NEWS
author blanchet
Mon, 04 Apr 2011 19:09:10 +0200
changeset 43089 3bf2eea43dac
parent 43051 a6c141925a8a
child 43110 e48baf91aeab
permissions -rw-r--r--
document "type_sys" option
     1 Isabelle NEWS -- history user-relevant changes
     2 ==============================================
     3 
     4 New in this Isabelle version
     5 ----------------------------
     6 
     7 *** General ***
     8 
     9 * Theory loader: source files are identified by content via SHA1
    10 digests.  Discontinued former path/modtime identification and optional
    11 ISABELLE_FILE_IDENT plugin scripts.
    12 
    13 * Parallelization of nested Isar proofs is subject to
    14 Goal.parallel_proofs_threshold (default 100).  See also isabelle
    15 usedir option -Q.
    16 
    17 * Discontinued support for Poly/ML 5.2, which was the last version
    18 without proper multithreading and TimeLimit implementation.
    19 
    20 * Discontinued old lib/scripts/polyml-platform, which has been
    21 obsolete since Isabelle2009-2.
    22 
    23 * Theory loader: source files are exclusively located via the master
    24 directory of each theory node (where the .thy file itself resides).
    25 The global load path (such as src/HOL/Library) is has been
    26 discontinued.  INCOMPATIBILITY.
    27 
    28 * Various optional external tools are referenced more robustly and
    29 uniformly by explicit Isabelle settings as follows:
    30 
    31   ISABELLE_CSDP   (formerly CSDP_EXE)
    32   ISABELLE_GHC    (formerly EXEC_GHC or GHC_PATH)
    33   ISABELLE_OCAML  (formerly EXEC_OCAML)
    34   ISABELLE_SWIPL  (formerly EXEC_SWIPL)
    35   ISABELLE_YAP    (formerly EXEC_YAP)
    36 
    37 Note that automated detection from the file-system or search path has
    38 been discontinued.  INCOMPATIBILITY.
    39 
    40 
    41 *** HOL ***
    42 
    43 * Nitpick:
    44   - Added "need" and "total_consts" options.
    45   - Reintroduced "show_skolems" option by popular demand.
    46   - Renamed attribute: nitpick_def ~> nitpick_unfold.
    47     INCOMPATIBILITY.
    48 
    49 * Sledgehammer:
    50   - sledgehammer available_provers ~> sledgehammer supported_provers
    51     INCOMPATIBILITY.
    52   - Added "monomorphize", "monomorphize_limit", and "type_sys" options.
    53 
    54 * "try":
    55   - Added "simp:", "intro:", and "elim:" options.
    56 
    57 * Quickcheck:
    58   - Added "eval" option to evaluate terms for the found counterexample
    59     (currently only supported by the default (exhaustive) tester)
    60   - Added post-processing of terms to obtain readable counterexamples
    61     (currently only supported by the default (exhaustive) tester)
    62 
    63 * Function package: discontinued option "tailrec".
    64 INCOMPATIBILITY. Use partial_function instead.
    65 
    66 * HOL-Probability:
    67   - Caratheodory's extension lemma is now proved for ring_of_sets.
    68   - Infinite products of probability measures are now available.
    69   - Use extended reals instead of positive extended reals.
    70     INCOMPATIBILITY.
    71 
    72 *** Document preparation ***
    73 
    74 * New term style "isub" as ad-hoc conversion of variables x1, y23 into
    75 subscripted form x\<^isub>1, y\<^isub>2\<^isub>3.
    76 
    77 
    78 *** ML ***
    79 
    80 * Structure Timing provides various operations for timing; supersedes
    81 former start_timing/end_timing etc.
    82 
    83 * Path.print is the official way to show file-system paths to users
    84 (including quotes etc.).
    85 
    86 * Inner syntax: identifiers in parse trees of generic categories
    87 "logic", "aprop", "idt" etc. carry position information (disguised as
    88 type constraints).  Occasional INCOMPATIBILITY with non-compliant
    89 translations that choke on unexpected type constraints.  Positions can
    90 be stripped in ML translations via Syntax.strip_positions /
    91 Syntax.strip_positions_ast, or via the syntax constant
    92 "_strip_positions" within parse trees.  As last resort, positions can
    93 be disabled via the configuration option Syntax.positions, which is
    94 called "syntax_positions" in Isar attribute syntax.
    95 
    96 
    97 
    98 New in Isabelle2011 (January 2011)
    99 ----------------------------------
   100 
   101 *** General ***
   102 
   103 * Experimental Prover IDE based on Isabelle/Scala and jEdit (see
   104 src/Tools/jEdit).  This also serves as IDE for Isabelle/ML, with
   105 useful tooltips and hyperlinks produced from its static analysis.  The
   106 bundled component provides an executable Isabelle tool that can be run
   107 like this:
   108 
   109   Isabelle2011/bin/isabelle jedit
   110 
   111 * Significantly improved Isabelle/Isar implementation manual.
   112 
   113 * System settings: ISABELLE_HOME_USER now includes ISABELLE_IDENTIFIER
   114 (and thus refers to something like $HOME/.isabelle/Isabelle2011),
   115 while the default heap location within that directory lacks that extra
   116 suffix.  This isolates multiple Isabelle installations from each
   117 other, avoiding problems with old settings in new versions.
   118 INCOMPATIBILITY, need to copy/upgrade old user settings manually.
   119 
   120 * Source files are always encoded as UTF-8, instead of old-fashioned
   121 ISO-Latin-1.  INCOMPATIBILITY.  Isabelle LaTeX documents might require
   122 the following package declarations:
   123 
   124   \usepackage[utf8]{inputenc}
   125   \usepackage{textcomp}
   126 
   127 * Explicit treatment of UTF-8 sequences as Isabelle symbols, such that
   128 a Unicode character is treated as a single symbol, not a sequence of
   129 non-ASCII bytes as before.  Since Isabelle/ML string literals may
   130 contain symbols without further backslash escapes, Unicode can now be
   131 used here as well.  Recall that Symbol.explode in ML provides a
   132 consistent view on symbols, while raw explode (or String.explode)
   133 merely give a byte-oriented representation.
   134 
   135 * Theory loader: source files are primarily located via the master
   136 directory of each theory node (where the .thy file itself resides).
   137 The global load path is still partially available as legacy feature.
   138 Minor INCOMPATIBILITY due to subtle change in file lookup: use
   139 explicit paths, relatively to the theory.
   140 
   141 * Special treatment of ML file names has been discontinued.
   142 Historically, optional extensions .ML or .sml were added on demand --
   143 at the cost of clarity of file dependencies.  Recall that Isabelle/ML
   144 files exclusively use the .ML extension.  Minor INCOMPATIBILTY.
   145 
   146 * Various options that affect pretty printing etc. are now properly
   147 handled within the context via configuration options, instead of
   148 unsynchronized references or print modes.  There are both ML Config.T
   149 entities and Isar declaration attributes to access these.
   150 
   151   ML (Config.T)                 Isar (attribute)
   152 
   153   eta_contract                  eta_contract
   154   show_brackets                 show_brackets
   155   show_sorts                    show_sorts
   156   show_types                    show_types
   157   show_question_marks           show_question_marks
   158   show_consts                   show_consts
   159   show_abbrevs                  show_abbrevs
   160 
   161   Syntax.ast_trace              syntax_ast_trace
   162   Syntax.ast_stat               syntax_ast_stat
   163   Syntax.ambiguity_level        syntax_ambiguity_level
   164 
   165   Goal_Display.goals_limit      goals_limit
   166   Goal_Display.show_main_goal   show_main_goal
   167 
   168   Method.rule_trace             rule_trace
   169 
   170   Thy_Output.display            thy_output_display
   171   Thy_Output.quotes             thy_output_quotes
   172   Thy_Output.indent             thy_output_indent
   173   Thy_Output.source             thy_output_source
   174   Thy_Output.break              thy_output_break
   175 
   176 Note that corresponding "..._default" references in ML may only be
   177 changed globally at the ROOT session setup, but *not* within a theory.
   178 The option "show_abbrevs" supersedes the former print mode
   179 "no_abbrevs" with inverted meaning.
   180 
   181 * More systematic naming of some configuration options.
   182 INCOMPATIBILITY.
   183 
   184   trace_simp  ~>  simp_trace
   185   debug_simp  ~>  simp_debug
   186 
   187 * Support for real valued configuration options, using simplistic
   188 floating-point notation that coincides with the inner syntax for
   189 float_token.
   190 
   191 * Support for real valued preferences (with approximative PGIP type):
   192 front-ends need to accept "pgint" values in float notation.
   193 INCOMPATIBILITY.
   194 
   195 * The IsabelleText font now includes Cyrillic, Hebrew, Arabic from
   196 DejaVu Sans.
   197 
   198 * Discontinued support for Poly/ML 5.0 and 5.1 versions.
   199 
   200 
   201 *** Pure ***
   202 
   203 * Command 'type_synonym' (with single argument) replaces somewhat
   204 outdated 'types', which is still available as legacy feature for some
   205 time.
   206 
   207 * Command 'nonterminal' (with 'and' separated list of arguments)
   208 replaces somewhat outdated 'nonterminals'.  INCOMPATIBILITY.
   209 
   210 * Command 'notepad' replaces former 'example_proof' for
   211 experimentation in Isar without any result.  INCOMPATIBILITY.
   212 
   213 * Locale interpretation commands 'interpret' and 'sublocale' accept
   214 lists of equations to map definitions in a locale to appropriate
   215 entities in the context of the interpretation.  The 'interpretation'
   216 command already provided this functionality.
   217 
   218 * Diagnostic command 'print_dependencies' prints the locale instances
   219 that would be activated if the specified expression was interpreted in
   220 the current context.  Variant "print_dependencies!" assumes a context
   221 without interpretations.
   222 
   223 * Diagnostic command 'print_interps' prints interpretations in proofs
   224 in addition to interpretations in theories.
   225 
   226 * Discontinued obsolete 'global' and 'local' commands to manipulate
   227 the theory name space.  Rare INCOMPATIBILITY.  The ML functions
   228 Sign.root_path and Sign.local_path may be applied directly where this
   229 feature is still required for historical reasons.
   230 
   231 * Discontinued obsolete 'constdefs' command.  INCOMPATIBILITY, use
   232 'definition' instead.
   233 
   234 * The "prems" fact, which refers to the accidental collection of
   235 foundational premises in the context, is now explicitly marked as
   236 legacy feature and will be discontinued soon.  Consider using "assms"
   237 of the head statement or reference facts by explicit names.
   238 
   239 * Document antiquotations @{class} and @{type} print classes and type
   240 constructors.
   241 
   242 * Document antiquotation @{file} checks file/directory entries within
   243 the local file system.
   244 
   245 
   246 *** HOL ***
   247 
   248 * Coercive subtyping: functions can be declared as coercions and type
   249 inference will add them as necessary upon input of a term.  Theory
   250 Complex_Main declares real :: nat => real and real :: int => real as
   251 coercions. A coercion function f is declared like this:
   252 
   253   declare [[coercion f]]
   254 
   255 To lift coercions through type constructors (e.g. from nat => real to
   256 nat list => real list), map functions can be declared, e.g.
   257 
   258   declare [[coercion_map map]]
   259 
   260 Currently coercion inference is activated only in theories including
   261 real numbers, i.e. descendants of Complex_Main.  This is controlled by
   262 the configuration option "coercion_enabled", e.g. it can be enabled in
   263 other theories like this:
   264 
   265   declare [[coercion_enabled]]
   266 
   267 * Command 'partial_function' provides basic support for recursive
   268 function definitions over complete partial orders.  Concrete instances
   269 are provided for i) the option type, ii) tail recursion on arbitrary
   270 types, and iii) the heap monad of Imperative_HOL.  See
   271 src/HOL/ex/Fundefs.thy and src/HOL/Imperative_HOL/ex/Linked_Lists.thy
   272 for examples.
   273 
   274 * Function package: f.psimps rules are no longer implicitly declared
   275 as [simp].  INCOMPATIBILITY.
   276 
   277 * Datatype package: theorems generated for executable equality (class
   278 "eq") carry proper names and are treated as default code equations.
   279 
   280 * Inductive package: now offers command 'inductive_simps' to
   281 automatically derive instantiated and simplified equations for
   282 inductive predicates, similar to 'inductive_cases'.
   283 
   284 * Command 'enriched_type' allows to register properties of the
   285 functorial structure of types.
   286 
   287 * Improved infrastructure for term evaluation using code generator
   288 techniques, in particular static evaluation conversions.
   289 
   290 * Code generator: Scala (2.8 or higher) has been added to the target
   291 languages.
   292 
   293 * Code generator: globbing constant expressions "*" and "Theory.*"
   294 have been replaced by the more idiomatic "_" and "Theory._".
   295 INCOMPATIBILITY.
   296 
   297 * Code generator: export_code without explicit file declaration prints
   298 to standard output.  INCOMPATIBILITY.
   299 
   300 * Code generator: do not print function definitions for case
   301 combinators any longer.
   302 
   303 * Code generator: simplification with rules determined with
   304 src/Tools/Code/code_simp.ML and method "code_simp".
   305 
   306 * Code generator for records: more idiomatic representation of record
   307 types.  Warning: records are not covered by ancient SML code
   308 generation any longer.  INCOMPATIBILITY.  In cases of need, a suitable
   309 rep_datatype declaration helps to succeed then:
   310 
   311   record 'a foo = ...
   312   ...
   313   rep_datatype foo_ext ...
   314 
   315 * Records: logical foundation type for records does not carry a
   316 '_type' suffix any longer (obsolete due to authentic syntax).
   317 INCOMPATIBILITY.
   318 
   319 * Quickcheck now by default uses exhaustive testing instead of random
   320 testing.  Random testing can be invoked by "quickcheck [random]",
   321 exhaustive testing by "quickcheck [exhaustive]".
   322 
   323 * Quickcheck instantiates polymorphic types with small finite
   324 datatypes by default. This enables a simple execution mechanism to
   325 handle quantifiers and function equality over the finite datatypes.
   326 
   327 * Quickcheck random generator has been renamed from "code" to
   328 "random".  INCOMPATIBILITY.
   329 
   330 * Quickcheck now has a configurable time limit which is set to 30
   331 seconds by default. This can be changed by adding [timeout = n] to the
   332 quickcheck command. The time limit for Auto Quickcheck is still set
   333 independently.
   334 
   335 * Quickcheck in locales considers interpretations of that locale for
   336 counter example search.
   337 
   338 * Sledgehammer:
   339   - Added "smt" and "remote_smt" provers based on the "smt" proof
   340     method. See the Sledgehammer manual for details ("isabelle doc
   341     sledgehammer").
   342   - Renamed commands:
   343     sledgehammer atp_info ~> sledgehammer running_provers
   344     sledgehammer atp_kill ~> sledgehammer kill_provers
   345     sledgehammer available_atps ~> sledgehammer available_provers
   346     INCOMPATIBILITY.
   347   - Renamed options:
   348     sledgehammer [atps = ...] ~> sledgehammer [provers = ...]
   349     sledgehammer [atp = ...] ~> sledgehammer [prover = ...]
   350     sledgehammer [timeout = 77 s] ~> sledgehammer [timeout = 77]
   351     (and "ms" and "min" are no longer supported)
   352     INCOMPATIBILITY.
   353 
   354 * Nitpick:
   355   - Renamed options:
   356     nitpick [timeout = 77 s] ~> nitpick [timeout = 77]
   357     nitpick [tac_timeout = 777 ms] ~> nitpick [tac_timeout = 0.777]
   358     INCOMPATIBILITY.
   359   - Added support for partial quotient types.
   360   - Added local versions of the "Nitpick.register_xxx" functions.
   361   - Added "whack" option.
   362   - Allow registration of quotient types as codatatypes.
   363   - Improved "merge_type_vars" option to merge more types.
   364   - Removed unsound "fast_descrs" option.
   365   - Added custom symmetry breaking for datatypes, making it possible to reach
   366     higher cardinalities.
   367   - Prevent the expansion of too large definitions.
   368 
   369 * Proof methods "metis" and "meson" now have configuration options
   370 "meson_trace", "metis_trace", and "metis_verbose" that can be enabled
   371 to diagnose these tools. E.g.
   372 
   373     using [[metis_trace = true]]
   374 
   375 * Auto Solve: Renamed "Auto Solve Direct".  The tool is now available
   376 manually as command 'solve_direct'.
   377 
   378 * The default SMT solver Z3 must be enabled explicitly (due to
   379 licensing issues) by setting the environment variable
   380 Z3_NON_COMMERCIAL in etc/settings of the component, for example.  For
   381 commercial applications, the SMT solver CVC3 is provided as fall-back;
   382 changing the SMT solver is done via the configuration option
   383 "smt_solver".
   384 
   385 * Remote SMT solvers need to be referred to by the "remote_" prefix,
   386 i.e. "remote_cvc3" and "remote_z3".
   387 
   388 * Added basic SMT support for datatypes, records, and typedefs using
   389 the oracle mode (no proofs).  Direct support of pairs has been dropped
   390 in exchange (pass theorems fst_conv snd_conv pair_collapse to the SMT
   391 support for a similar behavior).  Minor INCOMPATIBILITY.
   392 
   393 * Changed SMT configuration options:
   394   - Renamed:
   395     z3_proofs ~> smt_oracle (with inverted meaning)
   396     z3_trace_assms ~> smt_trace_used_facts
   397     INCOMPATIBILITY.
   398   - Added:
   399     smt_verbose
   400     smt_random_seed
   401     smt_datatypes
   402     smt_infer_triggers
   403     smt_monomorph_limit
   404     cvc3_options
   405     remote_cvc3_options
   406     remote_z3_options
   407     yices_options
   408 
   409 * Boogie output files (.b2i files) need to be declared in the theory
   410 header.
   411 
   412 * Simplification procedure "list_to_set_comprehension" rewrites list
   413 comprehensions applied to List.set to set comprehensions.  Occasional
   414 INCOMPATIBILITY, may be deactivated like this:
   415 
   416   declare [[simproc del: list_to_set_comprehension]]
   417 
   418 * Removed old version of primrec package.  INCOMPATIBILITY.
   419 
   420 * Removed simplifier congruence rule of "prod_case", as has for long
   421 been the case with "split".  INCOMPATIBILITY.
   422 
   423 * String.literal is a type, but not a datatype.  INCOMPATIBILITY.
   424 
   425 * Removed [split_format ... and ... and ...] version of
   426 [split_format].  Potential INCOMPATIBILITY.
   427 
   428 * Predicate "sorted" now defined inductively, with nice induction
   429 rules.  INCOMPATIBILITY: former sorted.simps now named sorted_simps.
   430 
   431 * Constant "contents" renamed to "the_elem", to free the generic name
   432 contents for other uses.  INCOMPATIBILITY.
   433 
   434 * Renamed class eq and constant eq (for code generation) to class
   435 equal and constant equal, plus renaming of related facts and various
   436 tuning.  INCOMPATIBILITY.
   437 
   438 * Dropped type classes mult_mono and mult_mono1.  INCOMPATIBILITY.
   439 
   440 * Removed output syntax "'a ~=> 'b" for "'a => 'b option".
   441 INCOMPATIBILITY.
   442 
   443 * Renamed theory Fset to Cset, type Fset.fset to Cset.set, in order to
   444 avoid confusion with finite sets.  INCOMPATIBILITY.
   445 
   446 * Abandoned locales equiv, congruent and congruent2 for equivalence
   447 relations.  INCOMPATIBILITY: use equivI rather than equiv_intro (same
   448 for congruent(2)).
   449 
   450 * Some previously unqualified names have been qualified:
   451 
   452   types
   453     bool ~> HOL.bool
   454     nat ~> Nat.nat
   455 
   456   constants
   457     Trueprop ~> HOL.Trueprop
   458     True ~> HOL.True
   459     False ~> HOL.False
   460     op & ~> HOL.conj
   461     op | ~> HOL.disj
   462     op --> ~> HOL.implies
   463     op = ~> HOL.eq
   464     Not ~> HOL.Not
   465     The ~> HOL.The
   466     All ~> HOL.All
   467     Ex ~> HOL.Ex
   468     Ex1 ~> HOL.Ex1
   469     Let ~> HOL.Let
   470     If ~> HOL.If
   471     Ball ~> Set.Ball
   472     Bex ~> Set.Bex
   473     Suc ~> Nat.Suc
   474     Pair ~> Product_Type.Pair
   475     fst ~> Product_Type.fst
   476     snd ~> Product_Type.snd
   477     curry ~> Product_Type.curry
   478     op : ~> Set.member
   479     Collect ~> Set.Collect
   480 
   481 INCOMPATIBILITY.
   482 
   483 * More canonical naming convention for some fundamental definitions:
   484 
   485     bot_bool_eq ~> bot_bool_def
   486     top_bool_eq ~> top_bool_def
   487     inf_bool_eq ~> inf_bool_def
   488     sup_bool_eq ~> sup_bool_def
   489     bot_fun_eq  ~> bot_fun_def
   490     top_fun_eq  ~> top_fun_def
   491     inf_fun_eq  ~> inf_fun_def
   492     sup_fun_eq  ~> sup_fun_def
   493 
   494 INCOMPATIBILITY.
   495 
   496 * More stylized fact names:
   497 
   498   expand_fun_eq ~> fun_eq_iff
   499   expand_set_eq ~> set_eq_iff
   500   set_ext       ~> set_eqI
   501   nat_number    ~> eval_nat_numeral
   502 
   503 INCOMPATIBILITY.
   504 
   505 * Refactoring of code-generation specific operations in theory List:
   506 
   507   constants
   508     null ~> List.null
   509 
   510   facts
   511     mem_iff ~> member_def
   512     null_empty ~> null_def
   513 
   514 INCOMPATIBILITY.  Note that these were not supposed to be used
   515 regularly unless for striking reasons; their main purpose was code
   516 generation.
   517 
   518 Various operations from the Haskell prelude are used for generating
   519 Haskell code.
   520 
   521 * Term "bij f" is now an abbreviation of "bij_betw f UNIV UNIV".  Term
   522 "surj f" is now an abbreviation of "range f = UNIV".  The theorems
   523 bij_def and surj_def are unchanged.  INCOMPATIBILITY.
   524 
   525 * Abolished some non-alphabetic type names: "prod" and "sum" replace
   526 "*" and "+" respectively.  INCOMPATIBILITY.
   527 
   528 * Name "Plus" of disjoint sum operator "<+>" is now hidden.  Write
   529 "Sum_Type.Plus" instead.
   530 
   531 * Constant "split" has been merged with constant "prod_case"; names of
   532 ML functions, facts etc. involving split have been retained so far,
   533 though.  INCOMPATIBILITY.
   534 
   535 * Dropped old infix syntax "_ mem _" for List.member; use "_ : set _"
   536 instead.  INCOMPATIBILITY.
   537 
   538 * Removed lemma "Option.is_none_none" which duplicates "is_none_def".
   539 INCOMPATIBILITY.
   540 
   541 * Former theory Library/Enum is now part of the HOL-Main image.
   542 INCOMPATIBILITY: all constants of the Enum theory now have to be
   543 referred to by its qualified name.
   544 
   545   enum    ~>  Enum.enum
   546   nlists  ~>  Enum.nlists
   547   product ~>  Enum.product
   548 
   549 * Theory Library/Monad_Syntax provides do-syntax for monad types.
   550 Syntax in Library/State_Monad has been changed to avoid ambiguities.
   551 INCOMPATIBILITY.
   552 
   553 * Theory Library/SetsAndFunctions has been split into
   554 Library/Function_Algebras and Library/Set_Algebras; canonical names
   555 for instance definitions for functions; various improvements.
   556 INCOMPATIBILITY.
   557 
   558 * Theory Library/Multiset provides stable quicksort implementation of
   559 sort_key.
   560 
   561 * Theory Library/Multiset: renamed empty_idemp ~> empty_neutral.
   562 INCOMPATIBILITY.
   563 
   564 * Session Multivariate_Analysis: introduced a type class for euclidean
   565 space.  Most theorems are now stated in terms of euclidean spaces
   566 instead of finite cartesian products.
   567 
   568   types
   569     real ^ 'n ~>  'a::real_vector
   570               ~>  'a::euclidean_space
   571               ~>  'a::ordered_euclidean_space
   572         (depends on your needs)
   573 
   574   constants
   575      _ $ _        ~> _ $$ _
   576      \<chi> x. _  ~> \<chi>\<chi> x. _
   577      CARD('n)     ~> DIM('a)
   578 
   579 Also note that the indices are now natural numbers and not from some
   580 finite type. Finite cartesian products of euclidean spaces, products
   581 of euclidean spaces the real and complex numbers are instantiated to
   582 be euclidean_spaces.  INCOMPATIBILITY.
   583 
   584 * Session Probability: introduced pextreal as positive extended real
   585 numbers.  Use pextreal as value for measures.  Introduce the
   586 Radon-Nikodym derivative, product spaces and Fubini's theorem for
   587 arbitrary sigma finite measures.  Introduces Lebesgue measure based on
   588 the integral in Multivariate Analysis.  INCOMPATIBILITY.
   589 
   590 * Session Imperative_HOL: revamped, corrected dozens of inadequacies.
   591 INCOMPATIBILITY.
   592 
   593 * Session SPARK (with image HOL-SPARK) provides commands to load and
   594 prove verification conditions generated by the SPARK Ada program
   595 verifier.  See also src/HOL/SPARK and src/HOL/SPARK/Examples.
   596 
   597 
   598 *** HOL-Algebra ***
   599 
   600 * Theorems for additive ring operations (locale abelian_monoid and
   601 descendants) are generated by interpretation from their multiplicative
   602 counterparts.  Names (in particular theorem names) have the mandatory
   603 qualifier 'add'.  Previous theorem names are redeclared for
   604 compatibility.
   605 
   606 * Structure "int_ring" is now an abbreviation (previously a
   607 definition).  This fits more natural with advanced interpretations.
   608 
   609 
   610 *** HOLCF ***
   611 
   612 * The domain package now runs in definitional mode by default: The
   613 former command 'new_domain' is now called 'domain'.  To use the domain
   614 package in its original axiomatic mode, use 'domain (unsafe)'.
   615 INCOMPATIBILITY.
   616 
   617 * The new class "domain" is now the default sort.  Class "predomain"
   618 is an unpointed version of "domain". Theories can be updated by
   619 replacing sort annotations as shown below.  INCOMPATIBILITY.
   620 
   621   'a::type ~> 'a::countable
   622   'a::cpo  ~> 'a::predomain
   623   'a::pcpo ~> 'a::domain
   624 
   625 * The old type class "rep" has been superseded by class "domain".
   626 Accordingly, users of the definitional package must remove any
   627 "default_sort rep" declarations.  INCOMPATIBILITY.
   628 
   629 * The domain package (definitional mode) now supports unpointed
   630 predomain argument types, as long as they are marked 'lazy'. (Strict
   631 arguments must be in class "domain".) For example, the following
   632 domain definition now works:
   633 
   634   domain natlist = nil | cons (lazy "nat discr") (lazy "natlist")
   635 
   636 * Theory HOLCF/Library/HOL_Cpo provides cpo and predomain class
   637 instances for types from main HOL: bool, nat, int, char, 'a + 'b,
   638 'a option, and 'a list.  Additionally, it configures fixrec and the
   639 domain package to work with these types.  For example:
   640 
   641   fixrec isInl :: "('a + 'b) u -> tr"
   642     where "isInl$(up$(Inl x)) = TT" | "isInl$(up$(Inr y)) = FF"
   643 
   644   domain V = VFun (lazy "V -> V") | VCon (lazy "nat") (lazy "V list")
   645 
   646 * The "(permissive)" option of fixrec has been replaced with a
   647 per-equation "(unchecked)" option. See
   648 src/HOL/HOLCF/Tutorial/Fixrec_ex.thy for examples. INCOMPATIBILITY.
   649 
   650 * The "bifinite" class no longer fixes a constant "approx"; the class
   651 now just asserts that such a function exists.  INCOMPATIBILITY.
   652 
   653 * Former type "alg_defl" has been renamed to "defl".  HOLCF no longer
   654 defines an embedding of type 'a defl into udom by default; instances
   655 of "bifinite" and "domain" classes are available in
   656 src/HOL/HOLCF/Library/Defl_Bifinite.thy.
   657 
   658 * The syntax "REP('a)" has been replaced with "DEFL('a)".
   659 
   660 * The predicate "directed" has been removed.  INCOMPATIBILITY.
   661 
   662 * The type class "finite_po" has been removed.  INCOMPATIBILITY.
   663 
   664 * The function "cprod_map" has been renamed to "prod_map".
   665 INCOMPATIBILITY.
   666 
   667 * The monadic bind operator on each powerdomain has new binder syntax
   668 similar to sets, e.g. "\<Union>\<sharp>x\<in>xs. t" represents
   669 "upper_bind\<cdot>xs\<cdot>(\<Lambda> x. t)".
   670 
   671 * The infix syntax for binary union on each powerdomain has changed
   672 from e.g. "+\<sharp>" to "\<union>\<sharp>", for consistency with set
   673 syntax.  INCOMPATIBILITY.
   674 
   675 * The constant "UU" has been renamed to "bottom".  The syntax "UU" is
   676 still supported as an input translation.
   677 
   678 * Renamed some theorems (the original names are also still available).
   679 
   680   expand_fun_below   ~> fun_below_iff
   681   below_fun_ext      ~> fun_belowI
   682   expand_cfun_eq     ~> cfun_eq_iff
   683   ext_cfun           ~> cfun_eqI
   684   expand_cfun_below  ~> cfun_below_iff
   685   below_cfun_ext     ~> cfun_belowI
   686   cont2cont_Rep_CFun ~> cont2cont_APP
   687 
   688 * The Abs and Rep functions for various types have changed names.
   689 Related theorem names have also changed to match. INCOMPATIBILITY.
   690 
   691   Rep_CFun  ~> Rep_cfun
   692   Abs_CFun  ~> Abs_cfun
   693   Rep_Sprod ~> Rep_sprod
   694   Abs_Sprod ~> Abs_sprod
   695   Rep_Ssum  ~> Rep_ssum
   696   Abs_Ssum  ~> Abs_ssum
   697 
   698 * Lemmas with names of the form *_defined_iff or *_strict_iff have
   699 been renamed to *_bottom_iff.  INCOMPATIBILITY.
   700 
   701 * Various changes to bisimulation/coinduction with domain package:
   702 
   703   - Definitions of "bisim" constants no longer mention definedness.
   704   - With mutual recursion, "bisim" predicate is now curried.
   705   - With mutual recursion, each type gets a separate coind theorem.
   706   - Variable names in bisim_def and coinduct rules have changed.
   707 
   708 INCOMPATIBILITY.
   709 
   710 * Case combinators generated by the domain package for type "foo" are
   711 now named "foo_case" instead of "foo_when".  INCOMPATIBILITY.
   712 
   713 * Several theorems have been renamed to more accurately reflect the
   714 names of constants and types involved.  INCOMPATIBILITY.
   715 
   716   thelub_const    ~> lub_const
   717   lub_const       ~> is_lub_const
   718   thelubI         ~> lub_eqI
   719   is_lub_lub      ~> is_lubD2
   720   lubI            ~> is_lub_lub
   721   unique_lub      ~> is_lub_unique
   722   is_ub_lub       ~> is_lub_rangeD1
   723   lub_bin_chain   ~> is_lub_bin_chain
   724   lub_fun         ~> is_lub_fun
   725   thelub_fun      ~> lub_fun
   726   thelub_cfun     ~> lub_cfun
   727   thelub_Pair     ~> lub_Pair
   728   lub_cprod       ~> is_lub_prod
   729   thelub_cprod    ~> lub_prod
   730   minimal_cprod   ~> minimal_prod
   731   inst_cprod_pcpo ~> inst_prod_pcpo
   732   UU_I            ~> bottomI
   733   compact_UU      ~> compact_bottom
   734   deflation_UU    ~> deflation_bottom
   735   finite_deflation_UU ~> finite_deflation_bottom
   736 
   737 * Many legacy theorem names have been discontinued.  INCOMPATIBILITY.
   738 
   739   sq_ord_less_eq_trans ~> below_eq_trans
   740   sq_ord_eq_less_trans ~> eq_below_trans
   741   refl_less            ~> below_refl
   742   trans_less           ~> below_trans
   743   antisym_less         ~> below_antisym
   744   antisym_less_inverse ~> po_eq_conv [THEN iffD1]
   745   box_less             ~> box_below
   746   rev_trans_less       ~> rev_below_trans
   747   not_less2not_eq      ~> not_below2not_eq
   748   less_UU_iff          ~> below_UU_iff
   749   flat_less_iff        ~> flat_below_iff
   750   adm_less             ~> adm_below
   751   adm_not_less         ~> adm_not_below
   752   adm_compact_not_less ~> adm_compact_not_below
   753   less_fun_def         ~> below_fun_def
   754   expand_fun_less      ~> fun_below_iff
   755   less_fun_ext         ~> fun_belowI
   756   less_discr_def       ~> below_discr_def
   757   discr_less_eq        ~> discr_below_eq
   758   less_unit_def        ~> below_unit_def
   759   less_cprod_def       ~> below_prod_def
   760   prod_lessI           ~> prod_belowI
   761   Pair_less_iff        ~> Pair_below_iff
   762   fst_less_iff         ~> fst_below_iff
   763   snd_less_iff         ~> snd_below_iff
   764   expand_cfun_less     ~> cfun_below_iff
   765   less_cfun_ext        ~> cfun_belowI
   766   injection_less       ~> injection_below
   767   less_up_def          ~> below_up_def
   768   not_Iup_less         ~> not_Iup_below
   769   Iup_less             ~> Iup_below
   770   up_less              ~> up_below
   771   Def_inject_less_eq   ~> Def_below_Def
   772   Def_less_is_eq       ~> Def_below_iff
   773   spair_less_iff       ~> spair_below_iff
   774   less_sprod           ~> below_sprod
   775   spair_less           ~> spair_below
   776   sfst_less_iff        ~> sfst_below_iff
   777   ssnd_less_iff        ~> ssnd_below_iff
   778   fix_least_less       ~> fix_least_below
   779   dist_less_one        ~> dist_below_one
   780   less_ONE             ~> below_ONE
   781   ONE_less_iff         ~> ONE_below_iff
   782   less_sinlD           ~> below_sinlD
   783   less_sinrD           ~> below_sinrD
   784 
   785 
   786 *** FOL and ZF ***
   787 
   788 * All constant names are now qualified internally and use proper
   789 identifiers, e.g. "IFOL.eq" instead of "op =".  INCOMPATIBILITY.
   790 
   791 
   792 *** ML ***
   793 
   794 * Antiquotation @{assert} inlines a function bool -> unit that raises
   795 Fail if the argument is false.  Due to inlining the source position of
   796 failed assertions is included in the error output.
   797 
   798 * Discontinued antiquotation @{theory_ref}, which is obsolete since ML
   799 text is in practice always evaluated with a stable theory checkpoint.
   800 Minor INCOMPATIBILITY, use (Theory.check_thy @{theory}) instead.
   801 
   802 * Antiquotation @{theory A} refers to theory A from the ancestry of
   803 the current context, not any accidental theory loader state as before.
   804 Potential INCOMPATIBILITY, subtle change in semantics.
   805 
   806 * Syntax.pretty_priority (default 0) configures the required priority
   807 of pretty-printed output and thus affects insertion of parentheses.
   808 
   809 * Syntax.default_root (default "any") configures the inner syntax
   810 category (nonterminal symbol) for parsing of terms.
   811 
   812 * Former exception Library.UnequalLengths now coincides with
   813 ListPair.UnequalLengths.
   814 
   815 * Renamed structure MetaSimplifier to Raw_Simplifier.  Note that the
   816 main functionality is provided by structure Simplifier.
   817 
   818 * Renamed raw "explode" function to "raw_explode" to emphasize its
   819 meaning.  Note that internally to Isabelle, Symbol.explode is used in
   820 almost all situations.
   821 
   822 * Discontinued obsolete function sys_error and exception SYS_ERROR.
   823 See implementation manual for further details on exceptions in
   824 Isabelle/ML.
   825 
   826 * Renamed setmp_noncritical to Unsynchronized.setmp to emphasize its
   827 meaning.
   828 
   829 * Renamed structure PureThy to Pure_Thy and moved most of its
   830 operations to structure Global_Theory, to emphasize that this is
   831 rarely-used global-only stuff.
   832 
   833 * Discontinued Output.debug.  Minor INCOMPATIBILITY, use plain writeln
   834 instead (or tracing for high-volume output).
   835 
   836 * Configuration option show_question_marks only affects regular pretty
   837 printing of types and terms, not raw Term.string_of_vname.
   838 
   839 * ML_Context.thm and ML_Context.thms are no longer pervasive.  Rare
   840 INCOMPATIBILITY, superseded by static antiquotations @{thm} and
   841 @{thms} for most purposes.
   842 
   843 * ML structure Unsynchronized is never opened, not even in Isar
   844 interaction mode as before.  Old Unsynchronized.set etc. have been
   845 discontinued -- use plain := instead.  This should be *rare* anyway,
   846 since modern tools always work via official context data, notably
   847 configuration options.
   848 
   849 * Parallel and asynchronous execution requires special care concerning
   850 interrupts.  Structure Exn provides some convenience functions that
   851 avoid working directly with raw Interrupt.  User code must not absorb
   852 interrupts -- intermediate handling (for cleanup etc.) needs to be
   853 followed by re-raising of the original exception.  Another common
   854 source of mistakes are "handle _" patterns, which make the meaning of
   855 the program subject to physical effects of the environment.
   856 
   857 
   858 
   859 New in Isabelle2009-2 (June 2010)
   860 ---------------------------------
   861 
   862 *** General ***
   863 
   864 * Authentic syntax for *all* logical entities (type classes, type
   865 constructors, term constants): provides simple and robust
   866 correspondence between formal entities and concrete syntax.  Within
   867 the parse tree / AST representations, "constants" are decorated by
   868 their category (class, type, const) and spelled out explicitly with
   869 their full internal name.
   870 
   871 Substantial INCOMPATIBILITY concerning low-level syntax declarations
   872 and translations (translation rules and translation functions in ML).
   873 Some hints on upgrading:
   874 
   875   - Many existing uses of 'syntax' and 'translations' can be replaced
   876     by more modern 'type_notation', 'notation' and 'abbreviation',
   877     which are independent of this issue.
   878 
   879   - 'translations' require markup within the AST; the term syntax
   880     provides the following special forms:
   881 
   882       CONST c   -- produces syntax version of constant c from context
   883       XCONST c  -- literally c, checked as constant from context
   884       c         -- literally c, if declared by 'syntax'
   885 
   886     Plain identifiers are treated as AST variables -- occasionally the
   887     system indicates accidental variables via the error "rhs contains
   888     extra variables".
   889 
   890     Type classes and type constructors are marked according to their
   891     concrete syntax.  Some old translations rules need to be written
   892     for the "type" category, using type constructor application
   893     instead of pseudo-term application of the default category
   894     "logic".
   895 
   896   - 'parse_translation' etc. in ML may use the following
   897     antiquotations:
   898 
   899       @{class_syntax c}   -- type class c within parse tree / AST
   900       @{term_syntax c}    -- type constructor c within parse tree / AST
   901       @{const_syntax c}   -- ML version of "CONST c" above
   902       @{syntax_const c}   -- literally c (checked wrt. 'syntax' declarations)
   903 
   904   - Literal types within 'typed_print_translations', i.e. those *not*
   905     represented as pseudo-terms are represented verbatim.  Use @{class
   906     c} or @{type_name c} here instead of the above syntax
   907     antiquotations.
   908 
   909 Note that old non-authentic syntax was based on unqualified base
   910 names, so all of the above "constant" names would coincide.  Recall
   911 that 'print_syntax' and ML_command "set Syntax.trace_ast" help to
   912 diagnose syntax problems.
   913 
   914 * Type constructors admit general mixfix syntax, not just infix.
   915 
   916 * Concrete syntax may be attached to local entities without a proof
   917 body, too.  This works via regular mixfix annotations for 'fix',
   918 'def', 'obtain' etc. or via the explicit 'write' command, which is
   919 similar to the 'notation' command in theory specifications.
   920 
   921 * Discontinued unnamed infix syntax (legacy feature for many years) --
   922 need to specify constant name and syntax separately.  Internal ML
   923 datatype constructors have been renamed from InfixName to Infix etc.
   924 Minor INCOMPATIBILITY.
   925 
   926 * Schematic theorem statements need to be explicitly markup as such,
   927 via commands 'schematic_lemma', 'schematic_theorem',
   928 'schematic_corollary'.  Thus the relevance of the proof is made
   929 syntactically clear, which impacts performance in a parallel or
   930 asynchronous interactive environment.  Minor INCOMPATIBILITY.
   931 
   932 * Use of cumulative prems via "!" in some proof methods has been
   933 discontinued (old legacy feature).
   934 
   935 * References 'trace_simp' and 'debug_simp' have been replaced by
   936 configuration options stored in the context. Enabling tracing (the
   937 case of debugging is similar) in proofs works via
   938 
   939   using [[trace_simp = true]]
   940 
   941 Tracing is then active for all invocations of the simplifier in
   942 subsequent goal refinement steps. Tracing may also still be enabled or
   943 disabled via the ProofGeneral settings menu.
   944 
   945 * Separate commands 'hide_class', 'hide_type', 'hide_const',
   946 'hide_fact' replace the former 'hide' KIND command.  Minor
   947 INCOMPATIBILITY.
   948 
   949 * Improved parallelism of proof term normalization: usedir -p2 -q0 is
   950 more efficient than combinations with -q1 or -q2.
   951 
   952 
   953 *** Pure ***
   954 
   955 * Proofterms record type-class reasoning explicitly, using the
   956 "unconstrain" operation internally.  This eliminates all sort
   957 constraints from a theorem and proof, introducing explicit
   958 OFCLASS-premises.  On the proof term level, this operation is
   959 automatically applied at theorem boundaries, such that closed proofs
   960 are always free of sort constraints.  INCOMPATIBILITY for tools that
   961 inspect proof terms.
   962 
   963 * Local theory specifications may depend on extra type variables that
   964 are not present in the result type -- arguments TYPE('a) :: 'a itself
   965 are added internally.  For example:
   966 
   967   definition unitary :: bool where "unitary = (ALL (x::'a) y. x = y)"
   968 
   969 * Predicates of locales introduced by classes carry a mandatory
   970 "class" prefix.  INCOMPATIBILITY.
   971 
   972 * Vacuous class specifications observe default sort.  INCOMPATIBILITY.
   973 
   974 * Old 'axclass' command has been discontinued.  INCOMPATIBILITY, use
   975 'class' instead.
   976 
   977 * Command 'code_reflect' allows to incorporate generated ML code into
   978 runtime environment; replaces immature code_datatype antiquotation.
   979 INCOMPATIBILITY.
   980 
   981 * Code generator: simple concept for abstract datatypes obeying
   982 invariants.
   983 
   984 * Code generator: details of internal data cache have no impact on the
   985 user space functionality any longer.
   986 
   987 * Methods "unfold_locales" and "intro_locales" ignore non-locale
   988 subgoals.  This is more appropriate for interpretations with 'where'.
   989 INCOMPATIBILITY.
   990 
   991 * Command 'example_proof' opens an empty proof body.  This allows to
   992 experiment with Isar, without producing any persistent result.
   993 
   994 * Commands 'type_notation' and 'no_type_notation' declare type syntax
   995 within a local theory context, with explicit checking of the
   996 constructors involved (in contrast to the raw 'syntax' versions).
   997 
   998 * Commands 'types' and 'typedecl' now work within a local theory
   999 context -- without introducing dependencies on parameters or
  1000 assumptions, which is not possible in Isabelle/Pure.
  1001 
  1002 * Command 'defaultsort' has been renamed to 'default_sort', it works
  1003 within a local theory context.  Minor INCOMPATIBILITY.
  1004 
  1005 
  1006 *** HOL ***
  1007 
  1008 * Command 'typedef' now works within a local theory context -- without
  1009 introducing dependencies on parameters or assumptions, which is not
  1010 possible in Isabelle/Pure/HOL.  Note that the logical environment may
  1011 contain multiple interpretations of local typedefs (with different
  1012 non-emptiness proofs), even in a global theory context.
  1013 
  1014 * New package for quotient types.  Commands 'quotient_type' and
  1015 'quotient_definition' may be used for defining types and constants by
  1016 quotient constructions.  An example is the type of integers created by
  1017 quotienting pairs of natural numbers:
  1018 
  1019   fun
  1020     intrel :: "(nat * nat) => (nat * nat) => bool"
  1021   where
  1022     "intrel (x, y) (u, v) = (x + v = u + y)"
  1023 
  1024   quotient_type int = "nat * nat" / intrel
  1025     by (auto simp add: equivp_def expand_fun_eq)
  1026 
  1027   quotient_definition
  1028     "0::int" is "(0::nat, 0::nat)"
  1029 
  1030 The method "lifting" can be used to lift of theorems from the
  1031 underlying "raw" type to the quotient type.  The example
  1032 src/HOL/Quotient_Examples/FSet.thy includes such a quotient
  1033 construction and provides a reasoning infrastructure for finite sets.
  1034 
  1035 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
  1036 clash with new theory Quotient in Main HOL.
  1037 
  1038 * Moved the SMT binding into the main HOL session, eliminating
  1039 separate HOL-SMT session.
  1040 
  1041 * List membership infix mem operation is only an input abbreviation.
  1042 INCOMPATIBILITY.
  1043 
  1044 * Theory Library/Word.thy has been removed.  Use library Word/Word.thy
  1045 for future developements; former Library/Word.thy is still present in
  1046 the AFP entry RSAPPS.
  1047 
  1048 * Theorem Int.int_induct renamed to Int.int_of_nat_induct and is no
  1049 longer shadowed.  INCOMPATIBILITY.
  1050 
  1051 * Dropped theorem duplicate comp_arith; use semiring_norm instead.
  1052 INCOMPATIBILITY.
  1053 
  1054 * Dropped theorem RealPow.real_sq_order; use power2_le_imp_le instead.
  1055 INCOMPATIBILITY.
  1056 
  1057 * Dropped normalizing_semiring etc; use the facts in semiring classes
  1058 instead.  INCOMPATIBILITY.
  1059 
  1060 * Dropped several real-specific versions of lemmas about floor and
  1061 ceiling; use the generic lemmas from theory "Archimedean_Field"
  1062 instead.  INCOMPATIBILITY.
  1063 
  1064   floor_number_of_eq         ~> floor_number_of
  1065   le_floor_eq_number_of      ~> number_of_le_floor
  1066   le_floor_eq_zero           ~> zero_le_floor
  1067   le_floor_eq_one            ~> one_le_floor
  1068   floor_less_eq_number_of    ~> floor_less_number_of
  1069   floor_less_eq_zero         ~> floor_less_zero
  1070   floor_less_eq_one          ~> floor_less_one
  1071   less_floor_eq_number_of    ~> number_of_less_floor
  1072   less_floor_eq_zero         ~> zero_less_floor
  1073   less_floor_eq_one          ~> one_less_floor
  1074   floor_le_eq_number_of      ~> floor_le_number_of
  1075   floor_le_eq_zero           ~> floor_le_zero
  1076   floor_le_eq_one            ~> floor_le_one
  1077   floor_subtract_number_of   ~> floor_diff_number_of
  1078   floor_subtract_one         ~> floor_diff_one
  1079   ceiling_number_of_eq       ~> ceiling_number_of
  1080   ceiling_le_eq_number_of    ~> ceiling_le_number_of
  1081   ceiling_le_zero_eq         ~> ceiling_le_zero
  1082   ceiling_le_eq_one          ~> ceiling_le_one
  1083   less_ceiling_eq_number_of  ~> number_of_less_ceiling
  1084   less_ceiling_eq_zero       ~> zero_less_ceiling
  1085   less_ceiling_eq_one        ~> one_less_ceiling
  1086   ceiling_less_eq_number_of  ~> ceiling_less_number_of
  1087   ceiling_less_eq_zero       ~> ceiling_less_zero
  1088   ceiling_less_eq_one        ~> ceiling_less_one
  1089   le_ceiling_eq_number_of    ~> number_of_le_ceiling
  1090   le_ceiling_eq_zero         ~> zero_le_ceiling
  1091   le_ceiling_eq_one          ~> one_le_ceiling
  1092   ceiling_subtract_number_of ~> ceiling_diff_number_of
  1093   ceiling_subtract_one       ~> ceiling_diff_one
  1094 
  1095 * Theory "Finite_Set": various folding_XXX locales facilitate the
  1096 application of the various fold combinators on finite sets.
  1097 
  1098 * Library theory "RBT" renamed to "RBT_Impl"; new library theory "RBT"
  1099 provides abstract red-black tree type which is backed by "RBT_Impl" as
  1100 implementation.  INCOMPATIBILTY.
  1101 
  1102 * Theory Library/Coinductive_List has been removed -- superseded by
  1103 AFP/thys/Coinductive.
  1104 
  1105 * Theory PReal, including the type "preal" and related operations, has
  1106 been removed.  INCOMPATIBILITY.
  1107 
  1108 * Real: new development using Cauchy Sequences.
  1109 
  1110 * Split off theory "Big_Operators" containing setsum, setprod,
  1111 Inf_fin, Sup_fin, Min, Max from theory Finite_Set.  INCOMPATIBILITY.
  1112 
  1113 * Theory "Rational" renamed to "Rat", for consistency with "Nat",
  1114 "Int" etc.  INCOMPATIBILITY.
  1115 
  1116 * Constant Rat.normalize needs to be qualified.  INCOMPATIBILITY.
  1117 
  1118 * New set of rules "ac_simps" provides combined assoc / commute
  1119 rewrites for all interpretations of the appropriate generic locales.
  1120 
  1121 * Renamed theory "OrderedGroup" to "Groups" and split theory
  1122 "Ring_and_Field" into theories "Rings" and "Fields"; for more
  1123 appropriate and more consistent names suitable for name prefixes
  1124 within the HOL theories.  INCOMPATIBILITY.
  1125 
  1126 * Some generic constants have been put to appropriate theories:
  1127   - less_eq, less: Orderings
  1128   - zero, one, plus, minus, uminus, times, abs, sgn: Groups
  1129   - inverse, divide: Rings
  1130 INCOMPATIBILITY.
  1131 
  1132 * More consistent naming of type classes involving orderings (and
  1133 lattices):
  1134 
  1135     lower_semilattice                   ~> semilattice_inf
  1136     upper_semilattice                   ~> semilattice_sup
  1137 
  1138     dense_linear_order                  ~> dense_linorder
  1139 
  1140     pordered_ab_group_add               ~> ordered_ab_group_add
  1141     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
  1142     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
  1143     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
  1144     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
  1145     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
  1146     pordered_cancel_semiring            ~> ordered_cancel_semiring
  1147     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
  1148     pordered_comm_ring                  ~> ordered_comm_ring
  1149     pordered_comm_semiring              ~> ordered_comm_semiring
  1150     pordered_ring                       ~> ordered_ring
  1151     pordered_ring_abs                   ~> ordered_ring_abs
  1152     pordered_semiring                   ~> ordered_semiring
  1153 
  1154     ordered_ab_group_add                ~> linordered_ab_group_add
  1155     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
  1156     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
  1157     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
  1158     ordered_field                       ~> linordered_field
  1159     ordered_field_no_lb                 ~> linordered_field_no_lb
  1160     ordered_field_no_ub                 ~> linordered_field_no_ub
  1161     ordered_field_dense_linear_order    ~> dense_linordered_field
  1162     ordered_idom                        ~> linordered_idom
  1163     ordered_ring                        ~> linordered_ring
  1164     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
  1165     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
  1166     ordered_ring_strict                 ~> linordered_ring_strict
  1167     ordered_semidom                     ~> linordered_semidom
  1168     ordered_semiring                    ~> linordered_semiring
  1169     ordered_semiring_1                  ~> linordered_semiring_1
  1170     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
  1171     ordered_semiring_strict             ~> linordered_semiring_strict
  1172 
  1173   The following slightly odd type classes have been moved to a
  1174   separate theory Library/Lattice_Algebras:
  1175 
  1176     lordered_ab_group_add               ~> lattice_ab_group_add
  1177     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
  1178     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
  1179     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
  1180     lordered_ring                       ~> lattice_ring
  1181 
  1182 INCOMPATIBILITY.
  1183 
  1184 * Refined field classes:
  1185   - classes division_ring_inverse_zero, field_inverse_zero,
  1186     linordered_field_inverse_zero include rule inverse 0 = 0 --
  1187     subsumes former division_by_zero class;
  1188   - numerous lemmas have been ported from field to division_ring.
  1189 INCOMPATIBILITY.
  1190 
  1191 * Refined algebra theorem collections:
  1192   - dropped theorem group group_simps, use algebra_simps instead;
  1193   - dropped theorem group ring_simps, use field_simps instead;
  1194   - proper theorem collection field_simps subsumes former theorem
  1195     groups field_eq_simps and field_simps;
  1196   - dropped lemma eq_minus_self_iff which is a duplicate for
  1197     equal_neg_zero.
  1198 INCOMPATIBILITY.
  1199 
  1200 * Theory Finite_Set and List: some lemmas have been generalized from
  1201 sets to lattices:
  1202 
  1203   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
  1204   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
  1205   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
  1206   union_Union_fold_union        ~> sup_Sup_fold_sup
  1207   Inter_fold_inter              ~> Inf_fold_inf
  1208   Union_fold_union              ~> Sup_fold_sup
  1209   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
  1210   union_UNION_fold_union        ~> sup_SUPR_fold_sup
  1211   INTER_fold_inter              ~> INFI_fold_inf
  1212   UNION_fold_union              ~> SUPR_fold_sup
  1213 
  1214 * Theory "Complete_Lattice": lemmas top_def and bot_def have been
  1215 replaced by the more convenient lemmas Inf_empty and Sup_empty.
  1216 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
  1217 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
  1218 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
  1219 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
  1220 
  1221 * Reorganized theory Multiset: swapped notation of pointwise and
  1222 multiset order:
  1223 
  1224   - pointwise ordering is instance of class order with standard syntax
  1225     <= and <;
  1226   - multiset ordering has syntax <=# and <#; partial order properties
  1227     are provided by means of interpretation with prefix
  1228     multiset_order;
  1229   - less duplication, less historical organization of sections,
  1230     conversion from associations lists to multisets, rudimentary code
  1231     generation;
  1232   - use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union,
  1233     if needed.
  1234 
  1235 Renamed:
  1236 
  1237   multiset_eq_conv_count_eq  ~>  multiset_ext_iff
  1238   multi_count_ext  ~>  multiset_ext
  1239   diff_union_inverse2  ~>  diff_union_cancelR
  1240 
  1241 INCOMPATIBILITY.
  1242 
  1243 * Theory Permutation: replaced local "remove" by List.remove1.
  1244 
  1245 * Code generation: ML and OCaml code is decorated with signatures.
  1246 
  1247 * Theory List: added transpose.
  1248 
  1249 * Library/Nat_Bijection.thy is a collection of bijective functions
  1250 between nat and other types, which supersedes the older libraries
  1251 Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.
  1252 
  1253   Constants:
  1254   Nat_Int_Bij.nat2_to_nat         ~> prod_encode
  1255   Nat_Int_Bij.nat_to_nat2         ~> prod_decode
  1256   Nat_Int_Bij.int_to_nat_bij      ~> int_encode
  1257   Nat_Int_Bij.nat_to_int_bij      ~> int_decode
  1258   Countable.pair_encode           ~> prod_encode
  1259   NatIso.prod2nat                 ~> prod_encode
  1260   NatIso.nat2prod                 ~> prod_decode
  1261   NatIso.sum2nat                  ~> sum_encode
  1262   NatIso.nat2sum                  ~> sum_decode
  1263   NatIso.list2nat                 ~> list_encode
  1264   NatIso.nat2list                 ~> list_decode
  1265   NatIso.set2nat                  ~> set_encode
  1266   NatIso.nat2set                  ~> set_decode
  1267 
  1268   Lemmas:
  1269   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
  1270   Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
  1271   Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
  1272   Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
  1273   Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
  1274   Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
  1275   Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
  1276   Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
  1277   Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
  1278   Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
  1279   Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
  1280   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
  1281   Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode
  1282 
  1283 * Sledgehammer:
  1284   - Renamed ATP commands:
  1285     atp_info     ~> sledgehammer running_atps
  1286     atp_kill     ~> sledgehammer kill_atps
  1287     atp_messages ~> sledgehammer messages
  1288     atp_minimize ~> sledgehammer minimize
  1289     print_atps   ~> sledgehammer available_atps
  1290     INCOMPATIBILITY.
  1291   - Added user's manual ("isabelle doc sledgehammer").
  1292   - Added option syntax and "sledgehammer_params" to customize
  1293     Sledgehammer's behavior.  See the manual for details.
  1294   - Modified the Isar proof reconstruction code so that it produces
  1295     direct proofs rather than proofs by contradiction.  (This feature
  1296     is still experimental.)
  1297   - Made Isar proof reconstruction work for SPASS, remote ATPs, and in
  1298     full-typed mode.
  1299   - Added support for TPTP syntax for SPASS via the "spass_tptp" ATP.
  1300 
  1301 * Nitpick:
  1302   - Added and implemented "binary_ints" and "bits" options.
  1303   - Added "std" option and implemented support for nonstandard models.
  1304   - Added and implemented "finitize" option to improve the precision
  1305     of infinite datatypes based on a monotonicity analysis.
  1306   - Added support for quotient types.
  1307   - Added support for "specification" and "ax_specification"
  1308     constructs.
  1309   - Added support for local definitions (for "function" and
  1310     "termination" proofs).
  1311   - Added support for term postprocessors.
  1312   - Optimized "Multiset.multiset" and "FinFun.finfun".
  1313   - Improved efficiency of "destroy_constrs" optimization.
  1314   - Fixed soundness bugs related to "destroy_constrs" optimization and
  1315     record getters.
  1316   - Fixed soundness bug related to higher-order constructors.
  1317   - Fixed soundness bug when "full_descrs" is enabled.
  1318   - Improved precision of set constructs.
  1319   - Added "atoms" option.
  1320   - Added cache to speed up repeated Kodkod invocations on the same
  1321     problems.
  1322   - Renamed "MiniSatJNI", "zChaffJNI", "BerkMinAlloy", and
  1323     "SAT4JLight" to "MiniSat_JNI", "zChaff_JNI", "BerkMin_Alloy", and
  1324     "SAT4J_Light".  INCOMPATIBILITY.
  1325   - Removed "skolemize", "uncurry", "sym_break", "flatten_prop",
  1326     "sharing_depth", and "show_skolems" options.  INCOMPATIBILITY.
  1327   - Removed "nitpick_intro" attribute.  INCOMPATIBILITY.
  1328 
  1329 * Method "induct" now takes instantiations of the form t, where t is not
  1330   a variable, as a shorthand for "x == t", where x is a fresh variable.
  1331   If this is not intended, t has to be enclosed in parentheses.
  1332   By default, the equalities generated by definitional instantiations
  1333   are pre-simplified, which may cause parameters of inductive cases
  1334   to disappear, or may even delete some of the inductive cases.
  1335   Use "induct (no_simp)" instead of "induct" to restore the old
  1336   behaviour. The (no_simp) option is also understood by the "cases"
  1337   and "nominal_induct" methods, which now perform pre-simplification, too.
  1338   INCOMPATIBILITY.
  1339 
  1340 
  1341 *** HOLCF ***
  1342 
  1343 * Variable names in lemmas generated by the domain package have
  1344 changed; the naming scheme is now consistent with the HOL datatype
  1345 package.  Some proof scripts may be affected, INCOMPATIBILITY.
  1346 
  1347 * The domain package no longer defines the function "foo_copy" for
  1348 recursive domain "foo".  The reach lemma is now stated directly in
  1349 terms of "foo_take".  Lemmas and proofs that mention "foo_copy" must
  1350 be reformulated in terms of "foo_take", INCOMPATIBILITY.
  1351 
  1352 * Most definedness lemmas generated by the domain package (previously
  1353 of the form "x ~= UU ==> foo$x ~= UU") now have an if-and-only-if form
  1354 like "foo$x = UU <-> x = UU", which works better as a simp rule.
  1355 Proofs that used definedness lemmas as intro rules may break,
  1356 potential INCOMPATIBILITY.
  1357 
  1358 * Induction and casedist rules generated by the domain package now
  1359 declare proper case_names (one called "bottom", and one named for each
  1360 constructor).  INCOMPATIBILITY.
  1361 
  1362 * For mutually-recursive domains, separate "reach" and "take_lemma"
  1363 rules are generated for each domain, INCOMPATIBILITY.
  1364 
  1365   foo_bar.reach       ~> foo.reach  bar.reach
  1366   foo_bar.take_lemmas ~> foo.take_lemma  bar.take_lemma
  1367 
  1368 * Some lemmas generated by the domain package have been renamed for
  1369 consistency with the datatype package, INCOMPATIBILITY.
  1370 
  1371   foo.ind        ~> foo.induct
  1372   foo.finite_ind ~> foo.finite_induct
  1373   foo.coind      ~> foo.coinduct
  1374   foo.casedist   ~> foo.exhaust
  1375   foo.exhaust    ~> foo.nchotomy
  1376 
  1377 * For consistency with other definition packages, the fixrec package
  1378 now generates qualified theorem names, INCOMPATIBILITY.
  1379 
  1380   foo_simps  ~> foo.simps
  1381   foo_unfold ~> foo.unfold
  1382   foo_induct ~> foo.induct
  1383 
  1384 * The "fixrec_simp" attribute has been removed.  The "fixrec_simp"
  1385 method and internal fixrec proofs now use the default simpset instead.
  1386 INCOMPATIBILITY.
  1387 
  1388 * The "contlub" predicate has been removed.  Proof scripts should use
  1389 lemma contI2 in place of monocontlub2cont, INCOMPATIBILITY.
  1390 
  1391 * The "admw" predicate has been removed, INCOMPATIBILITY.
  1392 
  1393 * The constants cpair, cfst, and csnd have been removed in favor of
  1394 Pair, fst, and snd from Isabelle/HOL, INCOMPATIBILITY.
  1395 
  1396 
  1397 *** ML ***
  1398 
  1399 * Antiquotations for basic formal entities:
  1400 
  1401     @{class NAME}         -- type class
  1402     @{class_syntax NAME}  -- syntax representation of the above
  1403 
  1404     @{type_name NAME}     -- logical type
  1405     @{type_abbrev NAME}   -- type abbreviation
  1406     @{nonterminal NAME}   -- type of concrete syntactic category
  1407     @{type_syntax NAME}   -- syntax representation of any of the above
  1408 
  1409     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
  1410     @{const_abbrev NAME}  -- abbreviated constant
  1411     @{const_syntax NAME}  -- syntax representation of any of the above
  1412 
  1413 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
  1414 syntax constant (cf. 'syntax' command).
  1415 
  1416 * Antiquotation @{make_string} inlines a function to print arbitrary
  1417 values similar to the ML toplevel.  The result is compiler dependent
  1418 and may fall back on "?" in certain situations.
  1419 
  1420 * Diagnostic commands 'ML_val' and 'ML_command' may refer to
  1421 antiquotations @{Isar.state} and @{Isar.goal}.  This replaces impure
  1422 Isar.state() and Isar.goal(), which belong to the old TTY loop and do
  1423 not work with the asynchronous Isar document model.
  1424 
  1425 * Configuration options now admit dynamic default values, depending on
  1426 the context or even global references.
  1427 
  1428 * SHA1.digest digests strings according to SHA-1 (see RFC 3174).  It
  1429 uses an efficient external library if available (for Poly/ML).
  1430 
  1431 * Renamed some important ML structures, while keeping the old names
  1432 for some time as aliases within the structure Legacy:
  1433 
  1434   OuterKeyword  ~>  Keyword
  1435   OuterLex      ~>  Token
  1436   OuterParse    ~>  Parse
  1437   OuterSyntax   ~>  Outer_Syntax
  1438   PrintMode     ~>  Print_Mode
  1439   SpecParse     ~>  Parse_Spec
  1440   ThyInfo       ~>  Thy_Info
  1441   ThyLoad       ~>  Thy_Load
  1442   ThyOutput     ~>  Thy_Output
  1443   TypeInfer     ~>  Type_Infer
  1444 
  1445 Note that "open Legacy" simplifies porting of sources, but forgetting
  1446 to remove it again will complicate porting again in the future.
  1447 
  1448 * Most operations that refer to a global context are named
  1449 accordingly, e.g. Simplifier.global_context or
  1450 ProofContext.init_global.  There are some situations where a global
  1451 context actually works, but under normal circumstances one needs to
  1452 pass the proper local context through the code!
  1453 
  1454 * Discontinued old TheoryDataFun with its copy/init operation -- data
  1455 needs to be pure.  Functor Theory_Data_PP retains the traditional
  1456 Pretty.pp argument to merge, which is absent in the standard
  1457 Theory_Data version.
  1458 
  1459 * Sorts.certify_sort and derived "cert" operations for types and terms
  1460 no longer minimize sorts.  Thus certification at the boundary of the
  1461 inference kernel becomes invariant under addition of class relations,
  1462 which is an important monotonicity principle.  Sorts are now minimized
  1463 in the syntax layer only, at the boundary between the end-user and the
  1464 system.  Subtle INCOMPATIBILITY, may have to use Sign.minimize_sort
  1465 explicitly in rare situations.
  1466 
  1467 * Renamed old-style Drule.standard to Drule.export_without_context, to
  1468 emphasize that this is in no way a standard operation.
  1469 INCOMPATIBILITY.
  1470 
  1471 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
  1472 usual for resolution.  Rare INCOMPATIBILITY.
  1473 
  1474 * Renamed varify/unvarify operations to varify_global/unvarify_global
  1475 to emphasize that these only work in a global situation (which is
  1476 quite rare).
  1477 
  1478 * Curried take and drop in library.ML; negative length is interpreted
  1479 as infinity (as in chop).  Subtle INCOMPATIBILITY.
  1480 
  1481 * Proof terms: type substitutions on proof constants now use canonical
  1482 order of type variables.  INCOMPATIBILITY for tools working with proof
  1483 terms.
  1484 
  1485 * Raw axioms/defs may no longer carry sort constraints, and raw defs
  1486 may no longer carry premises.  User-level specifications are
  1487 transformed accordingly by Thm.add_axiom/add_def.
  1488 
  1489 
  1490 *** System ***
  1491 
  1492 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
  1493 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
  1494 proof terms are enabled unconditionally in the new HOL-Proofs image.
  1495 
  1496 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
  1497 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
  1498 respectively.
  1499 
  1500 * Old lib/scripts/polyml-platform is superseded by the
  1501 ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
  1502 variant, even on a 64 bit machine.  The following example setting
  1503 prefers 64 bit if available:
  1504 
  1505   ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"
  1506 
  1507 * The preliminary Isabelle/jEdit application demonstrates the emerging
  1508 Isabelle/Scala layer for advanced prover interaction and integration.
  1509 See src/Tools/jEdit or "isabelle jedit" provided by the properly built
  1510 component.
  1511 
  1512 * "IsabelleText" is a Unicode font derived from Bitstream Vera Mono
  1513 and Bluesky TeX fonts.  It provides the usual Isabelle symbols,
  1514 similar to the default assignment of the document preparation system
  1515 (cf. isabellesym.sty).  The Isabelle/Scala class Isabelle_System
  1516 provides some operations for direct access to the font without asking
  1517 the user for manual installation.
  1518 
  1519 
  1520 
  1521 New in Isabelle2009-1 (December 2009)
  1522 -------------------------------------
  1523 
  1524 *** General ***
  1525 
  1526 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
  1527 one backslash should be used, even in ML sources.
  1528 
  1529 
  1530 *** Pure ***
  1531 
  1532 * Locale interpretation propagates mixins along the locale hierarchy.
  1533 The currently only available mixins are the equations used to map
  1534 local definitions to terms of the target domain of an interpretation.
  1535 
  1536 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
  1537 loc" to print all interpretations of locale "loc" in the theory.
  1538 Interpretations in proofs are not shown.
  1539 
  1540 * Thoroughly revised locales tutorial.  New section on conditional
  1541 interpretation.
  1542 
  1543 * On instantiation of classes, remaining undefined class parameters
  1544 are formally declared.  INCOMPATIBILITY.
  1545 
  1546 
  1547 *** Document preparation ***
  1548 
  1549 * New generalized style concept for printing terms: @{foo (style) ...}
  1550 instead of @{foo_style style ...}  (old form is still retained for
  1551 backward compatibility).  Styles can be also applied for
  1552 antiquotations prop, term_type and typeof.
  1553 
  1554 
  1555 *** HOL ***
  1556 
  1557 * New proof method "smt" for a combination of first-order logic with
  1558 equality, linear and nonlinear (natural/integer/real) arithmetic, and
  1559 fixed-size bitvectors; there is also basic support for higher-order
  1560 features (esp. lambda abstractions).  It is an incomplete decision
  1561 procedure based on external SMT solvers using the oracle mechanism;
  1562 for the SMT solver Z3, this method is proof-producing.  Certificates
  1563 are provided to avoid calling the external solvers solely for
  1564 re-checking proofs.  Due to a remote SMT service there is no need for
  1565 installing SMT solvers locally.  See src/HOL/SMT.
  1566 
  1567 * New commands to load and prove verification conditions generated by
  1568 the Boogie program verifier or derived systems (e.g. the Verifying C
  1569 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
  1570 
  1571 * New counterexample generator tool 'nitpick' based on the Kodkod
  1572 relational model finder.  See src/HOL/Tools/Nitpick and
  1573 src/HOL/Nitpick_Examples.
  1574 
  1575 * New commands 'code_pred' and 'values' to invoke the predicate
  1576 compiler and to enumerate values of inductive predicates.
  1577 
  1578 * A tabled implementation of the reflexive transitive closure.
  1579 
  1580 * New implementation of quickcheck uses generic code generator;
  1581 default generators are provided for all suitable HOL types, records
  1582 and datatypes.  Old quickcheck can be re-activated importing theory
  1583 Library/SML_Quickcheck.
  1584 
  1585 * New testing tool Mirabelle for automated proof tools.  Applies
  1586 several tools and tactics like sledgehammer, metis, or quickcheck, to
  1587 every proof step in a theory.  To be used in batch mode via the
  1588 "mirabelle" utility.
  1589 
  1590 * New proof method "sos" (sum of squares) for nonlinear real
  1591 arithmetic (originally due to John Harison). It requires theory
  1592 Library/Sum_Of_Squares.  It is not a complete decision procedure but
  1593 works well in practice on quantifier-free real arithmetic with +, -,
  1594 *, ^, =, <= and <, i.e. boolean combinations of equalities and
  1595 inequalities between polynomials.  It makes use of external
  1596 semidefinite programming solvers.  Method "sos" generates a
  1597 certificate that can be pasted into the proof thus avoiding the need
  1598 to call an external tool every time the proof is checked.  See
  1599 src/HOL/Library/Sum_Of_Squares.
  1600 
  1601 * New method "linarith" invokes existing linear arithmetic decision
  1602 procedure only.
  1603 
  1604 * New command 'atp_minimal' reduces result produced by Sledgehammer.
  1605 
  1606 * New Sledgehammer option "Full Types" in Proof General settings menu.
  1607 Causes full type information to be output to the ATPs.  This slows
  1608 ATPs down considerably but eliminates a source of unsound "proofs"
  1609 that fail later.
  1610 
  1611 * New method "metisFT": A version of metis that uses full type
  1612 information in order to avoid failures of proof reconstruction.
  1613 
  1614 * New evaluator "approximate" approximates an real valued term using
  1615 the same method as the approximation method.
  1616 
  1617 * Method "approximate" now supports arithmetic expressions as
  1618 boundaries of intervals and implements interval splitting and Taylor
  1619 series expansion.
  1620 
  1621 * ML antiquotation @{code_datatype} inserts definition of a datatype
  1622 generated by the code generator; e.g. see src/HOL/Predicate.thy.
  1623 
  1624 * New theory SupInf of the supremum and infimum operators for sets of
  1625 reals.
  1626 
  1627 * New theory Probability, which contains a development of measure
  1628 theory, eventually leading to Lebesgue integration and probability.
  1629 
  1630 * Extended Multivariate Analysis to include derivation and Brouwer's
  1631 fixpoint theorem.
  1632 
  1633 * Reorganization of number theory, INCOMPATIBILITY:
  1634   - new number theory development for nat and int, in theories Divides
  1635     and GCD as well as in new session Number_Theory
  1636   - some constants and facts now suffixed with _nat and _int
  1637     accordingly
  1638   - former session NumberTheory now named Old_Number_Theory, including
  1639     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
  1640   - moved theory Pocklington from src/HOL/Library to
  1641     src/HOL/Old_Number_Theory
  1642 
  1643 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
  1644 lcm of finite and infinite sets. It is shown that they form a complete
  1645 lattice.
  1646 
  1647 * Class semiring_div requires superclass no_zero_divisors and proof of
  1648 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
  1649 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
  1650 generalized to class semiring_div, subsuming former theorems
  1651 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
  1652 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
  1653 INCOMPATIBILITY.
  1654 
  1655 * Refinements to lattice classes and sets:
  1656   - less default intro/elim rules in locale variant, more default
  1657     intro/elim rules in class variant: more uniformity
  1658   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
  1659     le_inf_iff
  1660   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
  1661     sup_aci)
  1662   - renamed ACI to inf_sup_aci
  1663   - new class "boolean_algebra"
  1664   - class "complete_lattice" moved to separate theory
  1665     "Complete_Lattice"; corresponding constants (and abbreviations)
  1666     renamed and with authentic syntax:
  1667     Set.Inf ~>    Complete_Lattice.Inf
  1668     Set.Sup ~>    Complete_Lattice.Sup
  1669     Set.INFI ~>   Complete_Lattice.INFI
  1670     Set.SUPR ~>   Complete_Lattice.SUPR
  1671     Set.Inter ~>  Complete_Lattice.Inter
  1672     Set.Union ~>  Complete_Lattice.Union
  1673     Set.INTER ~>  Complete_Lattice.INTER
  1674     Set.UNION ~>  Complete_Lattice.UNION
  1675   - authentic syntax for
  1676     Set.Pow
  1677     Set.image
  1678   - mere abbreviations:
  1679     Set.empty               (for bot)
  1680     Set.UNIV                (for top)
  1681     Set.inter               (for inf, formerly Set.Int)
  1682     Set.union               (for sup, formerly Set.Un)
  1683     Complete_Lattice.Inter  (for Inf)
  1684     Complete_Lattice.Union  (for Sup)
  1685     Complete_Lattice.INTER  (for INFI)
  1686     Complete_Lattice.UNION  (for SUPR)
  1687   - object-logic definitions as far as appropriate
  1688 
  1689 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
  1690 Un_subset_iff are explicitly deleted as default simp rules; then also
  1691 their lattice counterparts le_inf_iff and le_sup_iff have to be
  1692 deleted to achieve the desired effect.
  1693 
  1694 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
  1695 rules by default any longer; the same applies to min_max.inf_absorb1
  1696 etc.  INCOMPATIBILITY.
  1697 
  1698 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
  1699 pred_set_conv by default.  INCOMPATIBILITY.
  1700 
  1701 * Power operations on relations and functions are now one dedicated
  1702 constant "compow" with infix syntax "^^".  Power operation on
  1703 multiplicative monoids retains syntax "^" and is now defined generic
  1704 in class power.  INCOMPATIBILITY.
  1705 
  1706 * Relation composition "R O S" now has a more standard argument order:
  1707 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
  1708 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
  1709 break, since the O_assoc rule was not rewritten like this.  Fix using
  1710 O_assoc[symmetric].  The same applies to the curried version "R OO S".
  1711 
  1712 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
  1713 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
  1714 INCOMPATIBILITY.
  1715 
  1716 * Most rules produced by inductive and datatype package have mandatory
  1717 prefixes.  INCOMPATIBILITY.
  1718 
  1719 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
  1720 the attribute of the same name.  Each of the theorems in the list
  1721 DERIV_intros assumes composition with an additional function and
  1722 matches a variable to the derivative, which has to be solved by the
  1723 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
  1724 of most elementary terms.  Former Maclauren.DERIV_tac and
  1725 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
  1726 INCOMPATIBILITY.
  1727 
  1728 * Code generator attributes follow the usual underscore convention:
  1729     code_unfold     replaces    code unfold
  1730     code_post       replaces    code post
  1731     etc.
  1732   INCOMPATIBILITY.
  1733 
  1734 * Renamed methods:
  1735     sizechange -> size_change
  1736     induct_scheme -> induction_schema
  1737   INCOMPATIBILITY.
  1738 
  1739 * Discontinued abbreviation "arbitrary" of constant "undefined".
  1740 INCOMPATIBILITY, use "undefined" directly.
  1741 
  1742 * Renamed theorems:
  1743     Suc_eq_add_numeral_1 -> Suc_eq_plus1
  1744     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
  1745     Suc_plus1 -> Suc_eq_plus1
  1746     *anti_sym -> *antisym*
  1747     vector_less_eq_def -> vector_le_def
  1748   INCOMPATIBILITY.
  1749 
  1750 * Added theorem List.map_map as [simp].  Removed List.map_compose.
  1751 INCOMPATIBILITY.
  1752 
  1753 * Removed predicate "M hassize n" (<--> card M = n & finite M).
  1754 INCOMPATIBILITY.
  1755 
  1756 
  1757 *** HOLCF ***
  1758 
  1759 * Theory Representable defines a class "rep" of domains that are
  1760 representable (via an ep-pair) in the universal domain type "udom".
  1761 Instances are provided for all type constructors defined in HOLCF.
  1762 
  1763 * The 'new_domain' command is a purely definitional version of the
  1764 domain package, for representable domains.  Syntax is identical to the
  1765 old domain package.  The 'new_domain' package also supports indirect
  1766 recursion using previously-defined type constructors.  See
  1767 src/HOLCF/ex/New_Domain.thy for examples.
  1768 
  1769 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
  1770 on the left-hand side of an equation, and then performs
  1771 simplification.  Rewriting is done using rules declared with the
  1772 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
  1773 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
  1774 
  1775 * The pattern-match compiler in 'fixrec' can now handle constructors
  1776 with HOL function types.  Pattern-match combinators for the Pair
  1777 constructor are pre-configured.
  1778 
  1779 * The 'fixrec' package now produces better fixed-point induction rules
  1780 for mutually-recursive definitions:  Induction rules have conclusions
  1781 of the form "P foo bar" instead of "P <foo, bar>".
  1782 
  1783 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
  1784 been renamed to "below".  The name "below" now replaces "less" in many
  1785 theorem names.  (Legacy theorem names using "less" are still supported
  1786 as well.)
  1787 
  1788 * The 'fixrec' package now supports "bottom patterns".  Bottom
  1789 patterns can be used to generate strictness rules, or to make
  1790 functions more strict (much like the bang-patterns supported by the
  1791 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
  1792 examples.
  1793 
  1794 
  1795 *** ML ***
  1796 
  1797 * Support for Poly/ML 5.3.0, with improved reporting of compiler
  1798 errors and run-time exceptions, including detailed source positions.
  1799 
  1800 * Structure Name_Space (formerly NameSpace) now manages uniquely
  1801 identified entries, with some additional information such as source
  1802 position, logical grouping etc.
  1803 
  1804 * Theory and context data is now introduced by the simplified and
  1805 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
  1806 to be pure, but the old TheoryDataFun for mutable data (with explicit
  1807 copy operation) is still available for some time.
  1808 
  1809 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
  1810 provides a high-level programming interface to synchronized state
  1811 variables with atomic update.  This works via pure function
  1812 application within a critical section -- its runtime should be as
  1813 short as possible; beware of deadlocks if critical code is nested,
  1814 either directly or indirectly via other synchronized variables!
  1815 
  1816 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
  1817 wraps raw ML references, explicitly indicating their non-thread-safe
  1818 behaviour.  The Isar toplevel keeps this structure open, to
  1819 accommodate Proof General as well as quick and dirty interactive
  1820 experiments with references.
  1821 
  1822 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
  1823 parallel tactical reasoning.
  1824 
  1825 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
  1826 are similar to SUBPROOF, but are slightly more flexible: only the
  1827 specified parts of the subgoal are imported into the context, and the
  1828 body tactic may introduce new subgoals and schematic variables.
  1829 
  1830 * Old tactical METAHYPS, which does not observe the proof context, has
  1831 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
  1832 or Subgoal.FOCUS etc.
  1833 
  1834 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
  1835 functors have their own ML name space there is no point to mark them
  1836 separately.)  Minor INCOMPATIBILITY.
  1837 
  1838 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
  1839 
  1840 * Renamed several structures FooBar to Foo_Bar.  Occasional,
  1841 INCOMPATIBILITY.
  1842 
  1843 * Operations of structure Skip_Proof no longer require quick_and_dirty
  1844 mode, which avoids critical setmp.
  1845 
  1846 * Eliminated old Attrib.add_attributes, Method.add_methods and related
  1847 combinators for "args".  INCOMPATIBILITY, need to use simplified
  1848 Attrib/Method.setup introduced in Isabelle2009.
  1849 
  1850 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
  1851 back on global_simpset_of, global_claset_of, global_clasimpset_of as
  1852 last resort.  INCOMPATIBILITY.
  1853 
  1854 * Display.pretty_thm now requires a proper context (cf. former
  1855 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
  1856 or even Display.pretty_thm_without_context as last resort.
  1857 INCOMPATIBILITY.
  1858 
  1859 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
  1860 Syntax.pretty_typ/term directly, preferably with proper context
  1861 instead of global theory.
  1862 
  1863 
  1864 *** System ***
  1865 
  1866 * Further fine tuning of parallel proof checking, scales up to 8 cores
  1867 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
  1868 usedir option -q.
  1869 
  1870 * Support for additional "Isabelle components" via etc/components, see
  1871 also the system manual.
  1872 
  1873 * The isabelle makeall tool now operates on all components with
  1874 IsaMakefile, not just hardwired "logics".
  1875 
  1876 * Removed "compress" option from isabelle-process and isabelle usedir;
  1877 this is always enabled.
  1878 
  1879 * Discontinued support for Poly/ML 4.x versions.
  1880 
  1881 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
  1882 on a given logic image.  This requires the lighttpd webserver and is
  1883 currently supported on Linux only.
  1884 
  1885 
  1886 
  1887 New in Isabelle2009 (April 2009)
  1888 --------------------------------
  1889 
  1890 *** General ***
  1891 
  1892 * Simplified main Isabelle executables, with less surprises on
  1893 case-insensitive file-systems (such as Mac OS).
  1894 
  1895   - The main Isabelle tool wrapper is now called "isabelle" instead of
  1896     "isatool."
  1897 
  1898   - The former "isabelle" alias for "isabelle-process" has been
  1899     removed (should rarely occur to regular users).
  1900 
  1901   - The former "isabelle-interface" and its alias "Isabelle" have been
  1902     removed (interfaces are now regular Isabelle tools).
  1903 
  1904 Within scripts and make files, the Isabelle environment variables
  1905 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
  1906 respectively.  (The latter are still available as legacy feature.)
  1907 
  1908 The old isabelle-interface wrapper could react in confusing ways if
  1909 the interface was uninstalled or changed otherwise.  Individual
  1910 interface tool configuration is now more explicit, see also the
  1911 Isabelle system manual.  In particular, Proof General is now available
  1912 via "isabelle emacs".
  1913 
  1914 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
  1915 purge installed copies of Isabelle executables and re-run "isabelle
  1916 install -p ...", or use symlinks.
  1917 
  1918 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
  1919 old ~/isabelle, which was slightly non-standard and apt to cause
  1920 surprises on case-insensitive file-systems (such as Mac OS).
  1921 
  1922 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
  1923 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
  1924 care is required when using older releases of Isabelle.  Note that
  1925 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
  1926 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
  1927 
  1928 * Proofs of fully specified statements are run in parallel on
  1929 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
  1930 a regular 4-core machine, if the initial heap space is made reasonably
  1931 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
  1932 
  1933 * The main reference manuals ("isar-ref", "implementation", and
  1934 "system") have been updated and extended.  Formally checked references
  1935 as hyperlinks are now available uniformly.
  1936 
  1937 
  1938 *** Pure ***
  1939 
  1940 * Complete re-implementation of locales.  INCOMPATIBILITY in several
  1941 respects.  The most important changes are listed below.  See the
  1942 Tutorial on Locales ("locales" manual) for details.
  1943 
  1944 - In locale expressions, instantiation replaces renaming.  Parameters
  1945 must be declared in a for clause.  To aid compatibility with previous
  1946 parameter inheritance, in locale declarations, parameters that are not
  1947 'touched' (instantiation position "_" or omitted) are implicitly added
  1948 with their syntax at the beginning of the for clause.
  1949 
  1950 - Syntax from abbreviations and definitions in locales is available in
  1951 locale expressions and context elements.  The latter is particularly
  1952 useful in locale declarations.
  1953 
  1954 - More flexible mechanisms to qualify names generated by locale
  1955 expressions.  Qualifiers (prefixes) may be specified in locale
  1956 expressions, and can be marked as mandatory (syntax: "name!:") or
  1957 optional (syntax "name?:").  The default depends for plain "name:"
  1958 depends on the situation where a locale expression is used: in
  1959 commands 'locale' and 'sublocale' prefixes are optional, in
  1960 'interpretation' and 'interpret' prefixes are mandatory.  The old
  1961 implicit qualifiers derived from the parameter names of a locale are
  1962 no longer generated.
  1963 
  1964 - Command "sublocale l < e" replaces "interpretation l < e".  The
  1965 instantiation clause in "interpretation" and "interpret" (square
  1966 brackets) is no longer available.  Use locale expressions.
  1967 
  1968 - When converting proof scripts, mandatory qualifiers in
  1969 'interpretation' and 'interpret' should be retained by default, even
  1970 if this is an INCOMPATIBILITY compared to former behavior.  In the
  1971 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
  1972 in locale expressions range over a single locale instance only.
  1973 
  1974 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
  1975 In existing theorem specifications replace the includes element by the
  1976 respective context elements of the included locale, omitting those
  1977 that are already present in the theorem specification.  Multiple
  1978 assume elements of a locale should be replaced by a single one
  1979 involving the locale predicate.  In the proof body, declarations (most
  1980 notably theorems) may be regained by interpreting the respective
  1981 locales in the proof context as required (command "interpret").
  1982 
  1983 If using "includes" in replacement of a target solely because the
  1984 parameter types in the theorem are not as general as in the target,
  1985 consider declaring a new locale with additional type constraints on
  1986 the parameters (context element "constrains").
  1987 
  1988 - Discontinued "locale (open)".  INCOMPATIBILITY.
  1989 
  1990 - Locale interpretation commands no longer attempt to simplify goal.
  1991 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
  1992 methods intro_locales and unfold_locales to clarify.
  1993 
  1994 - Locale interpretation commands no longer accept interpretation
  1995 attributes.  INCOMPATIBILITY.
  1996 
  1997 * Class declaration: so-called "base sort" must not be given in import
  1998 list any longer, but is inferred from the specification.  Particularly
  1999 in HOL, write
  2000 
  2001     class foo = ...
  2002 
  2003 instead of
  2004 
  2005     class foo = type + ...
  2006 
  2007 * Class target: global versions of theorems stemming do not carry a
  2008 parameter prefix any longer.  INCOMPATIBILITY.
  2009 
  2010 * Class 'instance' command no longer accepts attached definitions.
  2011 INCOMPATIBILITY, use proper 'instantiation' target instead.
  2012 
  2013 * Recovered hiding of consts, which was accidentally broken in
  2014 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
  2015 makes c inaccessible; consider using ``hide (open) const c'' instead.
  2016 
  2017 * Slightly more coherent Pure syntax, with updated documentation in
  2018 isar-ref manual.  Removed locales meta_term_syntax and
  2019 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
  2020 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
  2021 directly in regular applications.
  2022 
  2023 * There is a new syntactic category "float_const" for signed decimal
  2024 fractions (e.g. 123.45 or -123.45).
  2025 
  2026 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
  2027 interface with 'setup' command instead.
  2028 
  2029 * Command 'local_setup' is similar to 'setup', but operates on a local
  2030 theory context.
  2031 
  2032 * The 'axiomatization' command now only works within a global theory
  2033 context.  INCOMPATIBILITY.
  2034 
  2035 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
  2036 hypotheses.  Sorts required in the course of reasoning need to be
  2037 covered by the constraints in the initial statement, completed by the
  2038 type instance information of the background theory.  Non-trivial sort
  2039 hypotheses, which rarely occur in practice, may be specified via
  2040 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
  2041 
  2042   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
  2043 
  2044 The result contains an implicit sort hypotheses as before --
  2045 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
  2046 normalization.
  2047 
  2048 * Generalized Isar history, with support for linear undo, direct state
  2049 addressing etc.
  2050 
  2051 * Changed defaults for unify configuration options:
  2052 
  2053   unify_trace_bound = 50 (formerly 25)
  2054   unify_search_bound = 60 (formerly 30)
  2055 
  2056 * Different bookkeeping for code equations (INCOMPATIBILITY):
  2057 
  2058   a) On theory merge, the last set of code equations for a particular
  2059      constant is taken (in accordance with the policy applied by other
  2060      parts of the code generator framework).
  2061 
  2062   b) Code equations stemming from explicit declarations (e.g. code
  2063      attribute) gain priority over default code equations stemming
  2064      from definition, primrec, fun etc.
  2065 
  2066 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
  2067 
  2068 * Unified theorem tables for both code generators.  Thus [code
  2069 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
  2070 
  2071 * Command 'find_consts' searches for constants based on type and name
  2072 patterns, e.g.
  2073 
  2074     find_consts "_ => bool"
  2075 
  2076 By default, matching is against subtypes, but it may be restricted to
  2077 the whole type.  Searching by name is possible.  Multiple queries are
  2078 conjunctive and queries may be negated by prefixing them with a
  2079 hyphen:
  2080 
  2081     find_consts strict: "_ => bool" name: "Int" -"int => int"
  2082 
  2083 * New 'find_theorems' criterion "solves" matches theorems that
  2084 directly solve the current goal (modulo higher-order unification).
  2085 
  2086 * Auto solve feature for main theorem statements: whenever a new goal
  2087 is stated, "find_theorems solves" is called; any theorems that could
  2088 solve the lemma directly are listed as part of the goal state.
  2089 Cf. associated options in Proof General Isabelle settings menu,
  2090 enabled by default, with reasonable timeout for pathological cases of
  2091 higher-order unification.
  2092 
  2093 
  2094 *** Document preparation ***
  2095 
  2096 * Antiquotation @{lemma} now imitates a regular terminal proof,
  2097 demanding keyword 'by' and supporting the full method expression
  2098 syntax just like the Isar command 'by'.
  2099 
  2100 
  2101 *** HOL ***
  2102 
  2103 * Integrated main parts of former image HOL-Complex with HOL.  Entry
  2104 points Main and Complex_Main remain as before.
  2105 
  2106 * Logic image HOL-Plain provides a minimal HOL with the most important
  2107 tools available (inductive, datatype, primrec, ...).  This facilitates
  2108 experimentation and tool development.  Note that user applications
  2109 (and library theories) should never refer to anything below theory
  2110 Main, as before.
  2111 
  2112 * Logic image HOL-Main stops at theory Main, and thus facilitates
  2113 experimentation due to shorter build times.
  2114 
  2115 * Logic image HOL-NSA contains theories of nonstandard analysis which
  2116 were previously part of former HOL-Complex.  Entry point Hyperreal
  2117 remains valid, but theories formerly using Complex_Main should now use
  2118 new entry point Hypercomplex.
  2119 
  2120 * Generic ATP manager for Sledgehammer, based on ML threads instead of
  2121 Posix processes.  Avoids potentially expensive forking of the ML
  2122 process.  New thread-based implementation also works on non-Unix
  2123 platforms (Cygwin).  Provers are no longer hardwired, but defined
  2124 within the theory via plain ML wrapper functions.  Basic Sledgehammer
  2125 commands are covered in the isar-ref manual.
  2126 
  2127 * Wrapper scripts for remote SystemOnTPTP service allows to use
  2128 sledgehammer without local ATP installation (Vampire etc.). Other
  2129 provers may be included via suitable ML wrappers, see also
  2130 src/HOL/ATP_Linkup.thy.
  2131 
  2132 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
  2133 menu.
  2134 
  2135 * The metis method no longer fails because the theorem is too trivial
  2136 (contains the empty clause).
  2137 
  2138 * The metis method now fails in the usual manner, rather than raising
  2139 an exception, if it determines that it cannot prove the theorem.
  2140 
  2141 * Method "coherent" implements a prover for coherent logic (see also
  2142 src/Tools/coherent.ML).
  2143 
  2144 * Constants "undefined" and "default" replace "arbitrary".  Usually
  2145 "undefined" is the right choice to replace "arbitrary", though
  2146 logically there is no difference.  INCOMPATIBILITY.
  2147 
  2148 * Command "value" now integrates different evaluation mechanisms.  The
  2149 result of the first successful evaluation mechanism is printed.  In
  2150 square brackets a particular named evaluation mechanisms may be
  2151 specified (currently, [SML], [code] or [nbe]).  See further
  2152 src/HOL/ex/Eval_Examples.thy.
  2153 
  2154 * Normalization by evaluation now allows non-leftlinear equations.
  2155 Declare with attribute [code nbe].
  2156 
  2157 * Methods "case_tac" and "induct_tac" now refer to the very same rules
  2158 as the structured Isar versions "cases" and "induct", cf. the
  2159 corresponding "cases" and "induct" attributes.  Mutual induction rules
  2160 are now presented as a list of individual projections
  2161 (e.g. foo_bar.inducts for types foo and bar); the old format with
  2162 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
  2163 rare situations a different rule is selected --- notably nested tuple
  2164 elimination instead of former prod.exhaust: use explicit (case_tac t
  2165 rule: prod.exhaust) here.
  2166 
  2167 * Attributes "cases", "induct", "coinduct" support "del" option.
  2168 
  2169 * Removed fact "case_split_thm", which duplicates "case_split".
  2170 
  2171 * The option datatype has been moved to a new theory Option.  Renamed
  2172 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
  2173 
  2174 * New predicate "strict_mono" classifies strict functions on partial
  2175 orders.  With strict functions on linear orders, reasoning about
  2176 (in)equalities is facilitated by theorems "strict_mono_eq",
  2177 "strict_mono_less_eq" and "strict_mono_less".
  2178 
  2179 * Some set operations are now proper qualified constants with
  2180 authentic syntax.  INCOMPATIBILITY:
  2181 
  2182     op Int ~>   Set.Int
  2183     op Un ~>    Set.Un
  2184     INTER ~>    Set.INTER
  2185     UNION ~>    Set.UNION
  2186     Inter ~>    Set.Inter
  2187     Union ~>    Set.Union
  2188     {} ~>       Set.empty
  2189     UNIV ~>     Set.UNIV
  2190 
  2191 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  2192 theory Set.
  2193 
  2194 * Auxiliary class "itself" has disappeared -- classes without any
  2195 parameter are treated as expected by the 'class' command.
  2196 
  2197 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  2198 
  2199 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  2200 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  2201 
  2202 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  2203 method "approximation".  It proves formulas on real values by using
  2204 interval arithmetic.  In the formulas are also the transcendental
  2205 functions sin, cos, tan, atan, ln, exp and the constant pi are
  2206 allowed. For examples see
  2207 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  2208 
  2209 * Theory "Reflection" now resides in HOL/Library.
  2210 
  2211 * Entry point to Word library now simply named "Word".
  2212 INCOMPATIBILITY.
  2213 
  2214 * Made source layout more coherent with logical distribution
  2215 structure:
  2216 
  2217     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  2218     src/HOL/Library/Code_Message.thy ~> src/HOL/
  2219     src/HOL/Library/GCD.thy ~> src/HOL/
  2220     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  2221     src/HOL/Library/Parity.thy ~> src/HOL/
  2222     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  2223     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  2224     src/HOL/Real/Lubs.thy ~> src/HOL/
  2225     src/HOL/Real/PReal.thy ~> src/HOL/
  2226     src/HOL/Real/Rational.thy ~> src/HOL/
  2227     src/HOL/Real/RComplete.thy ~> src/HOL/
  2228     src/HOL/Real/RealDef.thy ~> src/HOL/
  2229     src/HOL/Real/RealPow.thy ~> src/HOL/
  2230     src/HOL/Real/Real.thy ~> src/HOL/
  2231     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  2232     src/HOL/Complex/Complex.thy ~> src/HOL/
  2233     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  2234     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  2235     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  2236     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  2237     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  2238     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  2239     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  2240     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  2241     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  2242     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  2243     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  2244     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  2245     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  2246     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  2247     src/HOL/Real/Float ~> src/HOL/Library/
  2248     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  2249     src/HOL/Real/RealVector.thy ~> src/HOL/
  2250 
  2251     src/HOL/arith_data.ML ~> src/HOL/Tools
  2252     src/HOL/hologic.ML ~> src/HOL/Tools
  2253     src/HOL/simpdata.ML ~> src/HOL/Tools
  2254     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  2255     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  2256     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  2257     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  2258     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  2259     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  2260     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  2261 
  2262     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  2263     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  2264     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  2265     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  2266     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  2267     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  2268 
  2269 * If methods "eval" and "evaluation" encounter a structured proof
  2270 state with !!/==>, only the conclusion is evaluated to True (if
  2271 possible), avoiding strange error messages.
  2272 
  2273 * Method "sizechange" automates termination proofs using (a
  2274 modification of) the size-change principle.  Requires SAT solver.  See
  2275 src/HOL/ex/Termination.thy for examples.
  2276 
  2277 * Simplifier: simproc for let expressions now unfolds if bound
  2278 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  2279 
  2280 * Method "arith": Linear arithmetic now ignores all inequalities when
  2281 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  2282 
  2283 * New attribute "arith" for facts that should always be used
  2284 automatically by arithmetic. It is intended to be used locally in
  2285 proofs, e.g.
  2286 
  2287   assumes [arith]: "x > 0"
  2288 
  2289 Global usage is discouraged because of possible performance impact.
  2290 
  2291 * New classes "top" and "bot" with corresponding operations "top" and
  2292 "bot" in theory Orderings; instantiation of class "complete_lattice"
  2293 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  2294 
  2295 * Changed definition lemma "less_fun_def" in order to provide an
  2296 instance for preorders on functions; use lemma "less_le" instead.
  2297 INCOMPATIBILITY.
  2298 
  2299 * Theory Orderings: class "wellorder" moved here, with explicit
  2300 induction rule "less_induct" as assumption.  For instantiation of
  2301 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  2302 INCOMPATIBILITY.
  2303 
  2304 * Theory Orderings: added class "preorder" as superclass of "order".
  2305 INCOMPATIBILITY: Instantiation proofs for order, linorder
  2306 etc. slightly changed.  Some theorems named order_class.* now named
  2307 preorder_class.*.
  2308 
  2309 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  2310 "diag" to "Id_on".
  2311 
  2312 * Theory Finite_Set: added a new fold combinator of type
  2313 
  2314   ('a => 'b => 'b) => 'b => 'a set => 'b
  2315 
  2316 Occasionally this is more convenient than the old fold combinator
  2317 which is now defined in terms of the new one and renamed to
  2318 fold_image.
  2319 
  2320 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  2321 and "ring_simps" have been replaced by "algebra_simps" (which can be
  2322 extended with further lemmas!).  At the moment both still exist but
  2323 the former will disappear at some point.
  2324 
  2325 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  2326 class recpower.  Type-specific simp rules for various recpower types
  2327 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  2328 
  2329 rat_power_0    -> power_0
  2330 rat_power_Suc  -> power_Suc
  2331 realpow_0      -> power_0
  2332 realpow_Suc    -> power_Suc
  2333 complexpow_0   -> power_0
  2334 complexpow_Suc -> power_Suc
  2335 power_poly_0   -> power_0
  2336 power_poly_Suc -> power_Suc
  2337 
  2338 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  2339 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  2340 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  2341 of lemmas from Divides has been generalized from nat to class
  2342 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  2343 renames resulting from duplicate elimination:
  2344 
  2345     dvd_def_mod ~>          dvd_eq_mod_eq_0
  2346     zero_dvd_iff ~>         dvd_0_left_iff
  2347     dvd_0 ~>                dvd_0_right
  2348     DIVISION_BY_ZERO_DIV ~> div_by_0
  2349     DIVISION_BY_ZERO_MOD ~> mod_by_0
  2350     mult_div ~>             div_mult_self2_is_id
  2351     mult_mod ~>             mod_mult_self2_is_0
  2352 
  2353 * Theory IntDiv: removed many lemmas that are instances of class-based
  2354 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  2355 rename old lemmas as follows:
  2356 
  2357 dvd_diff               -> nat_dvd_diff
  2358 dvd_zminus_iff         -> dvd_minus_iff
  2359 mod_add1_eq            -> mod_add_eq
  2360 mod_mult1_eq           -> mod_mult_right_eq
  2361 mod_mult1_eq'          -> mod_mult_left_eq
  2362 mod_mult_distrib_mod   -> mod_mult_eq
  2363 nat_mod_add_left_eq    -> mod_add_left_eq
  2364 nat_mod_add_right_eq   -> mod_add_right_eq
  2365 nat_mod_div_trivial    -> mod_div_trivial
  2366 nat_mod_mod_trivial    -> mod_mod_trivial
  2367 zdiv_zadd_self1        -> div_add_self1
  2368 zdiv_zadd_self2        -> div_add_self2
  2369 zdiv_zmult_self1       -> div_mult_self2_is_id
  2370 zdiv_zmult_self2       -> div_mult_self1_is_id
  2371 zdvd_triv_left         -> dvd_triv_left
  2372 zdvd_triv_right        -> dvd_triv_right
  2373 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  2374 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  2375 zmod_zadd_left_eq      -> mod_add_left_eq
  2376 zmod_zadd_right_eq     -> mod_add_right_eq
  2377 zmod_zadd_self1        -> mod_add_self1
  2378 zmod_zadd_self2        -> mod_add_self2
  2379 zmod_zadd1_eq          -> mod_add_eq
  2380 zmod_zdiff1_eq         -> mod_diff_eq
  2381 zmod_zdvd_zmod         -> mod_mod_cancel
  2382 zmod_zmod_cancel       -> mod_mod_cancel
  2383 zmod_zmult_self1       -> mod_mult_self2_is_0
  2384 zmod_zmult_self2       -> mod_mult_self1_is_0
  2385 zmod_1                 -> mod_by_1
  2386 zdiv_1                 -> div_by_1
  2387 zdvd_abs1              -> abs_dvd_iff
  2388 zdvd_abs2              -> dvd_abs_iff
  2389 zdvd_refl              -> dvd_refl
  2390 zdvd_trans             -> dvd_trans
  2391 zdvd_zadd              -> dvd_add
  2392 zdvd_zdiff             -> dvd_diff
  2393 zdvd_zminus_iff        -> dvd_minus_iff
  2394 zdvd_zminus2_iff       -> minus_dvd_iff
  2395 zdvd_zmultD            -> dvd_mult_right
  2396 zdvd_zmultD2           -> dvd_mult_left
  2397 zdvd_zmult_mono        -> mult_dvd_mono
  2398 zdvd_0_right           -> dvd_0_right
  2399 zdvd_0_left            -> dvd_0_left_iff
  2400 zdvd_1_left            -> one_dvd
  2401 zminus_dvd_iff         -> minus_dvd_iff
  2402 
  2403 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  2404 
  2405 * The real numbers offer decimal input syntax: 12.34 is translated
  2406 into 1234/10^2. This translation is not reversed upon output.
  2407 
  2408 * Theory Library/Polynomial defines an abstract type 'a poly of
  2409 univariate polynomials with coefficients of type 'a.  In addition to
  2410 the standard ring operations, it also supports div and mod.  Code
  2411 generation is also supported, using list-style constructors.
  2412 
  2413 * Theory Library/Inner_Product defines a class of real_inner for real
  2414 inner product spaces, with an overloaded operation inner :: 'a => 'a
  2415 => real.  Class real_inner is a subclass of real_normed_vector from
  2416 theory RealVector.
  2417 
  2418 * Theory Library/Product_Vector provides instances for the product
  2419 type 'a * 'b of several classes from RealVector and Inner_Product.
  2420 Definitions of addition, subtraction, scalar multiplication, norms,
  2421 and inner products are included.
  2422 
  2423 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  2424 addition to the field operations, numerals and case syntax are also
  2425 supported.
  2426 
  2427 * Theory Library/Diagonalize provides constructive version of Cantor's
  2428 first diagonalization argument.
  2429 
  2430 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  2431 zlcm (for int); carried together from various gcd/lcm developements in
  2432 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  2433 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  2434 may recover tupled syntax as follows:
  2435 
  2436     hide (open) const gcd
  2437     abbreviation gcd where
  2438       "gcd == (%(a, b). GCD.gcd a b)"
  2439     notation (output)
  2440       GCD.gcd ("gcd '(_, _')")
  2441 
  2442 The same works for lcm, zgcd, zlcm.
  2443 
  2444 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  2445 instantiations for algebraic structures.  Removed some duplicate
  2446 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  2447 
  2448 * ML antiquotation @{code} takes a constant as argument and generates
  2449 corresponding code in background and inserts name of the corresponding
  2450 resulting ML value/function/datatype constructor binding in place.
  2451 All occurrences of @{code} with a single ML block are generated
  2452 simultaneously.  Provides a generic and safe interface for
  2453 instrumentalizing code generation.  See
  2454 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  2455 In future you ought to refrain from ad-hoc compiling generated SML
  2456 code on the ML toplevel.  Note that (for technical reasons) @{code}
  2457 cannot refer to constants for which user-defined serializations are
  2458 set.  Refer to the corresponding ML counterpart directly in that
  2459 cases.
  2460 
  2461 * Command 'rep_datatype': instead of theorem names the command now
  2462 takes a list of terms denoting the constructors of the type to be
  2463 represented as datatype.  The characteristic theorems have to be
  2464 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  2465 have disappeared in favour of existing ones:
  2466 
  2467     unit_induct                 ~> unit.induct
  2468     prod_induct                 ~> prod.induct
  2469     sum_induct                  ~> sum.induct
  2470     Suc_Suc_eq                  ~> nat.inject
  2471     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  2472 
  2473 
  2474 *** HOL-Algebra ***
  2475 
  2476 * New locales for orders and lattices where the equivalence relation
  2477 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  2478 locales use a record structure with field eq for the equivalence.
  2479 
  2480 * New theory of factorial domains.
  2481 
  2482 * Units_l_inv and Units_r_inv are now simp rules by default.
  2483 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  2484 and/or r_inv will now also require deletion of these lemmas.
  2485 
  2486 * Renamed the following theorems, INCOMPATIBILITY:
  2487 
  2488 UpperD ~> Upper_memD
  2489 LowerD ~> Lower_memD
  2490 least_carrier ~> least_closed
  2491 greatest_carrier ~> greatest_closed
  2492 greatest_Lower_above ~> greatest_Lower_below
  2493 one_zero ~> carrier_one_zero
  2494 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  2495 
  2496 
  2497 *** HOL-Nominal ***
  2498 
  2499 * Nominal datatypes can now contain type-variables.
  2500 
  2501 * Commands 'nominal_inductive' and 'equivariance' work with local
  2502 theory targets.
  2503 
  2504 * Nominal primrec can now works with local theory targets and its
  2505 specification syntax now conforms to the general format as seen in
  2506 'inductive' etc.
  2507 
  2508 * Method "perm_simp" honours the standard simplifier attributes
  2509 (no_asm), (no_asm_use) etc.
  2510 
  2511 * The new predicate #* is defined like freshness, except that on the
  2512 left hand side can be a set or list of atoms.
  2513 
  2514 * Experimental command 'nominal_inductive2' derives strong induction
  2515 principles for inductive definitions.  In contrast to
  2516 'nominal_inductive', which can only deal with a fixed number of
  2517 binders, it can deal with arbitrary expressions standing for sets of
  2518 atoms to be avoided.  The only inductive definition we have at the
  2519 moment that needs this generalisation is the typing rule for Lets in
  2520 the algorithm W:
  2521 
  2522  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  2523  -----------------------------------------------------------------
  2524          Gamma |- Let x be t1 in t2 : T2
  2525 
  2526 In this rule one wants to avoid all the binders that are introduced by
  2527 "close Gamma T1".  We are looking for other examples where this
  2528 feature might be useful.  Please let us know.
  2529 
  2530 
  2531 *** HOLCF ***
  2532 
  2533 * Reimplemented the simplification procedure for proving continuity
  2534 subgoals.  The new simproc is extensible; users can declare additional
  2535 continuity introduction rules with the attribute [cont2cont].
  2536 
  2537 * The continuity simproc now uses a different introduction rule for
  2538 solving continuity subgoals on terms with lambda abstractions.  In
  2539 some rare cases the new simproc may fail to solve subgoals that the
  2540 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  2541 Potential INCOMPATIBILITY.
  2542 
  2543 * Command 'fixrec': specification syntax now conforms to the general
  2544 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  2545 examples.  INCOMPATIBILITY.
  2546 
  2547 
  2548 *** ZF ***
  2549 
  2550 * Proof of Zorn's Lemma for partial orders.
  2551 
  2552 
  2553 *** ML ***
  2554 
  2555 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  2556 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  2557 depends on multithreading, so timouts will not work before Poly/ML
  2558 5.2.1!
  2559 
  2560 * High-level support for concurrent ML programming, see
  2561 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  2562 particularly convenient to organize independent functional
  2563 computations.  The concept of "synchronized variables" provides a
  2564 higher-order interface for components with shared state, avoiding the
  2565 delicate details of mutexes and condition variables.  (Requires
  2566 Poly/ML 5.2.1 or later.)
  2567 
  2568 * ML bindings produced via Isar commands are stored within the Isar
  2569 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  2570 become thread-safe and work with undo as expected (concerning
  2571 top-level bindings, not side-effects on global references).
  2572 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  2573 compiler at runtime; really global bindings need to be given outside a
  2574 theory.  (Requires Poly/ML 5.2 or later.)
  2575 
  2576 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  2577 context.  Top-level ML bindings are stored within the proof context in
  2578 a purely sequential fashion, disregarding the nested proof structure.
  2579 ML bindings introduced by 'ML_prf' are discarded at the end of the
  2580 proof.  (Requires Poly/ML 5.2 or later.)
  2581 
  2582 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  2583 and Method.setup, as well as Isar commands 'attribute_setup' and
  2584 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  2585 existing code accordingly, or use plain 'setup' together with old
  2586 Method.add_method.
  2587 
  2588 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  2589 to 'a -> thm, while results are always tagged with an authentic oracle
  2590 name.  The Isar command 'oracle' is now polymorphic, no argument type
  2591 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  2592 accordingly.  Note that extra performance may be gained by producing
  2593 the cterm carefully, avoiding slow Thm.cterm_of.
  2594 
  2595 * Simplified interface for defining document antiquotations via
  2596 ThyOutput.antiquotation, ThyOutput.output, and optionally
  2597 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  2598 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  2599 examples.
  2600 
  2601 * More systematic treatment of long names, abstract name bindings, and
  2602 name space operations.  Basic operations on qualified names have been
  2603 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  2604 Long_Name.append.  Old type bstring has been mostly replaced by
  2605 abstract type binding (see structure Binding), which supports precise
  2606 qualification by packages and local theory targets, as well as proper
  2607 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  2608 bstring values into Binding.name, or better pass through abstract
  2609 bindings everywhere.  See further src/Pure/General/long_name.ML,
  2610 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  2611 
  2612 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  2613 LocalTheory.note etc.) now refer to the *full* internal name, not the
  2614 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  2615 
  2616 * Disposed old type and term read functions (Sign.read_def_typ,
  2617 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  2618 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  2619 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  2620 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  2621 resort for legacy applications.
  2622 
  2623 * Disposed old declarations, tactics, tactic combinators that refer to
  2624 the simpset or claset of an implicit theory (such as Addsimps,
  2625 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  2626 embedded ML text, or local_simpset_of with a proper context passed as
  2627 explicit runtime argument.
  2628 
  2629 * Rules and tactics that read instantiations (read_instantiate,
  2630 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  2631 context, which is required for parsing and type-checking.  Moreover,
  2632 the variables are specified as plain indexnames, not string encodings
  2633 thereof.  INCOMPATIBILITY.
  2634 
  2635 * Generic Toplevel.add_hook interface allows to analyze the result of
  2636 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  2637 for theorem dependency output of transactions resulting in a new
  2638 theory state.
  2639 
  2640 * ML antiquotations: block-structured compilation context indicated by
  2641 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  2642 
  2643   @{binding name}                         - basic name binding
  2644   @{let ?pat = term}                      - term abbreviation (HO matching)
  2645   @{note name = fact}                     - fact abbreviation
  2646   @{thm fact}                             - singleton fact (with attributes)
  2647   @{thms fact}                            - general fact (with attributes)
  2648   @{lemma prop by method}                 - singleton goal
  2649   @{lemma prop by meth1 meth2}            - singleton goal
  2650   @{lemma prop1 ... propN by method}      - general goal
  2651   @{lemma prop1 ... propN by meth1 meth2} - general goal
  2652   @{lemma (open) ...}                     - open derivation
  2653 
  2654 
  2655 *** System ***
  2656 
  2657 * The Isabelle "emacs" tool provides a specific interface to invoke
  2658 Proof General / Emacs, with more explicit failure if that is not
  2659 installed (the old isabelle-interface script silently falls back on
  2660 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  2661 installation location of the Proof General distribution.
  2662 
  2663 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  2664 the Isabelle process into a JVM/Scala application.  See
  2665 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  2666 process wrapper has been discontinued.)
  2667 
  2668 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  2669 
  2670 * Various status messages (with exact source position information) are
  2671 emitted, if proper markup print mode is enabled.  This allows
  2672 user-interface components to provide detailed feedback on internal
  2673 prover operations.
  2674 
  2675 
  2676 
  2677 New in Isabelle2008 (June 2008)
  2678 -------------------------------
  2679 
  2680 *** General ***
  2681 
  2682 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  2683 and updated, with formally checked references as hyperlinks.
  2684 
  2685 * Theory loader: use_thy (and similar operations) no longer set the
  2686 implicit ML context, which was occasionally hard to predict and in
  2687 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  2688 provides a proper context already.
  2689 
  2690 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2691 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  2692 'use' within a theory file will do the job.
  2693 
  2694 * Name space merge now observes canonical order, i.e. the second space
  2695 is inserted into the first one, while existing entries in the first
  2696 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  2697 swap theory imports.
  2698 
  2699 * Syntax: symbol \<chi> is now considered a letter.  Potential
  2700 INCOMPATIBILITY in identifier syntax etc.
  2701 
  2702 * Outer syntax: string tokens no longer admit escaped white space,
  2703 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  2704 white space without escapes.
  2705 
  2706 * Outer syntax: string tokens may contain arbitrary character codes
  2707 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  2708 "foo_bar".
  2709 
  2710 
  2711 *** Pure ***
  2712 
  2713 * Context-dependent token translations.  Default setup reverts locally
  2714 fixed variables, and adds hilite markup for undeclared frees.
  2715 
  2716 * Unused theorems can be found using the new command 'unused_thms'.
  2717 There are three ways of invoking it:
  2718 
  2719 (1) unused_thms
  2720      Only finds unused theorems in the current theory.
  2721 
  2722 (2) unused_thms thy_1 ... thy_n -
  2723      Finds unused theorems in the current theory and all of its ancestors,
  2724      excluding the theories thy_1 ... thy_n and all of their ancestors.
  2725 
  2726 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  2727      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  2728      their ancestors, excluding the theories thy_1 ... thy_n and all of
  2729      their ancestors.
  2730 
  2731 In order to increase the readability of the list produced by
  2732 unused_thms, theorems that have been created by a particular instance
  2733 of a theory command such as 'inductive' or 'function' are considered
  2734 to belong to the same "group", meaning that if at least one theorem in
  2735 this group is used, the other theorems in the same group are no longer
  2736 reported as unused.  Moreover, if all theorems in the group are
  2737 unused, only one theorem in the group is displayed.
  2738 
  2739 Note that proof objects have to be switched on in order for
  2740 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  2741 usually the case when using Proof General with the default settings).
  2742 
  2743 * Authentic naming of facts disallows ad-hoc overwriting of previous
  2744 theorems within the same name space.  INCOMPATIBILITY, need to remove
  2745 duplicate fact bindings, or even accidental fact duplications.  Note
  2746 that tools may maintain dynamically scoped facts systematically, using
  2747 PureThy.add_thms_dynamic.
  2748 
  2749 * Command 'hide' now allows to hide from "fact" name space as well.
  2750 
  2751 * Eliminated destructive theorem database, simpset, claset, and
  2752 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  2753 update of theories within ML code.
  2754 
  2755 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  2756 INCOMPATIBILITY, object-logics depending on former Pure require
  2757 additional setup PureThy.old_appl_syntax_setup; object-logics
  2758 depending on former CPure need to refer to Pure.
  2759 
  2760 * Commands 'use' and 'ML' are now purely functional, operating on
  2761 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  2762 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  2763 INCOMPATIBILITY.
  2764 
  2765 * Command 'setup': discontinued implicit version with ML reference.
  2766 
  2767 * Instantiation target allows for simultaneous specification of class
  2768 instance operations together with an instantiation proof.
  2769 Type-checking phase allows to refer to class operations uniformly.
  2770 See src/HOL/Complex/Complex.thy for an Isar example and
  2771 src/HOL/Library/Eval.thy for an ML example.
  2772 
  2773 * Indexing of literal facts: be more serious about including only
  2774 facts from the visible specification/proof context, but not the
  2775 background context (locale etc.).  Affects `prop` notation and method
  2776 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  2777 situations.
  2778 
  2779 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  2780 "(open)" option, which used to expose internal bound variables to the
  2781 proof text.
  2782 
  2783 * Isar statements: removed obsolete case "rule_context".
  2784 INCOMPATIBILITY, better use explicit fixes/assumes.
  2785 
  2786 * Locale proofs: default proof step now includes 'unfold_locales';
  2787 hence 'proof' without argument may be used to unfold locale
  2788 predicates.
  2789 
  2790 
  2791 *** Document preparation ***
  2792 
  2793 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  2794 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  2795 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  2796 spot); renamed link color from "darkblue" to "linkcolor" (default
  2797 value unchanged, can be redefined via \definecolor); no longer sets
  2798 "a4paper" option (unnecessary or even intrusive).
  2799 
  2800 * Antiquotation @{lemma A method} proves proposition A by the given
  2801 method (either a method name or a method name plus (optional) method
  2802 arguments in parentheses) and prints A just like @{prop A}.
  2803 
  2804 
  2805 *** HOL ***
  2806 
  2807 * New primrec package.  Specification syntax conforms in style to
  2808 definition/function/....  No separate induction rule is provided.  The
  2809 "primrec" command distinguishes old-style and new-style specifications
  2810 by syntax.  The former primrec package is now named OldPrimrecPackage.
  2811 When adjusting theories, beware: constants stemming from new-style
  2812 primrec specifications have authentic syntax.
  2813 
  2814 * Metis prover is now an order of magnitude faster, and also works
  2815 with multithreading.
  2816 
  2817 * Metis: the maximum number of clauses that can be produced from a
  2818 theorem is now given by the attribute max_clauses.  Theorems that
  2819 exceed this number are ignored, with a warning printed.
  2820 
  2821 * Sledgehammer no longer produces structured proofs by default. To
  2822 enable, declare [[sledgehammer_full = true]].  Attributes
  2823 reconstruction_modulus, reconstruction_sorts renamed
  2824 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  2825 
  2826 * Method "induct_scheme" derives user-specified induction rules
  2827 from well-founded induction and completeness of patterns. This factors
  2828 out some operations that are done internally by the function package
  2829 and makes them available separately.  See
  2830 src/HOL/ex/Induction_Scheme.thy for examples.
  2831 
  2832 * More flexible generation of measure functions for termination
  2833 proofs: Measure functions can be declared by proving a rule of the
  2834 form "is_measure f" and giving it the [measure_function] attribute.
  2835 The "is_measure" predicate is logically meaningless (always true), and
  2836 just guides the heuristic.  To find suitable measure functions, the
  2837 termination prover sets up the goal "is_measure ?f" of the appropriate
  2838 type and generates all solutions by prolog-style backwards proof using
  2839 the declared rules.
  2840 
  2841 This setup also deals with rules like 
  2842 
  2843   "is_measure f ==> is_measure (list_size f)"
  2844 
  2845 which accommodates nested datatypes that recurse through lists.
  2846 Similar rules are predeclared for products and option types.
  2847 
  2848 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  2849 
  2850   INCOMPATIBILITIES:
  2851 
  2852   - Definitions of overloaded constants on sets have to be replaced by
  2853     definitions on => and bool.
  2854 
  2855   - Some definitions of overloaded operators on sets can now be proved
  2856     using the definitions of the operators on => and bool.  Therefore,
  2857     the following theorems have been renamed:
  2858 
  2859       subset_def   -> subset_eq
  2860       psubset_def  -> psubset_eq
  2861       set_diff_def -> set_diff_eq
  2862       Compl_def    -> Compl_eq
  2863       Sup_set_def  -> Sup_set_eq
  2864       Inf_set_def  -> Inf_set_eq
  2865       sup_set_def  -> sup_set_eq
  2866       inf_set_def  -> inf_set_eq
  2867 
  2868   - Due to the incompleteness of the HO unification algorithm, some
  2869     rules such as subst may require manual instantiation, if some of
  2870     the unknowns in the rule is a set.
  2871 
  2872   - Higher order unification and forward proofs:
  2873     The proof pattern
  2874 
  2875       have "P (S::'a set)" <...>
  2876       then have "EX S. P S" ..
  2877 
  2878     no longer works (due to the incompleteness of the HO unification
  2879     algorithm) and must be replaced by the pattern
  2880 
  2881       have "EX S. P S"
  2882       proof
  2883         show "P S" <...>
  2884       qed
  2885 
  2886   - Calculational reasoning with subst (or similar rules):
  2887     The proof pattern
  2888 
  2889       have "P (S::'a set)" <...>
  2890       also have "S = T" <...>
  2891       finally have "P T" .
  2892 
  2893     no longer works (for similar reasons as the previous example) and
  2894     must be replaced by something like
  2895 
  2896       have "P (S::'a set)" <...>
  2897       moreover have "S = T" <...>
  2898       ultimately have "P T" by simp
  2899 
  2900   - Tactics or packages written in ML code:
  2901     Code performing pattern matching on types via
  2902 
  2903       Type ("set", [T]) => ...
  2904 
  2905     must be rewritten. Moreover, functions like strip_type or
  2906     binder_types no longer return the right value when applied to a
  2907     type of the form
  2908 
  2909       T1 => ... => Tn => U => bool
  2910 
  2911     rather than
  2912 
  2913       T1 => ... => Tn => U set
  2914 
  2915 * Merged theories Wellfounded_Recursion, Accessible_Part and
  2916 Wellfounded_Relations to theory Wellfounded.
  2917 
  2918 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  2919 
  2920 * Class finite no longer treats UNIV as class parameter.  Use class
  2921 enum from theory Library/Enum instead to achieve a similar effect.
  2922 INCOMPATIBILITY.
  2923 
  2924 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  2925 and "Cons".  INCOMPATIBILITY.
  2926 
  2927 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  2928 Potential INCOMPATIBILITY.
  2929 
  2930 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  2931 injective_fst_snd removed, use split_eta and prod_eqI instead.
  2932 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  2933 
  2934 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  2935 the same name in theory Orderings:
  2936 
  2937   less_trans
  2938   less_linear
  2939   le_imp_less_or_eq
  2940   le_less_trans
  2941   less_le_trans
  2942   less_not_sym
  2943   less_asym
  2944 
  2945 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  2946 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  2947 and different variable names.
  2948 
  2949 * Library/Option_ord.thy: Canonical order on option type.
  2950 
  2951 * Library/RBT.thy: Red-black trees, an efficient implementation of
  2952 finite maps.
  2953 
  2954 * Library/Countable.thy: Type class for countable types.
  2955 
  2956 * Theory Int: The representation of numerals has changed.  The infix
  2957 operator BIT and the bit datatype with constructors B0 and B1 have
  2958 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  2959 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  2960 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  2961 accordingly.
  2962 
  2963 * Theory Nat: definition of <= and < on natural numbers no longer
  2964 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  2965 le_def and less_def have disappeared.  Consider lemmas not_less
  2966 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  2967 
  2968 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  2969 (whose purpose mainly is for various fold_set functionals) have been
  2970 abandoned in favor of the existing algebraic classes
  2971 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  2972 lower_semilattice (resp. upper_semilattice) and linorder.
  2973 INCOMPATIBILITY.
  2974 
  2975 * Theory Transitive_Closure: induct and cases rules now declare proper
  2976 case_names ("base" and "step").  INCOMPATIBILITY.
  2977 
  2978 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  2979 lattices.  The form set-specific version is available as
  2980 Inductive.lfp_ordinal_induct_set.
  2981 
  2982 * Renamed theorems "power.simps" to "power_int.simps".
  2983 INCOMPATIBILITY.
  2984 
  2985 * Class semiring_div provides basic abstract properties of semirings
  2986 with division and modulo operations.  Subsumes former class dvd_mod.
  2987 
  2988 * Merged theories IntDef, Numeral and IntArith into unified theory
  2989 Int.  INCOMPATIBILITY.
  2990 
  2991 * Theory Library/Code_Index: type "index" now represents natural
  2992 numbers rather than integers.  INCOMPATIBILITY.
  2993 
  2994 * New class "uminus" with operation "uminus" (split of from class
  2995 "minus" which now only has operation "minus", binary).
  2996 INCOMPATIBILITY.
  2997 
  2998 * Constants "card", "internal_split", "option_map" now with authentic
  2999 syntax.  INCOMPATIBILITY.
  3000 
  3001 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  3002 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  3003 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  3004 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  3005 Sup_set_def, le_def, less_def, option_map_def now with object
  3006 equality.  INCOMPATIBILITY.
  3007 
  3008 * Records. Removed K_record, and replaced it by pure lambda term
  3009 %x. c. The simplifier setup is now more robust against eta expansion.
  3010 INCOMPATIBILITY: in cases explicitly referring to K_record.
  3011 
  3012 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  3013 
  3014 * Library/ListVector: new theory of arithmetic vector operations.
  3015 
  3016 * Library/Order_Relation: new theory of various orderings as sets of
  3017 pairs.  Defines preorders, partial orders, linear orders and
  3018 well-orders on sets and on types.
  3019 
  3020 
  3021 *** ZF ***
  3022 
  3023 * Renamed some theories to allow to loading both ZF and HOL in the
  3024 same session:
  3025 
  3026   Datatype  -> Datatype_ZF
  3027   Inductive -> Inductive_ZF
  3028   Int       -> Int_ZF
  3029   IntDiv    -> IntDiv_ZF
  3030   Nat       -> Nat_ZF
  3031   List      -> List_ZF
  3032   Main      -> Main_ZF
  3033 
  3034 INCOMPATIBILITY: ZF theories that import individual theories below
  3035 Main might need to be adapted.  Regular theory Main is still
  3036 available, as trivial extension of Main_ZF.
  3037 
  3038 
  3039 *** ML ***
  3040 
  3041 * ML within Isar: antiquotation @{const name} or @{const
  3042 name(typargs)} produces statically-checked Const term.
  3043 
  3044 * Functor NamedThmsFun: data is available to the user as dynamic fact
  3045 (of the same name).  Removed obsolete print command.
  3046 
  3047 * Removed obsolete "use_legacy_bindings" function.
  3048 
  3049 * The ``print mode'' is now a thread-local value derived from a global
  3050 template (the former print_mode reference), thus access becomes
  3051 non-critical.  The global print_mode reference is for session
  3052 management only; user-code should use print_mode_value,
  3053 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  3054 
  3055 * Functions system/system_out provide a robust way to invoke external
  3056 shell commands, with propagation of interrupts (requires Poly/ML
  3057 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  3058 
  3059 
  3060 *** System ***
  3061 
  3062 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  3063 in accordance with Proof General 3.7, which prefers GNU emacs.
  3064 
  3065 * isatool tty runs Isabelle process with plain tty interaction;
  3066 optional line editor may be specified via ISABELLE_LINE_EDITOR
  3067 setting, the default settings attempt to locate "ledit" and "rlwrap".
  3068 
  3069 * isatool browser now works with Cygwin as well, using general
  3070 "javapath" function defined in Isabelle process environment.
  3071 
  3072 * YXML notation provides a simple and efficient alternative to
  3073 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  3074 isatool yxml as described in the Isabelle system manual.
  3075 
  3076 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  3077 provides general wrapper for managing an Isabelle process in a robust
  3078 fashion, with ``cooked'' output from stdin/stderr.
  3079 
  3080 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  3081 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  3082 
  3083 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  3084 way of changing the user's settings is via
  3085 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  3086 script.
  3087 
  3088 * Multithreading.max_threads := 0 refers to the number of actual CPU
  3089 cores of the underlying machine, which is a good starting point for
  3090 optimal performance tuning.  The corresponding usedir option -M allows
  3091 "max" as an alias for "0".  WARNING: does not work on certain versions
  3092 of Mac OS (with Poly/ML 5.1).
  3093 
  3094 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  3095 adverse effect of Isabelle flooding interactive front-ends (notably
  3096 ProofGeneral / XEmacs).
  3097 
  3098 
  3099 
  3100 New in Isabelle2007 (November 2007)
  3101 -----------------------------------
  3102 
  3103 *** General ***
  3104 
  3105 * More uniform information about legacy features, notably a
  3106 warning/error of "Legacy feature: ...", depending on the state of the
  3107 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  3108 legacy features will disappear eventually.
  3109 
  3110 * Theory syntax: the header format ``theory A = B + C:'' has been
  3111 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  3112 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  3113 
  3114 * Theory syntax: the old non-Isar theory file format has been
  3115 discontinued altogether.  Note that ML proof scripts may still be used
  3116 with Isar theories; migration is usually quite simple with the ML
  3117 function use_legacy_bindings.  INCOMPATIBILITY.
  3118 
  3119 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  3120 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  3121 quotes.
  3122 
  3123 * Theory loader: be more serious about observing the static theory
  3124 header specifications (including optional directories), but not the
  3125 accidental file locations of previously successful loads.  The strict
  3126 update policy of former update_thy is now already performed by
  3127 use_thy, so the former has been removed; use_thys updates several
  3128 theories simultaneously, just as 'imports' within a theory header
  3129 specification, but without merging the results.  Potential
  3130 INCOMPATIBILITY: may need to refine theory headers and commands
  3131 ROOT.ML which depend on load order.
  3132 
  3133 * Theory loader: optional support for content-based file
  3134 identification, instead of the traditional scheme of full physical
  3135 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  3136 (cf. the system manual).  The new scheme allows to work with
  3137 non-finished theories in persistent session images, such that source
  3138 files may be moved later on without requiring reloads.
  3139 
  3140 * Theory loader: old-style ML proof scripts being *attached* to a thy
  3141 file (with the same base name as the theory) are considered a legacy
  3142 feature, which will disappear eventually. Even now, the theory loader
  3143 no longer maintains dependencies on such files.
  3144 
  3145 * Syntax: the scope for resolving ambiguities via type-inference is
  3146 now limited to individual terms, instead of whole simultaneous
  3147 specifications as before. This greatly reduces the complexity of the
  3148 syntax module and improves flexibility by separating parsing and
  3149 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  3150 'fixes' etc.) are required in rare situations.
  3151 
  3152 * Syntax: constants introduced by new-style packages ('definition',
  3153 'abbreviation' etc.) are passed through the syntax module in
  3154 ``authentic mode''. This means that associated mixfix annotations
  3155 really stick to such constants, independently of potential name space
  3156 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  3157 trees are represented slightly differently, may need to adapt syntax
  3158 translations accordingly. Use CONST marker in 'translations' and
  3159 @{const_syntax} antiquotation in 'parse_translation' etc.
  3160 
  3161 * Legacy goal package: reduced interface to the bare minimum required
  3162 to keep existing proof scripts running.  Most other user-level
  3163 functions are now part of the OldGoals structure, which is *not* open
  3164 by default (consider isatool expandshort before open OldGoals).
  3165 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  3166 these tend to cause confusion about the actual goal (!) context being
  3167 used here, which is not necessarily the same as the_context().
  3168 
  3169 * Command 'find_theorems': supports "*" wild-card in "name:"
  3170 criterion; "with_dups" option.  Certain ProofGeneral versions might
  3171 support a specific search form (see ProofGeneral/CHANGES).
  3172 
  3173 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  3174 by default, which means that "prems" (and also "fixed variables") are
  3175 suppressed from proof state output.  Note that the ProofGeneral
  3176 settings mechanism allows to change and save options persistently, but
  3177 older versions of Isabelle will fail to start up if a negative prems
  3178 limit is imposed.
  3179 
  3180 * Local theory targets may be specified by non-nested blocks of
  3181 ``context/locale/class ... begin'' followed by ``end''.  The body may
  3182 contain definitions, theorems etc., including any derived mechanism
  3183 that has been implemented on top of these primitives.  This concept
  3184 generalizes the existing ``theorem (in ...)'' towards more versatility
  3185 and scalability.
  3186 
  3187 * Proof General interface: proper undo of final 'end' command;
  3188 discontinued Isabelle/classic mode (ML proof scripts).
  3189 
  3190 
  3191 *** Document preparation ***
  3192 
  3193 * Added antiquotation @{theory name} which prints the given name,
  3194 after checking that it refers to a valid ancestor theory in the
  3195 current context.
  3196 
  3197 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  3198 check the given source text as ML type/structure, printing verbatim.
  3199 
  3200 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  3201 "c args == rhs" given in the current context.  (Any number of
  3202 arguments may be given on the LHS.)
  3203 
  3204 
  3205 *** Pure ***
  3206 
  3207 * The 'class' package offers a combination of axclass and locale to
  3208 achieve Haskell-like type classes in Isabelle.  Definitions and
  3209 theorems within a class context produce both relative results (with
  3210 implicit parameters according to the locale context), and polymorphic
  3211 constants with qualified polymorphism (according to the class
  3212 context).  Within the body context of a 'class' target, a separate
  3213 syntax layer ("user space type system") takes care of converting
  3214 between global polymorphic consts and internal locale representation.
  3215 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  3216 "isatool doc classes" provides a tutorial.
  3217 
  3218 * Generic code generator framework allows to generate executable
  3219 code for ML and Haskell (including Isabelle classes).  A short usage
  3220 sketch:
  3221 
  3222     internal compilation:
  3223         export_code <list of constants (term syntax)> in SML
  3224     writing SML code to a file:
  3225         export_code <list of constants (term syntax)> in SML <filename>
  3226     writing OCaml code to a file:
  3227         export_code <list of constants (term syntax)> in OCaml <filename>
  3228     writing Haskell code to a bunch of files:
  3229         export_code <list of constants (term syntax)> in Haskell <filename>
  3230 
  3231     evaluating closed propositions to True/False using code generation:
  3232         method ``eval''
  3233 
  3234 Reasonable default setup of framework in HOL.
  3235 
  3236 Theorem attributs for selecting and transforming function equations theorems:
  3237 
  3238     [code fun]:        select a theorem as function equation for a specific constant
  3239     [code fun del]:    deselect a theorem as function equation for a specific constant
  3240     [code inline]:     select an equation theorem for unfolding (inlining) in place
  3241     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  3242 
  3243 User-defined serializations (target in {SML, OCaml, Haskell}):
  3244 
  3245     code_const <and-list of constants (term syntax)>
  3246       {(target) <and-list of const target syntax>}+
  3247 
  3248     code_type <and-list of type constructors>
  3249       {(target) <and-list of type target syntax>}+
  3250 
  3251     code_instance <and-list of instances>
  3252       {(target)}+
  3253         where instance ::= <type constructor> :: <class>
  3254 
  3255     code_class <and_list of classes>
  3256       {(target) <and-list of class target syntax>}+
  3257         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  3258 
  3259 code_instance and code_class only are effective to target Haskell.
  3260 
  3261 For example usage see src/HOL/ex/Codegenerator.thy and
  3262 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  3263 generation from Isabelle/HOL theories is available via "isatool doc
  3264 codegen".
  3265 
  3266 * Code generator: consts in 'consts_code' Isar commands are now
  3267 referred to by usual term syntax (including optional type
  3268 annotations).
  3269 
  3270 * Command 'no_translations' removes translation rules from theory
  3271 syntax.
  3272 
  3273 * Overloaded definitions are now actually checked for acyclic
  3274 dependencies.  The overloading scheme is slightly more general than
  3275 that of Haskell98, although Isabelle does not demand an exact
  3276 correspondence to type class and instance declarations.
  3277 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  3278 exotic versions of overloading -- at the discretion of the user!
  3279 
  3280 Polymorphic constants are represented via type arguments, i.e. the
  3281 instantiation that matches an instance against the most general
  3282 declaration given in the signature.  For example, with the declaration
  3283 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  3284 as c(nat).  Overloading is essentially simultaneous structural
  3285 recursion over such type arguments.  Incomplete specification patterns
  3286 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  3287 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  3288 Command 'print_theory' outputs the normalized system of recursive
  3289 equations, see section "definitions".
  3290 
  3291 * Configuration options are maintained within the theory or proof
  3292 context (with name and type bool/int/string), providing a very simple
  3293 interface to a poor-man's version of general context data.  Tools may
  3294 declare options in ML (e.g. using Attrib.config_int) and then refer to
  3295 these values using Config.get etc.  Users may change options via an
  3296 associated attribute of the same name.  This form of context
  3297 declaration works particularly well with commands 'declare' or
  3298 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  3299 very easy to avoid global references, which would not observe Isar
  3300 toplevel undo/redo and fail to work with multithreading.
  3301 
  3302 Various global ML references of Pure and HOL have been turned into
  3303 configuration options:
  3304 
  3305   Unify.search_bound		unify_search_bound
  3306   Unify.trace_bound		unify_trace_bound
  3307   Unify.trace_simp		unify_trace_simp
  3308   Unify.trace_types		unify_trace_types
  3309   Simplifier.simp_depth_limit	simp_depth_limit
  3310   Blast.depth_limit		blast_depth_limit
  3311   DatatypeProp.dtK		datatype_distinctness_limit
  3312   fast_arith_neq_limit  	fast_arith_neq_limit
  3313   fast_arith_split_limit	fast_arith_split_limit
  3314 
  3315 * Named collections of theorems may be easily installed as context
  3316 data using the functor NamedThmsFun (see also
  3317 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  3318 attributes; there is also a toplevel print command.  This facility is
  3319 just a common case of general context data, which is the preferred way
  3320 for anything more complex than just a list of facts in canonical
  3321 order.
  3322 
  3323 * Isar: command 'declaration' augments a local theory by generic
  3324 declaration functions written in ML.  This enables arbitrary content
  3325 being added to the context, depending on a morphism that tells the
  3326 difference of the original declaration context wrt. the application
  3327 context encountered later on.
  3328 
  3329 * Isar: proper interfaces for simplification procedures.  Command
  3330 'simproc_setup' declares named simprocs (with match patterns, and body
  3331 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  3332 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  3333 
  3334 * Isar: an extra pair of brackets around attribute declarations
  3335 abbreviates a theorem reference involving an internal dummy fact,
  3336 which will be ignored later --- only the effect of the attribute on
  3337 the background context will persist.  This form of in-place
  3338 declarations is particularly useful with commands like 'declare' and
  3339 'using', for example ``have A using [[simproc a]] by simp''.
  3340 
  3341 * Isar: method "assumption" (and implicit closing of subproofs) now
  3342 takes simple non-atomic goal assumptions into account: after applying
  3343 an assumption as a rule the resulting subgoals are solved by atomic
  3344 assumption steps.  This is particularly useful to finish 'obtain'
  3345 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  3346 without referring to the original premise "!!x. P x ==> thesis" in the
  3347 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  3348 more permissive.
  3349 
  3350 * Isar: implicit use of prems from the Isar proof context is
  3351 considered a legacy feature.  Common applications like ``have A .''
  3352 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  3353 referencing facts explicitly here improves readability and
  3354 maintainability of proof texts.
  3355 
  3356 * Isar: improper proof element 'guess' is like 'obtain', but derives
  3357 the obtained context from the course of reasoning!  For example:
  3358 
  3359   assume "EX x y. A x & B y"   -- "any previous fact"
  3360   then guess x and y by clarify
  3361 
  3362 This technique is potentially adventurous, depending on the facts and
  3363 proof tools being involved here.
  3364 
  3365 * Isar: known facts from the proof context may be specified as literal
  3366 propositions, using ASCII back-quote syntax.  This works wherever
  3367 named facts used to be allowed so far, in proof commands, proof
  3368 methods, attributes etc.  Literal facts are retrieved from the context
  3369 according to unification of type and term parameters.  For example,
  3370 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  3371 theorems in the current context, then these are valid literal facts:
  3372 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  3373 
  3374 There is also a proof method "fact" which does the same composition
  3375 for explicit goal states, e.g. the following proof texts coincide with
  3376 certain special cases of literal facts:
  3377 
  3378   have "A" by fact                 ==  note `A`
  3379   have "A ==> B" by fact           ==  note `A ==> B`
  3380   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  3381   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  3382 
  3383 * Isar: ":" (colon) is no longer a symbolic identifier character in
  3384 outer syntax.  Thus symbolic identifiers may be used without
  3385 additional white space in declarations like this: ``assume *: A''.
  3386 
  3387 * Isar: 'print_facts' prints all local facts of the current context,
  3388 both named and unnamed ones.
  3389 
  3390 * Isar: 'def' now admits simultaneous definitions, e.g.:
  3391 
  3392   def x == "t" and y == "u"
  3393 
  3394 * Isar: added command 'unfolding', which is structurally similar to
  3395 'using', but affects both the goal state and facts by unfolding given
  3396 rewrite rules.  Thus many occurrences of the 'unfold' method or
  3397 'unfolded' attribute may be replaced by first-class proof text.
  3398 
  3399 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  3400 and command 'unfolding' now all support object-level equalities
  3401 (potentially conditional).  The underlying notion of rewrite rule is
  3402 analogous to the 'rule_format' attribute, but *not* that of the
  3403 Simplifier (which is usually more generous).
  3404 
  3405 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  3406 premises of a theorem by n. Useful in conjunction with drule.
  3407 
  3408 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  3409 method expression within a sandbox consisting of the first N
  3410 sub-goals, which need to exist.  For example, ``simp_all [3]''
  3411 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  3412 simplifies all new goals that emerge from applying rule foo to the
  3413 originally first one.
  3414 
  3415 * Isar: schematic goals are no longer restricted to higher-order
  3416 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  3417 expected.
  3418 
  3419 * Isar: the conclusion of a long theorem statement is now either
  3420 'shows' (a simultaneous conjunction, as before), or 'obtains'
  3421 (essentially a disjunction of cases with local parameters and
  3422 assumptions).  The latter allows to express general elimination rules
  3423 adequately; in this notation common elimination rules look like this:
  3424 
  3425   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  3426     assumes "EX x. P x"
  3427     obtains x where "P x"
  3428 
  3429   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  3430     assumes "A & B"
  3431     obtains A and B
  3432 
  3433   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  3434     assumes "A | B"
  3435     obtains
  3436       A
  3437     | B
  3438 
  3439 The subsequent classical rules even refer to the formal "thesis"
  3440 explicitly:
  3441 
  3442   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  3443     obtains "~ thesis"
  3444 
  3445   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  3446     obtains "thesis ==> something"
  3447 
  3448 The actual proof of an 'obtains' statement is analogous to that of the
  3449 Isar proof element 'obtain', only that there may be several cases.
  3450 Optional case names may be specified in parentheses; these will be
  3451 available both in the present proof and as annotations in the
  3452 resulting rule, for later use with the 'cases' method (cf. attribute
  3453 case_names).
  3454 
  3455 * Isar: the assumptions of a long theorem statement are available as
  3456 "assms" fact in the proof context.  This is more appropriate than the
  3457 (historical) "prems", which refers to all assumptions of the current
  3458 context, including those from the target locale, proof body etc.
  3459 
  3460 * Isar: 'print_statement' prints theorems from the current theory or
  3461 proof context in long statement form, according to the syntax of a
  3462 top-level lemma.
  3463 
  3464 * Isar: 'obtain' takes an optional case name for the local context
  3465 introduction rule (default "that").
  3466 
  3467 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  3468 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  3469 to occur.
  3470 
  3471 * Pure: syntax "CONST name" produces a fully internalized constant
  3472 according to the current context.  This is particularly useful for
  3473 syntax translations that should refer to internal constant
  3474 representations independently of name spaces.
  3475 
  3476 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  3477 instead of "FOO ". This allows multiple binder declarations to coexist
  3478 in the same context.  INCOMPATIBILITY.
  3479 
  3480 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  3481 primitive that also works in a locale context (both for constants and
  3482 fixed variables). Type declaration and internal syntactic representation
  3483 of given constants retrieved from the context. Likewise, the
  3484 'no_notation' command allows to remove given syntax annotations from the
  3485 current context.
  3486 
  3487 * Isar/locales: new derived specification elements 'axiomatization',
  3488 'definition', 'abbreviation', which support type-inference, admit
  3489 object-level specifications (equality, equivalence).  See also the
  3490 isar-ref manual.  Examples:
  3491 
  3492   axiomatization
  3493     eq  (infix "===" 50) where
  3494     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  3495 
  3496   definition "f x y = x + y + 1"
  3497   definition g where "g x = f x x"
  3498 
  3499   abbreviation
  3500     neq  (infix "=!=" 50) where
  3501     "x =!= y == ~ (x === y)"
  3502 
  3503 These specifications may be also used in a locale context.  Then the
  3504 constants being introduced depend on certain fixed parameters, and the
  3505 constant name is qualified by the locale base name.  An internal
  3506 abbreviation takes care for convenient input and output, making the
  3507 parameters implicit and using the original short name.  See also
  3508 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  3509 entities from a monomorphic theory.
  3510 
  3511 Presently, abbreviations are only available 'in' a target locale, but
  3512 not inherited by general import expressions.  Also note that
  3513 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  3514 'translations' in common applications.  The "no_abbrevs" print mode
  3515 prevents folding of abbreviations in term output.
  3516 
  3517 Concrete syntax is attached to specified constants in internal form,
  3518 independently of name spaces.  The parse tree representation is
  3519 slightly different -- use 'notation' instead of raw 'syntax', and
  3520 'translations' with explicit "CONST" markup to accommodate this.
  3521 
  3522 * Pure/Isar: unified syntax for new-style specification mechanisms
  3523 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  3524 full type inference and dummy patterns ("_").  For example:
  3525 
  3526   definition "K x _ = x"
  3527 
  3528   inductive conj for A B
  3529   where "A ==> B ==> conj A B"
  3530 
  3531 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  3532 the current context.  Print mode "no_abbrevs" prevents inversion of
  3533 abbreviations on output.
  3534 
  3535 * Isar/locales: improved parameter handling: use of locales "var" and
  3536 "struct" no longer necessary; - parameter renamings are no longer
  3537 required to be injective.  For example, this allows to define
  3538 endomorphisms as locale endom = homom mult mult h.
  3539 
  3540 * Isar/locales: changed the way locales with predicates are defined.
  3541 Instead of accumulating the specification, the imported expression is
  3542 now an interpretation.  INCOMPATIBILITY: different normal form of
  3543 locale expressions.  In particular, in interpretations of locales with
  3544 predicates, goals repesenting already interpreted fragments are not
  3545 removed automatically.  Use methods `intro_locales' and
  3546 `unfold_locales'; see below.
  3547 
  3548 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  3549 provide backward reasoning on locales predicates.  The methods are
  3550 aware of interpretations and discharge corresponding goals.
  3551 `intro_locales' is less aggressive then `unfold_locales' and does not
  3552 unfold predicates to assumptions.
  3553 
  3554 * Isar/locales: the order in which locale fragments are accumulated
  3555 has changed.  This enables to override declarations from fragments due
  3556 to interpretations -- for example, unwanted simp rules.
  3557 
  3558 * Isar/locales: interpretation in theories and proof contexts has been
  3559 extended.  One may now specify (and prove) equations, which are
  3560 unfolded in interpreted theorems.  This is useful for replacing
  3561 defined concepts (constants depending on locale parameters) by
  3562 concepts already existing in the target context.  Example:
  3563 
  3564   interpretation partial_order ["op <= :: [int, int] => bool"]
  3565     where "partial_order.less (op <=) (x::int) y = (x < y)"
  3566 
  3567 Typically, the constant `partial_order.less' is created by a
  3568 definition specification element in the context of locale
  3569 partial_order.
  3570 
  3571 * Method "induct": improved internal context management to support
  3572 local fixes and defines on-the-fly. Thus explicit meta-level
  3573 connectives !!  and ==> are rarely required anymore in inductive goals
  3574 (using object-logic connectives for this purpose has been long
  3575 obsolete anyway). Common proof patterns are explained in
  3576 src/HOL/Induct/Common_Patterns.thy, see also
  3577 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  3578 examples.
  3579 
  3580 * Method "induct": improved handling of simultaneous goals. Instead of
  3581 introducing object-level conjunction, the statement is now split into
  3582 several conclusions, while the corresponding symbolic cases are nested
  3583 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  3584 see src/HOL/Induct/Common_Patterns.thy, for example.
  3585 
  3586 * Method "induct": mutual induction rules are now specified as a list
  3587 of rule sharing the same induction cases. HOL packages usually provide
  3588 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  3589 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  3590 mutual induction rules differently, i.e. like this:
  3591 
  3592   (induct rule: foo_bar.inducts)
  3593   (induct set: foo bar)
  3594   (induct pred: foo bar)
  3595   (induct type: foo bar)
  3596 
  3597 The ML function ProjectRule.projections turns old-style rules into the
  3598 new format.
  3599 
  3600 * Method "coinduct": dual of induction, see
  3601 src/HOL/Library/Coinductive_List.thy for various examples.
  3602 
  3603 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  3604 considered a legacy feature.
  3605 
  3606 * Attribute "symmetric" produces result with standardized schematic
  3607 variables (index 0).  Potential INCOMPATIBILITY.
  3608 
  3609 * Simplifier: by default the simplifier trace only shows top level
  3610 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  3611 default. Thus there is less danger of being flooded by the trace. The
  3612 trace indicates where parts have been suppressed.
  3613   
  3614 * Provers/classical: removed obsolete classical version of elim_format
  3615 attribute; classical elim/dest rules are now treated uniformly when
  3616 manipulating the claset.
  3617 
  3618 * Provers/classical: stricter checks to ensure that supplied intro,
  3619 dest and elim rules are well-formed; dest and elim rules must have at
  3620 least one premise.
  3621 
  3622 * Provers/classical: attributes dest/elim/intro take an optional
  3623 weight argument for the rule (just as the Pure versions).  Weights are
  3624 ignored by automated tools, but determine the search order of single
  3625 rule steps.
  3626 
  3627 * Syntax: input syntax now supports dummy variable binding "%_. b",
  3628 where the body does not mention the bound variable.  Note that dummy
  3629 patterns implicitly depend on their context of bounds, which makes
  3630 "{_. _}" match any set comprehension as expected.  Potential
  3631 INCOMPATIBILITY -- parse translations need to cope with syntactic
  3632 constant "_idtdummy" in the binding position.
  3633 
  3634 * Syntax: removed obsolete syntactic constant "_K" and its associated
  3635 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  3636 for example "A -> B" => "Pi A (%_. B)".
  3637 
  3638 * Pure: 'class_deps' command visualizes the subclass relation, using
  3639 the graph browser tool.
  3640 
  3641 * Pure: 'print_theory' now suppresses certain internal declarations by
  3642 default; use '!' option for full details.
  3643 
  3644 
  3645 *** HOL ***
  3646 
  3647 * Method "metis" proves goals by applying the Metis general-purpose
  3648 resolution prover (see also http://gilith.com/software/metis/).
  3649 Examples are in the directory MetisExamples.  WARNING: the
  3650 Isabelle/HOL-Metis integration does not yet work properly with
  3651 multi-threading.
  3652   
  3653 * Command 'sledgehammer' invokes external automatic theorem provers as
  3654 background processes.  It generates calls to the "metis" method if
  3655 successful. These can be pasted into the proof.  Users do not have to
  3656 wait for the automatic provers to return.  WARNING: does not really
  3657 work with multi-threading.
  3658 
  3659 * New "auto_quickcheck" feature tests outermost goal statements for
  3660 potential counter-examples.  Controlled by ML references
  3661 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  3662 5000 milliseconds).  Fails silently if statements is outside of
  3663 executable fragment, or any other codgenerator problem occurs.
  3664 
  3665 * New constant "undefined" with axiom "undefined x = undefined".
  3666 
  3667 * Added class "HOL.eq", allowing for code generation with polymorphic
  3668 equality.
  3669 
  3670 * Some renaming of class constants due to canonical name prefixing in
  3671 the new 'class' package:
  3672 
  3673     HOL.abs ~> HOL.abs_class.abs
  3674     HOL.divide ~> HOL.divide_class.divide
  3675     0 ~> HOL.zero_class.zero
  3676     1 ~> HOL.one_class.one
  3677     op + ~> HOL.plus_class.plus
  3678     op - ~> HOL.minus_class.minus
  3679     uminus ~> HOL.minus_class.uminus
  3680     op * ~> HOL.times_class.times
  3681     op < ~> HOL.ord_class.less
  3682     op <= > HOL.ord_class.less_eq
  3683     Nat.power ~> Power.power_class.power
  3684     Nat.size ~> Nat.size_class.size
  3685     Numeral.number_of ~> Numeral.number_class.number_of
  3686     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  3687     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  3688     Orderings.min ~> Orderings.ord_class.min
  3689     Orderings.max ~> Orderings.ord_class.max
  3690     Divides.op div ~> Divides.div_class.div
  3691     Divides.op mod ~> Divides.div_class.mod
  3692     Divides.op dvd ~> Divides.div_class.dvd
  3693 
  3694 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  3695 
  3696 a) User-defined constants using any of the names "plus", "minus",
  3697 "times", "less" or "less_eq". The standard syntax translations for
  3698 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  3699 names.
  3700 
  3701 b) Variables named "plus", "minus", "times", "less", "less_eq"
  3702 INCOMPATIBILITY: use more specific names.
  3703 
  3704 c) Permutative equations (e.g. "a + b = b + a")
  3705 Since the change of names also changes the order of terms, permutative
  3706 rewrite rules may get applied in a different order. Experience shows
  3707 that this is rarely the case (only two adaptions in the whole Isabelle
  3708 distribution).  INCOMPATIBILITY: rewrite proofs
  3709 
  3710 d) ML code directly refering to constant names
  3711 This in general only affects hand-written proof tactics, simprocs and
  3712 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  3713 Consider using @{const_name} antiquotation.
  3714 
  3715 * New class "default" with associated constant "default".
  3716 
  3717 * Function "sgn" is now overloaded and available on int, real, complex
  3718 (and other numeric types), using class "sgn".  Two possible defs of
  3719 sgn are given as equational assumptions in the classes sgn_if and
  3720 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  3721 INCOMPATIBILITY.
  3722 
  3723 * Locale "partial_order" now unified with class "order" (cf. theory
  3724 Orderings), added parameter "less".  INCOMPATIBILITY.
  3725 
  3726 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  3727 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  3728 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  3729 
  3730 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  3731 changed order of proof goals in instance proofs.
  3732 
  3733 * The transitivity reasoner for partial and linear orders is set up
  3734 for classes "order" and "linorder".  Instances of the reasoner are available
  3735 in all contexts importing or interpreting the corresponding locales.
  3736 Method "order" invokes the reasoner separately; the reasoner
  3737 is also integrated with the Simplifier as a solver.  Diagnostic
  3738 command 'print_orders' shows the available instances of the reasoner
  3739 in the current context.
  3740 
  3741 * Localized monotonicity predicate in theory "Orderings"; integrated
  3742 lemmas max_of_mono and min_of_mono with this predicate.
  3743 INCOMPATIBILITY.
  3744 
  3745 * Formulation of theorem "dense" changed slightly due to integration
  3746 with new class dense_linear_order.
  3747 
  3748 * Uniform lattice theory development in HOL.
  3749 
  3750     constants "meet" and "join" now named "inf" and "sup"
  3751     constant "Meet" now named "Inf"
  3752 
  3753     classes "meet_semilorder" and "join_semilorder" now named
  3754       "lower_semilattice" and "upper_semilattice"
  3755     class "lorder" now named "lattice"
  3756     class "comp_lat" now named "complete_lattice"
  3757 
  3758     Instantiation of lattice classes allows explicit definitions
  3759     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  3760 
  3761   INCOMPATIBILITY.  Theorem renames:
  3762 
  3763     meet_left_le            ~> inf_le1
  3764     meet_right_le           ~> inf_le2
  3765     join_left_le            ~> sup_ge1
  3766     join_right_le           ~> sup_ge2
  3767     meet_join_le            ~> inf_sup_ord
  3768     le_meetI                ~> le_infI
  3769     join_leI                ~> le_supI
  3770     le_meet                 ~> le_inf_iff
  3771     le_join                 ~> ge_sup_conv
  3772     meet_idempotent         ~> inf_idem
  3773     join_idempotent         ~> sup_idem
  3774     meet_comm               ~> inf_commute
  3775     join_comm               ~> sup_commute
  3776     meet_leI1               ~> le_infI1
  3777     meet_leI2               ~> le_infI2
  3778     le_joinI1               ~> le_supI1
  3779     le_joinI2               ~> le_supI2
  3780     meet_assoc              ~> inf_assoc
  3781     join_assoc              ~> sup_assoc
  3782     meet_left_comm          ~> inf_left_commute
  3783     meet_left_idempotent    ~> inf_left_idem
  3784     join_left_comm          ~> sup_left_commute
  3785     join_left_idempotent    ~> sup_left_idem
  3786     meet_aci                ~> inf_aci
  3787     join_aci                ~> sup_aci
  3788     le_def_meet             ~> le_iff_inf
  3789     le_def_join             ~> le_iff_sup
  3790     join_absorp2            ~> sup_absorb2
  3791     join_absorp1            ~> sup_absorb1
  3792     meet_absorp1            ~> inf_absorb1
  3793     meet_absorp2            ~> inf_absorb2
  3794     meet_join_absorp        ~> inf_sup_absorb
  3795     join_meet_absorp        ~> sup_inf_absorb
  3796     distrib_join_le         ~> distrib_sup_le
  3797     distrib_meet_le         ~> distrib_inf_le
  3798 
  3799     add_meet_distrib_left   ~> add_inf_distrib_left
  3800     add_join_distrib_left   ~> add_sup_distrib_left
  3801     is_join_neg_meet        ~> is_join_neg_inf
  3802     is_meet_neg_join        ~> is_meet_neg_sup
  3803     add_meet_distrib_right  ~> add_inf_distrib_right
  3804     add_join_distrib_right  ~> add_sup_distrib_right
  3805     add_meet_join_distribs  ~> add_sup_inf_distribs
  3806     join_eq_neg_meet        ~> sup_eq_neg_inf
  3807     meet_eq_neg_join        ~> inf_eq_neg_sup
  3808     add_eq_meet_join        ~> add_eq_inf_sup
  3809     meet_0_imp_0            ~> inf_0_imp_0
  3810     join_0_imp_0            ~> sup_0_imp_0
  3811     meet_0_eq_0             ~> inf_0_eq_0
  3812     join_0_eq_0             ~> sup_0_eq_0
  3813     neg_meet_eq_join        ~> neg_inf_eq_sup
  3814     neg_join_eq_meet        ~> neg_sup_eq_inf
  3815     join_eq_if              ~> sup_eq_if
  3816 
  3817     mono_meet               ~> mono_inf
  3818     mono_join               ~> mono_sup
  3819     meet_bool_eq            ~> inf_bool_eq
  3820     join_bool_eq            ~> sup_bool_eq
  3821     meet_fun_eq             ~> inf_fun_eq
  3822     join_fun_eq             ~> sup_fun_eq
  3823     meet_set_eq             ~> inf_set_eq
  3824     join_set_eq             ~> sup_set_eq
  3825     meet1_iff               ~> inf1_iff
  3826     meet2_iff               ~> inf2_iff
  3827     meet1I                  ~> inf1I
  3828     meet2I                  ~> inf2I
  3829     meet1D1                 ~> inf1D1
  3830     meet2D1                 ~> inf2D1
  3831     meet1D2                 ~> inf1D2
  3832     meet2D2                 ~> inf2D2
  3833     meet1E                  ~> inf1E
  3834     meet2E                  ~> inf2E
  3835     join1_iff               ~> sup1_iff
  3836     join2_iff               ~> sup2_iff
  3837     join1I1                 ~> sup1I1
  3838     join2I1                 ~> sup2I1
  3839     join1I1                 ~> sup1I1
  3840     join2I2                 ~> sup1I2
  3841     join1CI                 ~> sup1CI
  3842     join2CI                 ~> sup2CI
  3843     join1E                  ~> sup1E
  3844     join2E                  ~> sup2E
  3845 
  3846     is_meet_Meet            ~> is_meet_Inf
  3847     Meet_bool_def           ~> Inf_bool_def
  3848     Meet_fun_def            ~> Inf_fun_def
  3849     Meet_greatest           ~> Inf_greatest
  3850     Meet_lower              ~> Inf_lower
  3851     Meet_set_def            ~> Inf_set_def
  3852 
  3853     Sup_def                 ~> Sup_Inf
  3854     Sup_bool_eq             ~> Sup_bool_def
  3855     Sup_fun_eq              ~> Sup_fun_def
  3856     Sup_set_eq              ~> Sup_set_def
  3857 
  3858     listsp_meetI            ~> listsp_infI
  3859     listsp_meet_eq          ~> listsp_inf_eq
  3860 
  3861     meet_min                ~> inf_min
  3862     join_max                ~> sup_max
  3863 
  3864 * Added syntactic class "size"; overloaded constant "size" now has
  3865 type "'a::size ==> bool"
  3866 
  3867 * Internal reorganisation of `size' of datatypes: size theorems
  3868 "foo.size" are no longer subsumed by "foo.simps" (but are still
  3869 simplification rules by default!); theorems "prod.size" now named
  3870 "*.size".
  3871 
  3872 * Class "div" now inherits from class "times" rather than "type".
  3873 INCOMPATIBILITY.
  3874 
  3875 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  3876 Linorder etc.  have disappeared; operations defined in terms of
  3877 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  3878 
  3879 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  3880 
  3881 * HOL-Word: New extensive library and type for generic, fixed size
  3882 machine words, with arithemtic, bit-wise, shifting and rotating
  3883 operations, reflection into int, nat, and bool lists, automation for
  3884 linear arithmetic (by automatic reflection into nat or int), including
  3885 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  3886 arithmetic type classes, supporting automatic simplification of
  3887 numerals on all operations.
  3888 
  3889 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  3890 
  3891 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  3892 
  3893 * Code generator library theories:
  3894   - Code_Integer represents HOL integers by big integer literals in target
  3895     languages.
  3896   - Code_Char represents HOL characters by character literals in target
  3897     languages.
  3898   - Code_Char_chr like Code_Char, but also offers treatment of character
  3899     codes; includes Code_Integer.
  3900   - Executable_Set allows to generate code for finite sets using lists.
  3901   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  3902     denominator).
  3903   - Executable_Real implements a subset of real numbers, namly those
  3904     representable by rational numbers.
  3905   - Efficient_Nat implements natural numbers by integers, which in general will
  3906     result in higher efficency; pattern matching with 0/Suc is eliminated;
  3907     includes Code_Integer.
  3908   - Code_Index provides an additional datatype index which is mapped to
  3909     target-language built-in integers.
  3910   - Code_Message provides an additional datatype message_string which is isomorphic to
  3911     strings; messages are mapped to target-language strings.
  3912 
  3913 * New package for inductive predicates
  3914 
  3915   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  3916 
  3917     inductive
  3918       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3919       for z_1 :: U_1 and ... and z_n :: U_m
  3920     where
  3921       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3922     | ...
  3923 
  3924   with full support for type-inference, rather than
  3925 
  3926     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3927 
  3928     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3929     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3930 
  3931     inductive "s z_1 ... z_m"
  3932     intros
  3933       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3934       ...
  3935 
  3936   For backward compatibility, there is a wrapper allowing inductive
  3937   sets to be defined with the new package via
  3938 
  3939     inductive_set
  3940       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3941       for z_1 :: U_1 and ... and z_n :: U_m
  3942     where
  3943       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3944     | ...
  3945 
  3946   or
  3947 
  3948     inductive_set
  3949       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3950       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3951       for z_1 :: U_1 and ... and z_n :: U_m
  3952     where
  3953       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3954     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3955     | ...
  3956 
  3957   if the additional syntax "p ..." is required.
  3958 
  3959   Numerous examples can be found in the subdirectories src/HOL/Auth,
  3960   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  3961 
  3962   INCOMPATIBILITIES:
  3963 
  3964   - Since declaration and definition of inductive sets or predicates
  3965     is no longer separated, abbreviations involving the newly
  3966     introduced sets or predicates must be specified together with the
  3967     introduction rules after the 'where' keyword (see above), rather
  3968     than before the actual inductive definition.
  3969 
  3970   - The variables in induction and elimination rules are now
  3971     quantified in the order of their occurrence in the introduction
  3972     rules, rather than in alphabetical order. Since this may break
  3973     some proofs, these proofs either have to be repaired, e.g. by
  3974     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  3975     statements of the form
  3976 
  3977       case (rule_i a_i_1 ... a_i_{k_i})
  3978 
  3979     or the old order of quantification has to be restored by explicitly adding
  3980     meta-level quantifiers in the introduction rules, i.e.
  3981 
  3982       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  3983 
  3984   - The format of the elimination rules is now
  3985 
  3986       p z_1 ... z_m x_1 ... x_n ==>
  3987         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  3988         ==> ... ==> P
  3989 
  3990     for predicates and
  3991 
  3992       (x_1, ..., x_n) : s z_1 ... z_m ==>
  3993         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  3994         ==> ... ==> P
  3995 
  3996     for sets rather than
  3997 
  3998       x : s z_1 ... z_m ==>
  3999         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  4000         ==> ... ==> P
  4001 
  4002     This may require terms in goals to be expanded to n-tuples
  4003     (e.g. using case_tac or simplification with the split_paired_all
  4004     rule) before the above elimination rule is applicable.
  4005 
  4006   - The elimination or case analysis rules for (mutually) inductive
  4007     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  4008     list of rules "p_1_..._p_k.elims" is no longer available.
  4009 
  4010 * New package "function"/"fun" for general recursive functions,
  4011 supporting mutual and nested recursion, definitions in local contexts,
  4012 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  4013 for small examples, and the separate tutorial on the function
  4014 package. The old recdef "package" is still available as before, but
  4015 users are encouraged to use the new package.
  4016 
  4017 * Method "lexicographic_order" automatically synthesizes termination
  4018 relations as lexicographic combinations of size measures. 
  4019 
  4020 * Case-expressions allow arbitrary constructor-patterns (including
  4021 "_") and take their order into account, like in functional
  4022 programming.  Internally, this is translated into nested
  4023 case-expressions; missing cases are added and mapped to the predefined
  4024 constant "undefined". In complicated cases printing may no longer show
  4025 the original input but the internal form. Lambda-abstractions allow
  4026 the same form of pattern matching: "% pat1 => e1 | ..." is an
  4027 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  4028 variable.
  4029 
  4030 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  4031 is an abbreviation for "of_nat :: nat => int". The simplification
  4032 rules for "of_nat" have been changed to work like "int" did
  4033 previously.  Potential INCOMPATIBILITY:
  4034   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  4035   - of_nat_diff and of_nat_mult are no longer default simp rules
  4036 
  4037 * Method "algebra" solves polynomial equations over (semi)rings using
  4038 Groebner bases. The (semi)ring structure is defined by locales and the
  4039 tool setup depends on that generic context. Installing the method for
  4040 a specific type involves instantiating the locale and possibly adding
  4041 declarations for computation on the coefficients.  The method is
  4042 already instantiated for natural numbers and for the axiomatic class
  4043 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  4044 CALCULEMUS 2007 for the general principles underlying this
  4045 architecture of context-aware proof-tools.
  4046 
  4047 * Method "ferrack" implements quantifier elimination over
  4048 special-purpose dense linear orders using locales (analogous to
  4049 "algebra"). The method is already installed for class
  4050 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  4051 rat, etc.
  4052 
  4053 * Former constant "List.op @" now named "List.append".  Use ML
  4054 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  4055 circumvent possible incompatibilities when working on ML level.
  4056 
  4057 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  4058 
  4059 * New function listsum :: 'a list => 'a for arbitrary monoids.
  4060 Special syntax: "SUM x <- xs. f x" (and latex variants)
  4061 
  4062 * New syntax for Haskell-like list comprehension (input only), eg.
  4063 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  4064 
  4065 * The special syntax for function "filter" has changed from [x :
  4066 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  4067 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  4068 
  4069 * [a..b] is now defined for arbitrary linear orders.  It used to be
  4070 defined on nat only, as an abbreviation for [a..<Suc b]
  4071 INCOMPATIBILITY.
  4072 
  4073 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  4074 
  4075 * New functions "sorted" and "sort" in src/HOL/List.thy.
  4076 
  4077 * New lemma collection field_simps (an extension of ring_simps) for
  4078 manipulating (in)equations involving division. Multiplies with all
  4079 denominators that can be proved to be non-zero (in equations) or
  4080 positive/negative (in inequations).
  4081 
  4082 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  4083 have been improved and renamed to ring_simps, group_simps and
  4084 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  4085 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  4086 
  4087 * Theory Library/Commutative_Ring: switched from recdef to function
  4088 package; constants add, mul, pow now curried.  Infix syntax for
  4089 algebraic operations.
  4090 
  4091 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  4092 INCOMPATIBILITY.
  4093 
  4094 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  4095 INCOMPATIBILITY.
  4096 
  4097 * HOL/records: generalised field-update to take a function on the
  4098 field rather than the new value: r(|A := x|) is translated to A_update
  4099 (K x) r The K-combinator that is internally used is called K_record.
  4100 INCOMPATIBILITY: Usage of the plain update functions has to be
  4101 adapted.
  4102  
  4103 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  4104 * x = 0, which are required for a semiring.  Richer structures do not
  4105 inherit from semiring_0 anymore, because this property is a theorem
  4106 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  4107 there is more to prove, but this is mostly trivial.
  4108 
  4109 * Class "recpower" is generalized to arbitrary monoids, not just
  4110 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  4111 commutativity or semiring properties additionally.
  4112 
  4113 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  4114 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  4115 better use 'abbreviation'.
  4116 
  4117 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  4118 
  4119 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  4120 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  4121 significant changes for setting up numeral syntax for types:
  4122   - New constants Numeral.pred and Numeral.succ instead
  4123       of former Numeral.bin_pred and Numeral.bin_succ.
  4124   - Use integer operations instead of bin_add, bin_mult and so on.
  4125   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  4126   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  4127 
  4128 See src/HOL/Integ/IntArith.thy for an example setup.
  4129 
  4130 * Command 'normal_form' computes the normal form of a term that may
  4131 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  4132 produces ``[b, c, a]'' (without proof).  This command is suitable for
  4133 heavy-duty computations because the functions are compiled to ML
  4134 first.  Correspondingly, a method "normalization" is provided.  See
  4135 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  4136 
  4137 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  4138 25 like -->); output depends on the "iff" print_mode, the default is
  4139 "A = B" (with priority 50).
  4140 
  4141 * Relations less (<) and less_eq (<=) are also available on type bool.
  4142 Modified syntax to disallow nesting without explicit parentheses,
  4143 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  4144 INCOMPATIBILITY.
  4145 
  4146 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  4147 
  4148 * Relation composition operator "op O" now has precedence 75 and binds
  4149 stronger than union and intersection. INCOMPATIBILITY.
  4150 
  4151 * The old set interval syntax "{m..n(}" (and relatives) has been
  4152 removed.  Use "{m..<n}" (and relatives) instead.
  4153 
  4154 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  4155 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  4156 ``declare [[simproc del: neq]]''.
  4157 
  4158 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  4159 True/False.
  4160 
  4161 * Theorem Cons_eq_map_conv no longer declared as "simp".
  4162 
  4163 * Theorem setsum_mult renamed to setsum_right_distrib.
  4164 
  4165 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  4166 ``rule'' method.
  4167 
  4168 * Reimplemented methods "sat" and "satx", with several improvements:
  4169 goals no longer need to be stated as "<prems> ==> False", equivalences
  4170 (i.e. "=" on type bool) are handled, variable names of the form
  4171 "lit_<n>" are no longer reserved, significant speedup.
  4172 
  4173 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  4174 zChaff is still supported as well.
  4175 
  4176 * 'inductive' and 'datatype': provide projections of mutual rules,
  4177 bundled as foo_bar.inducts;
  4178 
  4179 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  4180 Library.
  4181 
  4182 * Library: moved theory Accessible_Part to main HOL.
  4183 
  4184 * Library: added theory Coinductive_List of potentially infinite lists
  4185 as greatest fixed-point.
  4186 
  4187 * Library: added theory AssocList which implements (finite) maps as
  4188 association lists.
  4189 
  4190 * Method "evaluation" solves goals (i.e. a boolean expression)
  4191 efficiently by compiling it to ML.  The goal is "proved" (via an
  4192 oracle) if it evaluates to True.
  4193 
  4194 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  4195 also when invoked by the simplifier.  This results in the Simplifier
  4196 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  4197 Configuration option fast_arith_split_limit=0 recovers the old
  4198 behavior.
  4199 
  4200 * Support for hex (0x20) and binary (0b1001) numerals.
  4201 
  4202 * New method: reify eqs (t), where eqs are equations for an
  4203 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  4204 parameter, computes a term s::'b and a list xs::'a list and proves the
  4205 theorem I xs s = t. This is also known as reification or quoting. The
  4206 resulting theorem is applied to the subgoal to substitute t with I xs
  4207 s.  If t is omitted, the subgoal itself is reified.
  4208 
  4209 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  4210 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  4211 where f is supposed to be a computable function (in the sense of code
  4212 generattion). The method uses reify to compute s and xs as above then
  4213 applies corr_thm and uses normalization by evaluation to "prove" f s =
  4214 r and finally gets the theorem t = r, which is again applied to the
  4215 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  4216 
  4217 * Reflection: Automatic reification now handels binding, an example is
  4218 available in src/HOL/ex/ReflectionEx.thy
  4219 
  4220 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  4221 command 'statespace' that is similar to 'record', but introduces an
  4222 abstract specification based on the locale infrastructure instead of
  4223 HOL types.  This leads to extra flexibility in composing state spaces,
  4224 in particular multiple inheritance and renaming of components.
  4225 
  4226 
  4227 *** HOL-Complex ***
  4228 
  4229 * Hyperreal: Functions root and sqrt are now defined on negative real
  4230 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  4231 Nonnegativity side conditions have been removed from many lemmas, so
  4232 that more subgoals may now be solved by simplification; potential
  4233 INCOMPATIBILITY.
  4234 
  4235 * Real: new type classes formalize real normed vector spaces and
  4236 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  4237 and norm :: 'a => real.
  4238 
  4239 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  4240 reals into other types. The overloaded constant Reals :: 'a set is now
  4241 defined as range of_real; potential INCOMPATIBILITY.
  4242 
  4243 * Real: proper support for ML code generation, including 'quickcheck'.
  4244 Reals are implemented as arbitrary precision rationals.
  4245 
  4246 * Hyperreal: Several constants that previously worked only for the
  4247 reals have been generalized, so they now work over arbitrary vector
  4248 spaces. Type annotations may need to be added in some cases; potential
  4249 INCOMPATIBILITY.
  4250 
  4251   Infinitesimal  :: ('a::real_normed_vector) star set
  4252   HFinite        :: ('a::real_normed_vector) star set
  4253   HInfinite      :: ('a::real_normed_vector) star set
  4254   approx         :: ('a::real_normed_vector) star => 'a star => bool
  4255   monad          :: ('a::real_normed_vector) star => 'a star set
  4256   galaxy         :: ('a::real_normed_vector) star => 'a star set
  4257   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  4258   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  4259   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  4260   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  4261   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  4262   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  4263   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  4264   sgn            :: 'a::real_normed_vector => 'a
  4265   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  4266 
  4267 * Complex: Some complex-specific constants are now abbreviations for
  4268 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  4269 hnorm.  Other constants have been entirely removed in favor of the
  4270 polymorphic versions (INCOMPATIBILITY):
  4271 
  4272   approx        <-- capprox
  4273   HFinite       <-- CFinite
  4274   HInfinite     <-- CInfinite
  4275   Infinitesimal <-- CInfinitesimal
  4276   monad         <-- cmonad
  4277   galaxy        <-- cgalaxy
  4278   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  4279   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  4280   (ns)deriv     <-- (ns)cderiv
  4281 
  4282 
  4283 *** HOL-Algebra ***
  4284 
  4285 * Formalisation of ideals and the quotient construction over rings.
  4286 
  4287 * Order and lattice theory no longer based on records.
  4288 INCOMPATIBILITY.
  4289 
  4290 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  4291 greatest_closed.  INCOMPATIBILITY.
  4292 
  4293 * Method algebra is now set up via an attribute.  For examples see
  4294 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  4295 of algebraic structures.
  4296 
  4297 * Renamed theory CRing to Ring.
  4298 
  4299 
  4300 *** HOL-Nominal ***
  4301 
  4302 * Substantial, yet incomplete support for nominal datatypes (binding
  4303 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  4304 src/HOL/Nominal/Examples.  Prospective users should consult
  4305 http://isabelle.in.tum.de/nominal/
  4306 
  4307 
  4308 *** ML ***
  4309 
  4310 * ML basics: just one true type int, which coincides with IntInf.int
  4311 (even on SML/NJ).
  4312 
  4313 * ML within Isar: antiquotations allow to embed statically-checked
  4314 formal entities in the source, referring to the context available at
  4315 compile-time.  For example:
  4316 
  4317 ML {* @{sort "{zero,one}"} *}
  4318 ML {* @{typ "'a => 'b"} *}
  4319 ML {* @{term "%x. x"} *}
  4320 ML {* @{prop "x == y"} *}
  4321 ML {* @{ctyp "'a => 'b"} *}
  4322 ML {* @{cterm "%x. x"} *}
  4323 ML {* @{cprop "x == y"} *}
  4324 ML {* @{thm asm_rl} *}
  4325 ML {* @{thms asm_rl} *}
  4326 ML {* @{type_name c} *}
  4327 ML {* @{type_syntax c} *}
  4328 ML {* @{const_name c} *}
  4329 ML {* @{const_syntax c} *}
  4330 ML {* @{context} *}
  4331 ML {* @{theory} *}
  4332 ML {* @{theory Pure} *}
  4333 ML {* @{theory_ref} *}
  4334 ML {* @{theory_ref Pure} *}
  4335 ML {* @{simpset} *}
  4336 ML {* @{claset} *}
  4337 ML {* @{clasimpset} *}
  4338 
  4339 The same works for sources being ``used'' within an Isar context.
  4340 
  4341 * ML in Isar: improved error reporting; extra verbosity with
  4342 ML_Context.trace enabled.
  4343 
  4344 * Pure/General/table.ML: the join operations now works via exceptions
  4345 DUP/SAME instead of type option. This is simpler in simple cases, and
  4346 admits slightly more efficient complex applications.
  4347 
  4348 * Pure: 'advanced' translation functions (parse_translation etc.) now
  4349 use Context.generic instead of just theory.
  4350 
  4351 * Pure: datatype Context.generic joins theory/Proof.context and
  4352 provides some facilities for code that works in either kind of
  4353 context, notably GenericDataFun for uniform theory and proof data.
  4354 
  4355 * Pure: simplified internal attribute type, which is now always
  4356 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  4357 local (Proof.context) attributes have been discontinued, while
  4358 minimizing code duplication. Thm.rule_attribute and
  4359 Thm.declaration_attribute build canonical attributes; see also structure
  4360 Context for further operations on Context.generic, notably
  4361 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  4362 declarations and definitions.
  4363 
  4364 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  4365 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  4366 init only required for impure data. INCOMPATIBILITY: empty really need
  4367 to be empty (no dependencies on theory content!)
  4368 
  4369 * Pure/kernel: consts certification ignores sort constraints given in
  4370 signature declarations. (This information is not relevant to the
  4371 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  4372 potential INCOMPATIBILITY.
  4373 
  4374 * Pure: axiomatic type classes are now purely definitional, with
  4375 explicit proofs of class axioms and super class relations performed
  4376 internally. See Pure/axclass.ML for the main internal interfaces --
  4377 notably AxClass.define_class supercedes AxClass.add_axclass, and
  4378 AxClass.axiomatize_class/classrel/arity supersede
  4379 Sign.add_classes/classrel/arities.
  4380 
  4381 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  4382 global/local versions on theory vs. Proof.context have been
  4383 discontinued; Attrib.syntax and Method.syntax have been adapted
  4384 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  4385 attributes, methods, etc.
  4386 
  4387 * Pure: several functions of signature "... -> theory -> theory * ..."
  4388 have been reoriented to "... -> theory -> ... * theory" in order to
  4389 allow natural usage in combination with the ||>, ||>>, |-> and
  4390 fold_map combinators.
  4391 
  4392 * Pure: official theorem names (closed derivations) and additional
  4393 comments (tags) are now strictly separate.  Name hints -- which are
  4394 maintained as tags -- may be attached any time without affecting the
  4395 derivation.
  4396 
  4397 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  4398 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  4399 achieve the old behaviour.
  4400 
  4401 * Pure: the "Goal" constant is now called "prop", supporting a
  4402 slightly more general idea of ``protecting'' meta-level rule
  4403 statements.
  4404 
  4405 * Pure: Logic.(un)varify only works in a global context, which is now
  4406 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  4407 Logic.legacy_(un)varify as temporary workaround.
  4408 
  4409 * Pure: structure Name provides scalable operations for generating
  4410 internal variable names, notably Name.variants etc.  This replaces
  4411 some popular functions from term.ML:
  4412 
  4413   Term.variant		->  Name.variant
  4414   Term.variantlist	->  Name.variant_list
  4415   Term.invent_names	->  Name.invent_list
  4416 
  4417 Note that low-level renaming rarely occurs in new code -- operations
  4418 from structure Variable are used instead (see below).
  4419 
  4420 * Pure: structure Variable provides fundamental operations for proper
  4421 treatment of fixed/schematic variables in a context.  For example,
  4422 Variable.import introduces fixes for schematics of given facts and
  4423 Variable.export reverses the effect (up to renaming) -- this replaces
  4424 various freeze_thaw operations.
  4425 
  4426 * Pure: structure Goal provides simple interfaces for
  4427 init/conclude/finish and tactical prove operations (replacing former
  4428 Tactic.prove).  Goal.prove is the canonical way to prove results
  4429 within a given context; Goal.prove_global is a degraded version for
  4430 theory level goals, including a global Drule.standard.  Note that
  4431 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  4432 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  4433 in a locale context).
  4434 
  4435 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  4436 and type checking (Syntax.check_term etc.), with common combinations
  4437 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  4438 which are considered legacy and await removal.
  4439 
  4440 * Pure/Syntax: generic interfaces for type unchecking
  4441 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  4442 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  4443 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  4444 available for convenience, but refer to the very same operations using
  4445 a mere theory instead of a full context.
  4446 
  4447 * Isar: simplified treatment of user-level errors, using exception
  4448 ERROR of string uniformly.  Function error now merely raises ERROR,
  4449 without any side effect on output channels.  The Isar toplevel takes
  4450 care of proper display of ERROR exceptions.  ML code may use plain
  4451 handle/can/try; cat_error may be used to concatenate errors like this:
  4452 
  4453   ... handle ERROR msg => cat_error msg "..."
  4454 
  4455 Toplevel ML code (run directly or through the Isar toplevel) may be
  4456 embedded into the Isar toplevel with exception display/debug like
  4457 this:
  4458 
  4459   Isar.toplevel (fn () => ...)
  4460 
  4461 INCOMPATIBILITY, removed special transform_error facilities, removed
  4462 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  4463 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  4464 -- use plain ERROR instead.
  4465 
  4466 * Isar: theory setup now has type (theory -> theory), instead of a
  4467 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  4468 
  4469 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  4470 ProofContext.debug/verbose flags.
  4471 
  4472 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  4473 theory before entering a proof state.  Transactions now always see a
  4474 quasi-functional intermediate checkpoint, both in interactive and
  4475 batch mode.
  4476 
  4477 * Isar: simplified interfaces for outer syntax.  Renamed
  4478 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  4479 OuterSyntax.add_parsers -- this functionality is now included in
  4480 OuterSyntax.command etc.  INCOMPATIBILITY.
  4481 
  4482 * Simplifier: the simpset of a running simplification process now
  4483 contains a proof context (cf. Simplifier.the_context), which is the
  4484 very context that the initial simpset has been retrieved from (by
  4485 simpset_of/local_simpset_of).  Consequently, all plug-in components
  4486 (solver, looper etc.) may depend on arbitrary proof data.
  4487 
  4488 * Simplifier.inherit_context inherits the proof context (plus the
  4489 local bounds) of the current simplification process; any simproc
  4490 etc. that calls the Simplifier recursively should do this!  Removed
  4491 former Simplifier.inherit_bounds, which is already included here --
  4492 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  4493 specify an explicit context using Simplifier.context/theory_context.
  4494 
  4495 * Simplifier/Classical Reasoner: more abstract interfaces
  4496 change_simpset/claset for modifying the simpset/claset reference of a
  4497 theory; raw versions simpset/claset_ref etc. have been discontinued --
  4498 INCOMPATIBILITY.
  4499 
  4500 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  4501 "Trueprop" etc.
  4502 
  4503 
  4504 *** System ***
  4505 
  4506 * settings: the default heap location within ISABELLE_HOME_USER now
  4507 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  4508 Isabelle installations.
  4509 
  4510 * isabelle-process: option -S (secure mode) disables some critical
  4511 operations, notably runtime compilation and evaluation of ML source
  4512 code.
  4513 
  4514 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  4515 
  4516 * Support for parallel execution, using native multicore support of
  4517 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  4518 independent theories, according to the given theory header
  4519 specifications. The maximum number of worker threads is specified via
  4520 usedir option -M or the "max-threads" setting in Proof General. A
  4521 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  4522 to 6 on a 8-core machine.  User-code needs to observe certain
  4523 guidelines for thread-safe programming, see appendix A in the Isar
  4524 Implementation manual.
  4525 
  4526 
  4527 
  4528 New in Isabelle2005 (October 2005)
  4529 ----------------------------------
  4530 
  4531 *** General ***
  4532 
  4533 * Theory headers: the new header syntax for Isar theories is
  4534 
  4535   theory <name>
  4536   imports <theory1> ... <theoryN>
  4537   uses <file1> ... <fileM>
  4538   begin
  4539 
  4540 where the 'uses' part is optional.  The previous syntax
  4541 
  4542   theory <name> = <theory1> + ... + <theoryN>:
  4543 
  4544 will disappear in the next release.  Use isatool fixheaders to convert
  4545 existing theory files.  Note that there is no change in ancient
  4546 non-Isar theories now, but these will disappear soon.
  4547 
  4548 * Theory loader: parent theories can now also be referred to via
  4549 relative and absolute paths.
  4550 
  4551 * Command 'find_theorems' searches for a list of criteria instead of a
  4552 list of constants. Known criteria are: intro, elim, dest, name:string,
  4553 simp:term, and any term. Criteria can be preceded by '-' to select
  4554 theorems that do not match. Intro, elim, dest select theorems that
  4555 match the current goal, name:s selects theorems whose fully qualified
  4556 name contain s, and simp:term selects all simplification rules whose
  4557 lhs match term.  Any other term is interpreted as pattern and selects
  4558 all theorems matching the pattern. Available in ProofGeneral under
  4559 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  4560 
  4561   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  4562 
  4563 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  4564 matching the current goal as introduction rule and not having "HOL."
  4565 in their name (i.e. not being defined in theory HOL).
  4566 
  4567 * Command 'thms_containing' has been discontinued in favour of
  4568 'find_theorems'; INCOMPATIBILITY.
  4569 
  4570 * Communication with Proof General is now 8bit clean, which means that
  4571 Unicode text in UTF-8 encoding may be used within theory texts (both
  4572 formal and informal parts).  Cf. option -U of the Isabelle Proof
  4573 General interface.  Here are some simple examples (cf. src/HOL/ex):
  4574 
  4575   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  4576   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  4577 
  4578 * Improved efficiency of the Simplifier and, to a lesser degree, the
  4579 Classical Reasoner.  Typical big applications run around 2 times
  4580 faster.
  4581 
  4582 
  4583 *** Document preparation ***
  4584 
  4585 * Commands 'display_drafts' and 'print_drafts' perform simple output
  4586 of raw sources.  Only those symbols that do not require additional
  4587 LaTeX packages (depending on comments in isabellesym.sty) are
  4588 displayed properly, everything else is left verbatim.  isatool display
  4589 and isatool print are used as front ends (these are subject to the
  4590 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  4591 
  4592 * Command tags control specific markup of certain regions of text,
  4593 notably folding and hiding.  Predefined tags include "theory" (for
  4594 theory begin and end), "proof" for proof commands, and "ML" for
  4595 commands involving ML code; the additional tags "visible" and
  4596 "invisible" are unused by default.  Users may give explicit tag
  4597 specifications in the text, e.g. ''by %invisible (auto)''.  The
  4598 interpretation of tags is determined by the LaTeX job during document
  4599 preparation: see option -V of isatool usedir, or options -n and -t of
  4600 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  4601 \isadroptag.
  4602 
  4603 Several document versions may be produced at the same time via isatool
  4604 usedir (the generated index.html will link all of them).  Typical
  4605 specifications include ''-V document=theory,proof,ML'' to present
  4606 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  4607 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  4608 these parts without any formal replacement text.  The Isabelle site
  4609 default settings produce ''document'' and ''outline'' versions as
  4610 specified above.
  4611 
  4612 * Several new antiquotations:
  4613 
  4614   @{term_type term} prints a term with its type annotated;
  4615 
  4616   @{typeof term} prints the type of a term;
  4617 
  4618   @{const const} is the same as @{term const}, but checks that the
  4619   argument is a known logical constant;
  4620 
  4621   @{term_style style term} and @{thm_style style thm} print a term or
  4622   theorem applying a "style" to it
  4623 
  4624   @{ML text}
  4625 
  4626 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  4627 definitions, equations, inequations etc., 'concl' printing only the
  4628 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  4629 to print the specified premise.  TermStyle.add_style provides an ML
  4630 interface for introducing further styles.  See also the "LaTeX Sugar"
  4631 document practical applications.  The ML antiquotation prints
  4632 type-checked ML expressions verbatim.
  4633 
  4634 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  4635 and 'text' support optional locale specification '(in loc)', which
  4636 specifies the default context for interpreting antiquotations.  For
  4637 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  4638 
  4639 * Option 'locale=NAME' of antiquotations specifies an alternative
  4640 context interpreting the subsequent argument.  For example: @{thm
  4641 [locale=lattice] inf_assoc}.
  4642 
  4643 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  4644 a proof context.
  4645 
  4646 * Proper output of antiquotations for theory commands involving a
  4647 proof context (such as 'locale' or 'theorem (in loc) ...').
  4648 
  4649 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  4650 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  4651 
  4652 * isatool usedir: new option -C (default true) controls whether option
  4653 -D should include a copy of the original document directory; -C false
  4654 prevents unwanted effects such as copying of administrative CVS data.
  4655 
  4656 
  4657 *** Pure ***
  4658 
  4659 * Considerably improved version of 'constdefs' command.  Now performs
  4660 automatic type-inference of declared constants; additional support for
  4661 local structure declarations (cf. locales and HOL records), see also
  4662 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  4663 sequential dependencies of definitions within a single 'constdefs'
  4664 section; moreover, the declared name needs to be an identifier.  If
  4665 all fails, consider to fall back on 'consts' and 'defs' separately.
  4666 
  4667 * Improved indexed syntax and implicit structures.  First of all,
  4668 indexed syntax provides a notational device for subscripted
  4669 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  4670 expressions.  Secondly, in a local context with structure
  4671 declarations, number indexes \<^sub>n or the empty index (default
  4672 number 1) refer to a certain fixed variable implicitly; option
  4673 show_structs controls printing of implicit structures.  Typical
  4674 applications of these concepts involve record types and locales.
  4675 
  4676 * New command 'no_syntax' removes grammar declarations (and
  4677 translations) resulting from the given syntax specification, which is
  4678 interpreted in the same manner as for the 'syntax' command.
  4679 
  4680 * 'Advanced' translation functions (parse_translation etc.) may depend
  4681 on the signature of the theory context being presently used for
  4682 parsing/printing, see also isar-ref manual.
  4683 
  4684 * Improved 'oracle' command provides a type-safe interface to turn an
  4685 ML expression of type theory -> T -> term into a primitive rule of
  4686 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  4687 is already included here); see also FOL/ex/IffExample.thy;
  4688 INCOMPATIBILITY.
  4689 
  4690 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  4691 before); "cI" is no longer bound, use "c.intro" instead.
  4692 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  4693 axclasses vs. locales.
  4694 
  4695 * Improved internal renaming of symbolic identifiers -- attach primes
  4696 instead of base 26 numbers.
  4697 
  4698 * New flag show_question_marks controls printing of leading question
  4699 marks in schematic variable names.
  4700 
  4701 * In schematic variable names, *any* symbol following \<^isub> or
  4702 \<^isup> is now treated as part of the base name.  For example, the
  4703 following works without printing of awkward ".0" indexes:
  4704 
  4705   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  4706     by simp
  4707 
  4708 * Inner syntax includes (*(*nested*) comments*).
  4709 
  4710 * Pretty printer now supports unbreakable blocks, specified in mixfix
  4711 annotations as "(00...)".
  4712 
  4713 * Clear separation of logical types and nonterminals, where the latter
  4714 may only occur in 'syntax' specifications or type abbreviations.
  4715 Before that distinction was only partially implemented via type class
  4716 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  4717 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  4718 exotic syntax specifications may require further adaption
  4719 (e.g. Cube/Cube.thy).
  4720 
  4721 * Removed obsolete type class "logic", use the top sort {} instead.
  4722 Note that non-logical types should be declared as 'nonterminals'
  4723 rather than 'types'.  INCOMPATIBILITY for new object-logic
  4724 specifications.
  4725 
  4726 * Attributes 'induct' and 'cases': type or set names may now be
  4727 locally fixed variables as well.
  4728 
  4729 * Simplifier: can now control the depth to which conditional rewriting
  4730 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  4731 Limit.
  4732 
  4733 * Simplifier: simplification procedures may now take the current
  4734 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  4735 interface), which is very useful for calling the Simplifier
  4736 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  4737 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  4738 low-level mk_simproc no longer applies Logic.varify internally, to
  4739 allow for use in a context of fixed variables.
  4740 
  4741 * thin_tac now works even if the assumption being deleted contains !!
  4742 or ==>.  More generally, erule now works even if the major premise of
  4743 the elimination rule contains !! or ==>.
  4744 
  4745 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  4746 
  4747 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  4748 from Pure, which contains all common declarations already.  Both
  4749 theories are defined via plain Isabelle/Isar .thy files.
  4750 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  4751 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  4752 use isatool fixcpure to adapt your theory and ML sources.
  4753 
  4754 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  4755 selections of theorems in named facts via index ranges.
  4756 
  4757 * 'print_theorems': in theory mode, really print the difference
  4758 wrt. the last state (works for interactive theory development only),
  4759 in proof mode print all local facts (cf. 'print_facts');
  4760 
  4761 * 'hide': option '(open)' hides only base names.
  4762 
  4763 * More efficient treatment of intermediate checkpoints in interactive
  4764 theory development.
  4765 
  4766 * Code generator is now invoked via code_module (incremental code
  4767 generation) and code_library (modular code generation, ML structures
  4768 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  4769 must be quoted when used as identifiers.
  4770 
  4771 * New 'value' command for reading, evaluating and printing terms using
  4772 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  4773 quoted when used as identifier.
  4774 
  4775 
  4776 *** Locales ***
  4777 
  4778 * New commands for the interpretation of locale expressions in
  4779 theories (1), locales (2) and proof contexts (3).  These generate
  4780 proof obligations from the expression specification.  After the
  4781 obligations have been discharged, theorems of the expression are added
  4782 to the theory, target locale or proof context.  The synopsis of the
  4783 commands is a follows:
  4784 
  4785   (1) interpretation expr inst
  4786   (2) interpretation target < expr
  4787   (3) interpret expr inst
  4788 
  4789 Interpretation in theories and proof contexts require a parameter
  4790 instantiation of terms from the current context.  This is applied to
  4791 specifications and theorems of the interpreted expression.
  4792 Interpretation in locales only permits parameter renaming through the
  4793 locale expression.  Interpretation is smart in that interpretations
  4794 that are active already do not occur in proof obligations, neither are
  4795 instantiated theorems stored in duplicate.  Use 'print_interps' to
  4796 inspect active interpretations of a particular locale.  For details,
  4797 see the Isar Reference manual.  Examples can be found in
  4798 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  4799 
  4800 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  4801 'interpret' instead.
  4802 
  4803 * New context element 'constrains' for adding type constraints to
  4804 parameters.
  4805 
  4806 * Context expressions: renaming of parameters with syntax
  4807 redeclaration.
  4808 
  4809 * Locale declaration: 'includes' disallowed.
  4810 
  4811 * Proper static binding of attribute syntax -- i.e. types / terms /
  4812 facts mentioned as arguments are always those of the locale definition
  4813 context, independently of the context of later invocations.  Moreover,
  4814 locale operations (renaming and type / term instantiation) are applied
  4815 to attribute arguments as expected.
  4816 
  4817 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  4818 actual attributes; rare situations may require Attrib.attribute to
  4819 embed those attributes into Attrib.src that lack concrete syntax.
  4820 Attribute implementations need to cooperate properly with the static
  4821 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  4822 Attrib.XXX_thm etc. already do the right thing without further
  4823 intervention.  Only unusual applications -- such as "where" or "of"
  4824 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  4825 on the context and the facts involved -- may have to assign parsed
  4826 values to argument tokens explicitly.
  4827 
  4828 * Changed parameter management in theorem generation for long goal
  4829 statements with 'includes'.  INCOMPATIBILITY: produces a different
  4830 theorem statement in rare situations.
  4831 
  4832 * Locale inspection command 'print_locale' omits notes elements.  Use
  4833 'print_locale!' to have them included in the output.
  4834 
  4835 
  4836 *** Provers ***
  4837 
  4838 * Provers/hypsubst.ML: improved version of the subst method, for
  4839 single-step rewriting: it now works in bound variable contexts. New is
  4840 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  4841 rewrite a different subterm than the original subst method, which is
  4842 still available as 'simplesubst'.
  4843 
  4844 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  4845 and quasi orders.
  4846 
  4847 * Provers/trancl.ML: new transitivity reasoner for transitive and
  4848 reflexive-transitive closure of relations.
  4849 
  4850 * Provers/blast.ML: new reference depth_limit to make blast's depth
  4851 limit (previously hard-coded with a value of 20) user-definable.
  4852 
  4853 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  4854 is peformed already.  Object-logics merely need to finish their
  4855 initial simpset configuration as before.  INCOMPATIBILITY.
  4856 
  4857 
  4858 *** HOL ***
  4859 
  4860 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  4861 
  4862   syntax (epsilon)
  4863     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  4864 
  4865 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  4866 and x-symbol; use option '-m epsilon' to get it actually printed.
  4867 Moreover, the mathematically important symbolic identifier \<epsilon>
  4868 becomes available as variable, constant etc.  INCOMPATIBILITY,
  4869 
  4870 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  4871 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  4872 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  4873 support corresponding Isar calculations.
  4874 
  4875 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  4876 instead of ":".
  4877 
  4878 * theory SetInterval: changed the syntax for open intervals:
  4879 
  4880   Old       New
  4881   {..n(}    {..<n}
  4882   {)n..}    {n<..}
  4883   {m..n(}   {m..<n}
  4884   {)m..n}   {m<..n}
  4885   {)m..n(}  {m<..<n}
  4886 
  4887 The old syntax is still supported but will disappear in the next
  4888 release.  For conversion use the following Emacs search and replace
  4889 patterns (these are not perfect but work quite well):
  4890 
  4891   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  4892   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  4893 
  4894 * Theory Commutative_Ring (in Library): method comm_ring for proving
  4895 equalities in commutative rings; method 'algebra' provides a generic
  4896 interface.
  4897 
  4898 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  4899 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  4900 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  4901 be a tuple pattern.
  4902 
  4903 Some new syntax forms are available:
  4904 
  4905   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  4906   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  4907   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  4908   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  4909 
  4910 The latter form "\<Sum>x < k. e" used to be based on a separate
  4911 function "Summation", which has been discontinued.
  4912 
  4913 * theory Finite_Set: in structured induction proofs, the insert case
  4914 is now 'case (insert x F)' instead of the old counterintuitive 'case
  4915 (insert F x)'.
  4916 
  4917 * The 'refute' command has been extended to support a much larger
  4918 fragment of HOL, including axiomatic type classes, constdefs and
  4919 typedefs, inductive datatypes and recursion.
  4920 
  4921 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  4922 Requires zChaff with proof generation to be installed.  See
  4923 HOL/ex/SAT_Examples.thy for examples.
  4924 
  4925 * Datatype induction via method 'induct' now preserves the name of the
  4926 induction variable. For example, when proving P(xs::'a list) by
  4927 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  4928 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  4929 in unstructured proof scripts.
  4930 
  4931 * Reworked implementation of records.  Improved scalability for
  4932 records with many fields, avoiding performance problems for type
  4933 inference. Records are no longer composed of nested field types, but
  4934 of nested extension types. Therefore the record type only grows linear
  4935 in the number of extensions and not in the number of fields.  The
  4936 top-level (users) view on records is preserved.  Potential
  4937 INCOMPATIBILITY only in strange cases, where the theory depends on the
  4938 old record representation. The type generated for a record is called
  4939 <record_name>_ext_type.
  4940 
  4941 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  4942 proofs triggered by a record definition or a simproc (if
  4943 quick_and_dirty is enabled).  Definitions of large records can take
  4944 quite long.
  4945 
  4946 New simproc record_upd_simproc for simplification of multiple record
  4947 updates enabled by default.  Moreover, trivial updates are also
  4948 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  4949 occasionally, since simplification is more powerful by default.
  4950 
  4951 * typedef: proper support for polymorphic sets, which contain extra
  4952 type-variables in the term.
  4953 
  4954 * Simplifier: automatically reasons about transitivity chains
  4955 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  4956 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  4957 old proofs break occasionally as simplification may now solve more
  4958 goals than previously.
  4959 
  4960 * Simplifier: converts x <= y into x = y if assumption y <= x is
  4961 present.  Works for all partial orders (class "order"), in particular
  4962 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  4963 just like y <= x.
  4964 
  4965 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  4966 bound variable or a constant then the let is unfolded.  Otherwise
  4967 first a is simplified to b, and then f b is simplified to g. If
  4968 possible we abstract b from g arriving at "let x = b in h x",
  4969 otherwise we unfold the let and arrive at g.  The simproc can be
  4970 enabled/disabled by the reference use_let_simproc.  Potential
  4971 INCOMPATIBILITY since simplification is more powerful by default.
  4972 
  4973 * Classical reasoning: the meson method now accepts theorems as arguments.
  4974 
  4975 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  4976 jobs to provide advice on the provability of subgoals.
  4977 
  4978 * Theory OrderedGroup and Ring_and_Field: various additions and
  4979 improvements to faciliate calculations involving equalities and
  4980 inequalities.
  4981 
  4982 The following theorems have been eliminated or modified
  4983 (INCOMPATIBILITY):
  4984 
  4985   abs_eq             now named abs_of_nonneg
  4986   abs_of_ge_0        now named abs_of_nonneg
  4987   abs_minus_eq       now named abs_of_nonpos
  4988   imp_abs_id         now named abs_of_nonneg
  4989   imp_abs_neg_id     now named abs_of_nonpos
  4990   mult_pos           now named mult_pos_pos
  4991   mult_pos_le        now named mult_nonneg_nonneg
  4992   mult_pos_neg_le    now named mult_nonneg_nonpos
  4993   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  4994   mult_neg           now named mult_neg_neg
  4995   mult_neg_le        now named mult_nonpos_nonpos
  4996 
  4997 * The following lemmas in Ring_and_Field have been added to the simplifier:
  4998      
  4999      zero_le_square
  5000      not_square_less_zero 
  5001 
  5002   The following lemmas have been deleted from Real/RealPow:
  5003   
  5004      realpow_zero_zero
  5005      realpow_two
  5006      realpow_less
  5007      zero_le_power
  5008      realpow_two_le
  5009      abs_realpow_two
  5010      realpow_two_abs     
  5011 
  5012 * Theory Parity: added rules for simplifying exponents.
  5013 
  5014 * Theory List:
  5015 
  5016 The following theorems have been eliminated or modified
  5017 (INCOMPATIBILITY):
  5018 
  5019   list_all_Nil       now named list_all.simps(1)
  5020   list_all_Cons      now named list_all.simps(2)
  5021   list_all_conv      now named list_all_iff
  5022   set_mem_eq         now named mem_iff
  5023 
  5024 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  5025 asymptotic "big O" calculations.  See the notes in BigO.thy.
  5026 
  5027 
  5028 *** HOL-Complex ***
  5029 
  5030 * Theory RealDef: better support for embedding natural numbers and
  5031 integers in the reals.
  5032 
  5033 The following theorems have been eliminated or modified
  5034 (INCOMPATIBILITY):
  5035 
  5036   exp_ge_add_one_self  now requires no hypotheses
  5037   real_of_int_add      reversed direction of equality (use [symmetric])
  5038   real_of_int_minus    reversed direction of equality (use [symmetric])
  5039   real_of_int_diff     reversed direction of equality (use [symmetric])
  5040   real_of_int_mult     reversed direction of equality (use [symmetric])
  5041 
  5042 * Theory RComplete: expanded support for floor and ceiling functions.
  5043 
  5044 * Theory Ln is new, with properties of the natural logarithm
  5045 
  5046 * Hyperreal: There is a new type constructor "star" for making
  5047 nonstandard types.  The old type names are now type synonyms:
  5048 
  5049   hypreal = real star
  5050   hypnat = nat star
  5051   hcomplex = complex star
  5052 
  5053 * Hyperreal: Many groups of similarly-defined constants have been
  5054 replaced by polymorphic versions (INCOMPATIBILITY):
  5055 
  5056   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  5057 
  5058   starset      <-- starsetNat, starsetC
  5059   *s*          <-- *sNat*, *sc*
  5060   starset_n    <-- starsetNat_n, starsetC_n
  5061   *sn*         <-- *sNatn*, *scn*
  5062   InternalSets <-- InternalNatSets, InternalCSets
  5063 
  5064   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  5065   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  5066   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  5067   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  5068   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  5069 
  5070 * Hyperreal: Many type-specific theorems have been removed in favor of
  5071 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  5072 
  5073   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  5074   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  5075   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  5076   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  5077   right_minus <-- hypreal_add_minus
  5078   left_minus <-- {hypreal,hcomplex}_add_minus_left
  5079   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  5080   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  5081   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  5082   mult_1_right <-- hcomplex_mult_one_right
  5083   mult_zero_left <-- hcomplex_mult_zero_left
  5084   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  5085   right_distrib <-- hypnat_add_mult_distrib2
  5086   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  5087   right_inverse <-- hypreal_mult_inverse
  5088   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  5089   order_refl <-- {hypreal,hypnat}_le_refl
  5090   order_trans <-- {hypreal,hypnat}_le_trans
  5091   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  5092   order_less_le <-- {hypreal,hypnat}_less_le
  5093   linorder_linear <-- {hypreal,hypnat}_le_linear
  5094   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  5095   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  5096   add_nonneg_nonneg <-- hypreal_le_add_order
  5097 
  5098 * Hyperreal: Separate theorems having to do with type-specific
  5099 versions of constants have been merged into theorems that apply to the
  5100 new polymorphic constants (INCOMPATIBILITY):
  5101 
  5102   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  5103   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  5104   STAR_Un <-- {STAR,NatStar,STARC}_Un
  5105   STAR_Int <-- {STAR,NatStar,STARC}_Int
  5106   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  5107   STAR_subset <-- {STAR,NatStar,STARC}_subset
  5108   STAR_mem <-- {STAR,NatStar,STARC}_mem
  5109   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  5110   STAR_diff <-- {STAR,STARC}_diff
  5111   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  5112     STARC_hcomplex_of_complex}_image_subset
  5113   starset_n_Un <-- starset{Nat,C}_n_Un
  5114   starset_n_Int <-- starset{Nat,C}_n_Int
  5115   starset_n_Compl <-- starset{Nat,C}_n_Compl
  5116   starset_n_diff <-- starset{Nat,C}_n_diff
  5117   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  5118   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  5119   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  5120   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  5121   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  5122   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  5123   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  5124   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  5125   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  5126   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  5127   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  5128   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  5129   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  5130   starfun_diff <-- starfun{C,RC,CR}_diff
  5131   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  5132   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  5133   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  5134   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  5135   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  5136   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  5137   starfun_Id <-- starfunC_Id
  5138   starfun_approx <-- starfun{Nat,CR}_approx
  5139   starfun_capprox <-- starfun{C,RC}_capprox
  5140   starfun_abs <-- starfunNat_rabs
  5141   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  5142   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  5143   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  5144   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  5145   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  5146   starfun_add_approx <-- starfunCR_add_approx
  5147   starfun_inverse_inverse <-- starfunC_inverse_inverse
  5148   starfun_divide <-- starfun{C,CR,RC}_divide
  5149   starfun_n <-- starfun{Nat,C}_n
  5150   starfun_n_mult <-- starfun{Nat,C}_n_mult
  5151   starfun_n_add <-- starfun{Nat,C}_n_add
  5152   starfun_n_add_minus <-- starfunNat_n_add_minus
  5153   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  5154   starfun_n_minus <-- starfun{Nat,C}_n_minus
  5155   starfun_n_eq <-- starfun{Nat,C}_n_eq
  5156 
  5157   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  5158   star_n_minus <-- {hypreal,hcomplex}_minus
  5159   star_n_diff <-- {hypreal,hcomplex}_diff
  5160   star_n_mult <-- {hypreal,hcomplex}_mult
  5161   star_n_inverse <-- {hypreal,hcomplex}_inverse
  5162   star_n_le <-- {hypreal,hypnat}_le
  5163   star_n_less <-- {hypreal,hypnat}_less
  5164   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  5165   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  5166   star_n_abs <-- hypreal_hrabs
  5167   star_n_divide <-- hcomplex_divide
  5168 
  5169   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  5170   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  5171   star_of_diff <-- hypreal_of_real_diff
  5172   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  5173   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  5174   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  5175   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  5176   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  5177   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  5178   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  5179   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  5180   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  5181   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  5182   star_of_number_of <-- {hypreal,hcomplex}_number_of
  5183   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  5184   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  5185   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  5186   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  5187   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  5188   star_of_power <-- hypreal_of_real_power
  5189   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  5190 
  5191 * Hyperreal: new method "transfer" that implements the transfer
  5192 principle of nonstandard analysis. With a subgoal that mentions
  5193 nonstandard types like "'a star", the command "apply transfer"
  5194 replaces it with an equivalent one that mentions only standard types.
  5195 To be successful, all free variables must have standard types; non-
  5196 standard variables must have explicit universal quantifiers.
  5197 
  5198 * Hyperreal: A theory of Taylor series.
  5199 
  5200 
  5201 *** HOLCF ***
  5202 
  5203 * Discontinued special version of 'constdefs' (which used to support
  5204 continuous functions) in favor of the general Pure one with full
  5205 type-inference.
  5206 
  5207 * New simplification procedure for solving continuity conditions; it
  5208 is much faster on terms with many nested lambda abstractions (cubic
  5209 instead of exponential time).
  5210 
  5211 * New syntax for domain package: selector names are now optional.
  5212 Parentheses should be omitted unless argument is lazy, for example:
  5213 
  5214   domain 'a stream = cons "'a" (lazy "'a stream")
  5215 
  5216 * New command 'fixrec' for defining recursive functions with pattern
  5217 matching; defining multiple functions with mutual recursion is also
  5218 supported.  Patterns may include the constants cpair, spair, up, sinl,
  5219 sinr, or any data constructor defined by the domain package. The given
  5220 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  5221 syntax and examples.
  5222 
  5223 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  5224 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  5225 but the proof obligation additionally includes an admissibility
  5226 requirement. The packages generate instances of class cpo or pcpo,
  5227 with continuity and strictness theorems for Rep and Abs.
  5228 
  5229 * HOLCF: Many theorems have been renamed according to a more standard naming
  5230 scheme (INCOMPATIBILITY):
  5231 
  5232   foo_inject:  "foo$x = foo$y ==> x = y"
  5233   foo_eq:      "(foo$x = foo$y) = (x = y)"
  5234   foo_less:    "(foo$x << foo$y) = (x << y)"
  5235   foo_strict:  "foo$UU = UU"
  5236   foo_defined: "... ==> foo$x ~= UU"
  5237   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  5238 
  5239 
  5240 *** ZF ***
  5241 
  5242 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  5243 including the First Isomorphism Theorem (on quotienting by the kernel
  5244 of a homomorphism).
  5245 
  5246 * ZF/Simplifier: install second copy of type solver that actually
  5247 makes use of TC rules declared to Isar proof contexts (or locales);
  5248 the old version is still required for ML proof scripts.
  5249 
  5250 
  5251 *** Cube ***
  5252 
  5253 * Converted to Isar theory format; use locales instead of axiomatic
  5254 theories.
  5255 
  5256 
  5257 *** ML ***
  5258 
  5259 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  5260 for ||>, ||>>, |>>,
  5261 
  5262 * Pure/library.ML no longer defines its own option datatype, but uses
  5263 that of the SML basis, which has constructors NONE and SOME instead of
  5264 None and Some, as well as exception Option.Option instead of OPTION.
  5265 The functions the, if_none, is_some, is_none have been adapted
  5266 accordingly, while Option.map replaces apsome.
  5267 
  5268 * Pure/library.ML: the exception LIST has been given up in favour of
  5269 the standard exceptions Empty and Subscript, as well as
  5270 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  5271 superceded by the standard hd and tl functions etc.
  5272 
  5273 A number of basic list functions are no longer exported to the ML
  5274 toplevel, as they are variants of predefined functions.  The following
  5275 suggests how one can translate existing code:
  5276 
  5277     rev_append xs ys = List.revAppend (xs, ys)
  5278     nth_elem (i, xs) = List.nth (xs, i)
  5279     last_elem xs = List.last xs
  5280     flat xss = List.concat xss
  5281     seq fs = List.app fs
  5282     partition P xs = List.partition P xs
  5283     mapfilter f xs = List.mapPartial f xs
  5284 
  5285 * Pure/library.ML: several combinators for linear functional
  5286 transformations, notably reverse application and composition:
  5287 
  5288   x |> f                f #> g
  5289   (x, y) |-> f          f #-> g
  5290 
  5291 * Pure/library.ML: introduced/changed precedence of infix operators:
  5292 
  5293   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  5294   infix 2 ?;
  5295   infix 3 o oo ooo oooo;
  5296   infix 4 ~~ upto downto;
  5297 
  5298 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  5299 infix operators.
  5300 
  5301 * Pure/library.ML: natural list combinators fold, fold_rev, and
  5302 fold_map support linear functional transformations and nesting.  For
  5303 example:
  5304 
  5305   fold f [x1, ..., xN] y =
  5306     y |> f x1 |> ... |> f xN
  5307 
  5308   (fold o fold) f [xs1, ..., xsN] y =
  5309     y |> fold f xs1 |> ... |> fold f xsN
  5310 
  5311   fold f [x1, ..., xN] =
  5312     f x1 #> ... #> f xN
  5313 
  5314   (fold o fold) f [xs1, ..., xsN] =
  5315     fold f xs1 #> ... #> fold f xsN
  5316 
  5317 * Pure/library.ML: the following selectors on type 'a option are
  5318 available:
  5319 
  5320   the:               'a option -> 'a  (*partial*)
  5321   these:             'a option -> 'a  where 'a = 'b list
  5322   the_default: 'a -> 'a option -> 'a
  5323   the_list:          'a option -> 'a list
  5324 
  5325 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5326 basic operations for association lists, following natural argument
  5327 order; moreover the explicit equality predicate passed here avoids
  5328 potentially expensive polymorphic runtime equality checks.
  5329 The old functions may be expressed as follows:
  5330 
  5331   assoc = uncurry (AList.lookup (op =))
  5332   assocs = these oo AList.lookup (op =)
  5333   overwrite = uncurry (AList.update (op =)) o swap
  5334 
  5335 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5336 
  5337   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  5338   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  5339 
  5340 replacing make_keylist and keyfilter (occassionally used)
  5341 Naive rewrites:
  5342 
  5343   make_keylist = AList.make
  5344   keyfilter = AList.find (op =)
  5345 
  5346 * eq_fst and eq_snd now take explicit equality parameter, thus
  5347   avoiding eqtypes. Naive rewrites:
  5348 
  5349     eq_fst = eq_fst (op =)
  5350     eq_snd = eq_snd (op =)
  5351 
  5352 * Removed deprecated apl and apr (rarely used).
  5353   Naive rewrites:
  5354 
  5355     apl (n, op) =>>= curry op n
  5356     apr (op, m) =>>= fn n => op (n, m)
  5357 
  5358 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  5359 provides a reasonably efficient light-weight implementation of sets as
  5360 lists.
  5361 
  5362 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  5363 few new operations; existing lookup and update are now curried to
  5364 follow natural argument order (for use with fold etc.);
  5365 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  5366 
  5367 * Pure/General: output via the Isabelle channels of
  5368 writeln/warning/error etc. is now passed through Output.output, with a
  5369 hook for arbitrary transformations depending on the print_mode
  5370 (cf. Output.add_mode -- the first active mode that provides a output
  5371 function wins).  Already formatted output may be embedded into further
  5372 text via Output.raw; the result of Pretty.string_of/str_of and derived
  5373 functions (string_of_term/cterm/thm etc.) is already marked raw to
  5374 accommodate easy composition of diagnostic messages etc.  Programmers
  5375 rarely need to care about Output.output or Output.raw at all, with
  5376 some notable exceptions: Output.output is required when bypassing the
  5377 standard channels (writeln etc.), or in token translations to produce
  5378 properly formatted results; Output.raw is required when capturing
  5379 already output material that will eventually be presented to the user
  5380 a second time.  For the default print mode, both Output.output and
  5381 Output.raw have no effect.
  5382 
  5383 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  5384 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  5385 cumulative results are displayed at the end of a batch session.
  5386 
  5387 * Pure/General: File.sysify_path and File.quote_sysify path have been
  5388 replaced by File.platform_path and File.shell_path (with appropriate
  5389 hooks).  This provides a clean interface for unusual systems where the
  5390 internal and external process view of file names are different.
  5391 
  5392 * Pure: more efficient orders for basic syntactic entities: added
  5393 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  5394 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  5395 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  5396 orders now -- potential INCOMPATIBILITY for code that depends on a
  5397 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  5398 Library.sort_strings on result).
  5399 
  5400 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  5401 fold_types traverse types/terms from left to right, observing natural
  5402 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  5403 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  5404 
  5405 * Pure: name spaces have been refined, with significant changes of the
  5406 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  5407 to extern(_table).  The plain name entry path is superceded by a
  5408 general 'naming' context, which also includes the 'policy' to produce
  5409 a fully qualified name and external accesses of a fully qualified
  5410 name; NameSpace.extend is superceded by context dependent
  5411 Sign.declare_name.  Several theory and proof context operations modify
  5412 the naming context.  Especially note Theory.restore_naming and
  5413 ProofContext.restore_naming to get back to a sane state; note that
  5414 Theory.add_path is no longer sufficient to recover from
  5415 Theory.absolute_path in particular.
  5416 
  5417 * Pure: new flags short_names (default false) and unique_names
  5418 (default true) for controlling output of qualified names.  If
  5419 short_names is set, names are printed unqualified.  If unique_names is
  5420 reset, the name prefix is reduced to the minimum required to achieve
  5421 the original result when interning again, even if there is an overlap
  5422 with earlier declarations.
  5423 
  5424 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  5425 now 'extend', and 'merge' gets an additional Pretty.pp argument
  5426 (useful for printing error messages).  INCOMPATIBILITY.
  5427 
  5428 * Pure: major reorganization of the theory context.  Type Sign.sg and
  5429 Theory.theory are now identified, referring to the universal
  5430 Context.theory (see Pure/context.ML).  Actual signature and theory
  5431 content is managed as theory data.  The old code and interfaces were
  5432 spread over many files and structures; the new arrangement introduces
  5433 considerable INCOMPATIBILITY to gain more clarity:
  5434 
  5435   Context -- theory management operations (name, identity, inclusion,
  5436     parents, ancestors, merge, etc.), plus generic theory data;
  5437 
  5438   Sign -- logical signature and syntax operations (declaring consts,
  5439     types, etc.), plus certify/read for common entities;
  5440 
  5441   Theory -- logical theory operations (stating axioms, definitions,
  5442     oracles), plus a copy of logical signature operations (consts,
  5443     types, etc.); also a few basic management operations (Theory.copy,
  5444     Theory.merge, etc.)
  5445 
  5446 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  5447 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  5448 for convenience -- they merely return the theory.
  5449 
  5450 * Pure: type Type.tsig is superceded by theory in most interfaces.
  5451 
  5452 * Pure: the Isar proof context type is already defined early in Pure
  5453 as Context.proof (note that ProofContext.context and Proof.context are
  5454 aliases, where the latter is the preferred name).  This enables other
  5455 Isabelle components to refer to that type even before Isar is present.
  5456 
  5457 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  5458 typeK, constK, axiomK, oracleK), but provide explicit operations for
  5459 any of these kinds.  For example, Sign.intern typeK is now
  5460 Sign.intern_type, Theory.hide_space Sign.typeK is now
  5461 Theory.hide_types.  Also note that former
  5462 Theory.hide_classes/types/consts are now
  5463 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  5464 internalize their arguments!  INCOMPATIBILITY.
  5465 
  5466 * Pure: get_thm interface (of PureThy and ProofContext) expects
  5467 datatype thmref (with constructors Name and NameSelection) instead of
  5468 plain string -- INCOMPATIBILITY;
  5469 
  5470 * Pure: cases produced by proof methods specify options, where NONE
  5471 means to remove case bindings -- INCOMPATIBILITY in
  5472 (RAW_)METHOD_CASES.
  5473 
  5474 * Pure: the following operations retrieve axioms or theorems from a
  5475 theory node or theory hierarchy, respectively:
  5476 
  5477   Theory.axioms_of: theory -> (string * term) list
  5478   Theory.all_axioms_of: theory -> (string * term) list
  5479   PureThy.thms_of: theory -> (string * thm) list
  5480   PureThy.all_thms_of: theory -> (string * thm) list
  5481 
  5482 * Pure: print_tac now outputs the goal through the trace channel.
  5483 
  5484 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  5485 Reference Toplevel.debug (default false) controls detailed printing
  5486 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  5487 controls execution profiling -- set to 1 for time and 2 for space
  5488 (both increase the runtime).
  5489 
  5490 * Isar session: The initial use of ROOT.ML is now always timed,
  5491 i.e. the log will show the actual process times, in contrast to the
  5492 elapsed wall-clock time that the outer shell wrapper produces.
  5493 
  5494 * Simplifier: improved handling of bound variables (nameless
  5495 representation, avoid allocating new strings).  Simprocs that invoke
  5496 the Simplifier recursively should use Simplifier.inherit_bounds to
  5497 avoid local name clashes.  Failure to do so produces warnings
  5498 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  5499 for further details.
  5500 
  5501 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  5502 bindings for all theorems stored within a given theory; this may help
  5503 in porting non-Isar theories to Isar ones, while keeping ML proof
  5504 scripts for the time being.
  5505 
  5506 * ML operator HTML.with_charset specifies the charset begin used for
  5507 generated HTML files.  For example:
  5508 
  5509   HTML.with_charset "utf-8" use_thy "Hebrew";
  5510   HTML.with_charset "utf-8" use_thy "Chinese";
  5511 
  5512 
  5513 *** System ***
  5514 
  5515 * Allow symlinks to all proper Isabelle executables (Isabelle,
  5516 isabelle, isatool etc.).
  5517 
  5518 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  5519 isatool doc, isatool mkdir, display_drafts etc.).
  5520 
  5521 * isatool usedir: option -f allows specification of the ML file to be
  5522 used by Isabelle; default is ROOT.ML.
  5523 
  5524 * New isatool version outputs the version identifier of the Isabelle
  5525 distribution being used.
  5526 
  5527 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  5528 (containing Boolean satisfiability problems) into Isabelle/HOL
  5529 theories.
  5530 
  5531 
  5532 
  5533 New in Isabelle2004 (April 2004)
  5534 --------------------------------
  5535 
  5536 *** General ***
  5537 
  5538 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  5539   Replaces linorder.ML.
  5540 
  5541 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  5542   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  5543   (\<a>...\<z>), are now considered normal letters, and can therefore
  5544   be used anywhere where an ASCII letter (a...zA...Z) has until
  5545   now. COMPATIBILITY: This obviously changes the parsing of some
  5546   terms, especially where a symbol has been used as a binder, say
  5547   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  5548   as an identifier.  Fix it by inserting a space around former
  5549   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  5550   existing theory and ML files.
  5551 
  5552 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  5553 
  5554 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  5555   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  5556   a normal (but invisible) letter. For multiple letter subscripts repeat
  5557   \<^isub> like this: x\<^isub>1\<^isub>2.
  5558 
  5559 * Pure: There are now sub-/superscripts that can span more than one
  5560   character. Text between \<^bsub> and \<^esub> is set in subscript in
  5561   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  5562   superscript. The new control characters are not identifier parts.
  5563 
  5564 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  5565   content of "..." to the latex file instead of \isacntrl... . The "..."
  5566   may consist of any printable characters excluding the end bracket >.
  5567 
  5568 * Pure: Using new Isar command "finalconsts" (or the ML functions
  5569   Theory.add_finals or Theory.add_finals_i) it is now possible to
  5570   declare constants "final", which prevents their being given a definition
  5571   later.  It is useful for constants whose behaviour is fixed axiomatically
  5572   rather than definitionally, such as the meta-logic connectives.
  5573 
  5574 * Pure: 'instance' now handles general arities with general sorts
  5575   (i.e. intersections of classes),
  5576 
  5577 * Presentation: generated HTML now uses a CSS style sheet to make layout
  5578   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  5579   It can be changed to alter the colors/layout of generated pages.
  5580 
  5581 
  5582 *** Isar ***
  5583 
  5584 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  5585   cut_tac, subgoal_tac and thin_tac:
  5586   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  5587     locales are no longer forced to write Isar proof scripts.
  5588     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  5589     emulations.
  5590   - INCOMPATIBILITY: names of variables to be instantiated may no
  5591     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  5592     This is consistent with the instantiation attribute "where".
  5593 
  5594 * Attributes "where" and "of":
  5595   - Now take type variables of instantiated theorem into account when reading
  5596     the instantiation string.  This fixes a bug that caused instantiated
  5597     theorems to have too special types in some circumstances.
  5598   - "where" permits explicit instantiations of type variables.
  5599 
  5600 * Calculation commands "moreover" and "also" no longer interfere with
  5601   current facts ("this"), admitting arbitrary combinations with "then"
  5602   and derived forms.
  5603 
  5604 * Locales:
  5605   - Goal statements involving the context element "includes" no longer
  5606     generate theorems with internal delta predicates (those ending on
  5607     "_axioms") in the premise.
  5608     Resolve particular premise with <locale>.intro to obtain old form.
  5609   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  5610     specification and "includes" elements in goal statement.
  5611   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  5612     [intro?] and [elim?] (respectively) by default.
  5613   - Experimental command for instantiation of locales in proof contexts:
  5614         instantiate <label>[<attrs>]: <loc>
  5615     Instantiates locale <loc> and adds all its theorems to the current context
  5616     taking into account their attributes.  Label and attrs are optional
  5617     modifiers, like in theorem declarations.  If present, names of
  5618     instantiated theorems are qualified with <label>, and the attributes
  5619     <attrs> are applied after any attributes these theorems might have already.
  5620       If the locale has assumptions, a chained fact of the form
  5621     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  5622     are derived.  The command does not support old-style locales declared
  5623     with "locale (open)".
  5624       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  5625 
  5626 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  5627   (Isar) contexts.
  5628 
  5629 
  5630 *** HOL ***
  5631 
  5632 * Proof import: new image HOL4 contains the imported library from
  5633   the HOL4 system with about 2500 theorems. It is imported by
  5634   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  5635   can be used like any other Isabelle image.  See
  5636   HOL/Import/HOL/README for more information.
  5637 
  5638 * Simplifier:
  5639   - Much improved handling of linear and partial orders.
  5640     Reasoners for linear and partial orders are set up for type classes
  5641     "linorder" and "order" respectively, and are added to the default simpset
  5642     as solvers.  This means that the simplifier can build transitivity chains
  5643     to solve goals from the assumptions.
  5644   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  5645     of blast or auto after simplification become unnecessary because the goal
  5646     is solved by simplification already.
  5647 
  5648 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  5649     all proved in axiomatic type classes for semirings, rings and fields.
  5650 
  5651 * Numerics:
  5652   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  5653     now formalized using the Ring_and_Field theory mentioned above.
  5654   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  5655     than before, because now they are set up once in a generic manner.
  5656   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  5657     Look for the general versions in Ring_and_Field (and Power if they concern
  5658     exponentiation).
  5659 
  5660 * Type "rat" of the rational numbers is now available in HOL-Complex.
  5661 
  5662 * Records:
  5663   - Record types are now by default printed with their type abbreviation
  5664     instead of the list of all field types. This can be configured via
  5665     the reference "print_record_type_abbr".
  5666   - Simproc "record_upd_simproc" for simplification of multiple updates added
  5667     (not enabled by default).
  5668   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  5669     EX x. x = sel r to True (not enabled by default).
  5670   - Tactic "record_split_simp_tac" to split and simplify records added.
  5671 
  5672 * 'specification' command added, allowing for definition by
  5673   specification.  There is also an 'ax_specification' command that
  5674   introduces the new constants axiomatically.
  5675 
  5676 * arith(_tac) is now able to generate counterexamples for reals as well.
  5677 
  5678 * HOL-Algebra: new locale "ring" for non-commutative rings.
  5679 
  5680 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  5681   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  5682 
  5683 * HOL-Matrix: a first theory for matrices in HOL with an application of
  5684   matrix theory to linear programming.
  5685 
  5686 * Unions and Intersections:
  5687   The latex output syntax of UN and INT has been changed
  5688   from "\Union x \in A. B" to "\Union_{x \in A} B"
  5689   i.e. the index formulae has become a subscript.
  5690   Similarly for "\Union x. B", and for \Inter instead of \Union.
  5691 
  5692 * Unions and Intersections over Intervals:
  5693   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  5694   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  5695   like in normal math, and corresponding versions for < and for intersection.
  5696 
  5697 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  5698   lexicographic dictonary ordering has been added as "lexord".
  5699 
  5700 * ML: the legacy theory structures Int and List have been removed. They had
  5701   conflicted with ML Basis Library structures having the same names.
  5702 
  5703 * 'refute' command added to search for (finite) countermodels.  Only works
  5704   for a fragment of HOL.  The installation of an external SAT solver is
  5705   highly recommended.  See "HOL/Refute.thy" for details.
  5706 
  5707 * 'quickcheck' command: Allows to find counterexamples by evaluating
  5708   formulae under an assignment of free variables to random values.
  5709   In contrast to 'refute', it can deal with inductive datatypes,
  5710   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  5711   for examples.
  5712 
  5713 
  5714 *** HOLCF ***
  5715 
  5716 * Streams now come with concatenation and are part of the HOLCF image
  5717 
  5718 
  5719 
  5720 New in Isabelle2003 (May 2003)
  5721 ------------------------------
  5722 
  5723 *** General ***
  5724 
  5725 * Provers/simplifier:
  5726 
  5727   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  5728     Assumptions are now subject to complete mutual simplification,
  5729     not just from left to right. The simplifier now preserves
  5730     the order of assumptions.
  5731 
  5732     Potential INCOMPATIBILITY:
  5733 
  5734     -- simp sometimes diverges where the old version did
  5735        not, e.g. invoking simp on the goal
  5736 
  5737         [| P (f x); y = x; f x = f y |] ==> Q
  5738 
  5739        now gives rise to the infinite reduction sequence
  5740 
  5741         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  5742 
  5743        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  5744        kind of problem.
  5745 
  5746     -- Tactics combining classical reasoner and simplification (such as auto)
  5747        are also affected by this change, because many of them rely on
  5748        simp. They may sometimes diverge as well or yield a different numbers
  5749        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  5750        in case of problems. Sometimes subsequent calls to the classical
  5751        reasoner will fail because a preceeding call to the simplifier too
  5752        eagerly simplified the goal, e.g. deleted redundant premises.
  5753 
  5754   - The simplifier trace now shows the names of the applied rewrite rules
  5755 
  5756   - You can limit the number of recursive invocations of the simplifier
  5757     during conditional rewriting (where the simplifie tries to solve the
  5758     conditions before applying the rewrite rule):
  5759     ML "simp_depth_limit := n"
  5760     where n is an integer. Thus you can force termination where previously
  5761     the simplifier would diverge.
  5762 
  5763   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  5764 
  5765   - No longer aborts on failed congruence proof.  Instead, the
  5766     congruence is ignored.
  5767 
  5768 * Pure: New generic framework for extracting programs from constructive
  5769   proofs. See HOL/Extraction.thy for an example instantiation, as well
  5770   as HOL/Extraction for some case studies.
  5771 
  5772 * Pure: The main goal of the proof state is no longer shown by default, only
  5773 the subgoals. This behaviour is controlled by a new flag.
  5774    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  5775 (ML: Proof.show_main_goal).
  5776 
  5777 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  5778 rules whose conclusion matches subgoal 1:
  5779       PG menu: Isabelle/Isar -> Show me -> matching rules
  5780 The rules are ordered by how closely they match the subgoal.
  5781 In particular, rules that solve a subgoal outright are displayed first
  5782 (or rather last, the way they are printed).
  5783 (ML: ProofGeneral.print_intros())
  5784 
  5785 * Pure: New flag trace_unify_fail causes unification to print
  5786 diagnostic information (PG: in trace buffer) when it fails. This is
  5787 useful for figuring out why single step proofs like rule, erule or
  5788 assumption failed.
  5789 
  5790 * Pure: Locale specifications now produce predicate definitions
  5791 according to the body of text (covering assumptions modulo local
  5792 definitions); predicate "loc_axioms" covers newly introduced text,
  5793 while "loc" is cumulative wrt. all included locale expressions; the
  5794 latter view is presented only on export into the global theory
  5795 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  5796 on the old view without predicates;
  5797 
  5798 * Pure: predefined locales "var" and "struct" are useful for sharing
  5799 parameters (as in CASL, for example); just specify something like
  5800 ``var x + var y + struct M'' as import;
  5801 
  5802 * Pure: improved thms_containing: proper indexing of facts instead of
  5803 raw theorems; check validity of results wrt. current name space;
  5804 include local facts of proof configuration (also covers active
  5805 locales), cover fixed variables in index; may use "_" in term
  5806 specification; an optional limit for the number of printed facts may
  5807 be given (the default is 40);
  5808 
  5809 * Pure: disallow duplicate fact bindings within new-style theory files
  5810 (batch-mode only);
  5811 
  5812 * Provers: improved induct method: assumptions introduced by case
  5813 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  5814 the goal statement); "foo" still refers to all facts collectively;
  5815 
  5816 * Provers: the function blast.overloaded has been removed: all constants
  5817 are regarded as potentially overloaded, which improves robustness in exchange
  5818 for slight decrease in efficiency;
  5819 
  5820 * Provers/linorder: New generic prover for transitivity reasoning over
  5821 linear orders.  Note: this prover is not efficient!
  5822 
  5823 * Isar: preview of problems to finish 'show' now produce an error
  5824 rather than just a warning (in interactive mode);
  5825 
  5826 
  5827 *** HOL ***
  5828 
  5829 * arith(_tac)
  5830 
  5831  - Produces a counter example if it cannot prove a goal.
  5832    Note that the counter example may be spurious if the goal is not a formula
  5833    of quantifier-free linear arithmetic.
  5834    In ProofGeneral the counter example appears in the trace buffer.
  5835 
  5836  - Knows about div k and mod k where k is a numeral of type nat or int.
  5837 
  5838  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  5839    linear arithmetic fails. This takes account of quantifiers and divisibility.
  5840    Presburger arithmetic can also be called explicitly via presburger(_tac).
  5841 
  5842 * simp's arithmetic capabilities have been enhanced a bit: it now
  5843 takes ~= in premises into account (by performing a case split);
  5844 
  5845 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  5846 are distributed over a sum of terms;
  5847 
  5848 * New tactic "trans_tac" and method "trans" instantiate
  5849 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  5850 "<=", "<" and "=").
  5851 
  5852 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  5853 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  5854 
  5855 * 'typedef' command has new option "open" to suppress the set
  5856 definition;
  5857 
  5858 * functions Min and Max on finite sets have been introduced (theory
  5859 Finite_Set);
  5860 
  5861 * attribute [symmetric] now works for relations as well; it turns
  5862 (x,y) : R^-1 into (y,x) : R, and vice versa;
  5863 
  5864 * induct over a !!-quantified statement (say !!x1..xn):
  5865   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  5866 
  5867 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  5868 %x. None. Warning: empty_def now refers to the previously hidden definition
  5869 of the empty set.
  5870 
  5871 * Algebra: formalization of classical algebra.  Intended as base for
  5872 any algebraic development in Isabelle.  Currently covers group theory
  5873 (up to Sylow's theorem) and ring theory (Universal Property of
  5874 Univariate Polynomials).  Contributions welcome;
  5875 
  5876 * GroupTheory: deleted, since its material has been moved to Algebra;
  5877 
  5878 * Complex: new directory of the complex numbers with numeric constants,
  5879 nonstandard complex numbers, and some complex analysis, standard and
  5880 nonstandard (Jacques Fleuriot);
  5881 
  5882 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  5883 
  5884 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  5885 Fleuriot);
  5886 
  5887 * Real/HahnBanach: updated and adapted to locales;
  5888 
  5889 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  5890 Gray and Kramer);
  5891 
  5892 * UNITY: added the Meier-Sanders theory of progress sets;
  5893 
  5894 * MicroJava: bytecode verifier and lightweight bytecode verifier
  5895 as abstract algorithms, instantiated to the JVM;
  5896 
  5897 * Bali: Java source language formalization. Type system, operational
  5898 semantics, axiomatic semantics. Supported language features:
  5899 classes, interfaces, objects,virtual methods, static methods,
  5900 static/instance fields, arrays, access modifiers, definite
  5901 assignment, exceptions.
  5902 
  5903 
  5904 *** ZF ***
  5905 
  5906 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  5907 universe, etc.);
  5908 
  5909 * Main ZF: virtually all theories converted to new-style format;
  5910 
  5911 
  5912 *** ML ***
  5913 
  5914 * Pure: Tactic.prove provides sane interface for internal proofs;
  5915 omits the infamous "standard" operation, so this is more appropriate
  5916 than prove_goalw_cterm in many situations (e.g. in simprocs);
  5917 
  5918 * Pure: improved error reporting of simprocs;
  5919 
  5920 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  5921 up simprocs;
  5922 
  5923 
  5924 *** Document preparation ***
  5925 
  5926 * uses \par instead of \\ for line breaks in theory text. This may
  5927 shift some page breaks in large documents. To get the old behaviour
  5928 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  5929 
  5930 * minimized dependencies of isabelle.sty and isabellesym.sty on
  5931 other packages
  5932 
  5933 * \<euro> now needs package babel/greek instead of marvosym (which
  5934 broke \Rightarrow)
  5935 
  5936 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  5937 textcomp package)
  5938 
  5939 
  5940 
  5941 New in Isabelle2002 (March 2002)
  5942 --------------------------------
  5943 
  5944 *** Document preparation ***
  5945 
  5946 * greatly simplified document preparation setup, including more
  5947 graceful interpretation of isatool usedir -i/-d/-D options, and more
  5948 instructive isatool mkdir; users should basically be able to get
  5949 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  5950 users may run a separate document processing stage manually like this:
  5951 "isatool usedir -D output HOL Test && isatool document Test/output";
  5952 
  5953 * theory dependency graph may now be incorporated into documents;
  5954 isatool usedir -g true will produce session_graph.eps/.pdf for use
  5955 with \includegraphics of LaTeX;
  5956 
  5957 * proper spacing of consecutive markup elements, especially text
  5958 blocks after section headings;
  5959 
  5960 * support bold style (for single symbols only), input syntax is like
  5961 this: "\<^bold>\<alpha>" or "\<^bold>A";
  5962 
  5963 * \<bullet> is now output as bold \cdot by default, which looks much
  5964 better in printed text;
  5965 
  5966 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  5967 note that these symbols are currently unavailable in Proof General /
  5968 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  5969 
  5970 * isatool latex no longer depends on changed TEXINPUTS, instead
  5971 isatool document copies the Isabelle style files to the target
  5972 location;
  5973 
  5974 
  5975 *** Isar ***
  5976 
  5977 * Pure/Provers: improved proof by cases and induction;
  5978   - 'case' command admits impromptu naming of parameters (such as
  5979     "case (Suc n)");
  5980   - 'induct' method divinates rule instantiation from the inductive
  5981     claim; no longer requires excessive ?P bindings for proper
  5982     instantiation of cases;
  5983   - 'induct' method properly enumerates all possibilities of set/type
  5984     rules; as a consequence facts may be also passed through *type*
  5985     rules without further ado;
  5986   - 'induct' method now derives symbolic cases from the *rulified*
  5987     rule (before it used to rulify cases stemming from the internal
  5988     atomized version); this means that the context of a non-atomic
  5989     statement becomes is included in the hypothesis, avoiding the
  5990     slightly cumbersome show "PROP ?case" form;
  5991   - 'induct' may now use elim-style induction rules without chaining
  5992     facts, using ``missing'' premises from the goal state; this allows
  5993     rules stemming from inductive sets to be applied in unstructured
  5994     scripts, while still benefitting from proper handling of non-atomic
  5995     statements; NB: major inductive premises need to be put first, all
  5996     the rest of the goal is passed through the induction;
  5997   - 'induct' proper support for mutual induction involving non-atomic
  5998     rule statements (uses the new concept of simultaneous goals, see
  5999     below);
  6000   - append all possible rule selections, but only use the first
  6001     success (no backtracking);
  6002   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  6003   - undeclared rule case names default to numbers 1, 2, 3, ...;
  6004   - added 'print_induct_rules' (covered by help item in recent Proof
  6005     General versions);
  6006   - moved induct/cases attributes to Pure, methods to Provers;
  6007   - generic method setup instantiated for FOL and HOL;
  6008 
  6009 * Pure: support multiple simultaneous goal statements, for example
  6010 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  6011 meta-level mechanism, this acts as if several individual goals had
  6012 been stated separately; in particular common proof methods need to be
  6013 repeated in order to cover all claims; note that a single elimination
  6014 step is *not* sufficient to establish the two conjunctions, so this
  6015 fails:
  6016 
  6017   assume "A & B" then have A and B ..   (*".." fails*)
  6018 
  6019 better use "obtain" in situations as above; alternative refer to
  6020 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  6021 
  6022 * Pure: proper integration with ``locales''; unlike the original
  6023 version by Florian Kammller, Isar locales package high-level proof
  6024 contexts rather than raw logical ones (e.g. we admit to include
  6025 attributes everywhere); operations on locales include merge and
  6026 rename; support for implicit arguments (``structures''); simultaneous
  6027 type-inference over imports and text; see also HOL/ex/Locales.thy for
  6028 some examples;
  6029 
  6030 * Pure: the following commands have been ``localized'', supporting a
  6031 target locale specification "(in name)": 'lemma', 'theorem',
  6032 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  6033 stored both within the locale and at the theory level (exported and
  6034 qualified by the locale name);
  6035 
  6036 * Pure: theory goals may now be specified in ``long'' form, with
  6037 ad-hoc contexts consisting of arbitrary locale elements. for example
  6038 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  6039 definitions may be given, too); the result is a meta-level rule with
  6040 the context elements being discharged in the obvious way;
  6041 
  6042 * Pure: new proof command 'using' allows to augment currently used
  6043 facts after a goal statement ('using' is syntactically analogous to
  6044 'apply', but acts on the goal's facts only); this allows chained facts
  6045 to be separated into parts given before and after a claim, as in
  6046 ``from a and b have C using d and e <proof>'';
  6047 
  6048 * Pure: renamed "antecedent" case to "rule_context";
  6049 
  6050 * Pure: new 'judgment' command records explicit information about the
  6051 object-logic embedding (used by several tools internally); no longer
  6052 use hard-wired "Trueprop";
  6053 
  6054 * Pure: added 'corollary' command;
  6055 
  6056 * Pure: fixed 'token_translation' command;
  6057 
  6058 * Pure: removed obsolete 'exported' attribute;
  6059 
  6060 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  6061 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  6062 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  6063 
  6064 * Pure: method 'atomize' presents local goal premises as object-level
  6065 statements (atomic meta-level propositions); setup controlled via
  6066 rewrite rules declarations of 'atomize' attribute; example
  6067 application: 'induct' method with proper rule statements in improper
  6068 proof *scripts*;
  6069 
  6070 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  6071 now consider the syntactic context of assumptions, giving a better
  6072 chance to get type-inference of the arguments right (this is
  6073 especially important for locales);
  6074 
  6075 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  6076 mode;
  6077 
  6078 * Pure/obtain: the formal conclusion "thesis", being marked as
  6079 ``internal'', may no longer be reference directly in the text;
  6080 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  6081 situations;
  6082 
  6083 * Pure: generic 'sym' attribute which declares a rule both as pure
  6084 'elim?' and for the 'symmetric' operation;
  6085 
  6086 * Pure: marginal comments ``--'' may now occur just anywhere in the
  6087 text; the fixed correlation with particular command syntax has been
  6088 discontinued;
  6089 
  6090 * Pure: new method 'rules' is particularly well-suited for proof
  6091 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  6092 but often produces more compact proof terms with less detours;
  6093 
  6094 * Pure/Provers/classical: simplified integration with pure rule
  6095 attributes and methods; the classical "intro?/elim?/dest?"
  6096 declarations coincide with the pure ones; the "rule" method no longer
  6097 includes classically swapped intros; "intro" and "elim" methods no
  6098 longer pick rules from the context; also got rid of ML declarations
  6099 AddXIs/AddXEs/AddXDs; all of this has some potential for
  6100 INCOMPATIBILITY;
  6101 
  6102 * Provers/classical: attribute 'swapped' produces classical inversions
  6103 of introduction rules;
  6104 
  6105 * Provers/simplifier: 'simplified' attribute may refer to explicit
  6106 rules instead of full simplifier context; 'iff' attribute handles
  6107 conditional rules;
  6108 
  6109 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  6110 
  6111 * HOL: 'recdef' now fails on unfinished automated proofs, use
  6112 "(permissive)" option to recover old behavior;
  6113 
  6114 * HOL: 'inductive' no longer features separate (collective) attributes
  6115 for 'intros' (was found too confusing);
  6116 
  6117 * HOL: properly declared induction rules less_induct and
  6118 wf_induct_rule;
  6119 
  6120 
  6121 *** HOL ***
  6122 
  6123 * HOL: moved over to sane numeral syntax; the new policy is as
  6124 follows:
  6125 
  6126   - 0 and 1 are polymorphic constants, which are defined on any
  6127   numeric type (nat, int, real etc.);
  6128 
  6129   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  6130   binary representation internally;
  6131 
  6132   - type nat has special constructor Suc, and generally prefers Suc 0
  6133   over 1::nat and Suc (Suc 0) over 2::nat;
  6134 
  6135 This change may cause significant problems of INCOMPATIBILITY; here
  6136 are some hints on converting existing sources:
  6137 
  6138   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  6139   entities, so expressions involving "-" (unary or binary minus) need
  6140   to be spaced properly;
  6141 
  6142   - existing occurrences of "1" may need to be constraint "1::nat" or
  6143   even replaced by Suc 0; similar for old "2";
  6144 
  6145   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  6146 
  6147   - remove all special provisions on numerals in proofs;
  6148 
  6149 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  6150 representation (depends on bin_arith_simps in the default context);
  6151 
  6152 * HOL: symbolic syntax for x^2 (numeral 2);
  6153 
  6154 * HOL: the class of all HOL types is now called "type" rather than
  6155 "term"; INCOMPATIBILITY, need to adapt references to this type class
  6156 in axclass/classes, instance/arities, and (usually rare) occurrences
  6157 in typings (of consts etc.); internally the class is called
  6158 "HOL.type", ML programs should refer to HOLogic.typeS;
  6159 
  6160 * HOL/record package improvements:
  6161   - new derived operations "fields" to build a partial record section,
  6162     "extend" to promote a fixed record to a record scheme, and
  6163     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  6164     declared as simp by default;
  6165   - shared operations ("more", "fields", etc.) now need to be always
  6166     qualified) --- potential INCOMPATIBILITY;
  6167   - removed "make_scheme" operations (use "make" with "extend") --
  6168     INCOMPATIBILITY;
  6169   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  6170   - provides cases/induct rules for use with corresponding Isar
  6171     methods (for concrete records, record schemes, concrete more
  6172     parts, and schematic more parts -- in that order);
  6173   - internal definitions directly based on a light-weight abstract
  6174     theory of product types over typedef rather than datatype;
  6175 
  6176 * HOL: generic code generator for generating executable ML code from
  6177 specifications; specific support for HOL constructs such as inductive
  6178 datatypes and sets, as well as recursive functions; can be invoked
  6179 via 'generate_code' theory section;
  6180 
  6181 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  6182 
  6183 * HOL: consolidated and renamed several theories.  In particular:
  6184         Ord.thy has been absorbed into HOL.thy
  6185         String.thy has been absorbed into List.thy
  6186 
  6187 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  6188 (beware of argument permutation!);
  6189 
  6190 * HOL: linorder_less_split superseded by linorder_cases;
  6191 
  6192 * HOL/List: "nodups" renamed to "distinct";
  6193 
  6194 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  6195 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  6196   - Ex_def has changed, now need to use some_eq_ex
  6197 
  6198 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  6199 in this (rare) case use:
  6200 
  6201   delSWrapper "split_all_tac"
  6202   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  6203 
  6204 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  6205 MAY FAIL;
  6206 
  6207 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  6208 Isabelle's type classes, ^ on functions and relations has too general
  6209 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  6210 necessary to attach explicit type constraints;
  6211 
  6212 * HOL/Relation: the prefix name of the infix "O" has been changed from
  6213 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  6214 renamed accordingly (eg "compI" -> "rel_compI").
  6215 
  6216 * HOL: syntax translations now work properly with numerals and records
  6217 expressions;
  6218 
  6219 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  6220 of "lam" -- INCOMPATIBILITY;
  6221 
  6222 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  6223 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  6224 renamed "Product_Type.unit";
  6225 
  6226 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  6227 
  6228 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  6229 the "cases" method);
  6230 
  6231 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  6232 Florian Kammller);
  6233 
  6234 * HOL/IMP: updated and converted to new-style theory format; several
  6235 parts turned into readable document, with proper Isar proof texts and
  6236 some explanations (by Gerwin Klein);
  6237 
  6238 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  6239 
  6240 * HOL-Hyperreal is now a logic image;
  6241 
  6242 
  6243 *** HOLCF ***
  6244 
  6245 * Isar: consts/constdefs supports mixfix syntax for continuous
  6246 operations;
  6247 
  6248 * Isar: domain package adapted to new-style theory format, e.g. see
  6249 HOLCF/ex/Dnat.thy;
  6250 
  6251 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  6252 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  6253 lift.induct_tac, always use UU instead of Undef;
  6254 
  6255 * HOLCF/IMP: updated and converted to new-style theory;
  6256 
  6257 
  6258 *** ZF ***
  6259 
  6260 * Isar: proper integration of logic-specific tools and packages,
  6261 including theory commands '(co)inductive', '(co)datatype',
  6262 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  6263 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  6264 
  6265 * theory Main no longer includes AC; for the Axiom of Choice, base
  6266 your theory on Main_ZFC;
  6267 
  6268 * the integer library now covers quotients and remainders, with many
  6269 laws relating division to addition, multiplication, etc.;
  6270 
  6271 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  6272 typeless version of the formalism;
  6273 
  6274 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  6275 format;
  6276 
  6277 * ZF/Induct: new directory for examples of inductive definitions,
  6278 including theory Multiset for multiset orderings; converted to
  6279 new-style theory format;
  6280 
  6281 * ZF: many new theorems about lists, ordinals, etc.;
  6282 
  6283 
  6284 *** General ***
  6285 
  6286 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  6287 variable proof controls level of detail: 0 = no proofs (only oracle
  6288 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  6289 also ref manual for further ML interfaces;
  6290 
  6291 * Pure/axclass: removed obsolete ML interface
  6292 goal_subclass/goal_arity;
  6293 
  6294 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  6295 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  6296 separate tokens, so expressions involving minus need to be spaced
  6297 properly;
  6298 
  6299 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  6300 rather than "infixl" or "infixr";
  6301 
  6302 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  6303 sort constraint specifications in type inference; e.g. "x::_::foo"
  6304 ensures that the type of "x" is of sort "foo" (but not necessarily a
  6305 type variable);
  6306 
  6307 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  6308 control output of nested => (types); the default behavior is
  6309 "type_brackets";
  6310 
  6311 * Pure/syntax: builtin parse translation for "_constify" turns valued
  6312 tokens into AST constants;
  6313 
  6314 * Pure/syntax: prefer later declarations of translations and print
  6315 translation functions; potential INCOMPATIBILITY: need to reverse
  6316 multiple declarations for same syntax element constant;
  6317 
  6318 * Pure/show_hyps reset by default (in accordance to existing Isar
  6319 practice);
  6320 
  6321 * Provers/classical: renamed addaltern to addafter, addSaltern to
  6322 addSafter;
  6323 
  6324 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  6325 as well;
  6326 
  6327 * system: tested support for MacOS X; should be able to get Isabelle +
  6328 Proof General to work in a plain Terminal after installing Poly/ML
  6329 (e.g. from the Isabelle distribution area) and GNU bash alone
  6330 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  6331 support requires further installations, e.g. from
  6332 http://fink.sourceforge.net/);
  6333 
  6334 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  6335 
  6336 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  6337 of 40 MB), cf. ML_OPTIONS;
  6338 
  6339 * system: Proof General keywords specification is now part of the
  6340 Isabelle distribution (see etc/isar-keywords.el);
  6341 
  6342 * system: support for persistent Proof General sessions (refrain from
  6343 outdating all loaded theories on startup); user may create writable
  6344 logic images like this: ``isabelle -q HOL Test'';
  6345 
  6346 * system: smart selection of Isabelle process versus Isabelle
  6347 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  6348 run both "isabelle" and "Isabelle" even if file names are badly
  6349 damaged (executable inspects the case of the first letter of its own
  6350 name); added separate "isabelle-process" and "isabelle-interface";
  6351 
  6352 * system: refrain from any attempt at filtering input streams; no
  6353 longer support ``8bit'' encoding of old isabelle font, instead proper
  6354 iso-latin characters may now be used; the related isatools
  6355 "symbolinput" and "nonascii" have disappeared as well;
  6356 
  6357 * system: removed old "xterm" interface (the print modes "xterm" and
  6358 "xterm_color" are still available for direct use in a suitable
  6359 terminal);
  6360 
  6361 
  6362 
  6363 New in Isabelle99-2 (February 2001)
  6364 -----------------------------------
  6365 
  6366 *** Overview of INCOMPATIBILITIES ***
  6367 
  6368 * HOL: please note that theories in the Library and elsewhere often use the
  6369 new-style (Isar) format; to refer to their theorems in an ML script you must
  6370 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  6371 
  6372 * HOL: inductive package no longer splits induction rule aggressively,
  6373 but only as far as specified by the introductions given; the old
  6374 format may be recovered via ML function complete_split_rule or attribute
  6375 'split_rule (complete)';
  6376 
  6377 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  6378 gfp_Tarski to gfp_unfold;
  6379 
  6380 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  6381 
  6382 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  6383 relation); infix "^^" has been renamed "``"; infix "``" has been
  6384 renamed "`"; "univalent" has been renamed "single_valued";
  6385 
  6386 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  6387 operation;
  6388 
  6389 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  6390 
  6391 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  6392 
  6393 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  6394 consequence, it is no longer monotonic wrt. the local goal context
  6395 (which is now passed through the inductive cases);
  6396 
  6397 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  6398 \<gg> to \<ggreater>;
  6399 
  6400 
  6401 *** Document preparation ***
  6402 
  6403 * \isabellestyle{NAME} selects version of Isabelle output (currently
  6404 available: are "it" for near math-mode best-style output, "sl" for
  6405 slanted text style, and "tt" for plain type-writer; if no
  6406 \isabellestyle command is given, output is according to slanted
  6407 type-writer);
  6408 
  6409 * support sub/super scripts (for single symbols only), input syntax is
  6410 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  6411 
  6412 * some more standard symbols; see Appendix A of the system manual for
  6413 the complete list of symbols defined in isabellesym.sty;
  6414 
  6415 * improved isabelle style files; more abstract symbol implementation
  6416 (should now use \isamath{...} and \isatext{...} in custom symbol
  6417 definitions);
  6418 
  6419 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  6420 state; Note that presentation of goal states does not conform to
  6421 actual human-readable proof documents.  Please do not include goal
  6422 states into document output unless you really know what you are doing!
  6423 
  6424 * proper indentation of antiquoted output with proportional LaTeX
  6425 fonts;
  6426 
  6427 * no_document ML operator temporarily disables LaTeX document
  6428 generation;
  6429 
  6430 * isatool unsymbolize tunes sources for plain ASCII communication;
  6431 
  6432 
  6433 *** Isar ***
  6434 
  6435 * Pure: Isar now suffers initial goal statements to contain unbound
  6436 schematic variables (this does not conform to actual readable proof
  6437 documents, due to unpredictable outcome and non-compositional proof
  6438 checking); users who know what they are doing may use schematic goals
  6439 for Prolog-style synthesis of proven results;
  6440 
  6441 * Pure: assumption method (an implicit finishing) now handles actual
  6442 rules as well;
  6443 
  6444 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  6445 initial goal, declare "that" only as Pure intro (only for single
  6446 steps); the "that" rule assumption may now be involved in implicit
  6447 finishing, thus ".." becomes a feasible for trivial obtains;
  6448 
  6449 * Pure: default proof step now includes 'intro_classes'; thus trivial
  6450 instance proofs may be performed by "..";
  6451 
  6452 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  6453 statements as well;
  6454 
  6455 * Pure: more robust selection of calculational rules;
  6456 
  6457 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  6458 rule (as well as the assumption rule);
  6459 
  6460 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  6461 lemmas, using the graph browser tool;
  6462 
  6463 * Pure: predict failure of "show" in interactive mode;
  6464 
  6465 * Pure: 'thms_containing' now takes actual terms as arguments;
  6466 
  6467 * HOL: improved method 'induct' --- now handles non-atomic goals
  6468 (potential INCOMPATIBILITY); tuned error handling;
  6469 
  6470 * HOL: cases and induct rules now provide explicit hints about the
  6471 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  6472 any remaining facts are inserted into the goal verbatim;
  6473 
  6474 * HOL: local contexts (aka cases) may now contain term bindings as
  6475 well; the 'cases' and 'induct' methods new provide a ?case binding for
  6476 the result to be shown in each case;
  6477 
  6478 * HOL: added 'recdef_tc' command;
  6479 
  6480 * isatool convert assists in eliminating legacy ML scripts;
  6481 
  6482 
  6483 *** HOL ***
  6484 
  6485 * HOL/Library: a collection of generic theories to be used together
  6486 with main HOL; the theory loader path already includes this directory
  6487 by default; the following existing theories have been moved here:
  6488 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  6489 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  6490 
  6491 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  6492 modelling and verification task performed in Isabelle/HOL +
  6493 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  6494 
  6495 * HOL/Algebra: special summation operator SUM no longer exists, it has
  6496 been replaced by setsum; infix 'assoc' now has priority 50 (like
  6497 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  6498 'domain', this makes the theory consistent with mathematical
  6499 literature;
  6500 
  6501 * HOL basics: added overloaded operations "inverse" and "divide"
  6502 (infix "/"), syntax for generic "abs" operation, generic summation
  6503 operator \<Sum>;
  6504 
  6505 * HOL/typedef: simplified package, provide more useful rules (see also
  6506 HOL/subset.thy);
  6507 
  6508 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  6509 now expressed as a proper nested rule (old-style tactic scripts may
  6510 require atomize_strip_tac to cope with non-atomic premises);
  6511 
  6512 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  6513 to "split_conv" (old name still available for compatibility);
  6514 
  6515 * HOL: improved concrete syntax for strings (e.g. allows translation
  6516 rules with string literals);
  6517 
  6518 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  6519  and Fleuriot's mechanization of analysis, including the transcendental
  6520  functions for the reals;
  6521 
  6522 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  6523 
  6524 
  6525 *** CTT ***
  6526 
  6527 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  6528 "lam" is displayed as TWO lambda-symbols
  6529 
  6530 * CTT: theory Main now available, containing everything (that is, Bool
  6531 and Arith);
  6532 
  6533 
  6534 *** General ***
  6535 
  6536 * Pure: the Simplifier has been implemented properly as a derived rule
  6537 outside of the actual kernel (at last!); the overall performance
  6538 penalty in practical applications is about 50%, while reliability of
  6539 the Isabelle inference kernel has been greatly improved;
  6540 
  6541 * print modes "brackets" and "no_brackets" control output of nested =>
  6542 (types) and ==> (props); the default behaviour is "brackets";
  6543 
  6544 * Provers: fast_tac (and friends) now handle actual object-logic rules
  6545 as assumptions as well;
  6546 
  6547 * system: support Poly/ML 4.0;
  6548 
  6549 * system: isatool install handles KDE version 1 or 2;
  6550 
  6551 
  6552 
  6553 New in Isabelle99-1 (October 2000)
  6554 ----------------------------------
  6555 
  6556 *** Overview of INCOMPATIBILITIES ***
  6557 
  6558 * HOL: simplification of natural numbers is much changed; to partly
  6559 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  6560 issue the following ML commands:
  6561 
  6562   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  6563   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  6564 
  6565 * HOL: simplification no longer dives into case-expressions; this is
  6566 controlled by "t.weak_case_cong" for each datatype t;
  6567 
  6568 * HOL: nat_less_induct renamed to less_induct;
  6569 
  6570 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  6571 fixsome to patch .thy and .ML sources automatically;
  6572 
  6573   select_equality  -> some_equality
  6574   select_eq_Ex     -> some_eq_ex
  6575   selectI2EX       -> someI2_ex
  6576   selectI2         -> someI2
  6577   selectI          -> someI
  6578   select1_equality -> some1_equality
  6579   Eps_sym_eq       -> some_sym_eq_trivial
  6580   Eps_eq           -> some_eq_trivial
  6581 
  6582 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  6583 
  6584 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  6585 instead);
  6586 
  6587 * HOL: the recursion equations generated by 'recdef' are now called
  6588 f.simps instead of f.rules;
  6589 
  6590 * HOL: qed_spec_mp now also handles bounded ALL as well;
  6591 
  6592 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  6593 sometimes be needed;
  6594 
  6595 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  6596 
  6597 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  6598 
  6599 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  6600 product is now "<*>" instead of "Times"; the lexicographic product is
  6601 now "<*lex*>" instead of "**";
  6602 
  6603 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  6604 of main HOL, but was unused); better use HOL's datatype package;
  6605 
  6606 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  6607 the old syntax may be recovered as follows:
  6608 
  6609   syntax (symbols)
  6610     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  6611       (infixl "\\<oplus>" 100)
  6612 
  6613 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  6614 
  6615 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  6616 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  6617 internally;
  6618 
  6619 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  6620 changed from A/r to A//r;
  6621 
  6622 * ZF: new treatment of arithmetic (nat & int) may break some old
  6623 proofs;
  6624 
  6625 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  6626 rulify -> rule_format, elimify -> elim_format, ...);
  6627 
  6628 * Isar/Provers: intro/elim/dest attributes changed; renamed
  6629 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  6630 should have to change intro!! to intro? only); replaced "delrule" by
  6631 "rule del";
  6632 
  6633 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  6634 
  6635 * Provers: strengthened force_tac by using new first_best_tac;
  6636 
  6637 * LaTeX document preparation: several changes of isabelle.sty (see
  6638 lib/texinputs);
  6639 
  6640 
  6641 *** Document preparation ***
  6642 
  6643 * formal comments (text blocks etc.) in new-style theories may now
  6644 contain antiquotations of thm/prop/term/typ/text to be presented
  6645 according to latex print mode; concrete syntax is like this:
  6646 @{term[show_types] "f(x) = a + x"};
  6647 
  6648 * isatool mkdir provides easy setup of Isabelle session directories,
  6649 including proper document sources;
  6650 
  6651 * generated LaTeX sources are now deleted after successful run
  6652 (isatool document -c); may retain a copy somewhere else via -D option
  6653 of isatool usedir;
  6654 
  6655 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  6656 style files, achieving self-contained LaTeX sources and simplifying
  6657 LaTeX debugging;
  6658 
  6659 * old-style theories now produce (crude) LaTeX output as well;
  6660 
  6661 * browser info session directories are now self-contained (may be put
  6662 on WWW server seperately); improved graphs of nested sessions; removed
  6663 graph for 'all sessions';
  6664 
  6665 * several improvements in isabelle style files; \isabellestyle{it}
  6666 produces fake math mode output; \isamarkupheader is now \section by
  6667 default; see lib/texinputs/isabelle.sty etc.;
  6668 
  6669 
  6670 *** Isar ***
  6671 
  6672 * Isar/Pure: local results and corresponding term bindings are now
  6673 subject to Hindley-Milner polymorphism (similar to ML); this
  6674 accommodates incremental type-inference very nicely;
  6675 
  6676 * Isar/Pure: new derived language element 'obtain' supports
  6677 generalized existence reasoning;
  6678 
  6679 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  6680 support accumulation of results, without applying any rules yet;
  6681 useful to collect intermediate results without explicit name
  6682 references, and for use with transitivity rules with more than 2
  6683 premises;
  6684 
  6685 * Isar/Pure: scalable support for case-analysis type proofs: new
  6686 'case' language element refers to local contexts symbolically, as
  6687 produced by certain proof methods; internally, case names are attached
  6688 to theorems as "tags";
  6689 
  6690 * Isar/Pure: theory command 'hide' removes declarations from
  6691 class/type/const name spaces;
  6692 
  6693 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  6694 indicate potential overloading;
  6695 
  6696 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  6697 
  6698 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  6699 "{a,b,c}" instead of {a,b,c};
  6700 
  6701 * Isar/Pure now provides its own version of intro/elim/dest
  6702 attributes; useful for building new logics, but beware of confusion
  6703 with the version in Provers/classical;
  6704 
  6705 * Isar/Pure: the local context of (non-atomic) goals is provided via
  6706 case name 'antecedent';
  6707 
  6708 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  6709 to the current context is now done automatically);
  6710 
  6711 * Isar/Pure: theory command 'method_setup' provides a simple interface
  6712 for definining proof methods in ML;
  6713 
  6714 * Isar/Provers: intro/elim/dest attributes changed; renamed
  6715 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  6716 most cases, one should have to change intro!! to intro? only);
  6717 replaced "delrule" by "rule del";
  6718 
  6719 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  6720 'symmetric' attribute (the latter supercedes [RS sym]);
  6721 
  6722 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  6723 method modifier); 'simp' method: 'only:' modifier removes loopers as
  6724 well (including splits);
  6725 
  6726 * Isar/Provers: Simplifier and Classical methods now support all kind
  6727 of modifiers used in the past, including 'cong', 'iff', etc.
  6728 
  6729 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  6730 of Simplifier and Classical reasoner);
  6731 
  6732 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  6733 now support named cases; major packages (inductive, datatype, primrec,
  6734 recdef) support case names and properly name parameters;
  6735 
  6736 * Isar/HOL: new transitivity rules for substitution in inequalities --
  6737 monotonicity conditions are extracted to be proven at end of
  6738 calculations;
  6739 
  6740 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  6741 method anyway;
  6742 
  6743 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  6744 split_if split_if_asm; datatype package provides theorems foo.splits =
  6745 foo.split foo.split_asm for each datatype;
  6746 
  6747 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  6748 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  6749 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  6750 use "(cases (simplified))" method in proper proof texts);
  6751 
  6752 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  6753 
  6754 * Isar: names of theorems etc. may be natural numbers as well;
  6755 
  6756 * Isar: 'pr' command: optional arguments for goals_limit and
  6757 ProofContext.prems_limit; no longer prints theory contexts, but only
  6758 proof states;
  6759 
  6760 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  6761 additional print modes to be specified; e.g. "pr(latex)" will print
  6762 proof state according to the Isabelle LaTeX style;
  6763 
  6764 * Isar: improved support for emulating tactic scripts, including proof
  6765 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  6766 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  6767 (for HOL datatypes);
  6768 
  6769 * Isar: simplified (more robust) goal selection of proof methods: 1st
  6770 goal, all goals, or explicit goal specifier (tactic emulation); thus
  6771 'proof method scripts' have to be in depth-first order;
  6772 
  6773 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  6774 
  6775 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  6776 should instead use individual commands for printing items
  6777 (print_commands, print_methods etc.);
  6778 
  6779 * Isar: added 'nothing' --- the empty list of theorems;
  6780 
  6781 
  6782 *** HOL ***
  6783 
  6784 * HOL/MicroJava: formalization of a fragment of Java, together with a
  6785 corresponding virtual machine and a specification of its bytecode
  6786 verifier and a lightweight bytecode verifier, including proofs of
  6787 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  6788 Cornelia Pusch (see also the homepage of project Bali at
  6789 http://isabelle.in.tum.de/Bali/);
  6790 
  6791 * HOL/Algebra: new theory of rings and univariate polynomials, by
  6792 Clemens Ballarin;
  6793 
  6794 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  6795 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  6796 Rasmussen;
  6797 
  6798 * HOL/Lattice: fundamental concepts of lattice theory and order
  6799 structures, including duals, properties of bounds versus algebraic
  6800 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  6801 Theorem for complete lattices etc.; may also serve as a demonstration
  6802 for abstract algebraic reasoning using axiomatic type classes, and
  6803 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  6804 
  6805 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  6806 von Oheimb;
  6807 
  6808 * HOL/IMPP: extension of IMP with local variables and mutually
  6809 recursive procedures, by David von Oheimb;
  6810 
  6811 * HOL/Lambda: converted into new-style theory and document;
  6812 
  6813 * HOL/ex/Multiquote: example of multiple nested quotations and
  6814 anti-quotations -- basically a generalized version of de-Bruijn
  6815 representation; very useful in avoiding lifting of operations;
  6816 
  6817 * HOL/record: added general record equality rule to simpset; fixed
  6818 select-update simplification procedure to handle extended records as
  6819 well; admit "r" as field name;
  6820 
  6821 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  6822 other numeric types and also as the identity of groups, rings, etc.;
  6823 
  6824 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  6825 Types nat and int belong to this axclass;
  6826 
  6827 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  6828    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  6829    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  6830   two terms #m*u and #n*u are replaced by #(m+n)*u
  6831     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  6832   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  6833     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  6834 
  6835 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  6836 powerful prover for predicate logic but knows nothing of clasets; see
  6837 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  6838 
  6839 * HOL: new version of "case_tac" subsumes both boolean case split and
  6840 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  6841 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  6842 
  6843 * HOL: simplification no longer dives into case-expressions: only the
  6844 selector expression is simplified, but not the remaining arms; to
  6845 enable full simplification of case-expressions for datatype t, you may
  6846 remove t.weak_case_cong from the simpset, either globally (Delcongs
  6847 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  6848 
  6849 * HOL/recdef: the recursion equations generated by 'recdef' for
  6850 function 'f' are now called f.simps instead of f.rules; if all
  6851 termination conditions are proved automatically, these simplification
  6852 rules are added to the simpset, as in primrec; rules may be named
  6853 individually as well, resulting in a separate list of theorems for
  6854 each equation;
  6855 
  6856 * HOL/While is a new theory that provides a while-combinator. It
  6857 permits the definition of tail-recursive functions without the
  6858 provision of a termination measure. The latter is necessary once the
  6859 invariant proof rule for while is applied.
  6860 
  6861 * HOL: new (overloaded) notation for the set of elements below/above
  6862 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  6863 
  6864 * HOL: theorems impI, allI, ballI bound as "strip";
  6865 
  6866 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  6867 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  6868 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  6869 
  6870 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  6871 
  6872 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  6873 main HOL, but was unused);
  6874 
  6875 * HOL: fewer consts declared as global (e.g. have to refer to
  6876 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  6877 
  6878 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  6879 in case of overlap with user translations (e.g. judgements over
  6880 tuples); (note that the underlying logical represenation is still
  6881 bogus);
  6882 
  6883 
  6884 *** ZF ***
  6885 
  6886 * ZF: simplification automatically cancels common terms in arithmetic
  6887 expressions over nat and int;
  6888 
  6889 * ZF: new treatment of nat to minimize type-checking: all operators
  6890 coerce their operands to a natural number using the function natify,
  6891 making the algebraic laws unconditional;
  6892 
  6893 * ZF: as above, for int: operators coerce their operands to an integer
  6894 using the function intify;
  6895 
  6896 * ZF: the integer library now contains many of the usual laws for the
  6897 orderings, including $<=, and monotonicity laws for $+ and $*;
  6898 
  6899 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  6900 simplification;
  6901 
  6902 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  6903 to the simplifier and classical reasoner simultaneously;
  6904 
  6905 
  6906 *** General ***
  6907 
  6908 * Provers: blast_tac now handles actual object-logic rules as
  6909 assumptions; note that auto_tac uses blast_tac internally as well;
  6910 
  6911 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  6912 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  6913 
  6914 * Provers: delrules now handles destruct rules as well (no longer need
  6915 explicit make_elim);
  6916 
  6917 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  6918   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  6919 use instead the strong form,
  6920   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  6921 in HOL, FOL and ZF the function cla_make_elim will create such rules
  6922 from destruct-rules;
  6923 
  6924 * Provers: Simplifier.easy_setup provides a fast path to basic
  6925 Simplifier setup for new object-logics;
  6926 
  6927 * Pure: AST translation rules no longer require constant head on LHS;
  6928 
  6929 * Pure: improved name spaces: ambiguous output is qualified; support
  6930 for hiding of names;
  6931 
  6932 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  6933 XSYMBOL_HOME; no longer need to do manual configuration in most
  6934 situations;
  6935 
  6936 * system: compression of ML heaps images may now be controlled via -c
  6937 option of isabelle and isatool usedir (currently only observed by
  6938 Poly/ML);
  6939 
  6940 * system: isatool installfonts may handle X-Symbol fonts as well (very
  6941 useful for remote X11);
  6942 
  6943 * system: provide TAGS file for Isabelle sources;
  6944 
  6945 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  6946 order;
  6947 
  6948 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  6949 timing flag supersedes proof_timing and Toplevel.trace;
  6950 
  6951 * ML: new combinators |>> and |>>> for incremental transformations
  6952 with secondary results (e.g. certain theory extensions):
  6953 
  6954 * ML: PureThy.add_defs gets additional argument to indicate potential
  6955 overloading (usually false);
  6956 
  6957 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  6958 results;
  6959 
  6960 
  6961 
  6962 New in Isabelle99 (October 1999)
  6963 --------------------------------
  6964 
  6965 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  6966 
  6967 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  6968 are no longer simplified.  (This allows the simplifier to unfold recursive
  6969 functional programs.)  To restore the old behaviour, declare
  6970 
  6971     Delcongs [if_weak_cong];
  6972 
  6973 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  6974 complement;
  6975 
  6976 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  6977 
  6978 * HOL/datatype: mutual_induct_tac no longer exists --
  6979   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  6980 
  6981 * HOL/typedef: fixed type inference for representing set; type
  6982 arguments now have to occur explicitly on the rhs as type constraints;
  6983 
  6984 * ZF: The con_defs part of an inductive definition may no longer refer
  6985 to constants declared in the same theory;
  6986 
  6987 * HOL, ZF: the function mk_cases, generated by the inductive
  6988 definition package, has lost an argument.  To simplify its result, it
  6989 uses the default simpset instead of a supplied list of theorems.
  6990 
  6991 * HOL/List: the constructors of type list are now Nil and Cons;
  6992 
  6993 * Simplifier: the type of the infix ML functions
  6994         setSSolver addSSolver setSolver addSolver
  6995 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  6996 for packaging solvers. A solver is created via
  6997         mk_solver: string -> (thm list -> int -> tactic) -> solver
  6998 where the string argument is only a comment.
  6999 
  7000 
  7001 *** Proof tools ***
  7002 
  7003 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  7004 decision procedure for linear arithmetic. Currently it is used for
  7005 types `nat', `int', and `real' in HOL (see below); it can, should and
  7006 will be instantiated for other types and logics as well.
  7007 
  7008 * The simplifier now accepts rewrite rules with flexible heads, eg
  7009      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  7010   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  7011   matching.
  7012 
  7013 
  7014 *** General ***
  7015 
  7016 * New Isabelle/Isar subsystem provides an alternative to traditional
  7017 tactical theorem proving; together with the ProofGeneral/isar user
  7018 interface it offers an interactive environment for developing human
  7019 readable proof documents (Isar == Intelligible semi-automated
  7020 reasoning); for further information see isatool doc isar-ref,
  7021 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  7022 
  7023 * improved and simplified presentation of theories: better HTML markup
  7024 (including colors), graph views in several sizes; isatool usedir now
  7025 provides a proper interface for user theories (via -P option); actual
  7026 document preparation based on (PDF)LaTeX is available as well (for
  7027 new-style theories only); see isatool doc system for more information;
  7028 
  7029 * native support for Proof General, both for classic Isabelle and
  7030 Isabelle/Isar;
  7031 
  7032 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  7033 using the graph browser tool;
  7034 
  7035 * Isabelle manuals now also available as PDF;
  7036 
  7037 * theory loader rewritten from scratch (may not be fully
  7038 bug-compatible); old loadpath variable has been replaced by show_path,
  7039 add_path, del_path, reset_path functions; new operations such as
  7040 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  7041 isatool doc ref);
  7042 
  7043 * improved isatool install: option -k creates KDE application icon,
  7044 option -p DIR installs standalone binaries;
  7045 
  7046 * added ML_PLATFORM setting (useful for cross-platform installations);
  7047 more robust handling of platform specific ML images for SML/NJ;
  7048 
  7049 * the settings environment is now statically scoped, i.e. it is never
  7050 created again in sub-processes invoked from isabelle, isatool, or
  7051 Isabelle;
  7052 
  7053 * path element specification '~~' refers to '$ISABELLE_HOME';
  7054 
  7055 * in locales, the "assumes" and "defines" parts may be omitted if
  7056 empty;
  7057 
  7058 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  7059 long arrows);
  7060 
  7061 * new print_mode "HTML";
  7062 
  7063 * new flag show_tags controls display of tags of theorems (which are
  7064 basically just comments that may be attached by some tools);
  7065 
  7066 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  7067 mode and goal output format:
  7068 
  7069 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  7070 244c244
  7071 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  7072 ---
  7073 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  7074 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  7075 181c181
  7076 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  7077 ---
  7078 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  7079 
  7080 * function bind_thms stores lists of theorems (cf. bind_thm);
  7081 
  7082 * new shorthand tactics ftac, eatac, datac, fatac;
  7083 
  7084 * qed (and friends) now accept "" as result name; in that case the
  7085 theorem is not stored, but proper checks and presentation of the
  7086 result still apply;
  7087 
  7088 * theorem database now also indexes constants "Trueprop", "all",
  7089 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  7090 
  7091 
  7092 *** HOL ***
  7093 
  7094 ** HOL arithmetic **
  7095 
  7096 * There are now decision procedures for linear arithmetic over nat and
  7097 int:
  7098 
  7099 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  7100 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  7101 are treated as atomic; subformulae not involving type `nat' or `int'
  7102 are ignored; quantified subformulae are ignored unless they are
  7103 positive universal or negative existential. The tactic has to be
  7104 invoked by hand and can be a little bit slow. In particular, the
  7105 running time is exponential in the number of occurrences of `min' and
  7106 `max', and `-' on `nat'.
  7107 
  7108 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  7109 (negated) (in)equalities among the premises and the conclusion into
  7110 account (i.e. no compound formulae) and does not know about `min' and
  7111 `max', and `-' on `nat'. It is fast and is used automatically by the
  7112 simplifier.
  7113 
  7114 NB: At the moment, these decision procedures do not cope with mixed
  7115 nat/int formulae where the two parts interact, such as `m < n ==>
  7116 int(m) < int(n)'.
  7117 
  7118 * HOL/Numeral provides a generic theory of numerals (encoded
  7119 efficiently as bit strings); setup for types nat/int/real is in place;
  7120 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  7121 int, existing theories and proof scripts may require a few additional
  7122 type constraints;
  7123 
  7124 * integer division and remainder can now be performed on constant
  7125 arguments;
  7126 
  7127 * many properties of integer multiplication, division and remainder
  7128 are now available;
  7129 
  7130 * An interface to the Stanford Validity Checker (SVC) is available through the
  7131 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  7132 are proved automatically.  SVC must be installed separately, and its results
  7133 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  7134 invocation of the underlying oracle).  For SVC see
  7135   http://verify.stanford.edu/SVC
  7136 
  7137 * IsaMakefile: the HOL-Real target now builds an actual image;
  7138 
  7139 
  7140 ** HOL misc **
  7141 
  7142 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  7143 (in Isabelle/Isar) -- by Gertrud Bauer;
  7144 
  7145 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  7146 analysis for assembly languages with subtypes;
  7147 
  7148 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  7149 -- avoids syntactic ambiguities and treats state, transition, and
  7150 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  7151 changed syntax and (many) tactics;
  7152 
  7153 * HOL/inductive: Now also handles more general introduction rules such
  7154   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  7155   theorems are now maintained within the theory (maintained via the
  7156   "mono" attribute);
  7157 
  7158 * HOL/datatype: Now also handles arbitrarily branching datatypes
  7159   (using function types) such as
  7160 
  7161   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  7162 
  7163 * HOL/record: record_simproc (part of the default simpset) takes care
  7164 of selectors applied to updated records; record_split_tac is no longer
  7165 part of the default claset; update_defs may now be removed from the
  7166 simpset in many cases; COMPATIBILITY: old behavior achieved by
  7167 
  7168   claset_ref () := claset() addSWrapper record_split_wrapper;
  7169   Delsimprocs [record_simproc]
  7170 
  7171 * HOL/typedef: fixed type inference for representing set; type
  7172 arguments now have to occur explicitly on the rhs as type constraints;
  7173 
  7174 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  7175 names rather than an ML expression;
  7176 
  7177 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  7178 supplied later.  Program schemes can be defined, such as
  7179     "While B C s = (if B s then While B C (C s) else s)"
  7180 where the well-founded relation can be chosen after B and C have been given.
  7181 
  7182 * HOL/List: the constructors of type list are now Nil and Cons;
  7183 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  7184 course, ML tools referring to List.list.op # etc. have to be adapted;
  7185 
  7186 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  7187 disabled by default; run isabelle with option -m HOL to get back to
  7188 the original Gordon/HOL-style output;
  7189 
  7190 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  7191 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  7192 
  7193 * HOL basic syntax simplified (more orthogonal): all variants of
  7194 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  7195 Eps operator is provided as well: "SOME x. P[x]";
  7196 
  7197 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  7198 
  7199 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  7200 thus available for user theories;
  7201 
  7202 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  7203 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  7204 time;
  7205 
  7206 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  7207 several times and then mp;
  7208 
  7209 
  7210 *** LK ***
  7211 
  7212 * the notation <<...>> is now available as a notation for sequences of
  7213 formulas;
  7214 
  7215 * the simplifier is now installed
  7216 
  7217 * the axiom system has been generalized (thanks to Soren Heilmann)
  7218 
  7219 * the classical reasoner now has a default rule database
  7220 
  7221 
  7222 *** ZF ***
  7223 
  7224 * new primrec section allows primitive recursive functions to be given
  7225 directly (as in HOL) over datatypes and the natural numbers;
  7226 
  7227 * new tactics induct_tac and exhaust_tac for induction (or case
  7228 analysis) over datatypes and the natural numbers;
  7229 
  7230 * the datatype declaration of type T now defines the recursor T_rec;
  7231 
  7232 * simplification automatically does freeness reasoning for datatype
  7233 constructors;
  7234 
  7235 * automatic type-inference, with AddTCs command to insert new
  7236 type-checking rules;
  7237 
  7238 * datatype introduction rules are now added as Safe Introduction rules
  7239 to the claset;
  7240 
  7241 * the syntax "if P then x else y" is now available in addition to
  7242 if(P,x,y);
  7243 
  7244 
  7245 *** Internal programming interfaces ***
  7246 
  7247 * tuned simplifier trace output; new flag debug_simp;
  7248 
  7249 * structures Vartab / Termtab (instances of TableFun) offer efficient
  7250 tables indexed by indexname_ord / term_ord (compatible with aconv);
  7251 
  7252 * AxClass.axclass_tac lost the theory argument;
  7253 
  7254 * tuned current_goals_markers semantics: begin / end goal avoids
  7255 printing empty lines;
  7256 
  7257 * removed prs and prs_fn hook, which was broken because it did not
  7258 include \n in its semantics, forcing writeln to add one
  7259 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  7260 string -> unit if you really want to output text without newline;
  7261 
  7262 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  7263 plain output, interface builders may have to enable 'isabelle_font'
  7264 mode to get Isabelle font glyphs as before;
  7265 
  7266 * refined token_translation interface; INCOMPATIBILITY: output length
  7267 now of type real instead of int;
  7268 
  7269 * theory loader actions may be traced via new ThyInfo.add_hook
  7270 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  7271 your own database of information attached to *whole* theories -- as
  7272 opposed to intra-theory data slots offered via TheoryDataFun;
  7273 
  7274 * proper handling of dangling sort hypotheses (at last!);
  7275 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  7276 extra sort hypotheses that can be witnessed from the type signature;
  7277 the force_strip_shyps flag is gone, any remaining shyps are simply
  7278 left in the theorem (with a warning issued by strip_shyps_warning);
  7279 
  7280 
  7281 
  7282 New in Isabelle98-1 (October 1998)
  7283 ----------------------------------
  7284 
  7285 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  7286 
  7287 * several changes of automated proof tools;
  7288 
  7289 * HOL: major changes to the inductive and datatype packages, including
  7290 some minor incompatibilities of theory syntax;
  7291 
  7292 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  7293 called `inj_on';
  7294 
  7295 * HOL: removed duplicate thms in Arith:
  7296   less_imp_add_less  should be replaced by  trans_less_add1
  7297   le_imp_add_le      should be replaced by  trans_le_add1
  7298 
  7299 * HOL: unary minus is now overloaded (new type constraints may be
  7300 required);
  7301 
  7302 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  7303 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  7304 now taken as an integer constant.
  7305 
  7306 * Pure: ML function 'theory_of' renamed to 'theory';
  7307 
  7308 
  7309 *** Proof tools ***
  7310 
  7311 * Simplifier:
  7312   1. Asm_full_simp_tac is now more aggressive.
  7313      1. It will sometimes reorient premises if that increases their power to
  7314         simplify.
  7315      2. It does no longer proceed strictly from left to right but may also
  7316         rotate premises to achieve further simplification.
  7317      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  7318      old Asm_full_simp_tac in that it does not rotate premises.
  7319   2. The simplifier now knows a little bit about nat-arithmetic.
  7320 
  7321 * Classical reasoner: wrapper mechanism for the classical reasoner now
  7322 allows for selected deletion of wrappers, by introduction of names for
  7323 wrapper functionals.  This implies that addbefore, addSbefore,
  7324 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  7325 and that adding two tactics with the same name overwrites the first
  7326 one (emitting a warning).
  7327   type wrapper = (int -> tactic) -> (int -> tactic)
  7328   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  7329   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  7330   delWrapper, delSWrapper: claset *  string            -> claset
  7331   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  7332 
  7333 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  7334 semantics; addbefore now affects only the unsafe part of step_tac
  7335 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  7336 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  7337 by Force_tac;
  7338 
  7339 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  7340 compWrapper; added safe wrapper (and access functions for it);
  7341 
  7342 * HOL/split_all_tac is now much faster and fails if there is nothing
  7343 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  7344 and the names of the automatically generated variables have changed.
  7345 split_all_tac has moved within claset() from unsafe wrappers to safe
  7346 wrappers, which means that !!-bound variables are split much more
  7347 aggressively, and safe_tac and clarify_tac now split such variables.
  7348 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  7349 Note: the same holds for record_split_tac, which does the job of
  7350 split_all_tac for record fields.
  7351 
  7352 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  7353 permanently to the default simpset using Addsplits just like
  7354 Addsimps. They can be removed via Delsplits just like
  7355 Delsimps. Lower-case versions are also available.
  7356 
  7357 * HOL/Simplifier: The rule split_if is now part of the default
  7358 simpset. This means that the simplifier will eliminate all occurrences
  7359 of if-then-else in the conclusion of a goal. To prevent this, you can
  7360 either remove split_if completely from the default simpset by
  7361 `Delsplits [split_if]' or remove it in a specific call of the
  7362 simplifier using `... delsplits [split_if]'.  You can also add/delete
  7363 other case splitting rules to/from the default simpset: every datatype
  7364 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  7365 t is the name of the datatype).
  7366 
  7367 * Classical reasoner / Simplifier combination: new force_tac (and
  7368 derivatives Force_tac, force) combines rewriting and classical
  7369 reasoning (and whatever other tools) similarly to auto_tac, but is
  7370 aimed to solve the given subgoal completely.
  7371 
  7372 
  7373 *** General ***
  7374 
  7375 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  7376 and `goalw': the theory is no longer needed as an explicit argument -
  7377 the current theory context is used; assumptions are no longer returned
  7378 at the ML-level unless one of them starts with ==> or !!; it is
  7379 recommended to convert to these new commands using isatool fixgoal
  7380 (backup your sources first!);
  7381 
  7382 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  7383 the current theory context, and 'theory' to lookup stored theories;
  7384 
  7385 * new theory section 'locale' for declaring constants, assumptions and
  7386 definitions that have local scope;
  7387 
  7388 * new theory section 'nonterminals' for purely syntactic types;
  7389 
  7390 * new theory section 'setup' for generic ML setup functions
  7391 (e.g. package initialization);
  7392 
  7393 * the distribution now includes Isabelle icons: see
  7394 lib/logo/isabelle-{small,tiny}.xpm;
  7395 
  7396 * isatool install - install binaries with absolute references to
  7397 ISABELLE_HOME/bin;
  7398 
  7399 * isatool logo -- create instances of the Isabelle logo (as EPS);
  7400 
  7401 * print mode 'emacs' reserved for Isamode;
  7402 
  7403 * support multiple print (ast) translations per constant name;
  7404 
  7405 * theorems involving oracles are now printed with a suffixed [!];
  7406 
  7407 
  7408 *** HOL ***
  7409 
  7410 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  7411 
  7412 * HOL/inductive package reorganized and improved: now supports mutual
  7413 definitions such as
  7414 
  7415   inductive EVEN ODD
  7416     intrs
  7417       null "0 : EVEN"
  7418       oddI "n : EVEN ==> Suc n : ODD"
  7419       evenI "n : ODD ==> Suc n : EVEN"
  7420 
  7421 new theorem list "elims" contains an elimination rule for each of the
  7422 recursive sets; inductive definitions now handle disjunctive premises
  7423 correctly (also ZF);
  7424 
  7425 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  7426 "mutual_induct" no longer exists - the induction rule is always
  7427 contained in "induct";
  7428 
  7429 
  7430 * HOL/datatype package re-implemented and greatly improved: now
  7431 supports mutually recursive datatypes such as
  7432 
  7433   datatype
  7434     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  7435             | SUM ('a aexp) ('a aexp)
  7436             | DIFF ('a aexp) ('a aexp)
  7437             | NUM 'a
  7438   and
  7439     'a bexp = LESS ('a aexp) ('a aexp)
  7440             | AND ('a bexp) ('a bexp)
  7441             | OR ('a bexp) ('a bexp)
  7442 
  7443 as well as indirectly recursive datatypes such as
  7444 
  7445   datatype
  7446     ('a, 'b) term = Var 'a
  7447                   | App 'b ((('a, 'b) term) list)
  7448 
  7449 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  7450 induction on mutually / indirectly recursive datatypes.
  7451 
  7452 Primrec equations are now stored in theory and can be accessed via
  7453 <function_name>.simps.
  7454 
  7455 INCOMPATIBILITIES:
  7456 
  7457   - Theories using datatypes must now have theory Datatype as an
  7458     ancestor.
  7459   - The specific <typename>.induct_tac no longer exists - use the
  7460     generic induct_tac instead.
  7461   - natE has been renamed to nat.exhaust - use exhaust_tac
  7462     instead of res_inst_tac ... natE. Note that the variable
  7463     names in nat.exhaust differ from the names in natE, this
  7464     may cause some "fragile" proofs to fail.
  7465   - The theorems split_<typename>_case and split_<typename>_case_asm
  7466     have been renamed to <typename>.split and <typename>.split_asm.
  7467   - Since default sorts of type variables are now handled correctly,
  7468     some datatype definitions may have to be annotated with explicit
  7469     sort constraints.
  7470   - Primrec definitions no longer require function name and type
  7471     of recursive argument.
  7472 
  7473 Consider using isatool fixdatatype to adapt your theories and proof
  7474 scripts to the new package (backup your sources first!).
  7475 
  7476 
  7477 * HOL/record package: considerably improved implementation; now
  7478 includes concrete syntax for record types, terms, updates; theorems
  7479 for surjective pairing and splitting !!-bound record variables; proof
  7480 support is as follows:
  7481 
  7482   1) standard conversions (selectors or updates applied to record
  7483 constructor terms) are part of the standard simpset;
  7484 
  7485   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  7486 made part of standard simpset and claset via addIffs;
  7487 
  7488   3) a tactic for record field splitting (record_split_tac) is part of
  7489 the standard claset (addSWrapper);
  7490 
  7491 To get a better idea about these rules you may retrieve them via
  7492 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  7493 the name of your record type.
  7494 
  7495 The split tactic 3) conceptually simplifies by the following rule:
  7496 
  7497   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  7498 
  7499 Thus any record variable that is bound by meta-all will automatically
  7500 blow up into some record constructor term, consequently the
  7501 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  7502 solve record problems automatically.
  7503 
  7504 
  7505 * reorganized the main HOL image: HOL/Integ and String loaded by
  7506 default; theory Main includes everything;
  7507 
  7508 * automatic simplification of integer sums and comparisons, using cancellation;
  7509 
  7510 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  7511 
  7512 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  7513 
  7514 * many new identities for unions, intersections, set difference, etc.;
  7515 
  7516 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  7517 called split_if, split_split, split_sum_case and split_nat_case (to go
  7518 with add/delsplits);
  7519 
  7520 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  7521 (?x::unit) = (); this is made part of the default simpset, which COULD
  7522 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  7523 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  7524 unit_abs_eta_conv is added in order to counter the effect of
  7525 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  7526 %u.f();
  7527 
  7528 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  7529 makes more sense);
  7530 
  7531 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  7532   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  7533   disjointness reasoning but breaking a few old proofs.
  7534 
  7535 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  7536 to 'converse' from 'inverse' (for compatibility with ZF and some
  7537 literature);
  7538 
  7539 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  7540 the well-founded relation;
  7541 
  7542 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  7543     Compl A.  The "Compl" syntax remains available as input syntax for this
  7544     release ONLY.
  7545 
  7546 * HOL/Update: new theory of function updates:
  7547     f(a:=b) == %x. if x=a then b else f x
  7548 may also be iterated as in f(a:=b,c:=d,...);
  7549 
  7550 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  7551 
  7552 * HOL/List:
  7553   - new function list_update written xs[i:=v] that updates the i-th
  7554     list position. May also be iterated as in xs[i:=a,j:=b,...].
  7555   - new function `upt' written [i..j(] which generates the list
  7556     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  7557     bound write [i..j], which is a shorthand for [i..j+1(].
  7558   - new lexicographic orderings and corresponding wellfoundedness theorems.
  7559 
  7560 * HOL/Arith:
  7561   - removed 'pred' (predecessor) function;
  7562   - generalized some theorems about n-1;
  7563   - many new laws about "div" and "mod";
  7564   - new laws about greatest common divisors (see theory ex/Primes);
  7565 
  7566 * HOL/Relation: renamed the relational operator r^-1 "converse"
  7567 instead of "inverse";
  7568 
  7569 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  7570   of the multiset ordering;
  7571 
  7572 * directory HOL/Real: a construction of the reals using Dedekind cuts
  7573   (not included by default);
  7574 
  7575 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  7576 
  7577 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  7578   programs, i.e. different program variables may have different types.
  7579 
  7580 * calling (stac rew i) now fails if "rew" has no effect on the goal
  7581   [previously, this check worked only if the rewrite rule was unconditional]
  7582   Now rew can involve either definitions or equalities (either == or =).
  7583 
  7584 
  7585 *** ZF ***
  7586 
  7587 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  7588   only the theorems proved on ZF.ML;
  7589 
  7590 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  7591   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  7592   disjointness reasoning but breaking a few old proofs.
  7593 
  7594 * ZF/Update: new theory of function updates
  7595     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  7596   may also be iterated as in f(a:=b,c:=d,...);
  7597 
  7598 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  7599 
  7600 * calling (stac rew i) now fails if "rew" has no effect on the goal
  7601   [previously, this check worked only if the rewrite rule was unconditional]
  7602   Now rew can involve either definitions or equalities (either == or =).
  7603 
  7604 * case_tac provided for compatibility with HOL
  7605     (like the old excluded_middle_tac, but with subgoals swapped)
  7606 
  7607 
  7608 *** Internal programming interfaces ***
  7609 
  7610 * Pure: several new basic modules made available for general use, see
  7611 also src/Pure/README;
  7612 
  7613 * improved the theory data mechanism to support encapsulation (data
  7614 kind name replaced by private Object.kind, acting as authorization
  7615 key); new type-safe user interface via functor TheoryDataFun; generic
  7616 print_data function becomes basically useless;
  7617 
  7618 * removed global_names compatibility flag -- all theory declarations
  7619 are qualified by default;
  7620 
  7621 * module Pure/Syntax now offers quote / antiquote translation
  7622 functions (useful for Hoare logic etc. with implicit dependencies);
  7623 see HOL/ex/Antiquote for an example use;
  7624 
  7625 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  7626 cterm -> thm;
  7627 
  7628 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  7629 subgoal;
  7630 
  7631 * Display.print_goals function moved to Locale.print_goals;
  7632 
  7633 * standard print function for goals supports current_goals_markers
  7634 variable for marking begin of proof, end of proof, start of goal; the
  7635 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  7636 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  7637 for example;
  7638 
  7639 
  7640 
  7641 New in Isabelle98 (January 1998)
  7642 --------------------------------
  7643 
  7644 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  7645 
  7646 * changed lexical syntax of terms / types: dots made part of long
  7647 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  7648 
  7649 * simpset (and claset) reference variable replaced by functions
  7650 simpset / simpset_ref;
  7651 
  7652 * no longer supports theory aliases (via merge) and non-trivial
  7653 implicit merge of thms' signatures;
  7654 
  7655 * most internal names of constants changed due to qualified names;
  7656 
  7657 * changed Pure/Sequence interface (see Pure/seq.ML);
  7658 
  7659 
  7660 *** General Changes ***
  7661 
  7662 * hierachically structured name spaces (for consts, types, axms, thms
  7663 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  7664 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  7665 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  7666 long_names for fully qualified output names; NOTE: ML programs
  7667 (special tactics, packages etc.) referring to internal names may have
  7668 to be adapted to cope with fully qualified names; in case of severe
  7669 backward campatibility problems try setting 'global_names' at compile
  7670 time to have enrything declared within a flat name space; one may also
  7671 fine tune name declarations in theories via the 'global' and 'local'
  7672 section;
  7673 
  7674 * reimplemented the implicit simpset and claset using the new anytype
  7675 data filed in signatures; references simpset:simpset ref etc. are
  7676 replaced by functions simpset:unit->simpset and
  7677 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  7678 to patch your ML files accordingly;
  7679 
  7680 * HTML output now includes theory graph data for display with Java
  7681 applet or isatool browser; data generated automatically via isatool
  7682 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  7683 
  7684 * defs may now be conditional; improved rewrite_goals_tac to handle
  7685 conditional equations;
  7686 
  7687 * defs now admits additional type arguments, using TYPE('a) syntax;
  7688 
  7689 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  7690 creates a new theory node; implicit merge of thms' signatures is
  7691 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  7692 transfer:theory->thm->thm in (rare) cases;
  7693 
  7694 * improved handling of draft signatures / theories; draft thms (and
  7695 ctyps, cterms) are automatically promoted to real ones;
  7696 
  7697 * slightly changed interfaces for oracles: admit many per theory, named
  7698 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  7699 
  7700 * print_goals: optional output of const types (set show_consts and
  7701 show_types);
  7702 
  7703 * improved output of warnings (###) and errors (***);
  7704 
  7705 * subgoal_tac displays a warning if the new subgoal has type variables;
  7706 
  7707 * removed old README and Makefiles;
  7708 
  7709 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  7710 
  7711 * removed obsolete init_pps and init_database;
  7712 
  7713 * deleted the obsolete tactical STATE, which was declared by
  7714     fun STATE tacfun st = tacfun st st;
  7715 
  7716 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  7717 (which abbreviates $HOME);
  7718 
  7719 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  7720 use isatool fixseq to adapt your ML programs (this works for fully
  7721 qualified references to the Sequence structure only!);
  7722 
  7723 * use_thy no longer requires writable current directory; it always
  7724 reloads .ML *and* .thy file, if either one is out of date;
  7725 
  7726 
  7727 *** Classical Reasoner ***
  7728 
  7729 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  7730 tactics that use classical reasoning to simplify a subgoal without
  7731 splitting it into several subgoals;
  7732 
  7733 * Safe_tac: like safe_tac but uses the default claset;
  7734 
  7735 
  7736 *** Simplifier ***
  7737 
  7738 * added simplification meta rules:
  7739     (asm_)(full_)simplify: simpset -> thm -> thm;
  7740 
  7741 * simplifier.ML no longer part of Pure -- has to be loaded by object
  7742 logics (again);
  7743 
  7744 * added prems argument to simplification procedures;
  7745 
  7746 * HOL, FOL, ZF: added infix function `addsplits':
  7747   instead of `<simpset> setloop (split_tac <thms>)'
  7748   you can simply write `<simpset> addsplits <thms>'
  7749 
  7750 
  7751 *** Syntax ***
  7752 
  7753 * TYPE('a) syntax for type reflection terms;
  7754 
  7755 * no longer handles consts with name "" -- declare as 'syntax' instead;
  7756 
  7757 * pretty printer: changed order of mixfix annotation preference (again!);
  7758 
  7759 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  7760 
  7761 
  7762 *** HOL ***
  7763 
  7764 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  7765   with `addloop' of the simplifier to faciliate case splitting in premises.
  7766 
  7767 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  7768 
  7769 * HOL/Auth: new protocol proofs including some for the Internet
  7770   protocol TLS;
  7771 
  7772 * HOL/Map: new theory of `maps' a la VDM;
  7773 
  7774 * HOL/simplifier: simplification procedures nat_cancel_sums for
  7775 cancelling out common nat summands from =, <, <= (in)equalities, or
  7776 differences; simplification procedures nat_cancel_factor for
  7777 cancelling common factor from =, <, <= (in)equalities over natural
  7778 sums; nat_cancel contains both kinds of procedures, it is installed by
  7779 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  7780 
  7781 * HOL/simplifier: terms of the form
  7782   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  7783   are rewritten to
  7784   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  7785   and those of the form
  7786   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  7787   are rewritten to
  7788   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  7789 
  7790 * HOL/datatype
  7791   Each datatype `t' now comes with a theorem `split_t_case' of the form
  7792 
  7793   P(t_case f1 ... fn x) =
  7794      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  7795         ...
  7796        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  7797      )
  7798 
  7799   and a theorem `split_t_case_asm' of the form
  7800 
  7801   P(t_case f1 ... fn x) =
  7802     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  7803         ...
  7804        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  7805      )
  7806   which can be added to a simpset via `addsplits'. The existing theorems
  7807   expand_list_case and expand_option_case have been renamed to
  7808   split_list_case and split_option_case.
  7809 
  7810 * HOL/Arithmetic:
  7811   - `pred n' is automatically converted to `n-1'.
  7812     Users are strongly encouraged not to use `pred' any longer,
  7813     because it will disappear altogether at some point.
  7814   - Users are strongly encouraged to write "0 < n" rather than
  7815     "n ~= 0". Theorems and proof tools have been modified towards this
  7816     `standard'.
  7817 
  7818 * HOL/Lists:
  7819   the function "set_of_list" has been renamed "set" (and its theorems too);
  7820   the function "nth" now takes its arguments in the reverse order and
  7821   has acquired the infix notation "!" as in "xs!n".
  7822 
  7823 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  7824 
  7825 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  7826   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  7827 
  7828 * HOL/record: extensible records with schematic structural subtyping
  7829 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  7830 still lacks various theorems and concrete record syntax;
  7831 
  7832 
  7833 *** HOLCF ***
  7834 
  7835 * removed "axioms" and "generated by" sections;
  7836 
  7837 * replaced "ops" section by extended "consts" section, which is capable of
  7838   handling the continuous function space "->" directly;
  7839 
  7840 * domain package:
  7841   . proves theorems immediately and stores them in the theory,
  7842   . creates hierachical name space,
  7843   . now uses normal mixfix annotations (instead of cinfix...),
  7844   . minor changes to some names and values (for consistency),
  7845   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  7846   . separator between mutual domain defs: changed "," to "and",
  7847   . improved handling of sort constraints;  now they have to
  7848     appear on the left-hand side of the equations only;
  7849 
  7850 * fixed LAM <x,y,zs>.b syntax;
  7851 
  7852 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  7853 adm (%x. P (t x)), where P is chainfinite and t continuous;
  7854 
  7855 
  7856 *** FOL and ZF ***
  7857 
  7858 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  7859   with `addloop' of the simplifier to faciliate case splitting in premises.
  7860 
  7861 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  7862 in HOL, they strip ALL and --> from proved theorems;
  7863 
  7864 
  7865 
  7866 New in Isabelle94-8 (May 1997)
  7867 ------------------------------
  7868 
  7869 *** General Changes ***
  7870 
  7871 * new utilities to build / run / maintain Isabelle etc. (in parts
  7872 still somewhat experimental); old Makefiles etc. still functional;
  7873 
  7874 * new 'Isabelle System Manual';
  7875 
  7876 * INSTALL text, together with ./configure and ./build scripts;
  7877 
  7878 * reimplemented type inference for greater efficiency, better error
  7879 messages and clean internal interface;
  7880 
  7881 * prlim command for dealing with lots of subgoals (an easier way of
  7882 setting goals_limit);
  7883 
  7884 
  7885 *** Syntax ***
  7886 
  7887 * supports alternative (named) syntax tables (parser and pretty
  7888 printer); internal interface is provided by add_modesyntax(_i);
  7889 
  7890 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  7891 be used in conjunction with the Isabelle symbol font; uses the
  7892 "symbols" syntax table;
  7893 
  7894 * added token_translation interface (may translate name tokens in
  7895 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  7896 the current print_mode); IMPORTANT: user print translation functions
  7897 are responsible for marking newly introduced bounds
  7898 (Syntax.mark_boundT);
  7899 
  7900 * token translations for modes "xterm" and "xterm_color" that display
  7901 names in bold, underline etc. or colors (which requires a color
  7902 version of xterm);
  7903 
  7904 * infixes may now be declared with names independent of their syntax;
  7905 
  7906 * added typed_print_translation (like print_translation, but may
  7907 access type of constant);
  7908 
  7909 
  7910 *** Classical Reasoner ***
  7911 
  7912 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  7913 some limitations.  Blast_tac...
  7914   + ignores addss, addbefore, addafter; this restriction is intrinsic
  7915   + ignores elimination rules that don't have the correct format
  7916         (the conclusion MUST be a formula variable)
  7917   + ignores types, which can make HOL proofs fail
  7918   + rules must not require higher-order unification, e.g. apply_type in ZF
  7919     [message "Function Var's argument not a bound variable" relates to this]
  7920   + its proof strategy is more general but can actually be slower
  7921 
  7922 * substitution with equality assumptions no longer permutes other
  7923 assumptions;
  7924 
  7925 * minor changes in semantics of addafter (now called addaltern); renamed
  7926 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  7927 (and access functions for it);
  7928 
  7929 * improved combination of classical reasoner and simplifier:
  7930   + functions for handling clasimpsets
  7931   + improvement of addss: now the simplifier is called _after_ the
  7932     safe steps.
  7933   + safe variant of addss called addSss: uses safe simplifications
  7934     _during_ the safe steps. It is more complete as it allows multiple
  7935     instantiations of unknowns (e.g. with slow_tac).
  7936 
  7937 *** Simplifier ***
  7938 
  7939 * added interface for simplification procedures (functions that
  7940 produce *proven* rewrite rules on the fly, depending on current
  7941 redex);
  7942 
  7943 * ordering on terms as parameter (used for ordered rewriting);
  7944 
  7945 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  7946 
  7947 * the solver is now split into a safe and an unsafe part.
  7948 This should be invisible for the normal user, except that the
  7949 functions setsolver and addsolver have been renamed to setSolver and
  7950 addSolver; added safe_asm_full_simp_tac;
  7951 
  7952 
  7953 *** HOL ***
  7954 
  7955 * a generic induction tactic `induct_tac' which works for all datatypes and
  7956 also for type `nat';
  7957 
  7958 * a generic case distinction tactic `exhaust_tac' which works for all
  7959 datatypes and also for type `nat';
  7960 
  7961 * each datatype comes with a function `size';
  7962 
  7963 * patterns in case expressions allow tuple patterns as arguments to
  7964 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  7965 
  7966 * primrec now also works with type nat;
  7967 
  7968 * recdef: a new declaration form, allows general recursive functions to be
  7969 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  7970 
  7971 * the constant for negation has been renamed from "not" to "Not" to
  7972 harmonize with FOL, ZF, LK, etc.;
  7973 
  7974 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  7975 infinite lists;
  7976 
  7977 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  7978 
  7979 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  7980 problems in commutative rings, using axiomatic type classes for + and *;
  7981 
  7982 * more examples in HOL/MiniML and HOL/Auth;
  7983 
  7984 * more default rewrite rules for quantifiers, union/intersection;
  7985 
  7986 * a new constant `arbitrary == @x.False';
  7987 
  7988 * HOLCF/IOA replaces old HOL/IOA;
  7989 
  7990 * HOLCF changes: derived all rules and arities
  7991   + axiomatic type classes instead of classes
  7992   + typedef instead of faking type definitions
  7993   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  7994   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  7995   + eliminated the types void, one, tr
  7996   + use unit lift and bool lift (with translations) instead of one and tr
  7997   + eliminated blift from Lift3.thy (use Def instead of blift)
  7998   all eliminated rules are derived as theorems --> no visible changes ;
  7999 
  8000 
  8001 *** ZF ***
  8002 
  8003 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  8004 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  8005 as ZF_cs addSIs [equalityI];
  8006 
  8007 
  8008 
  8009 New in Isabelle94-7 (November 96)
  8010 ---------------------------------
  8011 
  8012 * allowing negative levels (as offsets) in prlev and choplev;
  8013 
  8014 * super-linear speedup for large simplifications;
  8015 
  8016 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  8017 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  8018 FAIL); can suppress it using the command Delsimps (ex_simps @
  8019 all_simps); De Morgan laws are also now included, by default;
  8020 
  8021 * improved printing of ==>  :  ~:
  8022 
  8023 * new object-logic "Sequents" adds linear logic, while replacing LK
  8024 and Modal (thanks to Sara Kalvala);
  8025 
  8026 * HOL/Auth: correctness proofs for authentication protocols;
  8027 
  8028 * HOL: new auto_tac combines rewriting and classical reasoning (many
  8029 examples on HOL/Auth);
  8030 
  8031 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  8032 the rewriter and classical reasoner simultaneously;
  8033 
  8034 * function uresult no longer returns theorems in "standard" format;
  8035 regain previous version by: val uresult = standard o uresult;
  8036 
  8037 
  8038 
  8039 New in Isabelle94-6
  8040 -------------------
  8041 
  8042 * oracles -- these establish an interface between Isabelle and trusted
  8043 external reasoners, which may deliver results as theorems;
  8044 
  8045 * proof objects (in particular record all uses of oracles);
  8046 
  8047 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  8048 
  8049 * "constdefs" section in theory files;
  8050 
  8051 * "primrec" section (HOL) no longer requires names;
  8052 
  8053 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  8054 
  8055 
  8056 
  8057 New in Isabelle94-5
  8058 -------------------
  8059 
  8060 * reduced space requirements;
  8061 
  8062 * automatic HTML generation from theories;
  8063 
  8064 * theory files no longer require "..." (quotes) around most types;
  8065 
  8066 * new examples, including two proofs of the Church-Rosser theorem;
  8067 
  8068 * non-curried (1994) version of HOL is no longer distributed;
  8069 
  8070 
  8071 
  8072 New in Isabelle94-4
  8073 -------------------
  8074 
  8075 * greatly reduced space requirements;
  8076 
  8077 * theory files (.thy) no longer require \...\ escapes at line breaks;
  8078 
  8079 * searchable theorem database (see the section "Retrieving theorems" on
  8080 page 8 of the Reference Manual);
  8081 
  8082 * new examples, including Grabczewski's monumental case study of the
  8083 Axiom of Choice;
  8084 
  8085 * The previous version of HOL renamed to Old_HOL;
  8086 
  8087 * The new version of HOL (previously called CHOL) uses a curried syntax
  8088 for functions.  Application looks like f a b instead of f(a,b);
  8089 
  8090 * Mutually recursive inductive definitions finally work in HOL;
  8091 
  8092 * In ZF, pattern-matching on tuples is now available in all abstractions and
  8093 translates to the operator "split";
  8094 
  8095 
  8096 
  8097 New in Isabelle94-3
  8098 -------------------
  8099 
  8100 * new infix operator, addss, allowing the classical reasoner to
  8101 perform simplification at each step of its search.  Example:
  8102         fast_tac (cs addss ss)
  8103 
  8104 * a new logic, CHOL, the same as HOL, but with a curried syntax
  8105 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  8106 look like (a,b) instead of <a,b>;
  8107 
  8108 * PLEASE NOTE: CHOL will eventually replace HOL!
  8109 
  8110 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  8111 It translates to the operator "split".  A new theory of integers is available;
  8112 
  8113 * In ZF, integer numerals now denote two's-complement binary integers.
  8114 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  8115 
  8116 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  8117 of the Axiom of Choice;
  8118 
  8119 
  8120 
  8121 New in Isabelle94-2
  8122 -------------------
  8123 
  8124 * Significantly faster resolution;
  8125 
  8126 * the different sections in a .thy file can now be mixed and repeated
  8127 freely;
  8128 
  8129 * Database of theorems for FOL, HOL and ZF.  New
  8130 commands including qed, qed_goal and bind_thm store theorems in the database.
  8131 
  8132 * Simple database queries: return a named theorem (get_thm) or all theorems of
  8133 a given theory (thms_of), or find out what theory a theorem was proved in
  8134 (theory_of_thm);
  8135 
  8136 * Bugs fixed in the inductive definition and datatype packages;
  8137 
  8138 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  8139 and HOL_dup_cs obsolete;
  8140 
  8141 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  8142 have been removed;
  8143 
  8144 * Simpler definition of function space in ZF;
  8145 
  8146 * new results about cardinal and ordinal arithmetic in ZF;
  8147 
  8148 * 'subtype' facility in HOL for introducing new types as subsets of existing
  8149 types;
  8150 
  8151 :mode=text:wrap=hard:maxLineLen=72: