NEWS
author krauss
Fri Feb 25 16:57:43 2011 +0100 (2011-02-25)
changeset 41844 b933142e02d0
parent 41792 ff3cb0c418b7
child 41846 b368a7aee46a
permissions -rw-r--r--
generalize find_theorems filters to work on raw propositions, too
     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   - Renamed attribute: nitpick_def ~> nitpick_unfold.
    24     INCOMPATIBILITY.
    25 
    26 * Sledgehammer:
    27   - sledgehammer available_provers ~> sledgehammer supported_provers
    28     INCOMPATIBILITY.
    29 
    30 
    31 *** Document preparation ***
    32 
    33 * New term style "isub" as ad-hoc conversion of variables x1, y23 into
    34 subscripted form x\<^isub>1, y\<^isub>2\<^isub>3.
    35 
    36 
    37 
    38 New in Isabelle2011 (January 2011)
    39 ----------------------------------
    40 
    41 *** General ***
    42 
    43 * Experimental Prover IDE based on Isabelle/Scala and jEdit (see
    44 src/Tools/jEdit).  This also serves as IDE for Isabelle/ML, with
    45 useful tooltips and hyperlinks produced from its static analysis.  The
    46 bundled component provides an executable Isabelle tool that can be run
    47 like this:
    48 
    49   Isabelle2011/bin/isabelle jedit
    50 
    51 * Significantly improved Isabelle/Isar implementation manual.
    52 
    53 * System settings: ISABELLE_HOME_USER now includes ISABELLE_IDENTIFIER
    54 (and thus refers to something like $HOME/.isabelle/Isabelle2011),
    55 while the default heap location within that directory lacks that extra
    56 suffix.  This isolates multiple Isabelle installations from each
    57 other, avoiding problems with old settings in new versions.
    58 INCOMPATIBILITY, need to copy/upgrade old user settings manually.
    59 
    60 * Source files are always encoded as UTF-8, instead of old-fashioned
    61 ISO-Latin-1.  INCOMPATIBILITY.  Isabelle LaTeX documents might require
    62 the following package declarations:
    63 
    64   \usepackage[utf8]{inputenc}
    65   \usepackage{textcomp}
    66 
    67 * Explicit treatment of UTF-8 sequences as Isabelle symbols, such that
    68 a Unicode character is treated as a single symbol, not a sequence of
    69 non-ASCII bytes as before.  Since Isabelle/ML string literals may
    70 contain symbols without further backslash escapes, Unicode can now be
    71 used here as well.  Recall that Symbol.explode in ML provides a
    72 consistent view on symbols, while raw explode (or String.explode)
    73 merely give a byte-oriented representation.
    74 
    75 * Theory loader: source files are primarily located via the master
    76 directory of each theory node (where the .thy file itself resides).
    77 The global load path is still partially available as legacy feature.
    78 Minor INCOMPATIBILITY due to subtle change in file lookup: use
    79 explicit paths, relatively to the theory.
    80 
    81 * Special treatment of ML file names has been discontinued.
    82 Historically, optional extensions .ML or .sml were added on demand --
    83 at the cost of clarity of file dependencies.  Recall that Isabelle/ML
    84 files exclusively use the .ML extension.  Minor INCOMPATIBILTY.
    85 
    86 * Various options that affect pretty printing etc. are now properly
    87 handled within the context via configuration options, instead of
    88 unsynchronized references or print modes.  There are both ML Config.T
    89 entities and Isar declaration attributes to access these.
    90 
    91   ML (Config.T)                 Isar (attribute)
    92 
    93   eta_contract                  eta_contract
    94   show_brackets                 show_brackets
    95   show_sorts                    show_sorts
    96   show_types                    show_types
    97   show_question_marks           show_question_marks
    98   show_consts                   show_consts
    99   show_abbrevs                  show_abbrevs
   100 
   101   Syntax.ast_trace              syntax_ast_trace
   102   Syntax.ast_stat               syntax_ast_stat
   103   Syntax.ambiguity_level        syntax_ambiguity_level
   104 
   105   Goal_Display.goals_limit      goals_limit
   106   Goal_Display.show_main_goal   show_main_goal
   107 
   108   Method.rule_trace             rule_trace
   109 
   110   Thy_Output.display            thy_output_display
   111   Thy_Output.quotes             thy_output_quotes
   112   Thy_Output.indent             thy_output_indent
   113   Thy_Output.source             thy_output_source
   114   Thy_Output.break              thy_output_break
   115 
   116 Note that corresponding "..._default" references in ML may only be
   117 changed globally at the ROOT session setup, but *not* within a theory.
   118 The option "show_abbrevs" supersedes the former print mode
   119 "no_abbrevs" with inverted meaning.
   120 
   121 * More systematic naming of some configuration options.
   122 INCOMPATIBILITY.
   123 
   124   trace_simp  ~>  simp_trace
   125   debug_simp  ~>  simp_debug
   126 
   127 * Support for real valued configuration options, using simplistic
   128 floating-point notation that coincides with the inner syntax for
   129 float_token.
   130 
   131 * Support for real valued preferences (with approximative PGIP type):
   132 front-ends need to accept "pgint" values in float notation.
   133 INCOMPATIBILITY.
   134 
   135 * The IsabelleText font now includes Cyrillic, Hebrew, Arabic from
   136 DejaVu Sans.
   137 
   138 * Discontinued support for Poly/ML 5.0 and 5.1 versions.
   139 
   140 
   141 *** Pure ***
   142 
   143 * Command 'type_synonym' (with single argument) replaces somewhat
   144 outdated 'types', which is still available as legacy feature for some
   145 time.
   146 
   147 * Command 'nonterminal' (with 'and' separated list of arguments)
   148 replaces somewhat outdated 'nonterminals'.  INCOMPATIBILITY.
   149 
   150 * Command 'notepad' replaces former 'example_proof' for
   151 experimentation in Isar without any result.  INCOMPATIBILITY.
   152 
   153 * Locale interpretation commands 'interpret' and 'sublocale' accept
   154 lists of equations to map definitions in a locale to appropriate
   155 entities in the context of the interpretation.  The 'interpretation'
   156 command already provided this functionality.
   157 
   158 * Diagnostic command 'print_dependencies' prints the locale instances
   159 that would be activated if the specified expression was interpreted in
   160 the current context.  Variant "print_dependencies!" assumes a context
   161 without interpretations.
   162 
   163 * Diagnostic command 'print_interps' prints interpretations in proofs
   164 in addition to interpretations in theories.
   165 
   166 * Discontinued obsolete 'global' and 'local' commands to manipulate
   167 the theory name space.  Rare INCOMPATIBILITY.  The ML functions
   168 Sign.root_path and Sign.local_path may be applied directly where this
   169 feature is still required for historical reasons.
   170 
   171 * Discontinued obsolete 'constdefs' command.  INCOMPATIBILITY, use
   172 'definition' instead.
   173 
   174 * The "prems" fact, which refers to the accidental collection of
   175 foundational premises in the context, is now explicitly marked as
   176 legacy feature and will be discontinued soon.  Consider using "assms"
   177 of the head statement or reference facts by explicit names.
   178 
   179 * Document antiquotations @{class} and @{type} print classes and type
   180 constructors.
   181 
   182 * Document antiquotation @{file} checks file/directory entries within
   183 the local file system.
   184 
   185 
   186 *** HOL ***
   187 
   188 * Coercive subtyping: functions can be declared as coercions and type
   189 inference will add them as necessary upon input of a term.  Theory
   190 Complex_Main declares real :: nat => real and real :: int => real as
   191 coercions. A coercion function f is declared like this:
   192 
   193   declare [[coercion f]]
   194 
   195 To lift coercions through type constructors (e.g. from nat => real to
   196 nat list => real list), map functions can be declared, e.g.
   197 
   198   declare [[coercion_map map]]
   199 
   200 Currently coercion inference is activated only in theories including
   201 real numbers, i.e. descendants of Complex_Main.  This is controlled by
   202 the configuration option "coercion_enabled", e.g. it can be enabled in
   203 other theories like this:
   204 
   205   declare [[coercion_enabled]]
   206 
   207 * Command 'partial_function' provides basic support for recursive
   208 function definitions over complete partial orders.  Concrete instances
   209 are provided for i) the option type, ii) tail recursion on arbitrary
   210 types, and iii) the heap monad of Imperative_HOL.  See
   211 src/HOL/ex/Fundefs.thy and src/HOL/Imperative_HOL/ex/Linked_Lists.thy
   212 for examples.
   213 
   214 * Function package: f.psimps rules are no longer implicitly declared
   215 as [simp].  INCOMPATIBILITY.
   216 
   217 * Datatype package: theorems generated for executable equality (class
   218 "eq") carry proper names and are treated as default code equations.
   219 
   220 * Inductive package: now offers command 'inductive_simps' to
   221 automatically derive instantiated and simplified equations for
   222 inductive predicates, similar to 'inductive_cases'.
   223 
   224 * Command 'enriched_type' allows to register properties of the
   225 functorial structure of types.
   226 
   227 * Improved infrastructure for term evaluation using code generator
   228 techniques, in particular static evaluation conversions.
   229 
   230 * Code generator: Scala (2.8 or higher) has been added to the target
   231 languages.
   232 
   233 * Code generator: globbing constant expressions "*" and "Theory.*"
   234 have been replaced by the more idiomatic "_" and "Theory._".
   235 INCOMPATIBILITY.
   236 
   237 * Code generator: export_code without explicit file declaration prints
   238 to standard output.  INCOMPATIBILITY.
   239 
   240 * Code generator: do not print function definitions for case
   241 combinators any longer.
   242 
   243 * Code generator: simplification with rules determined with
   244 src/Tools/Code/code_simp.ML and method "code_simp".
   245 
   246 * Code generator for records: more idiomatic representation of record
   247 types.  Warning: records are not covered by ancient SML code
   248 generation any longer.  INCOMPATIBILITY.  In cases of need, a suitable
   249 rep_datatype declaration helps to succeed then:
   250 
   251   record 'a foo = ...
   252   ...
   253   rep_datatype foo_ext ...
   254 
   255 * Records: logical foundation type for records does not carry a
   256 '_type' suffix any longer (obsolete due to authentic syntax).
   257 INCOMPATIBILITY.
   258 
   259 * Quickcheck now by default uses exhaustive testing instead of random
   260 testing.  Random testing can be invoked by "quickcheck [random]",
   261 exhaustive testing by "quickcheck [exhaustive]".
   262 
   263 * Quickcheck instantiates polymorphic types with small finite
   264 datatypes by default. This enables a simple execution mechanism to
   265 handle quantifiers and function equality over the finite datatypes.
   266 
   267 * Quickcheck random generator has been renamed from "code" to
   268 "random".  INCOMPATIBILITY.
   269 
   270 * Quickcheck now has a configurable time limit which is set to 30
   271 seconds by default. This can be changed by adding [timeout = n] to the
   272 quickcheck command. The time limit for Auto Quickcheck is still set
   273 independently.
   274 
   275 * Quickcheck in locales considers interpretations of that locale for
   276 counter example search.
   277 
   278 * Sledgehammer:
   279   - Added "smt" and "remote_smt" provers based on the "smt" proof
   280     method. See the Sledgehammer manual for details ("isabelle doc
   281     sledgehammer").
   282   - Renamed commands:
   283     sledgehammer atp_info ~> sledgehammer running_provers
   284     sledgehammer atp_kill ~> sledgehammer kill_provers
   285     sledgehammer available_atps ~> sledgehammer available_provers
   286     INCOMPATIBILITY.
   287   - Renamed options:
   288     sledgehammer [atps = ...] ~> sledgehammer [provers = ...]
   289     sledgehammer [atp = ...] ~> sledgehammer [prover = ...]
   290     sledgehammer [timeout = 77 s] ~> sledgehammer [timeout = 77]
   291     (and "ms" and "min" are no longer supported)
   292     INCOMPATIBILITY.
   293 
   294 * Nitpick:
   295   - Renamed options:
   296     nitpick [timeout = 77 s] ~> nitpick [timeout = 77]
   297     nitpick [tac_timeout = 777 ms] ~> nitpick [tac_timeout = 0.777]
   298     INCOMPATIBILITY.
   299   - Added support for partial quotient types.
   300   - Added local versions of the "Nitpick.register_xxx" functions.
   301   - Added "whack" option.
   302   - Allow registration of quotient types as codatatypes.
   303   - Improved "merge_type_vars" option to merge more types.
   304   - Removed unsound "fast_descrs" option.
   305   - Added custom symmetry breaking for datatypes, making it possible to reach
   306     higher cardinalities.
   307   - Prevent the expansion of too large definitions.
   308 
   309 * Proof methods "metis" and "meson" now have configuration options
   310 "meson_trace", "metis_trace", and "metis_verbose" that can be enabled
   311 to diagnose these tools. E.g.
   312 
   313     using [[metis_trace = true]]
   314 
   315 * Auto Solve: Renamed "Auto Solve Direct".  The tool is now available
   316 manually as command 'solve_direct'.
   317 
   318 * The default SMT solver Z3 must be enabled explicitly (due to
   319 licensing issues) by setting the environment variable
   320 Z3_NON_COMMERCIAL in etc/settings of the component, for example.  For
   321 commercial applications, the SMT solver CVC3 is provided as fall-back;
   322 changing the SMT solver is done via the configuration option
   323 "smt_solver".
   324 
   325 * Remote SMT solvers need to be referred to by the "remote_" prefix,
   326 i.e. "remote_cvc3" and "remote_z3".
   327 
   328 * Added basic SMT support for datatypes, records, and typedefs using
   329 the oracle mode (no proofs).  Direct support of pairs has been dropped
   330 in exchange (pass theorems fst_conv snd_conv pair_collapse to the SMT
   331 support for a similar behavior).  Minor INCOMPATIBILITY.
   332 
   333 * Changed SMT configuration options:
   334   - Renamed:
   335     z3_proofs ~> smt_oracle (with inverted meaning)
   336     z3_trace_assms ~> smt_trace_used_facts
   337     INCOMPATIBILITY.
   338   - Added:
   339     smt_verbose
   340     smt_random_seed
   341     smt_datatypes
   342     smt_infer_triggers
   343     smt_monomorph_limit
   344     cvc3_options
   345     remote_cvc3_options
   346     remote_z3_options
   347     yices_options
   348 
   349 * Boogie output files (.b2i files) need to be declared in the theory
   350 header.
   351 
   352 * Simplification procedure "list_to_set_comprehension" rewrites list
   353 comprehensions applied to List.set to set comprehensions.  Occasional
   354 INCOMPATIBILITY, may be deactivated like this:
   355 
   356   declare [[simproc del: list_to_set_comprehension]]
   357 
   358 * Removed old version of primrec package.  INCOMPATIBILITY.
   359 
   360 * Removed simplifier congruence rule of "prod_case", as has for long
   361 been the case with "split".  INCOMPATIBILITY.
   362 
   363 * String.literal is a type, but not a datatype.  INCOMPATIBILITY.
   364 
   365 * Removed [split_format ... and ... and ...] version of
   366 [split_format].  Potential INCOMPATIBILITY.
   367 
   368 * Predicate "sorted" now defined inductively, with nice induction
   369 rules.  INCOMPATIBILITY: former sorted.simps now named sorted_simps.
   370 
   371 * Constant "contents" renamed to "the_elem", to free the generic name
   372 contents for other uses.  INCOMPATIBILITY.
   373 
   374 * Renamed class eq and constant eq (for code generation) to class
   375 equal and constant equal, plus renaming of related facts and various
   376 tuning.  INCOMPATIBILITY.
   377 
   378 * Dropped type classes mult_mono and mult_mono1.  INCOMPATIBILITY.
   379 
   380 * Removed output syntax "'a ~=> 'b" for "'a => 'b option".
   381 INCOMPATIBILITY.
   382 
   383 * Renamed theory Fset to Cset, type Fset.fset to Cset.set, in order to
   384 avoid confusion with finite sets.  INCOMPATIBILITY.
   385 
   386 * Abandoned locales equiv, congruent and congruent2 for equivalence
   387 relations.  INCOMPATIBILITY: use equivI rather than equiv_intro (same
   388 for congruent(2)).
   389 
   390 * Some previously unqualified names have been qualified:
   391 
   392   types
   393     bool ~> HOL.bool
   394     nat ~> Nat.nat
   395 
   396   constants
   397     Trueprop ~> HOL.Trueprop
   398     True ~> HOL.True
   399     False ~> HOL.False
   400     op & ~> HOL.conj
   401     op | ~> HOL.disj
   402     op --> ~> HOL.implies
   403     op = ~> HOL.eq
   404     Not ~> HOL.Not
   405     The ~> HOL.The
   406     All ~> HOL.All
   407     Ex ~> HOL.Ex
   408     Ex1 ~> HOL.Ex1
   409     Let ~> HOL.Let
   410     If ~> HOL.If
   411     Ball ~> Set.Ball
   412     Bex ~> Set.Bex
   413     Suc ~> Nat.Suc
   414     Pair ~> Product_Type.Pair
   415     fst ~> Product_Type.fst
   416     snd ~> Product_Type.snd
   417     curry ~> Product_Type.curry
   418     op : ~> Set.member
   419     Collect ~> Set.Collect
   420 
   421 INCOMPATIBILITY.
   422 
   423 * More canonical naming convention for some fundamental definitions:
   424 
   425     bot_bool_eq ~> bot_bool_def
   426     top_bool_eq ~> top_bool_def
   427     inf_bool_eq ~> inf_bool_def
   428     sup_bool_eq ~> sup_bool_def
   429     bot_fun_eq  ~> bot_fun_def
   430     top_fun_eq  ~> top_fun_def
   431     inf_fun_eq  ~> inf_fun_def
   432     sup_fun_eq  ~> sup_fun_def
   433 
   434 INCOMPATIBILITY.
   435 
   436 * More stylized fact names:
   437 
   438   expand_fun_eq ~> fun_eq_iff
   439   expand_set_eq ~> set_eq_iff
   440   set_ext       ~> set_eqI
   441   nat_number    ~> eval_nat_numeral
   442 
   443 INCOMPATIBILITY.
   444 
   445 * Refactoring of code-generation specific operations in theory List:
   446 
   447   constants
   448     null ~> List.null
   449 
   450   facts
   451     mem_iff ~> member_def
   452     null_empty ~> null_def
   453 
   454 INCOMPATIBILITY.  Note that these were not supposed to be used
   455 regularly unless for striking reasons; their main purpose was code
   456 generation.
   457 
   458 Various operations from the Haskell prelude are used for generating
   459 Haskell code.
   460 
   461 * Term "bij f" is now an abbreviation of "bij_betw f UNIV UNIV".  Term
   462 "surj f" is now an abbreviation of "range f = UNIV".  The theorems
   463 bij_def and surj_def are unchanged.  INCOMPATIBILITY.
   464 
   465 * Abolished some non-alphabetic type names: "prod" and "sum" replace
   466 "*" and "+" respectively.  INCOMPATIBILITY.
   467 
   468 * Name "Plus" of disjoint sum operator "<+>" is now hidden.  Write
   469 "Sum_Type.Plus" instead.
   470 
   471 * Constant "split" has been merged with constant "prod_case"; names of
   472 ML functions, facts etc. involving split have been retained so far,
   473 though.  INCOMPATIBILITY.
   474 
   475 * Dropped old infix syntax "_ mem _" for List.member; use "_ : set _"
   476 instead.  INCOMPATIBILITY.
   477 
   478 * Removed lemma "Option.is_none_none" which duplicates "is_none_def".
   479 INCOMPATIBILITY.
   480 
   481 * Former theory Library/Enum is now part of the HOL-Main image.
   482 INCOMPATIBILITY: all constants of the Enum theory now have to be
   483 referred to by its qualified name.
   484 
   485   enum    ~>  Enum.enum
   486   nlists  ~>  Enum.nlists
   487   product ~>  Enum.product
   488 
   489 * Theory Library/Monad_Syntax provides do-syntax for monad types.
   490 Syntax in Library/State_Monad has been changed to avoid ambiguities.
   491 INCOMPATIBILITY.
   492 
   493 * Theory Library/SetsAndFunctions has been split into
   494 Library/Function_Algebras and Library/Set_Algebras; canonical names
   495 for instance definitions for functions; various improvements.
   496 INCOMPATIBILITY.
   497 
   498 * Theory Library/Multiset provides stable quicksort implementation of
   499 sort_key.
   500 
   501 * Theory Library/Multiset: renamed empty_idemp ~> empty_neutral.
   502 INCOMPATIBILITY.
   503 
   504 * Session Multivariate_Analysis: introduced a type class for euclidean
   505 space.  Most theorems are now stated in terms of euclidean spaces
   506 instead of finite cartesian products.
   507 
   508   types
   509     real ^ 'n ~>  'a::real_vector
   510               ~>  'a::euclidean_space
   511               ~>  'a::ordered_euclidean_space
   512         (depends on your needs)
   513 
   514   constants
   515      _ $ _        ~> _ $$ _
   516      \<chi> x. _  ~> \<chi>\<chi> x. _
   517      CARD('n)     ~> DIM('a)
   518 
   519 Also note that the indices are now natural numbers and not from some
   520 finite type. Finite cartesian products of euclidean spaces, products
   521 of euclidean spaces the real and complex numbers are instantiated to
   522 be euclidean_spaces.  INCOMPATIBILITY.
   523 
   524 * Session Probability: introduced pextreal as positive extended real
   525 numbers.  Use pextreal as value for measures.  Introduce the
   526 Radon-Nikodym derivative, product spaces and Fubini's theorem for
   527 arbitrary sigma finite measures.  Introduces Lebesgue measure based on
   528 the integral in Multivariate Analysis.  INCOMPATIBILITY.
   529 
   530 * Session Imperative_HOL: revamped, corrected dozens of inadequacies.
   531 INCOMPATIBILITY.
   532 
   533 * Session SPARK (with image HOL-SPARK) provides commands to load and
   534 prove verification conditions generated by the SPARK Ada program
   535 verifier.  See also src/HOL/SPARK and src/HOL/SPARK/Examples.
   536 
   537 
   538 *** HOL-Algebra ***
   539 
   540 * Theorems for additive ring operations (locale abelian_monoid and
   541 descendants) are generated by interpretation from their multiplicative
   542 counterparts.  Names (in particular theorem names) have the mandatory
   543 qualifier 'add'.  Previous theorem names are redeclared for
   544 compatibility.
   545 
   546 * Structure "int_ring" is now an abbreviation (previously a
   547 definition).  This fits more natural with advanced interpretations.
   548 
   549 
   550 *** HOLCF ***
   551 
   552 * The domain package now runs in definitional mode by default: The
   553 former command 'new_domain' is now called 'domain'.  To use the domain
   554 package in its original axiomatic mode, use 'domain (unsafe)'.
   555 INCOMPATIBILITY.
   556 
   557 * The new class "domain" is now the default sort.  Class "predomain"
   558 is an unpointed version of "domain". Theories can be updated by
   559 replacing sort annotations as shown below.  INCOMPATIBILITY.
   560 
   561   'a::type ~> 'a::countable
   562   'a::cpo  ~> 'a::predomain
   563   'a::pcpo ~> 'a::domain
   564 
   565 * The old type class "rep" has been superseded by class "domain".
   566 Accordingly, users of the definitional package must remove any
   567 "default_sort rep" declarations.  INCOMPATIBILITY.
   568 
   569 * The domain package (definitional mode) now supports unpointed
   570 predomain argument types, as long as they are marked 'lazy'. (Strict
   571 arguments must be in class "domain".) For example, the following
   572 domain definition now works:
   573 
   574   domain natlist = nil | cons (lazy "nat discr") (lazy "natlist")
   575 
   576 * Theory HOLCF/Library/HOL_Cpo provides cpo and predomain class
   577 instances for types from main HOL: bool, nat, int, char, 'a + 'b,
   578 'a option, and 'a list.  Additionally, it configures fixrec and the
   579 domain package to work with these types.  For example:
   580 
   581   fixrec isInl :: "('a + 'b) u -> tr"
   582     where "isInl$(up$(Inl x)) = TT" | "isInl$(up$(Inr y)) = FF"
   583 
   584   domain V = VFun (lazy "V -> V") | VCon (lazy "nat") (lazy "V list")
   585 
   586 * The "(permissive)" option of fixrec has been replaced with a
   587 per-equation "(unchecked)" option. See
   588 src/HOL/HOLCF/Tutorial/Fixrec_ex.thy for examples. INCOMPATIBILITY.
   589 
   590 * The "bifinite" class no longer fixes a constant "approx"; the class
   591 now just asserts that such a function exists.  INCOMPATIBILITY.
   592 
   593 * Former type "alg_defl" has been renamed to "defl".  HOLCF no longer
   594 defines an embedding of type 'a defl into udom by default; instances
   595 of "bifinite" and "domain" classes are available in
   596 src/HOL/HOLCF/Library/Defl_Bifinite.thy.
   597 
   598 * The syntax "REP('a)" has been replaced with "DEFL('a)".
   599 
   600 * The predicate "directed" has been removed.  INCOMPATIBILITY.
   601 
   602 * The type class "finite_po" has been removed.  INCOMPATIBILITY.
   603 
   604 * The function "cprod_map" has been renamed to "prod_map".
   605 INCOMPATIBILITY.
   606 
   607 * The monadic bind operator on each powerdomain has new binder syntax
   608 similar to sets, e.g. "\<Union>\<sharp>x\<in>xs. t" represents
   609 "upper_bind\<cdot>xs\<cdot>(\<Lambda> x. t)".
   610 
   611 * The infix syntax for binary union on each powerdomain has changed
   612 from e.g. "+\<sharp>" to "\<union>\<sharp>", for consistency with set
   613 syntax.  INCOMPATIBILITY.
   614 
   615 * The constant "UU" has been renamed to "bottom".  The syntax "UU" is
   616 still supported as an input translation.
   617 
   618 * Renamed some theorems (the original names are also still available).
   619 
   620   expand_fun_below   ~> fun_below_iff
   621   below_fun_ext      ~> fun_belowI
   622   expand_cfun_eq     ~> cfun_eq_iff
   623   ext_cfun           ~> cfun_eqI
   624   expand_cfun_below  ~> cfun_below_iff
   625   below_cfun_ext     ~> cfun_belowI
   626   cont2cont_Rep_CFun ~> cont2cont_APP
   627 
   628 * The Abs and Rep functions for various types have changed names.
   629 Related theorem names have also changed to match. INCOMPATIBILITY.
   630 
   631   Rep_CFun  ~> Rep_cfun
   632   Abs_CFun  ~> Abs_cfun
   633   Rep_Sprod ~> Rep_sprod
   634   Abs_Sprod ~> Abs_sprod
   635   Rep_Ssum  ~> Rep_ssum
   636   Abs_Ssum  ~> Abs_ssum
   637 
   638 * Lemmas with names of the form *_defined_iff or *_strict_iff have
   639 been renamed to *_bottom_iff.  INCOMPATIBILITY.
   640 
   641 * Various changes to bisimulation/coinduction with domain package:
   642 
   643   - Definitions of "bisim" constants no longer mention definedness.
   644   - With mutual recursion, "bisim" predicate is now curried.
   645   - With mutual recursion, each type gets a separate coind theorem.
   646   - Variable names in bisim_def and coinduct rules have changed.
   647 
   648 INCOMPATIBILITY.
   649 
   650 * Case combinators generated by the domain package for type "foo" are
   651 now named "foo_case" instead of "foo_when".  INCOMPATIBILITY.
   652 
   653 * Several theorems have been renamed to more accurately reflect the
   654 names of constants and types involved.  INCOMPATIBILITY.
   655 
   656   thelub_const    ~> lub_const
   657   lub_const       ~> is_lub_const
   658   thelubI         ~> lub_eqI
   659   is_lub_lub      ~> is_lubD2
   660   lubI            ~> is_lub_lub
   661   unique_lub      ~> is_lub_unique
   662   is_ub_lub       ~> is_lub_rangeD1
   663   lub_bin_chain   ~> is_lub_bin_chain
   664   lub_fun         ~> is_lub_fun
   665   thelub_fun      ~> lub_fun
   666   thelub_cfun     ~> lub_cfun
   667   thelub_Pair     ~> lub_Pair
   668   lub_cprod       ~> is_lub_prod
   669   thelub_cprod    ~> lub_prod
   670   minimal_cprod   ~> minimal_prod
   671   inst_cprod_pcpo ~> inst_prod_pcpo
   672   UU_I            ~> bottomI
   673   compact_UU      ~> compact_bottom
   674   deflation_UU    ~> deflation_bottom
   675   finite_deflation_UU ~> finite_deflation_bottom
   676 
   677 * Many legacy theorem names have been discontinued.  INCOMPATIBILITY.
   678 
   679   sq_ord_less_eq_trans ~> below_eq_trans
   680   sq_ord_eq_less_trans ~> eq_below_trans
   681   refl_less            ~> below_refl
   682   trans_less           ~> below_trans
   683   antisym_less         ~> below_antisym
   684   antisym_less_inverse ~> po_eq_conv [THEN iffD1]
   685   box_less             ~> box_below
   686   rev_trans_less       ~> rev_below_trans
   687   not_less2not_eq      ~> not_below2not_eq
   688   less_UU_iff          ~> below_UU_iff
   689   flat_less_iff        ~> flat_below_iff
   690   adm_less             ~> adm_below
   691   adm_not_less         ~> adm_not_below
   692   adm_compact_not_less ~> adm_compact_not_below
   693   less_fun_def         ~> below_fun_def
   694   expand_fun_less      ~> fun_below_iff
   695   less_fun_ext         ~> fun_belowI
   696   less_discr_def       ~> below_discr_def
   697   discr_less_eq        ~> discr_below_eq
   698   less_unit_def        ~> below_unit_def
   699   less_cprod_def       ~> below_prod_def
   700   prod_lessI           ~> prod_belowI
   701   Pair_less_iff        ~> Pair_below_iff
   702   fst_less_iff         ~> fst_below_iff
   703   snd_less_iff         ~> snd_below_iff
   704   expand_cfun_less     ~> cfun_below_iff
   705   less_cfun_ext        ~> cfun_belowI
   706   injection_less       ~> injection_below
   707   less_up_def          ~> below_up_def
   708   not_Iup_less         ~> not_Iup_below
   709   Iup_less             ~> Iup_below
   710   up_less              ~> up_below
   711   Def_inject_less_eq   ~> Def_below_Def
   712   Def_less_is_eq       ~> Def_below_iff
   713   spair_less_iff       ~> spair_below_iff
   714   less_sprod           ~> below_sprod
   715   spair_less           ~> spair_below
   716   sfst_less_iff        ~> sfst_below_iff
   717   ssnd_less_iff        ~> ssnd_below_iff
   718   fix_least_less       ~> fix_least_below
   719   dist_less_one        ~> dist_below_one
   720   less_ONE             ~> below_ONE
   721   ONE_less_iff         ~> ONE_below_iff
   722   less_sinlD           ~> below_sinlD
   723   less_sinrD           ~> below_sinrD
   724 
   725 
   726 *** FOL and ZF ***
   727 
   728 * All constant names are now qualified internally and use proper
   729 identifiers, e.g. "IFOL.eq" instead of "op =".  INCOMPATIBILITY.
   730 
   731 
   732 *** ML ***
   733 
   734 * Antiquotation @{assert} inlines a function bool -> unit that raises
   735 Fail if the argument is false.  Due to inlining the source position of
   736 failed assertions is included in the error output.
   737 
   738 * Discontinued antiquotation @{theory_ref}, which is obsolete since ML
   739 text is in practice always evaluated with a stable theory checkpoint.
   740 Minor INCOMPATIBILITY, use (Theory.check_thy @{theory}) instead.
   741 
   742 * Antiquotation @{theory A} refers to theory A from the ancestry of
   743 the current context, not any accidental theory loader state as before.
   744 Potential INCOMPATIBILITY, subtle change in semantics.
   745 
   746 * Syntax.pretty_priority (default 0) configures the required priority
   747 of pretty-printed output and thus affects insertion of parentheses.
   748 
   749 * Syntax.default_root (default "any") configures the inner syntax
   750 category (nonterminal symbol) for parsing of terms.
   751 
   752 * Former exception Library.UnequalLengths now coincides with
   753 ListPair.UnequalLengths.
   754 
   755 * Renamed structure MetaSimplifier to Raw_Simplifier.  Note that the
   756 main functionality is provided by structure Simplifier.
   757 
   758 * Renamed raw "explode" function to "raw_explode" to emphasize its
   759 meaning.  Note that internally to Isabelle, Symbol.explode is used in
   760 almost all situations.
   761 
   762 * Discontinued obsolete function sys_error and exception SYS_ERROR.
   763 See implementation manual for further details on exceptions in
   764 Isabelle/ML.
   765 
   766 * Renamed setmp_noncritical to Unsynchronized.setmp to emphasize its
   767 meaning.
   768 
   769 * Renamed structure PureThy to Pure_Thy and moved most of its
   770 operations to structure Global_Theory, to emphasize that this is
   771 rarely-used global-only stuff.
   772 
   773 * Discontinued Output.debug.  Minor INCOMPATIBILITY, use plain writeln
   774 instead (or tracing for high-volume output).
   775 
   776 * Configuration option show_question_marks only affects regular pretty
   777 printing of types and terms, not raw Term.string_of_vname.
   778 
   779 * ML_Context.thm and ML_Context.thms are no longer pervasive.  Rare
   780 INCOMPATIBILITY, superseded by static antiquotations @{thm} and
   781 @{thms} for most purposes.
   782 
   783 * ML structure Unsynchronized is never opened, not even in Isar
   784 interaction mode as before.  Old Unsynchronized.set etc. have been
   785 discontinued -- use plain := instead.  This should be *rare* anyway,
   786 since modern tools always work via official context data, notably
   787 configuration options.
   788 
   789 * Parallel and asynchronous execution requires special care concerning
   790 interrupts.  Structure Exn provides some convenience functions that
   791 avoid working directly with raw Interrupt.  User code must not absorb
   792 interrupts -- intermediate handling (for cleanup etc.) needs to be
   793 followed by re-raising of the original exception.  Another common
   794 source of mistakes are "handle _" patterns, which make the meaning of
   795 the program subject to physical effects of the environment.
   796 
   797 
   798 
   799 New in Isabelle2009-2 (June 2010)
   800 ---------------------------------
   801 
   802 *** General ***
   803 
   804 * Authentic syntax for *all* logical entities (type classes, type
   805 constructors, term constants): provides simple and robust
   806 correspondence between formal entities and concrete syntax.  Within
   807 the parse tree / AST representations, "constants" are decorated by
   808 their category (class, type, const) and spelled out explicitly with
   809 their full internal name.
   810 
   811 Substantial INCOMPATIBILITY concerning low-level syntax declarations
   812 and translations (translation rules and translation functions in ML).
   813 Some hints on upgrading:
   814 
   815   - Many existing uses of 'syntax' and 'translations' can be replaced
   816     by more modern 'type_notation', 'notation' and 'abbreviation',
   817     which are independent of this issue.
   818 
   819   - 'translations' require markup within the AST; the term syntax
   820     provides the following special forms:
   821 
   822       CONST c   -- produces syntax version of constant c from context
   823       XCONST c  -- literally c, checked as constant from context
   824       c         -- literally c, if declared by 'syntax'
   825 
   826     Plain identifiers are treated as AST variables -- occasionally the
   827     system indicates accidental variables via the error "rhs contains
   828     extra variables".
   829 
   830     Type classes and type constructors are marked according to their
   831     concrete syntax.  Some old translations rules need to be written
   832     for the "type" category, using type constructor application
   833     instead of pseudo-term application of the default category
   834     "logic".
   835 
   836   - 'parse_translation' etc. in ML may use the following
   837     antiquotations:
   838 
   839       @{class_syntax c}   -- type class c within parse tree / AST
   840       @{term_syntax c}    -- type constructor c within parse tree / AST
   841       @{const_syntax c}   -- ML version of "CONST c" above
   842       @{syntax_const c}   -- literally c (checked wrt. 'syntax' declarations)
   843 
   844   - Literal types within 'typed_print_translations', i.e. those *not*
   845     represented as pseudo-terms are represented verbatim.  Use @{class
   846     c} or @{type_name c} here instead of the above syntax
   847     antiquotations.
   848 
   849 Note that old non-authentic syntax was based on unqualified base
   850 names, so all of the above "constant" names would coincide.  Recall
   851 that 'print_syntax' and ML_command "set Syntax.trace_ast" help to
   852 diagnose syntax problems.
   853 
   854 * Type constructors admit general mixfix syntax, not just infix.
   855 
   856 * Concrete syntax may be attached to local entities without a proof
   857 body, too.  This works via regular mixfix annotations for 'fix',
   858 'def', 'obtain' etc. or via the explicit 'write' command, which is
   859 similar to the 'notation' command in theory specifications.
   860 
   861 * Discontinued unnamed infix syntax (legacy feature for many years) --
   862 need to specify constant name and syntax separately.  Internal ML
   863 datatype constructors have been renamed from InfixName to Infix etc.
   864 Minor INCOMPATIBILITY.
   865 
   866 * Schematic theorem statements need to be explicitly markup as such,
   867 via commands 'schematic_lemma', 'schematic_theorem',
   868 'schematic_corollary'.  Thus the relevance of the proof is made
   869 syntactically clear, which impacts performance in a parallel or
   870 asynchronous interactive environment.  Minor INCOMPATIBILITY.
   871 
   872 * Use of cumulative prems via "!" in some proof methods has been
   873 discontinued (old legacy feature).
   874 
   875 * References 'trace_simp' and 'debug_simp' have been replaced by
   876 configuration options stored in the context. Enabling tracing (the
   877 case of debugging is similar) in proofs works via
   878 
   879   using [[trace_simp = true]]
   880 
   881 Tracing is then active for all invocations of the simplifier in
   882 subsequent goal refinement steps. Tracing may also still be enabled or
   883 disabled via the ProofGeneral settings menu.
   884 
   885 * Separate commands 'hide_class', 'hide_type', 'hide_const',
   886 'hide_fact' replace the former 'hide' KIND command.  Minor
   887 INCOMPATIBILITY.
   888 
   889 * Improved parallelism of proof term normalization: usedir -p2 -q0 is
   890 more efficient than combinations with -q1 or -q2.
   891 
   892 
   893 *** Pure ***
   894 
   895 * Proofterms record type-class reasoning explicitly, using the
   896 "unconstrain" operation internally.  This eliminates all sort
   897 constraints from a theorem and proof, introducing explicit
   898 OFCLASS-premises.  On the proof term level, this operation is
   899 automatically applied at theorem boundaries, such that closed proofs
   900 are always free of sort constraints.  INCOMPATIBILITY for tools that
   901 inspect proof terms.
   902 
   903 * Local theory specifications may depend on extra type variables that
   904 are not present in the result type -- arguments TYPE('a) :: 'a itself
   905 are added internally.  For example:
   906 
   907   definition unitary :: bool where "unitary = (ALL (x::'a) y. x = y)"
   908 
   909 * Predicates of locales introduced by classes carry a mandatory
   910 "class" prefix.  INCOMPATIBILITY.
   911 
   912 * Vacuous class specifications observe default sort.  INCOMPATIBILITY.
   913 
   914 * Old 'axclass' command has been discontinued.  INCOMPATIBILITY, use
   915 'class' instead.
   916 
   917 * Command 'code_reflect' allows to incorporate generated ML code into
   918 runtime environment; replaces immature code_datatype antiquotation.
   919 INCOMPATIBILITY.
   920 
   921 * Code generator: simple concept for abstract datatypes obeying
   922 invariants.
   923 
   924 * Code generator: details of internal data cache have no impact on the
   925 user space functionality any longer.
   926 
   927 * Methods "unfold_locales" and "intro_locales" ignore non-locale
   928 subgoals.  This is more appropriate for interpretations with 'where'.
   929 INCOMPATIBILITY.
   930 
   931 * Command 'example_proof' opens an empty proof body.  This allows to
   932 experiment with Isar, without producing any persistent result.
   933 
   934 * Commands 'type_notation' and 'no_type_notation' declare type syntax
   935 within a local theory context, with explicit checking of the
   936 constructors involved (in contrast to the raw 'syntax' versions).
   937 
   938 * Commands 'types' and 'typedecl' now work within a local theory
   939 context -- without introducing dependencies on parameters or
   940 assumptions, which is not possible in Isabelle/Pure.
   941 
   942 * Command 'defaultsort' has been renamed to 'default_sort', it works
   943 within a local theory context.  Minor INCOMPATIBILITY.
   944 
   945 
   946 *** HOL ***
   947 
   948 * Command 'typedef' now works within a local theory context -- without
   949 introducing dependencies on parameters or assumptions, which is not
   950 possible in Isabelle/Pure/HOL.  Note that the logical environment may
   951 contain multiple interpretations of local typedefs (with different
   952 non-emptiness proofs), even in a global theory context.
   953 
   954 * New package for quotient types.  Commands 'quotient_type' and
   955 'quotient_definition' may be used for defining types and constants by
   956 quotient constructions.  An example is the type of integers created by
   957 quotienting pairs of natural numbers:
   958 
   959   fun
   960     intrel :: "(nat * nat) => (nat * nat) => bool"
   961   where
   962     "intrel (x, y) (u, v) = (x + v = u + y)"
   963 
   964   quotient_type int = "nat * nat" / intrel
   965     by (auto simp add: equivp_def expand_fun_eq)
   966 
   967   quotient_definition
   968     "0::int" is "(0::nat, 0::nat)"
   969 
   970 The method "lifting" can be used to lift of theorems from the
   971 underlying "raw" type to the quotient type.  The example
   972 src/HOL/Quotient_Examples/FSet.thy includes such a quotient
   973 construction and provides a reasoning infrastructure for finite sets.
   974 
   975 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
   976 clash with new theory Quotient in Main HOL.
   977 
   978 * Moved the SMT binding into the main HOL session, eliminating
   979 separate HOL-SMT session.
   980 
   981 * List membership infix mem operation is only an input abbreviation.
   982 INCOMPATIBILITY.
   983 
   984 * Theory Library/Word.thy has been removed.  Use library Word/Word.thy
   985 for future developements; former Library/Word.thy is still present in
   986 the AFP entry RSAPPS.
   987 
   988 * Theorem Int.int_induct renamed to Int.int_of_nat_induct and is no
   989 longer shadowed.  INCOMPATIBILITY.
   990 
   991 * Dropped theorem duplicate comp_arith; use semiring_norm instead.
   992 INCOMPATIBILITY.
   993 
   994 * Dropped theorem RealPow.real_sq_order; use power2_le_imp_le instead.
   995 INCOMPATIBILITY.
   996 
   997 * Dropped normalizing_semiring etc; use the facts in semiring classes
   998 instead.  INCOMPATIBILITY.
   999 
  1000 * Dropped several real-specific versions of lemmas about floor and
  1001 ceiling; use the generic lemmas from theory "Archimedean_Field"
  1002 instead.  INCOMPATIBILITY.
  1003 
  1004   floor_number_of_eq         ~> floor_number_of
  1005   le_floor_eq_number_of      ~> number_of_le_floor
  1006   le_floor_eq_zero           ~> zero_le_floor
  1007   le_floor_eq_one            ~> one_le_floor
  1008   floor_less_eq_number_of    ~> floor_less_number_of
  1009   floor_less_eq_zero         ~> floor_less_zero
  1010   floor_less_eq_one          ~> floor_less_one
  1011   less_floor_eq_number_of    ~> number_of_less_floor
  1012   less_floor_eq_zero         ~> zero_less_floor
  1013   less_floor_eq_one          ~> one_less_floor
  1014   floor_le_eq_number_of      ~> floor_le_number_of
  1015   floor_le_eq_zero           ~> floor_le_zero
  1016   floor_le_eq_one            ~> floor_le_one
  1017   floor_subtract_number_of   ~> floor_diff_number_of
  1018   floor_subtract_one         ~> floor_diff_one
  1019   ceiling_number_of_eq       ~> ceiling_number_of
  1020   ceiling_le_eq_number_of    ~> ceiling_le_number_of
  1021   ceiling_le_zero_eq         ~> ceiling_le_zero
  1022   ceiling_le_eq_one          ~> ceiling_le_one
  1023   less_ceiling_eq_number_of  ~> number_of_less_ceiling
  1024   less_ceiling_eq_zero       ~> zero_less_ceiling
  1025   less_ceiling_eq_one        ~> one_less_ceiling
  1026   ceiling_less_eq_number_of  ~> ceiling_less_number_of
  1027   ceiling_less_eq_zero       ~> ceiling_less_zero
  1028   ceiling_less_eq_one        ~> ceiling_less_one
  1029   le_ceiling_eq_number_of    ~> number_of_le_ceiling
  1030   le_ceiling_eq_zero         ~> zero_le_ceiling
  1031   le_ceiling_eq_one          ~> one_le_ceiling
  1032   ceiling_subtract_number_of ~> ceiling_diff_number_of
  1033   ceiling_subtract_one       ~> ceiling_diff_one
  1034 
  1035 * Theory "Finite_Set": various folding_XXX locales facilitate the
  1036 application of the various fold combinators on finite sets.
  1037 
  1038 * Library theory "RBT" renamed to "RBT_Impl"; new library theory "RBT"
  1039 provides abstract red-black tree type which is backed by "RBT_Impl" as
  1040 implementation.  INCOMPATIBILTY.
  1041 
  1042 * Theory Library/Coinductive_List has been removed -- superseded by
  1043 AFP/thys/Coinductive.
  1044 
  1045 * Theory PReal, including the type "preal" and related operations, has
  1046 been removed.  INCOMPATIBILITY.
  1047 
  1048 * Real: new development using Cauchy Sequences.
  1049 
  1050 * Split off theory "Big_Operators" containing setsum, setprod,
  1051 Inf_fin, Sup_fin, Min, Max from theory Finite_Set.  INCOMPATIBILITY.
  1052 
  1053 * Theory "Rational" renamed to "Rat", for consistency with "Nat",
  1054 "Int" etc.  INCOMPATIBILITY.
  1055 
  1056 * Constant Rat.normalize needs to be qualified.  INCOMPATIBILITY.
  1057 
  1058 * New set of rules "ac_simps" provides combined assoc / commute
  1059 rewrites for all interpretations of the appropriate generic locales.
  1060 
  1061 * Renamed theory "OrderedGroup" to "Groups" and split theory
  1062 "Ring_and_Field" into theories "Rings" and "Fields"; for more
  1063 appropriate and more consistent names suitable for name prefixes
  1064 within the HOL theories.  INCOMPATIBILITY.
  1065 
  1066 * Some generic constants have been put to appropriate theories:
  1067   - less_eq, less: Orderings
  1068   - zero, one, plus, minus, uminus, times, abs, sgn: Groups
  1069   - inverse, divide: Rings
  1070 INCOMPATIBILITY.
  1071 
  1072 * More consistent naming of type classes involving orderings (and
  1073 lattices):
  1074 
  1075     lower_semilattice                   ~> semilattice_inf
  1076     upper_semilattice                   ~> semilattice_sup
  1077 
  1078     dense_linear_order                  ~> dense_linorder
  1079 
  1080     pordered_ab_group_add               ~> ordered_ab_group_add
  1081     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
  1082     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
  1083     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
  1084     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
  1085     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
  1086     pordered_cancel_semiring            ~> ordered_cancel_semiring
  1087     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
  1088     pordered_comm_ring                  ~> ordered_comm_ring
  1089     pordered_comm_semiring              ~> ordered_comm_semiring
  1090     pordered_ring                       ~> ordered_ring
  1091     pordered_ring_abs                   ~> ordered_ring_abs
  1092     pordered_semiring                   ~> ordered_semiring
  1093 
  1094     ordered_ab_group_add                ~> linordered_ab_group_add
  1095     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
  1096     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
  1097     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
  1098     ordered_field                       ~> linordered_field
  1099     ordered_field_no_lb                 ~> linordered_field_no_lb
  1100     ordered_field_no_ub                 ~> linordered_field_no_ub
  1101     ordered_field_dense_linear_order    ~> dense_linordered_field
  1102     ordered_idom                        ~> linordered_idom
  1103     ordered_ring                        ~> linordered_ring
  1104     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
  1105     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
  1106     ordered_ring_strict                 ~> linordered_ring_strict
  1107     ordered_semidom                     ~> linordered_semidom
  1108     ordered_semiring                    ~> linordered_semiring
  1109     ordered_semiring_1                  ~> linordered_semiring_1
  1110     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
  1111     ordered_semiring_strict             ~> linordered_semiring_strict
  1112 
  1113   The following slightly odd type classes have been moved to a
  1114   separate theory Library/Lattice_Algebras:
  1115 
  1116     lordered_ab_group_add               ~> lattice_ab_group_add
  1117     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
  1118     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
  1119     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
  1120     lordered_ring                       ~> lattice_ring
  1121 
  1122 INCOMPATIBILITY.
  1123 
  1124 * Refined field classes:
  1125   - classes division_ring_inverse_zero, field_inverse_zero,
  1126     linordered_field_inverse_zero include rule inverse 0 = 0 --
  1127     subsumes former division_by_zero class;
  1128   - numerous lemmas have been ported from field to division_ring.
  1129 INCOMPATIBILITY.
  1130 
  1131 * Refined algebra theorem collections:
  1132   - dropped theorem group group_simps, use algebra_simps instead;
  1133   - dropped theorem group ring_simps, use field_simps instead;
  1134   - proper theorem collection field_simps subsumes former theorem
  1135     groups field_eq_simps and field_simps;
  1136   - dropped lemma eq_minus_self_iff which is a duplicate for
  1137     equal_neg_zero.
  1138 INCOMPATIBILITY.
  1139 
  1140 * Theory Finite_Set and List: some lemmas have been generalized from
  1141 sets to lattices:
  1142 
  1143   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
  1144   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
  1145   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
  1146   union_Union_fold_union        ~> sup_Sup_fold_sup
  1147   Inter_fold_inter              ~> Inf_fold_inf
  1148   Union_fold_union              ~> Sup_fold_sup
  1149   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
  1150   union_UNION_fold_union        ~> sup_SUPR_fold_sup
  1151   INTER_fold_inter              ~> INFI_fold_inf
  1152   UNION_fold_union              ~> SUPR_fold_sup
  1153 
  1154 * Theory "Complete_Lattice": lemmas top_def and bot_def have been
  1155 replaced by the more convenient lemmas Inf_empty and Sup_empty.
  1156 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
  1157 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
  1158 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
  1159 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
  1160 
  1161 * Reorganized theory Multiset: swapped notation of pointwise and
  1162 multiset order:
  1163 
  1164   - pointwise ordering is instance of class order with standard syntax
  1165     <= and <;
  1166   - multiset ordering has syntax <=# and <#; partial order properties
  1167     are provided by means of interpretation with prefix
  1168     multiset_order;
  1169   - less duplication, less historical organization of sections,
  1170     conversion from associations lists to multisets, rudimentary code
  1171     generation;
  1172   - use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union,
  1173     if needed.
  1174 
  1175 Renamed:
  1176 
  1177   multiset_eq_conv_count_eq  ~>  multiset_ext_iff
  1178   multi_count_ext  ~>  multiset_ext
  1179   diff_union_inverse2  ~>  diff_union_cancelR
  1180 
  1181 INCOMPATIBILITY.
  1182 
  1183 * Theory Permutation: replaced local "remove" by List.remove1.
  1184 
  1185 * Code generation: ML and OCaml code is decorated with signatures.
  1186 
  1187 * Theory List: added transpose.
  1188 
  1189 * Library/Nat_Bijection.thy is a collection of bijective functions
  1190 between nat and other types, which supersedes the older libraries
  1191 Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.
  1192 
  1193   Constants:
  1194   Nat_Int_Bij.nat2_to_nat         ~> prod_encode
  1195   Nat_Int_Bij.nat_to_nat2         ~> prod_decode
  1196   Nat_Int_Bij.int_to_nat_bij      ~> int_encode
  1197   Nat_Int_Bij.nat_to_int_bij      ~> int_decode
  1198   Countable.pair_encode           ~> prod_encode
  1199   NatIso.prod2nat                 ~> prod_encode
  1200   NatIso.nat2prod                 ~> prod_decode
  1201   NatIso.sum2nat                  ~> sum_encode
  1202   NatIso.nat2sum                  ~> sum_decode
  1203   NatIso.list2nat                 ~> list_encode
  1204   NatIso.nat2list                 ~> list_decode
  1205   NatIso.set2nat                  ~> set_encode
  1206   NatIso.nat2set                  ~> set_decode
  1207 
  1208   Lemmas:
  1209   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
  1210   Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
  1211   Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
  1212   Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
  1213   Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
  1214   Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
  1215   Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
  1216   Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
  1217   Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
  1218   Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
  1219   Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
  1220   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
  1221   Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode
  1222 
  1223 * Sledgehammer:
  1224   - Renamed ATP commands:
  1225     atp_info     ~> sledgehammer running_atps
  1226     atp_kill     ~> sledgehammer kill_atps
  1227     atp_messages ~> sledgehammer messages
  1228     atp_minimize ~> sledgehammer minimize
  1229     print_atps   ~> sledgehammer available_atps
  1230     INCOMPATIBILITY.
  1231   - Added user's manual ("isabelle doc sledgehammer").
  1232   - Added option syntax and "sledgehammer_params" to customize
  1233     Sledgehammer's behavior.  See the manual for details.
  1234   - Modified the Isar proof reconstruction code so that it produces
  1235     direct proofs rather than proofs by contradiction.  (This feature
  1236     is still experimental.)
  1237   - Made Isar proof reconstruction work for SPASS, remote ATPs, and in
  1238     full-typed mode.
  1239   - Added support for TPTP syntax for SPASS via the "spass_tptp" ATP.
  1240 
  1241 * Nitpick:
  1242   - Added and implemented "binary_ints" and "bits" options.
  1243   - Added "std" option and implemented support for nonstandard models.
  1244   - Added and implemented "finitize" option to improve the precision
  1245     of infinite datatypes based on a monotonicity analysis.
  1246   - Added support for quotient types.
  1247   - Added support for "specification" and "ax_specification"
  1248     constructs.
  1249   - Added support for local definitions (for "function" and
  1250     "termination" proofs).
  1251   - Added support for term postprocessors.
  1252   - Optimized "Multiset.multiset" and "FinFun.finfun".
  1253   - Improved efficiency of "destroy_constrs" optimization.
  1254   - Fixed soundness bugs related to "destroy_constrs" optimization and
  1255     record getters.
  1256   - Fixed soundness bug related to higher-order constructors.
  1257   - Fixed soundness bug when "full_descrs" is enabled.
  1258   - Improved precision of set constructs.
  1259   - Added "atoms" option.
  1260   - Added cache to speed up repeated Kodkod invocations on the same
  1261     problems.
  1262   - Renamed "MiniSatJNI", "zChaffJNI", "BerkMinAlloy", and
  1263     "SAT4JLight" to "MiniSat_JNI", "zChaff_JNI", "BerkMin_Alloy", and
  1264     "SAT4J_Light".  INCOMPATIBILITY.
  1265   - Removed "skolemize", "uncurry", "sym_break", "flatten_prop",
  1266     "sharing_depth", and "show_skolems" options.  INCOMPATIBILITY.
  1267   - Removed "nitpick_intro" attribute.  INCOMPATIBILITY.
  1268 
  1269 * Method "induct" now takes instantiations of the form t, where t is not
  1270   a variable, as a shorthand for "x == t", where x is a fresh variable.
  1271   If this is not intended, t has to be enclosed in parentheses.
  1272   By default, the equalities generated by definitional instantiations
  1273   are pre-simplified, which may cause parameters of inductive cases
  1274   to disappear, or may even delete some of the inductive cases.
  1275   Use "induct (no_simp)" instead of "induct" to restore the old
  1276   behaviour. The (no_simp) option is also understood by the "cases"
  1277   and "nominal_induct" methods, which now perform pre-simplification, too.
  1278   INCOMPATIBILITY.
  1279 
  1280 
  1281 *** HOLCF ***
  1282 
  1283 * Variable names in lemmas generated by the domain package have
  1284 changed; the naming scheme is now consistent with the HOL datatype
  1285 package.  Some proof scripts may be affected, INCOMPATIBILITY.
  1286 
  1287 * The domain package no longer defines the function "foo_copy" for
  1288 recursive domain "foo".  The reach lemma is now stated directly in
  1289 terms of "foo_take".  Lemmas and proofs that mention "foo_copy" must
  1290 be reformulated in terms of "foo_take", INCOMPATIBILITY.
  1291 
  1292 * Most definedness lemmas generated by the domain package (previously
  1293 of the form "x ~= UU ==> foo$x ~= UU") now have an if-and-only-if form
  1294 like "foo$x = UU <-> x = UU", which works better as a simp rule.
  1295 Proofs that used definedness lemmas as intro rules may break,
  1296 potential INCOMPATIBILITY.
  1297 
  1298 * Induction and casedist rules generated by the domain package now
  1299 declare proper case_names (one called "bottom", and one named for each
  1300 constructor).  INCOMPATIBILITY.
  1301 
  1302 * For mutually-recursive domains, separate "reach" and "take_lemma"
  1303 rules are generated for each domain, INCOMPATIBILITY.
  1304 
  1305   foo_bar.reach       ~> foo.reach  bar.reach
  1306   foo_bar.take_lemmas ~> foo.take_lemma  bar.take_lemma
  1307 
  1308 * Some lemmas generated by the domain package have been renamed for
  1309 consistency with the datatype package, INCOMPATIBILITY.
  1310 
  1311   foo.ind        ~> foo.induct
  1312   foo.finite_ind ~> foo.finite_induct
  1313   foo.coind      ~> foo.coinduct
  1314   foo.casedist   ~> foo.exhaust
  1315   foo.exhaust    ~> foo.nchotomy
  1316 
  1317 * For consistency with other definition packages, the fixrec package
  1318 now generates qualified theorem names, INCOMPATIBILITY.
  1319 
  1320   foo_simps  ~> foo.simps
  1321   foo_unfold ~> foo.unfold
  1322   foo_induct ~> foo.induct
  1323 
  1324 * The "fixrec_simp" attribute has been removed.  The "fixrec_simp"
  1325 method and internal fixrec proofs now use the default simpset instead.
  1326 INCOMPATIBILITY.
  1327 
  1328 * The "contlub" predicate has been removed.  Proof scripts should use
  1329 lemma contI2 in place of monocontlub2cont, INCOMPATIBILITY.
  1330 
  1331 * The "admw" predicate has been removed, INCOMPATIBILITY.
  1332 
  1333 * The constants cpair, cfst, and csnd have been removed in favor of
  1334 Pair, fst, and snd from Isabelle/HOL, INCOMPATIBILITY.
  1335 
  1336 
  1337 *** ML ***
  1338 
  1339 * Antiquotations for basic formal entities:
  1340 
  1341     @{class NAME}         -- type class
  1342     @{class_syntax NAME}  -- syntax representation of the above
  1343 
  1344     @{type_name NAME}     -- logical type
  1345     @{type_abbrev NAME}   -- type abbreviation
  1346     @{nonterminal NAME}   -- type of concrete syntactic category
  1347     @{type_syntax NAME}   -- syntax representation of any of the above
  1348 
  1349     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
  1350     @{const_abbrev NAME}  -- abbreviated constant
  1351     @{const_syntax NAME}  -- syntax representation of any of the above
  1352 
  1353 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
  1354 syntax constant (cf. 'syntax' command).
  1355 
  1356 * Antiquotation @{make_string} inlines a function to print arbitrary
  1357 values similar to the ML toplevel.  The result is compiler dependent
  1358 and may fall back on "?" in certain situations.
  1359 
  1360 * Diagnostic commands 'ML_val' and 'ML_command' may refer to
  1361 antiquotations @{Isar.state} and @{Isar.goal}.  This replaces impure
  1362 Isar.state() and Isar.goal(), which belong to the old TTY loop and do
  1363 not work with the asynchronous Isar document model.
  1364 
  1365 * Configuration options now admit dynamic default values, depending on
  1366 the context or even global references.
  1367 
  1368 * SHA1.digest digests strings according to SHA-1 (see RFC 3174).  It
  1369 uses an efficient external library if available (for Poly/ML).
  1370 
  1371 * Renamed some important ML structures, while keeping the old names
  1372 for some time as aliases within the structure Legacy:
  1373 
  1374   OuterKeyword  ~>  Keyword
  1375   OuterLex      ~>  Token
  1376   OuterParse    ~>  Parse
  1377   OuterSyntax   ~>  Outer_Syntax
  1378   PrintMode     ~>  Print_Mode
  1379   SpecParse     ~>  Parse_Spec
  1380   ThyInfo       ~>  Thy_Info
  1381   ThyLoad       ~>  Thy_Load
  1382   ThyOutput     ~>  Thy_Output
  1383   TypeInfer     ~>  Type_Infer
  1384 
  1385 Note that "open Legacy" simplifies porting of sources, but forgetting
  1386 to remove it again will complicate porting again in the future.
  1387 
  1388 * Most operations that refer to a global context are named
  1389 accordingly, e.g. Simplifier.global_context or
  1390 ProofContext.init_global.  There are some situations where a global
  1391 context actually works, but under normal circumstances one needs to
  1392 pass the proper local context through the code!
  1393 
  1394 * Discontinued old TheoryDataFun with its copy/init operation -- data
  1395 needs to be pure.  Functor Theory_Data_PP retains the traditional
  1396 Pretty.pp argument to merge, which is absent in the standard
  1397 Theory_Data version.
  1398 
  1399 * Sorts.certify_sort and derived "cert" operations for types and terms
  1400 no longer minimize sorts.  Thus certification at the boundary of the
  1401 inference kernel becomes invariant under addition of class relations,
  1402 which is an important monotonicity principle.  Sorts are now minimized
  1403 in the syntax layer only, at the boundary between the end-user and the
  1404 system.  Subtle INCOMPATIBILITY, may have to use Sign.minimize_sort
  1405 explicitly in rare situations.
  1406 
  1407 * Renamed old-style Drule.standard to Drule.export_without_context, to
  1408 emphasize that this is in no way a standard operation.
  1409 INCOMPATIBILITY.
  1410 
  1411 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
  1412 usual for resolution.  Rare INCOMPATIBILITY.
  1413 
  1414 * Renamed varify/unvarify operations to varify_global/unvarify_global
  1415 to emphasize that these only work in a global situation (which is
  1416 quite rare).
  1417 
  1418 * Curried take and drop in library.ML; negative length is interpreted
  1419 as infinity (as in chop).  Subtle INCOMPATIBILITY.
  1420 
  1421 * Proof terms: type substitutions on proof constants now use canonical
  1422 order of type variables.  INCOMPATIBILITY for tools working with proof
  1423 terms.
  1424 
  1425 * Raw axioms/defs may no longer carry sort constraints, and raw defs
  1426 may no longer carry premises.  User-level specifications are
  1427 transformed accordingly by Thm.add_axiom/add_def.
  1428 
  1429 
  1430 *** System ***
  1431 
  1432 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
  1433 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
  1434 proof terms are enabled unconditionally in the new HOL-Proofs image.
  1435 
  1436 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
  1437 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
  1438 respectively.
  1439 
  1440 * Old lib/scripts/polyml-platform is superseded by the
  1441 ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
  1442 variant, even on a 64 bit machine.  The following example setting
  1443 prefers 64 bit if available:
  1444 
  1445   ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"
  1446 
  1447 * The preliminary Isabelle/jEdit application demonstrates the emerging
  1448 Isabelle/Scala layer for advanced prover interaction and integration.
  1449 See src/Tools/jEdit or "isabelle jedit" provided by the properly built
  1450 component.
  1451 
  1452 * "IsabelleText" is a Unicode font derived from Bitstream Vera Mono
  1453 and Bluesky TeX fonts.  It provides the usual Isabelle symbols,
  1454 similar to the default assignment of the document preparation system
  1455 (cf. isabellesym.sty).  The Isabelle/Scala class Isabelle_System
  1456 provides some operations for direct access to the font without asking
  1457 the user for manual installation.
  1458 
  1459 
  1460 
  1461 New in Isabelle2009-1 (December 2009)
  1462 -------------------------------------
  1463 
  1464 *** General ***
  1465 
  1466 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
  1467 one backslash should be used, even in ML sources.
  1468 
  1469 
  1470 *** Pure ***
  1471 
  1472 * Locale interpretation propagates mixins along the locale hierarchy.
  1473 The currently only available mixins are the equations used to map
  1474 local definitions to terms of the target domain of an interpretation.
  1475 
  1476 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
  1477 loc" to print all interpretations of locale "loc" in the theory.
  1478 Interpretations in proofs are not shown.
  1479 
  1480 * Thoroughly revised locales tutorial.  New section on conditional
  1481 interpretation.
  1482 
  1483 * On instantiation of classes, remaining undefined class parameters
  1484 are formally declared.  INCOMPATIBILITY.
  1485 
  1486 
  1487 *** Document preparation ***
  1488 
  1489 * New generalized style concept for printing terms: @{foo (style) ...}
  1490 instead of @{foo_style style ...}  (old form is still retained for
  1491 backward compatibility).  Styles can be also applied for
  1492 antiquotations prop, term_type and typeof.
  1493 
  1494 
  1495 *** HOL ***
  1496 
  1497 * New proof method "smt" for a combination of first-order logic with
  1498 equality, linear and nonlinear (natural/integer/real) arithmetic, and
  1499 fixed-size bitvectors; there is also basic support for higher-order
  1500 features (esp. lambda abstractions).  It is an incomplete decision
  1501 procedure based on external SMT solvers using the oracle mechanism;
  1502 for the SMT solver Z3, this method is proof-producing.  Certificates
  1503 are provided to avoid calling the external solvers solely for
  1504 re-checking proofs.  Due to a remote SMT service there is no need for
  1505 installing SMT solvers locally.  See src/HOL/SMT.
  1506 
  1507 * New commands to load and prove verification conditions generated by
  1508 the Boogie program verifier or derived systems (e.g. the Verifying C
  1509 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
  1510 
  1511 * New counterexample generator tool 'nitpick' based on the Kodkod
  1512 relational model finder.  See src/HOL/Tools/Nitpick and
  1513 src/HOL/Nitpick_Examples.
  1514 
  1515 * New commands 'code_pred' and 'values' to invoke the predicate
  1516 compiler and to enumerate values of inductive predicates.
  1517 
  1518 * A tabled implementation of the reflexive transitive closure.
  1519 
  1520 * New implementation of quickcheck uses generic code generator;
  1521 default generators are provided for all suitable HOL types, records
  1522 and datatypes.  Old quickcheck can be re-activated importing theory
  1523 Library/SML_Quickcheck.
  1524 
  1525 * New testing tool Mirabelle for automated proof tools.  Applies
  1526 several tools and tactics like sledgehammer, metis, or quickcheck, to
  1527 every proof step in a theory.  To be used in batch mode via the
  1528 "mirabelle" utility.
  1529 
  1530 * New proof method "sos" (sum of squares) for nonlinear real
  1531 arithmetic (originally due to John Harison). It requires theory
  1532 Library/Sum_Of_Squares.  It is not a complete decision procedure but
  1533 works well in practice on quantifier-free real arithmetic with +, -,
  1534 *, ^, =, <= and <, i.e. boolean combinations of equalities and
  1535 inequalities between polynomials.  It makes use of external
  1536 semidefinite programming solvers.  Method "sos" generates a
  1537 certificate that can be pasted into the proof thus avoiding the need
  1538 to call an external tool every time the proof is checked.  See
  1539 src/HOL/Library/Sum_Of_Squares.
  1540 
  1541 * New method "linarith" invokes existing linear arithmetic decision
  1542 procedure only.
  1543 
  1544 * New command 'atp_minimal' reduces result produced by Sledgehammer.
  1545 
  1546 * New Sledgehammer option "Full Types" in Proof General settings menu.
  1547 Causes full type information to be output to the ATPs.  This slows
  1548 ATPs down considerably but eliminates a source of unsound "proofs"
  1549 that fail later.
  1550 
  1551 * New method "metisFT": A version of metis that uses full type
  1552 information in order to avoid failures of proof reconstruction.
  1553 
  1554 * New evaluator "approximate" approximates an real valued term using
  1555 the same method as the approximation method.
  1556 
  1557 * Method "approximate" now supports arithmetic expressions as
  1558 boundaries of intervals and implements interval splitting and Taylor
  1559 series expansion.
  1560 
  1561 * ML antiquotation @{code_datatype} inserts definition of a datatype
  1562 generated by the code generator; e.g. see src/HOL/Predicate.thy.
  1563 
  1564 * New theory SupInf of the supremum and infimum operators for sets of
  1565 reals.
  1566 
  1567 * New theory Probability, which contains a development of measure
  1568 theory, eventually leading to Lebesgue integration and probability.
  1569 
  1570 * Extended Multivariate Analysis to include derivation and Brouwer's
  1571 fixpoint theorem.
  1572 
  1573 * Reorganization of number theory, INCOMPATIBILITY:
  1574   - new number theory development for nat and int, in theories Divides
  1575     and GCD as well as in new session Number_Theory
  1576   - some constants and facts now suffixed with _nat and _int
  1577     accordingly
  1578   - former session NumberTheory now named Old_Number_Theory, including
  1579     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
  1580   - moved theory Pocklington from src/HOL/Library to
  1581     src/HOL/Old_Number_Theory
  1582 
  1583 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
  1584 lcm of finite and infinite sets. It is shown that they form a complete
  1585 lattice.
  1586 
  1587 * Class semiring_div requires superclass no_zero_divisors and proof of
  1588 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
  1589 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
  1590 generalized to class semiring_div, subsuming former theorems
  1591 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
  1592 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
  1593 INCOMPATIBILITY.
  1594 
  1595 * Refinements to lattice classes and sets:
  1596   - less default intro/elim rules in locale variant, more default
  1597     intro/elim rules in class variant: more uniformity
  1598   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
  1599     le_inf_iff
  1600   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
  1601     sup_aci)
  1602   - renamed ACI to inf_sup_aci
  1603   - new class "boolean_algebra"
  1604   - class "complete_lattice" moved to separate theory
  1605     "Complete_Lattice"; corresponding constants (and abbreviations)
  1606     renamed and with authentic syntax:
  1607     Set.Inf ~>    Complete_Lattice.Inf
  1608     Set.Sup ~>    Complete_Lattice.Sup
  1609     Set.INFI ~>   Complete_Lattice.INFI
  1610     Set.SUPR ~>   Complete_Lattice.SUPR
  1611     Set.Inter ~>  Complete_Lattice.Inter
  1612     Set.Union ~>  Complete_Lattice.Union
  1613     Set.INTER ~>  Complete_Lattice.INTER
  1614     Set.UNION ~>  Complete_Lattice.UNION
  1615   - authentic syntax for
  1616     Set.Pow
  1617     Set.image
  1618   - mere abbreviations:
  1619     Set.empty               (for bot)
  1620     Set.UNIV                (for top)
  1621     Set.inter               (for inf, formerly Set.Int)
  1622     Set.union               (for sup, formerly Set.Un)
  1623     Complete_Lattice.Inter  (for Inf)
  1624     Complete_Lattice.Union  (for Sup)
  1625     Complete_Lattice.INTER  (for INFI)
  1626     Complete_Lattice.UNION  (for SUPR)
  1627   - object-logic definitions as far as appropriate
  1628 
  1629 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
  1630 Un_subset_iff are explicitly deleted as default simp rules; then also
  1631 their lattice counterparts le_inf_iff and le_sup_iff have to be
  1632 deleted to achieve the desired effect.
  1633 
  1634 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
  1635 rules by default any longer; the same applies to min_max.inf_absorb1
  1636 etc.  INCOMPATIBILITY.
  1637 
  1638 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
  1639 pred_set_conv by default.  INCOMPATIBILITY.
  1640 
  1641 * Power operations on relations and functions are now one dedicated
  1642 constant "compow" with infix syntax "^^".  Power operation on
  1643 multiplicative monoids retains syntax "^" and is now defined generic
  1644 in class power.  INCOMPATIBILITY.
  1645 
  1646 * Relation composition "R O S" now has a more standard argument order:
  1647 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
  1648 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
  1649 break, since the O_assoc rule was not rewritten like this.  Fix using
  1650 O_assoc[symmetric].  The same applies to the curried version "R OO S".
  1651 
  1652 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
  1653 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
  1654 INCOMPATIBILITY.
  1655 
  1656 * Most rules produced by inductive and datatype package have mandatory
  1657 prefixes.  INCOMPATIBILITY.
  1658 
  1659 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
  1660 the attribute of the same name.  Each of the theorems in the list
  1661 DERIV_intros assumes composition with an additional function and
  1662 matches a variable to the derivative, which has to be solved by the
  1663 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
  1664 of most elementary terms.  Former Maclauren.DERIV_tac and
  1665 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
  1666 INCOMPATIBILITY.
  1667 
  1668 * Code generator attributes follow the usual underscore convention:
  1669     code_unfold     replaces    code unfold
  1670     code_post       replaces    code post
  1671     etc.
  1672   INCOMPATIBILITY.
  1673 
  1674 * Renamed methods:
  1675     sizechange -> size_change
  1676     induct_scheme -> induction_schema
  1677   INCOMPATIBILITY.
  1678 
  1679 * Discontinued abbreviation "arbitrary" of constant "undefined".
  1680 INCOMPATIBILITY, use "undefined" directly.
  1681 
  1682 * Renamed theorems:
  1683     Suc_eq_add_numeral_1 -> Suc_eq_plus1
  1684     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
  1685     Suc_plus1 -> Suc_eq_plus1
  1686     *anti_sym -> *antisym*
  1687     vector_less_eq_def -> vector_le_def
  1688   INCOMPATIBILITY.
  1689 
  1690 * Added theorem List.map_map as [simp].  Removed List.map_compose.
  1691 INCOMPATIBILITY.
  1692 
  1693 * Removed predicate "M hassize n" (<--> card M = n & finite M).
  1694 INCOMPATIBILITY.
  1695 
  1696 
  1697 *** HOLCF ***
  1698 
  1699 * Theory Representable defines a class "rep" of domains that are
  1700 representable (via an ep-pair) in the universal domain type "udom".
  1701 Instances are provided for all type constructors defined in HOLCF.
  1702 
  1703 * The 'new_domain' command is a purely definitional version of the
  1704 domain package, for representable domains.  Syntax is identical to the
  1705 old domain package.  The 'new_domain' package also supports indirect
  1706 recursion using previously-defined type constructors.  See
  1707 src/HOLCF/ex/New_Domain.thy for examples.
  1708 
  1709 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
  1710 on the left-hand side of an equation, and then performs
  1711 simplification.  Rewriting is done using rules declared with the
  1712 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
  1713 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
  1714 
  1715 * The pattern-match compiler in 'fixrec' can now handle constructors
  1716 with HOL function types.  Pattern-match combinators for the Pair
  1717 constructor are pre-configured.
  1718 
  1719 * The 'fixrec' package now produces better fixed-point induction rules
  1720 for mutually-recursive definitions:  Induction rules have conclusions
  1721 of the form "P foo bar" instead of "P <foo, bar>".
  1722 
  1723 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
  1724 been renamed to "below".  The name "below" now replaces "less" in many
  1725 theorem names.  (Legacy theorem names using "less" are still supported
  1726 as well.)
  1727 
  1728 * The 'fixrec' package now supports "bottom patterns".  Bottom
  1729 patterns can be used to generate strictness rules, or to make
  1730 functions more strict (much like the bang-patterns supported by the
  1731 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
  1732 examples.
  1733 
  1734 
  1735 *** ML ***
  1736 
  1737 * Support for Poly/ML 5.3.0, with improved reporting of compiler
  1738 errors and run-time exceptions, including detailed source positions.
  1739 
  1740 * Structure Name_Space (formerly NameSpace) now manages uniquely
  1741 identified entries, with some additional information such as source
  1742 position, logical grouping etc.
  1743 
  1744 * Theory and context data is now introduced by the simplified and
  1745 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
  1746 to be pure, but the old TheoryDataFun for mutable data (with explicit
  1747 copy operation) is still available for some time.
  1748 
  1749 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
  1750 provides a high-level programming interface to synchronized state
  1751 variables with atomic update.  This works via pure function
  1752 application within a critical section -- its runtime should be as
  1753 short as possible; beware of deadlocks if critical code is nested,
  1754 either directly or indirectly via other synchronized variables!
  1755 
  1756 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
  1757 wraps raw ML references, explicitly indicating their non-thread-safe
  1758 behaviour.  The Isar toplevel keeps this structure open, to
  1759 accommodate Proof General as well as quick and dirty interactive
  1760 experiments with references.
  1761 
  1762 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
  1763 parallel tactical reasoning.
  1764 
  1765 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
  1766 are similar to SUBPROOF, but are slightly more flexible: only the
  1767 specified parts of the subgoal are imported into the context, and the
  1768 body tactic may introduce new subgoals and schematic variables.
  1769 
  1770 * Old tactical METAHYPS, which does not observe the proof context, has
  1771 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
  1772 or Subgoal.FOCUS etc.
  1773 
  1774 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
  1775 functors have their own ML name space there is no point to mark them
  1776 separately.)  Minor INCOMPATIBILITY.
  1777 
  1778 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
  1779 
  1780 * Renamed several structures FooBar to Foo_Bar.  Occasional,
  1781 INCOMPATIBILITY.
  1782 
  1783 * Operations of structure Skip_Proof no longer require quick_and_dirty
  1784 mode, which avoids critical setmp.
  1785 
  1786 * Eliminated old Attrib.add_attributes, Method.add_methods and related
  1787 combinators for "args".  INCOMPATIBILITY, need to use simplified
  1788 Attrib/Method.setup introduced in Isabelle2009.
  1789 
  1790 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
  1791 back on global_simpset_of, global_claset_of, global_clasimpset_of as
  1792 last resort.  INCOMPATIBILITY.
  1793 
  1794 * Display.pretty_thm now requires a proper context (cf. former
  1795 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
  1796 or even Display.pretty_thm_without_context as last resort.
  1797 INCOMPATIBILITY.
  1798 
  1799 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
  1800 Syntax.pretty_typ/term directly, preferably with proper context
  1801 instead of global theory.
  1802 
  1803 
  1804 *** System ***
  1805 
  1806 * Further fine tuning of parallel proof checking, scales up to 8 cores
  1807 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
  1808 usedir option -q.
  1809 
  1810 * Support for additional "Isabelle components" via etc/components, see
  1811 also the system manual.
  1812 
  1813 * The isabelle makeall tool now operates on all components with
  1814 IsaMakefile, not just hardwired "logics".
  1815 
  1816 * Removed "compress" option from isabelle-process and isabelle usedir;
  1817 this is always enabled.
  1818 
  1819 * Discontinued support for Poly/ML 4.x versions.
  1820 
  1821 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
  1822 on a given logic image.  This requires the lighttpd webserver and is
  1823 currently supported on Linux only.
  1824 
  1825 
  1826 
  1827 New in Isabelle2009 (April 2009)
  1828 --------------------------------
  1829 
  1830 *** General ***
  1831 
  1832 * Simplified main Isabelle executables, with less surprises on
  1833 case-insensitive file-systems (such as Mac OS).
  1834 
  1835   - The main Isabelle tool wrapper is now called "isabelle" instead of
  1836     "isatool."
  1837 
  1838   - The former "isabelle" alias for "isabelle-process" has been
  1839     removed (should rarely occur to regular users).
  1840 
  1841   - The former "isabelle-interface" and its alias "Isabelle" have been
  1842     removed (interfaces are now regular Isabelle tools).
  1843 
  1844 Within scripts and make files, the Isabelle environment variables
  1845 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
  1846 respectively.  (The latter are still available as legacy feature.)
  1847 
  1848 The old isabelle-interface wrapper could react in confusing ways if
  1849 the interface was uninstalled or changed otherwise.  Individual
  1850 interface tool configuration is now more explicit, see also the
  1851 Isabelle system manual.  In particular, Proof General is now available
  1852 via "isabelle emacs".
  1853 
  1854 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
  1855 purge installed copies of Isabelle executables and re-run "isabelle
  1856 install -p ...", or use symlinks.
  1857 
  1858 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
  1859 old ~/isabelle, which was slightly non-standard and apt to cause
  1860 surprises on case-insensitive file-systems (such as Mac OS).
  1861 
  1862 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
  1863 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
  1864 care is required when using older releases of Isabelle.  Note that
  1865 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
  1866 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
  1867 
  1868 * Proofs of fully specified statements are run in parallel on
  1869 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
  1870 a regular 4-core machine, if the initial heap space is made reasonably
  1871 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
  1872 
  1873 * The main reference manuals ("isar-ref", "implementation", and
  1874 "system") have been updated and extended.  Formally checked references
  1875 as hyperlinks are now available uniformly.
  1876 
  1877 
  1878 *** Pure ***
  1879 
  1880 * Complete re-implementation of locales.  INCOMPATIBILITY in several
  1881 respects.  The most important changes are listed below.  See the
  1882 Tutorial on Locales ("locales" manual) for details.
  1883 
  1884 - In locale expressions, instantiation replaces renaming.  Parameters
  1885 must be declared in a for clause.  To aid compatibility with previous
  1886 parameter inheritance, in locale declarations, parameters that are not
  1887 'touched' (instantiation position "_" or omitted) are implicitly added
  1888 with their syntax at the beginning of the for clause.
  1889 
  1890 - Syntax from abbreviations and definitions in locales is available in
  1891 locale expressions and context elements.  The latter is particularly
  1892 useful in locale declarations.
  1893 
  1894 - More flexible mechanisms to qualify names generated by locale
  1895 expressions.  Qualifiers (prefixes) may be specified in locale
  1896 expressions, and can be marked as mandatory (syntax: "name!:") or
  1897 optional (syntax "name?:").  The default depends for plain "name:"
  1898 depends on the situation where a locale expression is used: in
  1899 commands 'locale' and 'sublocale' prefixes are optional, in
  1900 'interpretation' and 'interpret' prefixes are mandatory.  The old
  1901 implicit qualifiers derived from the parameter names of a locale are
  1902 no longer generated.
  1903 
  1904 - Command "sublocale l < e" replaces "interpretation l < e".  The
  1905 instantiation clause in "interpretation" and "interpret" (square
  1906 brackets) is no longer available.  Use locale expressions.
  1907 
  1908 - When converting proof scripts, mandatory qualifiers in
  1909 'interpretation' and 'interpret' should be retained by default, even
  1910 if this is an INCOMPATIBILITY compared to former behavior.  In the
  1911 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
  1912 in locale expressions range over a single locale instance only.
  1913 
  1914 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
  1915 In existing theorem specifications replace the includes element by the
  1916 respective context elements of the included locale, omitting those
  1917 that are already present in the theorem specification.  Multiple
  1918 assume elements of a locale should be replaced by a single one
  1919 involving the locale predicate.  In the proof body, declarations (most
  1920 notably theorems) may be regained by interpreting the respective
  1921 locales in the proof context as required (command "interpret").
  1922 
  1923 If using "includes" in replacement of a target solely because the
  1924 parameter types in the theorem are not as general as in the target,
  1925 consider declaring a new locale with additional type constraints on
  1926 the parameters (context element "constrains").
  1927 
  1928 - Discontinued "locale (open)".  INCOMPATIBILITY.
  1929 
  1930 - Locale interpretation commands no longer attempt to simplify goal.
  1931 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
  1932 methods intro_locales and unfold_locales to clarify.
  1933 
  1934 - Locale interpretation commands no longer accept interpretation
  1935 attributes.  INCOMPATIBILITY.
  1936 
  1937 * Class declaration: so-called "base sort" must not be given in import
  1938 list any longer, but is inferred from the specification.  Particularly
  1939 in HOL, write
  1940 
  1941     class foo = ...
  1942 
  1943 instead of
  1944 
  1945     class foo = type + ...
  1946 
  1947 * Class target: global versions of theorems stemming do not carry a
  1948 parameter prefix any longer.  INCOMPATIBILITY.
  1949 
  1950 * Class 'instance' command no longer accepts attached definitions.
  1951 INCOMPATIBILITY, use proper 'instantiation' target instead.
  1952 
  1953 * Recovered hiding of consts, which was accidentally broken in
  1954 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
  1955 makes c inaccessible; consider using ``hide (open) const c'' instead.
  1956 
  1957 * Slightly more coherent Pure syntax, with updated documentation in
  1958 isar-ref manual.  Removed locales meta_term_syntax and
  1959 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
  1960 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
  1961 directly in regular applications.
  1962 
  1963 * There is a new syntactic category "float_const" for signed decimal
  1964 fractions (e.g. 123.45 or -123.45).
  1965 
  1966 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
  1967 interface with 'setup' command instead.
  1968 
  1969 * Command 'local_setup' is similar to 'setup', but operates on a local
  1970 theory context.
  1971 
  1972 * The 'axiomatization' command now only works within a global theory
  1973 context.  INCOMPATIBILITY.
  1974 
  1975 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
  1976 hypotheses.  Sorts required in the course of reasoning need to be
  1977 covered by the constraints in the initial statement, completed by the
  1978 type instance information of the background theory.  Non-trivial sort
  1979 hypotheses, which rarely occur in practice, may be specified via
  1980 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
  1981 
  1982   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
  1983 
  1984 The result contains an implicit sort hypotheses as before --
  1985 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
  1986 normalization.
  1987 
  1988 * Generalized Isar history, with support for linear undo, direct state
  1989 addressing etc.
  1990 
  1991 * Changed defaults for unify configuration options:
  1992 
  1993   unify_trace_bound = 50 (formerly 25)
  1994   unify_search_bound = 60 (formerly 30)
  1995 
  1996 * Different bookkeeping for code equations (INCOMPATIBILITY):
  1997 
  1998   a) On theory merge, the last set of code equations for a particular
  1999      constant is taken (in accordance with the policy applied by other
  2000      parts of the code generator framework).
  2001 
  2002   b) Code equations stemming from explicit declarations (e.g. code
  2003      attribute) gain priority over default code equations stemming
  2004      from definition, primrec, fun etc.
  2005 
  2006 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
  2007 
  2008 * Unified theorem tables for both code generators.  Thus [code
  2009 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
  2010 
  2011 * Command 'find_consts' searches for constants based on type and name
  2012 patterns, e.g.
  2013 
  2014     find_consts "_ => bool"
  2015 
  2016 By default, matching is against subtypes, but it may be restricted to
  2017 the whole type.  Searching by name is possible.  Multiple queries are
  2018 conjunctive and queries may be negated by prefixing them with a
  2019 hyphen:
  2020 
  2021     find_consts strict: "_ => bool" name: "Int" -"int => int"
  2022 
  2023 * New 'find_theorems' criterion "solves" matches theorems that
  2024 directly solve the current goal (modulo higher-order unification).
  2025 
  2026 * Auto solve feature for main theorem statements: whenever a new goal
  2027 is stated, "find_theorems solves" is called; any theorems that could
  2028 solve the lemma directly are listed as part of the goal state.
  2029 Cf. associated options in Proof General Isabelle settings menu,
  2030 enabled by default, with reasonable timeout for pathological cases of
  2031 higher-order unification.
  2032 
  2033 
  2034 *** Document preparation ***
  2035 
  2036 * Antiquotation @{lemma} now imitates a regular terminal proof,
  2037 demanding keyword 'by' and supporting the full method expression
  2038 syntax just like the Isar command 'by'.
  2039 
  2040 
  2041 *** HOL ***
  2042 
  2043 * Integrated main parts of former image HOL-Complex with HOL.  Entry
  2044 points Main and Complex_Main remain as before.
  2045 
  2046 * Logic image HOL-Plain provides a minimal HOL with the most important
  2047 tools available (inductive, datatype, primrec, ...).  This facilitates
  2048 experimentation and tool development.  Note that user applications
  2049 (and library theories) should never refer to anything below theory
  2050 Main, as before.
  2051 
  2052 * Logic image HOL-Main stops at theory Main, and thus facilitates
  2053 experimentation due to shorter build times.
  2054 
  2055 * Logic image HOL-NSA contains theories of nonstandard analysis which
  2056 were previously part of former HOL-Complex.  Entry point Hyperreal
  2057 remains valid, but theories formerly using Complex_Main should now use
  2058 new entry point Hypercomplex.
  2059 
  2060 * Generic ATP manager for Sledgehammer, based on ML threads instead of
  2061 Posix processes.  Avoids potentially expensive forking of the ML
  2062 process.  New thread-based implementation also works on non-Unix
  2063 platforms (Cygwin).  Provers are no longer hardwired, but defined
  2064 within the theory via plain ML wrapper functions.  Basic Sledgehammer
  2065 commands are covered in the isar-ref manual.
  2066 
  2067 * Wrapper scripts for remote SystemOnTPTP service allows to use
  2068 sledgehammer without local ATP installation (Vampire etc.). Other
  2069 provers may be included via suitable ML wrappers, see also
  2070 src/HOL/ATP_Linkup.thy.
  2071 
  2072 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
  2073 menu.
  2074 
  2075 * The metis method no longer fails because the theorem is too trivial
  2076 (contains the empty clause).
  2077 
  2078 * The metis method now fails in the usual manner, rather than raising
  2079 an exception, if it determines that it cannot prove the theorem.
  2080 
  2081 * Method "coherent" implements a prover for coherent logic (see also
  2082 src/Tools/coherent.ML).
  2083 
  2084 * Constants "undefined" and "default" replace "arbitrary".  Usually
  2085 "undefined" is the right choice to replace "arbitrary", though
  2086 logically there is no difference.  INCOMPATIBILITY.
  2087 
  2088 * Command "value" now integrates different evaluation mechanisms.  The
  2089 result of the first successful evaluation mechanism is printed.  In
  2090 square brackets a particular named evaluation mechanisms may be
  2091 specified (currently, [SML], [code] or [nbe]).  See further
  2092 src/HOL/ex/Eval_Examples.thy.
  2093 
  2094 * Normalization by evaluation now allows non-leftlinear equations.
  2095 Declare with attribute [code nbe].
  2096 
  2097 * Methods "case_tac" and "induct_tac" now refer to the very same rules
  2098 as the structured Isar versions "cases" and "induct", cf. the
  2099 corresponding "cases" and "induct" attributes.  Mutual induction rules
  2100 are now presented as a list of individual projections
  2101 (e.g. foo_bar.inducts for types foo and bar); the old format with
  2102 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
  2103 rare situations a different rule is selected --- notably nested tuple
  2104 elimination instead of former prod.exhaust: use explicit (case_tac t
  2105 rule: prod.exhaust) here.
  2106 
  2107 * Attributes "cases", "induct", "coinduct" support "del" option.
  2108 
  2109 * Removed fact "case_split_thm", which duplicates "case_split".
  2110 
  2111 * The option datatype has been moved to a new theory Option.  Renamed
  2112 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
  2113 
  2114 * New predicate "strict_mono" classifies strict functions on partial
  2115 orders.  With strict functions on linear orders, reasoning about
  2116 (in)equalities is facilitated by theorems "strict_mono_eq",
  2117 "strict_mono_less_eq" and "strict_mono_less".
  2118 
  2119 * Some set operations are now proper qualified constants with
  2120 authentic syntax.  INCOMPATIBILITY:
  2121 
  2122     op Int ~>   Set.Int
  2123     op Un ~>    Set.Un
  2124     INTER ~>    Set.INTER
  2125     UNION ~>    Set.UNION
  2126     Inter ~>    Set.Inter
  2127     Union ~>    Set.Union
  2128     {} ~>       Set.empty
  2129     UNIV ~>     Set.UNIV
  2130 
  2131 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  2132 theory Set.
  2133 
  2134 * Auxiliary class "itself" has disappeared -- classes without any
  2135 parameter are treated as expected by the 'class' command.
  2136 
  2137 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  2138 
  2139 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  2140 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  2141 
  2142 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  2143 method "approximation".  It proves formulas on real values by using
  2144 interval arithmetic.  In the formulas are also the transcendental
  2145 functions sin, cos, tan, atan, ln, exp and the constant pi are
  2146 allowed. For examples see
  2147 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  2148 
  2149 * Theory "Reflection" now resides in HOL/Library.
  2150 
  2151 * Entry point to Word library now simply named "Word".
  2152 INCOMPATIBILITY.
  2153 
  2154 * Made source layout more coherent with logical distribution
  2155 structure:
  2156 
  2157     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  2158     src/HOL/Library/Code_Message.thy ~> src/HOL/
  2159     src/HOL/Library/GCD.thy ~> src/HOL/
  2160     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  2161     src/HOL/Library/Parity.thy ~> src/HOL/
  2162     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  2163     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  2164     src/HOL/Real/Lubs.thy ~> src/HOL/
  2165     src/HOL/Real/PReal.thy ~> src/HOL/
  2166     src/HOL/Real/Rational.thy ~> src/HOL/
  2167     src/HOL/Real/RComplete.thy ~> src/HOL/
  2168     src/HOL/Real/RealDef.thy ~> src/HOL/
  2169     src/HOL/Real/RealPow.thy ~> src/HOL/
  2170     src/HOL/Real/Real.thy ~> src/HOL/
  2171     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  2172     src/HOL/Complex/Complex.thy ~> src/HOL/
  2173     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  2174     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  2175     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  2176     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  2177     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  2178     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  2179     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  2180     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  2181     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  2182     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  2183     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  2184     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  2185     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  2186     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  2187     src/HOL/Real/Float ~> src/HOL/Library/
  2188     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  2189     src/HOL/Real/RealVector.thy ~> src/HOL/
  2190 
  2191     src/HOL/arith_data.ML ~> src/HOL/Tools
  2192     src/HOL/hologic.ML ~> src/HOL/Tools
  2193     src/HOL/simpdata.ML ~> src/HOL/Tools
  2194     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  2195     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  2196     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  2197     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  2198     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  2199     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  2200     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  2201 
  2202     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  2203     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  2204     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  2205     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  2206     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  2207     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  2208 
  2209 * If methods "eval" and "evaluation" encounter a structured proof
  2210 state with !!/==>, only the conclusion is evaluated to True (if
  2211 possible), avoiding strange error messages.
  2212 
  2213 * Method "sizechange" automates termination proofs using (a
  2214 modification of) the size-change principle.  Requires SAT solver.  See
  2215 src/HOL/ex/Termination.thy for examples.
  2216 
  2217 * Simplifier: simproc for let expressions now unfolds if bound
  2218 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  2219 
  2220 * Method "arith": Linear arithmetic now ignores all inequalities when
  2221 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  2222 
  2223 * New attribute "arith" for facts that should always be used
  2224 automatically by arithmetic. It is intended to be used locally in
  2225 proofs, e.g.
  2226 
  2227   assumes [arith]: "x > 0"
  2228 
  2229 Global usage is discouraged because of possible performance impact.
  2230 
  2231 * New classes "top" and "bot" with corresponding operations "top" and
  2232 "bot" in theory Orderings; instantiation of class "complete_lattice"
  2233 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  2234 
  2235 * Changed definition lemma "less_fun_def" in order to provide an
  2236 instance for preorders on functions; use lemma "less_le" instead.
  2237 INCOMPATIBILITY.
  2238 
  2239 * Theory Orderings: class "wellorder" moved here, with explicit
  2240 induction rule "less_induct" as assumption.  For instantiation of
  2241 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  2242 INCOMPATIBILITY.
  2243 
  2244 * Theory Orderings: added class "preorder" as superclass of "order".
  2245 INCOMPATIBILITY: Instantiation proofs for order, linorder
  2246 etc. slightly changed.  Some theorems named order_class.* now named
  2247 preorder_class.*.
  2248 
  2249 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  2250 "diag" to "Id_on".
  2251 
  2252 * Theory Finite_Set: added a new fold combinator of type
  2253 
  2254   ('a => 'b => 'b) => 'b => 'a set => 'b
  2255 
  2256 Occasionally this is more convenient than the old fold combinator
  2257 which is now defined in terms of the new one and renamed to
  2258 fold_image.
  2259 
  2260 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  2261 and "ring_simps" have been replaced by "algebra_simps" (which can be
  2262 extended with further lemmas!).  At the moment both still exist but
  2263 the former will disappear at some point.
  2264 
  2265 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  2266 class recpower.  Type-specific simp rules for various recpower types
  2267 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  2268 
  2269 rat_power_0    -> power_0
  2270 rat_power_Suc  -> power_Suc
  2271 realpow_0      -> power_0
  2272 realpow_Suc    -> power_Suc
  2273 complexpow_0   -> power_0
  2274 complexpow_Suc -> power_Suc
  2275 power_poly_0   -> power_0
  2276 power_poly_Suc -> power_Suc
  2277 
  2278 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  2279 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  2280 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  2281 of lemmas from Divides has been generalized from nat to class
  2282 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  2283 renames resulting from duplicate elimination:
  2284 
  2285     dvd_def_mod ~>          dvd_eq_mod_eq_0
  2286     zero_dvd_iff ~>         dvd_0_left_iff
  2287     dvd_0 ~>                dvd_0_right
  2288     DIVISION_BY_ZERO_DIV ~> div_by_0
  2289     DIVISION_BY_ZERO_MOD ~> mod_by_0
  2290     mult_div ~>             div_mult_self2_is_id
  2291     mult_mod ~>             mod_mult_self2_is_0
  2292 
  2293 * Theory IntDiv: removed many lemmas that are instances of class-based
  2294 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  2295 rename old lemmas as follows:
  2296 
  2297 dvd_diff               -> nat_dvd_diff
  2298 dvd_zminus_iff         -> dvd_minus_iff
  2299 mod_add1_eq            -> mod_add_eq
  2300 mod_mult1_eq           -> mod_mult_right_eq
  2301 mod_mult1_eq'          -> mod_mult_left_eq
  2302 mod_mult_distrib_mod   -> mod_mult_eq
  2303 nat_mod_add_left_eq    -> mod_add_left_eq
  2304 nat_mod_add_right_eq   -> mod_add_right_eq
  2305 nat_mod_div_trivial    -> mod_div_trivial
  2306 nat_mod_mod_trivial    -> mod_mod_trivial
  2307 zdiv_zadd_self1        -> div_add_self1
  2308 zdiv_zadd_self2        -> div_add_self2
  2309 zdiv_zmult_self1       -> div_mult_self2_is_id
  2310 zdiv_zmult_self2       -> div_mult_self1_is_id
  2311 zdvd_triv_left         -> dvd_triv_left
  2312 zdvd_triv_right        -> dvd_triv_right
  2313 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  2314 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  2315 zmod_zadd_left_eq      -> mod_add_left_eq
  2316 zmod_zadd_right_eq     -> mod_add_right_eq
  2317 zmod_zadd_self1        -> mod_add_self1
  2318 zmod_zadd_self2        -> mod_add_self2
  2319 zmod_zadd1_eq          -> mod_add_eq
  2320 zmod_zdiff1_eq         -> mod_diff_eq
  2321 zmod_zdvd_zmod         -> mod_mod_cancel
  2322 zmod_zmod_cancel       -> mod_mod_cancel
  2323 zmod_zmult_self1       -> mod_mult_self2_is_0
  2324 zmod_zmult_self2       -> mod_mult_self1_is_0
  2325 zmod_1                 -> mod_by_1
  2326 zdiv_1                 -> div_by_1
  2327 zdvd_abs1              -> abs_dvd_iff
  2328 zdvd_abs2              -> dvd_abs_iff
  2329 zdvd_refl              -> dvd_refl
  2330 zdvd_trans             -> dvd_trans
  2331 zdvd_zadd              -> dvd_add
  2332 zdvd_zdiff             -> dvd_diff
  2333 zdvd_zminus_iff        -> dvd_minus_iff
  2334 zdvd_zminus2_iff       -> minus_dvd_iff
  2335 zdvd_zmultD            -> dvd_mult_right
  2336 zdvd_zmultD2           -> dvd_mult_left
  2337 zdvd_zmult_mono        -> mult_dvd_mono
  2338 zdvd_0_right           -> dvd_0_right
  2339 zdvd_0_left            -> dvd_0_left_iff
  2340 zdvd_1_left            -> one_dvd
  2341 zminus_dvd_iff         -> minus_dvd_iff
  2342 
  2343 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  2344 
  2345 * The real numbers offer decimal input syntax: 12.34 is translated
  2346 into 1234/10^2. This translation is not reversed upon output.
  2347 
  2348 * Theory Library/Polynomial defines an abstract type 'a poly of
  2349 univariate polynomials with coefficients of type 'a.  In addition to
  2350 the standard ring operations, it also supports div and mod.  Code
  2351 generation is also supported, using list-style constructors.
  2352 
  2353 * Theory Library/Inner_Product defines a class of real_inner for real
  2354 inner product spaces, with an overloaded operation inner :: 'a => 'a
  2355 => real.  Class real_inner is a subclass of real_normed_vector from
  2356 theory RealVector.
  2357 
  2358 * Theory Library/Product_Vector provides instances for the product
  2359 type 'a * 'b of several classes from RealVector and Inner_Product.
  2360 Definitions of addition, subtraction, scalar multiplication, norms,
  2361 and inner products are included.
  2362 
  2363 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  2364 addition to the field operations, numerals and case syntax are also
  2365 supported.
  2366 
  2367 * Theory Library/Diagonalize provides constructive version of Cantor's
  2368 first diagonalization argument.
  2369 
  2370 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  2371 zlcm (for int); carried together from various gcd/lcm developements in
  2372 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  2373 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  2374 may recover tupled syntax as follows:
  2375 
  2376     hide (open) const gcd
  2377     abbreviation gcd where
  2378       "gcd == (%(a, b). GCD.gcd a b)"
  2379     notation (output)
  2380       GCD.gcd ("gcd '(_, _')")
  2381 
  2382 The same works for lcm, zgcd, zlcm.
  2383 
  2384 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  2385 instantiations for algebraic structures.  Removed some duplicate
  2386 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  2387 
  2388 * ML antiquotation @{code} takes a constant as argument and generates
  2389 corresponding code in background and inserts name of the corresponding
  2390 resulting ML value/function/datatype constructor binding in place.
  2391 All occurrences of @{code} with a single ML block are generated
  2392 simultaneously.  Provides a generic and safe interface for
  2393 instrumentalizing code generation.  See
  2394 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  2395 In future you ought to refrain from ad-hoc compiling generated SML
  2396 code on the ML toplevel.  Note that (for technical reasons) @{code}
  2397 cannot refer to constants for which user-defined serializations are
  2398 set.  Refer to the corresponding ML counterpart directly in that
  2399 cases.
  2400 
  2401 * Command 'rep_datatype': instead of theorem names the command now
  2402 takes a list of terms denoting the constructors of the type to be
  2403 represented as datatype.  The characteristic theorems have to be
  2404 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  2405 have disappeared in favour of existing ones:
  2406 
  2407     unit_induct                 ~> unit.induct
  2408     prod_induct                 ~> prod.induct
  2409     sum_induct                  ~> sum.induct
  2410     Suc_Suc_eq                  ~> nat.inject
  2411     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  2412 
  2413 
  2414 *** HOL-Algebra ***
  2415 
  2416 * New locales for orders and lattices where the equivalence relation
  2417 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  2418 locales use a record structure with field eq for the equivalence.
  2419 
  2420 * New theory of factorial domains.
  2421 
  2422 * Units_l_inv and Units_r_inv are now simp rules by default.
  2423 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  2424 and/or r_inv will now also require deletion of these lemmas.
  2425 
  2426 * Renamed the following theorems, INCOMPATIBILITY:
  2427 
  2428 UpperD ~> Upper_memD
  2429 LowerD ~> Lower_memD
  2430 least_carrier ~> least_closed
  2431 greatest_carrier ~> greatest_closed
  2432 greatest_Lower_above ~> greatest_Lower_below
  2433 one_zero ~> carrier_one_zero
  2434 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  2435 
  2436 
  2437 *** HOL-Nominal ***
  2438 
  2439 * Nominal datatypes can now contain type-variables.
  2440 
  2441 * Commands 'nominal_inductive' and 'equivariance' work with local
  2442 theory targets.
  2443 
  2444 * Nominal primrec can now works with local theory targets and its
  2445 specification syntax now conforms to the general format as seen in
  2446 'inductive' etc.
  2447 
  2448 * Method "perm_simp" honours the standard simplifier attributes
  2449 (no_asm), (no_asm_use) etc.
  2450 
  2451 * The new predicate #* is defined like freshness, except that on the
  2452 left hand side can be a set or list of atoms.
  2453 
  2454 * Experimental command 'nominal_inductive2' derives strong induction
  2455 principles for inductive definitions.  In contrast to
  2456 'nominal_inductive', which can only deal with a fixed number of
  2457 binders, it can deal with arbitrary expressions standing for sets of
  2458 atoms to be avoided.  The only inductive definition we have at the
  2459 moment that needs this generalisation is the typing rule for Lets in
  2460 the algorithm W:
  2461 
  2462  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  2463  -----------------------------------------------------------------
  2464          Gamma |- Let x be t1 in t2 : T2
  2465 
  2466 In this rule one wants to avoid all the binders that are introduced by
  2467 "close Gamma T1".  We are looking for other examples where this
  2468 feature might be useful.  Please let us know.
  2469 
  2470 
  2471 *** HOLCF ***
  2472 
  2473 * Reimplemented the simplification procedure for proving continuity
  2474 subgoals.  The new simproc is extensible; users can declare additional
  2475 continuity introduction rules with the attribute [cont2cont].
  2476 
  2477 * The continuity simproc now uses a different introduction rule for
  2478 solving continuity subgoals on terms with lambda abstractions.  In
  2479 some rare cases the new simproc may fail to solve subgoals that the
  2480 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  2481 Potential INCOMPATIBILITY.
  2482 
  2483 * Command 'fixrec': specification syntax now conforms to the general
  2484 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  2485 examples.  INCOMPATIBILITY.
  2486 
  2487 
  2488 *** ZF ***
  2489 
  2490 * Proof of Zorn's Lemma for partial orders.
  2491 
  2492 
  2493 *** ML ***
  2494 
  2495 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  2496 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  2497 depends on multithreading, so timouts will not work before Poly/ML
  2498 5.2.1!
  2499 
  2500 * High-level support for concurrent ML programming, see
  2501 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  2502 particularly convenient to organize independent functional
  2503 computations.  The concept of "synchronized variables" provides a
  2504 higher-order interface for components with shared state, avoiding the
  2505 delicate details of mutexes and condition variables.  (Requires
  2506 Poly/ML 5.2.1 or later.)
  2507 
  2508 * ML bindings produced via Isar commands are stored within the Isar
  2509 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  2510 become thread-safe and work with undo as expected (concerning
  2511 top-level bindings, not side-effects on global references).
  2512 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  2513 compiler at runtime; really global bindings need to be given outside a
  2514 theory.  (Requires Poly/ML 5.2 or later.)
  2515 
  2516 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  2517 context.  Top-level ML bindings are stored within the proof context in
  2518 a purely sequential fashion, disregarding the nested proof structure.
  2519 ML bindings introduced by 'ML_prf' are discarded at the end of the
  2520 proof.  (Requires Poly/ML 5.2 or later.)
  2521 
  2522 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  2523 and Method.setup, as well as Isar commands 'attribute_setup' and
  2524 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  2525 existing code accordingly, or use plain 'setup' together with old
  2526 Method.add_method.
  2527 
  2528 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  2529 to 'a -> thm, while results are always tagged with an authentic oracle
  2530 name.  The Isar command 'oracle' is now polymorphic, no argument type
  2531 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  2532 accordingly.  Note that extra performance may be gained by producing
  2533 the cterm carefully, avoiding slow Thm.cterm_of.
  2534 
  2535 * Simplified interface for defining document antiquotations via
  2536 ThyOutput.antiquotation, ThyOutput.output, and optionally
  2537 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  2538 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  2539 examples.
  2540 
  2541 * More systematic treatment of long names, abstract name bindings, and
  2542 name space operations.  Basic operations on qualified names have been
  2543 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  2544 Long_Name.append.  Old type bstring has been mostly replaced by
  2545 abstract type binding (see structure Binding), which supports precise
  2546 qualification by packages and local theory targets, as well as proper
  2547 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  2548 bstring values into Binding.name, or better pass through abstract
  2549 bindings everywhere.  See further src/Pure/General/long_name.ML,
  2550 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  2551 
  2552 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  2553 LocalTheory.note etc.) now refer to the *full* internal name, not the
  2554 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  2555 
  2556 * Disposed old type and term read functions (Sign.read_def_typ,
  2557 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  2558 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  2559 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  2560 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  2561 resort for legacy applications.
  2562 
  2563 * Disposed old declarations, tactics, tactic combinators that refer to
  2564 the simpset or claset of an implicit theory (such as Addsimps,
  2565 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  2566 embedded ML text, or local_simpset_of with a proper context passed as
  2567 explicit runtime argument.
  2568 
  2569 * Rules and tactics that read instantiations (read_instantiate,
  2570 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  2571 context, which is required for parsing and type-checking.  Moreover,
  2572 the variables are specified as plain indexnames, not string encodings
  2573 thereof.  INCOMPATIBILITY.
  2574 
  2575 * Generic Toplevel.add_hook interface allows to analyze the result of
  2576 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  2577 for theorem dependency output of transactions resulting in a new
  2578 theory state.
  2579 
  2580 * ML antiquotations: block-structured compilation context indicated by
  2581 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  2582 
  2583   @{binding name}                         - basic name binding
  2584   @{let ?pat = term}                      - term abbreviation (HO matching)
  2585   @{note name = fact}                     - fact abbreviation
  2586   @{thm fact}                             - singleton fact (with attributes)
  2587   @{thms fact}                            - general fact (with attributes)
  2588   @{lemma prop by method}                 - singleton goal
  2589   @{lemma prop by meth1 meth2}            - singleton goal
  2590   @{lemma prop1 ... propN by method}      - general goal
  2591   @{lemma prop1 ... propN by meth1 meth2} - general goal
  2592   @{lemma (open) ...}                     - open derivation
  2593 
  2594 
  2595 *** System ***
  2596 
  2597 * The Isabelle "emacs" tool provides a specific interface to invoke
  2598 Proof General / Emacs, with more explicit failure if that is not
  2599 installed (the old isabelle-interface script silently falls back on
  2600 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  2601 installation location of the Proof General distribution.
  2602 
  2603 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  2604 the Isabelle process into a JVM/Scala application.  See
  2605 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  2606 process wrapper has been discontinued.)
  2607 
  2608 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  2609 
  2610 * Various status messages (with exact source position information) are
  2611 emitted, if proper markup print mode is enabled.  This allows
  2612 user-interface components to provide detailed feedback on internal
  2613 prover operations.
  2614 
  2615 
  2616 
  2617 New in Isabelle2008 (June 2008)
  2618 -------------------------------
  2619 
  2620 *** General ***
  2621 
  2622 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  2623 and updated, with formally checked references as hyperlinks.
  2624 
  2625 * Theory loader: use_thy (and similar operations) no longer set the
  2626 implicit ML context, which was occasionally hard to predict and in
  2627 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  2628 provides a proper context already.
  2629 
  2630 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2631 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  2632 'use' within a theory file will do the job.
  2633 
  2634 * Name space merge now observes canonical order, i.e. the second space
  2635 is inserted into the first one, while existing entries in the first
  2636 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  2637 swap theory imports.
  2638 
  2639 * Syntax: symbol \<chi> is now considered a letter.  Potential
  2640 INCOMPATIBILITY in identifier syntax etc.
  2641 
  2642 * Outer syntax: string tokens no longer admit escaped white space,
  2643 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  2644 white space without escapes.
  2645 
  2646 * Outer syntax: string tokens may contain arbitrary character codes
  2647 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  2648 "foo_bar".
  2649 
  2650 
  2651 *** Pure ***
  2652 
  2653 * Context-dependent token translations.  Default setup reverts locally
  2654 fixed variables, and adds hilite markup for undeclared frees.
  2655 
  2656 * Unused theorems can be found using the new command 'unused_thms'.
  2657 There are three ways of invoking it:
  2658 
  2659 (1) unused_thms
  2660      Only finds unused theorems in the current theory.
  2661 
  2662 (2) unused_thms thy_1 ... thy_n -
  2663      Finds unused theorems in the current theory and all of its ancestors,
  2664      excluding the theories thy_1 ... thy_n and all of their ancestors.
  2665 
  2666 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  2667      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  2668      their ancestors, excluding the theories thy_1 ... thy_n and all of
  2669      their ancestors.
  2670 
  2671 In order to increase the readability of the list produced by
  2672 unused_thms, theorems that have been created by a particular instance
  2673 of a theory command such as 'inductive' or 'function' are considered
  2674 to belong to the same "group", meaning that if at least one theorem in
  2675 this group is used, the other theorems in the same group are no longer
  2676 reported as unused.  Moreover, if all theorems in the group are
  2677 unused, only one theorem in the group is displayed.
  2678 
  2679 Note that proof objects have to be switched on in order for
  2680 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  2681 usually the case when using Proof General with the default settings).
  2682 
  2683 * Authentic naming of facts disallows ad-hoc overwriting of previous
  2684 theorems within the same name space.  INCOMPATIBILITY, need to remove
  2685 duplicate fact bindings, or even accidental fact duplications.  Note
  2686 that tools may maintain dynamically scoped facts systematically, using
  2687 PureThy.add_thms_dynamic.
  2688 
  2689 * Command 'hide' now allows to hide from "fact" name space as well.
  2690 
  2691 * Eliminated destructive theorem database, simpset, claset, and
  2692 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  2693 update of theories within ML code.
  2694 
  2695 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  2696 INCOMPATIBILITY, object-logics depending on former Pure require
  2697 additional setup PureThy.old_appl_syntax_setup; object-logics
  2698 depending on former CPure need to refer to Pure.
  2699 
  2700 * Commands 'use' and 'ML' are now purely functional, operating on
  2701 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  2702 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  2703 INCOMPATIBILITY.
  2704 
  2705 * Command 'setup': discontinued implicit version with ML reference.
  2706 
  2707 * Instantiation target allows for simultaneous specification of class
  2708 instance operations together with an instantiation proof.
  2709 Type-checking phase allows to refer to class operations uniformly.
  2710 See src/HOL/Complex/Complex.thy for an Isar example and
  2711 src/HOL/Library/Eval.thy for an ML example.
  2712 
  2713 * Indexing of literal facts: be more serious about including only
  2714 facts from the visible specification/proof context, but not the
  2715 background context (locale etc.).  Affects `prop` notation and method
  2716 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  2717 situations.
  2718 
  2719 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  2720 "(open)" option, which used to expose internal bound variables to the
  2721 proof text.
  2722 
  2723 * Isar statements: removed obsolete case "rule_context".
  2724 INCOMPATIBILITY, better use explicit fixes/assumes.
  2725 
  2726 * Locale proofs: default proof step now includes 'unfold_locales';
  2727 hence 'proof' without argument may be used to unfold locale
  2728 predicates.
  2729 
  2730 
  2731 *** Document preparation ***
  2732 
  2733 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  2734 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  2735 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  2736 spot); renamed link color from "darkblue" to "linkcolor" (default
  2737 value unchanged, can be redefined via \definecolor); no longer sets
  2738 "a4paper" option (unnecessary or even intrusive).
  2739 
  2740 * Antiquotation @{lemma A method} proves proposition A by the given
  2741 method (either a method name or a method name plus (optional) method
  2742 arguments in parentheses) and prints A just like @{prop A}.
  2743 
  2744 
  2745 *** HOL ***
  2746 
  2747 * New primrec package.  Specification syntax conforms in style to
  2748 definition/function/....  No separate induction rule is provided.  The
  2749 "primrec" command distinguishes old-style and new-style specifications
  2750 by syntax.  The former primrec package is now named OldPrimrecPackage.
  2751 When adjusting theories, beware: constants stemming from new-style
  2752 primrec specifications have authentic syntax.
  2753 
  2754 * Metis prover is now an order of magnitude faster, and also works
  2755 with multithreading.
  2756 
  2757 * Metis: the maximum number of clauses that can be produced from a
  2758 theorem is now given by the attribute max_clauses.  Theorems that
  2759 exceed this number are ignored, with a warning printed.
  2760 
  2761 * Sledgehammer no longer produces structured proofs by default. To
  2762 enable, declare [[sledgehammer_full = true]].  Attributes
  2763 reconstruction_modulus, reconstruction_sorts renamed
  2764 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  2765 
  2766 * Method "induct_scheme" derives user-specified induction rules
  2767 from well-founded induction and completeness of patterns. This factors
  2768 out some operations that are done internally by the function package
  2769 and makes them available separately.  See
  2770 src/HOL/ex/Induction_Scheme.thy for examples.
  2771 
  2772 * More flexible generation of measure functions for termination
  2773 proofs: Measure functions can be declared by proving a rule of the
  2774 form "is_measure f" and giving it the [measure_function] attribute.
  2775 The "is_measure" predicate is logically meaningless (always true), and
  2776 just guides the heuristic.  To find suitable measure functions, the
  2777 termination prover sets up the goal "is_measure ?f" of the appropriate
  2778 type and generates all solutions by prolog-style backwards proof using
  2779 the declared rules.
  2780 
  2781 This setup also deals with rules like 
  2782 
  2783   "is_measure f ==> is_measure (list_size f)"
  2784 
  2785 which accommodates nested datatypes that recurse through lists.
  2786 Similar rules are predeclared for products and option types.
  2787 
  2788 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  2789 
  2790   INCOMPATIBILITIES:
  2791 
  2792   - Definitions of overloaded constants on sets have to be replaced by
  2793     definitions on => and bool.
  2794 
  2795   - Some definitions of overloaded operators on sets can now be proved
  2796     using the definitions of the operators on => and bool.  Therefore,
  2797     the following theorems have been renamed:
  2798 
  2799       subset_def   -> subset_eq
  2800       psubset_def  -> psubset_eq
  2801       set_diff_def -> set_diff_eq
  2802       Compl_def    -> Compl_eq
  2803       Sup_set_def  -> Sup_set_eq
  2804       Inf_set_def  -> Inf_set_eq
  2805       sup_set_def  -> sup_set_eq
  2806       inf_set_def  -> inf_set_eq
  2807 
  2808   - Due to the incompleteness of the HO unification algorithm, some
  2809     rules such as subst may require manual instantiation, if some of
  2810     the unknowns in the rule is a set.
  2811 
  2812   - Higher order unification and forward proofs:
  2813     The proof pattern
  2814 
  2815       have "P (S::'a set)" <...>
  2816       then have "EX S. P S" ..
  2817 
  2818     no longer works (due to the incompleteness of the HO unification
  2819     algorithm) and must be replaced by the pattern
  2820 
  2821       have "EX S. P S"
  2822       proof
  2823         show "P S" <...>
  2824       qed
  2825 
  2826   - Calculational reasoning with subst (or similar rules):
  2827     The proof pattern
  2828 
  2829       have "P (S::'a set)" <...>
  2830       also have "S = T" <...>
  2831       finally have "P T" .
  2832 
  2833     no longer works (for similar reasons as the previous example) and
  2834     must be replaced by something like
  2835 
  2836       have "P (S::'a set)" <...>
  2837       moreover have "S = T" <...>
  2838       ultimately have "P T" by simp
  2839 
  2840   - Tactics or packages written in ML code:
  2841     Code performing pattern matching on types via
  2842 
  2843       Type ("set", [T]) => ...
  2844 
  2845     must be rewritten. Moreover, functions like strip_type or
  2846     binder_types no longer return the right value when applied to a
  2847     type of the form
  2848 
  2849       T1 => ... => Tn => U => bool
  2850 
  2851     rather than
  2852 
  2853       T1 => ... => Tn => U set
  2854 
  2855 * Merged theories Wellfounded_Recursion, Accessible_Part and
  2856 Wellfounded_Relations to theory Wellfounded.
  2857 
  2858 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  2859 
  2860 * Class finite no longer treats UNIV as class parameter.  Use class
  2861 enum from theory Library/Enum instead to achieve a similar effect.
  2862 INCOMPATIBILITY.
  2863 
  2864 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  2865 and "Cons".  INCOMPATIBILITY.
  2866 
  2867 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  2868 Potential INCOMPATIBILITY.
  2869 
  2870 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  2871 injective_fst_snd removed, use split_eta and prod_eqI instead.
  2872 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  2873 
  2874 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  2875 the same name in theory Orderings:
  2876 
  2877   less_trans
  2878   less_linear
  2879   le_imp_less_or_eq
  2880   le_less_trans
  2881   less_le_trans
  2882   less_not_sym
  2883   less_asym
  2884 
  2885 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  2886 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  2887 and different variable names.
  2888 
  2889 * Library/Option_ord.thy: Canonical order on option type.
  2890 
  2891 * Library/RBT.thy: Red-black trees, an efficient implementation of
  2892 finite maps.
  2893 
  2894 * Library/Countable.thy: Type class for countable types.
  2895 
  2896 * Theory Int: The representation of numerals has changed.  The infix
  2897 operator BIT and the bit datatype with constructors B0 and B1 have
  2898 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  2899 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  2900 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  2901 accordingly.
  2902 
  2903 * Theory Nat: definition of <= and < on natural numbers no longer
  2904 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  2905 le_def and less_def have disappeared.  Consider lemmas not_less
  2906 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  2907 
  2908 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  2909 (whose purpose mainly is for various fold_set functionals) have been
  2910 abandoned in favor of the existing algebraic classes
  2911 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  2912 lower_semilattice (resp. upper_semilattice) and linorder.
  2913 INCOMPATIBILITY.
  2914 
  2915 * Theory Transitive_Closure: induct and cases rules now declare proper
  2916 case_names ("base" and "step").  INCOMPATIBILITY.
  2917 
  2918 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  2919 lattices.  The form set-specific version is available as
  2920 Inductive.lfp_ordinal_induct_set.
  2921 
  2922 * Renamed theorems "power.simps" to "power_int.simps".
  2923 INCOMPATIBILITY.
  2924 
  2925 * Class semiring_div provides basic abstract properties of semirings
  2926 with division and modulo operations.  Subsumes former class dvd_mod.
  2927 
  2928 * Merged theories IntDef, Numeral and IntArith into unified theory
  2929 Int.  INCOMPATIBILITY.
  2930 
  2931 * Theory Library/Code_Index: type "index" now represents natural
  2932 numbers rather than integers.  INCOMPATIBILITY.
  2933 
  2934 * New class "uminus" with operation "uminus" (split of from class
  2935 "minus" which now only has operation "minus", binary).
  2936 INCOMPATIBILITY.
  2937 
  2938 * Constants "card", "internal_split", "option_map" now with authentic
  2939 syntax.  INCOMPATIBILITY.
  2940 
  2941 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  2942 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  2943 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  2944 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  2945 Sup_set_def, le_def, less_def, option_map_def now with object
  2946 equality.  INCOMPATIBILITY.
  2947 
  2948 * Records. Removed K_record, and replaced it by pure lambda term
  2949 %x. c. The simplifier setup is now more robust against eta expansion.
  2950 INCOMPATIBILITY: in cases explicitly referring to K_record.
  2951 
  2952 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  2953 
  2954 * Library/ListVector: new theory of arithmetic vector operations.
  2955 
  2956 * Library/Order_Relation: new theory of various orderings as sets of
  2957 pairs.  Defines preorders, partial orders, linear orders and
  2958 well-orders on sets and on types.
  2959 
  2960 
  2961 *** ZF ***
  2962 
  2963 * Renamed some theories to allow to loading both ZF and HOL in the
  2964 same session:
  2965 
  2966   Datatype  -> Datatype_ZF
  2967   Inductive -> Inductive_ZF
  2968   Int       -> Int_ZF
  2969   IntDiv    -> IntDiv_ZF
  2970   Nat       -> Nat_ZF
  2971   List      -> List_ZF
  2972   Main      -> Main_ZF
  2973 
  2974 INCOMPATIBILITY: ZF theories that import individual theories below
  2975 Main might need to be adapted.  Regular theory Main is still
  2976 available, as trivial extension of Main_ZF.
  2977 
  2978 
  2979 *** ML ***
  2980 
  2981 * ML within Isar: antiquotation @{const name} or @{const
  2982 name(typargs)} produces statically-checked Const term.
  2983 
  2984 * Functor NamedThmsFun: data is available to the user as dynamic fact
  2985 (of the same name).  Removed obsolete print command.
  2986 
  2987 * Removed obsolete "use_legacy_bindings" function.
  2988 
  2989 * The ``print mode'' is now a thread-local value derived from a global
  2990 template (the former print_mode reference), thus access becomes
  2991 non-critical.  The global print_mode reference is for session
  2992 management only; user-code should use print_mode_value,
  2993 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  2994 
  2995 * Functions system/system_out provide a robust way to invoke external
  2996 shell commands, with propagation of interrupts (requires Poly/ML
  2997 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  2998 
  2999 
  3000 *** System ***
  3001 
  3002 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  3003 in accordance with Proof General 3.7, which prefers GNU emacs.
  3004 
  3005 * isatool tty runs Isabelle process with plain tty interaction;
  3006 optional line editor may be specified via ISABELLE_LINE_EDITOR
  3007 setting, the default settings attempt to locate "ledit" and "rlwrap".
  3008 
  3009 * isatool browser now works with Cygwin as well, using general
  3010 "javapath" function defined in Isabelle process environment.
  3011 
  3012 * YXML notation provides a simple and efficient alternative to
  3013 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  3014 isatool yxml as described in the Isabelle system manual.
  3015 
  3016 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  3017 provides general wrapper for managing an Isabelle process in a robust
  3018 fashion, with ``cooked'' output from stdin/stderr.
  3019 
  3020 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  3021 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  3022 
  3023 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  3024 way of changing the user's settings is via
  3025 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  3026 script.
  3027 
  3028 * Multithreading.max_threads := 0 refers to the number of actual CPU
  3029 cores of the underlying machine, which is a good starting point for
  3030 optimal performance tuning.  The corresponding usedir option -M allows
  3031 "max" as an alias for "0".  WARNING: does not work on certain versions
  3032 of Mac OS (with Poly/ML 5.1).
  3033 
  3034 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  3035 adverse effect of Isabelle flooding interactive front-ends (notably
  3036 ProofGeneral / XEmacs).
  3037 
  3038 
  3039 
  3040 New in Isabelle2007 (November 2007)
  3041 -----------------------------------
  3042 
  3043 *** General ***
  3044 
  3045 * More uniform information about legacy features, notably a
  3046 warning/error of "Legacy feature: ...", depending on the state of the
  3047 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  3048 legacy features will disappear eventually.
  3049 
  3050 * Theory syntax: the header format ``theory A = B + C:'' has been
  3051 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  3052 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  3053 
  3054 * Theory syntax: the old non-Isar theory file format has been
  3055 discontinued altogether.  Note that ML proof scripts may still be used
  3056 with Isar theories; migration is usually quite simple with the ML
  3057 function use_legacy_bindings.  INCOMPATIBILITY.
  3058 
  3059 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  3060 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  3061 quotes.
  3062 
  3063 * Theory loader: be more serious about observing the static theory
  3064 header specifications (including optional directories), but not the
  3065 accidental file locations of previously successful loads.  The strict
  3066 update policy of former update_thy is now already performed by
  3067 use_thy, so the former has been removed; use_thys updates several
  3068 theories simultaneously, just as 'imports' within a theory header
  3069 specification, but without merging the results.  Potential
  3070 INCOMPATIBILITY: may need to refine theory headers and commands
  3071 ROOT.ML which depend on load order.
  3072 
  3073 * Theory loader: optional support for content-based file
  3074 identification, instead of the traditional scheme of full physical
  3075 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  3076 (cf. the system manual).  The new scheme allows to work with
  3077 non-finished theories in persistent session images, such that source
  3078 files may be moved later on without requiring reloads.
  3079 
  3080 * Theory loader: old-style ML proof scripts being *attached* to a thy
  3081 file (with the same base name as the theory) are considered a legacy
  3082 feature, which will disappear eventually. Even now, the theory loader
  3083 no longer maintains dependencies on such files.
  3084 
  3085 * Syntax: the scope for resolving ambiguities via type-inference is
  3086 now limited to individual terms, instead of whole simultaneous
  3087 specifications as before. This greatly reduces the complexity of the
  3088 syntax module and improves flexibility by separating parsing and
  3089 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  3090 'fixes' etc.) are required in rare situations.
  3091 
  3092 * Syntax: constants introduced by new-style packages ('definition',
  3093 'abbreviation' etc.) are passed through the syntax module in
  3094 ``authentic mode''. This means that associated mixfix annotations
  3095 really stick to such constants, independently of potential name space
  3096 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  3097 trees are represented slightly differently, may need to adapt syntax
  3098 translations accordingly. Use CONST marker in 'translations' and
  3099 @{const_syntax} antiquotation in 'parse_translation' etc.
  3100 
  3101 * Legacy goal package: reduced interface to the bare minimum required
  3102 to keep existing proof scripts running.  Most other user-level
  3103 functions are now part of the OldGoals structure, which is *not* open
  3104 by default (consider isatool expandshort before open OldGoals).
  3105 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  3106 these tend to cause confusion about the actual goal (!) context being
  3107 used here, which is not necessarily the same as the_context().
  3108 
  3109 * Command 'find_theorems': supports "*" wild-card in "name:"
  3110 criterion; "with_dups" option.  Certain ProofGeneral versions might
  3111 support a specific search form (see ProofGeneral/CHANGES).
  3112 
  3113 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  3114 by default, which means that "prems" (and also "fixed variables") are
  3115 suppressed from proof state output.  Note that the ProofGeneral
  3116 settings mechanism allows to change and save options persistently, but
  3117 older versions of Isabelle will fail to start up if a negative prems
  3118 limit is imposed.
  3119 
  3120 * Local theory targets may be specified by non-nested blocks of
  3121 ``context/locale/class ... begin'' followed by ``end''.  The body may
  3122 contain definitions, theorems etc., including any derived mechanism
  3123 that has been implemented on top of these primitives.  This concept
  3124 generalizes the existing ``theorem (in ...)'' towards more versatility
  3125 and scalability.
  3126 
  3127 * Proof General interface: proper undo of final 'end' command;
  3128 discontinued Isabelle/classic mode (ML proof scripts).
  3129 
  3130 
  3131 *** Document preparation ***
  3132 
  3133 * Added antiquotation @{theory name} which prints the given name,
  3134 after checking that it refers to a valid ancestor theory in the
  3135 current context.
  3136 
  3137 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  3138 check the given source text as ML type/structure, printing verbatim.
  3139 
  3140 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  3141 "c args == rhs" given in the current context.  (Any number of
  3142 arguments may be given on the LHS.)
  3143 
  3144 
  3145 *** Pure ***
  3146 
  3147 * The 'class' package offers a combination of axclass and locale to
  3148 achieve Haskell-like type classes in Isabelle.  Definitions and
  3149 theorems within a class context produce both relative results (with
  3150 implicit parameters according to the locale context), and polymorphic
  3151 constants with qualified polymorphism (according to the class
  3152 context).  Within the body context of a 'class' target, a separate
  3153 syntax layer ("user space type system") takes care of converting
  3154 between global polymorphic consts and internal locale representation.
  3155 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  3156 "isatool doc classes" provides a tutorial.
  3157 
  3158 * Generic code generator framework allows to generate executable
  3159 code for ML and Haskell (including Isabelle classes).  A short usage
  3160 sketch:
  3161 
  3162     internal compilation:
  3163         export_code <list of constants (term syntax)> in SML
  3164     writing SML code to a file:
  3165         export_code <list of constants (term syntax)> in SML <filename>
  3166     writing OCaml code to a file:
  3167         export_code <list of constants (term syntax)> in OCaml <filename>
  3168     writing Haskell code to a bunch of files:
  3169         export_code <list of constants (term syntax)> in Haskell <filename>
  3170 
  3171     evaluating closed propositions to True/False using code generation:
  3172         method ``eval''
  3173 
  3174 Reasonable default setup of framework in HOL.
  3175 
  3176 Theorem attributs for selecting and transforming function equations theorems:
  3177 
  3178     [code fun]:        select a theorem as function equation for a specific constant
  3179     [code fun del]:    deselect a theorem as function equation for a specific constant
  3180     [code inline]:     select an equation theorem for unfolding (inlining) in place
  3181     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  3182 
  3183 User-defined serializations (target in {SML, OCaml, Haskell}):
  3184 
  3185     code_const <and-list of constants (term syntax)>
  3186       {(target) <and-list of const target syntax>}+
  3187 
  3188     code_type <and-list of type constructors>
  3189       {(target) <and-list of type target syntax>}+
  3190 
  3191     code_instance <and-list of instances>
  3192       {(target)}+
  3193         where instance ::= <type constructor> :: <class>
  3194 
  3195     code_class <and_list of classes>
  3196       {(target) <and-list of class target syntax>}+
  3197         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  3198 
  3199 code_instance and code_class only are effective to target Haskell.
  3200 
  3201 For example usage see src/HOL/ex/Codegenerator.thy and
  3202 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  3203 generation from Isabelle/HOL theories is available via "isatool doc
  3204 codegen".
  3205 
  3206 * Code generator: consts in 'consts_code' Isar commands are now
  3207 referred to by usual term syntax (including optional type
  3208 annotations).
  3209 
  3210 * Command 'no_translations' removes translation rules from theory
  3211 syntax.
  3212 
  3213 * Overloaded definitions are now actually checked for acyclic
  3214 dependencies.  The overloading scheme is slightly more general than
  3215 that of Haskell98, although Isabelle does not demand an exact
  3216 correspondence to type class and instance declarations.
  3217 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  3218 exotic versions of overloading -- at the discretion of the user!
  3219 
  3220 Polymorphic constants are represented via type arguments, i.e. the
  3221 instantiation that matches an instance against the most general
  3222 declaration given in the signature.  For example, with the declaration
  3223 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  3224 as c(nat).  Overloading is essentially simultaneous structural
  3225 recursion over such type arguments.  Incomplete specification patterns
  3226 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  3227 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  3228 Command 'print_theory' outputs the normalized system of recursive
  3229 equations, see section "definitions".
  3230 
  3231 * Configuration options are maintained within the theory or proof
  3232 context (with name and type bool/int/string), providing a very simple
  3233 interface to a poor-man's version of general context data.  Tools may
  3234 declare options in ML (e.g. using Attrib.config_int) and then refer to
  3235 these values using Config.get etc.  Users may change options via an
  3236 associated attribute of the same name.  This form of context
  3237 declaration works particularly well with commands 'declare' or
  3238 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  3239 very easy to avoid global references, which would not observe Isar
  3240 toplevel undo/redo and fail to work with multithreading.
  3241 
  3242 Various global ML references of Pure and HOL have been turned into
  3243 configuration options:
  3244 
  3245   Unify.search_bound		unify_search_bound
  3246   Unify.trace_bound		unify_trace_bound
  3247   Unify.trace_simp		unify_trace_simp
  3248   Unify.trace_types		unify_trace_types
  3249   Simplifier.simp_depth_limit	simp_depth_limit
  3250   Blast.depth_limit		blast_depth_limit
  3251   DatatypeProp.dtK		datatype_distinctness_limit
  3252   fast_arith_neq_limit  	fast_arith_neq_limit
  3253   fast_arith_split_limit	fast_arith_split_limit
  3254 
  3255 * Named collections of theorems may be easily installed as context
  3256 data using the functor NamedThmsFun (see also
  3257 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  3258 attributes; there is also a toplevel print command.  This facility is
  3259 just a common case of general context data, which is the preferred way
  3260 for anything more complex than just a list of facts in canonical
  3261 order.
  3262 
  3263 * Isar: command 'declaration' augments a local theory by generic
  3264 declaration functions written in ML.  This enables arbitrary content
  3265 being added to the context, depending on a morphism that tells the
  3266 difference of the original declaration context wrt. the application
  3267 context encountered later on.
  3268 
  3269 * Isar: proper interfaces for simplification procedures.  Command
  3270 'simproc_setup' declares named simprocs (with match patterns, and body
  3271 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  3272 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  3273 
  3274 * Isar: an extra pair of brackets around attribute declarations
  3275 abbreviates a theorem reference involving an internal dummy fact,
  3276 which will be ignored later --- only the effect of the attribute on
  3277 the background context will persist.  This form of in-place
  3278 declarations is particularly useful with commands like 'declare' and
  3279 'using', for example ``have A using [[simproc a]] by simp''.
  3280 
  3281 * Isar: method "assumption" (and implicit closing of subproofs) now
  3282 takes simple non-atomic goal assumptions into account: after applying
  3283 an assumption as a rule the resulting subgoals are solved by atomic
  3284 assumption steps.  This is particularly useful to finish 'obtain'
  3285 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  3286 without referring to the original premise "!!x. P x ==> thesis" in the
  3287 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  3288 more permissive.
  3289 
  3290 * Isar: implicit use of prems from the Isar proof context is
  3291 considered a legacy feature.  Common applications like ``have A .''
  3292 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  3293 referencing facts explicitly here improves readability and
  3294 maintainability of proof texts.
  3295 
  3296 * Isar: improper proof element 'guess' is like 'obtain', but derives
  3297 the obtained context from the course of reasoning!  For example:
  3298 
  3299   assume "EX x y. A x & B y"   -- "any previous fact"
  3300   then guess x and y by clarify
  3301 
  3302 This technique is potentially adventurous, depending on the facts and
  3303 proof tools being involved here.
  3304 
  3305 * Isar: known facts from the proof context may be specified as literal
  3306 propositions, using ASCII back-quote syntax.  This works wherever
  3307 named facts used to be allowed so far, in proof commands, proof
  3308 methods, attributes etc.  Literal facts are retrieved from the context
  3309 according to unification of type and term parameters.  For example,
  3310 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  3311 theorems in the current context, then these are valid literal facts:
  3312 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  3313 
  3314 There is also a proof method "fact" which does the same composition
  3315 for explicit goal states, e.g. the following proof texts coincide with
  3316 certain special cases of literal facts:
  3317 
  3318   have "A" by fact                 ==  note `A`
  3319   have "A ==> B" by fact           ==  note `A ==> B`
  3320   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  3321   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  3322 
  3323 * Isar: ":" (colon) is no longer a symbolic identifier character in
  3324 outer syntax.  Thus symbolic identifiers may be used without
  3325 additional white space in declarations like this: ``assume *: A''.
  3326 
  3327 * Isar: 'print_facts' prints all local facts of the current context,
  3328 both named and unnamed ones.
  3329 
  3330 * Isar: 'def' now admits simultaneous definitions, e.g.:
  3331 
  3332   def x == "t" and y == "u"
  3333 
  3334 * Isar: added command 'unfolding', which is structurally similar to
  3335 'using', but affects both the goal state and facts by unfolding given
  3336 rewrite rules.  Thus many occurrences of the 'unfold' method or
  3337 'unfolded' attribute may be replaced by first-class proof text.
  3338 
  3339 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  3340 and command 'unfolding' now all support object-level equalities
  3341 (potentially conditional).  The underlying notion of rewrite rule is
  3342 analogous to the 'rule_format' attribute, but *not* that of the
  3343 Simplifier (which is usually more generous).
  3344 
  3345 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  3346 premises of a theorem by n. Useful in conjunction with drule.
  3347 
  3348 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  3349 method expression within a sandbox consisting of the first N
  3350 sub-goals, which need to exist.  For example, ``simp_all [3]''
  3351 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  3352 simplifies all new goals that emerge from applying rule foo to the
  3353 originally first one.
  3354 
  3355 * Isar: schematic goals are no longer restricted to higher-order
  3356 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  3357 expected.
  3358 
  3359 * Isar: the conclusion of a long theorem statement is now either
  3360 'shows' (a simultaneous conjunction, as before), or 'obtains'
  3361 (essentially a disjunction of cases with local parameters and
  3362 assumptions).  The latter allows to express general elimination rules
  3363 adequately; in this notation common elimination rules look like this:
  3364 
  3365   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  3366     assumes "EX x. P x"
  3367     obtains x where "P x"
  3368 
  3369   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  3370     assumes "A & B"
  3371     obtains A and B
  3372 
  3373   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  3374     assumes "A | B"
  3375     obtains
  3376       A
  3377     | B
  3378 
  3379 The subsequent classical rules even refer to the formal "thesis"
  3380 explicitly:
  3381 
  3382   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  3383     obtains "~ thesis"
  3384 
  3385   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  3386     obtains "thesis ==> something"
  3387 
  3388 The actual proof of an 'obtains' statement is analogous to that of the
  3389 Isar proof element 'obtain', only that there may be several cases.
  3390 Optional case names may be specified in parentheses; these will be
  3391 available both in the present proof and as annotations in the
  3392 resulting rule, for later use with the 'cases' method (cf. attribute
  3393 case_names).
  3394 
  3395 * Isar: the assumptions of a long theorem statement are available as
  3396 "assms" fact in the proof context.  This is more appropriate than the
  3397 (historical) "prems", which refers to all assumptions of the current
  3398 context, including those from the target locale, proof body etc.
  3399 
  3400 * Isar: 'print_statement' prints theorems from the current theory or
  3401 proof context in long statement form, according to the syntax of a
  3402 top-level lemma.
  3403 
  3404 * Isar: 'obtain' takes an optional case name for the local context
  3405 introduction rule (default "that").
  3406 
  3407 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  3408 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  3409 to occur.
  3410 
  3411 * Pure: syntax "CONST name" produces a fully internalized constant
  3412 according to the current context.  This is particularly useful for
  3413 syntax translations that should refer to internal constant
  3414 representations independently of name spaces.
  3415 
  3416 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  3417 instead of "FOO ". This allows multiple binder declarations to coexist
  3418 in the same context.  INCOMPATIBILITY.
  3419 
  3420 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  3421 primitive that also works in a locale context (both for constants and
  3422 fixed variables). Type declaration and internal syntactic representation
  3423 of given constants retrieved from the context. Likewise, the
  3424 'no_notation' command allows to remove given syntax annotations from the
  3425 current context.
  3426 
  3427 * Isar/locales: new derived specification elements 'axiomatization',
  3428 'definition', 'abbreviation', which support type-inference, admit
  3429 object-level specifications (equality, equivalence).  See also the
  3430 isar-ref manual.  Examples:
  3431 
  3432   axiomatization
  3433     eq  (infix "===" 50) where
  3434     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  3435 
  3436   definition "f x y = x + y + 1"
  3437   definition g where "g x = f x x"
  3438 
  3439   abbreviation
  3440     neq  (infix "=!=" 50) where
  3441     "x =!= y == ~ (x === y)"
  3442 
  3443 These specifications may be also used in a locale context.  Then the
  3444 constants being introduced depend on certain fixed parameters, and the
  3445 constant name is qualified by the locale base name.  An internal
  3446 abbreviation takes care for convenient input and output, making the
  3447 parameters implicit and using the original short name.  See also
  3448 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  3449 entities from a monomorphic theory.
  3450 
  3451 Presently, abbreviations are only available 'in' a target locale, but
  3452 not inherited by general import expressions.  Also note that
  3453 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  3454 'translations' in common applications.  The "no_abbrevs" print mode
  3455 prevents folding of abbreviations in term output.
  3456 
  3457 Concrete syntax is attached to specified constants in internal form,
  3458 independently of name spaces.  The parse tree representation is
  3459 slightly different -- use 'notation' instead of raw 'syntax', and
  3460 'translations' with explicit "CONST" markup to accommodate this.
  3461 
  3462 * Pure/Isar: unified syntax for new-style specification mechanisms
  3463 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  3464 full type inference and dummy patterns ("_").  For example:
  3465 
  3466   definition "K x _ = x"
  3467 
  3468   inductive conj for A B
  3469   where "A ==> B ==> conj A B"
  3470 
  3471 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  3472 the current context.  Print mode "no_abbrevs" prevents inversion of
  3473 abbreviations on output.
  3474 
  3475 * Isar/locales: improved parameter handling: use of locales "var" and
  3476 "struct" no longer necessary; - parameter renamings are no longer
  3477 required to be injective.  For example, this allows to define
  3478 endomorphisms as locale endom = homom mult mult h.
  3479 
  3480 * Isar/locales: changed the way locales with predicates are defined.
  3481 Instead of accumulating the specification, the imported expression is
  3482 now an interpretation.  INCOMPATIBILITY: different normal form of
  3483 locale expressions.  In particular, in interpretations of locales with
  3484 predicates, goals repesenting already interpreted fragments are not
  3485 removed automatically.  Use methods `intro_locales' and
  3486 `unfold_locales'; see below.
  3487 
  3488 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  3489 provide backward reasoning on locales predicates.  The methods are
  3490 aware of interpretations and discharge corresponding goals.
  3491 `intro_locales' is less aggressive then `unfold_locales' and does not
  3492 unfold predicates to assumptions.
  3493 
  3494 * Isar/locales: the order in which locale fragments are accumulated
  3495 has changed.  This enables to override declarations from fragments due
  3496 to interpretations -- for example, unwanted simp rules.
  3497 
  3498 * Isar/locales: interpretation in theories and proof contexts has been
  3499 extended.  One may now specify (and prove) equations, which are
  3500 unfolded in interpreted theorems.  This is useful for replacing
  3501 defined concepts (constants depending on locale parameters) by
  3502 concepts already existing in the target context.  Example:
  3503 
  3504   interpretation partial_order ["op <= :: [int, int] => bool"]
  3505     where "partial_order.less (op <=) (x::int) y = (x < y)"
  3506 
  3507 Typically, the constant `partial_order.less' is created by a
  3508 definition specification element in the context of locale
  3509 partial_order.
  3510 
  3511 * Method "induct": improved internal context management to support
  3512 local fixes and defines on-the-fly. Thus explicit meta-level
  3513 connectives !!  and ==> are rarely required anymore in inductive goals
  3514 (using object-logic connectives for this purpose has been long
  3515 obsolete anyway). Common proof patterns are explained in
  3516 src/HOL/Induct/Common_Patterns.thy, see also
  3517 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  3518 examples.
  3519 
  3520 * Method "induct": improved handling of simultaneous goals. Instead of
  3521 introducing object-level conjunction, the statement is now split into
  3522 several conclusions, while the corresponding symbolic cases are nested
  3523 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  3524 see src/HOL/Induct/Common_Patterns.thy, for example.
  3525 
  3526 * Method "induct": mutual induction rules are now specified as a list
  3527 of rule sharing the same induction cases. HOL packages usually provide
  3528 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  3529 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  3530 mutual induction rules differently, i.e. like this:
  3531 
  3532   (induct rule: foo_bar.inducts)
  3533   (induct set: foo bar)
  3534   (induct pred: foo bar)
  3535   (induct type: foo bar)
  3536 
  3537 The ML function ProjectRule.projections turns old-style rules into the
  3538 new format.
  3539 
  3540 * Method "coinduct": dual of induction, see
  3541 src/HOL/Library/Coinductive_List.thy for various examples.
  3542 
  3543 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  3544 considered a legacy feature.
  3545 
  3546 * Attribute "symmetric" produces result with standardized schematic
  3547 variables (index 0).  Potential INCOMPATIBILITY.
  3548 
  3549 * Simplifier: by default the simplifier trace only shows top level
  3550 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  3551 default. Thus there is less danger of being flooded by the trace. The
  3552 trace indicates where parts have been suppressed.
  3553   
  3554 * Provers/classical: removed obsolete classical version of elim_format
  3555 attribute; classical elim/dest rules are now treated uniformly when
  3556 manipulating the claset.
  3557 
  3558 * Provers/classical: stricter checks to ensure that supplied intro,
  3559 dest and elim rules are well-formed; dest and elim rules must have at
  3560 least one premise.
  3561 
  3562 * Provers/classical: attributes dest/elim/intro take an optional
  3563 weight argument for the rule (just as the Pure versions).  Weights are
  3564 ignored by automated tools, but determine the search order of single
  3565 rule steps.
  3566 
  3567 * Syntax: input syntax now supports dummy variable binding "%_. b",
  3568 where the body does not mention the bound variable.  Note that dummy
  3569 patterns implicitly depend on their context of bounds, which makes
  3570 "{_. _}" match any set comprehension as expected.  Potential
  3571 INCOMPATIBILITY -- parse translations need to cope with syntactic
  3572 constant "_idtdummy" in the binding position.
  3573 
  3574 * Syntax: removed obsolete syntactic constant "_K" and its associated
  3575 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  3576 for example "A -> B" => "Pi A (%_. B)".
  3577 
  3578 * Pure: 'class_deps' command visualizes the subclass relation, using
  3579 the graph browser tool.
  3580 
  3581 * Pure: 'print_theory' now suppresses certain internal declarations by
  3582 default; use '!' option for full details.
  3583 
  3584 
  3585 *** HOL ***
  3586 
  3587 * Method "metis" proves goals by applying the Metis general-purpose
  3588 resolution prover (see also http://gilith.com/software/metis/).
  3589 Examples are in the directory MetisExamples.  WARNING: the
  3590 Isabelle/HOL-Metis integration does not yet work properly with
  3591 multi-threading.
  3592   
  3593 * Command 'sledgehammer' invokes external automatic theorem provers as
  3594 background processes.  It generates calls to the "metis" method if
  3595 successful. These can be pasted into the proof.  Users do not have to
  3596 wait for the automatic provers to return.  WARNING: does not really
  3597 work with multi-threading.
  3598 
  3599 * New "auto_quickcheck" feature tests outermost goal statements for
  3600 potential counter-examples.  Controlled by ML references
  3601 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  3602 5000 milliseconds).  Fails silently if statements is outside of
  3603 executable fragment, or any other codgenerator problem occurs.
  3604 
  3605 * New constant "undefined" with axiom "undefined x = undefined".
  3606 
  3607 * Added class "HOL.eq", allowing for code generation with polymorphic
  3608 equality.
  3609 
  3610 * Some renaming of class constants due to canonical name prefixing in
  3611 the new 'class' package:
  3612 
  3613     HOL.abs ~> HOL.abs_class.abs
  3614     HOL.divide ~> HOL.divide_class.divide
  3615     0 ~> HOL.zero_class.zero
  3616     1 ~> HOL.one_class.one
  3617     op + ~> HOL.plus_class.plus
  3618     op - ~> HOL.minus_class.minus
  3619     uminus ~> HOL.minus_class.uminus
  3620     op * ~> HOL.times_class.times
  3621     op < ~> HOL.ord_class.less
  3622     op <= > HOL.ord_class.less_eq
  3623     Nat.power ~> Power.power_class.power
  3624     Nat.size ~> Nat.size_class.size
  3625     Numeral.number_of ~> Numeral.number_class.number_of
  3626     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  3627     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  3628     Orderings.min ~> Orderings.ord_class.min
  3629     Orderings.max ~> Orderings.ord_class.max
  3630     Divides.op div ~> Divides.div_class.div
  3631     Divides.op mod ~> Divides.div_class.mod
  3632     Divides.op dvd ~> Divides.div_class.dvd
  3633 
  3634 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  3635 
  3636 a) User-defined constants using any of the names "plus", "minus",
  3637 "times", "less" or "less_eq". The standard syntax translations for
  3638 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  3639 names.
  3640 
  3641 b) Variables named "plus", "minus", "times", "less", "less_eq"
  3642 INCOMPATIBILITY: use more specific names.
  3643 
  3644 c) Permutative equations (e.g. "a + b = b + a")
  3645 Since the change of names also changes the order of terms, permutative
  3646 rewrite rules may get applied in a different order. Experience shows
  3647 that this is rarely the case (only two adaptions in the whole Isabelle
  3648 distribution).  INCOMPATIBILITY: rewrite proofs
  3649 
  3650 d) ML code directly refering to constant names
  3651 This in general only affects hand-written proof tactics, simprocs and
  3652 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  3653 Consider using @{const_name} antiquotation.
  3654 
  3655 * New class "default" with associated constant "default".
  3656 
  3657 * Function "sgn" is now overloaded and available on int, real, complex
  3658 (and other numeric types), using class "sgn".  Two possible defs of
  3659 sgn are given as equational assumptions in the classes sgn_if and
  3660 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  3661 INCOMPATIBILITY.
  3662 
  3663 * Locale "partial_order" now unified with class "order" (cf. theory
  3664 Orderings), added parameter "less".  INCOMPATIBILITY.
  3665 
  3666 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  3667 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  3668 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  3669 
  3670 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  3671 changed order of proof goals in instance proofs.
  3672 
  3673 * The transitivity reasoner for partial and linear orders is set up
  3674 for classes "order" and "linorder".  Instances of the reasoner are available
  3675 in all contexts importing or interpreting the corresponding locales.
  3676 Method "order" invokes the reasoner separately; the reasoner
  3677 is also integrated with the Simplifier as a solver.  Diagnostic
  3678 command 'print_orders' shows the available instances of the reasoner
  3679 in the current context.
  3680 
  3681 * Localized monotonicity predicate in theory "Orderings"; integrated
  3682 lemmas max_of_mono and min_of_mono with this predicate.
  3683 INCOMPATIBILITY.
  3684 
  3685 * Formulation of theorem "dense" changed slightly due to integration
  3686 with new class dense_linear_order.
  3687 
  3688 * Uniform lattice theory development in HOL.
  3689 
  3690     constants "meet" and "join" now named "inf" and "sup"
  3691     constant "Meet" now named "Inf"
  3692 
  3693     classes "meet_semilorder" and "join_semilorder" now named
  3694       "lower_semilattice" and "upper_semilattice"
  3695     class "lorder" now named "lattice"
  3696     class "comp_lat" now named "complete_lattice"
  3697 
  3698     Instantiation of lattice classes allows explicit definitions
  3699     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  3700 
  3701   INCOMPATIBILITY.  Theorem renames:
  3702 
  3703     meet_left_le            ~> inf_le1
  3704     meet_right_le           ~> inf_le2
  3705     join_left_le            ~> sup_ge1
  3706     join_right_le           ~> sup_ge2
  3707     meet_join_le            ~> inf_sup_ord
  3708     le_meetI                ~> le_infI
  3709     join_leI                ~> le_supI
  3710     le_meet                 ~> le_inf_iff
  3711     le_join                 ~> ge_sup_conv
  3712     meet_idempotent         ~> inf_idem
  3713     join_idempotent         ~> sup_idem
  3714     meet_comm               ~> inf_commute
  3715     join_comm               ~> sup_commute
  3716     meet_leI1               ~> le_infI1
  3717     meet_leI2               ~> le_infI2
  3718     le_joinI1               ~> le_supI1
  3719     le_joinI2               ~> le_supI2
  3720     meet_assoc              ~> inf_assoc
  3721     join_assoc              ~> sup_assoc
  3722     meet_left_comm          ~> inf_left_commute
  3723     meet_left_idempotent    ~> inf_left_idem
  3724     join_left_comm          ~> sup_left_commute
  3725     join_left_idempotent    ~> sup_left_idem
  3726     meet_aci                ~> inf_aci
  3727     join_aci                ~> sup_aci
  3728     le_def_meet             ~> le_iff_inf
  3729     le_def_join             ~> le_iff_sup
  3730     join_absorp2            ~> sup_absorb2
  3731     join_absorp1            ~> sup_absorb1
  3732     meet_absorp1            ~> inf_absorb1
  3733     meet_absorp2            ~> inf_absorb2
  3734     meet_join_absorp        ~> inf_sup_absorb
  3735     join_meet_absorp        ~> sup_inf_absorb
  3736     distrib_join_le         ~> distrib_sup_le
  3737     distrib_meet_le         ~> distrib_inf_le
  3738 
  3739     add_meet_distrib_left   ~> add_inf_distrib_left
  3740     add_join_distrib_left   ~> add_sup_distrib_left
  3741     is_join_neg_meet        ~> is_join_neg_inf
  3742     is_meet_neg_join        ~> is_meet_neg_sup
  3743     add_meet_distrib_right  ~> add_inf_distrib_right
  3744     add_join_distrib_right  ~> add_sup_distrib_right
  3745     add_meet_join_distribs  ~> add_sup_inf_distribs
  3746     join_eq_neg_meet        ~> sup_eq_neg_inf
  3747     meet_eq_neg_join        ~> inf_eq_neg_sup
  3748     add_eq_meet_join        ~> add_eq_inf_sup
  3749     meet_0_imp_0            ~> inf_0_imp_0
  3750     join_0_imp_0            ~> sup_0_imp_0
  3751     meet_0_eq_0             ~> inf_0_eq_0
  3752     join_0_eq_0             ~> sup_0_eq_0
  3753     neg_meet_eq_join        ~> neg_inf_eq_sup
  3754     neg_join_eq_meet        ~> neg_sup_eq_inf
  3755     join_eq_if              ~> sup_eq_if
  3756 
  3757     mono_meet               ~> mono_inf
  3758     mono_join               ~> mono_sup
  3759     meet_bool_eq            ~> inf_bool_eq
  3760     join_bool_eq            ~> sup_bool_eq
  3761     meet_fun_eq             ~> inf_fun_eq
  3762     join_fun_eq             ~> sup_fun_eq
  3763     meet_set_eq             ~> inf_set_eq
  3764     join_set_eq             ~> sup_set_eq
  3765     meet1_iff               ~> inf1_iff
  3766     meet2_iff               ~> inf2_iff
  3767     meet1I                  ~> inf1I
  3768     meet2I                  ~> inf2I
  3769     meet1D1                 ~> inf1D1
  3770     meet2D1                 ~> inf2D1
  3771     meet1D2                 ~> inf1D2
  3772     meet2D2                 ~> inf2D2
  3773     meet1E                  ~> inf1E
  3774     meet2E                  ~> inf2E
  3775     join1_iff               ~> sup1_iff
  3776     join2_iff               ~> sup2_iff
  3777     join1I1                 ~> sup1I1
  3778     join2I1                 ~> sup2I1
  3779     join1I1                 ~> sup1I1
  3780     join2I2                 ~> sup1I2
  3781     join1CI                 ~> sup1CI
  3782     join2CI                 ~> sup2CI
  3783     join1E                  ~> sup1E
  3784     join2E                  ~> sup2E
  3785 
  3786     is_meet_Meet            ~> is_meet_Inf
  3787     Meet_bool_def           ~> Inf_bool_def
  3788     Meet_fun_def            ~> Inf_fun_def
  3789     Meet_greatest           ~> Inf_greatest
  3790     Meet_lower              ~> Inf_lower
  3791     Meet_set_def            ~> Inf_set_def
  3792 
  3793     Sup_def                 ~> Sup_Inf
  3794     Sup_bool_eq             ~> Sup_bool_def
  3795     Sup_fun_eq              ~> Sup_fun_def
  3796     Sup_set_eq              ~> Sup_set_def
  3797 
  3798     listsp_meetI            ~> listsp_infI
  3799     listsp_meet_eq          ~> listsp_inf_eq
  3800 
  3801     meet_min                ~> inf_min
  3802     join_max                ~> sup_max
  3803 
  3804 * Added syntactic class "size"; overloaded constant "size" now has
  3805 type "'a::size ==> bool"
  3806 
  3807 * Internal reorganisation of `size' of datatypes: size theorems
  3808 "foo.size" are no longer subsumed by "foo.simps" (but are still
  3809 simplification rules by default!); theorems "prod.size" now named
  3810 "*.size".
  3811 
  3812 * Class "div" now inherits from class "times" rather than "type".
  3813 INCOMPATIBILITY.
  3814 
  3815 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  3816 Linorder etc.  have disappeared; operations defined in terms of
  3817 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  3818 
  3819 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  3820 
  3821 * HOL-Word: New extensive library and type for generic, fixed size
  3822 machine words, with arithemtic, bit-wise, shifting and rotating
  3823 operations, reflection into int, nat, and bool lists, automation for
  3824 linear arithmetic (by automatic reflection into nat or int), including
  3825 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  3826 arithmetic type classes, supporting automatic simplification of
  3827 numerals on all operations.
  3828 
  3829 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  3830 
  3831 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  3832 
  3833 * Code generator library theories:
  3834   - Code_Integer represents HOL integers by big integer literals in target
  3835     languages.
  3836   - Code_Char represents HOL characters by character literals in target
  3837     languages.
  3838   - Code_Char_chr like Code_Char, but also offers treatment of character
  3839     codes; includes Code_Integer.
  3840   - Executable_Set allows to generate code for finite sets using lists.
  3841   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  3842     denominator).
  3843   - Executable_Real implements a subset of real numbers, namly those
  3844     representable by rational numbers.
  3845   - Efficient_Nat implements natural numbers by integers, which in general will
  3846     result in higher efficency; pattern matching with 0/Suc is eliminated;
  3847     includes Code_Integer.
  3848   - Code_Index provides an additional datatype index which is mapped to
  3849     target-language built-in integers.
  3850   - Code_Message provides an additional datatype message_string which is isomorphic to
  3851     strings; messages are mapped to target-language strings.
  3852 
  3853 * New package for inductive predicates
  3854 
  3855   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  3856 
  3857     inductive
  3858       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3859       for z_1 :: U_1 and ... and z_n :: U_m
  3860     where
  3861       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3862     | ...
  3863 
  3864   with full support for type-inference, rather than
  3865 
  3866     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3867 
  3868     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3869     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3870 
  3871     inductive "s z_1 ... z_m"
  3872     intros
  3873       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3874       ...
  3875 
  3876   For backward compatibility, there is a wrapper allowing inductive
  3877   sets to be defined with the new package via
  3878 
  3879     inductive_set
  3880       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3881       for z_1 :: U_1 and ... and z_n :: U_m
  3882     where
  3883       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3884     | ...
  3885 
  3886   or
  3887 
  3888     inductive_set
  3889       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3890       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3891       for z_1 :: U_1 and ... and z_n :: U_m
  3892     where
  3893       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3894     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3895     | ...
  3896 
  3897   if the additional syntax "p ..." is required.
  3898 
  3899   Numerous examples can be found in the subdirectories src/HOL/Auth,
  3900   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  3901 
  3902   INCOMPATIBILITIES:
  3903 
  3904   - Since declaration and definition of inductive sets or predicates
  3905     is no longer separated, abbreviations involving the newly
  3906     introduced sets or predicates must be specified together with the
  3907     introduction rules after the 'where' keyword (see above), rather
  3908     than before the actual inductive definition.
  3909 
  3910   - The variables in induction and elimination rules are now
  3911     quantified in the order of their occurrence in the introduction
  3912     rules, rather than in alphabetical order. Since this may break
  3913     some proofs, these proofs either have to be repaired, e.g. by
  3914     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  3915     statements of the form
  3916 
  3917       case (rule_i a_i_1 ... a_i_{k_i})
  3918 
  3919     or the old order of quantification has to be restored by explicitly adding
  3920     meta-level quantifiers in the introduction rules, i.e.
  3921 
  3922       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  3923 
  3924   - The format of the elimination rules is now
  3925 
  3926       p z_1 ... z_m x_1 ... x_n ==>
  3927         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  3928         ==> ... ==> P
  3929 
  3930     for predicates and
  3931 
  3932       (x_1, ..., x_n) : s z_1 ... z_m ==>
  3933         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  3934         ==> ... ==> P
  3935 
  3936     for sets rather than
  3937 
  3938       x : s z_1 ... z_m ==>
  3939         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  3940         ==> ... ==> P
  3941 
  3942     This may require terms in goals to be expanded to n-tuples
  3943     (e.g. using case_tac or simplification with the split_paired_all
  3944     rule) before the above elimination rule is applicable.
  3945 
  3946   - The elimination or case analysis rules for (mutually) inductive
  3947     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  3948     list of rules "p_1_..._p_k.elims" is no longer available.
  3949 
  3950 * New package "function"/"fun" for general recursive functions,
  3951 supporting mutual and nested recursion, definitions in local contexts,
  3952 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  3953 for small examples, and the separate tutorial on the function
  3954 package. The old recdef "package" is still available as before, but
  3955 users are encouraged to use the new package.
  3956 
  3957 * Method "lexicographic_order" automatically synthesizes termination
  3958 relations as lexicographic combinations of size measures. 
  3959 
  3960 * Case-expressions allow arbitrary constructor-patterns (including
  3961 "_") and take their order into account, like in functional
  3962 programming.  Internally, this is translated into nested
  3963 case-expressions; missing cases are added and mapped to the predefined
  3964 constant "undefined". In complicated cases printing may no longer show
  3965 the original input but the internal form. Lambda-abstractions allow
  3966 the same form of pattern matching: "% pat1 => e1 | ..." is an
  3967 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  3968 variable.
  3969 
  3970 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  3971 is an abbreviation for "of_nat :: nat => int". The simplification
  3972 rules for "of_nat" have been changed to work like "int" did
  3973 previously.  Potential INCOMPATIBILITY:
  3974   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  3975   - of_nat_diff and of_nat_mult are no longer default simp rules
  3976 
  3977 * Method "algebra" solves polynomial equations over (semi)rings using
  3978 Groebner bases. The (semi)ring structure is defined by locales and the
  3979 tool setup depends on that generic context. Installing the method for
  3980 a specific type involves instantiating the locale and possibly adding
  3981 declarations for computation on the coefficients.  The method is
  3982 already instantiated for natural numbers and for the axiomatic class
  3983 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  3984 CALCULEMUS 2007 for the general principles underlying this
  3985 architecture of context-aware proof-tools.
  3986 
  3987 * Method "ferrack" implements quantifier elimination over
  3988 special-purpose dense linear orders using locales (analogous to
  3989 "algebra"). The method is already installed for class
  3990 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  3991 rat, etc.
  3992 
  3993 * Former constant "List.op @" now named "List.append".  Use ML
  3994 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  3995 circumvent possible incompatibilities when working on ML level.
  3996 
  3997 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  3998 
  3999 * New function listsum :: 'a list => 'a for arbitrary monoids.
  4000 Special syntax: "SUM x <- xs. f x" (and latex variants)
  4001 
  4002 * New syntax for Haskell-like list comprehension (input only), eg.
  4003 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  4004 
  4005 * The special syntax for function "filter" has changed from [x :
  4006 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  4007 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  4008 
  4009 * [a..b] is now defined for arbitrary linear orders.  It used to be
  4010 defined on nat only, as an abbreviation for [a..<Suc b]
  4011 INCOMPATIBILITY.
  4012 
  4013 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  4014 
  4015 * New functions "sorted" and "sort" in src/HOL/List.thy.
  4016 
  4017 * New lemma collection field_simps (an extension of ring_simps) for
  4018 manipulating (in)equations involving division. Multiplies with all
  4019 denominators that can be proved to be non-zero (in equations) or
  4020 positive/negative (in inequations).
  4021 
  4022 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  4023 have been improved and renamed to ring_simps, group_simps and
  4024 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  4025 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  4026 
  4027 * Theory Library/Commutative_Ring: switched from recdef to function
  4028 package; constants add, mul, pow now curried.  Infix syntax for
  4029 algebraic operations.
  4030 
  4031 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  4032 INCOMPATIBILITY.
  4033 
  4034 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  4035 INCOMPATIBILITY.
  4036 
  4037 * HOL/records: generalised field-update to take a function on the
  4038 field rather than the new value: r(|A := x|) is translated to A_update
  4039 (K x) r The K-combinator that is internally used is called K_record.
  4040 INCOMPATIBILITY: Usage of the plain update functions has to be
  4041 adapted.
  4042  
  4043 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  4044 * x = 0, which are required for a semiring.  Richer structures do not
  4045 inherit from semiring_0 anymore, because this property is a theorem
  4046 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  4047 there is more to prove, but this is mostly trivial.
  4048 
  4049 * Class "recpower" is generalized to arbitrary monoids, not just
  4050 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  4051 commutativity or semiring properties additionally.
  4052 
  4053 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  4054 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  4055 better use 'abbreviation'.
  4056 
  4057 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  4058 
  4059 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  4060 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  4061 significant changes for setting up numeral syntax for types:
  4062   - New constants Numeral.pred and Numeral.succ instead
  4063       of former Numeral.bin_pred and Numeral.bin_succ.
  4064   - Use integer operations instead of bin_add, bin_mult and so on.
  4065   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  4066   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  4067 
  4068 See src/HOL/Integ/IntArith.thy for an example setup.
  4069 
  4070 * Command 'normal_form' computes the normal form of a term that may
  4071 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  4072 produces ``[b, c, a]'' (without proof).  This command is suitable for
  4073 heavy-duty computations because the functions are compiled to ML
  4074 first.  Correspondingly, a method "normalization" is provided.  See
  4075 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  4076 
  4077 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  4078 25 like -->); output depends on the "iff" print_mode, the default is
  4079 "A = B" (with priority 50).
  4080 
  4081 * Relations less (<) and less_eq (<=) are also available on type bool.
  4082 Modified syntax to disallow nesting without explicit parentheses,
  4083 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  4084 INCOMPATIBILITY.
  4085 
  4086 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  4087 
  4088 * Relation composition operator "op O" now has precedence 75 and binds
  4089 stronger than union and intersection. INCOMPATIBILITY.
  4090 
  4091 * The old set interval syntax "{m..n(}" (and relatives) has been
  4092 removed.  Use "{m..<n}" (and relatives) instead.
  4093 
  4094 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  4095 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  4096 ``declare [[simproc del: neq]]''.
  4097 
  4098 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  4099 True/False.
  4100 
  4101 * Theorem Cons_eq_map_conv no longer declared as "simp".
  4102 
  4103 * Theorem setsum_mult renamed to setsum_right_distrib.
  4104 
  4105 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  4106 ``rule'' method.
  4107 
  4108 * Reimplemented methods "sat" and "satx", with several improvements:
  4109 goals no longer need to be stated as "<prems> ==> False", equivalences
  4110 (i.e. "=" on type bool) are handled, variable names of the form
  4111 "lit_<n>" are no longer reserved, significant speedup.
  4112 
  4113 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  4114 zChaff is still supported as well.
  4115 
  4116 * 'inductive' and 'datatype': provide projections of mutual rules,
  4117 bundled as foo_bar.inducts;
  4118 
  4119 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  4120 Library.
  4121 
  4122 * Library: moved theory Accessible_Part to main HOL.
  4123 
  4124 * Library: added theory Coinductive_List of potentially infinite lists
  4125 as greatest fixed-point.
  4126 
  4127 * Library: added theory AssocList which implements (finite) maps as
  4128 association lists.
  4129 
  4130 * Method "evaluation" solves goals (i.e. a boolean expression)
  4131 efficiently by compiling it to ML.  The goal is "proved" (via an
  4132 oracle) if it evaluates to True.
  4133 
  4134 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  4135 also when invoked by the simplifier.  This results in the Simplifier
  4136 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  4137 Configuration option fast_arith_split_limit=0 recovers the old
  4138 behavior.
  4139 
  4140 * Support for hex (0x20) and binary (0b1001) numerals.
  4141 
  4142 * New method: reify eqs (t), where eqs are equations for an
  4143 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  4144 parameter, computes a term s::'b and a list xs::'a list and proves the
  4145 theorem I xs s = t. This is also known as reification or quoting. The
  4146 resulting theorem is applied to the subgoal to substitute t with I xs
  4147 s.  If t is omitted, the subgoal itself is reified.
  4148 
  4149 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  4150 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  4151 where f is supposed to be a computable function (in the sense of code
  4152 generattion). The method uses reify to compute s and xs as above then
  4153 applies corr_thm and uses normalization by evaluation to "prove" f s =
  4154 r and finally gets the theorem t = r, which is again applied to the
  4155 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  4156 
  4157 * Reflection: Automatic reification now handels binding, an example is
  4158 available in src/HOL/ex/ReflectionEx.thy
  4159 
  4160 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  4161 command 'statespace' that is similar to 'record', but introduces an
  4162 abstract specification based on the locale infrastructure instead of
  4163 HOL types.  This leads to extra flexibility in composing state spaces,
  4164 in particular multiple inheritance and renaming of components.
  4165 
  4166 
  4167 *** HOL-Complex ***
  4168 
  4169 * Hyperreal: Functions root and sqrt are now defined on negative real
  4170 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  4171 Nonnegativity side conditions have been removed from many lemmas, so
  4172 that more subgoals may now be solved by simplification; potential
  4173 INCOMPATIBILITY.
  4174 
  4175 * Real: new type classes formalize real normed vector spaces and
  4176 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  4177 and norm :: 'a => real.
  4178 
  4179 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  4180 reals into other types. The overloaded constant Reals :: 'a set is now
  4181 defined as range of_real; potential INCOMPATIBILITY.
  4182 
  4183 * Real: proper support for ML code generation, including 'quickcheck'.
  4184 Reals are implemented as arbitrary precision rationals.
  4185 
  4186 * Hyperreal: Several constants that previously worked only for the
  4187 reals have been generalized, so they now work over arbitrary vector
  4188 spaces. Type annotations may need to be added in some cases; potential
  4189 INCOMPATIBILITY.
  4190 
  4191   Infinitesimal  :: ('a::real_normed_vector) star set
  4192   HFinite        :: ('a::real_normed_vector) star set
  4193   HInfinite      :: ('a::real_normed_vector) star set
  4194   approx         :: ('a::real_normed_vector) star => 'a star => bool
  4195   monad          :: ('a::real_normed_vector) star => 'a star set
  4196   galaxy         :: ('a::real_normed_vector) star => 'a star set
  4197   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  4198   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  4199   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  4200   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  4201   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  4202   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  4203   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  4204   sgn            :: 'a::real_normed_vector => 'a
  4205   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  4206 
  4207 * Complex: Some complex-specific constants are now abbreviations for
  4208 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  4209 hnorm.  Other constants have been entirely removed in favor of the
  4210 polymorphic versions (INCOMPATIBILITY):
  4211 
  4212   approx        <-- capprox
  4213   HFinite       <-- CFinite
  4214   HInfinite     <-- CInfinite
  4215   Infinitesimal <-- CInfinitesimal
  4216   monad         <-- cmonad
  4217   galaxy        <-- cgalaxy
  4218   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  4219   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  4220   (ns)deriv     <-- (ns)cderiv
  4221 
  4222 
  4223 *** HOL-Algebra ***
  4224 
  4225 * Formalisation of ideals and the quotient construction over rings.
  4226 
  4227 * Order and lattice theory no longer based on records.
  4228 INCOMPATIBILITY.
  4229 
  4230 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  4231 greatest_closed.  INCOMPATIBILITY.
  4232 
  4233 * Method algebra is now set up via an attribute.  For examples see
  4234 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  4235 of algebraic structures.
  4236 
  4237 * Renamed theory CRing to Ring.
  4238 
  4239 
  4240 *** HOL-Nominal ***
  4241 
  4242 * Substantial, yet incomplete support for nominal datatypes (binding
  4243 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  4244 src/HOL/Nominal/Examples.  Prospective users should consult
  4245 http://isabelle.in.tum.de/nominal/
  4246 
  4247 
  4248 *** ML ***
  4249 
  4250 * ML basics: just one true type int, which coincides with IntInf.int
  4251 (even on SML/NJ).
  4252 
  4253 * ML within Isar: antiquotations allow to embed statically-checked
  4254 formal entities in the source, referring to the context available at
  4255 compile-time.  For example:
  4256 
  4257 ML {* @{sort "{zero,one}"} *}
  4258 ML {* @{typ "'a => 'b"} *}
  4259 ML {* @{term "%x. x"} *}
  4260 ML {* @{prop "x == y"} *}
  4261 ML {* @{ctyp "'a => 'b"} *}
  4262 ML {* @{cterm "%x. x"} *}
  4263 ML {* @{cprop "x == y"} *}
  4264 ML {* @{thm asm_rl} *}
  4265 ML {* @{thms asm_rl} *}
  4266 ML {* @{type_name c} *}
  4267 ML {* @{type_syntax c} *}
  4268 ML {* @{const_name c} *}
  4269 ML {* @{const_syntax c} *}
  4270 ML {* @{context} *}
  4271 ML {* @{theory} *}
  4272 ML {* @{theory Pure} *}
  4273 ML {* @{theory_ref} *}
  4274 ML {* @{theory_ref Pure} *}
  4275 ML {* @{simpset} *}
  4276 ML {* @{claset} *}
  4277 ML {* @{clasimpset} *}
  4278 
  4279 The same works for sources being ``used'' within an Isar context.
  4280 
  4281 * ML in Isar: improved error reporting; extra verbosity with
  4282 ML_Context.trace enabled.
  4283 
  4284 * Pure/General/table.ML: the join operations now works via exceptions
  4285 DUP/SAME instead of type option. This is simpler in simple cases, and
  4286 admits slightly more efficient complex applications.
  4287 
  4288 * Pure: 'advanced' translation functions (parse_translation etc.) now
  4289 use Context.generic instead of just theory.
  4290 
  4291 * Pure: datatype Context.generic joins theory/Proof.context and
  4292 provides some facilities for code that works in either kind of
  4293 context, notably GenericDataFun for uniform theory and proof data.
  4294 
  4295 * Pure: simplified internal attribute type, which is now always
  4296 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  4297 local (Proof.context) attributes have been discontinued, while
  4298 minimizing code duplication. Thm.rule_attribute and
  4299 Thm.declaration_attribute build canonical attributes; see also structure
  4300 Context for further operations on Context.generic, notably
  4301 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  4302 declarations and definitions.
  4303 
  4304 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  4305 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  4306 init only required for impure data. INCOMPATIBILITY: empty really need
  4307 to be empty (no dependencies on theory content!)
  4308 
  4309 * Pure/kernel: consts certification ignores sort constraints given in
  4310 signature declarations. (This information is not relevant to the
  4311 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  4312 potential INCOMPATIBILITY.
  4313 
  4314 * Pure: axiomatic type classes are now purely definitional, with
  4315 explicit proofs of class axioms and super class relations performed
  4316 internally. See Pure/axclass.ML for the main internal interfaces --
  4317 notably AxClass.define_class supercedes AxClass.add_axclass, and
  4318 AxClass.axiomatize_class/classrel/arity supersede
  4319 Sign.add_classes/classrel/arities.
  4320 
  4321 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  4322 global/local versions on theory vs. Proof.context have been
  4323 discontinued; Attrib.syntax and Method.syntax have been adapted
  4324 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  4325 attributes, methods, etc.
  4326 
  4327 * Pure: several functions of signature "... -> theory -> theory * ..."
  4328 have been reoriented to "... -> theory -> ... * theory" in order to
  4329 allow natural usage in combination with the ||>, ||>>, |-> and
  4330 fold_map combinators.
  4331 
  4332 * Pure: official theorem names (closed derivations) and additional
  4333 comments (tags) are now strictly separate.  Name hints -- which are
  4334 maintained as tags -- may be attached any time without affecting the
  4335 derivation.
  4336 
  4337 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  4338 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  4339 achieve the old behaviour.
  4340 
  4341 * Pure: the "Goal" constant is now called "prop", supporting a
  4342 slightly more general idea of ``protecting'' meta-level rule
  4343 statements.
  4344 
  4345 * Pure: Logic.(un)varify only works in a global context, which is now
  4346 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  4347 Logic.legacy_(un)varify as temporary workaround.
  4348 
  4349 * Pure: structure Name provides scalable operations for generating
  4350 internal variable names, notably Name.variants etc.  This replaces
  4351 some popular functions from term.ML:
  4352 
  4353   Term.variant		->  Name.variant
  4354   Term.variantlist	->  Name.variant_list
  4355   Term.invent_names	->  Name.invent_list
  4356 
  4357 Note that low-level renaming rarely occurs in new code -- operations
  4358 from structure Variable are used instead (see below).
  4359 
  4360 * Pure: structure Variable provides fundamental operations for proper
  4361 treatment of fixed/schematic variables in a context.  For example,
  4362 Variable.import introduces fixes for schematics of given facts and
  4363 Variable.export reverses the effect (up to renaming) -- this replaces
  4364 various freeze_thaw operations.
  4365 
  4366 * Pure: structure Goal provides simple interfaces for
  4367 init/conclude/finish and tactical prove operations (replacing former
  4368 Tactic.prove).  Goal.prove is the canonical way to prove results
  4369 within a given context; Goal.prove_global is a degraded version for
  4370 theory level goals, including a global Drule.standard.  Note that
  4371 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  4372 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  4373 in a locale context).
  4374 
  4375 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  4376 and type checking (Syntax.check_term etc.), with common combinations
  4377 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  4378 which are considered legacy and await removal.
  4379 
  4380 * Pure/Syntax: generic interfaces for type unchecking
  4381 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  4382 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  4383 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  4384 available for convenience, but refer to the very same operations using
  4385 a mere theory instead of a full context.
  4386 
  4387 * Isar: simplified treatment of user-level errors, using exception
  4388 ERROR of string uniformly.  Function error now merely raises ERROR,
  4389 without any side effect on output channels.  The Isar toplevel takes
  4390 care of proper display of ERROR exceptions.  ML code may use plain
  4391 handle/can/try; cat_error may be used to concatenate errors like this:
  4392 
  4393   ... handle ERROR msg => cat_error msg "..."
  4394 
  4395 Toplevel ML code (run directly or through the Isar toplevel) may be
  4396 embedded into the Isar toplevel with exception display/debug like
  4397 this:
  4398 
  4399   Isar.toplevel (fn () => ...)
  4400 
  4401 INCOMPATIBILITY, removed special transform_error facilities, removed
  4402 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  4403 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  4404 -- use plain ERROR instead.
  4405 
  4406 * Isar: theory setup now has type (theory -> theory), instead of a
  4407 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  4408 
  4409 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  4410 ProofContext.debug/verbose flags.
  4411 
  4412 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  4413 theory before entering a proof state.  Transactions now always see a
  4414 quasi-functional intermediate checkpoint, both in interactive and
  4415 batch mode.
  4416 
  4417 * Isar: simplified interfaces for outer syntax.  Renamed
  4418 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  4419 OuterSyntax.add_parsers -- this functionality is now included in
  4420 OuterSyntax.command etc.  INCOMPATIBILITY.
  4421 
  4422 * Simplifier: the simpset of a running simplification process now
  4423 contains a proof context (cf. Simplifier.the_context), which is the
  4424 very context that the initial simpset has been retrieved from (by
  4425 simpset_of/local_simpset_of).  Consequently, all plug-in components
  4426 (solver, looper etc.) may depend on arbitrary proof data.
  4427 
  4428 * Simplifier.inherit_context inherits the proof context (plus the
  4429 local bounds) of the current simplification process; any simproc
  4430 etc. that calls the Simplifier recursively should do this!  Removed
  4431 former Simplifier.inherit_bounds, which is already included here --
  4432 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  4433 specify an explicit context using Simplifier.context/theory_context.
  4434 
  4435 * Simplifier/Classical Reasoner: more abstract interfaces
  4436 change_simpset/claset for modifying the simpset/claset reference of a
  4437 theory; raw versions simpset/claset_ref etc. have been discontinued --
  4438 INCOMPATIBILITY.
  4439 
  4440 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  4441 "Trueprop" etc.
  4442 
  4443 
  4444 *** System ***
  4445 
  4446 * settings: the default heap location within ISABELLE_HOME_USER now
  4447 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  4448 Isabelle installations.
  4449 
  4450 * isabelle-process: option -S (secure mode) disables some critical
  4451 operations, notably runtime compilation and evaluation of ML source
  4452 code.
  4453 
  4454 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  4455 
  4456 * Support for parallel execution, using native multicore support of
  4457 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  4458 independent theories, according to the given theory header
  4459 specifications. The maximum number of worker threads is specified via
  4460 usedir option -M or the "max-threads" setting in Proof General. A
  4461 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  4462 to 6 on a 8-core machine.  User-code needs to observe certain
  4463 guidelines for thread-safe programming, see appendix A in the Isar
  4464 Implementation manual.
  4465 
  4466 
  4467 
  4468 New in Isabelle2005 (October 2005)
  4469 ----------------------------------
  4470 
  4471 *** General ***
  4472 
  4473 * Theory headers: the new header syntax for Isar theories is
  4474 
  4475   theory <name>
  4476   imports <theory1> ... <theoryN>
  4477   uses <file1> ... <fileM>
  4478   begin
  4479 
  4480 where the 'uses' part is optional.  The previous syntax
  4481 
  4482   theory <name> = <theory1> + ... + <theoryN>:
  4483 
  4484 will disappear in the next release.  Use isatool fixheaders to convert
  4485 existing theory files.  Note that there is no change in ancient
  4486 non-Isar theories now, but these will disappear soon.
  4487 
  4488 * Theory loader: parent theories can now also be referred to via
  4489 relative and absolute paths.
  4490 
  4491 * Command 'find_theorems' searches for a list of criteria instead of a
  4492 list of constants. Known criteria are: intro, elim, dest, name:string,
  4493 simp:term, and any term. Criteria can be preceded by '-' to select
  4494 theorems that do not match. Intro, elim, dest select theorems that
  4495 match the current goal, name:s selects theorems whose fully qualified
  4496 name contain s, and simp:term selects all simplification rules whose
  4497 lhs match term.  Any other term is interpreted as pattern and selects
  4498 all theorems matching the pattern. Available in ProofGeneral under
  4499 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  4500 
  4501   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  4502 
  4503 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  4504 matching the current goal as introduction rule and not having "HOL."
  4505 in their name (i.e. not being defined in theory HOL).
  4506 
  4507 * Command 'thms_containing' has been discontinued in favour of
  4508 'find_theorems'; INCOMPATIBILITY.
  4509 
  4510 * Communication with Proof General is now 8bit clean, which means that
  4511 Unicode text in UTF-8 encoding may be used within theory texts (both
  4512 formal and informal parts).  Cf. option -U of the Isabelle Proof
  4513 General interface.  Here are some simple examples (cf. src/HOL/ex):
  4514 
  4515   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  4516   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  4517 
  4518 * Improved efficiency of the Simplifier and, to a lesser degree, the
  4519 Classical Reasoner.  Typical big applications run around 2 times
  4520 faster.
  4521 
  4522 
  4523 *** Document preparation ***
  4524 
  4525 * Commands 'display_drafts' and 'print_drafts' perform simple output
  4526 of raw sources.  Only those symbols that do not require additional
  4527 LaTeX packages (depending on comments in isabellesym.sty) are
  4528 displayed properly, everything else is left verbatim.  isatool display
  4529 and isatool print are used as front ends (these are subject to the
  4530 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  4531 
  4532 * Command tags control specific markup of certain regions of text,
  4533 notably folding and hiding.  Predefined tags include "theory" (for
  4534 theory begin and end), "proof" for proof commands, and "ML" for
  4535 commands involving ML code; the additional tags "visible" and
  4536 "invisible" are unused by default.  Users may give explicit tag
  4537 specifications in the text, e.g. ''by %invisible (auto)''.  The
  4538 interpretation of tags is determined by the LaTeX job during document
  4539 preparation: see option -V of isatool usedir, or options -n and -t of
  4540 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  4541 \isadroptag.
  4542 
  4543 Several document versions may be produced at the same time via isatool
  4544 usedir (the generated index.html will link all of them).  Typical
  4545 specifications include ''-V document=theory,proof,ML'' to present
  4546 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  4547 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  4548 these parts without any formal replacement text.  The Isabelle site
  4549 default settings produce ''document'' and ''outline'' versions as
  4550 specified above.
  4551 
  4552 * Several new antiquotations:
  4553 
  4554   @{term_type term} prints a term with its type annotated;
  4555 
  4556   @{typeof term} prints the type of a term;
  4557 
  4558   @{const const} is the same as @{term const}, but checks that the
  4559   argument is a known logical constant;
  4560 
  4561   @{term_style style term} and @{thm_style style thm} print a term or
  4562   theorem applying a "style" to it
  4563 
  4564   @{ML text}
  4565 
  4566 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  4567 definitions, equations, inequations etc., 'concl' printing only the
  4568 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  4569 to print the specified premise.  TermStyle.add_style provides an ML
  4570 interface for introducing further styles.  See also the "LaTeX Sugar"
  4571 document practical applications.  The ML antiquotation prints
  4572 type-checked ML expressions verbatim.
  4573 
  4574 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  4575 and 'text' support optional locale specification '(in loc)', which
  4576 specifies the default context for interpreting antiquotations.  For
  4577 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  4578 
  4579 * Option 'locale=NAME' of antiquotations specifies an alternative
  4580 context interpreting the subsequent argument.  For example: @{thm
  4581 [locale=lattice] inf_assoc}.
  4582 
  4583 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  4584 a proof context.
  4585 
  4586 * Proper output of antiquotations for theory commands involving a
  4587 proof context (such as 'locale' or 'theorem (in loc) ...').
  4588 
  4589 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  4590 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  4591 
  4592 * isatool usedir: new option -C (default true) controls whether option
  4593 -D should include a copy of the original document directory; -C false
  4594 prevents unwanted effects such as copying of administrative CVS data.
  4595 
  4596 
  4597 *** Pure ***
  4598 
  4599 * Considerably improved version of 'constdefs' command.  Now performs
  4600 automatic type-inference of declared constants; additional support for
  4601 local structure declarations (cf. locales and HOL records), see also
  4602 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  4603 sequential dependencies of definitions within a single 'constdefs'
  4604 section; moreover, the declared name needs to be an identifier.  If
  4605 all fails, consider to fall back on 'consts' and 'defs' separately.
  4606 
  4607 * Improved indexed syntax and implicit structures.  First of all,
  4608 indexed syntax provides a notational device for subscripted
  4609 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  4610 expressions.  Secondly, in a local context with structure
  4611 declarations, number indexes \<^sub>n or the empty index (default
  4612 number 1) refer to a certain fixed variable implicitly; option
  4613 show_structs controls printing of implicit structures.  Typical
  4614 applications of these concepts involve record types and locales.
  4615 
  4616 * New command 'no_syntax' removes grammar declarations (and
  4617 translations) resulting from the given syntax specification, which is
  4618 interpreted in the same manner as for the 'syntax' command.
  4619 
  4620 * 'Advanced' translation functions (parse_translation etc.) may depend
  4621 on the signature of the theory context being presently used for
  4622 parsing/printing, see also isar-ref manual.
  4623 
  4624 * Improved 'oracle' command provides a type-safe interface to turn an
  4625 ML expression of type theory -> T -> term into a primitive rule of
  4626 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  4627 is already included here); see also FOL/ex/IffExample.thy;
  4628 INCOMPATIBILITY.
  4629 
  4630 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  4631 before); "cI" is no longer bound, use "c.intro" instead.
  4632 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  4633 axclasses vs. locales.
  4634 
  4635 * Improved internal renaming of symbolic identifiers -- attach primes
  4636 instead of base 26 numbers.
  4637 
  4638 * New flag show_question_marks controls printing of leading question
  4639 marks in schematic variable names.
  4640 
  4641 * In schematic variable names, *any* symbol following \<^isub> or
  4642 \<^isup> is now treated as part of the base name.  For example, the
  4643 following works without printing of awkward ".0" indexes:
  4644 
  4645   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  4646     by simp
  4647 
  4648 * Inner syntax includes (*(*nested*) comments*).
  4649 
  4650 * Pretty printer now supports unbreakable blocks, specified in mixfix
  4651 annotations as "(00...)".
  4652 
  4653 * Clear separation of logical types and nonterminals, where the latter
  4654 may only occur in 'syntax' specifications or type abbreviations.
  4655 Before that distinction was only partially implemented via type class
  4656 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  4657 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  4658 exotic syntax specifications may require further adaption
  4659 (e.g. Cube/Cube.thy).
  4660 
  4661 * Removed obsolete type class "logic", use the top sort {} instead.
  4662 Note that non-logical types should be declared as 'nonterminals'
  4663 rather than 'types'.  INCOMPATIBILITY for new object-logic
  4664 specifications.
  4665 
  4666 * Attributes 'induct' and 'cases': type or set names may now be
  4667 locally fixed variables as well.
  4668 
  4669 * Simplifier: can now control the depth to which conditional rewriting
  4670 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  4671 Limit.
  4672 
  4673 * Simplifier: simplification procedures may now take the current
  4674 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  4675 interface), which is very useful for calling the Simplifier
  4676 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  4677 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  4678 low-level mk_simproc no longer applies Logic.varify internally, to
  4679 allow for use in a context of fixed variables.
  4680 
  4681 * thin_tac now works even if the assumption being deleted contains !!
  4682 or ==>.  More generally, erule now works even if the major premise of
  4683 the elimination rule contains !! or ==>.
  4684 
  4685 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  4686 
  4687 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  4688 from Pure, which contains all common declarations already.  Both
  4689 theories are defined via plain Isabelle/Isar .thy files.
  4690 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  4691 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  4692 use isatool fixcpure to adapt your theory and ML sources.
  4693 
  4694 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  4695 selections of theorems in named facts via index ranges.
  4696 
  4697 * 'print_theorems': in theory mode, really print the difference
  4698 wrt. the last state (works for interactive theory development only),
  4699 in proof mode print all local facts (cf. 'print_facts');
  4700 
  4701 * 'hide': option '(open)' hides only base names.
  4702 
  4703 * More efficient treatment of intermediate checkpoints in interactive
  4704 theory development.
  4705 
  4706 * Code generator is now invoked via code_module (incremental code
  4707 generation) and code_library (modular code generation, ML structures
  4708 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  4709 must be quoted when used as identifiers.
  4710 
  4711 * New 'value' command for reading, evaluating and printing terms using
  4712 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  4713 quoted when used as identifier.
  4714 
  4715 
  4716 *** Locales ***
  4717 
  4718 * New commands for the interpretation of locale expressions in
  4719 theories (1), locales (2) and proof contexts (3).  These generate
  4720 proof obligations from the expression specification.  After the
  4721 obligations have been discharged, theorems of the expression are added
  4722 to the theory, target locale or proof context.  The synopsis of the
  4723 commands is a follows:
  4724 
  4725   (1) interpretation expr inst
  4726   (2) interpretation target < expr
  4727   (3) interpret expr inst
  4728 
  4729 Interpretation in theories and proof contexts require a parameter
  4730 instantiation of terms from the current context.  This is applied to
  4731 specifications and theorems of the interpreted expression.
  4732 Interpretation in locales only permits parameter renaming through the
  4733 locale expression.  Interpretation is smart in that interpretations
  4734 that are active already do not occur in proof obligations, neither are
  4735 instantiated theorems stored in duplicate.  Use 'print_interps' to
  4736 inspect active interpretations of a particular locale.  For details,
  4737 see the Isar Reference manual.  Examples can be found in
  4738 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  4739 
  4740 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  4741 'interpret' instead.
  4742 
  4743 * New context element 'constrains' for adding type constraints to
  4744 parameters.
  4745 
  4746 * Context expressions: renaming of parameters with syntax
  4747 redeclaration.
  4748 
  4749 * Locale declaration: 'includes' disallowed.
  4750 
  4751 * Proper static binding of attribute syntax -- i.e. types / terms /
  4752 facts mentioned as arguments are always those of the locale definition
  4753 context, independently of the context of later invocations.  Moreover,
  4754 locale operations (renaming and type / term instantiation) are applied
  4755 to attribute arguments as expected.
  4756 
  4757 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  4758 actual attributes; rare situations may require Attrib.attribute to
  4759 embed those attributes into Attrib.src that lack concrete syntax.
  4760 Attribute implementations need to cooperate properly with the static
  4761 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  4762 Attrib.XXX_thm etc. already do the right thing without further
  4763 intervention.  Only unusual applications -- such as "where" or "of"
  4764 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  4765 on the context and the facts involved -- may have to assign parsed
  4766 values to argument tokens explicitly.
  4767 
  4768 * Changed parameter management in theorem generation for long goal
  4769 statements with 'includes'.  INCOMPATIBILITY: produces a different
  4770 theorem statement in rare situations.
  4771 
  4772 * Locale inspection command 'print_locale' omits notes elements.  Use
  4773 'print_locale!' to have them included in the output.
  4774 
  4775 
  4776 *** Provers ***
  4777 
  4778 * Provers/hypsubst.ML: improved version of the subst method, for
  4779 single-step rewriting: it now works in bound variable contexts. New is
  4780 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  4781 rewrite a different subterm than the original subst method, which is
  4782 still available as 'simplesubst'.
  4783 
  4784 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  4785 and quasi orders.
  4786 
  4787 * Provers/trancl.ML: new transitivity reasoner for transitive and
  4788 reflexive-transitive closure of relations.
  4789 
  4790 * Provers/blast.ML: new reference depth_limit to make blast's depth
  4791 limit (previously hard-coded with a value of 20) user-definable.
  4792 
  4793 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  4794 is peformed already.  Object-logics merely need to finish their
  4795 initial simpset configuration as before.  INCOMPATIBILITY.
  4796 
  4797 
  4798 *** HOL ***
  4799 
  4800 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  4801 
  4802   syntax (epsilon)
  4803     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  4804 
  4805 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  4806 and x-symbol; use option '-m epsilon' to get it actually printed.
  4807 Moreover, the mathematically important symbolic identifier \<epsilon>
  4808 becomes available as variable, constant etc.  INCOMPATIBILITY,
  4809 
  4810 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  4811 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  4812 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  4813 support corresponding Isar calculations.
  4814 
  4815 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  4816 instead of ":".
  4817 
  4818 * theory SetInterval: changed the syntax for open intervals:
  4819 
  4820   Old       New
  4821   {..n(}    {..<n}
  4822   {)n..}    {n<..}
  4823   {m..n(}   {m..<n}
  4824   {)m..n}   {m<..n}
  4825   {)m..n(}  {m<..<n}
  4826 
  4827 The old syntax is still supported but will disappear in the next
  4828 release.  For conversion use the following Emacs search and replace
  4829 patterns (these are not perfect but work quite well):
  4830 
  4831   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  4832   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  4833 
  4834 * Theory Commutative_Ring (in Library): method comm_ring for proving
  4835 equalities in commutative rings; method 'algebra' provides a generic
  4836 interface.
  4837 
  4838 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  4839 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  4840 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  4841 be a tuple pattern.
  4842 
  4843 Some new syntax forms are available:
  4844 
  4845   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  4846   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  4847   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  4848   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  4849 
  4850 The latter form "\<Sum>x < k. e" used to be based on a separate
  4851 function "Summation", which has been discontinued.
  4852 
  4853 * theory Finite_Set: in structured induction proofs, the insert case
  4854 is now 'case (insert x F)' instead of the old counterintuitive 'case
  4855 (insert F x)'.
  4856 
  4857 * The 'refute' command has been extended to support a much larger
  4858 fragment of HOL, including axiomatic type classes, constdefs and
  4859 typedefs, inductive datatypes and recursion.
  4860 
  4861 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  4862 Requires zChaff with proof generation to be installed.  See
  4863 HOL/ex/SAT_Examples.thy for examples.
  4864 
  4865 * Datatype induction via method 'induct' now preserves the name of the
  4866 induction variable. For example, when proving P(xs::'a list) by
  4867 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  4868 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  4869 in unstructured proof scripts.
  4870 
  4871 * Reworked implementation of records.  Improved scalability for
  4872 records with many fields, avoiding performance problems for type
  4873 inference. Records are no longer composed of nested field types, but
  4874 of nested extension types. Therefore the record type only grows linear
  4875 in the number of extensions and not in the number of fields.  The
  4876 top-level (users) view on records is preserved.  Potential
  4877 INCOMPATIBILITY only in strange cases, where the theory depends on the
  4878 old record representation. The type generated for a record is called
  4879 <record_name>_ext_type.
  4880 
  4881 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  4882 proofs triggered by a record definition or a simproc (if
  4883 quick_and_dirty is enabled).  Definitions of large records can take
  4884 quite long.
  4885 
  4886 New simproc record_upd_simproc for simplification of multiple record
  4887 updates enabled by default.  Moreover, trivial updates are also
  4888 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  4889 occasionally, since simplification is more powerful by default.
  4890 
  4891 * typedef: proper support for polymorphic sets, which contain extra
  4892 type-variables in the term.
  4893 
  4894 * Simplifier: automatically reasons about transitivity chains
  4895 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  4896 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  4897 old proofs break occasionally as simplification may now solve more
  4898 goals than previously.
  4899 
  4900 * Simplifier: converts x <= y into x = y if assumption y <= x is
  4901 present.  Works for all partial orders (class "order"), in particular
  4902 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  4903 just like y <= x.
  4904 
  4905 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  4906 bound variable or a constant then the let is unfolded.  Otherwise
  4907 first a is simplified to b, and then f b is simplified to g. If
  4908 possible we abstract b from g arriving at "let x = b in h x",
  4909 otherwise we unfold the let and arrive at g.  The simproc can be
  4910 enabled/disabled by the reference use_let_simproc.  Potential
  4911 INCOMPATIBILITY since simplification is more powerful by default.
  4912 
  4913 * Classical reasoning: the meson method now accepts theorems as arguments.
  4914 
  4915 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  4916 jobs to provide advice on the provability of subgoals.
  4917 
  4918 * Theory OrderedGroup and Ring_and_Field: various additions and
  4919 improvements to faciliate calculations involving equalities and
  4920 inequalities.
  4921 
  4922 The following theorems have been eliminated or modified
  4923 (INCOMPATIBILITY):
  4924 
  4925   abs_eq             now named abs_of_nonneg
  4926   abs_of_ge_0        now named abs_of_nonneg
  4927   abs_minus_eq       now named abs_of_nonpos
  4928   imp_abs_id         now named abs_of_nonneg
  4929   imp_abs_neg_id     now named abs_of_nonpos
  4930   mult_pos           now named mult_pos_pos
  4931   mult_pos_le        now named mult_nonneg_nonneg
  4932   mult_pos_neg_le    now named mult_nonneg_nonpos
  4933   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  4934   mult_neg           now named mult_neg_neg
  4935   mult_neg_le        now named mult_nonpos_nonpos
  4936 
  4937 * The following lemmas in Ring_and_Field have been added to the simplifier:
  4938      
  4939      zero_le_square
  4940      not_square_less_zero 
  4941 
  4942   The following lemmas have been deleted from Real/RealPow:
  4943   
  4944      realpow_zero_zero
  4945      realpow_two
  4946      realpow_less
  4947      zero_le_power
  4948      realpow_two_le
  4949      abs_realpow_two
  4950      realpow_two_abs     
  4951 
  4952 * Theory Parity: added rules for simplifying exponents.
  4953 
  4954 * Theory List:
  4955 
  4956 The following theorems have been eliminated or modified
  4957 (INCOMPATIBILITY):
  4958 
  4959   list_all_Nil       now named list_all.simps(1)
  4960   list_all_Cons      now named list_all.simps(2)
  4961   list_all_conv      now named list_all_iff
  4962   set_mem_eq         now named mem_iff
  4963 
  4964 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  4965 asymptotic "big O" calculations.  See the notes in BigO.thy.
  4966 
  4967 
  4968 *** HOL-Complex ***
  4969 
  4970 * Theory RealDef: better support for embedding natural numbers and
  4971 integers in the reals.
  4972 
  4973 The following theorems have been eliminated or modified
  4974 (INCOMPATIBILITY):
  4975 
  4976   exp_ge_add_one_self  now requires no hypotheses
  4977   real_of_int_add      reversed direction of equality (use [symmetric])
  4978   real_of_int_minus    reversed direction of equality (use [symmetric])
  4979   real_of_int_diff     reversed direction of equality (use [symmetric])
  4980   real_of_int_mult     reversed direction of equality (use [symmetric])
  4981 
  4982 * Theory RComplete: expanded support for floor and ceiling functions.
  4983 
  4984 * Theory Ln is new, with properties of the natural logarithm
  4985 
  4986 * Hyperreal: There is a new type constructor "star" for making
  4987 nonstandard types.  The old type names are now type synonyms:
  4988 
  4989   hypreal = real star
  4990   hypnat = nat star
  4991   hcomplex = complex star
  4992 
  4993 * Hyperreal: Many groups of similarly-defined constants have been
  4994 replaced by polymorphic versions (INCOMPATIBILITY):
  4995 
  4996   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  4997 
  4998   starset      <-- starsetNat, starsetC
  4999   *s*          <-- *sNat*, *sc*
  5000   starset_n    <-- starsetNat_n, starsetC_n
  5001   *sn*         <-- *sNatn*, *scn*
  5002   InternalSets <-- InternalNatSets, InternalCSets
  5003 
  5004   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  5005   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  5006   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  5007   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  5008   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  5009 
  5010 * Hyperreal: Many type-specific theorems have been removed in favor of
  5011 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  5012 
  5013   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  5014   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  5015   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  5016   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  5017   right_minus <-- hypreal_add_minus
  5018   left_minus <-- {hypreal,hcomplex}_add_minus_left
  5019   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  5020   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  5021   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  5022   mult_1_right <-- hcomplex_mult_one_right
  5023   mult_zero_left <-- hcomplex_mult_zero_left
  5024   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  5025   right_distrib <-- hypnat_add_mult_distrib2
  5026   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  5027   right_inverse <-- hypreal_mult_inverse
  5028   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  5029   order_refl <-- {hypreal,hypnat}_le_refl
  5030   order_trans <-- {hypreal,hypnat}_le_trans
  5031   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  5032   order_less_le <-- {hypreal,hypnat}_less_le
  5033   linorder_linear <-- {hypreal,hypnat}_le_linear
  5034   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  5035   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  5036   add_nonneg_nonneg <-- hypreal_le_add_order
  5037 
  5038 * Hyperreal: Separate theorems having to do with type-specific
  5039 versions of constants have been merged into theorems that apply to the
  5040 new polymorphic constants (INCOMPATIBILITY):
  5041 
  5042   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  5043   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  5044   STAR_Un <-- {STAR,NatStar,STARC}_Un
  5045   STAR_Int <-- {STAR,NatStar,STARC}_Int
  5046   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  5047   STAR_subset <-- {STAR,NatStar,STARC}_subset
  5048   STAR_mem <-- {STAR,NatStar,STARC}_mem
  5049   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  5050   STAR_diff <-- {STAR,STARC}_diff
  5051   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  5052     STARC_hcomplex_of_complex}_image_subset
  5053   starset_n_Un <-- starset{Nat,C}_n_Un
  5054   starset_n_Int <-- starset{Nat,C}_n_Int
  5055   starset_n_Compl <-- starset{Nat,C}_n_Compl
  5056   starset_n_diff <-- starset{Nat,C}_n_diff
  5057   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  5058   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  5059   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  5060   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  5061   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  5062   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  5063   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  5064   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  5065   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  5066   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  5067   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  5068   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  5069   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  5070   starfun_diff <-- starfun{C,RC,CR}_diff
  5071   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  5072   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  5073   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  5074   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  5075   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  5076   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  5077   starfun_Id <-- starfunC_Id
  5078   starfun_approx <-- starfun{Nat,CR}_approx
  5079   starfun_capprox <-- starfun{C,RC}_capprox
  5080   starfun_abs <-- starfunNat_rabs
  5081   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  5082   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  5083   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  5084   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  5085   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  5086   starfun_add_approx <-- starfunCR_add_approx
  5087   starfun_inverse_inverse <-- starfunC_inverse_inverse
  5088   starfun_divide <-- starfun{C,CR,RC}_divide
  5089   starfun_n <-- starfun{Nat,C}_n
  5090   starfun_n_mult <-- starfun{Nat,C}_n_mult
  5091   starfun_n_add <-- starfun{Nat,C}_n_add
  5092   starfun_n_add_minus <-- starfunNat_n_add_minus
  5093   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  5094   starfun_n_minus <-- starfun{Nat,C}_n_minus
  5095   starfun_n_eq <-- starfun{Nat,C}_n_eq
  5096 
  5097   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  5098   star_n_minus <-- {hypreal,hcomplex}_minus
  5099   star_n_diff <-- {hypreal,hcomplex}_diff
  5100   star_n_mult <-- {hypreal,hcomplex}_mult
  5101   star_n_inverse <-- {hypreal,hcomplex}_inverse
  5102   star_n_le <-- {hypreal,hypnat}_le
  5103   star_n_less <-- {hypreal,hypnat}_less
  5104   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  5105   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  5106   star_n_abs <-- hypreal_hrabs
  5107   star_n_divide <-- hcomplex_divide
  5108 
  5109   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  5110   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  5111   star_of_diff <-- hypreal_of_real_diff
  5112   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  5113   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  5114   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  5115   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  5116   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  5117   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  5118   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  5119   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  5120   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  5121   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  5122   star_of_number_of <-- {hypreal,hcomplex}_number_of
  5123   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  5124   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  5125   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  5126   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  5127   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  5128   star_of_power <-- hypreal_of_real_power
  5129   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  5130 
  5131 * Hyperreal: new method "transfer" that implements the transfer
  5132 principle of nonstandard analysis. With a subgoal that mentions
  5133 nonstandard types like "'a star", the command "apply transfer"
  5134 replaces it with an equivalent one that mentions only standard types.
  5135 To be successful, all free variables must have standard types; non-
  5136 standard variables must have explicit universal quantifiers.
  5137 
  5138 * Hyperreal: A theory of Taylor series.
  5139 
  5140 
  5141 *** HOLCF ***
  5142 
  5143 * Discontinued special version of 'constdefs' (which used to support
  5144 continuous functions) in favor of the general Pure one with full
  5145 type-inference.
  5146 
  5147 * New simplification procedure for solving continuity conditions; it
  5148 is much faster on terms with many nested lambda abstractions (cubic
  5149 instead of exponential time).
  5150 
  5151 * New syntax for domain package: selector names are now optional.
  5152 Parentheses should be omitted unless argument is lazy, for example:
  5153 
  5154   domain 'a stream = cons "'a" (lazy "'a stream")
  5155 
  5156 * New command 'fixrec' for defining recursive functions with pattern
  5157 matching; defining multiple functions with mutual recursion is also
  5158 supported.  Patterns may include the constants cpair, spair, up, sinl,
  5159 sinr, or any data constructor defined by the domain package. The given
  5160 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  5161 syntax and examples.
  5162 
  5163 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  5164 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  5165 but the proof obligation additionally includes an admissibility
  5166 requirement. The packages generate instances of class cpo or pcpo,
  5167 with continuity and strictness theorems for Rep and Abs.
  5168 
  5169 * HOLCF: Many theorems have been renamed according to a more standard naming
  5170 scheme (INCOMPATIBILITY):
  5171 
  5172   foo_inject:  "foo$x = foo$y ==> x = y"
  5173   foo_eq:      "(foo$x = foo$y) = (x = y)"
  5174   foo_less:    "(foo$x << foo$y) = (x << y)"
  5175   foo_strict:  "foo$UU = UU"
  5176   foo_defined: "... ==> foo$x ~= UU"
  5177   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  5178 
  5179 
  5180 *** ZF ***
  5181 
  5182 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  5183 including the First Isomorphism Theorem (on quotienting by the kernel
  5184 of a homomorphism).
  5185 
  5186 * ZF/Simplifier: install second copy of type solver that actually
  5187 makes use of TC rules declared to Isar proof contexts (or locales);
  5188 the old version is still required for ML proof scripts.
  5189 
  5190 
  5191 *** Cube ***
  5192 
  5193 * Converted to Isar theory format; use locales instead of axiomatic
  5194 theories.
  5195 
  5196 
  5197 *** ML ***
  5198 
  5199 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  5200 for ||>, ||>>, |>>,
  5201 
  5202 * Pure/library.ML no longer defines its own option datatype, but uses
  5203 that of the SML basis, which has constructors NONE and SOME instead of
  5204 None and Some, as well as exception Option.Option instead of OPTION.
  5205 The functions the, if_none, is_some, is_none have been adapted
  5206 accordingly, while Option.map replaces apsome.
  5207 
  5208 * Pure/library.ML: the exception LIST has been given up in favour of
  5209 the standard exceptions Empty and Subscript, as well as
  5210 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  5211 superceded by the standard hd and tl functions etc.
  5212 
  5213 A number of basic list functions are no longer exported to the ML
  5214 toplevel, as they are variants of predefined functions.  The following
  5215 suggests how one can translate existing code:
  5216 
  5217     rev_append xs ys = List.revAppend (xs, ys)
  5218     nth_elem (i, xs) = List.nth (xs, i)
  5219     last_elem xs = List.last xs
  5220     flat xss = List.concat xss
  5221     seq fs = List.app fs
  5222     partition P xs = List.partition P xs
  5223     mapfilter f xs = List.mapPartial f xs
  5224 
  5225 * Pure/library.ML: several combinators for linear functional
  5226 transformations, notably reverse application and composition:
  5227 
  5228   x |> f                f #> g
  5229   (x, y) |-> f          f #-> g
  5230 
  5231 * Pure/library.ML: introduced/changed precedence of infix operators:
  5232 
  5233   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  5234   infix 2 ?;
  5235   infix 3 o oo ooo oooo;
  5236   infix 4 ~~ upto downto;
  5237 
  5238 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  5239 infix operators.
  5240 
  5241 * Pure/library.ML: natural list combinators fold, fold_rev, and
  5242 fold_map support linear functional transformations and nesting.  For
  5243 example:
  5244 
  5245   fold f [x1, ..., xN] y =
  5246     y |> f x1 |> ... |> f xN
  5247 
  5248   (fold o fold) f [xs1, ..., xsN] y =
  5249     y |> fold f xs1 |> ... |> fold f xsN
  5250 
  5251   fold f [x1, ..., xN] =
  5252     f x1 #> ... #> f xN
  5253 
  5254   (fold o fold) f [xs1, ..., xsN] =
  5255     fold f xs1 #> ... #> fold f xsN
  5256 
  5257 * Pure/library.ML: the following selectors on type 'a option are
  5258 available:
  5259 
  5260   the:               'a option -> 'a  (*partial*)
  5261   these:             'a option -> 'a  where 'a = 'b list
  5262   the_default: 'a -> 'a option -> 'a
  5263   the_list:          'a option -> 'a list
  5264 
  5265 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5266 basic operations for association lists, following natural argument
  5267 order; moreover the explicit equality predicate passed here avoids
  5268 potentially expensive polymorphic runtime equality checks.
  5269 The old functions may be expressed as follows:
  5270 
  5271   assoc = uncurry (AList.lookup (op =))
  5272   assocs = these oo AList.lookup (op =)
  5273   overwrite = uncurry (AList.update (op =)) o swap
  5274 
  5275 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5276 
  5277   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  5278   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  5279 
  5280 replacing make_keylist and keyfilter (occassionally used)
  5281 Naive rewrites:
  5282 
  5283   make_keylist = AList.make
  5284   keyfilter = AList.find (op =)
  5285 
  5286 * eq_fst and eq_snd now take explicit equality parameter, thus
  5287   avoiding eqtypes. Naive rewrites:
  5288 
  5289     eq_fst = eq_fst (op =)
  5290     eq_snd = eq_snd (op =)
  5291 
  5292 * Removed deprecated apl and apr (rarely used).
  5293   Naive rewrites:
  5294 
  5295     apl (n, op) =>>= curry op n
  5296     apr (op, m) =>>= fn n => op (n, m)
  5297 
  5298 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  5299 provides a reasonably efficient light-weight implementation of sets as
  5300 lists.
  5301 
  5302 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  5303 few new operations; existing lookup and update are now curried to
  5304 follow natural argument order (for use with fold etc.);
  5305 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  5306 
  5307 * Pure/General: output via the Isabelle channels of
  5308 writeln/warning/error etc. is now passed through Output.output, with a
  5309 hook for arbitrary transformations depending on the print_mode
  5310 (cf. Output.add_mode -- the first active mode that provides a output
  5311 function wins).  Already formatted output may be embedded into further
  5312 text via Output.raw; the result of Pretty.string_of/str_of and derived
  5313 functions (string_of_term/cterm/thm etc.) is already marked raw to
  5314 accommodate easy composition of diagnostic messages etc.  Programmers
  5315 rarely need to care about Output.output or Output.raw at all, with
  5316 some notable exceptions: Output.output is required when bypassing the
  5317 standard channels (writeln etc.), or in token translations to produce
  5318 properly formatted results; Output.raw is required when capturing
  5319 already output material that will eventually be presented to the user
  5320 a second time.  For the default print mode, both Output.output and
  5321 Output.raw have no effect.
  5322 
  5323 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  5324 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  5325 cumulative results are displayed at the end of a batch session.
  5326 
  5327 * Pure/General: File.sysify_path and File.quote_sysify path have been
  5328 replaced by File.platform_path and File.shell_path (with appropriate
  5329 hooks).  This provides a clean interface for unusual systems where the
  5330 internal and external process view of file names are different.
  5331 
  5332 * Pure: more efficient orders for basic syntactic entities: added
  5333 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  5334 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  5335 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  5336 orders now -- potential INCOMPATIBILITY for code that depends on a
  5337 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  5338 Library.sort_strings on result).
  5339 
  5340 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  5341 fold_types traverse types/terms from left to right, observing natural
  5342 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  5343 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  5344 
  5345 * Pure: name spaces have been refined, with significant changes of the
  5346 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  5347 to extern(_table).  The plain name entry path is superceded by a
  5348 general 'naming' context, which also includes the 'policy' to produce
  5349 a fully qualified name and external accesses of a fully qualified
  5350 name; NameSpace.extend is superceded by context dependent
  5351 Sign.declare_name.  Several theory and proof context operations modify
  5352 the naming context.  Especially note Theory.restore_naming and
  5353 ProofContext.restore_naming to get back to a sane state; note that
  5354 Theory.add_path is no longer sufficient to recover from
  5355 Theory.absolute_path in particular.
  5356 
  5357 * Pure: new flags short_names (default false) and unique_names
  5358 (default true) for controlling output of qualified names.  If
  5359 short_names is set, names are printed unqualified.  If unique_names is
  5360 reset, the name prefix is reduced to the minimum required to achieve
  5361 the original result when interning again, even if there is an overlap
  5362 with earlier declarations.
  5363 
  5364 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  5365 now 'extend', and 'merge' gets an additional Pretty.pp argument
  5366 (useful for printing error messages).  INCOMPATIBILITY.
  5367 
  5368 * Pure: major reorganization of the theory context.  Type Sign.sg and
  5369 Theory.theory are now identified, referring to the universal
  5370 Context.theory (see Pure/context.ML).  Actual signature and theory
  5371 content is managed as theory data.  The old code and interfaces were
  5372 spread over many files and structures; the new arrangement introduces
  5373 considerable INCOMPATIBILITY to gain more clarity:
  5374 
  5375   Context -- theory management operations (name, identity, inclusion,
  5376     parents, ancestors, merge, etc.), plus generic theory data;
  5377 
  5378   Sign -- logical signature and syntax operations (declaring consts,
  5379     types, etc.), plus certify/read for common entities;
  5380 
  5381   Theory -- logical theory operations (stating axioms, definitions,
  5382     oracles), plus a copy of logical signature operations (consts,
  5383     types, etc.); also a few basic management operations (Theory.copy,
  5384     Theory.merge, etc.)
  5385 
  5386 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  5387 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  5388 for convenience -- they merely return the theory.
  5389 
  5390 * Pure: type Type.tsig is superceded by theory in most interfaces.
  5391 
  5392 * Pure: the Isar proof context type is already defined early in Pure
  5393 as Context.proof (note that ProofContext.context and Proof.context are
  5394 aliases, where the latter is the preferred name).  This enables other
  5395 Isabelle components to refer to that type even before Isar is present.
  5396 
  5397 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  5398 typeK, constK, axiomK, oracleK), but provide explicit operations for
  5399 any of these kinds.  For example, Sign.intern typeK is now
  5400 Sign.intern_type, Theory.hide_space Sign.typeK is now
  5401 Theory.hide_types.  Also note that former
  5402 Theory.hide_classes/types/consts are now
  5403 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  5404 internalize their arguments!  INCOMPATIBILITY.
  5405 
  5406 * Pure: get_thm interface (of PureThy and ProofContext) expects
  5407 datatype thmref (with constructors Name and NameSelection) instead of
  5408 plain string -- INCOMPATIBILITY;
  5409 
  5410 * Pure: cases produced by proof methods specify options, where NONE
  5411 means to remove case bindings -- INCOMPATIBILITY in
  5412 (RAW_)METHOD_CASES.
  5413 
  5414 * Pure: the following operations retrieve axioms or theorems from a
  5415 theory node or theory hierarchy, respectively:
  5416 
  5417   Theory.axioms_of: theory -> (string * term) list
  5418   Theory.all_axioms_of: theory -> (string * term) list
  5419   PureThy.thms_of: theory -> (string * thm) list
  5420   PureThy.all_thms_of: theory -> (string * thm) list
  5421 
  5422 * Pure: print_tac now outputs the goal through the trace channel.
  5423 
  5424 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  5425 Reference Toplevel.debug (default false) controls detailed printing
  5426 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  5427 controls execution profiling -- set to 1 for time and 2 for space
  5428 (both increase the runtime).
  5429 
  5430 * Isar session: The initial use of ROOT.ML is now always timed,
  5431 i.e. the log will show the actual process times, in contrast to the
  5432 elapsed wall-clock time that the outer shell wrapper produces.
  5433 
  5434 * Simplifier: improved handling of bound variables (nameless
  5435 representation, avoid allocating new strings).  Simprocs that invoke
  5436 the Simplifier recursively should use Simplifier.inherit_bounds to
  5437 avoid local name clashes.  Failure to do so produces warnings
  5438 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  5439 for further details.
  5440 
  5441 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  5442 bindings for all theorems stored within a given theory; this may help
  5443 in porting non-Isar theories to Isar ones, while keeping ML proof
  5444 scripts for the time being.
  5445 
  5446 * ML operator HTML.with_charset specifies the charset begin used for
  5447 generated HTML files.  For example:
  5448 
  5449   HTML.with_charset "utf-8" use_thy "Hebrew";
  5450   HTML.with_charset "utf-8" use_thy "Chinese";
  5451 
  5452 
  5453 *** System ***
  5454 
  5455 * Allow symlinks to all proper Isabelle executables (Isabelle,
  5456 isabelle, isatool etc.).
  5457 
  5458 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  5459 isatool doc, isatool mkdir, display_drafts etc.).
  5460 
  5461 * isatool usedir: option -f allows specification of the ML file to be
  5462 used by Isabelle; default is ROOT.ML.
  5463 
  5464 * New isatool version outputs the version identifier of the Isabelle
  5465 distribution being used.
  5466 
  5467 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  5468 (containing Boolean satisfiability problems) into Isabelle/HOL
  5469 theories.
  5470 
  5471 
  5472 
  5473 New in Isabelle2004 (April 2004)
  5474 --------------------------------
  5475 
  5476 *** General ***
  5477 
  5478 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  5479   Replaces linorder.ML.
  5480 
  5481 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  5482   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  5483   (\<a>...\<z>), are now considered normal letters, and can therefore
  5484   be used anywhere where an ASCII letter (a...zA...Z) has until
  5485   now. COMPATIBILITY: This obviously changes the parsing of some
  5486   terms, especially where a symbol has been used as a binder, say
  5487   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  5488   as an identifier.  Fix it by inserting a space around former
  5489   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  5490   existing theory and ML files.
  5491 
  5492 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  5493 
  5494 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  5495   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  5496   a normal (but invisible) letter. For multiple letter subscripts repeat
  5497   \<^isub> like this: x\<^isub>1\<^isub>2.
  5498 
  5499 * Pure: There are now sub-/superscripts that can span more than one
  5500   character. Text between \<^bsub> and \<^esub> is set in subscript in
  5501   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  5502   superscript. The new control characters are not identifier parts.
  5503 
  5504 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  5505   content of "..." to the latex file instead of \isacntrl... . The "..."
  5506   may consist of any printable characters excluding the end bracket >.
  5507 
  5508 * Pure: Using new Isar command "finalconsts" (or the ML functions
  5509   Theory.add_finals or Theory.add_finals_i) it is now possible to
  5510   declare constants "final", which prevents their being given a definition
  5511   later.  It is useful for constants whose behaviour is fixed axiomatically
  5512   rather than definitionally, such as the meta-logic connectives.
  5513 
  5514 * Pure: 'instance' now handles general arities with general sorts
  5515   (i.e. intersections of classes),
  5516 
  5517 * Presentation: generated HTML now uses a CSS style sheet to make layout
  5518   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  5519   It can be changed to alter the colors/layout of generated pages.
  5520 
  5521 
  5522 *** Isar ***
  5523 
  5524 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  5525   cut_tac, subgoal_tac and thin_tac:
  5526   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  5527     locales are no longer forced to write Isar proof scripts.
  5528     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  5529     emulations.
  5530   - INCOMPATIBILITY: names of variables to be instantiated may no
  5531     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  5532     This is consistent with the instantiation attribute "where".
  5533 
  5534 * Attributes "where" and "of":
  5535   - Now take type variables of instantiated theorem into account when reading
  5536     the instantiation string.  This fixes a bug that caused instantiated
  5537     theorems to have too special types in some circumstances.
  5538   - "where" permits explicit instantiations of type variables.
  5539 
  5540 * Calculation commands "moreover" and "also" no longer interfere with
  5541   current facts ("this"), admitting arbitrary combinations with "then"
  5542   and derived forms.
  5543 
  5544 * Locales:
  5545   - Goal statements involving the context element "includes" no longer
  5546     generate theorems with internal delta predicates (those ending on
  5547     "_axioms") in the premise.
  5548     Resolve particular premise with <locale>.intro to obtain old form.
  5549   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  5550     specification and "includes" elements in goal statement.
  5551   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  5552     [intro?] and [elim?] (respectively) by default.
  5553   - Experimental command for instantiation of locales in proof contexts:
  5554         instantiate <label>[<attrs>]: <loc>
  5555     Instantiates locale <loc> and adds all its theorems to the current context
  5556     taking into account their attributes.  Label and attrs are optional
  5557     modifiers, like in theorem declarations.  If present, names of
  5558     instantiated theorems are qualified with <label>, and the attributes
  5559     <attrs> are applied after any attributes these theorems might have already.
  5560       If the locale has assumptions, a chained fact of the form
  5561     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  5562     are derived.  The command does not support old-style locales declared
  5563     with "locale (open)".
  5564       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  5565 
  5566 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  5567   (Isar) contexts.
  5568 
  5569 
  5570 *** HOL ***
  5571 
  5572 * Proof import: new image HOL4 contains the imported library from
  5573   the HOL4 system with about 2500 theorems. It is imported by
  5574   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  5575   can be used like any other Isabelle image.  See
  5576   HOL/Import/HOL/README for more information.
  5577 
  5578 * Simplifier:
  5579   - Much improved handling of linear and partial orders.
  5580     Reasoners for linear and partial orders are set up for type classes
  5581     "linorder" and "order" respectively, and are added to the default simpset
  5582     as solvers.  This means that the simplifier can build transitivity chains
  5583     to solve goals from the assumptions.
  5584   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  5585     of blast or auto after simplification become unnecessary because the goal
  5586     is solved by simplification already.
  5587 
  5588 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  5589     all proved in axiomatic type classes for semirings, rings and fields.
  5590 
  5591 * Numerics:
  5592   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  5593     now formalized using the Ring_and_Field theory mentioned above.
  5594   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  5595     than before, because now they are set up once in a generic manner.
  5596   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  5597     Look for the general versions in Ring_and_Field (and Power if they concern
  5598     exponentiation).
  5599 
  5600 * Type "rat" of the rational numbers is now available in HOL-Complex.
  5601 
  5602 * Records:
  5603   - Record types are now by default printed with their type abbreviation
  5604     instead of the list of all field types. This can be configured via
  5605     the reference "print_record_type_abbr".
  5606   - Simproc "record_upd_simproc" for simplification of multiple updates added
  5607     (not enabled by default).
  5608   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  5609     EX x. x = sel r to True (not enabled by default).
  5610   - Tactic "record_split_simp_tac" to split and simplify records added.
  5611 
  5612 * 'specification' command added, allowing for definition by
  5613   specification.  There is also an 'ax_specification' command that
  5614   introduces the new constants axiomatically.
  5615 
  5616 * arith(_tac) is now able to generate counterexamples for reals as well.
  5617 
  5618 * HOL-Algebra: new locale "ring" for non-commutative rings.
  5619 
  5620 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  5621   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  5622 
  5623 * HOL-Matrix: a first theory for matrices in HOL with an application of
  5624   matrix theory to linear programming.
  5625 
  5626 * Unions and Intersections:
  5627   The latex output syntax of UN and INT has been changed
  5628   from "\Union x \in A. B" to "\Union_{x \in A} B"
  5629   i.e. the index formulae has become a subscript.
  5630   Similarly for "\Union x. B", and for \Inter instead of \Union.
  5631 
  5632 * Unions and Intersections over Intervals:
  5633   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  5634   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  5635   like in normal math, and corresponding versions for < and for intersection.
  5636 
  5637 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  5638   lexicographic dictonary ordering has been added as "lexord".
  5639 
  5640 * ML: the legacy theory structures Int and List have been removed. They had
  5641   conflicted with ML Basis Library structures having the same names.
  5642 
  5643 * 'refute' command added to search for (finite) countermodels.  Only works
  5644   for a fragment of HOL.  The installation of an external SAT solver is
  5645   highly recommended.  See "HOL/Refute.thy" for details.
  5646 
  5647 * 'quickcheck' command: Allows to find counterexamples by evaluating
  5648   formulae under an assignment of free variables to random values.
  5649   In contrast to 'refute', it can deal with inductive datatypes,
  5650   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  5651   for examples.
  5652 
  5653 
  5654 *** HOLCF ***
  5655 
  5656 * Streams now come with concatenation and are part of the HOLCF image
  5657 
  5658 
  5659 
  5660 New in Isabelle2003 (May 2003)
  5661 ------------------------------
  5662 
  5663 *** General ***
  5664 
  5665 * Provers/simplifier:
  5666 
  5667   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  5668     Assumptions are now subject to complete mutual simplification,
  5669     not just from left to right. The simplifier now preserves
  5670     the order of assumptions.
  5671 
  5672     Potential INCOMPATIBILITY:
  5673 
  5674     -- simp sometimes diverges where the old version did
  5675        not, e.g. invoking simp on the goal
  5676 
  5677         [| P (f x); y = x; f x = f y |] ==> Q
  5678 
  5679        now gives rise to the infinite reduction sequence
  5680 
  5681         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  5682 
  5683        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  5684        kind of problem.
  5685 
  5686     -- Tactics combining classical reasoner and simplification (such as auto)
  5687        are also affected by this change, because many of them rely on
  5688        simp. They may sometimes diverge as well or yield a different numbers
  5689        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  5690        in case of problems. Sometimes subsequent calls to the classical
  5691        reasoner will fail because a preceeding call to the simplifier too
  5692        eagerly simplified the goal, e.g. deleted redundant premises.
  5693 
  5694   - The simplifier trace now shows the names of the applied rewrite rules
  5695 
  5696   - You can limit the number of recursive invocations of the simplifier
  5697     during conditional rewriting (where the simplifie tries to solve the
  5698     conditions before applying the rewrite rule):
  5699     ML "simp_depth_limit := n"
  5700     where n is an integer. Thus you can force termination where previously
  5701     the simplifier would diverge.
  5702 
  5703   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  5704 
  5705   - No longer aborts on failed congruence proof.  Instead, the
  5706     congruence is ignored.
  5707 
  5708 * Pure: New generic framework for extracting programs from constructive
  5709   proofs. See HOL/Extraction.thy for an example instantiation, as well
  5710   as HOL/Extraction for some case studies.
  5711 
  5712 * Pure: The main goal of the proof state is no longer shown by default, only
  5713 the subgoals. This behaviour is controlled by a new flag.
  5714    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  5715 (ML: Proof.show_main_goal).
  5716 
  5717 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  5718 rules whose conclusion matches subgoal 1:
  5719       PG menu: Isabelle/Isar -> Show me -> matching rules
  5720 The rules are ordered by how closely they match the subgoal.
  5721 In particular, rules that solve a subgoal outright are displayed first
  5722 (or rather last, the way they are printed).
  5723 (ML: ProofGeneral.print_intros())
  5724 
  5725 * Pure: New flag trace_unify_fail causes unification to print
  5726 diagnostic information (PG: in trace buffer) when it fails. This is
  5727 useful for figuring out why single step proofs like rule, erule or
  5728 assumption failed.
  5729 
  5730 * Pure: Locale specifications now produce predicate definitions
  5731 according to the body of text (covering assumptions modulo local
  5732 definitions); predicate "loc_axioms" covers newly introduced text,
  5733 while "loc" is cumulative wrt. all included locale expressions; the
  5734 latter view is presented only on export into the global theory
  5735 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  5736 on the old view without predicates;
  5737 
  5738 * Pure: predefined locales "var" and "struct" are useful for sharing
  5739 parameters (as in CASL, for example); just specify something like
  5740 ``var x + var y + struct M'' as import;
  5741 
  5742 * Pure: improved thms_containing: proper indexing of facts instead of
  5743 raw theorems; check validity of results wrt. current name space;
  5744 include local facts of proof configuration (also covers active
  5745 locales), cover fixed variables in index; may use "_" in term
  5746 specification; an optional limit for the number of printed facts may
  5747 be given (the default is 40);
  5748 
  5749 * Pure: disallow duplicate fact bindings within new-style theory files
  5750 (batch-mode only);
  5751 
  5752 * Provers: improved induct method: assumptions introduced by case
  5753 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  5754 the goal statement); "foo" still refers to all facts collectively;
  5755 
  5756 * Provers: the function blast.overloaded has been removed: all constants
  5757 are regarded as potentially overloaded, which improves robustness in exchange
  5758 for slight decrease in efficiency;
  5759 
  5760 * Provers/linorder: New generic prover for transitivity reasoning over
  5761 linear orders.  Note: this prover is not efficient!
  5762 
  5763 * Isar: preview of problems to finish 'show' now produce an error
  5764 rather than just a warning (in interactive mode);
  5765 
  5766 
  5767 *** HOL ***
  5768 
  5769 * arith(_tac)
  5770 
  5771  - Produces a counter example if it cannot prove a goal.
  5772    Note that the counter example may be spurious if the goal is not a formula
  5773    of quantifier-free linear arithmetic.
  5774    In ProofGeneral the counter example appears in the trace buffer.
  5775 
  5776  - Knows about div k and mod k where k is a numeral of type nat or int.
  5777 
  5778  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  5779    linear arithmetic fails. This takes account of quantifiers and divisibility.
  5780    Presburger arithmetic can also be called explicitly via presburger(_tac).
  5781 
  5782 * simp's arithmetic capabilities have been enhanced a bit: it now
  5783 takes ~= in premises into account (by performing a case split);
  5784 
  5785 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  5786 are distributed over a sum of terms;
  5787 
  5788 * New tactic "trans_tac" and method "trans" instantiate
  5789 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  5790 "<=", "<" and "=").
  5791 
  5792 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  5793 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  5794 
  5795 * 'typedef' command has new option "open" to suppress the set
  5796 definition;
  5797 
  5798 * functions Min and Max on finite sets have been introduced (theory
  5799 Finite_Set);
  5800 
  5801 * attribute [symmetric] now works for relations as well; it turns
  5802 (x,y) : R^-1 into (y,x) : R, and vice versa;
  5803 
  5804 * induct over a !!-quantified statement (say !!x1..xn):
  5805   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  5806 
  5807 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  5808 %x. None. Warning: empty_def now refers to the previously hidden definition
  5809 of the empty set.
  5810 
  5811 * Algebra: formalization of classical algebra.  Intended as base for
  5812 any algebraic development in Isabelle.  Currently covers group theory
  5813 (up to Sylow's theorem) and ring theory (Universal Property of
  5814 Univariate Polynomials).  Contributions welcome;
  5815 
  5816 * GroupTheory: deleted, since its material has been moved to Algebra;
  5817 
  5818 * Complex: new directory of the complex numbers with numeric constants,
  5819 nonstandard complex numbers, and some complex analysis, standard and
  5820 nonstandard (Jacques Fleuriot);
  5821 
  5822 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  5823 
  5824 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  5825 Fleuriot);
  5826 
  5827 * Real/HahnBanach: updated and adapted to locales;
  5828 
  5829 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  5830 Gray and Kramer);
  5831 
  5832 * UNITY: added the Meier-Sanders theory of progress sets;
  5833 
  5834 * MicroJava: bytecode verifier and lightweight bytecode verifier
  5835 as abstract algorithms, instantiated to the JVM;
  5836 
  5837 * Bali: Java source language formalization. Type system, operational
  5838 semantics, axiomatic semantics. Supported language features:
  5839 classes, interfaces, objects,virtual methods, static methods,
  5840 static/instance fields, arrays, access modifiers, definite
  5841 assignment, exceptions.
  5842 
  5843 
  5844 *** ZF ***
  5845 
  5846 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  5847 universe, etc.);
  5848 
  5849 * Main ZF: virtually all theories converted to new-style format;
  5850 
  5851 
  5852 *** ML ***
  5853 
  5854 * Pure: Tactic.prove provides sane interface for internal proofs;
  5855 omits the infamous "standard" operation, so this is more appropriate
  5856 than prove_goalw_cterm in many situations (e.g. in simprocs);
  5857 
  5858 * Pure: improved error reporting of simprocs;
  5859 
  5860 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  5861 up simprocs;
  5862 
  5863 
  5864 *** Document preparation ***
  5865 
  5866 * uses \par instead of \\ for line breaks in theory text. This may
  5867 shift some page breaks in large documents. To get the old behaviour
  5868 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  5869 
  5870 * minimized dependencies of isabelle.sty and isabellesym.sty on
  5871 other packages
  5872 
  5873 * \<euro> now needs package babel/greek instead of marvosym (which
  5874 broke \Rightarrow)
  5875 
  5876 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  5877 textcomp package)
  5878 
  5879 
  5880 
  5881 New in Isabelle2002 (March 2002)
  5882 --------------------------------
  5883 
  5884 *** Document preparation ***
  5885 
  5886 * greatly simplified document preparation setup, including more
  5887 graceful interpretation of isatool usedir -i/-d/-D options, and more
  5888 instructive isatool mkdir; users should basically be able to get
  5889 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  5890 users may run a separate document processing stage manually like this:
  5891 "isatool usedir -D output HOL Test && isatool document Test/output";
  5892 
  5893 * theory dependency graph may now be incorporated into documents;
  5894 isatool usedir -g true will produce session_graph.eps/.pdf for use
  5895 with \includegraphics of LaTeX;
  5896 
  5897 * proper spacing of consecutive markup elements, especially text
  5898 blocks after section headings;
  5899 
  5900 * support bold style (for single symbols only), input syntax is like
  5901 this: "\<^bold>\<alpha>" or "\<^bold>A";
  5902 
  5903 * \<bullet> is now output as bold \cdot by default, which looks much
  5904 better in printed text;
  5905 
  5906 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  5907 note that these symbols are currently unavailable in Proof General /
  5908 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  5909 
  5910 * isatool latex no longer depends on changed TEXINPUTS, instead
  5911 isatool document copies the Isabelle style files to the target
  5912 location;
  5913 
  5914 
  5915 *** Isar ***
  5916 
  5917 * Pure/Provers: improved proof by cases and induction;
  5918   - 'case' command admits impromptu naming of parameters (such as
  5919     "case (Suc n)");
  5920   - 'induct' method divinates rule instantiation from the inductive
  5921     claim; no longer requires excessive ?P bindings for proper
  5922     instantiation of cases;
  5923   - 'induct' method properly enumerates all possibilities of set/type
  5924     rules; as a consequence facts may be also passed through *type*
  5925     rules without further ado;
  5926   - 'induct' method now derives symbolic cases from the *rulified*
  5927     rule (before it used to rulify cases stemming from the internal
  5928     atomized version); this means that the context of a non-atomic
  5929     statement becomes is included in the hypothesis, avoiding the
  5930     slightly cumbersome show "PROP ?case" form;
  5931   - 'induct' may now use elim-style induction rules without chaining
  5932     facts, using ``missing'' premises from the goal state; this allows
  5933     rules stemming from inductive sets to be applied in unstructured
  5934     scripts, while still benefitting from proper handling of non-atomic
  5935     statements; NB: major inductive premises need to be put first, all
  5936     the rest of the goal is passed through the induction;
  5937   - 'induct' proper support for mutual induction involving non-atomic
  5938     rule statements (uses the new concept of simultaneous goals, see
  5939     below);
  5940   - append all possible rule selections, but only use the first
  5941     success (no backtracking);
  5942   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  5943   - undeclared rule case names default to numbers 1, 2, 3, ...;
  5944   - added 'print_induct_rules' (covered by help item in recent Proof
  5945     General versions);
  5946   - moved induct/cases attributes to Pure, methods to Provers;
  5947   - generic method setup instantiated for FOL and HOL;
  5948 
  5949 * Pure: support multiple simultaneous goal statements, for example
  5950 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  5951 meta-level mechanism, this acts as if several individual goals had
  5952 been stated separately; in particular common proof methods need to be
  5953 repeated in order to cover all claims; note that a single elimination
  5954 step is *not* sufficient to establish the two conjunctions, so this
  5955 fails:
  5956 
  5957   assume "A & B" then have A and B ..   (*".." fails*)
  5958 
  5959 better use "obtain" in situations as above; alternative refer to
  5960 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  5961 
  5962 * Pure: proper integration with ``locales''; unlike the original
  5963 version by Florian Kammller, Isar locales package high-level proof
  5964 contexts rather than raw logical ones (e.g. we admit to include
  5965 attributes everywhere); operations on locales include merge and
  5966 rename; support for implicit arguments (``structures''); simultaneous
  5967 type-inference over imports and text; see also HOL/ex/Locales.thy for
  5968 some examples;
  5969 
  5970 * Pure: the following commands have been ``localized'', supporting a
  5971 target locale specification "(in name)": 'lemma', 'theorem',
  5972 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  5973 stored both within the locale and at the theory level (exported and
  5974 qualified by the locale name);
  5975 
  5976 * Pure: theory goals may now be specified in ``long'' form, with
  5977 ad-hoc contexts consisting of arbitrary locale elements. for example
  5978 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  5979 definitions may be given, too); the result is a meta-level rule with
  5980 the context elements being discharged in the obvious way;
  5981 
  5982 * Pure: new proof command 'using' allows to augment currently used
  5983 facts after a goal statement ('using' is syntactically analogous to
  5984 'apply', but acts on the goal's facts only); this allows chained facts
  5985 to be separated into parts given before and after a claim, as in
  5986 ``from a and b have C using d and e <proof>'';
  5987 
  5988 * Pure: renamed "antecedent" case to "rule_context";
  5989 
  5990 * Pure: new 'judgment' command records explicit information about the
  5991 object-logic embedding (used by several tools internally); no longer
  5992 use hard-wired "Trueprop";
  5993 
  5994 * Pure: added 'corollary' command;
  5995 
  5996 * Pure: fixed 'token_translation' command;
  5997 
  5998 * Pure: removed obsolete 'exported' attribute;
  5999 
  6000 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  6001 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  6002 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  6003 
  6004 * Pure: method 'atomize' presents local goal premises as object-level
  6005 statements (atomic meta-level propositions); setup controlled via
  6006 rewrite rules declarations of 'atomize' attribute; example
  6007 application: 'induct' method with proper rule statements in improper
  6008 proof *scripts*;
  6009 
  6010 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  6011 now consider the syntactic context of assumptions, giving a better
  6012 chance to get type-inference of the arguments right (this is
  6013 especially important for locales);
  6014 
  6015 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  6016 mode;
  6017 
  6018 * Pure/obtain: the formal conclusion "thesis", being marked as
  6019 ``internal'', may no longer be reference directly in the text;
  6020 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  6021 situations;
  6022 
  6023 * Pure: generic 'sym' attribute which declares a rule both as pure
  6024 'elim?' and for the 'symmetric' operation;
  6025 
  6026 * Pure: marginal comments ``--'' may now occur just anywhere in the
  6027 text; the fixed correlation with particular command syntax has been
  6028 discontinued;
  6029 
  6030 * Pure: new method 'rules' is particularly well-suited for proof
  6031 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  6032 but often produces more compact proof terms with less detours;
  6033 
  6034 * Pure/Provers/classical: simplified integration with pure rule
  6035 attributes and methods; the classical "intro?/elim?/dest?"
  6036 declarations coincide with the pure ones; the "rule" method no longer
  6037 includes classically swapped intros; "intro" and "elim" methods no
  6038 longer pick rules from the context; also got rid of ML declarations
  6039 AddXIs/AddXEs/AddXDs; all of this has some potential for
  6040 INCOMPATIBILITY;
  6041 
  6042 * Provers/classical: attribute 'swapped' produces classical inversions
  6043 of introduction rules;
  6044 
  6045 * Provers/simplifier: 'simplified' attribute may refer to explicit
  6046 rules instead of full simplifier context; 'iff' attribute handles
  6047 conditional rules;
  6048 
  6049 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  6050 
  6051 * HOL: 'recdef' now fails on unfinished automated proofs, use
  6052 "(permissive)" option to recover old behavior;
  6053 
  6054 * HOL: 'inductive' no longer features separate (collective) attributes
  6055 for 'intros' (was found too confusing);
  6056 
  6057 * HOL: properly declared induction rules less_induct and
  6058 wf_induct_rule;
  6059 
  6060 
  6061 *** HOL ***
  6062 
  6063 * HOL: moved over to sane numeral syntax; the new policy is as
  6064 follows:
  6065 
  6066   - 0 and 1 are polymorphic constants, which are defined on any
  6067   numeric type (nat, int, real etc.);
  6068 
  6069   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  6070   binary representation internally;
  6071 
  6072   - type nat has special constructor Suc, and generally prefers Suc 0
  6073   over 1::nat and Suc (Suc 0) over 2::nat;
  6074 
  6075 This change may cause significant problems of INCOMPATIBILITY; here
  6076 are some hints on converting existing sources:
  6077 
  6078   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  6079   entities, so expressions involving "-" (unary or binary minus) need
  6080   to be spaced properly;
  6081 
  6082   - existing occurrences of "1" may need to be constraint "1::nat" or
  6083   even replaced by Suc 0; similar for old "2";
  6084 
  6085   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  6086 
  6087   - remove all special provisions on numerals in proofs;
  6088 
  6089 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  6090 representation (depends on bin_arith_simps in the default context);
  6091 
  6092 * HOL: symbolic syntax for x^2 (numeral 2);
  6093 
  6094 * HOL: the class of all HOL types is now called "type" rather than
  6095 "term"; INCOMPATIBILITY, need to adapt references to this type class
  6096 in axclass/classes, instance/arities, and (usually rare) occurrences
  6097 in typings (of consts etc.); internally the class is called
  6098 "HOL.type", ML programs should refer to HOLogic.typeS;
  6099 
  6100 * HOL/record package improvements:
  6101   - new derived operations "fields" to build a partial record section,
  6102     "extend" to promote a fixed record to a record scheme, and
  6103     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  6104     declared as simp by default;
  6105   - shared operations ("more", "fields", etc.) now need to be always
  6106     qualified) --- potential INCOMPATIBILITY;
  6107   - removed "make_scheme" operations (use "make" with "extend") --
  6108     INCOMPATIBILITY;
  6109   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  6110   - provides cases/induct rules for use with corresponding Isar
  6111     methods (for concrete records, record schemes, concrete more
  6112     parts, and schematic more parts -- in that order);
  6113   - internal definitions directly based on a light-weight abstract
  6114     theory of product types over typedef rather than datatype;
  6115 
  6116 * HOL: generic code generator for generating executable ML code from
  6117 specifications; specific support for HOL constructs such as inductive
  6118 datatypes and sets, as well as recursive functions; can be invoked
  6119 via 'generate_code' theory section;
  6120 
  6121 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  6122 
  6123 * HOL: consolidated and renamed several theories.  In particular:
  6124         Ord.thy has been absorbed into HOL.thy
  6125         String.thy has been absorbed into List.thy
  6126 
  6127 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  6128 (beware of argument permutation!);
  6129 
  6130 * HOL: linorder_less_split superseded by linorder_cases;
  6131 
  6132 * HOL/List: "nodups" renamed to "distinct";
  6133 
  6134 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  6135 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  6136   - Ex_def has changed, now need to use some_eq_ex
  6137 
  6138 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  6139 in this (rare) case use:
  6140 
  6141   delSWrapper "split_all_tac"
  6142   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  6143 
  6144 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  6145 MAY FAIL;
  6146 
  6147 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  6148 Isabelle's type classes, ^ on functions and relations has too general
  6149 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  6150 necessary to attach explicit type constraints;
  6151 
  6152 * HOL/Relation: the prefix name of the infix "O" has been changed from
  6153 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  6154 renamed accordingly (eg "compI" -> "rel_compI").
  6155 
  6156 * HOL: syntax translations now work properly with numerals and records
  6157 expressions;
  6158 
  6159 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  6160 of "lam" -- INCOMPATIBILITY;
  6161 
  6162 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  6163 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  6164 renamed "Product_Type.unit";
  6165 
  6166 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  6167 
  6168 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  6169 the "cases" method);
  6170 
  6171 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  6172 Florian Kammller);
  6173 
  6174 * HOL/IMP: updated and converted to new-style theory format; several
  6175 parts turned into readable document, with proper Isar proof texts and
  6176 some explanations (by Gerwin Klein);
  6177 
  6178 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  6179 
  6180 * HOL-Hyperreal is now a logic image;
  6181 
  6182 
  6183 *** HOLCF ***
  6184 
  6185 * Isar: consts/constdefs supports mixfix syntax for continuous
  6186 operations;
  6187 
  6188 * Isar: domain package adapted to new-style theory format, e.g. see
  6189 HOLCF/ex/Dnat.thy;
  6190 
  6191 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  6192 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  6193 lift.induct_tac, always use UU instead of Undef;
  6194 
  6195 * HOLCF/IMP: updated and converted to new-style theory;
  6196 
  6197 
  6198 *** ZF ***
  6199 
  6200 * Isar: proper integration of logic-specific tools and packages,
  6201 including theory commands '(co)inductive', '(co)datatype',
  6202 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  6203 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  6204 
  6205 * theory Main no longer includes AC; for the Axiom of Choice, base
  6206 your theory on Main_ZFC;
  6207 
  6208 * the integer library now covers quotients and remainders, with many
  6209 laws relating division to addition, multiplication, etc.;
  6210 
  6211 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  6212 typeless version of the formalism;
  6213 
  6214 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  6215 format;
  6216 
  6217 * ZF/Induct: new directory for examples of inductive definitions,
  6218 including theory Multiset for multiset orderings; converted to
  6219 new-style theory format;
  6220 
  6221 * ZF: many new theorems about lists, ordinals, etc.;
  6222 
  6223 
  6224 *** General ***
  6225 
  6226 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  6227 variable proof controls level of detail: 0 = no proofs (only oracle
  6228 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  6229 also ref manual for further ML interfaces;
  6230 
  6231 * Pure/axclass: removed obsolete ML interface
  6232 goal_subclass/goal_arity;
  6233 
  6234 * Pure/syntax: new token syntax "num" for plain numerals (without "#"