NEWS
author haftmann
Sun Jul 17 22:24:08 2011 +0200 (2011-07-17)
changeset 43873 8a2f339641c1
parent 43872 6b917e5877d2
child 43899 60ef6abb2f92
permissions -rw-r--r--
more on complement
     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) has been discontinued.
    26 Note that the path element ~~ may be used to reference theories in the
    27 Isabelle home folder -- for instance, "~~/src/HOL/Library/FuncSet".
    28 INCOMPATIBILITY.
    29 
    30 * Various optional external tools are referenced more robustly and
    31 uniformly by explicit Isabelle settings as follows:
    32 
    33   ISABELLE_CSDP   (formerly CSDP_EXE)
    34   ISABELLE_GHC    (formerly EXEC_GHC or GHC_PATH)
    35   ISABELLE_OCAML  (formerly EXEC_OCAML)
    36   ISABELLE_SWIPL  (formerly EXEC_SWIPL)
    37   ISABELLE_YAP    (formerly EXEC_YAP)
    38 
    39 Note that automated detection from the file-system or search path has
    40 been discontinued.  INCOMPATIBILITY.
    41 
    42 * Name space: former unsynchronized references are now proper
    43 configuration options, with more conventional names:
    44 
    45   long_names   ~> names_long
    46   short_names  ~> names_short
    47   unique_names ~> names_unique
    48 
    49 Minor INCOMPATIBILITY, need to declare options in context like this:
    50 
    51   declare [[names_unique = false]]
    52 
    53 * Literal facts `prop` may contain dummy patterns, e.g. `_ = _`.  Note
    54 that the result needs to be unique, which means fact specifications
    55 may have to be refined after enriching a proof context.
    56 
    57 * Isabelle/Isar reference manual provides more formal references in
    58 syntax diagrams.
    59 
    60 
    61 *** HOL ***
    62 
    63 * Classes bot and top require underlying partial order rather than preorder:
    64 uniqueness of bot and top is guaranteed.  INCOMPATIBILITY.
    65 
    66 * Class 'complete_lattice': generalized a couple of lemmas from sets;
    67 generalized theorems INF_cong and SUP_cong.  More consistent and less
    68 misunderstandable names:
    69   INFI_def ~> INF_def
    70   SUPR_def ~> SUP_def
    71   le_SUPI ~> le_SUP_I
    72   le_SUPI2 ~> le_SUP_I2
    73   le_INFI ~> le_INF_I
    74   INFI_bool_eq ~> INF_bool_eq
    75   SUPR_bool_eq ~> SUP_bool_eq
    76   INFI_apply ~> INF_apply
    77   SUPR_apply ~> SUP_apply
    78 INCOMPATIBILITY.
    79 
    80 * Archimedian_Field.thy:
    81     floor now is defined as parameter of a separate type class floor_ceiling.
    82  
    83 * Finite_Set.thy: more coherent development of fold_set locales:
    84 
    85     locale fun_left_comm ~> locale comp_fun_commute
    86     locale fun_left_comm_idem ~> locale comp_fun_idem
    87     
    88 Both use point-free characterisation; interpretation proofs may need adjustment.
    89 INCOMPATIBILITY.
    90 
    91 * Code generation:
    92   - theory Library/Code_Char_ord provides native ordering of characters
    93     in the target language.
    94     
    95 * Declare ext [intro] by default.  Rare INCOMPATIBILITY.
    96 
    97 * Nitpick:
    98   - Added "need" and "total_consts" options.
    99   - Reintroduced "show_skolems" option by popular demand.
   100   - Renamed attribute: nitpick_def ~> nitpick_unfold.
   101     INCOMPATIBILITY.
   102 
   103 * Sledgehammer:
   104   - sledgehammer available_provers ~> sledgehammer supported_provers.
   105     INCOMPATIBILITY.
   106   - Added support for SNARK and ToFoF-E on SystemOnTPTP and for simply typed
   107     TPTP problems (TFF).
   108   - Added "preplay_timeout", "slicing", "type_enc", "sound", "max_mono_iters",
   109     and "max_new_mono_instances" options.
   110   - Removed "explicit_apply" and "full_types" options as well as "Full Types"
   111     Proof General menu item. INCOMPATIBILITY.
   112 
   113 * Metis:
   114   - Removed "metisF" -- use "metis" instead. INCOMPATIBILITY.
   115   - Obsoleted "metisFT" -- use "metis (full_types)" instead. INCOMPATIBILITY.
   116 
   117 * "try":
   118   - Renamed "try_methods" and added "simp:", "intro:", "dest:", and "elim:"
   119     options. INCOMPATIBILITY.
   120   - Introduced "try" that not only runs "try_methods" but also "solve_direct",
   121     "sledgehammer", "quickcheck", and "nitpick".
   122 
   123 * Quickcheck:
   124   - Added "eval" option to evaluate terms for the found counterexample
   125     (currently only supported by the default (exhaustive) tester)
   126   - Added post-processing of terms to obtain readable counterexamples
   127     (currently only supported by the default (exhaustive) tester)
   128   - New counterexample generator quickcheck[narrowing] enables
   129     narrowing-based testing.
   130     It requires that the Glasgow Haskell compiler is installed and
   131     its location is known to Isabelle with the environment variable
   132     ISABELLE_GHC.
   133 
   134 * Function package: discontinued option "tailrec".
   135 INCOMPATIBILITY. Use partial_function instead.
   136 
   137 * HOL-Probability:
   138   - Caratheodory's extension lemma is now proved for ring_of_sets.
   139   - Infinite products of probability measures are now available.
   140   - Use extended reals instead of positive extended reals.
   141     INCOMPATIBILITY.
   142 
   143 
   144 *** Document preparation ***
   145 
   146 * Discontinued special treatment of hard tabulators, which are better
   147 avoided in the first place.  Implicit tab-width is 1.
   148 
   149 * Antiquotation @{rail} layouts railroad syntax diagrams, see also
   150 isar-ref manual.
   151 
   152 * Antiquotation @{value} evaluates the given term and presents its result.
   153 
   154 * Localized \isabellestyle switch can be used within blocks or groups
   155 like this:
   156 
   157   \isabellestyle{it}  %preferred default
   158   {\isabellestylett @{text "typewriter stuff"}}
   159 
   160 * New term style "isub" as ad-hoc conversion of variables x1, y23 into
   161 subscripted form x\<^isub>1, y\<^isub>2\<^isub>3.
   162 
   163 * Predefined LaTeX macros for Isabelle symbols \<bind> and \<then>
   164 (e.g. see ~~/src/HOL/Library/Monad_Syntax.thy).
   165 
   166 
   167 *** ML ***
   168 
   169 * The inner syntax of sort/type/term/prop supports inlined YXML
   170 representations within quoted string tokens.  By encoding logical
   171 entities via Term_XML (in ML or Scala) concrete syntax can be
   172 bypassed, which is particularly useful for producing bits of text
   173 under external program control.
   174 
   175 * Antiquotations for ML and document preparation are managed as theory
   176 data, which requires explicit setup.
   177 
   178 * Isabelle_Process.is_active allows tools to check if the official
   179 process wrapper is running (Isabelle/Scala/jEdit) or the old TTY loop
   180 (better known as Proof General).
   181 
   182 * Structure Proof_Context follows standard naming scheme.  Old
   183 ProofContext is still available for some time as legacy alias.
   184 
   185 * Structure Timing provides various operations for timing; supersedes
   186 former start_timing/end_timing etc.
   187 
   188 * Path.print is the official way to show file-system paths to users
   189 (including quotes etc.).
   190 
   191 * Inner syntax: identifiers in parse trees of generic categories
   192 "logic", "aprop", "idt" etc. carry position information (disguised as
   193 type constraints).  Occasional INCOMPATIBILITY with non-compliant
   194 translations that choke on unexpected type constraints.  Positions can
   195 be stripped in ML translations via Syntax.strip_positions /
   196 Syntax.strip_positions_ast, or via the syntax constant
   197 "_strip_positions" within parse trees.  As last resort, positions can
   198 be disabled via the configuration option Syntax.positions, which is
   199 called "syntax_positions" in Isar attribute syntax.
   200 
   201 * Discontinued special status of various ML structures that contribute
   202 to structure Syntax (Ast, Lexicon, Mixfix, Parser, Printer etc.): less
   203 pervasive content, no inclusion in structure Syntax.  INCOMPATIBILITY,
   204 refer directly to Ast.Constant, Lexicon.is_identifier,
   205 Syntax_Trans.mk_binder_tr etc.
   206 
   207 * Typed print translation: discontinued show_sorts argument, which is
   208 already available via context of "advanced" translation.
   209 
   210 * Refined PARALLEL_GOALS tactical: degrades gracefully for schematic
   211 goal states; body tactic needs to address all subgoals uniformly.
   212 
   213 * Slightly more special eq_list/eq_set, with shortcut involving
   214 pointer equality (assumes that eq relation is reflexive).
   215 
   216 * Classical tactics use proper Proof.context instead of historic types
   217 claset/clasimpset.  Old-style declarations like addIs, addEs, addDs
   218 operate directly on Proof.context.  Raw type claset retains its use as
   219 snapshot of the classical context, which can be recovered via
   220 (put_claset HOL_cs) etc.  Type clasimpset has been discontinued.
   221 INCOMPATIBILITY, classical tactics and derived proof methods require
   222 proper Proof.context.
   223 
   224 * Scala layer provides JVM method invocation service for static
   225 methods of type (String)String, see Invoke_Scala.method in ML.
   226 For example:
   227 
   228   Invoke_Scala.method "java.lang.System.getProperty" "java.home"
   229 
   230 
   231 
   232 New in Isabelle2011 (January 2011)
   233 ----------------------------------
   234 
   235 *** General ***
   236 
   237 * Experimental Prover IDE based on Isabelle/Scala and jEdit (see
   238 src/Tools/jEdit).  This also serves as IDE for Isabelle/ML, with
   239 useful tooltips and hyperlinks produced from its static analysis.  The
   240 bundled component provides an executable Isabelle tool that can be run
   241 like this:
   242 
   243   Isabelle2011/bin/isabelle jedit
   244 
   245 * Significantly improved Isabelle/Isar implementation manual.
   246 
   247 * System settings: ISABELLE_HOME_USER now includes ISABELLE_IDENTIFIER
   248 (and thus refers to something like $HOME/.isabelle/Isabelle2011),
   249 while the default heap location within that directory lacks that extra
   250 suffix.  This isolates multiple Isabelle installations from each
   251 other, avoiding problems with old settings in new versions.
   252 INCOMPATIBILITY, need to copy/upgrade old user settings manually.
   253 
   254 * Source files are always encoded as UTF-8, instead of old-fashioned
   255 ISO-Latin-1.  INCOMPATIBILITY.  Isabelle LaTeX documents might require
   256 the following package declarations:
   257 
   258   \usepackage[utf8]{inputenc}
   259   \usepackage{textcomp}
   260 
   261 * Explicit treatment of UTF-8 sequences as Isabelle symbols, such that
   262 a Unicode character is treated as a single symbol, not a sequence of
   263 non-ASCII bytes as before.  Since Isabelle/ML string literals may
   264 contain symbols without further backslash escapes, Unicode can now be
   265 used here as well.  Recall that Symbol.explode in ML provides a
   266 consistent view on symbols, while raw explode (or String.explode)
   267 merely give a byte-oriented representation.
   268 
   269 * Theory loader: source files are primarily located via the master
   270 directory of each theory node (where the .thy file itself resides).
   271 The global load path is still partially available as legacy feature.
   272 Minor INCOMPATIBILITY due to subtle change in file lookup: use
   273 explicit paths, relatively to the theory.
   274 
   275 * Special treatment of ML file names has been discontinued.
   276 Historically, optional extensions .ML or .sml were added on demand --
   277 at the cost of clarity of file dependencies.  Recall that Isabelle/ML
   278 files exclusively use the .ML extension.  Minor INCOMPATIBILTY.
   279 
   280 * Various options that affect pretty printing etc. are now properly
   281 handled within the context via configuration options, instead of
   282 unsynchronized references or print modes.  There are both ML Config.T
   283 entities and Isar declaration attributes to access these.
   284 
   285   ML (Config.T)                 Isar (attribute)
   286 
   287   eta_contract                  eta_contract
   288   show_brackets                 show_brackets
   289   show_sorts                    show_sorts
   290   show_types                    show_types
   291   show_question_marks           show_question_marks
   292   show_consts                   show_consts
   293   show_abbrevs                  show_abbrevs
   294 
   295   Syntax.ast_trace              syntax_ast_trace
   296   Syntax.ast_stat               syntax_ast_stat
   297   Syntax.ambiguity_level        syntax_ambiguity_level
   298 
   299   Goal_Display.goals_limit      goals_limit
   300   Goal_Display.show_main_goal   show_main_goal
   301 
   302   Method.rule_trace             rule_trace
   303 
   304   Thy_Output.display            thy_output_display
   305   Thy_Output.quotes             thy_output_quotes
   306   Thy_Output.indent             thy_output_indent
   307   Thy_Output.source             thy_output_source
   308   Thy_Output.break              thy_output_break
   309 
   310 Note that corresponding "..._default" references in ML may only be
   311 changed globally at the ROOT session setup, but *not* within a theory.
   312 The option "show_abbrevs" supersedes the former print mode
   313 "no_abbrevs" with inverted meaning.
   314 
   315 * More systematic naming of some configuration options.
   316 INCOMPATIBILITY.
   317 
   318   trace_simp  ~>  simp_trace
   319   debug_simp  ~>  simp_debug
   320 
   321 * Support for real valued configuration options, using simplistic
   322 floating-point notation that coincides with the inner syntax for
   323 float_token.
   324 
   325 * Support for real valued preferences (with approximative PGIP type):
   326 front-ends need to accept "pgint" values in float notation.
   327 INCOMPATIBILITY.
   328 
   329 * The IsabelleText font now includes Cyrillic, Hebrew, Arabic from
   330 DejaVu Sans.
   331 
   332 * Discontinued support for Poly/ML 5.0 and 5.1 versions.
   333 
   334 
   335 *** Pure ***
   336 
   337 * Command 'type_synonym' (with single argument) replaces somewhat
   338 outdated 'types', which is still available as legacy feature for some
   339 time.
   340 
   341 * Command 'nonterminal' (with 'and' separated list of arguments)
   342 replaces somewhat outdated 'nonterminals'.  INCOMPATIBILITY.
   343 
   344 * Command 'notepad' replaces former 'example_proof' for
   345 experimentation in Isar without any result.  INCOMPATIBILITY.
   346 
   347 * Locale interpretation commands 'interpret' and 'sublocale' accept
   348 lists of equations to map definitions in a locale to appropriate
   349 entities in the context of the interpretation.  The 'interpretation'
   350 command already provided this functionality.
   351 
   352 * Diagnostic command 'print_dependencies' prints the locale instances
   353 that would be activated if the specified expression was interpreted in
   354 the current context.  Variant "print_dependencies!" assumes a context
   355 without interpretations.
   356 
   357 * Diagnostic command 'print_interps' prints interpretations in proofs
   358 in addition to interpretations in theories.
   359 
   360 * Discontinued obsolete 'global' and 'local' commands to manipulate
   361 the theory name space.  Rare INCOMPATIBILITY.  The ML functions
   362 Sign.root_path and Sign.local_path may be applied directly where this
   363 feature is still required for historical reasons.
   364 
   365 * Discontinued obsolete 'constdefs' command.  INCOMPATIBILITY, use
   366 'definition' instead.
   367 
   368 * The "prems" fact, which refers to the accidental collection of
   369 foundational premises in the context, is now explicitly marked as
   370 legacy feature and will be discontinued soon.  Consider using "assms"
   371 of the head statement or reference facts by explicit names.
   372 
   373 * Document antiquotations @{class} and @{type} print classes and type
   374 constructors.
   375 
   376 * Document antiquotation @{file} checks file/directory entries within
   377 the local file system.
   378 
   379 
   380 *** HOL ***
   381 
   382 * Coercive subtyping: functions can be declared as coercions and type
   383 inference will add them as necessary upon input of a term.  Theory
   384 Complex_Main declares real :: nat => real and real :: int => real as
   385 coercions. A coercion function f is declared like this:
   386 
   387   declare [[coercion f]]
   388 
   389 To lift coercions through type constructors (e.g. from nat => real to
   390 nat list => real list), map functions can be declared, e.g.
   391 
   392   declare [[coercion_map map]]
   393 
   394 Currently coercion inference is activated only in theories including
   395 real numbers, i.e. descendants of Complex_Main.  This is controlled by
   396 the configuration option "coercion_enabled", e.g. it can be enabled in
   397 other theories like this:
   398 
   399   declare [[coercion_enabled]]
   400 
   401 * Command 'partial_function' provides basic support for recursive
   402 function definitions over complete partial orders.  Concrete instances
   403 are provided for i) the option type, ii) tail recursion on arbitrary
   404 types, and iii) the heap monad of Imperative_HOL.  See
   405 src/HOL/ex/Fundefs.thy and src/HOL/Imperative_HOL/ex/Linked_Lists.thy
   406 for examples.
   407 
   408 * Function package: f.psimps rules are no longer implicitly declared
   409 as [simp].  INCOMPATIBILITY.
   410 
   411 * Datatype package: theorems generated for executable equality (class
   412 "eq") carry proper names and are treated as default code equations.
   413 
   414 * Inductive package: now offers command 'inductive_simps' to
   415 automatically derive instantiated and simplified equations for
   416 inductive predicates, similar to 'inductive_cases'.
   417 
   418 * Command 'enriched_type' allows to register properties of the
   419 functorial structure of types.
   420 
   421 * Improved infrastructure for term evaluation using code generator
   422 techniques, in particular static evaluation conversions.
   423 
   424 * Code generator: Scala (2.8 or higher) has been added to the target
   425 languages.
   426 
   427 * Code generator: globbing constant expressions "*" and "Theory.*"
   428 have been replaced by the more idiomatic "_" and "Theory._".
   429 INCOMPATIBILITY.
   430 
   431 * Code generator: export_code without explicit file declaration prints
   432 to standard output.  INCOMPATIBILITY.
   433 
   434 * Code generator: do not print function definitions for case
   435 combinators any longer.
   436 
   437 * Code generator: simplification with rules determined with
   438 src/Tools/Code/code_simp.ML and method "code_simp".
   439 
   440 * Code generator for records: more idiomatic representation of record
   441 types.  Warning: records are not covered by ancient SML code
   442 generation any longer.  INCOMPATIBILITY.  In cases of need, a suitable
   443 rep_datatype declaration helps to succeed then:
   444 
   445   record 'a foo = ...
   446   ...
   447   rep_datatype foo_ext ...
   448 
   449 * Records: logical foundation type for records does not carry a
   450 '_type' suffix any longer (obsolete due to authentic syntax).
   451 INCOMPATIBILITY.
   452 
   453 * Quickcheck now by default uses exhaustive testing instead of random
   454 testing.  Random testing can be invoked by "quickcheck [random]",
   455 exhaustive testing by "quickcheck [exhaustive]".
   456 
   457 * Quickcheck instantiates polymorphic types with small finite
   458 datatypes by default. This enables a simple execution mechanism to
   459 handle quantifiers and function equality over the finite datatypes.
   460 
   461 * Quickcheck random generator has been renamed from "code" to
   462 "random".  INCOMPATIBILITY.
   463 
   464 * Quickcheck now has a configurable time limit which is set to 30
   465 seconds by default. This can be changed by adding [timeout = n] to the
   466 quickcheck command. The time limit for Auto Quickcheck is still set
   467 independently.
   468 
   469 * Quickcheck in locales considers interpretations of that locale for
   470 counter example search.
   471 
   472 * Sledgehammer:
   473   - Added "smt" and "remote_smt" provers based on the "smt" proof
   474     method. See the Sledgehammer manual for details ("isabelle doc
   475     sledgehammer").
   476   - Renamed commands:
   477     sledgehammer atp_info ~> sledgehammer running_provers
   478     sledgehammer atp_kill ~> sledgehammer kill_provers
   479     sledgehammer available_atps ~> sledgehammer available_provers
   480     INCOMPATIBILITY.
   481   - Renamed options:
   482     sledgehammer [atps = ...] ~> sledgehammer [provers = ...]
   483     sledgehammer [atp = ...] ~> sledgehammer [prover = ...]
   484     sledgehammer [timeout = 77 s] ~> sledgehammer [timeout = 77]
   485     (and "ms" and "min" are no longer supported)
   486     INCOMPATIBILITY.
   487 
   488 * Nitpick:
   489   - Renamed options:
   490     nitpick [timeout = 77 s] ~> nitpick [timeout = 77]
   491     nitpick [tac_timeout = 777 ms] ~> nitpick [tac_timeout = 0.777]
   492     INCOMPATIBILITY.
   493   - Added support for partial quotient types.
   494   - Added local versions of the "Nitpick.register_xxx" functions.
   495   - Added "whack" option.
   496   - Allow registration of quotient types as codatatypes.
   497   - Improved "merge_type_vars" option to merge more types.
   498   - Removed unsound "fast_descrs" option.
   499   - Added custom symmetry breaking for datatypes, making it possible to reach
   500     higher cardinalities.
   501   - Prevent the expansion of too large definitions.
   502 
   503 * Proof methods "metis" and "meson" now have configuration options
   504 "meson_trace", "metis_trace", and "metis_verbose" that can be enabled
   505 to diagnose these tools. E.g.
   506 
   507     using [[metis_trace = true]]
   508 
   509 * Auto Solve: Renamed "Auto Solve Direct".  The tool is now available
   510 manually as command 'solve_direct'.
   511 
   512 * The default SMT solver Z3 must be enabled explicitly (due to
   513 licensing issues) by setting the environment variable
   514 Z3_NON_COMMERCIAL in etc/settings of the component, for example.  For
   515 commercial applications, the SMT solver CVC3 is provided as fall-back;
   516 changing the SMT solver is done via the configuration option
   517 "smt_solver".
   518 
   519 * Remote SMT solvers need to be referred to by the "remote_" prefix,
   520 i.e. "remote_cvc3" and "remote_z3".
   521 
   522 * Added basic SMT support for datatypes, records, and typedefs using
   523 the oracle mode (no proofs).  Direct support of pairs has been dropped
   524 in exchange (pass theorems fst_conv snd_conv pair_collapse to the SMT
   525 support for a similar behavior).  Minor INCOMPATIBILITY.
   526 
   527 * Changed SMT configuration options:
   528   - Renamed:
   529     z3_proofs ~> smt_oracle (with inverted meaning)
   530     z3_trace_assms ~> smt_trace_used_facts
   531     INCOMPATIBILITY.
   532   - Added:
   533     smt_verbose
   534     smt_random_seed
   535     smt_datatypes
   536     smt_infer_triggers
   537     smt_monomorph_limit
   538     cvc3_options
   539     remote_cvc3_options
   540     remote_z3_options
   541     yices_options
   542 
   543 * Boogie output files (.b2i files) need to be declared in the theory
   544 header.
   545 
   546 * Simplification procedure "list_to_set_comprehension" rewrites list
   547 comprehensions applied to List.set to set comprehensions.  Occasional
   548 INCOMPATIBILITY, may be deactivated like this:
   549 
   550   declare [[simproc del: list_to_set_comprehension]]
   551 
   552 * Removed old version of primrec package.  INCOMPATIBILITY.
   553 
   554 * Removed simplifier congruence rule of "prod_case", as has for long
   555 been the case with "split".  INCOMPATIBILITY.
   556 
   557 * String.literal is a type, but not a datatype.  INCOMPATIBILITY.
   558 
   559 * Removed [split_format ... and ... and ...] version of
   560 [split_format].  Potential INCOMPATIBILITY.
   561 
   562 * Predicate "sorted" now defined inductively, with nice induction
   563 rules.  INCOMPATIBILITY: former sorted.simps now named sorted_simps.
   564 
   565 * Constant "contents" renamed to "the_elem", to free the generic name
   566 contents for other uses.  INCOMPATIBILITY.
   567 
   568 * Renamed class eq and constant eq (for code generation) to class
   569 equal and constant equal, plus renaming of related facts and various
   570 tuning.  INCOMPATIBILITY.
   571 
   572 * Dropped type classes mult_mono and mult_mono1.  INCOMPATIBILITY.
   573 
   574 * Removed output syntax "'a ~=> 'b" for "'a => 'b option".
   575 INCOMPATIBILITY.
   576 
   577 * Renamed theory Fset to Cset, type Fset.fset to Cset.set, in order to
   578 avoid confusion with finite sets.  INCOMPATIBILITY.
   579 
   580 * Abandoned locales equiv, congruent and congruent2 for equivalence
   581 relations.  INCOMPATIBILITY: use equivI rather than equiv_intro (same
   582 for congruent(2)).
   583 
   584 * Some previously unqualified names have been qualified:
   585 
   586   types
   587     bool ~> HOL.bool
   588     nat ~> Nat.nat
   589 
   590   constants
   591     Trueprop ~> HOL.Trueprop
   592     True ~> HOL.True
   593     False ~> HOL.False
   594     op & ~> HOL.conj
   595     op | ~> HOL.disj
   596     op --> ~> HOL.implies
   597     op = ~> HOL.eq
   598     Not ~> HOL.Not
   599     The ~> HOL.The
   600     All ~> HOL.All
   601     Ex ~> HOL.Ex
   602     Ex1 ~> HOL.Ex1
   603     Let ~> HOL.Let
   604     If ~> HOL.If
   605     Ball ~> Set.Ball
   606     Bex ~> Set.Bex
   607     Suc ~> Nat.Suc
   608     Pair ~> Product_Type.Pair
   609     fst ~> Product_Type.fst
   610     snd ~> Product_Type.snd
   611     curry ~> Product_Type.curry
   612     op : ~> Set.member
   613     Collect ~> Set.Collect
   614 
   615 INCOMPATIBILITY.
   616 
   617 * More canonical naming convention for some fundamental definitions:
   618 
   619     bot_bool_eq ~> bot_bool_def
   620     top_bool_eq ~> top_bool_def
   621     inf_bool_eq ~> inf_bool_def
   622     sup_bool_eq ~> sup_bool_def
   623     bot_fun_eq  ~> bot_fun_def
   624     top_fun_eq  ~> top_fun_def
   625     inf_fun_eq  ~> inf_fun_def
   626     sup_fun_eq  ~> sup_fun_def
   627 
   628 INCOMPATIBILITY.
   629 
   630 * More stylized fact names:
   631 
   632   expand_fun_eq ~> fun_eq_iff
   633   expand_set_eq ~> set_eq_iff
   634   set_ext       ~> set_eqI
   635   nat_number    ~> eval_nat_numeral
   636 
   637 INCOMPATIBILITY.
   638 
   639 * Refactoring of code-generation specific operations in theory List:
   640 
   641   constants
   642     null ~> List.null
   643 
   644   facts
   645     mem_iff ~> member_def
   646     null_empty ~> null_def
   647 
   648 INCOMPATIBILITY.  Note that these were not supposed to be used
   649 regularly unless for striking reasons; their main purpose was code
   650 generation.
   651 
   652 Various operations from the Haskell prelude are used for generating
   653 Haskell code.
   654 
   655 * Term "bij f" is now an abbreviation of "bij_betw f UNIV UNIV".  Term
   656 "surj f" is now an abbreviation of "range f = UNIV".  The theorems
   657 bij_def and surj_def are unchanged.  INCOMPATIBILITY.
   658 
   659 * Abolished some non-alphabetic type names: "prod" and "sum" replace
   660 "*" and "+" respectively.  INCOMPATIBILITY.
   661 
   662 * Name "Plus" of disjoint sum operator "<+>" is now hidden.  Write
   663 "Sum_Type.Plus" instead.
   664 
   665 * Constant "split" has been merged with constant "prod_case"; names of
   666 ML functions, facts etc. involving split have been retained so far,
   667 though.  INCOMPATIBILITY.
   668 
   669 * Dropped old infix syntax "_ mem _" for List.member; use "_ : set _"
   670 instead.  INCOMPATIBILITY.
   671 
   672 * Removed lemma "Option.is_none_none" which duplicates "is_none_def".
   673 INCOMPATIBILITY.
   674 
   675 * Former theory Library/Enum is now part of the HOL-Main image.
   676 INCOMPATIBILITY: all constants of the Enum theory now have to be
   677 referred to by its qualified name.
   678 
   679   enum    ~>  Enum.enum
   680   nlists  ~>  Enum.nlists
   681   product ~>  Enum.product
   682 
   683 * Theory Library/Monad_Syntax provides do-syntax for monad types.
   684 Syntax in Library/State_Monad has been changed to avoid ambiguities.
   685 INCOMPATIBILITY.
   686 
   687 * Theory Library/SetsAndFunctions has been split into
   688 Library/Function_Algebras and Library/Set_Algebras; canonical names
   689 for instance definitions for functions; various improvements.
   690 INCOMPATIBILITY.
   691 
   692 * Theory Library/Multiset provides stable quicksort implementation of
   693 sort_key.
   694 
   695 * Theory Library/Multiset: renamed empty_idemp ~> empty_neutral.
   696 INCOMPATIBILITY.
   697 
   698 * Session Multivariate_Analysis: introduced a type class for euclidean
   699 space.  Most theorems are now stated in terms of euclidean spaces
   700 instead of finite cartesian products.
   701 
   702   types
   703     real ^ 'n ~>  'a::real_vector
   704               ~>  'a::euclidean_space
   705               ~>  'a::ordered_euclidean_space
   706         (depends on your needs)
   707 
   708   constants
   709      _ $ _        ~> _ $$ _
   710      \<chi> x. _  ~> \<chi>\<chi> x. _
   711      CARD('n)     ~> DIM('a)
   712 
   713 Also note that the indices are now natural numbers and not from some
   714 finite type. Finite cartesian products of euclidean spaces, products
   715 of euclidean spaces the real and complex numbers are instantiated to
   716 be euclidean_spaces.  INCOMPATIBILITY.
   717 
   718 * Session Probability: introduced pextreal as positive extended real
   719 numbers.  Use pextreal as value for measures.  Introduce the
   720 Radon-Nikodym derivative, product spaces and Fubini's theorem for
   721 arbitrary sigma finite measures.  Introduces Lebesgue measure based on
   722 the integral in Multivariate Analysis.  INCOMPATIBILITY.
   723 
   724 * Session Imperative_HOL: revamped, corrected dozens of inadequacies.
   725 INCOMPATIBILITY.
   726 
   727 * Session SPARK (with image HOL-SPARK) provides commands to load and
   728 prove verification conditions generated by the SPARK Ada program
   729 verifier.  See also src/HOL/SPARK and src/HOL/SPARK/Examples.
   730 
   731 
   732 *** HOL-Algebra ***
   733 
   734 * Theorems for additive ring operations (locale abelian_monoid and
   735 descendants) are generated by interpretation from their multiplicative
   736 counterparts.  Names (in particular theorem names) have the mandatory
   737 qualifier 'add'.  Previous theorem names are redeclared for
   738 compatibility.
   739 
   740 * Structure "int_ring" is now an abbreviation (previously a
   741 definition).  This fits more natural with advanced interpretations.
   742 
   743 
   744 *** HOLCF ***
   745 
   746 * The domain package now runs in definitional mode by default: The
   747 former command 'new_domain' is now called 'domain'.  To use the domain
   748 package in its original axiomatic mode, use 'domain (unsafe)'.
   749 INCOMPATIBILITY.
   750 
   751 * The new class "domain" is now the default sort.  Class "predomain"
   752 is an unpointed version of "domain". Theories can be updated by
   753 replacing sort annotations as shown below.  INCOMPATIBILITY.
   754 
   755   'a::type ~> 'a::countable
   756   'a::cpo  ~> 'a::predomain
   757   'a::pcpo ~> 'a::domain
   758 
   759 * The old type class "rep" has been superseded by class "domain".
   760 Accordingly, users of the definitional package must remove any
   761 "default_sort rep" declarations.  INCOMPATIBILITY.
   762 
   763 * The domain package (definitional mode) now supports unpointed
   764 predomain argument types, as long as they are marked 'lazy'. (Strict
   765 arguments must be in class "domain".) For example, the following
   766 domain definition now works:
   767 
   768   domain natlist = nil | cons (lazy "nat discr") (lazy "natlist")
   769 
   770 * Theory HOLCF/Library/HOL_Cpo provides cpo and predomain class
   771 instances for types from main HOL: bool, nat, int, char, 'a + 'b,
   772 'a option, and 'a list.  Additionally, it configures fixrec and the
   773 domain package to work with these types.  For example:
   774 
   775   fixrec isInl :: "('a + 'b) u -> tr"
   776     where "isInl$(up$(Inl x)) = TT" | "isInl$(up$(Inr y)) = FF"
   777 
   778   domain V = VFun (lazy "V -> V") | VCon (lazy "nat") (lazy "V list")
   779 
   780 * The "(permissive)" option of fixrec has been replaced with a
   781 per-equation "(unchecked)" option. See
   782 src/HOL/HOLCF/Tutorial/Fixrec_ex.thy for examples. INCOMPATIBILITY.
   783 
   784 * The "bifinite" class no longer fixes a constant "approx"; the class
   785 now just asserts that such a function exists.  INCOMPATIBILITY.
   786 
   787 * Former type "alg_defl" has been renamed to "defl".  HOLCF no longer
   788 defines an embedding of type 'a defl into udom by default; instances
   789 of "bifinite" and "domain" classes are available in
   790 src/HOL/HOLCF/Library/Defl_Bifinite.thy.
   791 
   792 * The syntax "REP('a)" has been replaced with "DEFL('a)".
   793 
   794 * The predicate "directed" has been removed.  INCOMPATIBILITY.
   795 
   796 * The type class "finite_po" has been removed.  INCOMPATIBILITY.
   797 
   798 * The function "cprod_map" has been renamed to "prod_map".
   799 INCOMPATIBILITY.
   800 
   801 * The monadic bind operator on each powerdomain has new binder syntax
   802 similar to sets, e.g. "\<Union>\<sharp>x\<in>xs. t" represents
   803 "upper_bind\<cdot>xs\<cdot>(\<Lambda> x. t)".
   804 
   805 * The infix syntax for binary union on each powerdomain has changed
   806 from e.g. "+\<sharp>" to "\<union>\<sharp>", for consistency with set
   807 syntax.  INCOMPATIBILITY.
   808 
   809 * The constant "UU" has been renamed to "bottom".  The syntax "UU" is
   810 still supported as an input translation.
   811 
   812 * Renamed some theorems (the original names are also still available).
   813 
   814   expand_fun_below   ~> fun_below_iff
   815   below_fun_ext      ~> fun_belowI
   816   expand_cfun_eq     ~> cfun_eq_iff
   817   ext_cfun           ~> cfun_eqI
   818   expand_cfun_below  ~> cfun_below_iff
   819   below_cfun_ext     ~> cfun_belowI
   820   cont2cont_Rep_CFun ~> cont2cont_APP
   821 
   822 * The Abs and Rep functions for various types have changed names.
   823 Related theorem names have also changed to match. INCOMPATIBILITY.
   824 
   825   Rep_CFun  ~> Rep_cfun
   826   Abs_CFun  ~> Abs_cfun
   827   Rep_Sprod ~> Rep_sprod
   828   Abs_Sprod ~> Abs_sprod
   829   Rep_Ssum  ~> Rep_ssum
   830   Abs_Ssum  ~> Abs_ssum
   831 
   832 * Lemmas with names of the form *_defined_iff or *_strict_iff have
   833 been renamed to *_bottom_iff.  INCOMPATIBILITY.
   834 
   835 * Various changes to bisimulation/coinduction with domain package:
   836 
   837   - Definitions of "bisim" constants no longer mention definedness.
   838   - With mutual recursion, "bisim" predicate is now curried.
   839   - With mutual recursion, each type gets a separate coind theorem.
   840   - Variable names in bisim_def and coinduct rules have changed.
   841 
   842 INCOMPATIBILITY.
   843 
   844 * Case combinators generated by the domain package for type "foo" are
   845 now named "foo_case" instead of "foo_when".  INCOMPATIBILITY.
   846 
   847 * Several theorems have been renamed to more accurately reflect the
   848 names of constants and types involved.  INCOMPATIBILITY.
   849 
   850   thelub_const    ~> lub_const
   851   lub_const       ~> is_lub_const
   852   thelubI         ~> lub_eqI
   853   is_lub_lub      ~> is_lubD2
   854   lubI            ~> is_lub_lub
   855   unique_lub      ~> is_lub_unique
   856   is_ub_lub       ~> is_lub_rangeD1
   857   lub_bin_chain   ~> is_lub_bin_chain
   858   lub_fun         ~> is_lub_fun
   859   thelub_fun      ~> lub_fun
   860   thelub_cfun     ~> lub_cfun
   861   thelub_Pair     ~> lub_Pair
   862   lub_cprod       ~> is_lub_prod
   863   thelub_cprod    ~> lub_prod
   864   minimal_cprod   ~> minimal_prod
   865   inst_cprod_pcpo ~> inst_prod_pcpo
   866   UU_I            ~> bottomI
   867   compact_UU      ~> compact_bottom
   868   deflation_UU    ~> deflation_bottom
   869   finite_deflation_UU ~> finite_deflation_bottom
   870 
   871 * Many legacy theorem names have been discontinued.  INCOMPATIBILITY.
   872 
   873   sq_ord_less_eq_trans ~> below_eq_trans
   874   sq_ord_eq_less_trans ~> eq_below_trans
   875   refl_less            ~> below_refl
   876   trans_less           ~> below_trans
   877   antisym_less         ~> below_antisym
   878   antisym_less_inverse ~> po_eq_conv [THEN iffD1]
   879   box_less             ~> box_below
   880   rev_trans_less       ~> rev_below_trans
   881   not_less2not_eq      ~> not_below2not_eq
   882   less_UU_iff          ~> below_UU_iff
   883   flat_less_iff        ~> flat_below_iff
   884   adm_less             ~> adm_below
   885   adm_not_less         ~> adm_not_below
   886   adm_compact_not_less ~> adm_compact_not_below
   887   less_fun_def         ~> below_fun_def
   888   expand_fun_less      ~> fun_below_iff
   889   less_fun_ext         ~> fun_belowI
   890   less_discr_def       ~> below_discr_def
   891   discr_less_eq        ~> discr_below_eq
   892   less_unit_def        ~> below_unit_def
   893   less_cprod_def       ~> below_prod_def
   894   prod_lessI           ~> prod_belowI
   895   Pair_less_iff        ~> Pair_below_iff
   896   fst_less_iff         ~> fst_below_iff
   897   snd_less_iff         ~> snd_below_iff
   898   expand_cfun_less     ~> cfun_below_iff
   899   less_cfun_ext        ~> cfun_belowI
   900   injection_less       ~> injection_below
   901   less_up_def          ~> below_up_def
   902   not_Iup_less         ~> not_Iup_below
   903   Iup_less             ~> Iup_below
   904   up_less              ~> up_below
   905   Def_inject_less_eq   ~> Def_below_Def
   906   Def_less_is_eq       ~> Def_below_iff
   907   spair_less_iff       ~> spair_below_iff
   908   less_sprod           ~> below_sprod
   909   spair_less           ~> spair_below
   910   sfst_less_iff        ~> sfst_below_iff
   911   ssnd_less_iff        ~> ssnd_below_iff
   912   fix_least_less       ~> fix_least_below
   913   dist_less_one        ~> dist_below_one
   914   less_ONE             ~> below_ONE
   915   ONE_less_iff         ~> ONE_below_iff
   916   less_sinlD           ~> below_sinlD
   917   less_sinrD           ~> below_sinrD
   918 
   919 
   920 *** FOL and ZF ***
   921 
   922 * All constant names are now qualified internally and use proper
   923 identifiers, e.g. "IFOL.eq" instead of "op =".  INCOMPATIBILITY.
   924 
   925 
   926 *** ML ***
   927 
   928 * Antiquotation @{assert} inlines a function bool -> unit that raises
   929 Fail if the argument is false.  Due to inlining the source position of
   930 failed assertions is included in the error output.
   931 
   932 * Discontinued antiquotation @{theory_ref}, which is obsolete since ML
   933 text is in practice always evaluated with a stable theory checkpoint.
   934 Minor INCOMPATIBILITY, use (Theory.check_thy @{theory}) instead.
   935 
   936 * Antiquotation @{theory A} refers to theory A from the ancestry of
   937 the current context, not any accidental theory loader state as before.
   938 Potential INCOMPATIBILITY, subtle change in semantics.
   939 
   940 * Syntax.pretty_priority (default 0) configures the required priority
   941 of pretty-printed output and thus affects insertion of parentheses.
   942 
   943 * Syntax.default_root (default "any") configures the inner syntax
   944 category (nonterminal symbol) for parsing of terms.
   945 
   946 * Former exception Library.UnequalLengths now coincides with
   947 ListPair.UnequalLengths.
   948 
   949 * Renamed structure MetaSimplifier to Raw_Simplifier.  Note that the
   950 main functionality is provided by structure Simplifier.
   951 
   952 * Renamed raw "explode" function to "raw_explode" to emphasize its
   953 meaning.  Note that internally to Isabelle, Symbol.explode is used in
   954 almost all situations.
   955 
   956 * Discontinued obsolete function sys_error and exception SYS_ERROR.
   957 See implementation manual for further details on exceptions in
   958 Isabelle/ML.
   959 
   960 * Renamed setmp_noncritical to Unsynchronized.setmp to emphasize its
   961 meaning.
   962 
   963 * Renamed structure PureThy to Pure_Thy and moved most of its
   964 operations to structure Global_Theory, to emphasize that this is
   965 rarely-used global-only stuff.
   966 
   967 * Discontinued Output.debug.  Minor INCOMPATIBILITY, use plain writeln
   968 instead (or tracing for high-volume output).
   969 
   970 * Configuration option show_question_marks only affects regular pretty
   971 printing of types and terms, not raw Term.string_of_vname.
   972 
   973 * ML_Context.thm and ML_Context.thms are no longer pervasive.  Rare
   974 INCOMPATIBILITY, superseded by static antiquotations @{thm} and
   975 @{thms} for most purposes.
   976 
   977 * ML structure Unsynchronized is never opened, not even in Isar
   978 interaction mode as before.  Old Unsynchronized.set etc. have been
   979 discontinued -- use plain := instead.  This should be *rare* anyway,
   980 since modern tools always work via official context data, notably
   981 configuration options.
   982 
   983 * Parallel and asynchronous execution requires special care concerning
   984 interrupts.  Structure Exn provides some convenience functions that
   985 avoid working directly with raw Interrupt.  User code must not absorb
   986 interrupts -- intermediate handling (for cleanup etc.) needs to be
   987 followed by re-raising of the original exception.  Another common
   988 source of mistakes are "handle _" patterns, which make the meaning of
   989 the program subject to physical effects of the environment.
   990 
   991 
   992 
   993 New in Isabelle2009-2 (June 2010)
   994 ---------------------------------
   995 
   996 *** General ***
   997 
   998 * Authentic syntax for *all* logical entities (type classes, type
   999 constructors, term constants): provides simple and robust
  1000 correspondence between formal entities and concrete syntax.  Within
  1001 the parse tree / AST representations, "constants" are decorated by
  1002 their category (class, type, const) and spelled out explicitly with
  1003 their full internal name.
  1004 
  1005 Substantial INCOMPATIBILITY concerning low-level syntax declarations
  1006 and translations (translation rules and translation functions in ML).
  1007 Some hints on upgrading:
  1008 
  1009   - Many existing uses of 'syntax' and 'translations' can be replaced
  1010     by more modern 'type_notation', 'notation' and 'abbreviation',
  1011     which are independent of this issue.
  1012 
  1013   - 'translations' require markup within the AST; the term syntax
  1014     provides the following special forms:
  1015 
  1016       CONST c   -- produces syntax version of constant c from context
  1017       XCONST c  -- literally c, checked as constant from context
  1018       c         -- literally c, if declared by 'syntax'
  1019 
  1020     Plain identifiers are treated as AST variables -- occasionally the
  1021     system indicates accidental variables via the error "rhs contains
  1022     extra variables".
  1023 
  1024     Type classes and type constructors are marked according to their
  1025     concrete syntax.  Some old translations rules need to be written
  1026     for the "type" category, using type constructor application
  1027     instead of pseudo-term application of the default category
  1028     "logic".
  1029 
  1030   - 'parse_translation' etc. in ML may use the following
  1031     antiquotations:
  1032 
  1033       @{class_syntax c}   -- type class c within parse tree / AST
  1034       @{term_syntax c}    -- type constructor c within parse tree / AST
  1035       @{const_syntax c}   -- ML version of "CONST c" above
  1036       @{syntax_const c}   -- literally c (checked wrt. 'syntax' declarations)
  1037 
  1038   - Literal types within 'typed_print_translations', i.e. those *not*
  1039     represented as pseudo-terms are represented verbatim.  Use @{class
  1040     c} or @{type_name c} here instead of the above syntax
  1041     antiquotations.
  1042 
  1043 Note that old non-authentic syntax was based on unqualified base
  1044 names, so all of the above "constant" names would coincide.  Recall
  1045 that 'print_syntax' and ML_command "set Syntax.trace_ast" help to
  1046 diagnose syntax problems.
  1047 
  1048 * Type constructors admit general mixfix syntax, not just infix.
  1049 
  1050 * Concrete syntax may be attached to local entities without a proof
  1051 body, too.  This works via regular mixfix annotations for 'fix',
  1052 'def', 'obtain' etc. or via the explicit 'write' command, which is
  1053 similar to the 'notation' command in theory specifications.
  1054 
  1055 * Discontinued unnamed infix syntax (legacy feature for many years) --
  1056 need to specify constant name and syntax separately.  Internal ML
  1057 datatype constructors have been renamed from InfixName to Infix etc.
  1058 Minor INCOMPATIBILITY.
  1059 
  1060 * Schematic theorem statements need to be explicitly markup as such,
  1061 via commands 'schematic_lemma', 'schematic_theorem',
  1062 'schematic_corollary'.  Thus the relevance of the proof is made
  1063 syntactically clear, which impacts performance in a parallel or
  1064 asynchronous interactive environment.  Minor INCOMPATIBILITY.
  1065 
  1066 * Use of cumulative prems via "!" in some proof methods has been
  1067 discontinued (old legacy feature).
  1068 
  1069 * References 'trace_simp' and 'debug_simp' have been replaced by
  1070 configuration options stored in the context. Enabling tracing (the
  1071 case of debugging is similar) in proofs works via
  1072 
  1073   using [[trace_simp = true]]
  1074 
  1075 Tracing is then active for all invocations of the simplifier in
  1076 subsequent goal refinement steps. Tracing may also still be enabled or
  1077 disabled via the ProofGeneral settings menu.
  1078 
  1079 * Separate commands 'hide_class', 'hide_type', 'hide_const',
  1080 'hide_fact' replace the former 'hide' KIND command.  Minor
  1081 INCOMPATIBILITY.
  1082 
  1083 * Improved parallelism of proof term normalization: usedir -p2 -q0 is
  1084 more efficient than combinations with -q1 or -q2.
  1085 
  1086 
  1087 *** Pure ***
  1088 
  1089 * Proofterms record type-class reasoning explicitly, using the
  1090 "unconstrain" operation internally.  This eliminates all sort
  1091 constraints from a theorem and proof, introducing explicit
  1092 OFCLASS-premises.  On the proof term level, this operation is
  1093 automatically applied at theorem boundaries, such that closed proofs
  1094 are always free of sort constraints.  INCOMPATIBILITY for tools that
  1095 inspect proof terms.
  1096 
  1097 * Local theory specifications may depend on extra type variables that
  1098 are not present in the result type -- arguments TYPE('a) :: 'a itself
  1099 are added internally.  For example:
  1100 
  1101   definition unitary :: bool where "unitary = (ALL (x::'a) y. x = y)"
  1102 
  1103 * Predicates of locales introduced by classes carry a mandatory
  1104 "class" prefix.  INCOMPATIBILITY.
  1105 
  1106 * Vacuous class specifications observe default sort.  INCOMPATIBILITY.
  1107 
  1108 * Old 'axclass' command has been discontinued.  INCOMPATIBILITY, use
  1109 'class' instead.
  1110 
  1111 * Command 'code_reflect' allows to incorporate generated ML code into
  1112 runtime environment; replaces immature code_datatype antiquotation.
  1113 INCOMPATIBILITY.
  1114 
  1115 * Code generator: simple concept for abstract datatypes obeying
  1116 invariants.
  1117 
  1118 * Code generator: details of internal data cache have no impact on the
  1119 user space functionality any longer.
  1120 
  1121 * Methods "unfold_locales" and "intro_locales" ignore non-locale
  1122 subgoals.  This is more appropriate for interpretations with 'where'.
  1123 INCOMPATIBILITY.
  1124 
  1125 * Command 'example_proof' opens an empty proof body.  This allows to
  1126 experiment with Isar, without producing any persistent result.
  1127 
  1128 * Commands 'type_notation' and 'no_type_notation' declare type syntax
  1129 within a local theory context, with explicit checking of the
  1130 constructors involved (in contrast to the raw 'syntax' versions).
  1131 
  1132 * Commands 'types' and 'typedecl' now work within a local theory
  1133 context -- without introducing dependencies on parameters or
  1134 assumptions, which is not possible in Isabelle/Pure.
  1135 
  1136 * Command 'defaultsort' has been renamed to 'default_sort', it works
  1137 within a local theory context.  Minor INCOMPATIBILITY.
  1138 
  1139 
  1140 *** HOL ***
  1141 
  1142 * Command 'typedef' now works within a local theory context -- without
  1143 introducing dependencies on parameters or assumptions, which is not
  1144 possible in Isabelle/Pure/HOL.  Note that the logical environment may
  1145 contain multiple interpretations of local typedefs (with different
  1146 non-emptiness proofs), even in a global theory context.
  1147 
  1148 * New package for quotient types.  Commands 'quotient_type' and
  1149 'quotient_definition' may be used for defining types and constants by
  1150 quotient constructions.  An example is the type of integers created by
  1151 quotienting pairs of natural numbers:
  1152 
  1153   fun
  1154     intrel :: "(nat * nat) => (nat * nat) => bool"
  1155   where
  1156     "intrel (x, y) (u, v) = (x + v = u + y)"
  1157 
  1158   quotient_type int = "nat * nat" / intrel
  1159     by (auto simp add: equivp_def expand_fun_eq)
  1160 
  1161   quotient_definition
  1162     "0::int" is "(0::nat, 0::nat)"
  1163 
  1164 The method "lifting" can be used to lift of theorems from the
  1165 underlying "raw" type to the quotient type.  The example
  1166 src/HOL/Quotient_Examples/FSet.thy includes such a quotient
  1167 construction and provides a reasoning infrastructure for finite sets.
  1168 
  1169 * Renamed Library/Quotient.thy to Library/Quotient_Type.thy to avoid
  1170 clash with new theory Quotient in Main HOL.
  1171 
  1172 * Moved the SMT binding into the main HOL session, eliminating
  1173 separate HOL-SMT session.
  1174 
  1175 * List membership infix mem operation is only an input abbreviation.
  1176 INCOMPATIBILITY.
  1177 
  1178 * Theory Library/Word.thy has been removed.  Use library Word/Word.thy
  1179 for future developements; former Library/Word.thy is still present in
  1180 the AFP entry RSAPPS.
  1181 
  1182 * Theorem Int.int_induct renamed to Int.int_of_nat_induct and is no
  1183 longer shadowed.  INCOMPATIBILITY.
  1184 
  1185 * Dropped theorem duplicate comp_arith; use semiring_norm instead.
  1186 INCOMPATIBILITY.
  1187 
  1188 * Dropped theorem RealPow.real_sq_order; use power2_le_imp_le instead.
  1189 INCOMPATIBILITY.
  1190 
  1191 * Dropped normalizing_semiring etc; use the facts in semiring classes
  1192 instead.  INCOMPATIBILITY.
  1193 
  1194 * Dropped several real-specific versions of lemmas about floor and
  1195 ceiling; use the generic lemmas from theory "Archimedean_Field"
  1196 instead.  INCOMPATIBILITY.
  1197 
  1198   floor_number_of_eq         ~> floor_number_of
  1199   le_floor_eq_number_of      ~> number_of_le_floor
  1200   le_floor_eq_zero           ~> zero_le_floor
  1201   le_floor_eq_one            ~> one_le_floor
  1202   floor_less_eq_number_of    ~> floor_less_number_of
  1203   floor_less_eq_zero         ~> floor_less_zero
  1204   floor_less_eq_one          ~> floor_less_one
  1205   less_floor_eq_number_of    ~> number_of_less_floor
  1206   less_floor_eq_zero         ~> zero_less_floor
  1207   less_floor_eq_one          ~> one_less_floor
  1208   floor_le_eq_number_of      ~> floor_le_number_of
  1209   floor_le_eq_zero           ~> floor_le_zero
  1210   floor_le_eq_one            ~> floor_le_one
  1211   floor_subtract_number_of   ~> floor_diff_number_of
  1212   floor_subtract_one         ~> floor_diff_one
  1213   ceiling_number_of_eq       ~> ceiling_number_of
  1214   ceiling_le_eq_number_of    ~> ceiling_le_number_of
  1215   ceiling_le_zero_eq         ~> ceiling_le_zero
  1216   ceiling_le_eq_one          ~> ceiling_le_one
  1217   less_ceiling_eq_number_of  ~> number_of_less_ceiling
  1218   less_ceiling_eq_zero       ~> zero_less_ceiling
  1219   less_ceiling_eq_one        ~> one_less_ceiling
  1220   ceiling_less_eq_number_of  ~> ceiling_less_number_of
  1221   ceiling_less_eq_zero       ~> ceiling_less_zero
  1222   ceiling_less_eq_one        ~> ceiling_less_one
  1223   le_ceiling_eq_number_of    ~> number_of_le_ceiling
  1224   le_ceiling_eq_zero         ~> zero_le_ceiling
  1225   le_ceiling_eq_one          ~> one_le_ceiling
  1226   ceiling_subtract_number_of ~> ceiling_diff_number_of
  1227   ceiling_subtract_one       ~> ceiling_diff_one
  1228 
  1229 * Theory "Finite_Set": various folding_XXX locales facilitate the
  1230 application of the various fold combinators on finite sets.
  1231 
  1232 * Library theory "RBT" renamed to "RBT_Impl"; new library theory "RBT"
  1233 provides abstract red-black tree type which is backed by "RBT_Impl" as
  1234 implementation.  INCOMPATIBILTY.
  1235 
  1236 * Theory Library/Coinductive_List has been removed -- superseded by
  1237 AFP/thys/Coinductive.
  1238 
  1239 * Theory PReal, including the type "preal" and related operations, has
  1240 been removed.  INCOMPATIBILITY.
  1241 
  1242 * Real: new development using Cauchy Sequences.
  1243 
  1244 * Split off theory "Big_Operators" containing setsum, setprod,
  1245 Inf_fin, Sup_fin, Min, Max from theory Finite_Set.  INCOMPATIBILITY.
  1246 
  1247 * Theory "Rational" renamed to "Rat", for consistency with "Nat",
  1248 "Int" etc.  INCOMPATIBILITY.
  1249 
  1250 * Constant Rat.normalize needs to be qualified.  INCOMPATIBILITY.
  1251 
  1252 * New set of rules "ac_simps" provides combined assoc / commute
  1253 rewrites for all interpretations of the appropriate generic locales.
  1254 
  1255 * Renamed theory "OrderedGroup" to "Groups" and split theory
  1256 "Ring_and_Field" into theories "Rings" and "Fields"; for more
  1257 appropriate and more consistent names suitable for name prefixes
  1258 within the HOL theories.  INCOMPATIBILITY.
  1259 
  1260 * Some generic constants have been put to appropriate theories:
  1261   - less_eq, less: Orderings
  1262   - zero, one, plus, minus, uminus, times, abs, sgn: Groups
  1263   - inverse, divide: Rings
  1264 INCOMPATIBILITY.
  1265 
  1266 * More consistent naming of type classes involving orderings (and
  1267 lattices):
  1268 
  1269     lower_semilattice                   ~> semilattice_inf
  1270     upper_semilattice                   ~> semilattice_sup
  1271 
  1272     dense_linear_order                  ~> dense_linorder
  1273 
  1274     pordered_ab_group_add               ~> ordered_ab_group_add
  1275     pordered_ab_group_add_abs           ~> ordered_ab_group_add_abs
  1276     pordered_ab_semigroup_add           ~> ordered_ab_semigroup_add
  1277     pordered_ab_semigroup_add_imp_le    ~> ordered_ab_semigroup_add_imp_le
  1278     pordered_cancel_ab_semigroup_add    ~> ordered_cancel_ab_semigroup_add
  1279     pordered_cancel_comm_semiring       ~> ordered_cancel_comm_semiring
  1280     pordered_cancel_semiring            ~> ordered_cancel_semiring
  1281     pordered_comm_monoid_add            ~> ordered_comm_monoid_add
  1282     pordered_comm_ring                  ~> ordered_comm_ring
  1283     pordered_comm_semiring              ~> ordered_comm_semiring
  1284     pordered_ring                       ~> ordered_ring
  1285     pordered_ring_abs                   ~> ordered_ring_abs
  1286     pordered_semiring                   ~> ordered_semiring
  1287 
  1288     ordered_ab_group_add                ~> linordered_ab_group_add
  1289     ordered_ab_semigroup_add            ~> linordered_ab_semigroup_add
  1290     ordered_cancel_ab_semigroup_add     ~> linordered_cancel_ab_semigroup_add
  1291     ordered_comm_semiring_strict        ~> linordered_comm_semiring_strict
  1292     ordered_field                       ~> linordered_field
  1293     ordered_field_no_lb                 ~> linordered_field_no_lb
  1294     ordered_field_no_ub                 ~> linordered_field_no_ub
  1295     ordered_field_dense_linear_order    ~> dense_linordered_field
  1296     ordered_idom                        ~> linordered_idom
  1297     ordered_ring                        ~> linordered_ring
  1298     ordered_ring_le_cancel_factor       ~> linordered_ring_le_cancel_factor
  1299     ordered_ring_less_cancel_factor     ~> linordered_ring_less_cancel_factor
  1300     ordered_ring_strict                 ~> linordered_ring_strict
  1301     ordered_semidom                     ~> linordered_semidom
  1302     ordered_semiring                    ~> linordered_semiring
  1303     ordered_semiring_1                  ~> linordered_semiring_1
  1304     ordered_semiring_1_strict           ~> linordered_semiring_1_strict
  1305     ordered_semiring_strict             ~> linordered_semiring_strict
  1306 
  1307   The following slightly odd type classes have been moved to a
  1308   separate theory Library/Lattice_Algebras:
  1309 
  1310     lordered_ab_group_add               ~> lattice_ab_group_add
  1311     lordered_ab_group_add_abs           ~> lattice_ab_group_add_abs
  1312     lordered_ab_group_add_meet          ~> semilattice_inf_ab_group_add
  1313     lordered_ab_group_add_join          ~> semilattice_sup_ab_group_add
  1314     lordered_ring                       ~> lattice_ring
  1315 
  1316 INCOMPATIBILITY.
  1317 
  1318 * Refined field classes:
  1319   - classes division_ring_inverse_zero, field_inverse_zero,
  1320     linordered_field_inverse_zero include rule inverse 0 = 0 --
  1321     subsumes former division_by_zero class;
  1322   - numerous lemmas have been ported from field to division_ring.
  1323 INCOMPATIBILITY.
  1324 
  1325 * Refined algebra theorem collections:
  1326   - dropped theorem group group_simps, use algebra_simps instead;
  1327   - dropped theorem group ring_simps, use field_simps instead;
  1328   - proper theorem collection field_simps subsumes former theorem
  1329     groups field_eq_simps and field_simps;
  1330   - dropped lemma eq_minus_self_iff which is a duplicate for
  1331     equal_neg_zero.
  1332 INCOMPATIBILITY.
  1333 
  1334 * Theory Finite_Set and List: some lemmas have been generalized from
  1335 sets to lattices:
  1336 
  1337   fun_left_comm_idem_inter      ~> fun_left_comm_idem_inf
  1338   fun_left_comm_idem_union      ~> fun_left_comm_idem_sup
  1339   inter_Inter_fold_inter        ~> inf_Inf_fold_inf
  1340   union_Union_fold_union        ~> sup_Sup_fold_sup
  1341   Inter_fold_inter              ~> Inf_fold_inf
  1342   Union_fold_union              ~> Sup_fold_sup
  1343   inter_INTER_fold_inter        ~> inf_INFI_fold_inf
  1344   union_UNION_fold_union        ~> sup_SUPR_fold_sup
  1345   INTER_fold_inter              ~> INFI_fold_inf
  1346   UNION_fold_union              ~> SUPR_fold_sup
  1347 
  1348 * Theory "Complete_Lattice": lemmas top_def and bot_def have been
  1349 replaced by the more convenient lemmas Inf_empty and Sup_empty.
  1350 Dropped lemmas Inf_insert_simp and Sup_insert_simp, which are subsumed
  1351 by Inf_insert and Sup_insert.  Lemmas Inf_UNIV and Sup_UNIV replace
  1352 former Inf_Univ and Sup_Univ.  Lemmas inf_top_right and sup_bot_right
  1353 subsume inf_top and sup_bot respectively.  INCOMPATIBILITY.
  1354 
  1355 * Reorganized theory Multiset: swapped notation of pointwise and
  1356 multiset order:
  1357 
  1358   - pointwise ordering is instance of class order with standard syntax
  1359     <= and <;
  1360   - multiset ordering has syntax <=# and <#; partial order properties
  1361     are provided by means of interpretation with prefix
  1362     multiset_order;
  1363   - less duplication, less historical organization of sections,
  1364     conversion from associations lists to multisets, rudimentary code
  1365     generation;
  1366   - use insert_DiffM2 [symmetric] instead of elem_imp_eq_diff_union,
  1367     if needed.
  1368 
  1369 Renamed:
  1370 
  1371   multiset_eq_conv_count_eq  ~>  multiset_ext_iff
  1372   multi_count_ext  ~>  multiset_ext
  1373   diff_union_inverse2  ~>  diff_union_cancelR
  1374 
  1375 INCOMPATIBILITY.
  1376 
  1377 * Theory Permutation: replaced local "remove" by List.remove1.
  1378 
  1379 * Code generation: ML and OCaml code is decorated with signatures.
  1380 
  1381 * Theory List: added transpose.
  1382 
  1383 * Library/Nat_Bijection.thy is a collection of bijective functions
  1384 between nat and other types, which supersedes the older libraries
  1385 Library/Nat_Int_Bij.thy and HOLCF/NatIso.thy.  INCOMPATIBILITY.
  1386 
  1387   Constants:
  1388   Nat_Int_Bij.nat2_to_nat         ~> prod_encode
  1389   Nat_Int_Bij.nat_to_nat2         ~> prod_decode
  1390   Nat_Int_Bij.int_to_nat_bij      ~> int_encode
  1391   Nat_Int_Bij.nat_to_int_bij      ~> int_decode
  1392   Countable.pair_encode           ~> prod_encode
  1393   NatIso.prod2nat                 ~> prod_encode
  1394   NatIso.nat2prod                 ~> prod_decode
  1395   NatIso.sum2nat                  ~> sum_encode
  1396   NatIso.nat2sum                  ~> sum_decode
  1397   NatIso.list2nat                 ~> list_encode
  1398   NatIso.nat2list                 ~> list_decode
  1399   NatIso.set2nat                  ~> set_encode
  1400   NatIso.nat2set                  ~> set_decode
  1401 
  1402   Lemmas:
  1403   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_decode
  1404   Nat_Int_Bij.nat2_to_nat_inj     ~> inj_prod_encode
  1405   Nat_Int_Bij.nat2_to_nat_surj    ~> surj_prod_encode
  1406   Nat_Int_Bij.nat_to_nat2_inj     ~> inj_prod_decode
  1407   Nat_Int_Bij.nat_to_nat2_surj    ~> surj_prod_decode
  1408   Nat_Int_Bij.i2n_n2i_id          ~> int_encode_inverse
  1409   Nat_Int_Bij.n2i_i2n_id          ~> int_decode_inverse
  1410   Nat_Int_Bij.surj_nat_to_int_bij ~> surj_int_encode
  1411   Nat_Int_Bij.surj_int_to_nat_bij ~> surj_int_decode
  1412   Nat_Int_Bij.inj_nat_to_int_bij  ~> inj_int_encode
  1413   Nat_Int_Bij.inj_int_to_nat_bij  ~> inj_int_decode
  1414   Nat_Int_Bij.bij_nat_to_int_bij  ~> bij_int_encode
  1415   Nat_Int_Bij.bij_int_to_nat_bij  ~> bij_int_decode
  1416 
  1417 * Sledgehammer:
  1418   - Renamed ATP commands:
  1419     atp_info     ~> sledgehammer running_atps
  1420     atp_kill     ~> sledgehammer kill_atps
  1421     atp_messages ~> sledgehammer messages
  1422     atp_minimize ~> sledgehammer minimize
  1423     print_atps   ~> sledgehammer available_atps
  1424     INCOMPATIBILITY.
  1425   - Added user's manual ("isabelle doc sledgehammer").
  1426   - Added option syntax and "sledgehammer_params" to customize
  1427     Sledgehammer's behavior.  See the manual for details.
  1428   - Modified the Isar proof reconstruction code so that it produces
  1429     direct proofs rather than proofs by contradiction.  (This feature
  1430     is still experimental.)
  1431   - Made Isar proof reconstruction work for SPASS, remote ATPs, and in
  1432     full-typed mode.
  1433   - Added support for TPTP syntax for SPASS via the "spass_tptp" ATP.
  1434 
  1435 * Nitpick:
  1436   - Added and implemented "binary_ints" and "bits" options.
  1437   - Added "std" option and implemented support for nonstandard models.
  1438   - Added and implemented "finitize" option to improve the precision
  1439     of infinite datatypes based on a monotonicity analysis.
  1440   - Added support for quotient types.
  1441   - Added support for "specification" and "ax_specification"
  1442     constructs.
  1443   - Added support for local definitions (for "function" and
  1444     "termination" proofs).
  1445   - Added support for term postprocessors.
  1446   - Optimized "Multiset.multiset" and "FinFun.finfun".
  1447   - Improved efficiency of "destroy_constrs" optimization.
  1448   - Fixed soundness bugs related to "destroy_constrs" optimization and
  1449     record getters.
  1450   - Fixed soundness bug related to higher-order constructors.
  1451   - Fixed soundness bug when "full_descrs" is enabled.
  1452   - Improved precision of set constructs.
  1453   - Added "atoms" option.
  1454   - Added cache to speed up repeated Kodkod invocations on the same
  1455     problems.
  1456   - Renamed "MiniSatJNI", "zChaffJNI", "BerkMinAlloy", and
  1457     "SAT4JLight" to "MiniSat_JNI", "zChaff_JNI", "BerkMin_Alloy", and
  1458     "SAT4J_Light".  INCOMPATIBILITY.
  1459   - Removed "skolemize", "uncurry", "sym_break", "flatten_prop",
  1460     "sharing_depth", and "show_skolems" options.  INCOMPATIBILITY.
  1461   - Removed "nitpick_intro" attribute.  INCOMPATIBILITY.
  1462 
  1463 * Method "induct" now takes instantiations of the form t, where t is not
  1464   a variable, as a shorthand for "x == t", where x is a fresh variable.
  1465   If this is not intended, t has to be enclosed in parentheses.
  1466   By default, the equalities generated by definitional instantiations
  1467   are pre-simplified, which may cause parameters of inductive cases
  1468   to disappear, or may even delete some of the inductive cases.
  1469   Use "induct (no_simp)" instead of "induct" to restore the old
  1470   behaviour. The (no_simp) option is also understood by the "cases"
  1471   and "nominal_induct" methods, which now perform pre-simplification, too.
  1472   INCOMPATIBILITY.
  1473 
  1474 
  1475 *** HOLCF ***
  1476 
  1477 * Variable names in lemmas generated by the domain package have
  1478 changed; the naming scheme is now consistent with the HOL datatype
  1479 package.  Some proof scripts may be affected, INCOMPATIBILITY.
  1480 
  1481 * The domain package no longer defines the function "foo_copy" for
  1482 recursive domain "foo".  The reach lemma is now stated directly in
  1483 terms of "foo_take".  Lemmas and proofs that mention "foo_copy" must
  1484 be reformulated in terms of "foo_take", INCOMPATIBILITY.
  1485 
  1486 * Most definedness lemmas generated by the domain package (previously
  1487 of the form "x ~= UU ==> foo$x ~= UU") now have an if-and-only-if form
  1488 like "foo$x = UU <-> x = UU", which works better as a simp rule.
  1489 Proofs that used definedness lemmas as intro rules may break,
  1490 potential INCOMPATIBILITY.
  1491 
  1492 * Induction and casedist rules generated by the domain package now
  1493 declare proper case_names (one called "bottom", and one named for each
  1494 constructor).  INCOMPATIBILITY.
  1495 
  1496 * For mutually-recursive domains, separate "reach" and "take_lemma"
  1497 rules are generated for each domain, INCOMPATIBILITY.
  1498 
  1499   foo_bar.reach       ~> foo.reach  bar.reach
  1500   foo_bar.take_lemmas ~> foo.take_lemma  bar.take_lemma
  1501 
  1502 * Some lemmas generated by the domain package have been renamed for
  1503 consistency with the datatype package, INCOMPATIBILITY.
  1504 
  1505   foo.ind        ~> foo.induct
  1506   foo.finite_ind ~> foo.finite_induct
  1507   foo.coind      ~> foo.coinduct
  1508   foo.casedist   ~> foo.exhaust
  1509   foo.exhaust    ~> foo.nchotomy
  1510 
  1511 * For consistency with other definition packages, the fixrec package
  1512 now generates qualified theorem names, INCOMPATIBILITY.
  1513 
  1514   foo_simps  ~> foo.simps
  1515   foo_unfold ~> foo.unfold
  1516   foo_induct ~> foo.induct
  1517 
  1518 * The "fixrec_simp" attribute has been removed.  The "fixrec_simp"
  1519 method and internal fixrec proofs now use the default simpset instead.
  1520 INCOMPATIBILITY.
  1521 
  1522 * The "contlub" predicate has been removed.  Proof scripts should use
  1523 lemma contI2 in place of monocontlub2cont, INCOMPATIBILITY.
  1524 
  1525 * The "admw" predicate has been removed, INCOMPATIBILITY.
  1526 
  1527 * The constants cpair, cfst, and csnd have been removed in favor of
  1528 Pair, fst, and snd from Isabelle/HOL, INCOMPATIBILITY.
  1529 
  1530 
  1531 *** ML ***
  1532 
  1533 * Antiquotations for basic formal entities:
  1534 
  1535     @{class NAME}         -- type class
  1536     @{class_syntax NAME}  -- syntax representation of the above
  1537 
  1538     @{type_name NAME}     -- logical type
  1539     @{type_abbrev NAME}   -- type abbreviation
  1540     @{nonterminal NAME}   -- type of concrete syntactic category
  1541     @{type_syntax NAME}   -- syntax representation of any of the above
  1542 
  1543     @{const_name NAME}    -- logical constant (INCOMPATIBILITY)
  1544     @{const_abbrev NAME}  -- abbreviated constant
  1545     @{const_syntax NAME}  -- syntax representation of any of the above
  1546 
  1547 * Antiquotation @{syntax_const NAME} ensures that NAME refers to a raw
  1548 syntax constant (cf. 'syntax' command).
  1549 
  1550 * Antiquotation @{make_string} inlines a function to print arbitrary
  1551 values similar to the ML toplevel.  The result is compiler dependent
  1552 and may fall back on "?" in certain situations.
  1553 
  1554 * Diagnostic commands 'ML_val' and 'ML_command' may refer to
  1555 antiquotations @{Isar.state} and @{Isar.goal}.  This replaces impure
  1556 Isar.state() and Isar.goal(), which belong to the old TTY loop and do
  1557 not work with the asynchronous Isar document model.
  1558 
  1559 * Configuration options now admit dynamic default values, depending on
  1560 the context or even global references.
  1561 
  1562 * SHA1.digest digests strings according to SHA-1 (see RFC 3174).  It
  1563 uses an efficient external library if available (for Poly/ML).
  1564 
  1565 * Renamed some important ML structures, while keeping the old names
  1566 for some time as aliases within the structure Legacy:
  1567 
  1568   OuterKeyword  ~>  Keyword
  1569   OuterLex      ~>  Token
  1570   OuterParse    ~>  Parse
  1571   OuterSyntax   ~>  Outer_Syntax
  1572   PrintMode     ~>  Print_Mode
  1573   SpecParse     ~>  Parse_Spec
  1574   ThyInfo       ~>  Thy_Info
  1575   ThyLoad       ~>  Thy_Load
  1576   ThyOutput     ~>  Thy_Output
  1577   TypeInfer     ~>  Type_Infer
  1578 
  1579 Note that "open Legacy" simplifies porting of sources, but forgetting
  1580 to remove it again will complicate porting again in the future.
  1581 
  1582 * Most operations that refer to a global context are named
  1583 accordingly, e.g. Simplifier.global_context or
  1584 ProofContext.init_global.  There are some situations where a global
  1585 context actually works, but under normal circumstances one needs to
  1586 pass the proper local context through the code!
  1587 
  1588 * Discontinued old TheoryDataFun with its copy/init operation -- data
  1589 needs to be pure.  Functor Theory_Data_PP retains the traditional
  1590 Pretty.pp argument to merge, which is absent in the standard
  1591 Theory_Data version.
  1592 
  1593 * Sorts.certify_sort and derived "cert" operations for types and terms
  1594 no longer minimize sorts.  Thus certification at the boundary of the
  1595 inference kernel becomes invariant under addition of class relations,
  1596 which is an important monotonicity principle.  Sorts are now minimized
  1597 in the syntax layer only, at the boundary between the end-user and the
  1598 system.  Subtle INCOMPATIBILITY, may have to use Sign.minimize_sort
  1599 explicitly in rare situations.
  1600 
  1601 * Renamed old-style Drule.standard to Drule.export_without_context, to
  1602 emphasize that this is in no way a standard operation.
  1603 INCOMPATIBILITY.
  1604 
  1605 * Subgoal.FOCUS (and variants): resulting goal state is normalized as
  1606 usual for resolution.  Rare INCOMPATIBILITY.
  1607 
  1608 * Renamed varify/unvarify operations to varify_global/unvarify_global
  1609 to emphasize that these only work in a global situation (which is
  1610 quite rare).
  1611 
  1612 * Curried take and drop in library.ML; negative length is interpreted
  1613 as infinity (as in chop).  Subtle INCOMPATIBILITY.
  1614 
  1615 * Proof terms: type substitutions on proof constants now use canonical
  1616 order of type variables.  INCOMPATIBILITY for tools working with proof
  1617 terms.
  1618 
  1619 * Raw axioms/defs may no longer carry sort constraints, and raw defs
  1620 may no longer carry premises.  User-level specifications are
  1621 transformed accordingly by Thm.add_axiom/add_def.
  1622 
  1623 
  1624 *** System ***
  1625 
  1626 * Discontinued special HOL_USEDIR_OPTIONS for the main HOL image;
  1627 ISABELLE_USEDIR_OPTIONS applies uniformly to all sessions.  Note that
  1628 proof terms are enabled unconditionally in the new HOL-Proofs image.
  1629 
  1630 * Discontinued old ISABELLE and ISATOOL environment settings (legacy
  1631 feature since Isabelle2009).  Use ISABELLE_PROCESS and ISABELLE_TOOL,
  1632 respectively.
  1633 
  1634 * Old lib/scripts/polyml-platform is superseded by the
  1635 ISABELLE_PLATFORM setting variable, which defaults to the 32 bit
  1636 variant, even on a 64 bit machine.  The following example setting
  1637 prefers 64 bit if available:
  1638 
  1639   ML_PLATFORM="${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM}"
  1640 
  1641 * The preliminary Isabelle/jEdit application demonstrates the emerging
  1642 Isabelle/Scala layer for advanced prover interaction and integration.
  1643 See src/Tools/jEdit or "isabelle jedit" provided by the properly built
  1644 component.
  1645 
  1646 * "IsabelleText" is a Unicode font derived from Bitstream Vera Mono
  1647 and Bluesky TeX fonts.  It provides the usual Isabelle symbols,
  1648 similar to the default assignment of the document preparation system
  1649 (cf. isabellesym.sty).  The Isabelle/Scala class Isabelle_System
  1650 provides some operations for direct access to the font without asking
  1651 the user for manual installation.
  1652 
  1653 
  1654 
  1655 New in Isabelle2009-1 (December 2009)
  1656 -------------------------------------
  1657 
  1658 *** General ***
  1659 
  1660 * Discontinued old form of "escaped symbols" such as \\<forall>.  Only
  1661 one backslash should be used, even in ML sources.
  1662 
  1663 
  1664 *** Pure ***
  1665 
  1666 * Locale interpretation propagates mixins along the locale hierarchy.
  1667 The currently only available mixins are the equations used to map
  1668 local definitions to terms of the target domain of an interpretation.
  1669 
  1670 * Reactivated diagnostic command 'print_interps'.  Use "print_interps
  1671 loc" to print all interpretations of locale "loc" in the theory.
  1672 Interpretations in proofs are not shown.
  1673 
  1674 * Thoroughly revised locales tutorial.  New section on conditional
  1675 interpretation.
  1676 
  1677 * On instantiation of classes, remaining undefined class parameters
  1678 are formally declared.  INCOMPATIBILITY.
  1679 
  1680 
  1681 *** Document preparation ***
  1682 
  1683 * New generalized style concept for printing terms: @{foo (style) ...}
  1684 instead of @{foo_style style ...}  (old form is still retained for
  1685 backward compatibility).  Styles can be also applied for
  1686 antiquotations prop, term_type and typeof.
  1687 
  1688 
  1689 *** HOL ***
  1690 
  1691 * New proof method "smt" for a combination of first-order logic with
  1692 equality, linear and nonlinear (natural/integer/real) arithmetic, and
  1693 fixed-size bitvectors; there is also basic support for higher-order
  1694 features (esp. lambda abstractions).  It is an incomplete decision
  1695 procedure based on external SMT solvers using the oracle mechanism;
  1696 for the SMT solver Z3, this method is proof-producing.  Certificates
  1697 are provided to avoid calling the external solvers solely for
  1698 re-checking proofs.  Due to a remote SMT service there is no need for
  1699 installing SMT solvers locally.  See src/HOL/SMT.
  1700 
  1701 * New commands to load and prove verification conditions generated by
  1702 the Boogie program verifier or derived systems (e.g. the Verifying C
  1703 Compiler (VCC) or Spec#).  See src/HOL/Boogie.
  1704 
  1705 * New counterexample generator tool 'nitpick' based on the Kodkod
  1706 relational model finder.  See src/HOL/Tools/Nitpick and
  1707 src/HOL/Nitpick_Examples.
  1708 
  1709 * New commands 'code_pred' and 'values' to invoke the predicate
  1710 compiler and to enumerate values of inductive predicates.
  1711 
  1712 * A tabled implementation of the reflexive transitive closure.
  1713 
  1714 * New implementation of quickcheck uses generic code generator;
  1715 default generators are provided for all suitable HOL types, records
  1716 and datatypes.  Old quickcheck can be re-activated importing theory
  1717 Library/SML_Quickcheck.
  1718 
  1719 * New testing tool Mirabelle for automated proof tools.  Applies
  1720 several tools and tactics like sledgehammer, metis, or quickcheck, to
  1721 every proof step in a theory.  To be used in batch mode via the
  1722 "mirabelle" utility.
  1723 
  1724 * New proof method "sos" (sum of squares) for nonlinear real
  1725 arithmetic (originally due to John Harison). It requires theory
  1726 Library/Sum_Of_Squares.  It is not a complete decision procedure but
  1727 works well in practice on quantifier-free real arithmetic with +, -,
  1728 *, ^, =, <= and <, i.e. boolean combinations of equalities and
  1729 inequalities between polynomials.  It makes use of external
  1730 semidefinite programming solvers.  Method "sos" generates a
  1731 certificate that can be pasted into the proof thus avoiding the need
  1732 to call an external tool every time the proof is checked.  See
  1733 src/HOL/Library/Sum_Of_Squares.
  1734 
  1735 * New method "linarith" invokes existing linear arithmetic decision
  1736 procedure only.
  1737 
  1738 * New command 'atp_minimal' reduces result produced by Sledgehammer.
  1739 
  1740 * New Sledgehammer option "Full Types" in Proof General settings menu.
  1741 Causes full type information to be output to the ATPs.  This slows
  1742 ATPs down considerably but eliminates a source of unsound "proofs"
  1743 that fail later.
  1744 
  1745 * New method "metisFT": A version of metis that uses full type
  1746 information in order to avoid failures of proof reconstruction.
  1747 
  1748 * New evaluator "approximate" approximates an real valued term using
  1749 the same method as the approximation method.
  1750 
  1751 * Method "approximate" now supports arithmetic expressions as
  1752 boundaries of intervals and implements interval splitting and Taylor
  1753 series expansion.
  1754 
  1755 * ML antiquotation @{code_datatype} inserts definition of a datatype
  1756 generated by the code generator; e.g. see src/HOL/Predicate.thy.
  1757 
  1758 * New theory SupInf of the supremum and infimum operators for sets of
  1759 reals.
  1760 
  1761 * New theory Probability, which contains a development of measure
  1762 theory, eventually leading to Lebesgue integration and probability.
  1763 
  1764 * Extended Multivariate Analysis to include derivation and Brouwer's
  1765 fixpoint theorem.
  1766 
  1767 * Reorganization of number theory, INCOMPATIBILITY:
  1768   - new number theory development for nat and int, in theories Divides
  1769     and GCD as well as in new session Number_Theory
  1770   - some constants and facts now suffixed with _nat and _int
  1771     accordingly
  1772   - former session NumberTheory now named Old_Number_Theory, including
  1773     theories Legacy_GCD and Primes (prefer Number_Theory if possible)
  1774   - moved theory Pocklington from src/HOL/Library to
  1775     src/HOL/Old_Number_Theory
  1776 
  1777 * Theory GCD includes functions Gcd/GCD and Lcm/LCM for the gcd and
  1778 lcm of finite and infinite sets. It is shown that they form a complete
  1779 lattice.
  1780 
  1781 * Class semiring_div requires superclass no_zero_divisors and proof of
  1782 div_mult_mult1; theorems div_mult_mult1, div_mult_mult2,
  1783 div_mult_mult1_if, div_mult_mult1 and div_mult_mult2 have been
  1784 generalized to class semiring_div, subsuming former theorems
  1785 zdiv_zmult_zmult1, zdiv_zmult_zmult1_if, zdiv_zmult_zmult1 and
  1786 zdiv_zmult_zmult2.  div_mult_mult1 is now [simp] by default.
  1787 INCOMPATIBILITY.
  1788 
  1789 * Refinements to lattice classes and sets:
  1790   - less default intro/elim rules in locale variant, more default
  1791     intro/elim rules in class variant: more uniformity
  1792   - lemma ge_sup_conv renamed to le_sup_iff, in accordance with
  1793     le_inf_iff
  1794   - dropped lemma alias inf_ACI for inf_aci (same for sup_ACI and
  1795     sup_aci)
  1796   - renamed ACI to inf_sup_aci
  1797   - new class "boolean_algebra"
  1798   - class "complete_lattice" moved to separate theory
  1799     "Complete_Lattice"; corresponding constants (and abbreviations)
  1800     renamed and with authentic syntax:
  1801     Set.Inf ~>    Complete_Lattice.Inf
  1802     Set.Sup ~>    Complete_Lattice.Sup
  1803     Set.INFI ~>   Complete_Lattice.INFI
  1804     Set.SUPR ~>   Complete_Lattice.SUPR
  1805     Set.Inter ~>  Complete_Lattice.Inter
  1806     Set.Union ~>  Complete_Lattice.Union
  1807     Set.INTER ~>  Complete_Lattice.INTER
  1808     Set.UNION ~>  Complete_Lattice.UNION
  1809   - authentic syntax for
  1810     Set.Pow
  1811     Set.image
  1812   - mere abbreviations:
  1813     Set.empty               (for bot)
  1814     Set.UNIV                (for top)
  1815     Set.inter               (for inf, formerly Set.Int)
  1816     Set.union               (for sup, formerly Set.Un)
  1817     Complete_Lattice.Inter  (for Inf)
  1818     Complete_Lattice.Union  (for Sup)
  1819     Complete_Lattice.INTER  (for INFI)
  1820     Complete_Lattice.UNION  (for SUPR)
  1821   - object-logic definitions as far as appropriate
  1822 
  1823 INCOMPATIBILITY.  Care is required when theorems Int_subset_iff or
  1824 Un_subset_iff are explicitly deleted as default simp rules; then also
  1825 their lattice counterparts le_inf_iff and le_sup_iff have to be
  1826 deleted to achieve the desired effect.
  1827 
  1828 * Rules inf_absorb1, inf_absorb2, sup_absorb1, sup_absorb2 are no simp
  1829 rules by default any longer; the same applies to min_max.inf_absorb1
  1830 etc.  INCOMPATIBILITY.
  1831 
  1832 * Rules sup_Int_eq and sup_Un_eq are no longer declared as
  1833 pred_set_conv by default.  INCOMPATIBILITY.
  1834 
  1835 * Power operations on relations and functions are now one dedicated
  1836 constant "compow" with infix syntax "^^".  Power operation on
  1837 multiplicative monoids retains syntax "^" and is now defined generic
  1838 in class power.  INCOMPATIBILITY.
  1839 
  1840 * Relation composition "R O S" now has a more standard argument order:
  1841 "R O S = {(x, z). EX y. (x, y) : R & (y, z) : S}".  INCOMPATIBILITY,
  1842 rewrite propositions with "S O R" --> "R O S". Proofs may occasionally
  1843 break, since the O_assoc rule was not rewritten like this.  Fix using
  1844 O_assoc[symmetric].  The same applies to the curried version "R OO S".
  1845 
  1846 * Function "Inv" is renamed to "inv_into" and function "inv" is now an
  1847 abbreviation for "inv_into UNIV".  Lemmas are renamed accordingly.
  1848 INCOMPATIBILITY.
  1849 
  1850 * Most rules produced by inductive and datatype package have mandatory
  1851 prefixes.  INCOMPATIBILITY.
  1852 
  1853 * Changed "DERIV_intros" to a dynamic fact, which can be augmented by
  1854 the attribute of the same name.  Each of the theorems in the list
  1855 DERIV_intros assumes composition with an additional function and
  1856 matches a variable to the derivative, which has to be solved by the
  1857 Simplifier.  Hence (auto intro!: DERIV_intros) computes the derivative
  1858 of most elementary terms.  Former Maclauren.DERIV_tac and
  1859 Maclauren.deriv_tac should be replaced by (auto intro!: DERIV_intros).
  1860 INCOMPATIBILITY.
  1861 
  1862 * Code generator attributes follow the usual underscore convention:
  1863     code_unfold     replaces    code unfold
  1864     code_post       replaces    code post
  1865     etc.
  1866   INCOMPATIBILITY.
  1867 
  1868 * Renamed methods:
  1869     sizechange -> size_change
  1870     induct_scheme -> induction_schema
  1871   INCOMPATIBILITY.
  1872 
  1873 * Discontinued abbreviation "arbitrary" of constant "undefined".
  1874 INCOMPATIBILITY, use "undefined" directly.
  1875 
  1876 * Renamed theorems:
  1877     Suc_eq_add_numeral_1 -> Suc_eq_plus1
  1878     Suc_eq_add_numeral_1_left -> Suc_eq_plus1_left
  1879     Suc_plus1 -> Suc_eq_plus1
  1880     *anti_sym -> *antisym*
  1881     vector_less_eq_def -> vector_le_def
  1882   INCOMPATIBILITY.
  1883 
  1884 * Added theorem List.map_map as [simp].  Removed List.map_compose.
  1885 INCOMPATIBILITY.
  1886 
  1887 * Removed predicate "M hassize n" (<--> card M = n & finite M).
  1888 INCOMPATIBILITY.
  1889 
  1890 
  1891 *** HOLCF ***
  1892 
  1893 * Theory Representable defines a class "rep" of domains that are
  1894 representable (via an ep-pair) in the universal domain type "udom".
  1895 Instances are provided for all type constructors defined in HOLCF.
  1896 
  1897 * The 'new_domain' command is a purely definitional version of the
  1898 domain package, for representable domains.  Syntax is identical to the
  1899 old domain package.  The 'new_domain' package also supports indirect
  1900 recursion using previously-defined type constructors.  See
  1901 src/HOLCF/ex/New_Domain.thy for examples.
  1902 
  1903 * Method "fixrec_simp" unfolds one step of a fixrec-defined constant
  1904 on the left-hand side of an equation, and then performs
  1905 simplification.  Rewriting is done using rules declared with the
  1906 "fixrec_simp" attribute.  The "fixrec_simp" method is intended as a
  1907 replacement for "fixpat"; see src/HOLCF/ex/Fixrec_ex.thy for examples.
  1908 
  1909 * The pattern-match compiler in 'fixrec' can now handle constructors
  1910 with HOL function types.  Pattern-match combinators for the Pair
  1911 constructor are pre-configured.
  1912 
  1913 * The 'fixrec' package now produces better fixed-point induction rules
  1914 for mutually-recursive definitions:  Induction rules have conclusions
  1915 of the form "P foo bar" instead of "P <foo, bar>".
  1916 
  1917 * The constant "sq_le" (with infix syntax "<<" or "\<sqsubseteq>") has
  1918 been renamed to "below".  The name "below" now replaces "less" in many
  1919 theorem names.  (Legacy theorem names using "less" are still supported
  1920 as well.)
  1921 
  1922 * The 'fixrec' package now supports "bottom patterns".  Bottom
  1923 patterns can be used to generate strictness rules, or to make
  1924 functions more strict (much like the bang-patterns supported by the
  1925 Glasgow Haskell Compiler).  See src/HOLCF/ex/Fixrec_ex.thy for
  1926 examples.
  1927 
  1928 
  1929 *** ML ***
  1930 
  1931 * Support for Poly/ML 5.3.0, with improved reporting of compiler
  1932 errors and run-time exceptions, including detailed source positions.
  1933 
  1934 * Structure Name_Space (formerly NameSpace) now manages uniquely
  1935 identified entries, with some additional information such as source
  1936 position, logical grouping etc.
  1937 
  1938 * Theory and context data is now introduced by the simplified and
  1939 modernized functors Theory_Data, Proof_Data, Generic_Data.  Data needs
  1940 to be pure, but the old TheoryDataFun for mutable data (with explicit
  1941 copy operation) is still available for some time.
  1942 
  1943 * Structure Synchronized (cf. src/Pure/Concurrent/synchronized.ML)
  1944 provides a high-level programming interface to synchronized state
  1945 variables with atomic update.  This works via pure function
  1946 application within a critical section -- its runtime should be as
  1947 short as possible; beware of deadlocks if critical code is nested,
  1948 either directly or indirectly via other synchronized variables!
  1949 
  1950 * Structure Unsynchronized (cf. src/Pure/ML-Systems/unsynchronized.ML)
  1951 wraps raw ML references, explicitly indicating their non-thread-safe
  1952 behaviour.  The Isar toplevel keeps this structure open, to
  1953 accommodate Proof General as well as quick and dirty interactive
  1954 experiments with references.
  1955 
  1956 * PARALLEL_CHOICE and PARALLEL_GOALS provide basic support for
  1957 parallel tactical reasoning.
  1958 
  1959 * Tacticals Subgoal.FOCUS, Subgoal.FOCUS_PREMS, Subgoal.FOCUS_PARAMS
  1960 are similar to SUBPROOF, but are slightly more flexible: only the
  1961 specified parts of the subgoal are imported into the context, and the
  1962 body tactic may introduce new subgoals and schematic variables.
  1963 
  1964 * Old tactical METAHYPS, which does not observe the proof context, has
  1965 been renamed to Old_Goals.METAHYPS and awaits deletion.  Use SUBPROOF
  1966 or Subgoal.FOCUS etc.
  1967 
  1968 * Renamed functor TableFun to Table, and GraphFun to Graph.  (Since
  1969 functors have their own ML name space there is no point to mark them
  1970 separately.)  Minor INCOMPATIBILITY.
  1971 
  1972 * Renamed NamedThmsFun to Named_Thms.  INCOMPATIBILITY.
  1973 
  1974 * Renamed several structures FooBar to Foo_Bar.  Occasional,
  1975 INCOMPATIBILITY.
  1976 
  1977 * Operations of structure Skip_Proof no longer require quick_and_dirty
  1978 mode, which avoids critical setmp.
  1979 
  1980 * Eliminated old Attrib.add_attributes, Method.add_methods and related
  1981 combinators for "args".  INCOMPATIBILITY, need to use simplified
  1982 Attrib/Method.setup introduced in Isabelle2009.
  1983 
  1984 * Proper context for simpset_of, claset_of, clasimpset_of.  May fall
  1985 back on global_simpset_of, global_claset_of, global_clasimpset_of as
  1986 last resort.  INCOMPATIBILITY.
  1987 
  1988 * Display.pretty_thm now requires a proper context (cf. former
  1989 ProofContext.pretty_thm).  May fall back on Display.pretty_thm_global
  1990 or even Display.pretty_thm_without_context as last resort.
  1991 INCOMPATIBILITY.
  1992 
  1993 * Discontinued Display.pretty_ctyp/cterm etc.  INCOMPATIBILITY, use
  1994 Syntax.pretty_typ/term directly, preferably with proper context
  1995 instead of global theory.
  1996 
  1997 
  1998 *** System ***
  1999 
  2000 * Further fine tuning of parallel proof checking, scales up to 8 cores
  2001 (max. speedup factor 5.0).  See also Goal.parallel_proofs in ML and
  2002 usedir option -q.
  2003 
  2004 * Support for additional "Isabelle components" via etc/components, see
  2005 also the system manual.
  2006 
  2007 * The isabelle makeall tool now operates on all components with
  2008 IsaMakefile, not just hardwired "logics".
  2009 
  2010 * Removed "compress" option from isabelle-process and isabelle usedir;
  2011 this is always enabled.
  2012 
  2013 * Discontinued support for Poly/ML 4.x versions.
  2014 
  2015 * Isabelle tool "wwwfind" provides web interface for 'find_theorems'
  2016 on a given logic image.  This requires the lighttpd webserver and is
  2017 currently supported on Linux only.
  2018 
  2019 
  2020 
  2021 New in Isabelle2009 (April 2009)
  2022 --------------------------------
  2023 
  2024 *** General ***
  2025 
  2026 * Simplified main Isabelle executables, with less surprises on
  2027 case-insensitive file-systems (such as Mac OS).
  2028 
  2029   - The main Isabelle tool wrapper is now called "isabelle" instead of
  2030     "isatool."
  2031 
  2032   - The former "isabelle" alias for "isabelle-process" has been
  2033     removed (should rarely occur to regular users).
  2034 
  2035   - The former "isabelle-interface" and its alias "Isabelle" have been
  2036     removed (interfaces are now regular Isabelle tools).
  2037 
  2038 Within scripts and make files, the Isabelle environment variables
  2039 ISABELLE_TOOL and ISABELLE_PROCESS replace old ISATOOL and ISABELLE,
  2040 respectively.  (The latter are still available as legacy feature.)
  2041 
  2042 The old isabelle-interface wrapper could react in confusing ways if
  2043 the interface was uninstalled or changed otherwise.  Individual
  2044 interface tool configuration is now more explicit, see also the
  2045 Isabelle system manual.  In particular, Proof General is now available
  2046 via "isabelle emacs".
  2047 
  2048 INCOMPATIBILITY, need to adapt derivative scripts.  Users may need to
  2049 purge installed copies of Isabelle executables and re-run "isabelle
  2050 install -p ...", or use symlinks.
  2051 
  2052 * The default for ISABELLE_HOME_USER is now ~/.isabelle instead of the
  2053 old ~/isabelle, which was slightly non-standard and apt to cause
  2054 surprises on case-insensitive file-systems (such as Mac OS).
  2055 
  2056 INCOMPATIBILITY, need to move existing ~/isabelle/etc,
  2057 ~/isabelle/heaps, ~/isabelle/browser_info to the new place.  Special
  2058 care is required when using older releases of Isabelle.  Note that
  2059 ISABELLE_HOME_USER can be changed in Isabelle/etc/settings of any
  2060 Isabelle distribution, in order to use the new ~/.isabelle uniformly.
  2061 
  2062 * Proofs of fully specified statements are run in parallel on
  2063 multi-core systems.  A speedup factor of 2.5 to 3.2 can be expected on
  2064 a regular 4-core machine, if the initial heap space is made reasonably
  2065 large (cf. Poly/ML option -H).  (Requires Poly/ML 5.2.1 or later.)
  2066 
  2067 * The main reference manuals ("isar-ref", "implementation", and
  2068 "system") have been updated and extended.  Formally checked references
  2069 as hyperlinks are now available uniformly.
  2070 
  2071 
  2072 *** Pure ***
  2073 
  2074 * Complete re-implementation of locales.  INCOMPATIBILITY in several
  2075 respects.  The most important changes are listed below.  See the
  2076 Tutorial on Locales ("locales" manual) for details.
  2077 
  2078 - In locale expressions, instantiation replaces renaming.  Parameters
  2079 must be declared in a for clause.  To aid compatibility with previous
  2080 parameter inheritance, in locale declarations, parameters that are not
  2081 'touched' (instantiation position "_" or omitted) are implicitly added
  2082 with their syntax at the beginning of the for clause.
  2083 
  2084 - Syntax from abbreviations and definitions in locales is available in
  2085 locale expressions and context elements.  The latter is particularly
  2086 useful in locale declarations.
  2087 
  2088 - More flexible mechanisms to qualify names generated by locale
  2089 expressions.  Qualifiers (prefixes) may be specified in locale
  2090 expressions, and can be marked as mandatory (syntax: "name!:") or
  2091 optional (syntax "name?:").  The default depends for plain "name:"
  2092 depends on the situation where a locale expression is used: in
  2093 commands 'locale' and 'sublocale' prefixes are optional, in
  2094 'interpretation' and 'interpret' prefixes are mandatory.  The old
  2095 implicit qualifiers derived from the parameter names of a locale are
  2096 no longer generated.
  2097 
  2098 - Command "sublocale l < e" replaces "interpretation l < e".  The
  2099 instantiation clause in "interpretation" and "interpret" (square
  2100 brackets) is no longer available.  Use locale expressions.
  2101 
  2102 - When converting proof scripts, mandatory qualifiers in
  2103 'interpretation' and 'interpret' should be retained by default, even
  2104 if this is an INCOMPATIBILITY compared to former behavior.  In the
  2105 worst case, use the "name?:" form for non-mandatory ones.  Qualifiers
  2106 in locale expressions range over a single locale instance only.
  2107 
  2108 - Dropped locale element "includes".  This is a major INCOMPATIBILITY.
  2109 In existing theorem specifications replace the includes element by the
  2110 respective context elements of the included locale, omitting those
  2111 that are already present in the theorem specification.  Multiple
  2112 assume elements of a locale should be replaced by a single one
  2113 involving the locale predicate.  In the proof body, declarations (most
  2114 notably theorems) may be regained by interpreting the respective
  2115 locales in the proof context as required (command "interpret").
  2116 
  2117 If using "includes" in replacement of a target solely because the
  2118 parameter types in the theorem are not as general as in the target,
  2119 consider declaring a new locale with additional type constraints on
  2120 the parameters (context element "constrains").
  2121 
  2122 - Discontinued "locale (open)".  INCOMPATIBILITY.
  2123 
  2124 - Locale interpretation commands no longer attempt to simplify goal.
  2125 INCOMPATIBILITY: in rare situations the generated goal differs.  Use
  2126 methods intro_locales and unfold_locales to clarify.
  2127 
  2128 - Locale interpretation commands no longer accept interpretation
  2129 attributes.  INCOMPATIBILITY.
  2130 
  2131 * Class declaration: so-called "base sort" must not be given in import
  2132 list any longer, but is inferred from the specification.  Particularly
  2133 in HOL, write
  2134 
  2135     class foo = ...
  2136 
  2137 instead of
  2138 
  2139     class foo = type + ...
  2140 
  2141 * Class target: global versions of theorems stemming do not carry a
  2142 parameter prefix any longer.  INCOMPATIBILITY.
  2143 
  2144 * Class 'instance' command no longer accepts attached definitions.
  2145 INCOMPATIBILITY, use proper 'instantiation' target instead.
  2146 
  2147 * Recovered hiding of consts, which was accidentally broken in
  2148 Isabelle2007.  Potential INCOMPATIBILITY, ``hide const c'' really
  2149 makes c inaccessible; consider using ``hide (open) const c'' instead.
  2150 
  2151 * Slightly more coherent Pure syntax, with updated documentation in
  2152 isar-ref manual.  Removed locales meta_term_syntax and
  2153 meta_conjunction_syntax: TERM and &&& (formerly &&) are now permanent,
  2154 INCOMPATIBILITY in rare situations.  Note that &&& should not be used
  2155 directly in regular applications.
  2156 
  2157 * There is a new syntactic category "float_const" for signed decimal
  2158 fractions (e.g. 123.45 or -123.45).
  2159 
  2160 * Removed exotic 'token_translation' command.  INCOMPATIBILITY, use ML
  2161 interface with 'setup' command instead.
  2162 
  2163 * Command 'local_setup' is similar to 'setup', but operates on a local
  2164 theory context.
  2165 
  2166 * The 'axiomatization' command now only works within a global theory
  2167 context.  INCOMPATIBILITY.
  2168 
  2169 * Goal-directed proof now enforces strict proof irrelevance wrt. sort
  2170 hypotheses.  Sorts required in the course of reasoning need to be
  2171 covered by the constraints in the initial statement, completed by the
  2172 type instance information of the background theory.  Non-trivial sort
  2173 hypotheses, which rarely occur in practice, may be specified via
  2174 vacuous propositions of the form SORT_CONSTRAINT('a::c).  For example:
  2175 
  2176   lemma assumes "SORT_CONSTRAINT('a::empty)" shows False ...
  2177 
  2178 The result contains an implicit sort hypotheses as before --
  2179 SORT_CONSTRAINT premises are eliminated as part of the canonical rule
  2180 normalization.
  2181 
  2182 * Generalized Isar history, with support for linear undo, direct state
  2183 addressing etc.
  2184 
  2185 * Changed defaults for unify configuration options:
  2186 
  2187   unify_trace_bound = 50 (formerly 25)
  2188   unify_search_bound = 60 (formerly 30)
  2189 
  2190 * Different bookkeeping for code equations (INCOMPATIBILITY):
  2191 
  2192   a) On theory merge, the last set of code equations for a particular
  2193      constant is taken (in accordance with the policy applied by other
  2194      parts of the code generator framework).
  2195 
  2196   b) Code equations stemming from explicit declarations (e.g. code
  2197      attribute) gain priority over default code equations stemming
  2198      from definition, primrec, fun etc.
  2199 
  2200 * Keyword 'code_exception' now named 'code_abort'.  INCOMPATIBILITY.
  2201 
  2202 * Unified theorem tables for both code generators.  Thus [code
  2203 func] has disappeared and only [code] remains.  INCOMPATIBILITY.
  2204 
  2205 * Command 'find_consts' searches for constants based on type and name
  2206 patterns, e.g.
  2207 
  2208     find_consts "_ => bool"
  2209 
  2210 By default, matching is against subtypes, but it may be restricted to
  2211 the whole type.  Searching by name is possible.  Multiple queries are
  2212 conjunctive and queries may be negated by prefixing them with a
  2213 hyphen:
  2214 
  2215     find_consts strict: "_ => bool" name: "Int" -"int => int"
  2216 
  2217 * New 'find_theorems' criterion "solves" matches theorems that
  2218 directly solve the current goal (modulo higher-order unification).
  2219 
  2220 * Auto solve feature for main theorem statements: whenever a new goal
  2221 is stated, "find_theorems solves" is called; any theorems that could
  2222 solve the lemma directly are listed as part of the goal state.
  2223 Cf. associated options in Proof General Isabelle settings menu,
  2224 enabled by default, with reasonable timeout for pathological cases of
  2225 higher-order unification.
  2226 
  2227 
  2228 *** Document preparation ***
  2229 
  2230 * Antiquotation @{lemma} now imitates a regular terminal proof,
  2231 demanding keyword 'by' and supporting the full method expression
  2232 syntax just like the Isar command 'by'.
  2233 
  2234 
  2235 *** HOL ***
  2236 
  2237 * Integrated main parts of former image HOL-Complex with HOL.  Entry
  2238 points Main and Complex_Main remain as before.
  2239 
  2240 * Logic image HOL-Plain provides a minimal HOL with the most important
  2241 tools available (inductive, datatype, primrec, ...).  This facilitates
  2242 experimentation and tool development.  Note that user applications
  2243 (and library theories) should never refer to anything below theory
  2244 Main, as before.
  2245 
  2246 * Logic image HOL-Main stops at theory Main, and thus facilitates
  2247 experimentation due to shorter build times.
  2248 
  2249 * Logic image HOL-NSA contains theories of nonstandard analysis which
  2250 were previously part of former HOL-Complex.  Entry point Hyperreal
  2251 remains valid, but theories formerly using Complex_Main should now use
  2252 new entry point Hypercomplex.
  2253 
  2254 * Generic ATP manager for Sledgehammer, based on ML threads instead of
  2255 Posix processes.  Avoids potentially expensive forking of the ML
  2256 process.  New thread-based implementation also works on non-Unix
  2257 platforms (Cygwin).  Provers are no longer hardwired, but defined
  2258 within the theory via plain ML wrapper functions.  Basic Sledgehammer
  2259 commands are covered in the isar-ref manual.
  2260 
  2261 * Wrapper scripts for remote SystemOnTPTP service allows to use
  2262 sledgehammer without local ATP installation (Vampire etc.). Other
  2263 provers may be included via suitable ML wrappers, see also
  2264 src/HOL/ATP_Linkup.thy.
  2265 
  2266 * ATP selection (E/Vampire/Spass) is now via Proof General's settings
  2267 menu.
  2268 
  2269 * The metis method no longer fails because the theorem is too trivial
  2270 (contains the empty clause).
  2271 
  2272 * The metis method now fails in the usual manner, rather than raising
  2273 an exception, if it determines that it cannot prove the theorem.
  2274 
  2275 * Method "coherent" implements a prover for coherent logic (see also
  2276 src/Tools/coherent.ML).
  2277 
  2278 * Constants "undefined" and "default" replace "arbitrary".  Usually
  2279 "undefined" is the right choice to replace "arbitrary", though
  2280 logically there is no difference.  INCOMPATIBILITY.
  2281 
  2282 * Command "value" now integrates different evaluation mechanisms.  The
  2283 result of the first successful evaluation mechanism is printed.  In
  2284 square brackets a particular named evaluation mechanisms may be
  2285 specified (currently, [SML], [code] or [nbe]).  See further
  2286 src/HOL/ex/Eval_Examples.thy.
  2287 
  2288 * Normalization by evaluation now allows non-leftlinear equations.
  2289 Declare with attribute [code nbe].
  2290 
  2291 * Methods "case_tac" and "induct_tac" now refer to the very same rules
  2292 as the structured Isar versions "cases" and "induct", cf. the
  2293 corresponding "cases" and "induct" attributes.  Mutual induction rules
  2294 are now presented as a list of individual projections
  2295 (e.g. foo_bar.inducts for types foo and bar); the old format with
  2296 explicit HOL conjunction is no longer supported.  INCOMPATIBILITY, in
  2297 rare situations a different rule is selected --- notably nested tuple
  2298 elimination instead of former prod.exhaust: use explicit (case_tac t
  2299 rule: prod.exhaust) here.
  2300 
  2301 * Attributes "cases", "induct", "coinduct" support "del" option.
  2302 
  2303 * Removed fact "case_split_thm", which duplicates "case_split".
  2304 
  2305 * The option datatype has been moved to a new theory Option.  Renamed
  2306 option_map to Option.map, and o2s to Option.set, INCOMPATIBILITY.
  2307 
  2308 * New predicate "strict_mono" classifies strict functions on partial
  2309 orders.  With strict functions on linear orders, reasoning about
  2310 (in)equalities is facilitated by theorems "strict_mono_eq",
  2311 "strict_mono_less_eq" and "strict_mono_less".
  2312 
  2313 * Some set operations are now proper qualified constants with
  2314 authentic syntax.  INCOMPATIBILITY:
  2315 
  2316     op Int ~>   Set.Int
  2317     op Un ~>    Set.Un
  2318     INTER ~>    Set.INTER
  2319     UNION ~>    Set.UNION
  2320     Inter ~>    Set.Inter
  2321     Union ~>    Set.Union
  2322     {} ~>       Set.empty
  2323     UNIV ~>     Set.UNIV
  2324 
  2325 * Class complete_lattice with operations Inf, Sup, INFI, SUPR now in
  2326 theory Set.
  2327 
  2328 * Auxiliary class "itself" has disappeared -- classes without any
  2329 parameter are treated as expected by the 'class' command.
  2330 
  2331 * Leibnitz's Series for Pi and the arcus tangens and logarithm series.
  2332 
  2333 * Common decision procedures (Cooper, MIR, Ferrack, Approximation,
  2334 Dense_Linear_Order) are now in directory HOL/Decision_Procs.
  2335 
  2336 * Theory src/HOL/Decision_Procs/Approximation provides the new proof
  2337 method "approximation".  It proves formulas on real values by using
  2338 interval arithmetic.  In the formulas are also the transcendental
  2339 functions sin, cos, tan, atan, ln, exp and the constant pi are
  2340 allowed. For examples see
  2341 src/HOL/Descision_Procs/ex/Approximation_Ex.thy.
  2342 
  2343 * Theory "Reflection" now resides in HOL/Library.
  2344 
  2345 * Entry point to Word library now simply named "Word".
  2346 INCOMPATIBILITY.
  2347 
  2348 * Made source layout more coherent with logical distribution
  2349 structure:
  2350 
  2351     src/HOL/Library/RType.thy ~> src/HOL/Typerep.thy
  2352     src/HOL/Library/Code_Message.thy ~> src/HOL/
  2353     src/HOL/Library/GCD.thy ~> src/HOL/
  2354     src/HOL/Library/Order_Relation.thy ~> src/HOL/
  2355     src/HOL/Library/Parity.thy ~> src/HOL/
  2356     src/HOL/Library/Univ_Poly.thy ~> src/HOL/
  2357     src/HOL/Real/ContNotDenum.thy ~> src/HOL/Library/
  2358     src/HOL/Real/Lubs.thy ~> src/HOL/
  2359     src/HOL/Real/PReal.thy ~> src/HOL/
  2360     src/HOL/Real/Rational.thy ~> src/HOL/
  2361     src/HOL/Real/RComplete.thy ~> src/HOL/
  2362     src/HOL/Real/RealDef.thy ~> src/HOL/
  2363     src/HOL/Real/RealPow.thy ~> src/HOL/
  2364     src/HOL/Real/Real.thy ~> src/HOL/
  2365     src/HOL/Complex/Complex_Main.thy ~> src/HOL/
  2366     src/HOL/Complex/Complex.thy ~> src/HOL/
  2367     src/HOL/Complex/FrechetDeriv.thy ~> src/HOL/Library/
  2368     src/HOL/Complex/Fundamental_Theorem_Algebra.thy ~> src/HOL/Library/
  2369     src/HOL/Hyperreal/Deriv.thy ~> src/HOL/
  2370     src/HOL/Hyperreal/Fact.thy ~> src/HOL/
  2371     src/HOL/Hyperreal/Integration.thy ~> src/HOL/
  2372     src/HOL/Hyperreal/Lim.thy ~> src/HOL/
  2373     src/HOL/Hyperreal/Ln.thy ~> src/HOL/
  2374     src/HOL/Hyperreal/Log.thy ~> src/HOL/
  2375     src/HOL/Hyperreal/MacLaurin.thy ~> src/HOL/
  2376     src/HOL/Hyperreal/NthRoot.thy ~> src/HOL/
  2377     src/HOL/Hyperreal/Series.thy ~> src/HOL/
  2378     src/HOL/Hyperreal/SEQ.thy ~> src/HOL/
  2379     src/HOL/Hyperreal/Taylor.thy ~> src/HOL/
  2380     src/HOL/Hyperreal/Transcendental.thy ~> src/HOL/
  2381     src/HOL/Real/Float ~> src/HOL/Library/
  2382     src/HOL/Real/HahnBanach ~> src/HOL/HahnBanach
  2383     src/HOL/Real/RealVector.thy ~> src/HOL/
  2384 
  2385     src/HOL/arith_data.ML ~> src/HOL/Tools
  2386     src/HOL/hologic.ML ~> src/HOL/Tools
  2387     src/HOL/simpdata.ML ~> src/HOL/Tools
  2388     src/HOL/int_arith1.ML ~> src/HOL/Tools/int_arith.ML
  2389     src/HOL/int_factor_simprocs.ML ~> src/HOL/Tools
  2390     src/HOL/nat_simprocs.ML ~> src/HOL/Tools
  2391     src/HOL/Real/float_arith.ML ~> src/HOL/Tools
  2392     src/HOL/Real/float_syntax.ML ~> src/HOL/Tools
  2393     src/HOL/Real/rat_arith.ML ~> src/HOL/Tools
  2394     src/HOL/Real/real_arith.ML ~> src/HOL/Tools
  2395 
  2396     src/HOL/Library/Array.thy ~> src/HOL/Imperative_HOL
  2397     src/HOL/Library/Heap_Monad.thy ~> src/HOL/Imperative_HOL
  2398     src/HOL/Library/Heap.thy ~> src/HOL/Imperative_HOL
  2399     src/HOL/Library/Imperative_HOL.thy ~> src/HOL/Imperative_HOL
  2400     src/HOL/Library/Ref.thy ~> src/HOL/Imperative_HOL
  2401     src/HOL/Library/Relational.thy ~> src/HOL/Imperative_HOL
  2402 
  2403 * If methods "eval" and "evaluation" encounter a structured proof
  2404 state with !!/==>, only the conclusion is evaluated to True (if
  2405 possible), avoiding strange error messages.
  2406 
  2407 * Method "sizechange" automates termination proofs using (a
  2408 modification of) the size-change principle.  Requires SAT solver.  See
  2409 src/HOL/ex/Termination.thy for examples.
  2410 
  2411 * Simplifier: simproc for let expressions now unfolds if bound
  2412 variable occurs at most once in let expression body.  INCOMPATIBILITY.
  2413 
  2414 * Method "arith": Linear arithmetic now ignores all inequalities when
  2415 fast_arith_neq_limit is exceeded, instead of giving up entirely.
  2416 
  2417 * New attribute "arith" for facts that should always be used
  2418 automatically by arithmetic. It is intended to be used locally in
  2419 proofs, e.g.
  2420 
  2421   assumes [arith]: "x > 0"
  2422 
  2423 Global usage is discouraged because of possible performance impact.
  2424 
  2425 * New classes "top" and "bot" with corresponding operations "top" and
  2426 "bot" in theory Orderings; instantiation of class "complete_lattice"
  2427 requires instantiation of classes "top" and "bot".  INCOMPATIBILITY.
  2428 
  2429 * Changed definition lemma "less_fun_def" in order to provide an
  2430 instance for preorders on functions; use lemma "less_le" instead.
  2431 INCOMPATIBILITY.
  2432 
  2433 * Theory Orderings: class "wellorder" moved here, with explicit
  2434 induction rule "less_induct" as assumption.  For instantiation of
  2435 "wellorder" by means of predicate "wf", use rule wf_wellorderI.
  2436 INCOMPATIBILITY.
  2437 
  2438 * Theory Orderings: added class "preorder" as superclass of "order".
  2439 INCOMPATIBILITY: Instantiation proofs for order, linorder
  2440 etc. slightly changed.  Some theorems named order_class.* now named
  2441 preorder_class.*.
  2442 
  2443 * Theory Relation: renamed "refl" to "refl_on", "reflexive" to "refl,
  2444 "diag" to "Id_on".
  2445 
  2446 * Theory Finite_Set: added a new fold combinator of type
  2447 
  2448   ('a => 'b => 'b) => 'b => 'a set => 'b
  2449 
  2450 Occasionally this is more convenient than the old fold combinator
  2451 which is now defined in terms of the new one and renamed to
  2452 fold_image.
  2453 
  2454 * Theories Ring_and_Field and OrderedGroup: The lemmas "group_simps"
  2455 and "ring_simps" have been replaced by "algebra_simps" (which can be
  2456 extended with further lemmas!).  At the moment both still exist but
  2457 the former will disappear at some point.
  2458 
  2459 * Theory Power: Lemma power_Suc is now declared as a simp rule in
  2460 class recpower.  Type-specific simp rules for various recpower types
  2461 have been removed.  INCOMPATIBILITY, rename old lemmas as follows:
  2462 
  2463 rat_power_0    -> power_0
  2464 rat_power_Suc  -> power_Suc
  2465 realpow_0      -> power_0
  2466 realpow_Suc    -> power_Suc
  2467 complexpow_0   -> power_0
  2468 complexpow_Suc -> power_Suc
  2469 power_poly_0   -> power_0
  2470 power_poly_Suc -> power_Suc
  2471 
  2472 * Theories Ring_and_Field and Divides: Definition of "op dvd" has been
  2473 moved to separate class dvd in Ring_and_Field; a couple of lemmas on
  2474 dvd has been generalized to class comm_semiring_1.  Likewise a bunch
  2475 of lemmas from Divides has been generalized from nat to class
  2476 semiring_div.  INCOMPATIBILITY.  This involves the following theorem
  2477 renames resulting from duplicate elimination:
  2478 
  2479     dvd_def_mod ~>          dvd_eq_mod_eq_0
  2480     zero_dvd_iff ~>         dvd_0_left_iff
  2481     dvd_0 ~>                dvd_0_right
  2482     DIVISION_BY_ZERO_DIV ~> div_by_0
  2483     DIVISION_BY_ZERO_MOD ~> mod_by_0
  2484     mult_div ~>             div_mult_self2_is_id
  2485     mult_mod ~>             mod_mult_self2_is_0
  2486 
  2487 * Theory IntDiv: removed many lemmas that are instances of class-based
  2488 generalizations (from Divides and Ring_and_Field).  INCOMPATIBILITY,
  2489 rename old lemmas as follows:
  2490 
  2491 dvd_diff               -> nat_dvd_diff
  2492 dvd_zminus_iff         -> dvd_minus_iff
  2493 mod_add1_eq            -> mod_add_eq
  2494 mod_mult1_eq           -> mod_mult_right_eq
  2495 mod_mult1_eq'          -> mod_mult_left_eq
  2496 mod_mult_distrib_mod   -> mod_mult_eq
  2497 nat_mod_add_left_eq    -> mod_add_left_eq
  2498 nat_mod_add_right_eq   -> mod_add_right_eq
  2499 nat_mod_div_trivial    -> mod_div_trivial
  2500 nat_mod_mod_trivial    -> mod_mod_trivial
  2501 zdiv_zadd_self1        -> div_add_self1
  2502 zdiv_zadd_self2        -> div_add_self2
  2503 zdiv_zmult_self1       -> div_mult_self2_is_id
  2504 zdiv_zmult_self2       -> div_mult_self1_is_id
  2505 zdvd_triv_left         -> dvd_triv_left
  2506 zdvd_triv_right        -> dvd_triv_right
  2507 zdvd_zmult_cancel_disj -> dvd_mult_cancel_left
  2508 zmod_eq0_zdvd_iff      -> dvd_eq_mod_eq_0[symmetric]
  2509 zmod_zadd_left_eq      -> mod_add_left_eq
  2510 zmod_zadd_right_eq     -> mod_add_right_eq
  2511 zmod_zadd_self1        -> mod_add_self1
  2512 zmod_zadd_self2        -> mod_add_self2
  2513 zmod_zadd1_eq          -> mod_add_eq
  2514 zmod_zdiff1_eq         -> mod_diff_eq
  2515 zmod_zdvd_zmod         -> mod_mod_cancel
  2516 zmod_zmod_cancel       -> mod_mod_cancel
  2517 zmod_zmult_self1       -> mod_mult_self2_is_0
  2518 zmod_zmult_self2       -> mod_mult_self1_is_0
  2519 zmod_1                 -> mod_by_1
  2520 zdiv_1                 -> div_by_1
  2521 zdvd_abs1              -> abs_dvd_iff
  2522 zdvd_abs2              -> dvd_abs_iff
  2523 zdvd_refl              -> dvd_refl
  2524 zdvd_trans             -> dvd_trans
  2525 zdvd_zadd              -> dvd_add
  2526 zdvd_zdiff             -> dvd_diff
  2527 zdvd_zminus_iff        -> dvd_minus_iff
  2528 zdvd_zminus2_iff       -> minus_dvd_iff
  2529 zdvd_zmultD            -> dvd_mult_right
  2530 zdvd_zmultD2           -> dvd_mult_left
  2531 zdvd_zmult_mono        -> mult_dvd_mono
  2532 zdvd_0_right           -> dvd_0_right
  2533 zdvd_0_left            -> dvd_0_left_iff
  2534 zdvd_1_left            -> one_dvd
  2535 zminus_dvd_iff         -> minus_dvd_iff
  2536 
  2537 * Theory Rational: 'Fract k 0' now equals '0'.  INCOMPATIBILITY.
  2538 
  2539 * The real numbers offer decimal input syntax: 12.34 is translated
  2540 into 1234/10^2. This translation is not reversed upon output.
  2541 
  2542 * Theory Library/Polynomial defines an abstract type 'a poly of
  2543 univariate polynomials with coefficients of type 'a.  In addition to
  2544 the standard ring operations, it also supports div and mod.  Code
  2545 generation is also supported, using list-style constructors.
  2546 
  2547 * Theory Library/Inner_Product defines a class of real_inner for real
  2548 inner product spaces, with an overloaded operation inner :: 'a => 'a
  2549 => real.  Class real_inner is a subclass of real_normed_vector from
  2550 theory RealVector.
  2551 
  2552 * Theory Library/Product_Vector provides instances for the product
  2553 type 'a * 'b of several classes from RealVector and Inner_Product.
  2554 Definitions of addition, subtraction, scalar multiplication, norms,
  2555 and inner products are included.
  2556 
  2557 * Theory Library/Bit defines the field "bit" of integers modulo 2.  In
  2558 addition to the field operations, numerals and case syntax are also
  2559 supported.
  2560 
  2561 * Theory Library/Diagonalize provides constructive version of Cantor's
  2562 first diagonalization argument.
  2563 
  2564 * Theory Library/GCD: Curried operations gcd, lcm (for nat) and zgcd,
  2565 zlcm (for int); carried together from various gcd/lcm developements in
  2566 the HOL Distribution.  Constants zgcd and zlcm replace former igcd and
  2567 ilcm; corresponding theorems renamed accordingly.  INCOMPATIBILITY,
  2568 may recover tupled syntax as follows:
  2569 
  2570     hide (open) const gcd
  2571     abbreviation gcd where
  2572       "gcd == (%(a, b). GCD.gcd a b)"
  2573     notation (output)
  2574       GCD.gcd ("gcd '(_, _')")
  2575 
  2576 The same works for lcm, zgcd, zlcm.
  2577 
  2578 * Theory Library/Nat_Infinity: added addition, numeral syntax and more
  2579 instantiations for algebraic structures.  Removed some duplicate
  2580 theorems.  Changes in simp rules.  INCOMPATIBILITY.
  2581 
  2582 * ML antiquotation @{code} takes a constant as argument and generates
  2583 corresponding code in background and inserts name of the corresponding
  2584 resulting ML value/function/datatype constructor binding in place.
  2585 All occurrences of @{code} with a single ML block are generated
  2586 simultaneously.  Provides a generic and safe interface for
  2587 instrumentalizing code generation.  See
  2588 src/HOL/Decision_Procs/Ferrack.thy for a more ambitious application.
  2589 In future you ought to refrain from ad-hoc compiling generated SML
  2590 code on the ML toplevel.  Note that (for technical reasons) @{code}
  2591 cannot refer to constants for which user-defined serializations are
  2592 set.  Refer to the corresponding ML counterpart directly in that
  2593 cases.
  2594 
  2595 * Command 'rep_datatype': instead of theorem names the command now
  2596 takes a list of terms denoting the constructors of the type to be
  2597 represented as datatype.  The characteristic theorems have to be
  2598 proven.  INCOMPATIBILITY.  Also observe that the following theorems
  2599 have disappeared in favour of existing ones:
  2600 
  2601     unit_induct                 ~> unit.induct
  2602     prod_induct                 ~> prod.induct
  2603     sum_induct                  ~> sum.induct
  2604     Suc_Suc_eq                  ~> nat.inject
  2605     Suc_not_Zero Zero_not_Suc   ~> nat.distinct
  2606 
  2607 
  2608 *** HOL-Algebra ***
  2609 
  2610 * New locales for orders and lattices where the equivalence relation
  2611 is not restricted to equality.  INCOMPATIBILITY: all order and lattice
  2612 locales use a record structure with field eq for the equivalence.
  2613 
  2614 * New theory of factorial domains.
  2615 
  2616 * Units_l_inv and Units_r_inv are now simp rules by default.
  2617 INCOMPATIBILITY.  Simplifier proof that require deletion of l_inv
  2618 and/or r_inv will now also require deletion of these lemmas.
  2619 
  2620 * Renamed the following theorems, INCOMPATIBILITY:
  2621 
  2622 UpperD ~> Upper_memD
  2623 LowerD ~> Lower_memD
  2624 least_carrier ~> least_closed
  2625 greatest_carrier ~> greatest_closed
  2626 greatest_Lower_above ~> greatest_Lower_below
  2627 one_zero ~> carrier_one_zero
  2628 one_not_zero ~> carrier_one_not_zero  (collision with assumption)
  2629 
  2630 
  2631 *** HOL-Nominal ***
  2632 
  2633 * Nominal datatypes can now contain type-variables.
  2634 
  2635 * Commands 'nominal_inductive' and 'equivariance' work with local
  2636 theory targets.
  2637 
  2638 * Nominal primrec can now works with local theory targets and its
  2639 specification syntax now conforms to the general format as seen in
  2640 'inductive' etc.
  2641 
  2642 * Method "perm_simp" honours the standard simplifier attributes
  2643 (no_asm), (no_asm_use) etc.
  2644 
  2645 * The new predicate #* is defined like freshness, except that on the
  2646 left hand side can be a set or list of atoms.
  2647 
  2648 * Experimental command 'nominal_inductive2' derives strong induction
  2649 principles for inductive definitions.  In contrast to
  2650 'nominal_inductive', which can only deal with a fixed number of
  2651 binders, it can deal with arbitrary expressions standing for sets of
  2652 atoms to be avoided.  The only inductive definition we have at the
  2653 moment that needs this generalisation is the typing rule for Lets in
  2654 the algorithm W:
  2655 
  2656  Gamma |- t1 : T1   (x,close Gamma T1)::Gamma |- t2 : T2   x#Gamma
  2657  -----------------------------------------------------------------
  2658          Gamma |- Let x be t1 in t2 : T2
  2659 
  2660 In this rule one wants to avoid all the binders that are introduced by
  2661 "close Gamma T1".  We are looking for other examples where this
  2662 feature might be useful.  Please let us know.
  2663 
  2664 
  2665 *** HOLCF ***
  2666 
  2667 * Reimplemented the simplification procedure for proving continuity
  2668 subgoals.  The new simproc is extensible; users can declare additional
  2669 continuity introduction rules with the attribute [cont2cont].
  2670 
  2671 * The continuity simproc now uses a different introduction rule for
  2672 solving continuity subgoals on terms with lambda abstractions.  In
  2673 some rare cases the new simproc may fail to solve subgoals that the
  2674 old one could solve, and "simp add: cont2cont_LAM" may be necessary.
  2675 Potential INCOMPATIBILITY.
  2676 
  2677 * Command 'fixrec': specification syntax now conforms to the general
  2678 format as seen in 'inductive' etc.  See src/HOLCF/ex/Fixrec_ex.thy for
  2679 examples.  INCOMPATIBILITY.
  2680 
  2681 
  2682 *** ZF ***
  2683 
  2684 * Proof of Zorn's Lemma for partial orders.
  2685 
  2686 
  2687 *** ML ***
  2688 
  2689 * Multithreading for Poly/ML 5.1/5.2 is no longer supported, only for
  2690 Poly/ML 5.2.1 or later.  Important note: the TimeLimit facility
  2691 depends on multithreading, so timouts will not work before Poly/ML
  2692 5.2.1!
  2693 
  2694 * High-level support for concurrent ML programming, see
  2695 src/Pure/Cuncurrent.  The data-oriented model of "future values" is
  2696 particularly convenient to organize independent functional
  2697 computations.  The concept of "synchronized variables" provides a
  2698 higher-order interface for components with shared state, avoiding the
  2699 delicate details of mutexes and condition variables.  (Requires
  2700 Poly/ML 5.2.1 or later.)
  2701 
  2702 * ML bindings produced via Isar commands are stored within the Isar
  2703 context (theory or proof).  Consequently, commands like 'use' and 'ML'
  2704 become thread-safe and work with undo as expected (concerning
  2705 top-level bindings, not side-effects on global references).
  2706 INCOMPATIBILITY, need to provide proper Isar context when invoking the
  2707 compiler at runtime; really global bindings need to be given outside a
  2708 theory.  (Requires Poly/ML 5.2 or later.)
  2709 
  2710 * Command 'ML_prf' is analogous to 'ML' but works within a proof
  2711 context.  Top-level ML bindings are stored within the proof context in
  2712 a purely sequential fashion, disregarding the nested proof structure.
  2713 ML bindings introduced by 'ML_prf' are discarded at the end of the
  2714 proof.  (Requires Poly/ML 5.2 or later.)
  2715 
  2716 * Simplified ML attribute and method setup, cf. functions Attrib.setup
  2717 and Method.setup, as well as Isar commands 'attribute_setup' and
  2718 'method_setup'.  INCOMPATIBILITY for 'method_setup', need to simplify
  2719 existing code accordingly, or use plain 'setup' together with old
  2720 Method.add_method.
  2721 
  2722 * Simplified ML oracle interface Thm.add_oracle promotes 'a -> cterm
  2723 to 'a -> thm, while results are always tagged with an authentic oracle
  2724 name.  The Isar command 'oracle' is now polymorphic, no argument type
  2725 is specified.  INCOMPATIBILITY, need to simplify existing oracle code
  2726 accordingly.  Note that extra performance may be gained by producing
  2727 the cterm carefully, avoiding slow Thm.cterm_of.
  2728 
  2729 * Simplified interface for defining document antiquotations via
  2730 ThyOutput.antiquotation, ThyOutput.output, and optionally
  2731 ThyOutput.maybe_pretty_source.  INCOMPATIBILITY, need to simplify user
  2732 antiquotations accordingly, see src/Pure/Thy/thy_output.ML for common
  2733 examples.
  2734 
  2735 * More systematic treatment of long names, abstract name bindings, and
  2736 name space operations.  Basic operations on qualified names have been
  2737 move from structure NameSpace to Long_Name, e.g. Long_Name.base_name,
  2738 Long_Name.append.  Old type bstring has been mostly replaced by
  2739 abstract type binding (see structure Binding), which supports precise
  2740 qualification by packages and local theory targets, as well as proper
  2741 tracking of source positions.  INCOMPATIBILITY, need to wrap old
  2742 bstring values into Binding.name, or better pass through abstract
  2743 bindings everywhere.  See further src/Pure/General/long_name.ML,
  2744 src/Pure/General/binding.ML and src/Pure/General/name_space.ML
  2745 
  2746 * Result facts (from PureThy.note_thms, ProofContext.note_thms,
  2747 LocalTheory.note etc.) now refer to the *full* internal name, not the
  2748 bstring as before.  INCOMPATIBILITY, not detected by ML type-checking!
  2749 
  2750 * Disposed old type and term read functions (Sign.read_def_typ,
  2751 Sign.read_typ, Sign.read_def_terms, Sign.read_term,
  2752 Thm.read_def_cterms, Thm.read_cterm etc.).  INCOMPATIBILITY, should
  2753 use regular Syntax.read_typ, Syntax.read_term, Syntax.read_typ_global,
  2754 Syntax.read_term_global etc.; see also OldGoals.read_term as last
  2755 resort for legacy applications.
  2756 
  2757 * Disposed old declarations, tactics, tactic combinators that refer to
  2758 the simpset or claset of an implicit theory (such as Addsimps,
  2759 Simp_tac, SIMPSET).  INCOMPATIBILITY, should use @{simpset} etc. in
  2760 embedded ML text, or local_simpset_of with a proper context passed as
  2761 explicit runtime argument.
  2762 
  2763 * Rules and tactics that read instantiations (read_instantiate,
  2764 res_inst_tac, thin_tac, subgoal_tac etc.) now demand a proper proof
  2765 context, which is required for parsing and type-checking.  Moreover,
  2766 the variables are specified as plain indexnames, not string encodings
  2767 thereof.  INCOMPATIBILITY.
  2768 
  2769 * Generic Toplevel.add_hook interface allows to analyze the result of
  2770 transactions.  E.g. see src/Pure/ProofGeneral/proof_general_pgip.ML
  2771 for theorem dependency output of transactions resulting in a new
  2772 theory state.
  2773 
  2774 * ML antiquotations: block-structured compilation context indicated by
  2775 \<lbrace> ... \<rbrace>; additional antiquotation forms:
  2776 
  2777   @{binding name}                         - basic name binding
  2778   @{let ?pat = term}                      - term abbreviation (HO matching)
  2779   @{note name = fact}                     - fact abbreviation
  2780   @{thm fact}                             - singleton fact (with attributes)
  2781   @{thms fact}                            - general fact (with attributes)
  2782   @{lemma prop by method}                 - singleton goal
  2783   @{lemma prop by meth1 meth2}            - singleton goal
  2784   @{lemma prop1 ... propN by method}      - general goal
  2785   @{lemma prop1 ... propN by meth1 meth2} - general goal
  2786   @{lemma (open) ...}                     - open derivation
  2787 
  2788 
  2789 *** System ***
  2790 
  2791 * The Isabelle "emacs" tool provides a specific interface to invoke
  2792 Proof General / Emacs, with more explicit failure if that is not
  2793 installed (the old isabelle-interface script silently falls back on
  2794 isabelle-process).  The PROOFGENERAL_HOME setting determines the
  2795 installation location of the Proof General distribution.
  2796 
  2797 * Isabelle/lib/classes/Pure.jar provides basic support to integrate
  2798 the Isabelle process into a JVM/Scala application.  See
  2799 Isabelle/lib/jedit/plugin for a minimal example.  (The obsolete Java
  2800 process wrapper has been discontinued.)
  2801 
  2802 * Added homegrown Isabelle font with unicode layout, see lib/fonts.
  2803 
  2804 * Various status messages (with exact source position information) are
  2805 emitted, if proper markup print mode is enabled.  This allows
  2806 user-interface components to provide detailed feedback on internal
  2807 prover operations.
  2808 
  2809 
  2810 
  2811 New in Isabelle2008 (June 2008)
  2812 -------------------------------
  2813 
  2814 *** General ***
  2815 
  2816 * The Isabelle/Isar Reference Manual (isar-ref) has been reorganized
  2817 and updated, with formally checked references as hyperlinks.
  2818 
  2819 * Theory loader: use_thy (and similar operations) no longer set the
  2820 implicit ML context, which was occasionally hard to predict and in
  2821 conflict with concurrency.  INCOMPATIBILITY, use ML within Isar which
  2822 provides a proper context already.
  2823 
  2824 * Theory loader: old-style ML proof scripts being *attached* to a thy
  2825 file are no longer supported.  INCOMPATIBILITY, regular 'uses' and
  2826 'use' within a theory file will do the job.
  2827 
  2828 * Name space merge now observes canonical order, i.e. the second space
  2829 is inserted into the first one, while existing entries in the first
  2830 space take precedence.  INCOMPATIBILITY in rare situations, may try to
  2831 swap theory imports.
  2832 
  2833 * Syntax: symbol \<chi> is now considered a letter.  Potential
  2834 INCOMPATIBILITY in identifier syntax etc.
  2835 
  2836 * Outer syntax: string tokens no longer admit escaped white space,
  2837 which was an accidental (undocumented) feature.  INCOMPATIBILITY, use
  2838 white space without escapes.
  2839 
  2840 * Outer syntax: string tokens may contain arbitrary character codes
  2841 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
  2842 "foo_bar".
  2843 
  2844 
  2845 *** Pure ***
  2846 
  2847 * Context-dependent token translations.  Default setup reverts locally
  2848 fixed variables, and adds hilite markup for undeclared frees.
  2849 
  2850 * Unused theorems can be found using the new command 'unused_thms'.
  2851 There are three ways of invoking it:
  2852 
  2853 (1) unused_thms
  2854      Only finds unused theorems in the current theory.
  2855 
  2856 (2) unused_thms thy_1 ... thy_n -
  2857      Finds unused theorems in the current theory and all of its ancestors,
  2858      excluding the theories thy_1 ... thy_n and all of their ancestors.
  2859 
  2860 (3) unused_thms thy_1 ... thy_n - thy'_1 ... thy'_m
  2861      Finds unused theorems in the theories thy'_1 ... thy'_m and all of
  2862      their ancestors, excluding the theories thy_1 ... thy_n and all of
  2863      their ancestors.
  2864 
  2865 In order to increase the readability of the list produced by
  2866 unused_thms, theorems that have been created by a particular instance
  2867 of a theory command such as 'inductive' or 'function' are considered
  2868 to belong to the same "group", meaning that if at least one theorem in
  2869 this group is used, the other theorems in the same group are no longer
  2870 reported as unused.  Moreover, if all theorems in the group are
  2871 unused, only one theorem in the group is displayed.
  2872 
  2873 Note that proof objects have to be switched on in order for
  2874 unused_thms to work properly (i.e. !proofs must be >= 1, which is
  2875 usually the case when using Proof General with the default settings).
  2876 
  2877 * Authentic naming of facts disallows ad-hoc overwriting of previous
  2878 theorems within the same name space.  INCOMPATIBILITY, need to remove
  2879 duplicate fact bindings, or even accidental fact duplications.  Note
  2880 that tools may maintain dynamically scoped facts systematically, using
  2881 PureThy.add_thms_dynamic.
  2882 
  2883 * Command 'hide' now allows to hide from "fact" name space as well.
  2884 
  2885 * Eliminated destructive theorem database, simpset, claset, and
  2886 clasimpset.  Potential INCOMPATIBILITY, really need to observe linear
  2887 update of theories within ML code.
  2888 
  2889 * Eliminated theory ProtoPure and CPure, leaving just one Pure theory.
  2890 INCOMPATIBILITY, object-logics depending on former Pure require
  2891 additional setup PureThy.old_appl_syntax_setup; object-logics
  2892 depending on former CPure need to refer to Pure.
  2893 
  2894 * Commands 'use' and 'ML' are now purely functional, operating on
  2895 theory/local_theory.  Removed former 'ML_setup' (on theory), use 'ML'
  2896 instead.  Added 'ML_val' as mere diagnostic replacement for 'ML'.
  2897 INCOMPATIBILITY.
  2898 
  2899 * Command 'setup': discontinued implicit version with ML reference.
  2900 
  2901 * Instantiation target allows for simultaneous specification of class
  2902 instance operations together with an instantiation proof.
  2903 Type-checking phase allows to refer to class operations uniformly.
  2904 See src/HOL/Complex/Complex.thy for an Isar example and
  2905 src/HOL/Library/Eval.thy for an ML example.
  2906 
  2907 * Indexing of literal facts: be more serious about including only
  2908 facts from the visible specification/proof context, but not the
  2909 background context (locale etc.).  Affects `prop` notation and method
  2910 "fact".  INCOMPATIBILITY: need to name facts explicitly in rare
  2911 situations.
  2912 
  2913 * Method "cases", "induct", "coinduct": removed obsolete/undocumented
  2914 "(open)" option, which used to expose internal bound variables to the
  2915 proof text.
  2916 
  2917 * Isar statements: removed obsolete case "rule_context".
  2918 INCOMPATIBILITY, better use explicit fixes/assumes.
  2919 
  2920 * Locale proofs: default proof step now includes 'unfold_locales';
  2921 hence 'proof' without argument may be used to unfold locale
  2922 predicates.
  2923 
  2924 
  2925 *** Document preparation ***
  2926 
  2927 * Simplified pdfsetup.sty: color/hyperref is used unconditionally for
  2928 both pdf and dvi (hyperlinks usually work in xdvi as well); removed
  2929 obsolete thumbpdf setup (contemporary PDF viewers do this on the
  2930 spot); renamed link color from "darkblue" to "linkcolor" (default
  2931 value unchanged, can be redefined via \definecolor); no longer sets
  2932 "a4paper" option (unnecessary or even intrusive).
  2933 
  2934 * Antiquotation @{lemma A method} proves proposition A by the given
  2935 method (either a method name or a method name plus (optional) method
  2936 arguments in parentheses) and prints A just like @{prop A}.
  2937 
  2938 
  2939 *** HOL ***
  2940 
  2941 * New primrec package.  Specification syntax conforms in style to
  2942 definition/function/....  No separate induction rule is provided.  The
  2943 "primrec" command distinguishes old-style and new-style specifications
  2944 by syntax.  The former primrec package is now named OldPrimrecPackage.
  2945 When adjusting theories, beware: constants stemming from new-style
  2946 primrec specifications have authentic syntax.
  2947 
  2948 * Metis prover is now an order of magnitude faster, and also works
  2949 with multithreading.
  2950 
  2951 * Metis: the maximum number of clauses that can be produced from a
  2952 theorem is now given by the attribute max_clauses.  Theorems that
  2953 exceed this number are ignored, with a warning printed.
  2954 
  2955 * Sledgehammer no longer produces structured proofs by default. To
  2956 enable, declare [[sledgehammer_full = true]].  Attributes
  2957 reconstruction_modulus, reconstruction_sorts renamed
  2958 sledgehammer_modulus, sledgehammer_sorts.  INCOMPATIBILITY.
  2959 
  2960 * Method "induct_scheme" derives user-specified induction rules
  2961 from well-founded induction and completeness of patterns. This factors
  2962 out some operations that are done internally by the function package
  2963 and makes them available separately.  See
  2964 src/HOL/ex/Induction_Scheme.thy for examples.
  2965 
  2966 * More flexible generation of measure functions for termination
  2967 proofs: Measure functions can be declared by proving a rule of the
  2968 form "is_measure f" and giving it the [measure_function] attribute.
  2969 The "is_measure" predicate is logically meaningless (always true), and
  2970 just guides the heuristic.  To find suitable measure functions, the
  2971 termination prover sets up the goal "is_measure ?f" of the appropriate
  2972 type and generates all solutions by prolog-style backwards proof using
  2973 the declared rules.
  2974 
  2975 This setup also deals with rules like 
  2976 
  2977   "is_measure f ==> is_measure (list_size f)"
  2978 
  2979 which accommodates nested datatypes that recurse through lists.
  2980 Similar rules are predeclared for products and option types.
  2981 
  2982 * Turned the type of sets "'a set" into an abbreviation for "'a => bool"
  2983 
  2984   INCOMPATIBILITIES:
  2985 
  2986   - Definitions of overloaded constants on sets have to be replaced by
  2987     definitions on => and bool.
  2988 
  2989   - Some definitions of overloaded operators on sets can now be proved
  2990     using the definitions of the operators on => and bool.  Therefore,
  2991     the following theorems have been renamed:
  2992 
  2993       subset_def   -> subset_eq
  2994       psubset_def  -> psubset_eq
  2995       set_diff_def -> set_diff_eq
  2996       Compl_def    -> Compl_eq
  2997       Sup_set_def  -> Sup_set_eq
  2998       Inf_set_def  -> Inf_set_eq
  2999       sup_set_def  -> sup_set_eq
  3000       inf_set_def  -> inf_set_eq
  3001 
  3002   - Due to the incompleteness of the HO unification algorithm, some
  3003     rules such as subst may require manual instantiation, if some of
  3004     the unknowns in the rule is a set.
  3005 
  3006   - Higher order unification and forward proofs:
  3007     The proof pattern
  3008 
  3009       have "P (S::'a set)" <...>
  3010       then have "EX S. P S" ..
  3011 
  3012     no longer works (due to the incompleteness of the HO unification
  3013     algorithm) and must be replaced by the pattern
  3014 
  3015       have "EX S. P S"
  3016       proof
  3017         show "P S" <...>
  3018       qed
  3019 
  3020   - Calculational reasoning with subst (or similar rules):
  3021     The proof pattern
  3022 
  3023       have "P (S::'a set)" <...>
  3024       also have "S = T" <...>
  3025       finally have "P T" .
  3026 
  3027     no longer works (for similar reasons as the previous example) and
  3028     must be replaced by something like
  3029 
  3030       have "P (S::'a set)" <...>
  3031       moreover have "S = T" <...>
  3032       ultimately have "P T" by simp
  3033 
  3034   - Tactics or packages written in ML code:
  3035     Code performing pattern matching on types via
  3036 
  3037       Type ("set", [T]) => ...
  3038 
  3039     must be rewritten. Moreover, functions like strip_type or
  3040     binder_types no longer return the right value when applied to a
  3041     type of the form
  3042 
  3043       T1 => ... => Tn => U => bool
  3044 
  3045     rather than
  3046 
  3047       T1 => ... => Tn => U set
  3048 
  3049 * Merged theories Wellfounded_Recursion, Accessible_Part and
  3050 Wellfounded_Relations to theory Wellfounded.
  3051 
  3052 * Explicit class "eq" for executable equality.  INCOMPATIBILITY.
  3053 
  3054 * Class finite no longer treats UNIV as class parameter.  Use class
  3055 enum from theory Library/Enum instead to achieve a similar effect.
  3056 INCOMPATIBILITY.
  3057 
  3058 * Theory List: rule list_induct2 now has explicitly named cases "Nil"
  3059 and "Cons".  INCOMPATIBILITY.
  3060 
  3061 * HOL (and FOL): renamed variables in rules imp_elim and swap.
  3062 Potential INCOMPATIBILITY.
  3063 
  3064 * Theory Product_Type: duplicated lemmas split_Pair_apply and
  3065 injective_fst_snd removed, use split_eta and prod_eqI instead.
  3066 Renamed upd_fst to apfst and upd_snd to apsnd.  INCOMPATIBILITY.
  3067 
  3068 * Theory Nat: removed redundant lemmas that merely duplicate lemmas of
  3069 the same name in theory Orderings:
  3070 
  3071   less_trans
  3072   less_linear
  3073   le_imp_less_or_eq
  3074   le_less_trans
  3075   less_le_trans
  3076   less_not_sym
  3077   less_asym
  3078 
  3079 Renamed less_imp_le to less_imp_le_nat, and less_irrefl to
  3080 less_irrefl_nat.  Potential INCOMPATIBILITY due to more general types
  3081 and different variable names.
  3082 
  3083 * Library/Option_ord.thy: Canonical order on option type.
  3084 
  3085 * Library/RBT.thy: Red-black trees, an efficient implementation of
  3086 finite maps.
  3087 
  3088 * Library/Countable.thy: Type class for countable types.
  3089 
  3090 * Theory Int: The representation of numerals has changed.  The infix
  3091 operator BIT and the bit datatype with constructors B0 and B1 have
  3092 disappeared.  INCOMPATIBILITY, use "Int.Bit0 x" and "Int.Bit1 y" in
  3093 place of "x BIT bit.B0" and "y BIT bit.B1", respectively.  Theorems
  3094 involving BIT, B0, or B1 have been renamed with "Bit0" or "Bit1"
  3095 accordingly.
  3096 
  3097 * Theory Nat: definition of <= and < on natural numbers no longer
  3098 depend on well-founded relations.  INCOMPATIBILITY.  Definitions
  3099 le_def and less_def have disappeared.  Consider lemmas not_less
  3100 [symmetric, where ?'a = nat] and less_eq [symmetric] instead.
  3101 
  3102 * Theory Finite_Set: locales ACf, ACe, ACIf, ACIfSL and ACIfSLlin
  3103 (whose purpose mainly is for various fold_set functionals) have been
  3104 abandoned in favor of the existing algebraic classes
  3105 ab_semigroup_mult, comm_monoid_mult, ab_semigroup_idem_mult,
  3106 lower_semilattice (resp. upper_semilattice) and linorder.
  3107 INCOMPATIBILITY.
  3108 
  3109 * Theory Transitive_Closure: induct and cases rules now declare proper
  3110 case_names ("base" and "step").  INCOMPATIBILITY.
  3111 
  3112 * Theorem Inductive.lfp_ordinal_induct generalized to complete
  3113 lattices.  The form set-specific version is available as
  3114 Inductive.lfp_ordinal_induct_set.
  3115 
  3116 * Renamed theorems "power.simps" to "power_int.simps".
  3117 INCOMPATIBILITY.
  3118 
  3119 * Class semiring_div provides basic abstract properties of semirings
  3120 with division and modulo operations.  Subsumes former class dvd_mod.
  3121 
  3122 * Merged theories IntDef, Numeral and IntArith into unified theory
  3123 Int.  INCOMPATIBILITY.
  3124 
  3125 * Theory Library/Code_Index: type "index" now represents natural
  3126 numbers rather than integers.  INCOMPATIBILITY.
  3127 
  3128 * New class "uminus" with operation "uminus" (split of from class
  3129 "minus" which now only has operation "minus", binary).
  3130 INCOMPATIBILITY.
  3131 
  3132 * Constants "card", "internal_split", "option_map" now with authentic
  3133 syntax.  INCOMPATIBILITY.
  3134 
  3135 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
  3136 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
  3137 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
  3138 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
  3139 Sup_set_def, le_def, less_def, option_map_def now with object
  3140 equality.  INCOMPATIBILITY.
  3141 
  3142 * Records. Removed K_record, and replaced it by pure lambda term
  3143 %x. c. The simplifier setup is now more robust against eta expansion.
  3144 INCOMPATIBILITY: in cases explicitly referring to K_record.
  3145 
  3146 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
  3147 
  3148 * Library/ListVector: new theory of arithmetic vector operations.
  3149 
  3150 * Library/Order_Relation: new theory of various orderings as sets of
  3151 pairs.  Defines preorders, partial orders, linear orders and
  3152 well-orders on sets and on types.
  3153 
  3154 
  3155 *** ZF ***
  3156 
  3157 * Renamed some theories to allow to loading both ZF and HOL in the
  3158 same session:
  3159 
  3160   Datatype  -> Datatype_ZF
  3161   Inductive -> Inductive_ZF
  3162   Int       -> Int_ZF
  3163   IntDiv    -> IntDiv_ZF
  3164   Nat       -> Nat_ZF
  3165   List      -> List_ZF
  3166   Main      -> Main_ZF
  3167 
  3168 INCOMPATIBILITY: ZF theories that import individual theories below
  3169 Main might need to be adapted.  Regular theory Main is still
  3170 available, as trivial extension of Main_ZF.
  3171 
  3172 
  3173 *** ML ***
  3174 
  3175 * ML within Isar: antiquotation @{const name} or @{const
  3176 name(typargs)} produces statically-checked Const term.
  3177 
  3178 * Functor NamedThmsFun: data is available to the user as dynamic fact
  3179 (of the same name).  Removed obsolete print command.
  3180 
  3181 * Removed obsolete "use_legacy_bindings" function.
  3182 
  3183 * The ``print mode'' is now a thread-local value derived from a global
  3184 template (the former print_mode reference), thus access becomes
  3185 non-critical.  The global print_mode reference is for session
  3186 management only; user-code should use print_mode_value,
  3187 print_mode_active, PrintMode.setmp etc.  INCOMPATIBILITY.
  3188 
  3189 * Functions system/system_out provide a robust way to invoke external
  3190 shell commands, with propagation of interrupts (requires Poly/ML
  3191 5.2.1).  Do not use OS.Process.system etc. from the basis library!
  3192 
  3193 
  3194 *** System ***
  3195 
  3196 * Default settings: PROOFGENERAL_OPTIONS no longer impose xemacs ---
  3197 in accordance with Proof General 3.7, which prefers GNU emacs.
  3198 
  3199 * isatool tty runs Isabelle process with plain tty interaction;
  3200 optional line editor may be specified via ISABELLE_LINE_EDITOR
  3201 setting, the default settings attempt to locate "ledit" and "rlwrap".
  3202 
  3203 * isatool browser now works with Cygwin as well, using general
  3204 "javapath" function defined in Isabelle process environment.
  3205 
  3206 * YXML notation provides a simple and efficient alternative to
  3207 standard XML transfer syntax.  See src/Pure/General/yxml.ML and
  3208 isatool yxml as described in the Isabelle system manual.
  3209 
  3210 * JVM class isabelle.IsabelleProcess (located in Isabelle/lib/classes)
  3211 provides general wrapper for managing an Isabelle process in a robust
  3212 fashion, with ``cooked'' output from stdin/stderr.
  3213 
  3214 * Rudimentary Isabelle plugin for jEdit (see Isabelle/lib/jedit),
  3215 based on Isabelle/JVM process wrapper (see Isabelle/lib/classes).
  3216 
  3217 * Removed obsolete THIS_IS_ISABELLE_BUILD feature.  NB: the documented
  3218 way of changing the user's settings is via
  3219 ISABELLE_HOME_USER/etc/settings, which is a fully featured bash
  3220 script.
  3221 
  3222 * Multithreading.max_threads := 0 refers to the number of actual CPU
  3223 cores of the underlying machine, which is a good starting point for
  3224 optimal performance tuning.  The corresponding usedir option -M allows
  3225 "max" as an alias for "0".  WARNING: does not work on certain versions
  3226 of Mac OS (with Poly/ML 5.1).
  3227 
  3228 * isabelle-process: non-ML sessions are run with "nice", to reduce the
  3229 adverse effect of Isabelle flooding interactive front-ends (notably
  3230 ProofGeneral / XEmacs).
  3231 
  3232 
  3233 
  3234 New in Isabelle2007 (November 2007)
  3235 -----------------------------------
  3236 
  3237 *** General ***
  3238 
  3239 * More uniform information about legacy features, notably a
  3240 warning/error of "Legacy feature: ...", depending on the state of the
  3241 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
  3242 legacy features will disappear eventually.
  3243 
  3244 * Theory syntax: the header format ``theory A = B + C:'' has been
  3245 discontinued in favour of ``theory A imports B C begin''.  Use isatool
  3246 fixheaders to convert existing theory files.  INCOMPATIBILITY.
  3247 
  3248 * Theory syntax: the old non-Isar theory file format has been
  3249 discontinued altogether.  Note that ML proof scripts may still be used
  3250 with Isar theories; migration is usually quite simple with the ML
  3251 function use_legacy_bindings.  INCOMPATIBILITY.
  3252 
  3253 * Theory syntax: some popular names (e.g. 'class', 'declaration',
  3254 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
  3255 quotes.
  3256 
  3257 * Theory loader: be more serious about observing the static theory
  3258 header specifications (including optional directories), but not the
  3259 accidental file locations of previously successful loads.  The strict
  3260 update policy of former update_thy is now already performed by
  3261 use_thy, so the former has been removed; use_thys updates several
  3262 theories simultaneously, just as 'imports' within a theory header
  3263 specification, but without merging the results.  Potential
  3264 INCOMPATIBILITY: may need to refine theory headers and commands
  3265 ROOT.ML which depend on load order.
  3266 
  3267 * Theory loader: optional support for content-based file
  3268 identification, instead of the traditional scheme of full physical
  3269 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
  3270 (cf. the system manual).  The new scheme allows to work with
  3271 non-finished theories in persistent session images, such that source
  3272 files may be moved later on without requiring reloads.
  3273 
  3274 * Theory loader: old-style ML proof scripts being *attached* to a thy
  3275 file (with the same base name as the theory) are considered a legacy
  3276 feature, which will disappear eventually. Even now, the theory loader
  3277 no longer maintains dependencies on such files.
  3278 
  3279 * Syntax: the scope for resolving ambiguities via type-inference is
  3280 now limited to individual terms, instead of whole simultaneous
  3281 specifications as before. This greatly reduces the complexity of the
  3282 syntax module and improves flexibility by separating parsing and
  3283 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
  3284 'fixes' etc.) are required in rare situations.
  3285 
  3286 * Syntax: constants introduced by new-style packages ('definition',
  3287 'abbreviation' etc.) are passed through the syntax module in
  3288 ``authentic mode''. This means that associated mixfix annotations
  3289 really stick to such constants, independently of potential name space
  3290 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
  3291 trees are represented slightly differently, may need to adapt syntax
  3292 translations accordingly. Use CONST marker in 'translations' and
  3293 @{const_syntax} antiquotation in 'parse_translation' etc.
  3294 
  3295 * Legacy goal package: reduced interface to the bare minimum required
  3296 to keep existing proof scripts running.  Most other user-level
  3297 functions are now part of the OldGoals structure, which is *not* open
  3298 by default (consider isatool expandshort before open OldGoals).
  3299 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
  3300 these tend to cause confusion about the actual goal (!) context being
  3301 used here, which is not necessarily the same as the_context().
  3302 
  3303 * Command 'find_theorems': supports "*" wild-card in "name:"
  3304 criterion; "with_dups" option.  Certain ProofGeneral versions might
  3305 support a specific search form (see ProofGeneral/CHANGES).
  3306 
  3307 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
  3308 by default, which means that "prems" (and also "fixed variables") are
  3309 suppressed from proof state output.  Note that the ProofGeneral
  3310 settings mechanism allows to change and save options persistently, but
  3311 older versions of Isabelle will fail to start up if a negative prems
  3312 limit is imposed.
  3313 
  3314 * Local theory targets may be specified by non-nested blocks of
  3315 ``context/locale/class ... begin'' followed by ``end''.  The body may
  3316 contain definitions, theorems etc., including any derived mechanism
  3317 that has been implemented on top of these primitives.  This concept
  3318 generalizes the existing ``theorem (in ...)'' towards more versatility
  3319 and scalability.
  3320 
  3321 * Proof General interface: proper undo of final 'end' command;
  3322 discontinued Isabelle/classic mode (ML proof scripts).
  3323 
  3324 
  3325 *** Document preparation ***
  3326 
  3327 * Added antiquotation @{theory name} which prints the given name,
  3328 after checking that it refers to a valid ancestor theory in the
  3329 current context.
  3330 
  3331 * Added antiquotations @{ML_type text} and @{ML_struct text} which
  3332 check the given source text as ML type/structure, printing verbatim.
  3333 
  3334 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
  3335 "c args == rhs" given in the current context.  (Any number of
  3336 arguments may be given on the LHS.)
  3337 
  3338 
  3339 *** Pure ***
  3340 
  3341 * The 'class' package offers a combination of axclass and locale to
  3342 achieve Haskell-like type classes in Isabelle.  Definitions and
  3343 theorems within a class context produce both relative results (with
  3344 implicit parameters according to the locale context), and polymorphic
  3345 constants with qualified polymorphism (according to the class
  3346 context).  Within the body context of a 'class' target, a separate
  3347 syntax layer ("user space type system") takes care of converting
  3348 between global polymorphic consts and internal locale representation.
  3349 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
  3350 "isatool doc classes" provides a tutorial.
  3351 
  3352 * Generic code generator framework allows to generate executable
  3353 code for ML and Haskell (including Isabelle classes).  A short usage
  3354 sketch:
  3355 
  3356     internal compilation:
  3357         export_code <list of constants (term syntax)> in SML
  3358     writing SML code to a file:
  3359         export_code <list of constants (term syntax)> in SML <filename>
  3360     writing OCaml code to a file:
  3361         export_code <list of constants (term syntax)> in OCaml <filename>
  3362     writing Haskell code to a bunch of files:
  3363         export_code <list of constants (term syntax)> in Haskell <filename>
  3364 
  3365     evaluating closed propositions to True/False using code generation:
  3366         method ``eval''
  3367 
  3368 Reasonable default setup of framework in HOL.
  3369 
  3370 Theorem attributs for selecting and transforming function equations theorems:
  3371 
  3372     [code fun]:        select a theorem as function equation for a specific constant
  3373     [code fun del]:    deselect a theorem as function equation for a specific constant
  3374     [code inline]:     select an equation theorem for unfolding (inlining) in place
  3375     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
  3376 
  3377 User-defined serializations (target in {SML, OCaml, Haskell}):
  3378 
  3379     code_const <and-list of constants (term syntax)>
  3380       {(target) <and-list of const target syntax>}+
  3381 
  3382     code_type <and-list of type constructors>
  3383       {(target) <and-list of type target syntax>}+
  3384 
  3385     code_instance <and-list of instances>
  3386       {(target)}+
  3387         where instance ::= <type constructor> :: <class>
  3388 
  3389     code_class <and_list of classes>
  3390       {(target) <and-list of class target syntax>}+
  3391         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
  3392 
  3393 code_instance and code_class only are effective to target Haskell.
  3394 
  3395 For example usage see src/HOL/ex/Codegenerator.thy and
  3396 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
  3397 generation from Isabelle/HOL theories is available via "isatool doc
  3398 codegen".
  3399 
  3400 * Code generator: consts in 'consts_code' Isar commands are now
  3401 referred to by usual term syntax (including optional type
  3402 annotations).
  3403 
  3404 * Command 'no_translations' removes translation rules from theory
  3405 syntax.
  3406 
  3407 * Overloaded definitions are now actually checked for acyclic
  3408 dependencies.  The overloading scheme is slightly more general than
  3409 that of Haskell98, although Isabelle does not demand an exact
  3410 correspondence to type class and instance declarations.
  3411 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
  3412 exotic versions of overloading -- at the discretion of the user!
  3413 
  3414 Polymorphic constants are represented via type arguments, i.e. the
  3415 instantiation that matches an instance against the most general
  3416 declaration given in the signature.  For example, with the declaration
  3417 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
  3418 as c(nat).  Overloading is essentially simultaneous structural
  3419 recursion over such type arguments.  Incomplete specification patterns
  3420 impose global constraints on all occurrences, e.g. c('a * 'a) on the
  3421 LHS means that more general c('a * 'b) will be disallowed on any RHS.
  3422 Command 'print_theory' outputs the normalized system of recursive
  3423 equations, see section "definitions".
  3424 
  3425 * Configuration options are maintained within the theory or proof
  3426 context (with name and type bool/int/string), providing a very simple
  3427 interface to a poor-man's version of general context data.  Tools may
  3428 declare options in ML (e.g. using Attrib.config_int) and then refer to
  3429 these values using Config.get etc.  Users may change options via an
  3430 associated attribute of the same name.  This form of context
  3431 declaration works particularly well with commands 'declare' or
  3432 'using', for example ``declare [[foo = 42]]''.  Thus it has become
  3433 very easy to avoid global references, which would not observe Isar
  3434 toplevel undo/redo and fail to work with multithreading.
  3435 
  3436 Various global ML references of Pure and HOL have been turned into
  3437 configuration options:
  3438 
  3439   Unify.search_bound		unify_search_bound
  3440   Unify.trace_bound		unify_trace_bound
  3441   Unify.trace_simp		unify_trace_simp
  3442   Unify.trace_types		unify_trace_types
  3443   Simplifier.simp_depth_limit	simp_depth_limit
  3444   Blast.depth_limit		blast_depth_limit
  3445   DatatypeProp.dtK		datatype_distinctness_limit
  3446   fast_arith_neq_limit  	fast_arith_neq_limit
  3447   fast_arith_split_limit	fast_arith_split_limit
  3448 
  3449 * Named collections of theorems may be easily installed as context
  3450 data using the functor NamedThmsFun (see also
  3451 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
  3452 attributes; there is also a toplevel print command.  This facility is
  3453 just a common case of general context data, which is the preferred way
  3454 for anything more complex than just a list of facts in canonical
  3455 order.
  3456 
  3457 * Isar: command 'declaration' augments a local theory by generic
  3458 declaration functions written in ML.  This enables arbitrary content
  3459 being added to the context, depending on a morphism that tells the
  3460 difference of the original declaration context wrt. the application
  3461 context encountered later on.
  3462 
  3463 * Isar: proper interfaces for simplification procedures.  Command
  3464 'simproc_setup' declares named simprocs (with match patterns, and body
  3465 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
  3466 context.  ML antiquotation @{simproc name} retrieves named simprocs.
  3467 
  3468 * Isar: an extra pair of brackets around attribute declarations
  3469 abbreviates a theorem reference involving an internal dummy fact,
  3470 which will be ignored later --- only the effect of the attribute on
  3471 the background context will persist.  This form of in-place
  3472 declarations is particularly useful with commands like 'declare' and
  3473 'using', for example ``have A using [[simproc a]] by simp''.
  3474 
  3475 * Isar: method "assumption" (and implicit closing of subproofs) now
  3476 takes simple non-atomic goal assumptions into account: after applying
  3477 an assumption as a rule the resulting subgoals are solved by atomic
  3478 assumption steps.  This is particularly useful to finish 'obtain'
  3479 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
  3480 without referring to the original premise "!!x. P x ==> thesis" in the
  3481 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
  3482 more permissive.
  3483 
  3484 * Isar: implicit use of prems from the Isar proof context is
  3485 considered a legacy feature.  Common applications like ``have A .''
  3486 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
  3487 referencing facts explicitly here improves readability and
  3488 maintainability of proof texts.
  3489 
  3490 * Isar: improper proof element 'guess' is like 'obtain', but derives
  3491 the obtained context from the course of reasoning!  For example:
  3492 
  3493   assume "EX x y. A x & B y"   -- "any previous fact"
  3494   then guess x and y by clarify
  3495 
  3496 This technique is potentially adventurous, depending on the facts and
  3497 proof tools being involved here.
  3498 
  3499 * Isar: known facts from the proof context may be specified as literal
  3500 propositions, using ASCII back-quote syntax.  This works wherever
  3501 named facts used to be allowed so far, in proof commands, proof
  3502 methods, attributes etc.  Literal facts are retrieved from the context
  3503 according to unification of type and term parameters.  For example,
  3504 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
  3505 theorems in the current context, then these are valid literal facts:
  3506 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
  3507 
  3508 There is also a proof method "fact" which does the same composition
  3509 for explicit goal states, e.g. the following proof texts coincide with
  3510 certain special cases of literal facts:
  3511 
  3512   have "A" by fact                 ==  note `A`
  3513   have "A ==> B" by fact           ==  note `A ==> B`
  3514   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
  3515   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
  3516 
  3517 * Isar: ":" (colon) is no longer a symbolic identifier character in
  3518 outer syntax.  Thus symbolic identifiers may be used without
  3519 additional white space in declarations like this: ``assume *: A''.
  3520 
  3521 * Isar: 'print_facts' prints all local facts of the current context,
  3522 both named and unnamed ones.
  3523 
  3524 * Isar: 'def' now admits simultaneous definitions, e.g.:
  3525 
  3526   def x == "t" and y == "u"
  3527 
  3528 * Isar: added command 'unfolding', which is structurally similar to
  3529 'using', but affects both the goal state and facts by unfolding given
  3530 rewrite rules.  Thus many occurrences of the 'unfold' method or
  3531 'unfolded' attribute may be replaced by first-class proof text.
  3532 
  3533 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
  3534 and command 'unfolding' now all support object-level equalities
  3535 (potentially conditional).  The underlying notion of rewrite rule is
  3536 analogous to the 'rule_format' attribute, but *not* that of the
  3537 Simplifier (which is usually more generous).
  3538 
  3539 * Isar: the new attribute [rotated n] (default n = 1) rotates the
  3540 premises of a theorem by n. Useful in conjunction with drule.
  3541 
  3542 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
  3543 method expression within a sandbox consisting of the first N
  3544 sub-goals, which need to exist.  For example, ``simp_all [3]''
  3545 simplifies the first three sub-goals, while (rule foo, simp_all)[]
  3546 simplifies all new goals that emerge from applying rule foo to the
  3547 originally first one.
  3548 
  3549 * Isar: schematic goals are no longer restricted to higher-order
  3550 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
  3551 expected.
  3552 
  3553 * Isar: the conclusion of a long theorem statement is now either
  3554 'shows' (a simultaneous conjunction, as before), or 'obtains'
  3555 (essentially a disjunction of cases with local parameters and
  3556 assumptions).  The latter allows to express general elimination rules
  3557 adequately; in this notation common elimination rules look like this:
  3558 
  3559   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
  3560     assumes "EX x. P x"
  3561     obtains x where "P x"
  3562 
  3563   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
  3564     assumes "A & B"
  3565     obtains A and B
  3566 
  3567   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
  3568     assumes "A | B"
  3569     obtains
  3570       A
  3571     | B
  3572 
  3573 The subsequent classical rules even refer to the formal "thesis"
  3574 explicitly:
  3575 
  3576   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
  3577     obtains "~ thesis"
  3578 
  3579   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
  3580     obtains "thesis ==> something"
  3581 
  3582 The actual proof of an 'obtains' statement is analogous to that of the
  3583 Isar proof element 'obtain', only that there may be several cases.
  3584 Optional case names may be specified in parentheses; these will be
  3585 available both in the present proof and as annotations in the
  3586 resulting rule, for later use with the 'cases' method (cf. attribute
  3587 case_names).
  3588 
  3589 * Isar: the assumptions of a long theorem statement are available as
  3590 "assms" fact in the proof context.  This is more appropriate than the
  3591 (historical) "prems", which refers to all assumptions of the current
  3592 context, including those from the target locale, proof body etc.
  3593 
  3594 * Isar: 'print_statement' prints theorems from the current theory or
  3595 proof context in long statement form, according to the syntax of a
  3596 top-level lemma.
  3597 
  3598 * Isar: 'obtain' takes an optional case name for the local context
  3599 introduction rule (default "that").
  3600 
  3601 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
  3602 explicit (is "_ ==> ?foo") in the rare cases where this still happens
  3603 to occur.
  3604 
  3605 * Pure: syntax "CONST name" produces a fully internalized constant
  3606 according to the current context.  This is particularly useful for
  3607 syntax translations that should refer to internal constant
  3608 representations independently of name spaces.
  3609 
  3610 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
  3611 instead of "FOO ". This allows multiple binder declarations to coexist
  3612 in the same context.  INCOMPATIBILITY.
  3613 
  3614 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
  3615 primitive that also works in a locale context (both for constants and
  3616 fixed variables). Type declaration and internal syntactic representation
  3617 of given constants retrieved from the context. Likewise, the
  3618 'no_notation' command allows to remove given syntax annotations from the
  3619 current context.
  3620 
  3621 * Isar/locales: new derived specification elements 'axiomatization',
  3622 'definition', 'abbreviation', which support type-inference, admit
  3623 object-level specifications (equality, equivalence).  See also the
  3624 isar-ref manual.  Examples:
  3625 
  3626   axiomatization
  3627     eq  (infix "===" 50) where
  3628     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
  3629 
  3630   definition "f x y = x + y + 1"
  3631   definition g where "g x = f x x"
  3632 
  3633   abbreviation
  3634     neq  (infix "=!=" 50) where
  3635     "x =!= y == ~ (x === y)"
  3636 
  3637 These specifications may be also used in a locale context.  Then the
  3638 constants being introduced depend on certain fixed parameters, and the
  3639 constant name is qualified by the locale base name.  An internal
  3640 abbreviation takes care for convenient input and output, making the
  3641 parameters implicit and using the original short name.  See also
  3642 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
  3643 entities from a monomorphic theory.
  3644 
  3645 Presently, abbreviations are only available 'in' a target locale, but
  3646 not inherited by general import expressions.  Also note that
  3647 'abbreviation' may be used as a type-safe replacement for 'syntax' +
  3648 'translations' in common applications.  The "no_abbrevs" print mode
  3649 prevents folding of abbreviations in term output.
  3650 
  3651 Concrete syntax is attached to specified constants in internal form,
  3652 independently of name spaces.  The parse tree representation is
  3653 slightly different -- use 'notation' instead of raw 'syntax', and
  3654 'translations' with explicit "CONST" markup to accommodate this.
  3655 
  3656 * Pure/Isar: unified syntax for new-style specification mechanisms
  3657 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
  3658 full type inference and dummy patterns ("_").  For example:
  3659 
  3660   definition "K x _ = x"
  3661 
  3662   inductive conj for A B
  3663   where "A ==> B ==> conj A B"
  3664 
  3665 * Pure: command 'print_abbrevs' prints all constant abbreviations of
  3666 the current context.  Print mode "no_abbrevs" prevents inversion of
  3667 abbreviations on output.
  3668 
  3669 * Isar/locales: improved parameter handling: use of locales "var" and
  3670 "struct" no longer necessary; - parameter renamings are no longer
  3671 required to be injective.  For example, this allows to define
  3672 endomorphisms as locale endom = homom mult mult h.
  3673 
  3674 * Isar/locales: changed the way locales with predicates are defined.
  3675 Instead of accumulating the specification, the imported expression is
  3676 now an interpretation.  INCOMPATIBILITY: different normal form of
  3677 locale expressions.  In particular, in interpretations of locales with
  3678 predicates, goals repesenting already interpreted fragments are not
  3679 removed automatically.  Use methods `intro_locales' and
  3680 `unfold_locales'; see below.
  3681 
  3682 * Isar/locales: new methods `intro_locales' and `unfold_locales'
  3683 provide backward reasoning on locales predicates.  The methods are
  3684 aware of interpretations and discharge corresponding goals.
  3685 `intro_locales' is less aggressive then `unfold_locales' and does not
  3686 unfold predicates to assumptions.
  3687 
  3688 * Isar/locales: the order in which locale fragments are accumulated
  3689 has changed.  This enables to override declarations from fragments due
  3690 to interpretations -- for example, unwanted simp rules.
  3691 
  3692 * Isar/locales: interpretation in theories and proof contexts has been
  3693 extended.  One may now specify (and prove) equations, which are
  3694 unfolded in interpreted theorems.  This is useful for replacing
  3695 defined concepts (constants depending on locale parameters) by
  3696 concepts already existing in the target context.  Example:
  3697 
  3698   interpretation partial_order ["op <= :: [int, int] => bool"]
  3699     where "partial_order.less (op <=) (x::int) y = (x < y)"
  3700 
  3701 Typically, the constant `partial_order.less' is created by a
  3702 definition specification element in the context of locale
  3703 partial_order.
  3704 
  3705 * Method "induct": improved internal context management to support
  3706 local fixes and defines on-the-fly. Thus explicit meta-level
  3707 connectives !!  and ==> are rarely required anymore in inductive goals
  3708 (using object-logic connectives for this purpose has been long
  3709 obsolete anyway). Common proof patterns are explained in
  3710 src/HOL/Induct/Common_Patterns.thy, see also
  3711 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
  3712 examples.
  3713 
  3714 * Method "induct": improved handling of simultaneous goals. Instead of
  3715 introducing object-level conjunction, the statement is now split into
  3716 several conclusions, while the corresponding symbolic cases are nested
  3717 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
  3718 see src/HOL/Induct/Common_Patterns.thy, for example.
  3719 
  3720 * Method "induct": mutual induction rules are now specified as a list
  3721 of rule sharing the same induction cases. HOL packages usually provide
  3722 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
  3723 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
  3724 mutual induction rules differently, i.e. like this:
  3725 
  3726   (induct rule: foo_bar.inducts)
  3727   (induct set: foo bar)
  3728   (induct pred: foo bar)
  3729   (induct type: foo bar)
  3730 
  3731 The ML function ProjectRule.projections turns old-style rules into the
  3732 new format.
  3733 
  3734 * Method "coinduct": dual of induction, see
  3735 src/HOL/Library/Coinductive_List.thy for various examples.
  3736 
  3737 * Method "cases", "induct", "coinduct": the ``(open)'' option is
  3738 considered a legacy feature.
  3739 
  3740 * Attribute "symmetric" produces result with standardized schematic
  3741 variables (index 0).  Potential INCOMPATIBILITY.
  3742 
  3743 * Simplifier: by default the simplifier trace only shows top level
  3744 rewrites now. That is, trace_simp_depth_limit is set to 1 by
  3745 default. Thus there is less danger of being flooded by the trace. The
  3746 trace indicates where parts have been suppressed.
  3747   
  3748 * Provers/classical: removed obsolete classical version of elim_format
  3749 attribute; classical elim/dest rules are now treated uniformly when
  3750 manipulating the claset.
  3751 
  3752 * Provers/classical: stricter checks to ensure that supplied intro,
  3753 dest and elim rules are well-formed; dest and elim rules must have at
  3754 least one premise.
  3755 
  3756 * Provers/classical: attributes dest/elim/intro take an optional
  3757 weight argument for the rule (just as the Pure versions).  Weights are
  3758 ignored by automated tools, but determine the search order of single
  3759 rule steps.
  3760 
  3761 * Syntax: input syntax now supports dummy variable binding "%_. b",
  3762 where the body does not mention the bound variable.  Note that dummy
  3763 patterns implicitly depend on their context of bounds, which makes
  3764 "{_. _}" match any set comprehension as expected.  Potential
  3765 INCOMPATIBILITY -- parse translations need to cope with syntactic
  3766 constant "_idtdummy" in the binding position.
  3767 
  3768 * Syntax: removed obsolete syntactic constant "_K" and its associated
  3769 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
  3770 for example "A -> B" => "Pi A (%_. B)".
  3771 
  3772 * Pure: 'class_deps' command visualizes the subclass relation, using
  3773 the graph browser tool.
  3774 
  3775 * Pure: 'print_theory' now suppresses certain internal declarations by
  3776 default; use '!' option for full details.
  3777 
  3778 
  3779 *** HOL ***
  3780 
  3781 * Method "metis" proves goals by applying the Metis general-purpose
  3782 resolution prover (see also http://gilith.com/software/metis/).
  3783 Examples are in the directory MetisExamples.  WARNING: the
  3784 Isabelle/HOL-Metis integration does not yet work properly with
  3785 multi-threading.
  3786   
  3787 * Command 'sledgehammer' invokes external automatic theorem provers as
  3788 background processes.  It generates calls to the "metis" method if
  3789 successful. These can be pasted into the proof.  Users do not have to
  3790 wait for the automatic provers to return.  WARNING: does not really
  3791 work with multi-threading.
  3792 
  3793 * New "auto_quickcheck" feature tests outermost goal statements for
  3794 potential counter-examples.  Controlled by ML references
  3795 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
  3796 5000 milliseconds).  Fails silently if statements is outside of
  3797 executable fragment, or any other codgenerator problem occurs.
  3798 
  3799 * New constant "undefined" with axiom "undefined x = undefined".
  3800 
  3801 * Added class "HOL.eq", allowing for code generation with polymorphic
  3802 equality.
  3803 
  3804 * Some renaming of class constants due to canonical name prefixing in
  3805 the new 'class' package:
  3806 
  3807     HOL.abs ~> HOL.abs_class.abs
  3808     HOL.divide ~> HOL.divide_class.divide
  3809     0 ~> HOL.zero_class.zero
  3810     1 ~> HOL.one_class.one
  3811     op + ~> HOL.plus_class.plus
  3812     op - ~> HOL.minus_class.minus
  3813     uminus ~> HOL.minus_class.uminus
  3814     op * ~> HOL.times_class.times
  3815     op < ~> HOL.ord_class.less
  3816     op <= > HOL.ord_class.less_eq
  3817     Nat.power ~> Power.power_class.power
  3818     Nat.size ~> Nat.size_class.size
  3819     Numeral.number_of ~> Numeral.number_class.number_of
  3820     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
  3821     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
  3822     Orderings.min ~> Orderings.ord_class.min
  3823     Orderings.max ~> Orderings.ord_class.max
  3824     Divides.op div ~> Divides.div_class.div
  3825     Divides.op mod ~> Divides.div_class.mod
  3826     Divides.op dvd ~> Divides.div_class.dvd
  3827 
  3828 INCOMPATIBILITY.  Adaptions may be required in the following cases:
  3829 
  3830 a) User-defined constants using any of the names "plus", "minus",
  3831 "times", "less" or "less_eq". The standard syntax translations for
  3832 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  3833 names.
  3834 
  3835 b) Variables named "plus", "minus", "times", "less", "less_eq"
  3836 INCOMPATIBILITY: use more specific names.
  3837 
  3838 c) Permutative equations (e.g. "a + b = b + a")
  3839 Since the change of names also changes the order of terms, permutative
  3840 rewrite rules may get applied in a different order. Experience shows
  3841 that this is rarely the case (only two adaptions in the whole Isabelle
  3842 distribution).  INCOMPATIBILITY: rewrite proofs
  3843 
  3844 d) ML code directly refering to constant names
  3845 This in general only affects hand-written proof tactics, simprocs and
  3846 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  3847 Consider using @{const_name} antiquotation.
  3848 
  3849 * New class "default" with associated constant "default".
  3850 
  3851 * Function "sgn" is now overloaded and available on int, real, complex
  3852 (and other numeric types), using class "sgn".  Two possible defs of
  3853 sgn are given as equational assumptions in the classes sgn_if and
  3854 sgn_div_norm; ordered_idom now also inherits from sgn_if.
  3855 INCOMPATIBILITY.
  3856 
  3857 * Locale "partial_order" now unified with class "order" (cf. theory
  3858 Orderings), added parameter "less".  INCOMPATIBILITY.
  3859 
  3860 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
  3861 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
  3862 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
  3863 
  3864 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
  3865 changed order of proof goals in instance proofs.
  3866 
  3867 * The transitivity reasoner for partial and linear orders is set up
  3868 for classes "order" and "linorder".  Instances of the reasoner are available
  3869 in all contexts importing or interpreting the corresponding locales.
  3870 Method "order" invokes the reasoner separately; the reasoner
  3871 is also integrated with the Simplifier as a solver.  Diagnostic
  3872 command 'print_orders' shows the available instances of the reasoner
  3873 in the current context.
  3874 
  3875 * Localized monotonicity predicate in theory "Orderings"; integrated
  3876 lemmas max_of_mono and min_of_mono with this predicate.
  3877 INCOMPATIBILITY.
  3878 
  3879 * Formulation of theorem "dense" changed slightly due to integration
  3880 with new class dense_linear_order.
  3881 
  3882 * Uniform lattice theory development in HOL.
  3883 
  3884     constants "meet" and "join" now named "inf" and "sup"
  3885     constant "Meet" now named "Inf"
  3886 
  3887     classes "meet_semilorder" and "join_semilorder" now named
  3888       "lower_semilattice" and "upper_semilattice"
  3889     class "lorder" now named "lattice"
  3890     class "comp_lat" now named "complete_lattice"
  3891 
  3892     Instantiation of lattice classes allows explicit definitions
  3893     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
  3894 
  3895   INCOMPATIBILITY.  Theorem renames:
  3896 
  3897     meet_left_le            ~> inf_le1
  3898     meet_right_le           ~> inf_le2
  3899     join_left_le            ~> sup_ge1
  3900     join_right_le           ~> sup_ge2
  3901     meet_join_le            ~> inf_sup_ord
  3902     le_meetI                ~> le_infI
  3903     join_leI                ~> le_supI
  3904     le_meet                 ~> le_inf_iff
  3905     le_join                 ~> ge_sup_conv
  3906     meet_idempotent         ~> inf_idem
  3907     join_idempotent         ~> sup_idem
  3908     meet_comm               ~> inf_commute
  3909     join_comm               ~> sup_commute
  3910     meet_leI1               ~> le_infI1
  3911     meet_leI2               ~> le_infI2
  3912     le_joinI1               ~> le_supI1
  3913     le_joinI2               ~> le_supI2
  3914     meet_assoc              ~> inf_assoc
  3915     join_assoc              ~> sup_assoc
  3916     meet_left_comm          ~> inf_left_commute
  3917     meet_left_idempotent    ~> inf_left_idem
  3918     join_left_comm          ~> sup_left_commute
  3919     join_left_idempotent    ~> sup_left_idem
  3920     meet_aci                ~> inf_aci
  3921     join_aci                ~> sup_aci
  3922     le_def_meet             ~> le_iff_inf
  3923     le_def_join             ~> le_iff_sup
  3924     join_absorp2            ~> sup_absorb2
  3925     join_absorp1            ~> sup_absorb1
  3926     meet_absorp1            ~> inf_absorb1
  3927     meet_absorp2            ~> inf_absorb2
  3928     meet_join_absorp        ~> inf_sup_absorb
  3929     join_meet_absorp        ~> sup_inf_absorb
  3930     distrib_join_le         ~> distrib_sup_le
  3931     distrib_meet_le         ~> distrib_inf_le
  3932 
  3933     add_meet_distrib_left   ~> add_inf_distrib_left
  3934     add_join_distrib_left   ~> add_sup_distrib_left
  3935     is_join_neg_meet        ~> is_join_neg_inf
  3936     is_meet_neg_join        ~> is_meet_neg_sup
  3937     add_meet_distrib_right  ~> add_inf_distrib_right
  3938     add_join_distrib_right  ~> add_sup_distrib_right
  3939     add_meet_join_distribs  ~> add_sup_inf_distribs
  3940     join_eq_neg_meet        ~> sup_eq_neg_inf
  3941     meet_eq_neg_join        ~> inf_eq_neg_sup
  3942     add_eq_meet_join        ~> add_eq_inf_sup
  3943     meet_0_imp_0            ~> inf_0_imp_0
  3944     join_0_imp_0            ~> sup_0_imp_0
  3945     meet_0_eq_0             ~> inf_0_eq_0
  3946     join_0_eq_0             ~> sup_0_eq_0
  3947     neg_meet_eq_join        ~> neg_inf_eq_sup
  3948     neg_join_eq_meet        ~> neg_sup_eq_inf
  3949     join_eq_if              ~> sup_eq_if
  3950 
  3951     mono_meet               ~> mono_inf
  3952     mono_join               ~> mono_sup
  3953     meet_bool_eq            ~> inf_bool_eq
  3954     join_bool_eq            ~> sup_bool_eq
  3955     meet_fun_eq             ~> inf_fun_eq
  3956     join_fun_eq             ~> sup_fun_eq
  3957     meet_set_eq             ~> inf_set_eq
  3958     join_set_eq             ~> sup_set_eq
  3959     meet1_iff               ~> inf1_iff
  3960     meet2_iff               ~> inf2_iff
  3961     meet1I                  ~> inf1I
  3962     meet2I                  ~> inf2I
  3963     meet1D1                 ~> inf1D1
  3964     meet2D1                 ~> inf2D1
  3965     meet1D2                 ~> inf1D2
  3966     meet2D2                 ~> inf2D2
  3967     meet1E                  ~> inf1E
  3968     meet2E                  ~> inf2E
  3969     join1_iff               ~> sup1_iff
  3970     join2_iff               ~> sup2_iff
  3971     join1I1                 ~> sup1I1
  3972     join2I1                 ~> sup2I1
  3973     join1I1                 ~> sup1I1
  3974     join2I2                 ~> sup1I2
  3975     join1CI                 ~> sup1CI
  3976     join2CI                 ~> sup2CI
  3977     join1E                  ~> sup1E
  3978     join2E                  ~> sup2E
  3979 
  3980     is_meet_Meet            ~> is_meet_Inf
  3981     Meet_bool_def           ~> Inf_bool_def
  3982     Meet_fun_def            ~> Inf_fun_def
  3983     Meet_greatest           ~> Inf_greatest
  3984     Meet_lower              ~> Inf_lower
  3985     Meet_set_def            ~> Inf_set_def
  3986 
  3987     Sup_def                 ~> Sup_Inf
  3988     Sup_bool_eq             ~> Sup_bool_def
  3989     Sup_fun_eq              ~> Sup_fun_def
  3990     Sup_set_eq              ~> Sup_set_def
  3991 
  3992     listsp_meetI            ~> listsp_infI
  3993     listsp_meet_eq          ~> listsp_inf_eq
  3994 
  3995     meet_min                ~> inf_min
  3996     join_max                ~> sup_max
  3997 
  3998 * Added syntactic class "size"; overloaded constant "size" now has
  3999 type "'a::size ==> bool"
  4000 
  4001 * Internal reorganisation of `size' of datatypes: size theorems
  4002 "foo.size" are no longer subsumed by "foo.simps" (but are still
  4003 simplification rules by default!); theorems "prod.size" now named
  4004 "*.size".
  4005 
  4006 * Class "div" now inherits from class "times" rather than "type".
  4007 INCOMPATIBILITY.
  4008 
  4009 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
  4010 Linorder etc.  have disappeared; operations defined in terms of
  4011 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
  4012 
  4013 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
  4014 
  4015 * HOL-Word: New extensive library and type for generic, fixed size
  4016 machine words, with arithemtic, bit-wise, shifting and rotating
  4017 operations, reflection into int, nat, and bool lists, automation for
  4018 linear arithmetic (by automatic reflection into nat or int), including
  4019 lemmas on overflow and monotonicity.  Instantiated to all appropriate
  4020 arithmetic type classes, supporting automatic simplification of
  4021 numerals on all operations.
  4022 
  4023 * Library/Boolean_Algebra: locales for abstract boolean algebras.
  4024 
  4025 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
  4026 
  4027 * Code generator library theories:
  4028   - Code_Integer represents HOL integers by big integer literals in target
  4029     languages.
  4030   - Code_Char represents HOL characters by character literals in target
  4031     languages.
  4032   - Code_Char_chr like Code_Char, but also offers treatment of character
  4033     codes; includes Code_Integer.
  4034   - Executable_Set allows to generate code for finite sets using lists.
  4035   - Executable_Rat implements rational numbers as triples (sign, enumerator,
  4036     denominator).
  4037   - Executable_Real implements a subset of real numbers, namly those
  4038     representable by rational numbers.
  4039   - Efficient_Nat implements natural numbers by integers, which in general will
  4040     result in higher efficency; pattern matching with 0/Suc is eliminated;
  4041     includes Code_Integer.
  4042   - Code_Index provides an additional datatype index which is mapped to
  4043     target-language built-in integers.
  4044   - Code_Message provides an additional datatype message_string which is isomorphic to
  4045     strings; messages are mapped to target-language strings.
  4046 
  4047 * New package for inductive predicates
  4048 
  4049   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
  4050 
  4051     inductive
  4052       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  4053       for z_1 :: U_1 and ... and z_n :: U_m
  4054     where
  4055       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  4056     | ...
  4057 
  4058   with full support for type-inference, rather than
  4059 
  4060     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4061 
  4062     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  4063     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  4064 
  4065     inductive "s z_1 ... z_m"
  4066     intros
  4067       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  4068       ...
  4069 
  4070   For backward compatibility, there is a wrapper allowing inductive
  4071   sets to be defined with the new package via
  4072 
  4073     inductive_set
  4074       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4075       for z_1 :: U_1 and ... and z_n :: U_m
  4076     where
  4077       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
  4078     | ...
  4079 
  4080   or
  4081 
  4082     inductive_set
  4083       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
  4084       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
  4085       for z_1 :: U_1 and ... and z_n :: U_m
  4086     where
  4087       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
  4088     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
  4089     | ...
  4090 
  4091   if the additional syntax "p ..." is required.
  4092 
  4093   Numerous examples can be found in the subdirectories src/HOL/Auth,
  4094   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
  4095 
  4096   INCOMPATIBILITIES:
  4097 
  4098   - Since declaration and definition of inductive sets or predicates
  4099     is no longer separated, abbreviations involving the newly
  4100     introduced sets or predicates must be specified together with the
  4101     introduction rules after the 'where' keyword (see above), rather
  4102     than before the actual inductive definition.
  4103 
  4104   - The variables in induction and elimination rules are now
  4105     quantified in the order of their occurrence in the introduction
  4106     rules, rather than in alphabetical order. Since this may break
  4107     some proofs, these proofs either have to be repaired, e.g. by
  4108     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
  4109     statements of the form
  4110 
  4111       case (rule_i a_i_1 ... a_i_{k_i})
  4112 
  4113     or the old order of quantification has to be restored by explicitly adding
  4114     meta-level quantifiers in the introduction rules, i.e.
  4115 
  4116       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
  4117 
  4118   - The format of the elimination rules is now
  4119 
  4120       p z_1 ... z_m x_1 ... x_n ==>
  4121         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  4122         ==> ... ==> P
  4123 
  4124     for predicates and
  4125 
  4126       (x_1, ..., x_n) : s z_1 ... z_m ==>
  4127         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
  4128         ==> ... ==> P
  4129 
  4130     for sets rather than
  4131 
  4132       x : s z_1 ... z_m ==>
  4133         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
  4134         ==> ... ==> P
  4135 
  4136     This may require terms in goals to be expanded to n-tuples
  4137     (e.g. using case_tac or simplification with the split_paired_all
  4138     rule) before the above elimination rule is applicable.
  4139 
  4140   - The elimination or case analysis rules for (mutually) inductive
  4141     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
  4142     list of rules "p_1_..._p_k.elims" is no longer available.
  4143 
  4144 * New package "function"/"fun" for general recursive functions,
  4145 supporting mutual and nested recursion, definitions in local contexts,
  4146 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
  4147 for small examples, and the separate tutorial on the function
  4148 package. The old recdef "package" is still available as before, but
  4149 users are encouraged to use the new package.
  4150 
  4151 * Method "lexicographic_order" automatically synthesizes termination
  4152 relations as lexicographic combinations of size measures. 
  4153 
  4154 * Case-expressions allow arbitrary constructor-patterns (including
  4155 "_") and take their order into account, like in functional
  4156 programming.  Internally, this is translated into nested
  4157 case-expressions; missing cases are added and mapped to the predefined
  4158 constant "undefined". In complicated cases printing may no longer show
  4159 the original input but the internal form. Lambda-abstractions allow
  4160 the same form of pattern matching: "% pat1 => e1 | ..." is an
  4161 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
  4162 variable.
  4163 
  4164 * IntDef: The constant "int :: nat => int" has been removed; now "int"
  4165 is an abbreviation for "of_nat :: nat => int". The simplification
  4166 rules for "of_nat" have been changed to work like "int" did
  4167 previously.  Potential INCOMPATIBILITY:
  4168   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
  4169   - of_nat_diff and of_nat_mult are no longer default simp rules
  4170 
  4171 * Method "algebra" solves polynomial equations over (semi)rings using
  4172 Groebner bases. The (semi)ring structure is defined by locales and the
  4173 tool setup depends on that generic context. Installing the method for
  4174 a specific type involves instantiating the locale and possibly adding
  4175 declarations for computation on the coefficients.  The method is
  4176 already instantiated for natural numbers and for the axiomatic class
  4177 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
  4178 CALCULEMUS 2007 for the general principles underlying this
  4179 architecture of context-aware proof-tools.
  4180 
  4181 * Method "ferrack" implements quantifier elimination over
  4182 special-purpose dense linear orders using locales (analogous to
  4183 "algebra"). The method is already installed for class
  4184 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
  4185 rat, etc.
  4186 
  4187 * Former constant "List.op @" now named "List.append".  Use ML
  4188 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  4189 circumvent possible incompatibilities when working on ML level.
  4190 
  4191 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  4192 
  4193 * New function listsum :: 'a list => 'a for arbitrary monoids.
  4194 Special syntax: "SUM x <- xs. f x" (and latex variants)
  4195 
  4196 * New syntax for Haskell-like list comprehension (input only), eg.
  4197 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  4198 
  4199 * The special syntax for function "filter" has changed from [x :
  4200 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  4201 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  4202 
  4203 * [a..b] is now defined for arbitrary linear orders.  It used to be
  4204 defined on nat only, as an abbreviation for [a..<Suc b]
  4205 INCOMPATIBILITY.
  4206 
  4207 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  4208 
  4209 * New functions "sorted" and "sort" in src/HOL/List.thy.
  4210 
  4211 * New lemma collection field_simps (an extension of ring_simps) for
  4212 manipulating (in)equations involving division. Multiplies with all
  4213 denominators that can be proved to be non-zero (in equations) or
  4214 positive/negative (in inequations).
  4215 
  4216 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  4217 have been improved and renamed to ring_simps, group_simps and
  4218 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  4219 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  4220 
  4221 * Theory Library/Commutative_Ring: switched from recdef to function
  4222 package; constants add, mul, pow now curried.  Infix syntax for
  4223 algebraic operations.
  4224 
  4225 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  4226 INCOMPATIBILITY.
  4227 
  4228 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  4229 INCOMPATIBILITY.
  4230 
  4231 * HOL/records: generalised field-update to take a function on the
  4232 field rather than the new value: r(|A := x|) is translated to A_update
  4233 (K x) r The K-combinator that is internally used is called K_record.
  4234 INCOMPATIBILITY: Usage of the plain update functions has to be
  4235 adapted.
  4236  
  4237 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  4238 * x = 0, which are required for a semiring.  Richer structures do not
  4239 inherit from semiring_0 anymore, because this property is a theorem
  4240 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  4241 there is more to prove, but this is mostly trivial.
  4242 
  4243 * Class "recpower" is generalized to arbitrary monoids, not just
  4244 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  4245 commutativity or semiring properties additionally.
  4246 
  4247 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  4248 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  4249 better use 'abbreviation'.
  4250 
  4251 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  4252 
  4253 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  4254 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  4255 significant changes for setting up numeral syntax for types:
  4256   - New constants Numeral.pred and Numeral.succ instead
  4257       of former Numeral.bin_pred and Numeral.bin_succ.
  4258   - Use integer operations instead of bin_add, bin_mult and so on.
  4259   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  4260   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  4261 
  4262 See src/HOL/Integ/IntArith.thy for an example setup.
  4263 
  4264 * Command 'normal_form' computes the normal form of a term that may
  4265 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  4266 produces ``[b, c, a]'' (without proof).  This command is suitable for
  4267 heavy-duty computations because the functions are compiled to ML
  4268 first.  Correspondingly, a method "normalization" is provided.  See
  4269 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  4270 
  4271 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  4272 25 like -->); output depends on the "iff" print_mode, the default is
  4273 "A = B" (with priority 50).
  4274 
  4275 * Relations less (<) and less_eq (<=) are also available on type bool.
  4276 Modified syntax to disallow nesting without explicit parentheses,
  4277 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  4278 INCOMPATIBILITY.
  4279 
  4280 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  4281 
  4282 * Relation composition operator "op O" now has precedence 75 and binds
  4283 stronger than union and intersection. INCOMPATIBILITY.
  4284 
  4285 * The old set interval syntax "{m..n(}" (and relatives) has been
  4286 removed.  Use "{m..<n}" (and relatives) instead.
  4287 
  4288 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  4289 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  4290 ``declare [[simproc del: neq]]''.
  4291 
  4292 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  4293 True/False.
  4294 
  4295 * Theorem Cons_eq_map_conv no longer declared as "simp".
  4296 
  4297 * Theorem setsum_mult renamed to setsum_right_distrib.
  4298 
  4299 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  4300 ``rule'' method.
  4301 
  4302 * Reimplemented methods "sat" and "satx", with several improvements:
  4303 goals no longer need to be stated as "<prems> ==> False", equivalences
  4304 (i.e. "=" on type bool) are handled, variable names of the form
  4305 "lit_<n>" are no longer reserved, significant speedup.
  4306 
  4307 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  4308 zChaff is still supported as well.
  4309 
  4310 * 'inductive' and 'datatype': provide projections of mutual rules,
  4311 bundled as foo_bar.inducts;
  4312 
  4313 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  4314 Library.
  4315 
  4316 * Library: moved theory Accessible_Part to main HOL.
  4317 
  4318 * Library: added theory Coinductive_List of potentially infinite lists
  4319 as greatest fixed-point.
  4320 
  4321 * Library: added theory AssocList which implements (finite) maps as
  4322 association lists.
  4323 
  4324 * Method "evaluation" solves goals (i.e. a boolean expression)
  4325 efficiently by compiling it to ML.  The goal is "proved" (via an
  4326 oracle) if it evaluates to True.
  4327 
  4328 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  4329 also when invoked by the simplifier.  This results in the Simplifier
  4330 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  4331 Configuration option fast_arith_split_limit=0 recovers the old
  4332 behavior.
  4333 
  4334 * Support for hex (0x20) and binary (0b1001) numerals.
  4335 
  4336 * New method: reify eqs (t), where eqs are equations for an
  4337 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  4338 parameter, computes a term s::'b and a list xs::'a list and proves the
  4339 theorem I xs s = t. This is also known as reification or quoting. The
  4340 resulting theorem is applied to the subgoal to substitute t with I xs
  4341 s.  If t is omitted, the subgoal itself is reified.
  4342 
  4343 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  4344 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  4345 where f is supposed to be a computable function (in the sense of code
  4346 generattion). The method uses reify to compute s and xs as above then
  4347 applies corr_thm and uses normalization by evaluation to "prove" f s =
  4348 r and finally gets the theorem t = r, which is again applied to the
  4349 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  4350 
  4351 * Reflection: Automatic reification now handels binding, an example is
  4352 available in src/HOL/ex/ReflectionEx.thy
  4353 
  4354 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  4355 command 'statespace' that is similar to 'record', but introduces an
  4356 abstract specification based on the locale infrastructure instead of
  4357 HOL types.  This leads to extra flexibility in composing state spaces,
  4358 in particular multiple inheritance and renaming of components.
  4359 
  4360 
  4361 *** HOL-Complex ***
  4362 
  4363 * Hyperreal: Functions root and sqrt are now defined on negative real
  4364 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  4365 Nonnegativity side conditions have been removed from many lemmas, so
  4366 that more subgoals may now be solved by simplification; potential
  4367 INCOMPATIBILITY.
  4368 
  4369 * Real: new type classes formalize real normed vector spaces and
  4370 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  4371 and norm :: 'a => real.
  4372 
  4373 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  4374 reals into other types. The overloaded constant Reals :: 'a set is now
  4375 defined as range of_real; potential INCOMPATIBILITY.
  4376 
  4377 * Real: proper support for ML code generation, including 'quickcheck'.
  4378 Reals are implemented as arbitrary precision rationals.
  4379 
  4380 * Hyperreal: Several constants that previously worked only for the
  4381 reals have been generalized, so they now work over arbitrary vector
  4382 spaces. Type annotations may need to be added in some cases; potential
  4383 INCOMPATIBILITY.
  4384 
  4385   Infinitesimal  :: ('a::real_normed_vector) star set
  4386   HFinite        :: ('a::real_normed_vector) star set
  4387   HInfinite      :: ('a::real_normed_vector) star set
  4388   approx         :: ('a::real_normed_vector) star => 'a star => bool
  4389   monad          :: ('a::real_normed_vector) star => 'a star set
  4390   galaxy         :: ('a::real_normed_vector) star => 'a star set
  4391   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  4392   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  4393   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  4394   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  4395   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  4396   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  4397   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  4398   sgn            :: 'a::real_normed_vector => 'a
  4399   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  4400 
  4401 * Complex: Some complex-specific constants are now abbreviations for
  4402 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  4403 hnorm.  Other constants have been entirely removed in favor of the
  4404 polymorphic versions (INCOMPATIBILITY):
  4405 
  4406   approx        <-- capprox
  4407   HFinite       <-- CFinite
  4408   HInfinite     <-- CInfinite
  4409   Infinitesimal <-- CInfinitesimal
  4410   monad         <-- cmonad
  4411   galaxy        <-- cgalaxy
  4412   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  4413   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  4414   (ns)deriv     <-- (ns)cderiv
  4415 
  4416 
  4417 *** HOL-Algebra ***
  4418 
  4419 * Formalisation of ideals and the quotient construction over rings.
  4420 
  4421 * Order and lattice theory no longer based on records.
  4422 INCOMPATIBILITY.
  4423 
  4424 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  4425 greatest_closed.  INCOMPATIBILITY.
  4426 
  4427 * Method algebra is now set up via an attribute.  For examples see
  4428 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  4429 of algebraic structures.
  4430 
  4431 * Renamed theory CRing to Ring.
  4432 
  4433 
  4434 *** HOL-Nominal ***
  4435 
  4436 * Substantial, yet incomplete support for nominal datatypes (binding
  4437 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  4438 src/HOL/Nominal/Examples.  Prospective users should consult
  4439 http://isabelle.in.tum.de/nominal/
  4440 
  4441 
  4442 *** ML ***
  4443 
  4444 * ML basics: just one true type int, which coincides with IntInf.int
  4445 (even on SML/NJ).
  4446 
  4447 * ML within Isar: antiquotations allow to embed statically-checked
  4448 formal entities in the source, referring to the context available at
  4449 compile-time.  For example:
  4450 
  4451 ML {* @{sort "{zero,one}"} *}
  4452 ML {* @{typ "'a => 'b"} *}
  4453 ML {* @{term "%x. x"} *}
  4454 ML {* @{prop "x == y"} *}
  4455 ML {* @{ctyp "'a => 'b"} *}
  4456 ML {* @{cterm "%x. x"} *}
  4457 ML {* @{cprop "x == y"} *}
  4458 ML {* @{thm asm_rl} *}
  4459 ML {* @{thms asm_rl} *}
  4460 ML {* @{type_name c} *}
  4461 ML {* @{type_syntax c} *}
  4462 ML {* @{const_name c} *}
  4463 ML {* @{const_syntax c} *}
  4464 ML {* @{context} *}
  4465 ML {* @{theory} *}
  4466 ML {* @{theory Pure} *}
  4467 ML {* @{theory_ref} *}
  4468 ML {* @{theory_ref Pure} *}
  4469 ML {* @{simpset} *}
  4470 ML {* @{claset} *}
  4471 ML {* @{clasimpset} *}
  4472 
  4473 The same works for sources being ``used'' within an Isar context.
  4474 
  4475 * ML in Isar: improved error reporting; extra verbosity with
  4476 ML_Context.trace enabled.
  4477 
  4478 * Pure/General/table.ML: the join operations now works via exceptions
  4479 DUP/SAME instead of type option. This is simpler in simple cases, and
  4480 admits slightly more efficient complex applications.
  4481 
  4482 * Pure: 'advanced' translation functions (parse_translation etc.) now
  4483 use Context.generic instead of just theory.
  4484 
  4485 * Pure: datatype Context.generic joins theory/Proof.context and
  4486 provides some facilities for code that works in either kind of
  4487 context, notably GenericDataFun for uniform theory and proof data.
  4488 
  4489 * Pure: simplified internal attribute type, which is now always
  4490 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  4491 local (Proof.context) attributes have been discontinued, while
  4492 minimizing code duplication. Thm.rule_attribute and
  4493 Thm.declaration_attribute build canonical attributes; see also structure
  4494 Context for further operations on Context.generic, notably
  4495 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  4496 declarations and definitions.
  4497 
  4498 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  4499 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  4500 init only required for impure data. INCOMPATIBILITY: empty really need
  4501 to be empty (no dependencies on theory content!)
  4502 
  4503 * Pure/kernel: consts certification ignores sort constraints given in
  4504 signature declarations. (This information is not relevant to the
  4505 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  4506 potential INCOMPATIBILITY.
  4507 
  4508 * Pure: axiomatic type classes are now purely definitional, with
  4509 explicit proofs of class axioms and super class relations performed
  4510 internally. See Pure/axclass.ML for the main internal interfaces --
  4511 notably AxClass.define_class supercedes AxClass.add_axclass, and
  4512 AxClass.axiomatize_class/classrel/arity supersede
  4513 Sign.add_classes/classrel/arities.
  4514 
  4515 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  4516 global/local versions on theory vs. Proof.context have been
  4517 discontinued; Attrib.syntax and Method.syntax have been adapted
  4518 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  4519 attributes, methods, etc.
  4520 
  4521 * Pure: several functions of signature "... -> theory -> theory * ..."
  4522 have been reoriented to "... -> theory -> ... * theory" in order to
  4523 allow natural usage in combination with the ||>, ||>>, |-> and
  4524 fold_map combinators.
  4525 
  4526 * Pure: official theorem names (closed derivations) and additional
  4527 comments (tags) are now strictly separate.  Name hints -- which are
  4528 maintained as tags -- may be attached any time without affecting the
  4529 derivation.
  4530 
  4531 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  4532 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  4533 achieve the old behaviour.
  4534 
  4535 * Pure: the "Goal" constant is now called "prop", supporting a
  4536 slightly more general idea of ``protecting'' meta-level rule
  4537 statements.
  4538 
  4539 * Pure: Logic.(un)varify only works in a global context, which is now
  4540 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  4541 Logic.legacy_(un)varify as temporary workaround.
  4542 
  4543 * Pure: structure Name provides scalable operations for generating
  4544 internal variable names, notably Name.variants etc.  This replaces
  4545 some popular functions from term.ML:
  4546 
  4547   Term.variant		->  Name.variant
  4548   Term.variantlist	->  Name.variant_list
  4549   Term.invent_names	->  Name.invent_list
  4550 
  4551 Note that low-level renaming rarely occurs in new code -- operations
  4552 from structure Variable are used instead (see below).
  4553 
  4554 * Pure: structure Variable provides fundamental operations for proper
  4555 treatment of fixed/schematic variables in a context.  For example,
  4556 Variable.import introduces fixes for schematics of given facts and
  4557 Variable.export reverses the effect (up to renaming) -- this replaces
  4558 various freeze_thaw operations.
  4559 
  4560 * Pure: structure Goal provides simple interfaces for
  4561 init/conclude/finish and tactical prove operations (replacing former
  4562 Tactic.prove).  Goal.prove is the canonical way to prove results
  4563 within a given context; Goal.prove_global is a degraded version for
  4564 theory level goals, including a global Drule.standard.  Note that
  4565 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  4566 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  4567 in a locale context).
  4568 
  4569 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  4570 and type checking (Syntax.check_term etc.), with common combinations
  4571 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  4572 which are considered legacy and await removal.
  4573 
  4574 * Pure/Syntax: generic interfaces for type unchecking
  4575 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  4576 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  4577 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  4578 available for convenience, but refer to the very same operations using
  4579 a mere theory instead of a full context.
  4580 
  4581 * Isar: simplified treatment of user-level errors, using exception
  4582 ERROR of string uniformly.  Function error now merely raises ERROR,
  4583 without any side effect on output channels.  The Isar toplevel takes
  4584 care of proper display of ERROR exceptions.  ML code may use plain
  4585 handle/can/try; cat_error may be used to concatenate errors like this:
  4586 
  4587   ... handle ERROR msg => cat_error msg "..."
  4588 
  4589 Toplevel ML code (run directly or through the Isar toplevel) may be
  4590 embedded into the Isar toplevel with exception display/debug like
  4591 this:
  4592 
  4593   Isar.toplevel (fn () => ...)
  4594 
  4595 INCOMPATIBILITY, removed special transform_error facilities, removed
  4596 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  4597 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  4598 -- use plain ERROR instead.
  4599 
  4600 * Isar: theory setup now has type (theory -> theory), instead of a
  4601 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  4602 
  4603 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  4604 ProofContext.debug/verbose flags.
  4605 
  4606 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  4607 theory before entering a proof state.  Transactions now always see a
  4608 quasi-functional intermediate checkpoint, both in interactive and
  4609 batch mode.
  4610 
  4611 * Isar: simplified interfaces for outer syntax.  Renamed
  4612 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  4613 OuterSyntax.add_parsers -- this functionality is now included in
  4614 OuterSyntax.command etc.  INCOMPATIBILITY.
  4615 
  4616 * Simplifier: the simpset of a running simplification process now
  4617 contains a proof context (cf. Simplifier.the_context), which is the
  4618 very context that the initial simpset has been retrieved from (by
  4619 simpset_of/local_simpset_of).  Consequently, all plug-in components
  4620 (solver, looper etc.) may depend on arbitrary proof data.
  4621 
  4622 * Simplifier.inherit_context inherits the proof context (plus the
  4623 local bounds) of the current simplification process; any simproc
  4624 etc. that calls the Simplifier recursively should do this!  Removed
  4625 former Simplifier.inherit_bounds, which is already included here --
  4626 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  4627 specify an explicit context using Simplifier.context/theory_context.
  4628 
  4629 * Simplifier/Classical Reasoner: more abstract interfaces
  4630 change_simpset/claset for modifying the simpset/claset reference of a
  4631 theory; raw versions simpset/claset_ref etc. have been discontinued --
  4632 INCOMPATIBILITY.
  4633 
  4634 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  4635 "Trueprop" etc.
  4636 
  4637 
  4638 *** System ***
  4639 
  4640 * settings: the default heap location within ISABELLE_HOME_USER now
  4641 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  4642 Isabelle installations.
  4643 
  4644 * isabelle-process: option -S (secure mode) disables some critical
  4645 operations, notably runtime compilation and evaluation of ML source
  4646 code.
  4647 
  4648 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  4649 
  4650 * Support for parallel execution, using native multicore support of
  4651 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  4652 independent theories, according to the given theory header
  4653 specifications. The maximum number of worker threads is specified via
  4654 usedir option -M or the "max-threads" setting in Proof General. A
  4655 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  4656 to 6 on a 8-core machine.  User-code needs to observe certain
  4657 guidelines for thread-safe programming, see appendix A in the Isar
  4658 Implementation manual.
  4659 
  4660 
  4661 
  4662 New in Isabelle2005 (October 2005)
  4663 ----------------------------------
  4664 
  4665 *** General ***
  4666 
  4667 * Theory headers: the new header syntax for Isar theories is
  4668 
  4669   theory <name>
  4670   imports <theory1> ... <theoryN>
  4671   uses <file1> ... <fileM>
  4672   begin
  4673 
  4674 where the 'uses' part is optional.  The previous syntax
  4675 
  4676   theory <name> = <theory1> + ... + <theoryN>:
  4677 
  4678 will disappear in the next release.  Use isatool fixheaders to convert
  4679 existing theory files.  Note that there is no change in ancient
  4680 non-Isar theories now, but these will disappear soon.
  4681 
  4682 * Theory loader: parent theories can now also be referred to via
  4683 relative and absolute paths.
  4684 
  4685 * Command 'find_theorems' searches for a list of criteria instead of a
  4686 list of constants. Known criteria are: intro, elim, dest, name:string,
  4687 simp:term, and any term. Criteria can be preceded by '-' to select
  4688 theorems that do not match. Intro, elim, dest select theorems that
  4689 match the current goal, name:s selects theorems whose fully qualified
  4690 name contain s, and simp:term selects all simplification rules whose
  4691 lhs match term.  Any other term is interpreted as pattern and selects
  4692 all theorems matching the pattern. Available in ProofGeneral under
  4693 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  4694 
  4695   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  4696 
  4697 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  4698 matching the current goal as introduction rule and not having "HOL."
  4699 in their name (i.e. not being defined in theory HOL).
  4700 
  4701 * Command 'thms_containing' has been discontinued in favour of
  4702 'find_theorems'; INCOMPATIBILITY.
  4703 
  4704 * Communication with Proof General is now 8bit clean, which means that
  4705 Unicode text in UTF-8 encoding may be used within theory texts (both
  4706 formal and informal parts).  Cf. option -U of the Isabelle Proof
  4707 General interface.  Here are some simple examples (cf. src/HOL/ex):
  4708 
  4709   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  4710   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  4711 
  4712 * Improved efficiency of the Simplifier and, to a lesser degree, the
  4713 Classical Reasoner.  Typical big applications run around 2 times
  4714 faster.
  4715 
  4716 
  4717 *** Document preparation ***
  4718 
  4719 * Commands 'display_drafts' and 'print_drafts' perform simple output
  4720 of raw sources.  Only those symbols that do not require additional
  4721 LaTeX packages (depending on comments in isabellesym.sty) are
  4722 displayed properly, everything else is left verbatim.  isatool display
  4723 and isatool print are used as front ends (these are subject to the
  4724 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  4725 
  4726 * Command tags control specific markup of certain regions of text,
  4727 notably folding and hiding.  Predefined tags include "theory" (for
  4728 theory begin and end), "proof" for proof commands, and "ML" for
  4729 commands involving ML code; the additional tags "visible" and
  4730 "invisible" are unused by default.  Users may give explicit tag
  4731 specifications in the text, e.g. ''by %invisible (auto)''.  The
  4732 interpretation of tags is determined by the LaTeX job during document
  4733 preparation: see option -V of isatool usedir, or options -n and -t of
  4734 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  4735 \isadroptag.
  4736 
  4737 Several document versions may be produced at the same time via isatool
  4738 usedir (the generated index.html will link all of them).  Typical
  4739 specifications include ''-V document=theory,proof,ML'' to present
  4740 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  4741 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  4742 these parts without any formal replacement text.  The Isabelle site
  4743 default settings produce ''document'' and ''outline'' versions as
  4744 specified above.
  4745 
  4746 * Several new antiquotations:
  4747 
  4748   @{term_type term} prints a term with its type annotated;
  4749 
  4750   @{typeof term} prints the type of a term;
  4751 
  4752   @{const const} is the same as @{term const}, but checks that the
  4753   argument is a known logical constant;
  4754 
  4755   @{term_style style term} and @{thm_style style thm} print a term or
  4756   theorem applying a "style" to it
  4757 
  4758   @{ML text}
  4759 
  4760 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  4761 definitions, equations, inequations etc., 'concl' printing only the
  4762 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  4763 to print the specified premise.  TermStyle.add_style provides an ML
  4764 interface for introducing further styles.  See also the "LaTeX Sugar"
  4765 document practical applications.  The ML antiquotation prints
  4766 type-checked ML expressions verbatim.
  4767 
  4768 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  4769 and 'text' support optional locale specification '(in loc)', which
  4770 specifies the default context for interpreting antiquotations.  For
  4771 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  4772 
  4773 * Option 'locale=NAME' of antiquotations specifies an alternative
  4774 context interpreting the subsequent argument.  For example: @{thm
  4775 [locale=lattice] inf_assoc}.
  4776 
  4777 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  4778 a proof context.
  4779 
  4780 * Proper output of antiquotations for theory commands involving a
  4781 proof context (such as 'locale' or 'theorem (in loc) ...').
  4782 
  4783 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  4784 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  4785 
  4786 * isatool usedir: new option -C (default true) controls whether option
  4787 -D should include a copy of the original document directory; -C false
  4788 prevents unwanted effects such as copying of administrative CVS data.
  4789 
  4790 
  4791 *** Pure ***
  4792 
  4793 * Considerably improved version of 'constdefs' command.  Now performs
  4794 automatic type-inference of declared constants; additional support for
  4795 local structure declarations (cf. locales and HOL records), see also
  4796 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  4797 sequential dependencies of definitions within a single 'constdefs'
  4798 section; moreover, the declared name needs to be an identifier.  If
  4799 all fails, consider to fall back on 'consts' and 'defs' separately.
  4800 
  4801 * Improved indexed syntax and implicit structures.  First of all,
  4802 indexed syntax provides a notational device for subscripted
  4803 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  4804 expressions.  Secondly, in a local context with structure
  4805 declarations, number indexes \<^sub>n or the empty index (default
  4806 number 1) refer to a certain fixed variable implicitly; option
  4807 show_structs controls printing of implicit structures.  Typical
  4808 applications of these concepts involve record types and locales.
  4809 
  4810 * New command 'no_syntax' removes grammar declarations (and
  4811 translations) resulting from the given syntax specification, which is
  4812 interpreted in the same manner as for the 'syntax' command.
  4813 
  4814 * 'Advanced' translation functions (parse_translation etc.) may depend
  4815 on the signature of the theory context being presently used for
  4816 parsing/printing, see also isar-ref manual.
  4817 
  4818 * Improved 'oracle' command provides a type-safe interface to turn an
  4819 ML expression of type theory -> T -> term into a primitive rule of
  4820 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  4821 is already included here); see also FOL/ex/IffExample.thy;
  4822 INCOMPATIBILITY.
  4823 
  4824 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  4825 before); "cI" is no longer bound, use "c.intro" instead.
  4826 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  4827 axclasses vs. locales.
  4828 
  4829 * Improved internal renaming of symbolic identifiers -- attach primes
  4830 instead of base 26 numbers.
  4831 
  4832 * New flag show_question_marks controls printing of leading question
  4833 marks in schematic variable names.
  4834 
  4835 * In schematic variable names, *any* symbol following \<^isub> or
  4836 \<^isup> is now treated as part of the base name.  For example, the
  4837 following works without printing of awkward ".0" indexes:
  4838 
  4839   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  4840     by simp
  4841 
  4842 * Inner syntax includes (*(*nested*) comments*).
  4843 
  4844 * Pretty printer now supports unbreakable blocks, specified in mixfix
  4845 annotations as "(00...)".
  4846 
  4847 * Clear separation of logical types and nonterminals, where the latter
  4848 may only occur in 'syntax' specifications or type abbreviations.
  4849 Before that distinction was only partially implemented via type class
  4850 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  4851 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  4852 exotic syntax specifications may require further adaption
  4853 (e.g. Cube/Cube.thy).
  4854 
  4855 * Removed obsolete type class "logic", use the top sort {} instead.
  4856 Note that non-logical types should be declared as 'nonterminals'
  4857 rather than 'types'.  INCOMPATIBILITY for new object-logic
  4858 specifications.
  4859 
  4860 * Attributes 'induct' and 'cases': type or set names may now be
  4861 locally fixed variables as well.
  4862 
  4863 * Simplifier: can now control the depth to which conditional rewriting
  4864 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  4865 Limit.
  4866 
  4867 * Simplifier: simplification procedures may now take the current
  4868 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  4869 interface), which is very useful for calling the Simplifier
  4870 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  4871 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  4872 low-level mk_simproc no longer applies Logic.varify internally, to
  4873 allow for use in a context of fixed variables.
  4874 
  4875 * thin_tac now works even if the assumption being deleted contains !!
  4876 or ==>.  More generally, erule now works even if the major premise of
  4877 the elimination rule contains !! or ==>.
  4878 
  4879 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  4880 
  4881 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  4882 from Pure, which contains all common declarations already.  Both
  4883 theories are defined via plain Isabelle/Isar .thy files.
  4884 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  4885 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  4886 use isatool fixcpure to adapt your theory and ML sources.
  4887 
  4888 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  4889 selections of theorems in named facts via index ranges.
  4890 
  4891 * 'print_theorems': in theory mode, really print the difference
  4892 wrt. the last state (works for interactive theory development only),
  4893 in proof mode print all local facts (cf. 'print_facts');
  4894 
  4895 * 'hide': option '(open)' hides only base names.
  4896 
  4897 * More efficient treatment of intermediate checkpoints in interactive
  4898 theory development.
  4899 
  4900 * Code generator is now invoked via code_module (incremental code
  4901 generation) and code_library (modular code generation, ML structures
  4902 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  4903 must be quoted when used as identifiers.
  4904 
  4905 * New 'value' command for reading, evaluating and printing terms using
  4906 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  4907 quoted when used as identifier.
  4908 
  4909 
  4910 *** Locales ***
  4911 
  4912 * New commands for the interpretation of locale expressions in
  4913 theories (1), locales (2) and proof contexts (3).  These generate
  4914 proof obligations from the expression specification.  After the
  4915 obligations have been discharged, theorems of the expression are added
  4916 to the theory, target locale or proof context.  The synopsis of the
  4917 commands is a follows:
  4918 
  4919   (1) interpretation expr inst
  4920   (2) interpretation target < expr
  4921   (3) interpret expr inst
  4922 
  4923 Interpretation in theories and proof contexts require a parameter
  4924 instantiation of terms from the current context.  This is applied to
  4925 specifications and theorems of the interpreted expression.
  4926 Interpretation in locales only permits parameter renaming through the
  4927 locale expression.  Interpretation is smart in that interpretations
  4928 that are active already do not occur in proof obligations, neither are
  4929 instantiated theorems stored in duplicate.  Use 'print_interps' to
  4930 inspect active interpretations of a particular locale.  For details,
  4931 see the Isar Reference manual.  Examples can be found in
  4932 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  4933 
  4934 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  4935 'interpret' instead.
  4936 
  4937 * New context element 'constrains' for adding type constraints to
  4938 parameters.
  4939 
  4940 * Context expressions: renaming of parameters with syntax
  4941 redeclaration.
  4942 
  4943 * Locale declaration: 'includes' disallowed.
  4944 
  4945 * Proper static binding of attribute syntax -- i.e. types / terms /
  4946 facts mentioned as arguments are always those of the locale definition
  4947 context, independently of the context of later invocations.  Moreover,
  4948 locale operations (renaming and type / term instantiation) are applied
  4949 to attribute arguments as expected.
  4950 
  4951 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  4952 actual attributes; rare situations may require Attrib.attribute to
  4953 embed those attributes into Attrib.src that lack concrete syntax.
  4954 Attribute implementations need to cooperate properly with the static
  4955 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  4956 Attrib.XXX_thm etc. already do the right thing without further
  4957 intervention.  Only unusual applications -- such as "where" or "of"
  4958 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  4959 on the context and the facts involved -- may have to assign parsed
  4960 values to argument tokens explicitly.
  4961 
  4962 * Changed parameter management in theorem generation for long goal
  4963 statements with 'includes'.  INCOMPATIBILITY: produces a different
  4964 theorem statement in rare situations.
  4965 
  4966 * Locale inspection command 'print_locale' omits notes elements.  Use
  4967 'print_locale!' to have them included in the output.
  4968 
  4969 
  4970 *** Provers ***
  4971 
  4972 * Provers/hypsubst.ML: improved version of the subst method, for
  4973 single-step rewriting: it now works in bound variable contexts. New is
  4974 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  4975 rewrite a different subterm than the original subst method, which is
  4976 still available as 'simplesubst'.
  4977 
  4978 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  4979 and quasi orders.
  4980 
  4981 * Provers/trancl.ML: new transitivity reasoner for transitive and
  4982 reflexive-transitive closure of relations.
  4983 
  4984 * Provers/blast.ML: new reference depth_limit to make blast's depth
  4985 limit (previously hard-coded with a value of 20) user-definable.
  4986 
  4987 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  4988 is peformed already.  Object-logics merely need to finish their
  4989 initial simpset configuration as before.  INCOMPATIBILITY.
  4990 
  4991 
  4992 *** HOL ***
  4993 
  4994 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  4995 
  4996   syntax (epsilon)
  4997     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  4998 
  4999 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  5000 and x-symbol; use option '-m epsilon' to get it actually printed.
  5001 Moreover, the mathematically important symbolic identifier \<epsilon>
  5002 becomes available as variable, constant etc.  INCOMPATIBILITY,
  5003 
  5004 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  5005 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  5006 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  5007 support corresponding Isar calculations.
  5008 
  5009 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  5010 instead of ":".
  5011 
  5012 * theory SetInterval: changed the syntax for open intervals:
  5013 
  5014   Old       New
  5015   {..n(}    {..<n}
  5016   {)n..}    {n<..}
  5017   {m..n(}   {m..<n}
  5018   {)m..n}   {m<..n}
  5019   {)m..n(}  {m<..<n}
  5020 
  5021 The old syntax is still supported but will disappear in the next
  5022 release.  For conversion use the following Emacs search and replace
  5023 patterns (these are not perfect but work quite well):
  5024 
  5025   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  5026   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  5027 
  5028 * Theory Commutative_Ring (in Library): method comm_ring for proving
  5029 equalities in commutative rings; method 'algebra' provides a generic
  5030 interface.
  5031 
  5032 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  5033 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  5034 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  5035 be a tuple pattern.
  5036 
  5037 Some new syntax forms are available:
  5038 
  5039   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  5040   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  5041   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  5042   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  5043 
  5044 The latter form "\<Sum>x < k. e" used to be based on a separate
  5045 function "Summation", which has been discontinued.
  5046 
  5047 * theory Finite_Set: in structured induction proofs, the insert case
  5048 is now 'case (insert x F)' instead of the old counterintuitive 'case
  5049 (insert F x)'.
  5050 
  5051 * The 'refute' command has been extended to support a much larger
  5052 fragment of HOL, including axiomatic type classes, constdefs and
  5053 typedefs, inductive datatypes and recursion.
  5054 
  5055 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  5056 Requires zChaff with proof generation to be installed.  See
  5057 HOL/ex/SAT_Examples.thy for examples.
  5058 
  5059 * Datatype induction via method 'induct' now preserves the name of the
  5060 induction variable. For example, when proving P(xs::'a list) by
  5061 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  5062 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  5063 in unstructured proof scripts.
  5064 
  5065 * Reworked implementation of records.  Improved scalability for
  5066 records with many fields, avoiding performance problems for type
  5067 inference. Records are no longer composed of nested field types, but
  5068 of nested extension types. Therefore the record type only grows linear
  5069 in the number of extensions and not in the number of fields.  The
  5070 top-level (users) view on records is preserved.  Potential
  5071 INCOMPATIBILITY only in strange cases, where the theory depends on the
  5072 old record representation. The type generated for a record is called
  5073 <record_name>_ext_type.
  5074 
  5075 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  5076 proofs triggered by a record definition or a simproc (if
  5077 quick_and_dirty is enabled).  Definitions of large records can take
  5078 quite long.
  5079 
  5080 New simproc record_upd_simproc for simplification of multiple record
  5081 updates enabled by default.  Moreover, trivial updates are also
  5082 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  5083 occasionally, since simplification is more powerful by default.
  5084 
  5085 * typedef: proper support for polymorphic sets, which contain extra
  5086 type-variables in the term.
  5087 
  5088 * Simplifier: automatically reasons about transitivity chains
  5089 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  5090 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  5091 old proofs break occasionally as simplification may now solve more
  5092 goals than previously.
  5093 
  5094 * Simplifier: converts x <= y into x = y if assumption y <= x is
  5095 present.  Works for all partial orders (class "order"), in particular
  5096 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  5097 just like y <= x.
  5098 
  5099 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  5100 bound variable or a constant then the let is unfolded.  Otherwise
  5101 first a is simplified to b, and then f b is simplified to g. If
  5102 possible we abstract b from g arriving at "let x = b in h x",
  5103 otherwise we unfold the let and arrive at g.  The simproc can be
  5104 enabled/disabled by the reference use_let_simproc.  Potential
  5105 INCOMPATIBILITY since simplification is more powerful by default.
  5106 
  5107 * Classical reasoning: the meson method now accepts theorems as arguments.
  5108 
  5109 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  5110 jobs to provide advice on the provability of subgoals.
  5111 
  5112 * Theory OrderedGroup and Ring_and_Field: various additions and
  5113 improvements to faciliate calculations involving equalities and
  5114 inequalities.
  5115 
  5116 The following theorems have been eliminated or modified
  5117 (INCOMPATIBILITY):
  5118 
  5119   abs_eq             now named abs_of_nonneg
  5120   abs_of_ge_0        now named abs_of_nonneg
  5121   abs_minus_eq       now named abs_of_nonpos
  5122   imp_abs_id         now named abs_of_nonneg
  5123   imp_abs_neg_id     now named abs_of_nonpos
  5124   mult_pos           now named mult_pos_pos
  5125   mult_pos_le        now named mult_nonneg_nonneg
  5126   mult_pos_neg_le    now named mult_nonneg_nonpos
  5127   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  5128   mult_neg           now named mult_neg_neg
  5129   mult_neg_le        now named mult_nonpos_nonpos
  5130 
  5131 * The following lemmas in Ring_and_Field have been added to the simplifier:
  5132      
  5133      zero_le_square
  5134      not_square_less_zero 
  5135 
  5136   The following lemmas have been deleted from Real/RealPow:
  5137   
  5138      realpow_zero_zero
  5139      realpow_two
  5140      realpow_less
  5141      zero_le_power
  5142      realpow_two_le
  5143      abs_realpow_two
  5144      realpow_two_abs     
  5145 
  5146 * Theory Parity: added rules for simplifying exponents.
  5147 
  5148 * Theory List:
  5149 
  5150 The following theorems have been eliminated or modified
  5151 (INCOMPATIBILITY):
  5152 
  5153   list_all_Nil       now named list_all.simps(1)
  5154   list_all_Cons      now named list_all.simps(2)
  5155   list_all_conv      now named list_all_iff
  5156   set_mem_eq         now named mem_iff
  5157 
  5158 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  5159 asymptotic "big O" calculations.  See the notes in BigO.thy.
  5160 
  5161 
  5162 *** HOL-Complex ***
  5163 
  5164 * Theory RealDef: better support for embedding natural numbers and
  5165 integers in the reals.
  5166 
  5167 The following theorems have been eliminated or modified
  5168 (INCOMPATIBILITY):
  5169 
  5170   exp_ge_add_one_self  now requires no hypotheses
  5171   real_of_int_add      reversed direction of equality (use [symmetric])
  5172   real_of_int_minus    reversed direction of equality (use [symmetric])
  5173   real_of_int_diff     reversed direction of equality (use [symmetric])
  5174   real_of_int_mult     reversed direction of equality (use [symmetric])
  5175 
  5176 * Theory RComplete: expanded support for floor and ceiling functions.
  5177 
  5178 * Theory Ln is new, with properties of the natural logarithm
  5179 
  5180 * Hyperreal: There is a new type constructor "star" for making
  5181 nonstandard types.  The old type names are now type synonyms:
  5182 
  5183   hypreal = real star
  5184   hypnat = nat star
  5185   hcomplex = complex star
  5186 
  5187 * Hyperreal: Many groups of similarly-defined constants have been
  5188 replaced by polymorphic versions (INCOMPATIBILITY):
  5189 
  5190   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  5191 
  5192   starset      <-- starsetNat, starsetC
  5193   *s*          <-- *sNat*, *sc*
  5194   starset_n    <-- starsetNat_n, starsetC_n
  5195   *sn*         <-- *sNatn*, *scn*
  5196   InternalSets <-- InternalNatSets, InternalCSets
  5197 
  5198   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  5199   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  5200   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  5201   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  5202   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  5203 
  5204 * Hyperreal: Many type-specific theorems have been removed in favor of
  5205 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  5206 
  5207   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  5208   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  5209   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  5210   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  5211   right_minus <-- hypreal_add_minus
  5212   left_minus <-- {hypreal,hcomplex}_add_minus_left
  5213   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  5214   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  5215   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  5216   mult_1_right <-- hcomplex_mult_one_right
  5217   mult_zero_left <-- hcomplex_mult_zero_left
  5218   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  5219   right_distrib <-- hypnat_add_mult_distrib2
  5220   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  5221   right_inverse <-- hypreal_mult_inverse
  5222   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  5223   order_refl <-- {hypreal,hypnat}_le_refl
  5224   order_trans <-- {hypreal,hypnat}_le_trans
  5225   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  5226   order_less_le <-- {hypreal,hypnat}_less_le
  5227   linorder_linear <-- {hypreal,hypnat}_le_linear
  5228   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  5229   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  5230   add_nonneg_nonneg <-- hypreal_le_add_order
  5231 
  5232 * Hyperreal: Separate theorems having to do with type-specific
  5233 versions of constants have been merged into theorems that apply to the
  5234 new polymorphic constants (INCOMPATIBILITY):
  5235 
  5236   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  5237   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  5238   STAR_Un <-- {STAR,NatStar,STARC}_Un
  5239   STAR_Int <-- {STAR,NatStar,STARC}_Int
  5240   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  5241   STAR_subset <-- {STAR,NatStar,STARC}_subset
  5242   STAR_mem <-- {STAR,NatStar,STARC}_mem
  5243   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  5244   STAR_diff <-- {STAR,STARC}_diff
  5245   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  5246     STARC_hcomplex_of_complex}_image_subset
  5247   starset_n_Un <-- starset{Nat,C}_n_Un
  5248   starset_n_Int <-- starset{Nat,C}_n_Int
  5249   starset_n_Compl <-- starset{Nat,C}_n_Compl
  5250   starset_n_diff <-- starset{Nat,C}_n_diff
  5251   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  5252   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  5253   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  5254   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  5255   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  5256   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  5257   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  5258   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  5259   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  5260   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  5261   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  5262   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  5263   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  5264   starfun_diff <-- starfun{C,RC,CR}_diff
  5265   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  5266   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  5267   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  5268   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  5269   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  5270   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  5271   starfun_Id <-- starfunC_Id
  5272   starfun_approx <-- starfun{Nat,CR}_approx
  5273   starfun_capprox <-- starfun{C,RC}_capprox
  5274   starfun_abs <-- starfunNat_rabs
  5275   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  5276   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  5277   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  5278   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  5279   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  5280   starfun_add_approx <-- starfunCR_add_approx
  5281   starfun_inverse_inverse <-- starfunC_inverse_inverse
  5282   starfun_divide <-- starfun{C,CR,RC}_divide
  5283   starfun_n <-- starfun{Nat,C}_n
  5284   starfun_n_mult <-- starfun{Nat,C}_n_mult
  5285   starfun_n_add <-- starfun{Nat,C}_n_add
  5286   starfun_n_add_minus <-- starfunNat_n_add_minus
  5287   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  5288   starfun_n_minus <-- starfun{Nat,C}_n_minus
  5289   starfun_n_eq <-- starfun{Nat,C}_n_eq
  5290 
  5291   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  5292   star_n_minus <-- {hypreal,hcomplex}_minus
  5293   star_n_diff <-- {hypreal,hcomplex}_diff
  5294   star_n_mult <-- {hypreal,hcomplex}_mult
  5295   star_n_inverse <-- {hypreal,hcomplex}_inverse
  5296   star_n_le <-- {hypreal,hypnat}_le
  5297   star_n_less <-- {hypreal,hypnat}_less
  5298   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  5299   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  5300   star_n_abs <-- hypreal_hrabs
  5301   star_n_divide <-- hcomplex_divide
  5302 
  5303   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  5304   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  5305   star_of_diff <-- hypreal_of_real_diff
  5306   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  5307   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  5308   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  5309   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  5310   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  5311   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  5312   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  5313   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  5314   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  5315   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  5316   star_of_number_of <-- {hypreal,hcomplex}_number_of
  5317   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  5318   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  5319   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  5320   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  5321   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  5322   star_of_power <-- hypreal_of_real_power
  5323   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  5324 
  5325 * Hyperreal: new method "transfer" that implements the transfer
  5326 principle of nonstandard analysis. With a subgoal that mentions
  5327 nonstandard types like "'a star", the command "apply transfer"
  5328 replaces it with an equivalent one that mentions only standard types.
  5329 To be successful, all free variables must have standard types; non-
  5330 standard variables must have explicit universal quantifiers.
  5331 
  5332 * Hyperreal: A theory of Taylor series.
  5333 
  5334 
  5335 *** HOLCF ***
  5336 
  5337 * Discontinued special version of 'constdefs' (which used to support
  5338 continuous functions) in favor of the general Pure one with full
  5339 type-inference.
  5340 
  5341 * New simplification procedure for solving continuity conditions; it
  5342 is much faster on terms with many nested lambda abstractions (cubic
  5343 instead of exponential time).
  5344 
  5345 * New syntax for domain package: selector names are now optional.
  5346 Parentheses should be omitted unless argument is lazy, for example:
  5347 
  5348   domain 'a stream = cons "'a" (lazy "'a stream")
  5349 
  5350 * New command 'fixrec' for defining recursive functions with pattern
  5351 matching; defining multiple functions with mutual recursion is also
  5352 supported.  Patterns may include the constants cpair, spair, up, sinl,
  5353 sinr, or any data constructor defined by the domain package. The given
  5354 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  5355 syntax and examples.
  5356 
  5357 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  5358 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  5359 but the proof obligation additionally includes an admissibility
  5360 requirement. The packages generate instances of class cpo or pcpo,
  5361 with continuity and strictness theorems for Rep and Abs.
  5362 
  5363 * HOLCF: Many theorems have been renamed according to a more standard naming
  5364 scheme (INCOMPATIBILITY):
  5365 
  5366   foo_inject:  "foo$x = foo$y ==> x = y"
  5367   foo_eq:      "(foo$x = foo$y) = (x = y)"
  5368   foo_less:    "(foo$x << foo$y) = (x << y)"
  5369   foo_strict:  "foo$UU = UU"
  5370   foo_defined: "... ==> foo$x ~= UU"
  5371   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  5372 
  5373 
  5374 *** ZF ***
  5375 
  5376 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  5377 including the First Isomorphism Theorem (on quotienting by the kernel
  5378 of a homomorphism).
  5379 
  5380 * ZF/Simplifier: install second copy of type solver that actually
  5381 makes use of TC rules declared to Isar proof contexts (or locales);
  5382 the old version is still required for ML proof scripts.
  5383 
  5384 
  5385 *** Cube ***
  5386 
  5387 * Converted to Isar theory format; use locales instead of axiomatic
  5388 theories.
  5389 
  5390 
  5391 *** ML ***
  5392 
  5393 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  5394 for ||>, ||>>, |>>,
  5395 
  5396 * Pure/library.ML no longer defines its own option datatype, but uses
  5397 that of the SML basis, which has constructors NONE and SOME instead of
  5398 None and Some, as well as exception Option.Option instead of OPTION.
  5399 The functions the, if_none, is_some, is_none have been adapted
  5400 accordingly, while Option.map replaces apsome.
  5401 
  5402 * Pure/library.ML: the exception LIST has been given up in favour of
  5403 the standard exceptions Empty and Subscript, as well as
  5404 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  5405 superceded by the standard hd and tl functions etc.
  5406 
  5407 A number of basic list functions are no longer exported to the ML
  5408 toplevel, as they are variants of predefined functions.  The following
  5409 suggests how one can translate existing code:
  5410 
  5411     rev_append xs ys = List.revAppend (xs, ys)
  5412     nth_elem (i, xs) = List.nth (xs, i)
  5413     last_elem xs = List.last xs
  5414     flat xss = List.concat xss
  5415     seq fs = List.app fs
  5416     partition P xs = List.partition P xs
  5417     mapfilter f xs = List.mapPartial f xs
  5418 
  5419 * Pure/library.ML: several combinators for linear functional
  5420 transformations, notably reverse application and composition:
  5421 
  5422   x |> f                f #> g
  5423   (x, y) |-> f          f #-> g
  5424 
  5425 * Pure/library.ML: introduced/changed precedence of infix operators:
  5426 
  5427   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  5428   infix 2 ?;
  5429   infix 3 o oo ooo oooo;
  5430   infix 4 ~~ upto downto;
  5431 
  5432 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  5433 infix operators.
  5434 
  5435 * Pure/library.ML: natural list combinators fold, fold_rev, and
  5436 fold_map support linear functional transformations and nesting.  For
  5437 example:
  5438 
  5439   fold f [x1, ..., xN] y =
  5440     y |> f x1 |> ... |> f xN
  5441 
  5442   (fold o fold) f [xs1, ..., xsN] y =
  5443     y |> fold f xs1 |> ... |> fold f xsN
  5444 
  5445   fold f [x1, ..., xN] =
  5446     f x1 #> ... #> f xN
  5447 
  5448   (fold o fold) f [xs1, ..., xsN] =
  5449     fold f xs1 #> ... #> fold f xsN
  5450 
  5451 * Pure/library.ML: the following selectors on type 'a option are
  5452 available:
  5453 
  5454   the:               'a option -> 'a  (*partial*)
  5455   these:             'a option -> 'a  where 'a = 'b list
  5456   the_default: 'a -> 'a option -> 'a
  5457   the_list:          'a option -> 'a list
  5458 
  5459 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5460 basic operations for association lists, following natural argument
  5461 order; moreover the explicit equality predicate passed here avoids
  5462 potentially expensive polymorphic runtime equality checks.
  5463 The old functions may be expressed as follows:
  5464 
  5465   assoc = uncurry (AList.lookup (op =))
  5466   assocs = these oo AList.lookup (op =)
  5467   overwrite = uncurry (AList.update (op =)) o swap
  5468 
  5469 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  5470 
  5471   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  5472   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  5473 
  5474 replacing make_keylist and keyfilter (occassionally used)
  5475 Naive rewrites:
  5476 
  5477   make_keylist = AList.make
  5478   keyfilter = AList.find (op =)
  5479 
  5480 * eq_fst and eq_snd now take explicit equality parameter, thus
  5481   avoiding eqtypes. Naive rewrites:
  5482 
  5483     eq_fst = eq_fst (op =)
  5484     eq_snd = eq_snd (op =)
  5485 
  5486 * Removed deprecated apl and apr (rarely used).
  5487   Naive rewrites:
  5488 
  5489     apl (n, op) =>>= curry op n
  5490     apr (op, m) =>>= fn n => op (n, m)
  5491 
  5492 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  5493 provides a reasonably efficient light-weight implementation of sets as
  5494 lists.
  5495 
  5496 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  5497 few new operations; existing lookup and update are now curried to
  5498 follow natural argument order (for use with fold etc.);
  5499 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  5500 
  5501 * Pure/General: output via the Isabelle channels of
  5502 writeln/warning/error etc. is now passed through Output.output, with a
  5503 hook for arbitrary transformations depending on the print_mode
  5504 (cf. Output.add_mode -- the first active mode that provides a output
  5505 function wins).  Already formatted output may be embedded into further
  5506 text via Output.raw; the result of Pretty.string_of/str_of and derived
  5507 functions (string_of_term/cterm/thm etc.) is already marked raw to
  5508 accommodate easy composition of diagnostic messages etc.  Programmers
  5509 rarely need to care about Output.output or Output.raw at all, with
  5510 some notable exceptions: Output.output is required when bypassing the
  5511 standard channels (writeln etc.), or in token translations to produce
  5512 properly formatted results; Output.raw is required when capturing
  5513 already output material that will eventually be presented to the user
  5514 a second time.  For the default print mode, both Output.output and
  5515 Output.raw have no effect.
  5516 
  5517 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  5518 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  5519 cumulative results are displayed at the end of a batch session.
  5520 
  5521 * Pure/General: File.sysify_path and File.quote_sysify path have been
  5522 replaced by File.platform_path and File.shell_path (with appropriate
  5523 hooks).  This provides a clean interface for unusual systems where the
  5524 internal and external process view of file names are different.
  5525 
  5526 * Pure: more efficient orders for basic syntactic entities: added
  5527 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  5528 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  5529 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  5530 orders now -- potential INCOMPATIBILITY for code that depends on a
  5531 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  5532 Library.sort_strings on result).
  5533 
  5534 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  5535 fold_types traverse types/terms from left to right, observing natural
  5536 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  5537 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  5538 
  5539 * Pure: name spaces have been refined, with significant changes of the
  5540 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  5541 to extern(_table).  The plain name entry path is superceded by a
  5542 general 'naming' context, which also includes the 'policy' to produce
  5543 a fully qualified name and external accesses of a fully qualified
  5544 name; NameSpace.extend is superceded by context dependent
  5545 Sign.declare_name.  Several theory and proof context operations modify
  5546 the naming context.  Especially note Theory.restore_naming and
  5547 ProofContext.restore_naming to get back to a sane state; note that
  5548 Theory.add_path is no longer sufficient to recover from
  5549 Theory.absolute_path in particular.
  5550 
  5551 * Pure: new flags short_names (default false) and unique_names
  5552 (default true) for controlling output of qualified names.  If
  5553 short_names is set, names are printed unqualified.  If unique_names is
  5554 reset, the name prefix is reduced to the minimum required to achieve
  5555 the original result when interning again, even if there is an overlap
  5556 with earlier declarations.
  5557 
  5558 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  5559 now 'extend', and 'merge' gets an additional Pretty.pp argument
  5560 (useful for printing error messages).  INCOMPATIBILITY.
  5561 
  5562 * Pure: major reorganization of the theory context.  Type Sign.sg and
  5563 Theory.theory are now identified, referring to the universal
  5564 Context.theory (see Pure/context.ML).  Actual signature and theory
  5565 content is managed as theory data.  The old code and interfaces were
  5566 spread over many files and structures; the new arrangement introduces
  5567 considerable INCOMPATIBILITY to gain more clarity:
  5568 
  5569   Context -- theory management operations (name, identity, inclusion,
  5570     parents, ancestors, merge, etc.), plus generic theory data;
  5571 
  5572   Sign -- logical signature and syntax operations (declaring consts,
  5573     types, etc.), plus certify/read for common entities;
  5574 
  5575   Theory -- logical theory operations (stating axioms, definitions,
  5576     oracles), plus a copy of logical signature operations (consts,
  5577     types, etc.); also a few basic management operations (Theory.copy,
  5578     Theory.merge, etc.)
  5579 
  5580 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  5581 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  5582 for convenience -- they merely return the theory.
  5583 
  5584 * Pure: type Type.tsig is superceded by theory in most interfaces.
  5585 
  5586 * Pure: the Isar proof context type is already defined early in Pure
  5587 as Context.proof (note that ProofContext.context and Proof.context are
  5588 aliases, where the latter is the preferred name).  This enables other
  5589 Isabelle components to refer to that type even before Isar is present.
  5590 
  5591 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  5592 typeK, constK, axiomK, oracleK), but provide explicit operations for
  5593 any of these kinds.  For example, Sign.intern typeK is now
  5594 Sign.intern_type, Theory.hide_space Sign.typeK is now
  5595 Theory.hide_types.  Also note that former
  5596 Theory.hide_classes/types/consts are now
  5597 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  5598 internalize their arguments!  INCOMPATIBILITY.
  5599 
  5600 * Pure: get_thm interface (of PureThy and ProofContext) expects
  5601 datatype thmref (with constructors Name and NameSelection) instead of
  5602 plain string -- INCOMPATIBILITY;
  5603 
  5604 * Pure: cases produced by proof methods specify options, where NONE
  5605 means to remove case bindings -- INCOMPATIBILITY in
  5606 (RAW_)METHOD_CASES.
  5607 
  5608 * Pure: the following operations retrieve axioms or theorems from a
  5609 theory node or theory hierarchy, respectively:
  5610 
  5611   Theory.axioms_of: theory -> (string * term) list
  5612   Theory.all_axioms_of: theory -> (string * term) list
  5613   PureThy.thms_of: theory -> (string * thm) list
  5614   PureThy.all_thms_of: theory -> (string * thm) list
  5615 
  5616 * Pure: print_tac now outputs the goal through the trace channel.
  5617 
  5618 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  5619 Reference Toplevel.debug (default false) controls detailed printing
  5620 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  5621 controls execution profiling -- set to 1 for time and 2 for space
  5622 (both increase the runtime).
  5623 
  5624 * Isar session: The initial use of ROOT.ML is now always timed,
  5625 i.e. the log will show the actual process times, in contrast to the
  5626 elapsed wall-clock time that the outer shell wrapper produces.
  5627 
  5628 * Simplifier: improved handling of bound variables (nameless
  5629 representation, avoid allocating new strings).  Simprocs that invoke
  5630 the Simplifier recursively should use Simplifier.inherit_bounds to
  5631 avoid local name clashes.  Failure to do so produces warnings
  5632 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  5633 for further details.
  5634 
  5635 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  5636 bindings for all theorems stored within a given theory; this may help
  5637 in porting non-Isar theories to Isar ones, while keeping ML proof
  5638 scripts for the time being.
  5639 
  5640 * ML operator HTML.with_charset specifies the charset begin used for
  5641 generated HTML files.  For example:
  5642 
  5643   HTML.with_charset "utf-8" use_thy "Hebrew";
  5644   HTML.with_charset "utf-8" use_thy "Chinese";
  5645 
  5646 
  5647 *** System ***
  5648 
  5649 * Allow symlinks to all proper Isabelle executables (Isabelle,
  5650 isabelle, isatool etc.).
  5651 
  5652 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  5653 isatool doc, isatool mkdir, display_drafts etc.).
  5654 
  5655 * isatool usedir: option -f allows specification of the ML file to be
  5656 used by Isabelle; default is ROOT.ML.
  5657 
  5658 * New isatool version outputs the version identifier of the Isabelle
  5659 distribution being used.
  5660 
  5661 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  5662 (containing Boolean satisfiability problems) into Isabelle/HOL
  5663 theories.
  5664 
  5665 
  5666 
  5667 New in Isabelle2004 (April 2004)
  5668 --------------------------------
  5669 
  5670 *** General ***
  5671 
  5672 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  5673   Replaces linorder.ML.
  5674 
  5675 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  5676   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  5677   (\<a>...\<z>), are now considered normal letters, and can therefore
  5678   be used anywhere where an ASCII letter (a...zA...Z) has until
  5679   now. COMPATIBILITY: This obviously changes the parsing of some
  5680   terms, especially where a symbol has been used as a binder, say
  5681   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  5682   as an identifier.  Fix it by inserting a space around former
  5683   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  5684   existing theory and ML files.
  5685 
  5686 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  5687 
  5688 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  5689   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  5690   a normal (but invisible) letter. For multiple letter subscripts repeat
  5691   \<^isub> like this: x\<^isub>1\<^isub>2.
  5692 
  5693 * Pure: There are now sub-/superscripts that can span more than one
  5694   character. Text between \<^bsub> and \<^esub> is set in subscript in
  5695   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  5696   superscript. The new control characters are not identifier parts.
  5697 
  5698 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  5699   content of "..." to the latex file instead of \isacntrl... . The "..."
  5700   may consist of any printable characters excluding the end bracket >.
  5701 
  5702 * Pure: Using new Isar command "finalconsts" (or the ML functions
  5703   Theory.add_finals or Theory.add_finals_i) it is now possible to
  5704   declare constants "final", which prevents their being given a definition
  5705   later.  It is useful for constants whose behaviour is fixed axiomatically
  5706   rather than definitionally, such as the meta-logic connectives.
  5707 
  5708 * Pure: 'instance' now handles general arities with general sorts
  5709   (i.e. intersections of classes),
  5710 
  5711 * Presentation: generated HTML now uses a CSS style sheet to make layout
  5712   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  5713   It can be changed to alter the colors/layout of generated pages.
  5714 
  5715 
  5716 *** Isar ***
  5717 
  5718 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  5719   cut_tac, subgoal_tac and thin_tac:
  5720   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  5721     locales are no longer forced to write Isar proof scripts.
  5722     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  5723     emulations.
  5724   - INCOMPATIBILITY: names of variables to be instantiated may no
  5725     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  5726     This is consistent with the instantiation attribute "where".
  5727 
  5728 * Attributes "where" and "of":
  5729   - Now take type variables of instantiated theorem into account when reading
  5730     the instantiation string.  This fixes a bug that caused instantiated
  5731     theorems to have too special types in some circumstances.
  5732   - "where" permits explicit instantiations of type variables.
  5733 
  5734 * Calculation commands "moreover" and "also" no longer interfere with
  5735   current facts ("this"), admitting arbitrary combinations with "then"
  5736   and derived forms.
  5737 
  5738 * Locales:
  5739   - Goal statements involving the context element "includes" no longer
  5740     generate theorems with internal delta predicates (those ending on
  5741     "_axioms") in the premise.
  5742     Resolve particular premise with <locale>.intro to obtain old form.
  5743   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  5744     specification and "includes" elements in goal statement.
  5745   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  5746     [intro?] and [elim?] (respectively) by default.
  5747   - Experimental command for instantiation of locales in proof contexts:
  5748         instantiate <label>[<attrs>]: <loc>
  5749     Instantiates locale <loc> and adds all its theorems to the current context
  5750     taking into account their attributes.  Label and attrs are optional
  5751     modifiers, like in theorem declarations.  If present, names of
  5752     instantiated theorems are qualified with <label>, and the attributes
  5753     <attrs> are applied after any attributes these theorems might have already.
  5754       If the locale has assumptions, a chained fact of the form
  5755     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  5756     are derived.  The command does not support old-style locales declared
  5757     with "locale (open)".
  5758       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  5759 
  5760 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  5761   (Isar) contexts.
  5762 
  5763 
  5764 *** HOL ***
  5765 
  5766 * Proof import: new image HOL4 contains the imported library from
  5767   the HOL4 system with about 2500 theorems. It is imported by
  5768   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  5769   can be used like any other Isabelle image.  See
  5770   HOL/Import/HOL/README for more information.
  5771 
  5772 * Simplifier:
  5773   - Much improved handling of linear and partial orders.
  5774     Reasoners for linear and partial orders are set up for type classes
  5775     "linorder" and "order" respectively, and are added to the default simpset
  5776     as solvers.  This means that the simplifier can build transitivity chains
  5777     to solve goals from the assumptions.
  5778   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  5779     of blast or auto after simplification become unnecessary because the goal
  5780     is solved by simplification already.
  5781 
  5782 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  5783     all proved in axiomatic type classes for semirings, rings and fields.
  5784 
  5785 * Numerics:
  5786   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  5787     now formalized using the Ring_and_Field theory mentioned above.
  5788   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  5789     than before, because now they are set up once in a generic manner.
  5790   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  5791     Look for the general versions in Ring_and_Field (and Power if they concern
  5792     exponentiation).
  5793 
  5794 * Type "rat" of the rational numbers is now available in HOL-Complex.
  5795 
  5796 * Records:
  5797   - Record types are now by default printed with their type abbreviation
  5798     instead of the list of all field types. This can be configured via
  5799     the reference "print_record_type_abbr".
  5800   - Simproc "record_upd_simproc" for simplification of multiple updates added
  5801     (not enabled by default).
  5802   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  5803     EX x. x = sel r to True (not enabled by default).
  5804   - Tactic "record_split_simp_tac" to split and simplify records added.
  5805 
  5806 * 'specification' command added, allowing for definition by
  5807   specification.  There is also an 'ax_specification' command that
  5808   introduces the new constants axiomatically.
  5809 
  5810 * arith(_tac) is now able to generate counterexamples for reals as well.
  5811 
  5812 * HOL-Algebra: new locale "ring" for non-commutative rings.
  5813 
  5814 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  5815   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  5816 
  5817 * HOL-Matrix: a first theory for matrices in HOL with an application of
  5818   matrix theory to linear programming.
  5819 
  5820 * Unions and Intersections:
  5821   The latex output syntax of UN and INT has been changed
  5822   from "\Union x \in A. B" to "\Union_{x \in A} B"
  5823   i.e. the index formulae has become a subscript.
  5824   Similarly for "\Union x. B", and for \Inter instead of \Union.
  5825 
  5826 * Unions and Intersections over Intervals:
  5827   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  5828   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  5829   like in normal math, and corresponding versions for < and for intersection.
  5830 
  5831 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  5832   lexicographic dictonary ordering has been added as "lexord".
  5833 
  5834 * ML: the legacy theory structures Int and List have been removed. They had
  5835   conflicted with ML Basis Library structures having the same names.
  5836 
  5837 * 'refute' command added to search for (finite) countermodels.  Only works
  5838   for a fragment of HOL.  The installation of an external SAT solver is
  5839   highly recommended.  See "HOL/Refute.thy" for details.
  5840 
  5841 * 'quickcheck' command: Allows to find counterexamples by evaluating
  5842   formulae under an assignment of free variables to random values.
  5843   In contrast to 'refute', it can deal with inductive datatypes,
  5844   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  5845   for examples.
  5846 
  5847 
  5848 *** HOLCF ***
  5849 
  5850 * Streams now come with concatenation and are part of the HOLCF image
  5851 
  5852 
  5853 
  5854 New in Isabelle2003 (May 2003)
  5855 ------------------------------
  5856 
  5857 *** General ***
  5858 
  5859 * Provers/simplifier:
  5860 
  5861   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  5862     Assumptions are now subject to complete mutual simplification,
  5863     not just from left to right. The simplifier now preserves
  5864     the order of assumptions.
  5865 
  5866     Potential INCOMPATIBILITY:
  5867 
  5868     -- simp sometimes diverges where the old version did
  5869        not, e.g. invoking simp on the goal
  5870 
  5871         [| P (f x); y = x; f x = f y |] ==> Q
  5872 
  5873        now gives rise to the infinite reduction sequence
  5874 
  5875         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  5876 
  5877        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  5878        kind of problem.
  5879 
  5880     -- Tactics combining classical reasoner and simplification (such as auto)
  5881        are also affected by this change, because many of them rely on
  5882        simp. They may sometimes diverge as well or yield a different numbers
  5883        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  5884        in case of problems. Sometimes subsequent calls to the classical
  5885        reasoner will fail because a preceeding call to the simplifier too
  5886        eagerly simplified the goal, e.g. deleted redundant premises.
  5887 
  5888   - The simplifier trace now shows the names of the applied rewrite rules
  5889 
  5890   - You can limit the number of recursive invocations of the simplifier
  5891     during conditional rewriting (where the simplifie tries to solve the
  5892     conditions before applying the rewrite rule):
  5893     ML "simp_depth_limit := n"
  5894     where n is an integer. Thus you can force termination where previously
  5895     the simplifier would diverge.
  5896 
  5897   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  5898 
  5899   - No longer aborts on failed congruence proof.  Instead, the
  5900     congruence is ignored.
  5901 
  5902 * Pure: New generic framework for extracting programs from constructive
  5903   proofs. See HOL/Extraction.thy for an example instantiation, as well
  5904   as HOL/Extraction for some case studies.
  5905 
  5906 * Pure: The main goal of the proof state is no longer shown by default, only
  5907 the subgoals. This behaviour is controlled by a new flag.
  5908    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  5909 (ML: Proof.show_main_goal).
  5910 
  5911 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  5912 rules whose conclusion matches subgoal 1:
  5913       PG menu: Isabelle/Isar -> Show me -> matching rules
  5914 The rules are ordered by how closely they match the subgoal.
  5915 In particular, rules that solve a subgoal outright are displayed first
  5916 (or rather last, the way they are printed).
  5917 (ML: ProofGeneral.print_intros())
  5918 
  5919 * Pure: New flag trace_unify_fail causes unification to print
  5920 diagnostic information (PG: in trace buffer) when it fails. This is
  5921 useful for figuring out why single step proofs like rule, erule or
  5922 assumption failed.
  5923 
  5924 * Pure: Locale specifications now produce predicate definitions
  5925 according to the body of text (covering assumptions modulo local
  5926 definitions); predicate "loc_axioms" covers newly introduced text,
  5927 while "loc" is cumulative wrt. all included locale expressions; the
  5928 latter view is presented only on export into the global theory
  5929 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  5930 on the old view without predicates;
  5931 
  5932 * Pure: predefined locales "var" and "struct" are useful for sharing
  5933 parameters (as in CASL, for example); just specify something like
  5934 ``var x + var y + struct M'' as import;
  5935 
  5936 * Pure: improved thms_containing: proper indexing of facts instead of
  5937 raw theorems; check validity of results wrt. current name space;
  5938 include local facts of proof configuration (also covers active
  5939 locales), cover fixed variables in index; may use "_" in term
  5940 specification; an optional limit for the number of printed facts may
  5941 be given (the default is 40);
  5942 
  5943 * Pure: disallow duplicate fact bindings within new-style theory files
  5944 (batch-mode only);
  5945 
  5946 * Provers: improved induct method: assumptions introduced by case
  5947 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  5948 the goal statement); "foo" still refers to all facts collectively;
  5949 
  5950 * Provers: the function blast.overloaded has been removed: all constants
  5951 are regarded as potentially overloaded, which improves robustness in exchange
  5952 for slight decrease in efficiency;
  5953 
  5954 * Provers/linorder: New generic prover for transitivity reasoning over
  5955 linear orders.  Note: this prover is not efficient!
  5956 
  5957 * Isar: preview of problems to finish 'show' now produce an error
  5958 rather than just a warning (in interactive mode);
  5959 
  5960 
  5961 *** HOL ***
  5962 
  5963 * arith(_tac)
  5964 
  5965  - Produces a counter example if it cannot prove a goal.
  5966    Note that the counter example may be spurious if the goal is not a formula
  5967    of quantifier-free linear arithmetic.
  5968    In ProofGeneral the counter example appears in the trace buffer.
  5969 
  5970  - Knows about div k and mod k where k is a numeral of type nat or int.
  5971 
  5972  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  5973    linear arithmetic fails. This takes account of quantifiers and divisibility.
  5974    Presburger arithmetic can also be called explicitly via presburger(_tac).
  5975 
  5976 * simp's arithmetic capabilities have been enhanced a bit: it now
  5977 takes ~= in premises into account (by performing a case split);
  5978 
  5979 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  5980 are distributed over a sum of terms;
  5981 
  5982 * New tactic "trans_tac" and method "trans" instantiate
  5983 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  5984 "<=", "<" and "=").
  5985 
  5986 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  5987 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  5988 
  5989 * 'typedef' command has new option "open" to suppress the set
  5990 definition;
  5991 
  5992 * functions Min and Max on finite sets have been introduced (theory
  5993 Finite_Set);
  5994 
  5995 * attribute [symmetric] now works for relations as well; it turns
  5996 (x,y) : R^-1 into (y,x) : R, and vice versa;
  5997 
  5998 * induct over a !!-quantified statement (say !!x1..xn):
  5999   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  6000 
  6001 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  6002 %x. None. Warning: empty_def now refers to the previously hidden definition
  6003 of the empty set.
  6004 
  6005 * Algebra: formalization of classical algebra.  Intended as base for
  6006 any algebraic development in Isabelle.  Currently covers group theory
  6007 (up to Sylow's theorem) and ring theory (Universal Property of
  6008 Univariate Polynomials).  Contributions welcome;
  6009 
  6010 * GroupTheory: deleted, since its material has been moved to Algebra;
  6011 
  6012 * Complex: new directory of the complex numbers with numeric constants,
  6013 nonstandard complex numbers, and some complex analysis, standard and
  6014 nonstandard (Jacques Fleuriot);
  6015 
  6016 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  6017 
  6018 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  6019 Fleuriot);
  6020 
  6021 * Real/HahnBanach: updated and adapted to locales;
  6022 
  6023 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  6024 Gray and Kramer);
  6025 
  6026 * UNITY: added the Meier-Sanders theory of progress sets;
  6027 
  6028 * MicroJava: bytecode verifier and lightweight bytecode verifier
  6029 as abstract algorithms, instantiated to the JVM;
  6030 
  6031 * Bali: Java source language formalization. Type system, operational
  6032 semantics, axiomatic semantics. Supported language features:
  6033 classes, interfaces, objects,virtual methods, static methods,
  6034 static/instance fields, arrays, access modifiers, definite
  6035 assignment, exceptions.
  6036 
  6037 
  6038 *** ZF ***
  6039 
  6040 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  6041 universe, etc.);
  6042 
  6043 * Main ZF: virtually all theories converted to new-style format;
  6044 
  6045 
  6046 *** ML ***
  6047 
  6048 * Pure: Tactic.prove provides sane interface for internal proofs;
  6049 omits the infamous "standard" operation, so this is more appropriate
  6050 than prove_goalw_cterm in many situations (e.g. in simprocs);
  6051 
  6052 * Pure: improved error reporting of simprocs;
  6053 
  6054 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  6055 up simprocs;
  6056 
  6057 
  6058 *** Document preparation ***
  6059 
  6060 * uses \par instead of \\ for line breaks in theory text. This may
  6061 shift some page breaks in large documents. To get the old behaviour
  6062 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  6063 
  6064 * minimized dependencies of isabelle.sty and isabellesym.sty on
  6065 other packages
  6066 
  6067 * \<euro> now needs package babel/greek instead of marvosym (which
  6068 broke \Rightarrow)
  6069 
  6070 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  6071 textcomp package)
  6072 
  6073 
  6074 
  6075 New in Isabelle2002 (March 2002)
  6076 --------------------------------
  6077 
  6078 *** Document preparation ***
  6079 
  6080 * greatly simplified document preparation setup, including more
  6081 graceful interpretation of isatool usedir -i/-d/-D options, and more
  6082 instructive isatool mkdir; users should basically be able to get
  6083 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  6084 users may run a separate document processing stage manually like this:
  6085 "isatool usedir -D output HOL Test && isatool document Test/output";
  6086 
  6087 * theory dependency graph may now be incorporated into documents;
  6088 isatool usedir -g true will produce session_graph.eps/.pdf for use
  6089 with \includegraphics of LaTeX;
  6090 
  6091 * proper spacing of consecutive markup elements, especially text
  6092 blocks after section headings;
  6093 
  6094 * support bold style (for single symbols only), input syntax is like
  6095 this: "\<^bold>\<alpha>" or "\<^bold>A";
  6096 
  6097 * \<bullet> is now output as bold \cdot by default, which looks much
  6098 better in printed text;
  6099 
  6100 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  6101 note that these symbols are currently unavailable in Proof General /
  6102 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  6103 
  6104 * isatool latex no longer depends on changed TEXINPUTS, instead
  6105 isatool document copies the Isabelle style files to the target
  6106 location;
  6107 
  6108 
  6109 *** Isar ***
  6110 
  6111 * Pure/Provers: improved proof by cases and induction;
  6112   - 'case' command admits impromptu naming of parameters (such as
  6113     "case (Suc n)");
  6114   - 'induct' method divinates rule instantiation from the inductive
  6115     claim; no longer requires excessive ?P bindings for proper
  6116     instantiation of cases;
  6117   - 'induct' method properly enumerates all possibilities of set/type
  6118     rules; as a consequence facts may be also passed through *type*
  6119     rules without further ado;
  6120   - 'induct' method now derives symbolic cases from the *rulified*
  6121     rule (before it used to rulify cases stemming from the internal
  6122     atomized version); this means that the context of a non-atomic
  6123     statement becomes is included in the hypothesis, avoiding the
  6124     slightly cumbersome show "PROP ?case" form;
  6125   - 'induct' may now use elim-style induction rules without chaining
  6126     facts, using ``missing'' premises from the goal state; this allows
  6127     rules stemming from inductive sets to be applied in unstructured
  6128     scripts, while still benefitting from proper handling of non-atomic
  6129     statements; NB: major inductive premises need to be put first, all
  6130     the rest of the goal is passed through the induction;
  6131   - 'induct' proper support for mutual induction involving non-atomic
  6132     rule statements (uses the new concept of simultaneous goals, see
  6133     below);
  6134   - append all possible rule selections, but only use the first
  6135     success (no backtracking);
  6136   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  6137   - undeclared rule case names default to numbers 1, 2, 3, ...;
  6138   - added 'print_induct_rules' (covered by help item in recent Proof
  6139     General versions);
  6140   - moved induct/cases attributes to Pure, methods to Provers;
  6141   - generic method setup instantiated for FOL and HOL;
  6142 
  6143 * Pure: support multiple simultaneous goal statements, for example
  6144 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  6145 meta-level mechanism, this acts as if several individual goals had
  6146 been stated separately; in particular common proof methods need to be
  6147 repeated in order to cover all claims; note that a single elimination
  6148 step is *not* sufficient to establish the two conjunctions, so this
  6149 fails:
  6150 
  6151   assume "A & B" then have A and B ..   (*".." fails*)
  6152 
  6153 better use "obtain" in situations as above; alternative refer to
  6154 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  6155 
  6156 * Pure: proper integration with ``locales''; unlike the original
  6157 version by Florian Kammller, Isar locales package high-level proof
  6158 contexts rather than raw logical ones (e.g. we admit to include
  6159 attributes everywhere); operations on locales include merge and
  6160 rename; support for implicit arguments (``structures''); simultaneous
  6161 type-inference over imports and text; see also HOL/ex/Locales.thy for
  6162 some examples;
  6163 
  6164 * Pure: the following commands have been ``localized'', supporting a
  6165 target locale specification "(in name)": 'lemma', 'theorem',
  6166 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  6167 stored both within the locale and at the theory level (exported and
  6168 qualified by the locale name);
  6169 
  6170 * Pure: theory goals may now be specified in ``long'' form, with
  6171 ad-hoc contexts consisting of arbitrary locale elements. for example
  6172 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  6173 definitions may be given, too); the result is a meta-level rule with
  6174 the context elements being discharged in the obvious way;
  6175 
  6176 * Pure: new proof command 'using' allows to augment currently used
  6177 facts after a goal statement ('using' is syntactically analogous to
  6178 'apply', but acts on the goal's facts only); this allows chained facts
  6179 to be separated into parts given before and after a claim, as in
  6180 ``from a and b have C using d and e <proof>'';
  6181 
  6182 * Pure: renamed "antecedent" case to "rule_context";
  6183 
  6184 * Pure: new 'judgment' command records explicit information about the
  6185 object-logic embedding (used by several tools internally); no longer
  6186 use hard-wired "Trueprop";
  6187 
  6188 * Pure: added 'corollary' command;
  6189 
  6190 * Pure: fixed 'token_translation' command;
  6191 
  6192 * Pure: removed obsolete 'exported' attribute;
  6193 
  6194 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  6195 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  6196 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  6197 
  6198 * Pure: method 'atomize' presents local goal premises as object-level
  6199 statements (atomic meta-level propositions); setup controlled via
  6200 rewrite rules declarations of 'atomize' attribute; example
  6201 application: 'induct' method with proper rule statements in improper
  6202 proof *scripts*;
  6203 
  6204 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  6205 now consider the syntactic context of assumptions, giving a better
  6206 chance to get type-inference of the arguments right (this is
  6207 especially important for locales);
  6208 
  6209 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  6210 mode;
  6211 
  6212 * Pure/obtain: the formal conclusion "thesis", being marked as
  6213 ``internal'', may no longer be reference directly in the text;
  6214 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  6215 situations;
  6216 
  6217 * Pure: generic 'sym' attribute which declares a rule both as pure
  6218 'elim?' and for the 'symmetric' operation;
  6219 
  6220 * Pure: marginal comments ``--'' may now occur just anywhere in the
  6221 text; the fixed correlation with particular command syntax has been
  6222 discontinued;
  6223 
  6224 * Pure: new method 'rules' is particularly well-suited for proof
  6225 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  6226 but often produces more compact proof terms with less detours;
  6227 
  6228 * Pure/Provers/classical: simplified integration with pure rule
  6229 attributes and methods; the classical "intro?/elim?/dest?"
  6230 declarations coincide with the pure ones; the "rule" method no longer
  6231 includes classically swapped intros; "intro" and "elim" methods no