NEWS
author wenzelm
Tue, 05 Apr 2011 15:15:33 +0200
changeset 43110 e48baf91aeab
parent 43089 3bf2eea43dac
parent 43107 578a51fae383
child 43122 12fe41a92cd5
permissions -rw-r--r--
merged
     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 * Discontinued special treatment of structure Ast: no pervasive
    97 content, no inclusion in structure Syntax.  INCOMPATIBILITY, refer to
    98 qualified names like Ast.Constant etc.
    99 
   100 
   101 
   102 New in Isabelle2011 (January 2011)
   103 ----------------------------------
   104 
   105 *** General ***
   106 
   107 * Experimental Prover IDE based on Isabelle/Scala and jEdit (see
   108 src/Tools/jEdit).  This also serves as IDE for Isabelle/ML, with
   109 useful tooltips and hyperlinks produced from its static analysis.  The
   110 bundled component provides an executable Isabelle tool that can be run
   111 like this:
   112 
   113   Isabelle2011/bin/isabelle jedit
   114 
   115 * Significantly improved Isabelle/Isar implementation manual.
   116 
   117 * System settings: ISABELLE_HOME_USER now includes ISABELLE_IDENTIFIER
   118 (and thus refers to something like $HOME/.isabelle/Isabelle2011),
   119 while the default heap location within that directory lacks that extra
   120 suffix.  This isolates multiple Isabelle installations from each
   121 other, avoiding problems with old settings in new versions.
   122 INCOMPATIBILITY, need to copy/upgrade old user settings manually.
   123 
   124 * Source files are always encoded as UTF-8, instead of old-fashioned
   125 ISO-Latin-1.  INCOMPATIBILITY.  Isabelle LaTeX documents might require
   126 the following package declarations:
   127 
   128   \usepackage[utf8]{inputenc}
   129   \usepackage{textcomp}
   130 
   131 * Explicit treatment of UTF-8 sequences as Isabelle symbols, such that
   132 a Unicode character is treated as a single symbol, not a sequence of
   133 non-ASCII bytes as before.  Since Isabelle/ML string literals may
   134 contain symbols without further backslash escapes, Unicode can now be
   135 used here as well.  Recall that Symbol.explode in ML provides a
   136 consistent view on symbols, while raw explode (or String.explode)
   137 merely give a byte-oriented representation.
   138 
   139 * Theory loader: source files are primarily located via the master
   140 directory of each theory node (where the .thy file itself resides).
   141 The global load path is still partially available as legacy feature.
   142 Minor INCOMPATIBILITY due to subtle change in file lookup: use
   143 explicit paths, relatively to the theory.
   144 
   145 * Special treatment of ML file names has been discontinued.
   146 Historically, optional extensions .ML or .sml were added on demand --
   147 at the cost of clarity of file dependencies.  Recall that Isabelle/ML
   148 files exclusively use the .ML extension.  Minor INCOMPATIBILTY.
   149 
   150 * Various options that affect pretty printing etc. are now properly
   151 handled within the context via configuration options, instead of
   152 unsynchronized references or print modes.  There are both ML Config.T
   153 entities and Isar declaration attributes to access these.
   154 
   155   ML (Config.T)                 Isar (attribute)
   156 
   157   eta_contract                  eta_contract
   158   show_brackets                 show_brackets
   159   show_sorts                    show_sorts
   160   show_types                    show_types
   161   show_question_marks           show_question_marks
   162   show_consts                   show_consts
   163   show_abbrevs                  show_abbrevs
   164 
   165   Syntax.ast_trace              syntax_ast_trace
   166   Syntax.ast_stat               syntax_ast_stat
   167   Syntax.ambiguity_level        syntax_ambiguity_level
   168 
   169   Goal_Display.goals_limit      goals_limit
   170   Goal_Display.show_main_goal   show_main_goal
   171 
   172   Method.rule_trace             rule_trace
   173 
   174   Thy_Output.display            thy_output_display
   175   Thy_Output.quotes             thy_output_quotes
   176   Thy_Output.indent             thy_output_indent
   177   Thy_Output.source             thy_output_source
   178   Thy_Output.break              thy_output_break
   179 
   180 Note that corresponding "..._default" references in ML may only be
   181 changed globally at the ROOT session setup, but *not* within a theory.
   182 The option "show_abbrevs" supersedes the former print mode
   183 "no_abbrevs" with inverted meaning.
   184 
   185 * More systematic naming of some configuration options.
   186 INCOMPATIBILITY.
   187 
   188   trace_simp  ~>  simp_trace
   189   debug_simp  ~>  simp_debug
   190 
   191 * Support for real valued configuration options, using simplistic
   192 floating-point notation that coincides with the inner syntax for
   193 float_token.
   194 
   195 * Support for real valued preferences (with approximative PGIP type):
   196 front-ends need to accept "pgint" values in float notation.
   197 INCOMPATIBILITY.
   198 
   199 * The IsabelleText font now includes Cyrillic, Hebrew, Arabic from
   200 DejaVu Sans.
   201 
   202 * Discontinued support for Poly/ML 5.0 and 5.1 versions.
   203 
   204 
   205 *** Pure ***
   206 
   207 * Command 'type_synonym' (with single argument) replaces somewhat
   208 outdated 'types', which is still available as legacy feature for some
   209 time.
   210 
   211 * Command 'nonterminal' (with 'and' separated list of arguments)
   212 replaces somewhat outdated 'nonterminals'.  INCOMPATIBILITY.
   213 
   214 * Command 'notepad' replaces former 'example_proof' for
   215 experimentation in Isar without any result.  INCOMPATIBILITY.
   216 
   217 * Locale interpretation commands 'interpret' and 'sublocale' accept
   218 lists of equations to map definitions in a locale to appropriate
   219 entities in the context of the interpretation.  The 'interpretation'
   220 command already provided this functionality.
   221 
   222 * Diagnostic command 'print_dependencies' prints the locale instances
   223 that would be activated if the specified expression was interpreted in
   224 the current context.  Variant "print_dependencies!" assumes a context
   225 without interpretations.
   226 
   227 * Diagnostic command 'print_interps' prints interpretations in proofs
   228 in addition to interpretations in theories.
   229 
   230 * Discontinued obsolete 'global' and 'local' commands to manipulate
   231 the theory name space.  Rare INCOMPATIBILITY.  The ML functions
   232 Sign.root_path and Sign.local_path may be applied directly where this
   233 feature is still required for historical reasons.
   234 
   235 * Discontinued obsolete 'constdefs' command.  INCOMPATIBILITY, use
   236 'definition' instead.
   237 
   238 * The "prems" fact, which refers to the accidental collection of
   239 foundational premises in the context, is now explicitly marked as
   240 legacy feature and will be discontinued soon.  Consider using "assms"
   241 of the head statement or reference facts by explicit names.
   242 
   243 * Document antiquotations @{class} and @{type} print classes and type
   244 constructors.
   245 
   246 * Document antiquotation @{file} checks file/directory entries within
   247 the local file system.
   248 
   249 
   250 *** HOL ***
   251 
   252 * Coercive subtyping: functions can be declared as coercions and type
   253 inference will add them as necessary upon input of a term.  Theory
   254 Complex_Main declares real :: nat => real and real :: int => real as
   255 coercions. A coercion function f is declared like this:
   256 
   257   declare [[coercion f]]
   258 
   259 To lift coercions through type constructors (e.g. from nat => real to
   260 nat list => real list), map functions can be declared, e.g.
   261 
   262   declare [[coercion_map map]]
   263 
   264 Currently coercion inference is activated only in theories including
   265 real numbers, i.e. descendants of Complex_Main.  This is controlled by
   266 the configuration option "coercion_enabled", e.g. it can be enabled in
   267 other theories like this:
   268 
   269   declare [[coercion_enabled]]
   270 
   271 * Command 'partial_function' provides basic support for recursive
   272 function definitions over complete partial orders.  Concrete instances
   273 are provided for i) the option type, ii) tail recursion on arbitrary
   274 types, and iii) the heap monad of Imperative_HOL.  See
   275 src/HOL/ex/Fundefs.thy and src/HOL/Imperative_HOL/ex/Linked_Lists.thy
   276 for examples.
   277 
   278 * Function package: f.psimps rules are no longer implicitly declared
   279 as [simp].  INCOMPATIBILITY.
   280 
   281 * Datatype package: theorems generated for executable equality (class
   282 "eq") carry proper names and are treated as default code equations.
   283 
   284 * Inductive package: now offers command 'inductive_simps' to
   285 automatically derive instantiated and simplified equations for
   286 inductive predicates, similar to 'inductive_cases'.
   287 
   288 * Command 'enriched_type' allows to register properties of the
   289 functorial structure of types.
   290 
   291 * Improved infrastructure for term evaluation using code generator
   292 techniques, in particular static evaluation conversions.
   293 
   294 * Code generator: Scala (2.8 or higher) has been added to the target
   295 languages.
   296 
   297 * Code generator: globbing constant expressions "*" and "Theory.*"
   298 have been replaced by the more idiomatic "_" and "Theory._".
   299 INCOMPATIBILITY.
   300 
   301 * Code generator: export_code without explicit file declaration prints
   302 to standard output.  INCOMPATIBILITY.
   303 
   304 * Code generator: do not print function definitions for case
   305 combinators any longer.
   306 
   307 * Code generator: simplification with rules determined with
   308 src/Tools/Code/code_simp.ML and method "code_simp".
   309 
   310 * Code generator for records: more idiomatic representation of record
   311 types.  Warning: records are not covered by ancient SML code
   312 generation any longer.  INCOMPATIBILITY.  In cases of need, a suitable
   313 rep_datatype declaration helps to succeed then:
   314 
   315   record 'a foo = ...
   316   ...
   317   rep_datatype foo_ext ...
   318 
   319 * Records: logical foundation type for records does not carry a
   320 '_type' suffix any longer (obsolete due to authentic syntax).
   321 INCOMPATIBILITY.
   322 
   323 * Quickcheck now by default uses exhaustive testing instead of random
   324 testing.  Random testing can be invoked by "quickcheck [random]",
   325 exhaustive testing by "quickcheck [exhaustive]".
   326 
   327 * Quickcheck instantiates polymorphic types with small finite
   328 datatypes by default. This enables a simple execution mechanism to
   329 handle quantifiers and function equality over the finite datatypes.
   330 
   331 * Quickcheck random generator has been renamed from "code" to
   332 "random".  INCOMPATIBILITY.
   333 
   334 * Quickcheck now has a configurable time limit which is set to 30
   335 seconds by default. This can be changed by adding [timeout = n] to the
   336 quickcheck command. The time limit for Auto Quickcheck is still set
   337 independently.
   338 
   339 * Quickcheck in locales considers interpretations of that locale for
   340 counter example search.
   341 
   342 * Sledgehammer:
   343   - Added "smt" and "remote_smt" provers based on the "smt" proof
   344     method. See the Sledgehammer manual for details ("isabelle doc
   345     sledgehammer").
   346   - Renamed commands:
   347     sledgehammer atp_info ~> sledgehammer running_provers
   348     sledgehammer atp_kill ~> sledgehammer kill_provers
   349     sledgehammer available_atps ~> sledgehammer available_provers
   350     INCOMPATIBILITY.
   351   - Renamed options:
   352     sledgehammer [atps = ...] ~> sledgehammer [provers = ...]
   353     sledgehammer [atp = ...] ~> sledgehammer [prover = ...]
   354     sledgehammer [timeout = 77 s] ~> sledgehammer [timeout = 77]
   355     (and "ms" and "min" are no longer supported)
   356     INCOMPATIBILITY.
   357 
   358 * Nitpick:
   359   - Renamed options:
   360     nitpick [timeout = 77 s] ~> nitpick [timeout = 77]
   361     nitpick [tac_timeout = 777 ms] ~> nitpick [tac_timeout = 0.777]
   362     INCOMPATIBILITY.
   363   - Added support for partial quotient types.
   364   - Added local versions of the "Nitpick.register_xxx" functions.
   365   - Added "whack" option.
   366   - Allow registration of quotient types as codatatypes.
   367   - Improved "merge_type_vars" option to merge more types.
   368   - Removed unsound "fast_descrs" option.
   369   - Added custom symmetry breaking for datatypes, making it possible to reach
   370     higher cardinalities.
   371   - Prevent the expansion of too large definitions.
   372 
   373 * Proof methods "metis" and "meson" now have configuration options
   374 "meson_trace", "metis_trace", and "metis_verbose" that can be enabled
   375 to diagnose these tools. E.g.
   376 
   377     using [[metis_trace = true]]
   378 
   379 * Auto Solve: Renamed "Auto Solve Direct".  The tool is now available
   380 manually as command 'solve_direct'.
   381 
   382 * The default SMT solver Z3 must be enabled explicitly (due to
   383 licensing issues) by setting the environment variable
   384 Z3_NON_COMMERCIAL in etc/settings of the component, for example.  For
   385 commercial applications, the SMT solver CVC3 is provided as fall-back;
   386 changing the SMT solver is done via the configuration option
   387 "smt_solver".
   388 
   389 * Remote SMT solvers need to be referred to by the "remote_" prefix,
   390 i.e. "remote_cvc3" and "remote_z3".
   391 
   392 * Added basic SMT support for datatypes, records, and typedefs using
   393 the oracle mode (no proofs).  Direct support of pairs has been dropped
   394 in exchange (pass theorems fst_conv snd_conv pair_collapse to the SMT
   395 support for a similar behavior).  Minor INCOMPATIBILITY.
   396 
   397 * Changed SMT configuration options:
   398   - Renamed:
   399     z3_proofs ~> smt_oracle (with inverted meaning)
   400     z3_trace_assms ~> smt_trace_used_facts
   401     INCOMPATIBILITY.
   402   - Added:
   403     smt_verbose
   404     smt_random_seed
   405     smt_datatypes
   406     smt_infer_triggers
   407     smt_monomorph_limit
   408     cvc3_options
   409     remote_cvc3_options
   410     remote_z3_options
   411     yices_options
   412 
   413 * Boogie output files (.b2i files) need to be declared in the theory
   414 header.
   415 
   416 * Simplification procedure "list_to_set_comprehension" rewrites list
   417 comprehensions applied to List.set to set comprehensions.  Occasional
   418 INCOMPATIBILITY, may be deactivated like this:
   419 
   420   declare [[simproc del: list_to_set_comprehension]]
   421 
   422 * Removed old version of primrec package.  INCOMPATIBILITY.
   423 
   424 * Removed simplifier congruence rule of "prod_case", as has for long
   425 been the case with "split".  INCOMPATIBILITY.
   426 
   427 * String.literal is a type, but not a datatype.  INCOMPATIBILITY.
   428 
   429 * Removed [split_format ... and ... and ...] version of
   430 [split_format].  Potential INCOMPATIBILITY.
   431 
   432 * Predicate "sorted" now defined inductively, with nice induction
   433 rules.  INCOMPATIBILITY: former sorted.simps now named sorted_simps.
   434 
   435 * Constant "contents" renamed to "the_elem", to free the generic name
   436 contents for other uses.  INCOMPATIBILITY.
   437 
   438 * Renamed class eq and constant eq (for code generation) to class
   439 equal and constant equal, plus renaming of related facts and various
   440 tuning.  INCOMPATIBILITY.
   441 
   442 * Dropped type classes mult_mono and mult_mono1.  INCOMPATIBILITY.
   443 
   444 * Removed output syntax "'a ~=> 'b" for "'a => 'b option".
   445 INCOMPATIBILITY.
   446 
   447 * Renamed theory Fset to Cset, type Fset.fset to Cset.set, in order to
   448 avoid confusion with finite sets.  INCOMPATIBILITY.
   449 
   450 * Abandoned locales equiv, congruent and congruent2 for equivalence
   451 relations.  INCOMPATIBILITY: use equivI rather than equiv_intro (same
   452 for congruent(2)).
   453 
   454 * Some previously unqualified names have been qualified:
   455 
   456   types
   457     bool ~> HOL.bool
   458     nat ~> Nat.nat
   459 
   460   constants
   461     Trueprop ~> HOL.Trueprop
   462     True ~> HOL.True
   463     False ~> HOL.False
   464     op & ~> HOL.conj
   465     op | ~> HOL.disj
   466     op --> ~> HOL.implies
   467     op = ~> HOL.eq
   468     Not ~> HOL.Not
   469     The ~> HOL.The
   470     All ~> HOL.All
   471     Ex ~> HOL.Ex
   472     Ex1 ~> HOL.Ex1
   473     Let ~> HOL.Let
   474     If ~> HOL.If
   475     Ball ~> Set.Ball
   476     Bex ~> Set.Bex
   477     Suc ~> Nat.Suc
   478     Pair ~> Product_Type.Pair
   479     fst ~> Product_Type.fst
   480     snd ~> Product_Type.snd
   481     curry ~> Product_Type.curry
   482     op : ~> Set.member
   483     Collect ~> Set.Collect
   484 
   485 INCOMPATIBILITY.
   486 
   487 * More canonical naming convention for some fundamental definitions:
   488 
   489     bot_bool_eq ~> bot_bool_def
   490     top_bool_eq ~> top_bool_def
   491     inf_bool_eq ~> inf_bool_def
   492     sup_bool_eq ~> sup_bool_def
   493     bot_fun_eq  ~> bot_fun_def
   494     top_fun_eq  ~> top_fun_def
   495     inf_fun_eq  ~> inf_fun_def
   496     sup_fun_eq  ~> sup_fun_def
   497 
   498 INCOMPATIBILITY.
   499 
   500 * More stylized fact names:
   501 
   502   expand_fun_eq ~> fun_eq_iff
   503   expand_set_eq ~> set_eq_iff
   504   set_ext       ~> set_eqI
   505   nat_number    ~> eval_nat_numeral
   506 
   507 INCOMPATIBILITY.
   508 
   509 * Refactoring of code-generation specific operations in theory List:
   510 
   511   constants
   512     null ~> List.null
   513 
   514   facts
   515     mem_iff ~> member_def
   516     null_empty ~> null_def
   517 
   518 INCOMPATIBILITY.  Note that these were not supposed to be used
   519 regularly unless for striking reasons; their main purpose was code
   520 generation.
   521 
   522 Various operations from the Haskell prelude are used for generating
   523 Haskell code.
   524 
   525 * Term "bij f" is now an abbreviation of "bij_betw f UNIV UNIV".  Term
   526 "surj f" is now an abbreviation of "range f = UNIV".  The theorems
   527 bij_def and surj_def are unchanged.  INCOMPATIBILITY.
   528 
   529 * Abolished some non-alphabetic type names: "prod" and "sum" replace
   530 "*" and "+" respectively.  INCOMPATIBILITY.
   531 
   532 * Name "Plus" of disjoint sum operator "<+>" is now hidden.  Write
   533 "Sum_Type.Plus" instead.
   534 
   535 * Constant "split" has been merged with constant "prod_case"; names of
   536 ML functions, facts etc. involving split have been retained so far,
   537 though.  INCOMPATIBILITY.
   538 
   539 * Dropped old infix syntax "_ mem _" for List.member; use "_ : set _"
   540 instead.  INCOMPATIBILITY.
   541 
   542 * Removed lemma "Option.is_none_none" which duplicates "is_none_def".
   543 INCOMPATIBILITY.
   544 
   545 * Former theory Library/Enum is now part of the HOL-Main image.
   546 INCOMPATIBILITY: all constants of the Enum theory now have to be
   547 referred to by its qualified name.
   548 
   549   enum    ~>  Enum.enum
   550   nlists  ~>  Enum.nlists
   551   product ~>  Enum.product
   552 
   553 * Theory Library/Monad_Syntax provides do-syntax for monad types.
   554 Syntax in Library/State_Monad has been changed to avoid ambiguities.
   555 INCOMPATIBILITY.
   556 
   557 * Theory Library/SetsAndFunctions has been split into
   558 Library/Function_Algebras and Library/Set_Algebras; canonical names
   559 for instance definitions for functions; various improvements.
   560 INCOMPATIBILITY.
   561 
   562 * Theory Library/Multiset provides stable quicksort implementation of
   563 sort_key.
   564 
   565 * Theory Library/Multiset: renamed empty_idemp ~> empty_neutral.
   566 INCOMPATIBILITY.
   567 
   568 * Session Multivariate_Analysis: introduced a type class for euclidean
   569 space.  Most theorems are now stated in terms of euclidean spaces
   570 instead of finite cartesian products.
   571 
   572   types
   573     real ^ 'n ~>  'a::real_vector
   574               ~>  'a::euclidean_space
   575               ~>  'a::ordered_euclidean_space
   576         (depends on your needs)
   577 
   578   constants
   579      _ $ _        ~> _ $$ _
   580      \<chi> x. _  ~> \<chi>\<chi> x. _
   581      CARD('n)     ~> DIM('a)
   582 
   583 Also note that the indices are now natural numbers and not from some
   584 finite type. Finite cartesian products of euclidean spaces, products
   585 of euclidean spaces the real and complex numbers are instantiated to
   586 be euclidean_spaces.  INCOMPATIBILITY.
   587 
   588 * Session Probability: introduced pextreal as positive extended real
   589 numbers.  Use pextreal as value for measures.  Introduce the
   590 Radon-Nikodym derivative, product spaces and Fubini's theorem for
   591 arbitrary sigma finite measures.  Introduces Lebesgue measure based on
   592 the integral in Multivariate Analysis.  INCOMPATIBILITY.
   593 
   594 * Session Imperative_HOL: revamped, corrected dozens of inadequacies.
   595 INCOMPATIBILITY.
   596 
   597 * Session SPARK (with image HOL-SPARK) provides commands to load and
   598 prove verification conditions generated by the SPARK Ada program
   599 verifier.  See also src/HOL/SPARK and src/HOL/SPARK/Examples.
   600 
   601 
   602 *** HOL-Algebra ***
   603 
   604 * Theorems for additive ring operations (locale abelian_monoid and
   605 descendants) are generated by interpretation from their multiplicative
   606 counterparts.  Names (in particular theorem names) have the mandatory
   607 qualifier 'add'.  Previous theorem names are redeclared for
   608 compatibility.
   609 
   610 * Structure "int_ring" is now an abbreviation (previously a
   611 definition).  This fits more natural with advanced interpretations.
   612 
   613 
   614 *** HOLCF ***
   615 
   616 * The domain package now runs in definitional mode by default: The
   617 former command 'new_domain' is now called 'domain'.  To use the domain
   618 package in its original axiomatic mode, use 'domain (unsafe)'.
   619 INCOMPATIBILITY.
   620 
   621 * The new class "domain" is now the default sort.  Class "predomain"
   622 is an unpointed version of "domain". Theories can be updated by
   623 replacing sort annotations as shown below.  INCOMPATIBILITY.
   624 
   625   'a::type ~> 'a::countable
   626   'a::cpo  ~> 'a::predomain
   627   'a::pcpo ~> 'a::domain
   628 
   629 * The old type class "rep" has been superseded by class "domain".
   630 Accordingly, users of the definitional package must remove any
   631 "default_sort rep" declarations.  INCOMPATIBILITY.
   632 
   633 * The domain package (definitional mode) now supports unpointed
   634 predomain argument types, as long as they are marked 'lazy'. (Strict
   635 arguments must be in class "domain".) For example, the following
   636 domain definition now works:
   637 
   638   domain natlist = nil | cons (lazy "nat discr") (lazy "natlist")
   639 
   640 * Theory HOLCF/Library/HOL_Cpo provides cpo and predomain class
   641 instances for types from main HOL: bool, nat, int, char, 'a + 'b,
   642 'a option, and 'a list.  Additionally, it configures fixrec and the
   643 domain package to work with these types.  For example:
   644 
   645   fixrec isInl :: "('a + 'b) u -> tr"
   646     where "isInl$(up$(Inl x)) = TT" | "isInl$(up$(Inr y)) = FF"
   647 
   648   domain V = VFun (lazy "V -> V") | VCon (lazy "nat") (lazy "V list")
   649 
   650 * The "(permissive)" option of fixrec has been replaced with a
   651 per-equation "(unchecked)" option. See
   652 src/HOL/HOLCF/Tutorial/Fixrec_ex.thy for examples. INCOMPATIBILITY.
   653 
   654 * The "bifinite" class no longer fixes a constant "approx"; the class
   655 now just asserts that such a function exists.  INCOMPATIBILITY.
   656 
   657 * Former type "alg_defl" has been renamed to "defl".  HOLCF no longer
   658 defines an embedding of type 'a defl into udom by default; instances
   659 of "bifinite" and "domain" classes are available in
   660 src/HOL/HOLCF/Library/Defl_Bifinite.thy.
   661 
   662 * The syntax "REP('a)" has been replaced with "DEFL('a)".
   663 
   664 * The predicate "directed" has been removed.  INCOMPATIBILITY.
   665 
   666 * The type class "finite_po" has been removed.  INCOMPATIBILITY.
   667 
   668 * The function "cprod_map" has been renamed to "prod_map".
   669 INCOMPATIBILITY.
   670 
   671 * The monadic bind operator on each powerdomain has new binder syntax
   672 similar to sets, e.g. "\<Union>\<sharp>x\<in>xs. t" represents
   673 "upper_bind\<cdot>xs\<cdot>(\<Lambda> x. t)".
   674 
   675 * The infix syntax for binary union on each powerdomain has changed
   676 from e.g. "+\<sharp>" to "\<union>\<sharp>", for consistency with set
   677 syntax.  INCOMPATIBILITY.
   678 
   679 * The constant "UU" has been renamed to "bottom".  The syntax "UU" is
   680 still supported as an input translation.
   681 
   682 * Renamed some theorems (the original names are also still available).
   683 
   684   expand_fun_below   ~> fun_below_iff
   685   below_fun_ext      ~> fun_belowI
   686   expand_cfun_eq     ~> cfun_eq_iff
   687   ext_cfun           ~> cfun_eqI
   688   expand_cfun_below  ~> cfun_below_iff
   689   below_cfun_ext     ~> cfun_belowI
   690   cont2cont_Rep_CFun ~> cont2cont_APP
   691 
   692 * The Abs and Rep functions for various types have changed names.
   693 Related theorem names have also changed to match. INCOMPATIBILITY.
   694 
   695   Rep_CFun  ~> Rep_cfun
   696   Abs_CFun  ~> Abs_cfun
   697   Rep_Sprod ~> Rep_sprod
   698   Abs_Sprod ~> Abs_sprod
   699   Rep_Ssum  ~> Rep_ssum
   700   Abs_Ssum  ~> Abs_ssum
   701 
   702 * Lemmas with names of the form *_defined_iff or *_strict_iff have
   703 been renamed to *_bottom_iff.  INCOMPATIBILITY.
   704 
   705 * Various changes to bisimulation/coinduction with domain package:
   706 
   707   - Definitions of "bisim" constants no longer mention definedness.
   708   - With mutual recursion, "bisim" predicate is now curried.
   709   - With mutual recursion, each type gets a separate coind theorem.
   710   - Variable names in bisim_def and coinduct rules have changed.
   711 
   712 INCOMPATIBILITY.
   713 
   714 * Case combinators generated by the domain package for type "foo" are
   715 now named "foo_case" instead of "foo_when".  INCOMPATIBILITY.
   716 
   717 * Several theorems have been renamed to more accurately reflect the
   718 names of constants and types involved.  INCOMPATIBILITY.
   719 
   720   thelub_const    ~> lub_const
   721   lub_const       ~> is_lub_const
   722   thelubI         ~> lub_eqI
   723   is_lub_lub      ~> is_lubD2
   724   lubI            ~> is_lub_lub
   725   unique_lub      ~> is_lub_unique
   726   is_ub_lub       ~> is_lub_rangeD1
   727   lub_bin_chain   ~> is_lub_bin_chain
   728   lub_fun         ~> is_lub_fun
   729   thelub_fun      ~> lub_fun
   730   thelub_cfun     ~> lub_cfun
   731   thelub_Pair     ~> lub_Pair
   732   lub_cprod       ~> is_lub_prod
   733   thelub_cprod    ~> lub_prod
   734   minimal_cprod   ~> minimal_prod
   735   inst_cprod_pcpo ~> inst_prod_pcpo
   736   UU_I            ~> bottomI
   737   compact_UU      ~> compact_bottom
   738   deflation_UU    ~> deflation_bottom
   739   finite_deflation_UU ~> finite_deflation_bottom
   740 
   741 * Many legacy theorem names have been discontinued.  INCOMPATIBILITY.
   742 
   743   sq_ord_less_eq_trans ~> below_eq_trans
   744   sq_ord_eq_less_trans ~> eq_below_trans
   745   refl_less            ~> below_refl
   746   trans_less           ~> below_trans
   747   antisym_less         ~> below_antisym
   748   antisym_less_inverse ~> po_eq_conv [THEN iffD1]
   749   box_less             ~> box_below
   750   rev_trans_less       ~> rev_below_trans
   751   not_less2not_eq      ~> not_below2not_eq
   752   less_UU_iff          ~> below_UU_iff
   753   flat_less_iff        ~> flat_below_iff
   754   adm_less             ~> adm_below
   755   adm_not_less         ~> adm_not_below
   756   adm_compact_not_less ~> adm_compact_not_below
   757   less_fun_def         ~> below_fun_def
   758   expand_fun_less      ~> fun_below_iff
   759   less_fun_ext         ~> fun_belowI
   760   less_discr_def       ~> below_discr_def
   761   discr_less_eq        ~> discr_below_eq
   762   less_unit_def        ~> below_unit_def
   763   less_cprod_def       ~> below_prod_def
   764   prod_lessI           ~> prod_belowI
   765   Pair_less_iff        ~> Pair_below_iff
   766   fst_less_iff         ~> fst_below_iff
   767   snd_less_iff         ~> snd_below_iff
   768   expand_cfun_less     ~> cfun_below_iff
   769   less_cfun_ext        ~> cfun_belowI
   770   injection_less       ~> injection_below
   771   less_up_def          ~> below_up_def
   772   not_Iup_less         ~> not_Iup_below
   773   Iup_less             ~> Iup_below
   774   up_less              ~> up_below
   775   Def_inject_less_eq   ~> Def_below_Def
   776   Def_less_is_eq       ~> Def_below_iff
   777   spair_less_iff       ~> spair_below_iff
   778   less_sprod           ~> below_sprod
   779   spair_less           ~> spair_below
   780   sfst_less_iff        ~> sfst_below_iff
   781   ssnd_less_iff        ~> ssnd_below_iff
   782   fix_least_less       ~> fix_least_below
   783   dist_less_one        ~> dist_below_one
   784   less_ONE             ~> below_ONE
   785   ONE_less_iff         ~> ONE_below_iff
   786   less_sinlD           ~> below_sinlD
   787   less_sinrD           ~> below_sinrD
   788 
   789 
   790 *** FOL and ZF ***
   791 
   792 * All constant names are now qualified internally and use proper
   793 identifiers, e.g. "IFOL.eq" instead of "op =".  INCOMPATIBILITY.
   794 
   795 
   796 *** ML ***
   797 
   798 * Antiquotation @{assert} inlines a function bool -> unit that raises
   799 Fail if the argument is false.  Due to inlining the source position of
   800 failed assertions is included in the error output.
   801 
   802 * Discontinued antiquotation @{theory_ref}, which is obsolete since ML
   803 text is in practice always evaluated with a stable theory checkpoint.
   804 Minor INCOMPATIBILITY, use (Theory.check_thy @{theory}) instead.
   805 
   806 * Antiquotation @{theory A} refers to theory A from the ancestry of
   807 the current context, not any accidental theory loader state as before.
   808 Potential INCOMPATIBILITY, subtle change in semantics.
   809 
   810 * Syntax.pretty_priority (default 0) configures the required priority
   811 of pretty-printed output and thus affects insertion of parentheses.
   812 
   813 * Syntax.default_root (default "any") configures the inner syntax
   814 category (nonterminal symbol) for parsing of terms.
   815 
   816 * Former exception Library.UnequalLengths now coincides with
   817 ListPair.UnequalLengths.
   818 
   819 * Renamed structure MetaSimplifier to Raw_Simplifier.  Note that the
   820 main functionality is provided by structure Simplifier.
   821 
   822 * Renamed raw "explode" function to "raw_explode" to emphasize its
   823 meaning.  Note that internally to Isabelle, Symbol.explode is used in
   824 almost all situations.
   825 
   826 * Discontinued obsolete function sys_error and exception SYS_ERROR.
   827 See implementation manual for further details on exceptions in
   828 Isabelle/ML.
   829 
   830 * Renamed setmp_noncritical to Unsynchronized.setmp to emphasize its
   831 meaning.
   832 
   833 * Renamed structure PureThy to Pure_Thy and moved most of its
   834 operations to structure Global_Theory, to emphasize that this is
   835 rarely-used global-only stuff.
   836 
   837 * Discontinued Output.debug.  Minor INCOMPATIBILITY, use plain writeln
   838 instead (or tracing for high-volume output).
   839 
   840 * Configuration option show_question_marks only affects regular pretty
   841 printing of types and terms, not raw Term.string_of_vname.
   842 
   843 * ML_Context.thm and ML_Context.thms are no longer pervasive.  Rare
   844 INCOMPATIBILITY, superseded by static antiquotations @{thm} and
   845 @{thms} for most purposes.
   846 
   847 * ML structure Unsynchronized is never opened, not even in Isar
   848 interaction mode as before.  Old Unsynchronized.set etc. have been
   849 discontinued -- use plain := instead.  This should be *rare* anyway,
   850 since modern tools always work via official context data, notably
   851 configuration options.
   852 
   853 * Parallel and asynchronous execution requires special care concerning
   854 interrupts.  Structure Exn provides some convenience functions that
   855 avoid working directly with raw Interrupt.  User code must not absorb
   856 interrupts -- intermediate handling (for cleanup etc.) needs to be
   857 followed by re-raising of the original exception.  Another common
   858 source of mistakes are "handle _" patterns, which make the meaning of
   859 the program subject to physical effects of the environment.
   860 
   861 
   862 
   863 New in Isabelle2009-2 (June 2010)
   864 ---------------------------------
   865 
   866 *** General ***
   867 
   868 * Authentic syntax for *all* logical entities (type classes, type
   869 constructors, term constants): provides simple and robust
   870 correspondence between formal entities and concrete syntax.  Within
   871 the parse tree / AST representations, "constants" are decorated by
   872 their category (class, type, const) and spelled out explicitly with
   873 their full internal name.
   874 
   875 Substantial INCOMPATIBILITY concerning low-level syntax declarations
   876 and translations (translation rules and translation functions in ML).
   877 Some hints on upgrading:
   878 
   879   - Many existing uses of 'syntax' and 'translations' can be replaced
   880     by more modern 'type_notation', 'notation' and 'abbreviation',
   881     which are independent of this issue.
   882 
   883   - 'translations' require markup within the AST; the term syntax
   884     provides the following special forms:
   885 
   886       CONST c   -- produces syntax version of constant c from context
   887       XCONST c  -- literally c, checked as constant from context
   888       c         -- literally c, if declared by 'syntax'
   889 
   890     Plain identifiers are treated as AST variables -- occasionally the
   891     system indicates accidental variables via the error "rhs contains
   892     extra variables".
   893 
   894     Type classes and type constructors are marked according to their
   895     concrete syntax.  Some old translations rules need to be written
   896     for the "type" category, using type constructor application
   897     instead of pseudo-term application of the default category
   898     "logic".
   899 
   900   - 'parse_translation' etc. in ML may use the following
   901     antiquotations:
   902 
   903       @{class_syntax c}   -- type class c within parse tree / AST
   904       @{term_syntax c}    -- type constructor c within parse tree / AST
   905       @{const_syntax c}   -- ML version of "CONST c" above
   906       @{syntax_const c}   -- literally c (checked wrt. 'syntax' declarations)
   907 
   908   - Literal types within 'typed_print_translations', i.e. those *not*
   909     represented as pseudo-terms are represented verbatim.  Use @{class
   910     c} or @{type_name c} here instead of the above syntax
   911     antiquotations.
   912 
   913 Note that old non-authentic syntax was based on unqualified base
   914 names, so all of the above "constant" names would coincide.  Recall
   915 that 'print_syntax' and ML_command "set Syntax.trace_ast" help to
   916 diagnose syntax problems.
   917 
   918 * Type constructors admit general mixfix syntax, not just infix.
   919 
   920 * Concrete syntax may be attached to local entities without a proof
   921 body, too.  This works via regular mixfix annotations for 'fix',
   922 'def', 'obtain' etc. or via the explicit 'write' command, which is
   923 similar to the 'notation' command in theory specifications.
   924 
   925 * Discontinued unnamed infix syntax (legacy feature for many years) --
   926 need to specify constant name and syntax separately.  Internal ML
   927 datatype constructors have been renamed from InfixName to Infix etc.
   928 Minor INCOMPATIBILITY.
   929 
   930 * Schematic theorem statements need to be explicitly markup as such,
   931 via commands 'schematic_lemma', 'schematic_theorem',
   932 'schematic_corollary'.  Thus the relevance of the proof is made
   933 syntactically clear, which impacts performance in a parallel or
   934 asynchronous interactive environment.  Minor INCOMPATIBILITY.
   935 
   936 * Use of cumulative prems via "!" in some proof methods has been
   937 discontinued (old legacy feature).
   938 
   939 * References 'trace_simp' and 'debug_simp' have been replaced by
   940 configuration options stored in the context. Enabling tracing (the
   941 case of debugging is similar) in proofs works via
   942 
   943   using [[trace_simp = true]]
   944 
   945 Tracing is then active for all invocations of the simplifier in
   946 subsequent goal refinement steps. Tracing may also still be enabled or
   947 disabled via the ProofGeneral settings menu.
   948 
   949 * Separate commands 'hide_class', 'hide_type', 'hide_const',
   950 'hide_fact' replace the former 'hide' KIND command.  Minor
   951 INCOMPATIBILITY.
   952 
   953 * Improved parallelism of proof term normalization: usedir -p2 -q0 is
   954 more efficient than combinations with -q1 or -q2.
   955 
   956 
   957 *** Pure ***
   958 
   959 * Proofterms record type-class reasoning explicitly, using the
   960 "unconstrain" operation internally.  This eliminates all sort
   961 constraints from a theorem and proof, introducing explicit
   962 OFCLASS-premises.  On the proof term level, this operation is
   963 automatically applied at theorem boundaries, such that closed proofs
   964 are always free of sort constraints.  INCOMPATIBILITY for tools that
   965 inspect proof terms.
   966 
   967 * Local theory specifications may depend on extra type variables that
   968 are not present in the result type -- arguments TYPE('a) :: 'a itself
   969 are added internally.  For example:
   970 
   971   definition unitary :: bool where "unitary = (ALL (x::'a) y. x = y)"
   972 
   973 * Predicates of locales introduced by classes carry a mandatory
   974 "class" prefix.  INCOMPATIBILITY.
   975 
   976 * Vacuous class specifications observe default sort.  INCOMPATIBILITY.
   977 
   978 * Old 'axclass' command has been discontinued.  INCOMPATIBILITY, use
   979 'class' instead.
   980 
   981 * Command 'code_reflect' allows to incorporate generated ML code into
   982 runtime environment; replaces immature code_datatype antiquotation.
   983 INCOMPATIBILITY.
   984 
   985 * Code generator: simple concept for abstract datatypes obeying
   986 invariants.
   987 
   988 * Code generator: details of internal data cache have no impact on the
   989 user space functionality any longer.
   990 
   991 * Methods "unfold_locales" and "intro_locales" ignore non-locale
   992 subgoals.  This is more appropriate for interpretations with 'where'.
   993 INCOMPATIBILITY.
   994 
   995 * Command 'example_proof' opens an empty proof body.  This allows to
   996 experiment with Isar, without producing any persistent result.
   997 
   998 * Commands 'type_notation' and 'no_type_notation' declare type syntax
   999 within a local theory context, with explicit checking of the
  1000 constructors involved (in contrast to the raw 'syntax' versions).
  1001 
  1002 * Commands 'types' and 'typedecl' now work within a local theory
  1003 context -- without introducing dependencies on parameters or
  1004 assumptions, which is not possible in Isabelle/Pure.
  1005 
  1006 * Command 'defaultsort' has been renamed to 'default_sort', it works
  1007 within a local theory context.  Minor INCOMPATIBILITY.
  1008 
  1009 
  1010 *** HOL ***
  1011 
  1012 * Command 'typedef' now works within a local theory context -- without
  1013 introducing dependencies on parameters or assumptions, which is not
  1014 possible in Isabelle/Pure/HOL.  Note that the logical environment may
  1015 contain multiple interpretations of local typedefs (with different
  1016 non-emptiness proofs), even in a global theory context.
  1017 
  1018 * New package for quotient types.  Commands 'quotient_type' and
  1019 'quotient_definition' may be used for defining types and constants by
  1020 quotient constructions.  An example is the type of integers created by
  1021 quotienting pairs of natural numbers:
  1022 
  1023   fun
  1024     intrel :: "(nat * nat) => (nat * nat) => bool"
  1025   where
  1026     "intrel (x, y) (u, v) = (x + v = u + y)"
  1027 
  1028   quotient_type int = "nat * nat" / intrel
  1029     by (auto simp add: equivp_def expand_fun_eq)
  1030 
  1031   quotient_definition
  1032     "0::int" is "(0::nat, 0::nat)"
  1033 
  1034 The method "lifting" can be used to lift of theorems from the
  1035 underlying "raw" type to the quotient type.  The example
  1036 src/HOL/Quotient_Examples/FSet.thy includes such a quotient
  1037 construction and provides a reasoning infrastructure for finite sets.
  1038 
  1039 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
  1040 clash with new theory Quotient in Main HOL.
  1041 
  1042 * Moved the SMT binding into the main HOL session, eliminating
  1043 separate HOL-SMT session.
  1044 
  1045 * List membership infix mem operation is only an input abbreviation.
  1046 INCOMPATIBILITY.
  1047 
  1048 * Theory Library/Word.thy has been removed.  Use library Word/Word.thy
  1049 for future developements; former Library/Word.thy is still present in
  1050 the AFP entry RSAPPS.
  1051 
  1052 * Theorem Int.int_induct renamed to Int.int_of_nat_induct and is no
  1053 longer shadowed.  INCOMPATIBILITY.
  1054 
  1055 * Dropped theorem duplicate comp_arith; use semiring_norm instead.
  1056 INCOMPATIBILITY.
  1057 
  1058 * Dropped theorem RealPow.real_sq_order; use power2_le_imp_le instead.
  1059 INCOMPATIBILITY.
  1060 
  1061 * Dropped normalizing_semiring etc; use the facts in semiring classes
  1062 instead.  INCOMPATIBILITY.
  1063 
  1064 * Dropped several real-specific versions of lemmas about floor and
  1065 ceiling; use the generic lemmas from theory "Archimedean_Field"
  1066 instead.  INCOMPATIBILITY.
  1067 
  1068   floor_number_of_eq         ~> floor_number_of
  1069   le_floor_eq_number_of      ~> number_of_le_floor
  1070   le_floor_eq_zero           ~> zero_le_floor
  1071   le_floor_eq_one            ~> one_le_floor
  1072   floor_less_eq_number_of    ~> floor_less_number_of
  1073   floor_less_eq_zero         ~> floor_less_zero
  1074   floor_less_eq_one          ~> floor_less_one
  1075   less_floor_eq_number_of    ~> number_of_less_floor
  1076   less_floor_eq_zero         ~> zero_less_floor
  1077   less_floor_eq_one          ~> one_less_floor
  1078   floor_le_eq_number_of      ~> floor_le_number_of
  1079   floor_le_eq_zero           ~> floor_le_zero
  1080   floor_le_eq_one            ~> floor_le_one
  1081   floor_subtract_number_of   ~> floor_diff_number_of
  1082   floor_subtract_one         ~> floor_diff_one
  1083   ceiling_number_of_eq       ~> ceiling_number_of
  1084   ceiling_le_eq_number_of    ~> ceiling_le_number_of
  1085   ceiling_le_zero_eq         ~> ceiling_le_zero
  1086   ceiling_le_eq_one          ~> ceiling_le_one
  1087   less_ceiling_eq_number_of  ~> number_of_less_ceiling
  1088   less_ceiling_eq_zero       ~> zero_less_ceiling
  1089   less_ceiling_eq_one        ~> one_less_ceiling
  1090   ceiling_less_eq_number_of  ~> ceiling_less_number_of
  1091   ceiling_less_eq_zero       ~> ceiling_less_zero
  1092   ceiling_less_eq_one        ~> ceiling_less_one
  1093   le_ceiling_eq_number_of    ~> number_of_le_ceiling
  1094   le_ceiling_eq_zero         ~> zero_le_ceiling
  1095   le_ceiling_eq_one          ~> one_le_ceiling
  1096   ceiling_subtract_number_of ~> ceiling_diff_number_of
  1097   ceiling_subtract_one       ~> ceiling_diff_one
  1098 
  1099 * Theory "Finite_Set": various folding_XXX locales facilitate the
  1100 application of the various fold combinators on finite sets.
  1101 
  1102 * Library theory "RBT" renamed to "RBT_Impl"; new library theory "RBT"
  1103 provides abstract red-black tree type which is backed by "RBT_Impl" as
  1104 implementation.  INCOMPATIBILTY.
  1105 
  1106 * Theory Library/Coinductive_List has been removed -- superseded by
  1107 AFP/thys/Coinductive.
  1108 
  1109 * Theory PReal, including the type "preal" and related operations, has
  1110 been removed.  INCOMPATIBILITY.
  1111 
  1112 * Real: new development using Cauchy Sequences.
  1113 
  1114 * Split off theory "Big_Operators" containing setsum, setprod,
  1115 Inf_fin, Sup_fin, Min, Max from theory Finite_Set.  INCOMPATIBILITY.
  1116 
  1117 * Theory "Rational" renamed to "Rat", for consistency with "Nat",
  1118 "Int" etc.  INCOMPATIBILITY.
  1119 
  1120 * Constant Rat.normalize needs to be qualified.  INCOMPATIBILITY.
  1121 
  1122 * New set of rules "ac_simps" provides combined assoc / commute
  1123 rewrites for all interpretations of the appropriate generic locales.
  1124 
  1125 * Renamed theory "OrderedGroup" to "Groups" and split theory
  1126 "Ring_and_Field" into theories "Rings" and "Fields"; for more
  1127 appropriate and more consistent names suitable for name prefixes
  1128 within the HOL theories.  INCOMPATIBILITY.
  1129 
  1130 * Some generic constants have been put to appropriate theories:
  1131   - less_eq, less: Orderings
  1132   - zero, one, plus, minus, uminus, times, abs, sgn: Groups
  1133   - inverse, divide: Rings
  1134 INCOMPATIBILITY.
  1135 
  1136 * More consistent naming of type classes involving orderings (and
  1137 lattices):
  1138 
  1139     lower_semilattice                   ~> semilattice_inf
  1140     upper_semilattice                   ~> semilattice_sup
  1141 
  1142     dense_linear_order                  ~> dense_linorder
  1143 
  1144     pordered_ab_group_add               ~> ordered_ab_group_add
  1145     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
  1146     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
  1147     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
  1148     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
  1149     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
  1150     pordered_cancel_semiring            ~> ordered_cancel_semiring
  1151     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
  1152     pordered_comm_ring                  ~> ordered_comm_ring
  1153     pordered_comm_semiring              ~> ordered_comm_semiring
  1154     pordered_ring                       ~> ordered_ring
  1155     pordered_ring_abs                   ~> ordered_ring_abs
  1156     pordered_semiring                   ~> ordered_semiring
  1157 
  1158     ordered_ab_group_add                ~> linordered_ab_group_add
  1159     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
  1160     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
  1161     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
  1162     ordered_field                       ~> linordered_field
  1163     ordered_field_no_lb                 ~> linordered_field_no_lb
  1164     ordered_field_no_ub                 ~> linordered_field_no_ub
  1165     ordered_field_dense_linear_order    ~> dense_linordered_field
  1166     ordered_idom                        ~> linordered_idom
  1167     ordered_ring                        ~> linordered_ring
  1168     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
  1169     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
  1170     ordered_ring_strict                 ~> linordered_ring_strict
  1171     ordered_semidom                     ~> linordered_semidom
  1172     ordered_semiring                    ~> linordered_semiring
  1173     ordered_semiring_1                  ~> linordered_semiring_1
  1174     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
  1175     ordered_semiring_strict             ~> linordered_semiring_strict
  1176 
  1177   The following slightly odd type classes have been moved to a
  1178   separate theory Library/Lattice_Algebras:
  1179 
  1180     lordered_ab_group_add               ~> lattice_ab_group_add
  1181     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
  1182     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
  1183     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
  1184     lordered_ring                       ~> lattice_ring
  1185 
  1186 INCOMPATIBILITY.
  1187 
  1188 * Refined field classes:
  1189   - classes division_ring_inverse_zero, field_inverse_zero,
  1190     linordered_field_inverse_zero include rule inverse 0 = 0 --
  1191     subsumes former division_by_zero class;
  1192   - numerous lemmas have been ported from field to division_ring.
  1193 INCOMPATIBILITY.
  1194 
  1195 * Refined algebra theorem collections:
  1196   - dropped theorem group group_simps, use algebra_simps instead;
  1197   - dropped theorem group ring_simps, use field_simps instead;
  1198   - proper theorem collection field_simps subsumes former theorem
  1199     groups field_eq_simps and field_simps;
  1200   - dropped lemma eq_minus_self_iff which is a duplicate for
  1201     equal_neg_zero.
  1202 INCOMPATIBILITY.
  1203 
  1204 * Theory Finite_Set and List: some lemmas have been generalized from
  1205 sets to lattices:
  1206 
  1207   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
  1208   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
  1209   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
  1210   union_Union_fold_union        ~> sup_Sup_fold_sup
  1211   Inter_fold_inter              ~> Inf_fold_inf
  1212   Union_fold_union              ~> Sup_fold_sup
  1213   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
  1214   union_UNION_fold_union        ~> sup_SUPR_fold_sup
  1215   INTER_fold_inter              ~> INFI_fold_inf
  1216   UNION_fold_union              ~> SUPR_fold_sup
  1217 
  1218 * Theory "Complete_Lattice": lemmas top_def and bot_def have been
  1219 replaced by the more convenient lemmas Inf_empty and Sup_empty.
  1220 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
  1221 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
  1222 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
  1223 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
  1224 
  1225 * Reorganized theory Multiset: swapped notation of pointwise and
  1226 multiset order:
  1227 
  1228   - pointwise ordering is instance of class order with standard syntax
  1229     <= and <;
  1230   - multiset ordering has syntax <=# and <#; partial order properties
  1231     are provided by means of interpretation with prefix
  1232     multiset_order;
  1233   - less duplication, less historical organization of sections,
  1234     conversion from associations lists to multisets, rudimentary code
  1235     generation;
  1236   - use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union,
  1237     if needed.
  1238 
  1239 Renamed:
  1240 
  1241   multiset_eq_conv_count_eq  ~>  multiset_ext_iff
  1242   multi_count_ext  ~>  multiset_ext
  1243   diff_union_inverse2  ~>  diff_union_cancelR
  1244 
  1245 INCOMPATIBILITY.
  1246 
  1247 * Theory Permutation: replaced local "remove" by List.remove1.
  1248 
  1249 * Code generation: ML and OCaml code is decorated with signatures.
  1250 
  1251 * Theory List: added transpose.
  1252 
  1253 * Library/Nat_Bijection.thy is a collection of bijective functions
  1254 between nat and other types, which supersedes the older libraries
  1255 Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.
  1256 
  1257   Constants:
  1258   Nat_Int_Bij.nat2_to_nat         ~> prod_encode
  1259   Nat_Int_Bij.nat_to_nat2         ~> prod_decode
  1260   Nat_Int_Bij.int_to_nat_bij      ~> int_encode
  1261   Nat_Int_Bij.nat_to_int_bij      ~> int_decode
  1262   Countable.pair_encode           ~> prod_encode
  1263   NatIso.prod2nat                 ~> prod_encode
  1264   NatIso.nat2prod                 ~> prod_decode
  1265   NatIso.sum2nat                  ~> sum_encode
  1266   NatIso.nat2sum                  ~> sum_decode
  1267   NatIso.list2nat                 ~> list_encode
  1268   NatIso.nat2list                 ~> list_decode
  1269   NatIso.set2nat                  ~> set_encode
  1270   NatIso.nat2set                  ~> set_decode
  1271 
  1272   Lemmas:
  1273   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
  1274   Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
  1275   Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
  1276   Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
  1277   Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
  1278   Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
  1279   Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
  1280   Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
  1281   Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
  1282   Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
  1283   Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
  1284   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
  1285   Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode
  1286 
  1287 * Sledgehammer:
  1288   - Renamed ATP commands:
  1289     atp_info     ~> sledgehammer running_atps
  1290     atp_kill     ~> sledgehammer kill_atps
  1291     atp_messages ~> sledgehammer messages
  1292     atp_minimize ~> sledgehammer minimize
  1293     print_atps   ~> sledgehammer available_atps
  1294     INCOMPATIBILITY.
  1295   - Added user's manual ("isabelle doc sledgehammer").
  1296   - Added option syntax and "sledgehammer_params" to customize
  1297     Sledgehammer's behavior.  See the manual for details.
  1298   - Modified the Isar proof reconstruction code so that it produces
  1299     direct proofs rather than proofs by contradiction.  (This feature
  1300     is still experimental.)
  1301   - Made Isar proof reconstruction work for SPASS, remote ATPs, and in
  1302     full-typed mode.
  1303   - Added support for TPTP syntax for SPASS via the "spass_tptp" ATP.
  1304 
  1305 * Nitpick:
  1306   - Added and implemented "binary_ints" and "bits" options.
  1307   - Added "std" option and implemented support for nonstandard models.
  1308   - Added and implemented "finitize" option to improve the precision
  1309     of infinite datatypes based on a monotonicity analysis.
  1310   - Added support for quotient types.
  1311   - Added support for "specification" and "ax_specification"
  1312     constructs.
  1313   - Added support for local definitions (for "function" and
  1314     "termination" proofs).
  1315   - Added support for term postprocessors.
  1316   - Optimized "Multiset.multiset" and "FinFun.finfun".
  1317   - Improved efficiency of "destroy_constrs" optimization.
  1318   - Fixed soundness bugs related to "destroy_constrs" optimization and
  1319     record getters.
  1320   - Fixed soundness bug related to higher-order constructors.
  1321   - Fixed soundness bug when "full_descrs" is enabled.
  1322   - Improved precision of set constructs.
  1323   - Added "atoms" option.
  1324   - Added cache to speed up repeated Kodkod invocations on the same
  1325     problems.
  1326   - Renamed "MiniSatJNI", "zChaffJNI", "BerkMinAlloy", and
  1327     "SAT4JLight" to "MiniSat_JNI", "zChaff_JNI", "BerkMin_Alloy", and
  1328     "SAT4J_Light".  INCOMPATIBILITY.
  1329   - Removed "skolemize", "uncurry", "sym_break", "flatten_prop",
  1330     "sharing_depth", and "show_skolems" options.  INCOMPATIBILITY.
  1331   - Removed "nitpick_intro" attribute.  INCOMPATIBILITY.
  1332 
  1333 * Method "induct" now takes instantiations of the form t, where t is not
  1334   a variable, as a shorthand for "x == t", where x is a fresh variable.
  1335   If this is not intended, t has to be enclosed in parentheses.
  1336   By default, the equalities generated by definitional instantiations
  1337   are pre-simplified, which may cause parameters of inductive cases
  1338   to disappear, or may even delete some of the inductive cases.
  1339   Use "induct (no_simp)" instead of "induct" to restore the old
  1340   behaviour. The (no_simp) option is also understood by the "cases"
  1341   and "nominal_induct" methods, which now perform pre-simplification, too.
  1342   INCOMPATIBILITY.
  1343 
  1344 
  1345 *** HOLCF ***
  1346 
  1347 * Variable names in lemmas generated by the domain package have
  1348 changed; the naming scheme is now consistent with the HOL datatype
  1349 package.  Some proof scripts may be affected, INCOMPATIBILITY.
  1350 
  1351 * The domain package no longer defines the function "foo_copy" for
  1352 recursive domain "foo".  The reach lemma is now stated directly in
  1353 terms of "foo_take".  Lemmas and proofs that mention "foo_copy" must
  1354 be reformulated in terms of "foo_take", INCOMPATIBILITY.
  1355 
  1356 * Most definedness lemmas generated by the domain package (previously
  1357 of the form "x ~= UU ==> foo$x ~= UU") now have an if-and-only-if form
  1358 like "foo$x = UU <-> x = UU", which works better as a simp rule.
  1359 Proofs that used definedness lemmas as intro rules may break,
  1360 potential INCOMPATIBILITY.
  1361 
  1362 * Induction and casedist rules generated by the domain package now
  1363 declare proper case_names (one called "bottom", and one named for each
  1364 constructor).  INCOMPATIBILITY.
  1365 
  1366 * For mutually-recursive domains, separate "reach" and "take_lemma"
  1367 rules are generated for each domain, INCOMPATIBILITY.
  1368 
  1369   foo_bar.reach       ~> foo.reach  bar.reach
  1370   foo_bar.take_lemmas ~> foo.take_lemma  bar.take_lemma
  1371 
  1372 * Some lemmas generated by the domain package have been renamed for
  1373 consistency with the datatype package, INCOMPATIBILITY.
  1374 
  1375   foo.ind        ~> foo.induct
  1376   foo.finite_ind ~> foo.finite_induct
  1377   foo.coind      ~> foo.coinduct
  1378   foo.casedist   ~> foo.exhaust
  1379   foo.exhaust    ~> foo.nchotomy
  1380 
  1381 * For consistency with other definition packages, the fixrec package
  1382 now generates qualified theorem names, INCOMPATIBILITY.
  1383 
  1384   foo_simps  ~> foo.simps
  1385   foo_unfold ~> foo.unfold
  1386   foo_induct ~> foo.induct
  1387 
  1388 * The "fixrec_simp" attribute has been removed.  The "fixrec_simp"
  1389 method and internal fixrec proofs now use the default simpset instead.
  1390 INCOMPATIBILITY.
  1391 
  1392 * The "contlub" predicate has been removed.  Proof scripts should use
  1393 lemma contI2 in place of monocontlub2cont, INCOMPATIBILITY.
  1394 
  1395 * The "admw" predicate has been removed, INCOMPATIBILITY.
  1396 
  1397 * The constants cpair, cfst, and csnd have been removed in favor of
  1398 Pair, fst, and snd from Isabelle/HOL, INCOMPATIBILITY.
  1399 
  1400 
  1401 *** ML ***
  1402 
  1403 * Antiquotations for basic formal entities:
  1404 
  1405     @{class NAME}         -- type class
  1406     @{class_syntax NAME}  -- syntax representation of the above
  1407 
  1408     @{type_name NAME}     -- logical type
  1409     @{type_abbrev NAME}   -- type abbreviation
  1410     @{nonterminal NAME}   -- type of concrete syntactic category
  1411     @{type_syntax NAME}   -- syntax representation of any of the above
  1412 
  1413     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
  1414     @{const_abbrev NAME}  -- abbreviated constant
  1415     @{const_syntax NAME}  -- syntax representation of any of the above
  1416 
  1417 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
  1418 syntax constant (cf. 'syntax' command).
  1419 
  1420 * Antiquotation @{make_string} inlines a function to print arbitrary
  1421 values similar to the ML toplevel.  The result is compiler dependent
  1422 and may fall back on "?" in certain situations.
  1423 
  1424 * Diagnostic commands 'ML_val' and 'ML_command' may refer to
  1425 antiquotations @{Isar.state} and @{Isar.goal}.  This replaces impure
  1426 Isar.state() and Isar.goal(), which belong to the old TTY loop and do
  1427 not work with the asynchronous Isar document model.
  1428 
  1429 * Configuration options now admit dynamic default values, depending on
  1430 the context or even global references.
  1431 
  1432 * SHA1.digest digests strings according to SHA-1 (see RFC 3174).  It
  1433 uses an efficient external library if available (for Poly/ML).
  1434 
  1435 * Renamed some important ML structures, while keeping the old names
  1436 for some time as aliases within the structure Legacy:
  1437 
  1438   OuterKeyword  ~>  Keyword
  1439   OuterLex      ~>  Token
  1440   OuterParse    ~>  Parse
  1441   OuterSyntax   ~>  Outer_Syntax
  1442   PrintMode     ~>  Print_Mode
  1443   SpecParse     ~>  Parse_Spec
  1444   ThyInfo       ~>  Thy_Info
  1445   ThyLoad       ~>  Thy_Load
  1446   ThyOutput     ~>  Thy_Output
  1447   TypeInfer     ~>  Type_Infer
  1448 
  1449 Note that "open Legacy" simplifies porting of sources, but forgetting
  1450 to remove it again will complicate porting again in the future.
  1451 
  1452 * Most operations that refer to a global context are named
  1453 accordingly, e.g. Simplifier.global_context or
  1454 ProofContext.init_global.  There are some situations where a global
  1455 context actually works, but under normal circumstances one needs to
  1456 pass the proper local context through the code!
  1457 
  1458 * Discontinued old TheoryDataFun with its copy/init operation -- data
  1459 needs to be pure.  Functor Theory_Data_PP retains the traditional
  1460 Pretty.pp argument to merge, which is absent in the standard
  1461 Theory_Data version.
  1462 
  1463 * Sorts.certify_sort and derived "cert" operations for types and terms
  1464 no longer minimize sorts.  Thus certification at the boundary of the
  1465 inference kernel becomes invariant under addition of class relations,
  1466 which is an important monotonicity principle.  Sorts are now minimized
  1467 in the syntax layer only, at the boundary between the end-user and the
  1468 system.  Subtle INCOMPATIBILITY, may have to use Sign.minimize_sort
  1469 explicitly in rare situations.
  1470 
  1471 * Renamed old-style Drule.standard to Drule.export_without_context, to
  1472 emphasize that this is in no way a standard operation.
  1473 INCOMPATIBILITY.
  1474 
  1475 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
  1476 usual for resolution.  Rare INCOMPATIBILITY.
  1477 
  1478 * Renamed varify/unvarify operations to varify_global/unvarify_global
  1479 to emphasize that these only work in a global situation (which is
  1480 quite rare).
  1481 
  1482 * Curried take and drop in library.ML; negative length is interpreted
  1483 as infinity (as in chop).  Subtle INCOMPATIBILITY.
  1484 
  1485 * Proof terms: type substitutions on proof constants now use canonical
  1486 order of type variables.  INCOMPATIBILITY for tools working with proof
  1487 terms.
  1488 
  1489 * Raw axioms/defs may no longer carry sort constraints, and raw defs
  1490 may no longer carry premises.  User-level specifications are
  1491 transformed accordingly by Thm.add_axiom/add_def.
  1492 
  1493 
  1494 *** System ***
  1495 
  1496 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
  1497 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
  1498 proof terms are enabled unconditionally in the new HOL-Proofs image.
  1499 
  1500 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
  1501 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
  1502 respectively.
  1503 
  1504 * Old lib/scripts/polyml-platform is superseded by the
  1505 ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
  1506 variant, even on a 64 bit machine.  The following example setting
  1507 prefers 64 bit if available:
  1508 
  1509   ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"
  1510 
  1511 * The preliminary Isabelle/jEdit application demonstrates the emerging
  1512 Isabelle/Scala layer for advanced prover interaction and integration.
  1513 See src/Tools/jEdit or "isabelle jedit" provided by the properly built
  1514 component.
  1515 
  1516 * "IsabelleText" is a Unicode font derived from Bitstream Vera Mono
  1517 and Bluesky TeX fonts.  It provides the usual Isabelle symbols,
  1518 similar to the default assignment of the document preparation system
  1519 (cf. isabellesym.sty).  The Isabelle/Scala class Isabelle_System
  1520 provides some operations for direct access to the font without asking
  1521 the user for manual installation.
  1522 
  1523 
  1524 
  1525 New in Isabelle2009-1 (December 2009)
  1526 -------------------------------------
  1527 
  1528 *** General ***
  1529 
  1530 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
  1531 one backslash should be used, even in ML sources.
  1532 
  1533 
  1534 *** Pure ***
  1535 
  1536 * Locale interpretation propagates mixins along the locale hierarchy.
  1537 The currently only available mixins are the equations used to map
  1538 local definitions to terms of the target domain of an interpretation.
  1539 
  1540 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
  1541 loc" to print all interpretations of locale "loc" in the theory.
  1542 Interpretations in proofs are not shown.
  1543 
  1544 * Thoroughly revised locales tutorial.  New section on conditional
  1545 interpretation.
  1546 
  1547 * On instantiation of classes, remaining undefined class parameters
  1548 are formally declared.  INCOMPATIBILITY.
  1549 
  1550 
  1551 *** Document preparation ***
  1552 
  1553 * New generalized style concept for printing terms: @{foo (style) ...}
  1554 instead of @{foo_style style ...}  (old form is still retained for
  1555 backward compatibility).  Styles can be also applied for
  1556 antiquotations prop, term_type and typeof.
  1557 
  1558 
  1559 *** HOL ***
  1560 
  1561 * New proof method "smt" for a combination of first-order logic with
  1562 equality, linear and nonlinear (natural/integer/real) arithmetic, and
  1563 fixed-size bitvectors; there is also basic support for higher-order
  1564 features (esp. lambda abstractions).  It is an incomplete decision
  1565 procedure based on external SMT solvers using the oracle mechanism;
  1566 for the SMT solver Z3, this method is proof-producing.  Certificates
  1567 are provided to avoid calling the external solvers solely for
  1568 re-checking proofs.  Due to a remote SMT service there is no need for
  1569 installing SMT solvers locally.  See src/HOL/SMT.
  1570 
  1571 * New commands to load and prove verification conditions generated by
  1572 the Boogie program verifier or derived systems (e.g. the Verifying C
  1573 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
  1574 
  1575 * New counterexample generator tool 'nitpick' based on the Kodkod
  1576 relational model finder.  See src/HOL/Tools/Nitpick and
  1577 src/HOL/Nitpick_Examples.
  1578 
  1579 * New commands 'code_pred' and 'values' to invoke the predicate
  1580 compiler and to enumerate values of inductive predicates.
  1581 
  1582 * A tabled implementation of the reflexive transitive closure.
  1583 
  1584 * New implementation of quickcheck uses generic code generator;
  1585 default generators are provided for all suitable HOL types, records
  1586 and datatypes.  Old quickcheck can be re-activated importing theory
  1587 Library/SML_Quickcheck.
  1588 
  1589 * New testing tool Mirabelle for automated proof tools.  Applies
  1590 several tools and tactics like sledgehammer, metis, or quickcheck, to
  1591 every proof step in a theory.  To be used in batch mode via the
  1592 "mirabelle" utility.
  1593 
  1594 * New proof method "sos" (sum of squares) for nonlinear real
  1595 arithmetic (originally due to John Harison). It requires theory
  1596 Library/Sum_Of_Squares.  It is not a complete decision procedure but
  1597 works well in practice on quantifier-free real arithmetic with +, -,
  1598 *, ^, =, <= and <, i.e. boolean combinations of equalities and
  1599 inequalities between polynomials.  It makes use of external
  1600 semidefinite programming solvers.  Method "sos" generates a
  1601 certificate that can be pasted into the proof thus avoiding the need
  1602 to call an external tool every time the proof is checked.  See
  1603 src/HOL/Library/Sum_Of_Squares.
  1604 
  1605 * New method "linarith" invokes existing linear arithmetic decision
  1606 procedure only.
  1607 
  1608 * New command 'atp_minimal' reduces result produced by Sledgehammer.
  1609 
  1610 * New Sledgehammer option "Full Types" in Proof General settings menu.
  1611 Causes full type information to be output to the ATPs.  This slows
  1612 ATPs down considerably but eliminates a source of unsound "proofs"
  1613 that fail later.
  1614 
  1615 * New method "metisFT": A version of metis that uses full type
  1616 information in order to avoid failures of proof reconstruction.
  1617 
  1618 * New evaluator "approximate" approximates an real valued term using
  1619 the same method as the approximation method.
  1620 
  1621 * Method "approximate" now supports arithmetic expressions as
  1622 boundaries of intervals and implements interval splitting and Taylor
  1623 series expansion.
  1624 
  1625 * ML antiquotation @{code_datatype} inserts definition of a datatype
  1626 generated by the code generator; e.g. see src/HOL/Predicate.thy.
  1627 
  1628 * New theory SupInf of the supremum and infimum operators for sets of
  1629 reals.
  1630 
  1631 * New theory Probability, which contains a development of measure
  1632 theory, eventually leading to Lebesgue integration and probability.
  1633 
  1634 * Extended Multivariate Analysis to include derivation and Brouwer's
  1635 fixpoint theorem.
  1636 
  1637 * Reorganization of number theory, INCOMPATIBILITY:
  1638   - new number theory development for nat and int, in theories Divides
  1639     and GCD as well as in new session Number_Theory
  1640   - some constants and facts now suffixed with _nat and _int
  1641     accordingly
  1642   - former session NumberTheory now named Old_Number_Theory, including
  1643     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
  1644   - moved theory Pocklington from src/HOL/Library to
  1645     src/HOL/Old_Number_Theory
  1646 
  1647 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
  1648 lcm of finite and infinite sets. It is shown that they form a complete
  1649 lattice.
  1650 
  1651 * Class semiring_div requires superclass no_zero_divisors and proof of
  1652 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
  1653 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
  1654 generalized to class semiring_div, subsuming former theorems
  1655 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
  1656 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
  1657 INCOMPATIBILITY.
  1658 
  1659 * Refinements to lattice classes and sets:
  1660   - less default intro/elim rules in locale variant, more default
  1661     intro/elim rules in class variant: more uniformity
  1662   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
  1663     le_inf_iff
  1664   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
  1665     sup_aci)
  1666   - renamed ACI to inf_sup_aci
  1667   - new class "boolean_algebra"
  1668   - class "complete_lattice" moved to separate theory
  1669     "Complete_Lattice"; corresponding constants (and abbreviations)
  1670     renamed and with authentic syntax:
  1671     Set.Inf ~>    Complete_Lattice.Inf
  1672     Set.Sup ~>    Complete_Lattice.Sup
  1673     Set.INFI ~>   Complete_Lattice.INFI
  1674     Set.SUPR ~>   Complete_Lattice.SUPR
  1675     Set.Inter ~>  Complete_Lattice.Inter
  1676     Set.Union ~>  Complete_Lattice.Union
  1677     Set.INTER ~>  Complete_Lattice.INTER
  1678     Set.UNION ~>  Complete_Lattice.UNION
  1679   - authentic syntax for
  1680     Set.Pow
  1681     Set.image
  1682   - mere abbreviations:
  1683     Set.empty               (for bot)
  1684     Set.UNIV                (for top)
  1685     Set.inter               (for inf, formerly Set.Int)
  1686     Set.union               (for sup, formerly Set.Un)
  1687     Complete_Lattice.Inter  (for Inf)
  1688     Complete_Lattice.Union  (for Sup)
  1689     Complete_Lattice.INTER  (for INFI)
  1690     Complete_Lattice.UNION  (for SUPR)
  1691   - object-logic definitions as far as appropriate
  1692 
  1693 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
  1694 Un_subset_iff are explicitly deleted as default simp rules; then also
  1695 their lattice counterparts le_inf_iff and le_sup_iff have to be
  1696 deleted to achieve the desired effect.
  1697 
  1698 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
  1699 rules by default any longer; the same applies to min_max.inf_absorb1
  1700 etc.  INCOMPATIBILITY.
  1701 
  1702 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
  1703 pred_set_conv by default.  INCOMPATIBILITY.
  1704 
  1705 * Power operations on relations and functions are now one dedicated
  1706 constant "compow" with infix syntax "^^".  Power operation on
  1707 multiplicative monoids retains syntax "^" and is now defined generic
  1708 in class power.  INCOMPATIBILITY.
  1709 
  1710 * Relation composition "R O S" now has a more standard argument order:
  1711 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
  1712 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
  1713 break, since the O_assoc rule was not rewritten like this.  Fix using
  1714 O_assoc[symmetric].  The same applies to the curried version "R OO S".
  1715 
  1716 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
  1717 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
  1718 INCOMPATIBILITY.
  1719 
  1720 * Most rules produced by inductive and datatype package have mandatory
  1721 prefixes.  INCOMPATIBILITY.
  1722 
  1723 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
  1724 the attribute of the same name.  Each of the theorems in the list
  1725 DERIV_intros assumes composition with an additional function and
  1726 matches a variable to the derivative, which has to be solved by the
  1727 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
  1728 of most elementary terms.  Former Maclauren.DERIV_tac and
  1729 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
  1730 INCOMPATIBILITY.
  1731 
  1732 * Code generator attributes follow the usual underscore convention:
  1733     code_unfold     replaces    code unfold
  1734     code_post       replaces    code post
  1735     etc.
  1736   INCOMPATIBILITY.
  1737 
  1738 * Renamed methods:
  1739     sizechange -> size_change
  1740     induct_scheme -> induction_schema
  1741   INCOMPATIBILITY.
  1742 
  1743 * Discontinued abbreviation "arbitrary" of constant "undefined".
  1744 INCOMPATIBILITY, use "undefined" directly.
  1745 
  1746 * Renamed theorems:
  1747     Suc_eq_add_numeral_1 -> Suc_eq_plus1
  1748     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
  1749     Suc_plus1 -> Suc_eq_plus1
  1750     *anti_sym -> *antisym*
  1751     vector_less_eq_def -> vector_le_def
  1752   INCOMPATIBILITY.
  1753 
  1754 * Added theorem List.map_map as [simp].  Removed List.map_compose.
  1755 INCOMPATIBILITY.
  1756 
  1757 * Removed predicate "M hassize n" (<--> card M = n & finite M).
  1758 INCOMPATIBILITY.
  1759 
  1760 
  1761 *** HOLCF ***
  1762 
  1763 * Theory Representable defines a class "rep" of domains that are
  1764 representable (via an ep-pair) in the universal domain type "udom".
  1765 Instances are provided for all type constructors defined in HOLCF.
  1766 
  1767 * The 'new_domain' command is a purely definitional version of the
  1768 domain package, for representable domains.  Syntax is identical to the
  1769 old domain package.  The 'new_domain' package also supports indirect
  1770 recursion using previously-defined type constructors.  See
  1771 src/HOLCF/ex/New_Domain.thy for examples.
  1772 
  1773 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
  1774 on the left-hand side of an equation, and then performs
  1775 simplification.  Rewriting is done using rules declared with the
  1776 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
  1777 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
  1778 
  1779 * The pattern-match compiler in 'fixrec' can now handle constructors
  1780 with HOL function types.  Pattern-match combinators for the Pair
  1781 constructor are pre-configured.
  1782 
  1783 * The 'fixrec' package now produces better fixed-point induction rules
  1784 for mutually-recursive definitions:  Induction rules have conclusions
  1785 of the form "P foo bar" instead of "P <foo, bar>".
  1786 
  1787 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
  1788 been renamed to "below".  The name "below" now replaces "less" in many
  1789 theorem names.  (Legacy theorem names using "less" are still supported
  1790 as well.)
  1791 
  1792 * The 'fixrec' package now supports "bottom patterns".  Bottom
  1793 patterns can be used to generate strictness rules, or to make
  1794 functions more strict (much like the bang-patterns supported by the
  1795 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
  1796 examples.
  1797 
  1798 
  1799 *** ML ***
  1800 
  1801 * Support for Poly/ML 5.3.0, with improved reporting of compiler
  1802 errors and run-time exceptions, including detailed source positions.
  1803 
  1804 * Structure Name_Space (formerly NameSpace) now manages uniquely
  1805 identified entries, with some additional information such as source
  1806 position, logical grouping etc.
  1807 
  1808 * Theory and context data is now introduced by the simplified and
  1809 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
  1810 to be pure, but the old TheoryDataFun for mutable data (with explicit
  1811 copy operation) is still available for some time.
  1812 
  1813 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
  1814 provides a high-level programming interface to synchronized state
  1815 variables with atomic update.  This works via pure function
  1816 application within a critical section -- its runtime should be as
  1817 short as possible; beware of deadlocks if critical code is nested,
  1818 either directly or indirectly via other synchronized variables!
  1819 
  1820 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
  1821 wraps raw ML references, explicitly indicating their non-thread-safe
  1822 behaviour.  The Isar toplevel keeps this structure open, to
  1823 accommodate Proof General as well as quick and dirty interactive
  1824 experiments with references.
  1825 
  1826 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
  1827 parallel tactical reasoning.
  1828 
  1829 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
  1830 are similar to SUBPROOF, but are slightly more flexible: only the
  1831 specified parts of the subgoal are imported into the context, and the
  1832 body tactic may introduce new subgoals and schematic variables.
  1833 
  1834 * Old tactical METAHYPS, which does not observe the proof context, has
  1835 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
  1836 or Subgoal.FOCUS etc.
  1837 
  1838 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
  1839 functors have their own ML name space there is no point to mark them
  1840 separately.)  Minor INCOMPATIBILITY.
  1841 
  1842 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
  1843 
  1844 * Renamed several structures FooBar to Foo_Bar.  Occasional,
  1845 INCOMPATIBILITY.
  1846 
  1847 * Operations of structure Skip_Proof no longer require quick_and_dirty
  1848 mode, which avoids critical setmp.
  1849 
  1850 * Eliminated old Attrib.add_attributes, Method.add_methods and related
  1851 combinators for "args".  INCOMPATIBILITY, need to use simplified
  1852 Attrib/Method.setup introduced in Isabelle2009.
  1853 
  1854 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
  1855 back on global_simpset_of, global_claset_of, global_clasimpset_of as
  1856 last resort.  INCOMPATIBILITY.
  1857 
  1858 * Display.pretty_thm now requires a proper context (cf. former
  1859 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
  1860 or even Display.pretty_thm_without_context as last resort.
  1861 INCOMPATIBILITY.
  1862 
  1863 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
  1864 Syntax.pretty_typ/term directly, preferably with proper context
  1865 instead of global theory.
  1866 
  1867 
  1868 *** System ***
  1869 
  1870 * Further fine tuning of parallel proof checking, scales up to 8 cores
  1871 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
  1872 usedir option -q.
  1873 
  1874 * Support for additional "Isabelle components" via etc/components, see
  1875 also the system manual.
  1876 
  1877 * The isabelle makeall tool now operates on all components with
  1878 IsaMakefile, not just hardwired "logics".
  1879 
  1880 * Removed "compress" option from isabelle-process and isabelle usedir;
  1881 this is always enabled.
  1882 
  1883 * Discontinued support for Poly/ML 4.x versions.
  1884 
  1885 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
  1886 on a given logic image.  This requires the lighttpd webserver and is
  1887 currently supported on Linux only.
  1888 
  1889 
  1890 
  1891 New in Isabelle2009 (April 2009)
  1892 --------------------------------
  1893 
  1894 *** General ***
  1895 
  1896 * Simplified main Isabelle executables, with less surprises on
  1897 case-insensitive file-systems (such as Mac OS).
  1898 
  1899   - The main Isabelle tool wrapper is now called "isabelle" instead of
  1900     "isatool."
  1901 
  1902   - The former "isabelle" alias for "isabelle-process" has been
  1903     removed (should rarely occur to regular users).
  1904 
  1905   - The former "isabelle-interface" and its alias "Isabelle" have been
  1906     removed (interfaces are now regular Isabelle tools).
  1907 
  1908 Within scripts and make files, the Isabelle environment variables
  1909 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
  1910 respectively.  (The latter are still available as legacy feature.)
  1911 
  1912 The old isabelle-interface wrapper could react in confusing ways if
  1913 the interface was uninstalled or changed otherwise.  Individual
  1914 interface tool configuration is now more explicit, see also the
  1915 Isabelle system manual.  In particular, Proof General is now available
  1916 via "isabelle emacs".
  1917 
  1918 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
  1919 purge installed copies of Isabelle executables and re-run "isabelle
  1920 install -p ...", or use symlinks.
  1921 
  1922 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
  1923 old ~/isabelle, which was slightly non-standard and apt to cause
  1924 surprises on case-insensitive file-systems (such as Mac OS).
  1925 
  1926 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
  1927 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
  1928 care is required when using older releases of Isabelle.  Note that
  1929 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
  1930 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
  1931 
  1932 * Proofs of fully specified statements are run in parallel on
  1933 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
  1934 a regular 4-core machine, if the initial heap space is made reasonably
  1935 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
  1936 
  1937 * The main reference manuals ("isar-ref", "implementation", and
  1938 "system") have been updated and extended.  Formally checked references
  1939 as hyperlinks are now available uniformly.
  1940 
  1941 
  1942 *** Pure ***
  1943 
  1944 * Complete re-implementation of locales.  INCOMPATIBILITY in several
  1945 respects.  The most important changes are listed below.  See the
  1946 Tutorial on Locales ("locales" manual) for details.
  1947 
  1948 - In locale expressions, instantiation replaces renaming.  Parameters
  1949 must be declared in a for clause.  To aid compatibility with previous
  1950 parameter inheritance, in locale declarations, parameters that are not
  1951 'touched' (instantiation position "_" or omitted) are implicitly added
  1952 with their syntax at the beginning of the for clause.
  1953 
  1954 - Syntax from abbreviations and definitions in locales is available in
  1955 locale expressions and context elements.  The latter is particularly
  1956 useful in locale declarations.
  1957 
  1958 - More flexible mechanisms to qualify names generated by locale
  1959 expressions.  Qualifiers (prefixes) may be specified in locale
  1960 expressions, and can be marked as mandatory (syntax: "name!:") or
  1961 optional (syntax "name?:").  The default depends for plain "name:"
  1962 depends on the situation where a locale expression is used: in
  1963 commands 'locale' and 'sublocale' prefixes are optional, in
  1964 'interpretation' and 'interpret' prefixes are mandatory.  The old
  1965 implicit qualifiers derived from the parameter names of a locale are
  1966 no longer generated.
  1967 
  1968 - Command "sublocale l < e" replaces "interpretation l < e".  The
  1969 instantiation clause in "interpretation" and "interpret" (square
  1970 brackets) is no longer available.  Use locale expressions.
  1971 
  1972 - When converting proof scripts, mandatory qualifiers in
  1973 'interpretation' and 'interpret' should be retained by default, even
  1974 if this is an INCOMPATIBILITY compared to former behavior.  In the
  1975 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
  1976 in locale expressions range over a single locale instance only.
  1977 
  1978 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
  1979 In existing theorem specifications replace the includes element by the
  1980 respective context elements of the included locale, omitting those
  1981 that are already present in the theorem specification.  Multiple
  1982 assume elements of a locale should be replaced by a single one
  1983 involving the locale predicate.  In the proof body, declarations (most
  1984 notably theorems) may be regained by interpreting the respective
  1985 locales in the proof context as required (command "interpret").
  1986 
  1987 If using "includes" in replacement of a target solely because the
  1988 parameter types in the theorem are not as general as in the target,
  1989 consider declaring a new locale with additional type constraints on
  1990 the parameters (context element "constrains").
  1991 
  1992 - Discontinued "locale (open)".  INCOMPATIBILITY.
  1993 
  1994 - Locale interpretation commands no longer attempt to simplify goal.
  1995 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
  1996 methods intro_locales and unfold_locales to clarify.
  1997 
  1998 - Locale interpretation commands no longer accept interpretation
  1999 attributes.  INCOMPATIBILITY.
  2000 
  2001 * Class declaration: so-called "base sort" must not be given in import
  2002 list any longer, but is inferred from the specification.  Particularly
  2003 in HOL, write
  2004 
  2005     class foo = ...
  2006 
  2007 instead of
  2008 
  2009     class foo = type + ...
  2010 
  2011 * Class target: global versions of theorems stemming do not carry a
  2012 parameter prefix any longer.  INCOMPATIBILITY.
  2013 
  2014 * Class 'instance' command no longer accepts attached definitions.
  2015 INCOMPATIBILITY, use proper 'instantiation' target instead.
  2016 
  2017 * Recovered hiding of consts, which was accidentally broken in
  2018 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
  2019 makes c inaccessible; consider using ``hide (open) const c'' instead.
  2020 
  2021 * Slightly more coherent Pure syntax, with updated documentation in
  2022 isar-ref manual.  Removed locales meta_term_syntax and
  2023 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
  2024 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
  2025 directly in regular applications.
  2026 
  2027 * There is a new syntactic category "float_const" for signed decimal
  2028 fractions (e.g. 123.45 or -123.45).
  2029 
  2030 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
  2031 interface with 'setup' command instead.
  2032 
  2033 * Command 'local_setup' is similar to 'setup', but operates on a local
  2034 theory context.
  2035 
  2036 * The 'axiomatization' command now only works within a global theory
  2037 context.  INCOMPATIBILITY.
  2038 
  2039 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
  2040 hypotheses.  Sorts required in the course of reasoning need to be
  2041 covered by the constraints in the initial statement, completed by the
  2042 type instance information of the background theory.  Non-trivial sort
  2043 hypotheses, which rarely occur in practice, may be specified via
  2044 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
  2045 
  2046   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
  2047 
  2048 The result contains an implicit sort hypotheses as before --
  2049 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
  2050 normalization.
  2051 
  2052 * Generalized Isar history, with support for linear undo, direct state
  2053 addressing etc.
  2054 
  2055 * Changed defaults for unify configuration options:
  2056 
  2057   unify_trace_bound = 50 (formerly 25)
  2058   unify_search_bound = 60 (formerly 30)
  2059 
  2060 * Different bookkeeping for code equations (INCOMPATIBILITY):
  2061 
  2062   a) On theory merge, the last set of code equations for a particular
  2063      constant is taken (in accordance with the policy applied by other
  2064      parts of the code generator framework).
  2065 
  2066   b) Code equations stemming from explicit declarations (e.g. code
  2067      attribute) gain priority over default code equations stemming
  2068      from definition, primrec, fun etc.
  2069 
  2070 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
  2071 
  2072 * Unified theorem tables for both code generators.  Thus [code
  2073 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
  2074 
  2075 * Command 'find_consts' searches for constants based on type and name
  2076 patterns, e.g.
  2077 
  2078     find_consts "_ => bool"
  2079 
  2080 By default, matching is against subtypes, but it may be restricted to
  2081 the whole type.  Searching by name is possible.  Multiple queries are
  2082 conjunctive and queries may be negated by prefixing them with a
  2083 hyphen:
  2084 
  2085     find_consts strict: "_ => bool" name: "Int" -"int => int"
  2086 
  2087 * New 'find_theorems' criterion "solves" matches theorems that
  2088 directly solve the current goal (modulo higher-order unification).
  2089 
  2090 * Auto solve feature for main theorem statements: whenever a new goal
  2091 is stated, "find_theorems solves" is called; any theorems that could
  2092 solve the lemma directly are listed as part of the goal state.
  2093 Cf. associated options in Proof General Isabelle settings menu,
  2094 enabled by default, with reasonable timeout for pathological cases of
  2095 higher-order unification.
  2096 
  2097 
  2098 *** Document preparation ***
  2099 
  2100 * Antiquotation @{lemma} now imitates a regular terminal proof,
  2101 demanding keyword 'by' and supporting the full method expression
  2102 syntax just like the Isar command 'by'.
  2103 
  2104 
  2105 *** HOL ***
  2106 
  2107 * Integrated main parts of former image HOL-Complex with HOL.  Entry
  2108 points Main and Complex_Main remain as before.
  2109 
  2110 * Logic image HOL-Plain provides a minimal HOL with the most important
  2111 tools available (inductive, datatype, primrec, ...).  This facilitates
  2112 experimentation and tool development.  Note that user applications
  2113 (and library theories) should never refer to anything below theory
  2114 Main, as before.
  2115 
  2116 * Logic image HOL-Main stops at theory Main, and thus facilitates
  2117 experimentation due to shorter build times.
  2118 
  2119 * Logic image HOL-NSA contains theories of nonstandard analysis which
  2120 were previously part of former HOL-Complex.  Entry point Hyperreal
  2121 remains valid, but theories formerly using Complex_Main should now use
  2122 new entry point Hypercomplex.
  2123 
  2124 * Generic ATP manager for Sledgehammer, based on ML threads instead of
  2125 Posix processes.  Avoids potentially expensive forking of the ML
  2126 process.  New thread-based implementation also works on non-Unix
  2127 platforms (Cygwin).  Provers are no longer hardwired, but defined
  2128 within the theory via plain ML wrapper functions.  Basic Sledgehammer
  2129 commands are covered in the isar-ref manual.
  2130 
  2131 * Wrapper scripts for remote SystemOnTPTP service allows to use
  2132 sledgehammer without local ATP installation (Vampire etc.). Other
  2133 provers may be included via suitable ML wrappers, see also
  2134 src/HOL/ATP_Linkup.thy.
  2135 
  2136 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
  2137 menu.
  2138 
  2139 * The metis method no longer fails because the theorem is too trivial
  2140 (contains the empty clause).
  2141 
  2142 * The metis method now fails in the usual manner, rather than raising
  2143 an exception, if it determines that it cannot prove the theorem.
  2144 
  2145 * Method "coherent" implements a prover for coherent logic (see also
  2146 src/Tools/coherent.ML).
  2147 
  2148 * Constants "undefined" and "default" replace "arbitrary".  Usually
  2149 "undefined" is the right choice to replace "arbitrary", though
  2150 logically there is no difference.  INCOMPATIBILITY.
  2151 
  2152 * Command "value" now integrates different evaluation mechanisms.  The
  2153 result of the first successful evaluation mechanism is printed.  In
  2154 square brackets a particular named evaluation mechanisms may be
  2155 specified (currently, [SML], [code] or [nbe]).  See further
  2156 src/HOL/ex/Eval_Examples.thy.
  2157 
  2158 * Normalization by evaluation now allows non-leftlinear equations.
  2159 Declare with attribute [code nbe].
  2160 
  2161 * Methods "case_tac" and "induct_tac" now refer to the very same rules
  2162 as the structured Isar versions "cases" and "induct", cf. the
  2163 corresponding "cases" and "induct" attributes.  Mutual induction rules
  2164 are now presented as a list of individual projections
  2165 (e.g. foo_bar.inducts for types foo and bar); the old format with
  2166 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
  2167 rare situations a different rule is selected --- notably nested tuple
  2168 elimination instead of former prod.exhaust: use explicit (case_tac t
  2169 rule: prod.exhaust) here.
  2170 
  2171 * Attributes "cases", "induct", "coinduct" support "del" option.
  2172 
  2173 * Removed fact "case_split_thm", which duplicates "case_split".
  2174 
  2175 * The option datatype has been moved to a new theory Option.  Renamed
  2176 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
  2177 
  2178 * New predicate "strict_mono" classifies strict functions on partial
  2179 orders.  With strict functions on linear orders, reasoning about
  2180 (in)equalities is facilitated by theorems "strict_mono_eq",
  2181 "strict_mono_less_eq" and "strict_mono_less".
  2182 
  2183 * Some set operations are now proper qualified constants with
  2184 authentic syntax.  INCOMPATIBILITY:
  2185 
  2186     op Int ~>   Set.Int
  2187     op Un ~>    Set.Un
  2188     INTER ~>    Set.INTER
  2189     UNION ~>    Set.UNION
  2190     Inter ~>    Set.Inter
  2191     Union ~>    Set.Union
  2192     {} ~>       Set.empty
  2193     UNIV ~>     Set.UNIV
  2194 
  2195 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  2196 theory Set.
  2197 
  2198 * Auxiliary class "itself" has disappeared -- classes without any
  2199 parameter are treated as expected by the 'class' command.
  2200 
  2201 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  2202 
  2203 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  2204 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  2205 
  2206 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  2207 method "approximation".  It proves formulas on real values by using
  2208 interval arithmetic.  In the formulas are also the transcendental
  2209 functions sin, cos, tan, atan, ln, exp and the constant pi are
  2210 allowed. For examples see
  2211 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  2212 
  2213 * Theory "Reflection" now resides in HOL/Library.
  2214 
  2215 * Entry point to Word library now simply named "Word".
  2216 INCOMPATIBILITY.
  2217 
  2218 * Made source layout more coherent with logical distribution
  2219 structure:
  2220 
  2221     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  2222     src/HOL/Library/Code_Message.thy ~> src/HOL/
  2223     src/HOL/Library/GCD.thy ~> src/HOL/
  2224     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  2225     src/HOL/Library/Parity.thy ~> src/HOL/
  2226     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  2227     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  2228     src/HOL/Real/Lubs.thy ~> src/HOL/
  2229     src/HOL/Real/PReal.thy ~> src/HOL/
  2230     src/HOL/Real/Rational.thy ~> src/HOL/
  2231     src/HOL/Real/RComplete.thy ~> src/HOL/
  2232     src/HOL/Real/RealDef.thy ~> src/HOL/
  2233     src/HOL/Real/RealPow.thy ~> src/HOL/
  2234     src/HOL/Real/Real.thy ~> src/HOL/
  2235     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  2236     src/HOL/Complex/Complex.thy ~> src/HOL/
  2237     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  2238     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  2239     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  2240     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  2241     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  2242     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  2243     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  2244     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  2245     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  2246     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  2247     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  2248     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  2249     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  2250     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  2251     src/HOL/Real/Float ~> src/HOL/Library/
  2252     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  2253     src/HOL/Real/RealVector.thy ~> src/HOL/
  2254 
  2255     src/HOL/arith_data.ML ~> src/HOL/Tools
  2256     src/HOL/hologic.ML ~> src/HOL/Tools
  2257     src/HOL/simpdata.ML ~> src/HOL/Tools
  2258     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  2259     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  2260     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  2261     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  2262     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  2263     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  2264     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  2265 
  2266     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  2267     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  2268     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  2269     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  2270     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  2271     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  2272 
  2273 * If methods "eval" and "evaluation" encounter a structured proof
  2274 state with !!/==>, only the conclusion is evaluated to True (if
  2275 possible), avoiding strange error messages.
  2276 
  2277 * Method "sizechange" automates termination proofs using (a
  2278 modification of) the size-change principle.  Requires SAT solver.  See
  2279 src/HOL/ex/Termination.thy for examples.
  2280 
  2281 * Simplifier: simproc for let expressions now unfolds if bound
  2282 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  2283 
  2284 * Method "arith": Linear arithmetic now ignores all inequalities when
  2285 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  2286 
  2287 * New attribute "arith" for facts that should always be used
  2288 automatically by arithmetic. It is intended to be used locally in
  2289 proofs, e.g.
  2290 
  2291   assumes [arith]: "x > 0"
  2292 
  2293 Global usage is discouraged because of possible performance impact.
  2294 
  2295 * New classes "top" and "bot" with corresponding operations "top" and
  2296 "bot" in theory Orderings; instantiation of class "complete_lattice"
  2297 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  2298 
  2299 * Changed definition lemma "less_fun_def" in order to provide an
  2300 instance for preorders on functions; use lemma "less_le" instead.
  2301 INCOMPATIBILITY.
  2302 
  2303 * Theory Orderings: class "wellorder" moved here, with explicit
  2304 induction rule "less_induct" as assumption.  For instantiation of
  2305 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  2306 INCOMPATIBILITY.
  2307 
  2308 * Theory Orderings: added class "preorder" as superclass of "order".
  2309 INCOMPATIBILITY: Instantiation proofs for order, linorder
  2310 etc. slightly changed.  Some theorems named order_class.* now named
  2311 preorder_class.*.
  2312 
  2313 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  2314 "diag" to "Id_on".
  2315 
  2316 * Theory Finite_Set: added a new fold combinator of type
  2317 
  2318   ('a => 'b => 'b) => 'b => 'a set => 'b
  2319 
  2320 Occasionally this is more convenient than the old fold combinator
  2321 which is now defined in terms of the new one and renamed to
  2322 fold_image.
  2323 
  2324 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  2325 and "ring_simps" have been replaced by "algebra_simps" (which can be
  2326 extended with further lemmas!).  At the moment both still exist but
  2327 the former will disappear at some point.
  2328 
  2329 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  2330 class recpower.  Type-specific simp rules for various recpower types
  2331 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  2332 
  2333 rat_power_0    -> power_0
  2334 rat_power_Suc  -> power_Suc
  2335 realpow_0      -> power_0
  2336 realpow_Suc    -> power_Suc
  2337 complexpow_0   -> power_0
  2338 complexpow_Suc -> power_Suc
  2339 power_poly_0   -> power_0
  2340 power_poly_Suc -> power_Suc
  2341 
  2342 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  2343 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  2344 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  2345 of lemmas from Divides has been generalized from nat to class
  2346 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  2347 renames resulting from duplicate elimination:
  2348 
  2349     dvd_def_mod ~>          dvd_eq_mod_eq_0
  2350     zero_dvd_iff ~>         dvd_0_left_iff
  2351     dvd_0 ~>                dvd_0_right
  2352     DIVISION_BY_ZERO_DIV ~> div_by_0
  2353     DIVISION_BY_ZERO_MOD ~> mod_by_0
  2354     mult_div ~>             div_mult_self2_is_id
  2355     mult_mod ~>             mod_mult_self2_is_0
  2356 
  2357 * Theory IntDiv: removed many lemmas that are instances of class-based
  2358 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  2359 rename old lemmas as follows:
  2360 
  2361 dvd_diff               -> nat_dvd_diff
  2362 dvd_zminus_iff         -> dvd_minus_iff
  2363 mod_add1_eq            -> mod_add_eq
  2364 mod_mult1_eq           -> mod_mult_right_eq
  2365 mod_mult1_eq'          -> mod_mult_left_eq
  2366 mod_mult_distrib_mod   -> mod_mult_eq
  2367 nat_mod_add_left_eq    -> mod_add_left_eq
  2368 nat_mod_add_right_eq   -> mod_add_right_eq
  2369 nat_mod_div_trivial    -> mod_div_trivial
  2370 nat_mod_mod_trivial    -> mod_mod_trivial
  2371 zdiv_zadd_self1        -> div_add_self1
  2372 zdiv_zadd_self2        -> div_add_self2
  2373 zdiv_zmult_self1       -> div_mult_self2_is_id
  2374 zdiv_zmult_self2       -> div_mult_self1_is_id
  2375 zdvd_triv_left         -> dvd_triv_left
  2376 zdvd_triv_right        -> dvd_triv_right
  2377 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  2378 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  2379 zmod_zadd_left_eq      -> mod_add_left_eq
  2380 zmod_zadd_right_eq     -> mod_add_right_eq
  2381 zmod_zadd_self1        -> mod_add_self1
  2382 zmod_zadd_self2        -> mod_add_self2
  2383 zmod_zadd1_eq          -> mod_add_eq
  2384 zmod_zdiff1_eq         -> mod_diff_eq
  2385 zmod_zdvd_zmod         -> mod_mod_cancel
  2386 zmod_zmod_cancel       -> mod_mod_cancel
  2387 zmod_zmult_self1       -> mod_mult_self2_is_0
  2388 zmod_zmult_self2       -> mod_mult_self1_is_0
  2389 zmod_1                 -> mod_by_1
  2390 zdiv_1                 -> div_by_1
  2391 zdvd_abs1              -> abs_dvd_iff
  2392 zdvd_abs2              -> dvd_abs_iff
  2393 zdvd_refl              -> dvd_refl
  2394 zdvd_trans             -> dvd_trans
  2395 zdvd_zadd              -> dvd_add
  2396 zdvd_zdiff             -> dvd_diff
  2397 zdvd_zminus_iff        -> dvd_minus_iff
  2398 zdvd_zminus2_iff       -> minus_dvd_iff
  2399 zdvd_zmultD            -> dvd_mult_right
  2400 zdvd_zmultD2           -> dvd_mult_left
  2401 zdvd_zmult_mono        -> mult_dvd_mono
  2402 zdvd_0_right           -> dvd_0_right
  2403 zdvd_0_left            -> dvd_0_left_iff
  2404 zdvd_1_left            -> one_dvd
  2405 zminus_dvd_iff         -> minus_dvd_iff
  2406 
  2407 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  2408 
  2409 * The real numbers offer decimal input syntax: 12.34 is translated
  2410 into 1234/10^2. This translation is not reversed upon output.
  2411 
  2412 * Theory Library/Polynomial defines an abstract type 'a poly of
  2413 univariate polynomials with coefficients of type 'a.  In addition to
  2414 the standard ring operations, it also supports div and mod.  Code
  2415 generation is also supported, using list-style constructors.
  2416 
  2417 * Theory Library/Inner_Product defines a class of real_inner for real
  2418 inner product spaces, with an overloaded operation inner :: 'a => 'a
  2419 => real.  Class real_inner is a subclass of real_normed_vector from
  2420 theory RealVector.
  2421 
  2422 * Theory Library/Product_Vector provides instances for the product
  2423 type 'a * 'b of several classes from RealVector and Inner_Product.
  2424 Definitions of addition, subtraction, scalar multiplication, norms,
  2425 and inner products are included.
  2426 
  2427 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  2428 addition to the field operations, numerals and case syntax are also
  2429 supported.
  2430 
  2431 * Theory Library/Diagonalize provides constructive version of Cantor's
  2432 first diagonalization argument.
  2433 
  2434 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  2435 zlcm (for int); carried together from various gcd/lcm developements in
  2436 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  2437 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  2438 may recover tupled syntax as follows:
  2439 
  2440     hide (open) const gcd
  2441     abbreviation gcd where
  2442       "gcd == (%(a, b). GCD.gcd a b)"
  2443     notation (output)
  2444       GCD.gcd ("gcd '(_, _')")
  2445 
  2446 The same works for lcm, zgcd, zlcm.
  2447 
  2448 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  2449 instantiations for algebraic structures.  Removed some duplicate
  2450 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  2451 
  2452 * ML antiquotation @{code} takes a constant as argument and generates
  2453 corresponding code in background and inserts name of the corresponding
  2454 resulting ML value/function/datatype constructor binding in place.
  2455 All occurrences of @{code} with a single ML block are generated
  2456 simultaneously.  Provides a generic and safe interface for
  2457 instrumentalizing code generation.  See
  2458 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  2459 In future you ought to refrain from ad-hoc compiling generated SML
  2460 code on the ML toplevel.  Note that (for technical reasons) @{code}
  2461 cannot refer to constants for which user-defined serializations are
  2462 set.  Refer to the corresponding ML counterpart directly in that
  2463 cases.
  2464 
  2465 * Command 'rep_datatype': instead of theorem names the command now
  2466 takes a list of terms denoting the constructors of the type to be
  2467 represented as datatype.  The characteristic theorems have to be
  2468 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  2469 have disappeared in favour of existing ones:
  2470 
  2471     unit_induct                 ~> unit.induct
  2472     prod_induct                 ~> prod.induct
  2473     sum_induct                  ~> sum.induct
  2474     Suc_Suc_eq                  ~> nat.inject
  2475     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  2476 
  2477 
  2478 *** HOL-Algebra ***
  2479 
  2480 * New locales for orders and lattices where the equivalence relation
  2481 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  2482 locales use a record structure with field eq for the equivalence.
  2483 
  2484 * New theory of factorial domains.
  2485 
  2486 * Units_l_inv and Units_r_inv are now simp rules by default.
  2487 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  2488 and/or r_inv will now also require deletion of these lemmas.
  2489 
  2490 * Renamed the following theorems, INCOMPATIBILITY:
  2491 
  2492 UpperD ~> Upper_memD
  2493 LowerD ~> Lower_memD
  2494 least_carrier ~> least_closed
  2495 greatest_carrier ~> greatest_closed
  2496 greatest_Lower_above ~> greatest_Lower_below
  2497 one_zero ~> carrier_one_zero
  2498 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  2499 
  2500 
  2501 *** HOL-Nominal ***
  2502 
  2503 * Nominal datatypes can now contain type-variables.
  2504 
  2505 * Commands 'nominal_inductive' and 'equivariance' work with local
  2506 theory targets.
  2507 
  2508 * Nominal primrec can now works with local theory targets and its
  2509 specification syntax now conforms to the general format as seen in
  2510 'inductive' etc.
  2511 
  2512 * Method "perm_simp" honours the standard simplifier attributes
  2513 (no_asm), (no_asm_use) etc.
  2514 
  2515 * The new predicate #* is defined like freshness, except that on the
  2516 left hand side can be a set or list of atoms.
  2517 
  2518 * Experimental command 'nominal_inductive2' derives strong induction
  2519 principles for inductive definitions.  In contrast to
  2520 'nominal_inductive', which can only deal with a fixed number of
  2521 binders, it can deal with arbitrary expressions standing for sets of
  2522 atoms to be avoided.  The only inductive definition we have at the
  2523 moment that needs this generalisation is the typing rule for Lets in
  2524 the algorithm W:
  2525 
  2526  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  2527  -----------------------------------------------------------------
  2528          Gamma |- Let x be t1 in t2 : T2
  2529 
  2530 In this rule one wants to avoid all the binders that are introduced by
  2531 "close Gamma T1".  We are looking for other examples where this
  2532 feature might be useful.  Please let us know.
  2533 
  2534 
  2535 *** HOLCF ***
  2536 
  2537 * Reimplemented the simplification procedure for proving continuity
  2538 subgoals.  The new simproc is extensible; users can declare additional
  2539 continuity introduction rules with the attribute [cont2cont].
  2540 
  2541 * The continuity simproc now uses a different introduction rule for
  2542 solving continuity subgoals on terms with lambda abstractions.  In
  2543 some rare cases the new simproc may fail to solve subgoals that the
  2544 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  2545 Potential INCOMPATIBILITY.
  2546 
  2547 * Command 'fixrec': specification syntax now conforms to the general
  2548 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  2549 examples.  INCOMPATIBILITY.
  2550 
  2551 
  2552 *** ZF ***
  2553 
  2554 * Proof of Zorn's Lemma for partial orders.
  2555 
  2556 
  2557 *** ML ***
  2558 
  2559 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  2560 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  2561 depends on multithreading, so timouts will not work before Poly/ML
  2562 5.2.1!
  2563 
  2564 * High-level support for concurrent ML programming, see
  2565 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  2566 particularly convenient to organize independent functional
  2567 computations.  The concept of "synchronized variables" provides a
  2568 higher-order interface for components with shared state, avoiding the
  2569 delicate details of mutexes and condition variables.  (Requires
  2570 Poly/ML 5.2.1 or later.)
  2571 
  2572 * ML bindings produced via Isar commands are stored within the Isar
  2573 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  2574 become thread-safe and work with undo as expected (concerning
  2575 top-level bindings, not side-effects on global references).
  2576 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  2577 compiler at runtime; really global bindings need to be given outside a
  2578 theory.  (Requires Poly/ML 5.2 or later.)
  2579 
  2580 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  2581 context.  Top-level ML bindings are stored within the proof context in
  2582 a purely sequential fashion, disregarding the nested proof structure.
  2583 ML bindings introduced by 'ML_prf' are discarded at the end of the
  2584 proof.  (Requires Poly/ML 5.2 or later.)
  2585 
  2586 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  2587 and Method.setup, as well as Isar commands 'attribute_setup' and
  2588 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  2589 existing code accordingly, or use plain 'setup' together with old
  2590 Method.add_method.
  2591 
  2592 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  2593 to 'a -> thm, while results are always tagged with an authentic oracle
  2594 name.  The Isar command 'oracle' is now polymorphic, no argument type
  2595 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  2596 accordingly.  Note that extra performance may be gained by producing
  2597 the cterm carefully, avoiding slow Thm.cterm_of.
  2598 
  2599 * Simplified interface for defining document antiquotations via
  2600 ThyOutput.antiquotation, ThyOutput.output, and optionally
  2601 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  2602 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  2603 examples.
  2604 
  2605 * More systematic treatment of long names, abstract name bindings, and
  2606 name space operations.  Basic operations on qualified names have been
  2607 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  2608 Long_Name.append.  Old type bstring has been mostly replaced by
  2609 abstract type binding (see structure Binding), which supports precise
  2610 qualification by packages and local theory targets, as well as proper
  2611 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  2612 bstring values into Binding.name, or better pass through abstract
  2613 bindings everywhere.  See further src/Pure/General/long_name.ML,
  2614 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  2615 
  2616 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  2617 LocalTheory.note etc.) now refer to the *full* internal name, not the
  2618 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  2619 
  2620 * Disposed old type and term read functions (Sign.read_def_typ,
  2621 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  2622 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  2623 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  2624 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  2625 resort for legacy applications.
  2626 
  2627 * Disposed old declarations, tactics, tactic combinators that refer to
  2628 the simpset or claset of an implicit theory (such as Addsimps,
  2629 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  2630 embedded ML text, or local_simpset_of with a proper context passed as
  2631 explicit runtime argument.
  2632 
  2633 * Rules and tactics that read instantiations (read_instantiate,
  2634 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  2635 context, which is required for parsing and type-checking.  Moreover,
  2636 the variables are specified as plain indexnames, not string encodings
  2637 thereof.  INCOMPATIBILITY.
  2638 
  2639 * Generic Toplevel.add_hook interface allows to analyze the result of
  2640 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  2641 for theorem dependency output of transactions resulting in a new
  2642 theory state.
  2643 
  2644 * ML antiquotations: block-structured compilation context indicated by
  2645 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  2646 
  2647   @{binding name}                         - basic name binding
  2648   @{let ?pat = term}                      - term abbreviation (HO matching)
  2649   @{note name = fact}                     - fact abbreviation
  2650   @{thm fact}                             - singleton fact (with attributes)
  2651   @{thms fact}                            - general fact (with attributes)
  2652   @{lemma prop by method}                 - singleton goal
  2653   @{lemma prop by meth1 meth2}            - singleton goal
  2654   @{lemma prop1 ... propN by method}      - general goal
  2655   @{lemma prop1 ... propN by meth1 meth2} - general goal
  2656   @{lemma (open) ...}                     - open derivation
  2657 
  2658 
  2659 *** System ***
  2660 
  2661 * The Isabelle "emacs" tool provides a specific interface to invoke
  2662 Proof General / Emacs, with more explicit failure if that is not
  2663 installed (the old isabelle-interface script silently falls back on
  2664 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  2665 installation location of the Proof General distribution.
  2666 
  2667 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  2668 the Isabelle process into a JVM/Scala application.  See
  2669 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  2670 process wrapper has been discontinued.)
  2671 
  2672 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  2673 
  2674 * Various status messages (with exact source position information) are
  2675 emitted, if proper markup print mode is enabled.  This allows
  2676 user-interface components to provide detailed feedback on internal
  2677 prover operations.
  2678 
  2679 
  2680 
  2681 New in Isabelle2008 (June 2008)
  2682 -------------------------------
  2683 
  2684 *** General ***
  2685 
  2686 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  2687 and updated, with formally checked references as hyperlinks.
  2688 
  2689 * Theory loader: use_thy (and similar operations) no longer set the
  2690 implicit ML context, which was occasionally hard to predict and in
  2691 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  2692 provides a proper context already.
  2693 
  2694 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2695 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  2696 'use' within a theory file will do the job.
  2697 
  2698 * Name space merge now observes canonical order, i.e. the second space
  2699 is inserted into the first one, while existing entries in the first
  2700 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  2701 swap theory imports.
  2702 
  2703 * Syntax: symbol \<chi> is now considered a letter.  Potential
  2704 INCOMPATIBILITY in identifier syntax etc.
  2705 
  2706 * Outer syntax: string tokens no longer admit escaped white space,
  2707 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  2708 white space without escapes.
  2709 
  2710 * Outer syntax: string tokens may contain arbitrary character codes
  2711 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  2712 "foo_bar".
  2713 
  2714 
  2715 *** Pure ***
  2716 
  2717 * Context-dependent token translations.  Default setup reverts locally
  2718 fixed variables, and adds hilite markup for undeclared frees.
  2719 
  2720 * Unused theorems can be found using the new command 'unused_thms'.
  2721 There are three ways of invoking it:
  2722 
  2723 (1) unused_thms
  2724      Only finds unused theorems in the current theory.
  2725 
  2726 (2) unused_thms thy_1 ... thy_n -
  2727      Finds unused theorems in the current theory and all of its ancestors,
  2728      excluding the theories thy_1 ... thy_n and all of their ancestors.
  2729 
  2730 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  2731      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  2732      their ancestors, excluding the theories thy_1 ... thy_n and all of
  2733      their ancestors.
  2734 
  2735 In order to increase the readability of the list produced by
  2736 unused_thms, theorems that have been created by a particular instance
  2737 of a theory command such as 'inductive' or 'function' are considered
  2738 to belong to the same "group", meaning that if at least one theorem in
  2739 this group is used, the other theorems in the same group are no longer
  2740 reported as unused.  Moreover, if all theorems in the group are
  2741 unused, only one theorem in the group is displayed.
  2742 
  2743 Note that proof objects have to be switched on in order for
  2744 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  2745 usually the case when using Proof General with the default settings).
  2746 
  2747 * Authentic naming of facts disallows ad-hoc overwriting of previous
  2748 theorems within the same name space.  INCOMPATIBILITY, need to remove
  2749 duplicate fact bindings, or even accidental fact duplications.  Note
  2750 that tools may maintain dynamically scoped facts systematically, using
  2751 PureThy.add_thms_dynamic.
  2752 
  2753 * Command 'hide' now allows to hide from "fact" name space as well.
  2754 
  2755 * Eliminated destructive theorem database, simpset, claset, and
  2756 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  2757 update of theories within ML code.
  2758 
  2759 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  2760 INCOMPATIBILITY, object-logics depending on former Pure require
  2761 additional setup PureThy.old_appl_syntax_setup; object-logics
  2762 depending on former CPure need to refer to Pure.
  2763 
  2764 * Commands 'use' and 'ML' are now purely functional, operating on
  2765 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  2766 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  2767 INCOMPATIBILITY.
  2768 
  2769 * Command 'setup': discontinued implicit version with ML reference.
  2770 
  2771 * Instantiation target allows for simultaneous specification of class
  2772 instance operations together with an instantiation proof.
  2773 Type-checking phase allows to refer to class operations uniformly.
  2774 See src/HOL/Complex/Complex.thy for an Isar example and
  2775 src/HOL/Library/Eval.thy for an ML example.
  2776 
  2777 * Indexing of literal facts: be more serious about including only
  2778 facts from the visible specification/proof context, but not the
  2779 background context (locale etc.).  Affects `prop` notation and method
  2780 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  2781 situations.
  2782 
  2783 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  2784 "(open)" option, which used to expose internal bound variables to the
  2785 proof text.
  2786 
  2787 * Isar statements: removed obsolete case "rule_context".
  2788 INCOMPATIBILITY, better use explicit fixes/assumes.
  2789 
  2790 * Locale proofs: default proof step now includes 'unfold_locales';
  2791 hence 'proof' without argument may be used to unfold locale
  2792 predicates.
  2793 
  2794 
  2795 *** Document preparation ***
  2796 
  2797 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  2798 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  2799 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  2800 spot); renamed link color from "darkblue" to "linkcolor" (default
  2801 value unchanged, can be redefined via \definecolor); no longer sets
  2802 "a4paper" option (unnecessary or even intrusive).
  2803 
  2804 * Antiquotation @{lemma A method} proves proposition A by the given
  2805 method (either a method name or a method name plus (optional) method
  2806 arguments in parentheses) and prints A just like @{prop A}.
  2807 
  2808 
  2809 *** HOL ***
  2810 
  2811 * New primrec package.  Specification syntax conforms in style to
  2812 definition/function/....  No separate induction rule is provided.  The
  2813 "primrec" command distinguishes old-style and new-style specifications
  2814 by syntax.  The former primrec package is now named OldPrimrecPackage.
  2815 When adjusting theories, beware: constants stemming from new-style
  2816 primrec specifications have authentic syntax.
  2817 
  2818 * Metis prover is now an order of magnitude faster, and also works
  2819 with multithreading.
  2820 
  2821 * Metis: the maximum number of clauses that can be produced from a
  2822 theorem is now given by the attribute max_clauses.  Theorems that
  2823 exceed this number are ignored, with a warning printed.
  2824 
  2825 * Sledgehammer no longer produces structured proofs by default. To
  2826 enable, declare [[sledgehammer_full = true]].  Attributes
  2827 reconstruction_modulus, reconstruction_sorts renamed
  2828 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  2829 
  2830 * Method "induct_scheme" derives user-specified induction rules
  2831 from well-founded induction and completeness of patterns. This factors
  2832 out some operations that are done internally by the function package
  2833 and makes them available separately.  See
  2834 src/HOL/ex/Induction_Scheme.thy for examples.
  2835 
  2836 * More flexible generation of measure functions for termination
  2837 proofs: Measure functions can be declared by proving a rule of the
  2838 form "is_measure f" and giving it the [measure_function] attribute.
  2839 The "is_measure" predicate is logically meaningless (always true), and
  2840 just guides the heuristic.  To find suitable measure functions, the
  2841 termination prover sets up the goal "is_measure ?f" of the appropriate
  2842 type and generates all solutions by prolog-style backwards proof using
  2843 the declared rules.
  2844 
  2845 This setup also deals with rules like 
  2846 
  2847   "is_measure f ==> is_measure (list_size f)"
  2848 
  2849 which accommodates nested datatypes that recurse through lists.
  2850 Similar rules are predeclared for products and option types.
  2851 
  2852 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  2853 
  2854   INCOMPATIBILITIES:
  2855 
  2856   - Definitions of overloaded constants on sets have to be replaced by
  2857     definitions on => and bool.
  2858 
  2859   - Some definitions of overloaded operators on sets can now be proved
  2860     using the definitions of the operators on => and bool.  Therefore,
  2861     the following theorems have been renamed:
  2862 
  2863       subset_def   -> subset_eq
  2864       psubset_def  -> psubset_eq
  2865       set_diff_def -> set_diff_eq
  2866       Compl_def    -> Compl_eq
  2867       Sup_set_def  -> Sup_set_eq
  2868       Inf_set_def  -> Inf_set_eq
  2869       sup_set_def  -> sup_set_eq
  2870       inf_set_def  -> inf_set_eq
  2871 
  2872   - Due to the incompleteness of the HO unification algorithm, some
  2873     rules such as subst may require manual instantiation, if some of
  2874     the unknowns in the rule is a set.
  2875 
  2876   - Higher order unification and forward proofs:
  2877     The proof pattern
  2878 
  2879       have "P (S::'a set)" <...>
  2880       then have "EX S. P S" ..
  2881 
  2882     no longer works (due to the incompleteness of the HO unification
  2883     algorithm) and must be replaced by the pattern
  2884 
  2885       have "EX S. P S"
  2886       proof
  2887         show "P S" <...>
  2888       qed
  2889 
  2890   - Calculational reasoning with subst (or similar rules):
  2891     The proof pattern
  2892 
  2893       have "P (S::'a set)" <...>
  2894       also have "S = T" <...>
  2895       finally have "P T" .
  2896 
  2897     no longer works (for similar reasons as the previous example) and
  2898     must be replaced by something like
  2899 
  2900       have "P (S::'a set)" <...>
  2901       moreover have "S = T" <...>
  2902       ultimately have "P T" by simp
  2903 
  2904   - Tactics or packages written in ML code:
  2905     Code performing pattern matching on types via
  2906 
  2907       Type ("set", [T]) => ...
  2908 
  2909     must be rewritten. Moreover, functions like strip_type or
  2910     binder_types no longer return the right value when applied to a
  2911     type of the form
  2912 
  2913       T1 => ... => Tn => U => bool
  2914 
  2915     rather than
  2916 
  2917       T1 => ... => Tn => U set
  2918 
  2919 * Merged theories Wellfounded_Recursion, Accessible_Part and
  2920 Wellfounded_Relations to theory Wellfounded.
  2921 
  2922 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  2923 
  2924 * Class finite no longer treats UNIV as class parameter.  Use class
  2925 enum from theory Library/Enum instead to achieve a similar effect.
  2926 INCOMPATIBILITY.
  2927 
  2928 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  2929 and "Cons".  INCOMPATIBILITY.
  2930 
  2931 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  2932 Potential INCOMPATIBILITY.
  2933 
  2934 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  2935 injective_fst_snd removed, use split_eta and prod_eqI instead.
  2936 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  2937 
  2938 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  2939 the same name in theory Orderings:
  2940 
  2941   less_trans
  2942   less_linear
  2943   le_imp_less_or_eq
  2944   le_less_trans
  2945   less_le_trans
  2946   less_not_sym
  2947   less_asym
  2948 
  2949 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  2950 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  2951 and different variable names.
  2952 
  2953 * Library/Option_ord.thy: Canonical order on option type.
  2954 
  2955 * Library/RBT.thy: Red-black trees, an efficient implementation of
  2956 finite maps.
  2957 
  2958 * Library/Countable.thy: Type class for countable types.
  2959 
  2960 * Theory Int: The representation of numerals has changed.  The infix
  2961 operator BIT and the bit datatype with constructors B0 and B1 have
  2962 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  2963 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  2964 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  2965 accordingly.
  2966 
  2967 * Theory Nat: definition of <= and < on natural numbers no longer
  2968 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  2969 le_def and less_def have disappeared.  Consider lemmas not_less
  2970 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  2971 
  2972 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  2973 (whose purpose mainly is for various fold_set functionals) have been
  2974 abandoned in favor of the existing algebraic classes
  2975 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  2976 lower_semilattice (resp. upper_semilattice) and linorder.
  2977 INCOMPATIBILITY.
  2978 
  2979 * Theory Transitive_Closure: induct and cases rules now declare proper
  2980 case_names ("base" and "step").  INCOMPATIBILITY.
  2981 
  2982 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  2983 lattices.  The form set-specific version is available as
  2984 Inductive.lfp_ordinal_induct_set.
  2985 
  2986 * Renamed theorems "power.simps" to "power_int.simps".
  2987 INCOMPATIBILITY.
  2988 
  2989 * Class semiring_div provides basic abstract properties of semirings
  2990 with division and modulo operations.  Subsumes former class dvd_mod.
  2991 
  2992 * Merged theories IntDef, Numeral and IntArith into unified theory
  2993 Int.  INCOMPATIBILITY.
  2994 
  2995 * Theory Library/Code_Index: type "index" now represents natural
  2996 numbers rather than integers.  INCOMPATIBILITY.
  2997 
  2998 * New class "uminus" with operation "uminus" (split of from class
  2999 "minus" which now only has operation "minus", binary).
  3000 INCOMPATIBILITY.
  3001 
  3002 * Constants "card", "internal_split", "option_map" now with authentic
  3003 syntax.  INCOMPATIBILITY.
  3004 
  3005 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  3006 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  3007 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  3008 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  3009 Sup_set_def, le_def, less_def, option_map_def now with object
  3010 equality.  INCOMPATIBILITY.
  3011 
  3012 * Records. Removed K_record, and replaced it by pure lambda term
  3013 %x. c. The simplifier setup is now more robust against eta expansion.
  3014 INCOMPATIBILITY: in cases explicitly referring to K_record.
  3015 
  3016 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  3017 
  3018 * Library/ListVector: new theory of arithmetic vector operations.
  3019 
  3020 * Library/Order_Relation: new theory of various orderings as sets of
  3021 pairs.  Defines preorders, partial orders, linear orders and
  3022 well-orders on sets and on types.
  3023 
  3024 
  3025 *** ZF ***
  3026 
  3027 * Renamed some theories to allow to loading both ZF and HOL in the
  3028 same session:
  3029 
  3030   Datatype  -> Datatype_ZF
  3031   Inductive -> Inductive_ZF
  3032   Int       -> Int_ZF
  3033   IntDiv    -> IntDiv_ZF
  3034   Nat       -> Nat_ZF
  3035   List      -> List_ZF
  3036   Main      -> Main_ZF
  3037 
  3038 INCOMPATIBILITY: ZF theories that import individual theories below
  3039 Main might need to be adapted.  Regular theory Main is still
  3040 available, as trivial extension of Main_ZF.
  3041 
  3042 
  3043 *** ML ***
  3044 
  3045 * ML within Isar: antiquotation @{const name} or @{const
  3046 name(typargs)} produces statically-checked Const term.
  3047 
  3048 * Functor NamedThmsFun: data is available to the user as dynamic fact
  3049 (of the same name).  Removed obsolete print command.
  3050 
  3051 * Removed obsolete "use_legacy_bindings" function.
  3052 
  3053 * The ``print mode'' is now a thread-local value derived from a global
  3054 template (the former print_mode reference), thus access becomes
  3055 non-critical.  The global print_mode reference is for session
  3056 management only; user-code should use print_mode_value,
  3057 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  3058 
  3059 * Functions system/system_out provide a robust way to invoke external
  3060 shell commands, with propagation of interrupts (requires Poly/ML
  3061 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  3062 
  3063 
  3064 *** System ***
  3065 
  3066 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  3067 in accordance with Proof General 3.7, which prefers GNU emacs.
  3068 
  3069 * isatool tty runs Isabelle process with plain tty interaction;
  3070 optional line editor may be specified via ISABELLE_LINE_EDITOR
  3071 setting, the default settings attempt to locate "ledit" and "rlwrap".
  3072 
  3073 * isatool browser now works with Cygwin as well, using general
  3074 "javapath" function defined in Isabelle process environment.
  3075 
  3076 * YXML notation provides a simple and efficient alternative to
  3077 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  3078 isatool yxml as described in the Isabelle system manual.
  3079 
  3080 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  3081 provides general wrapper for managing an Isabelle process in a robust
  3082 fashion, with ``cooked'' output from stdin/stderr.
  3083 
  3084 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  3085 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  3086 
  3087 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  3088 way of changing the user's settings is via
  3089 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  3090 script.
  3091 
  3092 * Multithreading.max_threads := 0 refers to the number of actual CPU
  3093 cores of the underlying machine, which is a good starting point for
  3094 optimal performance tuning.  The corresponding usedir option -M allows
  3095 "max" as an alias for "0".  WARNING: does not work on certain versions
  3096 of Mac OS (with Poly/ML 5.1).
  3097 
  3098 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  3099 adverse effect of Isabelle flooding interactive front-ends (notably
  3100 ProofGeneral / XEmacs).
  3101 
  3102 
  3103 
  3104 New in Isabelle2007 (November 2007)
  3105 -----------------------------------
  3106 
  3107 *** General ***
  3108 
  3109 * More uniform information about legacy features, notably a
  3110 warning/error of "Legacy feature: ...", depending on the state of the
  3111 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  3112 legacy features will disappear eventually.
  3113 
  3114 * Theory syntax: the header format ``theory A = B + C:'' has been
  3115 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  3116 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  3117 
  3118 * Theory syntax: the old non-Isar theory file format has been
  3119 discontinued altogether.  Note that ML proof scripts may still be used
  3120 with Isar theories; migration is usually quite simple with the ML
  3121 function use_legacy_bindings.  INCOMPATIBILITY.
  3122 
  3123 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  3124 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  3125 quotes.
  3126 
  3127 * Theory loader: be more serious about observing the static theory
  3128 header specifications (including optional directories), but not the
  3129 accidental file locations of previously successful loads.  The strict
  3130 update policy of former update_thy is now already performed by
  3131 use_thy, so the former has been removed; use_thys updates several
  3132 theories simultaneously, just as 'imports' within a theory header
  3133 specification, but without merging the results.  Potential
  3134 INCOMPATIBILITY: may need to refine theory headers and commands
  3135 ROOT.ML which depend on load order.
  3136 
  3137 * Theory loader: optional support for content-based file
  3138 identification, instead of the traditional scheme of full physical
  3139 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  3140 (cf. the system manual).  The new scheme allows to work with
  3141 non-finished theories in persistent session images, such that source
  3142 files may be moved later on without requiring reloads.
  3143 
  3144 * Theory loader: old-style ML proof scripts being *attached* to a thy
  3145 file (with the same base name as the theory) are considered a legacy
  3146 feature, which will disappear eventually. Even now, the theory loader
  3147 no longer maintains dependencies on such files.
  3148 
  3149 * Syntax: the scope for resolving ambiguities via type-inference is
  3150 now limited to individual terms, instead of whole simultaneous
  3151 specifications as before. This greatly reduces the complexity of the
  3152 syntax module and improves flexibility by separating parsing and
  3153 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  3154 'fixes' etc.) are required in rare situations.
  3155 
  3156 * Syntax: constants introduced by new-style packages ('definition',
  3157 'abbreviation' etc.) are passed through the syntax module in
  3158 ``authentic mode''. This means that associated mixfix annotations
  3159 really stick to such constants, independently of potential name space
  3160 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  3161 trees are represented slightly differently, may need to adapt syntax
  3162 translations accordingly. Use CONST marker in 'translations' and
  3163 @{const_syntax} antiquotation in 'parse_translation' etc.
  3164 
  3165 * Legacy goal package: reduced interface to the bare minimum required
  3166 to keep existing proof scripts running.  Most other user-level
  3167 functions are now part of the OldGoals structure, which is *not* open
  3168 by default (consider isatool expandshort before open OldGoals).
  3169 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  3170 these tend to cause confusion about the actual goal (!) context being
  3171 used here, which is not necessarily the same as the_context().
  3172 
  3173 * Command 'find_theorems': supports "*" wild-card in "name:"
  3174 criterion; "with_dups" option.  Certain ProofGeneral versions might
  3175 support a specific search form (see ProofGeneral/CHANGES).
  3176 
  3177 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  3178 by default, which means that "prems" (and also "fixed variables") are
  3179 suppressed from proof state output.  Note that the ProofGeneral
  3180 settings mechanism allows to change and save options persistently, but
  3181 older versions of Isabelle will fail to start up if a negative prems
  3182 limit is imposed.
  3183 
  3184 * Local theory targets may be specified by non-nested blocks of
  3185 ``context/locale/class ... begin'' followed by ``end''.  The body may
  3186 contain definitions, theorems etc., including any derived mechanism
  3187 that has been implemented on top of these primitives.  This concept
  3188 generalizes the existing ``theorem (in ...)'' towards more versatility
  3189 and scalability.
  3190 
  3191 * Proof General interface: proper undo of final 'end' command;
  3192 discontinued Isabelle/classic mode (ML proof scripts).
  3193 
  3194 
  3195 *** Document preparation ***
  3196 
  3197 * Added antiquotation @{theory name} which prints the given name,
  3198 after checking that it refers to a valid ancestor theory in the
  3199 current context.
  3200 
  3201 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  3202 check the given source text as ML type/structure, printing verbatim.
  3203 
  3204 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  3205 "c args == rhs" given in the current context.  (Any number of
  3206 arguments may be given on the LHS.)
  3207 
  3208 
  3209 *** Pure ***
  3210 
  3211 * The 'class' package offers a combination of axclass and locale to
  3212 achieve Haskell-like type classes in Isabelle.  Definitions and
  3213 theorems within a class context produce both relative results (with
  3214 implicit parameters according to the locale context), and polymorphic
  3215 constants with qualified polymorphism (according to the class
  3216 context).  Within the body context of a 'class' target, a separate
  3217 syntax layer ("user space type system") takes care of converting
  3218 between global polymorphic consts and internal locale representation.
  3219 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  3220 "isatool doc classes" provides a tutorial.
  3221 
  3222 * Generic code generator framework allows to generate executable
  3223 code for ML and Haskell (including Isabelle classes).  A short usage
  3224 sketch:
  3225 
  3226     internal compilation:
  3227         export_code <list of constants (term syntax)> in SML
  3228     writing SML code to a file:
  3229         export_code <list of constants (term syntax)> in SML <filename>
  3230     writing OCaml code to a file:
  3231         export_code <list of constants (term syntax)> in OCaml <filename>
  3232     writing Haskell code to a bunch of files:
  3233         export_code <list of constants (term syntax)> in Haskell <filename>
  3234 
  3235     evaluating closed propositions to True/False using code generation:
  3236         method ``eval''
  3237 
  3238 Reasonable default setup of framework in HOL.
  3239 
  3240 Theorem attributs for selecting and transforming function equations theorems:
  3241 
  3242     [code fun]:        select a theorem as function equation for a specific constant
  3243     [code fun del]:    deselect a theorem as function equation for a specific constant
  3244     [code inline]:     select an equation theorem for unfolding (inlining) in place
  3245     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  3246 
  3247 User-defined serializations (target in {SML, OCaml, Haskell}):
  3248 
  3249     code_const <and-list of constants (term syntax)>
  3250       {(target) <and-list of const target syntax>}+
  3251 
  3252     code_type <and-list of type constructors>
  3253       {(target) <and-list of type target syntax>}+
  3254 
  3255     code_instance <and-list of instances>
  3256       {(target)}+
  3257         where instance ::= <type constructor> :: <class>
  3258 
  3259     code_class <and_list of classes>
  3260       {(target) <and-list of class target syntax>}+
  3261         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  3262 
  3263 code_instance and code_class only are effective to target Haskell.
  3264 
  3265 For example usage see src/HOL/ex/Codegenerator.thy and
  3266 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  3267 generation from Isabelle/HOL theories is available via "isatool doc
  3268 codegen".
  3269 
  3270 * Code generator: consts in 'consts_code' Isar commands are now
  3271 referred to by usual term syntax (including optional type
  3272 annotations).
  3273 
  3274 * Command 'no_translations' removes translation rules from theory
  3275 syntax.
  3276 
  3277 * Overloaded definitions are now actually checked for acyclic
  3278 dependencies.  The overloading scheme is slightly more general than
  3279 that of Haskell98, although Isabelle does not demand an exact
  3280 correspondence to type class and instance declarations.
  3281 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  3282 exotic versions of overloading -- at the discretion of the user!
  3283 
  3284 Polymorphic constants are represented via type arguments, i.e. the
  3285 instantiation that matches an instance against the most general
  3286 declaration given in the signature.  For example, with the declaration
  3287 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  3288 as c(nat).  Overloading is essentially simultaneous structural
  3289 recursion over such type arguments.  Incomplete specification patterns
  3290 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  3291 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  3292 Command 'print_theory' outputs the normalized system of recursive
  3293 equations, see section "definitions".
  3294 
  3295 * Configuration options are maintained within the theory or proof
  3296 context (with name and type bool/int/string), providing a very simple
  3297 interface to a poor-man's version of general context data.  Tools may
  3298 declare options in ML (e.g. using Attrib.config_int) and then refer to
  3299 these values using Config.get etc.  Users may change options via an
  3300 associated attribute of the same name.  This form of context
  3301 declaration works particularly well with commands 'declare' or
  3302 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  3303 very easy to avoid global references, which would not observe Isar
  3304 toplevel undo/redo and fail to work with multithreading.
  3305 
  3306 Various global ML references of Pure and HOL have been turned into
  3307 configuration options:
  3308 
  3309   Unify.search_bound		unify_search_bound
  3310   Unify.trace_bound		unify_trace_bound
  3311   Unify.trace_simp		unify_trace_simp
  3312   Unify.trace_types		unify_trace_types
  3313   Simplifier.simp_depth_limit	simp_depth_limit
  3314   Blast.depth_limit		blast_depth_limit
  3315   DatatypeProp.dtK		datatype_distinctness_limit
  3316   fast_arith_neq_limit  	fast_arith_neq_limit
  3317   fast_arith_split_limit	fast_arith_split_limit
  3318 
  3319 * Named collections of theorems may be easily installed as context
  3320 data using the functor NamedThmsFun (see also
  3321 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  3322 attributes; there is also a toplevel print command.  This facility is
  3323 just a common case of general context data, which is the preferred way
  3324 for anything more complex than just a list of facts in canonical
  3325 order.
  3326 
  3327 * Isar: command 'declaration' augments a local theory by generic
  3328 declaration functions written in ML.  This enables arbitrary content
  3329 being added to the context, depending on a morphism that tells the
  3330 difference of the original declaration context wrt. the application
  3331 context encountered later on.
  3332 
  3333 * Isar: proper interfaces for simplification procedures.  Command
  3334 'simproc_setup' declares named simprocs (with match patterns, and body
  3335 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  3336 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  3337 
  3338 * Isar: an extra pair of brackets around attribute declarations
  3339 abbreviates a theorem reference involving an internal dummy fact,
  3340 which will be ignored later --- only the effect of the attribute on
  3341 the background context will persist.  This form of in-place
  3342 declarations is particularly useful with commands like 'declare' and
  3343 'using', for example ``have A using [[simproc a]] by simp''.
  3344 
  3345 * Isar: method "assumption" (and implicit closing of subproofs) now
  3346 takes simple non-atomic goal assumptions into account: after applying
  3347 an assumption as a rule the resulting subgoals are solved by atomic
  3348 assumption steps.  This is particularly useful to finish 'obtain'
  3349 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  3350 without referring to the original premise "!!x. P x ==> thesis" in the
  3351 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  3352 more permissive.
  3353 
  3354 * Isar: implicit use of prems from the Isar proof context is
  3355 considered a legacy feature.  Common applications like ``have A .''
  3356 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  3357 referencing facts explicitly here improves readability and
  3358 maintainability of proof texts.
  3359 
  3360 * Isar: improper proof element 'guess' is like 'obtain', but derives
  3361 the obtained context from the course of reasoning!  For example:
  3362 
  3363   assume "EX x y. A x & B y"   -- "any previous fact"
  3364   then guess x and y by clarify
  3365 
  3366 This technique is potentially adventurous, depending on the facts and
  3367 proof tools being involved here.
  3368 
  3369 * Isar: known facts from the proof context may be specified as literal
  3370 propositions, using ASCII back-quote syntax.  This works wherever
  3371 named facts used to be allowed so far, in proof commands, proof
  3372 methods, attributes etc.  Literal facts are retrieved from the context
  3373 according to unification of type and term parameters.  For example,
  3374 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  3375 theorems in the current context, then these are valid literal facts:
  3376 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  3377 
  3378 There is also a proof method "fact" which does the same composition
  3379 for explicit goal states, e.g. the following proof texts coincide with
  3380 certain special cases of literal facts:
  3381 
  3382   have "A" by fact                 ==  note `A`
  3383   have "A ==> B" by fact           ==  note `A ==> B`
  3384   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  3385   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  3386 
  3387 * Isar: ":" (colon) is no longer a symbolic identifier character in
  3388 outer syntax.  Thus symbolic identifiers may be used without
  3389 additional white space in declarations like this: ``assume *: A''.
  3390 
  3391 * Isar: 'print_facts' prints all local facts of the current context,
  3392 both named and unnamed ones.
  3393 
  3394 * Isar: 'def' now admits simultaneous definitions, e.g.:
  3395 
  3396   def x == "t" and y == "u"
  3397 
  3398 * Isar: added command 'unfolding', which is structurally similar to
  3399 'using', but affects both the goal state and facts by unfolding given
  3400 rewrite rules.  Thus many occurrences of the 'unfold' method or
  3401 'unfolded' attribute may be replaced by first-class proof text.
  3402 
  3403 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  3404 and command 'unfolding' now all support object-level equalities
  3405 (potentially conditional).  The underlying notion of rewrite rule is
  3406 analogous to the 'rule_format' attribute, but *not* that of the
  3407 Simplifier (which is usually more generous).
  3408 
  3409 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  3410 premises of a theorem by n. Useful in conjunction with drule.
  3411 
  3412 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  3413 method expression within a sandbox consisting of the first N
  3414 sub-goals, which need to exist.  For example, ``simp_all [3]''
  3415 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  3416 simplifies all new goals that emerge from applying rule foo to the
  3417 originally first one.
  3418 
  3419 * Isar: schematic goals are no longer restricted to higher-order
  3420 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  3421 expected.
  3422 
  3423 * Isar: the conclusion of a long theorem statement is now either
  3424 'shows' (a simultaneous conjunction, as before), or 'obtains'
  3425 (essentially a disjunction of cases with local parameters and
  3426 assumptions).  The latter allows to express general elimination rules
  3427 adequately; in this notation common elimination rules look like this:
  3428 
  3429   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  3430     assumes "EX x. P x"
  3431     obtains x where "P x"
  3432 
  3433   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  3434     assumes "A & B"
  3435     obtains A and B
  3436 
  3437   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  3438     assumes "A | B"
  3439     obtains
  3440       A
  3441     | B
  3442 
  3443 The subsequent classical rules even refer to the formal "thesis"
  3444 explicitly:
  3445 
  3446   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  3447     obtains "~ thesis"
  3448 
  3449   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  3450     obtains "thesis ==> something"
  3451 
  3452 The actual proof of an 'obtains' statement is analogous to that of the
  3453 Isar proof element 'obtain', only that there may be several cases.
  3454 Optional case names may be specified in parentheses; these will be
  3455 available both in the present proof and as annotations in the
  3456 resulting rule, for later use with the 'cases' method (cf. attribute
  3457 case_names).
  3458 
  3459 * Isar: the assumptions of a long theorem statement are available as
  3460 "assms" fact in the proof context.  This is more appropriate than the
  3461 (historical) "prems", which refers to all assumptions of the current
  3462 context, including those from the target locale, proof body etc.
  3463 
  3464 * Isar: 'print_statement' prints theorems from the current theory or
  3465 proof context in long statement form, according to the syntax of a
  3466 top-level lemma.
  3467 
  3468 * Isar: 'obtain' takes an optional case name for the local context
  3469 introduction rule (default "that").
  3470 
  3471 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  3472 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  3473 to occur.
  3474 
  3475 * Pure: syntax "CONST name" produces a fully internalized constant
  3476 according to the current context.  This is particularly useful for
  3477 syntax translations that should refer to internal constant
  3478 representations independently of name spaces.
  3479 
  3480 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  3481 instead of "FOO ". This allows multiple binder declarations to coexist
  3482 in the same context.  INCOMPATIBILITY.
  3483 
  3484 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  3485 primitive that also works in a locale context (both for constants and
  3486 fixed variables). Type declaration and internal syntactic representation
  3487 of given constants retrieved from the context. Likewise, the
  3488 'no_notation' command allows to remove given syntax annotations from the
  3489 current context.
  3490 
  3491 * Isar/locales: new derived specification elements 'axiomatization',
  3492 'definition', 'abbreviation', which support type-inference, admit
  3493 object-level specifications (equality, equivalence).  See also the
  3494 isar-ref manual.  Examples:
  3495 
  3496   axiomatization
  3497     eq  (infix "===" 50) where
  3498     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  3499 
  3500   definition "f x y = x + y + 1"
  3501   definition g where "g x = f x x"
  3502 
  3503   abbreviation
  3504     neq  (infix "=!=" 50) where
  3505     "x =!= y == ~ (x === y)"
  3506 
  3507 These specifications may be also used in a locale context.  Then the
  3508 constants being introduced depend on certain fixed parameters, and the
  3509 constant name is qualified by the locale base name.  An internal
  3510 abbreviation takes care for convenient input and output, making the
  3511 parameters implicit and using the original short name.  See also
  3512 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  3513 entities from a monomorphic theory.
  3514 
  3515 Presently, abbreviations are only available 'in' a target locale, but
  3516 not inherited by general import expressions.  Also note that
  3517 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  3518 'translations' in common applications.  The "no_abbrevs" print mode
  3519 prevents folding of abbreviations in term output.
  3520 
  3521 Concrete syntax is attached to specified constants in internal form,
  3522 independently of name spaces.  The parse tree representation is
  3523 slightly different -- use 'notation' instead of raw 'syntax', and
  3524 'translations' with explicit "CONST" markup to accommodate this.
  3525 
  3526 * Pure/Isar: unified syntax for new-style specification mechanisms
  3527 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  3528 full type inference and dummy patterns ("_").  For example:
  3529 
  3530   definition "K x _ = x"
  3531 
  3532   inductive conj for A B
  3533   where "A ==> B ==> conj A B"
  3534 
  3535 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  3536 the current context.  Print mode "no_abbrevs" prevents inversion of
  3537 abbreviations on output.
  3538 
  3539 * Isar/locales: improved parameter handling: use of locales "var" and
  3540 "struct" no longer necessary; - parameter renamings are no longer
  3541 required to be injective.  For example, this allows to define
  3542 endomorphisms as locale endom = homom mult mult h.
  3543 
  3544 * Isar/locales: changed the way locales with predicates are defined.
  3545 Instead of accumulating the specification, the imported expression is
  3546 now an interpretation.  INCOMPATIBILITY: different normal form of
  3547 locale expressions.  In particular, in interpretations of locales with
  3548 predicates, goals repesenting already interpreted fragments are not
  3549 removed automatically.  Use methods `intro_locales' and
  3550 `unfold_locales'; see below.
  3551 
  3552 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  3553 provide backward reasoning on locales predicates.  The methods are
  3554 aware of interpretations and discharge corresponding goals.
  3555 `intro_locales' is less aggressive then `unfold_locales' and does not
  3556 unfold predicates to assumptions.
  3557 
  3558 * Isar/locales: the order in which locale fragments are accumulated
  3559 has changed.  This enables to override declarations from fragments due
  3560 to interpretations -- for example, unwanted simp rules.
  3561 
  3562 * Isar/locales: interpretation in theories and proof contexts has been
  3563 extended.  One may now specify (and prove) equations, which are
  3564 unfolded in interpreted theorems.  This is useful for replacing
  3565 defined concepts (constants depending on locale parameters) by
  3566 concepts already existing in the target context.  Example:
  3567 
  3568   interpretation partial_order ["op <= :: [int, int] => bool"]
  3569     where "partial_order.less (op <=) (x::int) y = (x < y)"
  3570 
  3571 Typically, the constant `partial_order.less' is created by a
  3572 definition specification element in the context of locale
  3573 partial_order.
  3574 
  3575 * Method "induct": improved internal context management to support
  3576 local fixes and defines on-the-fly. Thus explicit meta-level
  3577 connectives !!  and ==> are rarely required anymore in inductive goals
  3578 (using object-logic connectives for this purpose has been long
  3579 obsolete anyway). Common proof patterns are explained in
  3580 src/HOL/Induct/Common_Patterns.thy, see also
  3581 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  3582 examples.
  3583 
  3584 * Method "induct": improved handling of simultaneous goals. Instead of
  3585 introducing object-level conjunction, the statement is now split into
  3586 several conclusions, while the corresponding symbolic cases are nested
  3587 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  3588 see src/HOL/Induct/Common_Patterns.thy, for example.
  3589 
  3590 * Method "induct": mutual induction rules are now specified as a list
  3591 of rule sharing the same induction cases. HOL packages usually provide
  3592 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  3593 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  3594 mutual induction rules differently, i.e. like this:
  3595 
  3596   (induct rule: foo_bar.inducts)
  3597   (induct set: foo bar)
  3598   (induct pred: foo bar)
  3599   (induct type: foo bar)
  3600 
  3601 The ML function ProjectRule.projections turns old-style rules into the
  3602 new format.
  3603 
  3604 * Method "coinduct": dual of induction, see
  3605 src/HOL/Library/Coinductive_List.thy for various examples.
  3606 
  3607 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  3608 considered a legacy feature.
  3609 
  3610 * Attribute "symmetric" produces result with standardized schematic
  3611 variables (index 0).  Potential INCOMPATIBILITY.
  3612 
  3613 * Simplifier: by default the simplifier trace only shows top level
  3614 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  3615 default. Thus there is less danger of being flooded by the trace. The
  3616 trace indicates where parts have been suppressed.
  3617   
  3618 * Provers/classical: removed obsolete classical version of elim_format
  3619 attribute; classical elim/dest rules are now treated uniformly when
  3620 manipulating the claset.
  3621 
  3622 * Provers/classical: stricter checks to ensure that supplied intro,
  3623 dest and elim rules are well-formed; dest and elim rules must have at
  3624 least one premise.
  3625 
  3626 * Provers/classical: attributes dest/elim/intro take an optional
  3627 weight argument for the rule (just as the Pure versions).  Weights are
  3628 ignored by automated tools, but determine the search order of single
  3629 rule steps.
  3630 
  3631 * Syntax: input syntax now supports dummy variable binding "%_. b",
  3632 where the body does not mention the bound variable.  Note that dummy
  3633 patterns implicitly depend on their context of bounds, which makes
  3634 "{_. _}" match any set comprehension as expected.  Potential
  3635 INCOMPATIBILITY -- parse translations need to cope with syntactic
  3636 constant "_idtdummy" in the binding position.
  3637 
  3638 * Syntax: removed obsolete syntactic constant "_K" and its associated
  3639 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  3640 for example "A -> B" => "Pi A (%_. B)".
  3641 
  3642 * Pure: 'class_deps' command visualizes the subclass relation, using
  3643 the graph browser tool.
  3644 
  3645 * Pure: 'print_theory' now suppresses certain internal declarations by
  3646 default; use '!' option for full details.
  3647 
  3648 
  3649 *** HOL ***
  3650 
  3651 * Method "metis" proves goals by applying the Metis general-purpose
  3652 resolution prover (see also http://gilith.com/software/metis/).
  3653 Examples are in the directory MetisExamples.  WARNING: the
  3654 Isabelle/HOL-Metis integration does not yet work properly with
  3655 multi-threading.
  3656   
  3657 * Command 'sledgehammer' invokes external automatic theorem provers as
  3658 background processes.  It generates calls to the "metis" method if
  3659 successful. These can be pasted into the proof.  Users do not have to
  3660 wait for the automatic provers to return.  WARNING: does not really
  3661 work with multi-threading.
  3662 
  3663 * New "auto_quickcheck" feature tests outermost goal statements for
  3664 potential counter-examples.  Controlled by ML references
  3665 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  3666 5000 milliseconds).  Fails silently if statements is outside of
  3667 executable fragment, or any other codgenerator problem occurs.
  3668 
  3669 * New constant "undefined" with axiom "undefined x = undefined".
  3670 
  3671 * Added class "HOL.eq", allowing for code generation with polymorphic
  3672 equality.
  3673 
  3674 * Some renaming of class constants due to canonical name prefixing in
  3675 the new 'class' package:
  3676 
  3677     HOL.abs ~> HOL.abs_class.abs
  3678     HOL.divide ~> HOL.divide_class.divide
  3679     0 ~> HOL.zero_class.zero
  3680     1 ~> HOL.one_class.one
  3681     op + ~> HOL.plus_class.plus
  3682     op - ~> HOL.minus_class.minus
  3683     uminus ~> HOL.minus_class.uminus
  3684     op * ~> HOL.times_class.times
  3685     op < ~> HOL.ord_class.less
  3686     op <= > HOL.ord_class.less_eq
  3687     Nat.power ~> Power.power_class.power
  3688     Nat.size ~> Nat.size_class.size
  3689     Numeral.number_of ~> Numeral.number_class.number_of
  3690     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  3691     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  3692     Orderings.min ~> Orderings.ord_class.min
  3693     Orderings.max ~> Orderings.ord_class.max
  3694     Divides.op div ~> Divides.div_class.div
  3695     Divides.op mod ~> Divides.div_class.mod
  3696     Divides.op dvd ~> Divides.div_class.dvd
  3697 
  3698 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  3699 
  3700 a) User-defined constants using any of the names "plus", "minus",
  3701 "times", "less" or "less_eq". The standard syntax translations for
  3702 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  3703 names.
  3704 
  3705 b) Variables named "plus", "minus", "times", "less", "less_eq"
  3706 INCOMPATIBILITY: use more specific names.
  3707 
  3708 c) Permutative equations (e.g. "a + b = b + a")
  3709 Since the change of names also changes the order of terms, permutative
  3710 rewrite rules may get applied in a different order. Experience shows
  3711 that this is rarely the case (only two adaptions in the whole Isabelle
  3712 distribution).  INCOMPATIBILITY: rewrite proofs
  3713 
  3714 d) ML code directly refering to constant names
  3715 This in general only affects hand-written proof tactics, simprocs and
  3716 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  3717 Consider using @{const_name} antiquotation.
  3718 
  3719 * New class "default" with associated constant "default".
  3720 
  3721 * Function "sgn" is now overloaded and available on int, real, complex
  3722 (and other numeric types), using class "sgn".  Two possible defs of
  3723 sgn are given as equational assumptions in the classes sgn_if and
  3724 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  3725 INCOMPATIBILITY.
  3726 
  3727 * Locale "partial_order" now unified with class "order" (cf. theory
  3728 Orderings), added parameter "less".  INCOMPATIBILITY.
  3729 
  3730 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  3731 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  3732 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  3733 
  3734 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  3735 changed order of proof goals in instance proofs.
  3736 
  3737 * The transitivity reasoner for partial and linear orders is set up
  3738 for classes "order" and "linorder".  Instances of the reasoner are available
  3739 in all contexts importing or interpreting the corresponding locales.
  3740 Method "order" invokes the reasoner separately; the reasoner
  3741 is also integrated with the Simplifier as a solver.  Diagnostic
  3742 command 'print_orders' shows the available instances of the reasoner
  3743 in the current context.
  3744 
  3745 * Localized monotonicity predicate in theory "Orderings"; integrated
  3746 lemmas max_of_mono and min_of_mono with this predicate.
  3747 INCOMPATIBILITY.
  3748 
  3749 * Formulation of theorem "dense" changed slightly due to integration
  3750 with new class dense_linear_order.
  3751 
  3752 * Uniform lattice theory development in HOL.
  3753 
  3754     constants "meet" and "join" now named "inf" and "sup"
  3755     constant "Meet" now named "Inf"
  3756 
  3757     classes "meet_semilorder" and "join_semilorder" now named
  3758       "lower_semilattice" and "upper_semilattice"
  3759     class "lorder" now named "lattice"
  3760     class "comp_lat" now named "complete_lattice"
  3761 
  3762     Instantiation of lattice classes allows explicit definitions
  3763     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  3764 
  3765   INCOMPATIBILITY.  Theorem renames:
  3766 
  3767     meet_left_le            ~> inf_le1
  3768     meet_right_le           ~> inf_le2
  3769     join_left_le            ~> sup_ge1
  3770     join_right_le           ~> sup_ge2
  3771     meet_join_le            ~> inf_sup_ord
  3772     le_meetI                ~> le_infI
  3773     join_leI                ~> le_supI
  3774     le_meet                 ~> le_inf_iff
  3775     le_join                 ~> ge_sup_conv
  3776     meet_idempotent         ~> inf_idem
  3777     join_idempotent         ~> sup_idem
  3778     meet_comm               ~> inf_commute
  3779     join_comm               ~> sup_commute
  3780     meet_leI1               ~> le_infI1
  3781     meet_leI2               ~> le_infI2
  3782     le_joinI1               ~> le_supI1
  3783     le_joinI2               ~> le_supI2
  3784     meet_assoc              ~> inf_assoc
  3785     join_assoc              ~> sup_assoc
  3786     meet_left_comm          ~> inf_left_commute
  3787     meet_left_idempotent    ~> inf_left_idem
  3788     join_left_comm          ~> sup_left_commute
  3789     join_left_idempotent    ~> sup_left_idem
  3790     meet_aci                ~> inf_aci
  3791     join_aci                ~> sup_aci
  3792     le_def_meet             ~> le_iff_inf
  3793     le_def_join             ~> le_iff_sup
  3794     join_absorp2            ~> sup_absorb2
  3795     join_absorp1            ~> sup_absorb1
  3796     meet_absorp1            ~> inf_absorb1
  3797     meet_absorp2            ~> inf_absorb2
  3798     meet_join_absorp        ~> inf_sup_absorb
  3799     join_meet_absorp        ~> sup_inf_absorb
  3800     distrib_join_le         ~> distrib_sup_le
  3801     distrib_meet_le         ~> distrib_inf_le
  3802 
  3803     add_meet_distrib_left   ~> add_inf_distrib_left
  3804     add_join_distrib_left   ~> add_sup_distrib_left
  3805     is_join_neg_meet        ~> is_join_neg_inf
  3806     is_meet_neg_join        ~> is_meet_neg_sup
  3807     add_meet_distrib_right  ~> add_inf_distrib_right
  3808     add_join_distrib_right  ~> add_sup_distrib_right
  3809     add_meet_join_distribs  ~> add_sup_inf_distribs
  3810     join_eq_neg_meet        ~> sup_eq_neg_inf
  3811     meet_eq_neg_join        ~> inf_eq_neg_sup
  3812     add_eq_meet_join        ~> add_eq_inf_sup
  3813     meet_0_imp_0            ~> inf_0_imp_0
  3814     join_0_imp_0            ~> sup_0_imp_0
  3815     meet_0_eq_0             ~> inf_0_eq_0
  3816     join_0_eq_0             ~> sup_0_eq_0
  3817     neg_meet_eq_join        ~> neg_inf_eq_sup
  3818     neg_join_eq_meet        ~> neg_sup_eq_inf
  3819     join_eq_if              ~> sup_eq_if
  3820 
  3821     mono_meet               ~> mono_inf
  3822     mono_join               ~> mono_sup
  3823     meet_bool_eq            ~> inf_bool_eq
  3824     join_bool_eq            ~> sup_bool_eq
  3825     meet_fun_eq             ~> inf_fun_eq
  3826     join_fun_eq             ~> sup_fun_eq
  3827     meet_set_eq             ~> inf_set_eq
  3828     join_set_eq             ~> sup_set_eq
  3829     meet1_iff               ~> inf1_iff
  3830     meet2_iff               ~> inf2_iff
  3831     meet1I                  ~> inf1I
  3832     meet2I                  ~> inf2I
  3833     meet1D1                 ~> inf1D1
  3834     meet2D1                 ~> inf2D1
  3835     meet1D2                 ~> inf1D2
  3836     meet2D2                 ~> inf2D2
  3837     meet1E                  ~> inf1E
  3838     meet2E                  ~> inf2E
  3839     join1_iff               ~> sup1_iff
  3840     join2_iff               ~> sup2_iff
  3841     join1I1                 ~> sup1I1
  3842     join2I1                 ~> sup2I1
  3843     join1I1                 ~> sup1I1
  3844     join2I2                 ~> sup1I2
  3845     join1CI                 ~> sup1CI
  3846     join2CI                 ~> sup2CI
  3847     join1E                  ~> sup1E
  3848     join2E                  ~> sup2E
  3849 
  3850     is_meet_Meet            ~> is_meet_Inf
  3851     Meet_bool_def           ~> Inf_bool_def
  3852     Meet_fun_def            ~> Inf_fun_def
  3853     Meet_greatest           ~> Inf_greatest
  3854     Meet_lower              ~> Inf_lower
  3855     Meet_set_def            ~> Inf_set_def
  3856 
  3857     Sup_def                 ~> Sup_Inf
  3858     Sup_bool_eq             ~> Sup_bool_def
  3859     Sup_fun_eq              ~> Sup_fun_def
  3860     Sup_set_eq              ~> Sup_set_def
  3861 
  3862     listsp_meetI            ~> listsp_infI
  3863     listsp_meet_eq          ~> listsp_inf_eq
  3864 
  3865     meet_min                ~> inf_min
  3866     join_max                ~> sup_max
  3867 
  3868 * Added syntactic class "size"; overloaded constant "size" now has
  3869 type "'a::size ==> bool"
  3870 
  3871 * Internal reorganisation of `size' of datatypes: size theorems
  3872 "foo.size" are no longer subsumed by "foo.simps" (but are still
  3873 simplification rules by default!); theorems "prod.size" now named
  3874 "*.size".
  3875 
  3876 * Class "div" now inherits from class "times" rather than "type".
  3877 INCOMPATIBILITY.
  3878 
  3879 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  3880 Linorder etc.  have disappeared; operations defined in terms of
  3881 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  3882 
  3883 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  3884 
  3885 * HOL-Word: New extensive library and type for generic, fixed size
  3886 machine words, with arithemtic, bit-wise, shifting and rotating
  3887 operations, reflection into int, nat, and bool lists, automation for
  3888 linear arithmetic (by automatic reflection into nat or int), including
  3889 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  3890 arithmetic type classes, supporting automatic simplification of
  3891 numerals on all operations.
  3892 
  3893 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  3894 
  3895 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  3896 
  3897 * Code generator library theories:
  3898   - Code_Integer represents HOL integers by big integer literals in target
  3899     languages.
  3900   - Code_Char represents HOL characters by character literals in target
  3901     languages.
  3902   - Code_Char_chr like Code_Char, but also offers treatment of character
  3903     codes; includes Code_Integer.
  3904   - Executable_Set allows to generate code for finite sets using lists.
  3905   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  3906     denominator).
  3907   - Executable_Real implements a subset of real numbers, namly those
  3908     representable by rational numbers.
  3909   - Efficient_Nat implements natural numbers by integers, which in general will
  3910     result in higher efficency; pattern matching with 0/Suc is eliminated;
  3911     includes Code_Integer.
  3912   - Code_Index provides an additional datatype index which is mapped to
  3913     target-language built-in integers.
  3914   - Code_Message provides an additional datatype message_string which is isomorphic to
  3915     strings; messages are mapped to target-language strings.
  3916 
  3917 * New package for inductive predicates
  3918 
  3919   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  3920 
  3921     inductive
  3922       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3923       for z_1 :: U_1 and ... and z_n :: U_m
  3924     where
  3925       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3926     | ...
  3927 
  3928   with full support for type-inference, rather than
  3929 
  3930     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3931 
  3932     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3933     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3934 
  3935     inductive "s z_1 ... z_m"
  3936     intros
  3937       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3938       ...
  3939 
  3940   For backward compatibility, there is a wrapper allowing inductive
  3941   sets to be defined with the new package via
  3942 
  3943     inductive_set
  3944       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3945       for z_1 :: U_1 and ... and z_n :: U_m
  3946     where
  3947       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3948     | ...
  3949 
  3950   or
  3951 
  3952     inductive_set
  3953       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3954       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3955       for z_1 :: U_1 and ... and z_n :: U_m
  3956     where
  3957       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3958     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3959     | ...
  3960 
  3961   if the additional syntax "p ..." is required.
  3962 
  3963   Numerous examples can be found in the subdirectories src/HOL/Auth,
  3964   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  3965 
  3966   INCOMPATIBILITIES:
  3967 
  3968   - Since declaration and definition of inductive sets or predicates
  3969     is no longer separated, abbreviations involving the newly
  3970     introduced sets or predicates must be specified together with the
  3971     introduction rules after the 'where' keyword (see above), rather
  3972     than before the actual inductive definition.
  3973 
  3974   - The variables in induction and elimination rules are now
  3975     quantified in the order of their occurrence in the introduction
  3976     rules, rather than in alphabetical order. Since this may break
  3977     some proofs, these proofs either have to be repaired, e.g. by
  3978     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  3979     statements of the form
  3980 
  3981       case (rule_i a_i_1 ... a_i_{k_i})
  3982 
  3983     or the old order of quantification has to be restored by explicitly adding
  3984     meta-level quantifiers in the introduction rules, i.e.
  3985 
  3986       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  3987 
  3988   - The format of the elimination rules is now
  3989 
  3990       p z_1 ... z_m x_1 ... x_n ==>
  3991         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  3992         ==> ... ==> P
  3993 
  3994     for predicates and
  3995 
  3996       (x_1, ..., x_n) : s z_1 ... z_m ==>
  3997         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  3998         ==> ... ==> P
  3999 
  4000     for sets rather than
  4001 
  4002       x : s z_1 ... z_m ==>
  4003         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  4004         ==> ... ==> P
  4005 
  4006     This may require terms in goals to be expanded to n-tuples
  4007     (e.g. using case_tac or simplification with the split_paired_all
  4008     rule) before the above elimination rule is applicable.
  4009 
  4010   - The elimination or case analysis rules for (mutually) inductive
  4011     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  4012     list of rules "p_1_..._p_k.elims" is no longer available.
  4013 
  4014 * New package "function"/"fun" for general recursive functions,
  4015 supporting mutual and nested recursion, definitions in local contexts,
  4016 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  4017 for small examples, and the separate tutorial on the function
  4018 package. The old recdef "package" is still available as before, but
  4019 users are encouraged to use the new package.
  4020 
  4021 * Method "lexicographic_order" automatically synthesizes termination
  4022 relations as lexicographic combinations of size measures. 
  4023 
  4024 * Case-expressions allow arbitrary constructor-patterns (including
  4025 "_") and take their order into account, like in functional
  4026 programming.  Internally, this is translated into nested
  4027 case-expressions; missing cases are added and mapped to the predefined
  4028 constant "undefined". In complicated cases printing may no longer show
  4029 the original input but the internal form. Lambda-abstractions allow
  4030 the same form of pattern matching: "% pat1 => e1 | ..." is an
  4031 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  4032 variable.
  4033 
  4034 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  4035 is an abbreviation for "of_nat :: nat => int". The simplification
  4036 rules for "of_nat" have been changed to work like "int" did
  4037 previously.  Potential INCOMPATIBILITY:
  4038   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  4039   - of_nat_diff and of_nat_mult are no longer default simp rules
  4040 
  4041 * Method "algebra" solves polynomial equations over (semi)rings using
  4042 Groebner bases. The (semi)ring structure is defined by locales and the
  4043 tool setup depends on that generic context. Installing the method for
  4044 a specific type involves instantiating the locale and possibly adding
  4045 declarations for computation on the coefficients.  The method is
  4046 already instantiated for natural numbers and for the axiomatic class
  4047 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  4048 CALCULEMUS 2007 for the general principles underlying this
  4049 architecture of context-aware proof-tools.
  4050 
  4051 * Method "ferrack" implements quantifier elimination over
  4052 special-purpose dense linear orders using locales (analogous to
  4053 "algebra"). The method is already installed for class
  4054 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  4055 rat, etc.
  4056 
  4057 * Former constant "List.op @" now named "List.append".  Use ML
  4058 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  4059 circumvent possible incompatibilities when working on ML level.
  4060 
  4061 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  4062 
  4063 * New function listsum :: 'a list => 'a for arbitrary monoids.
  4064 Special syntax: "SUM x <- xs. f x" (and latex variants)
  4065 
  4066 * New syntax for Haskell-like list comprehension (input only), eg.
  4067 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  4068 
  4069 * The special syntax for function "filter" has changed from [x :
  4070 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  4071 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  4072 
  4073 * [a..b] is now defined for arbitrary linear orders.  It used to be
  4074 defined on nat only, as an abbreviation for [a..<Suc b]
  4075 INCOMPATIBILITY.
  4076 
  4077 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  4078 
  4079 * New functions "sorted" and "sort" in src/HOL/List.thy.
  4080 
  4081 * New lemma collection field_simps (an extension of ring_simps) for
  4082 manipulating (in)equations involving division. Multiplies with all
  4083 denominators that can be proved to be non-zero (in equations) or
  4084 positive/negative (in inequations).
  4085 
  4086 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  4087 have been improved and renamed to ring_simps, group_simps and
  4088 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  4089 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  4090 
  4091 * Theory Library/Commutative_Ring: switched from recdef to function
  4092 package; constants add, mul, pow now curried.  Infix syntax for
  4093 algebraic operations.
  4094 
  4095 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  4096 INCOMPATIBILITY.
  4097 
  4098 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  4099 INCOMPATIBILITY.
  4100 
  4101 * HOL/records: generalised field-update to take a function on the
  4102 field rather than the new value: r(|A := x|) is translated to A_update
  4103 (K x) r The K-combinator that is internally used is called K_record.
  4104 INCOMPATIBILITY: Usage of the plain update functions has to be
  4105 adapted.
  4106  
  4107 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  4108 * x = 0, which are required for a semiring.  Richer structures do not
  4109 inherit from semiring_0 anymore, because this property is a theorem
  4110 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  4111 there is more to prove, but this is mostly trivial.
  4112 
  4113 * Class "recpower" is generalized to arbitrary monoids, not just
  4114 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  4115 commutativity or semiring properties additionally.
  4116 
  4117 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  4118 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  4119 better use 'abbreviation'.
  4120 
  4121 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  4122 
  4123 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  4124 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  4125 significant changes for setting up numeral syntax for types:
  4126   - New constants Numeral.pred and Numeral.succ instead
  4127       of former Numeral.bin_pred and Numeral.bin_succ.
  4128   - Use integer operations instead of bin_add, bin_mult and so on.
  4129   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  4130   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  4131 
  4132 See src/HOL/Integ/IntArith.thy for an example setup.
  4133 
  4134 * Command 'normal_form' computes the normal form of a term that may
  4135 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  4136 produces ``[b, c, a]'' (without proof).  This command is suitable for
  4137 heavy-duty computations because the functions are compiled to ML
  4138 first.  Correspondingly, a method "normalization" is provided.  See
  4139 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  4140 
  4141 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  4142 25 like -->); output depends on the "iff" print_mode, the default is
  4143 "A = B" (with priority 50).
  4144 
  4145 * Relations less (<) and less_eq (<=) are also available on type bool.
  4146 Modified syntax to disallow nesting without explicit parentheses,
  4147 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  4148 INCOMPATIBILITY.
  4149 
  4150 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  4151 
  4152 * Relation composition operator "op O" now has precedence 75 and binds
  4153 stronger than union and intersection. INCOMPATIBILITY.
  4154 
  4155 * The old set interval syntax "{m..n(}" (and relatives) has been
  4156 removed.  Use "{m..<n}" (and relatives) instead.
  4157 
  4158 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  4159 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  4160 ``declare [[simproc del: neq]]''.
  4161 
  4162 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  4163 True/False.
  4164 
  4165 * Theorem Cons_eq_map_conv no longer declared as "simp".
  4166 
  4167 * Theorem setsum_mult renamed to setsum_right_distrib.
  4168 
  4169 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  4170 ``rule'' method.
  4171 
  4172 * Reimplemented methods "sat" and "satx", with several improvements:
  4173 goals no longer need to be stated as "<prems> ==> False", equivalences
  4174 (i.e. "=" on type bool) are handled, variable names of the form
  4175 "lit_<n>" are no longer reserved, significant speedup.
  4176 
  4177 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  4178 zChaff is still supported as well.
  4179 
  4180 * 'inductive' and 'datatype': provide projections of mutual rules,
  4181 bundled as foo_bar.inducts;
  4182 
  4183 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  4184 Library.
  4185 
  4186 * Library: moved theory Accessible_Part to main HOL.
  4187 
  4188 * Library: added theory Coinductive_List of potentially infinite lists
  4189 as greatest fixed-point.
  4190 
  4191 * Library: added theory AssocList which implements (finite) maps as
  4192 association lists.
  4193 
  4194 * Method "evaluation" solves goals (i.e. a boolean expression)
  4195 efficiently by compiling it to ML.  The goal is "proved" (via an
  4196 oracle) if it evaluates to True.
  4197 
  4198 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  4199 also when invoked by the simplifier.  This results in the Simplifier
  4200 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  4201 Configuration option fast_arith_split_limit=0 recovers the old
  4202 behavior.
  4203 
  4204 * Support for hex (0x20) and binary (0b1001) numerals.
  4205 
  4206 * New method: reify eqs (t), where eqs are equations for an
  4207 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  4208 parameter, computes a term s::'b and a list xs::'a list and proves the
  4209 theorem I xs s = t. This is also known as reification or quoting. The
  4210 resulting theorem is applied to the subgoal to substitute t with I xs
  4211 s.  If t is omitted, the subgoal itself is reified.
  4212 
  4213 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  4214 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  4215 where f is supposed to be a computable function (in the sense of code
  4216 generattion). The method uses reify to compute s and xs as above then
  4217 applies corr_thm and uses normalization by evaluation to "prove" f s =
  4218 r and finally gets the theorem t = r, which is again applied to the
  4219 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  4220 
  4221 * Reflection: Automatic reification now handels binding, an example is
  4222 available in src/HOL/ex/ReflectionEx.thy
  4223 
  4224 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  4225 command 'statespace' that is similar to 'record', but introduces an
  4226 abstract specification based on the locale infrastructure instead of
  4227 HOL types.  This leads to extra flexibility in composing state spaces,
  4228 in particular multiple inheritance and renaming of components.
  4229 
  4230 
  4231 *** HOL-Complex ***
  4232 
  4233 * Hyperreal: Functions root and sqrt are now defined on negative real
  4234 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  4235 Nonnegativity side conditions have been removed from many lemmas, so
  4236 that more subgoals may now be solved by simplification; potential
  4237 INCOMPATIBILITY.
  4238 
  4239 * Real: new type classes formalize real normed vector spaces and
  4240 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  4241 and norm :: 'a => real.
  4242 
  4243 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  4244 reals into other types. The overloaded constant Reals :: 'a set is now
  4245 defined as range of_real; potential INCOMPATIBILITY.
  4246 
  4247 * Real: proper support for ML code generation, including 'quickcheck'.
  4248 Reals are implemented as arbitrary precision rationals.
  4249 
  4250 * Hyperreal: Several constants that previously worked only for the
  4251 reals have been generalized, so they now work over arbitrary vector
  4252 spaces. Type annotations may need to be added in some cases; potential
  4253 INCOMPATIBILITY.
  4254 
  4255   Infinitesimal  :: ('a::real_normed_vector) star set
  4256   HFinite        :: ('a::real_normed_vector) star set
  4257   HInfinite      :: ('a::real_normed_vector) star set
  4258   approx         :: ('a::real_normed_vector) star => 'a star => bool
  4259   monad          :: ('a::real_normed_vector) star => 'a star set
  4260   galaxy         :: ('a::real_normed_vector) star => 'a star set
  4261   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  4262   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  4263   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  4264   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  4265   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  4266   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  4267   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  4268   sgn            :: 'a::real_normed_vector => 'a
  4269   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  4270 
  4271 * Complex: Some complex-specific constants are now abbreviations for
  4272 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  4273 hnorm.  Other constants have been entirely removed in favor of the
  4274 polymorphic versions (INCOMPATIBILITY):
  4275 
  4276   approx        <-- capprox
  4277   HFinite       <-- CFinite
  4278   HInfinite     <-- CInfinite
  4279   Infinitesimal <-- CInfinitesimal
  4280   monad         <-- cmonad
  4281   galaxy        <-- cgalaxy
  4282   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  4283   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  4284   (ns)deriv     <-- (ns)cderiv
  4285 
  4286 
  4287 *** HOL-Algebra ***
  4288 
  4289 * Formalisation of ideals and the quotient construction over rings.
  4290 
  4291 * Order and lattice theory no longer based on records.
  4292 INCOMPATIBILITY.
  4293 
  4294 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  4295 greatest_closed.  INCOMPATIBILITY.
  4296 
  4297 * Method algebra is now set up via an attribute.  For examples see
  4298 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  4299 of algebraic structures.
  4300 
  4301 * Renamed theory CRing to Ring.
  4302 
  4303 
  4304 *** HOL-Nominal ***
  4305 
  4306 * Substantial, yet incomplete support for nominal datatypes (binding
  4307 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  4308 src/HOL/Nominal/Examples.  Prospective users should consult
  4309 http://isabelle.in.tum.de/nominal/
  4310 
  4311 
  4312 *** ML ***
  4313 
  4314 * ML basics: just one true type int, which coincides with IntInf.int
  4315 (even on SML/NJ).
  4316 
  4317 * ML within Isar: antiquotations allow to embed statically-checked
  4318 formal entities in the source, referring to the context available at
  4319 compile-time.  For example:
  4320 
  4321 ML {* @{sort "{zero,one}"} *}
  4322 ML {* @{typ "'a => 'b"} *}
  4323 ML {* @{term "%x. x"} *}
  4324 ML {* @{prop "x == y"} *}
  4325 ML {* @{ctyp "'a => 'b"} *}
  4326 ML {* @{cterm "%x. x"} *}
  4327 ML {* @{cprop "x == y"} *}
  4328 ML {* @{thm asm_rl} *}
  4329 ML {* @{thms asm_rl} *}
  4330 ML {* @{type_name c} *}
  4331 ML {* @{type_syntax c} *}
  4332 ML {* @{const_name c} *}
  4333 ML {* @{const_syntax c} *}
  4334 ML {* @{context} *}
  4335 ML {* @{theory} *}
  4336 ML {* @{theory Pure} *}
  4337 ML {* @{theory_ref} *}
  4338 ML {* @{theory_ref Pure} *}
  4339 ML {* @{simpset} *}
  4340 ML {* @{claset} *}
  4341 ML {* @{clasimpset} *}
  4342 
  4343 The same works for sources being ``used'' within an Isar context.
  4344 
  4345 * ML in Isar: improved error reporting; extra verbosity with
  4346 ML_Context.trace enabled.
  4347 
  4348 * Pure/General/table.ML: the join operations now works via exceptions
  4349 DUP/SAME instead of type option. This is simpler in simple cases, and
  4350 admits slightly more efficient complex applications.
  4351 
  4352 * Pure: 'advanced' translation functions (parse_translation etc.) now
  4353 use Context.generic instead of just theory.
  4354 
  4355 * Pure: datatype Context.generic joins theory/Proof.context and
  4356 provides some facilities for code that works in either kind of
  4357 context, notably GenericDataFun for uniform theory and proof data.
  4358 
  4359 * Pure: simplified internal attribute type, which is now always
  4360 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  4361 local (Proof.context) attributes have been discontinued, while
  4362 minimizing code duplication. Thm.rule_attribute and
  4363 Thm.declaration_attribute build canonical attributes; see also structure
  4364 Context for further operations on Context.generic, notably
  4365 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  4366 declarations and definitions.
  4367 
  4368 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  4369 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  4370 init only required for impure data. INCOMPATIBILITY: empty really need
  4371 to be empty (no dependencies on theory content!)
  4372 
  4373 * Pure/kernel: consts certification ignores sort constraints given in
  4374 signature declarations. (This information is not relevant to the
  4375 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  4376 potential INCOMPATIBILITY.
  4377 
  4378 * Pure: axiomatic type classes are now purely definitional, with
  4379 explicit proofs of class axioms and super class relations performed
  4380 internally. See Pure/axclass.ML for the main internal interfaces --
  4381 notably AxClass.define_class supercedes AxClass.add_axclass, and
  4382 AxClass.axiomatize_class/classrel/arity supersede
  4383 Sign.add_classes/classrel/arities.
  4384 
  4385 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  4386 global/local versions on theory vs. Proof.context have been
  4387 discontinued; Attrib.syntax and Method.syntax have been adapted
  4388 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  4389 attributes, methods, etc.
  4390 
  4391 * Pure: several functions of signature "... -> theory -> theory * ..."
  4392 have been reoriented to "... -> theory -> ... * theory" in order to
  4393 allow natural usage in combination with the ||>, ||>>, |-> and
  4394 fold_map combinators.
  4395 
  4396 * Pure: official theorem names (closed derivations) and additional
  4397 comments (tags) are now strictly separate.  Name hints -- which are
  4398 maintained as tags -- may be attached any time without affecting the
  4399 derivation.
  4400 
  4401 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  4402 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  4403 achieve the old behaviour.
  4404 
  4405 * Pure: the "Goal" constant is now called "prop", supporting a
  4406 slightly more general idea of ``protecting'' meta-level rule
  4407 statements.
  4408 
  4409 * Pure: Logic.(un)varify only works in a global context, which is now
  4410 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  4411 Logic.legacy_(un)varify as temporary workaround.
  4412 
  4413 * Pure: structure Name provides scalable operations for generating
  4414 internal variable names, notably Name.variants etc.  This replaces
  4415 some popular functions from term.ML:
  4416 
  4417   Term.variant		->  Name.variant
  4418   Term.variantlist	->  Name.variant_list
  4419   Term.invent_names	->  Name.invent_list
  4420 
  4421 Note that low-level renaming rarely occurs in new code -- operations
  4422 from structure Variable are used instead (see below).
  4423 
  4424 * Pure: structure Variable provides fundamental operations for proper
  4425 treatment of fixed/schematic variables in a context.  For example,
  4426 Variable.import introduces fixes for schematics of given facts and
  4427 Variable.export reverses the effect (up to renaming) -- this replaces
  4428 various freeze_thaw operations.
  4429 
  4430 * Pure: structure Goal provides simple interfaces for
  4431 init/conclude/finish and tactical prove operations (replacing former
  4432 Tactic.prove).  Goal.prove is the canonical way to prove results
  4433 within a given context; Goal.prove_global is a degraded version for
  4434 theory level goals, including a global Drule.standard.  Note that
  4435 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  4436 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  4437 in a locale context).
  4438 
  4439 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  4440 and type checking (Syntax.check_term etc.), with common combinations
  4441 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  4442 which are considered legacy and await removal.
  4443 
  4444 * Pure/Syntax: generic interfaces for type unchecking
  4445 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  4446 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  4447 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  4448 available for convenience, but refer to the very same operations using
  4449 a mere theory instead of a full context.
  4450 
  4451 * Isar: simplified treatment of user-level errors, using exception
  4452 ERROR of string uniformly.  Function error now merely raises ERROR,
  4453 without any side effect on output channels.  The Isar toplevel takes
  4454 care of proper display of ERROR exceptions.  ML code may use plain
  4455 handle/can/try; cat_error may be used to concatenate errors like this:
  4456 
  4457   ... handle ERROR msg => cat_error msg "..."
  4458 
  4459 Toplevel ML code (run directly or through the Isar toplevel) may be
  4460 embedded into the Isar toplevel with exception display/debug like
  4461 this:
  4462 
  4463   Isar.toplevel (fn () => ...)
  4464 
  4465 INCOMPATIBILITY, removed special transform_error facilities, removed
  4466 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  4467 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  4468 -- use plain ERROR instead.
  4469 
  4470 * Isar: theory setup now has type (theory -> theory), instead of a
  4471 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  4472 
  4473 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  4474 ProofContext.debug/verbose flags.
  4475 
  4476 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  4477 theory before entering a proof state.  Transactions now always see a
  4478 quasi-functional intermediate checkpoint, both in interactive and
  4479 batch mode.
  4480 
  4481 * Isar: simplified interfaces for outer syntax.  Renamed
  4482 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  4483 OuterSyntax.add_parsers -- this functionality is now included in
  4484 OuterSyntax.command etc.  INCOMPATIBILITY.
  4485 
  4486 * Simplifier: the simpset of a running simplification process now
  4487 contains a proof context (cf. Simplifier.the_context), which is the
  4488 very context that the initial simpset has been retrieved from (by
  4489 simpset_of/local_simpset_of).  Consequently, all plug-in components
  4490 (solver, looper etc.) may depend on arbitrary proof data.
  4491 
  4492 * Simplifier.inherit_context inherits the proof context (plus the
  4493 local bounds) of the current simplification process; any simproc
  4494 etc. that calls the Simplifier recursively should do this!  Removed
  4495 former Simplifier.inherit_bounds, which is already included here --
  4496 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  4497 specify an explicit context using Simplifier.context/theory_context.
  4498 
  4499 * Simplifier/Classical Reasoner: more abstract interfaces
  4500 change_simpset/claset for modifying the simpset/claset reference of a
  4501 theory; raw versions simpset/claset_ref etc. have been discontinued --
  4502 INCOMPATIBILITY.
  4503 
  4504 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  4505 "Trueprop" etc.
  4506 
  4507 
  4508 *** System ***
  4509 
  4510 * settings: the default heap location within ISABELLE_HOME_USER now
  4511 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  4512 Isabelle installations.
  4513 
  4514 * isabelle-process: option -S (secure mode) disables some critical
  4515 operations, notably runtime compilation and evaluation of ML source
  4516 code.
  4517 
  4518 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  4519 
  4520 * Support for parallel execution, using native multicore support of
  4521 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  4522 independent theories, according to the given theory header
  4523 specifications. The maximum number of worker threads is specified via
  4524 usedir option -M or the "max-threads" setting in Proof General. A
  4525 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  4526 to 6 on a 8-core machine.  User-code needs to observe certain
  4527 guidelines for thread-safe programming, see appendix A in the Isar
  4528 Implementation manual.
  4529 
  4530 
  4531 
  4532 New in Isabelle2005 (October 2005)
  4533 ----------------------------------
  4534 
  4535 *** General ***
  4536 
  4537 * Theory headers: the new header syntax for Isar theories is
  4538 
  4539   theory <name>
  4540   imports <theory1> ... <theoryN>
  4541   uses <file1> ... <fileM>
  4542   begin
  4543 
  4544 where the 'uses' part is optional.  The previous syntax
  4545 
  4546   theory <name> = <theory1> + ... + <theoryN>:
  4547 
  4548 will disappear in the next release.  Use isatool fixheaders to convert
  4549 existing theory files.  Note that there is no change in ancient
  4550 non-Isar theories now, but these will disappear soon.
  4551 
  4552 * Theory loader: parent theories can now also be referred to via
  4553 relative and absolute paths.
  4554 
  4555 * Command 'find_theorems' searches for a list of criteria instead of a
  4556 list of constants. Known criteria are: intro, elim, dest, name:string,
  4557 simp:term, and any term. Criteria can be preceded by '-' to select
  4558 theorems that do not match. Intro, elim, dest select theorems that
  4559 match the current goal, name:s selects theorems whose fully qualified
  4560 name contain s, and simp:term selects all simplification rules whose
  4561 lhs match term.  Any other term is interpreted as pattern and selects
  4562 all theorems matching the pattern. Available in ProofGeneral under
  4563 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  4564 
  4565   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  4566 
  4567 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  4568 matching the current goal as introduction rule and not having "HOL."
  4569 in their name (i.e. not being defined in theory HOL).
  4570 
  4571 * Command 'thms_containing' has been discontinued in favour of
  4572 'find_theorems'; INCOMPATIBILITY.
  4573 
  4574 * Communication with Proof General is now 8bit clean, which means that
  4575 Unicode text in UTF-8 encoding may be used within theory texts (both
  4576 formal and informal parts).  Cf. option -U of the Isabelle Proof
  4577 General interface.  Here are some simple examples (cf. src/HOL/ex):
  4578 
  4579   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  4580   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  4581 
  4582 * Improved efficiency of the Simplifier and, to a lesser degree, the
  4583 Classical Reasoner.  Typical big applications run around 2 times
  4584 faster.
  4585 
  4586 
  4587 *** Document preparation ***
  4588 
  4589 * Commands 'display_drafts' and 'print_drafts' perform simple output
  4590 of raw sources.  Only those symbols that do not require additional
  4591 LaTeX packages (depending on comments in isabellesym.sty) are
  4592 displayed properly, everything else is left verbatim.  isatool display
  4593 and isatool print are used as front ends (these are subject to the
  4594 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  4595 
  4596 * Command tags control specific markup of certain regions of text,
  4597 notably folding and hiding.  Predefined tags include "theory" (for
  4598 theory begin and end), "proof" for proof commands, and "ML" for
  4599 commands involving ML code; the additional tags "visible" and
  4600 "invisible" are unused by default.  Users may give explicit tag
  4601 specifications in the text, e.g. ''by %invisible (auto)''.  The
  4602 interpretation of tags is determined by the LaTeX job during document
  4603 preparation: see option -V of isatool usedir, or options -n and -t of
  4604 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  4605 \isadroptag.
  4606 
  4607 Several document versions may be produced at the same time via isatool
  4608 usedir (the generated index.html will link all of them).  Typical
  4609 specifications include ''-V document=theory,proof,ML'' to present
  4610 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  4611 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  4612 these parts without any formal replacement text.  The Isabelle site
  4613 default settings produce ''document'' and ''outline'' versions as
  4614 specified above.
  4615 
  4616 * Several new antiquotations:
  4617 
  4618   @{term_type term} prints a term with its type annotated;
  4619 
  4620   @{typeof term} prints the type of a term;
  4621 
  4622   @{const const} is the same as @{term const}, but checks that the
  4623   argument is a known logical constant;
  4624 
  4625   @{term_style style term} and @{thm_style style thm} print a term or
  4626   theorem applying a "style" to it
  4627 
  4628   @{ML text}
  4629 
  4630 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  4631 definitions, equations, inequations etc., 'concl' printing only the
  4632 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  4633 to print the specified premise.  TermStyle.add_style provides an ML
  4634 interface for introducing further styles.  See also the "LaTeX Sugar"
  4635 document practical applications.  The ML antiquotation prints
  4636 type-checked ML expressions verbatim.
  4637 
  4638 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  4639 and 'text' support optional locale specification '(in loc)', which
  4640 specifies the default context for interpreting antiquotations.  For
  4641 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  4642 
  4643 * Option 'locale=NAME' of antiquotations specifies an alternative
  4644 context interpreting the subsequent argument.  For example: @{thm
  4645 [locale=lattice] inf_assoc}.
  4646 
  4647 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  4648 a proof context.
  4649 
  4650 * Proper output of antiquotations for theory commands involving a
  4651 proof context (such as 'locale' or 'theorem (in loc) ...').
  4652 
  4653 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  4654 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  4655 
  4656 * isatool usedir: new option -C (default true) controls whether option
  4657 -D should include a copy of the original document directory; -C false
  4658 prevents unwanted effects such as copying of administrative CVS data.
  4659 
  4660 
  4661 *** Pure ***
  4662 
  4663 * Considerably improved version of 'constdefs' command.  Now performs
  4664 automatic type-inference of declared constants; additional support for
  4665 local structure declarations (cf. locales and HOL records), see also
  4666 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  4667 sequential dependencies of definitions within a single 'constdefs'
  4668 section; moreover, the declared name needs to be an identifier.  If
  4669 all fails, consider to fall back on 'consts' and 'defs' separately.
  4670 
  4671 * Improved indexed syntax and implicit structures.  First of all,
  4672 indexed syntax provides a notational device for subscripted
  4673 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  4674 expressions.  Secondly, in a local context with structure
  4675 declarations, number indexes \<^sub>n or the empty index (default
  4676 number 1) refer to a certain fixed variable implicitly; option
  4677 show_structs controls printing of implicit structures.  Typical
  4678 applications of these concepts involve record types and locales.
  4679 
  4680 * New command 'no_syntax' removes grammar declarations (and
  4681 translations) resulting from the given syntax specification, which is
  4682 interpreted in the same manner as for the 'syntax' command.
  4683 
  4684 * 'Advanced' translation functions (parse_translation etc.) may depend
  4685 on the signature of the theory context being presently used for
  4686 parsing/printing, see also isar-ref manual.
  4687 
  4688 * Improved 'oracle' command provides a type-safe interface to turn an
  4689 ML expression of type theory -> T -> term into a primitive rule of
  4690 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  4691 is already included here); see also FOL/ex/IffExample.thy;
  4692 INCOMPATIBILITY.
  4693 
  4694 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  4695 before); "cI" is no longer bound, use "c.intro" instead.
  4696 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  4697 axclasses vs. locales.
  4698 
  4699 * Improved internal renaming of symbolic identifiers -- attach primes
  4700 instead of base 26 numbers.
  4701 
  4702 * New flag show_question_marks controls printing of leading question
  4703 marks in schematic variable names.
  4704 
  4705 * In schematic variable names, *any* symbol following \<^isub> or
  4706 \<^isup> is now treated as part of the base name.  For example, the
  4707 following works without printing of awkward ".0" indexes:
  4708 
  4709   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  4710     by simp
  4711 
  4712 * Inner syntax includes (*(*nested*) comments*).
  4713 
  4714 * Pretty printer now supports unbreakable blocks, specified in mixfix
  4715 annotations as "(00...)".
  4716 
  4717 * Clear separation of logical types and nonterminals, where the latter
  4718 may only occur in 'syntax' specifications or type abbreviations.
  4719 Before that distinction was only partially implemented via type class
  4720 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  4721 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  4722 exotic syntax specifications may require further adaption
  4723 (e.g. Cube/Cube.thy).
  4724 
  4725 * Removed obsolete type class "logic", use the top sort {} instead.
  4726 Note that non-logical types should be declared as 'nonterminals'
  4727 rather than 'types'.  INCOMPATIBILITY for new object-logic
  4728 specifications.
  4729 
  4730 * Attributes 'induct' and 'cases': type or set names may now be
  4731 locally fixed variables as well.
  4732 
  4733 * Simplifier: can now control the depth to which conditional rewriting
  4734 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  4735 Limit.
  4736 
  4737 * Simplifier: simplification procedures may now take the current
  4738 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  4739 interface), which is very useful for calling the Simplifier
  4740 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  4741 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  4742 low-level mk_simproc no longer applies Logic.varify internally, to
  4743 allow for use in a context of fixed variables.
  4744 
  4745 * thin_tac now works even if the assumption being deleted contains !!
  4746 or ==>.  More generally, erule now works even if the major premise of
  4747 the elimination rule contains !! or ==>.
  4748 
  4749 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  4750 
  4751 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  4752 from Pure, which contains all common declarations already.  Both
  4753 theories are defined via plain Isabelle/Isar .thy files.
  4754 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  4755 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  4756 use isatool fixcpure to adapt your theory and ML sources.
  4757 
  4758 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  4759 selections of theorems in named facts via index ranges.
  4760 
  4761 * 'print_theorems': in theory mode, really print the difference
  4762 wrt. the last state (works for interactive theory development only),
  4763 in proof mode print all local facts (cf. 'print_facts');
  4764 
  4765 * 'hide': option '(open)' hides only base names.
  4766 
  4767 * More efficient treatment of intermediate checkpoints in interactive
  4768 theory development.
  4769 
  4770 * Code generator is now invoked via code_module (incremental code
  4771 generation) and code_library (modular code generation, ML structures
  4772 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  4773 must be quoted when used as identifiers.
  4774 
  4775 * New 'value' command for reading, evaluating and printing terms using
  4776 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  4777 quoted when used as identifier.
  4778 
  4779 
  4780 *** Locales ***
  4781 
  4782 * New commands for the interpretation of locale expressions in
  4783 theories (1), locales (2) and proof contexts (3).  These generate
  4784 proof obligations from the expression specification.  After the
  4785 obligations have been discharged, theorems of the expression are added
  4786 to the theory, target locale or proof context.  The synopsis of the
  4787 commands is a follows:
  4788 
  4789   (1) interpretation expr inst
  4790   (2) interpretation target < expr
  4791   (3) interpret expr inst
  4792 
  4793 Interpretation in theories and proof contexts require a parameter
  4794 instantiation of terms from the current context.  This is applied to
  4795 specifications and theorems of the interpreted expression.
  4796 Interpretation in locales only permits parameter renaming through the
  4797 locale expression.  Interpretation is smart in that interpretations
  4798 that are active already do not occur in proof obligations, neither are
  4799 instantiated theorems stored in duplicate.  Use 'print_interps' to
  4800 inspect active interpretations of a particular locale.  For details,
  4801 see the Isar Reference manual.  Examples can be found in
  4802 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  4803 
  4804 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  4805 'interpret' instead.
  4806 
  4807 * New context element 'constrains' for adding type constraints to
  4808 parameters.
  4809 
  4810 * Context expressions: renaming of parameters with syntax
  4811 redeclaration.
  4812 
  4813 * Locale declaration: 'includes' disallowed.
  4814 
  4815 * Proper static binding of attribute syntax -- i.e. types / terms /
  4816 facts mentioned as arguments are always those of the locale definition
  4817 context, independently of the context of later invocations.  Moreover,
  4818 locale operations (renaming and type / term instantiation) are applied
  4819 to attribute arguments as expected.
  4820 
  4821 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  4822 actual attributes; rare situations may require Attrib.attribute to
  4823 embed those attributes into Attrib.src that lack concrete syntax.
  4824 Attribute implementations need to cooperate properly with the static
  4825 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  4826 Attrib.XXX_thm etc. already do the right thing without further
  4827 intervention.  Only unusual applications -- such as "where" or "of"
  4828 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  4829 on the context and the facts involved -- may have to assign parsed
  4830 values to argument tokens explicitly.
  4831 
  4832 * Changed parameter management in theorem generation for long goal
  4833 statements with 'includes'.  INCOMPATIBILITY: produces a different
  4834 theorem statement in rare situations.
  4835 
  4836 * Locale inspection command 'print_locale' omits notes elements.  Use
  4837 'print_locale!' to have them included in the output.
  4838 
  4839 
  4840 *** Provers ***
  4841 
  4842 * Provers/hypsubst.ML: improved version of the subst method, for
  4843 single-step rewriting: it now works in bound variable contexts. New is
  4844 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  4845 rewrite a different subterm than the original subst method, which is
  4846 still available as 'simplesubst'.
  4847 
  4848 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  4849 and quasi orders.
  4850 
  4851 * Provers/trancl.ML: new transitivity reasoner for transitive and
  4852 reflexive-transitive closure of relations.
  4853 
  4854 * Provers/blast.ML: new reference depth_limit to make blast's depth
  4855 limit (previously hard-coded with a value of 20) user-definable.
  4856 
  4857 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  4858 is peformed already.  Object-logics merely need to finish their
  4859 initial simpset configuration as before.  INCOMPATIBILITY.
  4860 
  4861 
  4862 *** HOL ***
  4863 
  4864 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  4865 
  4866   syntax (epsilon)
  4867     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  4868 
  4869 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  4870 and x-symbol; use option '-m epsilon' to get it actually printed.
  4871 Moreover, the mathematically important symbolic identifier \<epsilon>
  4872 becomes available as variable, constant etc.  INCOMPATIBILITY,
  4873 
  4874 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  4875 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  4876 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  4877 support corresponding Isar calculations.
  4878 
  4879 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  4880 instead of ":".
  4881 
  4882 * theory SetInterval: changed the syntax for open intervals:
  4883 
  4884   Old       New
  4885   {..n(}    {..<n}
  4886   {)n..}    {n<..}
  4887   {m..n(}   {m..<n}
  4888   {)m..n}   {m<..n}
  4889   {)m..n(}  {m<..<n}
  4890 
  4891 The old syntax is still supported but will disappear in the next
  4892 release.  For conversion use the following Emacs search and replace
  4893 patterns (these are not perfect but work quite well):
  4894 
  4895   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  4896   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  4897 
  4898 * Theory Commutative_Ring (in Library): method comm_ring for proving
  4899 equalities in commutative rings; method 'algebra' provides a generic
  4900 interface.
  4901 
  4902 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  4903 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  4904 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  4905 be a tuple pattern.
  4906 
  4907 Some new syntax forms are available:
  4908 
  4909   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  4910   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  4911   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  4912   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  4913 
  4914 The latter form "\<Sum>x < k. e" used to be based on a separate
  4915 function "Summation", which has been discontinued.
  4916 
  4917 * theory Finite_Set: in structured induction proofs, the insert case
  4918 is now 'case (insert x F)' instead of the old counterintuitive 'case
  4919 (insert F x)'.
  4920 
  4921 * The 'refute' command has been extended to support a much larger
  4922 fragment of HOL, including axiomatic type classes, constdefs and
  4923 typedefs, inductive datatypes and recursion.
  4924 
  4925 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  4926 Requires zChaff with proof generation to be installed.  See
  4927 HOL/ex/SAT_Examples.thy for examples.
  4928 
  4929 * Datatype induction via method 'induct' now preserves the name of the
  4930 induction variable. For example, when proving P(xs::'a list) by
  4931 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  4932 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  4933 in unstructured proof scripts.
  4934 
  4935 * Reworked implementation of records.  Improved scalability for
  4936 records with many fields, avoiding performance problems for type
  4937 inference. Records are no longer composed of nested field types, but
  4938 of nested extension types. Therefore the record type only grows linear
  4939 in the number of extensions and not in the number of fields.  The
  4940 top-level (users) view on records is preserved.  Potential
  4941 INCOMPATIBILITY only in strange cases, where the theory depends on the
  4942 old record representation. The type generated for a record is called
  4943 <record_name>_ext_type.
  4944 
  4945 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  4946 proofs triggered by a record definition or a simproc (if
  4947 quick_and_dirty is enabled).  Definitions of large records can take
  4948 quite long.
  4949 
  4950 New simproc record_upd_simproc for simplification of multiple record
  4951 updates enabled by default.  Moreover, trivial updates are also
  4952 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  4953 occasionally, since simplification is more powerful by default.
  4954 
  4955 * typedef: proper support for polymorphic sets, which contain extra
  4956 type-variables in the term.
  4957 
  4958 * Simplifier: automatically reasons about transitivity chains
  4959 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  4960 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  4961 old proofs break occasionally as simplification may now solve more
  4962 goals than previously.
  4963 
  4964 * Simplifier: converts x <= y into x = y if assumption y <= x is
  4965 present.  Works for all partial orders (class "order"), in particular
  4966 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  4967 just like y <= x.
  4968 
  4969 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  4970 bound variable or a constant then the let is unfolded.  Otherwise
  4971 first a is simplified to b, and then f b is simplified to g. If
  4972 possible we abstract b from g arriving at "let x = b in h x",
  4973 otherwise we unfold the let and arrive at g.  The simproc can be
  4974 enabled/disabled by the reference use_let_simproc.  Potential
  4975 INCOMPATIBILITY since simplification is more powerful by default.
  4976 
  4977 * Classical reasoning: the meson method now accepts theorems as arguments.
  4978 
  4979 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  4980 jobs to provide advice on the provability of subgoals.
  4981 
  4982 * Theory OrderedGroup and Ring_and_Field: various additions and
  4983 improvements to faciliate calculations involving equalities and
  4984 inequalities.
  4985 
  4986 The following theorems have been eliminated or modified
  4987 (INCOMPATIBILITY):
  4988 
  4989   abs_eq             now named abs_of_nonneg
  4990   abs_of_ge_0        now named abs_of_nonneg
  4991   abs_minus_eq       now named abs_of_nonpos
  4992   imp_abs_id         now named abs_of_nonneg
  4993   imp_abs_neg_id     now named abs_of_nonpos
  4994   mult_pos           now named mult_pos_pos
  4995   mult_pos_le        now named mult_nonneg_nonneg
  4996   mult_pos_neg_le    now named mult_nonneg_nonpos
  4997   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  4998   mult_neg           now named mult_neg_neg
  4999   mult_neg_le        now named mult_nonpos_nonpos
  5000 
  5001 * The following lemmas in Ring_and_Field have been added to the simplifier:
  5002      
  5003      zero_le_square
  5004      not_square_less_zero 
  5005 
  5006   The following lemmas have been deleted from Real/RealPow:
  5007   
  5008      realpow_zero_zero
  5009      realpow_two
  5010      realpow_less
  5011      zero_le_power
  5012      realpow_two_le
  5013      abs_realpow_two
  5014      realpow_two_abs     
  5015 
  5016 * Theory Parity: added rules for simplifying exponents.
  5017 
  5018 * Theory List:
  5019 
  5020 The following theorems have been eliminated or modified
  5021 (INCOMPATIBILITY):
  5022 
  5023   list_all_Nil       now named list_all.simps(1)
  5024   list_all_Cons      now named list_all.simps(2)
  5025   list_all_conv      now named list_all_iff
  5026   set_mem_eq         now named mem_iff
  5027 
  5028 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  5029 asymptotic "big O" calculations.  See the notes in BigO.thy.
  5030 
  5031 
  5032 *** HOL-Complex ***
  5033 
  5034 * Theory RealDef: better support for embedding natural numbers and
  5035 integers in the reals.
  5036 
  5037 The following theorems have been eliminated or modified
  5038 (INCOMPATIBILITY):
  5039 
  5040   exp_ge_add_one_self  now requires no hypotheses
  5041   real_of_int_add      reversed direction of equality (use [symmetric])
  5042   real_of_int_minus    reversed direction of equality (use [symmetric])
  5043   real_of_int_diff     reversed direction of equality (use [symmetric])
  5044   real_of_int_mult     reversed direction of equality (use [symmetric])
  5045 
  5046 * Theory RComplete: expanded support for floor and ceiling functions.
  5047 
  5048 * Theory Ln is new, with properties of the natural logarithm
  5049 
  5050 * Hyperreal: There is a new type constructor "star" for making
  5051 nonstandard types.  The old type names are now type synonyms:
  5052 
  5053   hypreal = real star
  5054   hypnat = nat star
  5055   hcomplex = complex star
  5056 
  5057 * Hyperreal: Many groups of similarly-defined constants have been
  5058 replaced by polymorphic versions (INCOMPATIBILITY):
  5059 
  5060   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  5061 
  5062   starset      <-- starsetNat, starsetC
  5063   *s*          <-- *sNat*, *sc*
  5064   starset_n    <-- starsetNat_n, starsetC_n
  5065   *sn*         <-- *sNatn*, *scn*
  5066   InternalSets <-- InternalNatSets, InternalCSets
  5067 
  5068   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  5069   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  5070   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  5071   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  5072   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  5073 
  5074 * Hyperreal: Many type-specific theorems have been removed in favor of
  5075 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  5076 
  5077   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  5078   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  5079   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  5080   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  5081   right_minus <-- hypreal_add_minus
  5082   left_minus <-- {hypreal,hcomplex}_add_minus_left
  5083   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  5084   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  5085   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  5086   mult_1_right <-- hcomplex_mult_one_right
  5087   mult_zero_left <-- hcomplex_mult_zero_left
  5088   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  5089   right_distrib <-- hypnat_add_mult_distrib2
  5090   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  5091   right_inverse <-- hypreal_mult_inverse
  5092   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  5093   order_refl <-- {hypreal,hypnat}_le_refl
  5094   order_trans <-- {hypreal,hypnat}_le_trans
  5095   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  5096   order_less_le <-- {hypreal,hypnat}_less_le
  5097   linorder_linear <-- {hypreal,hypnat}_le_linear
  5098   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  5099   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  5100   add_nonneg_nonneg <-- hypreal_le_add_order
  5101 
  5102 * Hyperreal: Separate theorems having to do with type-specific
  5103 versions of constants have been merged into theorems that apply to the
  5104 new polymorphic constants (INCOMPATIBILITY):
  5105 
  5106   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  5107   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  5108   STAR_Un <-- {STAR,NatStar,STARC}_Un
  5109   STAR_Int <-- {STAR,NatStar,STARC}_Int
  5110   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  5111   STAR_subset <-- {STAR,NatStar,STARC}_subset
  5112   STAR_mem <-- {STAR,NatStar,STARC}_mem
  5113   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  5114   STAR_diff <-- {STAR,STARC}_diff
  5115   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  5116     STARC_hcomplex_of_complex}_image_subset
  5117   starset_n_Un <-- starset{Nat,C}_n_Un
  5118   starset_n_Int <-- starset{Nat,C}_n_Int
  5119   starset_n_Compl <-- starset{Nat,C}_n_Compl
  5120   starset_n_diff <-- starset{Nat,C}_n_diff
  5121   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  5122   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  5123   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  5124   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  5125   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  5126   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  5127   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  5128   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  5129   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  5130   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  5131   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  5132   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  5133   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  5134   starfun_diff <-- starfun{C,RC,CR}_diff
  5135   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  5136   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  5137   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  5138   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  5139   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  5140   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  5141   starfun_Id <-- starfunC_Id
  5142   starfun_approx <-- starfun{Nat,CR}_approx
  5143   starfun_capprox <-- starfun{C,RC}_capprox
  5144   starfun_abs <-- starfunNat_rabs
  5145   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  5146   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  5147   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  5148   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  5149   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  5150   starfun_add_approx <-- starfunCR_add_approx
  5151   starfun_inverse_inverse <-- starfunC_inverse_inverse
  5152   starfun_divide <-- starfun{C,CR,RC}_divide
  5153   starfun_n <-- starfun{Nat,C}_n
  5154   starfun_n_mult <-- starfun{Nat,C}_n_mult
  5155   starfun_n_add <-- starfun{Nat,C}_n_add
  5156   starfun_n_add_minus <-- starfunNat_n_add_minus
  5157   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  5158   starfun_n_minus <-- starfun{Nat,C}_n_minus
  5159   starfun_n_eq <-- starfun{Nat,C}_n_eq
  5160 
  5161   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  5162   star_n_minus <-- {hypreal,hcomplex}_minus
  5163   star_n_diff <-- {hypreal,hcomplex}_diff
  5164   star_n_mult <-- {hypreal,hcomplex}_mult
  5165   star_n_inverse <-- {hypreal,hcomplex}_inverse
  5166   star_n_le <-- {hypreal,hypnat}_le
  5167   star_n_less <-- {hypreal,hypnat}_less
  5168   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  5169   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  5170   star_n_abs <-- hypreal_hrabs
  5171   star_n_divide <-- hcomplex_divide
  5172 
  5173   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  5174   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  5175   star_of_diff <-- hypreal_of_real_diff
  5176   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  5177   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  5178   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  5179   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  5180   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  5181   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  5182   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  5183   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  5184   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  5185   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  5186   star_of_number_of <-- {hypreal,hcomplex}_number_of
  5187   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  5188   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  5189   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  5190   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  5191   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  5192   star_of_power <-- hypreal_of_real_power
  5193   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  5194 
  5195 * Hyperreal: new method "transfer" that implements the transfer
  5196 principle of nonstandard analysis. With a subgoal that mentions
  5197 nonstandard types like "'a star", the command "apply transfer"
  5198 replaces it with an equivalent one that mentions only standard types.
  5199 To be successful, all free variables must have standard types; non-
  5200 standard variables must have explicit universal quantifiers.
  5201 
  5202 * Hyperreal: A theory of Taylor series.
  5203 
  5204 
  5205 *** HOLCF ***
  5206 
  5207 * Discontinued special version of 'constdefs' (which used to support
  5208 continuous functions) in favor of the general Pure one with full
  5209 type-inference.
  5210 
  5211 * New simplification procedure for solving continuity conditions; it
  5212 is much faster on terms with many nested lambda abstractions (cubic
  5213 instead of exponential time).
  5214 
  5215 * New syntax for domain package: selector names are now optional.
  5216 Parentheses should be omitted unless argument is lazy, for example:
  5217 
  5218   domain 'a stream = cons "'a" (lazy "'a stream")
  5219 
  5220 * New command 'fixrec' for defining recursive functions with pattern
  5221 matching; defining multiple functions with mutual recursion is also
  5222 supported.  Patterns may include the constants cpair, spair, up, sinl,
  5223 sinr, or any data constructor defined by the domain package. The given
  5224 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  5225 syntax and examples.
  5226 
  5227 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  5228 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  5229 but the proof obligation additionally includes an admissibility
  5230 requirement. The packages generate instances of class cpo or pcpo,
  5231 with continuity and strictness theorems for Rep and Abs.
  5232 
  5233 * HOLCF: Many theorems have been renamed according to a more standard naming
  5234 scheme (INCOMPATIBILITY):
  5235 
  5236   foo_inject:  "foo$x = foo$y ==> x = y"
  5237   foo_eq:      "(foo$x = foo$y) = (x = y)"
  5238   foo_less:    "(foo$x << foo$y) = (x << y)"
  5239   foo_strict:  "foo$UU = UU"
  5240   foo_defined: "... ==> foo$x ~= UU"
  5241   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  5242 
  5243 
  5244 *** ZF ***
  5245 
  5246 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  5247 including the First Isomorphism Theorem (on quotienting by the kernel
  5248 of a homomorphism).
  5249 
  5250 * ZF/Simplifier: install second copy of type solver that actually
  5251 makes use of TC rules declared to Isar proof contexts (or locales);
  5252 the old version is still required for ML proof scripts.
  5253 
  5254 
  5255 *** Cube ***
  5256 
  5257 * Converted to Isar theory format; use locales instead of axiomatic
  5258 theories.
  5259 
  5260 
  5261 *** ML ***
  5262 
  5263 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  5264 for ||>, ||>>, |>>,
  5265 
  5266 * Pure/library.ML no longer defines its own option datatype, but uses
  5267 that of the SML basis, which has constructors NONE and SOME instead of
  5268 None and Some, as well as exception Option.Option instead of OPTION.
  5269 The functions the, if_none, is_some, is_none have been adapted
  5270 accordingly, while Option.map replaces apsome.
  5271 
  5272 * Pure/library.ML: the exception LIST has been given up in favour of
  5273 the standard exceptions Empty and Subscript, as well as
  5274 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  5275 superceded by the standard hd and tl functions etc.
  5276 
  5277 A number of basic list functions are no longer exported to the ML
  5278 toplevel, as they are variants of predefined functions.  The following
  5279 suggests how one can translate existing code:
  5280 
  5281     rev_append xs ys = List.revAppend (xs, ys)
  5282     nth_elem (i, xs) = List.nth (xs, i)
  5283     last_elem xs = List.last xs
  5284     flat xss = List.concat xss
  5285     seq fs = List.app fs
  5286     partition P xs = List.partition P xs
  5287     mapfilter f xs = List.mapPartial f xs
  5288 
  5289 * Pure/library.ML: several combinators for linear functional
  5290 transformations, notably reverse application and composition:
  5291 
  5292   x |> f                f #> g
  5293   (x, y) |-> f          f #-> g
  5294 
  5295 * Pure/library.ML: introduced/changed precedence of infix operators:
  5296 
  5297   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  5298   infix 2 ?;
  5299   infix 3 o oo ooo oooo;
  5300   infix 4 ~~ upto downto;
  5301 
  5302 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  5303 infix operators.
  5304 
  5305 * Pure/library.ML: natural list combinators fold, fold_rev, and
  5306 fold_map support linear functional transformations and nesting.  For
  5307 example:
  5308 
  5309   fold f [x1, ..., xN] y =
  5310     y |> f x1 |> ... |> f xN
  5311 
  5312   (fold o fold) f [xs1, ..., xsN] y =
  5313     y |> fold f xs1 |> ... |> fold f xsN
  5314 
  5315   fold f [x1, ..., xN] =
  5316     f x1 #> ... #> f xN
  5317 
  5318   (fold o fold) f [xs1, ..., xsN] =
  5319     fold f xs1 #> ... #> fold f xsN
  5320 
  5321 * Pure/library.ML: the following selectors on type 'a option are
  5322 available:
  5323 
  5324   the:               'a option -> 'a  (*partial*)
  5325   these:             'a option -> 'a  where 'a = 'b list
  5326   the_default: 'a -> 'a option -> 'a
  5327   the_list:          'a option -> 'a list
  5328 
  5329 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5330 basic operations for association lists, following natural argument
  5331 order; moreover the explicit equality predicate passed here avoids
  5332 potentially expensive polymorphic runtime equality checks.
  5333 The old functions may be expressed as follows:
  5334 
  5335   assoc = uncurry (AList.lookup (op =))
  5336   assocs = these oo AList.lookup (op =)
  5337   overwrite = uncurry (AList.update (op =)) o swap
  5338 
  5339 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5340 
  5341   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  5342   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  5343 
  5344 replacing make_keylist and keyfilter (occassionally used)
  5345 Naive rewrites:
  5346 
  5347   make_keylist = AList.make
  5348   keyfilter = AList.find (op =)
  5349 
  5350 * eq_fst and eq_snd now take explicit equality parameter, thus
  5351   avoiding eqtypes. Naive rewrites:
  5352 
  5353     eq_fst = eq_fst (op =)
  5354     eq_snd = eq_snd (op =)
  5355 
  5356 * Removed deprecated apl and apr (rarely used).
  5357   Naive rewrites:
  5358 
  5359     apl (n, op) =>>= curry op n
  5360     apr (op, m) =>>= fn n => op (n, m)
  5361 
  5362 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  5363 provides a reasonably efficient light-weight implementation of sets as
  5364 lists.
  5365 
  5366 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  5367 few new operations; existing lookup and update are now curried to
  5368 follow natural argument order (for use with fold etc.);
  5369 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  5370 
  5371 * Pure/General: output via the Isabelle channels of
  5372 writeln/warning/error etc. is now passed through Output.output, with a
  5373 hook for arbitrary transformations depending on the print_mode
  5374 (cf. Output.add_mode -- the first active mode that provides a output
  5375 function wins).  Already formatted output may be embedded into further
  5376 text via Output.raw; the result of Pretty.string_of/str_of and derived
  5377 functions (string_of_term/cterm/thm etc.) is already marked raw to
  5378 accommodate easy composition of diagnostic messages etc.  Programmers
  5379 rarely need to care about Output.output or Output.raw at all, with
  5380 some notable exceptions: Output.output is required when bypassing the
  5381 standard channels (writeln etc.), or in token translations to produce
  5382 properly formatted results; Output.raw is required when capturing
  5383 already output material that will eventually be presented to the user
  5384 a second time.  For the default print mode, both Output.output and
  5385 Output.raw have no effect.
  5386 
  5387 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  5388 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  5389 cumulative results are displayed at the end of a batch session.
  5390 
  5391 * Pure/General: File.sysify_path and File.quote_sysify path have been
  5392 replaced by File.platform_path and File.shell_path (with appropriate
  5393 hooks).  This provides a clean interface for unusual systems where the
  5394 internal and external process view of file names are different.
  5395 
  5396 * Pure: more efficient orders for basic syntactic entities: added
  5397 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  5398 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  5399 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  5400 orders now -- potential INCOMPATIBILITY for code that depends on a
  5401 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  5402 Library.sort_strings on result).
  5403 
  5404 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  5405 fold_types traverse types/terms from left to right, observing natural
  5406 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  5407 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  5408 
  5409 * Pure: name spaces have been refined, with significant changes of the
  5410 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  5411 to extern(_table).  The plain name entry path is superceded by a
  5412 general 'naming' context, which also includes the 'policy' to produce
  5413 a fully qualified name and external accesses of a fully qualified
  5414 name; NameSpace.extend is superceded by context dependent
  5415 Sign.declare_name.  Several theory and proof context operations modify
  5416 the naming context.  Especially note Theory.restore_naming and
  5417 ProofContext.restore_naming to get back to a sane state; note that
  5418 Theory.add_path is no longer sufficient to recover from
  5419 Theory.absolute_path in particular.
  5420 
  5421 * Pure: new flags short_names (default false) and unique_names
  5422 (default true) for controlling output of qualified names.  If
  5423 short_names is set, names are printed unqualified.  If unique_names is
  5424 reset, the name prefix is reduced to the minimum required to achieve
  5425 the original result when interning again, even if there is an overlap
  5426 with earlier declarations.
  5427 
  5428 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  5429 now 'extend', and 'merge' gets an additional Pretty.pp argument
  5430 (useful for printing error messages).  INCOMPATIBILITY.
  5431 
  5432 * Pure: major reorganization of the theory context.  Type Sign.sg and
  5433 Theory.theory are now identified, referring to the universal
  5434 Context.theory (see Pure/context.ML).  Actual signature and theory
  5435 content is managed as theory data.  The old code and interfaces were
  5436 spread over many files and structures; the new arrangement introduces
  5437 considerable INCOMPATIBILITY to gain more clarity:
  5438 
  5439   Context -- theory management operations (name, identity, inclusion,
  5440     parents, ancestors, merge, etc.), plus generic theory data;
  5441 
  5442   Sign -- logical signature and syntax operations (declaring consts,
  5443     types, etc.), plus certify/read for common entities;
  5444 
  5445   Theory -- logical theory operations (stating axioms, definitions,
  5446     oracles), plus a copy of logical signature operations (consts,
  5447     types, etc.); also a few basic management operations (Theory.copy,
  5448     Theory.merge, etc.)
  5449 
  5450 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  5451 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  5452 for convenience -- they merely return the theory.
  5453 
  5454 * Pure: type Type.tsig is superceded by theory in most interfaces.
  5455 
  5456 * Pure: the Isar proof context type is already defined early in Pure
  5457 as Context.proof (note that ProofContext.context and Proof.context are
  5458 aliases, where the latter is the preferred name).  This enables other
  5459 Isabelle components to refer to that type even before Isar is present.
  5460 
  5461 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  5462 typeK, constK, axiomK, oracleK), but provide explicit operations for
  5463 any of these kinds.  For example, Sign.intern typeK is now
  5464 Sign.intern_type, Theory.hide_space Sign.typeK is now
  5465 Theory.hide_types.  Also note that former
  5466 Theory.hide_classes/types/consts are now
  5467 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  5468 internalize their arguments!  INCOMPATIBILITY.
  5469 
  5470 * Pure: get_thm interface (of PureThy and ProofContext) expects
  5471 datatype thmref (with constructors Name and NameSelection) instead of
  5472 plain string -- INCOMPATIBILITY;
  5473 
  5474 * Pure: cases produced by proof methods specify options, where NONE
  5475 means to remove case bindings -- INCOMPATIBILITY in
  5476 (RAW_)METHOD_CASES.
  5477 
  5478 * Pure: the following operations retrieve axioms or theorems from a
  5479 theory node or theory hierarchy, respectively:
  5480 
  5481   Theory.axioms_of: theory -> (string * term) list
  5482   Theory.all_axioms_of: theory -> (string * term) list
  5483   PureThy.thms_of: theory -> (string * thm) list
  5484   PureThy.all_thms_of: theory -> (string * thm) list
  5485 
  5486 * Pure: print_tac now outputs the goal through the trace channel.
  5487 
  5488 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  5489 Reference Toplevel.debug (default false) controls detailed printing
  5490 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  5491 controls execution profiling -- set to 1 for time and 2 for space
  5492 (both increase the runtime).
  5493 
  5494 * Isar session: The initial use of ROOT.ML is now always timed,
  5495 i.e. the log will show the actual process times, in contrast to the
  5496 elapsed wall-clock time that the outer shell wrapper produces.
  5497 
  5498 * Simplifier: improved handling of bound variables (nameless
  5499 representation, avoid allocating new strings).  Simprocs that invoke
  5500 the Simplifier recursively should use Simplifier.inherit_bounds to
  5501 avoid local name clashes.  Failure to do so produces warnings
  5502 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  5503 for further details.
  5504 
  5505 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  5506 bindings for all theorems stored within a given theory; this may help
  5507 in porting non-Isar theories to Isar ones, while keeping ML proof
  5508 scripts for the time being.
  5509 
  5510 * ML operator HTML.with_charset specifies the charset begin used for
  5511 generated HTML files.  For example:
  5512 
  5513   HTML.with_charset "utf-8" use_thy "Hebrew";
  5514   HTML.with_charset "utf-8" use_thy "Chinese";
  5515 
  5516 
  5517 *** System ***
  5518 
  5519 * Allow symlinks to all proper Isabelle executables (Isabelle,
  5520 isabelle, isatool etc.).
  5521 
  5522 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  5523 isatool doc, isatool mkdir, display_drafts etc.).
  5524 
  5525 * isatool usedir: option -f allows specification of the ML file to be
  5526 used by Isabelle; default is ROOT.ML.
  5527 
  5528 * New isatool version outputs the version identifier of the Isabelle
  5529 distribution being used.
  5530 
  5531 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  5532 (containing Boolean satisfiability problems) into Isabelle/HOL
  5533 theories.
  5534 
  5535 
  5536 
  5537 New in Isabelle2004 (April 2004)
  5538 --------------------------------
  5539 
  5540 *** General ***
  5541 
  5542 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  5543   Replaces linorder.ML.
  5544 
  5545 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  5546   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  5547   (\<a>...\<z>), are now considered normal letters, and can therefore
  5548   be used anywhere where an ASCII letter (a...zA...Z) has until
  5549   now. COMPATIBILITY: This obviously changes the parsing of some
  5550   terms, especially where a symbol has been used as a binder, say
  5551   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  5552   as an identifier.  Fix it by inserting a space around former
  5553   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  5554   existing theory and ML files.
  5555 
  5556 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  5557 
  5558 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  5559   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  5560   a normal (but invisible) letter. For multiple letter subscripts repeat
  5561   \<^isub> like this: x\<^isub>1\<^isub>2.
  5562 
  5563 * Pure: There are now sub-/superscripts that can span more than one
  5564   character. Text between \<^bsub> and \<^esub> is set in subscript in
  5565   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  5566   superscript. The new control characters are not identifier parts.
  5567 
  5568 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  5569   content of "..." to the latex file instead of \isacntrl... . The "..."
  5570   may consist of any printable characters excluding the end bracket >.
  5571 
  5572 * Pure: Using new Isar command "finalconsts" (or the ML functions
  5573   Theory.add_finals or Theory.add_finals_i) it is now possible to
  5574   declare constants "final", which prevents their being given a definition
  5575   later.  It is useful for constants whose behaviour is fixed axiomatically
  5576   rather than definitionally, such as the meta-logic connectives.
  5577 
  5578 * Pure: 'instance' now handles general arities with general sorts
  5579   (i.e. intersections of classes),
  5580 
  5581 * Presentation: generated HTML now uses a CSS style sheet to make layout
  5582   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  5583   It can be changed to alter the colors/layout of generated pages.
  5584 
  5585 
  5586 *** Isar ***
  5587 
  5588 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  5589   cut_tac, subgoal_tac and thin_tac:
  5590   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  5591     locales are no longer forced to write Isar proof scripts.
  5592     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  5593     emulations.
  5594   - INCOMPATIBILITY: names of variables to be instantiated may no
  5595     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  5596     This is consistent with the instantiation attribute "where".
  5597 
  5598 * Attributes "where" and "of":
  5599   - Now take type variables of instantiated theorem into account when reading
  5600     the instantiation string.  This fixes a bug that caused instantiated
  5601     theorems to have too special types in some circumstances.
  5602   - "where" permits explicit instantiations of type variables.
  5603 
  5604 * Calculation commands "moreover" and "also" no longer interfere with
  5605   current facts ("this"), admitting arbitrary combinations with "then"
  5606   and derived forms.
  5607 
  5608 * Locales:
  5609   - Goal statements involving the context element "includes" no longer
  5610     generate theorems with internal delta predicates (those ending on
  5611     "_axioms") in the premise.
  5612     Resolve particular premise with <locale>.intro to obtain old form.
  5613   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  5614     specification and "includes" elements in goal statement.
  5615   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  5616     [intro?] and [elim?] (respectively) by default.
  5617   - Experimental command for instantiation of locales in proof contexts:
  5618         instantiate <label>[<attrs>]: <loc>
  5619     Instantiates locale <loc> and adds all its theorems to the current context
  5620     taking into account their attributes.  Label and attrs are optional
  5621     modifiers, like in theorem declarations.  If present, names of
  5622     instantiated theorems are qualified with <label>, and the attributes
  5623     <attrs> are applied after any attributes these theorems might have already.
  5624       If the locale has assumptions, a chained fact of the form
  5625     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  5626     are derived.  The command does not support old-style locales declared
  5627     with "locale (open)".
  5628       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  5629 
  5630 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  5631   (Isar) contexts.
  5632 
  5633 
  5634 *** HOL ***
  5635 
  5636 * Proof import: new image HOL4 contains the imported library from
  5637   the HOL4 system with about 2500 theorems. It is imported by
  5638   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  5639   can be used like any other Isabelle image.  See
  5640   HOL/Import/HOL/README for more information.
  5641 
  5642 * Simplifier:
  5643   - Much improved handling of linear and partial orders.
  5644     Reasoners for linear and partial orders are set up for type classes
  5645     "linorder" and "order" respectively, and are added to the default simpset
  5646     as solvers.  This means that the simplifier can build transitivity chains
  5647     to solve goals from the assumptions.
  5648   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  5649     of blast or auto after simplification become unnecessary because the goal
  5650     is solved by simplification already.
  5651 
  5652 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  5653     all proved in axiomatic type classes for semirings, rings and fields.
  5654 
  5655 * Numerics:
  5656   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  5657     now formalized using the Ring_and_Field theory mentioned above.
  5658   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  5659     than before, because now they are set up once in a generic manner.
  5660   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  5661     Look for the general versions in Ring_and_Field (and Power if they concern
  5662     exponentiation).
  5663 
  5664 * Type "rat" of the rational numbers is now available in HOL-Complex.
  5665 
  5666 * Records:
  5667   - Record types are now by default printed with their type abbreviation
  5668     instead of the list of all field types. This can be configured via
  5669     the reference "print_record_type_abbr".
  5670   - Simproc "record_upd_simproc" for simplification of multiple updates added
  5671     (not enabled by default).
  5672   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  5673     EX x. x = sel r to True (not enabled by default).
  5674   - Tactic "record_split_simp_tac" to split and simplify records added.
  5675 
  5676 * 'specification' command added, allowing for definition by
  5677   specification.  There is also an 'ax_specification' command that
  5678   introduces the new constants axiomatically.
  5679 
  5680 * arith(_tac) is now able to generate counterexamples for reals as well.
  5681 
  5682 * HOL-Algebra: new locale "ring" for non-commutative rings.
  5683 
  5684 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  5685   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  5686 
  5687 * HOL-Matrix: a first theory for matrices in HOL with an application of
  5688   matrix theory to linear programming.
  5689 
  5690 * Unions and Intersections:
  5691   The latex output syntax of UN and INT has been changed
  5692   from "\Union x \in A. B" to "\Union_{x \in A} B"
  5693   i.e. the index formulae has become a subscript.
  5694   Similarly for "\Union x. B", and for \Inter instead of \Union.
  5695 
  5696 * Unions and Intersections over Intervals:
  5697   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  5698   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  5699   like in normal math, and corresponding versions for < and for intersection.
  5700 
  5701 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  5702   lexicographic dictonary ordering has been added as "lexord".
  5703 
  5704 * ML: the legacy theory structures Int and List have been removed. They had
  5705   conflicted with ML Basis Library structures having the same names.
  5706 
  5707 * 'refute' command added to search for (finite) countermodels.  Only works
  5708   for a fragment of HOL.  The installation of an external SAT solver is
  5709   highly recommended.  See "HOL/Refute.thy" for details.
  5710 
  5711 * 'quickcheck' command: Allows to find counterexamples by evaluating
  5712   formulae under an assignment of free variables to random values.
  5713   In contrast to 'refute', it can deal with inductive datatypes,
  5714   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  5715   for examples.
  5716 
  5717 
  5718 *** HOLCF ***
  5719 
  5720 * Streams now come with concatenation and are part of the HOLCF image
  5721 
  5722 
  5723 
  5724 New in Isabelle2003 (May 2003)
  5725 ------------------------------
  5726 
  5727 *** General ***
  5728 
  5729 * Provers/simplifier:
  5730 
  5731   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  5732     Assumptions are now subject to complete mutual simplification,
  5733     not just from left to right. The simplifier now preserves
  5734     the order of assumptions.
  5735 
  5736     Potential INCOMPATIBILITY:
  5737 
  5738     -- simp sometimes diverges where the old version did
  5739        not, e.g. invoking simp on the goal
  5740 
  5741         [| P (f x); y = x; f x = f y |] ==> Q
  5742 
  5743        now gives rise to the infinite reduction sequence
  5744 
  5745         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  5746 
  5747        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  5748        kind of problem.
  5749 
  5750     -- Tactics combining classical reasoner and simplification (such as auto)
  5751        are also affected by this change, because many of them rely on
  5752        simp. They may sometimes diverge as well or yield a different numbers
  5753        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  5754        in case of problems. Sometimes subsequent calls to the classical
  5755        reasoner will fail because a preceeding call to the simplifier too
  5756        eagerly simplified the goal, e.g. deleted redundant premises.
  5757 
  5758   - The simplifier trace now shows the names of the applied rewrite rules
  5759 
  5760   - You can limit the number of recursive invocations of the simplifier
  5761     during conditional rewriting (where the simplifie tries to solve the
  5762     conditions before applying the rewrite rule):
  5763     ML "simp_depth_limit := n"
  5764     where n is an integer. Thus you can force termination where previously
  5765     the simplifier would diverge.
  5766 
  5767   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  5768 
  5769   - No longer aborts on failed congruence proof.  Instead, the
  5770     congruence is ignored.
  5771 
  5772 * Pure: New generic framework for extracting programs from constructive
  5773   proofs. See HOL/Extraction.thy for an example instantiation, as well
  5774   as HOL/Extraction for some case studies.
  5775 
  5776 * Pure: The main goal of the proof state is no longer shown by default, only
  5777 the subgoals. This behaviour is controlled by a new flag.
  5778    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  5779 (ML: Proof.show_main_goal).
  5780 
  5781 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  5782 rules whose conclusion matches subgoal 1:
  5783       PG menu: Isabelle/Isar -> Show me -> matching rules
  5784 The rules are ordered by how closely they match the subgoal.
  5785 In particular, rules that solve a subgoal outright are displayed first
  5786 (or rather last, the way they are printed).
  5787 (ML: ProofGeneral.print_intros())
  5788 
  5789 * Pure: New flag trace_unify_fail causes unification to print
  5790 diagnostic information (PG: in trace buffer) when it fails. This is
  5791 useful for figuring out why single step proofs like rule, erule or
  5792 assumption failed.
  5793 
  5794 * Pure: Locale specifications now produce predicate definitions
  5795 according to the body of text (covering assumptions modulo local
  5796 definitions); predicate "loc_axioms" covers newly introduced text,
  5797 while "loc" is cumulative wrt. all included locale expressions; the
  5798 latter view is presented only on export into the global theory
  5799 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  5800 on the old view without predicates;
  5801 
  5802 * Pure: predefined locales "var" and "struct" are useful for sharing
  5803 parameters (as in CASL, for example); just specify something like
  5804 ``var x + var y + struct M'' as import;
  5805 
  5806 * Pure: improved thms_containing: proper indexing of facts instead of
  5807 raw theorems; check validity of results wrt. current name space;
  5808 include local facts of proof configuration (also covers active
  5809 locales), cover fixed variables in index; may use "_" in term
  5810 specification; an optional limit for the number of printed facts may
  5811 be given (the default is 40);
  5812 
  5813 * Pure: disallow duplicate fact bindings within new-style theory files
  5814 (batch-mode only);
  5815 
  5816 * Provers: improved induct method: assumptions introduced by case
  5817 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  5818 the goal statement); "foo" still refers to all facts collectively;
  5819 
  5820 * Provers: the function blast.overloaded has been removed: all constants
  5821 are regarded as potentially overloaded, which improves robustness in exchange
  5822 for slight decrease in efficiency;
  5823 
  5824 * Provers/linorder: New generic prover for transitivity reasoning over
  5825 linear orders.  Note: this prover is not efficient!
  5826 
  5827 * Isar: preview of problems to finish 'show' now produce an error
  5828 rather than just a warning (in interactive mode);
  5829 
  5830 
  5831 *** HOL ***
  5832 
  5833 * arith(_tac)
  5834 
  5835  - Produces a counter example if it cannot prove a goal.
  5836    Note that the counter example may be spurious if the goal is not a formula
  5837    of quantifier-free linear arithmetic.
  5838    In ProofGeneral the counter example appears in the trace buffer.
  5839 
  5840  - Knows about div k and mod k where k is a numeral of type nat or int.
  5841 
  5842  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  5843    linear arithmetic fails. This takes account of quantifiers and divisibility.
  5844    Presburger arithmetic can also be called explicitly via presburger(_tac).
  5845 
  5846 * simp's arithmetic capabilities have been enhanced a bit: it now
  5847 takes ~= in premises into account (by performing a case split);
  5848 
  5849 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  5850 are distributed over a sum of terms;
  5851 
  5852 * New tactic "trans_tac" and method "trans" instantiate
  5853 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  5854 "<=", "<" and "=").
  5855 
  5856 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  5857 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  5858 
  5859 * 'typedef' command has new option "open" to suppress the set
  5860 definition;
  5861 
  5862 * functions Min and Max on finite sets have been introduced (theory
  5863 Finite_Set);
  5864 
  5865 * attribute [symmetric] now works for relations as well; it turns
  5866 (x,y) : R^-1 into (y,x) : R, and vice versa;
  5867 
  5868 * induct over a !!-quantified statement (say !!x1..xn):
  5869   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  5870 
  5871 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  5872 %x. None. Warning: empty_def now refers to the previously hidden definition
  5873 of the empty set.
  5874 
  5875 * Algebra: formalization of classical algebra.  Intended as base for
  5876 any algebraic development in Isabelle.  Currently covers group theory
  5877 (up to Sylow's theorem) and ring theory (Universal Property of
  5878 Univariate Polynomials).  Contributions welcome;
  5879 
  5880 * GroupTheory: deleted, since its material has been moved to Algebra;
  5881 
  5882 * Complex: new directory of the complex numbers with numeric constants,
  5883 nonstandard complex numbers, and some complex analysis, standard and
  5884 nonstandard (Jacques Fleuriot);
  5885 
  5886 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  5887 
  5888 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  5889 Fleuriot);
  5890 
  5891 * Real/HahnBanach: updated and adapted to locales;
  5892 
  5893 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  5894 Gray and Kramer);
  5895 
  5896 * UNITY: added the Meier-Sanders theory of progress sets;
  5897 
  5898 * MicroJava: bytecode verifier and lightweight bytecode verifier
  5899 as abstract algorithms, instantiated to the JVM;
  5900 
  5901 * Bali: Java source language formalization. Type system, operational
  5902 semantics, axiomatic semantics. Supported language features:
  5903 classes, interfaces, objects,virtual methods, static methods,
  5904 static/instance fields, arrays, access modifiers, definite
  5905 assignment, exceptions.
  5906 
  5907 
  5908 *** ZF ***
  5909 
  5910 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  5911 universe, etc.);
  5912 
  5913 * Main ZF: virtually all theories converted to new-style format;
  5914 
  5915 
  5916 *** ML ***
  5917 
  5918 * Pure: Tactic.prove provides sane interface for internal proofs;
  5919 omits the infamous "standard" operation, so this is more appropriate
  5920 than prove_goalw_cterm in many situations (e.g. in simprocs);
  5921 
  5922 * Pure: improved error reporting of simprocs;
  5923 
  5924 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  5925 up simprocs;
  5926 
  5927 
  5928 *** Document preparation ***
  5929 
  5930 * uses \par instead of \\ for line breaks in theory text. This may
  5931 shift some page breaks in large documents. To get the old behaviour
  5932 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  5933 
  5934 * minimized dependencies of isabelle.sty and isabellesym.sty on
  5935 other packages
  5936 
  5937 * \<euro> now needs package babel/greek instead of marvosym (which
  5938 broke \Rightarrow)
  5939 
  5940 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  5941 textcomp package)
  5942 
  5943 
  5944 
  5945 New in Isabelle2002 (March 2002)
  5946 --------------------------------
  5947 
  5948 *** Document preparation ***
  5949 
  5950 * greatly simplified document preparation setup, including more
  5951 graceful interpretation of isatool usedir -i/-d/-D options, and more
  5952 instructive isatool mkdir; users should basically be able to get
  5953 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  5954 users may run a separate document processing stage manually like this:
  5955 "isatool usedir -D output HOL Test && isatool document Test/output";
  5956 
  5957 * theory dependency graph may now be incorporated into documents;
  5958 isatool usedir -g true will produce session_graph.eps/.pdf for use
  5959 with \includegraphics of LaTeX;
  5960 
  5961 * proper spacing of consecutive markup elements, especially text
  5962 blocks after section headings;
  5963 
  5964 * support bold style (for single symbols only), input syntax is like
  5965 this: "\<^bold>\<alpha>" or "\<^bold>A";
  5966 
  5967 * \<bullet> is now output as bold \cdot by default, which looks much
  5968 better in printed text;
  5969 
  5970 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  5971 note that these symbols are currently unavailable in Proof General /
  5972 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  5973 
  5974 * isatool latex no longer depends on changed TEXINPUTS, instead
  5975 isatool document copies the Isabelle style files to the target
  5976 location;
  5977 
  5978 
  5979 *** Isar ***
  5980 
  5981 * Pure/Provers: improved proof by cases and induction;
  5982   - 'case' command admits impromptu naming of parameters (such as
  5983     "case (Suc n)");
  5984   - 'induct' method divinates rule instantiation from the inductive
  5985     claim; no longer requires excessive ?P bindings for proper
  5986     instantiation of cases;
  5987   - 'induct' method properly enumerates all possibilities of set/type
  5988     rules; as a consequence facts may be also passed through *type*
  5989     rules without further ado;
  5990   - 'induct' method now derives symbolic cases from the *rulified*
  5991     rule (before it used to rulify cases stemming from the internal
  5992     atomized version); this means that the context of a non-atomic
  5993     statement becomes is included in the hypothesis, avoiding the
  5994     slightly cumbersome show "PROP ?case" form;
  5995   - 'induct' may now use elim-style induction rules without chaining
  5996     facts, using ``missing'' premises from the goal state; this allows
  5997     rules stemming from inductive sets to be applied in unstructured
  5998     scripts, while still benefitting from proper handling of non-atomic
  5999     statements; NB: major inductive premises need to be put first, all
  6000     the rest of the goal is passed through the induction;
  6001   - 'induct' proper support for mutual induction involving non-atomic
  6002     rule statements (uses the new concept of simultaneous goals, see
  6003     below);
  6004   - append all possible rule selections, but only use the first
  6005     success (no backtracking);
  6006   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  6007   - undeclared rule case names default to numbers 1, 2, 3, ...;
  6008   - added 'print_induct_rules' (covered by help item in recent Proof
  6009     General versions);
  6010   - moved induct/cases attributes to Pure, methods to Provers;
  6011   - generic method setup instantiated for FOL and HOL;
  6012 
  6013 * Pure: support multiple simultaneous goal statements, for example
  6014 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  6015 meta-level mechanism, this acts as if several individual goals had
  6016 been stated separately; in particular common proof methods need to be
  6017 repeated in order to cover all claims; note that a single elimination
  6018 step is *not* sufficient to establish the two conjunctions, so this
  6019 fails:
  6020 
  6021   assume "A & B" then have A and B ..   (*".." fails*)
  6022 
  6023 better use "obtain" in situations as above; alternative refer to
  6024 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  6025 
  6026 * Pure: proper integration with ``locales''; unlike the original
  6027 version by Florian Kammller, Isar locales package high-level proof
  6028 contexts rather than raw logical ones (e.g. we admit to include
  6029 attributes everywhere); operations on locales include merge and
  6030 rename; support for implicit arguments (``structures''); simultaneous
  6031 type-inference over imports and text; see also HOL/ex/Locales.thy for
  6032 some examples;
  6033 
  6034 * Pure: the following commands have been ``localized'', supporting a
  6035 target locale specification "(in name)": 'lemma', 'theorem',
  6036 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  6037 stored both within the locale and at the theory level (exported and
  6038 qualified by the locale name);
  6039 
  6040 * Pure: theory goals may now be specified in ``long'' form, with
  6041 ad-hoc contexts consisting of arbitrary locale elements. for example
  6042 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  6043 definitions may be given, too); the result is a meta-level rule with
  6044 the context elements being discharged in the obvious way;
  6045 
  6046 * Pure: new proof command 'using' allows to augment currently used
  6047 facts after a goal statement ('using' is syntactically analogous to
  6048 'apply', but acts on the goal's facts only); this allows chained facts
  6049 to be separated into parts given before and after a claim, as in
  6050 ``from a and b have C using d and e <proof>'';
  6051 
  6052 * Pure: renamed "antecedent" case to "rule_context";
  6053 
  6054 * Pure: new 'judgment' command records explicit information about the
  6055 object-logic embedding (used by several tools internally); no longer
  6056 use hard-wired "Trueprop";
  6057 
  6058 * Pure: added 'corollary' command;
  6059 
  6060 * Pure: fixed 'token_translation' command;
  6061 
  6062 * Pure: removed obsolete 'exported' attribute;
  6063 
  6064 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  6065 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  6066 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  6067 
  6068 * Pure: method 'atomize' presents local goal premises as object-level
  6069 statements (atomic meta-level propositions); setup controlled via
  6070 rewrite rules declarations of 'atomize' attribute; example
  6071 application: 'induct' method with proper rule statements in improper
  6072 proof *scripts*;
  6073 
  6074 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  6075 now consider the syntactic context of assumptions, giving a better
  6076 chance to get type-inference of the arguments right (this is
  6077 especially important for locales);
  6078 
  6079 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  6080 mode;
  6081 
  6082 * Pure/obtain: the formal conclusion "thesis", being marked as
  6083 ``internal'', may no longer be reference directly in the text;
  6084 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  6085 situations;
  6086 
  6087 * Pure: generic 'sym' attribute which declares a rule both as pure
  6088 'elim?' and for the 'symmetric' operation;
  6089 
  6090 * Pure: marginal comments ``--'' may now occur just anywhere in the
  6091 text; the fixed correlation with particular command syntax has been
  6092 discontinued;
  6093 
  6094 * Pure: new method 'rules' is particularly well-suited for proof
  6095 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  6096 but often produces more compact proof terms with less detours;
  6097 
  6098 * Pure/Provers/classical: simplified integration with pure rule
  6099 attributes and methods; the classical "intro?/elim?/dest?"
  6100 declarations coincide with the pure ones; the "rule" method no longer
  6101 includes classically swapped intros; "intro" and "elim" methods no
  6102 longer pick rules from the context; also got rid of ML declarations
  6103 AddXIs/AddXEs/AddXDs; all of this has some potential for
  6104 INCOMPATIBILITY;
  6105 
  6106 * Provers/classical: attribute 'swapped' produces classical inversions
  6107 of introduction rules;
  6108 
  6109 * Provers/simplifier: 'simplified' attribute may refer to explicit
  6110 rules instead of full simplifier context; 'iff' attribute handles
  6111 conditional rules;
  6112 
  6113 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  6114 
  6115 * HOL: 'recdef' now fails on unfinished automated proofs, use
  6116 "(permissive)" option to recover old behavior;
  6117 
  6118 * HOL: 'inductive' no longer features separate (collective) attributes
  6119 for 'intros' (was found too confusing);
  6120 
  6121 * HOL: properly declared induction rules less_induct and
  6122 wf_induct_rule;
  6123 
  6124 
  6125 *** HOL ***
  6126 
  6127 * HOL: moved over to sane numeral syntax; the new policy is as
  6128 follows:
  6129 
  6130   - 0 and 1 are polymorphic constants, which are defined on any
  6131   numeric type (nat, int, real etc.);
  6132 
  6133   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  6134   binary representation internally;
  6135 
  6136   - type nat has special constructor Suc, and generally prefers Suc 0
  6137   over 1::nat and Suc (Suc 0) over 2::nat;
  6138 
  6139 This change may cause significant problems of INCOMPATIBILITY; here
  6140 are some hints on converting existing sources:
  6141 
  6142   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  6143   entities, so expressions involving "-" (unary or binary minus) need
  6144   to be spaced properly;
  6145 
  6146   - existing occurrences of "1" may need to be constraint "1::nat" or
  6147   even replaced by Suc 0; similar for old "2";
  6148 
  6149   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  6150 
  6151   - remove all special provisions on numerals in proofs;
  6152 
  6153 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  6154 representation (depends on bin_arith_simps in the default context);
  6155 
  6156 * HOL: symbolic syntax for x^2 (numeral 2);
  6157 
  6158 * HOL: the class of all HOL types is now called "type" rather than
  6159 "term"; INCOMPATIBILITY, need to adapt references to this type class
  6160 in axclass/classes, instance/arities, and (usually rare) occurrences
  6161 in typings (of consts etc.); internally the class is called
  6162 "HOL.type", ML programs should refer to HOLogic.typeS;
  6163 
  6164 * HOL/record package improvements:
  6165   - new derived operations "fields" to build a partial record section,
  6166     "extend" to promote a fixed record to a record scheme, and
  6167     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  6168     declared as simp by default;
  6169   - shared operations ("more", "fields", etc.) now need to be always
  6170     qualified) --- potential INCOMPATIBILITY;
  6171   - removed "make_scheme" operations (use "make" with "extend") --
  6172     INCOMPATIBILITY;
  6173   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  6174   - provides cases/induct rules for use with corresponding Isar
  6175     methods (for concrete records, record schemes, concrete more
  6176     parts, and schematic more parts -- in that order);
  6177   - internal definitions directly based on a light-weight abstract
  6178     theory of product types over typedef rather than datatype;
  6179 
  6180 * HOL: generic code generator for generating executable ML code from
  6181 specifications; specific support for HOL constructs such as inductive
  6182 datatypes and sets, as well as recursive functions; can be invoked
  6183 via 'generate_code' theory section;
  6184 
  6185 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  6186 
  6187 * HOL: consolidated and renamed several theories.  In particular:
  6188         Ord.thy has been absorbed into HOL.thy
  6189         String.thy has been absorbed into List.thy
  6190 
  6191 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  6192 (beware of argument permutation!);
  6193 
  6194 * HOL: linorder_less_split superseded by linorder_cases;
  6195 
  6196 * HOL/List: "nodups" renamed to "distinct";
  6197 
  6198 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  6199 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  6200   - Ex_def has changed, now need to use some_eq_ex
  6201 
  6202 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  6203 in this (rare) case use:
  6204 
  6205   delSWrapper "split_all_tac"
  6206   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  6207 
  6208 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  6209 MAY FAIL;
  6210 
  6211 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  6212 Isabelle's type classes, ^ on functions and relations has too general
  6213 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  6214 necessary to attach explicit type constraints;
  6215 
  6216 * HOL/Relation: the prefix name of the infix "O" has been changed from
  6217 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  6218 renamed accordingly (eg "compI" -> "rel_compI").
  6219 
  6220 * HOL: syntax translations now work properly with numerals and records
  6221 expressions;
  6222 
  6223 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  6224 of "lam" -- INCOMPATIBILITY;
  6225 
  6226 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  6227 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  6228 renamed "Product_Type.unit";
  6229 
  6230 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  6231 
  6232 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  6233 the "cases" method);
  6234 
  6235 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  6236 Florian Kammller);
  6237 
  6238 * HOL/IMP: updated and converted to new-style theory format; several
  6239 parts turned into readable document, with proper Isar proof texts and
  6240 some explanations (by Gerwin Klein);
  6241 
  6242 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  6243 
  6244 * HOL-Hyperreal is now a logic image;
  6245 
  6246 
  6247 *** HOLCF ***
  6248 
  6249 * Isar: consts/constdefs supports mixfix syntax for continuous
  6250 operations;
  6251 
  6252 * Isar: domain package adapted to new-style theory format, e.g. see
  6253 HOLCF/ex/Dnat.thy;
  6254 
  6255 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  6256 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  6257 lift.induct_tac, always use UU instead of Undef;
  6258 
  6259 * HOLCF/IMP: updated and converted to new-style theory;
  6260 
  6261 
  6262 *** ZF ***
  6263 
  6264 * Isar: proper integration of logic-specific tools and packages,
  6265 including theory commands '(co)inductive', '(co)datatype',
  6266 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  6267 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  6268 
  6269 * theory Main no longer includes AC; for the Axiom of Choice, base
  6270 your theory on Main_ZFC;
  6271 
  6272 * the integer library now covers quotients and remainders, with many
  6273 laws relating division to addition, multiplication, etc.;
  6274 
  6275 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  6276 typeless version of the formalism;
  6277 
  6278 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  6279 format;
  6280 
  6281 * ZF/Induct: new directory for examples of inductive definitions,
  6282 including theory Multiset for multiset orderings; converted to
  6283 new-style theory format;
  6284 
  6285 * ZF: many new theorems about lists, ordinals, etc.;
  6286 
  6287 
  6288 *** General ***
  6289 
  6290 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  6291 variable proof controls level of detail: 0 = no proofs (only oracle
  6292 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  6293 also ref manual for further ML interfaces;
  6294 
  6295 * Pure/axclass: removed obsolete ML interface
  6296 goal_subclass/goal_arity;
  6297 
  6298 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  6299 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  6300 separate tokens, so expressions involving minus need to be spaced
  6301 properly;
  6302 
  6303 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  6304 rather than "infixl" or "infixr";
  6305 
  6306 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  6307 sort constraint specifications in type inference; e.g. "x::_::foo"
  6308 ensures that the type of "x" is of sort "foo" (but not necessarily a
  6309 type variable);
  6310 
  6311 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  6312 control output of nested => (types); the default behavior is
  6313 "type_brackets";
  6314 
  6315 * Pure/syntax: builtin parse translation for "_constify" turns valued
  6316 tokens into AST constants;
  6317 
  6318 * Pure/syntax: prefer later declarations of translations and print
  6319 translation functions; potential INCOMPATIBILITY: need to reverse
  6320 multiple declarations for same syntax element constant;
  6321 
  6322 * Pure/show_hyps reset by default (in accordance to existing Isar
  6323 practice);
  6324 
  6325 * Provers/classical: renamed addaltern to addafter, addSaltern to
  6326 addSafter;
  6327 
  6328 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  6329 as well;
  6330 
  6331 * system: tested support for MacOS X; should be able to get Isabelle +
  6332 Proof General to work in a plain Terminal after installing Poly/ML
  6333 (e.g. from the Isabelle distribution area) and GNU bash alone
  6334 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  6335 support requires further installations, e.g. from
  6336 http://fink.sourceforge.net/);
  6337 
  6338 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  6339 
  6340 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  6341 of 40 MB), cf. ML_OPTIONS;
  6342 
  6343 * system: Proof General keywords specification is now part of the
  6344 Isabelle distribution (see etc/isar-keywords.el);
  6345 
  6346 * system: support for persistent Proof General sessions (refrain from
  6347 outdating all loaded theories on startup); user may create writable
  6348 logic images like this: ``isabelle -q HOL Test'';
  6349 
  6350 * system: smart selection of Isabelle process versus Isabelle
  6351 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  6352 run both "isabelle" and "Isabelle" even if file names are badly
  6353 damaged (executable inspects the case of the first letter of its own
  6354 name); added separate "isabelle-process" and "isabelle-interface";
  6355 
  6356 * system: refrain from any attempt at filtering input streams; no
  6357 longer support ``8bit'' encoding of old isabelle font, instead proper
  6358 iso-latin characters may now be used; the related isatools
  6359 "symbolinput" and "nonascii" have disappeared as well;
  6360 
  6361 * system: removed old "xterm" interface (the print modes "xterm" and
  6362 "xterm_color" are still available for direct use in a suitable
  6363 terminal);
  6364 
  6365 
  6366 
  6367 New in Isabelle99-2 (February 2001)
  6368 -----------------------------------
  6369 
  6370 *** Overview of INCOMPATIBILITIES ***
  6371 
  6372 * HOL: please note that theories in the Library and elsewhere often use the
  6373 new-style (Isar) format; to refer to their theorems in an ML script you must
  6374 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  6375 
  6376 * HOL: inductive package no longer splits induction rule aggressively,
  6377 but only as far as specified by the introductions given; the old
  6378 format may be recovered via ML function complete_split_rule or attribute
  6379 'split_rule (complete)';
  6380 
  6381 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  6382 gfp_Tarski to gfp_unfold;
  6383 
  6384 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  6385 
  6386 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  6387 relation); infix "^^" has been renamed "``"; infix "``" has been
  6388 renamed "`"; "univalent" has been renamed "single_valued";
  6389 
  6390 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  6391 operation;
  6392 
  6393 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  6394 
  6395 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  6396 
  6397 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  6398 consequence, it is no longer monotonic wrt. the local goal context
  6399 (which is now passed through the inductive cases);
  6400 
  6401 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  6402 \<gg> to \<ggreater>;
  6403 
  6404 
  6405 *** Document preparation ***
  6406 
  6407 * \isabellestyle{NAME} selects version of Isabelle output (currently
  6408 available: are "it" for near math-mode best-style output, "sl" for
  6409 slanted text style, and "tt" for plain type-writer; if no
  6410 \isabellestyle command is given, output is according to slanted
  6411 type-writer);
  6412 
  6413 * support sub/super scripts (for single symbols only), input syntax is
  6414 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  6415 
  6416 * some more standard symbols; see Appendix A of the system manual for
  6417 the complete list of symbols defined in isabellesym.sty;
  6418 
  6419 * improved isabelle style files; more abstract symbol implementation
  6420 (should now use \isamath{...} and \isatext{...} in custom symbol
  6421 definitions);
  6422 
  6423 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  6424 state; Note that presentation of goal states does not conform to
  6425 actual human-readable proof documents.  Please do not include goal
  6426 states into document output unless you really know what you are doing!
  6427 
  6428 * proper indentation of antiquoted output with proportional LaTeX
  6429 fonts;
  6430 
  6431 * no_document ML operator temporarily disables LaTeX document
  6432 generation;
  6433 
  6434 * isatool unsymbolize tunes sources for plain ASCII communication;
  6435 
  6436 
  6437 *** Isar ***
  6438 
  6439 * Pure: Isar now suffers initial goal statements to contain unbound
  6440 schematic variables (this does not conform to actual readable proof
  6441 documents, due to unpredictable outcome and non-compositional proof
  6442 checking); users who know what they are doing may use schematic goals
  6443 for Prolog-style synthesis of proven results;
  6444 
  6445 * Pure: assumption method (an implicit finishing) now handles actual
  6446 rules as well;
  6447 
  6448 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  6449 initial goal, declare "that" only as Pure intro (only for single
  6450 steps); the "that" rule assumption may now be involved in implicit
  6451 finishing, thus ".." becomes a feasible for trivial obtains;
  6452 
  6453 * Pure: default proof step now includes 'intro_classes'; thus trivial
  6454 instance proofs may be performed by "..";
  6455 
  6456 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  6457 statements as well;
  6458 
  6459 * Pure: more robust selection of calculational rules;
  6460 
  6461 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  6462 rule (as well as the assumption rule);
  6463 
  6464 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  6465 lemmas, using the graph browser tool;
  6466 
  6467 * Pure: predict failure of "show" in interactive mode;
  6468 
  6469 * Pure: 'thms_containing' now takes actual terms as arguments;
  6470 
  6471 * HOL: improved method 'induct' --- now handles non-atomic goals
  6472 (potential INCOMPATIBILITY); tuned error handling;
  6473 
  6474 * HOL: cases and induct rules now provide explicit hints about the
  6475 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  6476 any remaining facts are inserted into the goal verbatim;
  6477 
  6478 * HOL: local contexts (aka cases) may now contain term bindings as
  6479 well; the 'cases' and 'induct' methods new provide a ?case binding for
  6480 the result to be shown in each case;
  6481 
  6482 * HOL: added 'recdef_tc' command;
  6483 
  6484 * isatool convert assists in eliminating legacy ML scripts;
  6485 
  6486 
  6487 *** HOL ***
  6488 
  6489 * HOL/Library: a collection of generic theories to be used together
  6490 with main HOL; the theory loader path already includes this directory
  6491 by default; the following existing theories have been moved here:
  6492 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  6493 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  6494 
  6495 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  6496 modelling and verification task performed in Isabelle/HOL +
  6497 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  6498 
  6499 * HOL/Algebra: special summation operator SUM no longer exists, it has
  6500 been replaced by setsum; infix 'assoc' now has priority 50 (like
  6501 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  6502 'domain', this makes the theory consistent with mathematical
  6503 literature;
  6504 
  6505 * HOL basics: added overloaded operations "inverse" and "divide"
  6506 (infix "/"), syntax for generic "abs" operation, generic summation
  6507 operator \<Sum>;
  6508 
  6509 * HOL/typedef: simplified package, provide more useful rules (see also
  6510 HOL/subset.thy);
  6511 
  6512 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  6513 now expressed as a proper nested rule (old-style tactic scripts may
  6514 require atomize_strip_tac to cope with non-atomic premises);
  6515 
  6516 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  6517 to "split_conv" (old name still available for compatibility);
  6518 
  6519 * HOL: improved concrete syntax for strings (e.g. allows translation
  6520 rules with string literals);
  6521 
  6522 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  6523  and Fleuriot's mechanization of analysis, including the transcendental
  6524  functions for the reals;
  6525 
  6526 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  6527 
  6528 
  6529 *** CTT ***
  6530 
  6531 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  6532 "lam" is displayed as TWO lambda-symbols
  6533 
  6534 * CTT: theory Main now available, containing everything (that is, Bool
  6535 and Arith);
  6536 
  6537 
  6538 *** General ***
  6539 
  6540 * Pure: the Simplifier has been implemented properly as a derived rule
  6541 outside of the actual kernel (at last!); the overall performance
  6542 penalty in practical applications is about 50%, while reliability of
  6543 the Isabelle inference kernel has been greatly improved;
  6544 
  6545 * print modes "brackets" and "no_brackets" control output of nested =>
  6546 (types) and ==> (props); the default behaviour is "brackets";
  6547 
  6548 * Provers: fast_tac (and friends) now handle actual object-logic rules
  6549 as assumptions as well;
  6550 
  6551 * system: support Poly/ML 4.0;
  6552 
  6553 * system: isatool install handles KDE version 1 or 2;
  6554 
  6555 
  6556 
  6557 New in Isabelle99-1 (October 2000)
  6558 ----------------------------------
  6559 
  6560 *** Overview of INCOMPATIBILITIES ***
  6561 
  6562 * HOL: simplification of natural numbers is much changed; to partly
  6563 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  6564 issue the following ML commands:
  6565 
  6566   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  6567   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  6568 
  6569 * HOL: simplification no longer dives into case-expressions; this is
  6570 controlled by "t.weak_case_cong" for each datatype t;
  6571 
  6572 * HOL: nat_less_induct renamed to less_induct;
  6573 
  6574 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  6575 fixsome to patch .thy and .ML sources automatically;
  6576 
  6577   select_equality  -> some_equality
  6578   select_eq_Ex     -> some_eq_ex
  6579   selectI2EX       -> someI2_ex
  6580   selectI2         -> someI2
  6581   selectI          -> someI
  6582   select1_equality -> some1_equality
  6583   Eps_sym_eq       -> some_sym_eq_trivial
  6584   Eps_eq           -> some_eq_trivial
  6585 
  6586 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  6587 
  6588 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  6589 instead);
  6590 
  6591 * HOL: the recursion equations generated by 'recdef' are now called
  6592 f.simps instead of f.rules;
  6593 
  6594 * HOL: qed_spec_mp now also handles bounded ALL as well;
  6595 
  6596 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  6597 sometimes be needed;
  6598 
  6599 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  6600 
  6601 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  6602 
  6603 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  6604 product is now "<*>" instead of "Times"; the lexicographic product is
  6605 now "<*lex*>" instead of "**";
  6606 
  6607 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  6608 of main HOL, but was unused); better use HOL's datatype package;
  6609 
  6610 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  6611 the old syntax may be recovered as follows:
  6612 
  6613   syntax (symbols)
  6614     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  6615       (infixl "\\<oplus>" 100)
  6616 
  6617 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  6618 
  6619 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  6620 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  6621 internally;
  6622 
  6623 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  6624 changed from A/r to A//r;
  6625 
  6626 * ZF: new treatment of arithmetic (nat & int) may break some old
  6627 proofs;
  6628 
  6629 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  6630 rulify -> rule_format, elimify -> elim_format, ...);
  6631 
  6632 * Isar/Provers: intro/elim/dest attributes changed; renamed
  6633 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  6634 should have to change intro!! to intro? only); replaced "delrule" by
  6635 "rule del";
  6636 
  6637 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  6638 
  6639 * Provers: strengthened force_tac by using new first_best_tac;
  6640 
  6641 * LaTeX document preparation: several changes of isabelle.sty (see
  6642 lib/texinputs);
  6643 
  6644 
  6645 *** Document preparation ***
  6646 
  6647 * formal comments (text blocks etc.) in new-style theories may now
  6648 contain antiquotations of thm/prop/term/typ/text to be presented
  6649 according to latex print mode; concrete syntax is like this:
  6650 @{term[show_types] "f(x) = a + x"};
  6651 
  6652 * isatool mkdir provides easy setup of Isabelle session directories,
  6653 including proper document sources;
  6654 
  6655 * generated LaTeX sources are now deleted after successful run
  6656 (isatool document -c); may retain a copy somewhere else via -D option
  6657 of isatool usedir;
  6658 
  6659 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  6660 style files, achieving self-contained LaTeX sources and simplifying
  6661 LaTeX debugging;
  6662 
  6663 * old-style theories now produce (crude) LaTeX output as well;
  6664 
  6665 * browser info session directories are now self-contained (may be put
  6666 on WWW server seperately); improved graphs of nested sessions; removed
  6667 graph for 'all sessions';
  6668 
  6669 * several improvements in isabelle style files; \isabellestyle{it}
  6670 produces fake math mode output; \isamarkupheader is now \section by
  6671 default; see lib/texinputs/isabelle.sty etc.;
  6672 
  6673 
  6674 *** Isar ***
  6675 
  6676 * Isar/Pure: local results and corresponding term bindings are now
  6677 subject to Hindley-Milner polymorphism (similar to ML); this
  6678 accommodates incremental type-inference very nicely;
  6679 
  6680 * Isar/Pure: new derived language element 'obtain' supports
  6681 generalized existence reasoning;
  6682 
  6683 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  6684 support accumulation of results, without applying any rules yet;
  6685 useful to collect intermediate results without explicit name
  6686 references, and for use with transitivity rules with more than 2
  6687 premises;
  6688 
  6689 * Isar/Pure: scalable support for case-analysis type proofs: new
  6690 'case' language element refers to local contexts symbolically, as
  6691 produced by certain proof methods; internally, case names are attached
  6692 to theorems as "tags";
  6693 
  6694 * Isar/Pure: theory command 'hide' removes declarations from
  6695 class/type/const name spaces;
  6696 
  6697 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  6698 indicate potential overloading;
  6699 
  6700 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  6701 
  6702 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  6703 "{a,b,c}" instead of {a,b,c};
  6704 
  6705 * Isar/Pure now provides its own version of intro/elim/dest
  6706 attributes; useful for building new logics, but beware of confusion
  6707 with the version in Provers/classical;
  6708 
  6709 * Isar/Pure: the local context of (non-atomic) goals is provided via
  6710 case name 'antecedent';
  6711 
  6712 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  6713 to the current context is now done automatically);
  6714 
  6715 * Isar/Pure: theory command 'method_setup' provides a simple interface
  6716 for definining proof methods in ML;
  6717 
  6718 * Isar/Provers: intro/elim/dest attributes changed; renamed
  6719 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  6720 most cases, one should have to change intro!! to intro? only);
  6721 replaced "delrule" by "rule del";
  6722 
  6723 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  6724 'symmetric' attribute (the latter supercedes [RS sym]);
  6725 
  6726 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  6727 method modifier); 'simp' method: 'only:' modifier removes loopers as
  6728 well (including splits);
  6729 
  6730 * Isar/Provers: Simplifier and Classical methods now support all kind
  6731 of modifiers used in the past, including 'cong', 'iff', etc.
  6732 
  6733 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  6734 of Simplifier and Classical reasoner);
  6735 
  6736 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  6737 now support named cases; major packages (inductive, datatype, primrec,
  6738 recdef) support case names and properly name parameters;
  6739 
  6740 * Isar/HOL: new transitivity rules for substitution in inequalities --
  6741 monotonicity conditions are extracted to be proven at end of
  6742 calculations;
  6743 
  6744 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  6745 method anyway;
  6746 
  6747 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  6748 split_if split_if_asm; datatype package provides theorems foo.splits =
  6749 foo.split foo.split_asm for each datatype;
  6750 
  6751 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  6752 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  6753 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  6754 use "(cases (simplified))" method in proper proof texts);
  6755 
  6756 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  6757 
  6758 * Isar: names of theorems etc. may be natural numbers as well;
  6759 
  6760 * Isar: 'pr' command: optional arguments for goals_limit and
  6761 ProofContext.prems_limit; no longer prints theory contexts, but only
  6762 proof states;
  6763 
  6764 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  6765 additional print modes to be specified; e.g. "pr(latex)" will print
  6766 proof state according to the Isabelle LaTeX style;
  6767 
  6768 * Isar: improved support for emulating tactic scripts, including proof
  6769 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  6770 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  6771 (for HOL datatypes);
  6772 
  6773 * Isar: simplified (more robust) goal selection of proof methods: 1st
  6774 goal, all goals, or explicit goal specifier (tactic emulation); thus
  6775 'proof method scripts' have to be in depth-first order;
  6776 
  6777 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  6778 
  6779 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  6780 should instead use individual commands for printing items
  6781 (print_commands, print_methods etc.);
  6782 
  6783 * Isar: added 'nothing' --- the empty list of theorems;
  6784 
  6785 
  6786 *** HOL ***
  6787 
  6788 * HOL/MicroJava: formalization of a fragment of Java, together with a
  6789 corresponding virtual machine and a specification of its bytecode
  6790 verifier and a lightweight bytecode verifier, including proofs of
  6791 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  6792 Cornelia Pusch (see also the homepage of project Bali at
  6793 http://isabelle.in.tum.de/Bali/);
  6794 
  6795 * HOL/Algebra: new theory of rings and univariate polynomials, by
  6796 Clemens Ballarin;
  6797 
  6798 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  6799 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  6800 Rasmussen;
  6801 
  6802 * HOL/Lattice: fundamental concepts of lattice theory and order
  6803 structures, including duals, properties of bounds versus algebraic
  6804 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  6805 Theorem for complete lattices etc.; may also serve as a demonstration
  6806 for abstract algebraic reasoning using axiomatic type classes, and
  6807 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  6808 
  6809 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  6810 von Oheimb;
  6811 
  6812 * HOL/IMPP: extension of IMP with local variables and mutually
  6813 recursive procedures, by David von Oheimb;
  6814 
  6815 * HOL/Lambda: converted into new-style theory and document;
  6816 
  6817 * HOL/ex/Multiquote: example of multiple nested quotations and
  6818 anti-quotations -- basically a generalized version of de-Bruijn
  6819 representation; very useful in avoiding lifting of operations;
  6820 
  6821 * HOL/record: added general record equality rule to simpset; fixed
  6822 select-update simplification procedure to handle extended records as
  6823 well; admit "r" as field name;
  6824 
  6825 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  6826 other numeric types and also as the identity of groups, rings, etc.;
  6827 
  6828 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  6829 Types nat and int belong to this axclass;
  6830 
  6831 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  6832    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  6833    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  6834   two terms #m*u and #n*u are replaced by #(m+n)*u
  6835     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  6836   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  6837     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  6838 
  6839 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  6840 powerful prover for predicate logic but knows nothing of clasets; see
  6841 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  6842 
  6843 * HOL: new version of "case_tac" subsumes both boolean case split and
  6844 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  6845 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  6846 
  6847 * HOL: simplification no longer dives into case-expressions: only the
  6848 selector expression is simplified, but not the remaining arms; to
  6849 enable full simplification of case-expressions for datatype t, you may
  6850 remove t.weak_case_cong from the simpset, either globally (Delcongs
  6851 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  6852 
  6853 * HOL/recdef: the recursion equations generated by 'recdef' for
  6854 function 'f' are now called f.simps instead of f.rules; if all
  6855 termination conditions are proved automatically, these simplification
  6856 rules are added to the simpset, as in primrec; rules may be named
  6857 individually as well, resulting in a separate list of theorems for
  6858 each equation;
  6859 
  6860 * HOL/While is a new theory that provides a while-combinator. It
  6861 permits the definition of tail-recursive functions without the
  6862 provision of a termination measure. The latter is necessary once the
  6863 invariant proof rule for while is applied.
  6864 
  6865 * HOL: new (overloaded) notation for the set of elements below/above
  6866 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  6867 
  6868 * HOL: theorems impI, allI, ballI bound as "strip";
  6869 
  6870 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  6871 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  6872 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  6873 
  6874 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  6875 
  6876 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  6877 main HOL, but was unused);
  6878 
  6879 * HOL: fewer consts declared as global (e.g. have to refer to
  6880 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  6881 
  6882 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  6883 in case of overlap with user translations (e.g. judgements over
  6884 tuples); (note that the underlying logical represenation is still
  6885 bogus);
  6886 
  6887 
  6888 *** ZF ***
  6889 
  6890 * ZF: simplification automatically cancels common terms in arithmetic
  6891 expressions over nat and int;
  6892 
  6893 * ZF: new treatment of nat to minimize type-checking: all operators
  6894 coerce their operands to a natural number using the function natify,
  6895 making the algebraic laws unconditional;
  6896 
  6897 * ZF: as above, for int: operators coerce their operands to an integer
  6898 using the function intify;
  6899 
  6900 * ZF: the integer library now contains many of the usual laws for the
  6901 orderings, including $<=, and monotonicity laws for $+ and $*;
  6902 
  6903 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  6904 simplification;
  6905 
  6906 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  6907 to the simplifier and classical reasoner simultaneously;
  6908 
  6909 
  6910 *** General ***
  6911 
  6912 * Provers: blast_tac now handles actual object-logic rules as
  6913 assumptions; note that auto_tac uses blast_tac internally as well;
  6914 
  6915 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  6916 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  6917 
  6918 * Provers: delrules now handles destruct rules as well (no longer need
  6919 explicit make_elim);
  6920 
  6921 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  6922   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  6923 use instead the strong form,
  6924   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  6925 in HOL, FOL and ZF the function cla_make_elim will create such rules
  6926 from destruct-rules;
  6927 
  6928 * Provers: Simplifier.easy_setup provides a fast path to basic
  6929 Simplifier setup for new object-logics;
  6930 
  6931 * Pure: AST translation rules no longer require constant head on LHS;
  6932 
  6933 * Pure: improved name spaces: ambiguous output is qualified; support
  6934 for hiding of names;
  6935 
  6936 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  6937 XSYMBOL_HOME; no longer need to do manual configuration in most
  6938 situations;
  6939 
  6940 * system: compression of ML heaps images may now be controlled via -c
  6941 option of isabelle and isatool usedir (currently only observed by
  6942 Poly/ML);
  6943 
  6944 * system: isatool installfonts may handle X-Symbol fonts as well (very
  6945 useful for remote X11);
  6946 
  6947 * system: provide TAGS file for Isabelle sources;
  6948 
  6949 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  6950 order;
  6951 
  6952 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  6953 timing flag supersedes proof_timing and Toplevel.trace;
  6954 
  6955 * ML: new combinators |>> and |>>> for incremental transformations
  6956 with secondary results (e.g. certain theory extensions):
  6957 
  6958 * ML: PureThy.add_defs gets additional argument to indicate potential
  6959 overloading (usually false);
  6960 
  6961 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  6962 results;
  6963 
  6964 
  6965 
  6966 New in Isabelle99 (October 1999)
  6967 --------------------------------
  6968 
  6969 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  6970 
  6971 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  6972 are no longer simplified.  (This allows the simplifier to unfold recursive
  6973 functional programs.)  To restore the old behaviour, declare
  6974 
  6975     Delcongs [if_weak_cong];
  6976 
  6977 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  6978 complement;
  6979 
  6980 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  6981 
  6982 * HOL/datatype: mutual_induct_tac no longer exists --
  6983   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  6984 
  6985 * HOL/typedef: fixed type inference for representing set; type
  6986 arguments now have to occur explicitly on the rhs as type constraints;
  6987 
  6988 * ZF: The con_defs part of an inductive definition may no longer refer
  6989 to constants declared in the same theory;
  6990 
  6991 * HOL, ZF: the function mk_cases, generated by the inductive
  6992 definition package, has lost an argument.  To simplify its result, it
  6993 uses the default simpset instead of a supplied list of theorems.
  6994 
  6995 * HOL/List: the constructors of type list are now Nil and Cons;
  6996 
  6997 * Simplifier: the type of the infix ML functions
  6998         setSSolver addSSolver setSolver addSolver
  6999 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  7000 for packaging solvers. A solver is created via
  7001         mk_solver: string -> (thm list -> int -> tactic) -> solver
  7002 where the string argument is only a comment.
  7003 
  7004 
  7005 *** Proof tools ***
  7006 
  7007 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  7008 decision procedure for linear arithmetic. Currently it is used for
  7009 types `nat', `int', and `real' in HOL (see below); it can, should and
  7010 will be instantiated for other types and logics as well.
  7011 
  7012 * The simplifier now accepts rewrite rules with flexible heads, eg
  7013      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  7014   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  7015   matching.
  7016 
  7017 
  7018 *** General ***
  7019 
  7020 * New Isabelle/Isar subsystem provides an alternative to traditional
  7021 tactical theorem proving; together with the ProofGeneral/isar user
  7022 interface it offers an interactive environment for developing human
  7023 readable proof documents (Isar == Intelligible semi-automated
  7024 reasoning); for further information see isatool doc isar-ref,
  7025 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  7026 
  7027 * improved and simplified presentation of theories: better HTML markup
  7028 (including colors), graph views in several sizes; isatool usedir now
  7029 provides a proper interface for user theories (via -P option); actual
  7030 document preparation based on (PDF)LaTeX is available as well (for
  7031 new-style theories only); see isatool doc system for more information;
  7032 
  7033 * native support for Proof General, both for classic Isabelle and
  7034 Isabelle/Isar;
  7035 
  7036 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  7037 using the graph browser tool;
  7038 
  7039 * Isabelle manuals now also available as PDF;
  7040 
  7041 * theory loader rewritten from scratch (may not be fully
  7042 bug-compatible); old loadpath variable has been replaced by show_path,
  7043 add_path, del_path, reset_path functions; new operations such as
  7044 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  7045 isatool doc ref);
  7046 
  7047 * improved isatool install: option -k creates KDE application icon,
  7048 option -p DIR installs standalone binaries;
  7049 
  7050 * added ML_PLATFORM setting (useful for cross-platform installations);
  7051 more robust handling of platform specific ML images for SML/NJ;
  7052 
  7053 * the settings environment is now statically scoped, i.e. it is never
  7054 created again in sub-processes invoked from isabelle, isatool, or
  7055 Isabelle;
  7056 
  7057 * path element specification '~~' refers to '$ISABELLE_HOME';
  7058 
  7059 * in locales, the "assumes" and "defines" parts may be omitted if
  7060 empty;
  7061 
  7062 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  7063 long arrows);
  7064 
  7065 * new print_mode "HTML";
  7066 
  7067 * new flag show_tags controls display of tags of theorems (which are
  7068 basically just comments that may be attached by some tools);
  7069 
  7070 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  7071 mode and goal output format:
  7072 
  7073 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  7074 244c244
  7075 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  7076 ---
  7077 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  7078 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  7079 181c181
  7080 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  7081 ---
  7082 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  7083 
  7084 * function bind_thms stores lists of theorems (cf. bind_thm);
  7085 
  7086 * new shorthand tactics ftac, eatac, datac, fatac;
  7087 
  7088 * qed (and friends) now accept "" as result name; in that case the
  7089 theorem is not stored, but proper checks and presentation of the
  7090 result still apply;
  7091 
  7092 * theorem database now also indexes constants "Trueprop", "all",
  7093 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  7094 
  7095 
  7096 *** HOL ***
  7097 
  7098 ** HOL arithmetic **
  7099 
  7100 * There are now decision procedures for linear arithmetic over nat and
  7101 int:
  7102 
  7103 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  7104 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  7105 are treated as atomic; subformulae not involving type `nat' or `int'
  7106 are ignored; quantified subformulae are ignored unless they are
  7107 positive universal or negative existential. The tactic has to be
  7108 invoked by hand and can be a little bit slow. In particular, the
  7109 running time is exponential in the number of occurrences of `min' and
  7110 `max', and `-' on `nat'.
  7111 
  7112 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  7113 (negated) (in)equalities among the premises and the conclusion into
  7114 account (i.e. no compound formulae) and does not know about `min' and
  7115 `max', and `-' on `nat'. It is fast and is used automatically by the
  7116 simplifier.
  7117 
  7118 NB: At the moment, these decision procedures do not cope with mixed
  7119 nat/int formulae where the two parts interact, such as `m < n ==>
  7120 int(m) < int(n)'.
  7121 
  7122 * HOL/Numeral provides a generic theory of numerals (encoded
  7123 efficiently as bit strings); setup for types nat/int/real is in place;
  7124 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  7125 int, existing theories and proof scripts may require a few additional
  7126 type constraints;
  7127 
  7128 * integer division and remainder can now be performed on constant
  7129 arguments;
  7130 
  7131 * many properties of integer multiplication, division and remainder
  7132 are now available;
  7133 
  7134 * An interface to the Stanford Validity Checker (SVC) is available through the
  7135 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  7136 are proved automatically.  SVC must be installed separately, and its results
  7137 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  7138 invocation of the underlying oracle).  For SVC see
  7139   http://verify.stanford.edu/SVC
  7140 
  7141 * IsaMakefile: the HOL-Real target now builds an actual image;
  7142 
  7143 
  7144 ** HOL misc **
  7145 
  7146 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  7147 (in Isabelle/Isar) -- by Gertrud Bauer;
  7148 
  7149 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  7150 analysis for assembly languages with subtypes;
  7151 
  7152 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  7153 -- avoids syntactic ambiguities and treats state, transition, and
  7154 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  7155 changed syntax and (many) tactics;
  7156 
  7157 * HOL/inductive: Now also handles more general introduction rules such
  7158   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  7159   theorems are now maintained within the theory (maintained via the
  7160   "mono" attribute);
  7161 
  7162 * HOL/datatype: Now also handles arbitrarily branching datatypes
  7163   (using function types) such as
  7164 
  7165   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  7166 
  7167 * HOL/record: record_simproc (part of the default simpset) takes care
  7168 of selectors applied to updated records; record_split_tac is no longer
  7169 part of the default claset; update_defs may now be removed from the
  7170 simpset in many cases; COMPATIBILITY: old behavior achieved by
  7171 
  7172   claset_ref () := claset() addSWrapper record_split_wrapper;
  7173   Delsimprocs [record_simproc]
  7174 
  7175 * HOL/typedef: fixed type inference for representing set; type
  7176 arguments now have to occur explicitly on the rhs as type constraints;
  7177 
  7178 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  7179 names rather than an ML expression;
  7180 
  7181 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  7182 supplied later.  Program schemes can be defined, such as
  7183     "While B C s = (if B s then While B C (C s) else s)"
  7184 where the well-founded relation can be chosen after B and C have been given.
  7185 
  7186 * HOL/List: the constructors of type list are now Nil and Cons;
  7187 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  7188 course, ML tools referring to List.list.op # etc. have to be adapted;
  7189 
  7190 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  7191 disabled by default; run isabelle with option -m HOL to get back to
  7192 the original Gordon/HOL-style output;
  7193 
  7194 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  7195 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  7196 
  7197 * HOL basic syntax simplified (more orthogonal): all variants of
  7198 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  7199 Eps operator is provided as well: "SOME x. P[x]";
  7200 
  7201 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  7202 
  7203 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  7204 thus available for user theories;
  7205 
  7206 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  7207 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  7208 time;
  7209 
  7210 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  7211 several times and then mp;
  7212 
  7213 
  7214 *** LK ***
  7215 
  7216 * the notation <<...>> is now available as a notation for sequences of
  7217 formulas;
  7218 
  7219 * the simplifier is now installed
  7220 
  7221 * the axiom system has been generalized (thanks to Soren Heilmann)
  7222 
  7223 * the classical reasoner now has a default rule database
  7224 
  7225 
  7226 *** ZF ***
  7227 
  7228 * new primrec section allows primitive recursive functions to be given
  7229 directly (as in HOL) over datatypes and the natural numbers;
  7230 
  7231 * new tactics induct_tac and exhaust_tac for induction (or case
  7232 analysis) over datatypes and the natural numbers;
  7233 
  7234 * the datatype declaration of type T now defines the recursor T_rec;
  7235 
  7236 * simplification automatically does freeness reasoning for datatype
  7237 constructors;
  7238 
  7239 * automatic type-inference, with AddTCs command to insert new
  7240 type-checking rules;
  7241 
  7242 * datatype introduction rules are now added as Safe Introduction rules
  7243 to the claset;
  7244 
  7245 * the syntax "if P then x else y" is now available in addition to
  7246 if(P,x,y);
  7247 
  7248 
  7249 *** Internal programming interfaces ***
  7250 
  7251 * tuned simplifier trace output; new flag debug_simp;
  7252 
  7253 * structures Vartab / Termtab (instances of TableFun) offer efficient
  7254 tables indexed by indexname_ord / term_ord (compatible with aconv);
  7255 
  7256 * AxClass.axclass_tac lost the theory argument;
  7257 
  7258 * tuned current_goals_markers semantics: begin / end goal avoids
  7259 printing empty lines;
  7260 
  7261 * removed prs and prs_fn hook, which was broken because it did not
  7262 include \n in its semantics, forcing writeln to add one
  7263 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  7264 string -> unit if you really want to output text without newline;
  7265 
  7266 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  7267 plain output, interface builders may have to enable 'isabelle_font'
  7268 mode to get Isabelle font glyphs as before;
  7269 
  7270 * refined token_translation interface; INCOMPATIBILITY: output length
  7271 now of type real instead of int;
  7272 
  7273 * theory loader actions may be traced via new ThyInfo.add_hook
  7274 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  7275 your own database of information attached to *whole* theories -- as
  7276 opposed to intra-theory data slots offered via TheoryDataFun;
  7277 
  7278 * proper handling of dangling sort hypotheses (at last!);
  7279 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  7280 extra sort hypotheses that can be witnessed from the type signature;
  7281 the force_strip_shyps flag is gone, any remaining shyps are simply
  7282 left in the theorem (with a warning issued by strip_shyps_warning);
  7283 
  7284 
  7285 
  7286 New in Isabelle98-1 (October 1998)
  7287 ----------------------------------
  7288 
  7289 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  7290 
  7291 * several changes of automated proof tools;
  7292 
  7293 * HOL: major changes to the inductive and datatype packages, including
  7294 some minor incompatibilities of theory syntax;
  7295 
  7296 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  7297 called `inj_on';
  7298 
  7299 * HOL: removed duplicate thms in Arith:
  7300   less_imp_add_less  should be replaced by  trans_less_add1
  7301   le_imp_add_le      should be replaced by  trans_le_add1
  7302 
  7303 * HOL: unary minus is now overloaded (new type constraints may be
  7304 required);
  7305 
  7306 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  7307 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  7308 now taken as an integer constant.
  7309 
  7310 * Pure: ML function 'theory_of' renamed to 'theory';
  7311 
  7312 
  7313 *** Proof tools ***
  7314 
  7315 * Simplifier:
  7316   1. Asm_full_simp_tac is now more aggressive.
  7317      1. It will sometimes reorient premises if that increases their power to
  7318         simplify.
  7319      2. It does no longer proceed strictly from left to right but may also
  7320         rotate premises to achieve further simplification.
  7321      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  7322      old Asm_full_simp_tac in that it does not rotate premises.
  7323   2. The simplifier now knows a little bit about nat-arithmetic.
  7324 
  7325 * Classical reasoner: wrapper mechanism for the classical reasoner now
  7326 allows for selected deletion of wrappers, by introduction of names for
  7327 wrapper functionals.  This implies that addbefore, addSbefore,
  7328 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  7329 and that adding two tactics with the same name overwrites the first
  7330 one (emitting a warning).
  7331   type wrapper = (int -> tactic) -> (int -> tactic)
  7332   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  7333   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  7334   delWrapper, delSWrapper: claset *  string            -> claset
  7335   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  7336 
  7337 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  7338 semantics; addbefore now affects only the unsafe part of step_tac
  7339 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  7340 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  7341 by Force_tac;
  7342 
  7343 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  7344 compWrapper; added safe wrapper (and access functions for it);
  7345 
  7346 * HOL/split_all_tac is now much faster and fails if there is nothing
  7347 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  7348 and the names of the automatically generated variables have changed.
  7349 split_all_tac has moved within claset() from unsafe wrappers to safe
  7350 wrappers, which means that !!-bound variables are split much more
  7351 aggressively, and safe_tac and clarify_tac now split such variables.
  7352 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  7353 Note: the same holds for record_split_tac, which does the job of
  7354 split_all_tac for record fields.
  7355 
  7356 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  7357 permanently to the default simpset using Addsplits just like
  7358 Addsimps. They can be removed via Delsplits just like
  7359 Delsimps. Lower-case versions are also available.
  7360 
  7361 * HOL/Simplifier: The rule split_if is now part of the default
  7362 simpset. This means that the simplifier will eliminate all occurrences
  7363 of if-then-else in the conclusion of a goal. To prevent this, you can
  7364 either remove split_if completely from the default simpset by
  7365 `Delsplits [split_if]' or remove it in a specific call of the
  7366 simplifier using `... delsplits [split_if]'.  You can also add/delete
  7367 other case splitting rules to/from the default simpset: every datatype
  7368 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  7369 t is the name of the datatype).
  7370 
  7371 * Classical reasoner / Simplifier combination: new force_tac (and
  7372 derivatives Force_tac, force) combines rewriting and classical
  7373 reasoning (and whatever other tools) similarly to auto_tac, but is
  7374 aimed to solve the given subgoal completely.
  7375 
  7376 
  7377 *** General ***
  7378 
  7379 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  7380 and `goalw': the theory is no longer needed as an explicit argument -
  7381 the current theory context is used; assumptions are no longer returned
  7382 at the ML-level unless one of them starts with ==> or !!; it is
  7383 recommended to convert to these new commands using isatool fixgoal
  7384 (backup your sources first!);
  7385 
  7386 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  7387 the current theory context, and 'theory' to lookup stored theories;
  7388 
  7389 * new theory section 'locale' for declaring constants, assumptions and
  7390 definitions that have local scope;
  7391 
  7392 * new theory section 'nonterminals' for purely syntactic types;
  7393 
  7394 * new theory section 'setup' for generic ML setup functions
  7395 (e.g. package initialization);
  7396 
  7397 * the distribution now includes Isabelle icons: see
  7398 lib/logo/isabelle-{small,tiny}.xpm;
  7399 
  7400 * isatool install - install binaries with absolute references to
  7401 ISABELLE_HOME/bin;
  7402 
  7403 * isatool logo -- create instances of the Isabelle logo (as EPS);
  7404 
  7405 * print mode 'emacs' reserved for Isamode;
  7406 
  7407 * support multiple print (ast) translations per constant name;
  7408 
  7409 * theorems involving oracles are now printed with a suffixed [!];
  7410 
  7411 
  7412 *** HOL ***
  7413 
  7414 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  7415 
  7416 * HOL/inductive package reorganized and improved: now supports mutual
  7417 definitions such as
  7418 
  7419   inductive EVEN ODD
  7420     intrs
  7421       null "0 : EVEN"
  7422       oddI "n : EVEN ==> Suc n : ODD"
  7423       evenI "n : ODD ==> Suc n : EVEN"
  7424 
  7425 new theorem list "elims" contains an elimination rule for each of the
  7426 recursive sets; inductive definitions now handle disjunctive premises
  7427 correctly (also ZF);
  7428 
  7429 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  7430 "mutual_induct" no longer exists - the induction rule is always
  7431 contained in "induct";
  7432 
  7433 
  7434 * HOL/datatype package re-implemented and greatly improved: now
  7435 supports mutually recursive datatypes such as
  7436 
  7437   datatype
  7438     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  7439             | SUM ('a aexp) ('a aexp)
  7440             | DIFF ('a aexp) ('a aexp)
  7441             | NUM 'a
  7442   and
  7443     'a bexp = LESS ('a aexp) ('a aexp)
  7444             | AND ('a bexp) ('a bexp)
  7445             | OR ('a bexp) ('a bexp)
  7446 
  7447 as well as indirectly recursive datatypes such as
  7448 
  7449   datatype
  7450     ('a, 'b) term = Var 'a
  7451                   | App 'b ((('a, 'b) term) list)
  7452 
  7453 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  7454 induction on mutually / indirectly recursive datatypes.
  7455 
  7456 Primrec equations are now stored in theory and can be accessed via
  7457 <function_name>.simps.
  7458 
  7459 INCOMPATIBILITIES:
  7460 
  7461   - Theories using datatypes must now have theory Datatype as an
  7462     ancestor.
  7463   - The specific <typename>.induct_tac no longer exists - use the
  7464     generic induct_tac instead.
  7465   - natE has been renamed to nat.exhaust - use exhaust_tac
  7466     instead of res_inst_tac ... natE. Note that the variable
  7467     names in nat.exhaust differ from the names in natE, this
  7468     may cause some "fragile" proofs to fail.
  7469   - The theorems split_<typename>_case and split_<typename>_case_asm
  7470     have been renamed to <typename>.split and <typename>.split_asm.
  7471   - Since default sorts of type variables are now handled correctly,
  7472     some datatype definitions may have to be annotated with explicit
  7473     sort constraints.
  7474   - Primrec definitions no longer require function name and type
  7475     of recursive argument.
  7476 
  7477 Consider using isatool fixdatatype to adapt your theories and proof
  7478 scripts to the new package (backup your sources first!).
  7479 
  7480 
  7481 * HOL/record package: considerably improved implementation; now
  7482 includes concrete syntax for record types, terms, updates; theorems
  7483 for surjective pairing and splitting !!-bound record variables; proof
  7484 support is as follows:
  7485 
  7486   1) standard conversions (selectors or updates applied to record
  7487 constructor terms) are part of the standard simpset;
  7488 
  7489   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  7490 made part of standard simpset and claset via addIffs;
  7491 
  7492   3) a tactic for record field splitting (record_split_tac) is part of
  7493 the standard claset (addSWrapper);
  7494 
  7495 To get a better idea about these rules you may retrieve them via
  7496 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  7497 the name of your record type.
  7498 
  7499 The split tactic 3) conceptually simplifies by the following rule:
  7500 
  7501   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  7502 
  7503 Thus any record variable that is bound by meta-all will automatically
  7504 blow up into some record constructor term, consequently the
  7505 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  7506 solve record problems automatically.
  7507 
  7508 
  7509 * reorganized the main HOL image: HOL/Integ and String loaded by
  7510 default; theory Main includes everything;
  7511 
  7512 * automatic simplification of integer sums and comparisons, using cancellation;
  7513 
  7514 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  7515 
  7516 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  7517 
  7518 * many new identities for unions, intersections, set difference, etc.;
  7519 
  7520 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  7521 called split_if, split_split, split_sum_case and split_nat_case (to go
  7522 with add/delsplits);
  7523 
  7524 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  7525 (?x::unit) = (); this is made part of the default simpset, which COULD
  7526 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  7527 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  7528 unit_abs_eta_conv is added in order to counter the effect of
  7529 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  7530 %u.f();
  7531 
  7532 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  7533 makes more sense);
  7534 
  7535 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  7536   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  7537   disjointness reasoning but breaking a few old proofs.
  7538 
  7539 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  7540 to 'converse' from 'inverse' (for compatibility with ZF and some
  7541 literature);
  7542 
  7543 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  7544 the well-founded relation;
  7545 
  7546 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  7547     Compl A.  The "Compl" syntax remains available as input syntax for this
  7548     release ONLY.
  7549 
  7550 * HOL/Update: new theory of function updates:
  7551     f(a:=b) == %x. if x=a then b else f x
  7552 may also be iterated as in f(a:=b,c:=d,...);
  7553 
  7554 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  7555 
  7556 * HOL/List:
  7557   - new function list_update written xs[i:=v] that updates the i-th
  7558     list position. May also be iterated as in xs[i:=a,j:=b,...].
  7559   - new function `upt' written [i..j(] which generates the list
  7560     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  7561     bound write [i..j], which is a shorthand for [i..j+1(].
  7562   - new lexicographic orderings and corresponding wellfoundedness theorems.
  7563 
  7564 * HOL/Arith:
  7565   - removed 'pred' (predecessor) function;
  7566   - generalized some theorems about n-1;
  7567   - many new laws about "div" and "mod";
  7568   - new laws about greatest common divisors (see theory ex/Primes);
  7569 
  7570 * HOL/Relation: renamed the relational operator r^-1 "converse"
  7571 instead of "inverse";
  7572 
  7573 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  7574   of the multiset ordering;
  7575 
  7576 * directory HOL/Real: a construction of the reals using Dedekind cuts
  7577   (not included by default);
  7578 
  7579 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  7580 
  7581 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  7582   programs, i.e. different program variables may have different types.
  7583 
  7584 * calling (stac rew i) now fails if "rew" has no effect on the goal
  7585   [previously, this check worked only if the rewrite rule was unconditional]
  7586   Now rew can involve either definitions or equalities (either == or =).
  7587 
  7588 
  7589 *** ZF ***
  7590 
  7591 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  7592   only the theorems proved on ZF.ML;
  7593 
  7594 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  7595   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  7596   disjointness reasoning but breaking a few old proofs.
  7597 
  7598 * ZF/Update: new theory of function updates
  7599     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  7600   may also be iterated as in f(a:=b,c:=d,...);
  7601 
  7602 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  7603 
  7604 * calling (stac rew i) now fails if "rew" has no effect on the goal
  7605   [previously, this check worked only if the rewrite rule was unconditional]
  7606   Now rew can involve either definitions or equalities (either == or =).
  7607 
  7608 * case_tac provided for compatibility with HOL
  7609     (like the old excluded_middle_tac, but with subgoals swapped)
  7610 
  7611 
  7612 *** Internal programming interfaces ***
  7613 
  7614 * Pure: several new basic modules made available for general use, see
  7615 also src/Pure/README;
  7616 
  7617 * improved the theory data mechanism to support encapsulation (data
  7618 kind name replaced by private Object.kind, acting as authorization
  7619 key); new type-safe user interface via functor TheoryDataFun; generic
  7620 print_data function becomes basically useless;
  7621 
  7622 * removed global_names compatibility flag -- all theory declarations
  7623 are qualified by default;
  7624 
  7625 * module Pure/Syntax now offers quote / antiquote translation
  7626 functions (useful for Hoare logic etc. with implicit dependencies);
  7627 see HOL/ex/Antiquote for an example use;
  7628 
  7629 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  7630 cterm -> thm;
  7631 
  7632 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  7633 subgoal;
  7634 
  7635 * Display.print_goals function moved to Locale.print_goals;
  7636 
  7637 * standard print function for goals supports current_goals_markers
  7638 variable for marking begin of proof, end of proof, start of goal; the
  7639 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  7640 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  7641 for example;
  7642 
  7643 
  7644 
  7645 New in Isabelle98 (January 1998)
  7646 --------------------------------
  7647 
  7648 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  7649 
  7650 * changed lexical syntax of terms / types: dots made part of long
  7651 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  7652 
  7653 * simpset (and claset) reference variable replaced by functions
  7654 simpset / simpset_ref;
  7655 
  7656 * no longer supports theory aliases (via merge) and non-trivial
  7657 implicit merge of thms' signatures;
  7658 
  7659 * most internal names of constants changed due to qualified names;
  7660 
  7661 * changed Pure/Sequence interface (see Pure/seq.ML);
  7662 
  7663 
  7664 *** General Changes ***
  7665 
  7666 * hierachically structured name spaces (for consts, types, axms, thms
  7667 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  7668 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  7669 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  7670 long_names for fully qualified output names; NOTE: ML programs
  7671 (special tactics, packages etc.) referring to internal names may have
  7672 to be adapted to cope with fully qualified names; in case of severe
  7673 backward campatibility problems try setting 'global_names' at compile
  7674 time to have enrything declared within a flat name space; one may also
  7675 fine tune name declarations in theories via the 'global' and 'local'
  7676 section;
  7677 
  7678 * reimplemented the implicit simpset and claset using the new anytype
  7679 data filed in signatures; references simpset:simpset ref etc. are
  7680 replaced by functions simpset:unit->simpset and
  7681 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  7682 to patch your ML files accordingly;
  7683 
  7684 * HTML output now includes theory graph data for display with Java
  7685 applet or isatool browser; data generated automatically via isatool
  7686 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  7687 
  7688 * defs may now be conditional; improved rewrite_goals_tac to handle
  7689 conditional equations;
  7690 
  7691 * defs now admits additional type arguments, using TYPE('a) syntax;
  7692 
  7693 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  7694 creates a new theory node; implicit merge of thms' signatures is
  7695 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  7696 transfer:theory->thm->thm in (rare) cases;
  7697 
  7698 * improved handling of draft signatures / theories; draft thms (and
  7699 ctyps, cterms) are automatically promoted to real ones;
  7700 
  7701 * slightly changed interfaces for oracles: admit many per theory, named
  7702 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  7703 
  7704 * print_goals: optional output of const types (set show_consts and
  7705 show_types);
  7706 
  7707 * improved output of warnings (###) and errors (***);
  7708 
  7709 * subgoal_tac displays a warning if the new subgoal has type variables;
  7710 
  7711 * removed old README and Makefiles;
  7712 
  7713 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  7714 
  7715 * removed obsolete init_pps and init_database;
  7716 
  7717 * deleted the obsolete tactical STATE, which was declared by
  7718     fun STATE tacfun st = tacfun st st;
  7719 
  7720 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  7721 (which abbreviates $HOME);
  7722 
  7723 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  7724 use isatool fixseq to adapt your ML programs (this works for fully
  7725 qualified references to the Sequence structure only!);
  7726 
  7727 * use_thy no longer requires writable current directory; it always
  7728 reloads .ML *and* .thy file, if either one is out of date;
  7729 
  7730 
  7731 *** Classical Reasoner ***
  7732 
  7733 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  7734 tactics that use classical reasoning to simplify a subgoal without
  7735 splitting it into several subgoals;
  7736 
  7737 * Safe_tac: like safe_tac but uses the default claset;
  7738 
  7739 
  7740 *** Simplifier ***
  7741 
  7742 * added simplification meta rules:
  7743     (asm_)(full_)simplify: simpset -> thm -> thm;
  7744 
  7745 * simplifier.ML no longer part of Pure -- has to be loaded by object
  7746 logics (again);
  7747 
  7748 * added prems argument to simplification procedures;
  7749 
  7750 * HOL, FOL, ZF: added infix function `addsplits':
  7751   instead of `<simpset> setloop (split_tac <thms>)'
  7752   you can simply write `<simpset> addsplits <thms>'
  7753 
  7754 
  7755 *** Syntax ***
  7756 
  7757 * TYPE('a) syntax for type reflection terms;
  7758 
  7759 * no longer handles consts with name "" -- declare as 'syntax' instead;
  7760 
  7761 * pretty printer: changed order of mixfix annotation preference (again!);
  7762 
  7763 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  7764 
  7765 
  7766 *** HOL ***
  7767 
  7768 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  7769   with `addloop' of the simplifier to faciliate case splitting in premises.
  7770 
  7771 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  7772 
  7773 * HOL/Auth: new protocol proofs including some for the Internet
  7774   protocol TLS;
  7775 
  7776 * HOL/Map: new theory of `maps' a la VDM;
  7777 
  7778 * HOL/simplifier: simplification procedures nat_cancel_sums for
  7779 cancelling out common nat summands from =, <, <= (in)equalities, or
  7780 differences; simplification procedures nat_cancel_factor for
  7781 cancelling common factor from =, <, <= (in)equalities over natural
  7782 sums; nat_cancel contains both kinds of procedures, it is installed by
  7783 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  7784 
  7785 * HOL/simplifier: terms of the form
  7786   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  7787   are rewritten to
  7788   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  7789   and those of the form
  7790   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  7791   are rewritten to
  7792   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  7793 
  7794 * HOL/datatype
  7795   Each datatype `t' now comes with a theorem `split_t_case' of the form
  7796 
  7797   P(t_case f1 ... fn x) =
  7798      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  7799         ...
  7800        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  7801      )
  7802 
  7803   and a theorem `split_t_case_asm' of the form
  7804 
  7805   P(t_case f1 ... fn x) =
  7806     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  7807         ...
  7808        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  7809      )
  7810   which can be added to a simpset via `addsplits'. The existing theorems
  7811   expand_list_case and expand_option_case have been renamed to
  7812   split_list_case and split_option_case.
  7813 
  7814 * HOL/Arithmetic:
  7815   - `pred n' is automatically converted to `n-1'.
  7816     Users are strongly encouraged not to use `pred' any longer,
  7817     because it will disappear altogether at some point.
  7818   - Users are strongly encouraged to write "0 < n" rather than
  7819     "n ~= 0". Theorems and proof tools have been modified towards this
  7820     `standard'.
  7821 
  7822 * HOL/Lists:
  7823   the function "set_of_list" has been renamed "set" (and its theorems too);
  7824   the function "nth" now takes its arguments in the reverse order and
  7825   has acquired the infix notation "!" as in "xs!n".
  7826 
  7827 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  7828 
  7829 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  7830   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  7831 
  7832 * HOL/record: extensible records with schematic structural subtyping
  7833 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  7834 still lacks various theorems and concrete record syntax;
  7835 
  7836 
  7837 *** HOLCF ***
  7838 
  7839 * removed "axioms" and "generated by" sections;
  7840 
  7841 * replaced "ops" section by extended "consts" section, which is capable of
  7842   handling the continuous function space "->" directly;
  7843 
  7844 * domain package:
  7845   . proves theorems immediately and stores them in the theory,
  7846   . creates hierachical name space,
  7847   . now uses normal mixfix annotations (instead of cinfix...),
  7848   . minor changes to some names and values (for consistency),
  7849   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  7850   . separator between mutual domain defs: changed "," to "and",
  7851   . improved handling of sort constraints;  now they have to
  7852     appear on the left-hand side of the equations only;
  7853 
  7854 * fixed LAM <x,y,zs>.b syntax;
  7855 
  7856 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  7857 adm (%x. P (t x)), where P is chainfinite and t continuous;
  7858 
  7859 
  7860 *** FOL and ZF ***
  7861 
  7862 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  7863   with `addloop' of the simplifier to faciliate case splitting in premises.
  7864 
  7865 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  7866 in HOL, they strip ALL and --> from proved theorems;
  7867 
  7868 
  7869 
  7870 New in Isabelle94-8 (May 1997)
  7871 ------------------------------
  7872 
  7873 *** General Changes ***
  7874 
  7875 * new utilities to build / run / maintain Isabelle etc. (in parts
  7876 still somewhat experimental); old Makefiles etc. still functional;
  7877 
  7878 * new 'Isabelle System Manual';
  7879 
  7880 * INSTALL text, together with ./configure and ./build scripts;
  7881 
  7882 * reimplemented type inference for greater efficiency, better error
  7883 messages and clean internal interface;
  7884 
  7885 * prlim command for dealing with lots of subgoals (an easier way of
  7886 setting goals_limit);
  7887 
  7888 
  7889 *** Syntax ***
  7890 
  7891 * supports alternative (named) syntax tables (parser and pretty
  7892 printer); internal interface is provided by add_modesyntax(_i);
  7893 
  7894 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  7895 be used in conjunction with the Isabelle symbol font; uses the
  7896 "symbols" syntax table;
  7897 
  7898 * added token_translation interface (may translate name tokens in
  7899 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  7900 the current print_mode); IMPORTANT: user print translation functions
  7901 are responsible for marking newly introduced bounds
  7902 (Syntax.mark_boundT);
  7903 
  7904 * token translations for modes "xterm" and "xterm_color" that display
  7905 names in bold, underline etc. or colors (which requires a color
  7906 version of xterm);
  7907 
  7908 * infixes may now be declared with names independent of their syntax;
  7909 
  7910 * added typed_print_translation (like print_translation, but may
  7911 access type of constant);
  7912 
  7913 
  7914 *** Classical Reasoner ***
  7915 
  7916 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  7917 some limitations.  Blast_tac...
  7918   + ignores addss, addbefore, addafter; this restriction is intrinsic
  7919   + ignores elimination rules that don't have the correct format
  7920         (the conclusion MUST be a formula variable)
  7921   + ignores types, which can make HOL proofs fail
  7922   + rules must not require higher-order unification, e.g. apply_type in ZF
  7923     [message "Function Var's argument not a bound variable" relates to this]
  7924   + its proof strategy is more general but can actually be slower
  7925 
  7926 * substitution with equality assumptions no longer permutes other
  7927 assumptions;
  7928 
  7929 * minor changes in semantics of addafter (now called addaltern); renamed
  7930 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  7931 (and access functions for it);
  7932 
  7933 * improved combination of classical reasoner and simplifier:
  7934   + functions for handling clasimpsets
  7935   + improvement of addss: now the simplifier is called _after_ the
  7936     safe steps.
  7937   + safe variant of addss called addSss: uses safe simplifications
  7938     _during_ the safe steps. It is more complete as it allows multiple
  7939     instantiations of unknowns (e.g. with slow_tac).
  7940 
  7941 *** Simplifier ***
  7942 
  7943 * added interface for simplification procedures (functions that
  7944 produce *proven* rewrite rules on the fly, depending on current
  7945 redex);
  7946 
  7947 * ordering on terms as parameter (used for ordered rewriting);
  7948 
  7949 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  7950 
  7951 * the solver is now split into a safe and an unsafe part.
  7952 This should be invisible for the normal user, except that the
  7953 functions setsolver and addsolver have been renamed to setSolver and
  7954 addSolver; added safe_asm_full_simp_tac;
  7955 
  7956 
  7957 *** HOL ***
  7958 
  7959 * a generic induction tactic `induct_tac' which works for all datatypes and
  7960 also for type `nat';
  7961 
  7962 * a generic case distinction tactic `exhaust_tac' which works for all
  7963 datatypes and also for type `nat';
  7964 
  7965 * each datatype comes with a function `size';
  7966 
  7967 * patterns in case expressions allow tuple patterns as arguments to
  7968 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  7969 
  7970 * primrec now also works with type nat;
  7971 
  7972 * recdef: a new declaration form, allows general recursive functions to be
  7973 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  7974 
  7975 * the constant for negation has been renamed from "not" to "Not" to
  7976 harmonize with FOL, ZF, LK, etc.;
  7977 
  7978 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  7979 infinite lists;
  7980 
  7981 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  7982 
  7983 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  7984 problems in commutative rings, using axiomatic type classes for + and *;
  7985 
  7986 * more examples in HOL/MiniML and HOL/Auth;
  7987 
  7988 * more default rewrite rules for quantifiers, union/intersection;
  7989 
  7990 * a new constant `arbitrary == @x.False';
  7991 
  7992 * HOLCF/IOA replaces old HOL/IOA;
  7993 
  7994 * HOLCF changes: derived all rules and arities
  7995   + axiomatic type classes instead of classes
  7996   + typedef instead of faking type definitions
  7997   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  7998   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  7999   + eliminated the types void, one, tr
  8000   + use unit lift and bool lift (with translations) instead of one and tr
  8001   + eliminated blift from Lift3.thy (use Def instead of blift)
  8002   all eliminated rules are derived as theorems --> no visible changes ;
  8003 
  8004 
  8005 *** ZF ***
  8006 
  8007 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  8008 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  8009 as ZF_cs addSIs [equalityI];
  8010 
  8011 
  8012 
  8013 New in Isabelle94-7 (November 96)
  8014 ---------------------------------
  8015 
  8016 * allowing negative levels (as offsets) in prlev and choplev;
  8017 
  8018 * super-linear speedup for large simplifications;
  8019 
  8020 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  8021 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  8022 FAIL); can suppress it using the command Delsimps (ex_simps @
  8023 all_simps); De Morgan laws are also now included, by default;
  8024 
  8025 * improved printing of ==>  :  ~:
  8026 
  8027 * new object-logic "Sequents" adds linear logic, while replacing LK
  8028 and Modal (thanks to Sara Kalvala);
  8029 
  8030 * HOL/Auth: correctness proofs for authentication protocols;
  8031 
  8032 * HOL: new auto_tac combines rewriting and classical reasoning (many
  8033 examples on HOL/Auth);
  8034 
  8035 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  8036 the rewriter and classical reasoner simultaneously;
  8037 
  8038 * function uresult no longer returns theorems in "standard" format;
  8039 regain previous version by: val uresult = standard o uresult;
  8040 
  8041 
  8042 
  8043 New in Isabelle94-6
  8044 -------------------
  8045 
  8046 * oracles -- these establish an interface between Isabelle and trusted
  8047 external reasoners, which may deliver results as theorems;
  8048 
  8049 * proof objects (in particular record all uses of oracles);
  8050 
  8051 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  8052 
  8053 * "constdefs" section in theory files;
  8054 
  8055 * "primrec" section (HOL) no longer requires names;
  8056 
  8057 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  8058 
  8059 
  8060 
  8061 New in Isabelle94-5
  8062 -------------------
  8063 
  8064 * reduced space requirements;
  8065 
  8066 * automatic HTML generation from theories;
  8067 
  8068 * theory files no longer require "..." (quotes) around most types;
  8069 
  8070 * new examples, including two proofs of the Church-Rosser theorem;
  8071 
  8072 * non-curried (1994) version of HOL is no longer distributed;
  8073 
  8074 
  8075 
  8076 New in Isabelle94-4
  8077 -------------------
  8078 
  8079 * greatly reduced space requirements;
  8080 
  8081 * theory files (.thy) no longer require \...\ escapes at line breaks;
  8082 
  8083 * searchable theorem database (see the section "Retrieving theorems" on
  8084 page 8 of the Reference Manual);
  8085 
  8086 * new examples, including Grabczewski's monumental case study of the
  8087 Axiom of Choice;
  8088 
  8089 * The previous version of HOL renamed to Old_HOL;
  8090 
  8091 * The new version of HOL (previously called CHOL) uses a curried syntax
  8092 for functions.  Application looks like f a b instead of f(a,b);
  8093 
  8094 * Mutually recursive inductive definitions finally work in HOL;
  8095 
  8096 * In ZF, pattern-matching on tuples is now available in all abstractions and
  8097 translates to the operator "split";
  8098 
  8099 
  8100 
  8101 New in Isabelle94-3
  8102 -------------------
  8103 
  8104 * new infix operator, addss, allowing the classical reasoner to
  8105 perform simplification at each step of its search.  Example:
  8106         fast_tac (cs addss ss)
  8107 
  8108 * a new logic, CHOL, the same as HOL, but with a curried syntax
  8109 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  8110 look like (a,b) instead of <a,b>;
  8111 
  8112 * PLEASE NOTE: CHOL will eventually replace HOL!
  8113 
  8114 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  8115 It translates to the operator "split".  A new theory of integers is available;
  8116 
  8117 * In ZF, integer numerals now denote two's-complement binary integers.
  8118 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  8119 
  8120 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  8121 of the Axiom of Choice;
  8122 
  8123 
  8124 
  8125 New in Isabelle94-2
  8126 -------------------
  8127 
  8128 * Significantly faster resolution;
  8129 
  8130 * the different sections in a .thy file can now be mixed and repeated
  8131 freely;
  8132 
  8133 * Database of theorems for FOL, HOL and ZF.  New
  8134 commands including qed, qed_goal and bind_thm store theorems in the database.
  8135 
  8136 * Simple database queries: return a named theorem (get_thm) or all theorems of
  8137 a given theory (thms_of), or find out what theory a theorem was proved in
  8138 (theory_of_thm);
  8139 
  8140 * Bugs fixed in the inductive definition and datatype packages;
  8141 
  8142 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  8143 and HOL_dup_cs obsolete;
  8144 
  8145 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  8146 have been removed;
  8147 
  8148 * Simpler definition of function space in ZF;
  8149 
  8150 * new results about cardinal and ordinal arithmetic in ZF;
  8151 
  8152 * 'subtype' facility in HOL for introducing new types as subsets of existing
  8153 types;
  8154 
  8155 :mode=text:wrap=hard:maxLineLen=72: