NEWS
author wenzelm
Fri Dec 07 22:19:51 2007 +0100 (2007-12-07)
changeset 25579 22869d9d545b
parent 25557 ea6b11021e79
child 25599 afdff3ad4057
permissions -rw-r--r--
(alt)string: allow explicit character codes (as in ML);
     1 Isabelle NEWS -- history user-relevant changes
     2 ==============================================
     3 
     4 New in this Isabelle version
     5 ----------------------------
     6 
     7 *** General ***
     8 
     9 * Syntax: symbol \<chi> is now considered a letter.  Potential
    10 INCOMPATIBILITY in identifier syntax etc.
    11 
    12 * Outer syntax: string tokens may contain arbitrary character codes
    13 specified via 3 decimal digits (as in SML).  E.g. "foo\095bar" for
    14 "foo_bar".
    15 
    16 
    17 *** Pure ***
    18 
    19 * Command "instance" now takes list of definitions in the same manner
    20 as the "definition" command.  Most notably, object equality is now
    21 possible.  Type inference is more canonical than it used to be.
    22 INCOMPATIBILITY: in some cases explicit type annotations are required.
    23 
    24 
    25 *** HOL ***
    26 
    27 * New primrec package.  Specification syntax conforms in style to
    28   definition/function/....  The "primrec" command distinguished old-style
    29   and new-style specifications by syntax.  The old primrec package is
    30   now named OldPrimrecPackage.
    31 
    32 * Library/Multiset: {#a, b, c#} abbreviates {#a#} + {#b#} + {#c#}.
    33 
    34 * Constants "card", "internal_split", "option_map" now with authentic
    35 syntax.
    36 
    37 * Definitions subset_def, psubset_def, set_diff_def, Compl_def,
    38 le_bool_def, less_bool_def, le_fun_def, less_fun_def, inf_bool_def,
    39 sup_bool_def, Inf_bool_def, Sup_bool_def, inf_fun_def, sup_fun_def,
    40 Inf_fun_def, Sup_fun_def, inf_set_def, sup_set_def, Inf_set_def,
    41 Sup_set_def, le_def, less_def, option_map_def now with object
    42 equality.
    43 
    44 
    45 
    46 New in Isabelle2007 (November 2007)
    47 -----------------------------------
    48 
    49 *** General ***
    50 
    51 * More uniform information about legacy features, notably a
    52 warning/error of "Legacy feature: ...", depending on the state of the
    53 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
    54 legacy features will disappear eventually.
    55 
    56 * Theory syntax: the header format ``theory A = B + C:'' has been
    57 discontinued in favour of ``theory A imports B C begin''.  Use isatool
    58 fixheaders to convert existing theory files.  INCOMPATIBILITY.
    59 
    60 * Theory syntax: the old non-Isar theory file format has been
    61 discontinued altogether.  Note that ML proof scripts may still be used
    62 with Isar theories; migration is usually quite simple with the ML
    63 function use_legacy_bindings.  INCOMPATIBILITY.
    64 
    65 * Theory syntax: some popular names (e.g. 'class', 'declaration',
    66 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
    67 quotes.
    68 
    69 * Theory loader: be more serious about observing the static theory
    70 header specifications (including optional directories), but not the
    71 accidental file locations of previously successful loads.  The strict
    72 update policy of former update_thy is now already performed by
    73 use_thy, so the former has been removed; use_thys updates several
    74 theories simultaneously, just as 'imports' within a theory header
    75 specification, but without merging the results.  Potential
    76 INCOMPATIBILITY: may need to refine theory headers and commands
    77 ROOT.ML which depend on load order.
    78 
    79 * Theory loader: optional support for content-based file
    80 identification, instead of the traditional scheme of full physical
    81 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
    82 (cf. the system manual).  The new scheme allows to work with
    83 non-finished theories in persistent session images, such that source
    84 files may be moved later on without requiring reloads.
    85 
    86 * Theory loader: old-style ML proof scripts being *attached* to a thy
    87 file (with the same base name as the theory) are considered a legacy
    88 feature, which will disappear eventually. Even now, the theory loader
    89 no longer maintains dependencies on such files.
    90 
    91 * Syntax: the scope for resolving ambiguities via type-inference is
    92 now limited to individual terms, instead of whole simultaneous
    93 specifications as before. This greatly reduces the complexity of the
    94 syntax module and improves flexibility by separating parsing and
    95 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
    96 'fixes' etc.) are required in rare situations.
    97 
    98 * Syntax: constants introduced by new-style packages ('definition',
    99 'abbreviation' etc.) are passed through the syntax module in
   100 ``authentic mode''. This means that associated mixfix annotations
   101 really stick to such constants, independently of potential name space
   102 ambiguities introduced later on. INCOMPATIBILITY: constants in parse
   103 trees are represented slightly differently, may need to adapt syntax
   104 translations accordingly. Use CONST marker in 'translations' and
   105 @{const_syntax} antiquotation in 'parse_translation' etc.
   106 
   107 * Legacy goal package: reduced interface to the bare minimum required
   108 to keep existing proof scripts running.  Most other user-level
   109 functions are now part of the OldGoals structure, which is *not* open
   110 by default (consider isatool expandshort before open OldGoals).
   111 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
   112 these tend to cause confusion about the actual goal (!) context being
   113 used here, which is not necessarily the same as the_context().
   114 
   115 * Command 'find_theorems': supports "*" wild-card in "name:"
   116 criterion; "with_dups" option.  Certain ProofGeneral versions might
   117 support a specific search form (see ProofGeneral/CHANGES).
   118 
   119 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
   120 by default, which means that "prems" (and also "fixed variables") are
   121 suppressed from proof state output.  Note that the ProofGeneral
   122 settings mechanism allows to change and save options persistently, but
   123 older versions of Isabelle will fail to start up if a negative prems
   124 limit is imposed.
   125 
   126 * Local theory targets may be specified by non-nested blocks of
   127 ``context/locale/class ... begin'' followed by ``end''.  The body may
   128 contain definitions, theorems etc., including any derived mechanism
   129 that has been implemented on top of these primitives.  This concept
   130 generalizes the existing ``theorem (in ...)'' towards more versatility
   131 and scalability.
   132 
   133 * Proof General interface: proper undo of final 'end' command;
   134 discontinued Isabelle/classic mode (ML proof scripts).
   135 
   136 
   137 *** Document preparation ***
   138 
   139 * Added antiquotation @{theory name} which prints the given name,
   140 after checking that it refers to a valid ancestor theory in the
   141 current context.
   142 
   143 * Added antiquotations @{ML_type text} and @{ML_struct text} which
   144 check the given source text as ML type/structure, printing verbatim.
   145 
   146 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
   147 "c args == rhs" given in the current context.  (Any number of
   148 arguments may be given on the LHS.)
   149 
   150 
   151 *** Pure ***
   152 
   153 * The 'class' package offers a combination of axclass and locale to
   154 achieve Haskell-like type classes in Isabelle.  Definitions and
   155 theorems within a class context produce both relative results (with
   156 implicit parameters according to the locale context), and polymorphic
   157 constants with qualified polymorphism (according to the class
   158 context).  Within the body context of a 'class' target, a separate
   159 syntax layer ("user space type system") takes care of converting
   160 between global polymorphic consts and internal locale representation.
   161 See src/HOL/ex/Classpackage.thy for examples (as well as main HOL).
   162 "isatool doc classes" provides a tutorial.
   163 
   164 * Generic code generator framework allows to generate executable
   165 code for ML and Haskell (including Isabelle classes).  A short usage
   166 sketch:
   167 
   168     internal compilation:
   169         export_code <list of constants (term syntax)> in SML
   170     writing SML code to a file:
   171         export_code <list of constants (term syntax)> in SML <filename>
   172     writing OCaml code to a file:
   173         export_code <list of constants (term syntax)> in OCaml <filename>
   174     writing Haskell code to a bunch of files:
   175         export_code <list of constants (term syntax)> in Haskell <filename>
   176 
   177     evaluating closed propositions to True/False using code generation:
   178         method ``eval''
   179 
   180 Reasonable default setup of framework in HOL.
   181 
   182 Theorem attributs for selecting and transforming function equations theorems:
   183 
   184     [code fun]:        select a theorem as function equation for a specific constant
   185     [code fun del]:    deselect a theorem as function equation for a specific constant
   186     [code inline]:     select an equation theorem for unfolding (inlining) in place
   187     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
   188 
   189 User-defined serializations (target in {SML, OCaml, Haskell}):
   190 
   191     code_const <and-list of constants (term syntax)>
   192       {(target) <and-list of const target syntax>}+
   193 
   194     code_type <and-list of type constructors>
   195       {(target) <and-list of type target syntax>}+
   196 
   197     code_instance <and-list of instances>
   198       {(target)}+
   199         where instance ::= <type constructor> :: <class>
   200 
   201     code_class <and_list of classes>
   202       {(target) <and-list of class target syntax>}+
   203         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
   204 
   205 code_instance and code_class only are effective to target Haskell.
   206 
   207 For example usage see src/HOL/ex/Codegenerator.thy and
   208 src/HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
   209 generation from Isabelle/HOL theories is available via "isatool doc
   210 codegen".
   211 
   212 * Code generator: consts in 'consts_code' Isar commands are now
   213 referred to by usual term syntax (including optional type
   214 annotations).
   215 
   216 * Command 'no_translations' removes translation rules from theory
   217 syntax.
   218 
   219 * Overloaded definitions are now actually checked for acyclic
   220 dependencies.  The overloading scheme is slightly more general than
   221 that of Haskell98, although Isabelle does not demand an exact
   222 correspondence to type class and instance declarations.
   223 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
   224 exotic versions of overloading -- at the discretion of the user!
   225 
   226 Polymorphic constants are represented via type arguments, i.e. the
   227 instantiation that matches an instance against the most general
   228 declaration given in the signature.  For example, with the declaration
   229 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
   230 as c(nat).  Overloading is essentially simultaneous structural
   231 recursion over such type arguments.  Incomplete specification patterns
   232 impose global constraints on all occurrences, e.g. c('a * 'a) on the
   233 LHS means that more general c('a * 'b) will be disallowed on any RHS.
   234 Command 'print_theory' outputs the normalized system of recursive
   235 equations, see section "definitions".
   236 
   237 * Configuration options are maintained within the theory or proof
   238 context (with name and type bool/int/string), providing a very simple
   239 interface to a poor-man's version of general context data.  Tools may
   240 declare options in ML (e.g. using Attrib.config_int) and then refer to
   241 these values using Config.get etc.  Users may change options via an
   242 associated attribute of the same name.  This form of context
   243 declaration works particularly well with commands 'declare' or
   244 'using', for example ``declare [[foo = 42]]''.  Thus it has become
   245 very easy to avoid global references, which would not observe Isar
   246 toplevel undo/redo and fail to work with multithreading.
   247 
   248 Various global ML references of Pure and HOL have been turned into
   249 configuration options:
   250 
   251   Unify.search_bound		unify_search_bound
   252   Unify.trace_bound		unify_trace_bound
   253   Unify.trace_simp		unify_trace_simp
   254   Unify.trace_types		unify_trace_types
   255   Simplifier.simp_depth_limit	simp_depth_limit
   256   Blast.depth_limit		blast_depth_limit
   257   DatatypeProp.dtK		datatype_distinctness_limit
   258   fast_arith_neq_limit  	fast_arith_neq_limit
   259   fast_arith_split_limit	fast_arith_split_limit
   260 
   261 * Named collections of theorems may be easily installed as context
   262 data using the functor NamedThmsFun (see also
   263 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
   264 attributes; there is also a toplevel print command.  This facility is
   265 just a common case of general context data, which is the preferred way
   266 for anything more complex than just a list of facts in canonical
   267 order.
   268 
   269 * Isar: command 'declaration' augments a local theory by generic
   270 declaration functions written in ML.  This enables arbitrary content
   271 being added to the context, depending on a morphism that tells the
   272 difference of the original declaration context wrt. the application
   273 context encountered later on.
   274 
   275 * Isar: proper interfaces for simplification procedures.  Command
   276 'simproc_setup' declares named simprocs (with match patterns, and body
   277 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
   278 context.  ML antiquotation @{simproc name} retrieves named simprocs.
   279 
   280 * Isar: an extra pair of brackets around attribute declarations
   281 abbreviates a theorem reference involving an internal dummy fact,
   282 which will be ignored later --- only the effect of the attribute on
   283 the background context will persist.  This form of in-place
   284 declarations is particularly useful with commands like 'declare' and
   285 'using', for example ``have A using [[simproc a]] by simp''.
   286 
   287 * Isar: method "assumption" (and implicit closing of subproofs) now
   288 takes simple non-atomic goal assumptions into account: after applying
   289 an assumption as a rule the resulting subgoals are solved by atomic
   290 assumption steps.  This is particularly useful to finish 'obtain'
   291 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
   292 without referring to the original premise "!!x. P x ==> thesis" in the
   293 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
   294 more permissive.
   295 
   296 * Isar: implicit use of prems from the Isar proof context is
   297 considered a legacy feature.  Common applications like ``have A .''
   298 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
   299 referencing facts explicitly here improves readability and
   300 maintainability of proof texts.
   301 
   302 * Isar: improper proof element 'guess' is like 'obtain', but derives
   303 the obtained context from the course of reasoning!  For example:
   304 
   305   assume "EX x y. A x & B y"   -- "any previous fact"
   306   then guess x and y by clarify
   307 
   308 This technique is potentially adventurous, depending on the facts and
   309 proof tools being involved here.
   310 
   311 * Isar: known facts from the proof context may be specified as literal
   312 propositions, using ASCII back-quote syntax.  This works wherever
   313 named facts used to be allowed so far, in proof commands, proof
   314 methods, attributes etc.  Literal facts are retrieved from the context
   315 according to unification of type and term parameters.  For example,
   316 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
   317 theorems in the current context, then these are valid literal facts:
   318 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
   319 
   320 There is also a proof method "fact" which does the same composition
   321 for explicit goal states, e.g. the following proof texts coincide with
   322 certain special cases of literal facts:
   323 
   324   have "A" by fact                 ==  note `A`
   325   have "A ==> B" by fact           ==  note `A ==> B`
   326   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
   327   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
   328 
   329 * Isar: ":" (colon) is no longer a symbolic identifier character in
   330 outer syntax.  Thus symbolic identifiers may be used without
   331 additional white space in declarations like this: ``assume *: A''.
   332 
   333 * Isar: 'print_facts' prints all local facts of the current context,
   334 both named and unnamed ones.
   335 
   336 * Isar: 'def' now admits simultaneous definitions, e.g.:
   337 
   338   def x == "t" and y == "u"
   339 
   340 * Isar: added command 'unfolding', which is structurally similar to
   341 'using', but affects both the goal state and facts by unfolding given
   342 rewrite rules.  Thus many occurrences of the 'unfold' method or
   343 'unfolded' attribute may be replaced by first-class proof text.
   344 
   345 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
   346 and command 'unfolding' now all support object-level equalities
   347 (potentially conditional).  The underlying notion of rewrite rule is
   348 analogous to the 'rule_format' attribute, but *not* that of the
   349 Simplifier (which is usually more generous).
   350 
   351 * Isar: the new attribute [rotated n] (default n = 1) rotates the
   352 premises of a theorem by n. Useful in conjunction with drule.
   353 
   354 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
   355 method expression within a sandbox consisting of the first N
   356 sub-goals, which need to exist.  For example, ``simp_all [3]''
   357 simplifies the first three sub-goals, while (rule foo, simp_all)[]
   358 simplifies all new goals that emerge from applying rule foo to the
   359 originally first one.
   360 
   361 * Isar: schematic goals are no longer restricted to higher-order
   362 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
   363 expected.
   364 
   365 * Isar: the conclusion of a long theorem statement is now either
   366 'shows' (a simultaneous conjunction, as before), or 'obtains'
   367 (essentially a disjunction of cases with local parameters and
   368 assumptions).  The latter allows to express general elimination rules
   369 adequately; in this notation common elimination rules look like this:
   370 
   371   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
   372     assumes "EX x. P x"
   373     obtains x where "P x"
   374 
   375   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
   376     assumes "A & B"
   377     obtains A and B
   378 
   379   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
   380     assumes "A | B"
   381     obtains
   382       A
   383     | B
   384 
   385 The subsequent classical rules even refer to the formal "thesis"
   386 explicitly:
   387 
   388   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
   389     obtains "~ thesis"
   390 
   391   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
   392     obtains "thesis ==> something"
   393 
   394 The actual proof of an 'obtains' statement is analogous to that of the
   395 Isar proof element 'obtain', only that there may be several cases.
   396 Optional case names may be specified in parentheses; these will be
   397 available both in the present proof and as annotations in the
   398 resulting rule, for later use with the 'cases' method (cf. attribute
   399 case_names).
   400 
   401 * Isar: the assumptions of a long theorem statement are available as
   402 "assms" fact in the proof context.  This is more appropriate than the
   403 (historical) "prems", which refers to all assumptions of the current
   404 context, including those from the target locale, proof body etc.
   405 
   406 * Isar: 'print_statement' prints theorems from the current theory or
   407 proof context in long statement form, according to the syntax of a
   408 top-level lemma.
   409 
   410 * Isar: 'obtain' takes an optional case name for the local context
   411 introduction rule (default "that").
   412 
   413 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
   414 explicit (is "_ ==> ?foo") in the rare cases where this still happens
   415 to occur.
   416 
   417 * Pure: syntax "CONST name" produces a fully internalized constant
   418 according to the current context.  This is particularly useful for
   419 syntax translations that should refer to internal constant
   420 representations independently of name spaces.
   421 
   422 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
   423 instead of "FOO ". This allows multiple binder declarations to coexist
   424 in the same context.  INCOMPATIBILITY.
   425 
   426 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
   427 primitive that also works in a locale context (both for constants and
   428 fixed variables). Type declaration and internal syntactic representation
   429 of given constants retrieved from the context. Likewise, the
   430 'no_notation' command allows to remove given syntax annotations from the
   431 current context.
   432 
   433 * Isar/locales: new derived specification elements 'axiomatization',
   434 'definition', 'abbreviation', which support type-inference, admit
   435 object-level specifications (equality, equivalence).  See also the
   436 isar-ref manual.  Examples:
   437 
   438   axiomatization
   439     eq  (infix "===" 50) where
   440     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
   441 
   442   definition "f x y = x + y + 1"
   443   definition g where "g x = f x x"
   444 
   445   abbreviation
   446     neq  (infix "=!=" 50) where
   447     "x =!= y == ~ (x === y)"
   448 
   449 These specifications may be also used in a locale context.  Then the
   450 constants being introduced depend on certain fixed parameters, and the
   451 constant name is qualified by the locale base name.  An internal
   452 abbreviation takes care for convenient input and output, making the
   453 parameters implicit and using the original short name.  See also
   454 src/HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
   455 entities from a monomorphic theory.
   456 
   457 Presently, abbreviations are only available 'in' a target locale, but
   458 not inherited by general import expressions.  Also note that
   459 'abbreviation' may be used as a type-safe replacement for 'syntax' +
   460 'translations' in common applications.  The "no_abbrevs" print mode
   461 prevents folding of abbreviations in term output.
   462 
   463 Concrete syntax is attached to specified constants in internal form,
   464 independently of name spaces.  The parse tree representation is
   465 slightly different -- use 'notation' instead of raw 'syntax', and
   466 'translations' with explicit "CONST" markup to accommodate this.
   467 
   468 * Pure/Isar: unified syntax for new-style specification mechanisms
   469 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
   470 full type inference and dummy patterns ("_").  For example:
   471 
   472   definition "K x _ = x"
   473 
   474   inductive conj for A B
   475   where "A ==> B ==> conj A B"
   476 
   477 * Pure: command 'print_abbrevs' prints all constant abbreviations of
   478 the current context.  Print mode "no_abbrevs" prevents inversion of
   479 abbreviations on output.
   480 
   481 * Isar/locales: improved parameter handling: use of locales "var" and
   482 "struct" no longer necessary; - parameter renamings are no longer
   483 required to be injective.  For example, this allows to define
   484 endomorphisms as locale endom = homom mult mult h.
   485 
   486 * Isar/locales: changed the way locales with predicates are defined.
   487 Instead of accumulating the specification, the imported expression is
   488 now an interpretation.  INCOMPATIBILITY: different normal form of
   489 locale expressions.  In particular, in interpretations of locales with
   490 predicates, goals repesenting already interpreted fragments are not
   491 removed automatically.  Use methods `intro_locales' and
   492 `unfold_locales'; see below.
   493 
   494 * Isar/locales: new methods `intro_locales' and `unfold_locales'
   495 provide backward reasoning on locales predicates.  The methods are
   496 aware of interpretations and discharge corresponding goals.
   497 `intro_locales' is less aggressive then `unfold_locales' and does not
   498 unfold predicates to assumptions.
   499 
   500 * Isar/locales: the order in which locale fragments are accumulated
   501 has changed.  This enables to override declarations from fragments due
   502 to interpretations -- for example, unwanted simp rules.
   503 
   504 * Isar/locales: interpretation in theories and proof contexts has been
   505 extended.  One may now specify (and prove) equations, which are
   506 unfolded in interpreted theorems.  This is useful for replacing
   507 defined concepts (constants depending on locale parameters) by
   508 concepts already existing in the target context.  Example:
   509 
   510   interpretation partial_order ["op <= :: [int, int] => bool"]
   511     where "partial_order.less (op <=) (x::int) y = (x < y)"
   512 
   513 Typically, the constant `partial_order.less' is created by a
   514 definition specification element in the context of locale
   515 partial_order.
   516 
   517 * Method "induct": improved internal context management to support
   518 local fixes and defines on-the-fly. Thus explicit meta-level
   519 connectives !!  and ==> are rarely required anymore in inductive goals
   520 (using object-logic connectives for this purpose has been long
   521 obsolete anyway). Common proof patterns are explained in
   522 src/HOL/Induct/Common_Patterns.thy, see also
   523 src/HOL/Isar_examples/Puzzle.thy and src/HOL/Lambda for realistic
   524 examples.
   525 
   526 * Method "induct": improved handling of simultaneous goals. Instead of
   527 introducing object-level conjunction, the statement is now split into
   528 several conclusions, while the corresponding symbolic cases are nested
   529 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
   530 see src/HOL/Induct/Common_Patterns.thy, for example.
   531 
   532 * Method "induct": mutual induction rules are now specified as a list
   533 of rule sharing the same induction cases. HOL packages usually provide
   534 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
   535 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
   536 mutual induction rules differently, i.e. like this:
   537 
   538   (induct rule: foo_bar.inducts)
   539   (induct set: foo bar)
   540   (induct pred: foo bar)
   541   (induct type: foo bar)
   542 
   543 The ML function ProjectRule.projections turns old-style rules into the
   544 new format.
   545 
   546 * Method "coinduct": dual of induction, see
   547 src/HOL/Library/Coinductive_List.thy for various examples.
   548 
   549 * Method "cases", "induct", "coinduct": the ``(open)'' option is
   550 considered a legacy feature.
   551 
   552 * Attribute "symmetric" produces result with standardized schematic
   553 variables (index 0).  Potential INCOMPATIBILITY.
   554 
   555 * Simplifier: by default the simplifier trace only shows top level
   556 rewrites now. That is, trace_simp_depth_limit is set to 1 by
   557 default. Thus there is less danger of being flooded by the trace. The
   558 trace indicates where parts have been suppressed.
   559   
   560 * Provers/classical: removed obsolete classical version of elim_format
   561 attribute; classical elim/dest rules are now treated uniformly when
   562 manipulating the claset.
   563 
   564 * Provers/classical: stricter checks to ensure that supplied intro,
   565 dest and elim rules are well-formed; dest and elim rules must have at
   566 least one premise.
   567 
   568 * Provers/classical: attributes dest/elim/intro take an optional
   569 weight argument for the rule (just as the Pure versions).  Weights are
   570 ignored by automated tools, but determine the search order of single
   571 rule steps.
   572 
   573 * Syntax: input syntax now supports dummy variable binding "%_. b",
   574 where the body does not mention the bound variable.  Note that dummy
   575 patterns implicitly depend on their context of bounds, which makes
   576 "{_. _}" match any set comprehension as expected.  Potential
   577 INCOMPATIBILITY -- parse translations need to cope with syntactic
   578 constant "_idtdummy" in the binding position.
   579 
   580 * Syntax: removed obsolete syntactic constant "_K" and its associated
   581 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
   582 for example "A -> B" => "Pi A (%_. B)".
   583 
   584 * Pure: 'class_deps' command visualizes the subclass relation, using
   585 the graph browser tool.
   586 
   587 * Pure: 'print_theory' now suppresses certain internal declarations by
   588 default; use '!' option for full details.
   589 
   590 
   591 *** HOL ***
   592 
   593 * Method "metis" proves goals by applying the Metis general-purpose
   594 resolution prover (see also http://gilith.com/software/metis/).
   595 Examples are in the directory MetisExamples.  WARNING: the
   596 Isabelle/HOL-Metis integration does not yet work properly with
   597 multi-threading.
   598   
   599 * Command 'sledgehammer' invokes external automatic theorem provers as
   600 background processes.  It generates calls to the "metis" method if
   601 successful. These can be pasted into the proof.  Users do not have to
   602 wait for the automatic provers to return.  WARNING: does not really
   603 work with multi-threading.
   604 
   605 * New "auto_quickcheck" feature tests outermost goal statements for
   606 potential counter-examples.  Controlled by ML references
   607 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
   608 5000 milliseconds).  Fails silently if statements is outside of
   609 executable fragment, or any other codgenerator problem occurs.
   610 
   611 * New constant "undefined" with axiom "undefined x = undefined".
   612 
   613 * Added class "HOL.eq", allowing for code generation with polymorphic
   614 equality.
   615 
   616 * Some renaming of class constants due to canonical name prefixing in
   617 the new 'class' package:
   618 
   619     HOL.abs ~> HOL.abs_class.abs
   620     HOL.divide ~> HOL.divide_class.divide
   621     0 ~> HOL.zero_class.zero
   622     1 ~> HOL.one_class.one
   623     op + ~> HOL.plus_class.plus
   624     op - ~> HOL.minus_class.minus
   625     uminus ~> HOL.minus_class.uminus
   626     op * ~> HOL.times_class.times
   627     op < ~> HOL.ord_class.less
   628     op <= > HOL.ord_class.less_eq
   629     Nat.power ~> Power.power_class.power
   630     Nat.size ~> Nat.size_class.size
   631     Numeral.number_of ~> Numeral.number_class.number_of
   632     FixedPoint.Inf ~> Lattices.complete_lattice_class.Inf
   633     FixedPoint.Sup ~> Lattices.complete_lattice_class.Sup
   634     Orderings.min ~> Orderings.ord_class.min
   635     Orderings.max ~> Orderings.ord_class.max
   636     Divides.op div ~> Divides.div_class.div
   637     Divides.op mod ~> Divides.div_class.mod
   638     Divides.op dvd ~> Divides.div_class.dvd
   639 
   640 INCOMPATIBILITY.  Adaptions may be required in the following cases:
   641 
   642 a) User-defined constants using any of the names "plus", "minus",
   643 "times", "less" or "less_eq". The standard syntax translations for
   644 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
   645 names.
   646 
   647 b) Variables named "plus", "minus", "times", "less", "less_eq"
   648 INCOMPATIBILITY: use more specific names.
   649 
   650 c) Permutative equations (e.g. "a + b = b + a")
   651 Since the change of names also changes the order of terms, permutative
   652 rewrite rules may get applied in a different order. Experience shows
   653 that this is rarely the case (only two adaptions in the whole Isabelle
   654 distribution).  INCOMPATIBILITY: rewrite proofs
   655 
   656 d) ML code directly refering to constant names
   657 This in general only affects hand-written proof tactics, simprocs and
   658 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
   659 Consider using @{const_name} antiquotation.
   660 
   661 * New class "default" with associated constant "default".
   662 
   663 * Function "sgn" is now overloaded and available on int, real, complex
   664 (and other numeric types), using class "sgn".  Two possible defs of
   665 sgn are given as equational assumptions in the classes sgn_if and
   666 sgn_div_norm; ordered_idom now also inherits from sgn_if.
   667 INCOMPATIBILITY.
   668 
   669 * Locale "partial_order" now unified with class "order" (cf. theory
   670 Orderings), added parameter "less".  INCOMPATIBILITY.
   671 
   672 * Renamings in classes "order" and "linorder": facts "refl", "trans" and
   673 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
   674 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
   675 
   676 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
   677 changed order of proof goals in instance proofs.
   678 
   679 * The transitivity reasoner for partial and linear orders is set up
   680 for classes "order" and "linorder".  Instances of the reasoner are available
   681 in all contexts importing or interpreting the corresponding locales.
   682 Method "order" invokes the reasoner separately; the reasoner
   683 is also integrated with the Simplifier as a solver.  Diagnostic
   684 command 'print_orders' shows the available instances of the reasoner
   685 in the current context.
   686 
   687 * Localized monotonicity predicate in theory "Orderings"; integrated
   688 lemmas max_of_mono and min_of_mono with this predicate.
   689 INCOMPATIBILITY.
   690 
   691 * Formulation of theorem "dense" changed slightly due to integration
   692 with new class dense_linear_order.
   693 
   694 * Uniform lattice theory development in HOL.
   695 
   696     constants "meet" and "join" now named "inf" and "sup"
   697     constant "Meet" now named "Inf"
   698 
   699     classes "meet_semilorder" and "join_semilorder" now named
   700       "lower_semilattice" and "upper_semilattice"
   701     class "lorder" now named "lattice"
   702     class "comp_lat" now named "complete_lattice"
   703 
   704     Instantiation of lattice classes allows explicit definitions
   705     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
   706 
   707   INCOMPATIBILITY.  Theorem renames:
   708 
   709     meet_left_le            ~> inf_le1
   710     meet_right_le           ~> inf_le2
   711     join_left_le            ~> sup_ge1
   712     join_right_le           ~> sup_ge2
   713     meet_join_le            ~> inf_sup_ord
   714     le_meetI                ~> le_infI
   715     join_leI                ~> le_supI
   716     le_meet                 ~> le_inf_iff
   717     le_join                 ~> ge_sup_conv
   718     meet_idempotent         ~> inf_idem
   719     join_idempotent         ~> sup_idem
   720     meet_comm               ~> inf_commute
   721     join_comm               ~> sup_commute
   722     meet_leI1               ~> le_infI1
   723     meet_leI2               ~> le_infI2
   724     le_joinI1               ~> le_supI1
   725     le_joinI2               ~> le_supI2
   726     meet_assoc              ~> inf_assoc
   727     join_assoc              ~> sup_assoc
   728     meet_left_comm          ~> inf_left_commute
   729     meet_left_idempotent    ~> inf_left_idem
   730     join_left_comm          ~> sup_left_commute
   731     join_left_idempotent    ~> sup_left_idem
   732     meet_aci                ~> inf_aci
   733     join_aci                ~> sup_aci
   734     le_def_meet             ~> le_iff_inf
   735     le_def_join             ~> le_iff_sup
   736     join_absorp2            ~> sup_absorb2
   737     join_absorp1            ~> sup_absorb1
   738     meet_absorp1            ~> inf_absorb1
   739     meet_absorp2            ~> inf_absorb2
   740     meet_join_absorp        ~> inf_sup_absorb
   741     join_meet_absorp        ~> sup_inf_absorb
   742     distrib_join_le         ~> distrib_sup_le
   743     distrib_meet_le         ~> distrib_inf_le
   744 
   745     add_meet_distrib_left   ~> add_inf_distrib_left
   746     add_join_distrib_left   ~> add_sup_distrib_left
   747     is_join_neg_meet        ~> is_join_neg_inf
   748     is_meet_neg_join        ~> is_meet_neg_sup
   749     add_meet_distrib_right  ~> add_inf_distrib_right
   750     add_join_distrib_right  ~> add_sup_distrib_right
   751     add_meet_join_distribs  ~> add_sup_inf_distribs
   752     join_eq_neg_meet        ~> sup_eq_neg_inf
   753     meet_eq_neg_join        ~> inf_eq_neg_sup
   754     add_eq_meet_join        ~> add_eq_inf_sup
   755     meet_0_imp_0            ~> inf_0_imp_0
   756     join_0_imp_0            ~> sup_0_imp_0
   757     meet_0_eq_0             ~> inf_0_eq_0
   758     join_0_eq_0             ~> sup_0_eq_0
   759     neg_meet_eq_join        ~> neg_inf_eq_sup
   760     neg_join_eq_meet        ~> neg_sup_eq_inf
   761     join_eq_if              ~> sup_eq_if
   762 
   763     mono_meet               ~> mono_inf
   764     mono_join               ~> mono_sup
   765     meet_bool_eq            ~> inf_bool_eq
   766     join_bool_eq            ~> sup_bool_eq
   767     meet_fun_eq             ~> inf_fun_eq
   768     join_fun_eq             ~> sup_fun_eq
   769     meet_set_eq             ~> inf_set_eq
   770     join_set_eq             ~> sup_set_eq
   771     meet1_iff               ~> inf1_iff
   772     meet2_iff               ~> inf2_iff
   773     meet1I                  ~> inf1I
   774     meet2I                  ~> inf2I
   775     meet1D1                 ~> inf1D1
   776     meet2D1                 ~> inf2D1
   777     meet1D2                 ~> inf1D2
   778     meet2D2                 ~> inf2D2
   779     meet1E                  ~> inf1E
   780     meet2E                  ~> inf2E
   781     join1_iff               ~> sup1_iff
   782     join2_iff               ~> sup2_iff
   783     join1I1                 ~> sup1I1
   784     join2I1                 ~> sup2I1
   785     join1I1                 ~> sup1I1
   786     join2I2                 ~> sup1I2
   787     join1CI                 ~> sup1CI
   788     join2CI                 ~> sup2CI
   789     join1E                  ~> sup1E
   790     join2E                  ~> sup2E
   791 
   792     is_meet_Meet            ~> is_meet_Inf
   793     Meet_bool_def           ~> Inf_bool_def
   794     Meet_fun_def            ~> Inf_fun_def
   795     Meet_greatest           ~> Inf_greatest
   796     Meet_lower              ~> Inf_lower
   797     Meet_set_def            ~> Inf_set_def
   798 
   799     Sup_def                 ~> Sup_Inf
   800     Sup_bool_eq             ~> Sup_bool_def
   801     Sup_fun_eq              ~> Sup_fun_def
   802     Sup_set_eq              ~> Sup_set_def
   803 
   804     listsp_meetI            ~> listsp_infI
   805     listsp_meet_eq          ~> listsp_inf_eq
   806 
   807     meet_min                ~> inf_min
   808     join_max                ~> sup_max
   809 
   810 * Added syntactic class "size"; overloaded constant "size" now has
   811 type "'a::size ==> bool"
   812 
   813 * Internal reorganisation of `size' of datatypes: size theorems
   814 "foo.size" are no longer subsumed by "foo.simps" (but are still
   815 simplification rules by default!); theorems "prod.size" now named
   816 "*.size".
   817 
   818 * Class "div" now inherits from class "times" rather than "type".
   819 INCOMPATIBILITY.
   820 
   821 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
   822 Linorder etc.  have disappeared; operations defined in terms of
   823 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
   824 
   825 * HOL/Nat: neq0_conv no longer declared as iff.  INCOMPATIBILITY.
   826 
   827 * HOL-Word: New extensive library and type for generic, fixed size
   828 machine words, with arithemtic, bit-wise, shifting and rotating
   829 operations, reflection into int, nat, and bool lists, automation for
   830 linear arithmetic (by automatic reflection into nat or int), including
   831 lemmas on overflow and monotonicity.  Instantiated to all appropriate
   832 arithmetic type classes, supporting automatic simplification of
   833 numerals on all operations.
   834 
   835 * Library/Boolean_Algebra: locales for abstract boolean algebras.
   836 
   837 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
   838 
   839 * Code generator library theories:
   840   - Code_Integer represents HOL integers by big integer literals in target
   841     languages.
   842   - Code_Char represents HOL characters by character literals in target
   843     languages.
   844   - Code_Char_chr like Code_Char, but also offers treatment of character
   845     codes; includes Code_Integer.
   846   - Executable_Set allows to generate code for finite sets using lists.
   847   - Executable_Rat implements rational numbers as triples (sign, enumerator,
   848     denominator).
   849   - Executable_Real implements a subset of real numbers, namly those
   850     representable by rational numbers.
   851   - Efficient_Nat implements natural numbers by integers, which in general will
   852     result in higher efficency; pattern matching with 0/Suc is eliminated;
   853     includes Code_Integer.
   854   - Code_Index provides an additional datatype index which is mapped to
   855     target-language built-in integers.
   856   - Code_Message provides an additional datatype message_string} which is isomorphic to
   857     strings; messages are mapped to target-language strings.
   858 
   859 * New package for inductive predicates
   860 
   861   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
   862 
   863     inductive
   864       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
   865       for z_1 :: U_1 and ... and z_n :: U_m
   866     where
   867       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
   868     | ...
   869 
   870   with full support for type-inference, rather than
   871 
   872     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
   873 
   874     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
   875     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
   876 
   877     inductive "s z_1 ... z_m"
   878     intros
   879       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
   880       ...
   881 
   882   For backward compatibility, there is a wrapper allowing inductive
   883   sets to be defined with the new package via
   884 
   885     inductive_set
   886       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
   887       for z_1 :: U_1 and ... and z_n :: U_m
   888     where
   889       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
   890     | ...
   891 
   892   or
   893 
   894     inductive_set
   895       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
   896       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
   897       for z_1 :: U_1 and ... and z_n :: U_m
   898     where
   899       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
   900     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
   901     | ...
   902 
   903   if the additional syntax "p ..." is required.
   904 
   905   Numerous examples can be found in the subdirectories src/HOL/Auth,
   906   src/HOL/Bali, src/HOL/Induct, and src/HOL/MicroJava.
   907 
   908   INCOMPATIBILITIES:
   909 
   910   - Since declaration and definition of inductive sets or predicates
   911     is no longer separated, abbreviations involving the newly
   912     introduced sets or predicates must be specified together with the
   913     introduction rules after the 'where' keyword (see above), rather
   914     than before the actual inductive definition.
   915 
   916   - The variables in induction and elimination rules are now
   917     quantified in the order of their occurrence in the introduction
   918     rules, rather than in alphabetical order. Since this may break
   919     some proofs, these proofs either have to be repaired, e.g. by
   920     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
   921     statements of the form
   922 
   923       case (rule_i a_i_1 ... a_i_{k_i})
   924 
   925     or the old order of quantification has to be restored by explicitly adding
   926     meta-level quantifiers in the introduction rules, i.e.
   927 
   928       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
   929 
   930   - The format of the elimination rules is now
   931 
   932       p z_1 ... z_m x_1 ... x_n ==>
   933         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
   934         ==> ... ==> P
   935 
   936     for predicates and
   937 
   938       (x_1, ..., x_n) : s z_1 ... z_m ==>
   939         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
   940         ==> ... ==> P
   941 
   942     for sets rather than
   943 
   944       x : s z_1 ... z_m ==>
   945         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
   946         ==> ... ==> P
   947 
   948     This may require terms in goals to be expanded to n-tuples
   949     (e.g. using case_tac or simplification with the split_paired_all
   950     rule) before the above elimination rule is applicable.
   951 
   952   - The elimination or case analysis rules for (mutually) inductive
   953     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
   954     list of rules "p_1_..._p_k.elims" is no longer available.
   955 
   956 * New package "function"/"fun" for general recursive functions,
   957 supporting mutual and nested recursion, definitions in local contexts,
   958 more general pattern matching and partiality. See HOL/ex/Fundefs.thy
   959 for small examples, and the separate tutorial on the function
   960 package. The old recdef "package" is still available as before, but
   961 users are encouraged to use the new package.
   962 
   963 * Method "lexicographic_order" automatically synthesizes termination
   964 relations as lexicographic combinations of size measures. 
   965 
   966 * Case-expressions allow arbitrary constructor-patterns (including
   967 "_") and take their order into account, like in functional
   968 programming.  Internally, this is translated into nested
   969 case-expressions; missing cases are added and mapped to the predefined
   970 constant "undefined". In complicated cases printing may no longer show
   971 the original input but the internal form. Lambda-abstractions allow
   972 the same form of pattern matching: "% pat1 => e1 | ..." is an
   973 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
   974 variable.
   975 
   976 * IntDef: The constant "int :: nat => int" has been removed; now "int"
   977 is an abbreviation for "of_nat :: nat => int". The simplification
   978 rules for "of_nat" have been changed to work like "int" did
   979 previously.  Potential INCOMPATIBILITY:
   980   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
   981   - of_nat_diff and of_nat_mult are no longer default simp rules
   982 
   983 * Method "algebra" solves polynomial equations over (semi)rings using
   984 Groebner bases. The (semi)ring structure is defined by locales and the
   985 tool setup depends on that generic context. Installing the method for
   986 a specific type involves instantiating the locale and possibly adding
   987 declarations for computation on the coefficients.  The method is
   988 already instantiated for natural numbers and for the axiomatic class
   989 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
   990 CALCULEMUS 2007 for the general principles underlying this
   991 architecture of context-aware proof-tools.
   992 
   993 * Method "ferrack" implements quantifier elimination over
   994 special-purpose dense linear orders using locales (analogous to
   995 "algebra"). The method is already installed for class
   996 {ordered_field,recpower,number_ring} which subsumes real, hyperreal,
   997 rat, etc.
   998 
   999 * Former constant "List.op @" now named "List.append".  Use ML
  1000 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
  1001 circumvent possible incompatibilities when working on ML level.
  1002 
  1003 * primrec: missing cases mapped to "undefined" instead of "arbitrary".
  1004 
  1005 * New function listsum :: 'a list => 'a for arbitrary monoids.
  1006 Special syntax: "SUM x <- xs. f x" (and latex variants)
  1007 
  1008 * New syntax for Haskell-like list comprehension (input only), eg.
  1009 [(x,y). x <- xs, y <- ys, x ~= y], see also src/HOL/List.thy.
  1010 
  1011 * The special syntax for function "filter" has changed from [x :
  1012 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
  1013 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
  1014 
  1015 * [a..b] is now defined for arbitrary linear orders.  It used to be
  1016 defined on nat only, as an abbreviation for [a..<Suc b]
  1017 INCOMPATIBILITY.
  1018 
  1019 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
  1020 
  1021 * New functions "sorted" and "sort" in src/HOL/List.thy.
  1022 
  1023 * New lemma collection field_simps (an extension of ring_simps) for
  1024 manipulating (in)equations involving division. Multiplies with all
  1025 denominators that can be proved to be non-zero (in equations) or
  1026 positive/negative (in inequations).
  1027 
  1028 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
  1029 have been improved and renamed to ring_simps, group_simps and
  1030 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
  1031 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
  1032 
  1033 * Theory Library/Commutative_Ring: switched from recdef to function
  1034 package; constants add, mul, pow now curried.  Infix syntax for
  1035 algebraic operations.
  1036 
  1037 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
  1038 INCOMPATIBILITY.
  1039 
  1040 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
  1041 INCOMPATIBILITY.
  1042 
  1043 * HOL/records: generalised field-update to take a function on the
  1044 field rather than the new value: r(|A := x|) is translated to A_update
  1045 (K x) r The K-combinator that is internally used is called K_record.
  1046 INCOMPATIBILITY: Usage of the plain update functions has to be
  1047 adapted.
  1048  
  1049 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
  1050 * x = 0, which are required for a semiring.  Richer structures do not
  1051 inherit from semiring_0 anymore, because this property is a theorem
  1052 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
  1053 there is more to prove, but this is mostly trivial.
  1054 
  1055 * Class "recpower" is generalized to arbitrary monoids, not just
  1056 commutative semirings.  INCOMPATIBILITY: may need to incorporate
  1057 commutativity or semiring properties additionally.
  1058 
  1059 * Constant "List.list_all2" in List.thy now uses authentic syntax.
  1060 INCOMPATIBILITY: translations containing list_all2 may go wrong,
  1061 better use 'abbreviation'.
  1062 
  1063 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
  1064 
  1065 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
  1066 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
  1067 significant changes for setting up numeral syntax for types:
  1068   - New constants Numeral.pred and Numeral.succ instead
  1069       of former Numeral.bin_pred and Numeral.bin_succ.
  1070   - Use integer operations instead of bin_add, bin_mult and so on.
  1071   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
  1072   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
  1073 
  1074 See src/HOL/Integ/IntArith.thy for an example setup.
  1075 
  1076 * Command 'normal_form' computes the normal form of a term that may
  1077 contain free variables.  For example ``normal_form "rev [a, b, c]"''
  1078 produces ``[b, c, a]'' (without proof).  This command is suitable for
  1079 heavy-duty computations because the functions are compiled to ML
  1080 first.  Correspondingly, a method "normalization" is provided.  See
  1081 further src/HOL/ex/NormalForm.thy and src/Tools/nbe.ML.
  1082 
  1083 * Alternative iff syntax "A <-> B" for equality on bool (with priority
  1084 25 like -->); output depends on the "iff" print_mode, the default is
  1085 "A = B" (with priority 50).
  1086 
  1087 * Relations less (<) and less_eq (<=) are also available on type bool.
  1088 Modified syntax to disallow nesting without explicit parentheses,
  1089 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  1090 INCOMPATIBILITY.
  1091 
  1092 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  1093 
  1094 * Relation composition operator "op O" now has precedence 75 and binds
  1095 stronger than union and intersection. INCOMPATIBILITY.
  1096 
  1097 * The old set interval syntax "{m..n(}" (and relatives) has been
  1098 removed.  Use "{m..<n}" (and relatives) instead.
  1099 
  1100 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  1101 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  1102 ``declare [[simproc del: neq]]''.
  1103 
  1104 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  1105 True/False.
  1106 
  1107 * Theorem Cons_eq_map_conv no longer declared as "simp".
  1108 
  1109 * Theorem setsum_mult renamed to setsum_right_distrib.
  1110 
  1111 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  1112 ``rule'' method.
  1113 
  1114 * Reimplemented methods "sat" and "satx", with several improvements:
  1115 goals no longer need to be stated as "<prems> ==> False", equivalences
  1116 (i.e. "=" on type bool) are handled, variable names of the form
  1117 "lit_<n>" are no longer reserved, significant speedup.
  1118 
  1119 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  1120 zChaff is still supported as well.
  1121 
  1122 * 'inductive' and 'datatype': provide projections of mutual rules,
  1123 bundled as foo_bar.inducts;
  1124 
  1125 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  1126 Library.
  1127 
  1128 * Library: moved theory Accessible_Part to main HOL.
  1129 
  1130 * Library: added theory Coinductive_List of potentially infinite lists
  1131 as greatest fixed-point.
  1132 
  1133 * Library: added theory AssocList which implements (finite) maps as
  1134 association lists.
  1135 
  1136 * Method "evaluation" solves goals (i.e. a boolean expression)
  1137 efficiently by compiling it to ML.  The goal is "proved" (via an
  1138 oracle) if it evaluates to True.
  1139 
  1140 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  1141 also when invoked by the simplifier.  This results in the Simplifier
  1142 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  1143 Configuration option fast_arith_split_limit=0 recovers the old
  1144 behavior.
  1145 
  1146 * Support for hex (0x20) and binary (0b1001) numerals.
  1147 
  1148 * New method: reify eqs (t), where eqs are equations for an
  1149 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  1150 parameter, computes a term s::'b and a list xs::'a list and proves the
  1151 theorem I xs s = t. This is also known as reification or quoting. The
  1152 resulting theorem is applied to the subgoal to substitute t with I xs
  1153 s.  If t is omitted, the subgoal itself is reified.
  1154 
  1155 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  1156 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  1157 where f is supposed to be a computable function (in the sense of code
  1158 generattion). The method uses reify to compute s and xs as above then
  1159 applies corr_thm and uses normalization by evaluation to "prove" f s =
  1160 r and finally gets the theorem t = r, which is again applied to the
  1161 subgoal. An Example is available in src/HOL/ex/ReflectionEx.thy.
  1162 
  1163 * Reflection: Automatic reification now handels binding, an example is
  1164 available in src/HOL/ex/ReflectionEx.thy
  1165 
  1166 * HOL-Statespace: ``State Spaces: The Locale Way'' introduces a
  1167 command 'statespace' that is similar to 'record', but introduces an
  1168 abstract specification based on the locale infrastructure instead of
  1169 HOL types.  This leads to extra flexibility in composing state spaces,
  1170 in particular multiple inheritance and renaming of components.
  1171 
  1172 
  1173 *** HOL-Complex ***
  1174 
  1175 * Hyperreal: Functions root and sqrt are now defined on negative real
  1176 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  1177 Nonnegativity side conditions have been removed from many lemmas, so
  1178 that more subgoals may now be solved by simplification; potential
  1179 INCOMPATIBILITY.
  1180 
  1181 * Real: new type classes formalize real normed vector spaces and
  1182 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  1183 and norm :: 'a => real.
  1184 
  1185 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  1186 reals into other types. The overloaded constant Reals :: 'a set is now
  1187 defined as range of_real; potential INCOMPATIBILITY.
  1188 
  1189 * Real: proper support for ML code generation, including 'quickcheck'.
  1190 Reals are implemented as arbitrary precision rationals.
  1191 
  1192 * Hyperreal: Several constants that previously worked only for the
  1193 reals have been generalized, so they now work over arbitrary vector
  1194 spaces. Type annotations may need to be added in some cases; potential
  1195 INCOMPATIBILITY.
  1196 
  1197   Infinitesimal  :: ('a::real_normed_vector) star set
  1198   HFinite        :: ('a::real_normed_vector) star set
  1199   HInfinite      :: ('a::real_normed_vector) star set
  1200   approx         :: ('a::real_normed_vector) star => 'a star => bool
  1201   monad          :: ('a::real_normed_vector) star => 'a star set
  1202   galaxy         :: ('a::real_normed_vector) star => 'a star set
  1203   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  1204   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  1205   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  1206   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  1207   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  1208   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  1209   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  1210   sgn            :: 'a::real_normed_vector => 'a
  1211   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  1212 
  1213 * Complex: Some complex-specific constants are now abbreviations for
  1214 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  1215 hnorm.  Other constants have been entirely removed in favor of the
  1216 polymorphic versions (INCOMPATIBILITY):
  1217 
  1218   approx        <-- capprox
  1219   HFinite       <-- CFinite
  1220   HInfinite     <-- CInfinite
  1221   Infinitesimal <-- CInfinitesimal
  1222   monad         <-- cmonad
  1223   galaxy        <-- cgalaxy
  1224   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  1225   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  1226   (ns)deriv     <-- (ns)cderiv
  1227 
  1228 
  1229 *** HOL-Algebra ***
  1230 
  1231 * Formalisation of ideals and the quotient construction over rings.
  1232 
  1233 * Order and lattice theory no longer based on records.
  1234 INCOMPATIBILITY.
  1235 
  1236 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  1237 greatest_closed.  INCOMPATIBILITY.
  1238 
  1239 * Method algebra is now set up via an attribute.  For examples see
  1240 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  1241 of algebraic structures.
  1242 
  1243 * Renamed theory CRing to Ring.
  1244 
  1245 
  1246 *** HOL-Nominal ***
  1247 
  1248 * Substantial, yet incomplete support for nominal datatypes (binding
  1249 structures) based on HOL-Nominal logic.  See src/HOL/Nominal and
  1250 src/HOL/Nominal/Examples.  Prospective users should consult
  1251 http://isabelle.in.tum.de/nominal/
  1252 
  1253 
  1254 *** ML ***
  1255 
  1256 * ML basics: just one true type int, which coincides with IntInf.int
  1257 (even on SML/NJ).
  1258 
  1259 * ML within Isar: antiquotations allow to embed statically-checked
  1260 formal entities in the source, referring to the context available at
  1261 compile-time.  For example:
  1262 
  1263 ML {* @{sort "{zero,one}"} *}
  1264 ML {* @{typ "'a => 'b"} *}
  1265 ML {* @{term "%x. x"} *}
  1266 ML {* @{prop "x == y"} *}
  1267 ML {* @{ctyp "'a => 'b"} *}
  1268 ML {* @{cterm "%x. x"} *}
  1269 ML {* @{cprop "x == y"} *}
  1270 ML {* @{thm asm_rl} *}
  1271 ML {* @{thms asm_rl} *}
  1272 ML {* @{type_name c} *}
  1273 ML {* @{type_syntax c} *}
  1274 ML {* @{const_name c} *}
  1275 ML {* @{const_syntax c} *}
  1276 ML {* @{context} *}
  1277 ML {* @{theory} *}
  1278 ML {* @{theory Pure} *}
  1279 ML {* @{theory_ref} *}
  1280 ML {* @{theory_ref Pure} *}
  1281 ML {* @{simpset} *}
  1282 ML {* @{claset} *}
  1283 ML {* @{clasimpset} *}
  1284 
  1285 The same works for sources being ``used'' within an Isar context.
  1286 
  1287 * ML in Isar: improved error reporting; extra verbosity with
  1288 ML_Context.trace enabled.
  1289 
  1290 * Pure/General/table.ML: the join operations now works via exceptions
  1291 DUP/SAME instead of type option. This is simpler in simple cases, and
  1292 admits slightly more efficient complex applications.
  1293 
  1294 * Pure: 'advanced' translation functions (parse_translation etc.) now
  1295 use Context.generic instead of just theory.
  1296 
  1297 * Pure: datatype Context.generic joins theory/Proof.context and
  1298 provides some facilities for code that works in either kind of
  1299 context, notably GenericDataFun for uniform theory and proof data.
  1300 
  1301 * Pure: simplified internal attribute type, which is now always
  1302 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  1303 local (Proof.context) attributes have been discontinued, while
  1304 minimizing code duplication. Thm.rule_attribute and
  1305 Thm.declaration_attribute build canonical attributes; see also structure
  1306 Context for further operations on Context.generic, notably
  1307 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  1308 declarations and definitions.
  1309 
  1310 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  1311 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  1312 init only required for impure data. INCOMPATIBILITY: empty really need
  1313 to be empty (no dependencies on theory content!)
  1314 
  1315 * Pure/kernel: consts certification ignores sort constraints given in
  1316 signature declarations. (This information is not relevant to the
  1317 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  1318 potential INCOMPATIBILITY.
  1319 
  1320 * Pure: axiomatic type classes are now purely definitional, with
  1321 explicit proofs of class axioms and super class relations performed
  1322 internally. See Pure/axclass.ML for the main internal interfaces --
  1323 notably AxClass.define_class supercedes AxClass.add_axclass, and
  1324 AxClass.axiomatize_class/classrel/arity supersede
  1325 Sign.add_classes/classrel/arities.
  1326 
  1327 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  1328 global/local versions on theory vs. Proof.context have been
  1329 discontinued; Attrib.syntax and Method.syntax have been adapted
  1330 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  1331 attributes, methods, etc.
  1332 
  1333 * Pure: several functions of signature "... -> theory -> theory * ..."
  1334 have been reoriented to "... -> theory -> ... * theory" in order to
  1335 allow natural usage in combination with the ||>, ||>>, |-> and
  1336 fold_map combinators.
  1337 
  1338 * Pure: official theorem names (closed derivations) and additional
  1339 comments (tags) are now strictly separate.  Name hints -- which are
  1340 maintained as tags -- may be attached any time without affecting the
  1341 derivation.
  1342 
  1343 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  1344 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  1345 achieve the old behaviour.
  1346 
  1347 * Pure: the "Goal" constant is now called "prop", supporting a
  1348 slightly more general idea of ``protecting'' meta-level rule
  1349 statements.
  1350 
  1351 * Pure: Logic.(un)varify only works in a global context, which is now
  1352 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  1353 Logic.legacy_(un)varify as temporary workaround.
  1354 
  1355 * Pure: structure Name provides scalable operations for generating
  1356 internal variable names, notably Name.variants etc.  This replaces
  1357 some popular functions from term.ML:
  1358 
  1359   Term.variant		->  Name.variant
  1360   Term.variantlist	->  Name.variant_list
  1361   Term.invent_names	->  Name.invent_list
  1362 
  1363 Note that low-level renaming rarely occurs in new code -- operations
  1364 from structure Variable are used instead (see below).
  1365 
  1366 * Pure: structure Variable provides fundamental operations for proper
  1367 treatment of fixed/schematic variables in a context.  For example,
  1368 Variable.import introduces fixes for schematics of given facts and
  1369 Variable.export reverses the effect (up to renaming) -- this replaces
  1370 various freeze_thaw operations.
  1371 
  1372 * Pure: structure Goal provides simple interfaces for
  1373 init/conclude/finish and tactical prove operations (replacing former
  1374 Tactic.prove).  Goal.prove is the canonical way to prove results
  1375 within a given context; Goal.prove_global is a degraded version for
  1376 theory level goals, including a global Drule.standard.  Note that
  1377 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  1378 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  1379 in a locale context).
  1380 
  1381 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  1382 and type checking (Syntax.check_term etc.), with common combinations
  1383 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  1384 which are considered legacy and await removal.
  1385 
  1386 * Pure/Syntax: generic interfaces for type unchecking
  1387 (Syntax.uncheck_terms etc.) and unparsing (Syntax.unparse_term etc.),
  1388 with common combinations (Syntax.pretty_term, Syntax.string_of_term
  1389 etc.).  Former Sign.pretty_term, Sign.string_of_term etc. are still
  1390 available for convenience, but refer to the very same operations using
  1391 a mere theory instead of a full context.
  1392 
  1393 * Isar: simplified treatment of user-level errors, using exception
  1394 ERROR of string uniformly.  Function error now merely raises ERROR,
  1395 without any side effect on output channels.  The Isar toplevel takes
  1396 care of proper display of ERROR exceptions.  ML code may use plain
  1397 handle/can/try; cat_error may be used to concatenate errors like this:
  1398 
  1399   ... handle ERROR msg => cat_error msg "..."
  1400 
  1401 Toplevel ML code (run directly or through the Isar toplevel) may be
  1402 embedded into the Isar toplevel with exception display/debug like
  1403 this:
  1404 
  1405   Isar.toplevel (fn () => ...)
  1406 
  1407 INCOMPATIBILITY, removed special transform_error facilities, removed
  1408 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  1409 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  1410 -- use plain ERROR instead.
  1411 
  1412 * Isar: theory setup now has type (theory -> theory), instead of a
  1413 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  1414 
  1415 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  1416 ProofContext.debug/verbose flags.
  1417 
  1418 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  1419 theory before entering a proof state.  Transactions now always see a
  1420 quasi-functional intermediate checkpoint, both in interactive and
  1421 batch mode.
  1422 
  1423 * Isar: simplified interfaces for outer syntax.  Renamed
  1424 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  1425 OuterSyntax.add_parsers -- this functionality is now included in
  1426 OuterSyntax.command etc.  INCOMPATIBILITY.
  1427 
  1428 * Simplifier: the simpset of a running simplification process now
  1429 contains a proof context (cf. Simplifier.the_context), which is the
  1430 very context that the initial simpset has been retrieved from (by
  1431 simpset_of/local_simpset_of).  Consequently, all plug-in components
  1432 (solver, looper etc.) may depend on arbitrary proof data.
  1433 
  1434 * Simplifier.inherit_context inherits the proof context (plus the
  1435 local bounds) of the current simplification process; any simproc
  1436 etc. that calls the Simplifier recursively should do this!  Removed
  1437 former Simplifier.inherit_bounds, which is already included here --
  1438 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  1439 specify an explicit context using Simplifier.context/theory_context.
  1440 
  1441 * Simplifier/Classical Reasoner: more abstract interfaces
  1442 change_simpset/claset for modifying the simpset/claset reference of a
  1443 theory; raw versions simpset/claset_ref etc. have been discontinued --
  1444 INCOMPATIBILITY.
  1445 
  1446 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  1447 "Trueprop" etc.
  1448 
  1449 
  1450 *** System ***
  1451 
  1452 * settings: the default heap location within ISABELLE_HOME_USER now
  1453 includes ISABELLE_IDENTIFIER.  This simplifies use of multiple
  1454 Isabelle installations.
  1455 
  1456 * isabelle-process: option -S (secure mode) disables some critical
  1457 operations, notably runtime compilation and evaluation of ML source
  1458 code.
  1459 
  1460 * Basic Isabelle mode for jEdit, see Isabelle/lib/jedit/.
  1461 
  1462 * Support for parallel execution, using native multicore support of
  1463 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  1464 independent theories, according to the given theory header
  1465 specifications. The maximum number of worker threads is specified via
  1466 usedir option -M or the "max-threads" setting in Proof General. A
  1467 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  1468 to 6 on a 8-core machine.  User-code needs to observe certain
  1469 guidelines for thread-safe programming, see appendix A in the Isar
  1470 Implementation manual.
  1471 
  1472 
  1473 
  1474 New in Isabelle2005 (October 2005)
  1475 ----------------------------------
  1476 
  1477 *** General ***
  1478 
  1479 * Theory headers: the new header syntax for Isar theories is
  1480 
  1481   theory <name>
  1482   imports <theory1> ... <theoryN>
  1483   uses <file1> ... <fileM>
  1484   begin
  1485 
  1486 where the 'uses' part is optional.  The previous syntax
  1487 
  1488   theory <name> = <theory1> + ... + <theoryN>:
  1489 
  1490 will disappear in the next release.  Use isatool fixheaders to convert
  1491 existing theory files.  Note that there is no change in ancient
  1492 non-Isar theories now, but these will disappear soon.
  1493 
  1494 * Theory loader: parent theories can now also be referred to via
  1495 relative and absolute paths.
  1496 
  1497 * Command 'find_theorems' searches for a list of criteria instead of a
  1498 list of constants. Known criteria are: intro, elim, dest, name:string,
  1499 simp:term, and any term. Criteria can be preceded by '-' to select
  1500 theorems that do not match. Intro, elim, dest select theorems that
  1501 match the current goal, name:s selects theorems whose fully qualified
  1502 name contain s, and simp:term selects all simplification rules whose
  1503 lhs match term.  Any other term is interpreted as pattern and selects
  1504 all theorems matching the pattern. Available in ProofGeneral under
  1505 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  1506 
  1507   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  1508 
  1509 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  1510 matching the current goal as introduction rule and not having "HOL."
  1511 in their name (i.e. not being defined in theory HOL).
  1512 
  1513 * Command 'thms_containing' has been discontinued in favour of
  1514 'find_theorems'; INCOMPATIBILITY.
  1515 
  1516 * Communication with Proof General is now 8bit clean, which means that
  1517 Unicode text in UTF-8 encoding may be used within theory texts (both
  1518 formal and informal parts).  Cf. option -U of the Isabelle Proof
  1519 General interface.  Here are some simple examples (cf. src/HOL/ex):
  1520 
  1521   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  1522   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  1523 
  1524 * Improved efficiency of the Simplifier and, to a lesser degree, the
  1525 Classical Reasoner.  Typical big applications run around 2 times
  1526 faster.
  1527 
  1528 
  1529 *** Document preparation ***
  1530 
  1531 * Commands 'display_drafts' and 'print_drafts' perform simple output
  1532 of raw sources.  Only those symbols that do not require additional
  1533 LaTeX packages (depending on comments in isabellesym.sty) are
  1534 displayed properly, everything else is left verbatim.  isatool display
  1535 and isatool print are used as front ends (these are subject to the
  1536 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  1537 
  1538 * Command tags control specific markup of certain regions of text,
  1539 notably folding and hiding.  Predefined tags include "theory" (for
  1540 theory begin and end), "proof" for proof commands, and "ML" for
  1541 commands involving ML code; the additional tags "visible" and
  1542 "invisible" are unused by default.  Users may give explicit tag
  1543 specifications in the text, e.g. ''by %invisible (auto)''.  The
  1544 interpretation of tags is determined by the LaTeX job during document
  1545 preparation: see option -V of isatool usedir, or options -n and -t of
  1546 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  1547 \isadroptag.
  1548 
  1549 Several document versions may be produced at the same time via isatool
  1550 usedir (the generated index.html will link all of them).  Typical
  1551 specifications include ''-V document=theory,proof,ML'' to present
  1552 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  1553 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  1554 these parts without any formal replacement text.  The Isabelle site
  1555 default settings produce ''document'' and ''outline'' versions as
  1556 specified above.
  1557 
  1558 * Several new antiquotations:
  1559 
  1560   @{term_type term} prints a term with its type annotated;
  1561 
  1562   @{typeof term} prints the type of a term;
  1563 
  1564   @{const const} is the same as @{term const}, but checks that the
  1565   argument is a known logical constant;
  1566 
  1567   @{term_style style term} and @{thm_style style thm} print a term or
  1568   theorem applying a "style" to it
  1569 
  1570   @{ML text}
  1571 
  1572 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  1573 definitions, equations, inequations etc., 'concl' printing only the
  1574 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  1575 to print the specified premise.  TermStyle.add_style provides an ML
  1576 interface for introducing further styles.  See also the "LaTeX Sugar"
  1577 document practical applications.  The ML antiquotation prints
  1578 type-checked ML expressions verbatim.
  1579 
  1580 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  1581 and 'text' support optional locale specification '(in loc)', which
  1582 specifies the default context for interpreting antiquotations.  For
  1583 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  1584 
  1585 * Option 'locale=NAME' of antiquotations specifies an alternative
  1586 context interpreting the subsequent argument.  For example: @{thm
  1587 [locale=lattice] inf_assoc}.
  1588 
  1589 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  1590 a proof context.
  1591 
  1592 * Proper output of antiquotations for theory commands involving a
  1593 proof context (such as 'locale' or 'theorem (in loc) ...').
  1594 
  1595 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  1596 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  1597 
  1598 * isatool usedir: new option -C (default true) controls whether option
  1599 -D should include a copy of the original document directory; -C false
  1600 prevents unwanted effects such as copying of administrative CVS data.
  1601 
  1602 
  1603 *** Pure ***
  1604 
  1605 * Considerably improved version of 'constdefs' command.  Now performs
  1606 automatic type-inference of declared constants; additional support for
  1607 local structure declarations (cf. locales and HOL records), see also
  1608 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  1609 sequential dependencies of definitions within a single 'constdefs'
  1610 section; moreover, the declared name needs to be an identifier.  If
  1611 all fails, consider to fall back on 'consts' and 'defs' separately.
  1612 
  1613 * Improved indexed syntax and implicit structures.  First of all,
  1614 indexed syntax provides a notational device for subscripted
  1615 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  1616 expressions.  Secondly, in a local context with structure
  1617 declarations, number indexes \<^sub>n or the empty index (default
  1618 number 1) refer to a certain fixed variable implicitly; option
  1619 show_structs controls printing of implicit structures.  Typical
  1620 applications of these concepts involve record types and locales.
  1621 
  1622 * New command 'no_syntax' removes grammar declarations (and
  1623 translations) resulting from the given syntax specification, which is
  1624 interpreted in the same manner as for the 'syntax' command.
  1625 
  1626 * 'Advanced' translation functions (parse_translation etc.) may depend
  1627 on the signature of the theory context being presently used for
  1628 parsing/printing, see also isar-ref manual.
  1629 
  1630 * Improved 'oracle' command provides a type-safe interface to turn an
  1631 ML expression of type theory -> T -> term into a primitive rule of
  1632 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  1633 is already included here); see also FOL/ex/IffExample.thy;
  1634 INCOMPATIBILITY.
  1635 
  1636 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  1637 before); "cI" is no longer bound, use "c.intro" instead.
  1638 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  1639 axclasses vs. locales.
  1640 
  1641 * Improved internal renaming of symbolic identifiers -- attach primes
  1642 instead of base 26 numbers.
  1643 
  1644 * New flag show_question_marks controls printing of leading question
  1645 marks in schematic variable names.
  1646 
  1647 * In schematic variable names, *any* symbol following \<^isub> or
  1648 \<^isup> is now treated as part of the base name.  For example, the
  1649 following works without printing of awkward ".0" indexes:
  1650 
  1651   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  1652     by simp
  1653 
  1654 * Inner syntax includes (*(*nested*) comments*).
  1655 
  1656 * Pretty printer now supports unbreakable blocks, specified in mixfix
  1657 annotations as "(00...)".
  1658 
  1659 * Clear separation of logical types and nonterminals, where the latter
  1660 may only occur in 'syntax' specifications or type abbreviations.
  1661 Before that distinction was only partially implemented via type class
  1662 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  1663 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  1664 exotic syntax specifications may require further adaption
  1665 (e.g. Cube/Cube.thy).
  1666 
  1667 * Removed obsolete type class "logic", use the top sort {} instead.
  1668 Note that non-logical types should be declared as 'nonterminals'
  1669 rather than 'types'.  INCOMPATIBILITY for new object-logic
  1670 specifications.
  1671 
  1672 * Attributes 'induct' and 'cases': type or set names may now be
  1673 locally fixed variables as well.
  1674 
  1675 * Simplifier: can now control the depth to which conditional rewriting
  1676 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  1677 Limit.
  1678 
  1679 * Simplifier: simplification procedures may now take the current
  1680 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  1681 interface), which is very useful for calling the Simplifier
  1682 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  1683 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  1684 low-level mk_simproc no longer applies Logic.varify internally, to
  1685 allow for use in a context of fixed variables.
  1686 
  1687 * thin_tac now works even if the assumption being deleted contains !!
  1688 or ==>.  More generally, erule now works even if the major premise of
  1689 the elimination rule contains !! or ==>.
  1690 
  1691 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  1692 
  1693 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  1694 from Pure, which contains all common declarations already.  Both
  1695 theories are defined via plain Isabelle/Isar .thy files.
  1696 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  1697 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  1698 use isatool fixcpure to adapt your theory and ML sources.
  1699 
  1700 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  1701 selections of theorems in named facts via index ranges.
  1702 
  1703 * 'print_theorems': in theory mode, really print the difference
  1704 wrt. the last state (works for interactive theory development only),
  1705 in proof mode print all local facts (cf. 'print_facts');
  1706 
  1707 * 'hide': option '(open)' hides only base names.
  1708 
  1709 * More efficient treatment of intermediate checkpoints in interactive
  1710 theory development.
  1711 
  1712 * Code generator is now invoked via code_module (incremental code
  1713 generation) and code_library (modular code generation, ML structures
  1714 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  1715 must be quoted when used as identifiers.
  1716 
  1717 * New 'value' command for reading, evaluating and printing terms using
  1718 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  1719 quoted when used as identifier.
  1720 
  1721 
  1722 *** Locales ***
  1723 
  1724 * New commands for the interpretation of locale expressions in
  1725 theories (1), locales (2) and proof contexts (3).  These generate
  1726 proof obligations from the expression specification.  After the
  1727 obligations have been discharged, theorems of the expression are added
  1728 to the theory, target locale or proof context.  The synopsis of the
  1729 commands is a follows:
  1730 
  1731   (1) interpretation expr inst
  1732   (2) interpretation target < expr
  1733   (3) interpret expr inst
  1734 
  1735 Interpretation in theories and proof contexts require a parameter
  1736 instantiation of terms from the current context.  This is applied to
  1737 specifications and theorems of the interpreted expression.
  1738 Interpretation in locales only permits parameter renaming through the
  1739 locale expression.  Interpretation is smart in that interpretations
  1740 that are active already do not occur in proof obligations, neither are
  1741 instantiated theorems stored in duplicate.  Use 'print_interps' to
  1742 inspect active interpretations of a particular locale.  For details,
  1743 see the Isar Reference manual.  Examples can be found in
  1744 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  1745 
  1746 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  1747 'interpret' instead.
  1748 
  1749 * New context element 'constrains' for adding type constraints to
  1750 parameters.
  1751 
  1752 * Context expressions: renaming of parameters with syntax
  1753 redeclaration.
  1754 
  1755 * Locale declaration: 'includes' disallowed.
  1756 
  1757 * Proper static binding of attribute syntax -- i.e. types / terms /
  1758 facts mentioned as arguments are always those of the locale definition
  1759 context, independently of the context of later invocations.  Moreover,
  1760 locale operations (renaming and type / term instantiation) are applied
  1761 to attribute arguments as expected.
  1762 
  1763 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  1764 actual attributes; rare situations may require Attrib.attribute to
  1765 embed those attributes into Attrib.src that lack concrete syntax.
  1766 Attribute implementations need to cooperate properly with the static
  1767 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  1768 Attrib.XXX_thm etc. already do the right thing without further
  1769 intervention.  Only unusual applications -- such as "where" or "of"
  1770 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  1771 on the context and the facts involved -- may have to assign parsed
  1772 values to argument tokens explicitly.
  1773 
  1774 * Changed parameter management in theorem generation for long goal
  1775 statements with 'includes'.  INCOMPATIBILITY: produces a different
  1776 theorem statement in rare situations.
  1777 
  1778 * Locale inspection command 'print_locale' omits notes elements.  Use
  1779 'print_locale!' to have them included in the output.
  1780 
  1781 
  1782 *** Provers ***
  1783 
  1784 * Provers/hypsubst.ML: improved version of the subst method, for
  1785 single-step rewriting: it now works in bound variable contexts. New is
  1786 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  1787 rewrite a different subterm than the original subst method, which is
  1788 still available as 'simplesubst'.
  1789 
  1790 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  1791 and quasi orders.
  1792 
  1793 * Provers/trancl.ML: new transitivity reasoner for transitive and
  1794 reflexive-transitive closure of relations.
  1795 
  1796 * Provers/blast.ML: new reference depth_limit to make blast's depth
  1797 limit (previously hard-coded with a value of 20) user-definable.
  1798 
  1799 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  1800 is peformed already.  Object-logics merely need to finish their
  1801 initial simpset configuration as before.  INCOMPATIBILITY.
  1802 
  1803 
  1804 *** HOL ***
  1805 
  1806 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  1807 
  1808   syntax (epsilon)
  1809     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  1810 
  1811 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  1812 and x-symbol; use option '-m epsilon' to get it actually printed.
  1813 Moreover, the mathematically important symbolic identifier \<epsilon>
  1814 becomes available as variable, constant etc.  INCOMPATIBILITY,
  1815 
  1816 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  1817 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  1818 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  1819 support corresponding Isar calculations.
  1820 
  1821 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  1822 instead of ":".
  1823 
  1824 * theory SetInterval: changed the syntax for open intervals:
  1825 
  1826   Old       New
  1827   {..n(}    {..<n}
  1828   {)n..}    {n<..}
  1829   {m..n(}   {m..<n}
  1830   {)m..n}   {m<..n}
  1831   {)m..n(}  {m<..<n}
  1832 
  1833 The old syntax is still supported but will disappear in the next
  1834 release.  For conversion use the following Emacs search and replace
  1835 patterns (these are not perfect but work quite well):
  1836 
  1837   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  1838   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  1839 
  1840 * Theory Commutative_Ring (in Library): method comm_ring for proving
  1841 equalities in commutative rings; method 'algebra' provides a generic
  1842 interface.
  1843 
  1844 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  1845 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  1846 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  1847 be a tuple pattern.
  1848 
  1849 Some new syntax forms are available:
  1850 
  1851   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  1852   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  1853   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  1854   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  1855 
  1856 The latter form "\<Sum>x < k. e" used to be based on a separate
  1857 function "Summation", which has been discontinued.
  1858 
  1859 * theory Finite_Set: in structured induction proofs, the insert case
  1860 is now 'case (insert x F)' instead of the old counterintuitive 'case
  1861 (insert F x)'.
  1862 
  1863 * The 'refute' command has been extended to support a much larger
  1864 fragment of HOL, including axiomatic type classes, constdefs and
  1865 typedefs, inductive datatypes and recursion.
  1866 
  1867 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  1868 Requires zChaff with proof generation to be installed.  See
  1869 HOL/ex/SAT_Examples.thy for examples.
  1870 
  1871 * Datatype induction via method 'induct' now preserves the name of the
  1872 induction variable. For example, when proving P(xs::'a list) by
  1873 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  1874 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  1875 in unstructured proof scripts.
  1876 
  1877 * Reworked implementation of records.  Improved scalability for
  1878 records with many fields, avoiding performance problems for type
  1879 inference. Records are no longer composed of nested field types, but
  1880 of nested extension types. Therefore the record type only grows linear
  1881 in the number of extensions and not in the number of fields.  The
  1882 top-level (users) view on records is preserved.  Potential
  1883 INCOMPATIBILITY only in strange cases, where the theory depends on the
  1884 old record representation. The type generated for a record is called
  1885 <record_name>_ext_type.
  1886 
  1887 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  1888 proofs triggered by a record definition or a simproc (if
  1889 quick_and_dirty is enabled).  Definitions of large records can take
  1890 quite long.
  1891 
  1892 New simproc record_upd_simproc for simplification of multiple record
  1893 updates enabled by default.  Moreover, trivial updates are also
  1894 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  1895 occasionally, since simplification is more powerful by default.
  1896 
  1897 * typedef: proper support for polymorphic sets, which contain extra
  1898 type-variables in the term.
  1899 
  1900 * Simplifier: automatically reasons about transitivity chains
  1901 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  1902 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  1903 old proofs break occasionally as simplification may now solve more
  1904 goals than previously.
  1905 
  1906 * Simplifier: converts x <= y into x = y if assumption y <= x is
  1907 present.  Works for all partial orders (class "order"), in particular
  1908 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  1909 just like y <= x.
  1910 
  1911 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  1912 bound variable or a constant then the let is unfolded.  Otherwise
  1913 first a is simplified to b, and then f b is simplified to g. If
  1914 possible we abstract b from g arriving at "let x = b in h x",
  1915 otherwise we unfold the let and arrive at g.  The simproc can be
  1916 enabled/disabled by the reference use_let_simproc.  Potential
  1917 INCOMPATIBILITY since simplification is more powerful by default.
  1918 
  1919 * Classical reasoning: the meson method now accepts theorems as arguments.
  1920 
  1921 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  1922 jobs to provide advice on the provability of subgoals.
  1923 
  1924 * Theory OrderedGroup and Ring_and_Field: various additions and
  1925 improvements to faciliate calculations involving equalities and
  1926 inequalities.
  1927 
  1928 The following theorems have been eliminated or modified
  1929 (INCOMPATIBILITY):
  1930 
  1931   abs_eq             now named abs_of_nonneg
  1932   abs_of_ge_0        now named abs_of_nonneg
  1933   abs_minus_eq       now named abs_of_nonpos
  1934   imp_abs_id         now named abs_of_nonneg
  1935   imp_abs_neg_id     now named abs_of_nonpos
  1936   mult_pos           now named mult_pos_pos
  1937   mult_pos_le        now named mult_nonneg_nonneg
  1938   mult_pos_neg_le    now named mult_nonneg_nonpos
  1939   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  1940   mult_neg           now named mult_neg_neg
  1941   mult_neg_le        now named mult_nonpos_nonpos
  1942 
  1943 * The following lemmas in Ring_and_Field have been added to the simplifier:
  1944      
  1945      zero_le_square
  1946      not_square_less_zero 
  1947 
  1948   The following lemmas have been deleted from Real/RealPow:
  1949   
  1950      realpow_zero_zero
  1951      realpow_two
  1952      realpow_less
  1953      zero_le_power
  1954      realpow_two_le
  1955      abs_realpow_two
  1956      realpow_two_abs     
  1957 
  1958 * Theory Parity: added rules for simplifying exponents.
  1959 
  1960 * Theory List:
  1961 
  1962 The following theorems have been eliminated or modified
  1963 (INCOMPATIBILITY):
  1964 
  1965   list_all_Nil       now named list_all.simps(1)
  1966   list_all_Cons      now named list_all.simps(2)
  1967   list_all_conv      now named list_all_iff
  1968   set_mem_eq         now named mem_iff
  1969 
  1970 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  1971 asymptotic "big O" calculations.  See the notes in BigO.thy.
  1972 
  1973 
  1974 *** HOL-Complex ***
  1975 
  1976 * Theory RealDef: better support for embedding natural numbers and
  1977 integers in the reals.
  1978 
  1979 The following theorems have been eliminated or modified
  1980 (INCOMPATIBILITY):
  1981 
  1982   exp_ge_add_one_self  now requires no hypotheses
  1983   real_of_int_add      reversed direction of equality (use [symmetric])
  1984   real_of_int_minus    reversed direction of equality (use [symmetric])
  1985   real_of_int_diff     reversed direction of equality (use [symmetric])
  1986   real_of_int_mult     reversed direction of equality (use [symmetric])
  1987 
  1988 * Theory RComplete: expanded support for floor and ceiling functions.
  1989 
  1990 * Theory Ln is new, with properties of the natural logarithm
  1991 
  1992 * Hyperreal: There is a new type constructor "star" for making
  1993 nonstandard types.  The old type names are now type synonyms:
  1994 
  1995   hypreal = real star
  1996   hypnat = nat star
  1997   hcomplex = complex star
  1998 
  1999 * Hyperreal: Many groups of similarly-defined constants have been
  2000 replaced by polymorphic versions (INCOMPATIBILITY):
  2001 
  2002   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  2003 
  2004   starset      <-- starsetNat, starsetC
  2005   *s*          <-- *sNat*, *sc*
  2006   starset_n    <-- starsetNat_n, starsetC_n
  2007   *sn*         <-- *sNatn*, *scn*
  2008   InternalSets <-- InternalNatSets, InternalCSets
  2009 
  2010   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  2011   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  2012   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  2013   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  2014   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  2015 
  2016 * Hyperreal: Many type-specific theorems have been removed in favor of
  2017 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  2018 
  2019   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  2020   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  2021   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  2022   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  2023   right_minus <-- hypreal_add_minus
  2024   left_minus <-- {hypreal,hcomplex}_add_minus_left
  2025   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  2026   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  2027   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  2028   mult_1_right <-- hcomplex_mult_one_right
  2029   mult_zero_left <-- hcomplex_mult_zero_left
  2030   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  2031   right_distrib <-- hypnat_add_mult_distrib2
  2032   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  2033   right_inverse <-- hypreal_mult_inverse
  2034   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  2035   order_refl <-- {hypreal,hypnat}_le_refl
  2036   order_trans <-- {hypreal,hypnat}_le_trans
  2037   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  2038   order_less_le <-- {hypreal,hypnat}_less_le
  2039   linorder_linear <-- {hypreal,hypnat}_le_linear
  2040   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  2041   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  2042   add_nonneg_nonneg <-- hypreal_le_add_order
  2043 
  2044 * Hyperreal: Separate theorems having to do with type-specific
  2045 versions of constants have been merged into theorems that apply to the
  2046 new polymorphic constants (INCOMPATIBILITY):
  2047 
  2048   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  2049   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  2050   STAR_Un <-- {STAR,NatStar,STARC}_Un
  2051   STAR_Int <-- {STAR,NatStar,STARC}_Int
  2052   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  2053   STAR_subset <-- {STAR,NatStar,STARC}_subset
  2054   STAR_mem <-- {STAR,NatStar,STARC}_mem
  2055   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  2056   STAR_diff <-- {STAR,STARC}_diff
  2057   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  2058     STARC_hcomplex_of_complex}_image_subset
  2059   starset_n_Un <-- starset{Nat,C}_n_Un
  2060   starset_n_Int <-- starset{Nat,C}_n_Int
  2061   starset_n_Compl <-- starset{Nat,C}_n_Compl
  2062   starset_n_diff <-- starset{Nat,C}_n_diff
  2063   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  2064   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  2065   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  2066   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  2067   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  2068   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  2069   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  2070   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  2071   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  2072   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  2073   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  2074   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  2075   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  2076   starfun_diff <-- starfun{C,RC,CR}_diff
  2077   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  2078   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  2079   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  2080   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  2081   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  2082   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  2083   starfun_Id <-- starfunC_Id
  2084   starfun_approx <-- starfun{Nat,CR}_approx
  2085   starfun_capprox <-- starfun{C,RC}_capprox
  2086   starfun_abs <-- starfunNat_rabs
  2087   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  2088   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  2089   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  2090   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  2091   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  2092   starfun_add_approx <-- starfunCR_add_approx
  2093   starfun_inverse_inverse <-- starfunC_inverse_inverse
  2094   starfun_divide <-- starfun{C,CR,RC}_divide
  2095   starfun_n <-- starfun{Nat,C}_n
  2096   starfun_n_mult <-- starfun{Nat,C}_n_mult
  2097   starfun_n_add <-- starfun{Nat,C}_n_add
  2098   starfun_n_add_minus <-- starfunNat_n_add_minus
  2099   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  2100   starfun_n_minus <-- starfun{Nat,C}_n_minus
  2101   starfun_n_eq <-- starfun{Nat,C}_n_eq
  2102 
  2103   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  2104   star_n_minus <-- {hypreal,hcomplex}_minus
  2105   star_n_diff <-- {hypreal,hcomplex}_diff
  2106   star_n_mult <-- {hypreal,hcomplex}_mult
  2107   star_n_inverse <-- {hypreal,hcomplex}_inverse
  2108   star_n_le <-- {hypreal,hypnat}_le
  2109   star_n_less <-- {hypreal,hypnat}_less
  2110   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  2111   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  2112   star_n_abs <-- hypreal_hrabs
  2113   star_n_divide <-- hcomplex_divide
  2114 
  2115   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  2116   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  2117   star_of_diff <-- hypreal_of_real_diff
  2118   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  2119   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  2120   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  2121   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  2122   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  2123   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  2124   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  2125   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  2126   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  2127   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  2128   star_of_number_of <-- {hypreal,hcomplex}_number_of
  2129   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  2130   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  2131   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  2132   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  2133   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  2134   star_of_power <-- hypreal_of_real_power
  2135   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  2136 
  2137 * Hyperreal: new method "transfer" that implements the transfer
  2138 principle of nonstandard analysis. With a subgoal that mentions
  2139 nonstandard types like "'a star", the command "apply transfer"
  2140 replaces it with an equivalent one that mentions only standard types.
  2141 To be successful, all free variables must have standard types; non-
  2142 standard variables must have explicit universal quantifiers.
  2143 
  2144 * Hyperreal: A theory of Taylor series.
  2145 
  2146 
  2147 *** HOLCF ***
  2148 
  2149 * Discontinued special version of 'constdefs' (which used to support
  2150 continuous functions) in favor of the general Pure one with full
  2151 type-inference.
  2152 
  2153 * New simplification procedure for solving continuity conditions; it
  2154 is much faster on terms with many nested lambda abstractions (cubic
  2155 instead of exponential time).
  2156 
  2157 * New syntax for domain package: selector names are now optional.
  2158 Parentheses should be omitted unless argument is lazy, for example:
  2159 
  2160   domain 'a stream = cons "'a" (lazy "'a stream")
  2161 
  2162 * New command 'fixrec' for defining recursive functions with pattern
  2163 matching; defining multiple functions with mutual recursion is also
  2164 supported.  Patterns may include the constants cpair, spair, up, sinl,
  2165 sinr, or any data constructor defined by the domain package. The given
  2166 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  2167 syntax and examples.
  2168 
  2169 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  2170 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  2171 but the proof obligation additionally includes an admissibility
  2172 requirement. The packages generate instances of class cpo or pcpo,
  2173 with continuity and strictness theorems for Rep and Abs.
  2174 
  2175 * HOLCF: Many theorems have been renamed according to a more standard naming
  2176 scheme (INCOMPATIBILITY):
  2177 
  2178   foo_inject:  "foo$x = foo$y ==> x = y"
  2179   foo_eq:      "(foo$x = foo$y) = (x = y)"
  2180   foo_less:    "(foo$x << foo$y) = (x << y)"
  2181   foo_strict:  "foo$UU = UU"
  2182   foo_defined: "... ==> foo$x ~= UU"
  2183   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  2184 
  2185 
  2186 *** ZF ***
  2187 
  2188 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  2189 including the First Isomorphism Theorem (on quotienting by the kernel
  2190 of a homomorphism).
  2191 
  2192 * ZF/Simplifier: install second copy of type solver that actually
  2193 makes use of TC rules declared to Isar proof contexts (or locales);
  2194 the old version is still required for ML proof scripts.
  2195 
  2196 
  2197 *** Cube ***
  2198 
  2199 * Converted to Isar theory format; use locales instead of axiomatic
  2200 theories.
  2201 
  2202 
  2203 *** ML ***
  2204 
  2205 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  2206 for ||>, ||>>, |>>,
  2207 
  2208 * Pure/library.ML no longer defines its own option datatype, but uses
  2209 that of the SML basis, which has constructors NONE and SOME instead of
  2210 None and Some, as well as exception Option.Option instead of OPTION.
  2211 The functions the, if_none, is_some, is_none have been adapted
  2212 accordingly, while Option.map replaces apsome.
  2213 
  2214 * Pure/library.ML: the exception LIST has been given up in favour of
  2215 the standard exceptions Empty and Subscript, as well as
  2216 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  2217 superceded by the standard hd and tl functions etc.
  2218 
  2219 A number of basic list functions are no longer exported to the ML
  2220 toplevel, as they are variants of predefined functions.  The following
  2221 suggests how one can translate existing code:
  2222 
  2223     rev_append xs ys = List.revAppend (xs, ys)
  2224     nth_elem (i, xs) = List.nth (xs, i)
  2225     last_elem xs = List.last xs
  2226     flat xss = List.concat xss
  2227     seq fs = List.app fs
  2228     partition P xs = List.partition P xs
  2229     mapfilter f xs = List.mapPartial f xs
  2230 
  2231 * Pure/library.ML: several combinators for linear functional
  2232 transformations, notably reverse application and composition:
  2233 
  2234   x |> f                f #> g
  2235   (x, y) |-> f          f #-> g
  2236 
  2237 * Pure/library.ML: introduced/changed precedence of infix operators:
  2238 
  2239   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  2240   infix 2 ?;
  2241   infix 3 o oo ooo oooo;
  2242   infix 4 ~~ upto downto;
  2243 
  2244 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  2245 infix operators.
  2246 
  2247 * Pure/library.ML: natural list combinators fold, fold_rev, and
  2248 fold_map support linear functional transformations and nesting.  For
  2249 example:
  2250 
  2251   fold f [x1, ..., xN] y =
  2252     y |> f x1 |> ... |> f xN
  2253 
  2254   (fold o fold) f [xs1, ..., xsN] y =
  2255     y |> fold f xs1 |> ... |> fold f xsN
  2256 
  2257   fold f [x1, ..., xN] =
  2258     f x1 #> ... #> f xN
  2259 
  2260   (fold o fold) f [xs1, ..., xsN] =
  2261     fold f xs1 #> ... #> fold f xsN
  2262 
  2263 * Pure/library.ML: the following selectors on type 'a option are
  2264 available:
  2265 
  2266   the:               'a option -> 'a  (*partial*)
  2267   these:             'a option -> 'a  where 'a = 'b list
  2268   the_default: 'a -> 'a option -> 'a
  2269   the_list:          'a option -> 'a list
  2270 
  2271 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  2272 basic operations for association lists, following natural argument
  2273 order; moreover the explicit equality predicate passed here avoids
  2274 potentially expensive polymorphic runtime equality checks.
  2275 The old functions may be expressed as follows:
  2276 
  2277   assoc = uncurry (AList.lookup (op =))
  2278   assocs = these oo AList.lookup (op =)
  2279   overwrite = uncurry (AList.update (op =)) o swap
  2280 
  2281 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  2282 
  2283   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  2284   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  2285 
  2286 replacing make_keylist and keyfilter (occassionally used)
  2287 Naive rewrites:
  2288 
  2289   make_keylist = AList.make
  2290   keyfilter = AList.find (op =)
  2291 
  2292 * eq_fst and eq_snd now take explicit equality parameter, thus
  2293   avoiding eqtypes. Naive rewrites:
  2294 
  2295     eq_fst = eq_fst (op =)
  2296     eq_snd = eq_snd (op =)
  2297 
  2298 * Removed deprecated apl and apr (rarely used).
  2299   Naive rewrites:
  2300 
  2301     apl (n, op) =>>= curry op n
  2302     apr (op, m) =>>= fn n => op (n, m)
  2303 
  2304 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  2305 provides a reasonably efficient light-weight implementation of sets as
  2306 lists.
  2307 
  2308 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  2309 few new operations; existing lookup and update are now curried to
  2310 follow natural argument order (for use with fold etc.);
  2311 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  2312 
  2313 * Pure/General: output via the Isabelle channels of
  2314 writeln/warning/error etc. is now passed through Output.output, with a
  2315 hook for arbitrary transformations depending on the print_mode
  2316 (cf. Output.add_mode -- the first active mode that provides a output
  2317 function wins).  Already formatted output may be embedded into further
  2318 text via Output.raw; the result of Pretty.string_of/str_of and derived
  2319 functions (string_of_term/cterm/thm etc.) is already marked raw to
  2320 accommodate easy composition of diagnostic messages etc.  Programmers
  2321 rarely need to care about Output.output or Output.raw at all, with
  2322 some notable exceptions: Output.output is required when bypassing the
  2323 standard channels (writeln etc.), or in token translations to produce
  2324 properly formatted results; Output.raw is required when capturing
  2325 already output material that will eventually be presented to the user
  2326 a second time.  For the default print mode, both Output.output and
  2327 Output.raw have no effect.
  2328 
  2329 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  2330 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  2331 cumulative results are displayed at the end of a batch session.
  2332 
  2333 * Pure/General: File.sysify_path and File.quote_sysify path have been
  2334 replaced by File.platform_path and File.shell_path (with appropriate
  2335 hooks).  This provides a clean interface for unusual systems where the
  2336 internal and external process view of file names are different.
  2337 
  2338 * Pure: more efficient orders for basic syntactic entities: added
  2339 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  2340 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  2341 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  2342 orders now -- potential INCOMPATIBILITY for code that depends on a
  2343 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  2344 Library.sort_strings on result).
  2345 
  2346 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  2347 fold_types traverse types/terms from left to right, observing natural
  2348 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  2349 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  2350 
  2351 * Pure: name spaces have been refined, with significant changes of the
  2352 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  2353 to extern(_table).  The plain name entry path is superceded by a
  2354 general 'naming' context, which also includes the 'policy' to produce
  2355 a fully qualified name and external accesses of a fully qualified
  2356 name; NameSpace.extend is superceded by context dependent
  2357 Sign.declare_name.  Several theory and proof context operations modify
  2358 the naming context.  Especially note Theory.restore_naming and
  2359 ProofContext.restore_naming to get back to a sane state; note that
  2360 Theory.add_path is no longer sufficient to recover from
  2361 Theory.absolute_path in particular.
  2362 
  2363 * Pure: new flags short_names (default false) and unique_names
  2364 (default true) for controlling output of qualified names.  If
  2365 short_names is set, names are printed unqualified.  If unique_names is
  2366 reset, the name prefix is reduced to the minimum required to achieve
  2367 the original result when interning again, even if there is an overlap
  2368 with earlier declarations.
  2369 
  2370 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  2371 now 'extend', and 'merge' gets an additional Pretty.pp argument
  2372 (useful for printing error messages).  INCOMPATIBILITY.
  2373 
  2374 * Pure: major reorganization of the theory context.  Type Sign.sg and
  2375 Theory.theory are now identified, referring to the universal
  2376 Context.theory (see Pure/context.ML).  Actual signature and theory
  2377 content is managed as theory data.  The old code and interfaces were
  2378 spread over many files and structures; the new arrangement introduces
  2379 considerable INCOMPATIBILITY to gain more clarity:
  2380 
  2381   Context -- theory management operations (name, identity, inclusion,
  2382     parents, ancestors, merge, etc.), plus generic theory data;
  2383 
  2384   Sign -- logical signature and syntax operations (declaring consts,
  2385     types, etc.), plus certify/read for common entities;
  2386 
  2387   Theory -- logical theory operations (stating axioms, definitions,
  2388     oracles), plus a copy of logical signature operations (consts,
  2389     types, etc.); also a few basic management operations (Theory.copy,
  2390     Theory.merge, etc.)
  2391 
  2392 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  2393 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  2394 for convenience -- they merely return the theory.
  2395 
  2396 * Pure: type Type.tsig is superceded by theory in most interfaces.
  2397 
  2398 * Pure: the Isar proof context type is already defined early in Pure
  2399 as Context.proof (note that ProofContext.context and Proof.context are
  2400 aliases, where the latter is the preferred name).  This enables other
  2401 Isabelle components to refer to that type even before Isar is present.
  2402 
  2403 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  2404 typeK, constK, axiomK, oracleK), but provide explicit operations for
  2405 any of these kinds.  For example, Sign.intern typeK is now
  2406 Sign.intern_type, Theory.hide_space Sign.typeK is now
  2407 Theory.hide_types.  Also note that former
  2408 Theory.hide_classes/types/consts are now
  2409 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  2410 internalize their arguments!  INCOMPATIBILITY.
  2411 
  2412 * Pure: get_thm interface (of PureThy and ProofContext) expects
  2413 datatype thmref (with constructors Name and NameSelection) instead of
  2414 plain string -- INCOMPATIBILITY;
  2415 
  2416 * Pure: cases produced by proof methods specify options, where NONE
  2417 means to remove case bindings -- INCOMPATIBILITY in
  2418 (RAW_)METHOD_CASES.
  2419 
  2420 * Pure: the following operations retrieve axioms or theorems from a
  2421 theory node or theory hierarchy, respectively:
  2422 
  2423   Theory.axioms_of: theory -> (string * term) list
  2424   Theory.all_axioms_of: theory -> (string * term) list
  2425   PureThy.thms_of: theory -> (string * thm) list
  2426   PureThy.all_thms_of: theory -> (string * thm) list
  2427 
  2428 * Pure: print_tac now outputs the goal through the trace channel.
  2429 
  2430 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  2431 Reference Toplevel.debug (default false) controls detailed printing
  2432 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  2433 controls execution profiling -- set to 1 for time and 2 for space
  2434 (both increase the runtime).
  2435 
  2436 * Isar session: The initial use of ROOT.ML is now always timed,
  2437 i.e. the log will show the actual process times, in contrast to the
  2438 elapsed wall-clock time that the outer shell wrapper produces.
  2439 
  2440 * Simplifier: improved handling of bound variables (nameless
  2441 representation, avoid allocating new strings).  Simprocs that invoke
  2442 the Simplifier recursively should use Simplifier.inherit_bounds to
  2443 avoid local name clashes.  Failure to do so produces warnings
  2444 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  2445 for further details.
  2446 
  2447 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  2448 bindings for all theorems stored within a given theory; this may help
  2449 in porting non-Isar theories to Isar ones, while keeping ML proof
  2450 scripts for the time being.
  2451 
  2452 * ML operator HTML.with_charset specifies the charset begin used for
  2453 generated HTML files.  For example:
  2454 
  2455   HTML.with_charset "utf-8" use_thy "Hebrew";
  2456   HTML.with_charset "utf-8" use_thy "Chinese";
  2457 
  2458 
  2459 *** System ***
  2460 
  2461 * Allow symlinks to all proper Isabelle executables (Isabelle,
  2462 isabelle, isatool etc.).
  2463 
  2464 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  2465 isatool doc, isatool mkdir, display_drafts etc.).
  2466 
  2467 * isatool usedir: option -f allows specification of the ML file to be
  2468 used by Isabelle; default is ROOT.ML.
  2469 
  2470 * New isatool version outputs the version identifier of the Isabelle
  2471 distribution being used.
  2472 
  2473 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  2474 (containing Boolean satisfiability problems) into Isabelle/HOL
  2475 theories.
  2476 
  2477 
  2478 
  2479 New in Isabelle2004 (April 2004)
  2480 --------------------------------
  2481 
  2482 *** General ***
  2483 
  2484 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  2485   Replaces linorder.ML.
  2486 
  2487 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  2488   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  2489   (\<a>...\<z>), are now considered normal letters, and can therefore
  2490   be used anywhere where an ASCII letter (a...zA...Z) has until
  2491   now. COMPATIBILITY: This obviously changes the parsing of some
  2492   terms, especially where a symbol has been used as a binder, say
  2493   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  2494   as an identifier.  Fix it by inserting a space around former
  2495   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  2496   existing theory and ML files.
  2497 
  2498 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  2499 
  2500 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  2501   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  2502   a normal (but invisible) letter. For multiple letter subscripts repeat
  2503   \<^isub> like this: x\<^isub>1\<^isub>2.
  2504 
  2505 * Pure: There are now sub-/superscripts that can span more than one
  2506   character. Text between \<^bsub> and \<^esub> is set in subscript in
  2507   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  2508   superscript. The new control characters are not identifier parts.
  2509 
  2510 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  2511   content of "..." to the latex file instead of \isacntrl... . The "..."
  2512   may consist of any printable characters excluding the end bracket >.
  2513 
  2514 * Pure: Using new Isar command "finalconsts" (or the ML functions
  2515   Theory.add_finals or Theory.add_finals_i) it is now possible to
  2516   declare constants "final", which prevents their being given a definition
  2517   later.  It is useful for constants whose behaviour is fixed axiomatically
  2518   rather than definitionally, such as the meta-logic connectives.
  2519 
  2520 * Pure: 'instance' now handles general arities with general sorts
  2521   (i.e. intersections of classes),
  2522 
  2523 * Presentation: generated HTML now uses a CSS style sheet to make layout
  2524   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  2525   It can be changed to alter the colors/layout of generated pages.
  2526 
  2527 
  2528 *** Isar ***
  2529 
  2530 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  2531   cut_tac, subgoal_tac and thin_tac:
  2532   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  2533     locales are no longer forced to write Isar proof scripts.
  2534     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  2535     emulations.
  2536   - INCOMPATIBILITY: names of variables to be instantiated may no
  2537     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  2538     This is consistent with the instantiation attribute "where".
  2539 
  2540 * Attributes "where" and "of":
  2541   - Now take type variables of instantiated theorem into account when reading
  2542     the instantiation string.  This fixes a bug that caused instantiated
  2543     theorems to have too special types in some circumstances.
  2544   - "where" permits explicit instantiations of type variables.
  2545 
  2546 * Calculation commands "moreover" and "also" no longer interfere with
  2547   current facts ("this"), admitting arbitrary combinations with "then"
  2548   and derived forms.
  2549 
  2550 * Locales:
  2551   - Goal statements involving the context element "includes" no longer
  2552     generate theorems with internal delta predicates (those ending on
  2553     "_axioms") in the premise.
  2554     Resolve particular premise with <locale>.intro to obtain old form.
  2555   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  2556     specification and "includes" elements in goal statement.
  2557   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  2558     [intro?] and [elim?] (respectively) by default.
  2559   - Experimental command for instantiation of locales in proof contexts:
  2560         instantiate <label>[<attrs>]: <loc>
  2561     Instantiates locale <loc> and adds all its theorems to the current context
  2562     taking into account their attributes.  Label and attrs are optional
  2563     modifiers, like in theorem declarations.  If present, names of
  2564     instantiated theorems are qualified with <label>, and the attributes
  2565     <attrs> are applied after any attributes these theorems might have already.
  2566       If the locale has assumptions, a chained fact of the form
  2567     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  2568     are derived.  The command does not support old-style locales declared
  2569     with "locale (open)".
  2570       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  2571 
  2572 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  2573   (Isar) contexts.
  2574 
  2575 
  2576 *** HOL ***
  2577 
  2578 * Proof import: new image HOL4 contains the imported library from
  2579   the HOL4 system with about 2500 theorems. It is imported by
  2580   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  2581   can be used like any other Isabelle image.  See
  2582   HOL/Import/HOL/README for more information.
  2583 
  2584 * Simplifier:
  2585   - Much improved handling of linear and partial orders.
  2586     Reasoners for linear and partial orders are set up for type classes
  2587     "linorder" and "order" respectively, and are added to the default simpset
  2588     as solvers.  This means that the simplifier can build transitivity chains
  2589     to solve goals from the assumptions.
  2590   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  2591     of blast or auto after simplification become unnecessary because the goal
  2592     is solved by simplification already.
  2593 
  2594 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  2595     all proved in axiomatic type classes for semirings, rings and fields.
  2596 
  2597 * Numerics:
  2598   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  2599     now formalized using the Ring_and_Field theory mentioned above.
  2600   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  2601     than before, because now they are set up once in a generic manner.
  2602   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  2603     Look for the general versions in Ring_and_Field (and Power if they concern
  2604     exponentiation).
  2605 
  2606 * Type "rat" of the rational numbers is now available in HOL-Complex.
  2607 
  2608 * Records:
  2609   - Record types are now by default printed with their type abbreviation
  2610     instead of the list of all field types. This can be configured via
  2611     the reference "print_record_type_abbr".
  2612   - Simproc "record_upd_simproc" for simplification of multiple updates added
  2613     (not enabled by default).
  2614   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  2615     EX x. x = sel r to True (not enabled by default).
  2616   - Tactic "record_split_simp_tac" to split and simplify records added.
  2617 
  2618 * 'specification' command added, allowing for definition by
  2619   specification.  There is also an 'ax_specification' command that
  2620   introduces the new constants axiomatically.
  2621 
  2622 * arith(_tac) is now able to generate counterexamples for reals as well.
  2623 
  2624 * HOL-Algebra: new locale "ring" for non-commutative rings.
  2625 
  2626 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  2627   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  2628 
  2629 * HOL-Matrix: a first theory for matrices in HOL with an application of
  2630   matrix theory to linear programming.
  2631 
  2632 * Unions and Intersections:
  2633   The latex output syntax of UN and INT has been changed
  2634   from "\Union x \in A. B" to "\Union_{x \in A} B"
  2635   i.e. the index formulae has become a subscript.
  2636   Similarly for "\Union x. B", and for \Inter instead of \Union.
  2637 
  2638 * Unions and Intersections over Intervals:
  2639   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  2640   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  2641   like in normal math, and corresponding versions for < and for intersection.
  2642 
  2643 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  2644   lexicographic dictonary ordering has been added as "lexord".
  2645 
  2646 * ML: the legacy theory structures Int and List have been removed. They had
  2647   conflicted with ML Basis Library structures having the same names.
  2648 
  2649 * 'refute' command added to search for (finite) countermodels.  Only works
  2650   for a fragment of HOL.  The installation of an external SAT solver is
  2651   highly recommended.  See "HOL/Refute.thy" for details.
  2652 
  2653 * 'quickcheck' command: Allows to find counterexamples by evaluating
  2654   formulae under an assignment of free variables to random values.
  2655   In contrast to 'refute', it can deal with inductive datatypes,
  2656   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  2657   for examples.
  2658 
  2659 
  2660 *** HOLCF ***
  2661 
  2662 * Streams now come with concatenation and are part of the HOLCF image
  2663 
  2664 
  2665 
  2666 New in Isabelle2003 (May 2003)
  2667 ------------------------------
  2668 
  2669 *** General ***
  2670 
  2671 * Provers/simplifier:
  2672 
  2673   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  2674     Assumptions are now subject to complete mutual simplification,
  2675     not just from left to right. The simplifier now preserves
  2676     the order of assumptions.
  2677 
  2678     Potential INCOMPATIBILITY:
  2679 
  2680     -- simp sometimes diverges where the old version did
  2681        not, e.g. invoking simp on the goal
  2682 
  2683         [| P (f x); y = x; f x = f y |] ==> Q
  2684 
  2685        now gives rise to the infinite reduction sequence
  2686 
  2687         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  2688 
  2689        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  2690        kind of problem.
  2691 
  2692     -- Tactics combining classical reasoner and simplification (such as auto)
  2693        are also affected by this change, because many of them rely on
  2694        simp. They may sometimes diverge as well or yield a different numbers
  2695        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  2696        in case of problems. Sometimes subsequent calls to the classical
  2697        reasoner will fail because a preceeding call to the simplifier too
  2698        eagerly simplified the goal, e.g. deleted redundant premises.
  2699 
  2700   - The simplifier trace now shows the names of the applied rewrite rules
  2701 
  2702   - You can limit the number of recursive invocations of the simplifier
  2703     during conditional rewriting (where the simplifie tries to solve the
  2704     conditions before applying the rewrite rule):
  2705     ML "simp_depth_limit := n"
  2706     where n is an integer. Thus you can force termination where previously
  2707     the simplifier would diverge.
  2708 
  2709   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  2710 
  2711   - No longer aborts on failed congruence proof.  Instead, the
  2712     congruence is ignored.
  2713 
  2714 * Pure: New generic framework for extracting programs from constructive
  2715   proofs. See HOL/Extraction.thy for an example instantiation, as well
  2716   as HOL/Extraction for some case studies.
  2717 
  2718 * Pure: The main goal of the proof state is no longer shown by default, only
  2719 the subgoals. This behaviour is controlled by a new flag.
  2720    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  2721 (ML: Proof.show_main_goal).
  2722 
  2723 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  2724 rules whose conclusion matches subgoal 1:
  2725       PG menu: Isabelle/Isar -> Show me -> matching rules
  2726 The rules are ordered by how closely they match the subgoal.
  2727 In particular, rules that solve a subgoal outright are displayed first
  2728 (or rather last, the way they are printed).
  2729 (ML: ProofGeneral.print_intros())
  2730 
  2731 * Pure: New flag trace_unify_fail causes unification to print
  2732 diagnostic information (PG: in trace buffer) when it fails. This is
  2733 useful for figuring out why single step proofs like rule, erule or
  2734 assumption failed.
  2735 
  2736 * Pure: Locale specifications now produce predicate definitions
  2737 according to the body of text (covering assumptions modulo local
  2738 definitions); predicate "loc_axioms" covers newly introduced text,
  2739 while "loc" is cumulative wrt. all included locale expressions; the
  2740 latter view is presented only on export into the global theory
  2741 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  2742 on the old view without predicates;
  2743 
  2744 * Pure: predefined locales "var" and "struct" are useful for sharing
  2745 parameters (as in CASL, for example); just specify something like
  2746 ``var x + var y + struct M'' as import;
  2747 
  2748 * Pure: improved thms_containing: proper indexing of facts instead of
  2749 raw theorems; check validity of results wrt. current name space;
  2750 include local facts of proof configuration (also covers active
  2751 locales), cover fixed variables in index; may use "_" in term
  2752 specification; an optional limit for the number of printed facts may
  2753 be given (the default is 40);
  2754 
  2755 * Pure: disallow duplicate fact bindings within new-style theory files
  2756 (batch-mode only);
  2757 
  2758 * Provers: improved induct method: assumptions introduced by case
  2759 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  2760 the goal statement); "foo" still refers to all facts collectively;
  2761 
  2762 * Provers: the function blast.overloaded has been removed: all constants
  2763 are regarded as potentially overloaded, which improves robustness in exchange
  2764 for slight decrease in efficiency;
  2765 
  2766 * Provers/linorder: New generic prover for transitivity reasoning over
  2767 linear orders.  Note: this prover is not efficient!
  2768 
  2769 * Isar: preview of problems to finish 'show' now produce an error
  2770 rather than just a warning (in interactive mode);
  2771 
  2772 
  2773 *** HOL ***
  2774 
  2775 * arith(_tac)
  2776 
  2777  - Produces a counter example if it cannot prove a goal.
  2778    Note that the counter example may be spurious if the goal is not a formula
  2779    of quantifier-free linear arithmetic.
  2780    In ProofGeneral the counter example appears in the trace buffer.
  2781 
  2782  - Knows about div k and mod k where k is a numeral of type nat or int.
  2783 
  2784  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  2785    linear arithmetic fails. This takes account of quantifiers and divisibility.
  2786    Presburger arithmetic can also be called explicitly via presburger(_tac).
  2787 
  2788 * simp's arithmetic capabilities have been enhanced a bit: it now
  2789 takes ~= in premises into account (by performing a case split);
  2790 
  2791 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  2792 are distributed over a sum of terms;
  2793 
  2794 * New tactic "trans_tac" and method "trans" instantiate
  2795 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  2796 "<=", "<" and "=").
  2797 
  2798 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  2799 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  2800 
  2801 * 'typedef' command has new option "open" to suppress the set
  2802 definition;
  2803 
  2804 * functions Min and Max on finite sets have been introduced (theory
  2805 Finite_Set);
  2806 
  2807 * attribute [symmetric] now works for relations as well; it turns
  2808 (x,y) : R^-1 into (y,x) : R, and vice versa;
  2809 
  2810 * induct over a !!-quantified statement (say !!x1..xn):
  2811   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  2812 
  2813 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  2814 %x. None. Warning: empty_def now refers to the previously hidden definition
  2815 of the empty set.
  2816 
  2817 * Algebra: formalization of classical algebra.  Intended as base for
  2818 any algebraic development in Isabelle.  Currently covers group theory
  2819 (up to Sylow's theorem) and ring theory (Universal Property of
  2820 Univariate Polynomials).  Contributions welcome;
  2821 
  2822 * GroupTheory: deleted, since its material has been moved to Algebra;
  2823 
  2824 * Complex: new directory of the complex numbers with numeric constants,
  2825 nonstandard complex numbers, and some complex analysis, standard and
  2826 nonstandard (Jacques Fleuriot);
  2827 
  2828 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  2829 
  2830 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  2831 Fleuriot);
  2832 
  2833 * Real/HahnBanach: updated and adapted to locales;
  2834 
  2835 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  2836 Gray and Kramer);
  2837 
  2838 * UNITY: added the Meier-Sanders theory of progress sets;
  2839 
  2840 * MicroJava: bytecode verifier and lightweight bytecode verifier
  2841 as abstract algorithms, instantiated to the JVM;
  2842 
  2843 * Bali: Java source language formalization. Type system, operational
  2844 semantics, axiomatic semantics. Supported language features:
  2845 classes, interfaces, objects,virtual methods, static methods,
  2846 static/instance fields, arrays, access modifiers, definite
  2847 assignment, exceptions.
  2848 
  2849 
  2850 *** ZF ***
  2851 
  2852 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  2853 universe, etc.);
  2854 
  2855 * Main ZF: virtually all theories converted to new-style format;
  2856 
  2857 
  2858 *** ML ***
  2859 
  2860 * Pure: Tactic.prove provides sane interface for internal proofs;
  2861 omits the infamous "standard" operation, so this is more appropriate
  2862 than prove_goalw_cterm in many situations (e.g. in simprocs);
  2863 
  2864 * Pure: improved error reporting of simprocs;
  2865 
  2866 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  2867 up simprocs;
  2868 
  2869 
  2870 *** Document preparation ***
  2871 
  2872 * uses \par instead of \\ for line breaks in theory text. This may
  2873 shift some page breaks in large documents. To get the old behaviour
  2874 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  2875 
  2876 * minimized dependencies of isabelle.sty and isabellesym.sty on
  2877 other packages
  2878 
  2879 * \<euro> now needs package babel/greek instead of marvosym (which
  2880 broke \Rightarrow)
  2881 
  2882 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  2883 textcomp package)
  2884 
  2885 
  2886 
  2887 New in Isabelle2002 (March 2002)
  2888 --------------------------------
  2889 
  2890 *** Document preparation ***
  2891 
  2892 * greatly simplified document preparation setup, including more
  2893 graceful interpretation of isatool usedir -i/-d/-D options, and more
  2894 instructive isatool mkdir; users should basically be able to get
  2895 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  2896 users may run a separate document processing stage manually like this:
  2897 "isatool usedir -D output HOL Test && isatool document Test/output";
  2898 
  2899 * theory dependency graph may now be incorporated into documents;
  2900 isatool usedir -g true will produce session_graph.eps/.pdf for use
  2901 with \includegraphics of LaTeX;
  2902 
  2903 * proper spacing of consecutive markup elements, especially text
  2904 blocks after section headings;
  2905 
  2906 * support bold style (for single symbols only), input syntax is like
  2907 this: "\<^bold>\<alpha>" or "\<^bold>A";
  2908 
  2909 * \<bullet> is now output as bold \cdot by default, which looks much
  2910 better in printed text;
  2911 
  2912 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  2913 note that these symbols are currently unavailable in Proof General /
  2914 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  2915 
  2916 * isatool latex no longer depends on changed TEXINPUTS, instead
  2917 isatool document copies the Isabelle style files to the target
  2918 location;
  2919 
  2920 
  2921 *** Isar ***
  2922 
  2923 * Pure/Provers: improved proof by cases and induction;
  2924   - 'case' command admits impromptu naming of parameters (such as
  2925     "case (Suc n)");
  2926   - 'induct' method divinates rule instantiation from the inductive
  2927     claim; no longer requires excessive ?P bindings for proper
  2928     instantiation of cases;
  2929   - 'induct' method properly enumerates all possibilities of set/type
  2930     rules; as a consequence facts may be also passed through *type*
  2931     rules without further ado;
  2932   - 'induct' method now derives symbolic cases from the *rulified*
  2933     rule (before it used to rulify cases stemming from the internal
  2934     atomized version); this means that the context of a non-atomic
  2935     statement becomes is included in the hypothesis, avoiding the
  2936     slightly cumbersome show "PROP ?case" form;
  2937   - 'induct' may now use elim-style induction rules without chaining
  2938     facts, using ``missing'' premises from the goal state; this allows
  2939     rules stemming from inductive sets to be applied in unstructured
  2940     scripts, while still benefitting from proper handling of non-atomic
  2941     statements; NB: major inductive premises need to be put first, all
  2942     the rest of the goal is passed through the induction;
  2943   - 'induct' proper support for mutual induction involving non-atomic
  2944     rule statements (uses the new concept of simultaneous goals, see
  2945     below);
  2946   - append all possible rule selections, but only use the first
  2947     success (no backtracking);
  2948   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  2949   - undeclared rule case names default to numbers 1, 2, 3, ...;
  2950   - added 'print_induct_rules' (covered by help item in recent Proof
  2951     General versions);
  2952   - moved induct/cases attributes to Pure, methods to Provers;
  2953   - generic method setup instantiated for FOL and HOL;
  2954 
  2955 * Pure: support multiple simultaneous goal statements, for example
  2956 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  2957 meta-level mechanism, this acts as if several individual goals had
  2958 been stated separately; in particular common proof methods need to be
  2959 repeated in order to cover all claims; note that a single elimination
  2960 step is *not* sufficient to establish the two conjunctions, so this
  2961 fails:
  2962 
  2963   assume "A & B" then have A and B ..   (*".." fails*)
  2964 
  2965 better use "obtain" in situations as above; alternative refer to
  2966 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  2967 
  2968 * Pure: proper integration with ``locales''; unlike the original
  2969 version by Florian Kammller, Isar locales package high-level proof
  2970 contexts rather than raw logical ones (e.g. we admit to include
  2971 attributes everywhere); operations on locales include merge and
  2972 rename; support for implicit arguments (``structures''); simultaneous
  2973 type-inference over imports and text; see also HOL/ex/Locales.thy for
  2974 some examples;
  2975 
  2976 * Pure: the following commands have been ``localized'', supporting a
  2977 target locale specification "(in name)": 'lemma', 'theorem',
  2978 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  2979 stored both within the locale and at the theory level (exported and
  2980 qualified by the locale name);
  2981 
  2982 * Pure: theory goals may now be specified in ``long'' form, with
  2983 ad-hoc contexts consisting of arbitrary locale elements. for example
  2984 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  2985 definitions may be given, too); the result is a meta-level rule with
  2986 the context elements being discharged in the obvious way;
  2987 
  2988 * Pure: new proof command 'using' allows to augment currently used
  2989 facts after a goal statement ('using' is syntactically analogous to
  2990 'apply', but acts on the goal's facts only); this allows chained facts
  2991 to be separated into parts given before and after a claim, as in
  2992 ``from a and b have C using d and e <proof>'';
  2993 
  2994 * Pure: renamed "antecedent" case to "rule_context";
  2995 
  2996 * Pure: new 'judgment' command records explicit information about the
  2997 object-logic embedding (used by several tools internally); no longer
  2998 use hard-wired "Trueprop";
  2999 
  3000 * Pure: added 'corollary' command;
  3001 
  3002 * Pure: fixed 'token_translation' command;
  3003 
  3004 * Pure: removed obsolete 'exported' attribute;
  3005 
  3006 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  3007 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  3008 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  3009 
  3010 * Pure: method 'atomize' presents local goal premises as object-level
  3011 statements (atomic meta-level propositions); setup controlled via
  3012 rewrite rules declarations of 'atomize' attribute; example
  3013 application: 'induct' method with proper rule statements in improper
  3014 proof *scripts*;
  3015 
  3016 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  3017 now consider the syntactic context of assumptions, giving a better
  3018 chance to get type-inference of the arguments right (this is
  3019 especially important for locales);
  3020 
  3021 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  3022 mode;
  3023 
  3024 * Pure/obtain: the formal conclusion "thesis", being marked as
  3025 ``internal'', may no longer be reference directly in the text;
  3026 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  3027 situations;
  3028 
  3029 * Pure: generic 'sym' attribute which declares a rule both as pure
  3030 'elim?' and for the 'symmetric' operation;
  3031 
  3032 * Pure: marginal comments ``--'' may now occur just anywhere in the
  3033 text; the fixed correlation with particular command syntax has been
  3034 discontinued;
  3035 
  3036 * Pure: new method 'rules' is particularly well-suited for proof
  3037 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  3038 but often produces more compact proof terms with less detours;
  3039 
  3040 * Pure/Provers/classical: simplified integration with pure rule
  3041 attributes and methods; the classical "intro?/elim?/dest?"
  3042 declarations coincide with the pure ones; the "rule" method no longer
  3043 includes classically swapped intros; "intro" and "elim" methods no
  3044 longer pick rules from the context; also got rid of ML declarations
  3045 AddXIs/AddXEs/AddXDs; all of this has some potential for
  3046 INCOMPATIBILITY;
  3047 
  3048 * Provers/classical: attribute 'swapped' produces classical inversions
  3049 of introduction rules;
  3050 
  3051 * Provers/simplifier: 'simplified' attribute may refer to explicit
  3052 rules instead of full simplifier context; 'iff' attribute handles
  3053 conditional rules;
  3054 
  3055 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  3056 
  3057 * HOL: 'recdef' now fails on unfinished automated proofs, use
  3058 "(permissive)" option to recover old behavior;
  3059 
  3060 * HOL: 'inductive' no longer features separate (collective) attributes
  3061 for 'intros' (was found too confusing);
  3062 
  3063 * HOL: properly declared induction rules less_induct and
  3064 wf_induct_rule;
  3065 
  3066 
  3067 *** HOL ***
  3068 
  3069 * HOL: moved over to sane numeral syntax; the new policy is as
  3070 follows:
  3071 
  3072   - 0 and 1 are polymorphic constants, which are defined on any
  3073   numeric type (nat, int, real etc.);
  3074 
  3075   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  3076   binary representation internally;
  3077 
  3078   - type nat has special constructor Suc, and generally prefers Suc 0
  3079   over 1::nat and Suc (Suc 0) over 2::nat;
  3080 
  3081 This change may cause significant problems of INCOMPATIBILITY; here
  3082 are some hints on converting existing sources:
  3083 
  3084   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  3085   entities, so expressions involving "-" (unary or binary minus) need
  3086   to be spaced properly;
  3087 
  3088   - existing occurrences of "1" may need to be constraint "1::nat" or
  3089   even replaced by Suc 0; similar for old "2";
  3090 
  3091   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  3092 
  3093   - remove all special provisions on numerals in proofs;
  3094 
  3095 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  3096 representation (depends on bin_arith_simps in the default context);
  3097 
  3098 * HOL: symbolic syntax for x^2 (numeral 2);
  3099 
  3100 * HOL: the class of all HOL types is now called "type" rather than
  3101 "term"; INCOMPATIBILITY, need to adapt references to this type class
  3102 in axclass/classes, instance/arities, and (usually rare) occurrences
  3103 in typings (of consts etc.); internally the class is called
  3104 "HOL.type", ML programs should refer to HOLogic.typeS;
  3105 
  3106 * HOL/record package improvements:
  3107   - new derived operations "fields" to build a partial record section,
  3108     "extend" to promote a fixed record to a record scheme, and
  3109     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  3110     declared as simp by default;
  3111   - shared operations ("more", "fields", etc.) now need to be always
  3112     qualified) --- potential INCOMPATIBILITY;
  3113   - removed "make_scheme" operations (use "make" with "extend") --
  3114     INCOMPATIBILITY;
  3115   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  3116   - provides cases/induct rules for use with corresponding Isar
  3117     methods (for concrete records, record schemes, concrete more
  3118     parts, and schematic more parts -- in that order);
  3119   - internal definitions directly based on a light-weight abstract
  3120     theory of product types over typedef rather than datatype;
  3121 
  3122 * HOL: generic code generator for generating executable ML code from
  3123 specifications; specific support for HOL constructs such as inductive
  3124 datatypes and sets, as well as recursive functions; can be invoked
  3125 via 'generate_code' theory section;
  3126 
  3127 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  3128 
  3129 * HOL: consolidated and renamed several theories.  In particular:
  3130         Ord.thy has been absorbed into HOL.thy
  3131         String.thy has been absorbed into List.thy
  3132 
  3133 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  3134 (beware of argument permutation!);
  3135 
  3136 * HOL: linorder_less_split superseded by linorder_cases;
  3137 
  3138 * HOL/List: "nodups" renamed to "distinct";
  3139 
  3140 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  3141 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  3142   - Ex_def has changed, now need to use some_eq_ex
  3143 
  3144 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  3145 in this (rare) case use:
  3146 
  3147   delSWrapper "split_all_tac"
  3148   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  3149 
  3150 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  3151 MAY FAIL;
  3152 
  3153 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  3154 Isabelle's type classes, ^ on functions and relations has too general
  3155 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  3156 necessary to attach explicit type constraints;
  3157 
  3158 * HOL/Relation: the prefix name of the infix "O" has been changed from
  3159 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  3160 renamed accordingly (eg "compI" -> "rel_compI").
  3161 
  3162 * HOL: syntax translations now work properly with numerals and records
  3163 expressions;
  3164 
  3165 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  3166 of "lam" -- INCOMPATIBILITY;
  3167 
  3168 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  3169 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  3170 renamed "Product_Type.unit";
  3171 
  3172 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  3173 
  3174 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  3175 the "cases" method);
  3176 
  3177 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  3178 Florian Kammller);
  3179 
  3180 * HOL/IMP: updated and converted to new-style theory format; several
  3181 parts turned into readable document, with proper Isar proof texts and
  3182 some explanations (by Gerwin Klein);
  3183 
  3184 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  3185 
  3186 * HOL-Hyperreal is now a logic image;
  3187 
  3188 
  3189 *** HOLCF ***
  3190 
  3191 * Isar: consts/constdefs supports mixfix syntax for continuous
  3192 operations;
  3193 
  3194 * Isar: domain package adapted to new-style theory format, e.g. see
  3195 HOLCF/ex/Dnat.thy;
  3196 
  3197 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  3198 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  3199 lift.induct_tac, always use UU instead of Undef;
  3200 
  3201 * HOLCF/IMP: updated and converted to new-style theory;
  3202 
  3203 
  3204 *** ZF ***
  3205 
  3206 * Isar: proper integration of logic-specific tools and packages,
  3207 including theory commands '(co)inductive', '(co)datatype',
  3208 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  3209 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  3210 
  3211 * theory Main no longer includes AC; for the Axiom of Choice, base
  3212 your theory on Main_ZFC;
  3213 
  3214 * the integer library now covers quotients and remainders, with many
  3215 laws relating division to addition, multiplication, etc.;
  3216 
  3217 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  3218 typeless version of the formalism;
  3219 
  3220 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  3221 format;
  3222 
  3223 * ZF/Induct: new directory for examples of inductive definitions,
  3224 including theory Multiset for multiset orderings; converted to
  3225 new-style theory format;
  3226 
  3227 * ZF: many new theorems about lists, ordinals, etc.;
  3228 
  3229 
  3230 *** General ***
  3231 
  3232 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  3233 variable proof controls level of detail: 0 = no proofs (only oracle
  3234 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  3235 also ref manual for further ML interfaces;
  3236 
  3237 * Pure/axclass: removed obsolete ML interface
  3238 goal_subclass/goal_arity;
  3239 
  3240 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  3241 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  3242 separate tokens, so expressions involving minus need to be spaced
  3243 properly;
  3244 
  3245 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  3246 rather than "infixl" or "infixr";
  3247 
  3248 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  3249 sort constraint specifications in type inference; e.g. "x::_::foo"
  3250 ensures that the type of "x" is of sort "foo" (but not necessarily a
  3251 type variable);
  3252 
  3253 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  3254 control output of nested => (types); the default behavior is
  3255 "type_brackets";
  3256 
  3257 * Pure/syntax: builtin parse translation for "_constify" turns valued
  3258 tokens into AST constants;
  3259 
  3260 * Pure/syntax: prefer later declarations of translations and print
  3261 translation functions; potential INCOMPATIBILITY: need to reverse
  3262 multiple declarations for same syntax element constant;
  3263 
  3264 * Pure/show_hyps reset by default (in accordance to existing Isar
  3265 practice);
  3266 
  3267 * Provers/classical: renamed addaltern to addafter, addSaltern to
  3268 addSafter;
  3269 
  3270 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  3271 as well;
  3272 
  3273 * system: tested support for MacOS X; should be able to get Isabelle +
  3274 Proof General to work in a plain Terminal after installing Poly/ML
  3275 (e.g. from the Isabelle distribution area) and GNU bash alone
  3276 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  3277 support requires further installations, e.g. from
  3278 http://fink.sourceforge.net/);
  3279 
  3280 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  3281 
  3282 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  3283 of 40 MB), cf. ML_OPTIONS;
  3284 
  3285 * system: Proof General keywords specification is now part of the
  3286 Isabelle distribution (see etc/isar-keywords.el);
  3287 
  3288 * system: support for persistent Proof General sessions (refrain from
  3289 outdating all loaded theories on startup); user may create writable
  3290 logic images like this: ``isabelle -q HOL Test'';
  3291 
  3292 * system: smart selection of Isabelle process versus Isabelle
  3293 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  3294 run both "isabelle" and "Isabelle" even if file names are badly
  3295 damaged (executable inspects the case of the first letter of its own
  3296 name); added separate "isabelle-process" and "isabelle-interface";
  3297 
  3298 * system: refrain from any attempt at filtering input streams; no
  3299 longer support ``8bit'' encoding of old isabelle font, instead proper
  3300 iso-latin characters may now be used; the related isatools
  3301 "symbolinput" and "nonascii" have disappeared as well;
  3302 
  3303 * system: removed old "xterm" interface (the print modes "xterm" and
  3304 "xterm_color" are still available for direct use in a suitable
  3305 terminal);
  3306 
  3307 
  3308 
  3309 New in Isabelle99-2 (February 2001)
  3310 -----------------------------------
  3311 
  3312 *** Overview of INCOMPATIBILITIES ***
  3313 
  3314 * HOL: please note that theories in the Library and elsewhere often use the
  3315 new-style (Isar) format; to refer to their theorems in an ML script you must
  3316 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  3317 
  3318 * HOL: inductive package no longer splits induction rule aggressively,
  3319 but only as far as specified by the introductions given; the old
  3320 format may be recovered via ML function complete_split_rule or attribute
  3321 'split_rule (complete)';
  3322 
  3323 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  3324 gfp_Tarski to gfp_unfold;
  3325 
  3326 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  3327 
  3328 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  3329 relation); infix "^^" has been renamed "``"; infix "``" has been
  3330 renamed "`"; "univalent" has been renamed "single_valued";
  3331 
  3332 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  3333 operation;
  3334 
  3335 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  3336 
  3337 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  3338 
  3339 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  3340 consequence, it is no longer monotonic wrt. the local goal context
  3341 (which is now passed through the inductive cases);
  3342 
  3343 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  3344 \<gg> to \<ggreater>;
  3345 
  3346 
  3347 *** Document preparation ***
  3348 
  3349 * \isabellestyle{NAME} selects version of Isabelle output (currently
  3350 available: are "it" for near math-mode best-style output, "sl" for
  3351 slanted text style, and "tt" for plain type-writer; if no
  3352 \isabellestyle command is given, output is according to slanted
  3353 type-writer);
  3354 
  3355 * support sub/super scripts (for single symbols only), input syntax is
  3356 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  3357 
  3358 * some more standard symbols; see Appendix A of the system manual for
  3359 the complete list of symbols defined in isabellesym.sty;
  3360 
  3361 * improved isabelle style files; more abstract symbol implementation
  3362 (should now use \isamath{...} and \isatext{...} in custom symbol
  3363 definitions);
  3364 
  3365 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  3366 state; Note that presentation of goal states does not conform to
  3367 actual human-readable proof documents.  Please do not include goal
  3368 states into document output unless you really know what you are doing!
  3369 
  3370 * proper indentation of antiquoted output with proportional LaTeX
  3371 fonts;
  3372 
  3373 * no_document ML operator temporarily disables LaTeX document
  3374 generation;
  3375 
  3376 * isatool unsymbolize tunes sources for plain ASCII communication;
  3377 
  3378 
  3379 *** Isar ***
  3380 
  3381 * Pure: Isar now suffers initial goal statements to contain unbound
  3382 schematic variables (this does not conform to actual readable proof
  3383 documents, due to unpredictable outcome and non-compositional proof
  3384 checking); users who know what they are doing may use schematic goals
  3385 for Prolog-style synthesis of proven results;
  3386 
  3387 * Pure: assumption method (an implicit finishing) now handles actual
  3388 rules as well;
  3389 
  3390 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  3391 initial goal, declare "that" only as Pure intro (only for single
  3392 steps); the "that" rule assumption may now be involved in implicit
  3393 finishing, thus ".." becomes a feasible for trivial obtains;
  3394 
  3395 * Pure: default proof step now includes 'intro_classes'; thus trivial
  3396 instance proofs may be performed by "..";
  3397 
  3398 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  3399 statements as well;
  3400 
  3401 * Pure: more robust selection of calculational rules;
  3402 
  3403 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  3404 rule (as well as the assumption rule);
  3405 
  3406 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  3407 lemmas, using the graph browser tool;
  3408 
  3409 * Pure: predict failure of "show" in interactive mode;
  3410 
  3411 * Pure: 'thms_containing' now takes actual terms as arguments;
  3412 
  3413 * HOL: improved method 'induct' --- now handles non-atomic goals
  3414 (potential INCOMPATIBILITY); tuned error handling;
  3415 
  3416 * HOL: cases and induct rules now provide explicit hints about the
  3417 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  3418 any remaining facts are inserted into the goal verbatim;
  3419 
  3420 * HOL: local contexts (aka cases) may now contain term bindings as
  3421 well; the 'cases' and 'induct' methods new provide a ?case binding for
  3422 the result to be shown in each case;
  3423 
  3424 * HOL: added 'recdef_tc' command;
  3425 
  3426 * isatool convert assists in eliminating legacy ML scripts;
  3427 
  3428 
  3429 *** HOL ***
  3430 
  3431 * HOL/Library: a collection of generic theories to be used together
  3432 with main HOL; the theory loader path already includes this directory
  3433 by default; the following existing theories have been moved here:
  3434 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  3435 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  3436 
  3437 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  3438 modelling and verification task performed in Isabelle/HOL +
  3439 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  3440 
  3441 * HOL/Algebra: special summation operator SUM no longer exists, it has
  3442 been replaced by setsum; infix 'assoc' now has priority 50 (like
  3443 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  3444 'domain', this makes the theory consistent with mathematical
  3445 literature;
  3446 
  3447 * HOL basics: added overloaded operations "inverse" and "divide"
  3448 (infix "/"), syntax for generic "abs" operation, generic summation
  3449 operator \<Sum>;
  3450 
  3451 * HOL/typedef: simplified package, provide more useful rules (see also
  3452 HOL/subset.thy);
  3453 
  3454 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  3455 now expressed as a proper nested rule (old-style tactic scripts may
  3456 require atomize_strip_tac to cope with non-atomic premises);
  3457 
  3458 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  3459 to "split_conv" (old name still available for compatibility);
  3460 
  3461 * HOL: improved concrete syntax for strings (e.g. allows translation
  3462 rules with string literals);
  3463 
  3464 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  3465  and Fleuriot's mechanization of analysis, including the transcendental
  3466  functions for the reals;
  3467 
  3468 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  3469 
  3470 
  3471 *** CTT ***
  3472 
  3473 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  3474 "lam" is displayed as TWO lambda-symbols
  3475 
  3476 * CTT: theory Main now available, containing everything (that is, Bool
  3477 and Arith);
  3478 
  3479 
  3480 *** General ***
  3481 
  3482 * Pure: the Simplifier has been implemented properly as a derived rule
  3483 outside of the actual kernel (at last!); the overall performance
  3484 penalty in practical applications is about 50%, while reliability of
  3485 the Isabelle inference kernel has been greatly improved;
  3486 
  3487 * print modes "brackets" and "no_brackets" control output of nested =>
  3488 (types) and ==> (props); the default behaviour is "brackets";
  3489 
  3490 * Provers: fast_tac (and friends) now handle actual object-logic rules
  3491 as assumptions as well;
  3492 
  3493 * system: support Poly/ML 4.0;
  3494 
  3495 * system: isatool install handles KDE version 1 or 2;
  3496 
  3497 
  3498 
  3499 New in Isabelle99-1 (October 2000)
  3500 ----------------------------------
  3501 
  3502 *** Overview of INCOMPATIBILITIES ***
  3503 
  3504 * HOL: simplification of natural numbers is much changed; to partly
  3505 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  3506 issue the following ML commands:
  3507 
  3508   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  3509   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  3510 
  3511 * HOL: simplification no longer dives into case-expressions; this is
  3512 controlled by "t.weak_case_cong" for each datatype t;
  3513 
  3514 * HOL: nat_less_induct renamed to less_induct;
  3515 
  3516 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  3517 fixsome to patch .thy and .ML sources automatically;
  3518 
  3519   select_equality  -> some_equality
  3520   select_eq_Ex     -> some_eq_ex
  3521   selectI2EX       -> someI2_ex
  3522   selectI2         -> someI2
  3523   selectI          -> someI
  3524   select1_equality -> some1_equality
  3525   Eps_sym_eq       -> some_sym_eq_trivial
  3526   Eps_eq           -> some_eq_trivial
  3527 
  3528 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  3529 
  3530 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  3531 instead);
  3532 
  3533 * HOL: the recursion equations generated by 'recdef' are now called
  3534 f.simps instead of f.rules;
  3535 
  3536 * HOL: qed_spec_mp now also handles bounded ALL as well;
  3537 
  3538 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  3539 sometimes be needed;
  3540 
  3541 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  3542 
  3543 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  3544 
  3545 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  3546 product is now "<*>" instead of "Times"; the lexicographic product is
  3547 now "<*lex*>" instead of "**";
  3548 
  3549 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  3550 of main HOL, but was unused); better use HOL's datatype package;
  3551 
  3552 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  3553 the old syntax may be recovered as follows:
  3554 
  3555   syntax (symbols)
  3556     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  3557       (infixl "\\<oplus>" 100)
  3558 
  3559 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  3560 
  3561 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  3562 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  3563 internally;
  3564 
  3565 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  3566 changed from A/r to A//r;
  3567 
  3568 * ZF: new treatment of arithmetic (nat & int) may break some old
  3569 proofs;
  3570 
  3571 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  3572 rulify -> rule_format, elimify -> elim_format, ...);
  3573 
  3574 * Isar/Provers: intro/elim/dest attributes changed; renamed
  3575 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  3576 should have to change intro!! to intro? only); replaced "delrule" by
  3577 "rule del";
  3578 
  3579 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  3580 
  3581 * Provers: strengthened force_tac by using new first_best_tac;
  3582 
  3583 * LaTeX document preparation: several changes of isabelle.sty (see
  3584 lib/texinputs);
  3585 
  3586 
  3587 *** Document preparation ***
  3588 
  3589 * formal comments (text blocks etc.) in new-style theories may now
  3590 contain antiquotations of thm/prop/term/typ/text to be presented
  3591 according to latex print mode; concrete syntax is like this:
  3592 @{term[show_types] "f(x) = a + x"};
  3593 
  3594 * isatool mkdir provides easy setup of Isabelle session directories,
  3595 including proper document sources;
  3596 
  3597 * generated LaTeX sources are now deleted after successful run
  3598 (isatool document -c); may retain a copy somewhere else via -D option
  3599 of isatool usedir;
  3600 
  3601 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  3602 style files, achieving self-contained LaTeX sources and simplifying
  3603 LaTeX debugging;
  3604 
  3605 * old-style theories now produce (crude) LaTeX output as well;
  3606 
  3607 * browser info session directories are now self-contained (may be put
  3608 on WWW server seperately); improved graphs of nested sessions; removed
  3609 graph for 'all sessions';
  3610 
  3611 * several improvements in isabelle style files; \isabellestyle{it}
  3612 produces fake math mode output; \isamarkupheader is now \section by
  3613 default; see lib/texinputs/isabelle.sty etc.;
  3614 
  3615 
  3616 *** Isar ***
  3617 
  3618 * Isar/Pure: local results and corresponding term bindings are now
  3619 subject to Hindley-Milner polymorphism (similar to ML); this
  3620 accommodates incremental type-inference very nicely;
  3621 
  3622 * Isar/Pure: new derived language element 'obtain' supports
  3623 generalized existence reasoning;
  3624 
  3625 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  3626 support accumulation of results, without applying any rules yet;
  3627 useful to collect intermediate results without explicit name
  3628 references, and for use with transitivity rules with more than 2
  3629 premises;
  3630 
  3631 * Isar/Pure: scalable support for case-analysis type proofs: new
  3632 'case' language element refers to local contexts symbolically, as
  3633 produced by certain proof methods; internally, case names are attached
  3634 to theorems as "tags";
  3635 
  3636 * Isar/Pure: theory command 'hide' removes declarations from
  3637 class/type/const name spaces;
  3638 
  3639 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  3640 indicate potential overloading;
  3641 
  3642 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  3643 
  3644 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  3645 "{a,b,c}" instead of {a,b,c};
  3646 
  3647 * Isar/Pure now provides its own version of intro/elim/dest
  3648 attributes; useful for building new logics, but beware of confusion
  3649 with the version in Provers/classical;
  3650 
  3651 * Isar/Pure: the local context of (non-atomic) goals is provided via
  3652 case name 'antecedent';
  3653 
  3654 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  3655 to the current context is now done automatically);
  3656 
  3657 * Isar/Pure: theory command 'method_setup' provides a simple interface
  3658 for definining proof methods in ML;
  3659 
  3660 * Isar/Provers: intro/elim/dest attributes changed; renamed
  3661 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  3662 most cases, one should have to change intro!! to intro? only);
  3663 replaced "delrule" by "rule del";
  3664 
  3665 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  3666 'symmetric' attribute (the latter supercedes [RS sym]);
  3667 
  3668 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  3669 method modifier); 'simp' method: 'only:' modifier removes loopers as
  3670 well (including splits);
  3671 
  3672 * Isar/Provers: Simplifier and Classical methods now support all kind
  3673 of modifiers used in the past, including 'cong', 'iff', etc.
  3674 
  3675 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  3676 of Simplifier and Classical reasoner);
  3677 
  3678 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  3679 now support named cases; major packages (inductive, datatype, primrec,
  3680 recdef) support case names and properly name parameters;
  3681 
  3682 * Isar/HOL: new transitivity rules for substitution in inequalities --
  3683 monotonicity conditions are extracted to be proven at end of
  3684 calculations;
  3685 
  3686 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  3687 method anyway;
  3688 
  3689 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  3690 split_if split_if_asm; datatype package provides theorems foo.splits =
  3691 foo.split foo.split_asm for each datatype;
  3692 
  3693 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  3694 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  3695 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  3696 use "(cases (simplified))" method in proper proof texts);
  3697 
  3698 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  3699 
  3700 * Isar: names of theorems etc. may be natural numbers as well;
  3701 
  3702 * Isar: 'pr' command: optional arguments for goals_limit and
  3703 ProofContext.prems_limit; no longer prints theory contexts, but only
  3704 proof states;
  3705 
  3706 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  3707 additional print modes to be specified; e.g. "pr(latex)" will print
  3708 proof state according to the Isabelle LaTeX style;
  3709 
  3710 * Isar: improved support for emulating tactic scripts, including proof
  3711 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  3712 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  3713 (for HOL datatypes);
  3714 
  3715 * Isar: simplified (more robust) goal selection of proof methods: 1st
  3716 goal, all goals, or explicit goal specifier (tactic emulation); thus
  3717 'proof method scripts' have to be in depth-first order;
  3718 
  3719 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  3720 
  3721 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  3722 should instead use individual commands for printing items
  3723 (print_commands, print_methods etc.);
  3724 
  3725 * Isar: added 'nothing' --- the empty list of theorems;
  3726 
  3727 
  3728 *** HOL ***
  3729 
  3730 * HOL/MicroJava: formalization of a fragment of Java, together with a
  3731 corresponding virtual machine and a specification of its bytecode
  3732 verifier and a lightweight bytecode verifier, including proofs of
  3733 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  3734 Cornelia Pusch (see also the homepage of project Bali at
  3735 http://isabelle.in.tum.de/Bali/);
  3736 
  3737 * HOL/Algebra: new theory of rings and univariate polynomials, by
  3738 Clemens Ballarin;
  3739 
  3740 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  3741 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  3742 Rasmussen;
  3743 
  3744 * HOL/Lattice: fundamental concepts of lattice theory and order
  3745 structures, including duals, properties of bounds versus algebraic
  3746 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  3747 Theorem for complete lattices etc.; may also serve as a demonstration
  3748 for abstract algebraic reasoning using axiomatic type classes, and
  3749 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  3750 
  3751 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  3752 von Oheimb;
  3753 
  3754 * HOL/IMPP: extension of IMP with local variables and mutually
  3755 recursive procedures, by David von Oheimb;
  3756 
  3757 * HOL/Lambda: converted into new-style theory and document;
  3758 
  3759 * HOL/ex/Multiquote: example of multiple nested quotations and
  3760 anti-quotations -- basically a generalized version of de-Bruijn
  3761 representation; very useful in avoiding lifting of operations;
  3762 
  3763 * HOL/record: added general record equality rule to simpset; fixed
  3764 select-update simplification procedure to handle extended records as
  3765 well; admit "r" as field name;
  3766 
  3767 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  3768 other numeric types and also as the identity of groups, rings, etc.;
  3769 
  3770 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  3771 Types nat and int belong to this axclass;
  3772 
  3773 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  3774    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  3775    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  3776   two terms #m*u and #n*u are replaced by #(m+n)*u
  3777     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  3778   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  3779     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  3780 
  3781 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  3782 powerful prover for predicate logic but knows nothing of clasets; see
  3783 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  3784 
  3785 * HOL: new version of "case_tac" subsumes both boolean case split and
  3786 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  3787 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  3788 
  3789 * HOL: simplification no longer dives into case-expressions: only the
  3790 selector expression is simplified, but not the remaining arms; to
  3791 enable full simplification of case-expressions for datatype t, you may
  3792 remove t.weak_case_cong from the simpset, either globally (Delcongs
  3793 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  3794 
  3795 * HOL/recdef: the recursion equations generated by 'recdef' for
  3796 function 'f' are now called f.simps instead of f.rules; if all
  3797 termination conditions are proved automatically, these simplification
  3798 rules are added to the simpset, as in primrec; rules may be named
  3799 individually as well, resulting in a separate list of theorems for
  3800 each equation;
  3801 
  3802 * HOL/While is a new theory that provides a while-combinator. It
  3803 permits the definition of tail-recursive functions without the
  3804 provision of a termination measure. The latter is necessary once the
  3805 invariant proof rule for while is applied.
  3806 
  3807 * HOL: new (overloaded) notation for the set of elements below/above
  3808 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  3809 
  3810 * HOL: theorems impI, allI, ballI bound as "strip";
  3811 
  3812 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  3813 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  3814 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  3815 
  3816 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  3817 
  3818 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  3819 main HOL, but was unused);
  3820 
  3821 * HOL: fewer consts declared as global (e.g. have to refer to
  3822 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  3823 
  3824 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  3825 in case of overlap with user translations (e.g. judgements over
  3826 tuples); (note that the underlying logical represenation is still
  3827 bogus);
  3828 
  3829 
  3830 *** ZF ***
  3831 
  3832 * ZF: simplification automatically cancels common terms in arithmetic
  3833 expressions over nat and int;
  3834 
  3835 * ZF: new treatment of nat to minimize type-checking: all operators
  3836 coerce their operands to a natural number using the function natify,
  3837 making the algebraic laws unconditional;
  3838 
  3839 * ZF: as above, for int: operators coerce their operands to an integer
  3840 using the function intify;
  3841 
  3842 * ZF: the integer library now contains many of the usual laws for the
  3843 orderings, including $<=, and monotonicity laws for $+ and $*;
  3844 
  3845 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  3846 simplification;
  3847 
  3848 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  3849 to the simplifier and classical reasoner simultaneously;
  3850 
  3851 
  3852 *** General ***
  3853 
  3854 * Provers: blast_tac now handles actual object-logic rules as
  3855 assumptions; note that auto_tac uses blast_tac internally as well;
  3856 
  3857 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  3858 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  3859 
  3860 * Provers: delrules now handles destruct rules as well (no longer need
  3861 explicit make_elim);
  3862 
  3863 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  3864   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  3865 use instead the strong form,
  3866   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  3867 in HOL, FOL and ZF the function cla_make_elim will create such rules
  3868 from destruct-rules;
  3869 
  3870 * Provers: Simplifier.easy_setup provides a fast path to basic
  3871 Simplifier setup for new object-logics;
  3872 
  3873 * Pure: AST translation rules no longer require constant head on LHS;
  3874 
  3875 * Pure: improved name spaces: ambiguous output is qualified; support
  3876 for hiding of names;
  3877 
  3878 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  3879 XSYMBOL_HOME; no longer need to do manual configuration in most
  3880 situations;
  3881 
  3882 * system: compression of ML heaps images may now be controlled via -c
  3883 option of isabelle and isatool usedir (currently only observed by
  3884 Poly/ML);
  3885 
  3886 * system: isatool installfonts may handle X-Symbol fonts as well (very
  3887 useful for remote X11);
  3888 
  3889 * system: provide TAGS file for Isabelle sources;
  3890 
  3891 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  3892 order;
  3893 
  3894 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  3895 timing flag supersedes proof_timing and Toplevel.trace;
  3896 
  3897 * ML: new combinators |>> and |>>> for incremental transformations
  3898 with secondary results (e.g. certain theory extensions):
  3899 
  3900 * ML: PureThy.add_defs gets additional argument to indicate potential
  3901 overloading (usually false);
  3902 
  3903 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  3904 results;
  3905 
  3906 
  3907 
  3908 New in Isabelle99 (October 1999)
  3909 --------------------------------
  3910 
  3911 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  3912 
  3913 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  3914 are no longer simplified.  (This allows the simplifier to unfold recursive
  3915 functional programs.)  To restore the old behaviour, declare
  3916 
  3917     Delcongs [if_weak_cong];
  3918 
  3919 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  3920 complement;
  3921 
  3922 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  3923 
  3924 * HOL/datatype: mutual_induct_tac no longer exists --
  3925   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  3926 
  3927 * HOL/typedef: fixed type inference for representing set; type
  3928 arguments now have to occur explicitly on the rhs as type constraints;
  3929 
  3930 * ZF: The con_defs part of an inductive definition may no longer refer
  3931 to constants declared in the same theory;
  3932 
  3933 * HOL, ZF: the function mk_cases, generated by the inductive
  3934 definition package, has lost an argument.  To simplify its result, it
  3935 uses the default simpset instead of a supplied list of theorems.
  3936 
  3937 * HOL/List: the constructors of type list are now Nil and Cons;
  3938 
  3939 * Simplifier: the type of the infix ML functions
  3940         setSSolver addSSolver setSolver addSolver
  3941 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  3942 for packaging solvers. A solver is created via
  3943         mk_solver: string -> (thm list -> int -> tactic) -> solver
  3944 where the string argument is only a comment.
  3945 
  3946 
  3947 *** Proof tools ***
  3948 
  3949 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  3950 decision procedure for linear arithmetic. Currently it is used for
  3951 types `nat', `int', and `real' in HOL (see below); it can, should and
  3952 will be instantiated for other types and logics as well.
  3953 
  3954 * The simplifier now accepts rewrite rules with flexible heads, eg
  3955      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  3956   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  3957   matching.
  3958 
  3959 
  3960 *** General ***
  3961 
  3962 * New Isabelle/Isar subsystem provides an alternative to traditional
  3963 tactical theorem proving; together with the ProofGeneral/isar user
  3964 interface it offers an interactive environment for developing human
  3965 readable proof documents (Isar == Intelligible semi-automated
  3966 reasoning); for further information see isatool doc isar-ref,
  3967 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  3968 
  3969 * improved and simplified presentation of theories: better HTML markup
  3970 (including colors), graph views in several sizes; isatool usedir now
  3971 provides a proper interface for user theories (via -P option); actual
  3972 document preparation based on (PDF)LaTeX is available as well (for
  3973 new-style theories only); see isatool doc system for more information;
  3974 
  3975 * native support for Proof General, both for classic Isabelle and
  3976 Isabelle/Isar;
  3977 
  3978 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  3979 using the graph browser tool;
  3980 
  3981 * Isabelle manuals now also available as PDF;
  3982 
  3983 * theory loader rewritten from scratch (may not be fully
  3984 bug-compatible); old loadpath variable has been replaced by show_path,
  3985 add_path, del_path, reset_path functions; new operations such as
  3986 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  3987 isatool doc ref);
  3988 
  3989 * improved isatool install: option -k creates KDE application icon,
  3990 option -p DIR installs standalone binaries;
  3991 
  3992 * added ML_PLATFORM setting (useful for cross-platform installations);
  3993 more robust handling of platform specific ML images for SML/NJ;
  3994 
  3995 * the settings environment is now statically scoped, i.e. it is never
  3996 created again in sub-processes invoked from isabelle, isatool, or
  3997 Isabelle;
  3998 
  3999 * path element specification '~~' refers to '$ISABELLE_HOME';
  4000 
  4001 * in locales, the "assumes" and "defines" parts may be omitted if
  4002 empty;
  4003 
  4004 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  4005 long arrows);
  4006 
  4007 * new print_mode "HTML";
  4008 
  4009 * new flag show_tags controls display of tags of theorems (which are
  4010 basically just comments that may be attached by some tools);
  4011 
  4012 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  4013 mode and goal output format:
  4014 
  4015 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  4016 244c244
  4017 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  4018 ---
  4019 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  4020 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  4021 181c181
  4022 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  4023 ---
  4024 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  4025 
  4026 * function bind_thms stores lists of theorems (cf. bind_thm);
  4027 
  4028 * new shorthand tactics ftac, eatac, datac, fatac;
  4029 
  4030 * qed (and friends) now accept "" as result name; in that case the
  4031 theorem is not stored, but proper checks and presentation of the
  4032 result still apply;
  4033 
  4034 * theorem database now also indexes constants "Trueprop", "all",
  4035 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  4036 
  4037 
  4038 *** HOL ***
  4039 
  4040 ** HOL arithmetic **
  4041 
  4042 * There are now decision procedures for linear arithmetic over nat and
  4043 int:
  4044 
  4045 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  4046 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  4047 are treated as atomic; subformulae not involving type `nat' or `int'
  4048 are ignored; quantified subformulae are ignored unless they are
  4049 positive universal or negative existential. The tactic has to be
  4050 invoked by hand and can be a little bit slow. In particular, the
  4051 running time is exponential in the number of occurrences of `min' and
  4052 `max', and `-' on `nat'.
  4053 
  4054 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  4055 (negated) (in)equalities among the premises and the conclusion into
  4056 account (i.e. no compound formulae) and does not know about `min' and
  4057 `max', and `-' on `nat'. It is fast and is used automatically by the
  4058 simplifier.
  4059 
  4060 NB: At the moment, these decision procedures do not cope with mixed
  4061 nat/int formulae where the two parts interact, such as `m < n ==>
  4062 int(m) < int(n)'.
  4063 
  4064 * HOL/Numeral provides a generic theory of numerals (encoded
  4065 efficiently as bit strings); setup for types nat/int/real is in place;
  4066 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  4067 int, existing theories and proof scripts may require a few additional
  4068 type constraints;
  4069 
  4070 * integer division and remainder can now be performed on constant
  4071 arguments;
  4072 
  4073 * many properties of integer multiplication, division and remainder
  4074 are now available;
  4075 
  4076 * An interface to the Stanford Validity Checker (SVC) is available through the
  4077 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  4078 are proved automatically.  SVC must be installed separately, and its results
  4079 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  4080 invocation of the underlying oracle).  For SVC see
  4081   http://verify.stanford.edu/SVC
  4082 
  4083 * IsaMakefile: the HOL-Real target now builds an actual image;
  4084 
  4085 
  4086 ** HOL misc **
  4087 
  4088 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  4089 (in Isabelle/Isar) -- by Gertrud Bauer;
  4090 
  4091 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  4092 analysis for assembly languages with subtypes;
  4093 
  4094 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  4095 -- avoids syntactic ambiguities and treats state, transition, and
  4096 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  4097 changed syntax and (many) tactics;
  4098 
  4099 * HOL/inductive: Now also handles more general introduction rules such
  4100   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  4101   theorems are now maintained within the theory (maintained via the
  4102   "mono" attribute);
  4103 
  4104 * HOL/datatype: Now also handles arbitrarily branching datatypes
  4105   (using function types) such as
  4106 
  4107   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  4108 
  4109 * HOL/record: record_simproc (part of the default simpset) takes care
  4110 of selectors applied to updated records; record_split_tac is no longer
  4111 part of the default claset; update_defs may now be removed from the
  4112 simpset in many cases; COMPATIBILITY: old behavior achieved by
  4113 
  4114   claset_ref () := claset() addSWrapper record_split_wrapper;
  4115   Delsimprocs [record_simproc]
  4116 
  4117 * HOL/typedef: fixed type inference for representing set; type
  4118 arguments now have to occur explicitly on the rhs as type constraints;
  4119 
  4120 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  4121 names rather than an ML expression;
  4122 
  4123 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  4124 supplied later.  Program schemes can be defined, such as
  4125     "While B C s = (if B s then While B C (C s) else s)"
  4126 where the well-founded relation can be chosen after B and C have been given.
  4127 
  4128 * HOL/List: the constructors of type list are now Nil and Cons;
  4129 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  4130 course, ML tools referring to List.list.op # etc. have to be adapted;
  4131 
  4132 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  4133 disabled by default; run isabelle with option -m HOL to get back to
  4134 the original Gordon/HOL-style output;
  4135 
  4136 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  4137 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  4138 
  4139 * HOL basic syntax simplified (more orthogonal): all variants of
  4140 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  4141 Eps operator is provided as well: "SOME x. P[x]";
  4142 
  4143 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  4144 
  4145 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  4146 thus available for user theories;
  4147 
  4148 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  4149 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  4150 time;
  4151 
  4152 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  4153 several times and then mp;
  4154 
  4155 
  4156 *** LK ***
  4157 
  4158 * the notation <<...>> is now available as a notation for sequences of
  4159 formulas;
  4160 
  4161 * the simplifier is now installed
  4162 
  4163 * the axiom system has been generalized (thanks to Soren Heilmann)
  4164 
  4165 * the classical reasoner now has a default rule database
  4166 
  4167 
  4168 *** ZF ***
  4169 
  4170 * new primrec section allows primitive recursive functions to be given
  4171 directly (as in HOL) over datatypes and the natural numbers;
  4172 
  4173 * new tactics induct_tac and exhaust_tac for induction (or case
  4174 analysis) over datatypes and the natural numbers;
  4175 
  4176 * the datatype declaration of type T now defines the recursor T_rec;
  4177 
  4178 * simplification automatically does freeness reasoning for datatype
  4179 constructors;
  4180 
  4181 * automatic type-inference, with AddTCs command to insert new
  4182 type-checking rules;
  4183 
  4184 * datatype introduction rules are now added as Safe Introduction rules
  4185 to the claset;
  4186 
  4187 * the syntax "if P then x else y" is now available in addition to
  4188 if(P,x,y);
  4189 
  4190 
  4191 *** Internal programming interfaces ***
  4192 
  4193 * tuned simplifier trace output; new flag debug_simp;
  4194 
  4195 * structures Vartab / Termtab (instances of TableFun) offer efficient
  4196 tables indexed by indexname_ord / term_ord (compatible with aconv);
  4197 
  4198 * AxClass.axclass_tac lost the theory argument;
  4199 
  4200 * tuned current_goals_markers semantics: begin / end goal avoids
  4201 printing empty lines;
  4202 
  4203 * removed prs and prs_fn hook, which was broken because it did not
  4204 include \n in its semantics, forcing writeln to add one
  4205 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  4206 string -> unit if you really want to output text without newline;
  4207 
  4208 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  4209 plain output, interface builders may have to enable 'isabelle_font'
  4210 mode to get Isabelle font glyphs as before;
  4211 
  4212 * refined token_translation interface; INCOMPATIBILITY: output length
  4213 now of type real instead of int;
  4214 
  4215 * theory loader actions may be traced via new ThyInfo.add_hook
  4216 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  4217 your own database of information attached to *whole* theories -- as
  4218 opposed to intra-theory data slots offered via TheoryDataFun;
  4219 
  4220 * proper handling of dangling sort hypotheses (at last!);
  4221 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  4222 extra sort hypotheses that can be witnessed from the type signature;
  4223 the force_strip_shyps flag is gone, any remaining shyps are simply
  4224 left in the theorem (with a warning issued by strip_shyps_warning);
  4225 
  4226 
  4227 
  4228 New in Isabelle98-1 (October 1998)
  4229 ----------------------------------
  4230 
  4231 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  4232 
  4233 * several changes of automated proof tools;
  4234 
  4235 * HOL: major changes to the inductive and datatype packages, including
  4236 some minor incompatibilities of theory syntax;
  4237 
  4238 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  4239 called `inj_on';
  4240 
  4241 * HOL: removed duplicate thms in Arith:
  4242   less_imp_add_less  should be replaced by  trans_less_add1
  4243   le_imp_add_le      should be replaced by  trans_le_add1
  4244 
  4245 * HOL: unary minus is now overloaded (new type constraints may be
  4246 required);
  4247 
  4248 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  4249 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  4250 now taken as an integer constant.
  4251 
  4252 * Pure: ML function 'theory_of' renamed to 'theory';
  4253 
  4254 
  4255 *** Proof tools ***
  4256 
  4257 * Simplifier:
  4258   1. Asm_full_simp_tac is now more aggressive.
  4259      1. It will sometimes reorient premises if that increases their power to
  4260         simplify.
  4261      2. It does no longer proceed strictly from left to right but may also
  4262         rotate premises to achieve further simplification.
  4263      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  4264      old Asm_full_simp_tac in that it does not rotate premises.
  4265   2. The simplifier now knows a little bit about nat-arithmetic.
  4266 
  4267 * Classical reasoner: wrapper mechanism for the classical reasoner now
  4268 allows for selected deletion of wrappers, by introduction of names for
  4269 wrapper functionals.  This implies that addbefore, addSbefore,
  4270 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  4271 and that adding two tactics with the same name overwrites the first
  4272 one (emitting a warning).
  4273   type wrapper = (int -> tactic) -> (int -> tactic)
  4274   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  4275   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  4276   delWrapper, delSWrapper: claset *  string            -> claset
  4277   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  4278 
  4279 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  4280 semantics; addbefore now affects only the unsafe part of step_tac
  4281 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  4282 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  4283 by Force_tac;
  4284 
  4285 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  4286 compWrapper; added safe wrapper (and access functions for it);
  4287 
  4288 * HOL/split_all_tac is now much faster and fails if there is nothing
  4289 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  4290 and the names of the automatically generated variables have changed.
  4291 split_all_tac has moved within claset() from unsafe wrappers to safe
  4292 wrappers, which means that !!-bound variables are split much more
  4293 aggressively, and safe_tac and clarify_tac now split such variables.
  4294 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  4295 Note: the same holds for record_split_tac, which does the job of
  4296 split_all_tac for record fields.
  4297 
  4298 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  4299 permanently to the default simpset using Addsplits just like
  4300 Addsimps. They can be removed via Delsplits just like
  4301 Delsimps. Lower-case versions are also available.
  4302 
  4303 * HOL/Simplifier: The rule split_if is now part of the default
  4304 simpset. This means that the simplifier will eliminate all occurrences
  4305 of if-then-else in the conclusion of a goal. To prevent this, you can
  4306 either remove split_if completely from the default simpset by
  4307 `Delsplits [split_if]' or remove it in a specific call of the
  4308 simplifier using `... delsplits [split_if]'.  You can also add/delete
  4309 other case splitting rules to/from the default simpset: every datatype
  4310 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  4311 t is the name of the datatype).
  4312 
  4313 * Classical reasoner / Simplifier combination: new force_tac (and
  4314 derivatives Force_tac, force) combines rewriting and classical
  4315 reasoning (and whatever other tools) similarly to auto_tac, but is
  4316 aimed to solve the given subgoal completely.
  4317 
  4318 
  4319 *** General ***
  4320 
  4321 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  4322 and `goalw': the theory is no longer needed as an explicit argument -
  4323 the current theory context is used; assumptions are no longer returned
  4324 at the ML-level unless one of them starts with ==> or !!; it is
  4325 recommended to convert to these new commands using isatool fixgoal
  4326 (backup your sources first!);
  4327 
  4328 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  4329 the current theory context, and 'theory' to lookup stored theories;
  4330 
  4331 * new theory section 'locale' for declaring constants, assumptions and
  4332 definitions that have local scope;
  4333 
  4334 * new theory section 'nonterminals' for purely syntactic types;
  4335 
  4336 * new theory section 'setup' for generic ML setup functions
  4337 (e.g. package initialization);
  4338 
  4339 * the distribution now includes Isabelle icons: see
  4340 lib/logo/isabelle-{small,tiny}.xpm;
  4341 
  4342 * isatool install - install binaries with absolute references to
  4343 ISABELLE_HOME/bin;
  4344 
  4345 * isatool logo -- create instances of the Isabelle logo (as EPS);
  4346 
  4347 * print mode 'emacs' reserved for Isamode;
  4348 
  4349 * support multiple print (ast) translations per constant name;
  4350 
  4351 * theorems involving oracles are now printed with a suffixed [!];
  4352 
  4353 
  4354 *** HOL ***
  4355 
  4356 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  4357 
  4358 * HOL/inductive package reorganized and improved: now supports mutual
  4359 definitions such as
  4360 
  4361   inductive EVEN ODD
  4362     intrs
  4363       null "0 : EVEN"
  4364       oddI "n : EVEN ==> Suc n : ODD"
  4365       evenI "n : ODD ==> Suc n : EVEN"
  4366 
  4367 new theorem list "elims" contains an elimination rule for each of the
  4368 recursive sets; inductive definitions now handle disjunctive premises
  4369 correctly (also ZF);
  4370 
  4371 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  4372 "mutual_induct" no longer exists - the induction rule is always
  4373 contained in "induct";
  4374 
  4375 
  4376 * HOL/datatype package re-implemented and greatly improved: now
  4377 supports mutually recursive datatypes such as
  4378 
  4379   datatype
  4380     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  4381             | SUM ('a aexp) ('a aexp)
  4382             | DIFF ('a aexp) ('a aexp)
  4383             | NUM 'a
  4384   and
  4385     'a bexp = LESS ('a aexp) ('a aexp)
  4386             | AND ('a bexp) ('a bexp)
  4387             | OR ('a bexp) ('a bexp)
  4388 
  4389 as well as indirectly recursive datatypes such as
  4390 
  4391   datatype
  4392     ('a, 'b) term = Var 'a
  4393                   | App 'b ((('a, 'b) term) list)
  4394 
  4395 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  4396 induction on mutually / indirectly recursive datatypes.
  4397 
  4398 Primrec equations are now stored in theory and can be accessed via
  4399 <function_name>.simps.
  4400 
  4401 INCOMPATIBILITIES:
  4402 
  4403   - Theories using datatypes must now have theory Datatype as an
  4404     ancestor.
  4405   - The specific <typename>.induct_tac no longer exists - use the
  4406     generic induct_tac instead.
  4407   - natE has been renamed to nat.exhaust - use exhaust_tac
  4408     instead of res_inst_tac ... natE. Note that the variable
  4409     names in nat.exhaust differ from the names in natE, this
  4410     may cause some "fragile" proofs to fail.
  4411   - The theorems split_<typename>_case and split_<typename>_case_asm
  4412     have been renamed to <typename>.split and <typename>.split_asm.
  4413   - Since default sorts of type variables are now handled correctly,
  4414     some datatype definitions may have to be annotated with explicit
  4415     sort constraints.
  4416   - Primrec definitions no longer require function name and type
  4417     of recursive argument.
  4418 
  4419 Consider using isatool fixdatatype to adapt your theories and proof
  4420 scripts to the new package (backup your sources first!).
  4421 
  4422 
  4423 * HOL/record package: considerably improved implementation; now
  4424 includes concrete syntax for record types, terms, updates; theorems
  4425 for surjective pairing and splitting !!-bound record variables; proof
  4426 support is as follows:
  4427 
  4428   1) standard conversions (selectors or updates applied to record
  4429 constructor terms) are part of the standard simpset;
  4430 
  4431   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  4432 made part of standard simpset and claset via addIffs;
  4433 
  4434   3) a tactic for record field splitting (record_split_tac) is part of
  4435 the standard claset (addSWrapper);
  4436 
  4437 To get a better idea about these rules you may retrieve them via
  4438 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  4439 the name of your record type.
  4440 
  4441 The split tactic 3) conceptually simplifies by the following rule:
  4442 
  4443   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  4444 
  4445 Thus any record variable that is bound by meta-all will automatically
  4446 blow up into some record constructor term, consequently the
  4447 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  4448 solve record problems automatically.
  4449 
  4450 
  4451 * reorganized the main HOL image: HOL/Integ and String loaded by
  4452 default; theory Main includes everything;
  4453 
  4454 * automatic simplification of integer sums and comparisons, using cancellation;
  4455 
  4456 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  4457 
  4458 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  4459 
  4460 * many new identities for unions, intersections, set difference, etc.;
  4461 
  4462 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  4463 called split_if, split_split, split_sum_case and split_nat_case (to go
  4464 with add/delsplits);
  4465 
  4466 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  4467 (?x::unit) = (); this is made part of the default simpset, which COULD
  4468 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  4469 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  4470 unit_abs_eta_conv is added in order to counter the effect of
  4471 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  4472 %u.f();
  4473 
  4474 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  4475 makes more sense);
  4476 
  4477 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  4478   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  4479   disjointness reasoning but breaking a few old proofs.
  4480 
  4481 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  4482 to 'converse' from 'inverse' (for compatibility with ZF and some
  4483 literature);
  4484 
  4485 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  4486 the well-founded relation;
  4487 
  4488 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  4489     Compl A.  The "Compl" syntax remains available as input syntax for this
  4490     release ONLY.
  4491 
  4492 * HOL/Update: new theory of function updates:
  4493     f(a:=b) == %x. if x=a then b else f x
  4494 may also be iterated as in f(a:=b,c:=d,...);
  4495 
  4496 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  4497 
  4498 * HOL/List:
  4499   - new function list_update written xs[i:=v] that updates the i-th
  4500     list position. May also be iterated as in xs[i:=a,j:=b,...].
  4501   - new function `upt' written [i..j(] which generates the list
  4502     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  4503     bound write [i..j], which is a shorthand for [i..j+1(].
  4504   - new lexicographic orderings and corresponding wellfoundedness theorems.
  4505 
  4506 * HOL/Arith:
  4507   - removed 'pred' (predecessor) function;
  4508   - generalized some theorems about n-1;
  4509   - many new laws about "div" and "mod";
  4510   - new laws about greatest common divisors (see theory ex/Primes);
  4511 
  4512 * HOL/Relation: renamed the relational operator r^-1 "converse"
  4513 instead of "inverse";
  4514 
  4515 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  4516   of the multiset ordering;
  4517 
  4518 * directory HOL/Real: a construction of the reals using Dedekind cuts
  4519   (not included by default);
  4520 
  4521 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  4522 
  4523 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  4524   programs, i.e. different program variables may have different types.
  4525 
  4526 * calling (stac rew i) now fails if "rew" has no effect on the goal
  4527   [previously, this check worked only if the rewrite rule was unconditional]
  4528   Now rew can involve either definitions or equalities (either == or =).
  4529 
  4530 
  4531 *** ZF ***
  4532 
  4533 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  4534   only the theorems proved on ZF.ML;
  4535 
  4536 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  4537   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  4538   disjointness reasoning but breaking a few old proofs.
  4539 
  4540 * ZF/Update: new theory of function updates
  4541     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  4542   may also be iterated as in f(a:=b,c:=d,...);
  4543 
  4544 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  4545 
  4546 * calling (stac rew i) now fails if "rew" has no effect on the goal
  4547   [previously, this check worked only if the rewrite rule was unconditional]
  4548   Now rew can involve either definitions or equalities (either == or =).
  4549 
  4550 * case_tac provided for compatibility with HOL
  4551     (like the old excluded_middle_tac, but with subgoals swapped)
  4552 
  4553 
  4554 *** Internal programming interfaces ***
  4555 
  4556 * Pure: several new basic modules made available for general use, see
  4557 also src/Pure/README;
  4558 
  4559 * improved the theory data mechanism to support encapsulation (data
  4560 kind name replaced by private Object.kind, acting as authorization
  4561 key); new type-safe user interface via functor TheoryDataFun; generic
  4562 print_data function becomes basically useless;
  4563 
  4564 * removed global_names compatibility flag -- all theory declarations
  4565 are qualified by default;
  4566 
  4567 * module Pure/Syntax now offers quote / antiquote translation
  4568 functions (useful for Hoare logic etc. with implicit dependencies);
  4569 see HOL/ex/Antiquote for an example use;
  4570 
  4571 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  4572 cterm -> thm;
  4573 
  4574 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  4575 subgoal;
  4576 
  4577 * Display.print_goals function moved to Locale.print_goals;
  4578 
  4579 * standard print function for goals supports current_goals_markers
  4580 variable for marking begin of proof, end of proof, start of goal; the
  4581 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  4582 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  4583 for example;
  4584 
  4585 
  4586 
  4587 New in Isabelle98 (January 1998)
  4588 --------------------------------
  4589 
  4590 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  4591 
  4592 * changed lexical syntax of terms / types: dots made part of long
  4593 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  4594 
  4595 * simpset (and claset) reference variable replaced by functions
  4596 simpset / simpset_ref;
  4597 
  4598 * no longer supports theory aliases (via merge) and non-trivial
  4599 implicit merge of thms' signatures;
  4600 
  4601 * most internal names of constants changed due to qualified names;
  4602 
  4603 * changed Pure/Sequence interface (see Pure/seq.ML);
  4604 
  4605 
  4606 *** General Changes ***
  4607 
  4608 * hierachically structured name spaces (for consts, types, axms, thms
  4609 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  4610 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  4611 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  4612 long_names for fully qualified output names; NOTE: ML programs
  4613 (special tactics, packages etc.) referring to internal names may have
  4614 to be adapted to cope with fully qualified names; in case of severe
  4615 backward campatibility problems try setting 'global_names' at compile
  4616 time to have enrything declared within a flat name space; one may also
  4617 fine tune name declarations in theories via the 'global' and 'local'
  4618 section;
  4619 
  4620 * reimplemented the implicit simpset and claset using the new anytype
  4621 data filed in signatures; references simpset:simpset ref etc. are
  4622 replaced by functions simpset:unit->simpset and
  4623 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  4624 to patch your ML files accordingly;
  4625 
  4626 * HTML output now includes theory graph data for display with Java
  4627 applet or isatool browser; data generated automatically via isatool
  4628 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  4629 
  4630 * defs may now be conditional; improved rewrite_goals_tac to handle
  4631 conditional equations;
  4632 
  4633 * defs now admits additional type arguments, using TYPE('a) syntax;
  4634 
  4635 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  4636 creates a new theory node; implicit merge of thms' signatures is
  4637 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  4638 transfer:theory->thm->thm in (rare) cases;
  4639 
  4640 * improved handling of draft signatures / theories; draft thms (and
  4641 ctyps, cterms) are automatically promoted to real ones;
  4642 
  4643 * slightly changed interfaces for oracles: admit many per theory, named
  4644 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  4645 
  4646 * print_goals: optional output of const types (set show_consts and
  4647 show_types);
  4648 
  4649 * improved output of warnings (###) and errors (***);
  4650 
  4651 * subgoal_tac displays a warning if the new subgoal has type variables;
  4652 
  4653 * removed old README and Makefiles;
  4654 
  4655 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  4656 
  4657 * removed obsolete init_pps and init_database;
  4658 
  4659 * deleted the obsolete tactical STATE, which was declared by
  4660     fun STATE tacfun st = tacfun st st;
  4661 
  4662 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  4663 (which abbreviates $HOME);
  4664 
  4665 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  4666 use isatool fixseq to adapt your ML programs (this works for fully
  4667 qualified references to the Sequence structure only!);
  4668 
  4669 * use_thy no longer requires writable current directory; it always
  4670 reloads .ML *and* .thy file, if either one is out of date;
  4671 
  4672 
  4673 *** Classical Reasoner ***
  4674 
  4675 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  4676 tactics that use classical reasoning to simplify a subgoal without
  4677 splitting it into several subgoals;
  4678 
  4679 * Safe_tac: like safe_tac but uses the default claset;
  4680 
  4681 
  4682 *** Simplifier ***
  4683 
  4684 * added simplification meta rules:
  4685     (asm_)(full_)simplify: simpset -> thm -> thm;
  4686 
  4687 * simplifier.ML no longer part of Pure -- has to be loaded by object
  4688 logics (again);
  4689 
  4690 * added prems argument to simplification procedures;
  4691 
  4692 * HOL, FOL, ZF: added infix function `addsplits':
  4693   instead of `<simpset> setloop (split_tac <thms>)'
  4694   you can simply write `<simpset> addsplits <thms>'
  4695 
  4696 
  4697 *** Syntax ***
  4698 
  4699 * TYPE('a) syntax for type reflection terms;
  4700 
  4701 * no longer handles consts with name "" -- declare as 'syntax' instead;
  4702 
  4703 * pretty printer: changed order of mixfix annotation preference (again!);
  4704 
  4705 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  4706 
  4707 
  4708 *** HOL ***
  4709 
  4710 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  4711   with `addloop' of the simplifier to faciliate case splitting in premises.
  4712 
  4713 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  4714 
  4715 * HOL/Auth: new protocol proofs including some for the Internet
  4716   protocol TLS;
  4717 
  4718 * HOL/Map: new theory of `maps' a la VDM;
  4719 
  4720 * HOL/simplifier: simplification procedures nat_cancel_sums for
  4721 cancelling out common nat summands from =, <, <= (in)equalities, or
  4722 differences; simplification procedures nat_cancel_factor for
  4723 cancelling common factor from =, <, <= (in)equalities over natural
  4724 sums; nat_cancel contains both kinds of procedures, it is installed by
  4725 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  4726 
  4727 * HOL/simplifier: terms of the form
  4728   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  4729   are rewritten to
  4730   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  4731   and those of the form
  4732   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  4733   are rewritten to
  4734   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  4735 
  4736 * HOL/datatype
  4737   Each datatype `t' now comes with a theorem `split_t_case' of the form
  4738 
  4739   P(t_case f1 ... fn x) =
  4740      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  4741         ...
  4742        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  4743      )
  4744 
  4745   and a theorem `split_t_case_asm' of the form
  4746 
  4747   P(t_case f1 ... fn x) =
  4748     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  4749         ...
  4750        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  4751      )
  4752   which can be added to a simpset via `addsplits'. The existing theorems
  4753   expand_list_case and expand_option_case have been renamed to
  4754   split_list_case and split_option_case.
  4755 
  4756 * HOL/Arithmetic:
  4757   - `pred n' is automatically converted to `n-1'.
  4758     Users are strongly encouraged not to use `pred' any longer,
  4759     because it will disappear altogether at some point.
  4760   - Users are strongly encouraged to write "0 < n" rather than
  4761     "n ~= 0". Theorems and proof tools have been modified towards this
  4762     `standard'.
  4763 
  4764 * HOL/Lists:
  4765   the function "set_of_list" has been renamed "set" (and its theorems too);
  4766   the function "nth" now takes its arguments in the reverse order and
  4767   has acquired the infix notation "!" as in "xs!n".
  4768 
  4769 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  4770 
  4771 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  4772   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  4773 
  4774 * HOL/record: extensible records with schematic structural subtyping
  4775 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  4776 still lacks various theorems and concrete record syntax;
  4777 
  4778 
  4779 *** HOLCF ***
  4780 
  4781 * removed "axioms" and "generated by" sections;
  4782 
  4783 * replaced "ops" section by extended "consts" section, which is capable of
  4784   handling the continuous function space "->" directly;
  4785 
  4786 * domain package:
  4787   . proves theorems immediately and stores them in the theory,
  4788   . creates hierachical name space,
  4789   . now uses normal mixfix annotations (instead of cinfix...),
  4790   . minor changes to some names and values (for consistency),
  4791   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  4792   . separator between mutual domain defs: changed "," to "and",
  4793   . improved handling of sort constraints;  now they have to
  4794     appear on the left-hand side of the equations only;
  4795 
  4796 * fixed LAM <x,y,zs>.b syntax;
  4797 
  4798 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  4799 adm (%x. P (t x)), where P is chainfinite and t continuous;
  4800 
  4801 
  4802 *** FOL and ZF ***
  4803 
  4804 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  4805   with `addloop' of the simplifier to faciliate case splitting in premises.
  4806 
  4807 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  4808 in HOL, they strip ALL and --> from proved theorems;
  4809 
  4810 
  4811 
  4812 New in Isabelle94-8 (May 1997)
  4813 ------------------------------
  4814 
  4815 *** General Changes ***
  4816 
  4817 * new utilities to build / run / maintain Isabelle etc. (in parts
  4818 still somewhat experimental); old Makefiles etc. still functional;
  4819 
  4820 * new 'Isabelle System Manual';
  4821 
  4822 * INSTALL text, together with ./configure and ./build scripts;
  4823 
  4824 * reimplemented type inference for greater efficiency, better error
  4825 messages and clean internal interface;
  4826 
  4827 * prlim command for dealing with lots of subgoals (an easier way of
  4828 setting goals_limit);
  4829 
  4830 
  4831 *** Syntax ***
  4832 
  4833 * supports alternative (named) syntax tables (parser and pretty
  4834 printer); internal interface is provided by add_modesyntax(_i);
  4835 
  4836 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  4837 be used in conjunction with the Isabelle symbol font; uses the
  4838 "symbols" syntax table;
  4839 
  4840 * added token_translation interface (may translate name tokens in
  4841 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  4842 the current print_mode); IMPORTANT: user print translation functions
  4843 are responsible for marking newly introduced bounds
  4844 (Syntax.mark_boundT);
  4845 
  4846 * token translations for modes "xterm" and "xterm_color" that display
  4847 names in bold, underline etc. or colors (which requires a color
  4848 version of xterm);
  4849 
  4850 * infixes may now be declared with names independent of their syntax;
  4851 
  4852 * added typed_print_translation (like print_translation, but may
  4853 access type of constant);
  4854 
  4855 
  4856 *** Classical Reasoner ***
  4857 
  4858 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  4859 some limitations.  Blast_tac...
  4860   + ignores addss, addbefore, addafter; this restriction is intrinsic
  4861   + ignores elimination rules that don't have the correct format
  4862         (the conclusion MUST be a formula variable)
  4863   + ignores types, which can make HOL proofs fail
  4864   + rules must not require higher-order unification, e.g. apply_type in ZF
  4865     [message "Function Var's argument not a bound variable" relates to this]
  4866   + its proof strategy is more general but can actually be slower
  4867 
  4868 * substitution with equality assumptions no longer permutes other
  4869 assumptions;
  4870 
  4871 * minor changes in semantics of addafter (now called addaltern); renamed
  4872 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  4873 (and access functions for it);
  4874 
  4875 * improved combination of classical reasoner and simplifier:
  4876   + functions for handling clasimpsets
  4877   + improvement of addss: now the simplifier is called _after_ the
  4878     safe steps.
  4879   + safe variant of addss called addSss: uses safe simplifications
  4880     _during_ the safe steps. It is more complete as it allows multiple
  4881     instantiations of unknowns (e.g. with slow_tac).
  4882 
  4883 *** Simplifier ***
  4884 
  4885 * added interface for simplification procedures (functions that
  4886 produce *proven* rewrite rules on the fly, depending on current
  4887 redex);
  4888 
  4889 * ordering on terms as parameter (used for ordered rewriting);
  4890 
  4891 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  4892 
  4893 * the solver is now split into a safe and an unsafe part.
  4894 This should be invisible for the normal user, except that the
  4895 functions setsolver and addsolver have been renamed to setSolver and
  4896 addSolver; added safe_asm_full_simp_tac;
  4897 
  4898 
  4899 *** HOL ***
  4900 
  4901 * a generic induction tactic `induct_tac' which works for all datatypes and
  4902 also for type `nat';
  4903 
  4904 * a generic case distinction tactic `exhaust_tac' which works for all
  4905 datatypes and also for type `nat';
  4906 
  4907 * each datatype comes with a function `size';
  4908 
  4909 * patterns in case expressions allow tuple patterns as arguments to
  4910 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  4911 
  4912 * primrec now also works with type nat;
  4913 
  4914 * recdef: a new declaration form, allows general recursive functions to be
  4915 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  4916 
  4917 * the constant for negation has been renamed from "not" to "Not" to
  4918 harmonize with FOL, ZF, LK, etc.;
  4919 
  4920 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  4921 infinite lists;
  4922 
  4923 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  4924 
  4925 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  4926 problems in commutative rings, using axiomatic type classes for + and *;
  4927 
  4928 * more examples in HOL/MiniML and HOL/Auth;
  4929 
  4930 * more default rewrite rules for quantifiers, union/intersection;
  4931 
  4932 * a new constant `arbitrary == @x.False';
  4933 
  4934 * HOLCF/IOA replaces old HOL/IOA;
  4935 
  4936 * HOLCF changes: derived all rules and arities
  4937   + axiomatic type classes instead of classes
  4938   + typedef instead of faking type definitions
  4939   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  4940   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  4941   + eliminated the types void, one, tr
  4942   + use unit lift and bool lift (with translations) instead of one and tr
  4943   + eliminated blift from Lift3.thy (use Def instead of blift)
  4944   all eliminated rules are derived as theorems --> no visible changes ;
  4945 
  4946 
  4947 *** ZF ***
  4948 
  4949 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  4950 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  4951 as ZF_cs addSIs [equalityI];
  4952 
  4953 
  4954 
  4955 New in Isabelle94-7 (November 96)
  4956 ---------------------------------
  4957 
  4958 * allowing negative levels (as offsets) in prlev and choplev;
  4959 
  4960 * super-linear speedup for large simplifications;
  4961 
  4962 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  4963 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  4964 FAIL); can suppress it using the command Delsimps (ex_simps @
  4965 all_simps); De Morgan laws are also now included, by default;
  4966 
  4967 * improved printing of ==>  :  ~:
  4968 
  4969 * new object-logic "Sequents" adds linear logic, while replacing LK
  4970 and Modal (thanks to Sara Kalvala);
  4971 
  4972 * HOL/Auth: correctness proofs for authentication protocols;
  4973 
  4974 * HOL: new auto_tac combines rewriting and classical reasoning (many
  4975 examples on HOL/Auth);
  4976 
  4977 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  4978 the rewriter and classical reasoner simultaneously;
  4979 
  4980 * function uresult no longer returns theorems in "standard" format;
  4981 regain previous version by: val uresult = standard o uresult;
  4982 
  4983 
  4984 
  4985 New in Isabelle94-6
  4986 -------------------
  4987 
  4988 * oracles -- these establish an interface between Isabelle and trusted
  4989 external reasoners, which may deliver results as theorems;
  4990 
  4991 * proof objects (in particular record all uses of oracles);
  4992 
  4993 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  4994 
  4995 * "constdefs" section in theory files;
  4996 
  4997 * "primrec" section (HOL) no longer requires names;
  4998 
  4999 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  5000 
  5001 
  5002 
  5003 New in Isabelle94-5
  5004 -------------------
  5005 
  5006 * reduced space requirements;
  5007 
  5008 * automatic HTML generation from theories;
  5009 
  5010 * theory files no longer require "..." (quotes) around most types;
  5011 
  5012 * new examples, including two proofs of the Church-Rosser theorem;
  5013 
  5014 * non-curried (1994) version of HOL is no longer distributed;
  5015 
  5016 
  5017 
  5018 New in Isabelle94-4
  5019 -------------------
  5020 
  5021 * greatly reduced space requirements;
  5022 
  5023 * theory files (.thy) no longer require \...\ escapes at line breaks;
  5024 
  5025 * searchable theorem database (see the section "Retrieving theorems" on
  5026 page 8 of the Reference Manual);
  5027 
  5028 * new examples, including Grabczewski's monumental case study of the
  5029 Axiom of Choice;
  5030 
  5031 * The previous version of HOL renamed to Old_HOL;
  5032 
  5033 * The new version of HOL (previously called CHOL) uses a curried syntax
  5034 for functions.  Application looks like f a b instead of f(a,b);
  5035 
  5036 * Mutually recursive inductive definitions finally work in HOL;
  5037 
  5038 * In ZF, pattern-matching on tuples is now available in all abstractions and
  5039 translates to the operator "split";
  5040 
  5041 
  5042 
  5043 New in Isabelle94-3
  5044 -------------------
  5045 
  5046 * new infix operator, addss, allowing the classical reasoner to
  5047 perform simplification at each step of its search.  Example:
  5048         fast_tac (cs addss ss)
  5049 
  5050 * a new logic, CHOL, the same as HOL, but with a curried syntax
  5051 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  5052 look like (a,b) instead of <a,b>;
  5053 
  5054 * PLEASE NOTE: CHOL will eventually replace HOL!
  5055 
  5056 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  5057 It translates to the operator "split".  A new theory of integers is available;
  5058 
  5059 * In ZF, integer numerals now denote two's-complement binary integers.
  5060 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  5061 
  5062 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  5063 of the Axiom of Choice;
  5064 
  5065 
  5066 
  5067 New in Isabelle94-2
  5068 -------------------
  5069 
  5070 * Significantly faster resolution;
  5071 
  5072 * the different sections in a .thy file can now be mixed and repeated
  5073 freely;
  5074 
  5075 * Database of theorems for FOL, HOL and ZF.  New
  5076 commands including qed, qed_goal and bind_thm store theorems in the database.
  5077 
  5078 * Simple database queries: return a named theorem (get_thm) or all theorems of
  5079 a given theory (thms_of), or find out what theory a theorem was proved in
  5080 (theory_of_thm);
  5081 
  5082 * Bugs fixed in the inductive definition and datatype packages;
  5083 
  5084 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  5085 and HOL_dup_cs obsolete;
  5086 
  5087 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  5088 have been removed;
  5089 
  5090 * Simpler definition of function space in ZF;
  5091 
  5092 * new results about cardinal and ordinal arithmetic in ZF;
  5093 
  5094 * 'subtype' facility in HOL for introducing new types as subsets of existing
  5095 types;
  5096 
  5097 :mode=text:wrap=hard:maxLineLen=72:
  5098 $Id$