
  4016 
  4017 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  4018 
  4019 * New functions "sorted" and "sort" in src/HOL/List.thy.
  4020 
  4021 * New lemma collection field_simps (an extension of ring_simps) for
  4022 manipulating (in)equations involving division. Multiplies with all
  4023 denominators that can be proved to be non-zero (in equations) or
  4024 positive/negative (in inequations).
  4025 
  4026 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  4027 have been improved and renamed to ring_simps, group_simps and
  4028 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  4029 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  4030 
  4031 * Theory Library/Commutative_Ring: switched from recdef to function
  4032 package; constants add, mul, pow now curried.  Infix syntax for
  4033 algebraic operations.
  4034 
  4035 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  4036 INCOMPATIBILITY.
  4037 
  4038 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  4039 INCOMPATIBILITY.
  4040 
  4041 * HOL/records: generalised field-update to take a function on the
  4042 field rather than the new value: r(|A := x|) is translated to A_update
  4043 (K x) r The K-combinator that is internally used is called K_record.
  4044 INCOMPATIBILITY: Usage of the plain update functions has to be
  4045 adapted.
  4046  
  4047 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  4048 * x = 0, which are required for a semiring.  Richer structures do not
  4049 inherit from semiring_0 anymore, because this property is a theorem
  4050 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  4051 there is more to prove, but this is mostly trivial.
  4052 
  4053 * Class "recpower" is generalized to arbitrary monoids, not just
  4054 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  4055 commutativity or semiring properties additionally.
  4056 
  4057 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  4058 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  4059 better use 'abbreviation'.
  4060 
  4061 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  4062 
  4063 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  4064 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  4065 significant changes for setting up numeral syntax for types:
  4066   - New constants Numeral.pred and Numeral.succ instead
  4067       of former Numeral.bin_pred and Numeral.bin_succ.
  4068   - Use integer operations instead of bin_add, bin_mult and so on.
  4069   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  4070   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  4071 
  4072 See src/HOL/Integ/IntArith.thy for an example setup.
  4073 
  4074 * Command 'normal_form' computes the normal form of a term that may
  4075 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  4076 produces ``[b, c, a]'' (without proof).  This command is suitable for
  4077 heavy-duty computations because the functions are compiled to ML
  4078 first.  Correspondingly, a method "normalization" is provided.  See
  4079 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  4080 
  4081 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  4082 25 like -->); output depends on the "iff" print_mode, the default is
  4083 "A = B" (with priority 50).
  4084 
  4085 * Relations less (<) and less_eq (<=) are also available on type bool.
  4086 Modified syntax to disallow nesting without explicit parentheses,
  4087 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  4088 INCOMPATIBILITY.
  4089 
  4090 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  4091 
  4092 * Relation composition operator "op O" now has precedence 75 and binds
  4093 stronger than union and intersection. INCOMPATIBILITY.
  4094 
  4095 * The old set interval syntax "{m..n(}" (and relatives) has been
  4096 removed.  Use "{m..<n}" (and relatives) instead.
  4097 
  4098 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  4099 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  4100 ``declare [[simproc del: neq]]''.
  4101 
  4102 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  4103 True/False.
  4104 
  4105 * Theorem Cons_eq_map_conv no longer declared as "simp".
  4106 
  4107 * Theorem setsum_mult renamed to setsum_right_distrib.
  4108 
  4109 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  4110 ``rule'' method.
  4111 
  4112 * Reimplemented methods "sat" and "satx", with several improvements:
  4113 goals no longer need to be stated as "<prems> ==> False", equivalences
  4114 (i.e. "=" on type bool) are handled, variable names of the form
  4115 "lit_<n>" are no longer reserved, significant speedup.
  4116 
  4117 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  4118 zChaff is still supported as well.
  4119 
  4120 * 'inductive' and 'datatype': provide projections of mutual rules,
  4121 bundled as foo_bar.inducts;
  4122 
  4123 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  4124 Library.
  4125 
  4126 * Library: moved theory Accessible_Part to main HOL.
  4127 
  4128 * Library: added theory Coinductive_List of potentially infinite lists
  4129 as greatest fixed-point.
  4130 
  4131 * Library: added theory AssocList which implements (finite) maps as
  4132 association lists.
  4133 
  4134 * Method "evaluation" solves goals (i.e. a boolean expression)
  4135 efficiently by compiling it to ML.  The goal is "proved" (via an
  4136 oracle) if it evaluates to True.
  4137 
  4138 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  4139 also when invoked by the simplifier.  This results in the Simplifier
  4140 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  4141 Configuration option fast_arith_split_limit=0 recovers the old
  4142 behavior.
  4143 
  4144 * Support for hex (0x20) and binary (0b1001) numerals.
  4145 
  4146 * New method: reify eqs (t), where eqs are equations for an
  4147 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  4148 parameter, computes a term s::'b and a list xs::'a list and proves the
  4149 theorem I xs s = t. This is also known as reification or quoting. The
  4150 resulting theorem is applied to the subgoal to substitute t with I xs
  4151 s.  If t is omitted, the subgoal itself is reified.
  4152 
  4153 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  4154 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  4155 where f is supposed to be a computable function (in the sense of code
  4156 generattion). The method uses reify to compute s and xs as above then
  4157 applies corr_thm and uses normalization by evaluation to "prove" f s =
  4158 r and finally gets the theorem t = r, which is again applied to the
  4159 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  4160 
  4161 * Reflection: Automatic reification now handels binding, an example is
  4162 available in src/HOL/ex/ReflectionEx.thy
  4163 
  4164 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  4165 command 'statespace' that is similar to 'record', but introduces an
  4166 abstract specification based on the locale infrastructure instead of
  4167 HOL types.  This leads to extra flexibility in composing state spaces,
  4168 in particular multiple inheritance and renaming of components.
  4169 
  4170 
  4171 *** HOL-Complex ***
  4172 
  4173 * Hyperreal: Functions root and sqrt are now defined on negative real
  4174 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  4175 Nonnegativity side conditions have been removed from many lemmas, so
  4176 that more subgoals may now be solved by simplification; potential
  4177 INCOMPATIBILITY.
  4178 
  4179 * Real: new type classes formalize real normed vector spaces and
  4180 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  4181 and norm :: 'a => real.
  4182 
  4183 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  4184 reals into other types. The overloaded constant Reals :: 'a set is now
  4185 defined as range of_real; potential INCOMPATIBILITY.
  4186 
  4187 * Real: proper support for ML code generation, including 'quickcheck'.
  4188 Reals are implemented as arbitrary precision rationals.
  4189 
  4190 * Hyperreal: Several constants that previously worked only for the
  4191 reals have been generalized, so they now work over arbitrary vector
  4192 spaces. Type annotations may need to be added in some cases; potential
  4193 INCOMPATIBILITY.
  4194 
  4195   Infinitesimal  :: ('a::real_normed_vector) star set
  4196   HFinite        :: ('a::real_normed_vector) star set
  4197   HInfinite      :: ('a::real_normed_vector) star set
  4198   approx         :: ('a::real_normed_vector) star => 'a star => bool
  4199   monad          :: ('a::real_normed_vector) star => 'a star set
  4200   galaxy         :: ('a::real_normed_vector) star => 'a star set
  4201   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  4202   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  4203   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  4204   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  4205   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  4206   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  4207   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  4208   sgn            :: 'a::real_normed_vector => 'a
  4209   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  4210 
  4211 * Complex: Some complex-specific constants are now abbreviations for
  4212 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  4213 hnorm.  Other constants have been entirely removed in favor of the
  4214 polymorphic versions (INCOMPATIBILITY):
  4215 
  4216   approx        <-- capprox
  4217   HFinite       <-- CFinite
  4218   HInfinite     <-- CInfinite
  4219   Infinitesimal <-- CInfinitesimal
  4220   monad         <-- cmonad
  4221   galaxy        <-- cgalaxy
  4222   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  4223   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  4224   (ns)deriv     <-- (ns)cderiv
  4225 
  4226 
  4227 *** HOL-Algebra ***
  4228 
  4229 * Formalisation of ideals and the quotient construction over rings.
  4230 
  4231 * Order and lattice theory no longer based on records.
  4232 INCOMPATIBILITY.
  4233 
  4234 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  4235 greatest_closed.  INCOMPATIBILITY.
  4236 
  4237 * Method algebra is now set up via an attribute.  For examples see
  4238 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  4239 of algebraic structures.
  4240 
  4241 * Renamed theory CRing to Ring.
  4242 
  4243 
  4244 *** HOL-Nominal ***
  4245 
  4246 * Substantial, yet incomplete support for nominal datatypes (binding
  4247 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  4248 src/HOL/Nominal/Examples.  Prospective users should consult
  4249 http://isabelle.in.tum.de/nominal/
  4250 
  4251 
  4252 *** ML ***
  4253 
  4254 * ML basics: just one true type int, which coincides with IntInf.int
  4255 (even on SML/NJ).
  4256 
  4257 * ML within Isar: antiquotations allow to embed statically-checked
  4258 formal entities in the source, referring to the context available at
  4259 compile-time.  For example:
  4260 
  4261 ML {* @{sort "{zero,one}"} *}
  4262 ML {* @{typ "'a => 'b"} *}
  4263 ML {* @{term "%x. x"} *}
  4264 ML {* @{prop "x == y"} *}
  4265 ML {* @{ctyp "'a => 'b"} *}
  4266 ML {* @{cterm "%x. x"} *}
  4267 ML {* @{cprop "x == y"} *}
  4268 ML {* @{thm asm_rl} *}
  4269 ML {* @{thms asm_rl} *}
  4270 ML {* @{type_name c} *}
  4271 ML {* @{type_syntax c} *}
  4272 ML {* @{const_name c} *}
  4273 ML {* @{const_syntax c} *}
  4274 ML {* @{context} *}
  4275 ML {* @{theory} *}
  4276 ML {* @{theory Pure} *}
  4277 ML {* @{theory_ref} *}
  4278 ML {* @{theory_ref Pure} *}
  4279 ML {* @{simpset} *}
  4280 ML {* @{claset} *}
  4281 ML {* @{clasimpset} *}
  4282 
  4283 The same works for sources being ``used'' within an Isar context.
  4284 
  4285 * ML in Isar: improved error reporting; extra verbosity with
  4286 ML_Context.trace enabled.
  4287 
  4288 * Pure/General/table.ML: the join operations now works via exceptions
  4289 DUP/SAME instead of type option. This is simpler in simple cases, and
  4290 admits slightly more efficient complex applications.
  4291 
  4292 * Pure: 'advanced' translation functions (parse_translation etc.) now
  4293 use Context.generic instead of just theory.
  4294 
  4295 * Pure: datatype Context.generic joins theory/Proof.context and
  4296 provides some facilities for code that works in either kind of
  4297 context, notably GenericDataFun for uniform theory and proof data.
  4298 
  4299 * Pure: simplified internal attribute type, which is now always
  4300 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  4301 local (Proof.context) attributes have been discontinued, while
  4302 minimizing code duplication. Thm.rule_attribute and
  4303 Thm.declaration_attribute build canonical attributes; see also structure
  4304 Context for further operations on Context.generic, notably
  4305 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  4306 declarations and definitions.
  4307 
  4308 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  4309 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  4310 init only required for impure data. INCOMPATIBILITY: empty really need
  4311 to be empty (no dependencies on theory content!)
  4312 
  4313 * Pure/kernel: consts certification ignores sort constraints given in
  4314 signature declarations. (This information is not relevant to the
  4315 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  4316 potential INCOMPATIBILITY.
  4317 
  4318 * Pure: axiomatic type classes are now purely definitional, with
  4319 explicit proofs of class axioms and super class relations performed
  4320 internally. See Pure/axclass.ML for the main internal interfaces --
  4321 notably AxClass.define_class supercedes AxClass.add_axclass, and
  4322 AxClass.axiomatize_class/classrel/arity supersede
  4323 Sign.add_classes/classrel/arities.
  4324 
  4325 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  4326 global/local versions on theory vs. Proof.context have been
  4327 discontinued; Attrib.syntax and Method.syntax have been adapted
  4328 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  4329 attributes, methods, etc.
  4330 
  4331 * Pure: several functions of signature "... -> theory -> theory * ..."
  4332 have been reoriented to "... -> theory -> ... * theory" in order to
  4333 allow natural usage in combination with the ||>, ||>>, |-> and
  4334 fold_map combinators.
  4335 
  4336 * Pure: official theorem names (closed derivations) and additional
  4337 comments (tags) are now strictly separate.  Name hints -- which are
  4338 maintained as tags -- may be attached any time without affecting the
  4339 derivation.
  4340 
  4341 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  4342 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  4343 achieve the old behaviour.
  4344 
  4345 * Pure: the "Goal" constant is now called "prop", supporting a
  4346 slightly more general idea of ``protecting'' meta-level rule
  4347 statements.
  4348 
  4349 * Pure: Logic.(un)varify only works in a global context, which is now
  4350 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  4351 Logic.legacy_(un)varify as temporary workaround.
  4352 
  4353 * Pure: structure Name provides scalable operations for generating
  4354 internal variable names, notably Name.variants etc.  This replaces
  4355 some popular functions from term.ML:
  4356 
  4357   Term.variant		->  Name.variant
  4358   Term.variantlist	->  Name.variant_list
  4359   Term.invent_names	->  Name.invent_list
  4360 
  4361 Note that low-level renaming rarely occurs in new code -- operations
  4362 from structure Variable are used instead (see below).
  4363 
  4364 * Pure: structure Variable provides fundamental operations for proper
  4365 treatment of fixed/schematic variables in a context.  For example,
  4366 Variable.import introduces fixes for schematics of given facts and
  4367 Variable.export reverses the effect (up to renaming) -- this replaces
  4368 various freeze_thaw operations.
  4369 
  4370 * Pure: structure Goal provides simple interfaces for
  4371 init/conclude/finish and tactical prove operations (replacing former
  4372 Tactic.prove).  Goal.prove is the canonical way to prove results
  4373 within a given context; Goal.prove_global is a degraded version for
  4374 theory level goals, including a global Drule.standard.  Note that
  4375 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  4376 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  4377 in a locale context).
  4378 
  4379 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  4380 and type checking (Syntax.check_term etc.), with common combinations
  4381 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  4382 which are considered legacy and await removal.
  4383 
  4384 * Pure/Syntax: generic interfaces for type unchecking
  4385 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  4386 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  4387 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  4388 available for convenience, but refer to the very same operations using
  4389 a mere theory instead of a full context.
  4390 
  4391 * Isar: simplified treatment of user-level errors, using exception
  4392 ERROR of string uniformly.  Function error now merely raises ERROR,
  4393 without any side effect on output channels.  The Isar toplevel takes
  4394 care of proper display of ERROR exceptions.  ML code may use plain
  4395 handle/can/try; cat_error may be used to concatenate errors like this:
  4396 
  4397   ... handle ERROR msg => cat_error msg "..."
  4398 
  4399 Toplevel ML code (run directly or through the Isar toplevel) may be
  4400 embedded into the Isar toplevel with exception display/debug like
  4401 this:
  4402 
  4403   Isar.toplevel (fn () => ...)
  4404 
  4405 INCOMPATIBILITY, removed special transform_error facilities, removed
  4406 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  4407 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  4408 -- use plain ERROR instead.
  4409 
  4410 * Isar: theory setup now has type (theory -> theory), instead of a
  4411 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  4412 
  4413 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  4414 ProofContext.debug/verbose flags.
  4415 
  4416 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  4417 theory before entering a proof state.  Transactions now always see a
  4418 quasi-functional intermediate checkpoint, both in interactive and
  4419 batch mode.
  4420 
  4421 * Isar: simplified interfaces for outer syntax.  Renamed
  4422 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  4423 OuterSyntax.add_parsers -- this functionality is now included in
  4424 OuterSyntax.command etc.  INCOMPATIBILITY.
  4425 
  4426 * Simplifier: the simpset of a running simplification process now
  4427 contains a proof context (cf. Simplifier.the_context), which is the
  4428 very context that the initial simpset has been retrieved from (by
  4429 simpset_of/local_simpset_of).  Consequently, all plug-in components
  4430 (solver, looper etc.) may depend on arbitrary proof data.
  4431 
  4432 * Simplifier.inherit_context inherits the proof context (plus the
  4433 local bounds) of the current simplification process; any simproc
  4434 etc. that calls the Simplifier recursively should do this!  Removed
  4435 former Simplifier.inherit_bounds, which is already included here --
  4436 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  4437 specify an explicit context using Simplifier.context/theory_context.
  4438 
  4439 * Simplifier/Classical Reasoner: more abstract interfaces
  4440 change_simpset/claset for modifying the simpset/claset reference of a
  4441 theory; raw versions simpset/claset_ref etc. have been discontinued --
  4442 INCOMPATIBILITY.
  4443 
  4444 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  4445 "Trueprop" etc.
  4446 
  4447 
  4448 *** System ***
  4449 
  4450 * settings: the default heap location within ISABELLE_HOME_USER now
  4451 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  4452 Isabelle installations.
  4453 
  4454 * isabelle-process: option -S (secure mode) disables some critical
  4455 operations, notably runtime compilation and evaluation of ML source
  4456 code.
  4457 
  4458 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  4459 
  4460 * Support for parallel execution, using native multicore support of
  4461 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  4462 independent theories, according to the given theory header
  4463 specifications. The maximum number of worker threads is specified via
  4464 usedir option -M or the "max-threads" setting in Proof General. A
  4465 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  4466 to 6 on a 8-core machine.  User-code needs to observe certain
  4467 guidelines for thread-safe programming, see appendix A in the Isar
  4468 Implementation manual.
  4469 
  4470 
  4471 
  4472 New in Isabelle2005 (October 2005)
  4473 ----------------------------------
  4474 
  4475 *** General ***
  4476 
  4477 * Theory headers: the new header syntax for Isar theories is
  4478 
  4479   theory <name>
  4480   imports <theory1> ... <theoryN>
  4481   uses <file1> ... <fileM>
  4482   begin
  4483 
  4484 where the 'uses' part is optional.  The previous syntax
  4485 
  4486   theory <name> = <theory1> + ... + <theoryN>:
  4487 
  4488 will disappear in the next release.  Use isatool fixheaders to convert
  4489 existing theory files.  Note that there is no change in ancient
  4490 non-Isar theories now, but these will disappear soon.
  4491 
  4492 * Theory loader: parent theories can now also be referred to via
  4493 relative and absolute paths.
  4494 
  4495 * Command 'find_theorems' searches for a list of criteria instead of a
  4496 list of constants. Known criteria are: intro, elim, dest, name:string,
  4497 simp:term, and any term. Criteria can be preceded by '-' to select
  4498 theorems that do not match. Intro, elim, dest select theorems that
  4499 match the current goal, name:s selects theorems whose fully qualified
  4500 name contain s, and simp:term selects all simplification rules whose
  4501 lhs match term.  Any other term is interpreted as pattern and selects
  4502 all theorems matching the pattern. Available in ProofGeneral under
  4503 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  4504 
  4505   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  4506 
  4507 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  4508 matching the current goal as introduction rule and not having "HOL."
  4509 in their name (i.e. not being defined in theory HOL).
  4510 
  4511 * Command 'thms_containing' has been discontinued in favour of
  4512 'find_theorems'; INCOMPATIBILITY.
  4513 
  4514 * Communication with Proof General is now 8bit clean, which means that
  4515 Unicode text in UTF-8 encoding may be used within theory texts (both
  4516 formal and informal parts).  Cf. option -U of the Isabelle Proof
  4517 General interface.  Here are some simple examples (cf. src/HOL/ex):
  4518 
  4519   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  4520   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  4521 
  4522 * Improved efficiency of the Simplifier and, to a lesser degree, the
  4523 Classical Reasoner.  Typical big applications run around 2 times
  4524 faster.
  4525 
  4526 
  4527 *** Document preparation ***
  4528 
  4529 * Commands 'display_drafts' and 'print_drafts' perform simple output
  4530 of raw sources.  Only those symbols that do not require additional
  4531 LaTeX packages (depending on comments in isabellesym.sty) are
  4532 displayed properly, everything else is left verbatim.  isatool display
  4533 and isatool print are used as front ends (these are subject to the
  4534 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  4535 
  4536 * Command tags control specific markup of certain regions of text,
  4537 notably folding and hiding.  Predefined tags include "theory" (for
  4538 theory begin and end), "proof" for proof commands, and "ML" for
  4539 commands involving ML code; the additional tags "visible" and
  4540 "invisible" are unused by default.  Users may give explicit tag
  4541 specifications in the text, e.g. ''by %invisible (auto)''.  The
  4542 interpretation of tags is determined by the LaTeX job during document
  4543 preparation: see option -V of isatool usedir, or options -n and -t of
  4544 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  4545 \isadroptag.
  4546 
  4547 Several document versions may be produced at the same time via isatool
  4548 usedir (the generated index.html will link all of them).  Typical
  4549 specifications include ''-V document=theory,proof,ML'' to present
  4550 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  4551 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  4552 these parts without any formal replacement text.  The Isabelle site
  4553 default settings produce ''document'' and ''outline'' versions as
  4554 specified above.
  4555 
  4556 * Several new antiquotations:
  4557 
  4558   @{term_type term} prints a term with its type annotated;
  4559 
  4560   @{typeof term} prints the type of a term;
  4561 
  4562   @{const const} is the same as @{term const}, but checks that the
  4563   argument is a known logical constant;
  4564 
  4565   @{term_style style term} and @{thm_style style thm} print a term or
  4566   theorem applying a "style" to it
  4567 
  4568   @{ML text}
  4569 
  4570 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  4571 definitions, equations, inequations etc., 'concl' printing only the
  4572 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  4573 to print the specified premise.  TermStyle.add_style provides an ML
  4574 interface for introducing further styles.  See also the "LaTeX Sugar"
  4575 document practical applications.  The ML antiquotation prints
  4576 type-checked ML expressions verbatim.
  4577 
  4578 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  4579 and 'text' support optional locale specification '(in loc)', which
  4580 specifies the default context for interpreting antiquotations.  For
  4581 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  4582 
  4583 * Option 'locale=NAME' of antiquotations specifies an alternative
  4584 context interpreting the subsequent argument.  For example: @{thm
  4585 [locale=lattice] inf_assoc}.
  4586 
  4587 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  4588 a proof context.
  4589 
  4590 * Proper output of antiquotations for theory commands involving a
  4591 proof context (such as 'locale' or 'theorem (in loc) ...').
  4592 
  4593 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  4594 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  4595 
  4596 * isatool usedir: new option -C (default true) controls whether option
  4597 -D should include a copy of the original document directory; -C false
  4598 prevents unwanted effects such as copying of administrative CVS data.
  4599 
  4600 
  4601 *** Pure ***
  4602 
  4603 * Considerably improved version of 'constdefs' command.  Now performs
  4604 automatic type-inference of declared constants; additional support for
  4605 local structure declarations (cf. locales and HOL records), see also
  4606 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  4607 sequential dependencies of definitions within a single 'constdefs'
  4608 section; moreover, the declared name needs to be an identifier.  If
  4609 all fails, consider to fall back on 'consts' and 'defs' separately.
  4610 
  4611 * Improved indexed syntax and implicit structures.  First of all,
  4612 indexed syntax provides a notational device for subscripted
  4613 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  4614 expressions.  Secondly, in a local context with structure
  4615 declarations, number indexes \<^sub>n or the empty index (default
  4616 number 1) refer to a certain fixed variable implicitly; option
  4617 show_structs controls printing of implicit structures.  Typical
  4618 applications of these concepts involve record types and locales.
  4619 
  4620 * New command 'no_syntax' removes grammar declarations (and
  4621 translations) resulting from the given syntax specification, which is
  4622 interpreted in the same manner as for the 'syntax' command.
  4623 
  4624 * 'Advanced' translation functions (parse_translation etc.) may depend
  4625 on the signature of the theory context being presently used for
  4626 parsing/printing, see also isar-ref manual.
  4627 
  4628 * Improved 'oracle' command provides a type-safe interface to turn an
  4629 ML expression of type theory -> T -> term into a primitive rule of
  4630 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  4631 is already included here); see also FOL/ex/IffExample.thy;
  4632 INCOMPATIBILITY.
  4633 
  4634 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  4635 before); "cI" is no longer bound, use "c.intro" instead.
  4636 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  4637 axclasses vs. locales.
  4638 
  4639 * Improved internal renaming of symbolic identifiers -- attach primes
  4640 instead of base 26 numbers.
  4641 
  4642 * New flag show_question_marks controls printing of leading question
  4643 marks in schematic variable names.
  4644 
  4645 * In schematic variable names, *any* symbol following \<^isub> or
  4646 \<^isup> is now treated as part of the base name.  For example, the
  4647 following works without printing of awkward ".0" indexes:
  4648 
  4649   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  4650     by simp
  4651 
  4652 * Inner syntax includes (*(*nested*) comments*).
  4653 
  4654 * Pretty printer now supports unbreakable blocks, specified in mixfix
  4655 annotations as "(00...)".
  4656 
  4657 * Clear separation of logical types and nonterminals, where the latter
  4658 may only occur in 'syntax' specifications or type abbreviations.
  4659 Before that distinction was only partially implemented via type class
  4660 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  4661 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  4662 exotic syntax specifications may require further adaption
  4663 (e.g. Cube/Cube.thy).
  4664 
  4665 * Removed obsolete type class "logic", use the top sort {} instead.
  4666 Note that non-logical types should be declared as 'nonterminals'
  4667 rather than 'types'.  INCOMPATIBILITY for new object-logic
  4668 specifications.
  4669 
  4670 * Attributes 'induct' and 'cases': type or set names may now be
  4671 locally fixed variables as well.
  4672 
  4673 * Simplifier: can now control the depth to which conditional rewriting
  4674 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  4675 Limit.
  4676 
  4677 * Simplifier: simplification procedures may now take the current
  4678 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  4679 interface), which is very useful for calling the Simplifier
  4680 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  4681 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  4682 low-level mk_simproc no longer applies Logic.varify internally, to
  4683 allow for use in a context of fixed variables.
  4684 
  4685 * thin_tac now works even if the assumption being deleted contains !!
  4686 or ==>.  More generally, erule now works even if the major premise of
  4687 the elimination rule contains !! or ==>.
  4688 
  4689 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  4690 
  4691 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  4692 from Pure, which contains all common declarations already.  Both
  4693 theories are defined via plain Isabelle/Isar .thy files.
  4694 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  4695 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  4696 use isatool fixcpure to adapt your theory and ML sources.
  4697 
  4698 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  4699 selections of theorems in named facts via index ranges.
  4700 
  4701 * 'print_theorems': in theory mode, really print the difference
  4702 wrt. the last state (works for interactive theory development only),
  4703 in proof mode print all local facts (cf. 'print_facts');
  4704 
  4705 * 'hide': option '(open)' hides only base names.
  4706 
  4707 * More efficient treatment of intermediate checkpoints in interactive
  4708 theory development.
  4709 
  4710 * Code generator is now invoked via code_module (incremental code
  4711 generation) and code_library (modular code generation, ML structures
  4712 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  4713 must be quoted when used as identifiers.
  4714 
  4715 * New 'value' command for reading, evaluating and printing terms using
  4716 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  4717 quoted when used as identifier.
  4718 
  4719 
  4720 *** Locales ***
  4721 
  4722 * New commands for the interpretation of locale expressions in
  4723 theories (1), locales (2) and proof contexts (3).  These generate
  4724 proof obligations from the expression specification.  After the
  4725 obligations have been discharged, theorems of the expression are added
  4726 to the theory, target locale or proof context.  The synopsis of the
  4727 commands is a follows:
  4728 
  4729   (1) interpretation expr inst
  4730   (2) interpretation target < expr
  4731   (3) interpret expr inst
  4732 
  4733 Interpretation in theories and proof contexts require a parameter
  4734 instantiation of terms from the current context.  This is applied to
  4735 specifications and theorems of the interpreted expression.
  4736 Interpretation in locales only permits parameter renaming through the
  4737 locale expression.  Interpretation is smart in that interpretations
  4738 that are active already do not occur in proof obligations, neither are
  4739 instantiated theorems stored in duplicate.  Use 'print_interps' to
  4740 inspect active interpretations of a particular locale.  For details,
  4741 see the Isar Reference manual.  Examples can be found in
  4742 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  4743 
  4744 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  4745 'interpret' instead.
  4746 
  4747 * New context element 'constrains' for adding type constraints to
  4748 parameters.
  4749 
  4750 * Context expressions: renaming of parameters with syntax
  4751 redeclaration.
  4752 
  4753 * Locale declaration: 'includes' disallowed.
  4754 
  4755 * Proper static binding of attribute syntax -- i.e. types / terms /
  4756 facts mentioned as arguments are always those of the locale definition
  4757 context, independently of the context of later invocations.  Moreover,
  4758 locale operations (renaming and type / term instantiation) are applied
  4759 to attribute arguments as expected.
  4760 
  4761 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  4762 actual attributes; rare situations may require Attrib.attribute to
  4763 embed those attributes into Attrib.src that lack concrete syntax.
  4764 Attribute implementations need to cooperate properly with the static
  4765 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  4766 Attrib.XXX_thm etc. already do the right thing without further
  4767 intervention.  Only unusual applications -- such as "where" or "of"
  4768 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  4769 on the context and the facts involved -- may have to assign parsed
  4770 values to argument tokens explicitly.
  4771 
  4772 * Changed parameter management in theorem generation for long goal
  4773 statements with 'includes'.  INCOMPATIBILITY: produces a different
  4774 theorem statement in rare situations.
  4775 
  4776 * Locale inspection command 'print_locale' omits notes elements.  Use
  4777 'print_locale!' to have them included in the output.
  4778 
  4779 
  4780 *** Provers ***
  4781 
  4782 * Provers/hypsubst.ML: improved version of the subst method, for
  4783 single-step rewriting: it now works in bound variable contexts. New is
  4784 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  4785 rewrite a different subterm than the original subst method, which is
  4786 still available as 'simplesubst'.
  4787 
  4788 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  4789 and quasi orders.
  4790 
  4791 * Provers/trancl.ML: new transitivity reasoner for transitive and
  4792 reflexive-transitive closure of relations.
  4793 
  4794 * Provers/blast.ML: new reference depth_limit to make blast's depth
  4795 limit (previously hard-coded with a value of 20) user-definable.
  4796 
  4797 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  4798 is peformed already.  Object-logics merely need to finish their
  4799 initial simpset configuration as before.  INCOMPATIBILITY.
  4800 
  4801 
  4802 *** HOL ***
  4803 
  4804 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  4805 
  4806   syntax (epsilon)
  4807     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  4808 
  4809 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  4810 and x-symbol; use option '-m epsilon' to get it actually printed.
  4811 Moreover, the mathematically important symbolic identifier \<epsilon>
  4812 becomes available as variable, constant etc.  INCOMPATIBILITY,
  4813 
  4814 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  4815 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  4816 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  4817 support corresponding Isar calculations.
  4818 
  4819 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  4820 instead of ":".
  4821 
  4822 * theory SetInterval: changed the syntax for open intervals:
  4823 
  4824   Old       New
  4825   {..n(}    {..<n}
  4826   {)n..}    {n<..}
  4827   {m..n(}   {m..<n}
  4828   {)m..n}   {m<..n}
  4829   {)m..n(}  {m<..<n}
  4830 
  4831 The old syntax is still supported but will disappear in the next
  4832 release.  For conversion use the following Emacs search and replace
  4833 patterns (these are not perfect but work quite well):
  4834 
  4835   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  4836   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  4837 
  4838 * Theory Commutative_Ring (in Library): method comm_ring for proving
  4839 equalities in commutative rings; method 'algebra' provides a generic
  4840 interface.
  4841 
  4842 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  4843 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  4844 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  4845 be a tuple pattern.
  4846 
  4847 Some new syntax forms are available:
  4848 
  4849   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  4850   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  4851   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  4852   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  4853 
  4854 The latter form "\<Sum>x < k. e" used to be based on a separate
  4855 function "Summation", which has been discontinued.
  4856 
  4857 * theory Finite_Set: in structured induction proofs, the insert case
  4858 is now 'case (insert x F)' instead of the old counterintuitive 'case
  4859 (insert F x)'.
  4860 
  4861 * The 'refute' command has been extended to support a much larger
  4862 fragment of HOL, including axiomatic type classes, constdefs and
  4863 typedefs, inductive datatypes and recursion.
  4864 
  4865 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  4866 Requires zChaff with proof generation to be installed.  See
  4867 HOL/ex/SAT_Examples.thy for examples.
  4868 
  4869 * Datatype induction via method 'induct' now preserves the name of the
  4870 induction variable. For example, when proving P(xs::'a list) by
  4871 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  4872 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  4873 in unstructured proof scripts.
  4874 
  4875 * Reworked implementation of records.  Improved scalability for
  4876 records with many fields, avoiding performance problems for type
  4877 inference. Records are no longer composed of nested field types, but
  4878 of nested extension types. Therefore the record type only grows linear
  4879 in the number of extensions and not in the number of fields.  The
  4880 top-level (users) view on records is preserved.  Potential
  4881 INCOMPATIBILITY only in strange cases, where the theory depends on the
  4882 old record representation. The type generated for a record is called
  4883 <record_name>_ext_type.
  4884 
  4885 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  4886 proofs triggered by a record definition or a simproc (if
  4887 quick_and_dirty is enabled).  Definitions of large records can take
  4888 quite long.
  4889 
  4890 New simproc record_upd_simproc for simplification of multiple record
  4891 updates enabled by default.  Moreover, trivial updates are also
  4892 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  4893 occasionally, since simplification is more powerful by default.
  4894 
  4895 * typedef: proper support for polymorphic sets, which contain extra
  4896 type-variables in the term.
  4897 
  4898 * Simplifier: automatically reasons about transitivity chains
  4899 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  4900 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  4901 old proofs break occasionally as simplification may now solve more
  4902 goals than previously.
  4903 
  4904 * Simplifier: converts x <= y into x = y if assumption y <= x is
  4905 present.  Works for all partial orders (class "order"), in particular
  4906 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  4907 just like y <= x.
  4908 
  4909 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  4910 bound variable or a constant then the let is unfolded.  Otherwise
  4911 first a is simplified to b, and then f b is simplified to g. If
  4912 possible we abstract b from g arriving at "let x = b in h x",
  4913 otherwise we unfold the let and arrive at g.  The simproc can be
  4914 enabled/disabled by the reference use_let_simproc.  Potential
  4915 INCOMPATIBILITY since simplification is more powerful by default.
  4916 
  4917 * Classical reasoning: the meson method now accepts theorems as arguments.
  4918 
  4919 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  4920 jobs to provide advice on the provability of subgoals.
  4921 
  4922 * Theory OrderedGroup and Ring_and_Field: various additions and
  4923 improvements to faciliate calculations involving equalities and
  4924 inequalities.
  4925 
  4926 The following theorems have been eliminated or modified
  4927 (INCOMPATIBILITY):
  4928 
  4929   abs_eq             now named abs_of_nonneg
  4930   abs_of_ge_0        now named abs_of_nonneg
  4931   abs_minus_eq       now named abs_of_nonpos
  4932   imp_abs_id         now named abs_of_nonneg
  4933   imp_abs_neg_id     now named abs_of_nonpos
  4934   mult_pos           now named mult_pos_pos
  4935   mult_pos_le        now named mult_nonneg_nonneg
  4936   mult_pos_neg_le    now named mult_nonneg_nonpos
  4937   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  4938   mult_neg           now named mult_neg_neg
  4939   mult_neg_le        now named mult_nonpos_nonpos
  4940 
  4941 * The following lemmas in Ring_and_Field have been added to the simplifier:
  4942      
  4943      zero_le_square
  4944      not_square_less_zero 
  4945 
  4946   The following lemmas have been deleted from Real/RealPow:
  4947   
  4948      realpow_zero_zero
  4949      realpow_two
  4950      realpow_less
  4951      zero_le_power
  4952      realpow_two_le
  4953      abs_realpow_two
  4954      realpow_two_abs     
  4955 
  4956 * Theory Parity: added rules for simplifying exponents.
  4957 
  4958 * Theory List:
  4959 
  4960 The following theorems have been eliminated or modified
  4961 (INCOMPATIBILITY):
  4962 
  4963   list_all_Nil       now named list_all.simps(1)
  4964   list_all_Cons      now named list_all.simps(2)
  4965   list_all_conv      now named list_all_iff
  4966   set_mem_eq         now named mem_iff
  4967 
  4968 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  4969 asymptotic "big O" calculations.  See the notes in BigO.thy.
  4970 
  4971 
  4972 *** HOL-Complex ***
  4973 
  4974 * Theory RealDef: better support for embedding natural numbers and
  4975 integers in the reals.
  4976 
  4977 The following theorems have been eliminated or modified
  4978 (INCOMPATIBILITY):
  4979 
  4980   exp_ge_add_one_self  now requires no hypotheses
  4981   real_of_int_add      reversed direction of equality (use [symmetric])
  4982   real_of_int_minus    reversed direction of equality (use [symmetric])
  4983   real_of_int_diff     reversed direction of equality (use [symmetric])
  4984   real_of_int_mult     reversed direction of equality (use [symmetric])
  4985 
  4986 * Theory RComplete: expanded support for floor and ceiling functions.
  4987 
  4988 * Theory Ln is new, with properties of the natural logarithm
  4989 
  4990 * Hyperreal: There is a new type constructor "star" for making
  4991 nonstandard types.  The old type names are now type synonyms:
  4992 
  4993   hypreal = real star
  4994   hypnat = nat star
  4995   hcomplex = complex star
  4996 
  4997 * Hyperreal: Many groups of similarly-defined constants have been
  4998 replaced by polymorphic versions (INCOMPATIBILITY):
  4999 
  5000   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  5001 
  5002   starset      <-- starsetNat, starsetC
  5003   *s*          <-- *sNat*, *sc*
  5004   starset_n    <-- starsetNat_n, starsetC_n
  5005   *sn*         <-- *sNatn*, *scn*
  5006   InternalSets <-- InternalNatSets, InternalCSets
  5007 
  5008   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  5009   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  5010   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  5011   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  5012   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  5013 
  5014 * Hyperreal: Many type-specific theorems have been removed in favor of
  5015 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  5016 
  5017   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  5018   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  5019   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  5020   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  5021   right_minus <-- hypreal_add_minus
  5022   left_minus <-- {hypreal,hcomplex}_add_minus_left
  5023   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  5024   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  5025   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  5026   mult_1_right <-- hcomplex_mult_one_right
  5027   mult_zero_left <-- hcomplex_mult_zero_left
  5028   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  5029   right_distrib <-- hypnat_add_mult_distrib2
  5030   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  5031   right_inverse <-- hypreal_mult_inverse
  5032   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  5033   order_refl <-- {hypreal,hypnat}_le_refl
  5034   order_trans <-- {hypreal,hypnat}_le_trans
  5035   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  5036   order_less_le <-- {hypreal,hypnat}_less_le
  5037   linorder_linear <-- {hypreal,hypnat}_le_linear
  5038   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  5039   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  5040   add_nonneg_nonneg <-- hypreal_le_add_order
  5041 
  5042 * Hyperreal: Separate theorems having to do with type-specific
  5043 versions of constants have been merged into theorems that apply to the
  5044 new polymorphic constants (INCOMPATIBILITY):
  5045 
  5046   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  5047   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  5048   STAR_Un <-- {STAR,NatStar,STARC}_Un
  5049   STAR_Int <-- {STAR,NatStar,STARC}_Int
  5050   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  5051   STAR_subset <-- {STAR,NatStar,STARC}_subset
  5052   STAR_mem <-- {STAR,NatStar,STARC}_mem
  5053   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  5054   STAR_diff <-- {STAR,STARC}_diff
  5055   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  5056     STARC_hcomplex_of_complex}_image_subset
  5057   starset_n_Un <-- starset{Nat,C}_n_Un
  5058   starset_n_Int <-- starset{Nat,C}_n_Int
  5059   starset_n_Compl <-- starset{Nat,C}_n_Compl
  5060   starset_n_diff <-- starset{Nat,C}_n_diff
  5061   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  5062   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  5063   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  5064   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  5065   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  5066   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  5067   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  5068   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  5069   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  5070   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  5071   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  5072   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  5073   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  5074   starfun_diff <-- starfun{C,RC,CR}_diff
  5075   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  5076   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  5077   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  5078   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  5079   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  5080   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  5081   starfun_Id <-- starfunC_Id
  5082   starfun_approx <-- starfun{Nat,CR}_approx
  5083   starfun_capprox <-- starfun{C,RC}_capprox
  5084   starfun_abs <-- starfunNat_rabs
  5085   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  5086   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  5087   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  5088   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  5089   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  5090   starfun_add_approx <-- starfunCR_add_approx
  5091   starfun_inverse_inverse <-- starfunC_inverse_inverse
  5092   starfun_divide <-- starfun{C,CR,RC}_divide
  5093   starfun_n <-- starfun{Nat,C}_n
  5094   starfun_n_mult <-- starfun{Nat,C}_n_mult
  5095   starfun_n_add <-- starfun{Nat,C}_n_add
  5096   starfun_n_add_minus <-- starfunNat_n_add_minus
  5097   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  5098   starfun_n_minus <-- starfun{Nat,C}_n_minus
  5099   starfun_n_eq <-- starfun{Nat,C}_n_eq
  5100 
  5101   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  5102   star_n_minus <-- {hypreal,hcomplex}_minus
  5103   star_n_diff <-- {hypreal,hcomplex}_diff
  5104   star_n_mult <-- {hypreal,hcomplex}_mult
  5105   star_n_inverse <-- {hypreal,hcomplex}_inverse
  5106   star_n_le <-- {hypreal,hypnat}_le
  5107   star_n_less <-- {hypreal,hypnat}_less
  5108   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  5109   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  5110   star_n_abs <-- hypreal_hrabs
  5111   star_n_divide <-- hcomplex_divide
  5112 
  5113   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  5114   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  5115   star_of_diff <-- hypreal_of_real_diff
  5116   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  5117   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  5118   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  5119   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  5120   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  5121   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  5122   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  5123   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  5124   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  5125   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  5126   star_of_number_of <-- {hypreal,hcomplex}_number_of
  5127   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  5128   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  5129   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  5130   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  5131   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  5132   star_of_power <-- hypreal_of_real_power
  5133   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  5134 
  5135 * Hyperreal: new method "transfer" that implements the transfer
  5136 principle of nonstandard analysis. With a subgoal that mentions
  5137 nonstandard types like "'a star", the command "apply transfer"
  5138 replaces it with an equivalent one that mentions only standard types.
  5139 To be successful, all free variables must have standard types; non-
  5140 standard variables must have explicit universal quantifiers.
  5141 
  5142 * Hyperreal: A theory of Taylor series.
  5143 
  5144 
  5145 *** HOLCF ***
  5146 
  5147 * Discontinued special version of 'constdefs' (which used to support
  5148 continuous functions) in favor of the general Pure one with full
  5149 type-inference.
  5150 
  5151 * New simplification procedure for solving continuity conditions; it
  5152 is much faster on terms with many nested lambda abstractions (cubic
  5153 instead of exponential time).
  5154 
  5155 * New syntax for domain package: selector names are now optional.
  5156 Parentheses should be omitted unless argument is lazy, for example:
  5157 
  5158   domain 'a stream = cons "'a" (lazy "'a stream")
  5159 
  5160 * New command 'fixrec' for defining recursive functions with pattern
  5161 matching; defining multiple functions with mutual recursion is also
  5162 supported.  Patterns may include the constants cpair, spair, up, sinl,
  5163 sinr, or any data constructor defined by the domain package. The given
  5164 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  5165 syntax and examples.
  5166 
  5167 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  5168 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  5169 but the proof obligation additionally includes an admissibility
  5170 requirement. The packages generate instances of class cpo or pcpo,
  5171 with continuity and strictness theorems for Rep and Abs.
  5172 
  5173 * HOLCF: Many theorems have been renamed according to a more standard naming
  5174 scheme (INCOMPATIBILITY):
  5175 
  5176   foo_inject:  "foo$x = foo$y ==> x = y"
  5177   foo_eq:      "(foo$x = foo$y) = (x = y)"
  5178   foo_less:    "(foo$x << foo$y) = (x << y)"
  5179   foo_strict:  "foo$UU = UU"
  5180   foo_defined: "... ==> foo$x ~= UU"
  5181   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  5182 
  5183 
  5184 *** ZF ***
  5185 
  5186 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  5187 including the First Isomorphism Theorem (on quotienting by the kernel
  5188 of a homomorphism).
  5189 
  5190 * ZF/Simplifier: install second copy of type solver that actually
  5191 makes use of TC rules declared to Isar proof contexts (or locales);
  5192 the old version is still required for ML proof scripts.
  5193 
  5194 
  5195 *** Cube ***
  5196 
  5197 * Converted to Isar theory format; use locales instead of axiomatic
  5198 theories.
  5199 
  5200 
  5201 *** ML ***
  5202 
  5203 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  5204 for ||>, ||>>, |>>,
  5205 
  5206 * Pure/library.ML no longer defines its own option datatype, but uses
  5207 that of the SML basis, which has constructors NONE and SOME instead of
  5208 None and Some, as well as exception Option.Option instead of OPTION.
  5209 The functions the, if_none, is_some, is_none have been adapted
  5210 accordingly, while Option.map replaces apsome.
  5211 
  5212 * Pure/library.ML: the exception LIST has been given up in favour of
  5213 the standard exceptions Empty and Subscript, as well as
  5214 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  5215 superceded by the standard hd and tl functions etc.
  5216 
  5217 A number of basic list functions are no longer exported to the ML
  5218 toplevel, as they are variants of predefined functions.  The following
  5219 suggests how one can translate existing code:
  5220 
  5221     rev_append xs ys = List.revAppend (xs, ys)
  5222     nth_elem (i, xs) = List.nth (xs, i)
  5223     last_elem xs = List.last xs
  5224     flat xss = List.concat xss
  5225     seq fs = List.app fs
  5226     partition P xs = List.partition P xs
  5227     mapfilter f xs = List.mapPartial f xs
  5228 
  5229 * Pure/library.ML: several combinators for linear functional
  5230 transformations, notably reverse application and composition:
  5231 
  5232   x |> f                f #> g
  5233   (x, y) |-> f          f #-> g
  5234 
  5235 * Pure/library.ML: introduced/changed precedence of infix operators:
  5236 
  5237   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  5238   infix 2 ?;
  5239   infix 3 o oo ooo oooo;
  5240   infix 4 ~~ upto downto;
  5241 
  5242 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  5243 infix operators.
  5244 
  5245 * Pure/library.ML: natural list combinators fold, fold_rev, and
  5246 fold_map support linear functional transformations and nesting.  For
  5247 example:
  5248 
  5249   fold f [x1, ..., xN] y =
  5250     y |> f x1 |> ... |> f xN
  5251 
  5252   (fold o fold) f [xs1, ..., xsN] y =
  5253     y |> fold f xs1 |> ... |> fold f xsN
  5254 
  5255   fold f [x1, ..., xN] =
  5256     f x1 #> ... #> f xN
  5257 
  5258   (fold o fold) f [xs1, ..., xsN] =
  5259     fold f xs1 #> ... #> fold f xsN
  5260 
  5261 * Pure/library.ML: the following selectors on type 'a option are
  5262 available:
  5263 
  5264   the:               'a option -> 'a  (*partial*)
  5265   these:             'a option -> 'a  where 'a = 'b list
  5266   the_default: 'a -> 'a option -> 'a
  5267   the_list:          'a option -> 'a list
  5268 
  5269 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5270 basic operations for association lists, following natural argument
  5271 order; moreover the explicit equality predicate passed here avoids
  5272 potentially expensive polymorphic runtime equality checks.
  5273 The old functions may be expressed as follows:
  5274 
  5275   assoc = uncurry (AList.lookup (op =))
  5276   assocs = these oo AList.lookup (op =)
  5277   overwrite = uncurry (AList.update (op =)) o swap
  5278 
  5279 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5280 
  5281   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  5282   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  5283 
  5284 replacing make_keylist and keyfilter (occassionally used)
  5285 Naive rewrites:
  5286 
  5287   make_keylist = AList.make
  5288   keyfilter = AList.find (op =)
  5289 
  5290 * eq_fst and eq_snd now take explicit equality parameter, thus
  5291   avoiding eqtypes. Naive rewrites:
  5292 
  5293     eq_fst = eq_fst (op =)
  5294     eq_snd = eq_snd (op =)
  5295 
  5296 * Removed deprecated apl and apr (rarely used).
  5297   Naive rewrites:
  5298 
  5299     apl (n, op) =>>= curry op n
  5300     apr (op, m) =>>= fn n => op (n, m)
  5301 
  5302 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  5303 provides a reasonably efficient light-weight implementation of sets as
  5304 lists.
  5305 
  5306 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  5307 few new operations; existing lookup and update are now curried to
  5308 follow natural argument order (for use with fold etc.);
  5309 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  5310 
  5311 * Pure/General: output via the Isabelle channels of
  5312 writeln/warning/error etc. is now passed through Output.output, with a
  5313 hook for arbitrary transformations depending on the print_mode
  5314 (cf. Output.add_mode -- the first active mode that provides a output
  5315 function wins).  Already formatted output may be embedded into further
  5316 text via Output.raw; the result of Pretty.string_of/str_of and derived
  5317 functions (string_of_term/cterm/thm etc.) is already marked raw to
  5318 accommodate easy composition of diagnostic messages etc.  Programmers
  5319 rarely need to care about Output.output or Output.raw at all, with
  5320 some notable exceptions: Output.output is required when bypassing the
  5321 standard channels (writeln etc.), or in token translations to produce
  5322 properly formatted results; Output.raw is required when capturing
  5323 already output material that will eventually be presented to the user
  5324 a second time.  For the default print mode, both Output.output and
  5325 Output.raw have no effect.
  5326 
  5327 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  5328 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  5329 cumulative results are displayed at the end of a batch session.
  5330 
  5331 * Pure/General: File.sysify_path and File.quote_sysify path have been
  5332 replaced by File.platform_path and File.shell_path (with appropriate
  5333 hooks).  This provides a clean interface for unusual systems where the
  5334 internal and external process view of file names are different.
  5335 
  5336 * Pure: more efficient orders for basic syntactic entities: added
  5337 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  5338 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  5339 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  5340 orders now -- potential INCOMPATIBILITY for code that depends on a
  5341 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  5342 Library.sort_strings on result).
  5343 
  5344 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  5345 fold_types traverse types/terms from left to right, observing natural
  5346 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  5347 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  5348 
  5349 * Pure: name spaces have been refined, with significant changes of the
  5350 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  5351 to extern(_table).  The plain name entry path is superceded by a
  5352 general 'naming' context, which also includes the 'policy' to produce
  5353 a fully qualified name and external accesses of a fully qualified
  5354 name; NameSpace.extend is superceded by context dependent
  5355 Sign.declare_name.  Several theory and proof context operations modify
  5356 the naming context.  Especially note Theory.restore_naming and
  5357 ProofContext.restore_naming to get back to a sane state; note that
  5358 Theory.add_path is no longer sufficient to recover from
  5359 Theory.absolute_path in particular.
  5360 
  5361 * Pure: new flags short_names (default false) and unique_names
  5362 (default true) for controlling output of qualified names.  If
  5363 short_names is set, names are printed unqualified.  If unique_names is
  5364 reset, the name prefix is reduced to the minimum required to achieve
  5365 the original result when interning again, even if there is an overlap
  5366 with earlier declarations.
  5367 
  5368 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  5369 now 'extend', and 'merge' gets an additional Pretty.pp argument
  5370 (useful for printing error messages).  INCOMPATIBILITY.
  5371 
  5372 * Pure: major reorganization of the theory context.  Type Sign.sg and
  5373 Theory.theory are now identified, referring to the universal
  5374 Context.theory (see Pure/context.ML).  Actual signature and theory
  5375 content is managed as theory data.  The old code and interfaces were
  5376 spread over many files and structures; the new arrangement introduces
  5377 considerable INCOMPATIBILITY to gain more clarity:
  5378 
  5379   Context -- theory management operations (name, identity, inclusion,
  5380     parents, ancestors, merge, etc.), plus generic theory data;
  5381 
  5382   Sign -- logical signature and syntax operations (declaring consts,
  5383     types, etc.), plus certify/read for common entities;
  5384 
  5385   Theory -- logical theory operations (stating axioms, definitions,
  5386     oracles), plus a copy of logical signature operations (consts,
  5387     types, etc.); also a few basic management operations (Theory.copy,
  5388     Theory.merge, etc.)
  5389 
  5390 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  5391 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  5392 for convenience -- they merely return the theory.
  5393 
  5394 * Pure: type Type.tsig is superceded by theory in most interfaces.
  5395 
  5396 * Pure: the Isar proof context type is already defined early in Pure
  5397 as Context.proof (note that ProofContext.context and Proof.context are
  5398 aliases, where the latter is the preferred name).  This enables other
  5399 Isabelle components to refer to that type even before Isar is present.
  5400 
  5401 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  5402 typeK, constK, axiomK, oracleK), but provide explicit operations for
  5403 any of these kinds.  For example, Sign.intern typeK is now
  5404 Sign.intern_type, Theory.hide_space Sign.typeK is now
  5405 Theory.hide_types.  Also note that former
  5406 Theory.hide_classes/types/consts are now
  5407 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  5408 internalize their arguments!  INCOMPATIBILITY.
  5409 
  5410 * Pure: get_thm interface (of PureThy and ProofContext) expects
  5411 datatype thmref (with constructors Name and NameSelection) instead of
  5412 plain string -- INCOMPATIBILITY;
  5413 
  5414 * Pure: cases produced by proof methods specify options, where NONE
  5415 means to remove case bindings -- INCOMPATIBILITY in
  5416 (RAW_)METHOD_CASES.
  5417 
  5418 * Pure: the following operations retrieve axioms or theorems from a
  5419 theory node or theory hierarchy, respectively:
  5420 
  5421   Theory.axioms_of: theory -> (string * term) list
  5422   Theory.all_axioms_of: theory -> (string * term) list
  5423   PureThy.thms_of: theory -> (string * thm) list
  5424   PureThy.all_thms_of: theory -> (string * thm) list
  5425 
  5426 * Pure: print_tac now outputs the goal through the trace channel.
  5427 
  5428 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  5429 Reference Toplevel.debug (default false) controls detailed printing
  5430 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  5431 controls execution profiling -- set to 1 for time and 2 for space
  5432 (both increase the runtime).
  5433 
  5434 * Isar session: The initial use of ROOT.ML is now always timed,
  5435 i.e. the log will show the actual process times, in contrast to the
  5436 elapsed wall-clock time that the outer shell wrapper produces.
  5437 
  5438 * Simplifier: improved handling of bound variables (nameless
  5439 representation, avoid allocating new strings).  Simprocs that invoke
  5440 the Simplifier recursively should use Simplifier.inherit_bounds to
  5441 avoid local name clashes.  Failure to do so produces warnings
  5442 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  5443 for further details.
  5444 
  5445 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  5446 bindings for all theorems stored within a given theory; this may help
  5447 in porting non-Isar theories to Isar ones, while keeping ML proof
  5448 scripts for the time being.
  5449 
  5450 * ML operator HTML.with_charset specifies the charset begin used for
  5451 generated HTML files.  For example:
  5452 
  5453   HTML.with_charset "utf-8" use_thy "Hebrew";
  5454   HTML.with_charset "utf-8" use_thy "Chinese";
  5455 
  5456 
  5457 *** System ***
  5458 
  5459 * Allow symlinks to all proper Isabelle executables (Isabelle,
  5460 isabelle, isatool etc.).
  5461 
  5462 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  5463 isatool doc, isatool mkdir, display_drafts etc.).
  5464 
  5465 * isatool usedir: option -f allows specification of the ML file to be
  5466 used by Isabelle; default is ROOT.ML.
  5467 
  5468 * New isatool version outputs the version identifier of the Isabelle
  5469 distribution being used.
  5470 
  5471 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  5472 (containing Boolean satisfiability problems) into Isabelle/HOL
  5473 theories.
  5474 
  5475 
  5476 
  5477 New in Isabelle2004 (April 2004)
  5478 --------------------------------
  5479 
  5480 *** General ***
  5481 
  5482 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  5483   Replaces linorder.ML.
  5484 
  5485 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  5486   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  5487   (\<a>...\<z>), are now considered normal letters, and can therefore
  5488   be used anywhere where an ASCII letter (a...zA...Z) has until
  5489   now. COMPATIBILITY: This obviously changes the parsing of some
  5490   terms, especially where a symbol has been used as a binder, say
  5491   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  5492   as an identifier.  Fix it by inserting a space around former
  5493   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  5494   existing theory and ML files.
  5495 
  5496 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  5497 
  5498 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  5499   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  5500   a normal (but invisible) letter. For multiple letter subscripts repeat
  5501   \<^isub> like this: x\<^isub>1\<^isub>2.
  5502 
  5503 * Pure: There are now sub-/superscripts that can span more than one
  5504   character. Text between \<^bsub> and \<^esub> is set in subscript in
  5505   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  5506   superscript. The new control characters are not identifier parts.
  5507 
  5508 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  5509   content of "..." to the latex file instead of \isacntrl... . The "..."
  5510   may consist of any printable characters excluding the end bracket >.
  5511 
  5512 * Pure: Using new Isar command "finalconsts" (or the ML functions
  5513   Theory.add_finals or Theory.add_finals_i) it is now possible to
  5514   declare constants "final", which prevents their being given a definition
  5515   later.  It is useful for constants whose behaviour is fixed axiomatically
  5516   rather than definitionally, such as the meta-logic connectives.
  5517 
  5518 * Pure: 'instance' now handles general arities with general sorts
  5519   (i.e. intersections of classes),
  5520 
  5521 * Presentation: generated HTML now uses a CSS style sheet to make layout
  5522   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  5523   It can be changed to alter the colors/layout of generated pages.
  5524 
  5525 
  5526 *** Isar ***
  5527 
  5528 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  5529   cut_tac, subgoal_tac and thin_tac:
  5530   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  5531     locales are no longer forced to write Isar proof scripts.
  5532     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  5533     emulations.
  5534   - INCOMPATIBILITY: names of variables to be instantiated may no
  5535     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  5536     This is consistent with the instantiation attribute "where".
  5537 
  5538 * Attributes "where" and "of":
  5539   - Now take type variables of instantiated theorem into account when reading
  5540     the instantiation string.  This fixes a bug that caused instantiated
  5541     theorems to have too special types in some circumstances.
  5542   - "where" permits explicit instantiations of type variables.
  5543 
  5544 * Calculation commands "moreover" and "also" no longer interfere with
  5545   current facts ("this"), admitting arbitrary combinations with "then"
  5546   and derived forms.
  5547 
  5548 * Locales:
  5549   - Goal statements involving the context element "includes" no longer
  5550     generate theorems with internal delta predicates (those ending on
  5551     "_axioms") in the premise.
  5552     Resolve particular premise with <locale>.intro to obtain old form.
  5553   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  5554     specification and "includes" elements in goal statement.
  5555   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  5556     [intro?] and [elim?] (respectively) by default.
  5557   - Experimental command for instantiation of locales in proof contexts:
  5558         instantiate <label>[<attrs>]: <loc>
  5559     Instantiates locale <loc> and adds all its theorems to the current context
  5560     taking into account their attributes.  Label and attrs are optional
  5561     modifiers, like in theorem declarations.  If present, names of
  5562     instantiated theorems are qualified with <label>, and the attributes
  5563     <attrs> are applied after any attributes these theorems might have already.
  5564       If the locale has assumptions, a chained fact of the form
  5565     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  5566     are derived.  The command does not support old-style locales declared
  5567     with "locale (open)".
  5568       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  5569 
  5570 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  5571   (Isar) contexts.
  5572 
  5573 
  5574 *** HOL ***
  5575 
  5576 * Proof import: new image HOL4 contains the imported library from
  5577   the HOL4 system with about 2500 theorems. It is imported by
  5578   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  5579   can be used like any other Isabelle image.  See
  5580   HOL/Import/HOL/README for more information.
  5581 
  5582 * Simplifier:
  5583   - Much improved handling of linear and partial orders.
  5584     Reasoners for linear and partial orders are set up for type classes
  5585     "linorder" and "order" respectively, and are added to the default simpset
  5586     as solvers.  This means that the simplifier can build transitivity chains
  5587     to solve goals from the assumptions.
  5588   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  5589     of blast or auto after simplification become unnecessary because the goal
  5590     is solved by simplification already.
  5591 
  5592 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  5593     all proved in axiomatic type classes for semirings, rings and fields.
  5594 
  5595 * Numerics:
  5596   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  5597     now formalized using the Ring_and_Field theory mentioned above.
  5598   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  5599     than before, because now they are set up once in a generic manner.
  5600   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  5601     Look for the general versions in Ring_and_Field (and Power if they concern
  5602     exponentiation).
  5603 
  5604 * Type "rat" of the rational numbers is now available in HOL-Complex.
  5605 
  5606 * Records:
  5607   - Record types are now by default printed with their type abbreviation
  5608     instead of the list of all field types. This can be configured via
  5609     the reference "print_record_type_abbr".
  5610   - Simproc "record_upd_simproc" for simplification of multiple updates added
  5611     (not enabled by default).
  5612   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  5613     EX x. x = sel r to True (not enabled by default).
  5614   - Tactic "record_split_simp_tac" to split and simplify records added.
  5615 
  5616 * 'specification' command added, allowing for definition by
  5617   specification.  There is also an 'ax_specification' command that
  5618   introduces the new constants axiomatically.
  5619 
  5620 * arith(_tac) is now able to generate counterexamples for reals as well.
  5621 
  5622 * HOL-Algebra: new locale "ring" for non-commutative rings.
  5623 
  5624 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  5625   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  5626 
  5627 * HOL-Matrix: a first theory for matrices in HOL with an application of
  5628   matrix theory to linear programming.
  5629 
  5630 * Unions and Intersections:
  5631   The latex output syntax of UN and INT has been changed
  5632   from "\Union x \in A. B" to "\Union_{x \in A} B"
  5633   i.e. the index formulae has become a subscript.
  5634   Similarly for "\Union x. B", and for \Inter instead of \Union.
  5635 
  5636 * Unions and Intersections over Intervals:
  5637   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  5638   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  5639   like in normal math, and corresponding versions for < and for intersection.
  5640 
  5641 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  5642   lexicographic dictonary ordering has been added as "lexord".
  5643 
  5644 * ML: the legacy theory structures Int and List have been removed. They had
  5645   conflicted with ML Basis Library structures having the same names.
  5646 
  5647 * 'refute' command added to search for (finite) countermodels.  Only works
  5648   for a fragment of HOL.  The installation of an external SAT solver is
  5649   highly recommended.  See "HOL/Refute.thy" for details.
  5650 
  5651 * 'quickcheck' command: Allows to find counterexamples by evaluating
  5652   formulae under an assignment of free variables to random values.
  5653   In contrast to 'refute', it can deal with inductive datatypes,
  5654   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  5655   for examples.
  5656 
  5657 
  5658 *** HOLCF ***
  5659 
  5660 * Streams now come with concatenation and are part of the HOLCF image
  5661 
  5662 
  5663 
  5664 New in Isabelle2003 (May 2003)
  5665 ------------------------------
  5666 
  5667 *** General ***
  5668 
  5669 * Provers/simplifier:
  5670 
  5671   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  5672     Assumptions are now subject to complete mutual simplification,
  5673     not just from left to right. The simplifier now preserves
  5674     the order of assumptions.
  5675 
  5676     Potential INCOMPATIBILITY:
  5677 
  5678     -- simp sometimes diverges where the old version did
  5679        not, e.g. invoking simp on the goal
  5680 
  5681         [| P (f x); y = x; f x = f y |] ==> Q
  5682 
  5683        now gives rise to the infinite reduction sequence
  5684 
  5685         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  5686 
  5687        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  5688        kind of problem.
  5689 
  5690     -- Tactics combining classical reasoner and simplification (such as auto)
  5691        are also affected by this change, because many of them rely on
  5692        simp. They may sometimes diverge as well or yield a different numbers
  5693        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  5694        in case of problems. Sometimes subsequent calls to the classical
  5695        reasoner will fail because a preceeding call to the simplifier too
  5696        eagerly simplified the goal, e.g. deleted redundant premises.
  5697 
  5698   - The simplifier trace now shows the names of the applied rewrite rules
  5699 
  5700   - You can limit the number of recursive invocations of the simplifier
  5701     during conditional rewriting (where the simplifie tries to solve the
  5702     conditions before applying the rewrite rule):
  5703     ML "simp_depth_limit := n"
  5704     where n is an integer. Thus you can force termination where previously
  5705     the simplifier would diverge.
  5706 
  5707   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  5708 
  5709   - No longer aborts on failed congruence proof.  Instead, the
  5710     congruence is ignored.
  5711 
  5712 * Pure: New generic framework for extracting programs from constructive
  5713   proofs. See HOL/Extraction.thy for an example instantiation, as well
  5714   as HOL/Extraction for some case studies.
  5715 
  5716 * Pure: The main goal of the proof state is no longer shown by default, only
  5717 the subgoals. This behaviour is controlled by a new flag.
  5718    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  5719 (ML: Proof.show_main_goal).
  5720 
  5721 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  5722 rules whose conclusion matches subgoal 1:
  5723       PG menu: Isabelle/Isar -> Show me -> matching rules
  5724 The rules are ordered by how closely they match the subgoal.
  5725 In particular, rules that solve a subgoal outright are displayed first
  5726 (or rather last, the way they are printed).
  5727 (ML: ProofGeneral.print_intros())
  5728 
  5729 * Pure: New flag trace_unify_fail causes unification to print
  5730 diagnostic information (PG: in trace buffer) when it fails. This is
  5731 useful for figuring out why single step proofs like rule, erule or
  5732 assumption failed.
  5733 
  5734 * Pure: Locale specifications now produce predicate definitions
  5735 according to the body of text (covering assumptions modulo local
  5736 definitions); predicate "loc_axioms" covers newly introduced text,
  5737 while "loc" is cumulative wrt. all included locale expressions; the
  5738 latter view is presented only on export into the global theory
  5739 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  5740 on the old view without predicates;
  5741 
  5742 * Pure: predefined locales "var" and "struct" are useful for sharing
  5743 parameters (as in CASL, for example); just specify something like
  5744 ``var x + var y + struct M'' as import;
  5745 
  5746 * Pure: improved thms_containing: proper indexing of facts instead of
  5747 raw theorems; check validity of results wrt. current name space;
  5748 include local facts of proof configuration (also covers active
  5749 locales), cover fixed variables in index; may use "_" in term
  5750 specification; an optional limit for the number of printed facts may
  5751 be given (the default is 40);
  5752 
  5753 * Pure: disallow duplicate fact bindings within new-style theory files
  5754 (batch-mode only);
  5755 
  5756 * Provers: improved induct method: assumptions introduced by case
  5757 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  5758 the goal statement); "foo" still refers to all facts collectively;
  5759 
  5760 * Provers: the function blast.overloaded has been removed: all constants
  5761 are regarded as potentially overloaded, which improves robustness in exchange
  5762 for slight decrease in efficiency;
  5763 
  5764 * Provers/linorder: New generic prover for transitivity reasoning over
  5765 linear orders.  Note: this prover is not efficient!
  5766 
  5767 * Isar: preview of problems to finish 'show' now produce an error
  5768 rather than just a warning (in interactive mode);
  5769 
  5770 
  5771 *** HOL ***
  5772 
  5773 * arith(_tac)
  5774 
  5775  - Produces a counter example if it cannot prove a goal.
  5776    Note that the counter example may be spurious if the goal is not a formula
  5777    of quantifier-free linear arithmetic.
  5778    In ProofGeneral the counter example appears in the trace buffer.
  5779 
  5780  - Knows about div k and mod k where k is a numeral of type nat or int.
  5781 
  5782  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  5783    linear arithmetic fails. This takes account of quantifiers and divisibility.
  5784    Presburger arithmetic can also be called explicitly via presburger(_tac).
  5785 
  5786 * simp's arithmetic capabilities have been enhanced a bit: it now
  5787 takes ~= in premises into account (by performing a case split);
  5788 
  5789 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  5790 are distributed over a sum of terms;
  5791 
  5792 * New tactic "trans_tac" and method "trans" instantiate
  5793 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  5794 "<=", "<" and "=").
  5795 
  5796 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  5797 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  5798 
  5799 * 'typedef' command has new option "open" to suppress the set
  5800 definition;
  5801 
  5802 * functions Min and Max on finite sets have been introduced (theory
  5803 Finite_Set);
  5804 
  5805 * attribute [symmetric] now works for relations as well; it turns
  5806 (x,y) : R^-1 into (y,x) : R, and vice versa;
  5807 
  5808 * induct over a !!-quantified statement (say !!x1..xn):
  5809   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  5810 
  5811 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  5812 %x. None. Warning: empty_def now refers to the previously hidden definition
  5813 of the empty set.
  5814 
  5815 * Algebra: formalization of classical algebra.  Intended as base for
  5816 any algebraic development in Isabelle.  Currently covers group theory
  5817 (up to Sylow's theorem) and ring theory (Universal Property of
  5818 Univariate Polynomials).  Contributions welcome;
  5819 
  5820 * GroupTheory: deleted, since its material has been moved to Algebra;
  5821 
  5822 * Complex: new directory of the complex numbers with numeric constants,
  5823 nonstandard complex numbers, and some complex analysis, standard and
  5824 nonstandard (Jacques Fleuriot);
  5825 
  5826 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  5827 
  5828 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  5829 Fleuriot);
  5830 
  5831 * Real/HahnBanach: updated and adapted to locales;
  5832 
  5833 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  5834 Gray and Kramer);
  5835 
  5836 * UNITY: added the Meier-Sanders theory of progress sets;
  5837 
  5838 * MicroJava: bytecode verifier and lightweight bytecode verifier
  5839 as abstract algorithms, instantiated to the JVM;
  5840 
  5841 * Bali: Java source language formalization. Type system, operational
  5842 semantics, axiomatic semantics. Supported language features:
  5843 classes, interfaces, objects,virtual methods, static methods,
  5844 static/instance fields, arrays, access modifiers, definite
  5845 assignment, exceptions.
  5846 
  5847 
  5848 *** ZF ***
  5849 
  5850 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  5851 universe, etc.);
  5852 
  5853 * Main ZF: virtually all theories converted to new-style format;
  5854 
  5855 
  5856 *** ML ***
  5857 
  5858 * Pure: Tactic.prove provides sane interface for internal proofs;
  5859 omits the infamous "standard" operation, so this is more appropriate
  5860 than prove_goalw_cterm in many situations (e.g. in simprocs);
  5861 
  5862 * Pure: improved error reporting of simprocs;
  5863 
  5864 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  5865 up simprocs;
  5866 
  5867 
  5868 *** Document preparation ***
  5869 
  5870 * uses \par instead of \\ for line breaks in theory text. This may
  5871 shift some page breaks in large documents. To get the old behaviour
  5872 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  5873 
  5874 * minimized dependencies of isabelle.sty and isabellesym.sty on
  5875 other packages
  5876 
  5877 * \<euro> now needs package babel/greek instead of marvosym (which
  5878 broke \Rightarrow)
  5879 
  5880 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  5881 textcomp package)
  5882 
  5883 
  5884 
  5885 New in Isabelle2002 (March 2002)
  5886 --------------------------------
  5887 
  5888 *** Document preparation ***
  5889 
  5890 * greatly simplified document preparation setup, including more
  5891 graceful interpretation of isatool usedir -i/-d/-D options, and more
  5892 instructive isatool mkdir; users should basically be able to get
  5893 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  5894 users may run a separate document processing stage manually like this:
  5895 "isatool usedir -D output HOL Test && isatool document Test/output";
  5896 
  5897 * theory dependency graph may now be incorporated into documents;
  5898 isatool usedir -g true will produce session_graph.eps/.pdf for use
  5899 with \includegraphics of LaTeX;
  5900 
  5901 * proper spacing of consecutive markup elements, especially text
  5902 blocks after section headings;
  5903 
  5904 * support bold style (for single symbols only), input syntax is like
  5905 this: "\<^bold>\<alpha>" or "\<^bold>A";
  5906 
  5907 * \<bullet> is now output as bold \cdot by default, which looks much
  5908 better in printed text;
  5909 
  5910 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  5911 note that these symbols are currently unavailable in Proof General /
  5912 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  5913 
  5914 * isatool latex no longer depends on changed TEXINPUTS, instead
  5915 isatool document copies the Isabelle style files to the target
  5916 location;
  5917 
  5918 
  5919 *** Isar ***
  5920 
  5921 * Pure/Provers: improved proof by cases and induction;
  5922   - 'case' command admits impromptu naming of parameters (such as
  5923     "case (Suc n)");
  5924   - 'induct' method divinates rule instantiation from the inductive
  5925     claim; no longer requires excessive ?P bindings for proper
  5926     instantiation of cases;
  5927   - 'induct' method properly enumerates all possibilities of set/type
  5928     rules; as a consequence facts may be also passed through *type*
  5929     rules without further ado;
  5930   - 'induct' method now derives symbolic cases from the *rulified*
  5931     rule (before it used to rulify cases stemming from the internal
  5932     atomized version); this means that the context of a non-atomic
  5933     statement becomes is included in the hypothesis, avoiding the
  5934     slightly cumbersome show "PROP ?case" form;
  5935   - 'induct' may now use elim-style induction rules without chaining
  5936     facts, using ``missing'' premises from the goal state; this allows
  5937     rules stemming from inductive sets to be applied in unstructured
  5938     scripts, while still benefitting from proper handling of non-atomic
  5939     statements; NB: major inductive premises need to be put first, all
  5940     the rest of the goal is passed through the induction;
  5941   - 'induct' proper support for mutual induction involving non-atomic
  5942     rule statements (uses the new concept of simultaneous goals, see
  5943     below);
  5944   - append all possible rule selections, but only use the first
  5945     success (no backtracking);
  5946   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  5947   - undeclared rule case names default to numbers 1, 2, 3, ...;
  5948   - added 'print_induct_rules' (covered by help item in recent Proof
  5949     General versions);
  5950   - moved induct/cases attributes to Pure, methods to Provers;
  5951   - generic method setup instantiated for FOL and HOL;
  5952 
  5953 * Pure: support multiple simultaneous goal statements, for example
  5954 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  5955 meta-level mechanism, this acts as if several individual goals had
  5956 been stated separately; in particular common proof methods need to be
  5957 repeated in order to cover all claims; note that a single elimination
  5958 step is *not* sufficient to establish the two conjunctions, so this
  5959 fails:
  5960 
  5961   assume "A & B" then have A and B ..   (*".." fails*)
  5962 
  5963 better use "obtain" in situations as above; alternative refer to
  5964 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  5965 
  5966 * Pure: proper integration with ``locales''; unlike the original
  5967 version by Florian Kammller, Isar locales package high-level proof
  5968 contexts rather than raw logical ones (e.g. we admit to include
  5969 attributes everywhere); operations on locales include merge and
  5970 rename; support for implicit arguments (``structures''); simultaneous
  5971 type-inference over imports and text; see also HOL/ex/Locales.thy for
  5972 some examples;
  5973 
  5974 * Pure: the following commands have been ``localized'', supporting a
  5975 target locale specification "(in name)": 'lemma', 'theorem',
  5976 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  5977 stored both within the locale and at the theory level (exported and
  5978 qualified by the locale name);
  5979 
  5980 * Pure: theory goals may now be specified in ``long'' form, with
  5981 ad-hoc contexts consisting of arbitrary locale elements. for example
  5982 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  5983 definitions may be given, too); the result is a meta-level rule with
  5984 the context elements being discharged in the obvious way;
  5985 
  5986 * Pure: new proof command 'using' allows to augment currently used
  5987 facts after a goal statement ('using' is syntactically analogous to
  5988 'apply', but acts on the goal's facts only); this allows chained facts
  5989 to be separated into parts given before and after a claim, as in
  5990 ``from a and b have C using d and e <proof>'';
  5991 
  5992 * Pure: renamed "antecedent" case to "rule_context";
  5993 
  5994 * Pure: new 'judgment' command records explicit information about the
  5995 object-logic embedding (used by several tools internally); no longer
  5996 use hard-wired "Trueprop";
  5997 
  5998 * Pure: added 'corollary' command;
  5999 
  6000 * Pure: fixed 'token_translation' command;
  6001 
  6002 * Pure: removed obsolete 'exported' attribute;
  6003 
  6004 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  6005 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  6006 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  6007 
  6008 * Pure: method 'atomize' presents local goal premises as object-level
  6009 statements (atomic meta-level propositions); setup controlled via
  6010 rewrite rules declarations of 'atomize' attribute; example
  6011 application: 'induct' method with proper rule statements in improper
  6012 proof *scripts*;
  6013 
  6014 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  6015 now consider the syntactic context of assumptions, giving a better
  6016 chance to get type-inference of the arguments right (this is
  6017 especially important for locales);
  6018 
  6019 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  6020 mode;
  6021 
  6022 * Pure/obtain: the formal conclusion "thesis", being marked as
  6023 ``internal'', may no longer be reference directly in the text;
  6024 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  6025 situations;
  6026 
  6027 * Pure: generic 'sym' attribute which declares a rule both as pure
  6028 'elim?' and for the 'symmetric' operation;
  6029 
  6030 * Pure: marginal comments ``--'' may now occur just anywhere in the
  6031 text; the fixed correlation with particular command syntax has been
  6032 discontinued;
  6033 
  6034 * Pure: new method 'rules' is particularly well-suited for proof
  6035 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  6036 but often produces more compact proof terms with less detours;
  6037 
  6038 * Pure/Provers/classical: simplified integration with pure rule
  6039 attributes and methods; the classical "intro?/elim?/dest?"
  6040 declarations coincide with the pure ones; the "rule" method no longer
  6041 includes classically swapped intros; "intro" and "elim" methods no
  6042 longer pick rules from the context; also got rid of ML declarations
  6043 AddXIs/AddXEs/AddXDs; all of this has some potential for
  6044 INCOMPATIBILITY;
  6045 
  6046 * Provers/classical: attribute 'swapped' produces classical inversions
  6047 of introduction rules;
  6048 
  6049 * Provers/simplifier: 'simplified' attribute may refer to explicit
  6050 rules instead of full simplifier context; 'iff' attribute handles
  6051 conditional rules;
  6052 
  6053 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  6054 
  6055 * HOL: 'recdef' now fails on unfinished automated proofs, use
  6056 "(permissive)" option to recover old behavior;
  6057 
  6058 * HOL: 'inductive' no longer features separate (collective) attributes
  6059 for 'intros' (was found too confusing);
  6060 
  6061 * HOL: properly declared induction rules less_induct and
  6062 wf_induct_rule;
  6063 
  6064 
  6065 *** HOL ***
  6066 
  6067 * HOL: moved over to sane numeral syntax; the new policy is as
  6068 follows:
  6069 
  6070   - 0 and 1 are polymorphic constants, which are defined on any
  6071   numeric type (nat, int, real etc.);
  6072 
  6073   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  6074   binary representation internally;
  6075 
  6076   - type nat has special constructor Suc, and generally prefers Suc 0
  6077   over 1::nat and Suc (Suc 0) over 2::nat;
  6078 
  6079 This change may cause significant problems of INCOMPATIBILITY; here
  6080 are some hints on converting existing sources:
  6081 
  6082   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  6083   entities, so expressions involving "-" (unary or binary minus) need
  6084   to be spaced properly;
  6085 
  6086   - existing occurrences of "1" may need to be constraint "1::nat" or
  6087   even replaced by Suc 0; similar for old "2";
  6088 
  6089   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  6090 
  6091   - remove all special provisions on numerals in proofs;
  6092 
  6093 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  6094 representation (depends on bin_arith_simps in the default context);
  6095 
  6096 * HOL: symbolic syntax for x^2 (numeral 2);
  6097 
  6098 * HOL: the class of all HOL types is now called "type" rather than
  6099 "term"; INCOMPATIBILITY, need to adapt references to this type class
  6100 in axclass/classes, instance/arities, and (usually rare) occurrences
  6101 in typings (of consts etc.); internally the class is called
  6102 "HOL.type", ML programs should refer to HOLogic.typeS;
  6103 
  6104 * HOL/record package improvements:
  6105   - new derived operations "fields" to build a partial record section,
  6106     "extend" to promote a fixed record to a record scheme, and
  6107     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  6108     declared as simp by default;
  6109   - shared operations ("more", "fields", etc.) now need to be always
  6110     qualified) --- potential INCOMPATIBILITY;
  6111   - removed "make_scheme" operations (use "make" with "extend") --
  6112     INCOMPATIBILITY;
  6113   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  6114   - provides cases/induct rules for use with corresponding Isar
  6115     methods (for concrete records, record schemes, concrete more
  6116     parts, and schematic more parts -- in that order);
  6117   - internal definitions directly based on a light-weight abstract
  6118     theory of product types over typedef rather than datatype;
  6119 
  6120 * HOL: generic code generator for generating executable ML code from
  6121 specifications; specific support for HOL constructs such as inductive
  6122 datatypes and sets, as well as recursive functions; can be invoked
  6123 via 'generate_code' theory section;
  6124 
  6125 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  6126 
  6127 * HOL: consolidated and renamed several theories.  In particular:
  6128         Ord.thy has been absorbed into HOL.thy
  6129         String.thy has been absorbed into List.thy
  6130 
  6131 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  6132 (beware of argument permutation!);
  6133 
  6134 * HOL: linorder_less_split superseded by linorder_cases;
  6135 
  6136 * HOL/List: "nodups" renamed to "distinct";
  6137 
  6138 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  6139 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  6140   - Ex_def has changed, now need to use some_eq_ex
  6141 
  6142 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  6143 in this (rare) case use:
  6144 
  6145   delSWrapper "split_all_tac"
  6146   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  6147 
  6148 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  6149 MAY FAIL;
  6150 
  6151 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  6152 Isabelle's type classes, ^ on functions and relations has too general
  6153 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  6154 necessary to attach explicit type constraints;
  6155 
  6156 * HOL/Relation: the prefix name of the infix "O" has been changed from
  6157 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  6158 renamed accordingly (eg "compI" -> "rel_compI").
  6159 
  6160 * HOL: syntax translations now work properly with numerals and records
  6161 expressions;
  6162 
  6163 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  6164 of "lam" -- INCOMPATIBILITY;
  6165 
  6166 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  6167 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  6168 renamed "Product_Type.unit";
  6169 
  6170 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  6171 
  6172 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  6173 the "cases" method);
  6174 
  6175 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  6176 Florian Kammller);
  6177 
  6178 * HOL/IMP: updated and converted to new-style theory format; several
  6179 parts turned into readable document, with proper Isar proof texts and
  6180 some explanations (by Gerwin Klein);
  6181 
  6182 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  6183 
  6184 * HOL-Hyperreal is now a logic image;
  6185 
  6186 
  6187 *** HOLCF ***
  6188 
  6189 * Isar: consts/constdefs supports mixfix syntax for continuous
  6190 operations;
  6191 
  6192 * Isar: domain package adapted to new-style theory format, e.g. see
  6193 HOLCF/ex/Dnat.thy;
  6194 
  6195 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  6196 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  6197 lift.induct_tac, always use UU instead of Undef;
  6198 
  6199 * HOLCF/IMP: updated and converted to new-style theory;
  6200 
  6201 
  6202 *** ZF ***
  6203 
  6204 * Isar: proper integration of logic-specific tools and packages,
  6205 including theory commands '(co)inductive', '(co)datatype',
  6206 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  6207 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  6208 
  6209 * theory Main no longer includes AC; for the Axiom of Choice, base
  6210 your theory on Main_ZFC;
  6211 
  6212 * the integer library now covers quotients and remainders, with many
  6213 laws relating division to addition, multiplication, etc.;
  6214 
  6215 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  6216 typeless version of the formalism;
  6217 
  6218 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  6219 format;
  6220 
  6221 * ZF/Induct: new directory for examples of inductive definitions,
  6222 including theory Multiset for multiset orderings; converted to
  6223 new-style theory format;
  6224 
  6225 * ZF: many new theorems about lists, ordinals, etc.;
  6226 
  6227 
  6228 *** General ***
  6229 
  6230 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  6231 variable proof controls level of detail: 0 = no proofs (only oracle
  6232 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  6233 also ref manual for further ML interfaces;
  6234 
  6235 * Pure/axclass: removed obsolete ML interface
  6236 goal_subclass/goal_arity;
  6237 
  6238 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  6239 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  6240 separate tokens, so expressions involving minus need to be spaced
  6241 properly;
  6242 
  6243 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  6244 rather than "infixl" or "infixr";
  6245 
  6246 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  6247 sort constraint specifications in type inference; e.g. "x::_::foo"
  6248 ensures that the type of "x" is of sort "foo" (but not necessarily a
  6249 type variable);
  6250 
  6251 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  6252 control output of nested => (types); the default behavior is
  6253 "type_brackets";
  6254 
  6255 * Pure/syntax: builtin parse translation for "_constify" turns valued
  6256 tokens into AST constants;
  6257 
  6258 * Pure/syntax: prefer later declarations of translations and print
  6259 translation functions; potential INCOMPATIBILITY: need to reverse
  6260 multiple declarations for same syntax element constant;
  6261 
  6262 * Pure/show_hyps reset by default (in accordance to existing Isar
  6263 practice);
  6264 
  6265 * Provers/classical: renamed addaltern to addafter, addSaltern to
  6266 addSafter;
  6267 
  6268 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  6269 as well;
  6270 
  6271 * system: tested support for MacOS X; should be able to get Isabelle +
  6272 Proof General to work in a plain Terminal after installing Poly/ML
  6273 (e.g. from the Isabelle distribution area) and GNU bash alone
  6274 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  6275 support requires further installations, e.g. from
  6276 http://fink.sourceforge.net/);
  6277 
  6278 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  6279 
  6280 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  6281 of 40 MB), cf. ML_OPTIONS;
  6282 
  6283 * system: Proof General keywords specification is now part of the
  6284 Isabelle distribution (see etc/isar-keywords.el);
  6285 
  6286 * system: support for persistent Proof General sessions (refrain from
  6287 outdating all loaded theories on startup); user may create writable
  6288 logic images like this: ``isabelle -q HOL Test'';
  6289 
  6290 * system: smart selection of Isabelle process versus Isabelle
  6291 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  6292 run both "isabelle" and "Isabelle" even if file names are badly
  6293 damaged (executable inspects the case of the first letter of its own
  6294 name); added separate "isabelle-process" and "isabelle-interface";
  6295 
  6296 * system: refrain from any attempt at filtering input streams; no
  6297 longer support ``8bit'' encoding of old isabelle font, instead proper
  6298 iso-latin characters may now be used; the related isatools
  6299 "symbolinput" and "nonascii" have disappeared as well;
  6300 
  6301 * system: removed old "xterm" interface (the print modes "xterm" and
  6302 "xterm_color" are still available for direct use in a suitable
  6303 terminal);
  6304 
  6305 
  6306 
  6307 New in Isabelle99-2 (February 2001)
  6308 -----------------------------------
  6309 
  6310 *** Overview of INCOMPATIBILITIES ***
  6311 
  6312 * HOL: please note that theories in the Library and elsewhere often use the
  6313 new-style (Isar) format; to refer to their theorems in an ML script you must
  6314 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  6315 
  6316 * HOL: inductive package no longer splits induction rule aggressively,
  6317 but only as far as specified by the introductions given; the old
  6318 format may be recovered via ML function complete_split_rule or attribute
  6319 'split_rule (complete)';
  6320 
  6321 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  6322 gfp_Tarski to gfp_unfold;
  6323 
  6324 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  6325 
  6326 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  6327 relation); infix "^^" has been renamed "``"; infix "``" has been
  6328 renamed "`"; "univalent" has been renamed "single_valued";
  6329 
  6330 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  6331 operation;
  6332 
  6333 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  6334 
  6335 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  6336 
  6337 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  6338 consequence, it is no longer monotonic wrt. the local goal context
  6339 (which is now passed through the inductive cases);
  6340 
  6341 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  6342 \<gg> to \<ggreater>;
  6343 
  6344 
  6345 *** Document preparation ***
  6346 
  6347 * \isabellestyle{NAME} selects version of Isabelle output (currently
  6348 available: are "it" for near math-mode best-style output, "sl" for
  6349 slanted text style, and "tt" for plain type-writer; if no
  6350 \isabellestyle command is given, output is according to slanted
  6351 type-writer);
  6352 
  6353 * support sub/super scripts (for single symbols only), input syntax is
  6354 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  6355 
  6356 * some more standard symbols; see Appendix A of the system manual for
  6357 the complete list of symbols defined in isabellesym.sty;
  6358 
  6359 * improved isabelle style files; more abstract symbol implementation
  6360 (should now use \isamath{...} and \isatext{...} in custom symbol
  6361 definitions);
  6362 
  6363 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  6364 state; Note that presentation of goal states does not conform to
  6365 actual human-readable proof documents.  Please do not include goal
  6366 states into document output unless you really know what you are doing!
  6367 
  6368 * proper indentation of antiquoted output with proportional LaTeX
  6369 fonts;
  6370 
  6371 * no_document ML operator temporarily disables LaTeX document
  6372 generation;
  6373 
  6374 * isatool unsymbolize tunes sources for plain ASCII communication;
  6375 
  6376 
  6377 *** Isar ***
  6378 
  6379 * Pure: Isar now suffers initial goal statements to contain unbound
  6380 schematic variables (this does not conform to actual readable proof
  6381 documents, due to unpredictable outcome and non-compositional proof
  6382 checking); users who know what they are doing may use schematic goals
  6383 for Prolog-style synthesis of proven results;
  6384 
  6385 * Pure: assumption method (an implicit finishing) now handles actual
  6386 rules as well;
  6387 
  6388 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  6389 initial goal, declare "that" only as Pure intro (only for single
  6390 steps); the "that" rule assumption may now be involved in implicit
  6391 finishing, thus ".." becomes a feasible for trivial obtains;
  6392 
  6393 * Pure: default proof step now includes 'intro_classes'; thus trivial
  6394 instance proofs may be performed by "..";
  6395 
  6396 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  6397 statements as well;
  6398 
  6399 * Pure: more robust selection of calculational rules;
  6400 
  6401 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  6402 rule (as well as the assumption rule);
  6403 
  6404 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  6405 lemmas, using the graph browser tool;
  6406 
  6407 * Pure: predict failure of "show" in interactive mode;
  6408 
  6409 * Pure: 'thms_containing' now takes actual terms as arguments;
  6410 
  6411 * HOL: improved method 'induct' --- now handles non-atomic goals
  6412 (potential INCOMPATIBILITY); tuned error handling;
  6413 
  6414 * HOL: cases and induct rules now provide explicit hints about the
  6415 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  6416 any remaining facts are inserted into the goal verbatim;
  6417 
  6418 * HOL: local contexts (aka cases) may now contain term bindings as
  6419 well; the 'cases' and 'induct' methods new provide a ?case binding for
  6420 the result to be shown in each case;
  6421 
  6422 * HOL: added 'recdef_tc' command;
  6423 
  6424 * isatool convert assists in eliminating legacy ML scripts;
  6425 
  6426 
  6427 *** HOL ***
  6428 
  6429 * HOL/Library: a collection of generic theories to be used together
  6430 with main HOL; the theory loader path already includes this directory
  6431 by default; the following existing theories have been moved here:
  6432 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  6433 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  6434 
  6435 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  6436 modelling and verification task performed in Isabelle/HOL +
  6437 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  6438 
  6439 * HOL/Algebra: special summation operator SUM no longer exists, it has
  6440 been replaced by setsum; infix 'assoc' now has priority 50 (like
  6441 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  6442 'domain', this makes the theory consistent with mathematical
  6443 literature;
  6444 
  6445 * HOL basics: added overloaded operations "inverse" and "divide"
  6446 (infix "/"), syntax for generic "abs" operation, generic summation
  6447 operator \<Sum>;
  6448 
  6449 * HOL/typedef: simplified package, provide more useful rules (see also
  6450 HOL/subset.thy);
  6451 
  6452 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  6453 now expressed as a proper nested rule (old-style tactic scripts may
  6454 require atomize_strip_tac to cope with non-atomic premises);
  6455 
  6456 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  6457 to "split_conv" (old name still available for compatibility);
  6458 
  6459 * HOL: improved concrete syntax for strings (e.g. allows translation
  6460 rules with string literals);
  6461 
  6462 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  6463  and Fleuriot's mechanization of analysis, including the transcendental
  6464  functions for the reals;
  6465 
  6466 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  6467 
  6468 
  6469 *** CTT ***
  6470 
  6471 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  6472 "lam" is displayed as TWO lambda-symbols
  6473 
  6474 * CTT: theory Main now available, containing everything (that is, Bool
  6475 and Arith);
  6476 
  6477 
  6478 *** General ***
  6479 
  6480 * Pure: the Simplifier has been implemented properly as a derived rule
  6481 outside of the actual kernel (at last!); the overall performance
  6482 penalty in practical applications is about 50%, while reliability of
  6483 the Isabelle inference kernel has been greatly improved;
  6484 
  6485 * print modes "brackets" and "no_brackets" control output of nested =>
  6486 (types) and ==> (props); the default behaviour is "brackets";
  6487 
  6488 * Provers: fast_tac (and friends) now handle actual object-logic rules
  6489 as assumptions as well;
  6490 
  6491 * system: support Poly/ML 4.0;
  6492 
  6493 * system: isatool install handles KDE version 1 or 2;
  6494 
  6495 
  6496 
  6497 New in Isabelle99-1 (October 2000)
  6498 ----------------------------------
  6499 
  6500 *** Overview of INCOMPATIBILITIES ***
  6501 
  6502 * HOL: simplification of natural numbers is much changed; to partly
  6503 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  6504 issue the following ML commands:
  6505 
  6506   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  6507   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  6508 
  6509 * HOL: simplification no longer dives into case-expressions; this is
  6510 controlled by "t.weak_case_cong" for each datatype t;
  6511 
  6512 * HOL: nat_less_induct renamed to less_induct;
  6513 
  6514 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  6515 fixsome to patch .thy and .ML sources automatically;
  6516 
  6517   select_equality  -> some_equality
  6518   select_eq_Ex     -> some_eq_ex
  6519   selectI2EX       -> someI2_ex
  6520   selectI2         -> someI2
  6521   selectI          -> someI
  6522   select1_equality -> some1_equality
  6523   Eps_sym_eq       -> some_sym_eq_trivial
  6524   Eps_eq           -> some_eq_trivial
  6525 
  6526 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  6527 
  6528 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  6529 instead);
  6530 
  6531 * HOL: the recursion equations generated by 'recdef' are now called
  6532 f.simps instead of f.rules;
  6533 
  6534 * HOL: qed_spec_mp now also handles bounded ALL as well;
  6535 
  6536 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  6537 sometimes be needed;
  6538 
  6539 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  6540 
  6541 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  6542 
  6543 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  6544 product is now "<*>" instead of "Times"; the lexicographic product is
  6545 now "<*lex*>" instead of "**";
  6546 
  6547 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  6548 of main HOL, but was unused); better use HOL's datatype package;
  6549 
  6550 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  6551 the old syntax may be recovered as follows:
  6552 
  6553   syntax (symbols)
  6554     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  6555       (infixl "\\<oplus>" 100)
  6556 
  6557 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  6558 
  6559 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  6560 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  6561 internally;
  6562 
  6563 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  6564 changed from A/r to A//r;
  6565 
  6566 * ZF: new treatment of arithmetic (nat & int) may break some old
  6567 proofs;
  6568 
  6569 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  6570 rulify -> rule_format, elimify -> elim_format, ...);
  6571 
  6572 * Isar/Provers: intro/elim/dest attributes changed; renamed
  6573 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  6574 should have to change intro!! to intro? only); replaced "delrule" by
  6575 "rule del";
  6576 
  6577 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  6578 
  6579 * Provers: strengthened force_tac by using new first_best_tac;
  6580 
  6581 * LaTeX document preparation: several changes of isabelle.sty (see
  6582 lib/texinputs);
  6583 
  6584 
  6585 *** Document preparation ***
  6586 
  6587 * formal comments (text blocks etc.) in new-style theories may now
  6588 contain antiquotations of thm/prop/term/typ/text to be presented
  6589 according to latex print mode; concrete syntax is like this:
  6590 @{term[show_types] "f(x) = a + x"};
  6591 
  6592 * isatool mkdir provides easy setup of Isabelle session directories,
  6593 including proper document sources;
  6594 
  6595 * generated LaTeX sources are now deleted after successful run
  6596 (isatool document -c); may retain a copy somewhere else via -D option
  6597 of isatool usedir;
  6598 
  6599 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  6600 style files, achieving self-contained LaTeX sources and simplifying
  6601 LaTeX debugging;
  6602 
  6603 * old-style theories now produce (crude) LaTeX output as well;
  6604 
  6605 * browser info session directories are now self-contained (may be put
  6606 on WWW server seperately); improved graphs of nested sessions; removed
  6607 graph for 'all sessions';
  6608 
  6609 * several improvements in isabelle style files; \isabellestyle{it}
  6610 produces fake math mode output; \isamarkupheader is now \section by
  6611 default; see lib/texinputs/isabelle.sty etc.;
  6612 
  6613 
  6614 *** Isar ***
  6615 
  6616 * Isar/Pure: local results and corresponding term bindings are now
  6617 subject to Hindley-Milner polymorphism (similar to ML); this
  6618 accommodates incremental type-inference very nicely;
  6619 
  6620 * Isar/Pure: new derived language element 'obtain' supports
  6621 generalized existence reasoning;
  6622 
  6623 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  6624 support accumulation of results, without applying any rules yet;
  6625 useful to collect intermediate results without explicit name
  6626 references, and for use with transitivity rules with more than 2
  6627 premises;
  6628 
  6629 * Isar/Pure: scalable support for case-analysis type proofs: new
  6630 'case' language element refers to local contexts symbolically, as
  6631 produced by certain proof methods; internally, case names are attached
  6632 to theorems as "tags";
  6633 
  6634 * Isar/Pure: theory command 'hide' removes declarations from
  6635 class/type/const name spaces;
  6636 
  6637 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  6638 indicate potential overloading;
  6639 
  6640 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  6641 
  6642 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  6643 "{a,b,c}" instead of {a,b,c};
  6644 
  6645 * Isar/Pure now provides its own version of intro/elim/dest
  6646 attributes; useful for building new logics, but beware of confusion
  6647 with the version in Provers/classical;
  6648 
  6649 * Isar/Pure: the local context of (non-atomic) goals is provided via
  6650 case name 'antecedent';
  6651 
  6652 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  6653 to the current context is now done automatically);
  6654 
  6655 * Isar/Pure: theory command 'method_setup' provides a simple interface
  6656 for definining proof methods in ML;
  6657 
  6658 * Isar/Provers: intro/elim/dest attributes changed; renamed
  6659 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  6660 most cases, one should have to change intro!! to intro? only);
  6661 replaced "delrule" by "rule del";
  6662 
  6663 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  6664 'symmetric' attribute (the latter supercedes [RS sym]);
  6665 
  6666 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  6667 method modifier); 'simp' method: 'only:' modifier removes loopers as
  6668 well (including splits);
  6669 
  6670 * Isar/Provers: Simplifier and Classical methods now support all kind
  6671 of modifiers used in the past, including 'cong', 'iff', etc.
  6672 
  6673 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  6674 of Simplifier and Classical reasoner);
  6675 
  6676 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  6677 now support named cases; major packages (inductive, datatype, primrec,
  6678 recdef) support case names and properly name parameters;
  6679 
  6680 * Isar/HOL: new transitivity rules for substitution in inequalities --
  6681 monotonicity conditions are extracted to be proven at end of
  6682 calculations;
  6683 
  6684 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  6685 method anyway;
  6686 
  6687 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  6688 split_if split_if_asm; datatype package provides theorems foo.splits =
  6689 foo.split foo.split_asm for each datatype;
  6690 
  6691 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  6692 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  6693 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  6694 use "(cases (simplified))" method in proper proof texts);
  6695 
  6696 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  6697 
  6698 * Isar: names of theorems etc. may be natural numbers as well;
  6699 
  6700 * Isar: 'pr' command: optional arguments for goals_limit and
  6701 ProofContext.prems_limit; no longer prints theory contexts, but only
  6702 proof states;
  6703 
  6704 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  6705 additional print modes to be specified; e.g. "pr(latex)" will print
  6706 proof state according to the Isabelle LaTeX style;
  6707 
  6708 * Isar: improved support for emulating tactic scripts, including proof
  6709 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  6710 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  6711 (for HOL datatypes);
  6712 
  6713 * Isar: simplified (more robust) goal selection of proof methods: 1st
  6714 goal, all goals, or explicit goal specifier (tactic emulation); thus
  6715 'proof method scripts' have to be in depth-first order;
  6716 
  6717 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  6718 
  6719 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  6720 should instead use individual commands for printing items
  6721 (print_commands, print_methods etc.);
  6722 
  6723 * Isar: added 'nothing' --- the empty list of theorems;
  6724 
  6725 
  6726 *** HOL ***
  6727 
  6728 * HOL/MicroJava: formalization of a fragment of Java, together with a
  6729 corresponding virtual machine and a specification of its bytecode
  6730 verifier and a lightweight bytecode verifier, including proofs of
  6731 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  6732 Cornelia Pusch (see also the homepage of project Bali at
  6733 http://isabelle.in.tum.de/Bali/);
  6734 
  6735 * HOL/Algebra: new theory of rings and univariate polynomials, by
  6736 Clemens Ballarin;
  6737 
  6738 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  6739 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  6740 Rasmussen;
  6741 
  6742 * HOL/Lattice: fundamental concepts of lattice theory and order
  6743 structures, including duals, properties of bounds versus algebraic
  6744 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  6745 Theorem for complete lattices etc.; may also serve as a demonstration
  6746 for abstract algebraic reasoning using axiomatic type classes, and
  6747 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  6748 
  6749 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  6750 von Oheimb;
  6751 
  6752 * HOL/IMPP: extension of IMP with local variables and mutually
  6753 recursive procedures, by David von Oheimb;
  6754 
  6755 * HOL/Lambda: converted into new-style theory and document;
  6756 
  6757 * HOL/ex/Multiquote: example of multiple nested quotations and
  6758 anti-quotations -- basically a generalized version of de-Bruijn
  6759 representation; very useful in avoiding lifting of operations;
  6760 
  6761 * HOL/record: added general record equality rule to simpset; fixed
  6762 select-update simplification procedure to handle extended records as
  6763 well; admit "r" as field name;
  6764 
  6765 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  6766 other numeric types and also as the identity of groups, rings, etc.;
  6767 
  6768 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  6769 Types nat and int belong to this axclass;
  6770 
  6771 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  6772    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  6773    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  6774   two terms #m*u and #n*u are replaced by #(m+n)*u
  6775     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  6776   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  6777     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  6778 
  6779 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  6780 powerful prover for predicate logic but knows nothing of clasets; see
  6781 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  6782 
  6783 * HOL: new version of "case_tac" subsumes both boolean case split and
  6784 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  6785 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  6786 
  6787 * HOL: simplification no longer dives into case-expressions: only the
  6788 selector expression is simplified, but not the remaining arms; to
  6789 enable full simplification of case-expressions for datatype t, you may
  6790 remove t.weak_case_cong from the simpset, either globally (Delcongs
  6791 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  6792 
  6793 * HOL/recdef: the recursion equations generated by 'recdef' for
  6794 function 'f' are now called f.simps instead of f.rules; if all
  6795 termination conditions are proved automatically, these simplification
  6796 rules are added to the simpset, as in primrec; rules may be named
  6797 individually as well, resulting in a separate list of theorems for
  6798 each equation;
  6799 
  6800 * HOL/While is a new theory that provides a while-combinator. It
  6801 permits the definition of tail-recursive functions without the
  6802 provision of a termination measure. The latter is necessary once the
  6803 invariant proof rule for while is applied.
  6804 
  6805 * HOL: new (overloaded) notation for the set of elements below/above
  6806 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  6807 
  6808 * HOL: theorems impI, allI, ballI bound as "strip";
  6809 
  6810 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  6811 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  6812 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  6813 
  6814 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  6815 
  6816 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  6817 main HOL, but was unused);
  6818 
  6819 * HOL: fewer consts declared as global (e.g. have to refer to
  6820 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  6821 
  6822 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  6823 in case of overlap with user translations (e.g. judgements over
  6824 tuples); (note that the underlying logical represenation is still
  6825 bogus);
  6826 
  6827 
  6828 *** ZF ***
  6829 
  6830 * ZF: simplification automatically cancels common terms in arithmetic
  6831 expressions over nat and int;
  6832 
  6833 * ZF: new treatment of nat to minimize type-checking: all operators
  6834 coerce their operands to a natural number using the function natify,
  6835 making the algebraic laws unconditional;
  6836 
  6837 * ZF: as above, for int: operators coerce their operands to an integer
  6838 using the function intify;
  6839 
  6840 * ZF: the integer library now contains many of the usual laws for the
  6841 orderings, including $<=, and monotonicity laws for $+ and $*;
  6842 
  6843 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  6844 simplification;
  6845 
  6846 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  6847 to the simplifier and classical reasoner simultaneously;
  6848 
  6849 
  6850 *** General ***
  6851 
  6852 * Provers: blast_tac now handles actual object-logic rules as
  6853 assumptions; note that auto_tac uses blast_tac internally as well;
  6854 
  6855 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  6856 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  6857 
  6858 * Provers: delrules now handles destruct rules as well (no longer need
  6859 explicit make_elim);
  6860 
  6861 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  6862   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  6863 use instead the strong form,
  6864   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  6865 in HOL, FOL and ZF the function cla_make_elim will create such rules
  6866 from destruct-rules;
  6867 
  6868 * Provers: Simplifier.easy_setup provides a fast path to basic
  6869 Simplifier setup for new object-logics;
  6870 
  6871 * Pure: AST translation rules no longer require constant head on LHS;
  6872 
  6873 * Pure: improved name spaces: ambiguous output is qualified; support
  6874 for hiding of names;
  6875 
  6876 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  6877 XSYMBOL_HOME; no longer need to do manual configuration in most
  6878 situations;
  6879 
  6880 * system: compression of ML heaps images may now be controlled via -c
  6881 option of isabelle and isatool usedir (currently only observed by
  6882 Poly/ML);
  6883 
  6884 * system: isatool installfonts may handle X-Symbol fonts as well (very
  6885 useful for remote X11);
  6886 
  6887 * system: provide TAGS file for Isabelle sources;
  6888 
  6889 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  6890 order;
  6891 
  6892 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  6893 timing flag supersedes proof_timing and Toplevel.trace;
  6894 
  6895 * ML: new combinators |>> and |>>> for incremental transformations
  6896 with secondary results (e.g. certain theory extensions):
  6897 
  6898 * ML: PureThy.add_defs gets additional argument to indicate potential
  6899 overloading (usually false);
  6900 
  6901 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  6902 results;
  6903 
  6904 
  6905 
  6906 New in Isabelle99 (October 1999)
  6907 --------------------------------
  6908 
  6909 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  6910 
  6911 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  6912 are no longer simplified.  (This allows the simplifier to unfold recursive
  6913 functional programs.)  To restore the old behaviour, declare
  6914 
  6915     Delcongs [if_weak_cong];
  6916 
  6917 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  6918 complement;
  6919 
  6920 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  6921 
  6922 * HOL/datatype: mutual_induct_tac no longer exists --
  6923   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  6924 
  6925 * HOL/typedef: fixed type inference for representing set; type
  6926 arguments now have to occur explicitly on the rhs as type constraints;
  6927 
  6928 * ZF: The con_defs part of an inductive definition may no longer refer
  6929 to constants declared in the same theory;
  6930 
  6931 * HOL, ZF: the function mk_cases, generated by the inductive
  6932 definition package, has lost an argument.  To simplify its result, it
  6933 uses the default simpset instead of a supplied list of theorems.
  6934 
  6935 * HOL/List: the constructors of type list are now Nil and Cons;
  6936 
  6937 * Simplifier: the type of the infix ML functions
  6938         setSSolver addSSolver setSolver addSolver
  6939 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  6940 for packaging solvers. A solver is created via
  6941         mk_solver: string -> (thm list -> int -> tactic) -> solver
  6942 where the string argument is only a comment.
  6943 
  6944 
  6945 *** Proof tools ***
  6946 
  6947 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  6948 decision procedure for linear arithmetic. Currently it is used for
  6949 types `nat', `int', and `real' in HOL (see below); it can, should and
  6950 will be instantiated for other types and logics as well.
  6951 
  6952 * The simplifier now accepts rewrite rules with flexible heads, eg
  6953      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  6954   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  6955   matching.
  6956 
  6957 
  6958 *** General ***
  6959 
  6960 * New Isabelle/Isar subsystem provides an alternative to traditional
  6961 tactical theorem proving; together with the ProofGeneral/isar user
  6962 interface it offers an interactive environment for developing human
  6963 readable proof documents (Isar == Intelligible semi-automated
  6964 reasoning); for further information see isatool doc isar-ref,
  6965 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  6966 
  6967 * improved and simplified presentation of theories: better HTML markup
  6968 (including colors), graph views in several sizes; isatool usedir now
  6969 provides a proper interface for user theories (via -P option); actual
  6970 document preparation based on (PDF)LaTeX is available as well (for
  6971 new-style theories only); see isatool doc system for more information;
  6972 
  6973 * native support for Proof General, both for classic Isabelle and
  6974 Isabelle/Isar;
  6975 
  6976 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  6977 using the graph browser tool;
  6978 
  6979 * Isabelle manuals now also available as PDF;
  6980 
  6981 * theory loader rewritten from scratch (may not be fully
  6982 bug-compatible); old loadpath variable has been replaced by show_path,
  6983 add_path, del_path, reset_path functions; new operations such as
  6984 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  6985 isatool doc ref);
  6986 
  6987 * improved isatool install: option -k creates KDE application icon,
  6988 option -p DIR installs standalone binaries;
  6989 
  6990 * added ML_PLATFORM setting (useful for cross-platform installations);
  6991 more robust handling of platform specific ML images for SML/NJ;
  6992 
  6993 * the settings environment is now statically scoped, i.e. it is never
  6994 created again in sub-processes invoked from isabelle, isatool, or
  6995 Isabelle;
  6996 
  6997 * path element specification '~~' refers to '$ISABELLE_HOME';
  6998 
  6999 * in locales, the "assumes" and "defines" parts may be omitted if
  7000 empty;
  7001 
  7002 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  7003 long arrows);
  7004 
  7005 * new print_mode "HTML";
  7006 
  7007 * new flag show_tags controls display of tags of theorems (which are
  7008 basically just comments that may be attached by some tools);
  7009 
  7010 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  7011 mode and goal output format:
  7012 
  7013 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  7014 244c244
  7015 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  7016 ---
  7017 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  7018 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  7019 181c181
  7020 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  7021 ---
  7022 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  7023 
  7024 * function bind_thms stores lists of theorems (cf. bind_thm);
  7025 
  7026 * new shorthand tactics ftac, eatac, datac, fatac;
  7027 
  7028 * qed (and friends) now accept "" as result name; in that case the
  7029 theorem is not stored, but proper checks and presentation of the
  7030 result still apply;
  7031 
  7032 * theorem database now also indexes constants "Trueprop", "all",
  7033 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  7034 
  7035 
  7036 *** HOL ***
  7037 
  7038 ** HOL arithmetic **
  7039 
  7040 * There are now decision procedures for linear arithmetic over nat and
  7041 int:
  7042 
  7043 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  7044 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  7045 are treated as atomic; subformulae not involving type `nat' or `int'
  7046 are ignored; quantified subformulae are ignored unless they are
  7047 positive universal or negative existential. The tactic has to be
  7048 invoked by hand and can be a little bit slow. In particular, the
  7049 running time is exponential in the number of occurrences of `min' and
  7050 `max', and `-' on `nat'.
  7051 
  7052 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  7053 (negated) (in)equalities among the premises and the conclusion into
  7054 account (i.e. no compound formulae) and does not know about `min' and
  7055 `max', and `-' on `nat'. It is fast and is used automatically by the
  7056 simplifier.
  7057 
  7058 NB: At the moment, these decision procedures do not cope with mixed
  7059 nat/int formulae where the two parts interact, such as `m < n ==>
  7060 int(m) < int(n)'.
  7061 
  7062 * HOL/Numeral provides a generic theory of numerals (encoded
  7063 efficiently as bit strings); setup for types nat/int/real is in place;
  7064 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  7065 int, existing theories and proof scripts may require a few additional
  7066 type constraints;
  7067 
  7068 * integer division and remainder can now be performed on constant
  7069 arguments;
  7070 
  7071 * many properties of integer multiplication, division and remainder
  7072 are now available;
  7073 
  7074 * An interface to the Stanford Validity Checker (SVC) is available through the
  7075 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  7076 are proved automatically.  SVC must be installed separately, and its results
  7077 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  7078 invocation of the underlying oracle).  For SVC see
  7079   http://verify.stanford.edu/SVC
  7080 
  7081 * IsaMakefile: the HOL-Real target now builds an actual image;
  7082 
  7083 
  7084 ** HOL misc **
  7085 
  7086 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  7087 (in Isabelle/Isar) -- by Gertrud Bauer;
  7088 
  7089 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  7090 analysis for assembly languages with subtypes;
  7091 
  7092 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  7093 -- avoids syntactic ambiguities and treats state, transition, and
  7094 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  7095 changed syntax and (many) tactics;
  7096 
  7097 * HOL/inductive: Now also handles more general introduction rules such
  7098   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  7099   theorems are now maintained within the theory (maintained via the
  7100   "mono" attribute);
  7101 
  7102 * HOL/datatype: Now also handles arbitrarily branching datatypes
  7103   (using function types) such as
  7104 
  7105   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  7106 
  7107 * HOL/record: record_simproc (part of the default simpset) takes care
  7108 of selectors applied to updated records; record_split_tac is no longer
  7109 part of the default claset; update_defs may now be removed from the
  7110 simpset in many cases; COMPATIBILITY: old behavior achieved by
  7111 
  7112   claset_ref () := claset() addSWrapper record_split_wrapper;
  7113   Delsimprocs [record_simproc]
  7114 
  7115 * HOL/typedef: fixed type inference for representing set; type
  7116 arguments now have to occur explicitly on the rhs as type constraints;
  7117 
  7118 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  7119 names rather than an ML expression;
  7120 
  7121 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  7122 supplied later.  Program schemes can be defined, such as
  7123     "While B C s = (if B s then While B C (C s) else s)"
  7124 where the well-founded relation can be chosen after B and C have been given.
  7125 
  7126 * HOL/List: the constructors of type list are now Nil and Cons;
  7127 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  7128 course, ML tools referring to List.list.op # etc. have to be adapted;
  7129 
  7130 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  7131 disabled by default; run isabelle with option -m HOL to get back to
  7132 the original Gordon/HOL-style output;
  7133 
  7134 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  7135 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  7136 
  7137 * HOL basic syntax simplified (more orthogonal): all variants of
  7138 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  7139 Eps operator is provided as well: "SOME x. P[x]";
  7140 
  7141 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  7142 
  7143 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  7144 thus available for user theories;
  7145 
  7146 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  7147 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  7148 time;
  7149 
  7150 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  7151 several times and then mp;
  7152 
  7153 
  7154 *** LK ***
  7155 
  7156 * the notation <<...>> is now available as a notation for sequences of
  7157 formulas;
  7158 
  7159 * the simplifier is now installed
  7160 
  7161 * the axiom system has been generalized (thanks to Soren Heilmann)
  7162 
  7163 * the classical reasoner now has a default rule database
  7164 
  7165 
  7166 *** ZF ***
  7167 
  7168 * new primrec section allows primitive recursive functions to be given
  7169 directly (as in HOL) over datatypes and the natural numbers;
  7170 
  7171 * new tactics induct_tac and exhaust_tac for induction (or case
  7172 analysis) over datatypes and the natural numbers;
  7173 
  7174 * the datatype declaration of type T now defines the recursor T_rec;
  7175 
  7176 * simplification automatically does freeness reasoning for datatype
  7177 constructors;
  7178 
  7179 * automatic type-inference, with AddTCs command to insert new
  7180 type-checking rules;
  7181 
  7182 * datatype introduction rules are now added as Safe Introduction rules
  7183 to the claset;
  7184 
  7185 * the syntax "if P then x else y" is now available in addition to
  7186 if(P,x,y);
  7187 
  7188 
  7189 *** Internal programming interfaces ***
  7190 
  7191 * tuned simplifier trace output; new flag debug_simp;
  7192 
  7193 * structures Vartab / Termtab (instances of TableFun) offer efficient
  7194 tables indexed by indexname_ord / term_ord (compatible with aconv);
  7195 
  7196 * AxClass.axclass_tac lost the theory argument;
  7197 
  7198 * tuned current_goals_markers semantics: begin / end goal avoids
  7199 printing empty lines;
  7200 
  7201 * removed prs and prs_fn hook, which was broken because it did not
  7202 include \n in its semantics, forcing writeln to add one
  7203 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  7204 string -> unit if you really want to output text without newline;
  7205 
  7206 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  7207 plain output, interface builders may have to enable 'isabelle_font'
  7208 mode to get Isabelle font glyphs as before;
  7209 
  7210 * refined token_translation interface; INCOMPATIBILITY: output length
  7211 now of type real instead of int;
  7212 
  7213 * theory loader actions may be traced via new ThyInfo.add_hook
  7214 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  7215 your own database of information attached to *whole* theories -- as
  7216 opposed to intra-theory data slots offered via TheoryDataFun;
  7217 
  7218 * proper handling of dangling sort hypotheses (at last!);
  7219 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  7220 extra sort hypotheses that can be witnessed from the type signature;
  7221 the force_strip_shyps flag is gone, any remaining shyps are simply
  7222 left in the theorem (with a warning issued by strip_shyps_warning);
  7223 
  7224 
  7225 
  7226 New in Isabelle98-1 (October 1998)
  7227 ----------------------------------
  7228 
  7229 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  7230 
  7231 * several changes of automated proof tools;
  7232 
  7233 * HOL: major changes to the inductive and datatype packages, including
  7234 some minor incompatibilities of theory syntax;
  7235 
  7236 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  7237 called `inj_on';
  7238 
  7239 * HOL: removed duplicate thms in Arith:
  7240   less_imp_add_less  should be replaced by  trans_less_add1
  7241   le_imp_add_le      should be replaced by  trans_le_add1
  7242 
  7243 * HOL: unary minus is now overloaded (new type constraints may be
  7244 required);
  7245 
  7246 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  7247 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  7248 now taken as an integer constant.
  7249 
  7250 * Pure: ML function 'theory_of' renamed to 'theory';
  7251 
  7252 
  7253 *** Proof tools ***
  7254 
  7255 * Simplifier:
  7256   1. Asm_full_simp_tac is now more aggressive.
  7257      1. It will sometimes reorient premises if that increases their power to
  7258         simplify.
  7259      2. It does no longer proceed strictly from left to right but may also
  7260         rotate premises to achieve further simplification.
  7261      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  7262      old Asm_full_simp_tac in that it does not rotate premises.
  7263   2. The simplifier now knows a little bit about nat-arithmetic.
  7264 
  7265 * Classical reasoner: wrapper mechanism for the classical reasoner now
  7266 allows for selected deletion of wrappers, by introduction of names for
  7267 wrapper functionals.  This implies that addbefore, addSbefore,
  7268 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  7269 and that adding two tactics with the same name overwrites the first
  7270 one (emitting a warning).
  7271   type wrapper = (int -> tactic) -> (int -> tactic)
  7272   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  7273   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  7274   delWrapper, delSWrapper: claset *  string            -> claset
  7275   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  7276 
  7277 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  7278 semantics; addbefore now affects only the unsafe part of step_tac
  7279 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  7280 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  7281 by Force_tac;
  7282 
  7283 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  7284 compWrapper; added safe wrapper (and access functions for it);
  7285 
  7286 * HOL/split_all_tac is now much faster and fails if there is nothing
  7287 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  7288 and the names of the automatically generated variables have changed.
  7289 split_all_tac has moved within claset() from unsafe wrappers to safe
  7290 wrappers, which means that !!-bound variables are split much more
  7291 aggressively, and safe_tac and clarify_tac now split such variables.
  7292 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  7293 Note: the same holds for record_split_tac, which does the job of
  7294 split_all_tac for record fields.
  7295 
  7296 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  7297 permanently to the default simpset using Addsplits just like
  7298 Addsimps. They can be removed via Delsplits just like
  7299 Delsimps. Lower-case versions are also available.
  7300 
  7301 * HOL/Simplifier: The rule split_if is now part of the default
  7302 simpset. This means that the simplifier will eliminate all occurrences
  7303 of if-then-else in the conclusion of a goal. To prevent this, you can
  7304 either remove split_if completely from the default simpset by
  7305 `Delsplits [split_if]' or remove it in a specific call of the
  7306 simplifier using `... delsplits [split_if]'.  You can also add/delete
  7307 other case splitting rules to/from the default simpset: every datatype
  7308 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  7309 t is the name of the datatype).
  7310 
  7311 * Classical reasoner / Simplifier combination: new force_tac (and
  7312 derivatives Force_tac, force) combines rewriting and classical
  7313 reasoning (and whatever other tools) similarly to auto_tac, but is
  7314 aimed to solve the given subgoal completely.
  7315 
  7316 
  7317 *** General ***
  7318 
  7319 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  7320 and `goalw': the theory is no longer needed as an explicit argument -
  7321 the current theory context is used; assumptions are no longer returned
  7322 at the ML-level unless one of them starts with ==> or !!; it is
  7323 recommended to convert to these new commands using isatool fixgoal
  7324 (backup your sources first!);
  7325 
  7326 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  7327 the current theory context, and 'theory' to lookup stored theories;
  7328 
  7329 * new theory section 'locale' for declaring constants, assumptions and
  7330 definitions that have local scope;
  7331 
  7332 * new theory section 'nonterminals' for purely syntactic types;
  7333 
  7334 * new theory section 'setup' for generic ML setup functions
  7335 (e.g. package initialization);
  7336 
  7337 * the distribution now includes Isabelle icons: see
  7338 lib/logo/isabelle-{small,tiny}.xpm;
  7339 
  7340 * isatool install - install binaries with absolute references to
  7341 ISABELLE_HOME/bin;
  7342 
  7343 * isatool logo -- create instances of the Isabelle logo (as EPS);
  7344 
  7345 * print mode 'emacs' reserved for Isamode;
  7346 
  7347 * support multiple print (ast) translations per constant name;
  7348 
  7349 * theorems involving oracles are now printed with a suffixed [!];
  7350 
  7351 
  7352 *** HOL ***
  7353 
  7354 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  7355 
  7356 * HOL/inductive package reorganized and improved: now supports mutual
  7357 definitions such as
  7358 
  7359   inductive EVEN ODD
  7360     intrs
  7361       null "0 : EVEN"
  7362       oddI "n : EVEN ==> Suc n : ODD"
  7363       evenI "n : ODD ==> Suc n : EVEN"
  7364 
  7365 new theorem list "elims" contains an elimination rule for each of the
  7366 recursive sets; inductive definitions now handle disjunctive premises
  7367 correctly (also ZF);
  7368 
  7369 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  7370 "mutual_induct" no longer exists - the induction rule is always
  7371 contained in "induct";
  7372 
  7373 
  7374 * HOL/datatype package re-implemented and greatly improved: now
  7375 supports mutually recursive datatypes such as
  7376 
  7377   datatype
  7378     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  7379             | SUM ('a aexp) ('a aexp)
  7380             | DIFF ('a aexp) ('a aexp)
  7381             | NUM 'a
  7382   and
  7383     'a bexp = LESS ('a aexp) ('a aexp)
  7384             | AND ('a bexp) ('a bexp)
  7385             | OR ('a bexp) ('a bexp)
  7386 
  7387 as well as indirectly recursive datatypes such as
  7388 
  7389   datatype
  7390     ('a, 'b) term = Var 'a
  7391                   | App 'b ((('a, 'b) term) list)
  7392 
  7393 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  7394 induction on mutually / indirectly recursive datatypes.
  7395 
  7396 Primrec equations are now stored in theory and can be accessed via
  7397 <function_name>.simps.
  7398 
  7399 INCOMPATIBILITIES:
  7400 
  7401   - Theories using datatypes must now have theory Datatype as an
  7402     ancestor.
  7403   - The specific <typename>.induct_tac no longer exists - use the
  7404     generic induct_tac instead.
  7405   - natE has been renamed to nat.exhaust - use exhaust_tac
  7406     instead of res_inst_tac ... natE. Note that the variable
  7407     names in nat.exhaust differ from the names in natE, this
  7408     may cause some "fragile" proofs to fail.
  7409   - The theorems split_<typename>_case and split_<typename>_case_asm
  7410     have been renamed to <typename>.split and <typename>.split_asm.
  7411   - Since default sorts of type variables are now handled correctly,
  7412     some datatype definitions may have to be annotated with explicit
  7413     sort constraints.
  7414   - Primrec definitions no longer require function name and type
  7415     of recursive argument.
  7416 
  7417 Consider using isatool fixdatatype to adapt your theories and proof
  7418 scripts to the new package (backup your sources first!).
  7419 
  7420 
  7421 * HOL/record package: considerably improved implementation; now
  7422 includes concrete syntax for record types, terms, updates; theorems
  7423 for surjective pairing and splitting !!-bound record variables; proof
  7424 support is as follows:
  7425 
  7426   1) standard conversions (selectors or updates applied to record
  7427 constructor terms) are part of the standard simpset;
  7428 
  7429   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  7430 made part of standard simpset and claset via addIffs;
  7431 
  7432   3) a tactic for record field splitting (record_split_tac) is part of
  7433 the standard claset (addSWrapper);
  7434 
  7435 To get a better idea about these rules you may retrieve them via
  7436 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  7437 the name of your record type.
  7438 
  7439 The split tactic 3) conceptually simplifies by the following rule:
  7440 
  7441   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  7442 
  7443 Thus any record variable that is bound by meta-all will automatically
  7444 blow up into some record constructor term, consequently the
  7445 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  7446 solve record problems automatically.
  7447 
  7448 
  7449 * reorganized the main HOL image: HOL/Integ and String loaded by
  7450 default; theory Main includes everything;
  7451 
  7452 * automatic simplification of integer sums and comparisons, using cancellation;
  7453 
  7454 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  7455 
  7456 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  7457 
  7458 * many new identities for unions, intersections, set difference, etc.;
  7459 
  7460 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  7461 called split_if, split_split, split_sum_case and split_nat_case (to go
  7462 with add/delsplits);
  7463 
  7464 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  7465 (?x::unit) = (); this is made part of the default simpset, which COULD
  7466 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  7467 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  7468 unit_abs_eta_conv is added in order to counter the effect of
  7469 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  7470 %u.f();
  7471 
  7472 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  7473 makes more sense);
  7474 
  7475 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  7476   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  7477   disjointness reasoning but breaking a few old proofs.
  7478 
  7479 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  7480 to 'converse' from 'inverse' (for compatibility with ZF and some
  7481 literature);
  7482 
  7483 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  7484 the well-founded relation;
  7485 
  7486 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  7487     Compl A.  The "Compl" syntax remains available as input syntax for this
  7488     release ONLY.
  7489 
  7490 * HOL/Update: new theory of function updates:
  7491     f(a:=b) == %x. if x=a then b else f x
  7492 may also be iterated as in f(a:=b,c:=d,...);
  7493 
  7494 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  7495 
  7496 * HOL/List:
  7497   - new function list_update written xs[i:=v] that updates the i-th
  7498     list position. May also be iterated as in xs[i:=a,j:=b,...].
  7499   - new function `upt' written [i..j(] which generates the list
  7500     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  7501     bound write [i..j], which is a shorthand for [i..j+1(].
  7502   - new lexicographic orderings and corresponding wellfoundedness theorems.
  7503 
  7504 * HOL/Arith:
  7505   - removed 'pred' (predecessor) function;
  7506   - generalized some theorems about n-1;
  7507   - many new laws about "div" and "mod";
  7508   - new laws about greatest common divisors (see theory ex/Primes);
  7509 
  7510 * HOL/Relation: renamed the relational operator r^-1 "converse"
  7511 instead of "inverse";
  7512 
  7513 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  7514   of the multiset ordering;
  7515 
  7516 * directory HOL/Real: a construction of the reals using Dedekind cuts
  7517   (not included by default);
  7518 
  7519 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  7520 
  7521 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  7522   programs, i.e. different program variables may have different types.
  7523 
  7524 * calling (stac rew i) now fails if "rew" has no effect on the goal
  7525   [previously, this check worked only if the rewrite rule was unconditional]
  7526   Now rew can involve either definitions or equalities (either == or =).
  7527 
  7528 
  7529 *** ZF ***
  7530 
  7531 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  7532   only the theorems proved on ZF.ML;
  7533 
  7534 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  7535   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  7536   disjointness reasoning but breaking a few old proofs.
  7537 
  7538 * ZF/Update: new theory of function updates
  7539     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  7540   may also be iterated as in f(a:=b,c:=d,...);
  7541 
  7542 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  7543 
  7544 * calling (stac rew i) now fails if "rew" has no effect on the goal
  7545   [previously, this check worked only if the rewrite rule was unconditional]
  7546   Now rew can involve either definitions or equalities (either == or =).
  7547 
  7548 * case_tac provided for compatibility with HOL
  7549     (like the old excluded_middle_tac, but with subgoals swapped)
  7550 
  7551 
  7552 *** Internal programming interfaces ***
  7553 
  7554 * Pure: several new basic modules made available for general use, see
  7555 also src/Pure/README;
  7556 
  7557 * improved the theory data mechanism to support encapsulation (data
  7558 kind name replaced by private Object.kind, acting as authorization
  7559 key); new type-safe user interface via functor TheoryDataFun; generic
  7560 print_data function becomes basically useless;
  7561 
  7562 * removed global_names compatibility flag -- all theory declarations
  7563 are qualified by default;
  7564 
  7565 * module Pure/Syntax now offers quote / antiquote translation
  7566 functions (useful for Hoare logic etc. with implicit dependencies);
  7567 see HOL/ex/Antiquote for an example use;
  7568 
  7569 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  7570 cterm -> thm;
  7571 
  7572 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  7573 subgoal;
  7574 
  7575 * Display.print_goals function moved to Locale.print_goals;
  7576 
  7577 * standard print function for goals supports current_goals_markers
  7578 variable for marking begin of proof, end of proof, start of goal; the
  7579 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  7580 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  7581 for example;
  7582 
  7583 
  7584 
  7585 New in Isabelle98 (January 1998)
  7586 --------------------------------
  7587 
  7588 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  7589 
  7590 * changed lexical syntax of terms / types: dots made part of long
  7591 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  7592 
  7593 * simpset (and claset) reference variable replaced by functions
  7594 simpset / simpset_ref;
  7595 
  7596 * no longer supports theory aliases (via merge) and non-trivial
  7597 implicit merge of thms' signatures;
  7598 
  7599 * most internal names of constants changed due to qualified names;
  7600 
  7601 * changed Pure/Sequence interface (see Pure/seq.ML);
  7602 
  7603 
  7604 *** General Changes ***
  7605 
  7606 * hierachically structured name spaces (for consts, types, axms, thms
  7607 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  7608 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  7609 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  7610 long_names for fully qualified output names; NOTE: ML programs
  7611 (special tactics, packages etc.) referring to internal names may have
  7612 to be adapted to cope with fully qualified names; in case of severe
  7613 backward campatibility problems try setting 'global_names' at compile
  7614 time to have enrything declared within a flat name space; one may also
  7615 fine tune name declarations in theories via the 'global' and 'local'
  7616 section;
  7617 
  7618 * reimplemented the implicit simpset and claset using the new anytype
  7619 data filed in signatures; references simpset:simpset ref etc. are
  7620 replaced by functions simpset:unit->simpset and
  7621 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  7622 to patch your ML files accordingly;
  7623 
  7624 * HTML output now includes theory graph data for display with Java
  7625 applet or isatool browser; data generated automatically via isatool
  7626 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  7627 
  7628 * defs may now be conditional; improved rewrite_goals_tac to handle
  7629 conditional equations;
  7630 
  7631 * defs now admits additional type arguments, using TYPE('a) syntax;
  7632 
  7633 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  7634 creates a new theory node; implicit merge of thms' signatures is
  7635 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  7636 transfer:theory->thm->thm in (rare) cases;
  7637 
  7638 * improved handling of draft signatures / theories; draft thms (and
  7639 ctyps, cterms) are automatically promoted to real ones;
  7640 
  7641 * slightly changed interfaces for oracles: admit many per theory, named
  7642 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  7643 
  7644 * print_goals: optional output of const types (set show_consts and
  7645 show_types);
  7646 
  7647 * improved output of warnings (###) and errors (***);
  7648 
  7649 * subgoal_tac displays a warning if the new subgoal has type variables;
  7650 
  7651 * removed old README and Makefiles;
  7652 
  7653 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  7654 
  7655 * removed obsolete init_pps and init_database;
  7656 
  7657 * deleted the obsolete tactical STATE, which was declared by
  7658     fun STATE tacfun st = tacfun st st;
  7659 
  7660 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  7661 (which abbreviates $HOME);
  7662 
  7663 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  7664 use isatool fixseq to adapt your ML programs (this works for fully
  7665 qualified references to the Sequence structure only!);
  7666 
  7667 * use_thy no longer requires writable current directory; it always
  7668 reloads .ML *and* .thy file, if either one is out of date;
  7669 
  7670 
  7671 *** Classical Reasoner ***
  7672 
  7673 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  7674 tactics that use classical reasoning to simplify a subgoal without
  7675 splitting it into several subgoals;
  7676 
  7677 * Safe_tac: like safe_tac but uses the default claset;
  7678 
  7679 
  7680 *** Simplifier ***
  7681 
  7682 * added simplification meta rules:
  7683     (asm_)(full_)simplify: simpset -> thm -> thm;
  7684 
  7685 * simplifier.ML no longer part of Pure -- has to be loaded by object
  7686 logics (again);
  7687 
  7688 * added prems argument to simplification procedures;
  7689 
  7690 * HOL, FOL, ZF: added infix function `addsplits':
  7691   instead of `<simpset> setloop (split_tac <thms>)'
  7692   you can simply write `<simpset> addsplits <thms>'
  7693 
  7694 
  7695 *** Syntax ***
  7696 
  7697 * TYPE('a) syntax for type reflection terms;
  7698 
  7699 * no longer handles consts with name "" -- declare as 'syntax' instead;
  7700 
  7701 * pretty printer: changed order of mixfix annotation preference (again!);
  7702 
  7703 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  7704 
  7705 
  7706 *** HOL ***
  7707 
  7708 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  7709   with `addloop' of the simplifier to faciliate case splitting in premises.
  7710 
  7711 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  7712 
  7713 * HOL/Auth: new protocol proofs including some for the Internet
  7714   protocol TLS;
  7715 
  7716 * HOL/Map: new theory of `maps' a la VDM;
  7717 
  7718 * HOL/simplifier: simplification procedures nat_cancel_sums for
  7719 cancelling out common nat summands from =, <, <= (in)equalities, or
  7720 differences; simplification procedures nat_cancel_factor for
  7721 cancelling common factor from =, <, <= (in)equalities over natural
  7722 sums; nat_cancel contains both kinds of procedures, it is installed by
  7723 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  7724 
  7725 * HOL/simplifier: terms of the form
  7726   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  7727   are rewritten to
  7728   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  7729   and those of the form
  7730   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  7731   are rewritten to
  7732   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  7733 
  7734 * HOL/datatype
  7735   Each datatype `t' now comes with a theorem `split_t_case' of the form
  7736 
  7737   P(t_case f1 ... fn x) =
  7738      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  7739         ...
  7740        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  7741      )
  7742 
  7743   and a theorem `split_t_case_asm' of the form
  7744 
  7745   P(t_case f1 ... fn x) =
  7746     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  7747         ...
  7748        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  7749      )
  7750   which can be added to a simpset via `addsplits'. The existing theorems
  7751   expand_list_case and expand_option_case have been renamed to
  7752   split_list_case and split_option_case.
  7753 
  7754 * HOL/Arithmetic:
  7755   - `pred n' is automatically converted to `n-1'.
  7756     Users are strongly encouraged not to use `pred' any longer,
  7757     because it will disappear altogether at some point.
  7758   - Users are strongly encouraged to write "0 < n" rather than
  7759     "n ~= 0". Theorems and proof tools have been modified towards this
  7760     `standard'.
  7761 
  7762 * HOL/Lists:
  7763   the function "set_of_list" has been renamed "set" (and its theorems too);
  7764   the function "nth" now takes its arguments in the reverse order and
  7765   has acquired the infix notation "!" as in "xs!n".
  7766 
  7767 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  7768 
  7769 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  7770   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  7771 
  7772 * HOL/record: extensible records with schematic structural subtyping
  7773 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  7774 still lacks various theorems and concrete record syntax;
  7775 
  7776 
  7777 *** HOLCF ***
  7778 
  7779 * removed "axioms" and "generated by" sections;
  7780 
  7781 * replaced "ops" section by extended "consts" section, which is capable of
  7782   handling the continuous function space "->" directly;
  7783 
  7784 * domain package:
  7785   . proves theorems immediately and stores them in the theory,
  7786   . creates hierachical name space,
  7787   . now uses normal mixfix annotations (instead of cinfix...),
  7788   . minor changes to some names and values (for consistency),
  7789   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  7790   . separator between mutual domain defs: changed "," to "and",
  7791   . improved handling of sort constraints;  now they have to
  7792     appear on the left-hand side of the equations only;
  7793 
  7794 * fixed LAM <x,y,zs>.b syntax;
  7795 
  7796 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  7797 adm (%x. P (t x)), where P is chainfinite and t continuous;
  7798 
  7799 
  7800 *** FOL and ZF ***
  7801 
  7802 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  7803   with `addloop' of the simplifier to faciliate case splitting in premises.
  7804 
  7805 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  7806 in HOL, they strip ALL and --> from proved theorems;
  7807 
  7808 
  7809 
  7810 New in Isabelle94-8 (May 1997)
  7811 ------------------------------
  7812 
  7813 *** General Changes ***
  7814 
  7815 * new utilities to build / run / maintain Isabelle etc. (in parts
  7816 still somewhat experimental); old Makefiles etc. still functional;
  7817 
  7818 * new 'Isabelle System Manual';
  7819 
  7820 * INSTALL text, together with ./configure and ./build scripts;
  7821 
  7822 * reimplemented type inference for greater efficiency, better error
  7823 messages and clean internal interface;
  7824 
  7825 * prlim command for dealing with lots of subgoals (an easier way of
  7826 setting goals_limit);
  7827 
  7828 
  7829 *** Syntax ***
  7830 
  7831 * supports alternative (named) syntax tables (parser and pretty
  7832 printer); internal interface is provided by add_modesyntax(_i);
  7833 
  7834 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  7835 be used in conjunction with the Isabelle symbol font; uses the
  7836 "symbols" syntax table;
  7837 
  7838 * added token_translation interface (may translate name tokens in
  7839 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  7840 the current print_mode); IMPORTANT: user print translation functions
  7841 are responsible for marking newly introduced bounds
  7842 (Syntax.mark_boundT);
  7843 
  7844 * token translations for modes "xterm" and "xterm_color" that display
  7845 names in bold, underline etc. or colors (which requires a color
  7846 version of xterm);
  7847 
  7848 * infixes may now be declared with names independent of their syntax;
  7849 
  7850 * added typed_print_translation (like print_translation, but may
  7851 access type of constant);
  7852 
  7853 
  7854 *** Classical Reasoner ***
  7855 
  7856 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  7857 some limitations.  Blast_tac...
  7858   + ignores addss, addbefore, addafter; this restriction is intrinsic
  7859   + ignores elimination rules that don't have the correct format
  7860         (the conclusion MUST be a formula variable)
  7861   + ignores types, which can make HOL proofs fail
  7862   + rules must not require higher-order unification, e.g. apply_type in ZF
  7863     [message "Function Var's argument not a bound variable" relates to this]
  7864   + its proof strategy is more general but can actually be slower
  7865 
  7866 * substitution with equality assumptions no longer permutes other
  7867 assumptions;
  7868 
  7869 * minor changes in semantics of addafter (now called addaltern); renamed
  7870 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  7871 (and access functions for it);
  7872 
  7873 * improved combination of classical reasoner and simplifier:
  7874   + functions for handling clasimpsets
  7875   + improvement of addss: now the simplifier is called _after_ the
  7876     safe steps.
  7877   + safe variant of addss called addSss: uses safe simplifications
  7878     _during_ the safe steps. It is more complete as it allows multiple
  7879     instantiations of unknowns (e.g. with slow_tac).
  7880 
  7881 *** Simplifier ***
  7882 
  7883 * added interface for simplification procedures (functions that
  7884 produce *proven* rewrite rules on the fly, depending on current
  7885 redex);
  7886 
  7887 * ordering on terms as parameter (used for ordered rewriting);
  7888 
  7889 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  7890 
  7891 * the solver is now split into a safe and an unsafe part.
  7892 This should be invisible for the normal user, except that the
  7893 functions setsolver and addsolver have been renamed to setSolver and
  7894 addSolver; added safe_asm_full_simp_tac;
  7895 
  7896 
  7897 *** HOL ***
  7898 
  7899 * a generic induction tactic `induct_tac' which works for all datatypes and
  7900 also for type `nat';
  7901 
  7902 * a generic case distinction tactic `exhaust_tac' which works for all
  7903 datatypes and also for type `nat';
  7904 
  7905 * each datatype comes with a function `size';
  7906 
  7907 * patterns in case expressions allow tuple patterns as arguments to
  7908 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  7909 
  7910 * primrec now also works with type nat;
  7911 
  7912 * recdef: a new declaration form, allows general recursive functions to be
  7913 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  7914 
  7915 * the constant for negation has been renamed from "not" to "Not" to
  7916 harmonize with FOL, ZF, LK, etc.;
  7917 
  7918 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  7919 infinite lists;
  7920 
  7921 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  7922 
  7923 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  7924 problems in commutative rings, using axiomatic type classes for + and *;
  7925 
  7926 * more examples in HOL/MiniML and HOL/Auth;
  7927 
  7928 * more default rewrite rules for quantifiers, union/intersection;
  7929 
  7930 * a new constant `arbitrary == @x.False';
  7931 
  7932 * HOLCF/IOA replaces old HOL/IOA;
  7933 
  7934 * HOLCF changes: derived all rules and arities
  7935   + axiomatic type classes instead of classes
  7936   + typedef instead of faking type definitions
  7937   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  7938   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  7939   + eliminated the types void, one, tr
  7940   + use unit lift and bool lift (with translations) instead of one and tr
  7941   + eliminated blift from Lift3.thy (use Def instead of blift)
  7942   all eliminated rules are derived as theorems --> no visible changes ;
  7943 
  7944 
  7945 *** ZF ***
  7946 
  7947 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  7948 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  7949 as ZF_cs addSIs [equalityI];
  7950 
  7951 
  7952 
  7953 New in Isabelle94-7 (November 96)
  7954 ---------------------------------
  7955 
  7956 * allowing negative levels (as offsets) in prlev and choplev;
  7957 
  7958 * super-linear speedup for large simplifications;
  7959 
  7960 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  7961 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  7962 FAIL); can suppress it using the command Delsimps (ex_simps @
  7963 all_simps); De Morgan laws are also now included, by default;
  7964 
  7965 * improved printing of ==>  :  ~:
  7966 
  7967 * new object-logic "Sequents" adds linear logic, while replacing LK
  7968 and Modal (thanks to Sara Kalvala);
  7969 
  7970 * HOL/Auth: correctness proofs for authentication protocols;
  7971 
  7972 * HOL: new auto_tac combines rewriting and classical reasoning (many
  7973 examples on HOL/Auth);
  7974 
  7975 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  7976 the rewriter and classical reasoner simultaneously;
  7977 
  7978 * function uresult no longer returns theorems in "standard" format;
  7979 regain previous version by: val uresult = standard o uresult;
  7980 
  7981 
  7982 
  7983 New in Isabelle94-6
  7984 -------------------
  7985 
  7986 * oracles -- these establish an interface between Isabelle and trusted
  7987 external reasoners, which may deliver results as theorems;
  7988 
  7989 * proof objects (in particular record all uses of oracles);
  7990 
  7991 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  7992 
  7993 * "constdefs" section in theory files;
  7994 
  7995 * "primrec" section (HOL) no longer requires names;
  7996 
  7997 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  7998 
  7999 
  8000 
  8001 New in Isabelle94-5
  8002 -------------------
  8003 
  8004 * reduced space requirements;
  8005 
  8006 * automatic HTML generation from theories;
  8007 
  8008 * theory files no longer require "..." (quotes) around most types;
  8009 
  8010 * new examples, including two proofs of the Church-Rosser theorem;
  8011 
  8012 * non-curried (1994) version of HOL is no longer distributed;
  8013 
  8014 
  8015 
  8016 New in Isabelle94-4
  8017 -------------------
  8018 
  8019 * greatly reduced space requirements;
  8020 
  8021 * theory files (.thy) no longer require \...\ escapes at line breaks;
  8022 
  8023 * searchable theorem database (see the section "Retrieving theorems" on
  8024 page 8 of the Reference Manual);
  8025 
  8026 * new examples, including Grabczewski's monumental case study of the
  8027 Axiom of Choice;
  8028 
  8029 * The previous version of HOL renamed to Old_HOL;
  8030 
  8031 * The new version of HOL (previously called CHOL) uses a curried syntax
  8032 for functions.  Application looks like f a b instead of f(a,b);
  8033 
  8034 * Mutually recursive inductive definitions finally work in HOL;
  8035 
  8036 * In ZF, pattern-matching on tuples is now available in all abstractions and
  8037 translates to the operator "split";
  8038 
  8039 
  8040 
  8041 New in Isabelle94-3
  8042 -------------------
  8043 
  8044 * new infix operator, addss, allowing the classical reasoner to
  8045 perform simplification at each step of its search.  Example:
  8046         fast_tac (cs addss ss)
  8047 
  8048 * a new logic, CHOL, the same as HOL, but with a curried syntax
  8049 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  8050 look like (a,b) instead of <a,b>;
  8051 
  8052 * PLEASE NOTE: CHOL will eventually replace HOL!
  8053 
  8054 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  8055 It translates to the operator "split".  A new theory of integers is available;
  8056 
  8057 * In ZF, integer numerals now denote two's-complement binary integers.
  8058 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  8059 
  8060 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  8061 of the Axiom of Choice;
  8062 
  8063 
  8064 
  8065 New in Isabelle94-2
  8066 -------------------
  8067 
  8068 * Significantly faster resolution;
  8069 
  8070 * the different sections in a .thy file can now be mixed and repeated
  8071 freely;
  8072 
  8073 * Database of theorems for FOL, HOL and ZF.  New
  8074 commands including qed, qed_goal and bind_thm store theorems in the database.
  8075 
  8076 * Simple database queries: return a named theorem (get_thm) or all theorems of
  8077 a given theory (thms_of), or find out what theory a theorem was proved in
  8078 (theory_of_thm);
  8079 
  8080 * Bugs fixed in the inductive definition and datatype packages;
  8081 
  8082 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  8083 and HOL_dup_cs obsolete;
  8084 
  8085 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  8086 have been removed;
  8087 
  8088 * Simpler definition of function space in ZF;
  8089 
  8090 * new results about cardinal and ordinal arithmetic in ZF;
  8091 
  8092 * 'subtype' facility in HOL for introducing new types as subsets of existing
  8093 types;
  8094 
  8095 :mode=text:wrap=hard:maxLineLen=72: