NEWS
author haftmann
Fri May 20 12:09:54 2011 +0200 (2011-05-20)
changeset 42874 f115492c7c8d
parent 42843 0e594ba0b324
child 42897 6bc8a6dcb3e0
permissions -rw-r--r--
NEWS
     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 * Name space: former unsynchronized references are now proper
    41 configuration options, with more conventional names:
    42 
    43   long_names   ~> names_long
    44   short_names  ~> names_short
    45   unique_names ~> names_unique
    46 
    47 Minor INCOMPATIBILITY, need to declare options in context like this:
    48 
    49   declare [[names_unique = false]]
    50 
    51 * Literal facts `prop` may contain dummy patterns, e.g. `_ = _`.  Note
    52 that the result needs to be unique, which means fact specifications
    53 may have to be refined after enriching a proof context.
    54 
    55 * Isabelle/Isar reference manual provides more formal references in
    56 syntax diagrams.
    57 
    58 
    59 *** HOL ***
    60 
    61 * Finite_Set.thy: more coherent development of fold_set locales:
    62 
    63     locale fun_left_comm ~> locale comp_fun_commute
    64     locale fun_left_comm_idem ~> locale comp_fun_idem
    65     
    66 Both use point-free characterisation; interpretation proofs may need adjustment.
    67 INCOMPATIBILITY.
    68 
    69 * Code generation:
    70   - theory Library/Code_Char_ord provides native ordering of characters
    71     in the target language.
    72     
    73 * Declare ext [intro] by default.  Rare INCOMPATIBILITY.
    74 
    75 * Nitpick:
    76   - Added "need" and "total_consts" options.
    77   - Reintroduced "show_skolems" option by popular demand.
    78   - Renamed attribute: nitpick_def ~> nitpick_unfold.
    79     INCOMPATIBILITY.
    80 
    81 * Sledgehammer:
    82   - sledgehammer available_provers ~> sledgehammer supported_provers
    83     INCOMPATIBILITY.
    84   - Added support for SNARK and ToFoF-E on SystemOnTPTP and for simply typed
    85     TPTP problems (TFF).
    86   - Added "type_sys", "max_mono_iters", and "max_new_mono_instances" options.
    87 
    88 * "try":
    89   - Added "simp:", "intro:", and "elim:" options.
    90 
    91 * Quickcheck:
    92   - Added "eval" option to evaluate terms for the found counterexample
    93     (currently only supported by the default (exhaustive) tester)
    94   - Added post-processing of terms to obtain readable counterexamples
    95     (currently only supported by the default (exhaustive) tester)
    96 
    97 * Function package: discontinued option "tailrec".
    98 INCOMPATIBILITY. Use partial_function instead.
    99 
   100 * HOL-Probability:
   101   - Caratheodory's extension lemma is now proved for ring_of_sets.
   102   - Infinite products of probability measures are now available.
   103   - Use extended reals instead of positive extended reals.
   104     INCOMPATIBILITY.
   105 
   106 
   107 *** Document preparation ***
   108 
   109 * Antiquotation @{rail} layouts railroad syntax diagrams, see also
   110 isar-ref manual.
   111 
   112 * Localized \isabellestyle switch can be used within blocks or groups
   113 like this:
   114 
   115   \isabellestyle{it}  %preferred default
   116   {\isabellestylett @{text "typewriter stuff"}}
   117 
   118 * New term style "isub" as ad-hoc conversion of variables x1, y23 into
   119 subscripted form x\<^isub>1, y\<^isub>2\<^isub>3.
   120 
   121 * Predefined LaTeX macros for Isabelle symbols \<bind> and \<then>
   122 (e.g. see ~~/src/HOL/Library/Monad_Syntax.thy).
   123 
   124 
   125 *** ML ***
   126 
   127 * Structure Proof_Context follows standard naming scheme.  Old
   128 ProofContext is still available for some time as legacy alias.
   129 
   130 * Structure Timing provides various operations for timing; supersedes
   131 former start_timing/end_timing etc.
   132 
   133 * Path.print is the official way to show file-system paths to users
   134 (including quotes etc.).
   135 
   136 * Inner syntax: identifiers in parse trees of generic categories
   137 "logic", "aprop", "idt" etc. carry position information (disguised as
   138 type constraints).  Occasional INCOMPATIBILITY with non-compliant
   139 translations that choke on unexpected type constraints.  Positions can
   140 be stripped in ML translations via Syntax.strip_positions /
   141 Syntax.strip_positions_ast, or via the syntax constant
   142 "_strip_positions" within parse trees.  As last resort, positions can
   143 be disabled via the configuration option Syntax.positions, which is
   144 called "syntax_positions" in Isar attribute syntax.
   145 
   146 * Discontinued special status of various ML structures that contribute
   147 to structure Syntax (Ast, Lexicon, Mixfix, Parser, Printer etc.): less
   148 pervasive content, no inclusion in structure Syntax.  INCOMPATIBILITY,
   149 refer directly to Ast.Constant, Lexicon.is_identifier,
   150 Syntax_Trans.mk_binder_tr etc.
   151 
   152 * Typed print translation: discontinued show_sorts argument, which is
   153 already available via context of "advanced" translation.
   154 
   155 * Refined PARALLEL_GOALS tactical: degrades gracefully for schematic
   156 goal states; body tactic needs to address all subgoals uniformly.
   157 
   158 * Slightly more special eq_list/eq_set, with shortcut involving
   159 pointer equality (assumes that eq relation is reflexive).
   160 
   161 * Classical tactics use proper Proof.context instead of historic types
   162 claset/clasimpset.  Old-style declarations like addIs, addEs, addDs
   163 operate directly on Proof.context.  Raw type claset retains its use as
   164 snapshot of the classical context, which can be recovered via
   165 (put_claset HOL_cs) etc.  Type clasimpset has been discontinued.
   166 INCOMPATIBILITY, classical tactics and derived proof methods require
   167 proper Proof.context.
   168 
   169 
   170 
   171 New in Isabelle2011 (January 2011)
   172 ----------------------------------
   173 
   174 *** General ***
   175 
   176 * Experimental Prover IDE based on Isabelle/Scala and jEdit (see
   177 src/Tools/jEdit).  This also serves as IDE for Isabelle/ML, with
   178 useful tooltips and hyperlinks produced from its static analysis.  The
   179 bundled component provides an executable Isabelle tool that can be run
   180 like this:
   181 
   182   Isabelle2011/bin/isabelle jedit
   183 
   184 * Significantly improved Isabelle/Isar implementation manual.
   185 
   186 * System settings: ISABELLE_HOME_USER now includes ISABELLE_IDENTIFIER
   187 (and thus refers to something like $HOME/.isabelle/Isabelle2011),
   188 while the default heap location within that directory lacks that extra
   189 suffix.  This isolates multiple Isabelle installations from each
   190 other, avoiding problems with old settings in new versions.
   191 INCOMPATIBILITY, need to copy/upgrade old user settings manually.
   192 
   193 * Source files are always encoded as UTF-8, instead of old-fashioned
   194 ISO-Latin-1.  INCOMPATIBILITY.  Isabelle LaTeX documents might require
   195 the following package declarations:
   196 
   197   \usepackage[utf8]{inputenc}
   198   \usepackage{textcomp}
   199 
   200 * Explicit treatment of UTF-8 sequences as Isabelle symbols, such that
   201 a Unicode character is treated as a single symbol, not a sequence of
   202 non-ASCII bytes as before.  Since Isabelle/ML string literals may
   203 contain symbols without further backslash escapes, Unicode can now be
   204 used here as well.  Recall that Symbol.explode in ML provides a
   205 consistent view on symbols, while raw explode (or String.explode)
   206 merely give a byte-oriented representation.
   207 
   208 * Theory loader: source files are primarily located via the master
   209 directory of each theory node (where the .thy file itself resides).
   210 The global load path is still partially available as legacy feature.
   211 Minor INCOMPATIBILITY due to subtle change in file lookup: use
   212 explicit paths, relatively to the theory.
   213 
   214 * Special treatment of ML file names has been discontinued.
   215 Historically, optional extensions .ML or .sml were added on demand --
   216 at the cost of clarity of file dependencies.  Recall that Isabelle/ML
   217 files exclusively use the .ML extension.  Minor INCOMPATIBILTY.
   218 
   219 * Various options that affect pretty printing etc. are now properly
   220 handled within the context via configuration options, instead of
   221 unsynchronized references or print modes.  There are both ML Config.T
   222 entities and Isar declaration attributes to access these.
   223 
   224   ML (Config.T)                 Isar (attribute)
   225 
   226   eta_contract                  eta_contract
   227   show_brackets                 show_brackets
   228   show_sorts                    show_sorts
   229   show_types                    show_types
   230   show_question_marks           show_question_marks
   231   show_consts                   show_consts
   232   show_abbrevs                  show_abbrevs
   233 
   234   Syntax.ast_trace              syntax_ast_trace
   235   Syntax.ast_stat               syntax_ast_stat
   236   Syntax.ambiguity_level        syntax_ambiguity_level
   237 
   238   Goal_Display.goals_limit      goals_limit
   239   Goal_Display.show_main_goal   show_main_goal
   240 
   241   Method.rule_trace             rule_trace
   242 
   243   Thy_Output.display            thy_output_display
   244   Thy_Output.quotes             thy_output_quotes
   245   Thy_Output.indent             thy_output_indent
   246   Thy_Output.source             thy_output_source
   247   Thy_Output.break              thy_output_break
   248 
   249 Note that corresponding "..._default" references in ML may only be
   250 changed globally at the ROOT session setup, but *not* within a theory.
   251 The option "show_abbrevs" supersedes the former print mode
   252 "no_abbrevs" with inverted meaning.
   253 
   254 * More systematic naming of some configuration options.
   255 INCOMPATIBILITY.
   256 
   257   trace_simp  ~>  simp_trace
   258   debug_simp  ~>  simp_debug
   259 
   260 * Support for real valued configuration options, using simplistic
   261 floating-point notation that coincides with the inner syntax for
   262 float_token.
   263 
   264 * Support for real valued preferences (with approximative PGIP type):
   265 front-ends need to accept "pgint" values in float notation.
   266 INCOMPATIBILITY.
   267 
   268 * The IsabelleText font now includes Cyrillic, Hebrew, Arabic from
   269 DejaVu Sans.
   270 
   271 * Discontinued support for Poly/ML 5.0 and 5.1 versions.
   272 
   273 
   274 *** Pure ***
   275 
   276 * Command 'type_synonym' (with single argument) replaces somewhat
   277 outdated 'types', which is still available as legacy feature for some
   278 time.
   279 
   280 * Command 'nonterminal' (with 'and' separated list of arguments)
   281 replaces somewhat outdated 'nonterminals'.  INCOMPATIBILITY.
   282 
   283 * Command 'notepad' replaces former 'example_proof' for
   284 experimentation in Isar without any result.  INCOMPATIBILITY.
   285 
   286 * Locale interpretation commands 'interpret' and 'sublocale' accept
   287 lists of equations to map definitions in a locale to appropriate
   288 entities in the context of the interpretation.  The 'interpretation'
   289 command already provided this functionality.
   290 
   291 * Diagnostic command 'print_dependencies' prints the locale instances
   292 that would be activated if the specified expression was interpreted in
   293 the current context.  Variant "print_dependencies!" assumes a context
   294 without interpretations.
   295 
   296 * Diagnostic command 'print_interps' prints interpretations in proofs
   297 in addition to interpretations in theories.
   298 
   299 * Discontinued obsolete 'global' and 'local' commands to manipulate
   300 the theory name space.  Rare INCOMPATIBILITY.  The ML functions
   301 Sign.root_path and Sign.local_path may be applied directly where this
   302 feature is still required for historical reasons.
   303 
   304 * Discontinued obsolete 'constdefs' command.  INCOMPATIBILITY, use
   305 'definition' instead.
   306 
   307 * The "prems" fact, which refers to the accidental collection of
   308 foundational premises in the context, is now explicitly marked as
   309 legacy feature and will be discontinued soon.  Consider using "assms"
   310 of the head statement or reference facts by explicit names.
   311 
   312 * Document antiquotations @{class} and @{type} print classes and type
   313 constructors.
   314 
   315 * Document antiquotation @{file} checks file/directory entries within
   316 the local file system.
   317 
   318 
   319 *** HOL ***
   320 
   321 * Coercive subtyping: functions can be declared as coercions and type
   322 inference will add them as necessary upon input of a term.  Theory
   323 Complex_Main declares real :: nat => real and real :: int => real as
   324 coercions. A coercion function f is declared like this:
   325 
   326   declare [[coercion f]]
   327 
   328 To lift coercions through type constructors (e.g. from nat => real to
   329 nat list => real list), map functions can be declared, e.g.
   330 
   331   declare [[coercion_map map]]
   332 
   333 Currently coercion inference is activated only in theories including
   334 real numbers, i.e. descendants of Complex_Main.  This is controlled by
   335 the configuration option "coercion_enabled", e.g. it can be enabled in
   336 other theories like this:
   337 
   338   declare [[coercion_enabled]]
   339 
   340 * Command 'partial_function' provides basic support for recursive
   341 function definitions over complete partial orders.  Concrete instances
   342 are provided for i) the option type, ii) tail recursion on arbitrary
   343 types, and iii) the heap monad of Imperative_HOL.  See
   344 src/HOL/ex/Fundefs.thy and src/HOL/Imperative_HOL/ex/Linked_Lists.thy
   345 for examples.
   346 
   347 * Function package: f.psimps rules are no longer implicitly declared
   348 as [simp].  INCOMPATIBILITY.
   349 
   350 * Datatype package: theorems generated for executable equality (class
   351 "eq") carry proper names and are treated as default code equations.
   352 
   353 * Inductive package: now offers command 'inductive_simps' to
   354 automatically derive instantiated and simplified equations for
   355 inductive predicates, similar to 'inductive_cases'.
   356 
   357 * Command 'enriched_type' allows to register properties of the
   358 functorial structure of types.
   359 
   360 * Improved infrastructure for term evaluation using code generator
   361 techniques, in particular static evaluation conversions.
   362 
   363 * Code generator: Scala (2.8 or higher) has been added to the target
   364 languages.
   365 
   366 * Code generator: globbing constant expressions "*" and "Theory.*"
   367 have been replaced by the more idiomatic "_" and "Theory._".
   368 INCOMPATIBILITY.
   369 
   370 * Code generator: export_code without explicit file declaration prints
   371 to standard output.  INCOMPATIBILITY.
   372 
   373 * Code generator: do not print function definitions for case
   374 combinators any longer.
   375 
   376 * Code generator: simplification with rules determined with
   377 src/Tools/Code/code_simp.ML and method "code_simp".
   378 
   379 * Code generator for records: more idiomatic representation of record
   380 types.  Warning: records are not covered by ancient SML code
   381 generation any longer.  INCOMPATIBILITY.  In cases of need, a suitable
   382 rep_datatype declaration helps to succeed then:
   383 
   384   record 'a foo = ...
   385   ...
   386   rep_datatype foo_ext ...
   387 
   388 * Records: logical foundation type for records does not carry a
   389 '_type' suffix any longer (obsolete due to authentic syntax).
   390 INCOMPATIBILITY.
   391 
   392 * Quickcheck now by default uses exhaustive testing instead of random
   393 testing.  Random testing can be invoked by "quickcheck [random]",
   394 exhaustive testing by "quickcheck [exhaustive]".
   395 
   396 * Quickcheck instantiates polymorphic types with small finite
   397 datatypes by default. This enables a simple execution mechanism to
   398 handle quantifiers and function equality over the finite datatypes.
   399 
   400 * Quickcheck random generator has been renamed from "code" to
   401 "random".  INCOMPATIBILITY.
   402 
   403 * Quickcheck now has a configurable time limit which is set to 30
   404 seconds by default. This can be changed by adding [timeout = n] to the
   405 quickcheck command. The time limit for Auto Quickcheck is still set
   406 independently.
   407 
   408 * Quickcheck in locales considers interpretations of that locale for
   409 counter example search.
   410 
   411 * Sledgehammer:
   412   - Added "smt" and "remote_smt" provers based on the "smt" proof
   413     method. See the Sledgehammer manual for details ("isabelle doc
   414     sledgehammer").
   415   - Renamed commands:
   416     sledgehammer atp_info ~> sledgehammer running_provers
   417     sledgehammer atp_kill ~> sledgehammer kill_provers
   418     sledgehammer available_atps ~> sledgehammer available_provers
   419     INCOMPATIBILITY.
   420   - Renamed options:
   421     sledgehammer [atps = ...] ~> sledgehammer [provers = ...]
   422     sledgehammer [atp = ...] ~> sledgehammer [prover = ...]
   423     sledgehammer [timeout = 77 s] ~> sledgehammer [timeout = 77]
   424     (and "ms" and "min" are no longer supported)
   425     INCOMPATIBILITY.
   426 
   427 * Nitpick:
   428   - Renamed options:
   429     nitpick [timeout = 77 s] ~> nitpick [timeout = 77]
   430     nitpick [tac_timeout = 777 ms] ~> nitpick [tac_timeout = 0.777]
   431     INCOMPATIBILITY.
   432   - Added support for partial quotient types.
   433   - Added local versions of the "Nitpick.register_xxx" functions.
   434   - Added "whack" option.
   435   - Allow registration of quotient types as codatatypes.
   436   - Improved "merge_type_vars" option to merge more types.
   437   - Removed unsound "fast_descrs" option.
   438   - Added custom symmetry breaking for datatypes, making it possible to reach
   439     higher cardinalities.
   440   - Prevent the expansion of too large definitions.
   441 
   442 * Proof methods "metis" and "meson" now have configuration options
   443 "meson_trace", "metis_trace", and "metis_verbose" that can be enabled
   444 to diagnose these tools. E.g.
   445 
   446     using [[metis_trace = true]]
   447 
   448 * Auto Solve: Renamed "Auto Solve Direct".  The tool is now available
   449 manually as command 'solve_direct'.
   450 
   451 * The default SMT solver Z3 must be enabled explicitly (due to
   452 licensing issues) by setting the environment variable
   453 Z3_NON_COMMERCIAL in etc/settings of the component, for example.  For
   454 commercial applications, the SMT solver CVC3 is provided as fall-back;
   455 changing the SMT solver is done via the configuration option
   456 "smt_solver".
   457 
   458 * Remote SMT solvers need to be referred to by the "remote_" prefix,
   459 i.e. "remote_cvc3" and "remote_z3".
   460 
   461 * Added basic SMT support for datatypes, records, and typedefs using
   462 the oracle mode (no proofs).  Direct support of pairs has been dropped
   463 in exchange (pass theorems fst_conv snd_conv pair_collapse to the SMT
   464 support for a similar behavior).  Minor INCOMPATIBILITY.
   465 
   466 * Changed SMT configuration options:
   467   - Renamed:
   468     z3_proofs ~> smt_oracle (with inverted meaning)
   469     z3_trace_assms ~> smt_trace_used_facts
   470     INCOMPATIBILITY.
   471   - Added:
   472     smt_verbose
   473     smt_random_seed
   474     smt_datatypes
   475     smt_infer_triggers
   476     smt_monomorph_limit
   477     cvc3_options
   478     remote_cvc3_options
   479     remote_z3_options
   480     yices_options
   481 
   482 * Boogie output files (.b2i files) need to be declared in the theory
   483 header.
   484 
   485 * Simplification procedure "list_to_set_comprehension" rewrites list
   486 comprehensions applied to List.set to set comprehensions.  Occasional
   487 INCOMPATIBILITY, may be deactivated like this:
   488 
   489   declare [[simproc del: list_to_set_comprehension]]
   490 
   491 * Removed old version of primrec package.  INCOMPATIBILITY.
   492 
   493 * Removed simplifier congruence rule of "prod_case", as has for long
   494 been the case with "split".  INCOMPATIBILITY.
   495 
   496 * String.literal is a type, but not a datatype.  INCOMPATIBILITY.
   497 
   498 * Removed [split_format ... and ... and ...] version of
   499 [split_format].  Potential INCOMPATIBILITY.
   500 
   501 * Predicate "sorted" now defined inductively, with nice induction
   502 rules.  INCOMPATIBILITY: former sorted.simps now named sorted_simps.
   503 
   504 * Constant "contents" renamed to "the_elem", to free the generic name
   505 contents for other uses.  INCOMPATIBILITY.
   506 
   507 * Renamed class eq and constant eq (for code generation) to class
   508 equal and constant equal, plus renaming of related facts and various
   509 tuning.  INCOMPATIBILITY.
   510 
   511 * Dropped type classes mult_mono and mult_mono1.  INCOMPATIBILITY.
   512 
   513 * Removed output syntax "'a ~=> 'b" for "'a => 'b option".
   514 INCOMPATIBILITY.
   515 
   516 * Renamed theory Fset to Cset, type Fset.fset to Cset.set, in order to
   517 avoid confusion with finite sets.  INCOMPATIBILITY.
   518 
   519 * Abandoned locales equiv, congruent and congruent2 for equivalence
   520 relations.  INCOMPATIBILITY: use equivI rather than equiv_intro (same
   521 for congruent(2)).
   522 
   523 * Some previously unqualified names have been qualified:
   524 
   525   types
   526     bool ~> HOL.bool
   527     nat ~> Nat.nat
   528 
   529   constants
   530     Trueprop ~> HOL.Trueprop
   531     True ~> HOL.True
   532     False ~> HOL.False
   533     op & ~> HOL.conj
   534     op | ~> HOL.disj
   535     op --> ~> HOL.implies
   536     op = ~> HOL.eq
   537     Not ~> HOL.Not
   538     The ~> HOL.The
   539     All ~> HOL.All
   540     Ex ~> HOL.Ex
   541     Ex1 ~> HOL.Ex1
   542     Let ~> HOL.Let
   543     If ~> HOL.If
   544     Ball ~> Set.Ball
   545     Bex ~> Set.Bex
   546     Suc ~> Nat.Suc
   547     Pair ~> Product_Type.Pair
   548     fst ~> Product_Type.fst
   549     snd ~> Product_Type.snd
   550     curry ~> Product_Type.curry
   551     op : ~> Set.member
   552     Collect ~> Set.Collect
   553 
   554 INCOMPATIBILITY.
   555 
   556 * More canonical naming convention for some fundamental definitions:
   557 
   558     bot_bool_eq ~> bot_bool_def
   559     top_bool_eq ~> top_bool_def
   560     inf_bool_eq ~> inf_bool_def
   561     sup_bool_eq ~> sup_bool_def
   562     bot_fun_eq  ~> bot_fun_def
   563     top_fun_eq  ~> top_fun_def
   564     inf_fun_eq  ~> inf_fun_def
   565     sup_fun_eq  ~> sup_fun_def
   566 
   567 INCOMPATIBILITY.
   568 
   569 * More stylized fact names:
   570 
   571   expand_fun_eq ~> fun_eq_iff
   572   expand_set_eq ~> set_eq_iff
   573   set_ext       ~> set_eqI
   574   nat_number    ~> eval_nat_numeral
   575 
   576 INCOMPATIBILITY.
   577 
   578 * Refactoring of code-generation specific operations in theory List:
   579 
   580   constants
   581     null ~> List.null
   582 
   583   facts
   584     mem_iff ~> member_def
   585     null_empty ~> null_def
   586 
   587 INCOMPATIBILITY.  Note that these were not supposed to be used
   588 regularly unless for striking reasons; their main purpose was code
   589 generation.
   590 
   591 Various operations from the Haskell prelude are used for generating
   592 Haskell code.
   593 
   594 * Term "bij f" is now an abbreviation of "bij_betw f UNIV UNIV".  Term
   595 "surj f" is now an abbreviation of "range f = UNIV".  The theorems
   596 bij_def and surj_def are unchanged.  INCOMPATIBILITY.
   597 
   598 * Abolished some non-alphabetic type names: "prod" and "sum" replace
   599 "*" and "+" respectively.  INCOMPATIBILITY.
   600 
   601 * Name "Plus" of disjoint sum operator "<+>" is now hidden.  Write
   602 "Sum_Type.Plus" instead.
   603 
   604 * Constant "split" has been merged with constant "prod_case"; names of
   605 ML functions, facts etc. involving split have been retained so far,
   606 though.  INCOMPATIBILITY.
   607 
   608 * Dropped old infix syntax "_ mem _" for List.member; use "_ : set _"
   609 instead.  INCOMPATIBILITY.
   610 
   611 * Removed lemma "Option.is_none_none" which duplicates "is_none_def".
   612 INCOMPATIBILITY.
   613 
   614 * Former theory Library/Enum is now part of the HOL-Main image.
   615 INCOMPATIBILITY: all constants of the Enum theory now have to be
   616 referred to by its qualified name.
   617 
   618   enum    ~>  Enum.enum
   619   nlists  ~>  Enum.nlists
   620   product ~>  Enum.product
   621 
   622 * Theory Library/Monad_Syntax provides do-syntax for monad types.
   623 Syntax in Library/State_Monad has been changed to avoid ambiguities.
   624 INCOMPATIBILITY.
   625 
   626 * Theory Library/SetsAndFunctions has been split into
   627 Library/Function_Algebras and Library/Set_Algebras; canonical names
   628 for instance definitions for functions; various improvements.
   629 INCOMPATIBILITY.
   630 
   631 * Theory Library/Multiset provides stable quicksort implementation of
   632 sort_key.
   633 
   634 * Theory Library/Multiset: renamed empty_idemp ~> empty_neutral.
   635 INCOMPATIBILITY.
   636 
   637 * Session Multivariate_Analysis: introduced a type class for euclidean
   638 space.  Most theorems are now stated in terms of euclidean spaces
   639 instead of finite cartesian products.
   640 
   641   types
   642     real ^ 'n ~>  'a::real_vector
   643               ~>  'a::euclidean_space
   644               ~>  'a::ordered_euclidean_space
   645         (depends on your needs)
   646 
   647   constants
   648      _ $ _        ~> _ $$ _
   649      \<chi> x. _  ~> \<chi>\<chi> x. _
   650      CARD('n)     ~> DIM('a)
   651 
   652 Also note that the indices are now natural numbers and not from some
   653 finite type. Finite cartesian products of euclidean spaces, products
   654 of euclidean spaces the real and complex numbers are instantiated to
   655 be euclidean_spaces.  INCOMPATIBILITY.
   656 
   657 * Session Probability: introduced pextreal as positive extended real
   658 numbers.  Use pextreal as value for measures.  Introduce the
   659 Radon-Nikodym derivative, product spaces and Fubini's theorem for
   660 arbitrary sigma finite measures.  Introduces Lebesgue measure based on
   661 the integral in Multivariate Analysis.  INCOMPATIBILITY.
   662 
   663 * Session Imperative_HOL: revamped, corrected dozens of inadequacies.
   664 INCOMPATIBILITY.
   665 
   666 * Session SPARK (with image HOL-SPARK) provides commands to load and
   667 prove verification conditions generated by the SPARK Ada program
   668 verifier.  See also src/HOL/SPARK and src/HOL/SPARK/Examples.
   669 
   670 
   671 *** HOL-Algebra ***
   672 
   673 * Theorems for additive ring operations (locale abelian_monoid and
   674 descendants) are generated by interpretation from their multiplicative
   675 counterparts.  Names (in particular theorem names) have the mandatory
   676 qualifier 'add'.  Previous theorem names are redeclared for
   677 compatibility.
   678 
   679 * Structure "int_ring" is now an abbreviation (previously a
   680 definition).  This fits more natural with advanced interpretations.
   681 
   682 
   683 *** HOLCF ***
   684 
   685 * The domain package now runs in definitional mode by default: The
   686 former command 'new_domain' is now called 'domain'.  To use the domain
   687 package in its original axiomatic mode, use 'domain (unsafe)'.
   688 INCOMPATIBILITY.
   689 
   690 * The new class "domain" is now the default sort.  Class "predomain"
   691 is an unpointed version of "domain". Theories can be updated by
   692 replacing sort annotations as shown below.  INCOMPATIBILITY.
   693 
   694   'a::type ~> 'a::countable
   695   'a::cpo  ~> 'a::predomain
   696   'a::pcpo ~> 'a::domain
   697 
   698 * The old type class "rep" has been superseded by class "domain".
   699 Accordingly, users of the definitional package must remove any
   700 "default_sort rep" declarations.  INCOMPATIBILITY.
   701 
   702 * The domain package (definitional mode) now supports unpointed
   703 predomain argument types, as long as they are marked 'lazy'. (Strict
   704 arguments must be in class "domain".) For example, the following
   705 domain definition now works:
   706 
   707   domain natlist = nil | cons (lazy "nat discr") (lazy "natlist")
   708 
   709 * Theory HOLCF/Library/HOL_Cpo provides cpo and predomain class
   710 instances for types from main HOL: bool, nat, int, char, 'a + 'b,
   711 'a option, and 'a list.  Additionally, it configures fixrec and the
   712 domain package to work with these types.  For example:
   713 
   714   fixrec isInl :: "('a + 'b) u -> tr"
   715     where "isInl$(up$(Inl x)) = TT" | "isInl$(up$(Inr y)) = FF"
   716 
   717   domain V = VFun (lazy "V -> V") | VCon (lazy "nat") (lazy "V list")
   718 
   719 * The "(permissive)" option of fixrec has been replaced with a
   720 per-equation "(unchecked)" option. See
   721 src/HOL/HOLCF/Tutorial/Fixrec_ex.thy for examples. INCOMPATIBILITY.
   722 
   723 * The "bifinite" class no longer fixes a constant "approx"; the class
   724 now just asserts that such a function exists.  INCOMPATIBILITY.
   725 
   726 * Former type "alg_defl" has been renamed to "defl".  HOLCF no longer
   727 defines an embedding of type 'a defl into udom by default; instances
   728 of "bifinite" and "domain" classes are available in
   729 src/HOL/HOLCF/Library/Defl_Bifinite.thy.
   730 
   731 * The syntax "REP('a)" has been replaced with "DEFL('a)".
   732 
   733 * The predicate "directed" has been removed.  INCOMPATIBILITY.
   734 
   735 * The type class "finite_po" has been removed.  INCOMPATIBILITY.
   736 
   737 * The function "cprod_map" has been renamed to "prod_map".
   738 INCOMPATIBILITY.
   739 
   740 * The monadic bind operator on each powerdomain has new binder syntax
   741 similar to sets, e.g. "\<Union>\<sharp>x\<in>xs. t" represents
   742 "upper_bind\<cdot>xs\<cdot>(\<Lambda> x. t)".
   743 
   744 * The infix syntax for binary union on each powerdomain has changed
   745 from e.g. "+\<sharp>" to "\<union>\<sharp>", for consistency with set
   746 syntax.  INCOMPATIBILITY.
   747 
   748 * The constant "UU" has been renamed to "bottom".  The syntax "UU" is
   749 still supported as an input translation.
   750 
   751 * Renamed some theorems (the original names are also still available).
   752 
   753   expand_fun_below   ~> fun_below_iff
   754   below_fun_ext      ~> fun_belowI
   755   expand_cfun_eq     ~> cfun_eq_iff
   756   ext_cfun           ~> cfun_eqI
   757   expand_cfun_below  ~> cfun_below_iff
   758   below_cfun_ext     ~> cfun_belowI
   759   cont2cont_Rep_CFun ~> cont2cont_APP
   760 
   761 * The Abs and Rep functions for various types have changed names.
   762 Related theorem names have also changed to match. INCOMPATIBILITY.
   763 
   764   Rep_CFun  ~> Rep_cfun
   765   Abs_CFun  ~> Abs_cfun
   766   Rep_Sprod ~> Rep_sprod
   767   Abs_Sprod ~> Abs_sprod
   768   Rep_Ssum  ~> Rep_ssum
   769   Abs_Ssum  ~> Abs_ssum
   770 
   771 * Lemmas with names of the form *_defined_iff or *_strict_iff have
   772 been renamed to *_bottom_iff.  INCOMPATIBILITY.
   773 
   774 * Various changes to bisimulation/coinduction with domain package:
   775 
   776   - Definitions of "bisim" constants no longer mention definedness.
   777   - With mutual recursion, "bisim" predicate is now curried.
   778   - With mutual recursion, each type gets a separate coind theorem.
   779   - Variable names in bisim_def and coinduct rules have changed.
   780 
   781 INCOMPATIBILITY.
   782 
   783 * Case combinators generated by the domain package for type "foo" are
   784 now named "foo_case" instead of "foo_when".  INCOMPATIBILITY.
   785 
   786 * Several theorems have been renamed to more accurately reflect the
   787 names of constants and types involved.  INCOMPATIBILITY.
   788 
   789   thelub_const    ~> lub_const
   790   lub_const       ~> is_lub_const
   791   thelubI         ~> lub_eqI
   792   is_lub_lub      ~> is_lubD2
   793   lubI            ~> is_lub_lub
   794   unique_lub      ~> is_lub_unique
   795   is_ub_lub       ~> is_lub_rangeD1
   796   lub_bin_chain   ~> is_lub_bin_chain
   797   lub_fun         ~> is_lub_fun
   798   thelub_fun      ~> lub_fun
   799   thelub_cfun     ~> lub_cfun
   800   thelub_Pair     ~> lub_Pair
   801   lub_cprod       ~> is_lub_prod
   802   thelub_cprod    ~> lub_prod
   803   minimal_cprod   ~> minimal_prod
   804   inst_cprod_pcpo ~> inst_prod_pcpo
   805   UU_I            ~> bottomI
   806   compact_UU      ~> compact_bottom
   807   deflation_UU    ~> deflation_bottom
   808   finite_deflation_UU ~> finite_deflation_bottom
   809 
   810 * Many legacy theorem names have been discontinued.  INCOMPATIBILITY.
   811 
   812   sq_ord_less_eq_trans ~> below_eq_trans
   813   sq_ord_eq_less_trans ~> eq_below_trans
   814   refl_less            ~> below_refl
   815   trans_less           ~> below_trans
   816   antisym_less         ~> below_antisym
   817   antisym_less_inverse ~> po_eq_conv [THEN iffD1]
   818   box_less             ~> box_below
   819   rev_trans_less       ~> rev_below_trans
   820   not_less2not_eq      ~> not_below2not_eq
   821   less_UU_iff          ~> below_UU_iff
   822   flat_less_iff        ~> flat_below_iff
   823   adm_less             ~> adm_below
   824   adm_not_less         ~> adm_not_below
   825   adm_compact_not_less ~> adm_compact_not_below
   826   less_fun_def         ~> below_fun_def
   827   expand_fun_less      ~> fun_below_iff
   828   less_fun_ext         ~> fun_belowI
   829   less_discr_def       ~> below_discr_def
   830   discr_less_eq        ~> discr_below_eq
   831   less_unit_def        ~> below_unit_def
   832   less_cprod_def       ~> below_prod_def
   833   prod_lessI           ~> prod_belowI
   834   Pair_less_iff        ~> Pair_below_iff
   835   fst_less_iff         ~> fst_below_iff
   836   snd_less_iff         ~> snd_below_iff
   837   expand_cfun_less     ~> cfun_below_iff
   838   less_cfun_ext        ~> cfun_belowI
   839   injection_less       ~> injection_below
   840   less_up_def          ~> below_up_def
   841   not_Iup_less         ~> not_Iup_below
   842   Iup_less             ~> Iup_below
   843   up_less              ~> up_below
   844   Def_inject_less_eq   ~> Def_below_Def
   845   Def_less_is_eq       ~> Def_below_iff
   846   spair_less_iff       ~> spair_below_iff
   847   less_sprod           ~> below_sprod
   848   spair_less           ~> spair_below
   849   sfst_less_iff        ~> sfst_below_iff
   850   ssnd_less_iff        ~> ssnd_below_iff
   851   fix_least_less       ~> fix_least_below
   852   dist_less_one        ~> dist_below_one
   853   less_ONE             ~> below_ONE
   854   ONE_less_iff         ~> ONE_below_iff
   855   less_sinlD           ~> below_sinlD
   856   less_sinrD           ~> below_sinrD
   857 
   858 
   859 *** FOL and ZF ***
   860 
   861 * All constant names are now qualified internally and use proper
   862 identifiers, e.g. "IFOL.eq" instead of "op =".  INCOMPATIBILITY.
   863 
   864 
   865 *** ML ***
   866 
   867 * Antiquotation @{assert} inlines a function bool -> unit that raises
   868 Fail if the argument is false.  Due to inlining the source position of
   869 failed assertions is included in the error output.
   870 
   871 * Discontinued antiquotation @{theory_ref}, which is obsolete since ML
   872 text is in practice always evaluated with a stable theory checkpoint.
   873 Minor INCOMPATIBILITY, use (Theory.check_thy @{theory}) instead.
   874 
   875 * Antiquotation @{theory A} refers to theory A from the ancestry of
   876 the current context, not any accidental theory loader state as before.
   877 Potential INCOMPATIBILITY, subtle change in semantics.
   878 
   879 * Syntax.pretty_priority (default 0) configures the required priority
   880 of pretty-printed output and thus affects insertion of parentheses.
   881 
   882 * Syntax.default_root (default "any") configures the inner syntax
   883 category (nonterminal symbol) for parsing of terms.
   884 
   885 * Former exception Library.UnequalLengths now coincides with
   886 ListPair.UnequalLengths.
   887 
   888 * Renamed structure MetaSimplifier to Raw_Simplifier.  Note that the
   889 main functionality is provided by structure Simplifier.
   890 
   891 * Renamed raw "explode" function to "raw_explode" to emphasize its
   892 meaning.  Note that internally to Isabelle, Symbol.explode is used in
   893 almost all situations.
   894 
   895 * Discontinued obsolete function sys_error and exception SYS_ERROR.
   896 See implementation manual for further details on exceptions in
   897 Isabelle/ML.
   898 
   899 * Renamed setmp_noncritical to Unsynchronized.setmp to emphasize its
   900 meaning.
   901 
   902 * Renamed structure PureThy to Pure_Thy and moved most of its
   903 operations to structure Global_Theory, to emphasize that this is
   904 rarely-used global-only stuff.
   905 
   906 * Discontinued Output.debug.  Minor INCOMPATIBILITY, use plain writeln
   907 instead (or tracing for high-volume output).
   908 
   909 * Configuration option show_question_marks only affects regular pretty
   910 printing of types and terms, not raw Term.string_of_vname.
   911 
   912 * ML_Context.thm and ML_Context.thms are no longer pervasive.  Rare
   913 INCOMPATIBILITY, superseded by static antiquotations @{thm} and
   914 @{thms} for most purposes.
   915 
   916 * ML structure Unsynchronized is never opened, not even in Isar
   917 interaction mode as before.  Old Unsynchronized.set etc. have been
   918 discontinued -- use plain := instead.  This should be *rare* anyway,
   919 since modern tools always work via official context data, notably
   920 configuration options.
   921 
   922 * Parallel and asynchronous execution requires special care concerning
   923 interrupts.  Structure Exn provides some convenience functions that
   924 avoid working directly with raw Interrupt.  User code must not absorb
   925 interrupts -- intermediate handling (for cleanup etc.) needs to be
   926 followed by re-raising of the original exception.  Another common
   927 source of mistakes are "handle _" patterns, which make the meaning of
   928 the program subject to physical effects of the environment.
   929 
   930 
   931 
   932 New in Isabelle2009-2 (June 2010)
   933 ---------------------------------
   934 
   935 *** General ***
   936 
   937 * Authentic syntax for *all* logical entities (type classes, type
   938 constructors, term constants): provides simple and robust
   939 correspondence between formal entities and concrete syntax.  Within
   940 the parse tree / AST representations, "constants" are decorated by
   941 their category (class, type, const) and spelled out explicitly with
   942 their full internal name.
   943 
   944 Substantial INCOMPATIBILITY concerning low-level syntax declarations
   945 and translations (translation rules and translation functions in ML).
   946 Some hints on upgrading:
   947 
   948   - Many existing uses of 'syntax' and 'translations' can be replaced
   949     by more modern 'type_notation', 'notation' and 'abbreviation',
   950     which are independent of this issue.
   951 
   952   - 'translations' require markup within the AST; the term syntax
   953     provides the following special forms:
   954 
   955       CONST c   -- produces syntax version of constant c from context
   956       XCONST c  -- literally c, checked as constant from context
   957       c         -- literally c, if declared by 'syntax'
   958 
   959     Plain identifiers are treated as AST variables -- occasionally the
   960     system indicates accidental variables via the error "rhs contains
   961     extra variables".
   962 
   963     Type classes and type constructors are marked according to their
   964     concrete syntax.  Some old translations rules need to be written
   965     for the "type" category, using type constructor application
   966     instead of pseudo-term application of the default category
   967     "logic".
   968 
   969   - 'parse_translation' etc. in ML may use the following
   970     antiquotations:
   971 
   972       @{class_syntax c}   -- type class c within parse tree / AST
   973       @{term_syntax c}    -- type constructor c within parse tree / AST
   974       @{const_syntax c}   -- ML version of "CONST c" above
   975       @{syntax_const c}   -- literally c (checked wrt. 'syntax' declarations)
   976 
   977   - Literal types within 'typed_print_translations', i.e. those *not*
   978     represented as pseudo-terms are represented verbatim.  Use @{class
   979     c} or @{type_name c} here instead of the above syntax
   980     antiquotations.
   981 
   982 Note that old non-authentic syntax was based on unqualified base
   983 names, so all of the above "constant" names would coincide.  Recall
   984 that 'print_syntax' and ML_command "set Syntax.trace_ast" help to
   985 diagnose syntax problems.
   986 
   987 * Type constructors admit general mixfix syntax, not just infix.
   988 
   989 * Concrete syntax may be attached to local entities without a proof
   990 body, too.  This works via regular mixfix annotations for 'fix',
   991 'def', 'obtain' etc. or via the explicit 'write' command, which is
   992 similar to the 'notation' command in theory specifications.
   993 
   994 * Discontinued unnamed infix syntax (legacy feature for many years) --
   995 need to specify constant name and syntax separately.  Internal ML
   996 datatype constructors have been renamed from InfixName to Infix etc.
   997 Minor INCOMPATIBILITY.
   998 
   999 * Schematic theorem statements need to be explicitly markup as such,
  1000 via commands 'schematic_lemma', 'schematic_theorem',
  1001 'schematic_corollary'.  Thus the relevance of the proof is made
  1002 syntactically clear, which impacts performance in a parallel or
  1003 asynchronous interactive environment.  Minor INCOMPATIBILITY.
  1004 
  1005 * Use of cumulative prems via "!" in some proof methods has been
  1006 discontinued (old legacy feature).
  1007 
  1008 * References 'trace_simp' and 'debug_simp' have been replaced by
  1009 configuration options stored in the context. Enabling tracing (the
  1010 case of debugging is similar) in proofs works via
  1011 
  1012   using [[trace_simp = true]]
  1013 
  1014 Tracing is then active for all invocations of the simplifier in
  1015 subsequent goal refinement steps. Tracing may also still be enabled or
  1016 disabled via the ProofGeneral settings menu.
  1017 
  1018 * Separate commands 'hide_class', 'hide_type', 'hide_const',
  1019 'hide_fact' replace the former 'hide' KIND command.  Minor
  1020 INCOMPATIBILITY.
  1021 
  1022 * Improved parallelism of proof term normalization: usedir -p2 -q0 is
  1023 more efficient than combinations with -q1 or -q2.
  1024 
  1025 
  1026 *** Pure ***
  1027 
  1028 * Proofterms record type-class reasoning explicitly, using the
  1029 "unconstrain" operation internally.  This eliminates all sort
  1030 constraints from a theorem and proof, introducing explicit
  1031 OFCLASS-premises.  On the proof term level, this operation is
  1032 automatically applied at theorem boundaries, such that closed proofs
  1033 are always free of sort constraints.  INCOMPATIBILITY for tools that
  1034 inspect proof terms.
  1035 
  1036 * Local theory specifications may depend on extra type variables that
  1037 are not present in the result type -- arguments TYPE('a) :: 'a itself
  1038 are added internally.  For example:
  1039 
  1040   definition unitary :: bool where "unitary = (ALL (x::'a) y. x = y)"
  1041 
  1042 * Predicates of locales introduced by classes carry a mandatory
  1043 "class" prefix.  INCOMPATIBILITY.
  1044 
  1045 * Vacuous class specifications observe default sort.  INCOMPATIBILITY.
  1046 
  1047 * Old 'axclass' command has been discontinued.  INCOMPATIBILITY, use
  1048 'class' instead.
  1049 
  1050 * Command 'code_reflect' allows to incorporate generated ML code into
  1051 runtime environment; replaces immature code_datatype antiquotation.
  1052 INCOMPATIBILITY.
  1053 
  1054 * Code generator: simple concept for abstract datatypes obeying
  1055 invariants.
  1056 
  1057 * Code generator: details of internal data cache have no impact on the
  1058 user space functionality any longer.
  1059 
  1060 * Methods "unfold_locales" and "intro_locales" ignore non-locale
  1061 subgoals.  This is more appropriate for interpretations with 'where'.
  1062 INCOMPATIBILITY.
  1063 
  1064 * Command 'example_proof' opens an empty proof body.  This allows to
  1065 experiment with Isar, without producing any persistent result.
  1066 
  1067 * Commands 'type_notation' and 'no_type_notation' declare type syntax
  1068 within a local theory context, with explicit checking of the
  1069 constructors involved (in contrast to the raw 'syntax' versions).
  1070 
  1071 * Commands 'types' and 'typedecl' now work within a local theory
  1072 context -- without introducing dependencies on parameters or
  1073 assumptions, which is not possible in Isabelle/Pure.
  1074 
  1075 * Command 'defaultsort' has been renamed to 'default_sort', it works
  1076 within a local theory context.  Minor INCOMPATIBILITY.
  1077 
  1078 
  1079 *** HOL ***
  1080 
  1081 * Command 'typedef' now works within a local theory context -- without
  1082 introducing dependencies on parameters or assumptions, which is not
  1083 possible in Isabelle/Pure/HOL.  Note that the logical environment may
  1084 contain multiple interpretations of local typedefs (with different
  1085 non-emptiness proofs), even in a global theory context.
  1086 
  1087 * New package for quotient types.  Commands 'quotient_type' and
  1088 'quotient_definition' may be used for defining types and constants by
  1089 quotient constructions.  An example is the type of integers created by
  1090 quotienting pairs of natural numbers:
  1091 
  1092   fun
  1093     intrel :: "(nat * nat) => (nat * nat) => bool"
  1094   where
  1095     "intrel (x, y) (u, v) = (x + v = u + y)"
  1096 
  1097   quotient_type int = "nat * nat" / intrel
  1098     by (auto simp add: equivp_def expand_fun_eq)
  1099 
  1100   quotient_definition
  1101     "0::int" is "(0::nat, 0::nat)"
  1102 
  1103 The method "lifting" can be used to lift of theorems from the
  1104 underlying "raw" type to the quotient type.  The example
  1105 src/HOL/Quotient_Examples/FSet.thy includes such a quotient
  1106 construction and provides a reasoning infrastructure for finite sets.
  1107 
  1108 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
  1109 clash with new theory Quotient in Main HOL.
  1110 
  1111 * Moved the SMT binding into the main HOL session, eliminating
  1112 separate HOL-SMT session.
  1113 
  1114 * List membership infix mem operation is only an input abbreviation.
  1115 INCOMPATIBILITY.
  1116 
  1117 * Theory Library/Word.thy has been removed.  Use library Word/Word.thy
  1118 for future developements; former Library/Word.thy is still present in
  1119 the AFP entry RSAPPS.
  1120 
  1121 * Theorem Int.int_induct renamed to Int.int_of_nat_induct and is no
  1122 longer shadowed.  INCOMPATIBILITY.
  1123 
  1124 * Dropped theorem duplicate comp_arith; use semiring_norm instead.
  1125 INCOMPATIBILITY.
  1126 
  1127 * Dropped theorem RealPow.real_sq_order; use power2_le_imp_le instead.
  1128 INCOMPATIBILITY.
  1129 
  1130 * Dropped normalizing_semiring etc; use the facts in semiring classes
  1131 instead.  INCOMPATIBILITY.
  1132 
  1133 * Dropped several real-specific versions of lemmas about floor and
  1134 ceiling; use the generic lemmas from theory "Archimedean_Field"
  1135 instead.  INCOMPATIBILITY.
  1136 
  1137   floor_number_of_eq         ~> floor_number_of
  1138   le_floor_eq_number_of      ~> number_of_le_floor
  1139   le_floor_eq_zero           ~> zero_le_floor
  1140   le_floor_eq_one            ~> one_le_floor
  1141   floor_less_eq_number_of    ~> floor_less_number_of
  1142   floor_less_eq_zero         ~> floor_less_zero
  1143   floor_less_eq_one          ~> floor_less_one
  1144   less_floor_eq_number_of    ~> number_of_less_floor
  1145   less_floor_eq_zero         ~> zero_less_floor
  1146   less_floor_eq_one          ~> one_less_floor
  1147   floor_le_eq_number_of      ~> floor_le_number_of
  1148   floor_le_eq_zero           ~> floor_le_zero
  1149   floor_le_eq_one            ~> floor_le_one
  1150   floor_subtract_number_of   ~> floor_diff_number_of
  1151   floor_subtract_one         ~> floor_diff_one
  1152   ceiling_number_of_eq       ~> ceiling_number_of
  1153   ceiling_le_eq_number_of    ~> ceiling_le_number_of
  1154   ceiling_le_zero_eq         ~> ceiling_le_zero
  1155   ceiling_le_eq_one          ~> ceiling_le_one
  1156   less_ceiling_eq_number_of  ~> number_of_less_ceiling
  1157   less_ceiling_eq_zero       ~> zero_less_ceiling
  1158   less_ceiling_eq_one        ~> one_less_ceiling
  1159   ceiling_less_eq_number_of  ~> ceiling_less_number_of
  1160   ceiling_less_eq_zero       ~> ceiling_less_zero
  1161   ceiling_less_eq_one        ~> ceiling_less_one
  1162   le_ceiling_eq_number_of    ~> number_of_le_ceiling
  1163   le_ceiling_eq_zero         ~> zero_le_ceiling
  1164   le_ceiling_eq_one          ~> one_le_ceiling
  1165   ceiling_subtract_number_of ~> ceiling_diff_number_of
  1166   ceiling_subtract_one       ~> ceiling_diff_one
  1167 
  1168 * Theory "Finite_Set": various folding_XXX locales facilitate the
  1169 application of the various fold combinators on finite sets.
  1170 
  1171 * Library theory "RBT" renamed to "RBT_Impl"; new library theory "RBT"
  1172 provides abstract red-black tree type which is backed by "RBT_Impl" as
  1173 implementation.  INCOMPATIBILTY.
  1174 
  1175 * Theory Library/Coinductive_List has been removed -- superseded by
  1176 AFP/thys/Coinductive.
  1177 
  1178 * Theory PReal, including the type "preal" and related operations, has
  1179 been removed.  INCOMPATIBILITY.
  1180 
  1181 * Real: new development using Cauchy Sequences.
  1182 
  1183 * Split off theory "Big_Operators" containing setsum, setprod,
  1184 Inf_fin, Sup_fin, Min, Max from theory Finite_Set.  INCOMPATIBILITY.
  1185 
  1186 * Theory "Rational" renamed to "Rat", for consistency with "Nat",
  1187 "Int" etc.  INCOMPATIBILITY.
  1188 
  1189 * Constant Rat.normalize needs to be qualified.  INCOMPATIBILITY.
  1190 
  1191 * New set of rules "ac_simps" provides combined assoc / commute
  1192 rewrites for all interpretations of the appropriate generic locales.
  1193 
  1194 * Renamed theory "OrderedGroup" to "Groups" and split theory
  1195 "Ring_and_Field" into theories "Rings" and "Fields"; for more
  1196 appropriate and more consistent names suitable for name prefixes
  1197 within the HOL theories.  INCOMPATIBILITY.
  1198 
  1199 * Some generic constants have been put to appropriate theories:
  1200   - less_eq, less: Orderings
  1201   - zero, one, plus, minus, uminus, times, abs, sgn: Groups
  1202   - inverse, divide: Rings
  1203 INCOMPATIBILITY.
  1204 
  1205 * More consistent naming of type classes involving orderings (and
  1206 lattices):
  1207 
  1208     lower_semilattice                   ~> semilattice_inf
  1209     upper_semilattice                   ~> semilattice_sup
  1210 
  1211     dense_linear_order                  ~> dense_linorder
  1212 
  1213     pordered_ab_group_add               ~> ordered_ab_group_add
  1214     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
  1215     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
  1216     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
  1217     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
  1218     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
  1219     pordered_cancel_semiring            ~> ordered_cancel_semiring
  1220     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
  1221     pordered_comm_ring                  ~> ordered_comm_ring
  1222     pordered_comm_semiring              ~> ordered_comm_semiring
  1223     pordered_ring                       ~> ordered_ring
  1224     pordered_ring_abs                   ~> ordered_ring_abs
  1225     pordered_semiring                   ~> ordered_semiring
  1226 
  1227     ordered_ab_group_add                ~> linordered_ab_group_add
  1228     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
  1229     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
  1230     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
  1231     ordered_field                       ~> linordered_field
  1232     ordered_field_no_lb                 ~> linordered_field_no_lb
  1233     ordered_field_no_ub                 ~> linordered_field_no_ub
  1234     ordered_field_dense_linear_order    ~> dense_linordered_field
  1235     ordered_idom                        ~> linordered_idom
  1236     ordered_ring                        ~> linordered_ring
  1237     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
  1238     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
  1239     ordered_ring_strict                 ~> linordered_ring_strict
  1240     ordered_semidom                     ~> linordered_semidom
  1241     ordered_semiring                    ~> linordered_semiring
  1242     ordered_semiring_1                  ~> linordered_semiring_1
  1243     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
  1244     ordered_semiring_strict             ~> linordered_semiring_strict
  1245 
  1246   The following slightly odd type classes have been moved to a
  1247   separate theory Library/Lattice_Algebras:
  1248 
  1249     lordered_ab_group_add               ~> lattice_ab_group_add
  1250     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
  1251     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
  1252     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
  1253     lordered_ring                       ~> lattice_ring
  1254 
  1255 INCOMPATIBILITY.
  1256 
  1257 * Refined field classes:
  1258   - classes division_ring_inverse_zero, field_inverse_zero,
  1259     linordered_field_inverse_zero include rule inverse 0 = 0 --
  1260     subsumes former division_by_zero class;
  1261   - numerous lemmas have been ported from field to division_ring.
  1262 INCOMPATIBILITY.
  1263 
  1264 * Refined algebra theorem collections:
  1265   - dropped theorem group group_simps, use algebra_simps instead;
  1266   - dropped theorem group ring_simps, use field_simps instead;
  1267   - proper theorem collection field_simps subsumes former theorem
  1268     groups field_eq_simps and field_simps;
  1269   - dropped lemma eq_minus_self_iff which is a duplicate for
  1270     equal_neg_zero.
  1271 INCOMPATIBILITY.
  1272 
  1273 * Theory Finite_Set and List: some lemmas have been generalized from
  1274 sets to lattices:
  1275 
  1276   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
  1277   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
  1278   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
  1279   union_Union_fold_union        ~> sup_Sup_fold_sup
  1280   Inter_fold_inter              ~> Inf_fold_inf
  1281   Union_fold_union              ~> Sup_fold_sup
  1282   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
  1283   union_UNION_fold_union        ~> sup_SUPR_fold_sup
  1284   INTER_fold_inter              ~> INFI_fold_inf
  1285   UNION_fold_union              ~> SUPR_fold_sup
  1286 
  1287 * Theory "Complete_Lattice": lemmas top_def and bot_def have been
  1288 replaced by the more convenient lemmas Inf_empty and Sup_empty.
  1289 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
  1290 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
  1291 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
  1292 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
  1293 
  1294 * Reorganized theory Multiset: swapped notation of pointwise and
  1295 multiset order:
  1296 
  1297   - pointwise ordering is instance of class order with standard syntax
  1298     <= and <;
  1299   - multiset ordering has syntax <=# and <#; partial order properties
  1300     are provided by means of interpretation with prefix
  1301     multiset_order;
  1302   - less duplication, less historical organization of sections,
  1303     conversion from associations lists to multisets, rudimentary code
  1304     generation;
  1305   - use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union,
  1306     if needed.
  1307 
  1308 Renamed:
  1309 
  1310   multiset_eq_conv_count_eq  ~>  multiset_ext_iff
  1311   multi_count_ext  ~>  multiset_ext
  1312   diff_union_inverse2  ~>  diff_union_cancelR
  1313 
  1314 INCOMPATIBILITY.
  1315 
  1316 * Theory Permutation: replaced local "remove" by List.remove1.
  1317 
  1318 * Code generation: ML and OCaml code is decorated with signatures.
  1319 
  1320 * Theory List: added transpose.
  1321 
  1322 * Library/Nat_Bijection.thy is a collection of bijective functions
  1323 between nat and other types, which supersedes the older libraries
  1324 Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.
  1325 
  1326   Constants:
  1327   Nat_Int_Bij.nat2_to_nat         ~> prod_encode
  1328   Nat_Int_Bij.nat_to_nat2         ~> prod_decode
  1329   Nat_Int_Bij.int_to_nat_bij      ~> int_encode
  1330   Nat_Int_Bij.nat_to_int_bij      ~> int_decode
  1331   Countable.pair_encode           ~> prod_encode
  1332   NatIso.prod2nat                 ~> prod_encode
  1333   NatIso.nat2prod                 ~> prod_decode
  1334   NatIso.sum2nat                  ~> sum_encode
  1335   NatIso.nat2sum                  ~> sum_decode
  1336   NatIso.list2nat                 ~> list_encode
  1337   NatIso.nat2list                 ~> list_decode
  1338   NatIso.set2nat                  ~> set_encode
  1339   NatIso.nat2set                  ~> set_decode
  1340 
  1341   Lemmas:
  1342   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
  1343   Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
  1344   Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
  1345   Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
  1346   Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
  1347   Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
  1348   Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
  1349   Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
  1350   Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
  1351   Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
  1352   Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
  1353   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
  1354   Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode
  1355 
  1356 * Sledgehammer:
  1357   - Renamed ATP commands:
  1358     atp_info     ~> sledgehammer running_atps
  1359     atp_kill     ~> sledgehammer kill_atps
  1360     atp_messages ~> sledgehammer messages
  1361     atp_minimize ~> sledgehammer minimize
  1362     print_atps   ~> sledgehammer available_atps
  1363     INCOMPATIBILITY.
  1364   - Added user's manual ("isabelle doc sledgehammer").
  1365   - Added option syntax and "sledgehammer_params" to customize
  1366     Sledgehammer's behavior.  See the manual for details.
  1367   - Modified the Isar proof reconstruction code so that it produces
  1368     direct proofs rather than proofs by contradiction.  (This feature
  1369     is still experimental.)
  1370   - Made Isar proof reconstruction work for SPASS, remote ATPs, and in
  1371     full-typed mode.
  1372   - Added support for TPTP syntax for SPASS via the "spass_tptp" ATP.
  1373 
  1374 * Nitpick:
  1375   - Added and implemented "binary_ints" and "bits" options.
  1376   - Added "std" option and implemented support for nonstandard models.
  1377   - Added and implemented "finitize" option to improve the precision
  1378     of infinite datatypes based on a monotonicity analysis.
  1379   - Added support for quotient types.
  1380   - Added support for "specification" and "ax_specification"
  1381     constructs.
  1382   - Added support for local definitions (for "function" and
  1383     "termination" proofs).
  1384   - Added support for term postprocessors.
  1385   - Optimized "Multiset.multiset" and "FinFun.finfun".
  1386   - Improved efficiency of "destroy_constrs" optimization.
  1387   - Fixed soundness bugs related to "destroy_constrs" optimization and
  1388     record getters.
  1389   - Fixed soundness bug related to higher-order constructors.
  1390   - Fixed soundness bug when "full_descrs" is enabled.
  1391   - Improved precision of set constructs.
  1392   - Added "atoms" option.
  1393   - Added cache to speed up repeated Kodkod invocations on the same
  1394     problems.
  1395   - Renamed "MiniSatJNI", "zChaffJNI", "BerkMinAlloy", and
  1396     "SAT4JLight" to "MiniSat_JNI", "zChaff_JNI", "BerkMin_Alloy", and
  1397     "SAT4J_Light".  INCOMPATIBILITY.
  1398   - Removed "skolemize", "uncurry", "sym_break", "flatten_prop",
  1399     "sharing_depth", and "show_skolems" options.  INCOMPATIBILITY.
  1400   - Removed "nitpick_intro" attribute.  INCOMPATIBILITY.
  1401 
  1402 * Method "induct" now takes instantiations of the form t, where t is not
  1403   a variable, as a shorthand for "x == t", where x is a fresh variable.
  1404   If this is not intended, t has to be enclosed in parentheses.
  1405   By default, the equalities generated by definitional instantiations
  1406   are pre-simplified, which may cause parameters of inductive cases
  1407   to disappear, or may even delete some of the inductive cases.
  1408   Use "induct (no_simp)" instead of "induct" to restore the old
  1409   behaviour. The (no_simp) option is also understood by the "cases"
  1410   and "nominal_induct" methods, which now perform pre-simplification, too.
  1411   INCOMPATIBILITY.
  1412 
  1413 
  1414 *** HOLCF ***
  1415 
  1416 * Variable names in lemmas generated by the domain package have
  1417 changed; the naming scheme is now consistent with the HOL datatype
  1418 package.  Some proof scripts may be affected, INCOMPATIBILITY.
  1419 
  1420 * The domain package no longer defines the function "foo_copy" for
  1421 recursive domain "foo".  The reach lemma is now stated directly in
  1422 terms of "foo_take".  Lemmas and proofs that mention "foo_copy" must
  1423 be reformulated in terms of "foo_take", INCOMPATIBILITY.
  1424 
  1425 * Most definedness lemmas generated by the domain package (previously
  1426 of the form "x ~= UU ==> foo$x ~= UU") now have an if-and-only-if form
  1427 like "foo$x = UU <-> x = UU", which works better as a simp rule.
  1428 Proofs that used definedness lemmas as intro rules may break,
  1429 potential INCOMPATIBILITY.
  1430 
  1431 * Induction and casedist rules generated by the domain package now
  1432 declare proper case_names (one called "bottom", and one named for each
  1433 constructor).  INCOMPATIBILITY.
  1434 
  1435 * For mutually-recursive domains, separate "reach" and "take_lemma"
  1436 rules are generated for each domain, INCOMPATIBILITY.
  1437 
  1438   foo_bar.reach       ~> foo.reach  bar.reach
  1439   foo_bar.take_lemmas ~> foo.take_lemma  bar.take_lemma
  1440 
  1441 * Some lemmas generated by the domain package have been renamed for
  1442 consistency with the datatype package, INCOMPATIBILITY.
  1443 
  1444   foo.ind        ~> foo.induct
  1445   foo.finite_ind ~> foo.finite_induct
  1446   foo.coind      ~> foo.coinduct
  1447   foo.casedist   ~> foo.exhaust
  1448   foo.exhaust    ~> foo.nchotomy
  1449 
  1450 * For consistency with other definition packages, the fixrec package
  1451 now generates qualified theorem names, INCOMPATIBILITY.
  1452 
  1453   foo_simps  ~> foo.simps
  1454   foo_unfold ~> foo.unfold
  1455   foo_induct ~> foo.induct
  1456 
  1457 * The "fixrec_simp" attribute has been removed.  The "fixrec_simp"
  1458 method and internal fixrec proofs now use the default simpset instead.
  1459 INCOMPATIBILITY.
  1460 
  1461 * The "contlub" predicate has been removed.  Proof scripts should use
  1462 lemma contI2 in place of monocontlub2cont, INCOMPATIBILITY.
  1463 
  1464 * The "admw" predicate has been removed, INCOMPATIBILITY.
  1465 
  1466 * The constants cpair, cfst, and csnd have been removed in favor of
  1467 Pair, fst, and snd from Isabelle/HOL, INCOMPATIBILITY.
  1468 
  1469 
  1470 *** ML ***
  1471 
  1472 * Antiquotations for basic formal entities:
  1473 
  1474     @{class NAME}         -- type class
  1475     @{class_syntax NAME}  -- syntax representation of the above
  1476 
  1477     @{type_name NAME}     -- logical type
  1478     @{type_abbrev NAME}   -- type abbreviation
  1479     @{nonterminal NAME}   -- type of concrete syntactic category
  1480     @{type_syntax NAME}   -- syntax representation of any of the above
  1481 
  1482     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
  1483     @{const_abbrev NAME}  -- abbreviated constant
  1484     @{const_syntax NAME}  -- syntax representation of any of the above
  1485 
  1486 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
  1487 syntax constant (cf. 'syntax' command).
  1488 
  1489 * Antiquotation @{make_string} inlines a function to print arbitrary
  1490 values similar to the ML toplevel.  The result is compiler dependent
  1491 and may fall back on "?" in certain situations.
  1492 
  1493 * Diagnostic commands 'ML_val' and 'ML_command' may refer to
  1494 antiquotations @{Isar.state} and @{Isar.goal}.  This replaces impure
  1495 Isar.state() and Isar.goal(), which belong to the old TTY loop and do
  1496 not work with the asynchronous Isar document model.
  1497 
  1498 * Configuration options now admit dynamic default values, depending on
  1499 the context or even global references.
  1500 
  1501 * SHA1.digest digests strings according to SHA-1 (see RFC 3174).  It
  1502 uses an efficient external library if available (for Poly/ML).
  1503 
  1504 * Renamed some important ML structures, while keeping the old names
  1505 for some time as aliases within the structure Legacy:
  1506 
  1507   OuterKeyword  ~>  Keyword
  1508   OuterLex      ~>  Token
  1509   OuterParse    ~>  Parse
  1510   OuterSyntax   ~>  Outer_Syntax
  1511   PrintMode     ~>  Print_Mode
  1512   SpecParse     ~>  Parse_Spec
  1513   ThyInfo       ~>  Thy_Info
  1514   ThyLoad       ~>  Thy_Load
  1515   ThyOutput     ~>  Thy_Output
  1516   TypeInfer     ~>  Type_Infer
  1517 
  1518 Note that "open Legacy" simplifies porting of sources, but forgetting
  1519 to remove it again will complicate porting again in the future.
  1520 
  1521 * Most operations that refer to a global context are named
  1522 accordingly, e.g. Simplifier.global_context or
  1523 ProofContext.init_global.  There are some situations where a global
  1524 context actually works, but under normal circumstances one needs to
  1525 pass the proper local context through the code!
  1526 
  1527 * Discontinued old TheoryDataFun with its copy/init operation -- data
  1528 needs to be pure.  Functor Theory_Data_PP retains the traditional
  1529 Pretty.pp argument to merge, which is absent in the standard
  1530 Theory_Data version.
  1531 
  1532 * Sorts.certify_sort and derived "cert" operations for types and terms
  1533 no longer minimize sorts.  Thus certification at the boundary of the
  1534 inference kernel becomes invariant under addition of class relations,
  1535 which is an important monotonicity principle.  Sorts are now minimized
  1536 in the syntax layer only, at the boundary between the end-user and the
  1537 system.  Subtle INCOMPATIBILITY, may have to use Sign.minimize_sort
  1538 explicitly in rare situations.
  1539 
  1540 * Renamed old-style Drule.standard to Drule.export_without_context, to
  1541 emphasize that this is in no way a standard operation.
  1542 INCOMPATIBILITY.
  1543 
  1544 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
  1545 usual for resolution.  Rare INCOMPATIBILITY.
  1546 
  1547 * Renamed varify/unvarify operations to varify_global/unvarify_global
  1548 to emphasize that these only work in a global situation (which is
  1549 quite rare).
  1550 
  1551 * Curried take and drop in library.ML; negative length is interpreted
  1552 as infinity (as in chop).  Subtle INCOMPATIBILITY.
  1553 
  1554 * Proof terms: type substitutions on proof constants now use canonical
  1555 order of type variables.  INCOMPATIBILITY for tools working with proof
  1556 terms.
  1557 
  1558 * Raw axioms/defs may no longer carry sort constraints, and raw defs
  1559 may no longer carry premises.  User-level specifications are
  1560 transformed accordingly by Thm.add_axiom/add_def.
  1561 
  1562 
  1563 *** System ***
  1564 
  1565 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
  1566 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
  1567 proof terms are enabled unconditionally in the new HOL-Proofs image.
  1568 
  1569 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
  1570 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
  1571 respectively.
  1572 
  1573 * Old lib/scripts/polyml-platform is superseded by the
  1574 ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
  1575 variant, even on a 64 bit machine.  The following example setting
  1576 prefers 64 bit if available:
  1577 
  1578   ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"
  1579 
  1580 * The preliminary Isabelle/jEdit application demonstrates the emerging
  1581 Isabelle/Scala layer for advanced prover interaction and integration.
  1582 See src/Tools/jEdit or "isabelle jedit" provided by the properly built
  1583 component.
  1584 
  1585 * "IsabelleText" is a Unicode font derived from Bitstream Vera Mono
  1586 and Bluesky TeX fonts.  It provides the usual Isabelle symbols,
  1587 similar to the default assignment of the document preparation system
  1588 (cf. isabellesym.sty).  The Isabelle/Scala class Isabelle_System
  1589 provides some operations for direct access to the font without asking
  1590 the user for manual installation.
  1591 
  1592 
  1593 
  1594 New in Isabelle2009-1 (December 2009)
  1595 -------------------------------------
  1596 
  1597 *** General ***
  1598 
  1599 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
  1600 one backslash should be used, even in ML sources.
  1601 
  1602 
  1603 *** Pure ***
  1604 
  1605 * Locale interpretation propagates mixins along the locale hierarchy.
  1606 The currently only available mixins are the equations used to map
  1607 local definitions to terms of the target domain of an interpretation.
  1608 
  1609 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
  1610 loc" to print all interpretations of locale "loc" in the theory.
  1611 Interpretations in proofs are not shown.
  1612 
  1613 * Thoroughly revised locales tutorial.  New section on conditional
  1614 interpretation.
  1615 
  1616 * On instantiation of classes, remaining undefined class parameters
  1617 are formally declared.  INCOMPATIBILITY.
  1618 
  1619 
  1620 *** Document preparation ***
  1621 
  1622 * New generalized style concept for printing terms: @{foo (style) ...}
  1623 instead of @{foo_style style ...}  (old form is still retained for
  1624 backward compatibility).  Styles can be also applied for
  1625 antiquotations prop, term_type and typeof.
  1626 
  1627 
  1628 *** HOL ***
  1629 
  1630 * New proof method "smt" for a combination of first-order logic with
  1631 equality, linear and nonlinear (natural/integer/real) arithmetic, and
  1632 fixed-size bitvectors; there is also basic support for higher-order
  1633 features (esp. lambda abstractions).  It is an incomplete decision
  1634 procedure based on external SMT solvers using the oracle mechanism;
  1635 for the SMT solver Z3, this method is proof-producing.  Certificates
  1636 are provided to avoid calling the external solvers solely for
  1637 re-checking proofs.  Due to a remote SMT service there is no need for
  1638 installing SMT solvers locally.  See src/HOL/SMT.
  1639 
  1640 * New commands to load and prove verification conditions generated by
  1641 the Boogie program verifier or derived systems (e.g. the Verifying C
  1642 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
  1643 
  1644 * New counterexample generator tool 'nitpick' based on the Kodkod
  1645 relational model finder.  See src/HOL/Tools/Nitpick and
  1646 src/HOL/Nitpick_Examples.
  1647 
  1648 * New commands 'code_pred' and 'values' to invoke the predicate
  1649 compiler and to enumerate values of inductive predicates.
  1650 
  1651 * A tabled implementation of the reflexive transitive closure.
  1652 
  1653 * New implementation of quickcheck uses generic code generator;
  1654 default generators are provided for all suitable HOL types, records
  1655 and datatypes.  Old quickcheck can be re-activated importing theory
  1656 Library/SML_Quickcheck.
  1657 
  1658 * New testing tool Mirabelle for automated proof tools.  Applies
  1659 several tools and tactics like sledgehammer, metis, or quickcheck, to
  1660 every proof step in a theory.  To be used in batch mode via the
  1661 "mirabelle" utility.
  1662 
  1663 * New proof method "sos" (sum of squares) for nonlinear real
  1664 arithmetic (originally due to John Harison). It requires theory
  1665 Library/Sum_Of_Squares.  It is not a complete decision procedure but
  1666 works well in practice on quantifier-free real arithmetic with +, -,
  1667 *, ^, =, <= and <, i.e. boolean combinations of equalities and
  1668 inequalities between polynomials.  It makes use of external
  1669 semidefinite programming solvers.  Method "sos" generates a
  1670 certificate that can be pasted into the proof thus avoiding the need
  1671 to call an external tool every time the proof is checked.  See
  1672 src/HOL/Library/Sum_Of_Squares.
  1673 
  1674 * New method "linarith" invokes existing linear arithmetic decision
  1675 procedure only.
  1676 
  1677 * New command 'atp_minimal' reduces result produced by Sledgehammer.
  1678 
  1679 * New Sledgehammer option "Full Types" in Proof General settings menu.
  1680 Causes full type information to be output to the ATPs.  This slows
  1681 ATPs down considerably but eliminates a source of unsound "proofs"
  1682 that fail later.
  1683 
  1684 * New method "metisFT": A version of metis that uses full type
  1685 information in order to avoid failures of proof reconstruction.
  1686 
  1687 * New evaluator "approximate" approximates an real valued term using
  1688 the same method as the approximation method.
  1689 
  1690 * Method "approximate" now supports arithmetic expressions as
  1691 boundaries of intervals and implements interval splitting and Taylor
  1692 series expansion.
  1693 
  1694 * ML antiquotation @{code_datatype} inserts definition of a datatype
  1695 generated by the code generator; e.g. see src/HOL/Predicate.thy.
  1696 
  1697 * New theory SupInf of the supremum and infimum operators for sets of
  1698 reals.
  1699 
  1700 * New theory Probability, which contains a development of measure
  1701 theory, eventually leading to Lebesgue integration and probability.
  1702 
  1703 * Extended Multivariate Analysis to include derivation and Brouwer's
  1704 fixpoint theorem.
  1705 
  1706 * Reorganization of number theory, INCOMPATIBILITY:
  1707   - new number theory development for nat and int, in theories Divides
  1708     and GCD as well as in new session Number_Theory
  1709   - some constants and facts now suffixed with _nat and _int
  1710     accordingly
  1711   - former session NumberTheory now named Old_Number_Theory, including
  1712     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
  1713   - moved theory Pocklington from src/HOL/Library to
  1714     src/HOL/Old_Number_Theory
  1715 
  1716 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
  1717 lcm of finite and infinite sets. It is shown that they form a complete
  1718 lattice.
  1719 
  1720 * Class semiring_div requires superclass no_zero_divisors and proof of
  1721 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
  1722 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
  1723 generalized to class semiring_div, subsuming former theorems
  1724 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
  1725 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
  1726 INCOMPATIBILITY.
  1727 
  1728 * Refinements to lattice classes and sets:
  1729   - less default intro/elim rules in locale variant, more default
  1730     intro/elim rules in class variant: more uniformity
  1731   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
  1732     le_inf_iff
  1733   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
  1734     sup_aci)
  1735   - renamed ACI to inf_sup_aci
  1736   - new class "boolean_algebra"
  1737   - class "complete_lattice" moved to separate theory
  1738     "Complete_Lattice"; corresponding constants (and abbreviations)
  1739     renamed and with authentic syntax:
  1740     Set.Inf ~>    Complete_Lattice.Inf
  1741     Set.Sup ~>    Complete_Lattice.Sup
  1742     Set.INFI ~>   Complete_Lattice.INFI
  1743     Set.SUPR ~>   Complete_Lattice.SUPR
  1744     Set.Inter ~>  Complete_Lattice.Inter
  1745     Set.Union ~>  Complete_Lattice.Union
  1746     Set.INTER ~>  Complete_Lattice.INTER
  1747     Set.UNION ~>  Complete_Lattice.UNION
  1748   - authentic syntax for
  1749     Set.Pow
  1750     Set.image
  1751   - mere abbreviations:
  1752     Set.empty               (for bot)
  1753     Set.UNIV                (for top)
  1754     Set.inter               (for inf, formerly Set.Int)
  1755     Set.union               (for sup, formerly Set.Un)
  1756     Complete_Lattice.Inter  (for Inf)
  1757     Complete_Lattice.Union  (for Sup)
  1758     Complete_Lattice.INTER  (for INFI)
  1759     Complete_Lattice.UNION  (for SUPR)
  1760   - object-logic definitions as far as appropriate
  1761 
  1762 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
  1763 Un_subset_iff are explicitly deleted as default simp rules; then also
  1764 their lattice counterparts le_inf_iff and le_sup_iff have to be
  1765 deleted to achieve the desired effect.
  1766 
  1767 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
  1768 rules by default any longer; the same applies to min_max.inf_absorb1
  1769 etc.  INCOMPATIBILITY.
  1770 
  1771 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
  1772 pred_set_conv by default.  INCOMPATIBILITY.
  1773 
  1774 * Power operations on relations and functions are now one dedicated
  1775 constant "compow" with infix syntax "^^".  Power operation on
  1776 multiplicative monoids retains syntax "^" and is now defined generic
  1777 in class power.  INCOMPATIBILITY.
  1778 
  1779 * Relation composition "R O S" now has a more standard argument order:
  1780 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
  1781 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
  1782 break, since the O_assoc rule was not rewritten like this.  Fix using
  1783 O_assoc[symmetric].  The same applies to the curried version "R OO S".
  1784 
  1785 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
  1786 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
  1787 INCOMPATIBILITY.
  1788 
  1789 * Most rules produced by inductive and datatype package have mandatory
  1790 prefixes.  INCOMPATIBILITY.
  1791 
  1792 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
  1793 the attribute of the same name.  Each of the theorems in the list
  1794 DERIV_intros assumes composition with an additional function and
  1795 matches a variable to the derivative, which has to be solved by the
  1796 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
  1797 of most elementary terms.  Former Maclauren.DERIV_tac and
  1798 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
  1799 INCOMPATIBILITY.
  1800 
  1801 * Code generator attributes follow the usual underscore convention:
  1802     code_unfold     replaces    code unfold
  1803     code_post       replaces    code post
  1804     etc.
  1805   INCOMPATIBILITY.
  1806 
  1807 * Renamed methods:
  1808     sizechange -> size_change
  1809     induct_scheme -> induction_schema
  1810   INCOMPATIBILITY.
  1811 
  1812 * Discontinued abbreviation "arbitrary" of constant "undefined".
  1813 INCOMPATIBILITY, use "undefined" directly.
  1814 
  1815 * Renamed theorems:
  1816     Suc_eq_add_numeral_1 -> Suc_eq_plus1
  1817     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
  1818     Suc_plus1 -> Suc_eq_plus1
  1819     *anti_sym -> *antisym*
  1820     vector_less_eq_def -> vector_le_def
  1821   INCOMPATIBILITY.
  1822 
  1823 * Added theorem List.map_map as [simp].  Removed List.map_compose.
  1824 INCOMPATIBILITY.
  1825 
  1826 * Removed predicate "M hassize n" (<--> card M = n & finite M).
  1827 INCOMPATIBILITY.
  1828 
  1829 
  1830 *** HOLCF ***
  1831 
  1832 * Theory Representable defines a class "rep" of domains that are
  1833 representable (via an ep-pair) in the universal domain type "udom".
  1834 Instances are provided for all type constructors defined in HOLCF.
  1835 
  1836 * The 'new_domain' command is a purely definitional version of the
  1837 domain package, for representable domains.  Syntax is identical to the
  1838 old domain package.  The 'new_domain' package also supports indirect
  1839 recursion using previously-defined type constructors.  See
  1840 src/HOLCF/ex/New_Domain.thy for examples.
  1841 
  1842 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
  1843 on the left-hand side of an equation, and then performs
  1844 simplification.  Rewriting is done using rules declared with the
  1845 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
  1846 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
  1847 
  1848 * The pattern-match compiler in 'fixrec' can now handle constructors
  1849 with HOL function types.  Pattern-match combinators for the Pair
  1850 constructor are pre-configured.
  1851 
  1852 * The 'fixrec' package now produces better fixed-point induction rules
  1853 for mutually-recursive definitions:  Induction rules have conclusions
  1854 of the form "P foo bar" instead of "P <foo, bar>".
  1855 
  1856 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
  1857 been renamed to "below".  The name "below" now replaces "less" in many
  1858 theorem names.  (Legacy theorem names using "less" are still supported
  1859 as well.)
  1860 
  1861 * The 'fixrec' package now supports "bottom patterns".  Bottom
  1862 patterns can be used to generate strictness rules, or to make
  1863 functions more strict (much like the bang-patterns supported by the
  1864 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
  1865 examples.
  1866 
  1867 
  1868 *** ML ***
  1869 
  1870 * Support for Poly/ML 5.3.0, with improved reporting of compiler
  1871 errors and run-time exceptions, including detailed source positions.
  1872 
  1873 * Structure Name_Space (formerly NameSpace) now manages uniquely
  1874 identified entries, with some additional information such as source
  1875 position, logical grouping etc.
  1876 
  1877 * Theory and context data is now introduced by the simplified and
  1878 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
  1879 to be pure, but the old TheoryDataFun for mutable data (with explicit
  1880 copy operation) is still available for some time.
  1881 
  1882 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
  1883 provides a high-level programming interface to synchronized state
  1884 variables with atomic update.  This works via pure function
  1885 application within a critical section -- its runtime should be as
  1886 short as possible; beware of deadlocks if critical code is nested,
  1887 either directly or indirectly via other synchronized variables!
  1888 
  1889 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
  1890 wraps raw ML references, explicitly indicating their non-thread-safe
  1891 behaviour.  The Isar toplevel keeps this structure open, to
  1892 accommodate Proof General as well as quick and dirty interactive
  1893 experiments with references.
  1894 
  1895 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
  1896 parallel tactical reasoning.
  1897 
  1898 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
  1899 are similar to SUBPROOF, but are slightly more flexible: only the
  1900 specified parts of the subgoal are imported into the context, and the
  1901 body tactic may introduce new subgoals and schematic variables.
  1902 
  1903 * Old tactical METAHYPS, which does not observe the proof context, has
  1904 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
  1905 or Subgoal.FOCUS etc.
  1906 
  1907 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
  1908 functors have their own ML name space there is no point to mark them
  1909 separately.)  Minor INCOMPATIBILITY.
  1910 
  1911 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
  1912 
  1913 * Renamed several structures FooBar to Foo_Bar.  Occasional,
  1914 INCOMPATIBILITY.
  1915 
  1916 * Operations of structure Skip_Proof no longer require quick_and_dirty
  1917 mode, which avoids critical setmp.
  1918 
  1919 * Eliminated old Attrib.add_attributes, Method.add_methods and related
  1920 combinators for "args".  INCOMPATIBILITY, need to use simplified
  1921 Attrib/Method.setup introduced in Isabelle2009.
  1922 
  1923 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
  1924 back on global_simpset_of, global_claset_of, global_clasimpset_of as
  1925 last resort.  INCOMPATIBILITY.
  1926 
  1927 * Display.pretty_thm now requires a proper context (cf. former
  1928 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
  1929 or even Display.pretty_thm_without_context as last resort.
  1930 INCOMPATIBILITY.
  1931 
  1932 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
  1933 Syntax.pretty_typ/term directly, preferably with proper context
  1934 instead of global theory.
  1935 
  1936 
  1937 *** System ***
  1938 
  1939 * Further fine tuning of parallel proof checking, scales up to 8 cores
  1940 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
  1941 usedir option -q.
  1942 
  1943 * Support for additional "Isabelle components" via etc/components, see
  1944 also the system manual.
  1945 
  1946 * The isabelle makeall tool now operates on all components with
  1947 IsaMakefile, not just hardwired "logics".
  1948 
  1949 * Removed "compress" option from isabelle-process and isabelle usedir;
  1950 this is always enabled.
  1951 
  1952 * Discontinued support for Poly/ML 4.x versions.
  1953 
  1954 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
  1955 on a given logic image.  This requires the lighttpd webserver and is
  1956 currently supported on Linux only.
  1957 
  1958 
  1959 
  1960 New in Isabelle2009 (April 2009)
  1961 --------------------------------
  1962 
  1963 *** General ***
  1964 
  1965 * Simplified main Isabelle executables, with less surprises on
  1966 case-insensitive file-systems (such as Mac OS).
  1967 
  1968   - The main Isabelle tool wrapper is now called "isabelle" instead of
  1969     "isatool."
  1970 
  1971   - The former "isabelle" alias for "isabelle-process" has been
  1972     removed (should rarely occur to regular users).
  1973 
  1974   - The former "isabelle-interface" and its alias "Isabelle" have been
  1975     removed (interfaces are now regular Isabelle tools).
  1976 
  1977 Within scripts and make files, the Isabelle environment variables
  1978 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
  1979 respectively.  (The latter are still available as legacy feature.)
  1980 
  1981 The old isabelle-interface wrapper could react in confusing ways if
  1982 the interface was uninstalled or changed otherwise.  Individual
  1983 interface tool configuration is now more explicit, see also the
  1984 Isabelle system manual.  In particular, Proof General is now available
  1985 via "isabelle emacs".
  1986 
  1987 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
  1988 purge installed copies of Isabelle executables and re-run "isabelle
  1989 install -p ...", or use symlinks.
  1990 
  1991 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
  1992 old ~/isabelle, which was slightly non-standard and apt to cause
  1993 surprises on case-insensitive file-systems (such as Mac OS).
  1994 
  1995 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
  1996 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
  1997 care is required when using older releases of Isabelle.  Note that
  1998 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
  1999 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
  2000 
  2001 * Proofs of fully specified statements are run in parallel on
  2002 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
  2003 a regular 4-core machine, if the initial heap space is made reasonably
  2004 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
  2005 
  2006 * The main reference manuals ("isar-ref", "implementation", and
  2007 "system") have been updated and extended.  Formally checked references
  2008 as hyperlinks are now available uniformly.
  2009 
  2010 
  2011 *** Pure ***
  2012 
  2013 * Complete re-implementation of locales.  INCOMPATIBILITY in several
  2014 respects.  The most important changes are listed below.  See the
  2015 Tutorial on Locales ("locales" manual) for details.
  2016 
  2017 - In locale expressions, instantiation replaces renaming.  Parameters
  2018 must be declared in a for clause.  To aid compatibility with previous
  2019 parameter inheritance, in locale declarations, parameters that are not
  2020 'touched' (instantiation position "_" or omitted) are implicitly added
  2021 with their syntax at the beginning of the for clause.
  2022 
  2023 - Syntax from abbreviations and definitions in locales is available in
  2024 locale expressions and context elements.  The latter is particularly
  2025 useful in locale declarations.
  2026 
  2027 - More flexible mechanisms to qualify names generated by locale
  2028 expressions.  Qualifiers (prefixes) may be specified in locale
  2029 expressions, and can be marked as mandatory (syntax: "name!:") or
  2030 optional (syntax "name?:").  The default depends for plain "name:"
  2031 depends on the situation where a locale expression is used: in
  2032 commands 'locale' and 'sublocale' prefixes are optional, in
  2033 'interpretation' and 'interpret' prefixes are mandatory.  The old
  2034 implicit qualifiers derived from the parameter names of a locale are
  2035 no longer generated.
  2036 
  2037 - Command "sublocale l < e" replaces "interpretation l < e".  The
  2038 instantiation clause in "interpretation" and "interpret" (square
  2039 brackets) is no longer available.  Use locale expressions.
  2040 
  2041 - When converting proof scripts, mandatory qualifiers in
  2042 'interpretation' and 'interpret' should be retained by default, even
  2043 if this is an INCOMPATIBILITY compared to former behavior.  In the
  2044 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
  2045 in locale expressions range over a single locale instance only.
  2046 
  2047 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
  2048 In existing theorem specifications replace the includes element by the
  2049 respective context elements of the included locale, omitting those
  2050 that are already present in the theorem specification.  Multiple
  2051 assume elements of a locale should be replaced by a single one
  2052 involving the locale predicate.  In the proof body, declarations (most
  2053 notably theorems) may be regained by interpreting the respective
  2054 locales in the proof context as required (command "interpret").
  2055 
  2056 If using "includes" in replacement of a target solely because the
  2057 parameter types in the theorem are not as general as in the target,
  2058 consider declaring a new locale with additional type constraints on
  2059 the parameters (context element "constrains").
  2060 
  2061 - Discontinued "locale (open)".  INCOMPATIBILITY.
  2062 
  2063 - Locale interpretation commands no longer attempt to simplify goal.
  2064 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
  2065 methods intro_locales and unfold_locales to clarify.
  2066 
  2067 - Locale interpretation commands no longer accept interpretation
  2068 attributes.  INCOMPATIBILITY.
  2069 
  2070 * Class declaration: so-called "base sort" must not be given in import
  2071 list any longer, but is inferred from the specification.  Particularly
  2072 in HOL, write
  2073 
  2074     class foo = ...
  2075 
  2076 instead of
  2077 
  2078     class foo = type + ...
  2079 
  2080 * Class target: global versions of theorems stemming do not carry a
  2081 parameter prefix any longer.  INCOMPATIBILITY.
  2082 
  2083 * Class 'instance' command no longer accepts attached definitions.
  2084 INCOMPATIBILITY, use proper 'instantiation' target instead.
  2085 
  2086 * Recovered hiding of consts, which was accidentally broken in
  2087 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
  2088 makes c inaccessible; consider using ``hide (open) const c'' instead.
  2089 
  2090 * Slightly more coherent Pure syntax, with updated documentation in
  2091 isar-ref manual.  Removed locales meta_term_syntax and
  2092 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
  2093 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
  2094 directly in regular applications.
  2095 
  2096 * There is a new syntactic category "float_const" for signed decimal
  2097 fractions (e.g. 123.45 or -123.45).
  2098 
  2099 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
  2100 interface with 'setup' command instead.
  2101 
  2102 * Command 'local_setup' is similar to 'setup', but operates on a local
  2103 theory context.
  2104 
  2105 * The 'axiomatization' command now only works within a global theory
  2106 context.  INCOMPATIBILITY.
  2107 
  2108 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
  2109 hypotheses.  Sorts required in the course of reasoning need to be
  2110 covered by the constraints in the initial statement, completed by the
  2111 type instance information of the background theory.  Non-trivial sort
  2112 hypotheses, which rarely occur in practice, may be specified via
  2113 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
  2114 
  2115   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
  2116 
  2117 The result contains an implicit sort hypotheses as before --
  2118 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
  2119 normalization.
  2120 
  2121 * Generalized Isar history, with support for linear undo, direct state
  2122 addressing etc.
  2123 
  2124 * Changed defaults for unify configuration options:
  2125 
  2126   unify_trace_bound = 50 (formerly 25)
  2127   unify_search_bound = 60 (formerly 30)
  2128 
  2129 * Different bookkeeping for code equations (INCOMPATIBILITY):
  2130 
  2131   a) On theory merge, the last set of code equations for a particular
  2132      constant is taken (in accordance with the policy applied by other
  2133      parts of the code generator framework).
  2134 
  2135   b) Code equations stemming from explicit declarations (e.g. code
  2136      attribute) gain priority over default code equations stemming
  2137      from definition, primrec, fun etc.
  2138 
  2139 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
  2140 
  2141 * Unified theorem tables for both code generators.  Thus [code
  2142 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
  2143 
  2144 * Command 'find_consts' searches for constants based on type and name
  2145 patterns, e.g.
  2146 
  2147     find_consts "_ => bool"
  2148 
  2149 By default, matching is against subtypes, but it may be restricted to
  2150 the whole type.  Searching by name is possible.  Multiple queries are
  2151 conjunctive and queries may be negated by prefixing them with a
  2152 hyphen:
  2153 
  2154     find_consts strict: "_ => bool" name: "Int" -"int => int"
  2155 
  2156 * New 'find_theorems' criterion "solves" matches theorems that
  2157 directly solve the current goal (modulo higher-order unification).
  2158 
  2159 * Auto solve feature for main theorem statements: whenever a new goal
  2160 is stated, "find_theorems solves" is called; any theorems that could
  2161 solve the lemma directly are listed as part of the goal state.
  2162 Cf. associated options in Proof General Isabelle settings menu,
  2163 enabled by default, with reasonable timeout for pathological cases of
  2164 higher-order unification.
  2165 
  2166 
  2167 *** Document preparation ***
  2168 
  2169 * Antiquotation @{lemma} now imitates a regular terminal proof,
  2170 demanding keyword 'by' and supporting the full method expression
  2171 syntax just like the Isar command 'by'.
  2172 
  2173 
  2174 *** HOL ***
  2175 
  2176 * Integrated main parts of former image HOL-Complex with HOL.  Entry
  2177 points Main and Complex_Main remain as before.
  2178 
  2179 * Logic image HOL-Plain provides a minimal HOL with the most important
  2180 tools available (inductive, datatype, primrec, ...).  This facilitates
  2181 experimentation and tool development.  Note that user applications
  2182 (and library theories) should never refer to anything below theory
  2183 Main, as before.
  2184 
  2185 * Logic image HOL-Main stops at theory Main, and thus facilitates
  2186 experimentation due to shorter build times.
  2187 
  2188 * Logic image HOL-NSA contains theories of nonstandard analysis which
  2189 were previously part of former HOL-Complex.  Entry point Hyperreal
  2190 remains valid, but theories formerly using Complex_Main should now use
  2191 new entry point Hypercomplex.
  2192 
  2193 * Generic ATP manager for Sledgehammer, based on ML threads instead of
  2194 Posix processes.  Avoids potentially expensive forking of the ML
  2195 process.  New thread-based implementation also works on non-Unix
  2196 platforms (Cygwin).  Provers are no longer hardwired, but defined
  2197 within the theory via plain ML wrapper functions.  Basic Sledgehammer
  2198 commands are covered in the isar-ref manual.
  2199 
  2200 * Wrapper scripts for remote SystemOnTPTP service allows to use
  2201 sledgehammer without local ATP installation (Vampire etc.). Other
  2202 provers may be included via suitable ML wrappers, see also
  2203 src/HOL/ATP_Linkup.thy.
  2204 
  2205 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
  2206 menu.
  2207 
  2208 * The metis method no longer fails because the theorem is too trivial
  2209 (contains the empty clause).
  2210 
  2211 * The metis method now fails in the usual manner, rather than raising
  2212 an exception, if it determines that it cannot prove the theorem.
  2213 
  2214 * Method "coherent" implements a prover for coherent logic (see also
  2215 src/Tools/coherent.ML).
  2216 
  2217 * Constants "undefined" and "default" replace "arbitrary".  Usually
  2218 "undefined" is the right choice to replace "arbitrary", though
  2219 logically there is no difference.  INCOMPATIBILITY.
  2220 
  2221 * Command "value" now integrates different evaluation mechanisms.  The
  2222 result of the first successful evaluation mechanism is printed.  In
  2223 square brackets a particular named evaluation mechanisms may be
  2224 specified (currently, [SML], [code] or [nbe]).  See further
  2225 src/HOL/ex/Eval_Examples.thy.
  2226 
  2227 * Normalization by evaluation now allows non-leftlinear equations.
  2228 Declare with attribute [code nbe].
  2229 
  2230 * Methods "case_tac" and "induct_tac" now refer to the very same rules
  2231 as the structured Isar versions "cases" and "induct", cf. the
  2232 corresponding "cases" and "induct" attributes.  Mutual induction rules
  2233 are now presented as a list of individual projections
  2234 (e.g. foo_bar.inducts for types foo and bar); the old format with
  2235 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
  2236 rare situations a different rule is selected --- notably nested tuple
  2237 elimination instead of former prod.exhaust: use explicit (case_tac t
  2238 rule: prod.exhaust) here.
  2239 
  2240 * Attributes "cases", "induct", "coinduct" support "del" option.
  2241 
  2242 * Removed fact "case_split_thm", which duplicates "case_split".
  2243 
  2244 * The option datatype has been moved to a new theory Option.  Renamed
  2245 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
  2246 
  2247 * New predicate "strict_mono" classifies strict functions on partial
  2248 orders.  With strict functions on linear orders, reasoning about
  2249 (in)equalities is facilitated by theorems "strict_mono_eq",
  2250 "strict_mono_less_eq" and "strict_mono_less".
  2251 
  2252 * Some set operations are now proper qualified constants with
  2253 authentic syntax.  INCOMPATIBILITY:
  2254 
  2255     op Int ~>   Set.Int
  2256     op Un ~>    Set.Un
  2257     INTER ~>    Set.INTER
  2258     UNION ~>    Set.UNION
  2259     Inter ~>    Set.Inter
  2260     Union ~>    Set.Union
  2261     {} ~>       Set.empty
  2262     UNIV ~>     Set.UNIV
  2263 
  2264 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  2265 theory Set.
  2266 
  2267 * Auxiliary class "itself" has disappeared -- classes without any
  2268 parameter are treated as expected by the 'class' command.
  2269 
  2270 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  2271 
  2272 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  2273 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  2274 
  2275 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  2276 method "approximation".  It proves formulas on real values by using
  2277 interval arithmetic.  In the formulas are also the transcendental
  2278 functions sin, cos, tan, atan, ln, exp and the constant pi are
  2279 allowed. For examples see
  2280 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  2281 
  2282 * Theory "Reflection" now resides in HOL/Library.
  2283 
  2284 * Entry point to Word library now simply named "Word".
  2285 INCOMPATIBILITY.
  2286 
  2287 * Made source layout more coherent with logical distribution
  2288 structure:
  2289 
  2290     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  2291     src/HOL/Library/Code_Message.thy ~> src/HOL/
  2292     src/HOL/Library/GCD.thy ~> src/HOL/
  2293     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  2294     src/HOL/Library/Parity.thy ~> src/HOL/
  2295     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  2296     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  2297     src/HOL/Real/Lubs.thy ~> src/HOL/
  2298     src/HOL/Real/PReal.thy ~> src/HOL/
  2299     src/HOL/Real/Rational.thy ~> src/HOL/
  2300     src/HOL/Real/RComplete.thy ~> src/HOL/
  2301     src/HOL/Real/RealDef.thy ~> src/HOL/
  2302     src/HOL/Real/RealPow.thy ~> src/HOL/
  2303     src/HOL/Real/Real.thy ~> src/HOL/
  2304     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  2305     src/HOL/Complex/Complex.thy ~> src/HOL/
  2306     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  2307     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  2308     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  2309     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  2310     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  2311     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  2312     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  2313     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  2314     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  2315     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  2316     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  2317     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  2318     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  2319     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  2320     src/HOL/Real/Float ~> src/HOL/Library/
  2321     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  2322     src/HOL/Real/RealVector.thy ~> src/HOL/
  2323 
  2324     src/HOL/arith_data.ML ~> src/HOL/Tools
  2325     src/HOL/hologic.ML ~> src/HOL/Tools
  2326     src/HOL/simpdata.ML ~> src/HOL/Tools
  2327     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  2328     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  2329     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  2330     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  2331     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  2332     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  2333     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  2334 
  2335     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  2336     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  2337     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  2338     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  2339     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  2340     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  2341 
  2342 * If methods "eval" and "evaluation" encounter a structured proof
  2343 state with !!/==>, only the conclusion is evaluated to True (if
  2344 possible), avoiding strange error messages.
  2345 
  2346 * Method "sizechange" automates termination proofs using (a
  2347 modification of) the size-change principle.  Requires SAT solver.  See
  2348 src/HOL/ex/Termination.thy for examples.
  2349 
  2350 * Simplifier: simproc for let expressions now unfolds if bound
  2351 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  2352 
  2353 * Method "arith": Linear arithmetic now ignores all inequalities when
  2354 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  2355 
  2356 * New attribute "arith" for facts that should always be used
  2357 automatically by arithmetic. It is intended to be used locally in
  2358 proofs, e.g.
  2359 
  2360   assumes [arith]: "x > 0"
  2361 
  2362 Global usage is discouraged because of possible performance impact.
  2363 
  2364 * New classes "top" and "bot" with corresponding operations "top" and
  2365 "bot" in theory Orderings; instantiation of class "complete_lattice"
  2366 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  2367 
  2368 * Changed definition lemma "less_fun_def" in order to provide an
  2369 instance for preorders on functions; use lemma "less_le" instead.
  2370 INCOMPATIBILITY.
  2371 
  2372 * Theory Orderings: class "wellorder" moved here, with explicit
  2373 induction rule "less_induct" as assumption.  For instantiation of
  2374 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  2375 INCOMPATIBILITY.
  2376 
  2377 * Theory Orderings: added class "preorder" as superclass of "order".
  2378 INCOMPATIBILITY: Instantiation proofs for order, linorder
  2379 etc. slightly changed.  Some theorems named order_class.* now named
  2380 preorder_class.*.
  2381 
  2382 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  2383 "diag" to "Id_on".
  2384 
  2385 * Theory Finite_Set: added a new fold combinator of type
  2386 
  2387   ('a => 'b => 'b) => 'b => 'a set => 'b
  2388 
  2389 Occasionally this is more convenient than the old fold combinator
  2390 which is now defined in terms of the new one and renamed to
  2391 fold_image.
  2392 
  2393 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  2394 and "ring_simps" have been replaced by "algebra_simps" (which can be
  2395 extended with further lemmas!).  At the moment both still exist but
  2396 the former will disappear at some point.
  2397 
  2398 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  2399 class recpower.  Type-specific simp rules for various recpower types
  2400 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  2401 
  2402 rat_power_0    -> power_0
  2403 rat_power_Suc  -> power_Suc
  2404 realpow_0      -> power_0
  2405 realpow_Suc    -> power_Suc
  2406 complexpow_0   -> power_0
  2407 complexpow_Suc -> power_Suc
  2408 power_poly_0   -> power_0
  2409 power_poly_Suc -> power_Suc
  2410 
  2411 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  2412 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  2413 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  2414 of lemmas from Divides has been generalized from nat to class
  2415 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  2416 renames resulting from duplicate elimination:
  2417 
  2418     dvd_def_mod ~>          dvd_eq_mod_eq_0
  2419     zero_dvd_iff ~>         dvd_0_left_iff
  2420     dvd_0 ~>                dvd_0_right
  2421     DIVISION_BY_ZERO_DIV ~> div_by_0
  2422     DIVISION_BY_ZERO_MOD ~> mod_by_0
  2423     mult_div ~>             div_mult_self2_is_id
  2424     mult_mod ~>             mod_mult_self2_is_0
  2425 
  2426 * Theory IntDiv: removed many lemmas that are instances of class-based
  2427 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  2428 rename old lemmas as follows:
  2429 
  2430 dvd_diff               -> nat_dvd_diff
  2431 dvd_zminus_iff         -> dvd_minus_iff
  2432 mod_add1_eq            -> mod_add_eq
  2433 mod_mult1_eq           -> mod_mult_right_eq
  2434 mod_mult1_eq'          -> mod_mult_left_eq
  2435 mod_mult_distrib_mod   -> mod_mult_eq
  2436 nat_mod_add_left_eq    -> mod_add_left_eq
  2437 nat_mod_add_right_eq   -> mod_add_right_eq
  2438 nat_mod_div_trivial    -> mod_div_trivial
  2439 nat_mod_mod_trivial    -> mod_mod_trivial
  2440 zdiv_zadd_self1        -> div_add_self1
  2441 zdiv_zadd_self2        -> div_add_self2
  2442 zdiv_zmult_self1       -> div_mult_self2_is_id
  2443 zdiv_zmult_self2       -> div_mult_self1_is_id
  2444 zdvd_triv_left         -> dvd_triv_left
  2445 zdvd_triv_right        -> dvd_triv_right
  2446 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  2447 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  2448 zmod_zadd_left_eq      -> mod_add_left_eq
  2449 zmod_zadd_right_eq     -> mod_add_right_eq
  2450 zmod_zadd_self1        -> mod_add_self1
  2451 zmod_zadd_self2        -> mod_add_self2
  2452 zmod_zadd1_eq          -> mod_add_eq
  2453 zmod_zdiff1_eq         -> mod_diff_eq
  2454 zmod_zdvd_zmod         -> mod_mod_cancel
  2455 zmod_zmod_cancel       -> mod_mod_cancel
  2456 zmod_zmult_self1       -> mod_mult_self2_is_0
  2457 zmod_zmult_self2       -> mod_mult_self1_is_0
  2458 zmod_1                 -> mod_by_1
  2459 zdiv_1                 -> div_by_1
  2460 zdvd_abs1              -> abs_dvd_iff
  2461 zdvd_abs2              -> dvd_abs_iff
  2462 zdvd_refl              -> dvd_refl
  2463 zdvd_trans             -> dvd_trans
  2464 zdvd_zadd              -> dvd_add
  2465 zdvd_zdiff             -> dvd_diff
  2466 zdvd_zminus_iff        -> dvd_minus_iff
  2467 zdvd_zminus2_iff       -> minus_dvd_iff
  2468 zdvd_zmultD            -> dvd_mult_right
  2469 zdvd_zmultD2           -> dvd_mult_left
  2470 zdvd_zmult_mono        -> mult_dvd_mono
  2471 zdvd_0_right           -> dvd_0_right
  2472 zdvd_0_left            -> dvd_0_left_iff
  2473 zdvd_1_left            -> one_dvd
  2474 zminus_dvd_iff         -> minus_dvd_iff
  2475 
  2476 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  2477 
  2478 * The real numbers offer decimal input syntax: 12.34 is translated
  2479 into 1234/10^2. This translation is not reversed upon output.
  2480 
  2481 * Theory Library/Polynomial defines an abstract type 'a poly of
  2482 univariate polynomials with coefficients of type 'a.  In addition to
  2483 the standard ring operations, it also supports div and mod.  Code
  2484 generation is also supported, using list-style constructors.
  2485 
  2486 * Theory Library/Inner_Product defines a class of real_inner for real
  2487 inner product spaces, with an overloaded operation inner :: 'a => 'a
  2488 => real.  Class real_inner is a subclass of real_normed_vector from
  2489 theory RealVector.
  2490 
  2491 * Theory Library/Product_Vector provides instances for the product
  2492 type 'a * 'b of several classes from RealVector and Inner_Product.
  2493 Definitions of addition, subtraction, scalar multiplication, norms,
  2494 and inner products are included.
  2495 
  2496 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  2497 addition to the field operations, numerals and case syntax are also
  2498 supported.
  2499 
  2500 * Theory Library/Diagonalize provides constructive version of Cantor's
  2501 first diagonalization argument.
  2502 
  2503 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  2504 zlcm (for int); carried together from various gcd/lcm developements in
  2505 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  2506 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  2507 may recover tupled syntax as follows:
  2508 
  2509     hide (open) const gcd
  2510     abbreviation gcd where
  2511       "gcd == (%(a, b). GCD.gcd a b)"
  2512     notation (output)
  2513       GCD.gcd ("gcd '(_, _')")
  2514 
  2515 The same works for lcm, zgcd, zlcm.
  2516 
  2517 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  2518 instantiations for algebraic structures.  Removed some duplicate
  2519 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  2520 
  2521 * ML antiquotation @{code} takes a constant as argument and generates
  2522 corresponding code in background and inserts name of the corresponding
  2523 resulting ML value/function/datatype constructor binding in place.
  2524 All occurrences of @{code} with a single ML block are generated
  2525 simultaneously.  Provides a generic and safe interface for
  2526 instrumentalizing code generation.  See
  2527 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  2528 In future you ought to refrain from ad-hoc compiling generated SML
  2529 code on the ML toplevel.  Note that (for technical reasons) @{code}
  2530 cannot refer to constants for which user-defined serializations are
  2531 set.  Refer to the corresponding ML counterpart directly in that
  2532 cases.
  2533 
  2534 * Command 'rep_datatype': instead of theorem names the command now
  2535 takes a list of terms denoting the constructors of the type to be
  2536 represented as datatype.  The characteristic theorems have to be
  2537 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  2538 have disappeared in favour of existing ones:
  2539 
  2540     unit_induct                 ~> unit.induct
  2541     prod_induct                 ~> prod.induct
  2542     sum_induct                  ~> sum.induct
  2543     Suc_Suc_eq                  ~> nat.inject
  2544     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  2545 
  2546 
  2547 *** HOL-Algebra ***
  2548 
  2549 * New locales for orders and lattices where the equivalence relation
  2550 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  2551 locales use a record structure with field eq for the equivalence.
  2552 
  2553 * New theory of factorial domains.
  2554 
  2555 * Units_l_inv and Units_r_inv are now simp rules by default.
  2556 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  2557 and/or r_inv will now also require deletion of these lemmas.
  2558 
  2559 * Renamed the following theorems, INCOMPATIBILITY:
  2560 
  2561 UpperD ~> Upper_memD
  2562 LowerD ~> Lower_memD
  2563 least_carrier ~> least_closed
  2564 greatest_carrier ~> greatest_closed
  2565 greatest_Lower_above ~> greatest_Lower_below
  2566 one_zero ~> carrier_one_zero
  2567 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  2568 
  2569 
  2570 *** HOL-Nominal ***
  2571 
  2572 * Nominal datatypes can now contain type-variables.
  2573 
  2574 * Commands 'nominal_inductive' and 'equivariance' work with local
  2575 theory targets.
  2576 
  2577 * Nominal primrec can now works with local theory targets and its
  2578 specification syntax now conforms to the general format as seen in
  2579 'inductive' etc.
  2580 
  2581 * Method "perm_simp" honours the standard simplifier attributes
  2582 (no_asm), (no_asm_use) etc.
  2583 
  2584 * The new predicate #* is defined like freshness, except that on the
  2585 left hand side can be a set or list of atoms.
  2586 
  2587 * Experimental command 'nominal_inductive2' derives strong induction
  2588 principles for inductive definitions.  In contrast to
  2589 'nominal_inductive', which can only deal with a fixed number of
  2590 binders, it can deal with arbitrary expressions standing for sets of
  2591 atoms to be avoided.  The only inductive definition we have at the
  2592 moment that needs this generalisation is the typing rule for Lets in
  2593 the algorithm W:
  2594 
  2595  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  2596  -----------------------------------------------------------------
  2597          Gamma |- Let x be t1 in t2 : T2
  2598 
  2599 In this rule one wants to avoid all the binders that are introduced by
  2600 "close Gamma T1".  We are looking for other examples where this
  2601 feature might be useful.  Please let us know.
  2602 
  2603 
  2604 *** HOLCF ***
  2605 
  2606 * Reimplemented the simplification procedure for proving continuity
  2607 subgoals.  The new simproc is extensible; users can declare additional
  2608 continuity introduction rules with the attribute [cont2cont].
  2609 
  2610 * The continuity simproc now uses a different introduction rule for
  2611 solving continuity subgoals on terms with lambda abstractions.  In
  2612 some rare cases the new simproc may fail to solve subgoals that the
  2613 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  2614 Potential INCOMPATIBILITY.
  2615 
  2616 * Command 'fixrec': specification syntax now conforms to the general
  2617 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  2618 examples.  INCOMPATIBILITY.
  2619 
  2620 
  2621 *** ZF ***
  2622 
  2623 * Proof of Zorn's Lemma for partial orders.
  2624 
  2625 
  2626 *** ML ***
  2627 
  2628 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  2629 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  2630 depends on multithreading, so timouts will not work before Poly/ML
  2631 5.2.1!
  2632 
  2633 * High-level support for concurrent ML programming, see
  2634 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  2635 particularly convenient to organize independent functional
  2636 computations.  The concept of "synchronized variables" provides a
  2637 higher-order interface for components with shared state, avoiding the
  2638 delicate details of mutexes and condition variables.  (Requires
  2639 Poly/ML 5.2.1 or later.)
  2640 
  2641 * ML bindings produced via Isar commands are stored within the Isar
  2642 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  2643 become thread-safe and work with undo as expected (concerning
  2644 top-level bindings, not side-effects on global references).
  2645 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  2646 compiler at runtime; really global bindings need to be given outside a
  2647 theory.  (Requires Poly/ML 5.2 or later.)
  2648 
  2649 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  2650 context.  Top-level ML bindings are stored within the proof context in
  2651 a purely sequential fashion, disregarding the nested proof structure.
  2652 ML bindings introduced by 'ML_prf' are discarded at the end of the
  2653 proof.  (Requires Poly/ML 5.2 or later.)
  2654 
  2655 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  2656 and Method.setup, as well as Isar commands 'attribute_setup' and
  2657 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  2658 existing code accordingly, or use plain 'setup' together with old
  2659 Method.add_method.
  2660 
  2661 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  2662 to 'a -> thm, while results are always tagged with an authentic oracle
  2663 name.  The Isar command 'oracle' is now polymorphic, no argument type
  2664 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  2665 accordingly.  Note that extra performance may be gained by producing
  2666 the cterm carefully, avoiding slow Thm.cterm_of.
  2667 
  2668 * Simplified interface for defining document antiquotations via
  2669 ThyOutput.antiquotation, ThyOutput.output, and optionally
  2670 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  2671 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  2672 examples.
  2673 
  2674 * More systematic treatment of long names, abstract name bindings, and
  2675 name space operations.  Basic operations on qualified names have been
  2676 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  2677 Long_Name.append.  Old type bstring has been mostly replaced by
  2678 abstract type binding (see structure Binding), which supports precise
  2679 qualification by packages and local theory targets, as well as proper
  2680 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  2681 bstring values into Binding.name, or better pass through abstract
  2682 bindings everywhere.  See further src/Pure/General/long_name.ML,
  2683 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  2684 
  2685 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  2686 LocalTheory.note etc.) now refer to the *full* internal name, not the
  2687 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  2688 
  2689 * Disposed old type and term read functions (Sign.read_def_typ,
  2690 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  2691 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  2692 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  2693 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  2694 resort for legacy applications.
  2695 
  2696 * Disposed old declarations, tactics, tactic combinators that refer to
  2697 the simpset or claset of an implicit theory (such as Addsimps,
  2698 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  2699 embedded ML text, or local_simpset_of with a proper context passed as
  2700 explicit runtime argument.
  2701 
  2702 * Rules and tactics that read instantiations (read_instantiate,
  2703 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  2704 context, which is required for parsing and type-checking.  Moreover,
  2705 the variables are specified as plain indexnames, not string encodings
  2706 thereof.  INCOMPATIBILITY.
  2707 
  2708 * Generic Toplevel.add_hook interface allows to analyze the result of
  2709 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  2710 for theorem dependency output of transactions resulting in a new
  2711 theory state.
  2712 
  2713 * ML antiquotations: block-structured compilation context indicated by
  2714 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  2715 
  2716   @{binding name}                         - basic name binding
  2717   @{let ?pat = term}                      - term abbreviation (HO matching)
  2718   @{note name = fact}                     - fact abbreviation
  2719   @{thm fact}                             - singleton fact (with attributes)
  2720   @{thms fact}                            - general fact (with attributes)
  2721   @{lemma prop by method}                 - singleton goal
  2722   @{lemma prop by meth1 meth2}            - singleton goal
  2723   @{lemma prop1 ... propN by method}      - general goal
  2724   @{lemma prop1 ... propN by meth1 meth2} - general goal
  2725   @{lemma (open) ...}                     - open derivation
  2726 
  2727 
  2728 *** System ***
  2729 
  2730 * The Isabelle "emacs" tool provides a specific interface to invoke
  2731 Proof General / Emacs, with more explicit failure if that is not
  2732 installed (the old isabelle-interface script silently falls back on
  2733 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  2734 installation location of the Proof General distribution.
  2735 
  2736 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  2737 the Isabelle process into a JVM/Scala application.  See
  2738 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  2739 process wrapper has been discontinued.)
  2740 
  2741 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  2742 
  2743 * Various status messages (with exact source position information) are
  2744 emitted, if proper markup print mode is enabled.  This allows
  2745 user-interface components to provide detailed feedback on internal
  2746 prover operations.
  2747 
  2748 
  2749 
  2750 New in Isabelle2008 (June 2008)
  2751 -------------------------------
  2752 
  2753 *** General ***
  2754 
  2755 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  2756 and updated, with formally checked references as hyperlinks.
  2757 
  2758 * Theory loader: use_thy (and similar operations) no longer set the
  2759 implicit ML context, which was occasionally hard to predict and in
  2760 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  2761 provides a proper context already.
  2762 
  2763 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2764 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  2765 'use' within a theory file will do the job.
  2766 
  2767 * Name space merge now observes canonical order, i.e. the second space
  2768 is inserted into the first one, while existing entries in the first
  2769 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  2770 swap theory imports.
  2771 
  2772 * Syntax: symbol \<chi> is now considered a letter.  Potential
  2773 INCOMPATIBILITY in identifier syntax etc.
  2774 
  2775 * Outer syntax: string tokens no longer admit escaped white space,
  2776 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  2777 white space without escapes.
  2778 
  2779 * Outer syntax: string tokens may contain arbitrary character codes
  2780 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  2781 "foo_bar".
  2782 
  2783 
  2784 *** Pure ***
  2785 
  2786 * Context-dependent token translations.  Default setup reverts locally
  2787 fixed variables, and adds hilite markup for undeclared frees.
  2788 
  2789 * Unused theorems can be found using the new command 'unused_thms'.
  2790 There are three ways of invoking it:
  2791 
  2792 (1) unused_thms
  2793      Only finds unused theorems in the current theory.
  2794 
  2795 (2) unused_thms thy_1 ... thy_n -
  2796      Finds unused theorems in the current theory and all of its ancestors,
  2797      excluding the theories thy_1 ... thy_n and all of their ancestors.
  2798 
  2799 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  2800      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  2801      their ancestors, excluding the theories thy_1 ... thy_n and all of
  2802      their ancestors.
  2803 
  2804 In order to increase the readability of the list produced by
  2805 unused_thms, theorems that have been created by a particular instance
  2806 of a theory command such as 'inductive' or 'function' are considered
  2807 to belong to the same "group", meaning that if at least one theorem in
  2808 this group is used, the other theorems in the same group are no longer
  2809 reported as unused.  Moreover, if all theorems in the group are
  2810 unused, only one theorem in the group is displayed.
  2811 
  2812 Note that proof objects have to be switched on in order for
  2813 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  2814 usually the case when using Proof General with the default settings).
  2815 
  2816 * Authentic naming of facts disallows ad-hoc overwriting of previous
  2817 theorems within the same name space.  INCOMPATIBILITY, need to remove
  2818 duplicate fact bindings, or even accidental fact duplications.  Note
  2819 that tools may maintain dynamically scoped facts systematically, using
  2820 PureThy.add_thms_dynamic.
  2821 
  2822 * Command 'hide' now allows to hide from "fact" name space as well.
  2823 
  2824 * Eliminated destructive theorem database, simpset, claset, and
  2825 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  2826 update of theories within ML code.
  2827 
  2828 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  2829 INCOMPATIBILITY, object-logics depending on former Pure require
  2830 additional setup PureThy.old_appl_syntax_setup; object-logics
  2831 depending on former CPure need to refer to Pure.
  2832 
  2833 * Commands 'use' and 'ML' are now purely functional, operating on
  2834 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  2835 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  2836 INCOMPATIBILITY.
  2837 
  2838 * Command 'setup': discontinued implicit version with ML reference.
  2839 
  2840 * Instantiation target allows for simultaneous specification of class
  2841 instance operations together with an instantiation proof.
  2842 Type-checking phase allows to refer to class operations uniformly.
  2843 See src/HOL/Complex/Complex.thy for an Isar example and
  2844 src/HOL/Library/Eval.thy for an ML example.
  2845 
  2846 * Indexing of literal facts: be more serious about including only
  2847 facts from the visible specification/proof context, but not the
  2848 background context (locale etc.).  Affects `prop` notation and method
  2849 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  2850 situations.
  2851 
  2852 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  2853 "(open)" option, which used to expose internal bound variables to the
  2854 proof text.
  2855 
  2856 * Isar statements: removed obsolete case "rule_context".
  2857 INCOMPATIBILITY, better use explicit fixes/assumes.
  2858 
  2859 * Locale proofs: default proof step now includes 'unfold_locales';
  2860 hence 'proof' without argument may be used to unfold locale
  2861 predicates.
  2862 
  2863 
  2864 *** Document preparation ***
  2865 
  2866 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  2867 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  2868 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  2869 spot); renamed link color from "darkblue" to "linkcolor" (default
  2870 value unchanged, can be redefined via \definecolor); no longer sets
  2871 "a4paper" option (unnecessary or even intrusive).
  2872 
  2873 * Antiquotation @{lemma A method} proves proposition A by the given
  2874 method (either a method name or a method name plus (optional) method
  2875 arguments in parentheses) and prints A just like @{prop A}.
  2876 
  2877 
  2878 *** HOL ***
  2879 
  2880 * New primrec package.  Specification syntax conforms in style to
  2881 definition/function/....  No separate induction rule is provided.  The
  2882 "primrec" command distinguishes old-style and new-style specifications
  2883 by syntax.  The former primrec package is now named OldPrimrecPackage.
  2884 When adjusting theories, beware: constants stemming from new-style
  2885 primrec specifications have authentic syntax.
  2886 
  2887 * Metis prover is now an order of magnitude faster, and also works
  2888 with multithreading.
  2889 
  2890 * Metis: the maximum number of clauses that can be produced from a
  2891 theorem is now given by the attribute max_clauses.  Theorems that
  2892 exceed this number are ignored, with a warning printed.
  2893 
  2894 * Sledgehammer no longer produces structured proofs by default. To
  2895 enable, declare [[sledgehammer_full = true]].  Attributes
  2896 reconstruction_modulus, reconstruction_sorts renamed
  2897 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  2898 
  2899 * Method "induct_scheme" derives user-specified induction rules
  2900 from well-founded induction and completeness of patterns. This factors
  2901 out some operations that are done internally by the function package
  2902 and makes them available separately.  See
  2903 src/HOL/ex/Induction_Scheme.thy for examples.
  2904 
  2905 * More flexible generation of measure functions for termination
  2906 proofs: Measure functions can be declared by proving a rule of the
  2907 form "is_measure f" and giving it the [measure_function] attribute.
  2908 The "is_measure" predicate is logically meaningless (always true), and
  2909 just guides the heuristic.  To find suitable measure functions, the
  2910 termination prover sets up the goal "is_measure ?f" of the appropriate
  2911 type and generates all solutions by prolog-style backwards proof using
  2912 the declared rules.
  2913 
  2914 This setup also deals with rules like 
  2915 
  2916   "is_measure f ==> is_measure (list_size f)"
  2917 
  2918 which accommodates nested datatypes that recurse through lists.
  2919 Similar rules are predeclared for products and option types.
  2920 
  2921 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  2922 
  2923   INCOMPATIBILITIES:
  2924 
  2925   - Definitions of overloaded constants on sets have to be replaced by
  2926     definitions on => and bool.
  2927 
  2928   - Some definitions of overloaded operators on sets can now be proved
  2929     using the definitions of the operators on => and bool.  Therefore,
  2930     the following theorems have been renamed:
  2931 
  2932       subset_def   -> subset_eq
  2933       psubset_def  -> psubset_eq
  2934       set_diff_def -> set_diff_eq
  2935       Compl_def    -> Compl_eq
  2936       Sup_set_def  -> Sup_set_eq
  2937       Inf_set_def  -> Inf_set_eq
  2938       sup_set_def  -> sup_set_eq
  2939       inf_set_def  -> inf_set_eq
  2940 
  2941   - Due to the incompleteness of the HO unification algorithm, some
  2942     rules such as subst may require manual instantiation, if some of
  2943     the unknowns in the rule is a set.
  2944 
  2945   - Higher order unification and forward proofs:
  2946     The proof pattern
  2947 
  2948       have "P (S::'a set)" <...>
  2949       then have "EX S. P S" ..
  2950 
  2951     no longer works (due to the incompleteness of the HO unification
  2952     algorithm) and must be replaced by the pattern
  2953 
  2954       have "EX S. P S"
  2955       proof
  2956         show "P S" <...>
  2957       qed
  2958 
  2959   - Calculational reasoning with subst (or similar rules):
  2960     The proof pattern
  2961 
  2962       have "P (S::'a set)" <...>
  2963       also have "S = T" <...>
  2964       finally have "P T" .
  2965 
  2966     no longer works (for similar reasons as the previous example) and
  2967     must be replaced by something like
  2968 
  2969       have "P (S::'a set)" <...>
  2970       moreover have "S = T" <...>
  2971       ultimately have "P T" by simp
  2972 
  2973   - Tactics or packages written in ML code:
  2974     Code performing pattern matching on types via
  2975 
  2976       Type ("set", [T]) => ...
  2977 
  2978     must be rewritten. Moreover, functions like strip_type or
  2979     binder_types no longer return the right value when applied to a
  2980     type of the form
  2981 
  2982       T1 => ... => Tn => U => bool
  2983 
  2984     rather than
  2985 
  2986       T1 => ... => Tn => U set
  2987 
  2988 * Merged theories Wellfounded_Recursion, Accessible_Part and
  2989 Wellfounded_Relations to theory Wellfounded.
  2990 
  2991 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  2992 
  2993 * Class finite no longer treats UNIV as class parameter.  Use class
  2994 enum from theory Library/Enum instead to achieve a similar effect.
  2995 INCOMPATIBILITY.
  2996 
  2997 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  2998 and "Cons".  INCOMPATIBILITY.
  2999 
  3000 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  3001 Potential INCOMPATIBILITY.
  3002 
  3003 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  3004 injective_fst_snd removed, use split_eta and prod_eqI instead.
  3005 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  3006 
  3007 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  3008 the same name in theory Orderings:
  3009 
  3010   less_trans
  3011   less_linear
  3012   le_imp_less_or_eq
  3013   le_less_trans
  3014   less_le_trans
  3015   less_not_sym
  3016   less_asym
  3017 
  3018 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  3019 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  3020 and different variable names.
  3021 
  3022 * Library/Option_ord.thy: Canonical order on option type.
  3023 
  3024 * Library/RBT.thy: Red-black trees, an efficient implementation of
  3025 finite maps.
  3026 
  3027 * Library/Countable.thy: Type class for countable types.
  3028 
  3029 * Theory Int: The representation of numerals has changed.  The infix
  3030 operator BIT and the bit datatype with constructors B0 and B1 have
  3031 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  3032 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  3033 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  3034 accordingly.
  3035 
  3036 * Theory Nat: definition of <= and < on natural numbers no longer
  3037 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  3038 le_def and less_def have disappeared.  Consider lemmas not_less
  3039 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  3040 
  3041 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  3042 (whose purpose mainly is for various fold_set functionals) have been
  3043 abandoned in favor of the existing algebraic classes
  3044 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  3045 lower_semilattice (resp. upper_semilattice) and linorder.
  3046 INCOMPATIBILITY.
  3047 
  3048 * Theory Transitive_Closure: induct and cases rules now declare proper
  3049 case_names ("base" and "step").  INCOMPATIBILITY.
  3050 
  3051 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  3052 lattices.  The form set-specific version is available as
  3053 Inductive.lfp_ordinal_induct_set.
  3054 
  3055 * Renamed theorems "power.simps" to "power_int.simps".
  3056 INCOMPATIBILITY.
  3057 
  3058 * Class semiring_div provides basic abstract properties of semirings
  3059 with division and modulo operations.  Subsumes former class dvd_mod.
  3060 
  3061 * Merged theories IntDef, Numeral and IntArith into unified theory
  3062 Int.  INCOMPATIBILITY.
  3063 
  3064 * Theory Library/Code_Index: type "index" now represents natural
  3065 numbers rather than integers.  INCOMPATIBILITY.
  3066 
  3067 * New class "uminus" with operation "uminus" (split of from class
  3068 "minus" which now only has operation "minus", binary).
  3069 INCOMPATIBILITY.
  3070 
  3071 * Constants "card", "internal_split", "option_map" now with authentic
  3072 syntax.  INCOMPATIBILITY.
  3073 
  3074 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  3075 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  3076 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  3077 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  3078 Sup_set_def, le_def, less_def, option_map_def now with object
  3079 equality.  INCOMPATIBILITY.
  3080 
  3081 * Records. Removed K_record, and replaced it by pure lambda term
  3082 %x. c. The simplifier setup is now more robust against eta expansion.
  3083 INCOMPATIBILITY: in cases explicitly referring to K_record.
  3084 
  3085 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  3086 
  3087 * Library/ListVector: new theory of arithmetic vector operations.
  3088 
  3089 * Library/Order_Relation: new theory of various orderings as sets of
  3090 pairs.  Defines preorders, partial orders, linear orders and
  3091 well-orders on sets and on types.
  3092 
  3093 
  3094 *** ZF ***
  3095 
  3096 * Renamed some theories to allow to loading both ZF and HOL in the
  3097 same session:
  3098 
  3099   Datatype  -> Datatype_ZF
  3100   Inductive -> Inductive_ZF
  3101   Int       -> Int_ZF
  3102   IntDiv    -> IntDiv_ZF
  3103   Nat       -> Nat_ZF
  3104   List      -> List_ZF
  3105   Main      -> Main_ZF
  3106 
  3107 INCOMPATIBILITY: ZF theories that import individual theories below
  3108 Main might need to be adapted.  Regular theory Main is still
  3109 available, as trivial extension of Main_ZF.
  3110 
  3111 
  3112 *** ML ***
  3113 
  3114 * ML within Isar: antiquotation @{const name} or @{const
  3115 name(typargs)} produces statically-checked Const term.
  3116 
  3117 * Functor NamedThmsFun: data is available to the user as dynamic fact
  3118 (of the same name).  Removed obsolete print command.
  3119 
  3120 * Removed obsolete "use_legacy_bindings" function.
  3121 
  3122 * The ``print mode'' is now a thread-local value derived from a global
  3123 template (the former print_mode reference), thus access becomes
  3124 non-critical.  The global print_mode reference is for session
  3125 management only; user-code should use print_mode_value,
  3126 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  3127 
  3128 * Functions system/system_out provide a robust way to invoke external
  3129 shell commands, with propagation of interrupts (requires Poly/ML
  3130 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  3131 
  3132 
  3133 *** System ***
  3134 
  3135 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  3136 in accordance with Proof General 3.7, which prefers GNU emacs.
  3137 
  3138 * isatool tty runs Isabelle process with plain tty interaction;
  3139 optional line editor may be specified via ISABELLE_LINE_EDITOR
  3140 setting, the default settings attempt to locate "ledit" and "rlwrap".
  3141 
  3142 * isatool browser now works with Cygwin as well, using general
  3143 "javapath" function defined in Isabelle process environment.
  3144 
  3145 * YXML notation provides a simple and efficient alternative to
  3146 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  3147 isatool yxml as described in the Isabelle system manual.
  3148 
  3149 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  3150 provides general wrapper for managing an Isabelle process in a robust
  3151 fashion, with ``cooked'' output from stdin/stderr.
  3152 
  3153 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  3154 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  3155 
  3156 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  3157 way of changing the user's settings is via
  3158 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  3159 script.
  3160 
  3161 * Multithreading.max_threads := 0 refers to the number of actual CPU
  3162 cores of the underlying machine, which is a good starting point for
  3163 optimal performance tuning.  The corresponding usedir option -M allows
  3164 "max" as an alias for "0".  WARNING: does not work on certain versions
  3165 of Mac OS (with Poly/ML 5.1).
  3166 
  3167 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  3168 adverse effect of Isabelle flooding interactive front-ends (notably
  3169 ProofGeneral / XEmacs).
  3170 
  3171 
  3172 
  3173 New in Isabelle2007 (November 2007)
  3174 -----------------------------------
  3175 
  3176 *** General ***
  3177 
  3178 * More uniform information about legacy features, notably a
  3179 warning/error of "Legacy feature: ...", depending on the state of the
  3180 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  3181 legacy features will disappear eventually.
  3182 
  3183 * Theory syntax: the header format ``theory A = B + C:'' has been
  3184 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  3185 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  3186 
  3187 * Theory syntax: the old non-Isar theory file format has been
  3188 discontinued altogether.  Note that ML proof scripts may still be used
  3189 with Isar theories; migration is usually quite simple with the ML
  3190 function use_legacy_bindings.  INCOMPATIBILITY.
  3191 
  3192 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  3193 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  3194 quotes.
  3195 
  3196 * Theory loader: be more serious about observing the static theory
  3197 header specifications (including optional directories), but not the
  3198 accidental file locations of previously successful loads.  The strict
  3199 update policy of former update_thy is now already performed by
  3200 use_thy, so the former has been removed; use_thys updates several
  3201 theories simultaneously, just as 'imports' within a theory header
  3202 specification, but without merging the results.  Potential
  3203 INCOMPATIBILITY: may need to refine theory headers and commands
  3204 ROOT.ML which depend on load order.
  3205 
  3206 * Theory loader: optional support for content-based file
  3207 identification, instead of the traditional scheme of full physical
  3208 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  3209 (cf. the system manual).  The new scheme allows to work with
  3210 non-finished theories in persistent session images, such that source
  3211 files may be moved later on without requiring reloads.
  3212 
  3213 * Theory loader: old-style ML proof scripts being *attached* to a thy
  3214 file (with the same base name as the theory) are considered a legacy
  3215 feature, which will disappear eventually. Even now, the theory loader
  3216 no longer maintains dependencies on such files.
  3217 
  3218 * Syntax: the scope for resolving ambiguities via type-inference is
  3219 now limited to individual terms, instead of whole simultaneous
  3220 specifications as before. This greatly reduces the complexity of the
  3221 syntax module and improves flexibility by separating parsing and
  3222 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  3223 'fixes' etc.) are required in rare situations.
  3224 
  3225 * Syntax: constants introduced by new-style packages ('definition',
  3226 'abbreviation' etc.) are passed through the syntax module in
  3227 ``authentic mode''. This means that associated mixfix annotations
  3228 really stick to such constants, independently of potential name space
  3229 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  3230 trees are represented slightly differently, may need to adapt syntax
  3231 translations accordingly. Use CONST marker in 'translations' and
  3232 @{const_syntax} antiquotation in 'parse_translation' etc.
  3233 
  3234 * Legacy goal package: reduced interface to the bare minimum required
  3235 to keep existing proof scripts running.  Most other user-level
  3236 functions are now part of the OldGoals structure, which is *not* open
  3237 by default (consider isatool expandshort before open OldGoals).
  3238 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  3239 these tend to cause confusion about the actual goal (!) context being
  3240 used here, which is not necessarily the same as the_context().
  3241 
  3242 * Command 'find_theorems': supports "*" wild-card in "name:"
  3243 criterion; "with_dups" option.  Certain ProofGeneral versions might
  3244 support a specific search form (see ProofGeneral/CHANGES).
  3245 
  3246 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  3247 by default, which means that "prems" (and also "fixed variables") are
  3248 suppressed from proof state output.  Note that the ProofGeneral
  3249 settings mechanism allows to change and save options persistently, but
  3250 older versions of Isabelle will fail to start up if a negative prems
  3251 limit is imposed.
  3252 
  3253 * Local theory targets may be specified by non-nested blocks of
  3254 ``context/locale/class ... begin'' followed by ``end''.  The body may
  3255 contain definitions, theorems etc., including any derived mechanism
  3256 that has been implemented on top of these primitives.  This concept
  3257 generalizes the existing ``theorem (in ...)'' towards more versatility
  3258 and scalability.
  3259 
  3260 * Proof General interface: proper undo of final 'end' command;
  3261 discontinued Isabelle/classic mode (ML proof scripts).
  3262 
  3263 
  3264 *** Document preparation ***
  3265 
  3266 * Added antiquotation @{theory name} which prints the given name,
  3267 after checking that it refers to a valid ancestor theory in the
  3268 current context.
  3269 
  3270 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  3271 check the given source text as ML type/structure, printing verbatim.
  3272 
  3273 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  3274 "c args == rhs" given in the current context.  (Any number of
  3275 arguments may be given on the LHS.)
  3276 
  3277 
  3278 *** Pure ***
  3279 
  3280 * The 'class' package offers a combination of axclass and locale to
  3281 achieve Haskell-like type classes in Isabelle.  Definitions and
  3282 theorems within a class context produce both relative results (with
  3283 implicit parameters according to the locale context), and polymorphic
  3284 constants with qualified polymorphism (according to the class
  3285 context).  Within the body context of a 'class' target, a separate
  3286 syntax layer ("user space type system") takes care of converting
  3287 between global polymorphic consts and internal locale representation.
  3288 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  3289 "isatool doc classes" provides a tutorial.
  3290 
  3291 * Generic code generator framework allows to generate executable
  3292 code for ML and Haskell (including Isabelle classes).  A short usage
  3293 sketch:
  3294 
  3295     internal compilation:
  3296         export_code <list of constants (term syntax)> in SML
  3297     writing SML code to a file:
  3298         export_code <list of constants (term syntax)> in SML <filename>
  3299     writing OCaml code to a file:
  3300         export_code <list of constants (term syntax)> in OCaml <filename>
  3301     writing Haskell code to a bunch of files:
  3302         export_code <list of constants (term syntax)> in Haskell <filename>
  3303 
  3304     evaluating closed propositions to True/False using code generation:
  3305         method ``eval''
  3306 
  3307 Reasonable default setup of framework in HOL.
  3308 
  3309 Theorem attributs for selecting and transforming function equations theorems:
  3310 
  3311     [code fun]:        select a theorem as function equation for a specific constant
  3312     [code fun del]:    deselect a theorem as function equation for a specific constant
  3313     [code inline]:     select an equation theorem for unfolding (inlining) in place
  3314     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  3315 
  3316 User-defined serializations (target in {SML, OCaml, Haskell}):
  3317 
  3318     code_const <and-list of constants (term syntax)>
  3319       {(target) <and-list of const target syntax>}+
  3320 
  3321     code_type <and-list of type constructors>
  3322       {(target) <and-list of type target syntax>}+
  3323 
  3324     code_instance <and-list of instances>
  3325       {(target)}+
  3326         where instance ::= <type constructor> :: <class>
  3327 
  3328     code_class <and_list of classes>
  3329       {(target) <and-list of class target syntax>}+
  3330         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  3331 
  3332 code_instance and code_class only are effective to target Haskell.
  3333 
  3334 For example usage see src/HOL/ex/Codegenerator.thy and
  3335 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  3336 generation from Isabelle/HOL theories is available via "isatool doc
  3337 codegen".
  3338 
  3339 * Code generator: consts in 'consts_code' Isar commands are now
  3340 referred to by usual term syntax (including optional type
  3341 annotations).
  3342 
  3343 * Command 'no_translations' removes translation rules from theory
  3344 syntax.
  3345 
  3346 * Overloaded definitions are now actually checked for acyclic
  3347 dependencies.  The overloading scheme is slightly more general than
  3348 that of Haskell98, although Isabelle does not demand an exact
  3349 correspondence to type class and instance declarations.
  3350 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  3351 exotic versions of overloading -- at the discretion of the user!
  3352 
  3353 Polymorphic constants are represented via type arguments, i.e. the
  3354 instantiation that matches an instance against the most general
  3355 declaration given in the signature.  For example, with the declaration
  3356 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  3357 as c(nat).  Overloading is essentially simultaneous structural
  3358 recursion over such type arguments.  Incomplete specification patterns
  3359 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  3360 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  3361 Command 'print_theory' outputs the normalized system of recursive
  3362 equations, see section "definitions".
  3363 
  3364 * Configuration options are maintained within the theory or proof
  3365 context (with name and type bool/int/string), providing a very simple
  3366 interface to a poor-man's version of general context data.  Tools may
  3367 declare options in ML (e.g. using Attrib.config_int) and then refer to
  3368 these values using Config.get etc.  Users may change options via an
  3369 associated attribute of the same name.  This form of context
  3370 declaration works particularly well with commands 'declare' or
  3371 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  3372 very easy to avoid global references, which would not observe Isar
  3373 toplevel undo/redo and fail to work with multithreading.
  3374 
  3375 Various global ML references of Pure and HOL have been turned into
  3376 configuration options:
  3377 
  3378   Unify.search_bound		unify_search_bound
  3379   Unify.trace_bound		unify_trace_bound
  3380   Unify.trace_simp		unify_trace_simp
  3381   Unify.trace_types		unify_trace_types
  3382   Simplifier.simp_depth_limit	simp_depth_limit
  3383   Blast.depth_limit		blast_depth_limit
  3384   DatatypeProp.dtK		datatype_distinctness_limit
  3385   fast_arith_neq_limit  	fast_arith_neq_limit
  3386   fast_arith_split_limit	fast_arith_split_limit
  3387 
  3388 * Named collections of theorems may be easily installed as context
  3389 data using the functor NamedThmsFun (see also
  3390 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  3391 attributes; there is also a toplevel print command.  This facility is
  3392 just a common case of general context data, which is the preferred way
  3393 for anything more complex than just a list of facts in canonical
  3394 order.
  3395 
  3396 * Isar: command 'declaration' augments a local theory by generic
  3397 declaration functions written in ML.  This enables arbitrary content
  3398 being added to the context, depending on a morphism that tells the
  3399 difference of the original declaration context wrt. the application
  3400 context encountered later on.
  3401 
  3402 * Isar: proper interfaces for simplification procedures.  Command
  3403 'simproc_setup' declares named simprocs (with match patterns, and body
  3404 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  3405 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  3406 
  3407 * Isar: an extra pair of brackets around attribute declarations
  3408 abbreviates a theorem reference involving an internal dummy fact,
  3409 which will be ignored later --- only the effect of the attribute on
  3410 the background context will persist.  This form of in-place
  3411 declarations is particularly useful with commands like 'declare' and
  3412 'using', for example ``have A using [[simproc a]] by simp''.
  3413 
  3414 * Isar: method "assumption" (and implicit closing of subproofs) now
  3415 takes simple non-atomic goal assumptions into account: after applying
  3416 an assumption as a rule the resulting subgoals are solved by atomic
  3417 assumption steps.  This is particularly useful to finish 'obtain'
  3418 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  3419 without referring to the original premise "!!x. P x ==> thesis" in the
  3420 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  3421 more permissive.
  3422 
  3423 * Isar: implicit use of prems from the Isar proof context is
  3424 considered a legacy feature.  Common applications like ``have A .''
  3425 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  3426 referencing facts explicitly here improves readability and
  3427 maintainability of proof texts.
  3428 
  3429 * Isar: improper proof element 'guess' is like 'obtain', but derives
  3430 the obtained context from the course of reasoning!  For example:
  3431 
  3432   assume "EX x y. A x & B y"   -- "any previous fact"
  3433   then guess x and y by clarify
  3434 
  3435 This technique is potentially adventurous, depending on the facts and
  3436 proof tools being involved here.
  3437 
  3438 * Isar: known facts from the proof context may be specified as literal
  3439 propositions, using ASCII back-quote syntax.  This works wherever
  3440 named facts used to be allowed so far, in proof commands, proof
  3441 methods, attributes etc.  Literal facts are retrieved from the context
  3442 according to unification of type and term parameters.  For example,
  3443 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  3444 theorems in the current context, then these are valid literal facts:
  3445 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  3446 
  3447 There is also a proof method "fact" which does the same composition
  3448 for explicit goal states, e.g. the following proof texts coincide with
  3449 certain special cases of literal facts:
  3450 
  3451   have "A" by fact                 ==  note `A`
  3452   have "A ==> B" by fact           ==  note `A ==> B`
  3453   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  3454   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  3455 
  3456 * Isar: ":" (colon) is no longer a symbolic identifier character in
  3457 outer syntax.  Thus symbolic identifiers may be used without
  3458 additional white space in declarations like this: ``assume *: A''.
  3459 
  3460 * Isar: 'print_facts' prints all local facts of the current context,
  3461 both named and unnamed ones.
  3462 
  3463 * Isar: 'def' now admits simultaneous definitions, e.g.:
  3464 
  3465   def x == "t" and y == "u"
  3466 
  3467 * Isar: added command 'unfolding', which is structurally similar to
  3468 'using', but affects both the goal state and facts by unfolding given
  3469 rewrite rules.  Thus many occurrences of the 'unfold' method or
  3470 'unfolded' attribute may be replaced by first-class proof text.
  3471 
  3472 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  3473 and command 'unfolding' now all support object-level equalities
  3474 (potentially conditional).  The underlying notion of rewrite rule is
  3475 analogous to the 'rule_format' attribute, but *not* that of the
  3476 Simplifier (which is usually more generous).
  3477 
  3478 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  3479 premises of a theorem by n. Useful in conjunction with drule.
  3480 
  3481 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  3482 method expression within a sandbox consisting of the first N
  3483 sub-goals, which need to exist.  For example, ``simp_all [3]''
  3484 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  3485 simplifies all new goals that emerge from applying rule foo to the
  3486 originally first one.
  3487 
  3488 * Isar: schematic goals are no longer restricted to higher-order
  3489 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  3490 expected.
  3491 
  3492 * Isar: the conclusion of a long theorem statement is now either
  3493 'shows' (a simultaneous conjunction, as before), or 'obtains'
  3494 (essentially a disjunction of cases with local parameters and
  3495 assumptions).  The latter allows to express general elimination rules
  3496 adequately; in this notation common elimination rules look like this:
  3497 
  3498   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  3499     assumes "EX x. P x"
  3500     obtains x where "P x"
  3501 
  3502   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  3503     assumes "A & B"
  3504     obtains A and B
  3505 
  3506   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  3507     assumes "A | B"
  3508     obtains
  3509       A
  3510     | B
  3511 
  3512 The subsequent classical rules even refer to the formal "thesis"
  3513 explicitly:
  3514 
  3515   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  3516     obtains "~ thesis"
  3517 
  3518   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  3519     obtains "thesis ==> something"
  3520 
  3521 The actual proof of an 'obtains' statement is analogous to that of the
  3522 Isar proof element 'obtain', only that there may be several cases.
  3523 Optional case names may be specified in parentheses; these will be
  3524 available both in the present proof and as annotations in the
  3525 resulting rule, for later use with the 'cases' method (cf. attribute
  3526 case_names).
  3527 
  3528 * Isar: the assumptions of a long theorem statement are available as
  3529 "assms" fact in the proof context.  This is more appropriate than the
  3530 (historical) "prems", which refers to all assumptions of the current
  3531 context, including those from the target locale, proof body etc.
  3532 
  3533 * Isar: 'print_statement' prints theorems from the current theory or
  3534 proof context in long statement form, according to the syntax of a
  3535 top-level lemma.
  3536 
  3537 * Isar: 'obtain' takes an optional case name for the local context
  3538 introduction rule (default "that").
  3539 
  3540 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  3541 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  3542 to occur.
  3543 
  3544 * Pure: syntax "CONST name" produces a fully internalized constant
  3545 according to the current context.  This is particularly useful for
  3546 syntax translations that should refer to internal constant
  3547 representations independently of name spaces.
  3548 
  3549 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  3550 instead of "FOO ". This allows multiple binder declarations to coexist
  3551 in the same context.  INCOMPATIBILITY.
  3552 
  3553 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  3554 primitive that also works in a locale context (both for constants and
  3555 fixed variables). Type declaration and internal syntactic representation
  3556 of given constants retrieved from the context. Likewise, the
  3557 'no_notation' command allows to remove given syntax annotations from the
  3558 current context.
  3559 
  3560 * Isar/locales: new derived specification elements 'axiomatization',
  3561 'definition', 'abbreviation', which support type-inference, admit
  3562 object-level specifications (equality, equivalence).  See also the
  3563 isar-ref manual.  Examples:
  3564 
  3565   axiomatization
  3566     eq  (infix "===" 50) where
  3567     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  3568 
  3569   definition "f x y = x + y + 1"
  3570   definition g where "g x = f x x"
  3571 
  3572   abbreviation
  3573     neq  (infix "=!=" 50) where
  3574     "x =!= y == ~ (x === y)"
  3575 
  3576 These specifications may be also used in a locale context.  Then the
  3577 constants being introduced depend on certain fixed parameters, and the
  3578 constant name is qualified by the locale base name.  An internal
  3579 abbreviation takes care for convenient input and output, making the
  3580 parameters implicit and using the original short name.  See also
  3581 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  3582 entities from a monomorphic theory.
  3583 
  3584 Presently, abbreviations are only available 'in' a target locale, but
  3585 not inherited by general import expressions.  Also note that
  3586 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  3587 'translations' in common applications.  The "no_abbrevs" print mode
  3588 prevents folding of abbreviations in term output.
  3589 
  3590 Concrete syntax is attached to specified constants in internal form,
  3591 independently of name spaces.  The parse tree representation is
  3592 slightly different -- use 'notation' instead of raw 'syntax', and
  3593 'translations' with explicit "CONST" markup to accommodate this.
  3594 
  3595 * Pure/Isar: unified syntax for new-style specification mechanisms
  3596 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  3597 full type inference and dummy patterns ("_").  For example:
  3598 
  3599   definition "K x _ = x"
  3600 
  3601   inductive conj for A B
  3602   where "A ==> B ==> conj A B"
  3603 
  3604 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  3605 the current context.  Print mode "no_abbrevs" prevents inversion of
  3606 abbreviations on output.
  3607 
  3608 * Isar/locales: improved parameter handling: use of locales "var" and
  3609 "struct" no longer necessary; - parameter renamings are no longer
  3610 required to be injective.  For example, this allows to define
  3611 endomorphisms as locale endom = homom mult mult h.
  3612 
  3613 * Isar/locales: changed the way locales with predicates are defined.
  3614 Instead of accumulating the specification, the imported expression is
  3615 now an interpretation.  INCOMPATIBILITY: different normal form of
  3616 locale expressions.  In particular, in interpretations of locales with
  3617 predicates, goals repesenting already interpreted fragments are not
  3618 removed automatically.  Use methods `intro_locales' and
  3619 `unfold_locales'; see below.
  3620 
  3621 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  3622 provide backward reasoning on locales predicates.  The methods are
  3623 aware of interpretations and discharge corresponding goals.
  3624 `intro_locales' is less aggressive then `unfold_locales' and does not
  3625 unfold predicates to assumptions.
  3626 
  3627 * Isar/locales: the order in which locale fragments are accumulated
  3628 has changed.  This enables to override declarations from fragments due
  3629 to interpretations -- for example, unwanted simp rules.
  3630 
  3631 * Isar/locales: interpretation in theories and proof contexts has been
  3632 extended.  One may now specify (and prove) equations, which are
  3633 unfolded in interpreted theorems.  This is useful for replacing
  3634 defined concepts (constants depending on locale parameters) by
  3635 concepts already existing in the target context.  Example:
  3636 
  3637   interpretation partial_order ["op <= :: [int, int] => bool"]
  3638     where "partial_order.less (op <=) (x::int) y = (x < y)"
  3639 
  3640 Typically, the constant `partial_order.less' is created by a
  3641 definition specification element in the context of locale
  3642 partial_order.
  3643 
  3644 * Method "induct": improved internal context management to support
  3645 local fixes and defines on-the-fly. Thus explicit meta-level
  3646 connectives !!  and ==> are rarely required anymore in inductive goals
  3647 (using object-logic connectives for this purpose has been long
  3648 obsolete anyway). Common proof patterns are explained in
  3649 src/HOL/Induct/Common_Patterns.thy, see also
  3650 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  3651 examples.
  3652 
  3653 * Method "induct": improved handling of simultaneous goals. Instead of
  3654 introducing object-level conjunction, the statement is now split into
  3655 several conclusions, while the corresponding symbolic cases are nested
  3656 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  3657 see src/HOL/Induct/Common_Patterns.thy, for example.
  3658 
  3659 * Method "induct": mutual induction rules are now specified as a list
  3660 of rule sharing the same induction cases. HOL packages usually provide
  3661 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  3662 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  3663 mutual induction rules differently, i.e. like this:
  3664 
  3665   (induct rule: foo_bar.inducts)
  3666   (induct set: foo bar)
  3667   (induct pred: foo bar)
  3668   (induct type: foo bar)
  3669 
  3670 The ML function ProjectRule.projections turns old-style rules into the
  3671 new format.
  3672 
  3673 * Method "coinduct": dual of induction, see
  3674 src/HOL/Library/Coinductive_List.thy for various examples.
  3675 
  3676 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  3677 considered a legacy feature.
  3678 
  3679 * Attribute "symmetric" produces result with standardized schematic
  3680 variables (index 0).  Potential INCOMPATIBILITY.
  3681 
  3682 * Simplifier: by default the simplifier trace only shows top level
  3683 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  3684 default. Thus there is less danger of being flooded by the trace. The
  3685 trace indicates where parts have been suppressed.
  3686   
  3687 * Provers/classical: removed obsolete classical version of elim_format
  3688 attribute; classical elim/dest rules are now treated uniformly when
  3689 manipulating the claset.
  3690 
  3691 * Provers/classical: stricter checks to ensure that supplied intro,
  3692 dest and elim rules are well-formed; dest and elim rules must have at
  3693 least one premise.
  3694 
  3695 * Provers/classical: attributes dest/elim/intro take an optional
  3696 weight argument for the rule (just as the Pure versions).  Weights are
  3697 ignored by automated tools, but determine the search order of single
  3698 rule steps.
  3699 
  3700 * Syntax: input syntax now supports dummy variable binding "%_. b",
  3701 where the body does not mention the bound variable.  Note that dummy
  3702 patterns implicitly depend on their context of bounds, which makes
  3703 "{_. _}" match any set comprehension as expected.  Potential
  3704 INCOMPATIBILITY -- parse translations need to cope with syntactic
  3705 constant "_idtdummy" in the binding position.
  3706 
  3707 * Syntax: removed obsolete syntactic constant "_K" and its associated
  3708 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  3709 for example "A -> B" => "Pi A (%_. B)".
  3710 
  3711 * Pure: 'class_deps' command visualizes the subclass relation, using
  3712 the graph browser tool.
  3713 
  3714 * Pure: 'print_theory' now suppresses certain internal declarations by
  3715 default; use '!' option for full details.
  3716 
  3717 
  3718 *** HOL ***
  3719 
  3720 * Method "metis" proves goals by applying the Metis general-purpose
  3721 resolution prover (see also http://gilith.com/software/metis/).
  3722 Examples are in the directory MetisExamples.  WARNING: the
  3723 Isabelle/HOL-Metis integration does not yet work properly with
  3724 multi-threading.
  3725   
  3726 * Command 'sledgehammer' invokes external automatic theorem provers as
  3727 background processes.  It generates calls to the "metis" method if
  3728 successful. These can be pasted into the proof.  Users do not have to
  3729 wait for the automatic provers to return.  WARNING: does not really
  3730 work with multi-threading.
  3731 
  3732 * New "auto_quickcheck" feature tests outermost goal statements for
  3733 potential counter-examples.  Controlled by ML references
  3734 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  3735 5000 milliseconds).  Fails silently if statements is outside of
  3736 executable fragment, or any other codgenerator problem occurs.
  3737 
  3738 * New constant "undefined" with axiom "undefined x = undefined".
  3739 
  3740 * Added class "HOL.eq", allowing for code generation with polymorphic
  3741 equality.
  3742 
  3743 * Some renaming of class constants due to canonical name prefixing in
  3744 the new 'class' package:
  3745 
  3746     HOL.abs ~> HOL.abs_class.abs
  3747     HOL.divide ~> HOL.divide_class.divide
  3748     0 ~> HOL.zero_class.zero
  3749     1 ~> HOL.one_class.one
  3750     op + ~> HOL.plus_class.plus
  3751     op - ~> HOL.minus_class.minus
  3752     uminus ~> HOL.minus_class.uminus
  3753     op * ~> HOL.times_class.times
  3754     op < ~> HOL.ord_class.less
  3755     op <= > HOL.ord_class.less_eq
  3756     Nat.power ~> Power.power_class.power
  3757     Nat.size ~> Nat.size_class.size
  3758     Numeral.number_of ~> Numeral.number_class.number_of
  3759     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  3760     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  3761     Orderings.min ~> Orderings.ord_class.min
  3762     Orderings.max ~> Orderings.ord_class.max
  3763     Divides.op div ~> Divides.div_class.div
  3764     Divides.op mod ~> Divides.div_class.mod
  3765     Divides.op dvd ~> Divides.div_class.dvd
  3766 
  3767 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  3768 
  3769 a) User-defined constants using any of the names "plus", "minus",
  3770 "times", "less" or "less_eq". The standard syntax translations for
  3771 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  3772 names.
  3773 
  3774 b) Variables named "plus", "minus", "times", "less", "less_eq"
  3775 INCOMPATIBILITY: use more specific names.
  3776 
  3777 c) Permutative equations (e.g. "a + b = b + a")
  3778 Since the change of names also changes the order of terms, permutative
  3779 rewrite rules may get applied in a different order. Experience shows
  3780 that this is rarely the case (only two adaptions in the whole Isabelle
  3781 distribution).  INCOMPATIBILITY: rewrite proofs
  3782 
  3783 d) ML code directly refering to constant names
  3784 This in general only affects hand-written proof tactics, simprocs and
  3785 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  3786 Consider using @{const_name} antiquotation.
  3787 
  3788 * New class "default" with associated constant "default".
  3789 
  3790 * Function "sgn" is now overloaded and available on int, real, complex
  3791 (and other numeric types), using class "sgn".  Two possible defs of
  3792 sgn are given as equational assumptions in the classes sgn_if and
  3793 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  3794 INCOMPATIBILITY.
  3795 
  3796 * Locale "partial_order" now unified with class "order" (cf. theory
  3797 Orderings), added parameter "less".  INCOMPATIBILITY.
  3798 
  3799 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  3800 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  3801 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  3802 
  3803 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  3804 changed order of proof goals in instance proofs.
  3805 
  3806 * The transitivity reasoner for partial and linear orders is set up
  3807 for classes "order" and "linorder".  Instances of the reasoner are available
  3808 in all contexts importing or interpreting the corresponding locales.
  3809 Method "order" invokes the reasoner separately; the reasoner
  3810 is also integrated with the Simplifier as a solver.  Diagnostic
  3811 command 'print_orders' shows the available instances of the reasoner
  3812 in the current context.
  3813 
  3814 * Localized monotonicity predicate in theory "Orderings"; integrated
  3815 lemmas max_of_mono and min_of_mono with this predicate.
  3816 INCOMPATIBILITY.
  3817 
  3818 * Formulation of theorem "dense" changed slightly due to integration
  3819 with new class dense_linear_order.
  3820 
  3821 * Uniform lattice theory development in HOL.
  3822 
  3823     constants "meet" and "join" now named "inf" and "sup"
  3824     constant "Meet" now named "Inf"
  3825 
  3826     classes "meet_semilorder" and "join_semilorder" now named
  3827       "lower_semilattice" and "upper_semilattice"
  3828     class "lorder" now named "lattice"
  3829     class "comp_lat" now named "complete_lattice"
  3830 
  3831     Instantiation of lattice classes allows explicit definitions
  3832     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  3833 
  3834   INCOMPATIBILITY.  Theorem renames:
  3835 
  3836     meet_left_le            ~> inf_le1
  3837     meet_right_le           ~> inf_le2
  3838     join_left_le            ~> sup_ge1
  3839     join_right_le           ~> sup_ge2
  3840     meet_join_le            ~> inf_sup_ord
  3841     le_meetI                ~> le_infI
  3842     join_leI                ~> le_supI
  3843     le_meet                 ~> le_inf_iff
  3844     le_join                 ~> ge_sup_conv
  3845     meet_idempotent         ~> inf_idem
  3846     join_idempotent         ~> sup_idem
  3847     meet_comm               ~> inf_commute
  3848     join_comm               ~> sup_commute
  3849     meet_leI1               ~> le_infI1
  3850     meet_leI2               ~> le_infI2
  3851     le_joinI1               ~> le_supI1
  3852     le_joinI2               ~> le_supI2
  3853     meet_assoc              ~> inf_assoc
  3854     join_assoc              ~> sup_assoc
  3855     meet_left_comm          ~> inf_left_commute
  3856     meet_left_idempotent    ~> inf_left_idem
  3857     join_left_comm          ~> sup_left_commute
  3858     join_left_idempotent    ~> sup_left_idem
  3859     meet_aci                ~> inf_aci
  3860     join_aci                ~> sup_aci
  3861     le_def_meet             ~> le_iff_inf
  3862     le_def_join             ~> le_iff_sup
  3863     join_absorp2            ~> sup_absorb2
  3864     join_absorp1            ~> sup_absorb1
  3865     meet_absorp1            ~> inf_absorb1
  3866     meet_absorp2            ~> inf_absorb2
  3867     meet_join_absorp        ~> inf_sup_absorb
  3868     join_meet_absorp        ~> sup_inf_absorb
  3869     distrib_join_le         ~> distrib_sup_le
  3870     distrib_meet_le         ~> distrib_inf_le
  3871 
  3872     add_meet_distrib_left   ~> add_inf_distrib_left
  3873     add_join_distrib_left   ~> add_sup_distrib_left
  3874     is_join_neg_meet        ~> is_join_neg_inf
  3875     is_meet_neg_join        ~> is_meet_neg_sup
  3876     add_meet_distrib_right  ~> add_inf_distrib_right
  3877     add_join_distrib_right  ~> add_sup_distrib_right
  3878     add_meet_join_distribs  ~> add_sup_inf_distribs
  3879     join_eq_neg_meet        ~> sup_eq_neg_inf
  3880     meet_eq_neg_join        ~> inf_eq_neg_sup
  3881     add_eq_meet_join        ~> add_eq_inf_sup
  3882     meet_0_imp_0            ~> inf_0_imp_0
  3883     join_0_imp_0            ~> sup_0_imp_0
  3884     meet_0_eq_0             ~> inf_0_eq_0
  3885     join_0_eq_0             ~> sup_0_eq_0
  3886     neg_meet_eq_join        ~> neg_inf_eq_sup
  3887     neg_join_eq_meet        ~> neg_sup_eq_inf
  3888     join_eq_if              ~> sup_eq_if
  3889 
  3890     mono_meet               ~> mono_inf
  3891     mono_join               ~> mono_sup
  3892     meet_bool_eq            ~> inf_bool_eq
  3893     join_bool_eq            ~> sup_bool_eq
  3894     meet_fun_eq             ~> inf_fun_eq
  3895     join_fun_eq             ~> sup_fun_eq
  3896     meet_set_eq             ~> inf_set_eq
  3897     join_set_eq             ~> sup_set_eq
  3898     meet1_iff               ~> inf1_iff
  3899     meet2_iff               ~> inf2_iff
  3900     meet1I                  ~> inf1I
  3901     meet2I                  ~> inf2I
  3902     meet1D1                 ~> inf1D1
  3903     meet2D1                 ~> inf2D1
  3904     meet1D2                 ~> inf1D2
  3905     meet2D2                 ~> inf2D2
  3906     meet1E                  ~> inf1E
  3907     meet2E                  ~> inf2E
  3908     join1_iff               ~> sup1_iff
  3909     join2_iff               ~> sup2_iff
  3910     join1I1                 ~> sup1I1
  3911     join2I1                 ~> sup2I1
  3912     join1I1                 ~> sup1I1
  3913     join2I2                 ~> sup1I2
  3914     join1CI                 ~> sup1CI
  3915     join2CI                 ~> sup2CI
  3916     join1E                  ~> sup1E
  3917     join2E                  ~> sup2E
  3918 
  3919     is_meet_Meet            ~> is_meet_Inf
  3920     Meet_bool_def           ~> Inf_bool_def
  3921     Meet_fun_def            ~> Inf_fun_def
  3922     Meet_greatest           ~> Inf_greatest
  3923     Meet_lower              ~> Inf_lower
  3924     Meet_set_def            ~> Inf_set_def
  3925 
  3926     Sup_def                 ~> Sup_Inf
  3927     Sup_bool_eq             ~> Sup_bool_def
  3928     Sup_fun_eq              ~> Sup_fun_def
  3929     Sup_set_eq              ~> Sup_set_def
  3930 
  3931     listsp_meetI            ~> listsp_infI
  3932     listsp_meet_eq          ~> listsp_inf_eq
  3933 
  3934     meet_min                ~> inf_min
  3935     join_max                ~> sup_max
  3936 
  3937 * Added syntactic class "size"; overloaded constant "size" now has
  3938 type "'a::size ==> bool"
  3939 
  3940 * Internal reorganisation of `size' of datatypes: size theorems
  3941 "foo.size" are no longer subsumed by "foo.simps" (but are still
  3942 simplification rules by default!); theorems "prod.size" now named
  3943 "*.size".
  3944 
  3945 * Class "div" now inherits from class "times" rather than "type".
  3946 INCOMPATIBILITY.
  3947 
  3948 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  3949 Linorder etc.  have disappeared; operations defined in terms of
  3950 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  3951 
  3952 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  3953 
  3954 * HOL-Word: New extensive library and type for generic, fixed size
  3955 machine words, with arithemtic, bit-wise, shifting and rotating
  3956 operations, reflection into int, nat, and bool lists, automation for
  3957 linear arithmetic (by automatic reflection into nat or int), including
  3958 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  3959 arithmetic type classes, supporting automatic simplification of
  3960 numerals on all operations.
  3961 
  3962 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  3963 
  3964 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  3965 
  3966 * Code generator library theories:
  3967   - Code_Integer represents HOL integers by big integer literals in target
  3968     languages.
  3969   - Code_Char represents HOL characters by character literals in target
  3970     languages.
  3971   - Code_Char_chr like Code_Char, but also offers treatment of character
  3972     codes; includes Code_Integer.
  3973   - Executable_Set allows to generate code for finite sets using lists.
  3974   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  3975     denominator).
  3976   - Executable_Real implements a subset of real numbers, namly those
  3977     representable by rational numbers.
  3978   - Efficient_Nat implements natural numbers by integers, which in general will
  3979     result in higher efficency; pattern matching with 0/Suc is eliminated;
  3980     includes Code_Integer.
  3981   - Code_Index provides an additional datatype index which is mapped to
  3982     target-language built-in integers.
  3983   - Code_Message provides an additional datatype message_string which is isomorphic to
  3984     strings; messages are mapped to target-language strings.
  3985 
  3986 * New package for inductive predicates
  3987 
  3988   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  3989 
  3990     inductive
  3991       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  3992       for z_1 :: U_1 and ... and z_n :: U_m
  3993     where
  3994       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  3995     | ...
  3996 
  3997   with full support for type-inference, rather than
  3998 
  3999     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4000 
  4001     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  4002     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  4003 
  4004     inductive "s z_1 ... z_m"
  4005     intros
  4006       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  4007       ...
  4008 
  4009   For backward compatibility, there is a wrapper allowing inductive
  4010   sets to be defined with the new package via
  4011 
  4012     inductive_set
  4013       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4014       for z_1 :: U_1 and ... and z_n :: U_m
  4015     where
  4016       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  4017     | ...
  4018 
  4019   or
  4020 
  4021     inductive_set
  4022       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4023       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  4024       for z_1 :: U_1 and ... and z_n :: U_m
  4025     where
  4026       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  4027     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  4028     | ...
  4029 
  4030   if the additional syntax "p ..." is required.
  4031 
  4032   Numerous examples can be found in the subdirectories src/HOL/Auth,
  4033   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  4034 
  4035   INCOMPATIBILITIES:
  4036 
  4037   - Since declaration and definition of inductive sets or predicates
  4038     is no longer separated, abbreviations involving the newly
  4039     introduced sets or predicates must be specified together with the
  4040     introduction rules after the 'where' keyword (see above), rather
  4041     than before the actual inductive definition.
  4042 
  4043   - The variables in induction and elimination rules are now
  4044     quantified in the order of their occurrence in the introduction
  4045     rules, rather than in alphabetical order. Since this may break
  4046     some proofs, these proofs either have to be repaired, e.g. by
  4047     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  4048     statements of the form
  4049 
  4050       case (rule_i a_i_1 ... a_i_{k_i})
  4051 
  4052     or the old order of quantification has to be restored by explicitly adding
  4053     meta-level quantifiers in the introduction rules, i.e.
  4054 
  4055       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  4056 
  4057   - The format of the elimination rules is now
  4058 
  4059       p z_1 ... z_m x_1 ... x_n ==>
  4060         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  4061         ==> ... ==> P
  4062 
  4063     for predicates and
  4064 
  4065       (x_1, ..., x_n) : s z_1 ... z_m ==>
  4066         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  4067         ==> ... ==> P
  4068 
  4069     for sets rather than
  4070 
  4071       x : s z_1 ... z_m ==>
  4072         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  4073         ==> ... ==> P
  4074 
  4075     This may require terms in goals to be expanded to n-tuples
  4076     (e.g. using case_tac or simplification with the split_paired_all
  4077     rule) before the above elimination rule is applicable.
  4078 
  4079   - The elimination or case analysis rules for (mutually) inductive
  4080     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  4081     list of rules "p_1_..._p_k.elims" is no longer available.
  4082 
  4083 * New package "function"/"fun" for general recursive functions,
  4084 supporting mutual and nested recursion, definitions in local contexts,
  4085 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  4086 for small examples, and the separate tutorial on the function
  4087 package. The old recdef "package" is still available as before, but
  4088 users are encouraged to use the new package.
  4089 
  4090 * Method "lexicographic_order" automatically synthesizes termination
  4091 relations as lexicographic combinations of size measures. 
  4092 
  4093 * Case-expressions allow arbitrary constructor-patterns (including
  4094 "_") and take their order into account, like in functional
  4095 programming.  Internally, this is translated into nested
  4096 case-expressions; missing cases are added and mapped to the predefined
  4097 constant "undefined". In complicated cases printing may no longer show
  4098 the original input but the internal form. Lambda-abstractions allow
  4099 the same form of pattern matching: "% pat1 => e1 | ..." is an
  4100 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  4101 variable.
  4102 
  4103 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  4104 is an abbreviation for "of_nat :: nat => int". The simplification
  4105 rules for "of_nat" have been changed to work like "int" did
  4106 previously.  Potential INCOMPATIBILITY:
  4107   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  4108   - of_nat_diff and of_nat_mult are no longer default simp rules
  4109 
  4110 * Method "algebra" solves polynomial equations over (semi)rings using
  4111 Groebner bases. The (semi)ring structure is defined by locales and the
  4112 tool setup depends on that generic context. Installing the method for
  4113 a specific type involves instantiating the locale and possibly adding
  4114 declarations for computation on the coefficients.  The method is
  4115 already instantiated for natural numbers and for the axiomatic class
  4116 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  4117 CALCULEMUS 2007 for the general principles underlying this
  4118 architecture of context-aware proof-tools.
  4119 
  4120 * Method "ferrack" implements quantifier elimination over
  4121 special-purpose dense linear orders using locales (analogous to
  4122 "algebra"). The method is already installed for class
  4123 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  4124 rat, etc.
  4125 
  4126 * Former constant "List.op @" now named "List.append".  Use ML
  4127 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  4128 circumvent possible incompatibilities when working on ML level.
  4129 
  4130 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  4131 
  4132 * New function listsum :: 'a list => 'a for arbitrary monoids.
  4133 Special syntax: "SUM x <- xs. f x" (and latex variants)
  4134 
  4135 * New syntax for Haskell-like list comprehension (input only), eg.
  4136 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  4137 
  4138 * The special syntax for function "filter" has changed from [x :
  4139 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  4140 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  4141 
  4142 * [a..b] is now defined for arbitrary linear orders.  It used to be
  4143 defined on nat only, as an abbreviation for [a..<Suc b]
  4144 INCOMPATIBILITY.
  4145 
  4146 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  4147 
  4148 * New functions "sorted" and "sort" in src/HOL/List.thy.
  4149 
  4150 * New lemma collection field_simps (an extension of ring_simps) for
  4151 manipulating (in)equations involving division. Multiplies with all
  4152 denominators that can be proved to be non-zero (in equations) or
  4153 positive/negative (in inequations).
  4154 
  4155 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  4156 have been improved and renamed to ring_simps, group_simps and
  4157 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  4158 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  4159 
  4160 * Theory Library/Commutative_Ring: switched from recdef to function
  4161 package; constants add, mul, pow now curried.  Infix syntax for
  4162 algebraic operations.
  4163 
  4164 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  4165 INCOMPATIBILITY.
  4166 
  4167 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  4168 INCOMPATIBILITY.
  4169 
  4170 * HOL/records: generalised field-update to take a function on the
  4171 field rather than the new value: r(|A := x|) is translated to A_update
  4172 (K x) r The K-combinator that is internally used is called K_record.
  4173 INCOMPATIBILITY: Usage of the plain update functions has to be
  4174 adapted.
  4175  
  4176 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  4177 * x = 0, which are required for a semiring.  Richer structures do not
  4178 inherit from semiring_0 anymore, because this property is a theorem
  4179 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  4180 there is more to prove, but this is mostly trivial.
  4181 
  4182 * Class "recpower" is generalized to arbitrary monoids, not just
  4183 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  4184 commutativity or semiring properties additionally.
  4185 
  4186 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  4187 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  4188 better use 'abbreviation'.
  4189 
  4190 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  4191 
  4192 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  4193 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  4194 significant changes for setting up numeral syntax for types:
  4195   - New constants Numeral.pred and Numeral.succ instead
  4196       of former Numeral.bin_pred and Numeral.bin_succ.
  4197   - Use integer operations instead of bin_add, bin_mult and so on.
  4198   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  4199   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  4200 
  4201 See src/HOL/Integ/IntArith.thy for an example setup.
  4202 
  4203 * Command 'normal_form' computes the normal form of a term that may
  4204 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  4205 produces ``[b, c, a]'' (without proof).  This command is suitable for
  4206 heavy-duty computations because the functions are compiled to ML
  4207 first.  Correspondingly, a method "normalization" is provided.  See
  4208 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  4209 
  4210 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  4211 25 like -->); output depends on the "iff" print_mode, the default is
  4212 "A = B" (with priority 50).
  4213 
  4214 * Relations less (<) and less_eq (<=) are also available on type bool.
  4215 Modified syntax to disallow nesting without explicit parentheses,
  4216 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  4217 INCOMPATIBILITY.
  4218 
  4219 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  4220 
  4221 * Relation composition operator "op O" now has precedence 75 and binds
  4222 stronger than union and intersection. INCOMPATIBILITY.
  4223 
  4224 * The old set interval syntax "{m..n(}" (and relatives) has been
  4225 removed.  Use "{m..<n}" (and relatives) instead.
  4226 
  4227 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  4228 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  4229 ``declare [[simproc del: neq]]''.
  4230 
  4231 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  4232 True/False.
  4233 
  4234 * Theorem Cons_eq_map_conv no longer declared as "simp".
  4235 
  4236 * Theorem setsum_mult renamed to setsum_right_distrib.
  4237 
  4238 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  4239 ``rule'' method.
  4240 
  4241 * Reimplemented methods "sat" and "satx", with several improvements:
  4242 goals no longer need to be stated as "<prems> ==> False", equivalences
  4243 (i.e. "=" on type bool) are handled, variable names of the form
  4244 "lit_<n>" are no longer reserved, significant speedup.
  4245 
  4246 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  4247 zChaff is still supported as well.
  4248 
  4249 * 'inductive' and 'datatype': provide projections of mutual rules,
  4250 bundled as foo_bar.inducts;
  4251 
  4252 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  4253 Library.
  4254 
  4255 * Library: moved theory Accessible_Part to main HOL.
  4256 
  4257 * Library: added theory Coinductive_List of potentially infinite lists
  4258 as greatest fixed-point.
  4259 
  4260 * Library: added theory AssocList which implements (finite) maps as
  4261 association lists.
  4262 
  4263 * Method "evaluation" solves goals (i.e. a boolean expression)
  4264 efficiently by compiling it to ML.  The goal is "proved" (via an
  4265 oracle) if it evaluates to True.
  4266 
  4267 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  4268 also when invoked by the simplifier.  This results in the Simplifier
  4269 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  4270 Configuration option fast_arith_split_limit=0 recovers the old
  4271 behavior.
  4272 
  4273 * Support for hex (0x20) and binary (0b1001) numerals.
  4274 
  4275 * New method: reify eqs (t), where eqs are equations for an
  4276 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  4277 parameter, computes a term s::'b and a list xs::'a list and proves the
  4278 theorem I xs s = t. This is also known as reification or quoting. The
  4279 resulting theorem is applied to the subgoal to substitute t with I xs
  4280 s.  If t is omitted, the subgoal itself is reified.
  4281 
  4282 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  4283 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  4284 where f is supposed to be a computable function (in the sense of code
  4285 generattion). The method uses reify to compute s and xs as above then
  4286 applies corr_thm and uses normalization by evaluation to "prove" f s =
  4287 r and finally gets the theorem t = r, which is again applied to the
  4288 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  4289 
  4290 * Reflection: Automatic reification now handels binding, an example is
  4291 available in src/HOL/ex/ReflectionEx.thy
  4292 
  4293 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  4294 command 'statespace' that is similar to 'record', but introduces an
  4295 abstract specification based on the locale infrastructure instead of
  4296 HOL types.  This leads to extra flexibility in composing state spaces,
  4297 in particular multiple inheritance and renaming of components.
  4298 
  4299 
  4300 *** HOL-Complex ***
  4301 
  4302 * Hyperreal: Functions root and sqrt are now defined on negative real
  4303 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  4304 Nonnegativity side conditions have been removed from many lemmas, so
  4305 that more subgoals may now be solved by simplification; potential
  4306 INCOMPATIBILITY.
  4307 
  4308 * Real: new type classes formalize real normed vector spaces and
  4309 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  4310 and norm :: 'a => real.
  4311 
  4312 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  4313 reals into other types. The overloaded constant Reals :: 'a set is now
  4314 defined as range of_real; potential INCOMPATIBILITY.
  4315 
  4316 * Real: proper support for ML code generation, including 'quickcheck'.
  4317 Reals are implemented as arbitrary precision rationals.
  4318 
  4319 * Hyperreal: Several constants that previously worked only for the
  4320 reals have been generalized, so they now work over arbitrary vector
  4321 spaces. Type annotations may need to be added in some cases; potential
  4322 INCOMPATIBILITY.
  4323 
  4324   Infinitesimal  :: ('a::real_normed_vector) star set
  4325   HFinite        :: ('a::real_normed_vector) star set
  4326   HInfinite      :: ('a::real_normed_vector) star set
  4327   approx         :: ('a::real_normed_vector) star => 'a star => bool
  4328   monad          :: ('a::real_normed_vector) star => 'a star set
  4329   galaxy         :: ('a::real_normed_vector) star => 'a star set
  4330   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  4331   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  4332   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  4333   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  4334   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  4335   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  4336   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  4337   sgn            :: 'a::real_normed_vector => 'a
  4338   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  4339 
  4340 * Complex: Some complex-specific constants are now abbreviations for
  4341 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  4342 hnorm.  Other constants have been entirely removed in favor of the
  4343 polymorphic versions (INCOMPATIBILITY):
  4344 
  4345   approx        <-- capprox
  4346   HFinite       <-- CFinite
  4347   HInfinite     <-- CInfinite
  4348   Infinitesimal <-- CInfinitesimal
  4349   monad         <-- cmonad
  4350   galaxy        <-- cgalaxy
  4351   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  4352   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  4353   (ns)deriv     <-- (ns)cderiv
  4354 
  4355 
  4356 *** HOL-Algebra ***
  4357 
  4358 * Formalisation of ideals and the quotient construction over rings.
  4359 
  4360 * Order and lattice theory no longer based on records.
  4361 INCOMPATIBILITY.
  4362 
  4363 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  4364 greatest_closed.  INCOMPATIBILITY.
  4365 
  4366 * Method algebra is now set up via an attribute.  For examples see
  4367 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  4368 of algebraic structures.
  4369 
  4370 * Renamed theory CRing to Ring.
  4371 
  4372 
  4373 *** HOL-Nominal ***
  4374 
  4375 * Substantial, yet incomplete support for nominal datatypes (binding
  4376 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  4377 src/HOL/Nominal/Examples.  Prospective users should consult
  4378 http://isabelle.in.tum.de/nominal/
  4379 
  4380 
  4381 *** ML ***
  4382 
  4383 * ML basics: just one true type int, which coincides with IntInf.int
  4384 (even on SML/NJ).
  4385 
  4386 * ML within Isar: antiquotations allow to embed statically-checked
  4387 formal entities in the source, referring to the context available at
  4388 compile-time.  For example:
  4389 
  4390 ML {* @{sort "{zero,one}"} *}
  4391 ML {* @{typ "'a => 'b"} *}
  4392 ML {* @{term "%x. x"} *}
  4393 ML {* @{prop "x == y"} *}
  4394 ML {* @{ctyp "'a => 'b"} *}
  4395 ML {* @{cterm "%x. x"} *}
  4396 ML {* @{cprop "x == y"} *}
  4397 ML {* @{thm asm_rl} *}
  4398 ML {* @{thms asm_rl} *}
  4399 ML {* @{type_name c} *}
  4400 ML {* @{type_syntax c} *}
  4401 ML {* @{const_name c} *}
  4402 ML {* @{const_syntax c} *}
  4403 ML {* @{context} *}
  4404 ML {* @{theory} *}
  4405 ML {* @{theory Pure} *}
  4406 ML {* @{theory_ref} *}
  4407 ML {* @{theory_ref Pure} *}
  4408 ML {* @{simpset} *}
  4409 ML {* @{claset} *}
  4410 ML {* @{clasimpset} *}
  4411 
  4412 The same works for sources being ``used'' within an Isar context.
  4413 
  4414 * ML in Isar: improved error reporting; extra verbosity with
  4415 ML_Context.trace enabled.
  4416 
  4417 * Pure/General/table.ML: the join operations now works via exceptions
  4418 DUP/SAME instead of type option. This is simpler in simple cases, and
  4419 admits slightly more efficient complex applications.
  4420 
  4421 * Pure: 'advanced' translation functions (parse_translation etc.) now
  4422 use Context.generic instead of just theory.
  4423 
  4424 * Pure: datatype Context.generic joins theory/Proof.context and
  4425 provides some facilities for code that works in either kind of
  4426 context, notably GenericDataFun for uniform theory and proof data.
  4427 
  4428 * Pure: simplified internal attribute type, which is now always
  4429 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  4430 local (Proof.context) attributes have been discontinued, while
  4431 minimizing code duplication. Thm.rule_attribute and
  4432 Thm.declaration_attribute build canonical attributes; see also structure
  4433 Context for further operations on Context.generic, notably
  4434 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  4435 declarations and definitions.
  4436 
  4437 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  4438 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  4439 init only required for impure data. INCOMPATIBILITY: empty really need
  4440 to be empty (no dependencies on theory content!)
  4441 
  4442 * Pure/kernel: consts certification ignores sort constraints given in
  4443 signature declarations. (This information is not relevant to the
  4444 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  4445 potential INCOMPATIBILITY.
  4446 
  4447 * Pure: axiomatic type classes are now purely definitional, with
  4448 explicit proofs of class axioms and super class relations performed
  4449 internally. See Pure/axclass.ML for the main internal interfaces --
  4450 notably AxClass.define_class supercedes AxClass.add_axclass, and
  4451 AxClass.axiomatize_class/classrel/arity supersede
  4452 Sign.add_classes/classrel/arities.
  4453 
  4454 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  4455 global/local versions on theory vs. Proof.context have been
  4456 discontinued; Attrib.syntax and Method.syntax have been adapted
  4457 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  4458 attributes, methods, etc.
  4459 
  4460 * Pure: several functions of signature "... -> theory -> theory * ..."
  4461 have been reoriented to "... -> theory -> ... * theory" in order to
  4462 allow natural usage in combination with the ||>, ||>>, |-> and
  4463 fold_map combinators.
  4464 
  4465 * Pure: official theorem names (closed derivations) and additional
  4466 comments (tags) are now strictly separate.  Name hints -- which are
  4467 maintained as tags -- may be attached any time without affecting the
  4468 derivation.
  4469 
  4470 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  4471 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  4472 achieve the old behaviour.
  4473 
  4474 * Pure: the "Goal" constant is now called "prop", supporting a
  4475 slightly more general idea of ``protecting'' meta-level rule
  4476 statements.
  4477 
  4478 * Pure: Logic.(un)varify only works in a global context, which is now
  4479 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  4480 Logic.legacy_(un)varify as temporary workaround.
  4481 
  4482 * Pure: structure Name provides scalable operations for generating
  4483 internal variable names, notably Name.variants etc.  This replaces
  4484 some popular functions from term.ML:
  4485 
  4486   Term.variant		->  Name.variant
  4487   Term.variantlist	->  Name.variant_list
  4488   Term.invent_names	->  Name.invent_list
  4489 
  4490 Note that low-level renaming rarely occurs in new code -- operations
  4491 from structure Variable are used instead (see below).
  4492 
  4493 * Pure: structure Variable provides fundamental operations for proper
  4494 treatment of fixed/schematic variables in a context.  For example,
  4495 Variable.import introduces fixes for schematics of given facts and
  4496 Variable.export reverses the effect (up to renaming) -- this replaces
  4497 various freeze_thaw operations.
  4498 
  4499 * Pure: structure Goal provides simple interfaces for
  4500 init/conclude/finish and tactical prove operations (replacing former
  4501 Tactic.prove).  Goal.prove is the canonical way to prove results
  4502 within a given context; Goal.prove_global is a degraded version for
  4503 theory level goals, including a global Drule.standard.  Note that
  4504 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  4505 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  4506 in a locale context).
  4507 
  4508 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  4509 and type checking (Syntax.check_term etc.), with common combinations
  4510 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  4511 which are considered legacy and await removal.
  4512 
  4513 * Pure/Syntax: generic interfaces for type unchecking
  4514 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  4515 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  4516 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  4517 available for convenience, but refer to the very same operations using
  4518 a mere theory instead of a full context.
  4519 
  4520 * Isar: simplified treatment of user-level errors, using exception
  4521 ERROR of string uniformly.  Function error now merely raises ERROR,
  4522 without any side effect on output channels.  The Isar toplevel takes
  4523 care of proper display of ERROR exceptions.  ML code may use plain
  4524 handle/can/try; cat_error may be used to concatenate errors like this:
  4525 
  4526   ... handle ERROR msg => cat_error msg "..."
  4527 
  4528 Toplevel ML code (run directly or through the Isar toplevel) may be
  4529 embedded into the Isar toplevel with exception display/debug like
  4530 this:
  4531 
  4532   Isar.toplevel (fn () => ...)
  4533 
  4534 INCOMPATIBILITY, removed special transform_error facilities, removed
  4535 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  4536 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  4537 -- use plain ERROR instead.
  4538 
  4539 * Isar: theory setup now has type (theory -> theory), instead of a
  4540 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  4541 
  4542 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  4543 ProofContext.debug/verbose flags.
  4544 
  4545 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  4546 theory before entering a proof state.  Transactions now always see a
  4547 quasi-functional intermediate checkpoint, both in interactive and
  4548 batch mode.
  4549 
  4550 * Isar: simplified interfaces for outer syntax.  Renamed
  4551 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  4552 OuterSyntax.add_parsers -- this functionality is now included in
  4553 OuterSyntax.command etc.  INCOMPATIBILITY.
  4554 
  4555 * Simplifier: the simpset of a running simplification process now
  4556 contains a proof context (cf. Simplifier.the_context), which is the
  4557 very context that the initial simpset has been retrieved from (by
  4558 simpset_of/local_simpset_of).  Consequently, all plug-in components
  4559 (solver, looper etc.) may depend on arbitrary proof data.
  4560 
  4561 * Simplifier.inherit_context inherits the proof context (plus the
  4562 local bounds) of the current simplification process; any simproc
  4563 etc. that calls the Simplifier recursively should do this!  Removed
  4564 former Simplifier.inherit_bounds, which is already included here --
  4565 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  4566 specify an explicit context using Simplifier.context/theory_context.
  4567 
  4568 * Simplifier/Classical Reasoner: more abstract interfaces
  4569 change_simpset/claset for modifying the simpset/claset reference of a
  4570 theory; raw versions simpset/claset_ref etc. have been discontinued --
  4571 INCOMPATIBILITY.
  4572 
  4573 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  4574 "Trueprop" etc.
  4575 
  4576 
  4577 *** System ***
  4578 
  4579 * settings: the default heap location within ISABELLE_HOME_USER now
  4580 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  4581 Isabelle installations.
  4582 
  4583 * isabelle-process: option -S (secure mode) disables some critical
  4584 operations, notably runtime compilation and evaluation of ML source
  4585 code.
  4586 
  4587 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  4588 
  4589 * Support for parallel execution, using native multicore support of
  4590 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  4591 independent theories, according to the given theory header
  4592 specifications. The maximum number of worker threads is specified via
  4593 usedir option -M or the "max-threads" setting in Proof General. A
  4594 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  4595 to 6 on a 8-core machine.  User-code needs to observe certain
  4596 guidelines for thread-safe programming, see appendix A in the Isar
  4597 Implementation manual.
  4598 
  4599 
  4600 
  4601 New in Isabelle2005 (October 2005)
  4602 ----------------------------------
  4603 
  4604 *** General ***
  4605 
  4606 * Theory headers: the new header syntax for Isar theories is
  4607 
  4608   theory <name>
  4609   imports <theory1> ... <theoryN>
  4610   uses <file1> ... <fileM>
  4611   begin
  4612 
  4613 where the 'uses' part is optional.  The previous syntax
  4614 
  4615   theory <name> = <theory1> + ... + <theoryN>:
  4616 
  4617 will disappear in the next release.  Use isatool fixheaders to convert
  4618 existing theory files.  Note that there is no change in ancient
  4619 non-Isar theories now, but these will disappear soon.
  4620 
  4621 * Theory loader: parent theories can now also be referred to via
  4622 relative and absolute paths.
  4623 
  4624 * Command 'find_theorems' searches for a list of criteria instead of a
  4625 list of constants. Known criteria are: intro, elim, dest, name:string,
  4626 simp:term, and any term. Criteria can be preceded by '-' to select
  4627 theorems that do not match. Intro, elim, dest select theorems that
  4628 match the current goal, name:s selects theorems whose fully qualified
  4629 name contain s, and simp:term selects all simplification rules whose
  4630 lhs match term.  Any other term is interpreted as pattern and selects
  4631 all theorems matching the pattern. Available in ProofGeneral under
  4632 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  4633 
  4634   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  4635 
  4636 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  4637 matching the current goal as introduction rule and not having "HOL."
  4638 in their name (i.e. not being defined in theory HOL).
  4639 
  4640 * Command 'thms_containing' has been discontinued in favour of
  4641 'find_theorems'; INCOMPATIBILITY.
  4642 
  4643 * Communication with Proof General is now 8bit clean, which means that
  4644 Unicode text in UTF-8 encoding may be used within theory texts (both
  4645 formal and informal parts).  Cf. option -U of the Isabelle Proof
  4646 General interface.  Here are some simple examples (cf. src/HOL/ex):
  4647 
  4648   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  4649   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  4650 
  4651 * Improved efficiency of the Simplifier and, to a lesser degree, the
  4652 Classical Reasoner.  Typical big applications run around 2 times
  4653 faster.
  4654 
  4655 
  4656 *** Document preparation ***
  4657 
  4658 * Commands 'display_drafts' and 'print_drafts' perform simple output
  4659 of raw sources.  Only those symbols that do not require additional
  4660 LaTeX packages (depending on comments in isabellesym.sty) are
  4661 displayed properly, everything else is left verbatim.  isatool display
  4662 and isatool print are used as front ends (these are subject to the
  4663 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  4664 
  4665 * Command tags control specific markup of certain regions of text,
  4666 notably folding and hiding.  Predefined tags include "theory" (for
  4667 theory begin and end), "proof" for proof commands, and "ML" for
  4668 commands involving ML code; the additional tags "visible" and
  4669 "invisible" are unused by default.  Users may give explicit tag
  4670 specifications in the text, e.g. ''by %invisible (auto)''.  The
  4671 interpretation of tags is determined by the LaTeX job during document
  4672 preparation: see option -V of isatool usedir, or options -n and -t of
  4673 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  4674 \isadroptag.
  4675 
  4676 Several document versions may be produced at the same time via isatool
  4677 usedir (the generated index.html will link all of them).  Typical
  4678 specifications include ''-V document=theory,proof,ML'' to present
  4679 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  4680 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  4681 these parts without any formal replacement text.  The Isabelle site
  4682 default settings produce ''document'' and ''outline'' versions as
  4683 specified above.
  4684 
  4685 * Several new antiquotations:
  4686 
  4687   @{term_type term} prints a term with its type annotated;
  4688 
  4689   @{typeof term} prints the type of a term;
  4690 
  4691   @{const const} is the same as @{term const}, but checks that the
  4692   argument is a known logical constant;
  4693 
  4694   @{term_style style term} and @{thm_style style thm} print a term or
  4695   theorem applying a "style" to it
  4696 
  4697   @{ML text}
  4698 
  4699 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  4700 definitions, equations, inequations etc., 'concl' printing only the
  4701 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  4702 to print the specified premise.  TermStyle.add_style provides an ML
  4703 interface for introducing further styles.  See also the "LaTeX Sugar"
  4704 document practical applications.  The ML antiquotation prints
  4705 type-checked ML expressions verbatim.
  4706 
  4707 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  4708 and 'text' support optional locale specification '(in loc)', which
  4709 specifies the default context for interpreting antiquotations.  For
  4710 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  4711 
  4712 * Option 'locale=NAME' of antiquotations specifies an alternative
  4713 context interpreting the subsequent argument.  For example: @{thm
  4714 [locale=lattice] inf_assoc}.
  4715 
  4716 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  4717 a proof context.
  4718 
  4719 * Proper output of antiquotations for theory commands involving a
  4720 proof context (such as 'locale' or 'theorem (in loc) ...').
  4721 
  4722 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  4723 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  4724 
  4725 * isatool usedir: new option -C (default true) controls whether option
  4726 -D should include a copy of the original document directory; -C false
  4727 prevents unwanted effects such as copying of administrative CVS data.
  4728 
  4729 
  4730 *** Pure ***
  4731 
  4732 * Considerably improved version of 'constdefs' command.  Now performs
  4733 automatic type-inference of declared constants; additional support for
  4734 local structure declarations (cf. locales and HOL records), see also
  4735 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  4736 sequential dependencies of definitions within a single 'constdefs'
  4737 section; moreover, the declared name needs to be an identifier.  If
  4738 all fails, consider to fall back on 'consts' and 'defs' separately.
  4739 
  4740 * Improved indexed syntax and implicit structures.  First of all,
  4741 indexed syntax provides a notational device for subscripted
  4742 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  4743 expressions.  Secondly, in a local context with structure
  4744 declarations, number indexes \<^sub>n or the empty index (default
  4745 number 1) refer to a certain fixed variable implicitly; option
  4746 show_structs controls printing of implicit structures.  Typical
  4747 applications of these concepts involve record types and locales.
  4748 
  4749 * New command 'no_syntax' removes grammar declarations (and
  4750 translations) resulting from the given syntax specification, which is
  4751 interpreted in the same manner as for the 'syntax' command.
  4752 
  4753 * 'Advanced' translation functions (parse_translation etc.) may depend
  4754 on the signature of the theory context being presently used for
  4755 parsing/printing, see also isar-ref manual.
  4756 
  4757 * Improved 'oracle' command provides a type-safe interface to turn an
  4758 ML expression of type theory -> T -> term into a primitive rule of
  4759 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  4760 is already included here); see also FOL/ex/IffExample.thy;
  4761 INCOMPATIBILITY.
  4762 
  4763 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  4764 before); "cI" is no longer bound, use "c.intro" instead.
  4765 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  4766 axclasses vs. locales.
  4767 
  4768 * Improved internal renaming of symbolic identifiers -- attach primes
  4769 instead of base 26 numbers.
  4770 
  4771 * New flag show_question_marks controls printing of leading question
  4772 marks in schematic variable names.
  4773 
  4774 * In schematic variable names, *any* symbol following \<^isub> or
  4775 \<^isup> is now treated as part of the base name.  For example, the
  4776 following works without printing of awkward ".0" indexes:
  4777 
  4778   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  4779     by simp
  4780 
  4781 * Inner syntax includes (*(*nested*) comments*).
  4782 
  4783 * Pretty printer now supports unbreakable blocks, specified in mixfix
  4784 annotations as "(00...)".
  4785 
  4786 * Clear separation of logical types and nonterminals, where the latter
  4787 may only occur in 'syntax' specifications or type abbreviations.
  4788 Before that distinction was only partially implemented via type class
  4789 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  4790 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  4791 exotic syntax specifications may require further adaption
  4792 (e.g. Cube/Cube.thy).
  4793 
  4794 * Removed obsolete type class "logic", use the top sort {} instead.
  4795 Note that non-logical types should be declared as 'nonterminals'
  4796 rather than 'types'.  INCOMPATIBILITY for new object-logic
  4797 specifications.
  4798 
  4799 * Attributes 'induct' and 'cases': type or set names may now be
  4800 locally fixed variables as well.
  4801 
  4802 * Simplifier: can now control the depth to which conditional rewriting
  4803 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  4804 Limit.
  4805 
  4806 * Simplifier: simplification procedures may now take the current
  4807 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  4808 interface), which is very useful for calling the Simplifier
  4809 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  4810 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  4811 low-level mk_simproc no longer applies Logic.varify internally, to
  4812 allow for use in a context of fixed variables.
  4813 
  4814 * thin_tac now works even if the assumption being deleted contains !!
  4815 or ==>.  More generally, erule now works even if the major premise of
  4816 the elimination rule contains !! or ==>.
  4817 
  4818 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  4819 
  4820 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  4821 from Pure, which contains all common declarations already.  Both
  4822 theories are defined via plain Isabelle/Isar .thy files.
  4823 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  4824 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  4825 use isatool fixcpure to adapt your theory and ML sources.
  4826 
  4827 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  4828 selections of theorems in named facts via index ranges.
  4829 
  4830 * 'print_theorems': in theory mode, really print the difference
  4831 wrt. the last state (works for interactive theory development only),
  4832 in proof mode print all local facts (cf. 'print_facts');
  4833 
  4834 * 'hide': option '(open)' hides only base names.
  4835 
  4836 * More efficient treatment of intermediate checkpoints in interactive
  4837 theory development.
  4838 
  4839 * Code generator is now invoked via code_module (incremental code
  4840 generation) and code_library (modular code generation, ML structures
  4841 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  4842 must be quoted when used as identifiers.
  4843 
  4844 * New 'value' command for reading, evaluating and printing terms using
  4845 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  4846 quoted when used as identifier.
  4847 
  4848 
  4849 *** Locales ***
  4850 
  4851 * New commands for the interpretation of locale expressions in
  4852 theories (1), locales (2) and proof contexts (3).  These generate
  4853 proof obligations from the expression specification.  After the
  4854 obligations have been discharged, theorems of the expression are added
  4855 to the theory, target locale or proof context.  The synopsis of the
  4856 commands is a follows:
  4857 
  4858   (1) interpretation expr inst
  4859   (2) interpretation target < expr
  4860   (3) interpret expr inst
  4861 
  4862 Interpretation in theories and proof contexts require a parameter
  4863 instantiation of terms from the current context.  This is applied to
  4864 specifications and theorems of the interpreted expression.
  4865 Interpretation in locales only permits parameter renaming through the
  4866 locale expression.  Interpretation is smart in that interpretations
  4867 that are active already do not occur in proof obligations, neither are
  4868 instantiated theorems stored in duplicate.  Use 'print_interps' to
  4869 inspect active interpretations of a particular locale.  For details,
  4870 see the Isar Reference manual.  Examples can be found in
  4871 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  4872 
  4873 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  4874 'interpret' instead.
  4875 
  4876 * New context element 'constrains' for adding type constraints to
  4877 parameters.
  4878 
  4879 * Context expressions: renaming of parameters with syntax
  4880 redeclaration.
  4881 
  4882 * Locale declaration: 'includes' disallowed.
  4883 
  4884 * Proper static binding of attribute syntax -- i.e. types / terms /
  4885 facts mentioned as arguments are always those of the locale definition
  4886 context, independently of the context of later invocations.  Moreover,
  4887 locale operations (renaming and type / term instantiation) are applied
  4888 to attribute arguments as expected.
  4889 
  4890 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  4891 actual attributes; rare situations may require Attrib.attribute to
  4892 embed those attributes into Attrib.src that lack concrete syntax.
  4893 Attribute implementations need to cooperate properly with the static
  4894 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  4895 Attrib.XXX_thm etc. already do the right thing without further
  4896 intervention.  Only unusual applications -- such as "where" or "of"
  4897 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  4898 on the context and the facts involved -- may have to assign parsed
  4899 values to argument tokens explicitly.
  4900 
  4901 * Changed parameter management in theorem generation for long goal
  4902 statements with 'includes'.  INCOMPATIBILITY: produces a different
  4903 theorem statement in rare situations.
  4904 
  4905 * Locale inspection command 'print_locale' omits notes elements.  Use
  4906 'print_locale!' to have them included in the output.
  4907 
  4908 
  4909 *** Provers ***
  4910 
  4911 * Provers/hypsubst.ML: improved version of the subst method, for
  4912 single-step rewriting: it now works in bound variable contexts. New is
  4913 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  4914 rewrite a different subterm than the original subst method, which is
  4915 still available as 'simplesubst'.
  4916 
  4917 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  4918 and quasi orders.
  4919 
  4920 * Provers/trancl.ML: new transitivity reasoner for transitive and
  4921 reflexive-transitive closure of relations.
  4922 
  4923 * Provers/blast.ML: new reference depth_limit to make blast's depth
  4924 limit (previously hard-coded with a value of 20) user-definable.
  4925 
  4926 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  4927 is peformed already.  Object-logics merely need to finish their
  4928 initial simpset configuration as before.  INCOMPATIBILITY.
  4929 
  4930 
  4931 *** HOL ***
  4932 
  4933 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  4934 
  4935   syntax (epsilon)
  4936     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  4937 
  4938 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  4939 and x-symbol; use option '-m epsilon' to get it actually printed.
  4940 Moreover, the mathematically important symbolic identifier \<epsilon>
  4941 becomes available as variable, constant etc.  INCOMPATIBILITY,
  4942 
  4943 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  4944 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  4945 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  4946 support corresponding Isar calculations.
  4947 
  4948 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  4949 instead of ":".
  4950 
  4951 * theory SetInterval: changed the syntax for open intervals:
  4952 
  4953   Old       New
  4954   {..n(}    {..<n}
  4955   {)n..}    {n<..}
  4956   {m..n(}   {m..<n}
  4957   {)m..n}   {m<..n}
  4958   {)m..n(}  {m<..<n}
  4959 
  4960 The old syntax is still supported but will disappear in the next
  4961 release.  For conversion use the following Emacs search and replace
  4962 patterns (these are not perfect but work quite well):
  4963 
  4964   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  4965   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  4966 
  4967 * Theory Commutative_Ring (in Library): method comm_ring for proving
  4968 equalities in commutative rings; method 'algebra' provides a generic
  4969 interface.
  4970 
  4971 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  4972 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  4973 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  4974 be a tuple pattern.
  4975 
  4976 Some new syntax forms are available:
  4977 
  4978   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  4979   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  4980   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  4981   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  4982 
  4983 The latter form "\<Sum>x < k. e" used to be based on a separate
  4984 function "Summation", which has been discontinued.
  4985 
  4986 * theory Finite_Set: in structured induction proofs, the insert case
  4987 is now 'case (insert x F)' instead of the old counterintuitive 'case
  4988 (insert F x)'.
  4989 
  4990 * The 'refute' command has been extended to support a much larger
  4991 fragment of HOL, including axiomatic type classes, constdefs and
  4992 typedefs, inductive datatypes and recursion.
  4993 
  4994 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  4995 Requires zChaff with proof generation to be installed.  See
  4996 HOL/ex/SAT_Examples.thy for examples.
  4997 
  4998 * Datatype induction via method 'induct' now preserves the name of the
  4999 induction variable. For example, when proving P(xs::'a list) by
  5000 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  5001 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  5002 in unstructured proof scripts.
  5003 
  5004 * Reworked implementation of records.  Improved scalability for
  5005 records with many fields, avoiding performance problems for type
  5006 inference. Records are no longer composed of nested field types, but
  5007 of nested extension types. Therefore the record type only grows linear
  5008 in the number of extensions and not in the number of fields.  The
  5009 top-level (users) view on records is preserved.  Potential
  5010 INCOMPATIBILITY only in strange cases, where the theory depends on the
  5011 old record representation. The type generated for a record is called
  5012 <record_name>_ext_type.
  5013 
  5014 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  5015 proofs triggered by a record definition or a simproc (if
  5016 quick_and_dirty is enabled).  Definitions of large records can take
  5017 quite long.
  5018 
  5019 New simproc record_upd_simproc for simplification of multiple record
  5020 updates enabled by default.  Moreover, trivial updates are also
  5021 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  5022 occasionally, since simplification is more powerful by default.
  5023 
  5024 * typedef: proper support for polymorphic sets, which contain extra
  5025 type-variables in the term.
  5026 
  5027 * Simplifier: automatically reasons about transitivity chains
  5028 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  5029 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  5030 old proofs break occasionally as simplification may now solve more
  5031 goals than previously.
  5032 
  5033 * Simplifier: converts x <= y into x = y if assumption y <= x is
  5034 present.  Works for all partial orders (class "order"), in particular
  5035 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  5036 just like y <= x.
  5037 
  5038 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  5039 bound variable or a constant then the let is unfolded.  Otherwise
  5040 first a is simplified to b, and then f b is simplified to g. If
  5041 possible we abstract b from g arriving at "let x = b in h x",
  5042 otherwise we unfold the let and arrive at g.  The simproc can be
  5043 enabled/disabled by the reference use_let_simproc.  Potential
  5044 INCOMPATIBILITY since simplification is more powerful by default.
  5045 
  5046 * Classical reasoning: the meson method now accepts theorems as arguments.
  5047 
  5048 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  5049 jobs to provide advice on the provability of subgoals.
  5050 
  5051 * Theory OrderedGroup and Ring_and_Field: various additions and
  5052 improvements to faciliate calculations involving equalities and
  5053 inequalities.
  5054 
  5055 The following theorems have been eliminated or modified
  5056 (INCOMPATIBILITY):
  5057 
  5058   abs_eq             now named abs_of_nonneg
  5059   abs_of_ge_0        now named abs_of_nonneg
  5060   abs_minus_eq       now named abs_of_nonpos
  5061   imp_abs_id         now named abs_of_nonneg
  5062   imp_abs_neg_id     now named abs_of_nonpos
  5063   mult_pos           now named mult_pos_pos
  5064   mult_pos_le        now named mult_nonneg_nonneg
  5065   mult_pos_neg_le    now named mult_nonneg_nonpos
  5066   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  5067   mult_neg           now named mult_neg_neg
  5068   mult_neg_le        now named mult_nonpos_nonpos
  5069 
  5070 * The following lemmas in Ring_and_Field have been added to the simplifier:
  5071      
  5072      zero_le_square
  5073      not_square_less_zero 
  5074 
  5075   The following lemmas have been deleted from Real/RealPow:
  5076   
  5077      realpow_zero_zero
  5078      realpow_two
  5079      realpow_less
  5080      zero_le_power
  5081      realpow_two_le
  5082      abs_realpow_two
  5083      realpow_two_abs     
  5084 
  5085 * Theory Parity: added rules for simplifying exponents.
  5086 
  5087 * Theory List:
  5088 
  5089 The following theorems have been eliminated or modified
  5090 (INCOMPATIBILITY):
  5091 
  5092   list_all_Nil       now named list_all.simps(1)
  5093   list_all_Cons      now named list_all.simps(2)
  5094   list_all_conv      now named list_all_iff
  5095   set_mem_eq         now named mem_iff
  5096 
  5097 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  5098 asymptotic "big O" calculations.  See the notes in BigO.thy.
  5099 
  5100 
  5101 *** HOL-Complex ***
  5102 
  5103 * Theory RealDef: better support for embedding natural numbers and
  5104 integers in the reals.
  5105 
  5106 The following theorems have been eliminated or modified
  5107 (INCOMPATIBILITY):
  5108 
  5109   exp_ge_add_one_self  now requires no hypotheses
  5110   real_of_int_add      reversed direction of equality (use [symmetric])
  5111   real_of_int_minus    reversed direction of equality (use [symmetric])
  5112   real_of_int_diff     reversed direction of equality (use [symmetric])
  5113   real_of_int_mult     reversed direction of equality (use [symmetric])
  5114 
  5115 * Theory RComplete: expanded support for floor and ceiling functions.
  5116 
  5117 * Theory Ln is new, with properties of the natural logarithm
  5118 
  5119 * Hyperreal: There is a new type constructor "star" for making
  5120 nonstandard types.  The old type names are now type synonyms:
  5121 
  5122   hypreal = real star
  5123   hypnat = nat star
  5124   hcomplex = complex star
  5125 
  5126 * Hyperreal: Many groups of similarly-defined constants have been
  5127 replaced by polymorphic versions (INCOMPATIBILITY):
  5128 
  5129   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  5130 
  5131   starset      <-- starsetNat, starsetC
  5132   *s*          <-- *sNat*, *sc*
  5133   starset_n    <-- starsetNat_n, starsetC_n
  5134   *sn*         <-- *sNatn*, *scn*
  5135   InternalSets <-- InternalNatSets, InternalCSets
  5136 
  5137   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  5138   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  5139   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  5140   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  5141   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  5142 
  5143 * Hyperreal: Many type-specific theorems have been removed in favor of
  5144 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  5145 
  5146   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  5147   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  5148   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  5149   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  5150   right_minus <-- hypreal_add_minus
  5151   left_minus <-- {hypreal,hcomplex}_add_minus_left
  5152   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  5153   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  5154   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  5155   mult_1_right <-- hcomplex_mult_one_right
  5156   mult_zero_left <-- hcomplex_mult_zero_left
  5157   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  5158   right_distrib <-- hypnat_add_mult_distrib2
  5159   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  5160   right_inverse <-- hypreal_mult_inverse
  5161   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  5162   order_refl <-- {hypreal,hypnat}_le_refl
  5163   order_trans <-- {hypreal,hypnat}_le_trans
  5164   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  5165   order_less_le <-- {hypreal,hypnat}_less_le
  5166   linorder_linear <-- {hypreal,hypnat}_le_linear
  5167   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  5168   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  5169   add_nonneg_nonneg <-- hypreal_le_add_order
  5170 
  5171 * Hyperreal: Separate theorems having to do with type-specific
  5172 versions of constants have been merged into theorems that apply to the
  5173 new polymorphic constants (INCOMPATIBILITY):
  5174 
  5175   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  5176   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  5177   STAR_Un <-- {STAR,NatStar,STARC}_Un
  5178   STAR_Int <-- {STAR,NatStar,STARC}_Int
  5179   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  5180   STAR_subset <-- {STAR,NatStar,STARC}_subset
  5181   STAR_mem <-- {STAR,NatStar,STARC}_mem
  5182   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  5183   STAR_diff <-- {STAR,STARC}_diff
  5184   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  5185     STARC_hcomplex_of_complex}_image_subset
  5186   starset_n_Un <-- starset{Nat,C}_n_Un
  5187   starset_n_Int <-- starset{Nat,C}_n_Int
  5188   starset_n_Compl <-- starset{Nat,C}_n_Compl
  5189   starset_n_diff <-- starset{Nat,C}_n_diff
  5190   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  5191   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  5192   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  5193   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  5194   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  5195   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  5196   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  5197   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  5198   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  5199   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  5200   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  5201   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  5202   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  5203   starfun_diff <-- starfun{C,RC,CR}_diff
  5204   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  5205   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  5206   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  5207   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  5208   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  5209   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  5210   starfun_Id <-- starfunC_Id
  5211   starfun_approx <-- starfun{Nat,CR}_approx
  5212   starfun_capprox <-- starfun{C,RC}_capprox
  5213   starfun_abs <-- starfunNat_rabs
  5214   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  5215   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  5216   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  5217   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  5218   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  5219   starfun_add_approx <-- starfunCR_add_approx
  5220   starfun_inverse_inverse <-- starfunC_inverse_inverse
  5221   starfun_divide <-- starfun{C,CR,RC}_divide
  5222   starfun_n <-- starfun{Nat,C}_n
  5223   starfun_n_mult <-- starfun{Nat,C}_n_mult
  5224   starfun_n_add <-- starfun{Nat,C}_n_add
  5225   starfun_n_add_minus <-- starfunNat_n_add_minus
  5226   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  5227   starfun_n_minus <-- starfun{Nat,C}_n_minus
  5228   starfun_n_eq <-- starfun{Nat,C}_n_eq
  5229 
  5230   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  5231   star_n_minus <-- {hypreal,hcomplex}_minus
  5232   star_n_diff <-- {hypreal,hcomplex}_diff
  5233   star_n_mult <-- {hypreal,hcomplex}_mult
  5234   star_n_inverse <-- {hypreal,hcomplex}_inverse
  5235   star_n_le <-- {hypreal,hypnat}_le
  5236   star_n_less <-- {hypreal,hypnat}_less
  5237   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  5238   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  5239   star_n_abs <-- hypreal_hrabs
  5240   star_n_divide <-- hcomplex_divide
  5241 
  5242   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  5243   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  5244   star_of_diff <-- hypreal_of_real_diff
  5245   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  5246   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  5247   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  5248   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  5249   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  5250   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  5251   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  5252   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  5253   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  5254   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  5255   star_of_number_of <-- {hypreal,hcomplex}_number_of
  5256   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  5257   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  5258   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  5259   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  5260   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  5261   star_of_power <-- hypreal_of_real_power
  5262   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  5263 
  5264 * Hyperreal: new method "transfer" that implements the transfer
  5265 principle of nonstandard analysis. With a subgoal that mentions
  5266 nonstandard types like "'a star", the command "apply transfer"
  5267 replaces it with an equivalent one that mentions only standard types.
  5268 To be successful, all free variables must have standard types; non-
  5269 standard variables must have explicit universal quantifiers.
  5270 
  5271 * Hyperreal: A theory of Taylor series.
  5272 
  5273 
  5274 *** HOLCF ***
  5275 
  5276 * Discontinued special version of 'constdefs' (which used to support
  5277 continuous functions) in favor of the general Pure one with full
  5278 type-inference.
  5279 
  5280 * New simplification procedure for solving continuity conditions; it
  5281 is much faster on terms with many nested lambda abstractions (cubic
  5282 instead of exponential time).
  5283 
  5284 * New syntax for domain package: selector names are now optional.
  5285 Parentheses should be omitted unless argument is lazy, for example:
  5286 
  5287   domain 'a stream = cons "'a" (lazy "'a stream")
  5288 
  5289 * New command 'fixrec' for defining recursive functions with pattern
  5290 matching; defining multiple functions with mutual recursion is also
  5291 supported.  Patterns may include the constants cpair, spair, up, sinl,
  5292 sinr, or any data constructor defined by the domain package. The given
  5293 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  5294 syntax and examples.
  5295 
  5296 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  5297 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  5298 but the proof obligation additionally includes an admissibility
  5299 requirement. The packages generate instances of class cpo or pcpo,
  5300 with continuity and strictness theorems for Rep and Abs.
  5301 
  5302 * HOLCF: Many theorems have been renamed according to a more standard naming
  5303 scheme (INCOMPATIBILITY):
  5304 
  5305   foo_inject:  "foo$x = foo$y ==> x = y"
  5306   foo_eq:      "(foo$x = foo$y) = (x = y)"
  5307   foo_less:    "(foo$x << foo$y) = (x << y)"
  5308   foo_strict:  "foo$UU = UU"
  5309   foo_defined: "... ==> foo$x ~= UU"
  5310   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  5311 
  5312 
  5313 *** ZF ***
  5314 
  5315 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  5316 including the First Isomorphism Theorem (on quotienting by the kernel
  5317 of a homomorphism).
  5318 
  5319 * ZF/Simplifier: install second copy of type solver that actually
  5320 makes use of TC rules declared to Isar proof contexts (or locales);
  5321 the old version is still required for ML proof scripts.
  5322 
  5323 
  5324 *** Cube ***
  5325 
  5326 * Converted to Isar theory format; use locales instead of axiomatic
  5327 theories.
  5328 
  5329 
  5330 *** ML ***
  5331 
  5332 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  5333 for ||>, ||>>, |>>,
  5334 
  5335 * Pure/library.ML no longer defines its own option datatype, but uses
  5336 that of the SML basis, which has constructors NONE and SOME instead of
  5337 None and Some, as well as exception Option.Option instead of OPTION.
  5338 The functions the, if_none, is_some, is_none have been adapted
  5339 accordingly, while Option.map replaces apsome.
  5340 
  5341 * Pure/library.ML: the exception LIST has been given up in favour of
  5342 the standard exceptions Empty and Subscript, as well as
  5343 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  5344 superceded by the standard hd and tl functions etc.
  5345 
  5346 A number of basic list functions are no longer exported to the ML
  5347 toplevel, as they are variants of predefined functions.  The following
  5348 suggests how one can translate existing code:
  5349 
  5350     rev_append xs ys = List.revAppend (xs, ys)
  5351     nth_elem (i, xs) = List.nth (xs, i)
  5352     last_elem xs = List.last xs
  5353     flat xss = List.concat xss
  5354     seq fs = List.app fs
  5355     partition P xs = List.partition P xs
  5356     mapfilter f xs = List.mapPartial f xs
  5357 
  5358 * Pure/library.ML: several combinators for linear functional
  5359 transformations, notably reverse application and composition:
  5360 
  5361   x |> f                f #> g
  5362   (x, y) |-> f          f #-> g
  5363 
  5364 * Pure/library.ML: introduced/changed precedence of infix operators:
  5365 
  5366   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  5367   infix 2 ?;
  5368   infix 3 o oo ooo oooo;
  5369   infix 4 ~~ upto downto;
  5370 
  5371 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  5372 infix operators.
  5373 
  5374 * Pure/library.ML: natural list combinators fold, fold_rev, and
  5375 fold_map support linear functional transformations and nesting.  For
  5376 example:
  5377 
  5378   fold f [x1, ..., xN] y =
  5379     y |> f x1 |> ... |> f xN
  5380 
  5381   (fold o fold) f [xs1, ..., xsN] y =
  5382     y |> fold f xs1 |> ... |> fold f xsN
  5383 
  5384   fold f [x1, ..., xN] =
  5385     f x1 #> ... #> f xN
  5386 
  5387   (fold o fold) f [xs1, ..., xsN] =
  5388     fold f xs1 #> ... #> fold f xsN
  5389 
  5390 * Pure/library.ML: the following selectors on type 'a option are
  5391 available:
  5392 
  5393   the:               'a option -> 'a  (*partial*)
  5394   these:             'a option -> 'a  where 'a = 'b list
  5395   the_default: 'a -> 'a option -> 'a
  5396   the_list:          'a option -> 'a list
  5397 
  5398 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5399 basic operations for association lists, following natural argument
  5400 order; moreover the explicit equality predicate passed here avoids
  5401 potentially expensive polymorphic runtime equality checks.
  5402 The old functions may be expressed as follows:
  5403 
  5404   assoc = uncurry (AList.lookup (op =))
  5405   assocs = these oo AList.lookup (op =)
  5406   overwrite = uncurry (AList.update (op =)) o swap
  5407 
  5408 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5409 
  5410   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  5411   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  5412 
  5413 replacing make_keylist and keyfilter (occassionally used)
  5414 Naive rewrites:
  5415 
  5416   make_keylist = AList.make
  5417   keyfilter = AList.find (op =)
  5418 
  5419 * eq_fst and eq_snd now take explicit equality parameter, thus
  5420   avoiding eqtypes. Naive rewrites:
  5421 
  5422     eq_fst = eq_fst (op =)
  5423     eq_snd = eq_snd (op =)
  5424 
  5425 * Removed deprecated apl and apr (rarely used).
  5426   Naive rewrites:
  5427 
  5428     apl (n, op) =>>= curry op n
  5429     apr (op, m) =>>= fn n => op (n, m)
  5430 
  5431 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  5432 provides a reasonably efficient light-weight implementation of sets as
  5433 lists.
  5434 
  5435 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  5436 few new operations; existing lookup and update are now curried to
  5437 follow natural argument order (for use with fold etc.);
  5438 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  5439 
  5440 * Pure/General: output via the Isabelle channels of
  5441 writeln/warning/error etc. is now passed through Output.output, with a
  5442 hook for arbitrary transformations depending on the print_mode
  5443 (cf. Output.add_mode -- the first active mode that provides a output
  5444 function wins).  Already formatted output may be embedded into further
  5445 text via Output.raw; the result of Pretty.string_of/str_of and derived
  5446 functions (string_of_term/cterm/thm etc.) is already marked raw to
  5447 accommodate easy composition of diagnostic messages etc.  Programmers
  5448 rarely need to care about Output.output or Output.raw at all, with
  5449 some notable exceptions: Output.output is required when bypassing the
  5450 standard channels (writeln etc.), or in token translations to produce
  5451 properly formatted results; Output.raw is required when capturing
  5452 already output material that will eventually be presented to the user
  5453 a second time.  For the default print mode, both Output.output and
  5454 Output.raw have no effect.
  5455 
  5456 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  5457 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  5458 cumulative results are displayed at the end of a batch session.
  5459 
  5460 * Pure/General: File.sysify_path and File.quote_sysify path have been
  5461 replaced by File.platform_path and File.shell_path (with appropriate
  5462 hooks).  This provides a clean interface for unusual systems where the
  5463 internal and external process view of file names are different.
  5464 
  5465 * Pure: more efficient orders for basic syntactic entities: added
  5466 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  5467 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  5468 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  5469 orders now -- potential INCOMPATIBILITY for code that depends on a
  5470 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  5471 Library.sort_strings on result).
  5472 
  5473 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  5474 fold_types traverse types/terms from left to right, observing natural
  5475 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  5476 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  5477 
  5478 * Pure: name spaces have been refined, with significant changes of the
  5479 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  5480 to extern(_table).  The plain name entry path is superceded by a
  5481 general 'naming' context, which also includes the 'policy' to produce
  5482 a fully qualified name and external accesses of a fully qualified
  5483 name; NameSpace.extend is superceded by context dependent
  5484 Sign.declare_name.  Several theory and proof context operations modify
  5485 the naming context.  Especially note Theory.restore_naming and
  5486 ProofContext.restore_naming to get back to a sane state; note that
  5487 Theory.add_path is no longer sufficient to recover from
  5488 Theory.absolute_path in particular.
  5489 
  5490 * Pure: new flags short_names (default false) and unique_names
  5491 (default true) for controlling output of qualified names.  If
  5492 short_names is set, names are printed unqualified.  If unique_names is
  5493 reset, the name prefix is reduced to the minimum required to achieve
  5494 the original result when interning again, even if there is an overlap
  5495 with earlier declarations.
  5496 
  5497 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  5498 now 'extend', and 'merge' gets an additional Pretty.pp argument
  5499 (useful for printing error messages).  INCOMPATIBILITY.
  5500 
  5501 * Pure: major reorganization of the theory context.  Type Sign.sg and
  5502 Theory.theory are now identified, referring to the universal
  5503 Context.theory (see Pure/context.ML).  Actual signature and theory
  5504 content is managed as theory data.  The old code and interfaces were
  5505 spread over many files and structures; the new arrangement introduces
  5506 considerable INCOMPATIBILITY to gain more clarity:
  5507 
  5508   Context -- theory management operations (name, identity, inclusion,
  5509     parents, ancestors, merge, etc.), plus generic theory data;
  5510 
  5511   Sign -- logical signature and syntax operations (declaring consts,
  5512     types, etc.), plus certify/read for common entities;
  5513 
  5514   Theory -- logical theory operations (stating axioms, definitions,
  5515     oracles), plus a copy of logical signature operations (consts,
  5516     types, etc.); also a few basic management operations (Theory.copy,
  5517     Theory.merge, etc.)
  5518 
  5519 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  5520 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  5521 for convenience -- they merely return the theory.
  5522 
  5523 * Pure: type Type.tsig is superceded by theory in most interfaces.
  5524 
  5525 * Pure: the Isar proof context type is already defined early in Pure
  5526 as Context.proof (note that ProofContext.context and Proof.context are
  5527 aliases, where the latter is the preferred name).  This enables other
  5528 Isabelle components to refer to that type even before Isar is present.
  5529 
  5530 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  5531 typeK, constK, axiomK, oracleK), but provide explicit operations for
  5532 any of these kinds.  For example, Sign.intern typeK is now
  5533 Sign.intern_type, Theory.hide_space Sign.typeK is now
  5534 Theory.hide_types.  Also note that former
  5535 Theory.hide_classes/types/consts are now
  5536 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  5537 internalize their arguments!  INCOMPATIBILITY.
  5538 
  5539 * Pure: get_thm interface (of PureThy and ProofContext) expects
  5540 datatype thmref (with constructors Name and NameSelection) instead of
  5541 plain string -- INCOMPATIBILITY;
  5542 
  5543 * Pure: cases produced by proof methods specify options, where NONE
  5544 means to remove case bindings -- INCOMPATIBILITY in
  5545 (RAW_)METHOD_CASES.
  5546 
  5547 * Pure: the following operations retrieve axioms or theorems from a
  5548 theory node or theory hierarchy, respectively:
  5549 
  5550   Theory.axioms_of: theory -> (string * term) list
  5551   Theory.all_axioms_of: theory -> (string * term) list
  5552   PureThy.thms_of: theory -> (string * thm) list
  5553   PureThy.all_thms_of: theory -> (string * thm) list
  5554 
  5555 * Pure: print_tac now outputs the goal through the trace channel.
  5556 
  5557 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  5558 Reference Toplevel.debug (default false) controls detailed printing
  5559 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  5560 controls execution profiling -- set to 1 for time and 2 for space
  5561 (both increase the runtime).
  5562 
  5563 * Isar session: The initial use of ROOT.ML is now always timed,
  5564 i.e. the log will show the actual process times, in contrast to the
  5565 elapsed wall-clock time that the outer shell wrapper produces.
  5566 
  5567 * Simplifier: improved handling of bound variables (nameless
  5568 representation, avoid allocating new strings).  Simprocs that invoke
  5569 the Simplifier recursively should use Simplifier.inherit_bounds to
  5570 avoid local name clashes.  Failure to do so produces warnings
  5571 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  5572 for further details.
  5573 
  5574 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  5575 bindings for all theorems stored within a given theory; this may help
  5576 in porting non-Isar theories to Isar ones, while keeping ML proof
  5577 scripts for the time being.
  5578 
  5579 * ML operator HTML.with_charset specifies the charset begin used for
  5580 generated HTML files.  For example:
  5581 
  5582   HTML.with_charset "utf-8" use_thy "Hebrew";
  5583   HTML.with_charset "utf-8" use_thy "Chinese";
  5584 
  5585 
  5586 *** System ***
  5587 
  5588 * Allow symlinks to all proper Isabelle executables (Isabelle,
  5589 isabelle, isatool etc.).
  5590 
  5591 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  5592 isatool doc, isatool mkdir, display_drafts etc.).
  5593 
  5594 * isatool usedir: option -f allows specification of the ML file to be
  5595 used by Isabelle; default is ROOT.ML.
  5596 
  5597 * New isatool version outputs the version identifier of the Isabelle
  5598 distribution being used.
  5599 
  5600 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  5601 (containing Boolean satisfiability problems) into Isabelle/HOL
  5602 theories.
  5603 
  5604 
  5605 
  5606 New in Isabelle2004 (April 2004)
  5607 --------------------------------
  5608 
  5609 *** General ***
  5610 
  5611 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  5612   Replaces linorder.ML.
  5613 
  5614 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  5615   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  5616   (\<a>...\<z>), are now considered normal letters, and can therefore
  5617   be used anywhere where an ASCII letter (a...zA...Z) has until
  5618   now. COMPATIBILITY: This obviously changes the parsing of some
  5619   terms, especially where a symbol has been used as a binder, say
  5620   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  5621   as an identifier.  Fix it by inserting a space around former
  5622   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  5623   existing theory and ML files.
  5624 
  5625 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  5626 
  5627 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  5628   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  5629   a normal (but invisible) letter. For multiple letter subscripts repeat
  5630   \<^isub> like this: x\<^isub>1\<^isub>2.
  5631 
  5632 * Pure: There are now sub-/superscripts that can span more than one
  5633   character. Text between \<^bsub> and \<^esub> is set in subscript in
  5634   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  5635   superscript. The new control characters are not identifier parts.
  5636 
  5637 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  5638   content of "..." to the latex file instead of \isacntrl... . The "..."
  5639   may consist of any printable characters excluding the end bracket >.
  5640 
  5641 * Pure: Using new Isar command "finalconsts" (or the ML functions
  5642   Theory.add_finals or Theory.add_finals_i) it is now possible to
  5643   declare constants "final", which prevents their being given a definition
  5644   later.  It is useful for constants whose behaviour is fixed axiomatically
  5645   rather than definitionally, such as the meta-logic connectives.
  5646 
  5647 * Pure: 'instance' now handles general arities with general sorts
  5648   (i.e. intersections of classes),
  5649 
  5650 * Presentation: generated HTML now uses a CSS style sheet to make layout
  5651   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  5652   It can be changed to alter the colors/layout of generated pages.
  5653 
  5654 
  5655 *** Isar ***
  5656 
  5657 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  5658   cut_tac, subgoal_tac and thin_tac:
  5659   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  5660     locales are no longer forced to write Isar proof scripts.
  5661     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  5662     emulations.
  5663   - INCOMPATIBILITY: names of variables to be instantiated may no
  5664     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  5665     This is consistent with the instantiation attribute "where".
  5666 
  5667 * Attributes "where" and "of":
  5668   - Now take type variables of instantiated theorem into account when reading
  5669     the instantiation string.  This fixes a bug that caused instantiated
  5670     theorems to have too special types in some circumstances.
  5671   - "where" permits explicit instantiations of type variables.
  5672 
  5673 * Calculation commands "moreover" and "also" no longer interfere with
  5674   current facts ("this"), admitting arbitrary combinations with "then"
  5675   and derived forms.
  5676 
  5677 * Locales:
  5678   - Goal statements involving the context element "includes" no longer
  5679     generate theorems with internal delta predicates (those ending on
  5680     "_axioms") in the premise.
  5681     Resolve particular premise with <locale>.intro to obtain old form.
  5682   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  5683     specification and "includes" elements in goal statement.
  5684   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  5685     [intro?] and [elim?] (respectively) by default.
  5686   - Experimental command for instantiation of locales in proof contexts:
  5687         instantiate <label>[<attrs>]: <loc>
  5688     Instantiates locale <loc> and adds all its theorems to the current context
  5689     taking into account their attributes.  Label and attrs are optional
  5690     modifiers, like in theorem declarations.  If present, names of
  5691     instantiated theorems are qualified with <label>, and the attributes
  5692     <attrs> are applied after any attributes these theorems might have already.
  5693       If the locale has assumptions, a chained fact of the form
  5694     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  5695     are derived.  The command does not support old-style locales declared
  5696     with "locale (open)".
  5697       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  5698 
  5699 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  5700   (Isar) contexts.
  5701 
  5702 
  5703 *** HOL ***
  5704 
  5705 * Proof import: new image HOL4 contains the imported library from
  5706   the HOL4 system with about 2500 theorems. It is imported by
  5707   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  5708   can be used like any other Isabelle image.  See
  5709   HOL/Import/HOL/README for more information.
  5710 
  5711 * Simplifier:
  5712   - Much improved handling of linear and partial orders.
  5713     Reasoners for linear and partial orders are set up for type classes
  5714     "linorder" and "order" respectively, and are added to the default simpset
  5715     as solvers.  This means that the simplifier can build transitivity chains
  5716     to solve goals from the assumptions.
  5717   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  5718     of blast or auto after simplification become unnecessary because the goal
  5719     is solved by simplification already.
  5720 
  5721 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  5722     all proved in axiomatic type classes for semirings, rings and fields.
  5723 
  5724 * Numerics:
  5725   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  5726     now formalized using the Ring_and_Field theory mentioned above.
  5727   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  5728     than before, because now they are set up once in a generic manner.
  5729   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  5730     Look for the general versions in Ring_and_Field (and Power if they concern
  5731     exponentiation).
  5732 
  5733 * Type "rat" of the rational numbers is now available in HOL-Complex.
  5734 
  5735 * Records:
  5736   - Record types are now by default printed with their type abbreviation
  5737     instead of the list of all field types. This can be configured via
  5738     the reference "print_record_type_abbr".
  5739   - Simproc "record_upd_simproc" for simplification of multiple updates added
  5740     (not enabled by default).
  5741   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  5742     EX x. x = sel r to True (not enabled by default).
  5743   - Tactic "record_split_simp_tac" to split and simplify records added.
  5744 
  5745 * 'specification' command added, allowing for definition by
  5746   specification.  There is also an 'ax_specification' command that
  5747   introduces the new constants axiomatically.
  5748 
  5749 * arith(_tac) is now able to generate counterexamples for reals as well.
  5750 
  5751 * HOL-Algebra: new locale "ring" for non-commutative rings.
  5752 
  5753 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  5754   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  5755 
  5756 * HOL-Matrix: a first theory for matrices in HOL with an application of
  5757   matrix theory to linear programming.
  5758 
  5759 * Unions and Intersections:
  5760   The latex output syntax of UN and INT has been changed
  5761   from "\Union x \in A. B" to "\Union_{x \in A} B"
  5762   i.e. the index formulae has become a subscript.
  5763   Similarly for "\Union x. B", and for \Inter instead of \Union.
  5764 
  5765 * Unions and Intersections over Intervals:
  5766   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  5767   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  5768   like in normal math, and corresponding versions for < and for intersection.
  5769 
  5770 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  5771   lexicographic dictonary ordering has been added as "lexord".
  5772 
  5773 * ML: the legacy theory structures Int and List have been removed. They had
  5774   conflicted with ML Basis Library structures having the same names.
  5775 
  5776 * 'refute' command added to search for (finite) countermodels.  Only works
  5777   for a fragment of HOL.  The installation of an external SAT solver is
  5778   highly recommended.  See "HOL/Refute.thy" for details.
  5779 
  5780 * 'quickcheck' command: Allows to find counterexamples by evaluating
  5781   formulae under an assignment of free variables to random values.
  5782   In contrast to 'refute', it can deal with inductive datatypes,
  5783   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  5784   for examples.
  5785 
  5786 
  5787 *** HOLCF ***
  5788 
  5789 * Streams now come with concatenation and are part of the HOLCF image
  5790 
  5791 
  5792 
  5793 New in Isabelle2003 (May 2003)
  5794 ------------------------------
  5795 
  5796 *** General ***
  5797 
  5798 * Provers/simplifier:
  5799 
  5800   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  5801     Assumptions are now subject to complete mutual simplification,
  5802     not just from left to right. The simplifier now preserves
  5803     the order of assumptions.
  5804 
  5805     Potential INCOMPATIBILITY:
  5806 
  5807     -- simp sometimes diverges where the old version did
  5808        not, e.g. invoking simp on the goal
  5809 
  5810         [| P (f x); y = x; f x = f y |] ==> Q
  5811 
  5812        now gives rise to the infinite reduction sequence
  5813 
  5814         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  5815 
  5816        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  5817        kind of problem.
  5818 
  5819     -- Tactics combining classical reasoner and simplification (such as auto)
  5820        are also affected by this change, because many of them rely on
  5821        simp. They may sometimes diverge as well or yield a different numbers
  5822        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  5823        in case of problems. Sometimes subsequent calls to the classical
  5824        reasoner will fail because a preceeding call to the simplifier too
  5825        eagerly simplified the goal, e.g. deleted redundant premises.
  5826 
  5827   - The simplifier trace now shows the names of the applied rewrite rules
  5828 
  5829   - You can limit the number of recursive invocations of the simplifier
  5830     during conditional rewriting (where the simplifie tries to solve the
  5831     conditions before applying the rewrite rule):
  5832     ML "simp_depth_limit := n"
  5833     where n is an integer. Thus you can force termination where previously
  5834     the simplifier would diverge.
  5835 
  5836   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  5837 
  5838   - No longer aborts on failed congruence proof.  Instead, the
  5839     congruence is ignored.
  5840 
  5841 * Pure: New generic framework for extracting programs from constructive
  5842   proofs. See HOL/Extraction.thy for an example instantiation, as well
  5843   as HOL/Extraction for some case studies.
  5844 
  5845 * Pure: The main goal of the proof state is no longer shown by default, only
  5846 the subgoals. This behaviour is controlled by a new flag.
  5847    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  5848 (ML: Proof.show_main_goal).
  5849 
  5850 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  5851 rules whose conclusion matches subgoal 1:
  5852       PG menu: Isabelle/Isar -> Show me -> matching rules
  5853 The rules are ordered by how closely they match the subgoal.
  5854 In particular, rules that solve a subgoal outright are displayed first
  5855 (or rather last, the way they are printed).
  5856 (ML: ProofGeneral.print_intros())
  5857 
  5858 * Pure: New flag trace_unify_fail causes unification to print
  5859 diagnostic information (PG: in trace buffer) when it fails. This is
  5860 useful for figuring out why single step proofs like rule, erule or
  5861 assumption failed.
  5862 
  5863 * Pure: Locale specifications now produce predicate definitions
  5864 according to the body of text (covering assumptions modulo local
  5865 definitions); predicate "loc_axioms" covers newly introduced text,
  5866 while "loc" is cumulative wrt. all included locale expressions; the
  5867 latter view is presented only on export into the global theory
  5868 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  5869 on the old view without predicates;
  5870 
  5871 * Pure: predefined locales "var" and "struct" are useful for sharing
  5872 parameters (as in CASL, for example); just specify something like
  5873 ``var x + var y + struct M'' as import;
  5874 
  5875 * Pure: improved thms_containing: proper indexing of facts instead of
  5876 raw theorems; check validity of results wrt. current name space;
  5877 include local facts of proof configuration (also covers active
  5878 locales), cover fixed variables in index; may use "_" in term
  5879 specification; an optional limit for the number of printed facts may
  5880 be given (the default is 40);
  5881 
  5882 * Pure: disallow duplicate fact bindings within new-style theory files
  5883 (batch-mode only);
  5884 
  5885 * Provers: improved induct method: assumptions introduced by case
  5886 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  5887 the goal statement); "foo" still refers to all facts collectively;
  5888 
  5889 * Provers: the function blast.overloaded has been removed: all constants
  5890 are regarded as potentially overloaded, which improves robustness in exchange
  5891 for slight decrease in efficiency;
  5892 
  5893 * Provers/linorder: New generic prover for transitivity reasoning over
  5894 linear orders.  Note: this prover is not efficient!
  5895 
  5896 * Isar: preview of problems to finish 'show' now produce an error
  5897 rather than just a warning (in interactive mode);
  5898 
  5899 
  5900 *** HOL ***
  5901 
  5902 * arith(_tac)
  5903 
  5904  - Produces a counter example if it cannot prove a goal.
  5905    Note that the counter example may be spurious if the goal is not a formula
  5906    of quantifier-free linear arithmetic.
  5907    In ProofGeneral the counter example appears in the trace buffer.
  5908 
  5909  - Knows about div k and mod k where k is a numeral of type nat or int.
  5910 
  5911  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  5912    linear arithmetic fails. This takes account of quantifiers and divisibility.
  5913    Presburger arithmetic can also be called explicitly via presburger(_tac).
  5914 
  5915 * simp's arithmetic capabilities have been enhanced a bit: it now
  5916 takes ~= in premises into account (by performing a case split);
  5917 
  5918 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  5919 are distributed over a sum of terms;
  5920 
  5921 * New tactic "trans_tac" and method "trans" instantiate
  5922 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  5923 "<=", "<" and "=").
  5924 
  5925 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  5926 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  5927 
  5928 * 'typedef' command has new option "open" to suppress the set
  5929 definition;
  5930 
  5931 * functions Min and Max on finite sets have been introduced (theory
  5932 Finite_Set);
  5933 
  5934 * attribute [symmetric] now works for relations as well; it turns
  5935 (x,y) : R^-1 into (y,x) : R, and vice versa;
  5936 
  5937 * induct over a !!-quantified statement (say !!x1..xn):
  5938   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  5939 
  5940 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  5941 %x. None. Warning: empty_def now refers to the previously hidden definition
  5942 of the empty set.
  5943 
  5944 * Algebra: formalization of classical algebra.  Intended as base for
  5945 any algebraic development in Isabelle.  Currently covers group theory
  5946 (up to Sylow's theorem) and ring theory (Universal Property of
  5947 Univariate Polynomials).  Contributions welcome;
  5948 
  5949 * GroupTheory: deleted, since its material has been moved to Algebra;
  5950 
  5951 * Complex: new directory of the complex numbers with numeric constants,
  5952 nonstandard complex numbers, and some complex analysis, standard and
  5953 nonstandard (Jacques Fleuriot);
  5954 
  5955 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  5956 
  5957 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  5958 Fleuriot);
  5959 
  5960 * Real/HahnBanach: updated and adapted to locales;
  5961 
  5962 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  5963 Gray and Kramer);
  5964 
  5965 * UNITY: added the Meier-Sanders theory of progress sets;
  5966 
  5967 * MicroJava: bytecode verifier and lightweight bytecode verifier
  5968 as abstract algorithms, instantiated to the JVM;
  5969 
  5970 * Bali: Java source language formalization. Type system, operational
  5971 semantics, axiomatic semantics. Supported language features:
  5972 classes, interfaces, objects,virtual methods, static methods,
  5973 static/instance fields, arrays, access modifiers, definite
  5974 assignment, exceptions.
  5975 
  5976 
  5977 *** ZF ***
  5978 
  5979 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  5980 universe, etc.);
  5981 
  5982 * Main ZF: virtually all theories converted to new-style format;
  5983 
  5984 
  5985 *** ML ***
  5986 
  5987 * Pure: Tactic.prove provides sane interface for internal proofs;
  5988 omits the infamous "standard" operation, so this is more appropriate
  5989 than prove_goalw_cterm in many situations (e.g. in simprocs);
  5990 
  5991 * Pure: improved error reporting of simprocs;
  5992 
  5993 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  5994 up simprocs;
  5995 
  5996 
  5997 *** Document preparation ***
  5998 
  5999 * uses \par instead of \\ for line breaks in theory text. This may
  6000 shift some page breaks in large documents. To get the old behaviour
  6001 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  6002 
  6003 * minimized dependencies of isabelle.sty and isabellesym.sty on
  6004 other packages
  6005 
  6006 * \<euro> now needs package babel/greek instead of marvosym (which
  6007 broke \Rightarrow)
  6008 
  6009 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  6010 textcomp package)
  6011 
  6012 
  6013 
  6014 New in Isabelle2002 (March 2002)
  6015 --------------------------------
  6016 
  6017 *** Document preparation ***
  6018 
  6019 * greatly simplified document preparation setup, including more
  6020 graceful interpretation of isatool usedir -i/-d/-D options, and more
  6021 instructive isatool mkdir; users should basically be able to get
  6022 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  6023 users may run a separate document processing stage manually like this:
  6024 "isatool usedir -D output HOL Test && isatool document Test/output";
  6025 
  6026 * theory dependency graph may now be incorporated into documents;
  6027 isatool usedir -g true will produce session_graph.eps/.pdf for use
  6028 with \includegraphics of LaTeX;
  6029 
  6030 * proper spacing of consecutive markup elements, especially text
  6031 blocks after section headings;
  6032 
  6033 * support bold style (for single symbols only), input syntax is like
  6034 this: "\<^bold>\<alpha>" or "\<^bold>A";
  6035 
  6036 * \<bullet> is now output as bold \cdot by default, which looks much
  6037 better in printed text;
  6038 
  6039 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  6040 note that these symbols are currently unavailable in Proof General /
  6041 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  6042 
  6043 * isatool latex no longer depends on changed TEXINPUTS, instead
  6044 isatool document copies the Isabelle style files to the target
  6045 location;
  6046 
  6047 
  6048 *** Isar ***
  6049 
  6050 * Pure/Provers: improved proof by cases and induction;
  6051   - 'case' command admits impromptu naming of parameters (such as
  6052     "case (Suc n)");
  6053   - 'induct' method divinates rule instantiation from the inductive
  6054     claim; no longer requires excessive ?P bindings for proper
  6055     instantiation of cases;
  6056   - 'induct' method properly enumerates all possibilities of set/type
  6057     rules; as a consequence facts may be also passed through *type*
  6058     rules without further ado;
  6059   - 'induct' method now derives symbolic cases from the *rulified*
  6060     rule (before it used to rulify cases stemming from the internal
  6061     atomized version); this means that the context of a non-atomic
  6062     statement becomes is included in the hypothesis, avoiding the
  6063     slightly cumbersome show "PROP ?case" form;
  6064   - 'induct' may now use elim-style induction rules without chaining
  6065     facts, using ``missing'' premises from the goal state; this allows
  6066     rules stemming from inductive sets to be applied in unstructured
  6067     scripts, while still benefitting from proper handling of non-atomic
  6068     statements; NB: major inductive premises need to be put first, all
  6069     the rest of the goal is passed through the induction;
  6070   - 'induct' proper support for mutual induction involving non-atomic
  6071     rule statements (uses the new concept of simultaneous goals, see
  6072     below);
  6073   - append all possible rule selections, but only use the first
  6074     success (no backtracking);
  6075   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  6076   - undeclared rule case names default to numbers 1, 2, 3, ...;
  6077   - added 'print_induct_rules' (covered by help item in recent Proof
  6078     General versions);
  6079   - moved induct/cases attributes to Pure, methods to Provers;
  6080   - generic method setup instantiated for FOL and HOL;
  6081 
  6082 * Pure: support multiple simultaneous goal statements, for example
  6083 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  6084 meta-level mechanism, this acts as if several individual goals had
  6085 been stated separately; in particular common proof methods need to be
  6086 repeated in order to cover all claims; note that a single elimination
  6087 step is *not* sufficient to establish the two conjunctions, so this
  6088 fails:
  6089 
  6090   assume "A & B" then have A and B ..   (*".." fails*)
  6091 
  6092 better use "obtain" in situations as above; alternative refer to
  6093 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  6094 
  6095 * Pure: proper integration with ``locales''; unlike the original
  6096 version by Florian Kammller, Isar locales package high-level proof
  6097 contexts rather than raw logical ones (e.g. we admit to include
  6098 attributes everywhere); operations on locales include merge and
  6099 rename; support for implicit arguments (``structures''); simultaneous
  6100 type-inference over imports and text; see also HOL/ex/Locales.thy for
  6101 some examples;
  6102 
  6103 * Pure: the following commands have been ``localized'', supporting a
  6104 target locale specification "(in name)": 'lemma', 'theorem',
  6105 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  6106 stored both within the locale and at the theory level (exported and
  6107 qualified by the locale name);
  6108 
  6109 * Pure: theory goals may now be specified in ``long'' form, with
  6110 ad-hoc contexts consisting of arbitrary locale elements. for example
  6111 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  6112 definitions may be given, too); the result is a meta-level rule with
  6113 the context elements being discharged in the obvious way;
  6114 
  6115 * Pure: new proof command 'using' allows to augment currently used
  6116 facts after a goal statement ('using' is syntactically analogous to
  6117 'apply', but acts on the goal's facts only); this allows chained facts
  6118 to be separated into parts given before and after a claim, as in
  6119 ``from a and b have C using d and e <proof>'';
  6120 
  6121 * Pure: renamed "antecedent" case to "rule_context";
  6122 
  6123 * Pure: new 'judgment' command records explicit information about the
  6124 object-logic embedding (used by several tools internally); no longer
  6125 use hard-wired "Trueprop";
  6126 
  6127 * Pure: added 'corollary' command;
  6128 
  6129 * Pure: fixed 'token_translation' command;
  6130 
  6131 * Pure: removed obsolete 'exported' attribute;
  6132 
  6133 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  6134 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  6135 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  6136 
  6137 * Pure: method 'atomize' presents local goal premises as object-level
  6138 statements (atomic meta-level propositions); setup controlled via
  6139 rewrite rules declarations of 'atomize' attribute; example
  6140 application: 'induct' method with proper rule statements in improper
  6141 proof *scripts*;
  6142 
  6143 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  6144 now consider the syntactic context of assumptions, giving a better
  6145 chance to get type-inference of the arguments right (this is
  6146 especially important for locales);
  6147 
  6148 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  6149 mode;
  6150 
  6151 * Pure/obtain: the formal conclusion "thesis", being marked as
  6152 ``internal'', may no longer be reference directly in the text;
  6153 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  6154 situations;
  6155 
  6156 * Pure: generic 'sym' attribute which declares a rule both as pure
  6157 'elim?' and for the 'symmetric' operation;
  6158 
  6159 * Pure: marginal comments ``--'' may now occur just anywhere in the
  6160 text; the fixed correlation with particular command syntax has been
  6161 discontinued;
  6162 
  6163 * Pure: new method 'rules' is particularly well-suited for proof
  6164 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  6165 but often produces more compact proof terms with less detours;
  6166 
  6167 * Pure/Provers/classical: simplified integration with pure rule
  6168 attributes and methods; the classical "intro?/elim?/dest?"
  6169 declarations coincide with the pure ones; the "rule" method no longer
  6170 includes classically swapped intros; "intro" and "elim" methods no
  6171 longer pick rules from the context; also got rid of ML declarations
  6172 AddXIs/AddXEs/AddXDs; all of this has some potential for
  6173 INCOMPATIBILITY;
  6174 
  6175 * Provers/classical: attribute 'swapped' produces classical inversions
  6176 of introduction rules;
  6177 
  6178 * Provers/simplifier: 'simplified' attribute may refer to explicit
  6179 rules instead of full simplifier context; 'iff' attribute handles
  6180 conditional rules;
  6181 
  6182 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  6183 
  6184 * HOL: 'recdef' now fails on unfinished automated proofs, use
  6185 "(permissive)" option to recover old behavior;
  6186 
  6187 * HOL: 'inductive' no longer features separate (collective) attributes
  6188 for 'intros' (was found too confusing);
  6189 
  6190 * HOL: properly declared induction rules less_induct and
  6191 wf_induct_rule;
  6192 
  6193 
  6194 *** HOL ***
  6195 
  6196 * HOL: moved over to sane numeral syntax; the new policy is as
  6197 follows:
  6198 
  6199   - 0 and 1 are polymorphic constants, which are defined on any
  6200   numeric type (nat, int, real etc.);
  6201 
  6202   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  6203   binary representation internally;
  6204 
  6205   - type nat has special constructor Suc, and generally prefers Suc 0
  6206   over 1::nat and Suc (Suc 0) over 2::nat;
  6207 
  6208 This change may cause significant problems of INCOMPATIBILITY; here
  6209 are some hints on converting existing sources:
  6210 
  6211   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  6212   entities, so expressions involving "-" (unary or binary minus) need
  6213   to be spaced properly;
  6214 
  6215   - existing occurrences of "1" may need to be constraint "1::nat" or
  6216   even replaced by Suc 0; similar for old "2";
  6217 
  6218   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  6219 
  6220   - remove all special provisions on numerals in proofs;
  6221 
  6222 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  6223 representation (depends on bin_arith_simps in the default context);
  6224 
  6225 * HOL: symbolic syntax for x^2 (numeral 2);
  6226 
  6227 * HOL: the class of all HOL types is now called "type" rather than
  6228 "term"; INCOMPATIBILITY, need to adapt references to this type class
  6229 in axclass/classes, instance/arities, and (usually rare) occurrences
  6230 in typings (of consts etc.); internally the class is called
  6231 "HOL.type", ML programs should refer to HOLogic.typeS;
  6232 
  6233 * HOL/record package improvements:
  6234   - new derived operations "fields"