NEWS
author wenzelm
Tue, 22 Mar 2011 20:44:47 +0100
changeset 42938 3eba96ff3d3e
parent 42937 160a630b2c7e
child 43020 7e6f4ca198bb
permissions -rw-r--r--
more selective strip_positions in case patterns -- reactivate translations based on "case _ of _" in HOL and special patterns in HOLCF;
     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 
    53 * "try":
    54   - Added "simp:", "intro:", and "elim:" options.
    55 
    56 * Function package: discontinued option "tailrec".
    57 INCOMPATIBILITY. Use partial_function instead.
    58 
    59 
    60 *** Document preparation ***
    61 
    62 * New term style "isub" as ad-hoc conversion of variables x1, y23 into
    63 subscripted form x\<^isub>1, y\<^isub>2\<^isub>3.
    64 
    65 
    66 *** ML ***
    67 
    68 * Structure Timing provides various operations for timing; supersedes
    69 former start_timing/end_timing etc.
    70 
    71 * Path.print is the official way to show file-system paths to users
    72 (including quotes etc.).
    73 
    74 * Inner syntax: identifiers in parse trees of generic categories
    75 "logic", "aprop", "idt" etc. carry position information (disguised as
    76 type constraints).  Occasional INCOMPATIBILITY with non-compliant
    77 translations that choke on unexpected type constraints.  Positions can
    78 be stripped in ML translations via Syntax.strip_positions /
    79 Syntax.strip_positions_ast, or via the syntax constant
    80 "_strip_positions" within parse trees.  As last resort, positions can
    81 be disabled via the configuration option Syntax.positions, which is
    82 called "syntax_positions" in Isar attribute syntax.
    83 
    84 
    85 
    86 New in Isabelle2011 (January 2011)
    87 ----------------------------------
    88 
    89 *** General ***
    90 
    91 * Experimental Prover IDE based on Isabelle/Scala and jEdit (see
    92 src/Tools/jEdit).  This also serves as IDE for Isabelle/ML, with
    93 useful tooltips and hyperlinks produced from its static analysis.  The
    94 bundled component provides an executable Isabelle tool that can be run
    95 like this:
    96 
    97   Isabelle2011/bin/isabelle jedit
    98 
    99 * Significantly improved Isabelle/Isar implementation manual.
   100 
   101 * System settings: ISABELLE_HOME_USER now includes ISABELLE_IDENTIFIER
   102 (and thus refers to something like $HOME/.isabelle/Isabelle2011),
   103 while the default heap location within that directory lacks that extra
   104 suffix.  This isolates multiple Isabelle installations from each
   105 other, avoiding problems with old settings in new versions.
   106 INCOMPATIBILITY, need to copy/upgrade old user settings manually.
   107 
   108 * Source files are always encoded as UTF-8, instead of old-fashioned
   109 ISO-Latin-1.  INCOMPATIBILITY.  Isabelle LaTeX documents might require
   110 the following package declarations:
   111 
   112   \usepackage[utf8]{inputenc}
   113   \usepackage{textcomp}
   114 
   115 * Explicit treatment of UTF-8 sequences as Isabelle symbols, such that
   116 a Unicode character is treated as a single symbol, not a sequence of
   117 non-ASCII bytes as before.  Since Isabelle/ML string literals may
   118 contain symbols without further backslash escapes, Unicode can now be
   119 used here as well.  Recall that Symbol.explode in ML provides a
   120 consistent view on symbols, while raw explode (or String.explode)
   121 merely give a byte-oriented representation.
   122 
   123 * Theory loader: source files are primarily located via the master
   124 directory of each theory node (where the .thy file itself resides).
   125 The global load path is still partially available as legacy feature.
   126 Minor INCOMPATIBILITY due to subtle change in file lookup: use
   127 explicit paths, relatively to the theory.
   128 
   129 * Special treatment of ML file names has been discontinued.
   130 Historically, optional extensions .ML or .sml were added on demand --
   131 at the cost of clarity of file dependencies.  Recall that Isabelle/ML
   132 files exclusively use the .ML extension.  Minor INCOMPATIBILTY.
   133 
   134 * Various options that affect pretty printing etc. are now properly
   135 handled within the context via configuration options, instead of
   136 unsynchronized references or print modes.  There are both ML Config.T
   137 entities and Isar declaration attributes to access these.
   138 
   139   ML (Config.T)                 Isar (attribute)
   140 
   141   eta_contract                  eta_contract
   142   show_brackets                 show_brackets
   143   show_sorts                    show_sorts
   144   show_types                    show_types
   145   show_question_marks           show_question_marks
   146   show_consts                   show_consts
   147   show_abbrevs                  show_abbrevs
   148 
   149   Syntax.ast_trace              syntax_ast_trace
   150   Syntax.ast_stat               syntax_ast_stat
   151   Syntax.ambiguity_level        syntax_ambiguity_level
   152 
   153   Goal_Display.goals_limit      goals_limit
   154   Goal_Display.show_main_goal   show_main_goal
   155 
   156   Method.rule_trace             rule_trace
   157 
   158   Thy_Output.display            thy_output_display
   159   Thy_Output.quotes             thy_output_quotes
   160   Thy_Output.indent             thy_output_indent
   161   Thy_Output.source             thy_output_source
   162   Thy_Output.break              thy_output_break
   163 
   164 Note that corresponding "..._default" references in ML may only be
   165 changed globally at the ROOT session setup, but *not* within a theory.
   166 The option "show_abbrevs" supersedes the former print mode
   167 "no_abbrevs" with inverted meaning.
   168 
   169 * More systematic naming of some configuration options.
   170 INCOMPATIBILITY.
   171 
   172   trace_simp  ~>  simp_trace
   173   debug_simp  ~>  simp_debug
   174 
   175 * Support for real valued configuration options, using simplistic
   176 floating-point notation that coincides with the inner syntax for
   177 float_token.
   178 
   179 * Support for real valued preferences (with approximative PGIP type):
   180 front-ends need to accept "pgint" values in float notation.
   181 INCOMPATIBILITY.
   182 
   183 * The IsabelleText font now includes Cyrillic, Hebrew, Arabic from
   184 DejaVu Sans.
   185 
   186 * Discontinued support for Poly/ML 5.0 and 5.1 versions.
   187 
   188 
   189 *** Pure ***
   190 
   191 * Command 'type_synonym' (with single argument) replaces somewhat
   192 outdated 'types', which is still available as legacy feature for some
   193 time.
   194 
   195 * Command 'nonterminal' (with 'and' separated list of arguments)
   196 replaces somewhat outdated 'nonterminals'.  INCOMPATIBILITY.
   197 
   198 * Command 'notepad' replaces former 'example_proof' for
   199 experimentation in Isar without any result.  INCOMPATIBILITY.
   200 
   201 * Locale interpretation commands 'interpret' and 'sublocale' accept
   202 lists of equations to map definitions in a locale to appropriate
   203 entities in the context of the interpretation.  The 'interpretation'
   204 command already provided this functionality.
   205 
   206 * Diagnostic command 'print_dependencies' prints the locale instances
   207 that would be activated if the specified expression was interpreted in
   208 the current context.  Variant "print_dependencies!" assumes a context
   209 without interpretations.
   210 
   211 * Diagnostic command 'print_interps' prints interpretations in proofs
   212 in addition to interpretations in theories.
   213 
   214 * Discontinued obsolete 'global' and 'local' commands to manipulate
   215 the theory name space.  Rare INCOMPATIBILITY.  The ML functions
   216 Sign.root_path and Sign.local_path may be applied directly where this
   217 feature is still required for historical reasons.
   218 
   219 * Discontinued obsolete 'constdefs' command.  INCOMPATIBILITY, use
   220 'definition' instead.
   221 
   222 * The "prems" fact, which refers to the accidental collection of
   223 foundational premises in the context, is now explicitly marked as
   224 legacy feature and will be discontinued soon.  Consider using "assms"
   225 of the head statement or reference facts by explicit names.
   226 
   227 * Document antiquotations @{class} and @{type} print classes and type
   228 constructors.
   229 
   230 * Document antiquotation @{file} checks file/directory entries within
   231 the local file system.
   232 
   233 
   234 *** HOL ***
   235 
   236 * Coercive subtyping: functions can be declared as coercions and type
   237 inference will add them as necessary upon input of a term.  Theory
   238 Complex_Main declares real :: nat => real and real :: int => real as
   239 coercions. A coercion function f is declared like this:
   240 
   241   declare [[coercion f]]
   242 
   243 To lift coercions through type constructors (e.g. from nat => real to
   244 nat list => real list), map functions can be declared, e.g.
   245 
   246   declare [[coercion_map map]]
   247 
   248 Currently coercion inference is activated only in theories including
   249 real numbers, i.e. descendants of Complex_Main.  This is controlled by
   250 the configuration option "coercion_enabled", e.g. it can be enabled in
   251 other theories like this:
   252 
   253   declare [[coercion_enabled]]
   254 
   255 * Command 'partial_function' provides basic support for recursive
   256 function definitions over complete partial orders.  Concrete instances
   257 are provided for i) the option type, ii) tail recursion on arbitrary
   258 types, and iii) the heap monad of Imperative_HOL.  See
   259 src/HOL/ex/Fundefs.thy and src/HOL/Imperative_HOL/ex/Linked_Lists.thy
   260 for examples.
   261 
   262 * Function package: f.psimps rules are no longer implicitly declared
   263 as [simp].  INCOMPATIBILITY.
   264 
   265 * Datatype package: theorems generated for executable equality (class
   266 "eq") carry proper names and are treated as default code equations.
   267 
   268 * Inductive package: now offers command 'inductive_simps' to
   269 automatically derive instantiated and simplified equations for
   270 inductive predicates, similar to 'inductive_cases'.
   271 
   272 * Command 'enriched_type' allows to register properties of the
   273 functorial structure of types.
   274 
   275 * Improved infrastructure for term evaluation using code generator
   276 techniques, in particular static evaluation conversions.
   277 
   278 * Code generator: Scala (2.8 or higher) has been added to the target
   279 languages.
   280 
   281 * Code generator: globbing constant expressions "*" and "Theory.*"
   282 have been replaced by the more idiomatic "_" and "Theory._".
   283 INCOMPATIBILITY.
   284 
   285 * Code generator: export_code without explicit file declaration prints
   286 to standard output.  INCOMPATIBILITY.
   287 
   288 * Code generator: do not print function definitions for case
   289 combinators any longer.
   290 
   291 * Code generator: simplification with rules determined with
   292 src/Tools/Code/code_simp.ML and method "code_simp".
   293 
   294 * Code generator for records: more idiomatic representation of record
   295 types.  Warning: records are not covered by ancient SML code
   296 generation any longer.  INCOMPATIBILITY.  In cases of need, a suitable
   297 rep_datatype declaration helps to succeed then:
   298 
   299   record 'a foo = ...
   300   ...
   301   rep_datatype foo_ext ...
   302 
   303 * Records: logical foundation type for records does not carry a
   304 '_type' suffix any longer (obsolete due to authentic syntax).
   305 INCOMPATIBILITY.
   306 
   307 * Quickcheck now by default uses exhaustive testing instead of random
   308 testing.  Random testing can be invoked by "quickcheck [random]",
   309 exhaustive testing by "quickcheck [exhaustive]".
   310 
   311 * Quickcheck instantiates polymorphic types with small finite
   312 datatypes by default. This enables a simple execution mechanism to
   313 handle quantifiers and function equality over the finite datatypes.
   314 
   315 * Quickcheck random generator has been renamed from "code" to
   316 "random".  INCOMPATIBILITY.
   317 
   318 * Quickcheck now has a configurable time limit which is set to 30
   319 seconds by default. This can be changed by adding [timeout = n] to the
   320 quickcheck command. The time limit for Auto Quickcheck is still set
   321 independently.
   322 
   323 * Quickcheck in locales considers interpretations of that locale for
   324 counter example search.
   325 
   326 * Sledgehammer:
   327   - Added "smt" and "remote_smt" provers based on the "smt" proof
   328     method. See the Sledgehammer manual for details ("isabelle doc
   329     sledgehammer").
   330   - Renamed commands:
   331     sledgehammer atp_info ~> sledgehammer running_provers
   332     sledgehammer atp_kill ~> sledgehammer kill_provers
   333     sledgehammer available_atps ~> sledgehammer available_provers
   334     INCOMPATIBILITY.
   335   - Renamed options:
   336     sledgehammer [atps = ...] ~> sledgehammer [provers = ...]
   337     sledgehammer [atp = ...] ~> sledgehammer [prover = ...]
   338     sledgehammer [timeout = 77 s] ~> sledgehammer [timeout = 77]
   339     (and "ms" and "min" are no longer supported)
   340     INCOMPATIBILITY.
   341 
   342 * Nitpick:
   343   - Renamed options:
   344     nitpick [timeout = 77 s] ~> nitpick [timeout = 77]
   345     nitpick [tac_timeout = 777 ms] ~> nitpick [tac_timeout = 0.777]
   346     INCOMPATIBILITY.
   347   - Added support for partial quotient types.
   348   - Added local versions of the "Nitpick.register_xxx" functions.
   349   - Added "whack" option.
   350   - Allow registration of quotient types as codatatypes.
   351   - Improved "merge_type_vars" option to merge more types.
   352   - Removed unsound "fast_descrs" option.
   353   - Added custom symmetry breaking for datatypes, making it possible to reach
   354     higher cardinalities.
   355   - Prevent the expansion of too large definitions.
   356 
   357 * Proof methods "metis" and "meson" now have configuration options
   358 "meson_trace", "metis_trace", and "metis_verbose" that can be enabled
   359 to diagnose these tools. E.g.
   360 
   361     using [[metis_trace = true]]
   362 
   363 * Auto Solve: Renamed "Auto Solve Direct".  The tool is now available
   364 manually as command 'solve_direct'.
   365 
   366 * The default SMT solver Z3 must be enabled explicitly (due to
   367 licensing issues) by setting the environment variable
   368 Z3_NON_COMMERCIAL in etc/settings of the component, for example.  For
   369 commercial applications, the SMT solver CVC3 is provided as fall-back;
   370 changing the SMT solver is done via the configuration option
   371 "smt_solver".
   372 
   373 * Remote SMT solvers need to be referred to by the "remote_" prefix,
   374 i.e. "remote_cvc3" and "remote_z3".
   375 
   376 * Added basic SMT support for datatypes, records, and typedefs using
   377 the oracle mode (no proofs).  Direct support of pairs has been dropped
   378 in exchange (pass theorems fst_conv snd_conv pair_collapse to the SMT
   379 support for a similar behavior).  Minor INCOMPATIBILITY.
   380 
   381 * Changed SMT configuration options:
   382   - Renamed:
   383     z3_proofs ~> smt_oracle (with inverted meaning)
   384     z3_trace_assms ~> smt_trace_used_facts
   385     INCOMPATIBILITY.
   386   - Added:
   387     smt_verbose
   388     smt_random_seed
   389     smt_datatypes
   390     smt_infer_triggers
   391     smt_monomorph_limit
   392     cvc3_options
   393     remote_cvc3_options
   394     remote_z3_options
   395     yices_options
   396 
   397 * Boogie output files (.b2i files) need to be declared in the theory
   398 header.
   399 
   400 * Simplification procedure "list_to_set_comprehension" rewrites list
   401 comprehensions applied to List.set to set comprehensions.  Occasional
   402 INCOMPATIBILITY, may be deactivated like this:
   403 
   404   declare [[simproc del: list_to_set_comprehension]]
   405 
   406 * Removed old version of primrec package.  INCOMPATIBILITY.
   407 
   408 * Removed simplifier congruence rule of "prod_case", as has for long
   409 been the case with "split".  INCOMPATIBILITY.
   410 
   411 * String.literal is a type, but not a datatype.  INCOMPATIBILITY.
   412 
   413 * Removed [split_format ... and ... and ...] version of
   414 [split_format].  Potential INCOMPATIBILITY.
   415 
   416 * Predicate "sorted" now defined inductively, with nice induction
   417 rules.  INCOMPATIBILITY: former sorted.simps now named sorted_simps.
   418 
   419 * Constant "contents" renamed to "the_elem", to free the generic name
   420 contents for other uses.  INCOMPATIBILITY.
   421 
   422 * Renamed class eq and constant eq (for code generation) to class
   423 equal and constant equal, plus renaming of related facts and various
   424 tuning.  INCOMPATIBILITY.
   425 
   426 * Dropped type classes mult_mono and mult_mono1.  INCOMPATIBILITY.
   427 
   428 * Removed output syntax "'a ~=> 'b" for "'a => 'b option".
   429 INCOMPATIBILITY.
   430 
   431 * Renamed theory Fset to Cset, type Fset.fset to Cset.set, in order to
   432 avoid confusion with finite sets.  INCOMPATIBILITY.
   433 
   434 * Abandoned locales equiv, congruent and congruent2 for equivalence
   435 relations.  INCOMPATIBILITY: use equivI rather than equiv_intro (same
   436 for congruent(2)).
   437 
   438 * Some previously unqualified names have been qualified:
   439 
   440   types
   441     bool ~> HOL.bool
   442     nat ~> Nat.nat
   443 
   444   constants
   445     Trueprop ~> HOL.Trueprop
   446     True ~> HOL.True
   447     False ~> HOL.False
   448     op & ~> HOL.conj
   449     op | ~> HOL.disj
   450     op --> ~> HOL.implies
   451     op = ~> HOL.eq
   452     Not ~> HOL.Not
   453     The ~> HOL.The
   454     All ~> HOL.All
   455     Ex ~> HOL.Ex
   456     Ex1 ~> HOL.Ex1
   457     Let ~> HOL.Let
   458     If ~> HOL.If
   459     Ball ~> Set.Ball
   460     Bex ~> Set.Bex
   461     Suc ~> Nat.Suc
   462     Pair ~> Product_Type.Pair
   463     fst ~> Product_Type.fst
   464     snd ~> Product_Type.snd
   465     curry ~> Product_Type.curry
   466     op : ~> Set.member
   467     Collect ~> Set.Collect
   468 
   469 INCOMPATIBILITY.
   470 
   471 * More canonical naming convention for some fundamental definitions:
   472 
   473     bot_bool_eq ~> bot_bool_def
   474     top_bool_eq ~> top_bool_def
   475     inf_bool_eq ~> inf_bool_def
   476     sup_bool_eq ~> sup_bool_def
   477     bot_fun_eq  ~> bot_fun_def
   478     top_fun_eq  ~> top_fun_def
   479     inf_fun_eq  ~> inf_fun_def
   480     sup_fun_eq  ~> sup_fun_def
   481 
   482 INCOMPATIBILITY.
   483 
   484 * More stylized fact names:
   485 
   486   expand_fun_eq ~> fun_eq_iff
   487   expand_set_eq ~> set_eq_iff
   488   set_ext       ~> set_eqI
   489   nat_number    ~> eval_nat_numeral
   490 
   491 INCOMPATIBILITY.
   492 
   493 * Refactoring of code-generation specific operations in theory List:
   494 
   495   constants
   496     null ~> List.null
   497 
   498   facts
   499     mem_iff ~> member_def
   500     null_empty ~> null_def
   501 
   502 INCOMPATIBILITY.  Note that these were not supposed to be used
   503 regularly unless for striking reasons; their main purpose was code
   504 generation.
   505 
   506 Various operations from the Haskell prelude are used for generating
   507 Haskell code.
   508 
   509 * Term "bij f" is now an abbreviation of "bij_betw f UNIV UNIV".  Term
   510 "surj f" is now an abbreviation of "range f = UNIV".  The theorems
   511 bij_def and surj_def are unchanged.  INCOMPATIBILITY.
   512 
   513 * Abolished some non-alphabetic type names: "prod" and "sum" replace
   514 "*" and "+" respectively.  INCOMPATIBILITY.
   515 
   516 * Name "Plus" of disjoint sum operator "<+>" is now hidden.  Write
   517 "Sum_Type.Plus" instead.
   518 
   519 * Constant "split" has been merged with constant "prod_case"; names of
   520 ML functions, facts etc. involving split have been retained so far,
   521 though.  INCOMPATIBILITY.
   522 
   523 * Dropped old infix syntax "_ mem _" for List.member; use "_ : set _"
   524 instead.  INCOMPATIBILITY.
   525 
   526 * Removed lemma "Option.is_none_none" which duplicates "is_none_def".
   527 INCOMPATIBILITY.
   528 
   529 * Former theory Library/Enum is now part of the HOL-Main image.
   530 INCOMPATIBILITY: all constants of the Enum theory now have to be
   531 referred to by its qualified name.
   532 
   533   enum    ~>  Enum.enum
   534   nlists  ~>  Enum.nlists
   535   product ~>  Enum.product
   536 
   537 * Theory Library/Monad_Syntax provides do-syntax for monad types.
   538 Syntax in Library/State_Monad has been changed to avoid ambiguities.
   539 INCOMPATIBILITY.
   540 
   541 * Theory Library/SetsAndFunctions has been split into
   542 Library/Function_Algebras and Library/Set_Algebras; canonical names
   543 for instance definitions for functions; various improvements.
   544 INCOMPATIBILITY.
   545 
   546 * Theory Library/Multiset provides stable quicksort implementation of
   547 sort_key.
   548 
   549 * Theory Library/Multiset: renamed empty_idemp ~> empty_neutral.
   550 INCOMPATIBILITY.
   551 
   552 * Session Multivariate_Analysis: introduced a type class for euclidean
   553 space.  Most theorems are now stated in terms of euclidean spaces
   554 instead of finite cartesian products.
   555 
   556   types
   557     real ^ 'n ~>  'a::real_vector
   558               ~>  'a::euclidean_space
   559               ~>  'a::ordered_euclidean_space
   560         (depends on your needs)
   561 
   562   constants
   563      _ $ _        ~> _ $$ _
   564      \<chi> x. _  ~> \<chi>\<chi> x. _
   565      CARD('n)     ~> DIM('a)
   566 
   567 Also note that the indices are now natural numbers and not from some
   568 finite type. Finite cartesian products of euclidean spaces, products
   569 of euclidean spaces the real and complex numbers are instantiated to
   570 be euclidean_spaces.  INCOMPATIBILITY.
   571 
   572 * Session Probability: introduced pextreal as positive extended real
   573 numbers.  Use pextreal as value for measures.  Introduce the
   574 Radon-Nikodym derivative, product spaces and Fubini's theorem for
   575 arbitrary sigma finite measures.  Introduces Lebesgue measure based on
   576 the integral in Multivariate Analysis.  INCOMPATIBILITY.
   577 
   578 * Session Imperative_HOL: revamped, corrected dozens of inadequacies.
   579 INCOMPATIBILITY.
   580 
   581 * Session SPARK (with image HOL-SPARK) provides commands to load and
   582 prove verification conditions generated by the SPARK Ada program
   583 verifier.  See also src/HOL/SPARK and src/HOL/SPARK/Examples.
   584 
   585 
   586 *** HOL-Algebra ***
   587 
   588 * Theorems for additive ring operations (locale abelian_monoid and
   589 descendants) are generated by interpretation from their multiplicative
   590 counterparts.  Names (in particular theorem names) have the mandatory
   591 qualifier 'add'.  Previous theorem names are redeclared for
   592 compatibility.
   593 
   594 * Structure "int_ring" is now an abbreviation (previously a
   595 definition).  This fits more natural with advanced interpretations.
   596 
   597 
   598 *** HOLCF ***
   599 
   600 * The domain package now runs in definitional mode by default: The
   601 former command 'new_domain' is now called 'domain'.  To use the domain
   602 package in its original axiomatic mode, use 'domain (unsafe)'.
   603 INCOMPATIBILITY.
   604 
   605 * The new class "domain" is now the default sort.  Class "predomain"
   606 is an unpointed version of "domain". Theories can be updated by
   607 replacing sort annotations as shown below.  INCOMPATIBILITY.
   608 
   609   'a::type ~> 'a::countable
   610   'a::cpo  ~> 'a::predomain
   611   'a::pcpo ~> 'a::domain
   612 
   613 * The old type class "rep" has been superseded by class "domain".
   614 Accordingly, users of the definitional package must remove any
   615 "default_sort rep" declarations.  INCOMPATIBILITY.
   616 
   617 * The domain package (definitional mode) now supports unpointed
   618 predomain argument types, as long as they are marked 'lazy'. (Strict
   619 arguments must be in class "domain".) For example, the following
   620 domain definition now works:
   621 
   622   domain natlist = nil | cons (lazy "nat discr") (lazy "natlist")
   623 
   624 * Theory HOLCF/Library/HOL_Cpo provides cpo and predomain class
   625 instances for types from main HOL: bool, nat, int, char, 'a + 'b,
   626 'a option, and 'a list.  Additionally, it configures fixrec and the
   627 domain package to work with these types.  For example:
   628 
   629   fixrec isInl :: "('a + 'b) u -> tr"
   630     where "isInl$(up$(Inl x)) = TT" | "isInl$(up$(Inr y)) = FF"
   631 
   632   domain V = VFun (lazy "V -> V") | VCon (lazy "nat") (lazy "V list")
   633 
   634 * The "(permissive)" option of fixrec has been replaced with a
   635 per-equation "(unchecked)" option. See
   636 src/HOL/HOLCF/Tutorial/Fixrec_ex.thy for examples. INCOMPATIBILITY.
   637 
   638 * The "bifinite" class no longer fixes a constant "approx"; the class
   639 now just asserts that such a function exists.  INCOMPATIBILITY.
   640 
   641 * Former type "alg_defl" has been renamed to "defl".  HOLCF no longer
   642 defines an embedding of type 'a defl into udom by default; instances
   643 of "bifinite" and "domain" classes are available in
   644 src/HOL/HOLCF/Library/Defl_Bifinite.thy.
   645 
   646 * The syntax "REP('a)" has been replaced with "DEFL('a)".
   647 
   648 * The predicate "directed" has been removed.  INCOMPATIBILITY.
   649 
   650 * The type class "finite_po" has been removed.  INCOMPATIBILITY.
   651 
   652 * The function "cprod_map" has been renamed to "prod_map".
   653 INCOMPATIBILITY.
   654 
   655 * The monadic bind operator on each powerdomain has new binder syntax
   656 similar to sets, e.g. "\<Union>\<sharp>x\<in>xs. t" represents
   657 "upper_bind\<cdot>xs\<cdot>(\<Lambda> x. t)".
   658 
   659 * The infix syntax for binary union on each powerdomain has changed
   660 from e.g. "+\<sharp>" to "\<union>\<sharp>", for consistency with set
   661 syntax.  INCOMPATIBILITY.
   662 
   663 * The constant "UU" has been renamed to "bottom".  The syntax "UU" is
   664 still supported as an input translation.
   665 
   666 * Renamed some theorems (the original names are also still available).
   667 
   668   expand_fun_below   ~> fun_below_iff
   669   below_fun_ext      ~> fun_belowI
   670   expand_cfun_eq     ~> cfun_eq_iff
   671   ext_cfun           ~> cfun_eqI
   672   expand_cfun_below  ~> cfun_below_iff
   673   below_cfun_ext     ~> cfun_belowI
   674   cont2cont_Rep_CFun ~> cont2cont_APP
   675 
   676 * The Abs and Rep functions for various types have changed names.
   677 Related theorem names have also changed to match. INCOMPATIBILITY.
   678 
   679   Rep_CFun  ~> Rep_cfun
   680   Abs_CFun  ~> Abs_cfun
   681   Rep_Sprod ~> Rep_sprod
   682   Abs_Sprod ~> Abs_sprod
   683   Rep_Ssum  ~> Rep_ssum
   684   Abs_Ssum  ~> Abs_ssum
   685 
   686 * Lemmas with names of the form *_defined_iff or *_strict_iff have
   687 been renamed to *_bottom_iff.  INCOMPATIBILITY.
   688 
   689 * Various changes to bisimulation/coinduction with domain package:
   690 
   691   - Definitions of "bisim" constants no longer mention definedness.
   692   - With mutual recursion, "bisim" predicate is now curried.
   693   - With mutual recursion, each type gets a separate coind theorem.
   694   - Variable names in bisim_def and coinduct rules have changed.
   695 
   696 INCOMPATIBILITY.
   697 
   698 * Case combinators generated by the domain package for type "foo" are
   699 now named "foo_case" instead of "foo_when".  INCOMPATIBILITY.
   700 
   701 * Several theorems have been renamed to more accurately reflect the
   702 names of constants and types involved.  INCOMPATIBILITY.
   703 
   704   thelub_const    ~> lub_const
   705   lub_const       ~> is_lub_const
   706   thelubI         ~> lub_eqI
   707   is_lub_lub      ~> is_lubD2
   708   lubI            ~> is_lub_lub
   709   unique_lub      ~> is_lub_unique
   710   is_ub_lub       ~> is_lub_rangeD1
   711   lub_bin_chain   ~> is_lub_bin_chain
   712   lub_fun         ~> is_lub_fun
   713   thelub_fun      ~> lub_fun
   714   thelub_cfun     ~> lub_cfun
   715   thelub_Pair     ~> lub_Pair
   716   lub_cprod       ~> is_lub_prod
   717   thelub_cprod    ~> lub_prod
   718   minimal_cprod   ~> minimal_prod
   719   inst_cprod_pcpo ~> inst_prod_pcpo
   720   UU_I            ~> bottomI
   721   compact_UU      ~> compact_bottom
   722   deflation_UU    ~> deflation_bottom
   723   finite_deflation_UU ~> finite_deflation_bottom
   724 
   725 * Many legacy theorem names have been discontinued.  INCOMPATIBILITY.
   726 
   727   sq_ord_less_eq_trans ~> below_eq_trans
   728   sq_ord_eq_less_trans ~> eq_below_trans
   729   refl_less            ~> below_refl
   730   trans_less           ~> below_trans
   731   antisym_less         ~> below_antisym
   732   antisym_less_inverse ~> po_eq_conv [THEN iffD1]
   733   box_less             ~> box_below
   734   rev_trans_less       ~> rev_below_trans
   735   not_less2not_eq      ~> not_below2not_eq
   736   less_UU_iff          ~> below_UU_iff
   737   flat_less_iff        ~> flat_below_iff
   738   adm_less             ~> adm_below
   739   adm_not_less         ~> adm_not_below
   740   adm_compact_not_less ~> adm_compact_not_below
   741   less_fun_def         ~> below_fun_def
   742   expand_fun_less      ~> fun_below_iff
   743   less_fun_ext         ~> fun_belowI
   744   less_discr_def       ~> below_discr_def
   745   discr_less_eq        ~> discr_below_eq
   746   less_unit_def        ~> below_unit_def
   747   less_cprod_def       ~> below_prod_def
   748   prod_lessI           ~> prod_belowI
   749   Pair_less_iff        ~> Pair_below_iff
   750   fst_less_iff         ~> fst_below_iff
   751   snd_less_iff         ~> snd_below_iff
   752   expand_cfun_less     ~> cfun_below_iff
   753   less_cfun_ext        ~> cfun_belowI
   754   injection_less       ~> injection_below
   755   less_up_def          ~> below_up_def
   756   not_Iup_less         ~> not_Iup_below
   757   Iup_less             ~> Iup_below
   758   up_less              ~> up_below
   759   Def_inject_less_eq   ~> Def_below_Def
   760   Def_less_is_eq       ~> Def_below_iff
   761   spair_less_iff       ~> spair_below_iff
   762   less_sprod           ~> below_sprod
   763   spair_less           ~> spair_below
   764   sfst_less_iff        ~> sfst_below_iff
   765   ssnd_less_iff        ~> ssnd_below_iff
   766   fix_least_less       ~> fix_least_below
   767   dist_less_one        ~> dist_below_one
   768   less_ONE             ~> below_ONE
   769   ONE_less_iff         ~> ONE_below_iff
   770   less_sinlD           ~> below_sinlD
   771   less_sinrD           ~> below_sinrD
   772 
   773 
   774 *** FOL and ZF ***
   775 
   776 * All constant names are now qualified internally and use proper
   777 identifiers, e.g. "IFOL.eq" instead of "op =".  INCOMPATIBILITY.
   778 
   779 
   780 *** ML ***
   781 
   782 * Antiquotation @{assert} inlines a function bool -> unit that raises
   783 Fail if the argument is false.  Due to inlining the source position of
   784 failed assertions is included in the error output.
   785 
   786 * Discontinued antiquotation @{theory_ref}, which is obsolete since ML
   787 text is in practice always evaluated with a stable theory checkpoint.
   788 Minor INCOMPATIBILITY, use (Theory.check_thy @{theory}) instead.
   789 
   790 * Antiquotation @{theory A} refers to theory A from the ancestry of
   791 the current context, not any accidental theory loader state as before.
   792 Potential INCOMPATIBILITY, subtle change in semantics.
   793 
   794 * Syntax.pretty_priority (default 0) configures the required priority
   795 of pretty-printed output and thus affects insertion of parentheses.
   796 
   797 * Syntax.default_root (default "any") configures the inner syntax
   798 category (nonterminal symbol) for parsing of terms.
   799 
   800 * Former exception Library.UnequalLengths now coincides with
   801 ListPair.UnequalLengths.
   802 
   803 * Renamed structure MetaSimplifier to Raw_Simplifier.  Note that the
   804 main functionality is provided by structure Simplifier.
   805 
   806 * Renamed raw "explode" function to "raw_explode" to emphasize its
   807 meaning.  Note that internally to Isabelle, Symbol.explode is used in
   808 almost all situations.
   809 
   810 * Discontinued obsolete function sys_error and exception SYS_ERROR.
   811 See implementation manual for further details on exceptions in
   812 Isabelle/ML.
   813 
   814 * Renamed setmp_noncritical to Unsynchronized.setmp to emphasize its
   815 meaning.
   816 
   817 * Renamed structure PureThy to Pure_Thy and moved most of its
   818 operations to structure Global_Theory, to emphasize that this is
   819 rarely-used global-only stuff.
   820 
   821 * Discontinued Output.debug.  Minor INCOMPATIBILITY, use plain writeln
   822 instead (or tracing for high-volume output).
   823 
   824 * Configuration option show_question_marks only affects regular pretty
   825 printing of types and terms, not raw Term.string_of_vname.
   826 
   827 * ML_Context.thm and ML_Context.thms are no longer pervasive.  Rare
   828 INCOMPATIBILITY, superseded by static antiquotations @{thm} and
   829 @{thms} for most purposes.
   830 
   831 * ML structure Unsynchronized is never opened, not even in Isar
   832 interaction mode as before.  Old Unsynchronized.set etc. have been
   833 discontinued -- use plain := instead.  This should be *rare* anyway,
   834 since modern tools always work via official context data, notably
   835 configuration options.
   836 
   837 * Parallel and asynchronous execution requires special care concerning
   838 interrupts.  Structure Exn provides some convenience functions that
   839 avoid working directly with raw Interrupt.  User code must not absorb
   840 interrupts -- intermediate handling (for cleanup etc.) needs to be
   841 followed by re-raising of the original exception.  Another common
   842 source of mistakes are "handle _" patterns, which make the meaning of
   843 the program subject to physical effects of the environment.
   844 
   845 
   846 
   847 New in Isabelle2009-2 (June 2010)
   848 ---------------------------------
   849 
   850 *** General ***
   851 
   852 * Authentic syntax for *all* logical entities (type classes, type
   853 constructors, term constants): provides simple and robust
   854 correspondence between formal entities and concrete syntax.  Within
   855 the parse tree / AST representations, "constants" are decorated by
   856 their category (class, type, const) and spelled out explicitly with
   857 their full internal name.
   858 
   859 Substantial INCOMPATIBILITY concerning low-level syntax declarations
   860 and translations (translation rules and translation functions in ML).
   861 Some hints on upgrading:
   862 
   863   - Many existing uses of 'syntax' and 'translations' can be replaced
   864     by more modern 'type_notation', 'notation' and 'abbreviation',
   865     which are independent of this issue.
   866 
   867   - 'translations' require markup within the AST; the term syntax
   868     provides the following special forms:
   869 
   870       CONST c   -- produces syntax version of constant c from context
   871       XCONST c  -- literally c, checked as constant from context
   872       c         -- literally c, if declared by 'syntax'
   873 
   874     Plain identifiers are treated as AST variables -- occasionally the
   875     system indicates accidental variables via the error "rhs contains
   876     extra variables".
   877 
   878     Type classes and type constructors are marked according to their
   879     concrete syntax.  Some old translations rules need to be written
   880     for the "type" category, using type constructor application
   881     instead of pseudo-term application of the default category
   882     "logic".
   883 
   884   - 'parse_translation' etc. in ML may use the following
   885     antiquotations:
   886 
   887       @{class_syntax c}   -- type class c within parse tree / AST
   888       @{term_syntax c}    -- type constructor c within parse tree / AST
   889       @{const_syntax c}   -- ML version of "CONST c" above
   890       @{syntax_const c}   -- literally c (checked wrt. 'syntax' declarations)
   891 
   892   - Literal types within 'typed_print_translations', i.e. those *not*
   893     represented as pseudo-terms are represented verbatim.  Use @{class
   894     c} or @{type_name c} here instead of the above syntax
   895     antiquotations.
   896 
   897 Note that old non-authentic syntax was based on unqualified base
   898 names, so all of the above "constant" names would coincide.  Recall
   899 that 'print_syntax' and ML_command "set Syntax.trace_ast" help to
   900 diagnose syntax problems.
   901 
   902 * Type constructors admit general mixfix syntax, not just infix.
   903 
   904 * Concrete syntax may be attached to local entities without a proof
   905 body, too.  This works via regular mixfix annotations for 'fix',
   906 'def', 'obtain' etc. or via the explicit 'write' command, which is
   907 similar to the 'notation' command in theory specifications.
   908 
   909 * Discontinued unnamed infix syntax (legacy feature for many years) --
   910 need to specify constant name and syntax separately.  Internal ML
   911 datatype constructors have been renamed from InfixName to Infix etc.
   912 Minor INCOMPATIBILITY.
   913 
   914 * Schematic theorem statements need to be explicitly markup as such,
   915 via commands 'schematic_lemma', 'schematic_theorem',
   916 'schematic_corollary'.  Thus the relevance of the proof is made
   917 syntactically clear, which impacts performance in a parallel or
   918 asynchronous interactive environment.  Minor INCOMPATIBILITY.
   919 
   920 * Use of cumulative prems via "!" in some proof methods has been
   921 discontinued (old legacy feature).
   922 
   923 * References 'trace_simp' and 'debug_simp' have been replaced by
   924 configuration options stored in the context. Enabling tracing (the
   925 case of debugging is similar) in proofs works via
   926 
   927   using [[trace_simp = true]]
   928 
   929 Tracing is then active for all invocations of the simplifier in
   930 subsequent goal refinement steps. Tracing may also still be enabled or
   931 disabled via the ProofGeneral settings menu.
   932 
   933 * Separate commands 'hide_class', 'hide_type', 'hide_const',
   934 'hide_fact' replace the former 'hide' KIND command.  Minor
   935 INCOMPATIBILITY.
   936 
   937 * Improved parallelism of proof term normalization: usedir -p2 -q0 is
   938 more efficient than combinations with -q1 or -q2.
   939 
   940 
   941 *** Pure ***
   942 
   943 * Proofterms record type-class reasoning explicitly, using the
   944 "unconstrain" operation internally.  This eliminates all sort
   945 constraints from a theorem and proof, introducing explicit
   946 OFCLASS-premises.  On the proof term level, this operation is
   947 automatically applied at theorem boundaries, such that closed proofs
   948 are always free of sort constraints.  INCOMPATIBILITY for tools that
   949 inspect proof terms.
   950 
   951 * Local theory specifications may depend on extra type variables that
   952 are not present in the result type -- arguments TYPE('a) :: 'a itself
   953 are added internally.  For example:
   954 
   955   definition unitary :: bool where "unitary = (ALL (x::'a) y. x = y)"
   956 
   957 * Predicates of locales introduced by classes carry a mandatory
   958 "class" prefix.  INCOMPATIBILITY.
   959 
   960 * Vacuous class specifications observe default sort.  INCOMPATIBILITY.
   961 
   962 * Old 'axclass' command has been discontinued.  INCOMPATIBILITY, use
   963 'class' instead.
   964 
   965 * Command 'code_reflect' allows to incorporate generated ML code into
   966 runtime environment; replaces immature code_datatype antiquotation.
   967 INCOMPATIBILITY.
   968 
   969 * Code generator: simple concept for abstract datatypes obeying
   970 invariants.
   971 
   972 * Code generator: details of internal data cache have no impact on the
   973 user space functionality any longer.
   974 
   975 * Methods "unfold_locales" and "intro_locales" ignore non-locale
   976 subgoals.  This is more appropriate for interpretations with 'where'.
   977 INCOMPATIBILITY.
   978 
   979 * Command 'example_proof' opens an empty proof body.  This allows to
   980 experiment with Isar, without producing any persistent result.
   981 
   982 * Commands 'type_notation' and 'no_type_notation' declare type syntax
   983 within a local theory context, with explicit checking of the
   984 constructors involved (in contrast to the raw 'syntax' versions).
   985 
   986 * Commands 'types' and 'typedecl' now work within a local theory
   987 context -- without introducing dependencies on parameters or
   988 assumptions, which is not possible in Isabelle/Pure.
   989 
   990 * Command 'defaultsort' has been renamed to 'default_sort', it works
   991 within a local theory context.  Minor INCOMPATIBILITY.
   992 
   993 
   994 *** HOL ***
   995 
   996 * Command 'typedef' now works within a local theory context -- without
   997 introducing dependencies on parameters or assumptions, which is not
   998 possible in Isabelle/Pure/HOL.  Note that the logical environment may
   999 contain multiple interpretations of local typedefs (with different
  1000 non-emptiness proofs), even in a global theory context.
  1001 
  1002 * New package for quotient types.  Commands 'quotient_type' and
  1003 'quotient_definition' may be used for defining types and constants by
  1004 quotient constructions.  An example is the type of integers created by
  1005 quotienting pairs of natural numbers:
  1006 
  1007   fun
  1008     intrel :: "(nat * nat) => (nat * nat) => bool"
  1009   where
  1010     "intrel (x, y) (u, v) = (x + v = u + y)"
  1011 
  1012   quotient_type int = "nat * nat" / intrel
  1013     by (auto simp add: equivp_def expand_fun_eq)
  1014 
  1015   quotient_definition
  1016     "0::int" is "(0::nat, 0::nat)"
  1017 
  1018 The method "lifting" can be used to lift of theorems from the
  1019 underlying "raw" type to the quotient type.  The example
  1020 src/HOL/Quotient_Examples/FSet.thy includes such a quotient
  1021 construction and provides a reasoning infrastructure for finite sets.
  1022 
  1023 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
  1024 clash with new theory Quotient in Main HOL.
  1025 
  1026 * Moved the SMT binding into the main HOL session, eliminating
  1027 separate HOL-SMT session.
  1028 
  1029 * List membership infix mem operation is only an input abbreviation.
  1030 INCOMPATIBILITY.
  1031 
  1032 * Theory Library/Word.thy has been removed.  Use library Word/Word.thy
  1033 for future developements; former Library/Word.thy is still present in
  1034 the AFP entry RSAPPS.
  1035 
  1036 * Theorem Int.int_induct renamed to Int.int_of_nat_induct and is no
  1037 longer shadowed.  INCOMPATIBILITY.
  1038 
  1039 * Dropped theorem duplicate comp_arith; use semiring_norm instead.
  1040 INCOMPATIBILITY.
  1041 
  1042 * Dropped theorem RealPow.real_sq_order; use power2_le_imp_le instead.
  1043 INCOMPATIBILITY.
  1044 
  1045 * Dropped normalizing_semiring etc; use the facts in semiring classes
  1046 instead.  INCOMPATIBILITY.
  1047 
  1048 * Dropped several real-specific versions of lemmas about floor and
  1049 ceiling; use the generic lemmas from theory "Archimedean_Field"
  1050 instead.  INCOMPATIBILITY.
  1051 
  1052   floor_number_of_eq         ~> floor_number_of
  1053   le_floor_eq_number_of      ~> number_of_le_floor
  1054   le_floor_eq_zero           ~> zero_le_floor
  1055   le_floor_eq_one            ~> one_le_floor
  1056   floor_less_eq_number_of    ~> floor_less_number_of
  1057   floor_less_eq_zero         ~> floor_less_zero
  1058   floor_less_eq_one          ~> floor_less_one
  1059   less_floor_eq_number_of    ~> number_of_less_floor
  1060   less_floor_eq_zero         ~> zero_less_floor
  1061   less_floor_eq_one          ~> one_less_floor
  1062   floor_le_eq_number_of      ~> floor_le_number_of
  1063   floor_le_eq_zero           ~> floor_le_zero
  1064   floor_le_eq_one            ~> floor_le_one
  1065   floor_subtract_number_of   ~> floor_diff_number_of
  1066   floor_subtract_one         ~> floor_diff_one
  1067   ceiling_number_of_eq       ~> ceiling_number_of
  1068   ceiling_le_eq_number_of    ~> ceiling_le_number_of
  1069   ceiling_le_zero_eq         ~> ceiling_le_zero
  1070   ceiling_le_eq_one          ~> ceiling_le_one
  1071   less_ceiling_eq_number_of  ~> number_of_less_ceiling
  1072   less_ceiling_eq_zero       ~> zero_less_ceiling
  1073   less_ceiling_eq_one        ~> one_less_ceiling
  1074   ceiling_less_eq_number_of  ~> ceiling_less_number_of
  1075   ceiling_less_eq_zero       ~> ceiling_less_zero
  1076   ceiling_less_eq_one        ~> ceiling_less_one
  1077   le_ceiling_eq_number_of    ~> number_of_le_ceiling
  1078   le_ceiling_eq_zero         ~> zero_le_ceiling
  1079   le_ceiling_eq_one          ~> one_le_ceiling
  1080   ceiling_subtract_number_of ~> ceiling_diff_number_of
  1081   ceiling_subtract_one       ~> ceiling_diff_one
  1082 
  1083 * Theory "Finite_Set": various folding_XXX locales facilitate the
  1084 application of the various fold combinators on finite sets.
  1085 
  1086 * Library theory "RBT" renamed to "RBT_Impl"; new library theory "RBT"
  1087 provides abstract red-black tree type which is backed by "RBT_Impl" as
  1088 implementation.  INCOMPATIBILTY.
  1089 
  1090 * Theory Library/Coinductive_List has been removed -- superseded by
  1091 AFP/thys/Coinductive.
  1092 
  1093 * Theory PReal, including the type "preal" and related operations, has
  1094 been removed.  INCOMPATIBILITY.
  1095 
  1096 * Real: new development using Cauchy Sequences.
  1097 
  1098 * Split off theory "Big_Operators" containing setsum, setprod,
  1099 Inf_fin, Sup_fin, Min, Max from theory Finite_Set.  INCOMPATIBILITY.
  1100 
  1101 * Theory "Rational" renamed to "Rat", for consistency with "Nat",
  1102 "Int" etc.  INCOMPATIBILITY.
  1103 
  1104 * Constant Rat.normalize needs to be qualified.  INCOMPATIBILITY.
  1105 
  1106 * New set of rules "ac_simps" provides combined assoc / commute
  1107 rewrites for all interpretations of the appropriate generic locales.
  1108 
  1109 * Renamed theory "OrderedGroup" to "Groups" and split theory
  1110 "Ring_and_Field" into theories "Rings" and "Fields"; for more
  1111 appropriate and more consistent names suitable for name prefixes
  1112 within the HOL theories.  INCOMPATIBILITY.
  1113 
  1114 * Some generic constants have been put to appropriate theories:
  1115   - less_eq, less: Orderings
  1116   - zero, one, plus, minus, uminus, times, abs, sgn: Groups
  1117   - inverse, divide: Rings
  1118 INCOMPATIBILITY.
  1119 
  1120 * More consistent naming of type classes involving orderings (and
  1121 lattices):
  1122 
  1123     lower_semilattice                   ~> semilattice_inf
  1124     upper_semilattice                   ~> semilattice_sup
  1125 
  1126     dense_linear_order                  ~> dense_linorder
  1127 
  1128     pordered_ab_group_add               ~> ordered_ab_group_add
  1129     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
  1130     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
  1131     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
  1132     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
  1133     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
  1134     pordered_cancel_semiring            ~> ordered_cancel_semiring
  1135     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
  1136     pordered_comm_ring                  ~> ordered_comm_ring
  1137     pordered_comm_semiring              ~> ordered_comm_semiring
  1138     pordered_ring                       ~> ordered_ring
  1139     pordered_ring_abs                   ~> ordered_ring_abs
  1140     pordered_semiring                   ~> ordered_semiring
  1141 
  1142     ordered_ab_group_add                ~> linordered_ab_group_add
  1143     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
  1144     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
  1145     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
  1146     ordered_field                       ~> linordered_field
  1147     ordered_field_no_lb                 ~> linordered_field_no_lb
  1148     ordered_field_no_ub                 ~> linordered_field_no_ub
  1149     ordered_field_dense_linear_order    ~> dense_linordered_field
  1150     ordered_idom                        ~> linordered_idom
  1151     ordered_ring                        ~> linordered_ring
  1152     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
  1153     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
  1154     ordered_ring_strict                 ~> linordered_ring_strict
  1155     ordered_semidom                     ~> linordered_semidom
  1156     ordered_semiring                    ~> linordered_semiring
  1157     ordered_semiring_1                  ~> linordered_semiring_1
  1158     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
  1159     ordered_semiring_strict             ~> linordered_semiring_strict
  1160 
  1161   The following slightly odd type classes have been moved to a
  1162   separate theory Library/Lattice_Algebras:
  1163 
  1164     lordered_ab_group_add               ~> lattice_ab_group_add
  1165     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
  1166     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
  1167     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
  1168     lordered_ring                       ~> lattice_ring
  1169 
  1170 INCOMPATIBILITY.
  1171 
  1172 * Refined field classes:
  1173   - classes division_ring_inverse_zero, field_inverse_zero,
  1174     linordered_field_inverse_zero include rule inverse 0 = 0 --
  1175     subsumes former division_by_zero class;
  1176   - numerous lemmas have been ported from field to division_ring.
  1177 INCOMPATIBILITY.
  1178 
  1179 * Refined algebra theorem collections:
  1180   - dropped theorem group group_simps, use algebra_simps instead;
  1181   - dropped theorem group ring_simps, use field_simps instead;
  1182   - proper theorem collection field_simps subsumes former theorem
  1183     groups field_eq_simps and field_simps;
  1184   - dropped lemma eq_minus_self_iff which is a duplicate for
  1185     equal_neg_zero.
  1186 INCOMPATIBILITY.
  1187 
  1188 * Theory Finite_Set and List: some lemmas have been generalized from
  1189 sets to lattices:
  1190 
  1191   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
  1192   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
  1193   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
  1194   union_Union_fold_union        ~> sup_Sup_fold_sup
  1195   Inter_fold_inter              ~> Inf_fold_inf
  1196   Union_fold_union              ~> Sup_fold_sup
  1197   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
  1198   union_UNION_fold_union        ~> sup_SUPR_fold_sup
  1199   INTER_fold_inter              ~> INFI_fold_inf
  1200   UNION_fold_union              ~> SUPR_fold_sup
  1201 
  1202 * Theory "Complete_Lattice": lemmas top_def and bot_def have been
  1203 replaced by the more convenient lemmas Inf_empty and Sup_empty.
  1204 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
  1205 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
  1206 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
  1207 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
  1208 
  1209 * Reorganized theory Multiset: swapped notation of pointwise and
  1210 multiset order:
  1211 
  1212   - pointwise ordering is instance of class order with standard syntax
  1213     <= and <;
  1214   - multiset ordering has syntax <=# and <#; partial order properties
  1215     are provided by means of interpretation with prefix
  1216     multiset_order;
  1217   - less duplication, less historical organization of sections,
  1218     conversion from associations lists to multisets, rudimentary code
  1219     generation;
  1220   - use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union,
  1221     if needed.
  1222 
  1223 Renamed:
  1224 
  1225   multiset_eq_conv_count_eq  ~>  multiset_ext_iff
  1226   multi_count_ext  ~>  multiset_ext
  1227   diff_union_inverse2  ~>  diff_union_cancelR
  1228 
  1229 INCOMPATIBILITY.
  1230 
  1231 * Theory Permutation: replaced local "remove" by List.remove1.
  1232 
  1233 * Code generation: ML and OCaml code is decorated with signatures.
  1234 
  1235 * Theory List: added transpose.
  1236 
  1237 * Library/Nat_Bijection.thy is a collection of bijective functions
  1238 between nat and other types, which supersedes the older libraries
  1239 Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.
  1240 
  1241   Constants:
  1242   Nat_Int_Bij.nat2_to_nat         ~> prod_encode
  1243   Nat_Int_Bij.nat_to_nat2         ~> prod_decode
  1244   Nat_Int_Bij.int_to_nat_bij      ~> int_encode
  1245   Nat_Int_Bij.nat_to_int_bij      ~> int_decode
  1246   Countable.pair_encode           ~> prod_encode
  1247   NatIso.prod2nat                 ~> prod_encode
  1248   NatIso.nat2prod                 ~> prod_decode
  1249   NatIso.sum2nat                  ~> sum_encode
  1250   NatIso.nat2sum                  ~> sum_decode
  1251   NatIso.list2nat                 ~> list_encode
  1252   NatIso.nat2list                 ~> list_decode
  1253   NatIso.set2nat                  ~> set_encode
  1254   NatIso.nat2set                  ~> set_decode
  1255 
  1256   Lemmas:
  1257   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
  1258   Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
  1259   Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
  1260   Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
  1261   Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
  1262   Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
  1263   Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
  1264   Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
  1265   Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
  1266   Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
  1267   Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
  1268   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
  1269   Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode
  1270 
  1271 * Sledgehammer:
  1272   - Renamed ATP commands:
  1273     atp_info     ~> sledgehammer running_atps
  1274     atp_kill     ~> sledgehammer kill_atps
  1275     atp_messages ~> sledgehammer messages
  1276     atp_minimize ~> sledgehammer minimize
  1277     print_atps   ~> sledgehammer available_atps
  1278     INCOMPATIBILITY.
  1279   - Added user's manual ("isabelle doc sledgehammer").
  1280   - Added option syntax and "sledgehammer_params" to customize
  1281     Sledgehammer's behavior.  See the manual for details.
  1282   - Modified the Isar proof reconstruction code so that it produces
  1283     direct proofs rather than proofs by contradiction.  (This feature
  1284     is still experimental.)
  1285   - Made Isar proof reconstruction work for SPASS, remote ATPs, and in
  1286     full-typed mode.
  1287   - Added support for TPTP syntax for SPASS via the "spass_tptp" ATP.
  1288 
  1289 * Nitpick:
  1290   - Added and implemented "binary_ints" and "bits" options.
  1291   - Added "std" option and implemented support for nonstandard models.
  1292   - Added and implemented "finitize" option to improve the precision
  1293     of infinite datatypes based on a monotonicity analysis.
  1294   - Added support for quotient types.
  1295   - Added support for "specification" and "ax_specification"
  1296     constructs.
  1297   - Added support for local definitions (for "function" and
  1298     "termination" proofs).
  1299   - Added support for term postprocessors.
  1300   - Optimized "Multiset.multiset" and "FinFun.finfun".
  1301   - Improved efficiency of "destroy_constrs" optimization.
  1302   - Fixed soundness bugs related to "destroy_constrs" optimization and
  1303     record getters.
  1304   - Fixed soundness bug related to higher-order constructors.
  1305   - Fixed soundness bug when "full_descrs" is enabled.
  1306   - Improved precision of set constructs.
  1307   - Added "atoms" option.
  1308   - Added cache to speed up repeated Kodkod invocations on the same
  1309     problems.
  1310   - Renamed "MiniSatJNI", "zChaffJNI", "BerkMinAlloy", and
  1311     "SAT4JLight" to "MiniSat_JNI", "zChaff_JNI", "BerkMin_Alloy", and
  1312     "SAT4J_Light".  INCOMPATIBILITY.
  1313   - Removed "skolemize", "uncurry", "sym_break", "flatten_prop",
  1314     "sharing_depth", and "show_skolems" options.  INCOMPATIBILITY.
  1315   - Removed "nitpick_intro" attribute.  INCOMPATIBILITY.
  1316 
  1317 * Method "induct" now takes instantiations of the form t, where t is not
  1318   a variable, as a shorthand for "x == t", where x is a fresh variable.
  1319   If this is not intended, t has to be enclosed in parentheses.
  1320   By default, the equalities generated by definitional instantiations
  1321   are pre-simplified, which may cause parameters of inductive cases
  1322   to disappear, or may even delete some of the inductive cases.
  1323   Use "induct (no_simp)" instead of "induct" to restore the old
  1324   behaviour. The (no_simp) option is also understood by the "cases"
  1325   and "nominal_induct" methods, which now perform pre-simplification, too.
  1326   INCOMPATIBILITY.
  1327 
  1328 
  1329 *** HOLCF ***
  1330 
  1331 * Variable names in lemmas generated by the domain package have
  1332 changed; the naming scheme is now consistent with the HOL datatype
  1333 package.  Some proof scripts may be affected, INCOMPATIBILITY.
  1334 
  1335 * The domain package no longer defines the function "foo_copy" for
  1336 recursive domain "foo".  The reach lemma is now stated directly in
  1337 terms of "foo_take".  Lemmas and proofs that mention "foo_copy" must
  1338 be reformulated in terms of "foo_take", INCOMPATIBILITY.
  1339 
  1340 * Most definedness lemmas generated by the domain package (previously
  1341 of the form "x ~= UU ==> foo$x ~= UU") now have an if-and-only-if form
  1342 like "foo$x = UU <-> x = UU", which works better as a simp rule.
  1343 Proofs that used definedness lemmas as intro rules may break,
  1344 potential INCOMPATIBILITY.
  1345 
  1346 * Induction and casedist rules generated by the domain package now
  1347 declare proper case_names (one called "bottom", and one named for each
  1348 constructor).  INCOMPATIBILITY.
  1349 
  1350 * For mutually-recursive domains, separate "reach" and "take_lemma"
  1351 rules are generated for each domain, INCOMPATIBILITY.
  1352 
  1353   foo_bar.reach       ~> foo.reach  bar.reach
  1354   foo_bar.take_lemmas ~> foo.take_lemma  bar.take_lemma
  1355 
  1356 * Some lemmas generated by the domain package have been renamed for
  1357 consistency with the datatype package, INCOMPATIBILITY.
  1358 
  1359   foo.ind        ~> foo.induct
  1360   foo.finite_ind ~> foo.finite_induct
  1361   foo.coind      ~> foo.coinduct
  1362   foo.casedist   ~> foo.exhaust
  1363   foo.exhaust    ~> foo.nchotomy
  1364 
  1365 * For consistency with other definition packages, the fixrec package
  1366 now generates qualified theorem names, INCOMPATIBILITY.
  1367 
  1368   foo_simps  ~> foo.simps
  1369   foo_unfold ~> foo.unfold
  1370   foo_induct ~> foo.induct
  1371 
  1372 * The "fixrec_simp" attribute has been removed.  The "fixrec_simp"
  1373 method and internal fixrec proofs now use the default simpset instead.
  1374 INCOMPATIBILITY.
  1375 
  1376 * The "contlub" predicate has been removed.  Proof scripts should use
  1377 lemma contI2 in place of monocontlub2cont, INCOMPATIBILITY.
  1378 
  1379 * The "admw" predicate has been removed, INCOMPATIBILITY.
  1380 
  1381 * The constants cpair, cfst, and csnd have been removed in favor of
  1382 Pair, fst, and snd from Isabelle/HOL, INCOMPATIBILITY.
  1383 
  1384 
  1385 *** ML ***
  1386 
  1387 * Antiquotations for basic formal entities:
  1388 
  1389     @{class NAME}         -- type class
  1390     @{class_syntax NAME}  -- syntax representation of the above
  1391 
  1392     @{type_name NAME}     -- logical type
  1393     @{type_abbrev NAME}   -- type abbreviation
  1394     @{nonterminal NAME}   -- type of concrete syntactic category
  1395     @{type_syntax NAME}   -- syntax representation of any of the above
  1396 
  1397     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
  1398     @{const_abbrev NAME}  -- abbreviated constant
  1399     @{const_syntax NAME}  -- syntax representation of any of the above
  1400 
  1401 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
  1402 syntax constant (cf. 'syntax' command).
  1403 
  1404 * Antiquotation @{make_string} inlines a function to print arbitrary
  1405 values similar to the ML toplevel.  The result is compiler dependent
  1406 and may fall back on "?" in certain situations.
  1407 
  1408 * Diagnostic commands 'ML_val' and 'ML_command' may refer to
  1409 antiquotations @{Isar.state} and @{Isar.goal}.  This replaces impure
  1410 Isar.state() and Isar.goal(), which belong to the old TTY loop and do
  1411 not work with the asynchronous Isar document model.
  1412 
  1413 * Configuration options now admit dynamic default values, depending on
  1414 the context or even global references.
  1415 
  1416 * SHA1.digest digests strings according to SHA-1 (see RFC 3174).  It
  1417 uses an efficient external library if available (for Poly/ML).
  1418 
  1419 * Renamed some important ML structures, while keeping the old names
  1420 for some time as aliases within the structure Legacy:
  1421 
  1422   OuterKeyword  ~>  Keyword
  1423   OuterLex      ~>  Token
  1424   OuterParse    ~>  Parse
  1425   OuterSyntax   ~>  Outer_Syntax
  1426   PrintMode     ~>  Print_Mode
  1427   SpecParse     ~>  Parse_Spec
  1428   ThyInfo       ~>  Thy_Info
  1429   ThyLoad       ~>  Thy_Load
  1430   ThyOutput     ~>  Thy_Output
  1431   TypeInfer     ~>  Type_Infer
  1432 
  1433 Note that "open Legacy" simplifies porting of sources, but forgetting
  1434 to remove it again will complicate porting again in the future.
  1435 
  1436 * Most operations that refer to a global context are named
  1437 accordingly, e.g. Simplifier.global_context or
  1438 ProofContext.init_global.  There are some situations where a global
  1439 context actually works, but under normal circumstances one needs to
  1440 pass the proper local context through the code!
  1441 
  1442 * Discontinued old TheoryDataFun with its copy/init operation -- data
  1443 needs to be pure.  Functor Theory_Data_PP retains the traditional
  1444 Pretty.pp argument to merge, which is absent in the standard
  1445 Theory_Data version.
  1446 
  1447 * Sorts.certify_sort and derived "cert" operations for types and terms
  1448 no longer minimize sorts.  Thus certification at the boundary of the
  1449 inference kernel becomes invariant under addition of class relations,
  1450 which is an important monotonicity principle.  Sorts are now minimized
  1451 in the syntax layer only, at the boundary between the end-user and the
  1452 system.  Subtle INCOMPATIBILITY, may have to use Sign.minimize_sort
  1453 explicitly in rare situations.
  1454 
  1455 * Renamed old-style Drule.standard to Drule.export_without_context, to
  1456 emphasize that this is in no way a standard operation.
  1457 INCOMPATIBILITY.
  1458 
  1459 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
  1460 usual for resolution.  Rare INCOMPATIBILITY.
  1461 
  1462 * Renamed varify/unvarify operations to varify_global/unvarify_global
  1463 to emphasize that these only work in a global situation (which is
  1464 quite rare).
  1465 
  1466 * Curried take and drop in library.ML; negative length is interpreted
  1467 as infinity (as in chop).  Subtle INCOMPATIBILITY.
  1468 
  1469 * Proof terms: type substitutions on proof constants now use canonical
  1470 order of type variables.  INCOMPATIBILITY for tools working with proof
  1471 terms.
  1472 
  1473 * Raw axioms/defs may no longer carry sort constraints, and raw defs
  1474 may no longer carry premises.  User-level specifications are
  1475 transformed accordingly by Thm.add_axiom/add_def.
  1476 
  1477 
  1478 *** System ***
  1479 
  1480 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
  1481 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
  1482 proof terms are enabled unconditionally in the new HOL-Proofs image.
  1483 
  1484 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
  1485 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
  1486 respectively.
  1487 
  1488 * Old lib/scripts/polyml-platform is superseded by the
  1489 ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
  1490 variant, even on a 64 bit machine.  The following example setting
  1491 prefers 64 bit if available:
  1492 
  1493   ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"
  1494 
  1495 * The preliminary Isabelle/jEdit application demonstrates the emerging
  1496 Isabelle/Scala layer for advanced prover interaction and integration.
  1497 See src/Tools/jEdit or "isabelle jedit" provided by the properly built
  1498 component.
  1499 
  1500 * "IsabelleText" is a Unicode font derived from Bitstream Vera Mono
  1501 and Bluesky TeX fonts.  It provides the usual Isabelle symbols,
  1502 similar to the default assignment of the document preparation system
  1503 (cf. isabellesym.sty).  The Isabelle/Scala class Isabelle_System
  1504 provides some operations for direct access to the font without asking
  1505 the user for manual installation.
  1506 
  1507 
  1508 
  1509 New in Isabelle2009-1 (December 2009)
  1510 -------------------------------------
  1511 
  1512 *** General ***
  1513 
  1514 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
  1515 one backslash should be used, even in ML sources.
  1516 
  1517 
  1518 *** Pure ***
  1519 
  1520 * Locale interpretation propagates mixins along the locale hierarchy.
  1521 The currently only available mixins are the equations used to map
  1522 local definitions to terms of the target domain of an interpretation.
  1523 
  1524 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
  1525 loc" to print all interpretations of locale "loc" in the theory.
  1526 Interpretations in proofs are not shown.
  1527 
  1528 * Thoroughly revised locales tutorial.  New section on conditional
  1529 interpretation.
  1530 
  1531 * On instantiation of classes, remaining undefined class parameters
  1532 are formally declared.  INCOMPATIBILITY.
  1533 
  1534 
  1535 *** Document preparation ***
  1536 
  1537 * New generalized style concept for printing terms: @{foo (style) ...}
  1538 instead of @{foo_style style ...}  (old form is still retained for
  1539 backward compatibility).  Styles can be also applied for
  1540 antiquotations prop, term_type and typeof.
  1541 
  1542 
  1543 *** HOL ***
  1544 
  1545 * New proof method "smt" for a combination of first-order logic with
  1546 equality, linear and nonlinear (natural/integer/real) arithmetic, and
  1547 fixed-size bitvectors; there is also basic support for higher-order
  1548 features (esp. lambda abstractions).  It is an incomplete decision
  1549 procedure based on external SMT solvers using the oracle mechanism;
  1550 for the SMT solver Z3, this method is proof-producing.  Certificates
  1551 are provided to avoid calling the external solvers solely for
  1552 re-checking proofs.  Due to a remote SMT service there is no need for
  1553 installing SMT solvers locally.  See src/HOL/SMT.
  1554 
  1555 * New commands to load and prove verification conditions generated by
  1556 the Boogie program verifier or derived systems (e.g. the Verifying C
  1557 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
  1558 
  1559 * New counterexample generator tool 'nitpick' based on the Kodkod
  1560 relational model finder.  See src/HOL/Tools/Nitpick and
  1561 src/HOL/Nitpick_Examples.
  1562 
  1563 * New commands 'code_pred' and 'values' to invoke the predicate
  1564 compiler and to enumerate values of inductive predicates.
  1565 
  1566 * A tabled implementation of the reflexive transitive closure.
  1567 
  1568 * New implementation of quickcheck uses generic code generator;
  1569 default generators are provided for all suitable HOL types, records
  1570 and datatypes.  Old quickcheck can be re-activated importing theory
  1571 Library/SML_Quickcheck.
  1572 
  1573 * New testing tool Mirabelle for automated proof tools.  Applies
  1574 several tools and tactics like sledgehammer, metis, or quickcheck, to
  1575 every proof step in a theory.  To be used in batch mode via the
  1576 "mirabelle" utility.
  1577 
  1578 * New proof method "sos" (sum of squares) for nonlinear real
  1579 arithmetic (originally due to John Harison). It requires theory
  1580 Library/Sum_Of_Squares.  It is not a complete decision procedure but
  1581 works well in practice on quantifier-free real arithmetic with +, -,
  1582 *, ^, =, <= and <, i.e. boolean combinations of equalities and
  1583 inequalities between polynomials.  It makes use of external
  1584 semidefinite programming solvers.  Method "sos" generates a
  1585 certificate that can be pasted into the proof thus avoiding the need
  1586 to call an external tool every time the proof is checked.  See
  1587 src/HOL/Library/Sum_Of_Squares.
  1588 
  1589 * New method "linarith" invokes existing linear arithmetic decision
  1590 procedure only.
  1591 
  1592 * New command 'atp_minimal' reduces result produced by Sledgehammer.
  1593 
  1594 * New Sledgehammer option "Full Types" in Proof General settings menu.
  1595 Causes full type information to be output to the ATPs.  This slows
  1596 ATPs down considerably but eliminates a source of unsound "proofs"
  1597 that fail later.
  1598 
  1599 * New method "metisFT": A version of metis that uses full type
  1600 information in order to avoid failures of proof reconstruction.
  1601 
  1602 * New evaluator "approximate" approximates an real valued term using
  1603 the same method as the approximation method.
  1604 
  1605 * Method "approximate" now supports arithmetic expressions as
  1606 boundaries of intervals and implements interval splitting and Taylor
  1607 series expansion.
  1608 
  1609 * ML antiquotation @{code_datatype} inserts definition of a datatype
  1610 generated by the code generator; e.g. see src/HOL/Predicate.thy.
  1611 
  1612 * New theory SupInf of the supremum and infimum operators for sets of
  1613 reals.
  1614 
  1615 * New theory Probability, which contains a development of measure
  1616 theory, eventually leading to Lebesgue integration and probability.
  1617 
  1618 * Extended Multivariate Analysis to include derivation and Brouwer's
  1619 fixpoint theorem.
  1620 
  1621 * Reorganization of number theory, INCOMPATIBILITY:
  1622   - new number theory development for nat and int, in theories Divides
  1623     and GCD as well as in new session Number_Theory
  1624   - some constants and facts now suffixed with _nat and _int
  1625     accordingly
  1626   - former session NumberTheory now named Old_Number_Theory, including
  1627     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
  1628   - moved theory Pocklington from src/HOL/Library to
  1629     src/HOL/Old_Number_Theory
  1630 
  1631 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
  1632 lcm of finite and infinite sets. It is shown that they form a complete
  1633 lattice.
  1634 
  1635 * Class semiring_div requires superclass no_zero_divisors and proof of
  1636 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
  1637 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
  1638 generalized to class semiring_div, subsuming former theorems
  1639 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
  1640 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
  1641 INCOMPATIBILITY.
  1642 
  1643 * Refinements to lattice classes and sets:
  1644   - less default intro/elim rules in locale variant, more default
  1645     intro/elim rules in class variant: more uniformity
  1646   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
  1647     le_inf_iff
  1648   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
  1649     sup_aci)
  1650   - renamed ACI to inf_sup_aci
  1651   - new class "boolean_algebra"
  1652   - class "complete_lattice" moved to separate theory
  1653     "Complete_Lattice"; corresponding constants (and abbreviations)
  1654     renamed and with authentic syntax:
  1655     Set.Inf ~>    Complete_Lattice.Inf
  1656     Set.Sup ~>    Complete_Lattice.Sup
  1657     Set.INFI ~>   Complete_Lattice.INFI
  1658     Set.SUPR ~>   Complete_Lattice.SUPR
  1659     Set.Inter ~>  Complete_Lattice.Inter
  1660     Set.Union ~>  Complete_Lattice.Union
  1661     Set.INTER ~>  Complete_Lattice.INTER
  1662     Set.UNION ~>  Complete_Lattice.UNION
  1663   - authentic syntax for
  1664     Set.Pow
  1665     Set.image
  1666   - mere abbreviations:
  1667     Set.empty               (for bot)
  1668     Set.UNIV                (for top)
  1669     Set.inter               (for inf, formerly Set.Int)
  1670     Set.union               (for sup, formerly Set.Un)
  1671     Complete_Lattice.Inter  (for Inf)
  1672     Complete_Lattice.Union  (for Sup)
  1673     Complete_Lattice.INTER  (for INFI)
  1674     Complete_Lattice.UNION  (for SUPR)
  1675   - object-logic definitions as far as appropriate
  1676 
  1677 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
  1678 Un_subset_iff are explicitly deleted as default simp rules; then also
  1679 their lattice counterparts le_inf_iff and le_sup_iff have to be
  1680 deleted to achieve the desired effect.
  1681 
  1682 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
  1683 rules by default any longer; the same applies to min_max.inf_absorb1
  1684 etc.  INCOMPATIBILITY.
  1685 
  1686 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
  1687 pred_set_conv by default.  INCOMPATIBILITY.
  1688 
  1689 * Power operations on relations and functions are now one dedicated
  1690 constant "compow" with infix syntax "^^".  Power operation on
  1691 multiplicative monoids retains syntax "^" and is now defined generic
  1692 in class power.  INCOMPATIBILITY.
  1693 
  1694 * Relation composition "R O S" now has a more standard argument order:
  1695 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
  1696 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
  1697 break, since the O_assoc rule was not rewritten like this.  Fix using
  1698 O_assoc[symmetric].  The same applies to the curried version "R OO S".
  1699 
  1700 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
  1701 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
  1702 INCOMPATIBILITY.
  1703 
  1704 * Most rules produced by inductive and datatype package have mandatory
  1705 prefixes.  INCOMPATIBILITY.
  1706 
  1707 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
  1708 the attribute of the same name.  Each of the theorems in the list
  1709 DERIV_intros assumes composition with an additional function and
  1710 matches a variable to the derivative, which has to be solved by the
  1711 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
  1712 of most elementary terms.  Former Maclauren.DERIV_tac and
  1713 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
  1714 INCOMPATIBILITY.
  1715 
  1716 * Code generator attributes follow the usual underscore convention:
  1717     code_unfold     replaces    code unfold
  1718     code_post       replaces    code post
  1719     etc.
  1720   INCOMPATIBILITY.
  1721 
  1722 * Renamed methods:
  1723     sizechange -> size_change
  1724     induct_scheme -> induction_schema
  1725   INCOMPATIBILITY.
  1726 
  1727 * Discontinued abbreviation "arbitrary" of constant "undefined".
  1728 INCOMPATIBILITY, use "undefined" directly.
  1729 
  1730 * Renamed theorems:
  1731     Suc_eq_add_numeral_1 -> Suc_eq_plus1
  1732     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
  1733     Suc_plus1 -> Suc_eq_plus1
  1734     *anti_sym -> *antisym*
  1735     vector_less_eq_def -> vector_le_def
  1736   INCOMPATIBILITY.
  1737 
  1738 * Added theorem List.map_map as [simp].  Removed List.map_compose.
  1739 INCOMPATIBILITY.
  1740 
  1741 * Removed predicate "M hassize n" (<--> card M = n & finite M).
  1742 INCOMPATIBILITY.
  1743 
  1744 
  1745 *** HOLCF ***
  1746 
  1747 * Theory Representable defines a class "rep" of domains that are
  1748 representable (via an ep-pair) in the universal domain type "udom".
  1749 Instances are provided for all type constructors defined in HOLCF.
  1750 
  1751 * The 'new_domain' command is a purely definitional version of the
  1752 domain package, for representable domains.  Syntax is identical to the
  1753 old domain package.  The 'new_domain' package also supports indirect
  1754 recursion using previously-defined type constructors.  See
  1755 src/HOLCF/ex/New_Domain.thy for examples.
  1756 
  1757 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
  1758 on the left-hand side of an equation, and then performs
  1759 simplification.  Rewriting is done using rules declared with the
  1760 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
  1761 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
  1762 
  1763 * The pattern-match compiler in 'fixrec' can now handle constructors
  1764 with HOL function types.  Pattern-match combinators for the Pair
  1765 constructor are pre-configured.
  1766 
  1767 * The 'fixrec' package now produces better fixed-point induction rules
  1768 for mutually-recursive definitions:  Induction rules have conclusions
  1769 of the form "P foo bar" instead of "P <foo, bar>".
  1770 
  1771 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
  1772 been renamed to "below".  The name "below" now replaces "less" in many
  1773 theorem names.  (Legacy theorem names using "less" are still supported
  1774 as well.)
  1775 
  1776 * The 'fixrec' package now supports "bottom patterns".  Bottom
  1777 patterns can be used to generate strictness rules, or to make
  1778 functions more strict (much like the bang-patterns supported by the
  1779 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
  1780 examples.
  1781 
  1782 
  1783 *** ML ***
  1784 
  1785 * Support for Poly/ML 5.3.0, with improved reporting of compiler
  1786 errors and run-time exceptions, including detailed source positions.
  1787 
  1788 * Structure Name_Space (formerly NameSpace) now manages uniquely
  1789 identified entries, with some additional information such as source
  1790 position, logical grouping etc.
  1791 
  1792 * Theory and context data is now introduced by the simplified and
  1793 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
  1794 to be pure, but the old TheoryDataFun for mutable data (with explicit
  1795 copy operation) is still available for some time.
  1796 
  1797 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
  1798 provides a high-level programming interface to synchronized state
  1799 variables with atomic update.  This works via pure function
  1800 application within a critical section -- its runtime should be as
  1801 short as possible; beware of deadlocks if critical code is nested,
  1802 either directly or indirectly via other synchronized variables!
  1803 
  1804 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
  1805 wraps raw ML references, explicitly indicating their non-thread-safe
  1806 behaviour.  The Isar toplevel keeps this structure open, to
  1807 accommodate Proof General as well as quick and dirty interactive
  1808 experiments with references.
  1809 
  1810 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
  1811 parallel tactical reasoning.
  1812 
  1813 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
  1814 are similar to SUBPROOF, but are slightly more flexible: only the
  1815 specified parts of the subgoal are imported into the context, and the
  1816 body tactic may introduce new subgoals and schematic variables.
  1817 
  1818 * Old tactical METAHYPS, which does not observe the proof context, has
  1819 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
  1820 or Subgoal.FOCUS etc.
  1821 
  1822 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
  1823 functors have their own ML name space there is no point to mark them
  1824 separately.)  Minor INCOMPATIBILITY.
  1825 
  1826 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
  1827 
  1828 * Renamed several structures FooBar to Foo_Bar.  Occasional,
  1829 INCOMPATIBILITY.
  1830 
  1831 * Operations of structure Skip_Proof no longer require quick_and_dirty
  1832 mode, which avoids critical setmp.
  1833 
  1834 * Eliminated old Attrib.add_attributes, Method.add_methods and related
  1835 combinators for "args".  INCOMPATIBILITY, need to use simplified
  1836 Attrib/Method.setup introduced in Isabelle2009.
  1837 
  1838 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
  1839 back on global_simpset_of, global_claset_of, global_clasimpset_of as
  1840 last resort.  INCOMPATIBILITY.
  1841 
  1842 * Display.pretty_thm now requires a proper context (cf. former
  1843 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
  1844 or even Display.pretty_thm_without_context as last resort.
  1845 INCOMPATIBILITY.
  1846 
  1847 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
  1848 Syntax.pretty_typ/term directly, preferably with proper context
  1849 instead of global theory.
  1850 
  1851 
  1852 *** System ***
  1853 
  1854 * Further fine tuning of parallel proof checking, scales up to 8 cores
  1855 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
  1856 usedir option -q.
  1857 
  1858 * Support for additional "Isabelle components" via etc/components, see
  1859 also the system manual.
  1860 
  1861 * The isabelle makeall tool now operates on all components with
  1862 IsaMakefile, not just hardwired "logics".
  1863 
  1864 * Removed "compress" option from isabelle-process and isabelle usedir;
  1865 this is always enabled.
  1866 
  1867 * Discontinued support for Poly/ML 4.x versions.
  1868 
  1869 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
  1870 on a given logic image.  This requires the lighttpd webserver and is
  1871 currently supported on Linux only.
  1872 
  1873 
  1874 
  1875 New in Isabelle2009 (April 2009)
  1876 --------------------------------
  1877 
  1878 *** General ***
  1879 
  1880 * Simplified main Isabelle executables, with less surprises on
  1881 case-insensitive file-systems (such as Mac OS).
  1882 
  1883   - The main Isabelle tool wrapper is now called "isabelle" instead of
  1884     "isatool."
  1885 
  1886   - The former "isabelle" alias for "isabelle-process" has been
  1887     removed (should rarely occur to regular users).
  1888 
  1889   - The former "isabelle-interface" and its alias "Isabelle" have been
  1890     removed (interfaces are now regular Isabelle tools).
  1891 
  1892 Within scripts and make files, the Isabelle environment variables
  1893 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
  1894 respectively.  (The latter are still available as legacy feature.)
  1895 
  1896 The old isabelle-interface wrapper could react in confusing ways if
  1897 the interface was uninstalled or changed otherwise.  Individual
  1898 interface tool configuration is now more explicit, see also the
  1899 Isabelle system manual.  In particular, Proof General is now available
  1900 via "isabelle emacs".
  1901 
  1902 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
  1903 purge installed copies of Isabelle executables and re-run "isabelle
  1904 install -p ...", or use symlinks.
  1905 
  1906 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
  1907 old ~/isabelle, which was slightly non-standard and apt to cause
  1908 surprises on case-insensitive file-systems (such as Mac OS).
  1909 
  1910 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
  1911 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
  1912 care is required when using older releases of Isabelle.  Note that
  1913 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
  1914 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
  1915 
  1916 * Proofs of fully specified statements are run in parallel on
  1917 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
  1918 a regular 4-core machine, if the initial heap space is made reasonably
  1919 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
  1920 
  1921 * The main reference manuals ("isar-ref", "implementation", and
  1922 "system") have been updated and extended.  Formally checked references
  1923 as hyperlinks are now available uniformly.
  1924 
  1925 
  1926 *** Pure ***
  1927 
  1928 * Complete re-implementation of locales.  INCOMPATIBILITY in several
  1929 respects.  The most important changes are listed below.  See the
  1930 Tutorial on Locales ("locales" manual) for details.
  1931 
  1932 - In locale expressions, instantiation replaces renaming.  Parameters
  1933 must be declared in a for clause.  To aid compatibility with previous
  1934 parameter inheritance, in locale declarations, parameters that are not
  1935 'touched' (instantiation position "_" or omitted) are implicitly added
  1936 with their syntax at the beginning of the for clause.
  1937 
  1938 - Syntax from abbreviations and definitions in locales is available in
  1939 locale expressions and context elements.  The latter is particularly
  1940 useful in locale declarations.
  1941 
  1942 - More flexible mechanisms to qualify names generated by locale
  1943 expressions.  Qualifiers (prefixes) may be specified in locale
  1944 expressions, and can be marked as mandatory (syntax: "name!:") or
  1945 optional (syntax "name?:").  The default depends for plain "name:"
  1946 depends on the situation where a locale expression is used: in
  1947 commands 'locale' and 'sublocale' prefixes are optional, in
  1948 'interpretation' and 'interpret' prefixes are mandatory.  The old
  1949 implicit qualifiers derived from the parameter names of a locale are
  1950 no longer generated.
  1951 
  1952 - Command "sublocale l < e" replaces "interpretation l < e".  The
  1953 instantiation clause in "interpretation" and "interpret" (square
  1954 brackets) is no longer available.  Use locale expressions.
  1955 
  1956 - When converting proof scripts, mandatory qualifiers in
  1957 'interpretation' and 'interpret' should be retained by default, even
  1958 if this is an INCOMPATIBILITY compared to former behavior.  In the
  1959 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
  1960 in locale expressions range over a single locale instance only.
  1961 
  1962 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
  1963 In existing theorem specifications replace the includes element by the
  1964 respective context elements of the included locale, omitting those
  1965 that are already present in the theorem specification.  Multiple
  1966 assume elements of a locale should be replaced by a single one
  1967 involving the locale predicate.  In the proof body, declarations (most
  1968 notably theorems) may be regained by interpreting the respective
  1969 locales in the proof context as required (command "interpret").
  1970 
  1971 If using "includes" in replacement of a target solely because the
  1972 parameter types in the theorem are not as general as in the target,
  1973 consider declaring a new locale with additional type constraints on
  1974 the parameters (context element "constrains").
  1975 
  1976 - Discontinued "locale (open)".  INCOMPATIBILITY.
  1977 
  1978 - Locale interpretation commands no longer attempt to simplify goal.
  1979 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
  1980 methods intro_locales and unfold_locales to clarify.
  1981 
  1982 - Locale interpretation commands no longer accept interpretation
  1983 attributes.  INCOMPATIBILITY.
  1984 
  1985 * Class declaration: so-called "base sort" must not be given in import
  1986 list any longer, but is inferred from the specification.  Particularly
  1987 in HOL, write
  1988 
  1989     class foo = ...
  1990 
  1991 instead of
  1992 
  1993     class foo = type + ...
  1994 
  1995 * Class target: global versions of theorems stemming do not carry a
  1996 parameter prefix any longer.  INCOMPATIBILITY.
  1997 
  1998 * Class 'instance' command no longer accepts attached definitions.
  1999 INCOMPATIBILITY, use proper 'instantiation' target instead.
  2000 
  2001 * Recovered hiding of consts, which was accidentally broken in
  2002 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
  2003 makes c inaccessible; consider using ``hide (open) const c'' instead.
  2004 
  2005 * Slightly more coherent Pure syntax, with updated documentation in
  2006 isar-ref manual.  Removed locales meta_term_syntax and
  2007 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
  2008 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
  2009 directly in regular applications.
  2010 
  2011 * There is a new syntactic category "float_const" for signed decimal
  2012 fractions (e.g. 123.45 or -123.45).
  2013 
  2014 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
  2015 interface with 'setup' command instead.
  2016 
  2017 * Command 'local_setup' is similar to 'setup', but operates on a local
  2018 theory context.
  2019 
  2020 * The 'axiomatization' command now only works within a global theory
  2021 context.  INCOMPATIBILITY.
  2022 
  2023 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
  2024 hypotheses.  Sorts required in the course of reasoning need to be
  2025 covered by the constraints in the initial statement, completed by the
  2026 type instance information of the background theory.  Non-trivial sort
  2027 hypotheses, which rarely occur in practice, may be specified via
  2028 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
  2029 
  2030   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
  2031 
  2032 The result contains an implicit sort hypotheses as before --
  2033 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
  2034 normalization.
  2035 
  2036 * Generalized Isar history, with support for linear undo, direct state
  2037 addressing etc.
  2038 
  2039 * Changed defaults for unify configuration options:
  2040 
  2041   unify_trace_bound = 50 (formerly 25)
  2042   unify_search_bound = 60 (formerly 30)
  2043 
  2044 * Different bookkeeping for code equations (INCOMPATIBILITY):
  2045 
  2046   a) On theory merge, the last set of code equations for a particular
  2047      constant is taken (in accordance with the policy applied by other
  2048      parts of the code generator framework).
  2049 
  2050   b) Code equations stemming from explicit declarations (e.g. code
  2051      attribute) gain priority over default code equations stemming
  2052      from definition, primrec, fun etc.
  2053 
  2054 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
  2055 
  2056 * Unified theorem tables for both code generators.  Thus [code
  2057 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
  2058 
  2059 * Command 'find_consts' searches for constants based on type and name
  2060 patterns, e.g.
  2061 
  2062     find_consts "_ => bool"
  2063 
  2064 By default, matching is against subtypes, but it may be restricted to
  2065 the whole type.  Searching by name is possible.  Multiple queries are
  2066 conjunctive and queries may be negated by prefixing them with a
  2067 hyphen:
  2068 
  2069     find_consts strict: "_ => bool" name: "Int" -"int => int"
  2070 
  2071 * New 'find_theorems' criterion "solves" matches theorems that
  2072 directly solve the current goal (modulo higher-order unification).
  2073 
  2074 * Auto solve feature for main theorem statements: whenever a new goal
  2075 is stated, "find_theorems solves" is called; any theorems that could
  2076 solve the lemma directly are listed as part of the goal state.
  2077 Cf. associated options in Proof General Isabelle settings menu,
  2078 enabled by default, with reasonable timeout for pathological cases of
  2079 higher-order unification.
  2080 
  2081 
  2082 *** Document preparation ***
  2083 
  2084 * Antiquotation @{lemma} now imitates a regular terminal proof,
  2085 demanding keyword 'by' and supporting the full method expression
  2086 syntax just like the Isar command 'by'.
  2087 
  2088 
  2089 *** HOL ***
  2090 
  2091 * Integrated main parts of former image HOL-Complex with HOL.  Entry
  2092 points Main and Complex_Main remain as before.
  2093 
  2094 * Logic image HOL-Plain provides a minimal HOL with the most important
  2095 tools available (inductive, datatype, primrec, ...).  This facilitates
  2096 experimentation and tool development.  Note that user applications
  2097 (and library theories) should never refer to anything below theory
  2098 Main, as before.
  2099 
  2100 * Logic image HOL-Main stops at theory Main, and thus facilitates
  2101 experimentation due to shorter build times.
  2102 
  2103 * Logic image HOL-NSA contains theories of nonstandard analysis which
  2104 were previously part of former HOL-Complex.  Entry point Hyperreal
  2105 remains valid, but theories formerly using Complex_Main should now use
  2106 new entry point Hypercomplex.
  2107 
  2108 * Generic ATP manager for Sledgehammer, based on ML threads instead of
  2109 Posix processes.  Avoids potentially expensive forking of the ML
  2110 process.  New thread-based implementation also works on non-Unix
  2111 platforms (Cygwin).  Provers are no longer hardwired, but defined
  2112 within the theory via plain ML wrapper functions.  Basic Sledgehammer
  2113 commands are covered in the isar-ref manual.
  2114 
  2115 * Wrapper scripts for remote SystemOnTPTP service allows to use
  2116 sledgehammer without local ATP installation (Vampire etc.). Other
  2117 provers may be included via suitable ML wrappers, see also
  2118 src/HOL/ATP_Linkup.thy.
  2119 
  2120 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
  2121 menu.
  2122 
  2123 * The metis method no longer fails because the theorem is too trivial
  2124 (contains the empty clause).
  2125 
  2126 * The metis method now fails in the usual manner, rather than raising
  2127 an exception, if it determines that it cannot prove the theorem.
  2128 
  2129 * Method "coherent" implements a prover for coherent logic (see also
  2130 src/Tools/coherent.ML).
  2131 
  2132 * Constants "undefined" and "default" replace "arbitrary".  Usually
  2133 "undefined" is the right choice to replace "arbitrary", though
  2134 logically there is no difference.  INCOMPATIBILITY.
  2135 
  2136 * Command "value" now integrates different evaluation mechanisms.  The
  2137 result of the first successful evaluation mechanism is printed.  In
  2138 square brackets a particular named evaluation mechanisms may be
  2139 specified (currently, [SML], [code] or [nbe]).  See further
  2140 src/HOL/ex/Eval_Examples.thy.
  2141 
  2142 * Normalization by evaluation now allows non-leftlinear equations.
  2143 Declare with attribute [code nbe].
  2144 
  2145 * Methods "case_tac" and "induct_tac" now refer to the very same rules
  2146 as the structured Isar versions "cases" and "induct", cf. the
  2147 corresponding "cases" and "induct" attributes.  Mutual induction rules
  2148 are now presented as a list of individual projections
  2149 (e.g. foo_bar.inducts for types foo and bar); the old format with
  2150 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
  2151 rare situations a different rule is selected --- notably nested tuple
  2152 elimination instead of former prod.exhaust: use explicit (case_tac t
  2153 rule: prod.exhaust) here.
  2154 
  2155 * Attributes "cases", "induct", "coinduct" support "del" option.
  2156 
  2157 * Removed fact "case_split_thm", which duplicates "case_split".
  2158 
  2159 * The option datatype has been moved to a new theory Option.  Renamed
  2160 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
  2161 
  2162 * New predicate "strict_mono" classifies strict functions on partial
  2163 orders.  With strict functions on linear orders, reasoning about
  2164 (in)equalities is facilitated by theorems "strict_mono_eq",
  2165 "strict_mono_less_eq" and "strict_mono_less".
  2166 
  2167 * Some set operations are now proper qualified constants with
  2168 authentic syntax.  INCOMPATIBILITY:
  2169 
  2170     op Int ~>   Set.Int
  2171     op Un ~>    Set.Un
  2172     INTER ~>    Set.INTER
  2173     UNION ~>    Set.UNION
  2174     Inter ~>    Set.Inter
  2175     Union ~>    Set.Union
  2176     {} ~>       Set.empty
  2177     UNIV ~>     Set.UNIV
  2178 
  2179 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  2180 theory Set.
  2181 
  2182 * Auxiliary class "itself" has disappeared -- classes without any
  2183 parameter are treated as expected by the 'class' command.
  2184 
  2185 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  2186 
  2187 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  2188 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  2189 
  2190 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  2191 method "approximation".  It proves formulas on real values by using
  2192 interval arithmetic.  In the formulas are also the transcendental
  2193 functions sin, cos, tan, atan, ln, exp and the constant pi are
  2194 allowed. For examples see
  2195 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  2196 
  2197 * Theory "Reflection" now resides in HOL/Library.
  2198 
  2199 * Entry point to Word library now simply named "Word".
  2200 INCOMPATIBILITY.
  2201 
  2202 * Made source layout more coherent with logical distribution
  2203 structure:
  2204 
  2205     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  2206     src/HOL/Library/Code_Message.thy ~> src/HOL/
  2207     src/HOL/Library/GCD.thy ~> src/HOL/
  2208     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  2209     src/HOL/Library/Parity.thy ~> src/HOL/
  2210     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  2211     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  2212     src/HOL/Real/Lubs.thy ~> src/HOL/
  2213     src/HOL/Real/PReal.thy ~> src/HOL/
  2214     src/HOL/Real/Rational.thy ~> src/HOL/
  2215     src/HOL/Real/RComplete.thy ~> src/HOL/
  2216     src/HOL/Real/RealDef.thy ~> src/HOL/
  2217     src/HOL/Real/RealPow.thy ~> src/HOL/
  2218     src/HOL/Real/Real.thy ~> src/HOL/
  2219     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  2220     src/HOL/Complex/Complex.thy ~> src/HOL/
  2221     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  2222     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  2223     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  2224     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  2225     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  2226     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  2227     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  2228     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  2229     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  2230     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  2231     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  2232     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  2233     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  2234     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  2235     src/HOL/Real/Float ~> src/HOL/Library/
  2236     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  2237     src/HOL/Real/RealVector.thy ~> src/HOL/
  2238 
  2239     src/HOL/arith_data.ML ~> src/HOL/Tools
  2240     src/HOL/hologic.ML ~> src/HOL/Tools
  2241     src/HOL/simpdata.ML ~> src/HOL/Tools
  2242     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  2243     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  2244     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  2245     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  2246     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  2247     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  2248     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  2249 
  2250     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  2251     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  2252     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  2253     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  2254     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  2255     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  2256 
  2257 * If methods "eval" and "evaluation" encounter a structured proof
  2258 state with !!/==>, only the conclusion is evaluated to True (if
  2259 possible), avoiding strange error messages.
  2260 
  2261 * Method "sizechange" automates termination proofs using (a
  2262 modification of) the size-change principle.  Requires SAT solver.  See
  2263 src/HOL/ex/Termination.thy for examples.
  2264 
  2265 * Simplifier: simproc for let expressions now unfolds if bound
  2266 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  2267 
  2268 * Method "arith": Linear arithmetic now ignores all inequalities when
  2269 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  2270 
  2271 * New attribute "arith" for facts that should always be used
  2272 automatically by arithmetic. It is intended to be used locally in
  2273 proofs, e.g.
  2274 
  2275   assumes [arith]: "x > 0"
  2276 
  2277 Global usage is discouraged because of possible performance impact.
  2278 
  2279 * New classes "top" and "bot" with corresponding operations "top" and
  2280 "bot" in theory Orderings; instantiation of class "complete_lattice"
  2281 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  2282 
  2283 * Changed definition lemma "less_fun_def" in order to provide an
  2284 instance for preorders on functions; use lemma "less_le" instead.
  2285 INCOMPATIBILITY.
  2286 
  2287 * Theory Orderings: class "wellorder" moved here, with explicit
  2288 induction rule "less_induct" as assumption.  For instantiation of
  2289 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  2290 INCOMPATIBILITY.
  2291 
  2292 * Theory Orderings: added class "preorder" as superclass of "order".
  2293 INCOMPATIBILITY: Instantiation proofs for order, linorder
  2294 etc. slightly changed.  Some theorems named order_class.* now named
  2295 preorder_class.*.
  2296 
  2297 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  2298 "diag" to "Id_on".
  2299 
  2300 * Theory Finite_Set: added a new fold combinator of type
  2301 
  2302   ('a => 'b => 'b) => 'b => 'a set => 'b
  2303 
  2304 Occasionally this is more convenient than the old fold combinator
  2305 which is now defined in terms of the new one and renamed to
  2306 fold_image.
  2307 
  2308 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  2309 and "ring_simps" have been replaced by "algebra_simps" (which can be
  2310 extended with further lemmas!).  At the moment both still exist but
  2311 the former will disappear at some point.
  2312 
  2313 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  2314 class recpower.  Type-specific simp rules for various recpower types
  2315 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  2316 
  2317 rat_power_0    -> power_0
  2318 rat_power_Suc  -> power_Suc
  2319 realpow_0      -> power_0
  2320 realpow_Suc    -> power_Suc
  2321 complexpow_0   -> power_0
  2322 complexpow_Suc -> power_Suc
  2323 power_poly_0   -> power_0
  2324 power_poly_Suc -> power_Suc
  2325 
  2326 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  2327 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  2328 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  2329 of lemmas from Divides has been generalized from nat to class
  2330 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  2331 renames resulting from duplicate elimination:
  2332 
  2333     dvd_def_mod ~>          dvd_eq_mod_eq_0
  2334     zero_dvd_iff ~>         dvd_0_left_iff
  2335     dvd_0 ~>                dvd_0_right
  2336     DIVISION_BY_ZERO_DIV ~> div_by_0
  2337     DIVISION_BY_ZERO_MOD ~> mod_by_0
  2338     mult_div ~>             div_mult_self2_is_id
  2339     mult_mod ~>             mod_mult_self2_is_0
  2340 
  2341 * Theory IntDiv: removed many lemmas that are instances of class-based
  2342 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  2343 rename old lemmas as follows:
  2344 
  2345 dvd_diff               -> nat_dvd_diff
  2346 dvd_zminus_iff         -> dvd_minus_iff
  2347 mod_add1_eq            -> mod_add_eq
  2348 mod_mult1_eq           -> mod_mult_right_eq
  2349 mod_mult1_eq'          -> mod_mult_left_eq
  2350 mod_mult_distrib_mod   -> mod_mult_eq
  2351 nat_mod_add_left_eq    -> mod_add_left_eq
  2352 nat_mod_add_right_eq   -> mod_add_right_eq
  2353 nat_mod_div_trivial    -> mod_div_trivial
  2354 nat_mod_mod_trivial    -> mod_mod_trivial
  2355 zdiv_zadd_self1        -> div_add_self1
  2356 zdiv_zadd_self2        -> div_add_self2
  2357 zdiv_zmult_self1       -> div_mult_self2_is_id
  2358 zdiv_zmult_self2       -> div_mult_self1_is_id
  2359 zdvd_triv_left         -> dvd_triv_left
  2360 zdvd_triv_right        -> dvd_triv_right
  2361 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  2362 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  2363 zmod_zadd_left_eq      -> mod_add_left_eq
  2364 zmod_zadd_right_eq     -> mod_add_right_eq
  2365 zmod_zadd_self1        -> mod_add_self1
  2366 zmod_zadd_self2        -> mod_add_self2
  2367 zmod_zadd1_eq          -> mod_add_eq
  2368 zmod_zdiff1_eq         -> mod_diff_eq
  2369 zmod_zdvd_zmod         -> mod_mod_cancel
  2370 zmod_zmod_cancel       -> mod_mod_cancel
  2371 zmod_zmult_self1       -> mod_mult_self2_is_0
  2372 zmod_zmult_self2       -> mod_mult_self1_is_0
  2373 zmod_1                 -> mod_by_1
  2374 zdiv_1                 -> div_by_1
  2375 zdvd_abs1              -> abs_dvd_iff
  2376 zdvd_abs2              -> dvd_abs_iff
  2377 zdvd_refl              -> dvd_refl
  2378 zdvd_trans             -> dvd_trans
  2379 zdvd_zadd              -> dvd_add
  2380 zdvd_zdiff             -> dvd_diff
  2381 zdvd_zminus_iff        -> dvd_minus_iff
  2382 zdvd_zminus2_iff       -> minus_dvd_iff
  2383 zdvd_zmultD            -> dvd_mult_right
  2384 zdvd_zmultD2           -> dvd_mult_left
  2385 zdvd_zmult_mono        -> mult_dvd_mono
  2386 zdvd_0_right           -> dvd_0_right
  2387 zdvd_0_left            -> dvd_0_left_iff
  2388 zdvd_1_left            -> one_dvd
  2389 zminus_dvd_iff         -> minus_dvd_iff
  2390 
  2391 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  2392 
  2393 * The real numbers offer decimal input syntax: 12.34 is translated
  2394 into 1234/10^2. This translation is not reversed upon output.
  2395 
  2396 * Theory Library/Polynomial defines an abstract type 'a poly of
  2397 univariate polynomials with coefficients of type 'a.  In addition to
  2398 the standard ring operations, it also supports div and mod.  Code
  2399 generation is also supported, using list-style constructors.
  2400 
  2401 * Theory Library/Inner_Product defines a class of real_inner for real
  2402 inner product spaces, with an overloaded operation inner :: 'a => 'a
  2403 => real.  Class real_inner is a subclass of real_normed_vector from
  2404 theory RealVector.
  2405 
  2406 * Theory Library/Product_Vector provides instances for the product
  2407 type 'a * 'b of several classes from RealVector and Inner_Product.
  2408 Definitions of addition, subtraction, scalar multiplication, norms,
  2409 and inner products are included.
  2410 
  2411 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  2412 addition to the field operations, numerals and case syntax are also
  2413 supported.
  2414 
  2415 * Theory Library/Diagonalize provides constructive version of Cantor's
  2416 first diagonalization argument.
  2417 
  2418 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  2419 zlcm (for int); carried together from various gcd/lcm developements in
  2420 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  2421 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  2422 may recover tupled syntax as follows:
  2423 
  2424     hide (open) const gcd
  2425     abbreviation gcd where
  2426       "gcd == (%(a, b). GCD.gcd a b)"
  2427     notation (output)
  2428       GCD.gcd ("gcd '(_, _')")
  2429 
  2430 The same works for lcm, zgcd, zlcm.
  2431 
  2432 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  2433 instantiations for algebraic structures.  Removed some duplicate
  2434 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  2435 
  2436 * ML antiquotation @{code} takes a constant as argument and generates
  2437 corresponding code in background and inserts name of the corresponding
  2438 resulting ML value/function/datatype constructor binding in place.
  2439 All occurrences of @{code} with a single ML block are generated
  2440 simultaneously.  Provides a generic and safe interface for
  2441 instrumentalizing code generation.  See
  2442 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  2443 In future you ought to refrain from ad-hoc compiling generated SML
  2444 code on the ML toplevel.  Note that (for technical reasons) @{code}
  2445 cannot refer to constants for which user-defined serializations are
  2446 set.  Refer to the corresponding ML counterpart directly in that
  2447 cases.
  2448 
  2449 * Command 'rep_datatype': instead of theorem names the command now
  2450 takes a list of terms denoting the constructors of the type to be
  2451 represented as datatype.  The characteristic theorems have to be
  2452 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  2453 have disappeared in favour of existing ones:
  2454 
  2455     unit_induct                 ~> unit.induct
  2456     prod_induct                 ~> prod.induct
  2457     sum_induct                  ~> sum.induct
  2458     Suc_Suc_eq                  ~> nat.inject
  2459     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  2460 
  2461 
  2462 *** HOL-Algebra ***
  2463 
  2464 * New locales for orders and lattices where the equivalence relation
  2465 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  2466 locales use a record structure with field eq for the equivalence.
  2467 
  2468 * New theory of factorial domains.
  2469 
  2470 * Units_l_inv and Units_r_inv are now simp rules by default.
  2471 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  2472 and/or r_inv will now also require deletion of these lemmas.
  2473 
  2474 * Renamed the following theorems, INCOMPATIBILITY:
  2475 
  2476 UpperD ~> Upper_memD
  2477 LowerD ~> Lower_memD
  2478 least_carrier ~> least_closed
  2479 greatest_carrier ~> greatest_closed
  2480 greatest_Lower_above ~> greatest_Lower_below
  2481 one_zero ~> carrier_one_zero
  2482 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  2483 
  2484 
  2485 *** HOL-Nominal ***
  2486 
  2487 * Nominal datatypes can now contain type-variables.
  2488 
  2489 * Commands 'nominal_inductive' and 'equivariance' work with local
  2490 theory targets.
  2491 
  2492 * Nominal primrec can now works with local theory targets and its
  2493 specification syntax now conforms to the general format as seen in
  2494 'inductive' etc.
  2495 
  2496 * Method "perm_simp" honours the standard simplifier attributes
  2497 (no_asm), (no_asm_use) etc.
  2498 
  2499 * The new predicate #* is defined like freshness, except that on the
  2500 left hand side can be a set or list of atoms.
  2501 
  2502 * Experimental command 'nominal_inductive2' derives strong induction
  2503 principles for inductive definitions.  In contrast to
  2504 'nominal_inductive', which can only deal with a fixed number of
  2505 binders, it can deal with arbitrary expressions standing for sets of
  2506 atoms to be avoided.  The only inductive definition we have at the
  2507 moment that needs this generalisation is the typing rule for Lets in
  2508 the algorithm W:
  2509 
  2510  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  2511  -----------------------------------------------------------------
  2512          Gamma |- Let x be t1 in t2 : T2
  2513 
  2514 In this rule one wants to avoid all the binders that are introduced by
  2515 "close Gamma T1".  We are looking for other examples where this
  2516 feature might be useful.  Please let us know.
  2517 
  2518 
  2519 *** HOLCF ***
  2520 
  2521 * Reimplemented the simplification procedure for proving continuity
  2522 subgoals.  The new simproc is extensible; users can declare additional
  2523 continuity introduction rules with the attribute [cont2cont].
  2524 
  2525 * The continuity simproc now uses a different introduction rule for
  2526 solving continuity subgoals on terms with lambda abstractions.  In
  2527 some rare cases the new simproc may fail to solve subgoals that the
  2528 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  2529 Potential INCOMPATIBILITY.
  2530 
  2531 * Command 'fixrec': specification syntax now conforms to the general
  2532 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  2533 examples.  INCOMPATIBILITY.
  2534 
  2535 
  2536 *** ZF ***
  2537 
  2538 * Proof of Zorn's Lemma for partial orders.
  2539 
  2540 
  2541 *** ML ***
  2542 
  2543 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  2544 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  2545 depends on multithreading, so timouts will not work before Poly/ML
  2546 5.2.1!
  2547 
  2548 * High-level support for concurrent ML programming, see
  2549 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  2550 particularly convenient to organize independent functional
  2551 computations.  The concept of "synchronized variables" provides a
  2552 higher-order interface for components with shared state, avoiding the
  2553 delicate details of mutexes and condition variables.  (Requires
  2554 Poly/ML 5.2.1 or later.)
  2555 
  2556 * ML bindings produced via Isar commands are stored within the Isar
  2557 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  2558 become thread-safe and work with undo as expected (concerning
  2559 top-level bindings, not side-effects on global references).
  2560 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  2561 compiler at runtime; really global bindings need to be given outside a
  2562 theory.  (Requires Poly/ML 5.2 or later.)
  2563 
  2564 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  2565 context.  Top-level ML bindings are stored within the proof context in
  2566 a purely sequential fashion, disregarding the nested proof structure.
  2567 ML bindings introduced by 'ML_prf' are discarded at the end of the
  2568 proof.  (Requires Poly/ML 5.2 or later.)
  2569 
  2570 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  2571 and Method.setup, as well as Isar commands 'attribute_setup' and
  2572 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  2573 existing code accordingly, or use plain 'setup' together with old
  2574 Method.add_method.
  2575 
  2576 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  2577 to 'a -> thm, while results are always tagged with an authentic oracle
  2578 name.  The Isar command 'oracle' is now polymorphic, no argument type
  2579 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  2580 accordingly.  Note that extra performance may be gained by producing
  2581 the cterm carefully, avoiding slow Thm.cterm_of.
  2582 
  2583 * Simplified interface for defining document antiquotations via
  2584 ThyOutput.antiquotation, ThyOutput.output, and optionally
  2585 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  2586 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  2587 examples.
  2588 
  2589 * More systematic treatment of long names, abstract name bindings, and
  2590 name space operations.  Basic operations on qualified names have been
  2591 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  2592 Long_Name.append.  Old type bstring has been mostly replaced by
  2593 abstract type binding (see structure Binding), which supports precise
  2594 qualification by packages and local theory targets, as well as proper
  2595 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  2596 bstring values into Binding.name, or better pass through abstract
  2597 bindings everywhere.  See further src/Pure/General/long_name.ML,
  2598 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  2599 
  2600 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  2601 LocalTheory.note etc.) now refer to the *full* internal name, not the
  2602 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  2603 
  2604 * Disposed old type and term read functions (Sign.read_def_typ,
  2605 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  2606 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  2607 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  2608 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  2609 resort for legacy applications.
  2610 
  2611 * Disposed old declarations, tactics, tactic combinators that refer to
  2612 the simpset or claset of an implicit theory (such as Addsimps,
  2613 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  2614 embedded ML text, or local_simpset_of with a proper context passed as
  2615 explicit runtime argument.
  2616 
  2617 * Rules and tactics that read instantiations (read_instantiate,
  2618 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  2619 context, which is required for parsing and type-checking.  Moreover,
  2620 the variables are specified as plain indexnames, not string encodings
  2621 thereof.  INCOMPATIBILITY.
  2622 
  2623 * Generic Toplevel.add_hook interface allows to analyze the result of
  2624 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  2625 for theorem dependency output of transactions resulting in a new
  2626 theory state.
  2627 
  2628 * ML antiquotations: block-structured compilation context indicated by
  2629 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  2630 
  2631   @{binding name}                         - basic name binding
  2632   @{let ?pat = term}                      - term abbreviation (HO matching)
  2633   @{note name = fact}                     - fact abbreviation
  2634   @{thm fact}                             - singleton fact (with attributes)
  2635   @{thms fact}                            - general fact (with attributes)
  2636   @{lemma prop by method}                 - singleton goal
  2637   @{lemma prop by meth1 meth2}            - singleton goal
  2638   @{lemma prop1 ... propN by method}      - general goal
  2639   @{lemma prop1 ... propN by meth1 meth2} - general goal
  2640   @{lemma (open) ...}                     - open derivation
  2641 
  2642 
  2643 *** System ***
  2644 
  2645 * The Isabelle "emacs" tool provides a specific interface to invoke
  2646 Proof General / Emacs, with more explicit failure if that is not
  2647 installed (the old isabelle-interface script silently falls back on
  2648 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  2649 installation location of the Proof General distribution.
  2650 
  2651 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  2652 the Isabelle process into a JVM/Scala application.  See
  2653 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  2654 process wrapper has been discontinued.)
  2655 
  2656 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  2657 
  2658 * Various status messages (with exact source position information) are
  2659 emitted, if proper markup print mode is enabled.  This allows
  2660 user-interface components to provide detailed feedback on internal
  2661 prover operations.
  2662 
  2663 
  2664 
  2665 New in Isabelle2008 (June 2008)
  2666 -------------------------------
  2667 
  2668 *** General ***
  2669 
  2670 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  2671 and updated, with formally checked references as hyperlinks.
  2672 
  2673 * Theory loader: use_thy (and similar operations) no longer set the
  2674 implicit ML context, which was occasionally hard to predict and in
  2675 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  2676 provides a proper context already.
  2677 
  2678 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2679 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  2680 'use' within a theory file will do the job.
  2681 
  2682 * Name space merge now observes canonical order, i.e. the second space
  2683 is inserted into the first one, while existing entries in the first
  2684 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  2685 swap theory imports.
  2686 
  2687 * Syntax: symbol \<chi> is now considered a letter.  Potential
  2688 INCOMPATIBILITY in identifier syntax etc.
  2689 
  2690 * Outer syntax: string tokens no longer admit escaped white space,
  2691 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  2692 white space without escapes.
  2693 
  2694 * Outer syntax: string tokens may contain arbitrary character codes
  2695 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  2696 "foo_bar".
  2697 
  2698 
  2699 *** Pure ***
  2700 
  2701 * Context-dependent token translations.  Default setup reverts locally
  2702 fixed variables, and adds hilite markup for undeclared frees.
  2703 
  2704 * Unused theorems can be found using the new command 'unused_thms'.
  2705 There are three ways of invoking it:
  2706 
  2707 (1) unused_thms
  2708      Only finds unused theorems in the current theory.
  2709 
  2710 (2) unused_thms thy_1 ... thy_n -
  2711      Finds unused theorems in the current theory and all of its ancestors,
  2712      excluding the theories thy_1 ... thy_n and all of their ancestors.
  2713 
  2714 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  2715      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  2716      their ancestors, excluding the theories thy_1 ... thy_n and all of
  2717      their ancestors.
  2718 
  2719 In order to increase the readability of the list produced by
  2720 unused_thms, theorems that have been created by a particular instance
  2721 of a theory command such as 'inductive' or 'function' are considered
  2722 to belong to the same "group", meaning that if at least one theorem in
  2723 this group is used, the other theorems in the same group are no longer
  2724 reported as unused.  Moreover, if all theorems in the group are
  2725 unused, only one theorem in the group is displayed.
  2726 
  2727 Note that proof objects have to be switched on in order for
  2728 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  2729 usually the case when using Proof General with the default settings).
  2730 
  2731 * Authentic naming of facts disallows ad-hoc overwriting of previous
  2732 theorems within the same name space.  INCOMPATIBILITY, need to remove
  2733 duplicate fact bindings, or even accidental fact duplications.  Note
  2734 that tools may maintain dynamically scoped facts systematically, using
  2735 PureThy.add_thms_dynamic.
  2736 
  2737 * Command 'hide' now allows to hide from "fact" name space as well.
  2738 
  2739 * Eliminated destructive theorem database, simpset, claset, and
  2740 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  2741 update of theories within ML code.
  2742 
  2743 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  2744 INCOMPATIBILITY, object-logics depending on former Pure require
  2745 additional setup PureThy.old_appl_syntax_setup; object-logics
  2746 depending on former CPure need to refer to Pure.
  2747 
  2748 * Commands 'use' and 'ML' are now purely functional, operating on
  2749 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  2750 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  2751 INCOMPATIBILITY.
  2752 
  2753 * Command 'setup': discontinued implicit version with ML reference.
  2754 
  2755 * Instantiation target allows for simultaneous specification of class
  2756 instance operations together with an instantiation proof.
  2757 Type-checking phase allows to refer to class operations uniformly.
  2758 See src/HOL/Complex/Complex.thy for an Isar example and
  2759 src/HOL/Library/Eval.thy for an ML example.
  2760 
  2761 * Indexing of literal facts: be more serious about including only
  2762 facts from the visible specification/proof context, but not the
  2763 background context (locale etc.).  Affects `prop` notation and method
  2764 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  2765 situations.
  2766 
  2767 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  2768 "(open)" option, which used to expose internal bound variables to the
  2769 proof text.
  2770 
  2771 * Isar statements: removed obsolete case "rule_context".
  2772 INCOMPATIBILITY, better use explicit fixes/assumes.
  2773 
  2774 * Locale proofs: default proof step now includes 'unfold_locales';
  2775 hence 'proof' without argument may be used to unfold locale
  2776 predicates.
  2777 
  2778 
  2779 *** Document preparation ***
  2780 
  2781 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  2782 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  2783 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  2784 spot); renamed link color from "darkblue" to "linkcolor" (default
  2785 value unchanged, can be redefined via \definecolor); no longer sets
  2786 "a4paper" option (unnecessary or even intrusive).
  2787 
  2788 * Antiquotation @{lemma A method} proves proposition A by the given
  2789 method (either a method name or a method name plus (optional) method
  2790 arguments in parentheses) and prints A just like @{prop A}.
  2791 
  2792 
  2793 *** HOL ***
  2794 
  2795 * New primrec package.  Specification syntax conforms in style to
  2796 definition/function/....  No separate induction rule is provided.  The
  2797 "primrec" command distinguishes old-style and new-style specifications
  2798 by syntax.  The former primrec package is now named OldPrimrecPackage.
  2799 When adjusting theories, beware: constants stemming from new-style
  2800 primrec specifications have authentic syntax.
  2801 
  2802 * Metis prover is now an order of magnitude faster, and also works
  2803 with multithreading.
  2804 
  2805 * Metis: the maximum number of clauses that can be produced from a
  2806 theorem is now given by the attribute max_clauses.  Theorems that
  2807 exceed this number are ignored, with a warning printed.
  2808 
  2809 * Sledgehammer no longer produces structured proofs by default. To
  2810 enable, declare [[sledgehammer_full = true]].  Attributes
  2811 reconstruction_modulus, reconstruction_sorts renamed
  2812 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  2813 
  2814 * Method "induct_scheme" derives user-specified induction rules
  2815 from well-founded induction and completeness of patterns. This factors
  2816 out some operations that are done internally by the function package
  2817 and makes them available separately.  See
  2818 src/HOL/ex/Induction_Scheme.thy for examples.
  2819 
  2820 * More flexible generation of measure functions for termination
  2821 proofs: Measure functions can be declared by proving a rule of the
  2822 form "is_measure f" and giving it the [measure_function] attribute.
  2823 The "is_measure" predicate is logically meaningless (always true), and
  2824 just guides the heuristic.  To find suitable measure functions, the
  2825 termination prover sets up the goal "is_measure ?f" of the appropriate
  2826 type and generates all solutions by prolog-style backwards proof using
  2827 the declared rules.
  2828 
  2829 This setup also deals with rules like 
  2830 
  2831   "is_measure f ==> is_measure (list_size f)"
  2832 
  2833 which accommodates nested datatypes that recurse through lists.
  2834 Similar rules are predeclared for products and option types.
  2835 
  2836 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  2837 
  2838   INCOMPATIBILITIES:
  2839 
  2840   - Definitions of overloaded constants on sets have to be replaced by
  2841     definitions on => and bool.
  2842 
  2843   - Some definitions of overloaded operators on sets can now be proved
  2844     using the definitions of the operators on => and bool.  Therefore,
  2845     the following theorems have been renamed:
  2846 
  2847       subset_def   -> subset_eq
  2848       psubset_def  -> psubset_eq
  2849       set_diff_def -> set_diff_eq
  2850       Compl_def    -> Compl_eq
  2851       Sup_set_def  -> Sup_set_eq
  2852       Inf_set_def  -> Inf_set_eq
  2853       sup_set_def  -> sup_set_eq
  2854       inf_set_def  -> inf_set_eq
  2855 
  2856   - Due to the incompleteness of the HO unification algorithm, some
  2857     rules such as subst may require manual instantiation, if some of
  2858     the unknowns in the rule is a set.
  2859 
  2860   - Higher order unification and forward proofs:
  2861     The proof pattern
  2862 
  2863       have "P (S::'a set)" <...>
  2864       then have "EX S. P S" ..
  2865 
  2866     no longer works (due to the incompleteness of the HO unification
  2867     algorithm) and must be replaced by the pattern
  2868 
  2869       have "EX S. P S"
  2870       proof
  2871         show "P S" <...>
  2872       qed
  2873 
  2874   - Calculational reasoning with subst (or similar rules):
  2875     The proof pattern
  2876 
  2877       have "P (S::'a set)" <...>
  2878       also have "S = T" <...>
  2879       finally have "P T" .
  2880 
  2881     no longer works (for similar reasons as the previous example) and
  2882     must be replaced by something like
  2883 
  2884       have "P (S::'a set)" <...>
  2885       moreover have "S = T" <...>
  2886       ultimately have "P T" by simp
  2887 
  2888   - Tactics or packages written in ML code:
  2889     Code performing pattern matching on types via
  2890 
  2891       Type ("set", [T]) => ...
  2892 
  2893     must be rewritten. Moreover, functions like strip_type or
  2894     binder_types no longer return the right value when applied to a
  2895     type of the form
  2896 
  2897       T1 => ... => Tn => U => bool
  2898 
  2899     rather than
  2900 
  2901       T1 => ... => Tn => U set
  2902 
  2903 * Merged theories Wellfounded_Recursion, Accessible_Part and
  2904 Wellfounded_Relations to theory Wellfounded.
  2905 
  2906 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  2907 
  2908 * Class finite no longer treats UNIV as class parameter.  Use class
  2909 enum from theory Library/Enum instead to achieve a similar effect.
  2910 INCOMPATIBILITY.
  2911 
  2912 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  2913 and "Cons".  INCOMPATIBILITY.
  2914 
  2915 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  2916 Potential INCOMPATIBILITY.
  2917 
  2918 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  2919 injective_fst_snd removed, use split_eta and prod_eqI instead.
  2920 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  2921 
  2922 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  2923 the same name in theory Orderings:
  2924 
  2925   less_trans
  2926   less_linear
  2927   le_imp_less_or_eq
  2928   le_less_trans
  2929   less_le_trans
  2930   less_not_sym
  2931   less_asym
  2932 
  2933 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  2934 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  2935 and different variable names.
  2936 
  2937 * Library/Option_ord.thy: Canonical order on option type.
  2938 
  2939 * Library/RBT.thy: Red-black trees, an efficient implementation of
  2940 finite maps.
  2941 
  2942 * Library/Countable.thy: Type class for countable types.
  2943 
  2944 * Theory Int: The representation of numerals has changed.  The infix
  2945 operator BIT and the bit datatype with constructors B0 and B1 have
  2946 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  2947 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  2948 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  2949 accordingly.
  2950 
  2951 * Theory Nat: definition of <= and < on natural numbers no longer
  2952 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  2953 le_def and less_def have disappeared.  Consider lemmas not_less
  2954 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  2955 
  2956 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  2957 (whose purpose mainly is for various fold_set functionals) have been
  2958 abandoned in favor of the existing algebraic classes
  2959 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  2960 lower_semilattice (resp. upper_semilattice) and linorder.
  2961 INCOMPATIBILITY.
  2962 
  2963 * Theory Transitive_Closure: induct and cases rules now declare proper
  2964 case_names ("base" and "step").  INCOMPATIBILITY.
  2965 
  2966 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  2967 lattices.  The form set-specific version is available as
  2968 Inductive.lfp_ordinal_induct_set.
  2969 
  2970 * Renamed theorems "power.simps" to "power_int.simps".
  2971 INCOMPATIBILITY.
  2972 
  2973 * Class semiring_div provides basic abstract properties of semirings
  2974 with division and modulo operations.  Subsumes former class dvd_mod.
  2975 
  2976 * Merged theories IntDef, Numeral and IntArith into unified theory
  2977 Int.  INCOMPATIBILITY.
  2978 
  2979 * Theory Library/Code_Index: type "index" now represents natural
  2980 numbers rather than integers.  INCOMPATIBILITY.
  2981 
  2982 * New class "uminus" with operation "uminus" (split of from class
  2983 "minus" which now only has operation "minus", binary).
  2984 INCOMPATIBILITY.
  2985 
  2986 * Constants "card", "internal_split", "option_map" now with authentic
  2987 syntax.  INCOMPATIBILITY.
  2988 
  2989 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  2990 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  2991 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  2992 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  2993 Sup_set_def, le_def, less_def, option_map_def now with object
  2994 equality.  INCOMPATIBILITY.
  2995 
  2996 * Records. Removed K_record, and replaced it by pure lambda term
  2997 %x. c. The simplifier setup is now more robust against eta expansion.
  2998 INCOMPATIBILITY: in cases explicitly referring to K_record.
  2999 
  3000 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  3001 
  3002 * Library/ListVector: new theory of arithmetic vector operations.
  3003 
  3004 * Library/Order_Relation: new theory of various orderings as sets of
  3005 pairs.  Defines preorders, partial orders, linear orders and
  3006 well-orders on sets and on types.
  3007 
  3008 
  3009 *** ZF ***
  3010 
  3011 * Renamed some theories to allow to loading both ZF and HOL in the
  3012 same session:
  3013 
  3014   Datatype  -> Datatype_ZF
  3015   Inductive -> Inductive_ZF
  3016   Int       -> Int_ZF
  3017   IntDiv    -> IntDiv_ZF
  3018   Nat       -> Nat_ZF
  3019   List      -> List_ZF
  3020   Main      -> Main_ZF
  3021 
  3022 INCOMPATIBILITY: ZF theories that import individual theories below
  3023 Main might need to be adapted.  Regular theory Main is still
  3024 available, as trivial extension of Main_ZF.
  3025 
  3026 
  3027 *** ML ***
  3028 
  3029 * ML within Isar: antiquotation @{const name} or @{const
  3030 name(typargs)} produces statically-checked Const term.
  3031 
  3032 * Functor NamedThmsFun: data is available to the user as dynamic fact
  3033 (of the same name).  Removed obsolete print command.
  3034 
  3035 * Removed obsolete "use_legacy_bindings" function.
  3036 
  3037 * The ``print mode'' is now a thread-local value derived from a global
  3038 template (the former print_mode reference), thus access becomes
  3039 non-critical.  The global print_mode reference is for session
  3040 management only; user-code should use print_mode_value,
  3041 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  3042 
  3043 * Functions system/system_out provide a robust way to invoke external
  3044 shell commands, with propagation of interrupts (requires Poly/ML
  3045 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  3046 
  3047 
  3048 *** System ***
  3049 
  3050 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  3051 in accordance with Proof General 3.7, which prefers GNU emacs.
  3052 
  3053 * isatool tty runs Isabelle process with plain tty interaction;
  3054 optional line editor may be specified via ISABELLE_LINE_EDITOR
  3055 setting, the default settings attempt to locate "ledit" and "rlwrap".
  3056 
  3057 * isatool browser now works with Cygwin as well, using general
  3058 "javapath" function defined in Isabelle process environment.
  3059 
  3060 * YXML notation provides a simple and efficient alternative to
  3061 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  3062 isatool yxml as described in the Isabelle system manual.
  3063 
  3064 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  3065 provides general wrapper for managing an Isabelle process in a robust
  3066 fashion, with ``cooked'' output from stdin/stderr.
  3067 
  3068 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  3069 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  3070 
  3071 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  3072 way of changing the user's settings is via
  3073 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  3074 script.
  3075 
  3076 * Multithreading.max_threads := 0 refers to the number of actual CPU
  3077 cores of the underlying machine, which is a good starting point for
  3078 optimal performance tuning.  The corresponding usedir option -M allows
  3079 "max" as an alias for "0".  WARNING: does not work on certain versions
  3080 of Mac OS (with Poly/ML 5.1).
  3081 
  3082 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  3083 adverse effect of Isabelle flooding interactive front-ends (notably
  3084 ProofGeneral / XEmacs).
  3085 
  3086 
  3087 
  3088 New in Isabelle2007 (November 2007)
  3089 -----------------------------------
  3090 
  3091 *** General ***
  3092 
  3093 * More uniform information about legacy features, notably a
  3094 warning/error of "Legacy feature: ...", depending on the state of the
  3095 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  3096 legacy features will disappear eventually.
  3097 
  3098 * Theory syntax: the header format ``theory A = B + C:'' has been
  3099 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  3100 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  3101 
  3102 * Theory syntax: the old non-Isar theory file format has been
  3103 discontinued altogether.  Note that ML proof scripts may still be used
  3104 with Isar theories; migration is usually quite simple with the ML
  3105 function use_legacy_bindings.  INCOMPATIBILITY.
  3106 
  3107 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  3108 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  3109 quotes.
  3110 
  3111 * Theory loader: be more serious about observing the static theory
  3112 header specifications (including optional directories), but not the
  3113 accidental file locations of previously successful loads.  The strict
  3114 update policy of former update_thy is now already performed by
  3115 use_thy, so the former has been removed; use_thys updates several
  3116 theories simultaneously, just as 'imports' within a theory header
  3117 specification, but without merging the results.  Potential
  3118 INCOMPATIBILITY: may need to refine theory headers and commands
  3119 ROOT.ML which depend on load order.
  3120 
  3121 * Theory loader: optional support for content-based file
  3122 identification, instead of the traditional scheme of full physical
  3123 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  3124 (cf. the system manual).  The new scheme allows to work with
  3125 non-finished theories in persistent session images, such that source
  3126 files may be moved later on without requiring reloads.
  3127 
  3128 * Theory loader: old-style ML proof scripts being *attached* to a thy
  3129 file (with the same base name as the theory) are considered a legacy
  3130 feature, which will disappear eventually. Even now, the theory loader
  3131 no longer maintains dependencies on such files.
  3132 
  3133 * Syntax: the scope for resolving ambiguities via type-inference is
  3134 now limited to individual terms, instead of whole simultaneous
  3135 specifications as before. This greatly reduces the complexity of the
  3136 syntax module and improves flexibility by separating parsing and
  3137 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  3138 'fixes' etc.) are required in rare situations.
  3139 
  3140 * Syntax: constants introduced by new-style packages ('definition',
  3141 'abbreviation' etc.) are passed through the syntax module in
  3142 ``authentic mode''. This means that associated mixfix annotations
  3143 really stick to such constants, independently of potential name space
  3144 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  3145 trees are represented slightly differently, may need to adapt syntax
  3146 translations accordingly. Use CONST marker in 'translations' and
  3147 @{const_syntax} antiquotation in 'parse_translation' etc.
  3148 
  3149 * Legacy goal package: reduced interface to the bare minimum required
  3150 to keep existing proof scripts running.  Most other user-level
  3151 functions are now part of the OldGoals structure, which is *not* open
  3152 by default (consider isatool expandshort before open OldGoals).
  3153 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  3154 these tend to cause confusion about the actual goal (!) context being
  3155 used here, which is not necessarily the same as the_context().
  3156 
  3157 * Command 'find_theorems': supports "*" wild-card in "name:"
  3158 criterion; "with_dups" option.  Certain ProofGeneral versions might
  3159 support a specific search form (see ProofGeneral/CHANGES).
  3160 
  3161 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  3162 by default, which means that "prems" (and also "fixed variables") are
  3163 suppressed from proof state output.  Note that the ProofGeneral
  3164 settings mechanism allows to change and save options persistently, but
  3165 older versions of Isabelle will fail to start up if a negative prems
  3166 limit is imposed.
  3167 
  3168 * Local theory targets may be specified by non-nested blocks of
  3169 ``context/locale/class ... begin'' followed by ``end''.  The body may
  3170 contain definitions, theorems etc., including any derived mechanism
  3171 that has been implemented on top of these primitives.  This concept
  3172 generalizes the existing ``theorem (in ...)'' towards more versatility
  3173 and scalability.
  3174 
  3175 * Proof General interface: proper undo of final 'end' command;
  3176 discontinued Isabelle/classic mode (ML proof scripts).
  3177 
  3178 
  3179 *** Document preparation ***
  3180 
  3181 * Added antiquotation @{theory name} which prints the given name,
  3182 after checking that it refers to a valid ancestor theory in the
  3183 current context.
  3184 
  3185 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  3186 check the given source text as ML type/structure, printing verbatim.
  3187 
  3188 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  3189 "c args == rhs" given in the current context.  (Any number of
  3190 arguments may be given on the LHS.)
  3191 
  3192 
  3193 *** Pure ***
  3194 
  3195 * The 'class' package offers a combination of axclass and locale to
  3196 achieve Haskell-like type classes in Isabelle.  Definitions and
  3197 theorems within a class context produce both relative results (with
  3198 implicit parameters according to the locale context), and polymorphic
  3199 constants with qualified polymorphism (according to the class
  3200 context).  Within the body context of a 'class' target, a separate
  3201 syntax layer ("user space type system") takes care of converting
  3202 between global polymorphic consts and internal locale representation.
  3203 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  3204 "isatool doc classes" provides a tutorial.
  3205 
  3206 * Generic code generator framework allows to generate executable
  3207 code for ML and Haskell (including Isabelle classes).  A short usage
  3208 sketch:
  3209 
  3210     internal compilation:
  3211         export_code <list of constants (term syntax)> in SML
  3212     writing SML code to a file:
  3213         export_code <list of constants (term syntax)> in SML <filename>
  3214     writing OCaml code to a file:
  3215         export_code <list of constants (term syntax)> in OCaml <filename>
  3216     writing Haskell code to a bunch of files:
  3217         export_code <list of constants (term syntax)> in Haskell <filename>
  3218 
  3219     evaluating closed propositions to True/False using code generation:
  3220         method ``eval''
  3221 
  3222 Reasonable default setup of framework in HOL.
  3223 
  3224 Theorem attributs for selecting and transforming function equations theorems:
  3225 
  3226     [code fun]:        select a theorem as function equation for a specific constant
  3227     [code fun del]:    deselect a theorem as function equation for a specific constant
  3228     [code inline]:     select an equation theorem for unfolding (inlining) in place
  3229     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  3230 
  3231 User-defined serializations (target in {SML, OCaml, Haskell}):
  3232 
  3233     code_const <and-list of constants (term syntax)>
  3234       {(target) <and-list of const target syntax>}+
  3235 
  3236     code_type <and-list of type constructors>
  3237       {(target) <and-list of type target syntax>}+
  3238 
  3239     code_instance <and-list of instances>
  3240       {(target)}+
  3241         where instance ::= <type constructor> :: <class>
  3242 
  3243     code_class <and_list of classes>
  3244       {(target) <and-list of class target syntax>}+
  3245         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  3246 
  3247 code_instance and code_class only are effective to target Haskell.
  3248 
  3249 For example usage see src/HOL/ex/Codegenerator.thy and
  3250 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  3251 generation from Isabelle/HOL theories is available via "isatool doc
  3252 codegen".
  3253 
  3254 * Code generator: consts in 'consts_code' Isar commands are now
  3255 referred to by usual term syntax (including optional type
  3256 annotations).
  3257 
  3258 * Command 'no_translations' removes translation rules from theory
  3259 syntax.
  3260 
  3261 * Overloaded definitions are now actually checked for acyclic
  3262 dependencies.  The overloading scheme is slightly more general than
  3263 that of Haskell98, although Isabelle does not demand an exact
  3264 correspondence to type class and instance declarations.
  3265 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  3266 exotic versions of overloading -- at the discretion of the user!
  3267 
  3268 Polymorphic constants are represented via type arguments, i.e. the
  3269 instantiation that matches an instance against the most general
  3270 declaration given in the signature.  For example, with the declaration
  3271 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  3272 as c(nat).  Overloading is essentially simultaneous structural
  3273 recursion over such type arguments.  Incomplete specification patterns
  3274 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  3275 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  3276 Command 'print_theory' outputs the normalized system of recursive
  3277 equations, see section "definitions".
  3278 
  3279 * Configuration options are maintained within the theory or proof
  3280 context (with name and type bool/int/string), providing a very simple
  3281 interface to a poor-man's version of general context data.  Tools may
  3282 declare options in ML (e.g. using Attrib.config_int) and then refer to
  3283 these values using Config.get etc.  Users may change options via an
  3284 associated attribute of the same name.  This form of context
  3285 declaration works particularly well with commands 'declare' or
  3286 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  3287 very easy to avoid global references, which would not observe Isar
  3288 toplevel undo/redo and fail to work with multithreading.
  3289 
  3290 Various global ML references of Pure and HOL have been turned into
  3291 configuration options:
  3292 
  3293   Unify.search_bound		unify_search_bound
  3294   Unify.trace_bound		unify_trace_bound
  3295   Unify.trace_simp		unify_trace_simp
  3296   Unify.trace_types		unify_trace_types
  3297   Simplifier.simp_depth_limit	simp_depth_limit
  3298   Blast.depth_limit		blast_depth_limit
  3299   DatatypeProp.dtK		datatype_distinctness_limit
  3300   fast_arith_neq_limit  	fast_arith_neq_limit
  3301   fast_arith_split_limit	fast_arith_split_limit
  3302 
  3303 * Named collections of theorems may be easily installed as context
  3304 data using the functor NamedThmsFun (see also
  3305 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  3306 attributes; there is also a toplevel print command.  This facility is
  3307 just a common case of general context data, which is the preferred way
  3308 for anything more complex than just a list of facts in canonical
  3309 order.
  3310 
  3311 * Isar: command 'declaration' augments a local theory by generic
  3312 declaration functions written in ML.  This enables arbitrary content
  3313 being added to the context, depending on a morphism that tells the
  3314 difference of the original declaration context wrt. the application
  3315 context encountered later on.
  3316 
  3317 * Isar: proper interfaces for simplification procedures.  Command
  3318 'simproc_setup' declares named simprocs (with match patterns, and body
  3319 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  3320 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  3321 
  3322 * Isar: an extra pair of brackets around attribute declarations
  3323 abbreviates a theorem reference involving an internal dummy fact,
  3324 which will be ignored later --- only the effect of the attribute on
  3325 the background context will persist.  This form of in-place
  3326 declarations is particularly useful with commands like 'declare' and
  3327 'using', for example ``have A using [[simproc a]] by simp''.
  3328 
  3329 * Isar: method "assumption" (and implicit closing of subproofs) now
  3330 takes simple non-atomic goal assumptions into account: after applying
  3331 an assumption as a rule the resulting subgoals are solved by atomic
  3332 assumption steps.  This is particularly useful to finish 'obtain'
  3333 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  3334 without referring to the original premise "!!x. P x ==> thesis" in the
  3335 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  3336 more permissive.
  3337 
  3338 * Isar: implicit use of prems from the Isar proof context is
  3339 considered a legacy feature.  Common applications like ``have A .''
  3340 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  3341 referencing facts explicitly here improves readability and
  3342 maintainability of proof texts.
  3343 
  3344 * Isar: improper proof element 'guess' is like 'obtain', but derives
  3345 the obtained context from the course of reasoning!  For example:
  3346 
  3347   assume "EX x y. A x & B y"   -- "any previous fact"
  3348   then guess x and y by clarify
  3349 
  3350 This technique is potentially adventurous, depending on the facts and
  3351 proof tools being involved here.
  3352 
  3353 * Isar: known facts from the proof context may be specified as literal
  3354 propositions, using ASCII back-quote syntax.  This works wherever
  3355 named facts used to be allowed so far, in proof commands, proof
  3356 methods, attributes etc.  Literal facts are retrieved from the context
  3357 according to unification of type and term parameters.  For example,
  3358 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  3359 theorems in the current context, then these are valid literal facts:
  3360 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  3361 
  3362 There is also a proof method "fact" which does the same composition
  3363 for explicit goal states, e.g. the following proof texts coincide with
  3364 certain special cases of literal facts:
  3365 
  3366   have "A" by fact                 ==  note `A`
  3367   have "A ==> B" by fact           ==  note `A ==> B`
  3368   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  3369   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  3370 
  3371 * Isar: ":" (colon) is no longer a symbolic identifier character in
  3372 outer syntax.  Thus symbolic identifiers may be used without
  3373 additional white space in declarations like this: ``assume *: A''.
  3374 
  3375 * Isar: 'print_facts' prints all local facts of the current context,
  3376 both named and unnamed ones.
  3377 
  3378 * Isar: 'def' now admits simultaneous definitions, e.g.:
  3379 
  3380   def x == "t" and y == "u"
  3381 
  3382 * Isar: added command 'unfolding', which is structurally similar to
  3383 'using', but affects both the goal state and facts by unfolding given
  3384 rewrite rules.  Thus many occurrences of the 'unfold' method or
  3385 'unfolded' attribute may be replaced by first-class proof text.
  3386 
  3387 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  3388 and command 'unfolding' now all support object-level equalities
  3389 (potentially conditional).  The underlying notion of rewrite rule is
  3390 analogous to the 'rule_format' attribute, but *not* that of the
  3391 Simplifier (which is usually more generous).
  3392 
  3393 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  3394 premises of a theorem by n. Useful in conjunction with drule.
  3395 
  3396 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  3397 method expression within a sandbox consisting of the first N
  3398 sub-goals, which need to exist.  For example, ``simp_all [3]''
  3399 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  3400 simplifies all new goals that emerge from applying rule foo to the
  3401 originally first one.
  3402 
  3403 * Isar: schematic goals are no longer restricted to higher-order
  3404 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  3405 expected.
  3406 
  3407 * Isar: the conclusion of a long theorem statement is now either
  3408 'shows' (a simultaneous conjunction, as before), or 'obtains'
  3409 (essentially a disjunction of cases with local parameters and
  3410 assumptions).  The latter allows to express general elimination rules
  3411 adequately; in this notation common elimination rules look like this:
  3412 
  3413   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  3414     assumes "EX x. P x"
  3415     obtains x where "P x"
  3416 
  3417   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  3418     assumes "A & B"
  3419     obtains A and B
  3420 
  3421   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  3422     assumes "A | B"
  3423     obtains
  3424       A
  3425     | B
  3426 
  3427 The subsequent classical rules even refer to the formal "thesis"
  3428 explicitly:
  3429 
  3430   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  3431     obtains "~ thesis"
  3432 
  3433   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  3434     obtains "thesis ==> something"
  3435 
  3436 The actual proof of an 'obtains' statement is analogous to that of the
  3437 Isar proof element 'obtain', only that there may be several cases.
  3438 Optional case names may be specified in parentheses; these will be
  3439 available both in the present proof and as annotations in the
  3440 resulting rule, for later use with the 'cases' method (cf. attribute
  3441 case_names).
  3442 
  3443 * Isar: the assumptions of a long theorem statement are available as
  3444 "assms" fact in the proof context.  This is more appropriate than the
  3445 (historical) "prems", which refers to all assumptions of the current
  3446 context, including those from the target locale, proof body etc.
  3447 
  3448 * Isar: 'print_statement' prints theorems from the current theory or
  3449 proof context in long statement form, according to the syntax of a
  3450 top-level lemma.
  3451 
  3452 * Isar: 'obtain' takes an optional case name for the local context
  3453 introduction rule (default "that").
  3454 
  3455 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  3456 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  3457 to occur.
  3458 
  3459 * Pure: syntax "CONST name" produces a fully internalized constant
  3460 according to the current context.  This is particularly useful for
  3461 syntax translations that should refer to internal constant
  3462 representations independently of name spaces.
  3463 
  3464 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  3465 instead of "FOO ". This allows multiple binder declarations to coexist
  3466 in the same context.  INCOMPATIBILITY.
  3467 
  3468 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  3469 primitive that also works in a locale context (both for constants and
  3470 fixed variables). Type declaration and internal syntactic representation
  3471 of given constants retrieved from the context. Likewise, the
  3472 'no_notation' command allows to remove given syntax annotations from the
  3473 current context.
  3474 
  3475 * Isar/locales: new derived specification elements 'axiomatization',
  3476 'definition', 'abbreviation', which support type-inference, admit
  3477 object-level specifications (equality, equivalence).  See also the
  3478 isar-ref manual.  Examples:
  3479 
  3480   axiomatization
  3481     eq  (infix "===" 50) where
  3482     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  3483 
  3484   definition "f x y = x + y + 1"
  3485   definition g where "g x = f x x"
  3486 
  3487   abbreviation
  3488     neq  (infix "=!=" 50) where
  3489     "x =!= y == ~ (x === y)"
  3490 
  3491 These specifications may be also used in a locale context.  Then the
  3492 constants being introduced depend on certain fixed parameters, and the
  3493 constant name is qualified by the locale base name.  An internal
  3494 abbreviation takes care for convenient input and output, making the
  3495 parameters implicit and using the original short name.  See also
  3496 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  3497 entities from a monomorphic theory.
  3498 
  3499 Presently, abbreviations are only available 'in' a target locale, but
  3500 not inherited by general import expressions.  Also note that
  3501 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  3502 'translations' in common applications.  The "no_abbrevs" print mode
  3503 prevents folding of abbreviations in term output.
  3504 
  3505 Concrete syntax is attached to specified constants in internal form,
  3506 independently of name spaces.  The parse tree representation is
  3507 slightly different -- use 'notation' instead of raw 'syntax', and
  3508 'translations' with explicit "CONST" markup to accommodate this.
  3509 
  3510 * Pure/Isar: unified syntax for new-style specification mechanisms
  3511 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  3512 full type inference and dummy patterns ("_").  For example:
  3513 
  3514   definition "K x _ = x"
  3515 
  3516   inductive conj for A B
  3517   where "A ==> B ==> conj A B"
  3518 
  3519 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  3520 the current context.  Print mode "no_abbrevs" prevents inversion of
  3521 abbreviations on output.
  3522 
  3523 * Isar/locales: improved parameter handling: use of locales "var" and
  3524 "struct" no longer necessary; - parameter renamings are no longer
  3525 required to be injective.  For example, this allows to define
  3526 endomorphisms as locale endom = homom mult mult h.
  3527 
  3528 * Isar/locales: changed the way locales with predicates are defined.
  3529 Instead of accumulating the specification, the imported expression is
  3530 now an interpretation.  INCOMPATIBILITY: different normal form of
  3531 locale expressions.  In particular, in interpretations of locales with
  3532 predicates, goals repesenting already interpreted fragments are not
  3533 removed automatically.  Use methods `intro_locales' and
  3534 `unfold_locales'; see below.
  3535 
  3536 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  3537 provide backward reasoning on locales predicates.  The methods are
  3538 aware of interpretations and discharge corresponding goals.
  3539 `intro_locales' is less aggressive then `unfold_locales' and does not
  3540 unfold predicates to assumptions.
  3541 
  3542 * Isar/locales: the order in which locale fragments are accumulated
  3543 has changed.  This enables to override declarations from fragments due
  3544 to interpretations -- for example, unwanted simp rules.
  3545 
  3546 * Isar/locales: interpretation in theories and proof contexts has been
  3547 extended.  One may now specify (and prove) equations, which are
  3548 unfolded in interpreted theorems.  This is useful for replacing
  3549 defined concepts (constants depending on locale parameters) by
  3550 concepts already existing in the target context.  Example:
  3551 
  3552   interpretation partial_order ["op <= :: [int, int] => bool"]
  3553     where "partial_order.less (op <=) (x::int) y = (x < y)"
  3554 
  3555 Typically, the constant `partial_order.less' is created by a
  3556 definition specification element in the context of locale
  3557 partial_order.
  3558 
  3559 * Method "induct": improved internal context management to support
  3560 local fixes and defines on-the-fly. Thus explicit meta-level
  3561 connectives !!  and ==> are rarely required anymore in inductive goals
  3562 (using object-logic connectives for this purpose has been long
  3563 obsolete anyway). Common proof patterns are explained in
  3564 src/HOL/Induct/Common_Patterns.thy, see also
  3565 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  3566 examples.
  3567 
  3568 * Method "induct": improved handling of simultaneous goals. Instead of
  3569 introducing object-level conjunction, the statement is now split into
  3570 several conclusions, while the corresponding symbolic cases are nested
  3571 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  3572 see src/HOL/Induct/Common_Patterns.thy, for example.
  3573 
  3574 * Method "induct": mutual induction rules are now specified as a list
  3575 of rule sharing the same induction cases. HOL packages usually provide
  3576 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  3577 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  3578 mutual induction rules differently, i.e. like this:
  3579 
  3580   (induct rule: foo_bar.inducts)
  3581   (induct set: foo bar)
  3582   (induct pred: foo bar)
  3583   (induct type: foo bar)
  3584 
  3585 The ML function ProjectRule.projections turns old-style rules into the
  3586 new format.
  3587 
  3588 * Method "coinduct": dual of induction, see
  3589 src/HOL/Library/Coinductive_List.thy for various examples.
  3590 
  3591 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  3592 considered a legacy feature.
  3593 
  3594 * Attribute "symmetric" produces result with standardized schematic
  3595 variables (index 0).  Potential INCOMPATIBILITY.
  3596 
  3597 * Simplifier: by default the simplifier trace only shows top level
  3598 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  3599 default. Thus there is less danger of being flooded by the trace. The
  3600 trace indicates where parts have been suppressed.
  3601   
  3602 * Provers/classical: removed obsolete classical version of elim_format
  3603 attribute; classical elim/dest rules are now treated uniformly when
  3604 manipulating the claset.
  3605 
  3606 * Provers/classical: stricter checks to ensure that supplied intro,
  3607 dest and elim rules are well-formed; dest and elim rules must have at
  3608 least one premise.
  3609 
  3610 * Provers/classical: attributes dest/elim/intro take an optional
  3611 weight argument for the rule (just as the Pure versions).  Weights are
  3612 ignored by automated tools, but determine the search order of single
  3613 rule steps.
  3614 
  3615 * Syntax: input syntax now supports dummy variable binding "%_. b",
  3616 where the body does not mention the bound variable.  Note that dummy
  3617 patterns implicitly depend on their context of bounds, which makes
  3618 "{_. _}" match any set comprehension as expected.  Potential
  3619 INCOMPATIBILITY -- parse translations need to cope with syntactic
  3620 constant "_idtdummy" in the binding position.
  3621 
  3622 * Syntax: removed obsolete syntactic constant "_K" and its associated
  3623 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  3624 for example "A -> B" => "Pi A (%_. B)".
  3625 
  3626 * Pure: 'class_deps' command visualizes the subclass relation, using
  3627 the graph browser tool.
  3628 
  3629 * Pure: 'print_theory' now suppresses certain internal declarations by
  3630 default; use '!' option for full details.
  3631 
  3632 
  3633 *** HOL ***
  3634 
  3635 * Method "metis" proves goals by applying the Metis general-purpose
  3636 resolution prover (see also http://gilith.com/software/metis/).
  3637 Examples are in the directory MetisExamples.  WARNING: the
  3638 Isabelle/HOL-Metis integration does not yet work properly with
  3639 multi-threading.
  3640   
  3641 * Command 'sledgehammer' invokes external automatic theorem provers as
  3642 background processes.  It generates calls to the "metis" method if
  3643 successful. These can be pasted into the proof.  Users do not have to
  3644 wait for the automatic provers to return.  WARNING: does not really
  3645 work with multi-threading.
  3646 
  3647 * New "auto_quickcheck" feature tests outermost goal statements for
  3648 potential counter-examples.  Controlled by ML references
  3649 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  3650 5000 milliseconds).  Fails silently if statements is outside of
  3651 executable fragment, or any other codgenerator problem occurs.
  3652 
  3653 * New constant "undefined" with axiom "undefined x = undefined".
  3654 
  3655 * Added class "HOL.eq", allowing for code generation with polymorphic
  3656 equality.
  3657 
  3658 * Some renaming of class constants due to canonical name prefixing in
  3659 the new 'class' package:
  3660 
  3661     HOL.abs ~> HOL.abs_class.abs
  3662     HOL.divide ~> HOL.divide_class.divide
  3663     0 ~> HOL.zero_class.zero
  3664     1 ~> HOL.one_class.one
  3665     op + ~> HOL.plus_class.plus
  3666     op - ~> HOL.minus_class.minus
  3667     uminus ~> HOL.minus_class.uminus
  3668     op * ~> HOL.times_class.times
  3669     op < ~> HOL.ord_class.less
  3670     op <= > HOL.ord_class.less_eq
  3671     Nat.power ~> Power.power_class.power
  3672     Nat.size ~> Nat.size_class.size
  3673     Numeral.number_of ~> Numeral.number_class.number_of
  3674     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  3675     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  3676     Orderings.min ~> Orderings.ord_class.min
  3677     Orderings.max ~> Orderings.ord_class.max
  3678     Divides.op div ~> Divides.div_class.div
  3679     Divides.op mod ~> Divides.div_class.mod
  3680     Divides.op dvd ~> Divides.div_class.dvd
  3681 
  3682 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  3683 
  3684 a) User-defined constants using any of the names "plus", "minus",
  3685 "times", "less" or "less_eq". The standard syntax translations for
  3686 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  3687 names.
  3688 
  3689 b) Variables named "plus", "minus", "times", "less", "less_eq"
  3690 INCOMPATIBILITY: use more specific names.
  3691 
  3692 c) Permutative equations (e.g. "a + b = b + a")
  3693 Since the change of names also changes the order of terms, permutative
  3694 rewrite rules may get applied in a different order. Experience shows
  3695 that this is rarely the case (only two adaptions in the whole Isabelle
  3696 distribution).  INCOMPATIBILITY: rewrite proofs
  3697 
  3698 d) ML code directly refering to constant names
  3699 This in general only affects hand-written proof tactics, simprocs and
  3700 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  3701 Consider using @{const_name} antiquotation.
  3702 
  3703 * New class "default" with associated constant "default".
  3704 
  3705 * Function "sgn" is now overloaded and available on int, real, complex
  3706 (and other numeric types), using class "sgn".  Two possible defs of
  3707 sgn are given as equational assumptions in the classes sgn_if and
  3708 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  3709 INCOMPATIBILITY.
  3710 
  3711 * Locale "partial_order" now unified with class "order" (cf. theory
  3712 Orderings), added parameter "less".  INCOMPATIBILITY.
  3713 
  3714 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  3715 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  3716 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  3717 
  3718 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  3719 changed order of proof goals in instance proofs.
  3720 
  3721 * The transitivity reasoner for partial and linear orders is set up
  3722 for classes "order" and "linorder".  Instances of the reasoner are available
  3723 in all contexts importing or interpreting the corresponding locales.
  3724 Method "order" invokes the reasoner separately; the reasoner
  3725 is also integrated with the Simplifier as a solver.  Diagnostic
  3726 command 'print_orders' shows the available instances of the reasoner
  3727 in the current context.
  3728 
  3729 * Localized monotonicity predicate in theory "Orderings"; integrated
  3730 lemmas max_of_mono and min_of_mono with this predicate.
  3731 INCOMPATIBILITY.
  3732 
  3733 * Formulation of theorem "dense" changed slightly due to integration
  3734 with new class dense_linear_order.
  3735 
  3736 * Uniform lattice theory development in HOL.
  3737 
  3738     constants "meet" and "join" now named "inf" and "sup"
  3739     constant "Meet" now named "Inf"
  3740 
  3741     classes "meet_semilorder" and "join_semilorder" now named
  3742       "lower_semilattice" and "upper_semilattice"
  3743     class "lorder" now named "lattice"
  3744     class "comp_lat" now named "complete_lattice"
  3745 
  3746     Instantiation of lattice classes allows explicit definitions
  3747     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  3748 
  3749   INCOMPATIBILITY.  Theorem renames:
  3750 
  3751     meet_left_le            ~> inf_le1
  3752     meet_right_le           ~> inf_le2
  3753     join_left_le            ~> sup_ge1
  3754     join_right_le           ~> sup_ge2
  3755     meet_join_le            ~> inf_sup_ord
  3756     le_meetI                ~> le_infI
  3757     join_leI                ~> le_supI
  3758     le_meet                 ~> le_inf_iff
  3759     le_join                 ~> ge_sup_conv
  3760     meet_idempotent         ~> inf_idem
  3761     join_idempotent         ~> sup_idem
  3762     meet_comm               ~> inf_commute
  3763     join_comm               ~> sup_commute
  3764     meet_leI1               ~> le_infI1
  3765     meet_leI2               ~> le_infI2
  3766     le_joinI1               ~> le_supI1
  3767     le_joinI2               ~> le_supI2
  3768     meet_assoc              ~> inf_assoc
  3769     join_assoc              ~> sup_assoc
  3770     meet_left_comm          ~> inf_left_commute
  3771     meet_left_idempotent    ~> inf_left_idem
  3772     join_left_comm          ~> sup_left_commute
  3773     join_left_idempotent    ~> sup_left_idem
  3774     meet_aci                ~> inf_aci
  3775     join_aci                ~> sup_aci
  3776     le_def_meet             ~> le_iff_inf
  3777     le_def_join             ~> le_iff_sup
  3778     join_absorp2            ~> sup_absorb2
  3779     join_absorp1            ~> sup_absorb1
  3780     meet_absorp1            ~> inf_absorb1
  3781     meet_absorp2            ~> inf_absorb2
  3782     meet_join_absorp        ~> inf_sup_absorb
  3783     join_meet_absorp        ~> sup_inf_absorb
  3784     distrib_join_le         ~> distrib_sup_le
  3785     distrib_meet_le         ~> distrib_inf_le
  3786 
  3787     add_meet_distrib_left   ~> add_inf_distrib_left
  3788     add_join_distrib_left   ~> add_sup_distrib_left
  3789     is_join_neg_meet        ~> is_join_neg_inf
  3790     is_meet_neg_join        ~> is_meet_neg_sup
  3791     add_meet_distrib_right  ~> add_inf_distrib_right
  3792     add_join_distrib_right  ~> add_sup_distrib_right
  3793     add_meet_join_distribs  ~> add_sup_inf_distribs
  3794     join_eq_neg_meet        ~> sup_eq_neg_inf
  3795     meet_eq_neg_join        ~> inf_eq_neg_sup
  3796     add_eq_meet_join        ~> add_eq_inf_sup
  3797     meet_0_imp_0            ~> inf_0_imp_0
  3798     join_0_imp_0            ~> sup_0_imp_0
  3799     meet_0_eq_0             ~> inf_0_eq_0
  3800     join_0_eq_0             ~> sup_0_eq_0
  3801     neg_meet_eq_join        ~> neg_inf_eq_sup
  3802     neg_join_eq_meet        ~> neg_sup_eq_inf
  3803     join_eq_if              ~> sup_eq_if
  3804 
  3805     mono_meet               ~> mono_inf
  3806     mono_join               ~> mono_sup
  3807     meet_bool_eq            ~> inf_bool_eq
  3808     join_bool_eq            ~> sup_bool_eq
  3809     meet_fun_eq             ~> inf_fun_eq
  3810     join_fun_eq             ~> sup_fun_eq
  3811     meet_set_eq             ~> inf_set_eq
  3812     join_set_eq             ~> sup_set_eq
  3813     meet1_iff               ~> inf1_iff
  3814     meet2_iff               ~> inf2_iff
  3815     meet1I                  ~> inf1I
  3816     meet2I                  ~> inf2I
  3817     meet1D1                 ~> inf1D1
  3818     meet2D1                 ~> inf2D1
  3819     meet1D2                 ~> inf1D2
  3820     meet2D2                 ~> inf2D2
  3821     meet1E                  ~> inf1E
  3822     meet2E                  ~> inf2E
  3823     join1_iff               ~> sup1_iff
  3824     join2_iff               ~> sup2_iff
  3825     join1I1                 ~> sup1I1
  3826     join2I1                 ~> sup2I1
  3827     join1I1                 ~> sup1I1
  3828     join2I2                 ~> sup1I2
  3829     join1CI                 ~> sup1CI
  3830     join2CI                 ~> sup2CI
  3831     join1E                  ~> sup1E
  3832     join2E                  ~> sup2E
  3833 
  3834     is_meet_Meet            ~> is_meet_Inf
  3835     Meet_bool_def           ~> Inf_bool_def
  3836     Meet_fun_def            ~> Inf_fun_def
  3837     Meet_greatest           ~> Inf_greatest
  3838     Meet_lower              ~> Inf_lower
  3839     Meet_set_def            ~> Inf_set_def
  3840 
  3841     Sup_def                 ~> Sup_Inf
  3842     Sup_bool_eq             ~> Sup_bool_def
  3843     Sup_fun_eq              ~> Sup_fun_def
  3844     Sup_set_eq              ~> Sup_set_def
  3845 
  3846     listsp_meetI            ~> listsp_infI
  3847     listsp_meet_eq          ~> listsp_inf_eq
  3848 
  3849     meet_min                ~> inf_min
  3850     join_max                ~> sup_max
  3851 
  3852 * Added syntactic class "size"; overloaded constant "size" now has
  3853 type "'a::size ==> bool"
  3854 
  3855 * Internal reorganisation of `size' of datatypes: size theorems
  3856 "foo.size" are no longer subsumed by "foo.simps" (but are still
  3857 simplification rules by default!); theorems "prod.size" now named
  3858 "*.size".
  3859 
  3860 * Class "div" now inherits from class "times" rather than "type".
  3861 INCOMPATIBILITY.
  3862 
  3863 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  3864 Linorder etc.  have disappeared; operations defined in terms of
  3865 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  3866 
  3867 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  3868 
  3869 * HOL-Word: New extensive library and type for generic, fixed size
  3870 machine words, with arithemtic, bit-wise, shifting and rotating
  3871 operations, reflection into int, nat, and bool lists, automation for
  3872 linear arithmetic (by automatic reflection into nat or int), including
  3873 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  3874 arithmetic type classes, supporting automatic simplification of
  3875 numerals on all operations.
  3876 
  3877 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  3878 
  3879 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  3880 
  3881 * Code generator library theories:
  3882   - Code_Integer represents HOL integers by big integer literals in target
  3883     languages.
  3884   - Code_Char represents HOL characters by character literals in target
  3885     languages.
  3886   - Code_Char_chr like Code_Char, but also offers treatment of character
  3887     codes; includes Code_Integer.
  3888   - Executable_Set allows to generate code for finite sets using lists.
  3889   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  3890     denominator).
  3891   - Executable_Real implements a subset of real numbers, namly those
  3892     representable by rational numbers.
  3893   - Efficient_Nat implements natural numbers by integers, which in general will
  3894     result in higher efficency; pattern matching with 0/Suc is eliminated;
  3895     includes Code_Integer.
  3896   - Code_Index provides an additional datatype index which is mapped to
  3897     target-language built-in integers.
  3898   - Code_Message provides an additional datatype message_string which is isomorphic to
  3899     strings; messages are mapped to target-language strings.
  3900 
  3901 * New package for inductive predicates
  3902 
  3903   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  3904 
  3905     inductive
  3906       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3907       for z_1 :: U_1 and ... and z_n :: U_m
  3908     where
  3909       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3910     | ...
  3911 
  3912   with full support for type-inference, rather than
  3913 
  3914     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3915 
  3916     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3917     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3918 
  3919     inductive "s z_1 ... z_m"
  3920     intros
  3921       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3922       ...
  3923 
  3924   For backward compatibility, there is a wrapper allowing inductive
  3925   sets to be defined with the new package via
  3926 
  3927     inductive_set
  3928       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3929       for z_1 :: U_1 and ... and z_n :: U_m
  3930     where
  3931       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  3932     | ...
  3933 
  3934   or
  3935 
  3936     inductive_set
  3937       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  3938       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3939       for z_1 :: U_1 and ... and z_n :: U_m
  3940     where
  3941       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  3942     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3943     | ...
  3944 
  3945   if the additional syntax "p ..." is required.
  3946 
  3947   Numerous examples can be found in the subdirectories src/HOL/Auth,
  3948   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  3949 
  3950   INCOMPATIBILITIES:
  3951 
  3952   - Since declaration and definition of inductive sets or predicates
  3953     is no longer separated, abbreviations involving the newly
  3954     introduced sets or predicates must be specified together with the
  3955     introduction rules after the 'where' keyword (see above), rather
  3956     than before the actual inductive definition.
  3957 
  3958   - The variables in induction and elimination rules are now
  3959     quantified in the order of their occurrence in the introduction
  3960     rules, rather than in alphabetical order. Since this may break
  3961     some proofs, these proofs either have to be repaired, e.g. by
  3962     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  3963     statements of the form
  3964 
  3965       case (rule_i a_i_1 ... a_i_{k_i})
  3966 
  3967     or the old order of quantification has to be restored by explicitly adding
  3968     meta-level quantifiers in the introduction rules, i.e.
  3969 
  3970       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  3971 
  3972   - The format of the elimination rules is now
  3973 
  3974       p z_1 ... z_m x_1 ... x_n ==>
  3975         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  3976         ==> ... ==> P
  3977 
  3978     for predicates and
  3979 
  3980       (x_1, ..., x_n) : s z_1 ... z_m ==>
  3981         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  3982         ==> ... ==> P
  3983 
  3984     for sets rather than
  3985 
  3986       x : s z_1 ... z_m ==>
  3987         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  3988         ==> ... ==> P
  3989 
  3990     This may require terms in goals to be expanded to n-tuples
  3991     (e.g. using case_tac or simplification with the split_paired_all
  3992     rule) before the above elimination rule is applicable.
  3993 
  3994   - The elimination or case analysis rules for (mutually) inductive
  3995     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  3996     list of rules "p_1_..._p_k.elims" is no longer available.
  3997 
  3998 * New package "function"/"fun" for general recursive functions,
  3999 supporting mutual and nested recursion, definitions in local contexts,
  4000 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  4001 for small examples, and the separate tutorial on the function
  4002 package. The old recdef "package" is still available as before, but
  4003 users are encouraged to use the new package.
  4004 
  4005 * Method "lexicographic_order" automatically synthesizes termination
  4006 relations as lexicographic combinations of size measures. 
  4007 
  4008 * Case-expressions allow arbitrary constructor-patterns (including
  4009 "_") and take their order into account, like in functional
  4010 programming.  Internally, this is translated into nested
  4011 case-expressions; missing cases are added and mapped to the predefined
  4012 constant "undefined". In complicated cases printing may no longer show
  4013 the original input but the internal form. Lambda-abstractions allow
  4014 the same form of pattern matching: "% pat1 => e1 | ..." is an
  4015 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  4016 variable.
  4017 
  4018 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  4019 is an abbreviation for "of_nat :: nat => int". The simplification
  4020 rules for "of_nat" have been changed to work like "int" did
  4021 previously.  Potential INCOMPATIBILITY:
  4022   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  4023   - of_nat_diff and of_nat_mult are no longer default simp rules
  4024 
  4025 * Method "algebra" solves polynomial equations over (semi)rings using
  4026 Groebner bases. The (semi)ring structure is defined by locales and the
  4027 tool setup depends on that generic context. Installing the method for
  4028 a specific type involves instantiating the locale and possibly adding
  4029 declarations for computation on the coefficients.  The method is
  4030 already instantiated for natural numbers and for the axiomatic class
  4031 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  4032 CALCULEMUS 2007 for the general principles underlying this
  4033 architecture of context-aware proof-tools.
  4034 
  4035 * Method "ferrack" implements quantifier elimination over
  4036 special-purpose dense linear orders using locales (analogous to
  4037 "algebra"). The method is already installed for class
  4038 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  4039 rat, etc.
  4040 
  4041 * Former constant "List.op @" now named "List.append".  Use ML
  4042 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  4043 circumvent possible incompatibilities when working on ML level.
  4044 
  4045 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  4046 
  4047 * New function listsum :: 'a list => 'a for arbitrary monoids.
  4048 Special syntax: "SUM x <- xs. f x" (and latex variants)
  4049 
  4050 * New syntax for Haskell-like list comprehension (input only), eg.
  4051 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  4052 
  4053 * The special syntax for function "filter" has changed from [x :
  4054 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  4055 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  4056 
  4057 * [a..b] is now defined for arbitrary linear orders.  It used to be
  4058 defined on nat only, as an abbreviation for [a..<Suc b]
  4059 INCOMPATIBILITY.
  4060 
  4061 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  4062 
  4063 * New functions "sorted" and "sort" in src/HOL/List.thy.
  4064 
  4065 * New lemma collection field_simps (an extension of ring_simps) for
  4066 manipulating (in)equations involving division. Multiplies with all
  4067 denominators that can be proved to be non-zero (in equations) or
  4068 positive/negative (in inequations).
  4069 
  4070 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  4071 have been improved and renamed to ring_simps, group_simps and
  4072 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  4073 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  4074 
  4075 * Theory Library/Commutative_Ring: switched from recdef to function
  4076 package; constants add, mul, pow now curried.  Infix syntax for
  4077 algebraic operations.
  4078 
  4079 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  4080 INCOMPATIBILITY.
  4081 
  4082 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  4083 INCOMPATIBILITY.
  4084 
  4085 * HOL/records: generalised field-update to take a function on the
  4086 field rather than the new value: r(|A := x|) is translated to A_update
  4087 (K x) r The K-combinator that is internally used is called K_record.
  4088 INCOMPATIBILITY: Usage of the plain update functions has to be
  4089 adapted.
  4090  
  4091 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  4092 * x = 0, which are required for a semiring.  Richer structures do not
  4093 inherit from semiring_0 anymore, because this property is a theorem
  4094 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  4095 there is more to prove, but this is mostly trivial.
  4096 
  4097 * Class "recpower" is generalized to arbitrary monoids, not just
  4098 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  4099 commutativity or semiring properties additionally.
  4100 
  4101 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  4102 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  4103 better use 'abbreviation'.
  4104 
  4105 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  4106 
  4107 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  4108 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  4109 significant changes for setting up numeral syntax for types:
  4110   - New constants Numeral.pred and Numeral.succ instead
  4111       of former Numeral.bin_pred and Numeral.bin_succ.
  4112   - Use integer operations instead of bin_add, bin_mult and so on.
  4113   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  4114   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  4115 
  4116 See src/HOL/Integ/IntArith.thy for an example setup.
  4117 
  4118 * Command 'normal_form' computes the normal form of a term that may
  4119 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  4120 produces ``[b, c, a]'' (without proof).  This command is suitable for
  4121 heavy-duty computations because the functions are compiled to ML
  4122 first.  Correspondingly, a method "normalization" is provided.  See
  4123 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  4124 
  4125 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  4126 25 like -->); output depends on the "iff" print_mode, the default is
  4127 "A = B" (with priority 50).
  4128 
  4129 * Relations less (<) and less_eq (<=) are also available on type bool.
  4130 Modified syntax to disallow nesting without explicit parentheses,
  4131 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  4132 INCOMPATIBILITY.
  4133 
  4134 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  4135 
  4136 * Relation composition operator "op O" now has precedence 75 and binds
  4137 stronger than union and intersection. INCOMPATIBILITY.
  4138 
  4139 * The old set interval syntax "{m..n(}" (and relatives) has been
  4140 removed.  Use "{m..<n}" (and relatives) instead.
  4141 
  4142 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  4143 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  4144 ``declare [[simproc del: neq]]''.
  4145 
  4146 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  4147 True/False.
  4148 
  4149 * Theorem Cons_eq_map_conv no longer declared as "simp".
  4150 
  4151 * Theorem setsum_mult renamed to setsum_right_distrib.
  4152 
  4153 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  4154 ``rule'' method.
  4155 
  4156 * Reimplemented methods "sat" and "satx", with several improvements:
  4157 goals no longer need to be stated as "<prems> ==> False", equivalences
  4158 (i.e. "=" on type bool) are handled, variable names of the form
  4159 "lit_<n>" are no longer reserved, significant speedup.
  4160 
  4161 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  4162 zChaff is still supported as well.
  4163 
  4164 * 'inductive' and 'datatype': provide projections of mutual rules,
  4165 bundled as foo_bar.inducts;
  4166 
  4167 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  4168 Library.
  4169 
  4170 * Library: moved theory Accessible_Part to main HOL.
  4171 
  4172 * Library: added theory Coinductive_List of potentially infinite lists
  4173 as greatest fixed-point.
  4174 
  4175 * Library: added theory AssocList which implements (finite) maps as
  4176 association lists.
  4177 
  4178 * Method "evaluation" solves goals (i.e. a boolean expression)
  4179 efficiently by compiling it to ML.  The goal is "proved" (via an
  4180 oracle) if it evaluates to True.
  4181 
  4182 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  4183 also when invoked by the simplifier.  This results in the Simplifier
  4184 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  4185 Configuration option fast_arith_split_limit=0 recovers the old
  4186 behavior.
  4187 
  4188 * Support for hex (0x20) and binary (0b1001) numerals.
  4189 
  4190 * New method: reify eqs (t), where eqs are equations for an
  4191 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  4192 parameter, computes a term s::'b and a list xs::'a list and proves the
  4193 theorem I xs s = t. This is also known as reification or quoting. The
  4194 resulting theorem is applied to the subgoal to substitute t with I xs
  4195 s.  If t is omitted, the subgoal itself is reified.
  4196 
  4197 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  4198 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  4199 where f is supposed to be a computable function (in the sense of code
  4200 generattion). The method uses reify to compute s and xs as above then
  4201 applies corr_thm and uses normalization by evaluation to "prove" f s =
  4202 r and finally gets the theorem t = r, which is again applied to the
  4203 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  4204 
  4205 * Reflection: Automatic reification now handels binding, an example is
  4206 available in src/HOL/ex/ReflectionEx.thy
  4207 
  4208 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  4209 command 'statespace' that is similar to 'record', but introduces an
  4210 abstract specification based on the locale infrastructure instead of
  4211 HOL types.  This leads to extra flexibility in composing state spaces,
  4212 in particular multiple inheritance and renaming of components.
  4213 
  4214 
  4215 *** HOL-Complex ***
  4216 
  4217 * Hyperreal: Functions root and sqrt are now defined on negative real
  4218 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  4219 Nonnegativity side conditions have been removed from many lemmas, so
  4220 that more subgoals may now be solved by simplification; potential
  4221 INCOMPATIBILITY.
  4222 
  4223 * Real: new type classes formalize real normed vector spaces and
  4224 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  4225 and norm :: 'a => real.
  4226 
  4227 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  4228 reals into other types. The overloaded constant Reals :: 'a set is now
  4229 defined as range of_real; potential INCOMPATIBILITY.
  4230 
  4231 * Real: proper support for ML code generation, including 'quickcheck'.
  4232 Reals are implemented as arbitrary precision rationals.
  4233 
  4234 * Hyperreal: Several constants that previously worked only for the
  4235 reals have been generalized, so they now work over arbitrary vector
  4236 spaces. Type annotations may need to be added in some cases; potential
  4237 INCOMPATIBILITY.
  4238 
  4239   Infinitesimal  :: ('a::real_normed_vector) star set
  4240   HFinite        :: ('a::real_normed_vector) star set
  4241   HInfinite      :: ('a::real_normed_vector) star set
  4242   approx         :: ('a::real_normed_vector) star => 'a star => bool
  4243   monad          :: ('a::real_normed_vector) star => 'a star set
  4244   galaxy         :: ('a::real_normed_vector) star => 'a star set
  4245   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  4246   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  4247   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  4248   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  4249   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  4250   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  4251   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  4252   sgn            :: 'a::real_normed_vector => 'a
  4253   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  4254 
  4255 * Complex: Some complex-specific constants are now abbreviations for
  4256 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  4257 hnorm.  Other constants have been entirely removed in favor of the
  4258 polymorphic versions (INCOMPATIBILITY):
  4259 
  4260   approx        <-- capprox
  4261   HFinite       <-- CFinite
  4262   HInfinite     <-- CInfinite
  4263   Infinitesimal <-- CInfinitesimal
  4264   monad         <-- cmonad
  4265   galaxy        <-- cgalaxy
  4266   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  4267   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  4268   (ns)deriv     <-- (ns)cderiv
  4269 
  4270 
  4271 *** HOL-Algebra ***
  4272 
  4273 * Formalisation of ideals and the quotient construction over rings.
  4274 
  4275 * Order and lattice theory no longer based on records.
  4276 INCOMPATIBILITY.
  4277 
  4278 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  4279 greatest_closed.  INCOMPATIBILITY.
  4280 
  4281 * Method algebra is now set up via an attribute.  For examples see
  4282 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  4283 of algebraic structures.
  4284 
  4285 * Renamed theory CRing to Ring.
  4286 
  4287 
  4288 *** HOL-Nominal ***
  4289 
  4290 * Substantial, yet incomplete support for nominal datatypes (binding
  4291 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  4292 src/HOL/Nominal/Examples.  Prospective users should consult
  4293 http://isabelle.in.tum.de/nominal/
  4294 
  4295 
  4296 *** ML ***
  4297 
  4298 * ML basics: just one true type int, which coincides with IntInf.int
  4299 (even on SML/NJ).
  4300 
  4301 * ML within Isar: antiquotations allow to embed statically-checked
  4302 formal entities in the source, referring to the context available at
  4303 compile-time.  For example:
  4304 
  4305 ML {* @{sort "{zero,one}"} *}
  4306 ML {* @{typ "'a => 'b"} *}
  4307 ML {* @{term "%x. x"} *}
  4308 ML {* @{prop "x == y"} *}
  4309 ML {* @{ctyp "'a => 'b"} *}
  4310 ML {* @{cterm "%x. x"} *}
  4311 ML {* @{cprop "x == y"} *}
  4312 ML {* @{thm asm_rl} *}
  4313 ML {* @{thms asm_rl} *}
  4314 ML {* @{type_name c} *}
  4315 ML {* @{type_syntax c} *}
  4316 ML {* @{const_name c} *}
  4317 ML {* @{const_syntax c} *}
  4318 ML {* @{context} *}
  4319 ML {* @{theory} *}
  4320 ML {* @{theory Pure} *}
  4321 ML {* @{theory_ref} *}
  4322 ML {* @{theory_ref Pure} *}
  4323 ML {* @{simpset} *}
  4324 ML {* @{claset} *}
  4325 ML {* @{clasimpset} *}
  4326 
  4327 The same works for sources being ``used'' within an Isar context.
  4328 
  4329 * ML in Isar: improved error reporting; extra verbosity with
  4330 ML_Context.trace enabled.
  4331 
  4332 * Pure/General/table.ML: the join operations now works via exceptions
  4333 DUP/SAME instead of type option. This is simpler in simple cases, and
  4334 admits slightly more efficient complex applications.
  4335 
  4336 * Pure: 'advanced' translation functions (parse_translation etc.) now
  4337 use Context.generic instead of just theory.
  4338 
  4339 * Pure: datatype Context.generic joins theory/Proof.context and
  4340 provides some facilities for code that works in either kind of
  4341 context, notably GenericDataFun for uniform theory and proof data.
  4342 
  4343 * Pure: simplified internal attribute type, which is now always
  4344 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  4345 local (Proof.context) attributes have been discontinued, while
  4346 minimizing code duplication. Thm.rule_attribute and
  4347 Thm.declaration_attribute build canonical attributes; see also structure
  4348 Context for further operations on Context.generic, notably
  4349 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  4350 declarations and definitions.
  4351 
  4352 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  4353 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  4354 init only required for impure data. INCOMPATIBILITY: empty really need
  4355 to be empty (no dependencies on theory content!)
  4356 
  4357 * Pure/kernel: consts certification ignores sort constraints given in
  4358 signature declarations. (This information is not relevant to the
  4359 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  4360 potential INCOMPATIBILITY.
  4361 
  4362 * Pure: axiomatic type classes are now purely definitional, with
  4363 explicit proofs of class axioms and super class relations performed
  4364 internally. See Pure/axclass.ML for the main internal interfaces --
  4365 notably AxClass.define_class supercedes AxClass.add_axclass, and
  4366 AxClass.axiomatize_class/classrel/arity supersede
  4367 Sign.add_classes/classrel/arities.
  4368 
  4369 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  4370 global/local versions on theory vs. Proof.context have been
  4371 discontinued; Attrib.syntax and Method.syntax have been adapted
  4372 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  4373 attributes, methods, etc.
  4374 
  4375 * Pure: several functions of signature "... -> theory -> theory * ..."
  4376 have been reoriented to "... -> theory -> ... * theory" in order to
  4377 allow natural usage in combination with the ||>, ||>>, |-> and
  4378 fold_map combinators.
  4379 
  4380 * Pure: official theorem names (closed derivations) and additional
  4381 comments (tags) are now strictly separate.  Name hints -- which are
  4382 maintained as tags -- may be attached any time without affecting the
  4383 derivation.
  4384 
  4385 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  4386 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  4387 achieve the old behaviour.
  4388 
  4389 * Pure: the "Goal" constant is now called "prop", supporting a
  4390 slightly more general idea of ``protecting'' meta-level rule
  4391 statements.
  4392 
  4393 * Pure: Logic.(un)varify only works in a global context, which is now
  4394 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  4395 Logic.legacy_(un)varify as temporary workaround.
  4396 
  4397 * Pure: structure Name provides scalable operations for generating
  4398 internal variable names, notably Name.variants etc.  This replaces
  4399 some popular functions from term.ML:
  4400 
  4401   Term.variant		->  Name.variant
  4402   Term.variantlist	->  Name.variant_list
  4403   Term.invent_names	->  Name.invent_list
  4404 
  4405 Note that low-level renaming rarely occurs in new code -- operations
  4406 from structure Variable are used instead (see below).
  4407 
  4408 * Pure: structure Variable provides fundamental operations for proper
  4409 treatment of fixed/schematic variables in a context.  For example,
  4410 Variable.import introduces fixes for schematics of given facts and
  4411 Variable.export reverses the effect (up to renaming) -- this replaces
  4412 various freeze_thaw operations.
  4413 
  4414 * Pure: structure Goal provides simple interfaces for
  4415 init/conclude/finish and tactical prove operations (replacing former
  4416 Tactic.prove).  Goal.prove is the canonical way to prove results
  4417 within a given context; Goal.prove_global is a degraded version for
  4418 theory level goals, including a global Drule.standard.  Note that
  4419 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  4420 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  4421 in a locale context).
  4422 
  4423 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  4424 and type checking (Syntax.check_term etc.), with common combinations
  4425 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  4426 which are considered legacy and await removal.
  4427 
  4428 * Pure/Syntax: generic interfaces for type unchecking
  4429 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  4430 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  4431 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  4432 available for convenience, but refer to the very same operations using
  4433 a mere theory instead of a full context.
  4434 
  4435 * Isar: simplified treatment of user-level errors, using exception
  4436 ERROR of string uniformly.  Function error now merely raises ERROR,
  4437 without any side effect on output channels.  The Isar toplevel takes
  4438 care of proper display of ERROR exceptions.  ML code may use plain
  4439 handle/can/try; cat_error may be used to concatenate errors like this:
  4440 
  4441   ... handle ERROR msg => cat_error msg "..."
  4442 
  4443 Toplevel ML code (run directly or through the Isar toplevel) may be
  4444 embedded into the Isar toplevel with exception display/debug like
  4445 this:
  4446 
  4447   Isar.toplevel (fn () => ...)
  4448 
  4449 INCOMPATIBILITY, removed special transform_error facilities, removed
  4450 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  4451 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  4452 -- use plain ERROR instead.
  4453 
  4454 * Isar: theory setup now has type (theory -> theory), instead of a
  4455 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  4456 
  4457 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  4458 ProofContext.debug/verbose flags.
  4459 
  4460 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  4461 theory before entering a proof state.  Transactions now always see a
  4462 quasi-functional intermediate checkpoint, both in interactive and
  4463 batch mode.
  4464 
  4465 * Isar: simplified interfaces for outer syntax.  Renamed
  4466 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  4467 OuterSyntax.add_parsers -- this functionality is now included in
  4468 OuterSyntax.command etc.  INCOMPATIBILITY.
  4469 
  4470 * Simplifier: the simpset of a running simplification process now
  4471 contains a proof context (cf. Simplifier.the_context), which is the
  4472 very context that the initial simpset has been retrieved from (by
  4473 simpset_of/local_simpset_of).  Consequently, all plug-in components
  4474 (solver, looper etc.) may depend on arbitrary proof data.
  4475 
  4476 * Simplifier.inherit_context inherits the proof context (plus the
  4477 local bounds) of the current simplification process; any simproc
  4478 etc. that calls the Simplifier recursively should do this!  Removed
  4479 former Simplifier.inherit_bounds, which is already included here --
  4480 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  4481 specify an explicit context using Simplifier.context/theory_context.
  4482 
  4483 * Simplifier/Classical Reasoner: more abstract interfaces
  4484 change_simpset/claset for modifying the simpset/claset reference of a
  4485 theory; raw versions simpset/claset_ref etc. have been discontinued --
  4486 INCOMPATIBILITY.
  4487 
  4488 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  4489 "Trueprop" etc.
  4490 
  4491 
  4492 *** System ***
  4493 
  4494 * settings: the default heap location within ISABELLE_HOME_USER now
  4495 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  4496 Isabelle installations.
  4497 
  4498 * isabelle-process: option -S (secure mode) disables some critical
  4499 operations, notably runtime compilation and evaluation of ML source
  4500 code.
  4501 
  4502 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  4503 
  4504 * Support for parallel execution, using native multicore support of
  4505 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  4506 independent theories, according to the given theory header
  4507 specifications. The maximum number of worker threads is specified via
  4508 usedir option -M or the "max-threads" setting in Proof General. A
  4509 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  4510 to 6 on a 8-core machine.  User-code needs to observe certain
  4511 guidelines for thread-safe programming, see appendix A in the Isar
  4512 Implementation manual.
  4513 
  4514 
  4515 
  4516 New in Isabelle2005 (October 2005)
  4517 ----------------------------------
  4518 
  4519 *** General ***
  4520 
  4521 * Theory headers: the new header syntax for Isar theories is
  4522 
  4523   theory <name>
  4524   imports <theory1> ... <theoryN>
  4525   uses <file1> ... <fileM>
  4526   begin
  4527 
  4528 where the 'uses' part is optional.  The previous syntax
  4529 
  4530   theory <name> = <theory1> + ... + <theoryN>:
  4531 
  4532 will disappear in the next release.  Use isatool fixheaders to convert
  4533 existing theory files.  Note that there is no change in ancient
  4534 non-Isar theories now, but these will disappear soon.
  4535 
  4536 * Theory loader: parent theories can now also be referred to via
  4537 relative and absolute paths.
  4538 
  4539 * Command 'find_theorems' searches for a list of criteria instead of a
  4540 list of constants. Known criteria are: intro, elim, dest, name:string,
  4541 simp:term, and any term. Criteria can be preceded by '-' to select
  4542 theorems that do not match. Intro, elim, dest select theorems that
  4543 match the current goal, name:s selects theorems whose fully qualified
  4544 name contain s, and simp:term selects all simplification rules whose
  4545 lhs match term.  Any other term is interpreted as pattern and selects
  4546 all theorems matching the pattern. Available in ProofGeneral under
  4547 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  4548 
  4549   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  4550 
  4551 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  4552 matching the current goal as introduction rule and not having "HOL."
  4553 in their name (i.e. not being defined in theory HOL).
  4554 
  4555 * Command 'thms_containing' has been discontinued in favour of
  4556 'find_theorems'; INCOMPATIBILITY.
  4557 
  4558 * Communication with Proof General is now 8bit clean, which means that
  4559 Unicode text in UTF-8 encoding may be used within theory texts (both
  4560 formal and informal parts).  Cf. option -U of the Isabelle Proof
  4561 General interface.  Here are some simple examples (cf. src/HOL/ex):
  4562 
  4563   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  4564   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  4565 
  4566 * Improved efficiency of the Simplifier and, to a lesser degree, the
  4567 Classical Reasoner.  Typical big applications run around 2 times
  4568 faster.
  4569 
  4570 
  4571 *** Document preparation ***
  4572 
  4573 * Commands 'display_drafts' and 'print_drafts' perform simple output
  4574 of raw sources.  Only those symbols that do not require additional
  4575 LaTeX packages (depending on comments in isabellesym.sty) are
  4576 displayed properly, everything else is left verbatim.  isatool display
  4577 and isatool print are used as front ends (these are subject to the
  4578 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  4579 
  4580 * Command tags control specific markup of certain regions of text,
  4581 notably folding and hiding.  Predefined tags include "theory" (for
  4582 theory begin and end), "proof" for proof commands, and "ML" for
  4583 commands involving ML code; the additional tags "visible" and
  4584 "invisible" are unused by default.  Users may give explicit tag
  4585 specifications in the text, e.g. ''by %invisible (auto)''.  The
  4586 interpretation of tags is determined by the LaTeX job during document
  4587 preparation: see option -V of isatool usedir, or options -n and -t of
  4588 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  4589 \isadroptag.
  4590 
  4591 Several document versions may be produced at the same time via isatool
  4592 usedir (the generated index.html will link all of them).  Typical
  4593 specifications include ''-V document=theory,proof,ML'' to present
  4594 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  4595 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  4596 these parts without any formal replacement text.  The Isabelle site
  4597 default settings produce ''document'' and ''outline'' versions as
  4598 specified above.
  4599 
  4600 * Several new antiquotations:
  4601 
  4602   @{term_type term} prints a term with its type annotated;
  4603 
  4604   @{typeof term} prints the type of a term;
  4605 
  4606   @{const const} is the same as @{term const}, but checks that the
  4607   argument is a known logical constant;
  4608 
  4609   @{term_style style term} and @{thm_style style thm} print a term or
  4610   theorem applying a "style" to it
  4611 
  4612   @{ML text}
  4613 
  4614 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  4615 definitions, equations, inequations etc., 'concl' printing only the
  4616 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  4617 to print the specified premise.  TermStyle.add_style provides an ML
  4618 interface for introducing further styles.  See also the "LaTeX Sugar"
  4619 document practical applications.  The ML antiquotation prints
  4620 type-checked ML expressions verbatim.
  4621 
  4622 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  4623 and 'text' support optional locale specification '(in loc)', which
  4624 specifies the default context for interpreting antiquotations.  For
  4625 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  4626 
  4627 * Option 'locale=NAME' of antiquotations specifies an alternative
  4628 context interpreting the subsequent argument.  For example: @{thm
  4629 [locale=lattice] inf_assoc}.
  4630 
  4631 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  4632 a proof context.
  4633 
  4634 * Proper output of antiquotations for theory commands involving a
  4635 proof context (such as 'locale' or 'theorem (in loc) ...').
  4636 
  4637 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  4638 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  4639 
  4640 * isatool usedir: new option -C (default true) controls whether option
  4641 -D should include a copy of the original document directory; -C false
  4642 prevents unwanted effects such as copying of administrative CVS data.
  4643 
  4644 
  4645 *** Pure ***
  4646 
  4647 * Considerably improved version of 'constdefs' command.  Now performs
  4648 automatic type-inference of declared constants; additional support for
  4649 local structure declarations (cf. locales and HOL records), see also
  4650 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  4651 sequential dependencies of definitions within a single 'constdefs'
  4652 section; moreover, the declared name needs to be an identifier.  If
  4653 all fails, consider to fall back on 'consts' and 'defs' separately.
  4654 
  4655 * Improved indexed syntax and implicit structures.  First of all,
  4656 indexed syntax provides a notational device for subscripted
  4657 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  4658 expressions.  Secondly, in a local context with structure
  4659 declarations, number indexes \<^sub>n or the empty index (default
  4660 number 1) refer to a certain fixed variable implicitly; option
  4661 show_structs controls printing of implicit structures.  Typical
  4662 applications of these concepts involve record types and locales.
  4663 
  4664 * New command 'no_syntax' removes grammar declarations (and
  4665 translations) resulting from the given syntax specification, which is
  4666 interpreted in the same manner as for the 'syntax' command.
  4667 
  4668 * 'Advanced' translation functions (parse_translation etc.) may depend
  4669 on the signature of the theory context being presently used for
  4670 parsing/printing, see also isar-ref manual.
  4671 
  4672 * Improved 'oracle' command provides a type-safe interface to turn an
  4673 ML expression of type theory -> T -> term into a primitive rule of
  4674 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  4675 is already included here); see also FOL/ex/IffExample.thy;
  4676 INCOMPATIBILITY.
  4677 
  4678 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  4679 before); "cI" is no longer bound, use "c.intro" instead.
  4680 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  4681 axclasses vs. locales.
  4682 
  4683 * Improved internal renaming of symbolic identifiers -- attach primes
  4684 instead of base 26 numbers.
  4685 
  4686 * New flag show_question_marks controls printing of leading question
  4687 marks in schematic variable names.
  4688 
  4689 * In schematic variable names, *any* symbol following \<^isub> or
  4690 \<^isup> is now treated as part of the base name.  For example, the
  4691 following works without printing of awkward ".0" indexes:
  4692 
  4693   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  4694     by simp
  4695 
  4696 * Inner syntax includes (*(*nested*) comments*).
  4697 
  4698 * Pretty printer now supports unbreakable blocks, specified in mixfix
  4699 annotations as "(00...)".
  4700 
  4701 * Clear separation of logical types and nonterminals, where the latter
  4702 may only occur in 'syntax' specifications or type abbreviations.
  4703 Before that distinction was only partially implemented via type class
  4704 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  4705 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  4706 exotic syntax specifications may require further adaption
  4707 (e.g. Cube/Cube.thy).
  4708 
  4709 * Removed obsolete type class "logic", use the top sort {} instead.
  4710 Note that non-logical types should be declared as 'nonterminals'
  4711 rather than 'types'.  INCOMPATIBILITY for new object-logic
  4712 specifications.
  4713 
  4714 * Attributes 'induct' and 'cases': type or set names may now be
  4715 locally fixed variables as well.
  4716 
  4717 * Simplifier: can now control the depth to which conditional rewriting
  4718 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  4719 Limit.
  4720 
  4721 * Simplifier: simplification procedures may now take the current
  4722 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  4723 interface), which is very useful for calling the Simplifier
  4724 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  4725 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  4726 low-level mk_simproc no longer applies Logic.varify internally, to
  4727 allow for use in a context of fixed variables.
  4728 
  4729 * thin_tac now works even if the assumption being deleted contains !!
  4730 or ==>.  More generally, erule now works even if the major premise of
  4731 the elimination rule contains !! or ==>.
  4732 
  4733 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  4734 
  4735 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  4736 from Pure, which contains all common declarations already.  Both
  4737 theories are defined via plain Isabelle/Isar .thy files.
  4738 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  4739 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  4740 use isatool fixcpure to adapt your theory and ML sources.
  4741 
  4742 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  4743 selections of theorems in named facts via index ranges.
  4744 
  4745 * 'print_theorems': in theory mode, really print the difference
  4746 wrt. the last state (works for interactive theory development only),
  4747 in proof mode print all local facts (cf. 'print_facts');
  4748 
  4749 * 'hide': option '(open)' hides only base names.
  4750 
  4751 * More efficient treatment of intermediate checkpoints in interactive
  4752 theory development.
  4753 
  4754 * Code generator is now invoked via code_module (incremental code
  4755 generation) and code_library (modular code generation, ML structures
  4756 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  4757 must be quoted when used as identifiers.
  4758 
  4759 * New 'value' command for reading, evaluating and printing terms using
  4760 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  4761 quoted when used as identifier.
  4762 
  4763 
  4764 *** Locales ***
  4765 
  4766 * New commands for the interpretation of locale expressions in
  4767 theories (1), locales (2) and proof contexts (3).  These generate
  4768 proof obligations from the expression specification.  After the
  4769 obligations have been discharged, theorems of the expression are added
  4770 to the theory, target locale or proof context.  The synopsis of the
  4771 commands is a follows:
  4772 
  4773   (1) interpretation expr inst
  4774   (2) interpretation target < expr
  4775   (3) interpret expr inst
  4776 
  4777 Interpretation in theories and proof contexts require a parameter
  4778 instantiation of terms from the current context.  This is applied to
  4779 specifications and theorems of the interpreted expression.
  4780 Interpretation in locales only permits parameter renaming through the
  4781 locale expression.  Interpretation is smart in that interpretations
  4782 that are active already do not occur in proof obligations, neither are
  4783 instantiated theorems stored in duplicate.  Use 'print_interps' to
  4784 inspect active interpretations of a particular locale.  For details,
  4785 see the Isar Reference manual.  Examples can be found in
  4786 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  4787 
  4788 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  4789 'interpret' instead.
  4790 
  4791 * New context element 'constrains' for adding type constraints to
  4792 parameters.
  4793 
  4794 * Context expressions: renaming of parameters with syntax
  4795 redeclaration.
  4796 
  4797 * Locale declaration: 'includes' disallowed.
  4798 
  4799 * Proper static binding of attribute syntax -- i.e. types / terms /
  4800 facts mentioned as arguments are always those of the locale definition
  4801 context, independently of the context of later invocations.  Moreover,
  4802 locale operations (renaming and type / term instantiation) are applied
  4803 to attribute arguments as expected.
  4804 
  4805 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  4806 actual attributes; rare situations may require Attrib.attribute to
  4807 embed those attributes into Attrib.src that lack concrete syntax.
  4808 Attribute implementations need to cooperate properly with the static
  4809 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  4810 Attrib.XXX_thm etc. already do the right thing without further
  4811 intervention.  Only unusual applications -- such as "where" or "of"
  4812 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  4813 on the context and the facts involved -- may have to assign parsed
  4814 values to argument tokens explicitly.
  4815 
  4816 * Changed parameter management in theorem generation for long goal
  4817 statements with 'includes'.  INCOMPATIBILITY: produces a different
  4818 theorem statement in rare situations.
  4819 
  4820 * Locale inspection command 'print_locale' omits notes elements.  Use
  4821 'print_locale!' to have them included in the output.
  4822 
  4823 
  4824 *** Provers ***
  4825 
  4826 * Provers/hypsubst.ML: improved version of the subst method, for
  4827 single-step rewriting: it now works in bound variable contexts. New is
  4828 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  4829 rewrite a different subterm than the original subst method, which is
  4830 still available as 'simplesubst'.
  4831 
  4832 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  4833 and quasi orders.
  4834 
  4835 * Provers/trancl.ML: new transitivity reasoner for transitive and
  4836 reflexive-transitive closure of relations.
  4837 
  4838 * Provers/blast.ML: new reference depth_limit to make blast's depth
  4839 limit (previously hard-coded with a value of 20) user-definable.
  4840 
  4841 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  4842 is peformed already.  Object-logics merely need to finish their
  4843 initial simpset configuration as before.  INCOMPATIBILITY.
  4844 
  4845 
  4846 *** HOL ***
  4847 
  4848 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  4849 
  4850   syntax (epsilon)
  4851     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  4852 
  4853 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  4854 and x-symbol; use option '-m epsilon' to get it actually printed.
  4855 Moreover, the mathematically important symbolic identifier \<epsilon>
  4856 becomes available as variable, constant etc.  INCOMPATIBILITY,
  4857 
  4858 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  4859 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  4860 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  4861 support corresponding Isar calculations.
  4862 
  4863 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  4864 instead of ":".
  4865 
  4866 * theory SetInterval: changed the syntax for open intervals:
  4867 
  4868   Old       New
  4869   {..n(}    {..<n}
  4870   {)n..}    {n<..}
  4871   {m..n(}   {m..<n}
  4872   {)m..n}   {m<..n}
  4873   {)m..n(}  {m<..<n}
  4874 
  4875 The old syntax is still supported but will disappear in the next
  4876 release.  For conversion use the following Emacs search and replace
  4877 patterns (these are not perfect but work quite well):
  4878 
  4879   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  4880   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  4881 
  4882 * Theory Commutative_Ring (in Library): method comm_ring for proving
  4883 equalities in commutative rings; method 'algebra' provides a generic
  4884 interface.
  4885 
  4886 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  4887 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  4888 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  4889 be a tuple pattern.
  4890 
  4891 Some new syntax forms are available:
  4892 
  4893   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  4894   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  4895   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  4896   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  4897 
  4898 The latter form "\<Sum>x < k. e" used to be based on a separate
  4899 function "Summation", which has been discontinued.
  4900 
  4901 * theory Finite_Set: in structured induction proofs, the insert case
  4902 is now 'case (insert x F)' instead of the old counterintuitive 'case
  4903 (insert F x)'.
  4904 
  4905 * The 'refute' command has been extended to support a much larger
  4906 fragment of HOL, including axiomatic type classes, constdefs and
  4907 typedefs, inductive datatypes and recursion.
  4908 
  4909 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  4910 Requires zChaff with proof generation to be installed.  See
  4911 HOL/ex/SAT_Examples.thy for examples.
  4912 
  4913 * Datatype induction via method 'induct' now preserves the name of the
  4914 induction variable. For example, when proving P(xs::'a list) by
  4915 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  4916 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  4917 in unstructured proof scripts.
  4918 
  4919 * Reworked implementation of records.  Improved scalability for
  4920 records with many fields, avoiding performance problems for type
  4921 inference. Records are no longer composed of nested field types, but
  4922 of nested extension types. Therefore the record type only grows linear
  4923 in the number of extensions and not in the number of fields.  The
  4924 top-level (users) view on records is preserved.  Potential
  4925 INCOMPATIBILITY only in strange cases, where the theory depends on the
  4926 old record representation. The type generated for a record is called
  4927 <record_name>_ext_type.
  4928 
  4929 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  4930 proofs triggered by a record definition or a simproc (if
  4931 quick_and_dirty is enabled).  Definitions of large records can take
  4932 quite long.
  4933 
  4934 New simproc record_upd_simproc for simplification of multiple record
  4935 updates enabled by default.  Moreover, trivial updates are also
  4936 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  4937 occasionally, since simplification is more powerful by default.
  4938 
  4939 * typedef: proper support for polymorphic sets, which contain extra
  4940 type-variables in the term.
  4941 
  4942 * Simplifier: automatically reasons about transitivity chains
  4943 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  4944 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  4945 old proofs break occasionally as simplification may now solve more
  4946 goals than previously.
  4947 
  4948 * Simplifier: converts x <= y into x = y if assumption y <= x is
  4949 present.  Works for all partial orders (class "order"), in particular
  4950 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  4951 just like y <= x.
  4952 
  4953 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  4954 bound variable or a constant then the let is unfolded.  Otherwise
  4955 first a is simplified to b, and then f b is simplified to g. If
  4956 possible we abstract b from g arriving at "let x = b in h x",
  4957 otherwise we unfold the let and arrive at g.  The simproc can be
  4958 enabled/disabled by the reference use_let_simproc.  Potential
  4959 INCOMPATIBILITY since simplification is more powerful by default.
  4960 
  4961 * Classical reasoning: the meson method now accepts theorems as arguments.
  4962 
  4963 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  4964 jobs to provide advice on the provability of subgoals.
  4965 
  4966 * Theory OrderedGroup and Ring_and_Field: various additions and
  4967 improvements to faciliate calculations involving equalities and
  4968 inequalities.
  4969 
  4970 The following theorems have been eliminated or modified
  4971 (INCOMPATIBILITY):
  4972 
  4973   abs_eq             now named abs_of_nonneg
  4974   abs_of_ge_0        now named abs_of_nonneg
  4975   abs_minus_eq       now named abs_of_nonpos
  4976   imp_abs_id         now named abs_of_nonneg
  4977   imp_abs_neg_id     now named abs_of_nonpos
  4978   mult_pos           now named mult_pos_pos
  4979   mult_pos_le        now named mult_nonneg_nonneg
  4980   mult_pos_neg_le    now named mult_nonneg_nonpos
  4981   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  4982   mult_neg           now named mult_neg_neg
  4983   mult_neg_le        now named mult_nonpos_nonpos
  4984 
  4985 * The following lemmas in Ring_and_Field have been added to the simplifier:
  4986      
  4987      zero_le_square
  4988      not_square_less_zero 
  4989 
  4990   The following lemmas have been deleted from Real/RealPow:
  4991   
  4992      realpow_zero_zero
  4993      realpow_two
  4994      realpow_less
  4995      zero_le_power
  4996      realpow_two_le
  4997      abs_realpow_two
  4998      realpow_two_abs     
  4999 
  5000 * Theory Parity: added rules for simplifying exponents.
  5001 
  5002 * Theory List:
  5003 
  5004 The following theorems have been eliminated or modified
  5005 (INCOMPATIBILITY):
  5006 
  5007   list_all_Nil       now named list_all.simps(1)
  5008   list_all_Cons      now named list_all.simps(2)
  5009   list_all_conv      now named list_all_iff
  5010   set_mem_eq         now named mem_iff
  5011 
  5012 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  5013 asymptotic "big O" calculations.  See the notes in BigO.thy.
  5014 
  5015 
  5016 *** HOL-Complex ***
  5017 
  5018 * Theory RealDef: better support for embedding natural numbers and
  5019 integers in the reals.
  5020 
  5021 The following theorems have been eliminated or modified
  5022 (INCOMPATIBILITY):
  5023 
  5024   exp_ge_add_one_self  now requires no hypotheses
  5025   real_of_int_add      reversed direction of equality (use [symmetric])
  5026   real_of_int_minus    reversed direction of equality (use [symmetric])
  5027   real_of_int_diff     reversed direction of equality (use [symmetric])
  5028   real_of_int_mult     reversed direction of equality (use [symmetric])
  5029 
  5030 * Theory RComplete: expanded support for floor and ceiling functions.
  5031 
  5032 * Theory Ln is new, with properties of the natural logarithm
  5033 
  5034 * Hyperreal: There is a new type constructor "star" for making
  5035 nonstandard types.  The old type names are now type synonyms:
  5036 
  5037   hypreal = real star
  5038   hypnat = nat star
  5039   hcomplex = complex star
  5040 
  5041 * Hyperreal: Many groups of similarly-defined constants have been
  5042 replaced by polymorphic versions (INCOMPATIBILITY):
  5043 
  5044   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  5045 
  5046   starset      <-- starsetNat, starsetC
  5047   *s*          <-- *sNat*, *sc*
  5048   starset_n    <-- starsetNat_n, starsetC_n
  5049   *sn*         <-- *sNatn*, *scn*
  5050   InternalSets <-- InternalNatSets, InternalCSets
  5051 
  5052   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  5053   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  5054   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  5055   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  5056   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  5057 
  5058 * Hyperreal: Many type-specific theorems have been removed in favor of
  5059 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  5060 
  5061   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  5062   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  5063   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  5064   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  5065   right_minus <-- hypreal_add_minus
  5066   left_minus <-- {hypreal,hcomplex}_add_minus_left
  5067   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  5068   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  5069   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  5070   mult_1_right <-- hcomplex_mult_one_right
  5071   mult_zero_left <-- hcomplex_mult_zero_left
  5072   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  5073   right_distrib <-- hypnat_add_mult_distrib2
  5074   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  5075   right_inverse <-- hypreal_mult_inverse
  5076   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  5077   order_refl <-- {hypreal,hypnat}_le_refl
  5078   order_trans <-- {hypreal,hypnat}_le_trans
  5079   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  5080   order_less_le <-- {hypreal,hypnat}_less_le
  5081   linorder_linear <-- {hypreal,hypnat}_le_linear
  5082   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  5083   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  5084   add_nonneg_nonneg <-- hypreal_le_add_order
  5085 
  5086 * Hyperreal: Separate theorems having to do with type-specific
  5087 versions of constants have been merged into theorems that apply to the
  5088 new polymorphic constants (INCOMPATIBILITY):
  5089 
  5090   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  5091   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  5092   STAR_Un <-- {STAR,NatStar,STARC}_Un
  5093   STAR_Int <-- {STAR,NatStar,STARC}_Int
  5094   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  5095   STAR_subset <-- {STAR,NatStar,STARC}_subset
  5096   STAR_mem <-- {STAR,NatStar,STARC}_mem
  5097   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  5098   STAR_diff <-- {STAR,STARC}_diff
  5099   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  5100     STARC_hcomplex_of_complex}_image_subset
  5101   starset_n_Un <-- starset{Nat,C}_n_Un
  5102   starset_n_Int <-- starset{Nat,C}_n_Int
  5103   starset_n_Compl <-- starset{Nat,C}_n_Compl
  5104   starset_n_diff <-- starset{Nat,C}_n_diff
  5105   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  5106   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  5107   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  5108   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  5109   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  5110   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  5111   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  5112   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  5113   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  5114   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  5115   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  5116   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  5117   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  5118   starfun_diff <-- starfun{C,RC,CR}_diff
  5119   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  5120   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  5121   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  5122   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  5123   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  5124   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  5125   starfun_Id <-- starfunC_Id
  5126   starfun_approx <-- starfun{Nat,CR}_approx
  5127   starfun_capprox <-- starfun{C,RC}_capprox
  5128   starfun_abs <-- starfunNat_rabs
  5129   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  5130   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  5131   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  5132   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  5133   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  5134   starfun_add_approx <-- starfunCR_add_approx
  5135   starfun_inverse_inverse <-- starfunC_inverse_inverse
  5136   starfun_divide <-- starfun{C,CR,RC}_divide
  5137   starfun_n <-- starfun{Nat,C}_n
  5138   starfun_n_mult <-- starfun{Nat,C}_n_mult
  5139   starfun_n_add <-- starfun{Nat,C}_n_add
  5140   starfun_n_add_minus <-- starfunNat_n_add_minus
  5141   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  5142   starfun_n_minus <-- starfun{Nat,C}_n_minus
  5143   starfun_n_eq <-- starfun{Nat,C}_n_eq
  5144 
  5145   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  5146   star_n_minus <-- {hypreal,hcomplex}_minus
  5147   star_n_diff <-- {hypreal,hcomplex}_diff
  5148   star_n_mult <-- {hypreal,hcomplex}_mult
  5149   star_n_inverse <-- {hypreal,hcomplex}_inverse
  5150   star_n_le <-- {hypreal,hypnat}_le
  5151   star_n_less <-- {hypreal,hypnat}_less
  5152   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  5153   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  5154   star_n_abs <-- hypreal_hrabs
  5155   star_n_divide <-- hcomplex_divide
  5156 
  5157   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  5158   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  5159   star_of_diff <-- hypreal_of_real_diff
  5160   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  5161   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  5162   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  5163   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  5164   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  5165   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  5166   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  5167   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  5168   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  5169   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  5170   star_of_number_of <-- {hypreal,hcomplex}_number_of
  5171   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  5172   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  5173   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  5174   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  5175   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  5176   star_of_power <-- hypreal_of_real_power
  5177   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  5178 
  5179 * Hyperreal: new method "transfer" that implements the transfer
  5180 principle of nonstandard analysis. With a subgoal that mentions
  5181 nonstandard types like "'a star", the command "apply transfer"
  5182 replaces it with an equivalent one that mentions only standard types.
  5183 To be successful, all free variables must have standard types; non-
  5184 standard variables must have explicit universal quantifiers.
  5185 
  5186 * Hyperreal: A theory of Taylor series.
  5187 
  5188 
  5189 *** HOLCF ***
  5190 
  5191 * Discontinued special version of 'constdefs' (which used to support
  5192 continuous functions) in favor of the general Pure one with full
  5193 type-inference.
  5194 
  5195 * New simplification procedure for solving continuity conditions; it
  5196 is much faster on terms with many nested lambda abstractions (cubic
  5197 instead of exponential time).
  5198 
  5199 * New syntax for domain package: selector names are now optional.
  5200 Parentheses should be omitted unless argument is lazy, for example:
  5201 
  5202   domain 'a stream = cons "'a" (lazy "'a stream")
  5203 
  5204 * New command 'fixrec' for defining recursive functions with pattern
  5205 matching; defining multiple functions with mutual recursion is also
  5206 supported.  Patterns may include the constants cpair, spair, up, sinl,
  5207 sinr, or any data constructor defined by the domain package. The given
  5208 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  5209 syntax and examples.
  5210 
  5211 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  5212 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  5213 but the proof obligation additionally includes an admissibility
  5214 requirement. The packages generate instances of class cpo or pcpo,
  5215 with continuity and strictness theorems for Rep and Abs.
  5216 
  5217 * HOLCF: Many theorems have been renamed according to a more standard naming
  5218 scheme (INCOMPATIBILITY):
  5219 
  5220   foo_inject:  "foo$x = foo$y ==> x = y"
  5221   foo_eq:      "(foo$x = foo$y) = (x = y)"
  5222   foo_less:    "(foo$x << foo$y) = (x << y)"
  5223   foo_strict:  "foo$UU = UU"
  5224   foo_defined: "... ==> foo$x ~= UU"
  5225   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  5226 
  5227 
  5228 *** ZF ***
  5229 
  5230 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  5231 including the First Isomorphism Theorem (on quotienting by the kernel
  5232 of a homomorphism).
  5233 
  5234 * ZF/Simplifier: install second copy of type solver that actually
  5235 makes use of TC rules declared to Isar proof contexts (or locales);
  5236 the old version is still required for ML proof scripts.
  5237 
  5238 
  5239 *** Cube ***
  5240 
  5241 * Converted to Isar theory format; use locales instead of axiomatic
  5242 theories.
  5243 
  5244 
  5245 *** ML ***
  5246 
  5247 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  5248 for ||>, ||>>, |>>,
  5249 
  5250 * Pure/library.ML no longer defines its own option datatype, but uses
  5251 that of the SML basis, which has constructors NONE and SOME instead of
  5252 None and Some, as well as exception Option.Option instead of OPTION.
  5253 The functions the, if_none, is_some, is_none have been adapted
  5254 accordingly, while Option.map replaces apsome.
  5255 
  5256 * Pure/library.ML: the exception LIST has been given up in favour of
  5257 the standard exceptions Empty and Subscript, as well as
  5258 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  5259 superceded by the standard hd and tl functions etc.
  5260 
  5261 A number of basic list functions are no longer exported to the ML
  5262 toplevel, as they are variants of predefined functions.  The following
  5263 suggests how one can translate existing code:
  5264 
  5265     rev_append xs ys = List.revAppend (xs, ys)
  5266     nth_elem (i, xs) = List.nth (xs, i)
  5267     last_elem xs = List.last xs
  5268     flat xss = List.concat xss
  5269     seq fs = List.app fs
  5270     partition P xs = List.partition P xs
  5271     mapfilter f xs = List.mapPartial f xs
  5272 
  5273 * Pure/library.ML: several combinators for linear functional
  5274 transformations, notably reverse application and composition:
  5275 
  5276   x |> f                f #> g
  5277   (x, y) |-> f          f #-> g
  5278 
  5279 * Pure/library.ML: introduced/changed precedence of infix operators:
  5280 
  5281   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  5282   infix 2 ?;
  5283   infix 3 o oo ooo oooo;
  5284   infix 4 ~~ upto downto;
  5285 
  5286 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  5287 infix operators.
  5288 
  5289 * Pure/library.ML: natural list combinators fold, fold_rev, and
  5290 fold_map support linear functional transformations and nesting.  For
  5291 example:
  5292 
  5293   fold f [x1, ..., xN] y =
  5294     y |> f x1 |> ... |> f xN
  5295 
  5296   (fold o fold) f [xs1, ..., xsN] y =
  5297     y |> fold f xs1 |> ... |> fold f xsN
  5298 
  5299   fold f [x1, ..., xN] =
  5300     f x1 #> ... #> f xN
  5301 
  5302   (fold o fold) f [xs1, ..., xsN] =
  5303     fold f xs1 #> ... #> fold f xsN
  5304 
  5305 * Pure/library.ML: the following selectors on type 'a option are
  5306 available:
  5307 
  5308   the:               'a option -> 'a  (*partial*)
  5309   these:             'a option -> 'a  where 'a = 'b list
  5310   the_default: 'a -> 'a option -> 'a
  5311   the_list:          'a option -> 'a list
  5312 
  5313 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5314 basic operations for association lists, following natural argument
  5315 order; moreover the explicit equality predicate passed here avoids
  5316 potentially expensive polymorphic runtime equality checks.
  5317 The old functions may be expressed as follows:
  5318 
  5319   assoc = uncurry (AList.lookup (op =))
  5320   assocs = these oo AList.lookup (op =)
  5321   overwrite = uncurry (AList.update (op =)) o swap
  5322 
  5323 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5324 
  5325   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  5326   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  5327 
  5328 replacing make_keylist and keyfilter (occassionally used)
  5329 Naive rewrites:
  5330 
  5331   make_keylist = AList.make
  5332   keyfilter = AList.find (op =)
  5333 
  5334 * eq_fst and eq_snd now take explicit equality parameter, thus
  5335   avoiding eqtypes. Naive rewrites:
  5336 
  5337     eq_fst = eq_fst (op =)
  5338     eq_snd = eq_snd (op =)
  5339 
  5340 * Removed deprecated apl and apr (rarely used).
  5341   Naive rewrites:
  5342 
  5343     apl (n, op) =>>= curry op n
  5344     apr (op, m) =>>= fn n => op (n, m)
  5345 
  5346 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  5347 provides a reasonably efficient light-weight implementation of sets as
  5348 lists.
  5349 
  5350 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  5351 few new operations; existing lookup and update are now curried to
  5352 follow natural argument order (for use with fold etc.);
  5353 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  5354 
  5355 * Pure/General: output via the Isabelle channels of
  5356 writeln/warning/error etc. is now passed through Output.output, with a
  5357 hook for arbitrary transformations depending on the print_mode
  5358 (cf. Output.add_mode -- the first active mode that provides a output
  5359 function wins).  Already formatted output may be embedded into further
  5360 text via Output.raw; the result of Pretty.string_of/str_of and derived
  5361 functions (string_of_term/cterm/thm etc.) is already marked raw to
  5362 accommodate easy composition of diagnostic messages etc.  Programmers
  5363 rarely need to care about Output.output or Output.raw at all, with
  5364 some notable exceptions: Output.output is required when bypassing the
  5365 standard channels (writeln etc.), or in token translations to produce
  5366 properly formatted results; Output.raw is required when capturing
  5367 already output material that will eventually be presented to the user
  5368 a second time.  For the default print mode, both Output.output and
  5369 Output.raw have no effect.
  5370 
  5371 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  5372 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  5373 cumulative results are displayed at the end of a batch session.
  5374 
  5375 * Pure/General: File.sysify_path and File.quote_sysify path have been
  5376 replaced by File.platform_path and File.shell_path (with appropriate
  5377 hooks).  This provides a clean interface for unusual systems where the
  5378 internal and external process view of file names are different.
  5379 
  5380 * Pure: more efficient orders for basic syntactic entities: added
  5381 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  5382 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  5383 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  5384 orders now -- potential INCOMPATIBILITY for code that depends on a
  5385 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  5386 Library.sort_strings on result).
  5387 
  5388 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  5389 fold_types traverse types/terms from left to right, observing natural
  5390 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  5391 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  5392 
  5393 * Pure: name spaces have been refined, with significant changes of the
  5394 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  5395 to extern(_table).  The plain name entry path is superceded by a
  5396 general 'naming' context, which also includes the 'policy' to produce
  5397 a fully qualified name and external accesses of a fully qualified
  5398 name; NameSpace.extend is superceded by context dependent
  5399 Sign.declare_name.  Several theory and proof context operations modify
  5400 the naming context.  Especially note Theory.restore_naming and
  5401 ProofContext.restore_naming to get back to a sane state; note that
  5402 Theory.add_path is no longer sufficient to recover from
  5403 Theory.absolute_path in particular.
  5404 
  5405 * Pure: new flags short_names (default false) and unique_names
  5406 (default true) for controlling output of qualified names.  If
  5407 short_names is set, names are printed unqualified.  If unique_names is
  5408 reset, the name prefix is reduced to the minimum required to achieve
  5409 the original result when interning again, even if there is an overlap
  5410 with earlier declarations.
  5411 
  5412 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  5413 now 'extend', and 'merge' gets an additional Pretty.pp argument
  5414 (useful for printing error messages).  INCOMPATIBILITY.
  5415 
  5416 * Pure: major reorganization of the theory context.  Type Sign.sg and
  5417 Theory.theory are now identified, referring to the universal
  5418 Context.theory (see Pure/context.ML).  Actual signature and theory
  5419 content is managed as theory data.  The old code and interfaces were
  5420 spread over many files and structures; the new arrangement introduces
  5421 considerable INCOMPATIBILITY to gain more clarity:
  5422 
  5423   Context -- theory management operations (name, identity, inclusion,
  5424     parents, ancestors, merge, etc.), plus generic theory data;
  5425 
  5426   Sign -- logical signature and syntax operations (declaring consts,
  5427     types, etc.), plus certify/read for common entities;
  5428 
  5429   Theory -- logical theory operations (stating axioms, definitions,
  5430     oracles), plus a copy of logical signature operations (consts,
  5431     types, etc.); also a few basic management operations (Theory.copy,
  5432     Theory.merge, etc.)
  5433 
  5434 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  5435 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  5436 for convenience -- they merely return the theory.
  5437 
  5438 * Pure: type Type.tsig is superceded by theory in most interfaces.
  5439 
  5440 * Pure: the Isar proof context type is already defined early in Pure
  5441 as Context.proof (note that ProofContext.context and Proof.context are
  5442 aliases, where the latter is the preferred name).  This enables other
  5443 Isabelle components to refer to that type even before Isar is present.
  5444 
  5445 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  5446 typeK, constK, axiomK, oracleK), but provide explicit operations for
  5447 any of these kinds.  For example, Sign.intern typeK is now
  5448 Sign.intern_type, Theory.hide_space Sign.typeK is now
  5449 Theory.hide_types.  Also note that former
  5450 Theory.hide_classes/types/consts are now
  5451 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  5452 internalize their arguments!  INCOMPATIBILITY.
  5453 
  5454 * Pure: get_thm interface (of PureThy and ProofContext) expects
  5455 datatype thmref (with constructors Name and NameSelection) instead of
  5456 plain string -- INCOMPATIBILITY;
  5457 
  5458 * Pure: cases produced by proof methods specify options, where NONE
  5459 means to remove case bindings -- INCOMPATIBILITY in
  5460 (RAW_)METHOD_CASES.
  5461 
  5462 * Pure: the following operations retrieve axioms or theorems from a
  5463 theory node or theory hierarchy, respectively:
  5464 
  5465   Theory.axioms_of: theory -> (string * term) list
  5466   Theory.all_axioms_of: theory -> (string * term) list
  5467   PureThy.thms_of: theory -> (string * thm) list
  5468   PureThy.all_thms_of: theory -> (string * thm) list
  5469 
  5470 * Pure: print_tac now outputs the goal through the trace channel.
  5471 
  5472 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  5473 Reference Toplevel.debug (default false) controls detailed printing
  5474 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  5475 controls execution profiling -- set to 1 for time and 2 for space
  5476 (both increase the runtime).
  5477 
  5478 * Isar session: The initial use of ROOT.ML is now always timed,
  5479 i.e. the log will show the actual process times, in contrast to the
  5480 elapsed wall-clock time that the outer shell wrapper produces.
  5481 
  5482 * Simplifier: improved handling of bound variables (nameless
  5483 representation, avoid allocating new strings).  Simprocs that invoke
  5484 the Simplifier recursively should use Simplifier.inherit_bounds to
  5485 avoid local name clashes.  Failure to do so produces warnings
  5486 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  5487 for further details.
  5488 
  5489 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  5490 bindings for all theorems stored within a given theory; this may help
  5491 in porting non-Isar theories to Isar ones, while keeping ML proof
  5492 scripts for the time being.
  5493 
  5494 * ML operator HTML.with_charset specifies the charset begin used for
  5495 generated HTML files.  For example:
  5496 
  5497   HTML.with_charset "utf-8" use_thy "Hebrew";
  5498   HTML.with_charset "utf-8" use_thy "Chinese";
  5499 
  5500 
  5501 *** System ***
  5502 
  5503 * Allow symlinks to all proper Isabelle executables (Isabelle,
  5504 isabelle, isatool etc.).
  5505 
  5506 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  5507 isatool doc, isatool mkdir, display_drafts etc.).
  5508 
  5509 * isatool usedir: option -f allows specification of the ML file to be
  5510 used by Isabelle; default is ROOT.ML.
  5511 
  5512 * New isatool version outputs the version identifier of the Isabelle
  5513 distribution being used.
  5514 
  5515 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  5516 (containing Boolean satisfiability problems) into Isabelle/HOL
  5517 theories.
  5518 
  5519 
  5520 
  5521 New in Isabelle2004 (April 2004)
  5522 --------------------------------
  5523 
  5524 *** General ***
  5525 
  5526 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  5527   Replaces linorder.ML.
  5528 
  5529 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  5530   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  5531   (\<a>...\<z>), are now considered normal letters, and can therefore
  5532   be used anywhere where an ASCII letter (a...zA...Z) has until
  5533   now. COMPATIBILITY: This obviously changes the parsing of some
  5534   terms, especially where a symbol has been used as a binder, say
  5535   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  5536   as an identifier.  Fix it by inserting a space around former
  5537   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  5538   existing theory and ML files.
  5539 
  5540 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  5541 
  5542 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  5543   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  5544   a normal (but invisible) letter. For multiple letter subscripts repeat
  5545   \<^isub> like this: x\<^isub>1\<^isub>2.
  5546 
  5547 * Pure: There are now sub-/superscripts that can span more than one
  5548   character. Text between \<^bsub> and \<^esub> is set in subscript in
  5549   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  5550   superscript. The new control characters are not identifier parts.
  5551 
  5552 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  5553   content of "..." to the latex file instead of \isacntrl... . The "..."
  5554   may consist of any printable characters excluding the end bracket >.
  5555 
  5556 * Pure: Using new Isar command "finalconsts" (or the ML functions
  5557   Theory.add_finals or Theory.add_finals_i) it is now possible to
  5558   declare constants "final", which prevents their being given a definition
  5559   later.  It is useful for constants whose behaviour is fixed axiomatically
  5560   rather than definitionally, such as the meta-logic connectives.
  5561 
  5562 * Pure: 'instance' now handles general arities with general sorts
  5563   (i.e. intersections of classes),
  5564 
  5565 * Presentation: generated HTML now uses a CSS style sheet to make layout
  5566   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  5567   It can be changed to alter the colors/layout of generated pages.
  5568 
  5569 
  5570 *** Isar ***
  5571 
  5572 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  5573   cut_tac, subgoal_tac and thin_tac:
  5574   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  5575     locales are no longer forced to write Isar proof scripts.
  5576     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  5577     emulations.
  5578   - INCOMPATIBILITY: names of variables to be instantiated may no
  5579     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  5580     This is consistent with the instantiation attribute "where".
  5581 
  5582 * Attributes "where" and "of":
  5583   - Now take type variables of instantiated theorem into account when reading
  5584     the instantiation string.  This fixes a bug that caused instantiated
  5585     theorems to have too special types in some circumstances.
  5586   - "where" permits explicit instantiations of type variables.
  5587 
  5588 * Calculation commands "moreover" and "also" no longer interfere with
  5589   current facts ("this"), admitting arbitrary combinations with "then"
  5590   and derived forms.
  5591 
  5592 * Locales:
  5593   - Goal statements involving the context element "includes" no longer
  5594     generate theorems with internal delta predicates (those ending on
  5595     "_axioms") in the premise.
  5596     Resolve particular premise with <locale>.intro to obtain old form.
  5597   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  5598     specification and "includes" elements in goal statement.
  5599   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  5600     [intro?] and [elim?] (respectively) by default.
  5601   - Experimental command for instantiation of locales in proof contexts:
  5602         instantiate <label>[<attrs>]: <loc>
  5603     Instantiates locale <loc> and adds all its theorems to the current context
  5604     taking into account their attributes.  Label and attrs are optional
  5605     modifiers, like in theorem declarations.  If present, names of
  5606     instantiated theorems are qualified with <label>, and the attributes
  5607     <attrs> are applied after any attributes these theorems might have already.
  5608       If the locale has assumptions, a chained fact of the form
  5609     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  5610     are derived.  The command does not support old-style locales declared
  5611     with "locale (open)".
  5612       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  5613 
  5614 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  5615   (Isar) contexts.
  5616 
  5617 
  5618 *** HOL ***
  5619 
  5620 * Proof import: new image HOL4 contains the imported library from
  5621   the HOL4 system with about 2500 theorems. It is imported by
  5622   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  5623   can be used like any other Isabelle image.  See
  5624   HOL/Import/HOL/README for more information.
  5625 
  5626 * Simplifier:
  5627   - Much improved handling of linear and partial orders.
  5628     Reasoners for linear and partial orders are set up for type classes
  5629     "linorder" and "order" respectively, and are added to the default simpset
  5630     as solvers.  This means that the simplifier can build transitivity chains
  5631     to solve goals from the assumptions.
  5632   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  5633     of blast or auto after simplification become unnecessary because the goal
  5634     is solved by simplification already.
  5635 
  5636 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  5637     all proved in axiomatic type classes for semirings, rings and fields.
  5638 
  5639 * Numerics:
  5640   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  5641     now formalized using the Ring_and_Field theory mentioned above.
  5642   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  5643     than before, because now they are set up once in a generic manner.
  5644   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  5645     Look for the general versions in Ring_and_Field (and Power if they concern
  5646     exponentiation).
  5647 
  5648 * Type "rat" of the rational numbers is now available in HOL-Complex.
  5649 
  5650 * Records:
  5651   - Record types are now by default printed with their type abbreviation
  5652     instead of the list of all field types. This can be configured via
  5653     the reference "print_record_type_abbr".
  5654   - Simproc "record_upd_simproc" for simplification of multiple updates added
  5655     (not enabled by default).
  5656   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  5657     EX x. x = sel r to True (not enabled by default).
  5658   - Tactic "record_split_simp_tac" to split and simplify records added.
  5659 
  5660 * 'specification' command added, allowing for definition by
  5661   specification.  There is also an 'ax_specification' command that
  5662   introduces the new constants axiomatically.
  5663 
  5664 * arith(_tac) is now able to generate counterexamples for reals as well.
  5665 
  5666 * HOL-Algebra: new locale "ring" for non-commutative rings.
  5667 
  5668 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  5669   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  5670 
  5671 * HOL-Matrix: a first theory for matrices in HOL with an application of
  5672   matrix theory to linear programming.
  5673 
  5674 * Unions and Intersections:
  5675   The latex output syntax of UN and INT has been changed
  5676   from "\Union x \in A. B" to "\Union_{x \in A} B"
  5677   i.e. the index formulae has become a subscript.
  5678   Similarly for "\Union x. B", and for \Inter instead of \Union.
  5679 
  5680 * Unions and Intersections over Intervals:
  5681   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  5682   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  5683   like in normal math, and corresponding versions for < and for intersection.
  5684 
  5685 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  5686   lexicographic dictonary ordering has been added as "lexord".
  5687 
  5688 * ML: the legacy theory structures Int and List have been removed. They had
  5689   conflicted with ML Basis Library structures having the same names.
  5690 
  5691 * 'refute' command added to search for (finite) countermodels.  Only works
  5692   for a fragment of HOL.  The installation of an external SAT solver is
  5693   highly recommended.  See "HOL/Refute.thy" for details.
  5694 
  5695 * 'quickcheck' command: Allows to find counterexamples by evaluating
  5696   formulae under an assignment of free variables to random values.
  5697   In contrast to 'refute', it can deal with inductive datatypes,
  5698   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  5699   for examples.
  5700 
  5701 
  5702 *** HOLCF ***
  5703 
  5704 * Streams now come with concatenation and are part of the HOLCF image
  5705 
  5706 
  5707 
  5708 New in Isabelle2003 (May 2003)
  5709 ------------------------------
  5710 
  5711 *** General ***
  5712 
  5713 * Provers/simplifier:
  5714 
  5715   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  5716     Assumptions are now subject to complete mutual simplification,
  5717     not just from left to right. The simplifier now preserves
  5718     the order of assumptions.
  5719 
  5720     Potential INCOMPATIBILITY:
  5721 
  5722     -- simp sometimes diverges where the old version did
  5723        not, e.g. invoking simp on the goal
  5724 
  5725         [| P (f x); y = x; f x = f y |] ==> Q
  5726 
  5727        now gives rise to the infinite reduction sequence
  5728 
  5729         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  5730 
  5731        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  5732        kind of problem.
  5733 
  5734     -- Tactics combining classical reasoner and simplification (such as auto)
  5735        are also affected by this change, because many of them rely on
  5736        simp. They may sometimes diverge as well or yield a different numbers
  5737        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  5738        in case of problems. Sometimes subsequent calls to the classical
  5739        reasoner will fail because a preceeding call to the simplifier too
  5740        eagerly simplified the goal, e.g. deleted redundant premises.
  5741 
  5742   - The simplifier trace now shows the names of the applied rewrite rules
  5743 
  5744   - You can limit the number of recursive invocations of the simplifier
  5745     during conditional rewriting (where the simplifie tries to solve the
  5746     conditions before applying the rewrite rule):
  5747     ML "simp_depth_limit := n"
  5748     where n is an integer. Thus you can force termination where previously
  5749     the simplifier would diverge.
  5750 
  5751   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  5752 
  5753   - No longer aborts on failed congruence proof.  Instead, the
  5754     congruence is ignored.
  5755 
  5756 * Pure: New generic framework for extracting programs from constructive
  5757   proofs. See HOL/Extraction.thy for an example instantiation, as well
  5758   as HOL/Extraction for some case studies.
  5759 
  5760 * Pure: The main goal of the proof state is no longer shown by default, only
  5761 the subgoals. This behaviour is controlled by a new flag.
  5762    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  5763 (ML: Proof.show_main_goal).
  5764 
  5765 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  5766 rules whose conclusion matches subgoal 1:
  5767       PG menu: Isabelle/Isar -> Show me -> matching rules
  5768 The rules are ordered by how closely they match the subgoal.
  5769 In particular, rules that solve a subgoal outright are displayed first
  5770 (or rather last, the way they are printed).
  5771 (ML: ProofGeneral.print_intros())
  5772 
  5773 * Pure: New flag trace_unify_fail causes unification to print
  5774 diagnostic information (PG: in trace buffer) when it fails. This is
  5775 useful for figuring out why single step proofs like rule, erule or
  5776 assumption failed.
  5777 
  5778 * Pure: Locale specifications now produce predicate definitions
  5779 according to the body of text (covering assumptions modulo local
  5780 definitions); predicate "loc_axioms" covers newly introduced text,
  5781 while "loc" is cumulative wrt. all included locale expressions; the
  5782 latter view is presented only on export into the global theory
  5783 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  5784 on the old view without predicates;
  5785 
  5786 * Pure: predefined locales "var" and "struct" are useful for sharing
  5787 parameters (as in CASL, for example); just specify something like
  5788 ``var x + var y + struct M'' as import;
  5789 
  5790 * Pure: improved thms_containing: proper indexing of facts instead of
  5791 raw theorems; check validity of results wrt. current name space;
  5792 include local facts of proof configuration (also covers active
  5793 locales), cover fixed variables in index; may use "_" in term
  5794 specification; an optional limit for the number of printed facts may
  5795 be given (the default is 40);
  5796 
  5797 * Pure: disallow duplicate fact bindings within new-style theory files
  5798 (batch-mode only);
  5799 
  5800 * Provers: improved induct method: assumptions introduced by case
  5801 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  5802 the goal statement); "foo" still refers to all facts collectively;
  5803 
  5804 * Provers: the function blast.overloaded has been removed: all constants
  5805 are regarded as potentially overloaded, which improves robustness in exchange
  5806 for slight decrease in efficiency;
  5807 
  5808 * Provers/linorder: New generic prover for transitivity reasoning over
  5809 linear orders.  Note: this prover is not efficient!
  5810 
  5811 * Isar: preview of problems to finish 'show' now produce an error
  5812 rather than just a warning (in interactive mode);
  5813 
  5814 
  5815 *** HOL ***
  5816 
  5817 * arith(_tac)
  5818 
  5819  - Produces a counter example if it cannot prove a goal.
  5820    Note that the counter example may be spurious if the goal is not a formula
  5821    of quantifier-free linear arithmetic.
  5822    In ProofGeneral the counter example appears in the trace buffer.
  5823 
  5824  - Knows about div k and mod k where k is a numeral of type nat or int.
  5825 
  5826  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  5827    linear arithmetic fails. This takes account of quantifiers and divisibility.
  5828    Presburger arithmetic can also be called explicitly via presburger(_tac).
  5829 
  5830 * simp's arithmetic capabilities have been enhanced a bit: it now
  5831 takes ~= in premises into account (by performing a case split);
  5832 
  5833 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  5834 are distributed over a sum of terms;
  5835 
  5836 * New tactic "trans_tac" and method "trans" instantiate
  5837 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  5838 "<=", "<" and "=").
  5839 
  5840 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  5841 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  5842 
  5843 * 'typedef' command has new option "open" to suppress the set
  5844 definition;
  5845 
  5846 * functions Min and Max on finite sets have been introduced (theory
  5847 Finite_Set);
  5848 
  5849 * attribute [symmetric] now works for relations as well; it turns
  5850 (x,y) : R^-1 into (y,x) : R, and vice versa;
  5851 
  5852 * induct over a !!-quantified statement (say !!x1..xn):
  5853   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  5854 
  5855 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  5856 %x. None. Warning: empty_def now refers to the previously hidden definition
  5857 of the empty set.
  5858 
  5859 * Algebra: formalization of classical algebra.  Intended as base for
  5860 any algebraic development in Isabelle.  Currently covers group theory
  5861 (up to Sylow's theorem) and ring theory (Universal Property of
  5862 Univariate Polynomials).  Contributions welcome;
  5863 
  5864 * GroupTheory: deleted, since its material has been moved to Algebra;
  5865 
  5866 * Complex: new directory of the complex numbers with numeric constants,
  5867 nonstandard complex numbers, and some complex analysis, standard and
  5868 nonstandard (Jacques Fleuriot);
  5869 
  5870 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  5871 
  5872 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  5873 Fleuriot);
  5874 
  5875 * Real/HahnBanach: updated and adapted to locales;
  5876 
  5877 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  5878 Gray and Kramer);
  5879 
  5880 * UNITY: added the Meier-Sanders theory of progress sets;
  5881 
  5882 * MicroJava: bytecode verifier and lightweight bytecode verifier
  5883 as abstract algorithms, instantiated to the JVM;
  5884 
  5885 * Bali: Java source language formalization. Type system, operational
  5886 semantics, axiomatic semantics. Supported language features:
  5887 classes, interfaces, objects,virtual methods, static methods,
  5888 static/instance fields, arrays, access modifiers, definite
  5889 assignment, exceptions.
  5890 
  5891 
  5892 *** ZF ***
  5893 
  5894 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  5895 universe, etc.);
  5896 
  5897 * Main ZF: virtually all theories converted to new-style format;
  5898 
  5899 
  5900 *** ML ***
  5901 
  5902 * Pure: Tactic.prove provides sane interface for internal proofs;
  5903 omits the infamous "standard" operation, so this is more appropriate
  5904 than prove_goalw_cterm in many situations (e.g. in simprocs);
  5905 
  5906 * Pure: improved error reporting of simprocs;
  5907 
  5908 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  5909 up simprocs;
  5910 
  5911 
  5912 *** Document preparation ***
  5913 
  5914 * uses \par instead of \\ for line breaks in theory text. This may
  5915 shift some page breaks in large documents. To get the old behaviour
  5916 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  5917 
  5918 * minimized dependencies of isabelle.sty and isabellesym.sty on
  5919 other packages
  5920 
  5921 * \<euro> now needs package babel/greek instead of marvosym (which
  5922 broke \Rightarrow)
  5923 
  5924 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  5925 textcomp package)
  5926 
  5927 
  5928 
  5929 New in Isabelle2002 (March 2002)
  5930 --------------------------------
  5931 
  5932 *** Document preparation ***
  5933 
  5934 * greatly simplified document preparation setup, including more
  5935 graceful interpretation of isatool usedir -i/-d/-D options, and more
  5936 instructive isatool mkdir; users should basically be able to get
  5937 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  5938 users may run a separate document processing stage manually like this:
  5939 "isatool usedir -D output HOL Test && isatool document Test/output";
  5940 
  5941 * theory dependency graph may now be incorporated into documents;
  5942 isatool usedir -g true will produce session_graph.eps/.pdf for use
  5943 with \includegraphics of LaTeX;
  5944 
  5945 * proper spacing of consecutive markup elements, especially text
  5946 blocks after section headings;
  5947 
  5948 * support bold style (for single symbols only), input syntax is like
  5949 this: "\<^bold>\<alpha>" or "\<^bold>A";
  5950 
  5951 * \<bullet> is now output as bold \cdot by default, which looks much
  5952 better in printed text;
  5953 
  5954 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  5955 note that these symbols are currently unavailable in Proof General /
  5956 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  5957 
  5958 * isatool latex no longer depends on changed TEXINPUTS, instead
  5959 isatool document copies the Isabelle style files to the target
  5960 location;
  5961 
  5962 
  5963 *** Isar ***
  5964 
  5965 * Pure/Provers: improved proof by cases and induction;
  5966   - 'case' command admits impromptu naming of parameters (such as
  5967     "case (Suc n)");
  5968   - 'induct' method divinates rule instantiation from the inductive
  5969     claim; no longer requires excessive ?P bindings for proper
  5970     instantiation of cases;
  5971   - 'induct' method properly enumerates all possibilities of set/type
  5972     rules; as a consequence facts may be also passed through *type*
  5973     rules without further ado;
  5974   - 'induct' method now derives symbolic cases from the *rulified*
  5975     rule (before it used to rulify cases stemming from the internal
  5976     atomized version); this means that the context of a non-atomic
  5977     statement becomes is included in the hypothesis, avoiding the
  5978     slightly cumbersome show "PROP ?case" form;
  5979   - 'induct' may now use elim-style induction rules without chaining
  5980     facts, using ``missing'' premises from the goal state; this allows
  5981     rules stemming from inductive sets to be applied in unstructured
  5982     scripts, while still benefitting from proper handling of non-atomic
  5983     statements; NB: major inductive premises need to be put first, all
  5984     the rest of the goal is passed through the induction;
  5985   - 'induct' proper support for mutual induction involving non-atomic
  5986     rule statements (uses the new concept of simultaneous goals, see
  5987     below);
  5988   - append all possible rule selections, but only use the first
  5989     success (no backtracking);
  5990   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  5991   - undeclared rule case names default to numbers 1, 2, 3, ...;
  5992   - added 'print_induct_rules' (covered by help item in recent Proof
  5993     General versions);
  5994   - moved induct/cases attributes to Pure, methods to Provers;
  5995   - generic method setup instantiated for FOL and HOL;
  5996 
  5997 * Pure: support multiple simultaneous goal statements, for example
  5998 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  5999 meta-level mechanism, this acts as if several individual goals had
  6000 been stated separately; in particular common proof methods need to be
  6001 repeated in order to cover all claims; note that a single elimination
  6002 step is *not* sufficient to establish the two conjunctions, so this
  6003 fails:
  6004 
  6005   assume "A & B" then have A and B ..   (*".." fails*)
  6006 
  6007 better use "obtain" in situations as above; alternative refer to
  6008 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  6009 
  6010 * Pure: proper integration with ``locales''; unlike the original
  6011 version by Florian Kammller, Isar locales package high-level proof
  6012 contexts rather than raw logical ones (e.g. we admit to include
  6013 attributes everywhere); operations on locales include merge and
  6014 rename; support for implicit arguments (``structures''); simultaneous
  6015 type-inference over imports and text; see also HOL/ex/Locales.thy for
  6016 some examples;
  6017 
  6018 * Pure: the following commands have been ``localized'', supporting a
  6019 target locale specification "(in name)": 'lemma', 'theorem',
  6020 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  6021 stored both within the locale and at the theory level (exported and
  6022 qualified by the locale name);
  6023 
  6024 * Pure: theory goals may now be specified in ``long'' form, with
  6025 ad-hoc contexts consisting of arbitrary locale elements. for example
  6026 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  6027 definitions may be given, too); the result is a meta-level rule with
  6028 the context elements being discharged in the obvious way;
  6029 
  6030 * Pure: new proof command 'using' allows to augment currently used
  6031 facts after a goal statement ('using' is syntactically analogous to
  6032 'apply', but acts on the goal's facts only); this allows chained facts
  6033 to be separated into parts given before and after a claim, as in
  6034 ``from a and b have C using d and e <proof>'';
  6035 
  6036 * Pure: renamed "antecedent" case to "rule_context";
  6037 
  6038 * Pure: new 'judgment' command records explicit information about the
  6039 object-logic embedding (used by several tools internally); no longer
  6040 use hard-wired "Trueprop";
  6041 
  6042 * Pure: added 'corollary' command;
  6043 
  6044 * Pure: fixed 'token_translation' command;
  6045 
  6046 * Pure: removed obsolete 'exported' attribute;
  6047 
  6048 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  6049 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  6050 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  6051 
  6052 * Pure: method 'atomize' presents local goal premises as object-level
  6053 statements (atomic meta-level propositions); setup controlled via
  6054 rewrite rules declarations of 'atomize' attribute; example
  6055 application: 'induct' method with proper rule statements in improper
  6056 proof *scripts*;
  6057 
  6058 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  6059 now consider the syntactic context of assumptions, giving a better
  6060 chance to get type-inference of the arguments right (this is
  6061 especially important for locales);
  6062 
  6063 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  6064 mode;
  6065 
  6066 * Pure/obtain: the formal conclusion "thesis", being marked as
  6067 ``internal'', may no longer be reference directly in the text;
  6068 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  6069 situations;
  6070 
  6071 * Pure: generic 'sym' attribute which declares a rule both as pure
  6072 'elim?' and for the 'symmetric' operation;
  6073 
  6074 * Pure: marginal comments ``--'' may now occur just anywhere in the
  6075 text; the fixed correlation with particular command syntax has been
  6076 discontinued;
  6077 
  6078 * Pure: new method 'rules' is particularly well-suited for proof
  6079 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  6080 but often produces more compact proof terms with less detours;
  6081 
  6082 * Pure/Provers/classical: simplified integration with pure rule
  6083 attributes and methods; the classical "intro?/elim?/dest?"
  6084 declarations coincide with the pure ones; the "rule" method no longer
  6085 includes classically swapped intros; "intro" and "elim" methods no
  6086 longer pick rules from the context; also got rid of ML declarations
  6087 AddXIs/AddXEs/AddXDs; all of this has some potential for
  6088 INCOMPATIBILITY;
  6089 
  6090 * Provers/classical: attribute 'swapped' produces classical inversions
  6091 of introduction rules;
  6092 
  6093 * Provers/simplifier: 'simplified' attribute may refer to explicit
  6094 rules instead of full simplifier context; 'iff' attribute handles
  6095 conditional rules;
  6096 
  6097 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  6098 
  6099 * HOL: 'recdef' now fails on unfinished automated proofs, use
  6100 "(permissive)" option to recover old behavior;
  6101 
  6102 * HOL: 'inductive' no longer features separate (collective) attributes
  6103 for 'intros' (was found too confusing);
  6104 
  6105 * HOL: properly declared induction rules less_induct and
  6106 wf_induct_rule;
  6107 
  6108 
  6109 *** HOL ***
  6110 
  6111 * HOL: moved over to sane numeral syntax; the new policy is as
  6112 follows:
  6113 
  6114   - 0 and 1 are polymorphic constants, which are defined on any
  6115   numeric type (nat, int, real etc.);
  6116 
  6117   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  6118   binary representation internally;
  6119 
  6120   - type nat has special constructor Suc, and generally prefers Suc 0
  6121   over 1::nat and Suc (Suc 0) over 2::nat;
  6122 
  6123 This change may cause significant problems of INCOMPATIBILITY; here
  6124 are some hints on converting existing sources:
  6125 
  6126   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  6127   entities, so expressions involving "-" (unary or binary minus) need
  6128   to be spaced properly;
  6129 
  6130   - existing occurrences of "1" may need to be constraint "1::nat" or
  6131   even replaced by Suc 0; similar for old "2";
  6132 
  6133   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  6134 
  6135   - remove all special provisions on numerals in proofs;
  6136 
  6137 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  6138 representation (depends on bin_arith_simps in the default context);
  6139 
  6140 * HOL: symbolic syntax for x^2 (numeral 2);
  6141 
  6142 * HOL: the class of all HOL types is now called "type" rather than
  6143 "term"; INCOMPATIBILITY, need to adapt references to this type class
  6144 in axclass/classes, instance/arities, and (usually rare) occurrences
  6145 in typings (of consts etc.); internally the class is called
  6146 "HOL.type", ML programs should refer to HOLogic.typeS;
  6147 
  6148 * HOL/record package improvements:
  6149   - new derived operations "fields" to build a partial record section,
  6150     "extend" to promote a fixed record to a record scheme, and
  6151     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  6152     declared as simp by default;
  6153   - shared operations ("more", "fields", etc.) now need to be always
  6154     qualified) --- potential INCOMPATIBILITY;
  6155   - removed "make_scheme" operations (use "make" with "extend") --
  6156     INCOMPATIBILITY;
  6157   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  6158   - provides cases/induct rules for use with corresponding Isar
  6159     methods (for concrete records, record schemes, concrete more
  6160     parts, and schematic more parts -- in that order);
  6161   - internal definitions directly based on a light-weight abstract
  6162     theory of product types over typedef rather than datatype;
  6163 
  6164 * HOL: generic code generator for generating executable ML code from
  6165 specifications; specific support for HOL constructs such as inductive
  6166 datatypes and sets, as well as recursive functions; can be invoked
  6167 via 'generate_code' theory section;
  6168 
  6169 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  6170 
  6171 * HOL: consolidated and renamed several theories.  In particular:
  6172         Ord.thy has been absorbed into HOL.thy
  6173         String.thy has been absorbed into List.thy
  6174 
  6175 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  6176 (beware of argument permutation!);
  6177 
  6178 * HOL: linorder_less_split superseded by linorder_cases;
  6179 
  6180 * HOL/List: "nodups" renamed to "distinct";
  6181 
  6182 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  6183 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  6184   - Ex_def has changed, now need to use some_eq_ex
  6185 
  6186 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  6187 in this (rare) case use:
  6188 
  6189   delSWrapper "split_all_tac"
  6190   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  6191 
  6192 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  6193 MAY FAIL;
  6194 
  6195 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  6196 Isabelle's type classes, ^ on functions and relations has too general
  6197 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  6198 necessary to attach explicit type constraints;
  6199 
  6200 * HOL/Relation: the prefix name of the infix "O" has been changed from
  6201 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  6202 renamed accordingly (eg "compI" -> "rel_compI").
  6203 
  6204 * HOL: syntax translations now work properly with numerals and records
  6205 expressions;
  6206 
  6207 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  6208 of "lam" -- INCOMPATIBILITY;
  6209 
  6210 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  6211 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  6212 renamed "Product_Type.unit";
  6213 
  6214 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  6215 
  6216 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  6217 the "cases" method);
  6218 
  6219 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  6220 Florian Kammller);
  6221 
  6222 * HOL/IMP: updated and converted to new-style theory format; several
  6223 parts turned into readable document, with proper Isar proof texts and
  6224 some explanations (by Gerwin Klein);
  6225 
  6226 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  6227 
  6228 * HOL-Hyperreal is now a logic image;
  6229 
  6230 
  6231 *** HOLCF ***
  6232 
  6233 * Isar: consts/constdefs supports mixfix syntax for continuous
  6234 operations;
  6235 
  6236 * Isar: domain package adapted to new-style theory format, e.g. see
  6237 HOLCF/ex/Dnat.thy;
  6238 
  6239 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  6240 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  6241 lift.induct_tac, always use UU instead of Undef;
  6242 
  6243 * HOLCF/IMP: updated and converted to new-style theory;
  6244 
  6245 
  6246 *** ZF ***
  6247 
  6248 * Isar: proper integration of logic-specific tools and packages,
  6249 including theory commands '(co)inductive', '(co)datatype',
  6250 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  6251 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  6252 
  6253 * theory Main no longer includes AC; for the Axiom of Choice, base
  6254 your theory on Main_ZFC;
  6255 
  6256 * the integer library now covers quotients and remainders, with many
  6257 laws relating division to addition, multiplication, etc.;
  6258 
  6259 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  6260 typeless version of the formalism;
  6261 
  6262 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  6263 format;
  6264 
  6265 * ZF/Induct: new directory for examples of inductive definitions,
  6266 including theory Multiset for multiset orderings; converted to
  6267 new-style theory format;
  6268 
  6269 * ZF: many new theorems about lists, ordinals, etc.;
  6270 
  6271 
  6272 *** General ***
  6273 
  6274 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  6275 variable proof controls level of detail: 0 = no proofs (only oracle
  6276 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  6277 also ref manual for further ML interfaces;
  6278 
  6279 * Pure/axclass: removed obsolete ML interface
  6280 goal_subclass/goal_arity;
  6281 
  6282 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  6283 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  6284 separate tokens, so expressions involving minus need to be spaced
  6285 properly;
  6286 
  6287 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  6288 rather than "infixl" or "infixr";
  6289 
  6290 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  6291 sort constraint specifications in type inference; e.g. "x::_::foo"
  6292 ensures that the type of "x" is of sort "foo" (but not necessarily a
  6293 type variable);
  6294 
  6295 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  6296 control output of nested => (types); the default behavior is
  6297 "type_brackets";
  6298 
  6299 * Pure/syntax: builtin parse translation for "_constify" turns valued
  6300 tokens into AST constants;
  6301 
  6302 * Pure/syntax: prefer later declarations of translations and print
  6303 translation functions; potential INCOMPATIBILITY: need to reverse
  6304 multiple declarations for same syntax element constant;
  6305 
  6306 * Pure/show_hyps reset by default (in accordance to existing Isar
  6307 practice);
  6308 
  6309 * Provers/classical: renamed addaltern to addafter, addSaltern to
  6310 addSafter;
  6311 
  6312 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  6313 as well;
  6314 
  6315 * system: tested support for MacOS X; should be able to get Isabelle +
  6316 Proof General to work in a plain Terminal after installing Poly/ML
  6317 (e.g. from the Isabelle distribution area) and GNU bash alone
  6318 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  6319 support requires further installations, e.g. from
  6320 http://fink.sourceforge.net/);
  6321 
  6322 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  6323 
  6324 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  6325 of 40 MB), cf. ML_OPTIONS;
  6326 
  6327 * system: Proof General keywords specification is now part of the
  6328 Isabelle distribution (see etc/isar-keywords.el);
  6329 
  6330 * system: support for persistent Proof General sessions (refrain from
  6331 outdating all loaded theories on startup); user may create writable
  6332 logic images like this: ``isabelle -q HOL Test'';
  6333 
  6334 * system: smart selection of Isabelle process versus Isabelle
  6335 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  6336 run both "isabelle" and "Isabelle" even if file names are badly
  6337 damaged (executable inspects the case of the first letter of its own
  6338 name); added separate "isabelle-process" and "isabelle-interface";
  6339 
  6340 * system: refrain from any attempt at filtering input streams; no
  6341 longer support ``8bit'' encoding of old isabelle font, instead proper
  6342 iso-latin characters may now be used; the related isatools
  6343 "symbolinput" and "nonascii" have disappeared as well;
  6344 
  6345 * system: removed old "xterm" interface (the print modes "xterm" and
  6346 "xterm_color" are still available for direct use in a suitable
  6347 terminal);
  6348 
  6349 
  6350 
  6351 New in Isabelle99-2 (February 2001)
  6352 -----------------------------------
  6353 
  6354 *** Overview of INCOMPATIBILITIES ***
  6355 
  6356 * HOL: please note that theories in the Library and elsewhere often use the
  6357 new-style (Isar) format; to refer to their theorems in an ML script you must
  6358 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  6359 
  6360 * HOL: inductive package no longer splits induction rule aggressively,
  6361 but only as far as specified by the introductions given; the old
  6362 format may be recovered via ML function complete_split_rule or attribute
  6363 'split_rule (complete)';
  6364 
  6365 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  6366 gfp_Tarski to gfp_unfold;
  6367 
  6368 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  6369 
  6370 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  6371 relation); infix "^^" has been renamed "``"; infix "``" has been
  6372 renamed "`"; "univalent" has been renamed "single_valued";
  6373 
  6374 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  6375 operation;
  6376 
  6377 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  6378 
  6379 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  6380 
  6381 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  6382 consequence, it is no longer monotonic wrt. the local goal context
  6383 (which is now passed through the inductive cases);
  6384 
  6385 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  6386 \<gg> to \<ggreater>;
  6387 
  6388 
  6389 *** Document preparation ***
  6390 
  6391 * \isabellestyle{NAME} selects version of Isabelle output (currently
  6392 available: are "it" for near math-mode best-style output, "sl" for
  6393 slanted text style, and "tt" for plain type-writer; if no
  6394 \isabellestyle command is given, output is according to slanted
  6395 type-writer);
  6396 
  6397 * support sub/super scripts (for single symbols only), input syntax is
  6398 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  6399 
  6400 * some more standard symbols; see Appendix A of the system manual for
  6401 the complete list of symbols defined in isabellesym.sty;
  6402 
  6403 * improved isabelle style files; more abstract symbol implementation
  6404 (should now use \isamath{...} and \isatext{...} in custom symbol
  6405 definitions);
  6406 
  6407 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  6408 state; Note that presentation of goal states does not conform to
  6409 actual human-readable proof documents.  Please do not include goal
  6410 states into document output unless you really know what you are doing!
  6411 
  6412 * proper indentation of antiquoted output with proportional LaTeX
  6413 fonts;
  6414 
  6415 * no_document ML operator temporarily disables LaTeX document
  6416 generation;
  6417 
  6418 * isatool unsymbolize tunes sources for plain ASCII communication;
  6419 
  6420 
  6421 *** Isar ***
  6422 
  6423 * Pure: Isar now suffers initial goal statements to contain unbound
  6424 schematic variables (this does not conform to actual readable proof
  6425 documents, due to unpredictable outcome and non-compositional proof
  6426 checking); users who know what they are doing may use schematic goals
  6427 for Prolog-style synthesis of proven results;
  6428 
  6429 * Pure: assumption method (an implicit finishing) now handles actual
  6430 rules as well;
  6431 
  6432 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  6433 initial goal, declare "that" only as Pure intro (only for single
  6434 steps); the "that" rule assumption may now be involved in implicit
  6435 finishing, thus ".." becomes a feasible for trivial obtains;
  6436 
  6437 * Pure: default proof step now includes 'intro_classes'; thus trivial
  6438 instance proofs may be performed by "..";
  6439 
  6440 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  6441 statements as well;
  6442 
  6443 * Pure: more robust selection of calculational rules;
  6444 
  6445 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  6446 rule (as well as the assumption rule);
  6447 
  6448 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  6449 lemmas, using the graph browser tool;
  6450 
  6451 * Pure: predict failure of "show" in interactive mode;
  6452 
  6453 * Pure: 'thms_containing' now takes actual terms as arguments;
  6454 
  6455 * HOL: improved method 'induct' --- now handles non-atomic goals
  6456 (potential INCOMPATIBILITY); tuned error handling;
  6457 
  6458 * HOL: cases and induct rules now provide explicit hints about the
  6459 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  6460 any remaining facts are inserted into the goal verbatim;
  6461 
  6462 * HOL: local contexts (aka cases) may now contain term bindings as
  6463 well; the 'cases' and 'induct' methods new provide a ?case binding for
  6464 the result to be shown in each case;
  6465 
  6466 * HOL: added 'recdef_tc' command;
  6467 
  6468 * isatool convert assists in eliminating legacy ML scripts;
  6469 
  6470 
  6471 *** HOL ***
  6472 
  6473 * HOL/Library: a collection of generic theories to be used together
  6474 with main HOL; the theory loader path already includes this directory
  6475 by default; the following existing theories have been moved here:
  6476 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  6477 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  6478 
  6479 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  6480 modelling and verification task performed in Isabelle/HOL +
  6481 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  6482 
  6483 * HOL/Algebra: special summation operator SUM no longer exists, it has
  6484 been replaced by setsum; infix 'assoc' now has priority 50 (like
  6485 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  6486 'domain', this makes the theory consistent with mathematical
  6487 literature;
  6488 
  6489 * HOL basics: added overloaded operations "inverse" and "divide"
  6490 (infix "/"), syntax for generic "abs" operation, generic summation
  6491 operator \<Sum>;
  6492 
  6493 * HOL/typedef: simplified package, provide more useful rules (see also
  6494 HOL/subset.thy);
  6495 
  6496 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  6497 now expressed as a proper nested rule (old-style tactic scripts may
  6498 require atomize_strip_tac to cope with non-atomic premises);
  6499 
  6500 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  6501 to "split_conv" (old name still available for compatibility);
  6502 
  6503 * HOL: improved concrete syntax for strings (e.g. allows translation
  6504 rules with string literals);
  6505 
  6506 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  6507  and Fleuriot's mechanization of analysis, including the transcendental
  6508  functions for the reals;
  6509 
  6510 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  6511 
  6512 
  6513 *** CTT ***
  6514 
  6515 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  6516 "lam" is displayed as TWO lambda-symbols
  6517 
  6518 * CTT: theory Main now available, containing everything (that is, Bool
  6519 and Arith);
  6520 
  6521 
  6522 *** General ***
  6523 
  6524 * Pure: the Simplifier has been implemented properly as a derived rule
  6525 outside of the actual kernel (at last!); the overall performance
  6526 penalty in practical applications is about 50%, while reliability of
  6527 the Isabelle inference kernel has been greatly improved;
  6528 
  6529 * print modes "brackets" and "no_brackets" control output of nested =>
  6530 (types) and ==> (props); the default behaviour is "brackets";
  6531 
  6532 * Provers: fast_tac (and friends) now handle actual object-logic rules
  6533 as assumptions as well;
  6534 
  6535 * system: support Poly/ML 4.0;
  6536 
  6537 * system: isatool install handles KDE version 1 or 2;
  6538 
  6539 
  6540 
  6541 New in Isabelle99-1 (October 2000)
  6542 ----------------------------------
  6543 
  6544 *** Overview of INCOMPATIBILITIES ***
  6545 
  6546 * HOL: simplification of natural numbers is much changed; to partly
  6547 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  6548 issue the following ML commands:
  6549 
  6550   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  6551   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  6552 
  6553 * HOL: simplification no longer dives into case-expressions; this is
  6554 controlled by "t.weak_case_cong" for each datatype t;
  6555 
  6556 * HOL: nat_less_induct renamed to less_induct;
  6557 
  6558 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  6559 fixsome to patch .thy and .ML sources automatically;
  6560 
  6561   select_equality  -> some_equality
  6562   select_eq_Ex     -> some_eq_ex
  6563   selectI2EX       -> someI2_ex
  6564   selectI2         -> someI2
  6565   selectI          -> someI
  6566   select1_equality -> some1_equality
  6567   Eps_sym_eq       -> some_sym_eq_trivial
  6568   Eps_eq           -> some_eq_trivial
  6569 
  6570 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  6571 
  6572 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  6573 instead);
  6574 
  6575 * HOL: the recursion equations generated by 'recdef' are now called
  6576 f.simps instead of f.rules;
  6577 
  6578 * HOL: qed_spec_mp now also handles bounded ALL as well;
  6579 
  6580 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  6581 sometimes be needed;
  6582 
  6583 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  6584 
  6585 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  6586 
  6587 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  6588 product is now "<*>" instead of "Times"; the lexicographic product is
  6589 now "<*lex*>" instead of "**";
  6590 
  6591 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  6592 of main HOL, but was unused); better use HOL's datatype package;
  6593 
  6594 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  6595 the old syntax may be recovered as follows:
  6596 
  6597   syntax (symbols)
  6598     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  6599       (infixl "\\<oplus>" 100)
  6600 
  6601 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  6602 
  6603 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  6604 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  6605 internally;
  6606 
  6607 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  6608 changed from A/r to A//r;
  6609 
  6610 * ZF: new treatment of arithmetic (nat & int) may break some old
  6611 proofs;
  6612 
  6613 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  6614 rulify -> rule_format, elimify -> elim_format, ...);
  6615 
  6616 * Isar/Provers: intro/elim/dest attributes changed; renamed
  6617 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  6618 should have to change intro!! to intro? only); replaced "delrule" by
  6619 "rule del";
  6620 
  6621 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  6622 
  6623 * Provers: strengthened force_tac by using new first_best_tac;
  6624 
  6625 * LaTeX document preparation: several changes of isabelle.sty (see
  6626 lib/texinputs);
  6627 
  6628 
  6629 *** Document preparation ***
  6630 
  6631 * formal comments (text blocks etc.) in new-style theories may now
  6632 contain antiquotations of thm/prop/term/typ/text to be presented
  6633 according to latex print mode; concrete syntax is like this:
  6634 @{term[show_types] "f(x) = a + x"};
  6635 
  6636 * isatool mkdir provides easy setup of Isabelle session directories,
  6637 including proper document sources;
  6638 
  6639 * generated LaTeX sources are now deleted after successful run
  6640 (isatool document -c); may retain a copy somewhere else via -D option
  6641 of isatool usedir;
  6642 
  6643 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  6644 style files, achieving self-contained LaTeX sources and simplifying
  6645 LaTeX debugging;
  6646 
  6647 * old-style theories now produce (crude) LaTeX output as well;
  6648 
  6649 * browser info session directories are now self-contained (may be put
  6650 on WWW server seperately); improved graphs of nested sessions; removed
  6651 graph for 'all sessions';
  6652 
  6653 * several improvements in isabelle style files; \isabellestyle{it}
  6654 produces fake math mode output; \isamarkupheader is now \section by
  6655 default; see lib/texinputs/isabelle.sty etc.;
  6656 
  6657 
  6658 *** Isar ***
  6659 
  6660 * Isar/Pure: local results and corresponding term bindings are now
  6661 subject to Hindley-Milner polymorphism (similar to ML); this
  6662 accommodates incremental type-inference very nicely;
  6663 
  6664 * Isar/Pure: new derived language element 'obtain' supports
  6665 generalized existence reasoning;
  6666 
  6667 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  6668 support accumulation of results, without applying any rules yet;
  6669 useful to collect intermediate results without explicit name
  6670 references, and for use with transitivity rules with more than 2
  6671 premises;
  6672 
  6673 * Isar/Pure: scalable support for case-analysis type proofs: new
  6674 'case' language element refers to local contexts symbolically, as
  6675 produced by certain proof methods; internally, case names are attached
  6676 to theorems as "tags";
  6677 
  6678 * Isar/Pure: theory command 'hide' removes declarations from
  6679 class/type/const name spaces;
  6680 
  6681 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  6682 indicate potential overloading;
  6683 
  6684 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  6685 
  6686 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  6687 "{a,b,c}" instead of {a,b,c};
  6688 
  6689 * Isar/Pure now provides its own version of intro/elim/dest
  6690 attributes; useful for building new logics, but beware of confusion
  6691 with the version in Provers/classical;
  6692 
  6693 * Isar/Pure: the local context of (non-atomic) goals is provided via
  6694 case name 'antecedent';
  6695 
  6696 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  6697 to the current context is now done automatically);
  6698 
  6699 * Isar/Pure: theory command 'method_setup' provides a simple interface
  6700 for definining proof methods in ML;
  6701 
  6702 * Isar/Provers: intro/elim/dest attributes changed; renamed
  6703 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  6704 most cases, one should have to change intro!! to intro? only);
  6705 replaced "delrule" by "rule del";
  6706 
  6707 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  6708 'symmetric' attribute (the latter supercedes [RS sym]);
  6709 
  6710 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  6711 method modifier); 'simp' method: 'only:' modifier removes loopers as
  6712 well (including splits);
  6713 
  6714 * Isar/Provers: Simplifier and Classical methods now support all kind
  6715 of modifiers used in the past, including 'cong', 'iff', etc.
  6716 
  6717 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  6718 of Simplifier and Classical reasoner);
  6719 
  6720 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  6721 now support named cases; major packages (inductive, datatype, primrec,
  6722 recdef) support case names and properly name parameters;
  6723 
  6724 * Isar/HOL: new transitivity rules for substitution in inequalities --
  6725 monotonicity conditions are extracted to be proven at end of
  6726 calculations;
  6727 
  6728 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  6729 method anyway;
  6730 
  6731 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  6732 split_if split_if_asm; datatype package provides theorems foo.splits =
  6733 foo.split foo.split_asm for each datatype;
  6734 
  6735 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  6736 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  6737 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  6738 use "(cases (simplified))" method in proper proof texts);
  6739 
  6740 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  6741 
  6742 * Isar: names of theorems etc. may be natural numbers as well;
  6743 
  6744 * Isar: 'pr' command: optional arguments for goals_limit and
  6745 ProofContext.prems_limit; no longer prints theory contexts, but only
  6746 proof states;
  6747 
  6748 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  6749 additional print modes to be specified; e.g. "pr(latex)" will print
  6750 proof state according to the Isabelle LaTeX style;
  6751 
  6752 * Isar: improved support for emulating tactic scripts, including proof
  6753 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  6754 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  6755 (for HOL datatypes);
  6756 
  6757 * Isar: simplified (more robust) goal selection of proof methods: 1st
  6758 goal, all goals, or explicit goal specifier (tactic emulation); thus
  6759 'proof method scripts' have to be in depth-first order;
  6760 
  6761 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  6762 
  6763 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  6764 should instead use individual commands for printing items
  6765 (print_commands, print_methods etc.);
  6766 
  6767 * Isar: added 'nothing' --- the empty list of theorems;
  6768 
  6769 
  6770 *** HOL ***
  6771 
  6772 * HOL/MicroJava: formalization of a fragment of Java, together with a
  6773 corresponding virtual machine and a specification of its bytecode
  6774 verifier and a lightweight bytecode verifier, including proofs of
  6775 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  6776 Cornelia Pusch (see also the homepage of project Bali at
  6777 http://isabelle.in.tum.de/Bali/);
  6778 
  6779 * HOL/Algebra: new theory of rings and univariate polynomials, by
  6780 Clemens Ballarin;
  6781 
  6782 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  6783 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  6784 Rasmussen;
  6785 
  6786 * HOL/Lattice: fundamental concepts of lattice theory and order
  6787 structures, including duals, properties of bounds versus algebraic
  6788 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  6789 Theorem for complete lattices etc.; may also serve as a demonstration
  6790 for abstract algebraic reasoning using axiomatic type classes, and
  6791 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  6792 
  6793 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  6794 von Oheimb;
  6795 
  6796 * HOL/IMPP: extension of IMP with local variables and mutually
  6797 recursive procedures, by David von Oheimb;
  6798 
  6799 * HOL/Lambda: converted into new-style theory and document;
  6800 
  6801 * HOL/ex/Multiquote: example of multiple nested quotations and
  6802 anti-quotations -- basically a generalized version of de-Bruijn
  6803 representation; very useful in avoiding lifting of operations;
  6804 
  6805 * HOL/record: added general record equality rule to simpset; fixed
  6806 select-update simplification procedure to handle extended records as
  6807 well; admit "r" as field name;
  6808 
  6809 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  6810 other numeric types and also as the identity of groups, rings, etc.;
  6811 
  6812 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  6813 Types nat and int belong to this axclass;
  6814 
  6815 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  6816    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  6817    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  6818   two terms #m*u and #n*u are replaced by #(m+n)*u
  6819     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  6820   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  6821     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  6822 
  6823 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  6824 powerful prover for predicate logic but knows nothing of clasets; see
  6825 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  6826 
  6827 * HOL: new version of "case_tac" subsumes both boolean case split and
  6828 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  6829 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  6830 
  6831 * HOL: simplification no longer dives into case-expressions: only the
  6832 selector expression is simplified, but not the remaining arms; to
  6833 enable full simplification of case-expressions for datatype t, you may
  6834 remove t.weak_case_cong from the simpset, either globally (Delcongs
  6835 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  6836 
  6837 * HOL/recdef: the recursion equations generated by 'recdef' for
  6838 function 'f' are now called f.simps instead of f.rules; if all
  6839 termination conditions are proved automatically, these simplification
  6840 rules are added to the simpset, as in primrec; rules may be named
  6841 individually as well, resulting in a separate list of theorems for
  6842 each equation;
  6843 
  6844 * HOL/While is a new theory that provides a while-combinator. It
  6845 permits the definition of tail-recursive functions without the
  6846 provision of a termination measure. The latter is necessary once the
  6847 invariant proof rule for while is applied.
  6848 
  6849 * HOL: new (overloaded) notation for the set of elements below/above
  6850 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  6851 
  6852 * HOL: theorems impI, allI, ballI bound as "strip";
  6853 
  6854 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  6855 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  6856 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  6857 
  6858 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  6859 
  6860 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  6861 main HOL, but was unused);
  6862 
  6863 * HOL: fewer consts declared as global (e.g. have to refer to
  6864 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  6865 
  6866 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  6867 in case of overlap with user translations (e.g. judgements over
  6868 tuples); (note that the underlying logical represenation is still
  6869 bogus);
  6870 
  6871 
  6872 *** ZF ***
  6873 
  6874 * ZF: simplification automatically cancels common terms in arithmetic
  6875 expressions over nat and int;
  6876 
  6877 * ZF: new treatment of nat to minimize type-checking: all operators
  6878 coerce their operands to a natural number using the function natify,
  6879 making the algebraic laws unconditional;
  6880 
  6881 * ZF: as above, for int: operators coerce their operands to an integer
  6882 using the function intify;
  6883 
  6884 * ZF: the integer library now contains many of the usual laws for the
  6885 orderings, including $<=, and monotonicity laws for $+ and $*;
  6886 
  6887 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  6888 simplification;
  6889 
  6890 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  6891 to the simplifier and classical reasoner simultaneously;
  6892 
  6893 
  6894 *** General ***
  6895 
  6896 * Provers: blast_tac now handles actual object-logic rules as
  6897 assumptions; note that auto_tac uses blast_tac internally as well;
  6898 
  6899 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  6900 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  6901 
  6902 * Provers: delrules now handles destruct rules as well (no longer need
  6903 explicit make_elim);
  6904 
  6905 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  6906   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  6907 use instead the strong form,
  6908   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  6909 in HOL, FOL and ZF the function cla_make_elim will create such rules
  6910 from destruct-rules;
  6911 
  6912 * Provers: Simplifier.easy_setup provides a fast path to basic
  6913 Simplifier setup for new object-logics;
  6914 
  6915 * Pure: AST translation rules no longer require constant head on LHS;
  6916 
  6917 * Pure: improved name spaces: ambiguous output is qualified; support
  6918 for hiding of names;
  6919 
  6920 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  6921 XSYMBOL_HOME; no longer need to do manual configuration in most
  6922 situations;
  6923 
  6924 * system: compression of ML heaps images may now be controlled via -c
  6925 option of isabelle and isatool usedir (currently only observed by
  6926 Poly/ML);
  6927 
  6928 * system: isatool installfonts may handle X-Symbol fonts as well (very
  6929 useful for remote X11);
  6930 
  6931 * system: provide TAGS file for Isabelle sources;
  6932 
  6933 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  6934 order;
  6935 
  6936 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  6937 timing flag supersedes proof_timing and Toplevel.trace;
  6938 
  6939 * ML: new combinators |>> and |>>> for incremental transformations
  6940 with secondary results (e.g. certain theory extensions):
  6941 
  6942 * ML: PureThy.add_defs gets additional argument to indicate potential
  6943 overloading (usually false);
  6944 
  6945 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  6946 results;
  6947 
  6948 
  6949 
  6950 New in Isabelle99 (October 1999)
  6951 --------------------------------
  6952 
  6953 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  6954 
  6955 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  6956 are no longer simplified.  (This allows the simplifier to unfold recursive
  6957 functional programs.)  To restore the old behaviour, declare
  6958 
  6959     Delcongs [if_weak_cong];
  6960 
  6961 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  6962 complement;
  6963 
  6964 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  6965 
  6966 * HOL/datatype: mutual_induct_tac no longer exists --
  6967   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  6968 
  6969 * HOL/typedef: fixed type inference for representing set; type
  6970 arguments now have to occur explicitly on the rhs as type constraints;
  6971 
  6972 * ZF: The con_defs part of an inductive definition may no longer refer
  6973 to constants declared in the same theory;
  6974 
  6975 * HOL, ZF: the function mk_cases, generated by the inductive
  6976 definition package, has lost an argument.  To simplify its result, it
  6977 uses the default simpset instead of a supplied list of theorems.
  6978 
  6979 * HOL/List: the constructors of type list are now Nil and Cons;
  6980 
  6981 * Simplifier: the type of the infix ML functions
  6982         setSSolver addSSolver setSolver addSolver
  6983 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  6984 for packaging solvers. A solver is created via
  6985         mk_solver: string -> (thm list -> int -> tactic) -> solver
  6986 where the string argument is only a comment.
  6987 
  6988 
  6989 *** Proof tools ***
  6990 
  6991 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  6992 decision procedure for linear arithmetic. Currently it is used for
  6993 types `nat', `int', and `real' in HOL (see below); it can, should and
  6994 will be instantiated for other types and logics as well.
  6995 
  6996 * The simplifier now accepts rewrite rules with flexible heads, eg
  6997      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  6998   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  6999   matching.
  7000 
  7001 
  7002 *** General ***
  7003 
  7004 * New Isabelle/Isar subsystem provides an alternative to traditional
  7005 tactical theorem proving; together with the ProofGeneral/isar user
  7006 interface it offers an interactive environment for developing human
  7007 readable proof documents (Isar == Intelligible semi-automated
  7008 reasoning); for further information see isatool doc isar-ref,
  7009 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  7010 
  7011 * improved and simplified presentation of theories: better HTML markup
  7012 (including colors), graph views in several sizes; isatool usedir now
  7013 provides a proper interface for user theories (via -P option); actual
  7014 document preparation based on (PDF)LaTeX is available as well (for
  7015 new-style theories only); see isatool doc system for more information;
  7016 
  7017 * native support for Proof General, both for classic Isabelle and
  7018 Isabelle/Isar;
  7019 
  7020 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  7021 using the graph browser tool;
  7022 
  7023 * Isabelle manuals now also available as PDF;
  7024 
  7025 * theory loader rewritten from scratch (may not be fully
  7026 bug-compatible); old loadpath variable has been replaced by show_path,
  7027 add_path, del_path, reset_path functions; new operations such as
  7028 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  7029 isatool doc ref);
  7030 
  7031 * improved isatool install: option -k creates KDE application icon,
  7032 option -p DIR installs standalone binaries;
  7033 
  7034 * added ML_PLATFORM setting (useful for cross-platform installations);
  7035 more robust handling of platform specific ML images for SML/NJ;
  7036 
  7037 * the settings environment is now statically scoped, i.e. it is never
  7038 created again in sub-processes invoked from isabelle, isatool, or
  7039 Isabelle;
  7040 
  7041 * path element specification '~~' refers to '$ISABELLE_HOME';
  7042 
  7043 * in locales, the "assumes" and "defines" parts may be omitted if
  7044 empty;
  7045 
  7046 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  7047 long arrows);
  7048 
  7049 * new print_mode "HTML";
  7050 
  7051 * new flag show_tags controls display of tags of theorems (which are
  7052 basically just comments that may be attached by some tools);
  7053 
  7054 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  7055 mode and goal output format:
  7056 
  7057 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  7058 244c244
  7059 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  7060 ---
  7061 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  7062 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  7063 181c181
  7064 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  7065 ---
  7066 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  7067 
  7068 * function bind_thms stores lists of theorems (cf. bind_thm);
  7069 
  7070 * new shorthand tactics ftac, eatac, datac, fatac;
  7071 
  7072 * qed (and friends) now accept "" as result name; in that case the
  7073 theorem is not stored, but proper checks and presentation of the
  7074 result still apply;
  7075 
  7076 * theorem database now also indexes constants "Trueprop", "all",
  7077 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  7078 
  7079 
  7080 *** HOL ***
  7081 
  7082 ** HOL arithmetic **
  7083 
  7084 * There are now decision procedures for linear arithmetic over nat and
  7085 int:
  7086 
  7087 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  7088 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  7089 are treated as atomic; subformulae not involving type `nat' or `int'
  7090 are ignored; quantified subformulae are ignored unless they are
  7091 positive universal or negative existential. The tactic has to be
  7092 invoked by hand and can be a little bit slow. In particular, the
  7093 running time is exponential in the number of occurrences of `min' and
  7094 `max', and `-' on `nat'.
  7095 
  7096 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  7097 (negated) (in)equalities among the premises and the conclusion into
  7098 account (i.e. no compound formulae) and does not know about `min' and
  7099 `max', and `-' on `nat'. It is fast and is used automatically by the
  7100 simplifier.
  7101 
  7102 NB: At the moment, these decision procedures do not cope with mixed
  7103 nat/int formulae where the two parts interact, such as `m < n ==>
  7104 int(m) < int(n)'.
  7105 
  7106 * HOL/Numeral provides a generic theory of numerals (encoded
  7107 efficiently as bit strings); setup for types nat/int/real is in place;
  7108 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  7109 int, existing theories and proof scripts may require a few additional
  7110 type constraints;
  7111 
  7112 * integer division and remainder can now be performed on constant
  7113 arguments;
  7114 
  7115 * many properties of integer multiplication, division and remainder
  7116 are now available;
  7117 
  7118 * An interface to the Stanford Validity Checker (SVC) is available through the
  7119 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  7120 are proved automatically.  SVC must be installed separately, and its results
  7121 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  7122 invocation of the underlying oracle).  For SVC see
  7123   http://verify.stanford.edu/SVC
  7124 
  7125 * IsaMakefile: the HOL-Real target now builds an actual image;
  7126 
  7127 
  7128 ** HOL misc **
  7129 
  7130 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  7131 (in Isabelle/Isar) -- by Gertrud Bauer;
  7132 
  7133 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  7134 analysis for assembly languages with subtypes;
  7135 
  7136 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  7137 -- avoids syntactic ambiguities and treats state, transition, and
  7138 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  7139 changed syntax and (many) tactics;
  7140 
  7141 * HOL/inductive: Now also handles more general introduction rules such
  7142   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  7143   theorems are now maintained within the theory (maintained via the
  7144   "mono" attribute);
  7145 
  7146 * HOL/datatype: Now also handles arbitrarily branching datatypes
  7147   (using function types) such as
  7148 
  7149   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  7150 
  7151 * HOL/record: record_simproc (part of the default simpset) takes care
  7152 of selectors applied to updated records; record_split_tac is no longer
  7153 part of the default claset; update_defs may now be removed from the
  7154 simpset in many cases; COMPATIBILITY: old behavior achieved by
  7155 
  7156   claset_ref () := claset() addSWrapper record_split_wrapper;
  7157   Delsimprocs [record_simproc]
  7158 
  7159 * HOL/typedef: fixed type inference for representing set; type
  7160 arguments now have to occur explicitly on the rhs as type constraints;
  7161 
  7162 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  7163 names rather than an ML expression;
  7164 
  7165 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  7166 supplied later.  Program schemes can be defined, such as
  7167     "While B C s = (if B s then While B C (C s) else s)"
  7168 where the well-founded relation can be chosen after B and C have been given.
  7169 
  7170 * HOL/List: the constructors of type list are now Nil and Cons;
  7171 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  7172 course, ML tools referring to List.list.op # etc. have to be adapted;
  7173 
  7174 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  7175 disabled by default; run isabelle with option -m HOL to get back to
  7176 the original Gordon/HOL-style output;
  7177 
  7178 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  7179 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  7180 
  7181 * HOL basic syntax simplified (more orthogonal): all variants of
  7182 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  7183 Eps operator is provided as well: "SOME x. P[x]";
  7184 
  7185 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  7186 
  7187 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  7188 thus available for user theories;
  7189 
  7190 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  7191 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  7192 time;
  7193 
  7194 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  7195 several times and then mp;
  7196 
  7197 
  7198 *** LK ***
  7199 
  7200 * the notation <<...>> is now available as a notation for sequences of
  7201 formulas;
  7202 
  7203 * the simplifier is now installed
  7204 
  7205 * the axiom system has been generalized (thanks to Soren Heilmann)
  7206 
  7207 * the classical reasoner now has a default rule database
  7208 
  7209 
  7210 *** ZF ***
  7211 
  7212 * new primrec section allows primitive recursive functions to be given
  7213 directly (as in HOL) over datatypes and the natural numbers;
  7214 
  7215 * new tactics induct_tac and exhaust_tac for induction (or case
  7216 analysis) over datatypes and the natural numbers;
  7217 
  7218 * the datatype declaration of type T now defines the recursor T_rec;
  7219 
  7220 * simplification automatically does freeness reasoning for datatype
  7221 constructors;
  7222 
  7223 * automatic type-inference, with AddTCs command to insert new
  7224 type-checking rules;
  7225 
  7226 * datatype introduction rules are now added as Safe Introduction rules
  7227 to the claset;
  7228 
  7229 * the syntax "if P then x else y" is now available in addition to
  7230 if(P,x,y);
  7231 
  7232 
  7233 *** Internal programming interfaces ***
  7234 
  7235 * tuned simplifier trace output; new flag debug_simp;
  7236 
  7237 * structures Vartab / Termtab (instances of TableFun) offer efficient
  7238 tables indexed by indexname_ord / term_ord (compatible with aconv);
  7239 
  7240 * AxClass.axclass_tac lost the theory argument;
  7241 
  7242 * tuned current_goals_markers semantics: begin / end goal avoids
  7243 printing empty lines;
  7244 
  7245 * removed prs and prs_fn hook, which was broken because it did not
  7246 include \n in its semantics, forcing writeln to add one
  7247 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  7248 string -> unit if you really want to output text without newline;
  7249 
  7250 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  7251 plain output, interface builders may have to enable 'isabelle_font'
  7252 mode to get Isabelle font glyphs as before;
  7253 
  7254 * refined token_translation interface; INCOMPATIBILITY: output length
  7255 now of type real instead of int;
  7256 
  7257 * theory loader actions may be traced via new ThyInfo.add_hook
  7258 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  7259 your own database of information attached to *whole* theories -- as
  7260 opposed to intra-theory data slots offered via TheoryDataFun;
  7261 
  7262 * proper handling of dangling sort hypotheses (at last!);
  7263 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  7264 extra sort hypotheses that can be witnessed from the type signature;
  7265 the force_strip_shyps flag is gone, any remaining shyps are simply
  7266 left in the theorem (with a warning issued by strip_shyps_warning);
  7267 
  7268 
  7269 
  7270 New in Isabelle98-1 (October 1998)
  7271 ----------------------------------
  7272 
  7273 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  7274 
  7275 * several changes of automated proof tools;
  7276 
  7277 * HOL: major changes to the inductive and datatype packages, including
  7278 some minor incompatibilities of theory syntax;
  7279 
  7280 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  7281 called `inj_on';
  7282 
  7283 * HOL: removed duplicate thms in Arith:
  7284   less_imp_add_less  should be replaced by  trans_less_add1
  7285   le_imp_add_le      should be replaced by  trans_le_add1
  7286 
  7287 * HOL: unary minus is now overloaded (new type constraints may be
  7288 required);
  7289 
  7290 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  7291 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  7292 now taken as an integer constant.
  7293 
  7294 * Pure: ML function 'theory_of' renamed to 'theory';
  7295 
  7296 
  7297 *** Proof tools ***
  7298 
  7299 * Simplifier:
  7300   1. Asm_full_simp_tac is now more aggressive.
  7301      1. It will sometimes reorient premises if that increases their power to
  7302         simplify.
  7303      2. It does no longer proceed strictly from left to right but may also
  7304         rotate premises to achieve further simplification.
  7305      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  7306      old Asm_full_simp_tac in that it does not rotate premises.
  7307   2. The simplifier now knows a little bit about nat-arithmetic.
  7308 
  7309 * Classical reasoner: wrapper mechanism for the classical reasoner now
  7310 allows for selected deletion of wrappers, by introduction of names for
  7311 wrapper functionals.  This implies that addbefore, addSbefore,
  7312 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  7313 and that adding two tactics with the same name overwrites the first
  7314 one (emitting a warning).
  7315   type wrapper = (int -> tactic) -> (int -> tactic)
  7316   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  7317   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  7318   delWrapper, delSWrapper: claset *  string            -> claset
  7319   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  7320 
  7321 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  7322 semantics; addbefore now affects only the unsafe part of step_tac
  7323 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  7324 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  7325 by Force_tac;
  7326 
  7327 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  7328 compWrapper; added safe wrapper (and access functions for it);
  7329 
  7330 * HOL/split_all_tac is now much faster and fails if there is nothing
  7331 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  7332 and the names of the automatically generated variables have changed.
  7333 split_all_tac has moved within claset() from unsafe wrappers to safe
  7334 wrappers, which means that !!-bound variables are split much more
  7335 aggressively, and safe_tac and clarify_tac now split such variables.
  7336 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  7337 Note: the same holds for record_split_tac, which does the job of
  7338 split_all_tac for record fields.
  7339 
  7340 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  7341 permanently to the default simpset using Addsplits just like
  7342 Addsimps. They can be removed via Delsplits just like
  7343 Delsimps. Lower-case versions are also available.
  7344 
  7345 * HOL/Simplifier: The rule split_if is now part of the default
  7346 simpset. This means that the simplifier will eliminate all occurrences
  7347 of if-then-else in the conclusion of a goal. To prevent this, you can
  7348 either remove split_if completely from the default simpset by
  7349 `Delsplits [split_if]' or remove it in a specific call of the
  7350 simplifier using `... delsplits [split_if]'.  You can also add/delete
  7351 other case splitting rules to/from the default simpset: every datatype
  7352 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  7353 t is the name of the datatype).
  7354 
  7355 * Classical reasoner / Simplifier combination: new force_tac (and
  7356 derivatives Force_tac, force) combines rewriting and classical
  7357 reasoning (and whatever other tools) similarly to auto_tac, but is
  7358 aimed to solve the given subgoal completely.
  7359 
  7360 
  7361 *** General ***
  7362 
  7363 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  7364 and `goalw': the theory is no longer needed as an explicit argument -
  7365 the current theory context is used; assumptions are no longer returned
  7366 at the ML-level unless one of them starts with ==> or !!; it is
  7367 recommended to convert to these new commands using isatool fixgoal
  7368 (backup your sources first!);
  7369 
  7370 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  7371 the current theory context, and 'theory' to lookup stored theories;
  7372 
  7373 * new theory section 'locale' for declaring constants, assumptions and
  7374 definitions that have local scope;
  7375 
  7376 * new theory section 'nonterminals' for purely syntactic types;
  7377 
  7378 * new theory section 'setup' for generic ML setup functions
  7379 (e.g. package initialization);
  7380 
  7381 * the distribution now includes Isabelle icons: see
  7382 lib/logo/isabelle-{small,tiny}.xpm;
  7383 
  7384 * isatool install - install binaries with absolute references to
  7385 ISABELLE_HOME/bin;
  7386 
  7387 * isatool logo -- create instances of the Isabelle logo (as EPS);
  7388 
  7389 * print mode 'emacs' reserved for Isamode;
  7390 
  7391 * support multiple print (ast) translations per constant name;
  7392 
  7393 * theorems involving oracles are now printed with a suffixed [!];
  7394 
  7395 
  7396 *** HOL ***
  7397 
  7398 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  7399 
  7400 * HOL/inductive package reorganized and improved: now supports mutual
  7401 definitions such as
  7402 
  7403   inductive EVEN ODD
  7404     intrs
  7405       null "0 : EVEN"
  7406       oddI "n : EVEN ==> Suc n : ODD"
  7407       evenI "n : ODD ==> Suc n : EVEN"
  7408 
  7409 new theorem list "elims" contains an elimination rule for each of the
  7410 recursive sets; inductive definitions now handle disjunctive premises
  7411 correctly (also ZF);
  7412 
  7413 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  7414 "mutual_induct" no longer exists - the induction rule is always
  7415 contained in "induct";
  7416 
  7417 
  7418 * HOL/datatype package re-implemented and greatly improved: now
  7419 supports mutually recursive datatypes such as
  7420 
  7421   datatype
  7422     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  7423             | SUM ('a aexp) ('a aexp)
  7424             | DIFF ('a aexp) ('a aexp)
  7425             | NUM 'a
  7426   and
  7427     'a bexp = LESS ('a aexp) ('a aexp)
  7428             | AND ('a bexp) ('a bexp)
  7429             | OR ('a bexp) ('a bexp)
  7430 
  7431 as well as indirectly recursive datatypes such as
  7432 
  7433   datatype
  7434     ('a, 'b) term = Var 'a
  7435                   | App 'b ((('a, 'b) term) list)
  7436 
  7437 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  7438 induction on mutually / indirectly recursive datatypes.
  7439 
  7440 Primrec equations are now stored in theory and can be accessed via
  7441 <function_name>.simps.
  7442 
  7443 INCOMPATIBILITIES:
  7444 
  7445   - Theories using datatypes must now have theory Datatype as an
  7446     ancestor.
  7447   - The specific <typename>.induct_tac no longer exists - use the
  7448     generic induct_tac instead.
  7449   - natE has been renamed to nat.exhaust - use exhaust_tac
  7450     instead of res_inst_tac ... natE. Note that the variable
  7451     names in nat.exhaust differ from the names in natE, this
  7452     may cause some "fragile" proofs to fail.
  7453   - The theorems split_<typename>_case and split_<typename>_case_asm
  7454     have been renamed to <typename>.split and <typename>.split_asm.
  7455   - Since default sorts of type variables are now handled correctly,
  7456     some datatype definitions may have to be annotated with explicit
  7457     sort constraints.
  7458   - Primrec definitions no longer require function name and type
  7459     of recursive argument.
  7460 
  7461 Consider using isatool fixdatatype to adapt your theories and proof
  7462 scripts to the new package (backup your sources first!).
  7463 
  7464 
  7465 * HOL/record package: considerably improved implementation; now
  7466 includes concrete syntax for record types, terms, updates; theorems
  7467 for surjective pairing and splitting !!-bound record variables; proof
  7468 support is as follows:
  7469 
  7470   1) standard conversions (selectors or updates applied to record
  7471 constructor terms) are part of the standard simpset;
  7472 
  7473   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  7474 made part of standard simpset and claset via addIffs;
  7475 
  7476   3) a tactic for record field splitting (record_split_tac) is part of
  7477 the standard claset (addSWrapper);
  7478 
  7479 To get a better idea about these rules you may retrieve them via
  7480 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  7481 the name of your record type.
  7482 
  7483 The split tactic 3) conceptually simplifies by the following rule:
  7484 
  7485   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  7486 
  7487 Thus any record variable that is bound by meta-all will automatically
  7488 blow up into some record constructor term, consequently the
  7489 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  7490 solve record problems automatically.
  7491 
  7492 
  7493 * reorganized the main HOL image: HOL/Integ and String loaded by
  7494 default; theory Main includes everything;
  7495 
  7496 * automatic simplification of integer sums and comparisons, using cancellation;
  7497 
  7498 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  7499 
  7500 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  7501 
  7502 * many new identities for unions, intersections, set difference, etc.;
  7503 
  7504 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  7505 called split_if, split_split, split_sum_case and split_nat_case (to go
  7506 with add/delsplits);
  7507 
  7508 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  7509 (?x::unit) = (); this is made part of the default simpset, which COULD
  7510 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  7511 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  7512 unit_abs_eta_conv is added in order to counter the effect of
  7513 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  7514 %u.f();
  7515 
  7516 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  7517 makes more sense);
  7518 
  7519 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  7520   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  7521   disjointness reasoning but breaking a few old proofs.
  7522 
  7523 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  7524 to 'converse' from 'inverse' (for compatibility with ZF and some
  7525 literature);
  7526 
  7527 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  7528 the well-founded relation;
  7529 
  7530 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  7531     Compl A.  The "Compl" syntax remains available as input syntax for this
  7532     release ONLY.
  7533 
  7534 * HOL/Update: new theory of function updates:
  7535     f(a:=b) == %x. if x=a then b else f x
  7536 may also be iterated as in f(a:=b,c:=d,...);
  7537 
  7538 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  7539 
  7540 * HOL/List:
  7541   - new function list_update written xs[i:=v] that updates the i-th
  7542     list position. May also be iterated as in xs[i:=a,j:=b,...].
  7543   - new function `upt' written [i..j(] which generates the list
  7544     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  7545     bound write [i..j], which is a shorthand for [i..j+1(].
  7546   - new lexicographic orderings and corresponding wellfoundedness theorems.
  7547 
  7548 * HOL/Arith:
  7549   - removed 'pred' (predecessor) function;
  7550   - generalized some theorems about n-1;
  7551   - many new laws about "div" and "mod";
  7552   - new laws about greatest common divisors (see theory ex/Primes);
  7553 
  7554 * HOL/Relation: renamed the relational operator r^-1 "converse"
  7555 instead of "inverse";
  7556 
  7557 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  7558   of the multiset ordering;
  7559 
  7560 * directory HOL/Real: a construction of the reals using Dedekind cuts
  7561   (not included by default);
  7562 
  7563 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  7564 
  7565 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  7566   programs, i.e. different program variables may have different types.
  7567 
  7568 * calling (stac rew i) now fails if "rew" has no effect on the goal
  7569   [previously, this check worked only if the rewrite rule was unconditional]
  7570   Now rew can involve either definitions or equalities (either == or =).
  7571 
  7572 
  7573 *** ZF ***
  7574 
  7575 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  7576   only the theorems proved on ZF.ML;
  7577 
  7578 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  7579   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  7580   disjointness reasoning but breaking a few old proofs.
  7581 
  7582 * ZF/Update: new theory of function updates
  7583     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  7584   may also be iterated as in f(a:=b,c:=d,...);
  7585 
  7586 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  7587 
  7588 * calling (stac rew i) now fails if "rew" has no effect on the goal
  7589   [previously, this check worked only if the rewrite rule was unconditional]
  7590   Now rew can involve either definitions or equalities (either == or =).
  7591 
  7592 * case_tac provided for compatibility with HOL
  7593     (like the old excluded_middle_tac, but with subgoals swapped)
  7594 
  7595 
  7596 *** Internal programming interfaces ***
  7597 
  7598 * Pure: several new basic modules made available for general use, see
  7599 also src/Pure/README;
  7600 
  7601 * improved the theory data mechanism to support encapsulation (data
  7602 kind name replaced by private Object.kind, acting as authorization
  7603 key); new type-safe user interface via functor TheoryDataFun; generic
  7604 print_data function becomes basically useless;
  7605 
  7606 * removed global_names compatibility flag -- all theory declarations
  7607 are qualified by default;
  7608 
  7609 * module Pure/Syntax now offers quote / antiquote translation
  7610 functions (useful for Hoare logic etc. with implicit dependencies);
  7611 see HOL/ex/Antiquote for an example use;
  7612 
  7613 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  7614 cterm -> thm;
  7615 
  7616 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  7617 subgoal;
  7618 
  7619 * Display.print_goals function moved to Locale.print_goals;
  7620 
  7621 * standard print function for goals supports current_goals_markers
  7622 variable for marking begin of proof, end of proof, start of goal; the
  7623 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  7624 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  7625 for example;
  7626 
  7627 
  7628 
  7629 New in Isabelle98 (January 1998)
  7630 --------------------------------
  7631 
  7632 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  7633 
  7634 * changed lexical syntax of terms / types: dots made part of long
  7635 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  7636 
  7637 * simpset (and claset) reference variable replaced by functions
  7638 simpset / simpset_ref;
  7639 
  7640 * no longer supports theory aliases (via merge) and non-trivial
  7641 implicit merge of thms' signatures;
  7642 
  7643 * most internal names of constants changed due to qualified names;
  7644 
  7645 * changed Pure/Sequence interface (see Pure/seq.ML);
  7646 
  7647 
  7648 *** General Changes ***
  7649 
  7650 * hierachically structured name spaces (for consts, types, axms, thms
  7651 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  7652 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  7653 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  7654 long_names for fully qualified output names; NOTE: ML programs
  7655 (special tactics, packages etc.) referring to internal names may have
  7656 to be adapted to cope with fully qualified names; in case of severe
  7657 backward campatibility problems try setting 'global_names' at compile
  7658 time to have enrything declared within a flat name space; one may also
  7659 fine tune name declarations in theories via the 'global' and 'local'
  7660 section;
  7661 
  7662 * reimplemented the implicit simpset and claset using the new anytype
  7663 data filed in signatures; references simpset:simpset ref etc. are
  7664 replaced by functions simpset:unit->simpset and
  7665 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  7666 to patch your ML files accordingly;
  7667 
  7668 * HTML output now includes theory graph data for display with Java
  7669 applet or isatool browser; data generated automatically via isatool
  7670 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  7671 
  7672 * defs may now be conditional; improved rewrite_goals_tac to handle
  7673 conditional equations;
  7674 
  7675 * defs now admits additional type arguments, using TYPE('a) syntax;
  7676 
  7677 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  7678 creates a new theory node; implicit merge of thms' signatures is
  7679 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  7680 transfer:theory->thm->thm in (rare) cases;
  7681 
  7682 * improved handling of draft signatures / theories; draft thms (and
  7683 ctyps, cterms) are automatically promoted to real ones;
  7684 
  7685 * slightly changed interfaces for oracles: admit many per theory, named
  7686 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  7687 
  7688 * print_goals: optional output of const types (set show_consts and
  7689 show_types);
  7690 
  7691 * improved output of warnings (###) and errors (***);
  7692 
  7693 * subgoal_tac displays a warning if the new subgoal has type variables;
  7694 
  7695 * removed old README and Makefiles;
  7696 
  7697 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  7698 
  7699 * removed obsolete init_pps and init_database;
  7700 
  7701 * deleted the obsolete tactical STATE, which was declared by
  7702     fun STATE tacfun st = tacfun st st;
  7703 
  7704 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  7705 (which abbreviates $HOME);
  7706 
  7707 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  7708 use isatool fixseq to adapt your ML programs (this works for fully
  7709 qualified references to the Sequence structure only!);
  7710 
  7711 * use_thy no longer requires writable current directory; it always
  7712 reloads .ML *and* .thy file, if either one is out of date;
  7713 
  7714 
  7715 *** Classical Reasoner ***
  7716 
  7717 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  7718 tactics that use classical reasoning to simplify a subgoal without
  7719 splitting it into several subgoals;
  7720 
  7721 * Safe_tac: like safe_tac but uses the default claset;
  7722 
  7723 
  7724 *** Simplifier ***
  7725 
  7726 * added simplification meta rules:
  7727     (asm_)(full_)simplify: simpset -> thm -> thm;
  7728 
  7729 * simplifier.ML no longer part of Pure -- has to be loaded by object
  7730 logics (again);
  7731 
  7732 * added prems argument to simplification procedures;
  7733 
  7734 * HOL, FOL, ZF: added infix function `addsplits':
  7735   instead of `<simpset> setloop (split_tac <thms>)'
  7736   you can simply write `<simpset> addsplits <thms>'
  7737 
  7738 
  7739 *** Syntax ***
  7740 
  7741 * TYPE('a) syntax for type reflection terms;
  7742 
  7743 * no longer handles consts with name "" -- declare as 'syntax' instead;
  7744 
  7745 * pretty printer: changed order of mixfix annotation preference (again!);
  7746 
  7747 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  7748 
  7749 
  7750 *** HOL ***
  7751 
  7752 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  7753   with `addloop' of the simplifier to faciliate case splitting in premises.
  7754 
  7755 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  7756 
  7757 * HOL/Auth: new protocol proofs including some for the Internet
  7758   protocol TLS;
  7759 
  7760 * HOL/Map: new theory of `maps' a la VDM;
  7761 
  7762 * HOL/simplifier: simplification procedures nat_cancel_sums for
  7763 cancelling out common nat summands from =, <, <= (in)equalities, or
  7764 differences; simplification procedures nat_cancel_factor for
  7765 cancelling common factor from =, <, <= (in)equalities over natural
  7766 sums; nat_cancel contains both kinds of procedures, it is installed by
  7767 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  7768 
  7769 * HOL/simplifier: terms of the form
  7770   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  7771   are rewritten to
  7772   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  7773   and those of the form
  7774   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  7775   are rewritten to
  7776   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  7777 
  7778 * HOL/datatype
  7779   Each datatype `t' now comes with a theorem `split_t_case' of the form
  7780 
  7781   P(t_case f1 ... fn x) =
  7782      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  7783         ...
  7784        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  7785      )
  7786 
  7787   and a theorem `split_t_case_asm' of the form
  7788 
  7789   P(t_case f1 ... fn x) =
  7790     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  7791         ...
  7792        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  7793      )
  7794   which can be added to a simpset via `addsplits'. The existing theorems
  7795   expand_list_case and expand_option_case have been renamed to
  7796   split_list_case and split_option_case.
  7797 
  7798 * HOL/Arithmetic:
  7799   - `pred n' is automatically converted to `n-1'.
  7800     Users are strongly encouraged not to use `pred' any longer,
  7801     because it will disappear altogether at some point.
  7802   - Users are strongly encouraged to write "0 < n" rather than
  7803     "n ~= 0". Theorems and proof tools have been modified towards this
  7804     `standard'.
  7805 
  7806 * HOL/Lists:
  7807   the function "set_of_list" has been renamed "set" (and its theorems too);
  7808   the function "nth" now takes its arguments in the reverse order and
  7809   has acquired the infix notation "!" as in "xs!n".
  7810 
  7811 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  7812 
  7813 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  7814   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  7815 
  7816 * HOL/record: extensible records with schematic structural subtyping
  7817 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  7818 still lacks various theorems and concrete record syntax;
  7819 
  7820 
  7821 *** HOLCF ***
  7822 
  7823 * removed "axioms" and "generated by" sections;
  7824 
  7825 * replaced "ops" section by extended "consts" section, which is capable of
  7826   handling the continuous function space "->" directly;
  7827 
  7828 * domain package:
  7829   . proves theorems immediately and stores them in the theory,
  7830   . creates hierachical name space,
  7831   . now uses normal mixfix annotations (instead of cinfix...),
  7832   . minor changes to some names and values (for consistency),
  7833   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  7834   . separator between mutual domain defs: changed "," to "and",
  7835   . improved handling of sort constraints;  now they have to
  7836     appear on the left-hand side of the equations only;
  7837 
  7838 * fixed LAM <x,y,zs>.b syntax;
  7839 
  7840 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  7841 adm (%x. P (t x)), where P is chainfinite and t continuous;
  7842 
  7843 
  7844 *** FOL and ZF ***
  7845 
  7846 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  7847   with `addloop' of the simplifier to faciliate case splitting in premises.
  7848 
  7849 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  7850 in HOL, they strip ALL and --> from proved theorems;
  7851 
  7852 
  7853 
  7854 New in Isabelle94-8 (May 1997)
  7855 ------------------------------
  7856 
  7857 *** General Changes ***
  7858 
  7859 * new utilities to build / run / maintain Isabelle etc. (in parts
  7860 still somewhat experimental); old Makefiles etc. still functional;
  7861 
  7862 * new 'Isabelle System Manual';
  7863 
  7864 * INSTALL text, together with ./configure and ./build scripts;
  7865 
  7866 * reimplemented type inference for greater efficiency, better error
  7867 messages and clean internal interface;
  7868 
  7869 * prlim command for dealing with lots of subgoals (an easier way of
  7870 setting goals_limit);
  7871 
  7872 
  7873 *** Syntax ***
  7874 
  7875 * supports alternative (named) syntax tables (parser and pretty
  7876 printer); internal interface is provided by add_modesyntax(_i);
  7877 
  7878 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  7879 be used in conjunction with the Isabelle symbol font; uses the
  7880 "symbols" syntax table;
  7881 
  7882 * added token_translation interface (may translate name tokens in
  7883 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  7884 the current print_mode); IMPORTANT: user print translation functions
  7885 are responsible for marking newly introduced bounds
  7886 (Syntax.mark_boundT);
  7887 
  7888 * token translations for modes "xterm" and "xterm_color" that display
  7889 names in bold, underline etc. or colors (which requires a color
  7890 version of xterm);
  7891 
  7892 * infixes may now be declared with names independent of their syntax;
  7893 
  7894 * added typed_print_translation (like print_translation, but may
  7895 access type of constant);
  7896 
  7897 
  7898 *** Classical Reasoner ***
  7899 
  7900 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  7901 some limitations.  Blast_tac...
  7902   + ignores addss, addbefore, addafter; this restriction is intrinsic
  7903   + ignores elimination rules that don't have the correct format
  7904         (the conclusion MUST be a formula variable)
  7905   + ignores types, which can make HOL proofs fail
  7906   + rules must not require higher-order unification, e.g. apply_type in ZF
  7907     [message "Function Var's argument not a bound variable" relates to this]
  7908   + its proof strategy is more general but can actually be slower
  7909 
  7910 * substitution with equality assumptions no longer permutes other
  7911 assumptions;
  7912 
  7913 * minor changes in semantics of addafter (now called addaltern); renamed
  7914 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  7915 (and access functions for it);
  7916 
  7917 * improved combination of classical reasoner and simplifier:
  7918   + functions for handling clasimpsets
  7919   + improvement of addss: now the simplifier is called _after_ the
  7920     safe steps.
  7921   + safe variant of addss called addSss: uses safe simplifications
  7922     _during_ the safe steps. It is more complete as it allows multiple
  7923     instantiations of unknowns (e.g. with slow_tac).
  7924 
  7925 *** Simplifier ***
  7926 
  7927 * added interface for simplification procedures (functions that
  7928 produce *proven* rewrite rules on the fly, depending on current
  7929 redex);
  7930 
  7931 * ordering on terms as parameter (used for ordered rewriting);
  7932 
  7933 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  7934 
  7935 * the solver is now split into a safe and an unsafe part.
  7936 This should be invisible for the normal user, except that the
  7937 functions setsolver and addsolver have been renamed to setSolver and
  7938 addSolver; added safe_asm_full_simp_tac;
  7939 
  7940 
  7941 *** HOL ***
  7942 
  7943 * a generic induction tactic `induct_tac' which works for all datatypes and
  7944 also for type `nat';
  7945 
  7946 * a generic case distinction tactic `exhaust_tac' which works for all
  7947 datatypes and also for type `nat';
  7948 
  7949 * each datatype comes with a function `size';
  7950 
  7951 * patterns in case expressions allow tuple patterns as arguments to
  7952 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  7953 
  7954 * primrec now also works with type nat;
  7955 
  7956 * recdef: a new declaration form, allows general recursive functions to be
  7957 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  7958 
  7959 * the constant for negation has been renamed from "not" to "Not" to
  7960 harmonize with FOL, ZF, LK, etc.;
  7961 
  7962 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  7963 infinite lists;
  7964 
  7965 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  7966 
  7967 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  7968 problems in commutative rings, using axiomatic type classes for + and *;
  7969 
  7970 * more examples in HOL/MiniML and HOL/Auth;
  7971 
  7972 * more default rewrite rules for quantifiers, union/intersection;
  7973 
  7974 * a new constant `arbitrary == @x.False';
  7975 
  7976 * HOLCF/IOA replaces old HOL/IOA;
  7977 
  7978 * HOLCF changes: derived all rules and arities
  7979   + axiomatic type classes instead of classes
  7980   + typedef instead of faking type definitions
  7981   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  7982   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  7983   + eliminated the types void, one, tr
  7984   + use unit lift and bool lift (with translations) instead of one and tr
  7985   + eliminated blift from Lift3.thy (use Def instead of blift)
  7986   all eliminated rules are derived as theorems --> no visible changes ;
  7987 
  7988 
  7989 *** ZF ***
  7990 
  7991 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  7992 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  7993 as ZF_cs addSIs [equalityI];
  7994 
  7995 
  7996 
  7997 New in Isabelle94-7 (November 96)
  7998 ---------------------------------
  7999 
  8000 * allowing negative levels (as offsets) in prlev and choplev;
  8001 
  8002 * super-linear speedup for large simplifications;
  8003 
  8004 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  8005 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  8006 FAIL); can suppress it using the command Delsimps (ex_simps @
  8007 all_simps); De Morgan laws are also now included, by default;
  8008 
  8009 * improved printing of ==>  :  ~:
  8010 
  8011 * new object-logic "Sequents" adds linear logic, while replacing LK
  8012 and Modal (thanks to Sara Kalvala);
  8013 
  8014 * HOL/Auth: correctness proofs for authentication protocols;
  8015 
  8016 * HOL: new auto_tac combines rewriting and classical reasoning (many
  8017 examples on HOL/Auth);
  8018 
  8019 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  8020 the rewriter and classical reasoner simultaneously;
  8021 
  8022 * function uresult no longer returns theorems in "standard" format;
  8023 regain previous version by: val uresult = standard o uresult;
  8024 
  8025 
  8026 
  8027 New in Isabelle94-6
  8028 -------------------
  8029 
  8030 * oracles -- these establish an interface between Isabelle and trusted
  8031 external reasoners, which may deliver results as theorems;
  8032 
  8033 * proof objects (in particular record all uses of oracles);
  8034 
  8035 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  8036 
  8037 * "constdefs" section in theory files;
  8038 
  8039 * "primrec" section (HOL) no longer requires names;
  8040 
  8041 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  8042 
  8043 
  8044 
  8045 New in Isabelle94-5
  8046 -------------------
  8047 
  8048 * reduced space requirements;
  8049 
  8050 * automatic HTML generation from theories;
  8051 
  8052 * theory files no longer require "..." (quotes) around most types;
  8053 
  8054 * new examples, including two proofs of the Church-Rosser theorem;
  8055 
  8056 * non-curried (1994) version of HOL is no longer distributed;
  8057 
  8058 
  8059 
  8060 New in Isabelle94-4
  8061 -------------------
  8062 
  8063 * greatly reduced space requirements;
  8064 
  8065 * theory files (.thy) no longer require \...\ escapes at line breaks;
  8066 
  8067 * searchable theorem database (see the section "Retrieving theorems" on
  8068 page 8 of the Reference Manual);
  8069 
  8070 * new examples, including Grabczewski's monumental case study of the
  8071 Axiom of Choice;
  8072 
  8073 * The previous version of HOL renamed to Old_HOL;
  8074 
  8075 * The new version of HOL (previously called CHOL) uses a curried syntax
  8076 for functions.  Application looks like f a b instead of f(a,b);
  8077 
  8078 * Mutually recursive inductive definitions finally work in HOL;
  8079 
  8080 * In ZF, pattern-matching on tuples is now available in all abstractions and
  8081 translates to the operator "split";
  8082 
  8083 
  8084 
  8085 New in Isabelle94-3
  8086 -------------------
  8087 
  8088 * new infix operator, addss, allowing the classical reasoner to
  8089 perform simplification at each step of its search.  Example:
  8090         fast_tac (cs addss ss)
  8091 
  8092 * a new logic, CHOL, the same as HOL, but with a curried syntax
  8093 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  8094 look like (a,b) instead of <a,b>;
  8095 
  8096 * PLEASE NOTE: CHOL will eventually replace HOL!
  8097 
  8098 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  8099 It translates to the operator "split".  A new theory of integers is available;
  8100 
  8101 * In ZF, integer numerals now denote two's-complement binary integers.
  8102 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  8103 
  8104 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  8105 of the Axiom of Choice;
  8106 
  8107 
  8108 
  8109 New in Isabelle94-2
  8110 -------------------
  8111 
  8112 * Significantly faster resolution;
  8113 
  8114 * the different sections in a .thy file can now be mixed and repeated
  8115 freely;
  8116 
  8117 * Database of theorems for FOL, HOL and ZF.  New
  8118 commands including qed, qed_goal and bind_thm store theorems in the database.
  8119 
  8120 * Simple database queries: return a named theorem (get_thm) or all theorems of
  8121 a given theory (thms_of), or find out what theory a theorem was proved in
  8122 (theory_of_thm);
  8123 
  8124 * Bugs fixed in the inductive definition and datatype packages;
  8125 
  8126 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  8127 and HOL_dup_cs obsolete;
  8128 
  8129 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  8130 have been removed;
  8131 
  8132 * Simpler definition of function space in ZF;
  8133 
  8134 * new results about cardinal and ordinal arithmetic in ZF;
  8135 
  8136 * 'subtype' facility in HOL for introducing new types as subsets of existing
  8137 types;
  8138 
  8139 :mode=text:wrap=hard:maxLineLen=72: