NEWS
author wenzelm
Sat Oct 06 16:50:04 2007 +0200 (2007-10-06)
changeset 24867 e5b55d7be9bb
parent 24859 9b9b1599fb89
child 24891 df3581710b9b
permissions -rw-r--r--
simplified interfaces for outer syntax;
     1 Isabelle NEWS -- history user-relevant changes
     2 ==============================================
     3 
     4 New in Isabelle2007
     5 -------------------
     6 
     7 *** General ***
     8 
     9 * More uniform information about legacy features, notably a
    10 warning/error of "Legacy feature: ...", depending on the state of the
    11 tolerate_legacy_features flag (default true). FUTURE INCOMPATIBILITY:
    12 legacy features will disappear eventually.
    13 
    14 * Theory syntax: the header format ``theory A = B + C:'' has been
    15 discontinued in favour of ``theory A imports B C begin''.  Use isatool
    16 fixheaders to convert existing theory files.  INCOMPATIBILITY.
    17 
    18 * Theory syntax: the old non-Isar theory file format has been
    19 discontinued altogether.  Note that ML proof scripts may still be used
    20 with Isar theories; migration is usually quite simple with the ML
    21 function use_legacy_bindings.  INCOMPATIBILITY.
    22 
    23 * Theory syntax: some popular names (e.g. 'class', 'declaration',
    24 'fun', 'help', 'if') are now keywords.  INCOMPATIBILITY, use double
    25 quotes.
    26 
    27 * Theory loader: be more serious about observing the static theory
    28 header specifications (including optional directories), but not the
    29 accidental file locations of previously successful loads.  The strict
    30 update policy of former update_thy is now already performed by
    31 use_thy, so the former has been removed; use_thys updates several
    32 theories simultaneously, just as 'imports' within a theory header
    33 specification, but without merging the results.  Potential
    34 INCOMPATIBILITY: may need to refine theory headers and commands
    35 ROOT.ML which depend on load order.
    36 
    37 * Theory loader: optional support for content-based file
    38 identification, instead of the traditional scheme of full physical
    39 path plus date stamp; configured by the ISABELLE_FILE_IDENT setting
    40 (cf. the system manual).  The new scheme allows to work with
    41 non-finished theories in persistent session images, such that source
    42 files may be moved later on without requiring reloads.
    43 
    44 * Theory loader: old-style ML proof scripts being *attached* to a thy
    45 file (with the same base name as the theory) are considered a legacy
    46 feature, which will disappear eventually. Even now, the theory loader
    47 no longer maintains dependencies on such files.
    48 
    49 * Syntax: the scope for resolving ambiguities via type-inference is
    50 now limited to individual terms, instead of whole simultaneous
    51 specifications as before. This greatly reduces the complexity of the
    52 syntax module and improves flexibility by separating parsing and
    53 type-checking. INCOMPATIBILITY: additional type-constraints (explicit
    54 'fixes' etc.) are required in rare situations.
    55 
    56 * Legacy goal package: reduced interface to the bare minimum required
    57 to keep existing proof scripts running.  Most other user-level
    58 functions are now part of the OldGoals structure, which is *not* open
    59 by default (consider isatool expandshort before open OldGoals).
    60 Removed top_sg, prin, printyp, pprint_term/typ altogether, because
    61 these tend to cause confusion about the actual goal (!) context being
    62 used here, which is not necessarily the same as the_context().
    63 
    64 * Command 'find_theorems': supports "*" wild-card in "name:"
    65 criterion; "with_dups" option.  Certain ProofGeneral versions might
    66 support a specific search form (see ProofGeneral/CHANGES).
    67 
    68 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1
    69 by default, which means that "prems" (and also "fixed variables") are
    70 suppressed from proof state output.  Note that the ProofGeneral
    71 settings mechanism allows to change and save options persistently, but
    72 older versions of Isabelle will fail to start up if a negative prems
    73 limit is imposed.
    74 
    75 * Local theory targets may be specified by non-nested blocks of
    76 ``context/locale/class ... begin'' followed by ``end''.  The body may
    77 contain definitions, theorems etc., including any derived mechanism
    78 that has been implemented on top of these primitives.  This concept
    79 generalizes the existing ``theorem (in ...)'' towards more versatility
    80 and scalability.
    81 
    82 * Proof General interface: proper undo of final 'end' command;
    83 discontinued Isabelle/classic mode (ML proof scripts).
    84 
    85 
    86 *** Document preparation ***
    87 
    88 * Added antiquotation @{theory name} which prints the given name,
    89 after checking that it refers to a valid ancestor theory in the
    90 current context.
    91 
    92 * Added antiquotations @{ML_type text} and @{ML_struct text} which
    93 check the given source text as ML type/structure, printing verbatim.
    94 
    95 * Added antiquotation @{abbrev "c args"} which prints the abbreviation
    96 "c args == rhs" given in the current context.  (Any number of
    97 arguments may be given on the LHS.)
    98 
    99 
   100 
   101 *** Pure ***
   102 
   103 * Code generator: consts in 'consts_code' Isar commands are now
   104 referred to by usual term syntax (including optional type
   105 annotations).
   106 
   107 * Code generator: basic definitions (from 'definition', 'constdefs',
   108 or primitive 'instance' definitions) are added automatically to the
   109 table of defining equations.  Primitive defs are not used as defining
   110 equations by default any longer.  defining equations are now definitly
   111 restricted to meta "==" and object equality "=".
   112 
   113 * The 'class' package offers a combination of axclass and locale to
   114 achieve Haskell-like type classes in Isabelle.  See
   115 HOL/ex/Classpackage.thy for examples.
   116 
   117 * Yet another code generator framework allows to generate executable
   118 code for ML and Haskell (including Isabelle classes).  A short usage
   119 sketch:
   120 
   121     internal compilation:
   122         code_gen <list of constants (term syntax)> in SML
   123     writing SML code to a file:
   124         code_gen <list of constants (term syntax)> in SML <filename>
   125     writing OCaml code to a file:
   126         code_gen <list of constants (term syntax)> in OCaml <filename>
   127     writing Haskell code to a bunch of files:
   128         code_gen <list of constants (term syntax)> in Haskell <filename>
   129 
   130 Reasonable default setup of framework in HOL/Main.
   131 
   132 Theorem attributs for selecting and transforming function equations theorems:
   133 
   134     [code fun]:        select a theorem as function equation for a specific constant
   135     [code fun del]:    deselect a theorem as function equation for a specific constant
   136     [code inline]:     select an equation theorem for unfolding (inlining) in place
   137     [code inline del]: deselect an equation theorem for unfolding (inlining) in place
   138 
   139 User-defined serializations (target in {SML, OCaml, Haskell}):
   140 
   141     code_const <and-list of constants (term syntax)>
   142       {(target) <and-list of const target syntax>}+
   143 
   144     code_type <and-list of type constructors>
   145       {(target) <and-list of type target syntax>}+
   146 
   147     code_instance <and-list of instances>
   148       {(target)}+
   149         where instance ::= <type constructor> :: <class>
   150 
   151     code_class <and_list of classes>
   152       {(target) <and-list of class target syntax>}+
   153         where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?
   154 
   155 code_instance and code_class only apply to target Haskell.
   156 
   157 For example usage see HOL/ex/Codegenerator.thy and
   158 HOL/ex/Codegenerator_Pretty.thy.  A separate tutorial on code
   159 generation from Isabelle/HOL theories is available via "isatool doc
   160 codegen".
   161 
   162 * Command 'no_translations' removes translation rules from theory
   163 syntax.
   164 
   165 * Overloaded definitions are now actually checked for acyclic
   166 dependencies.  The overloading scheme is slightly more general than
   167 that of Haskell98, although Isabelle does not demand an exact
   168 correspondence to type class and instance declarations.
   169 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more
   170 exotic versions of overloading -- at the discretion of the user!
   171 
   172 Polymorphic constants are represented via type arguments, i.e. the
   173 instantiation that matches an instance against the most general
   174 declaration given in the signature.  For example, with the declaration
   175 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented
   176 as c(nat).  Overloading is essentially simultaneous structural
   177 recursion over such type arguments.  Incomplete specification patterns
   178 impose global constraints on all occurrences, e.g. c('a * 'a) on the
   179 LHS means that more general c('a * 'b) will be disallowed on any RHS.
   180 Command 'print_theory' outputs the normalized system of recursive
   181 equations, see section "definitions".
   182 
   183 * Configuration options are maintained within the theory or proof
   184 context (with name and type bool/int/string), providing a very simple
   185 interface to a poor-man's version of general context data.  Tools may
   186 declare options in ML (e.g. using Attrib.config_int) and then refer to
   187 these values using Config.get etc.  Users may change options via an
   188 associated attribute of the same name.  This form of context
   189 declaration works particularly well with commands 'declare' or
   190 'using', for example ``declare [[foo = 42]]''.  Thus it has become
   191 very easy to avoid global references, which would not observe Isar
   192 toplevel undo/redo and fail to work with multithreading.
   193 
   194 Various global ML references of Pure and HOL have been turned into
   195 configuration options:
   196 
   197   Unify.search_bound		unify_search_bound
   198   Unify.trace_bound		unify_trace_bound
   199   Unify.trace_simp		unify_trace_simp
   200   Unify.trace_types		unify_trace_types
   201   Simplifier.simp_depth_limit	simp_depth_limit
   202   Blast.depth_limit		blast_depth_limit
   203   DatatypeProp.dtK		datatype_distinctness_limit
   204   fast_arith_neq_limit  	fast_arith_neq_limit
   205   fast_arith_split_limit	fast_arith_split_limit
   206 
   207 * Named collections of theorems may be easily installed as context
   208 data using the functor NamedThmsFun (see also
   209 src/Pure/Tools/named_thms.ML).  The user may add or delete facts via
   210 attributes; there is also a toplevel print command.  This facility is
   211 just a common case of general context data, which is the preferred way
   212 for anything more complex than just a list of facts in canonical
   213 order.
   214 
   215 * Isar: command 'declaration' augments a local theory by generic
   216 declaration functions written in ML.  This enables arbitrary content
   217 being added to the context, depending on a morphism that tells the
   218 difference of the original declaration context wrt. the application
   219 context encountered later on.
   220 
   221 * Isar: proper interfaces for simplification procedures.  Command
   222 'simproc_setup' declares named simprocs (with match patterns, and body
   223 text in ML).  Attribute "simproc" adds/deletes simprocs in the current
   224 context.  ML antiquotation @{simproc name} retrieves named simprocs.
   225 
   226 * Isar: an extra pair of brackets around attribute declarations
   227 abbreviates a theorem reference involving an internal dummy fact,
   228 which will be ignored later --- only the effect of the attribute on
   229 the background context will persist.  This form of in-place
   230 declarations is particularly useful with commands like 'declare' and
   231 'using', for example ``have A using [[simproc a]] by simp''.
   232 
   233 * Isar: method "assumption" (and implicit closing of subproofs) now
   234 takes simple non-atomic goal assumptions into account: after applying
   235 an assumption as a rule the resulting subgoals are solved by atomic
   236 assumption steps.  This is particularly useful to finish 'obtain'
   237 goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
   238 without referring to the original premise "!!x. P x ==> thesis" in the
   239 Isar proof context.  POTENTIAL INCOMPATIBILITY: method "assumption" is
   240 more permissive.
   241 
   242 * Isar: implicit use of prems from the Isar proof context is
   243 considered a legacy feature.  Common applications like ``have A .''
   244 may be replaced by ``have A by fact'' or ``note `A`''.  In general,
   245 referencing facts explicitly here improves readability and
   246 maintainability of proof texts.
   247 
   248 * Isar: improper proof element 'guess' is like 'obtain', but derives
   249 the obtained context from the course of reasoning!  For example:
   250 
   251   assume "EX x y. A x & B y"   -- "any previous fact"
   252   then guess x and y by clarify
   253 
   254 This technique is potentially adventurous, depending on the facts and
   255 proof tools being involved here.
   256 
   257 * Isar: known facts from the proof context may be specified as literal
   258 propositions, using ASCII back-quote syntax.  This works wherever
   259 named facts used to be allowed so far, in proof commands, proof
   260 methods, attributes etc.  Literal facts are retrieved from the context
   261 according to unification of type and term parameters.  For example,
   262 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known
   263 theorems in the current context, then these are valid literal facts:
   264 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.
   265 
   266 There is also a proof method "fact" which does the same composition
   267 for explicit goal states, e.g. the following proof texts coincide with
   268 certain special cases of literal facts:
   269 
   270   have "A" by fact                 ==  note `A`
   271   have "A ==> B" by fact           ==  note `A ==> B`
   272   have "!!x. P x ==> Q x" by fact  ==  note `!!x. P x ==> Q x`
   273   have "P a ==> Q a" by fact       ==  note `P a ==> Q a`
   274 
   275 * Isar: ":" (colon) is no longer a symbolic identifier character in
   276 outer syntax.  Thus symbolic identifiers may be used without
   277 additional white space in declarations like this: ``assume *: A''.
   278 
   279 * Isar: 'print_facts' prints all local facts of the current context,
   280 both named and unnamed ones.
   281 
   282 * Isar: 'def' now admits simultaneous definitions, e.g.:
   283 
   284   def x == "t" and y == "u"
   285 
   286 * Isar: added command 'unfolding', which is structurally similar to
   287 'using', but affects both the goal state and facts by unfolding given
   288 rewrite rules.  Thus many occurrences of the 'unfold' method or
   289 'unfolded' attribute may be replaced by first-class proof text.
   290 
   291 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',
   292 and command 'unfolding' now all support object-level equalities
   293 (potentially conditional).  The underlying notion of rewrite rule is
   294 analogous to the 'rule_format' attribute, but *not* that of the
   295 Simplifier (which is usually more generous).
   296 
   297 * Isar: the new attribute [rotated n] (default n = 1) rotates the
   298 premises of a theorem by n. Useful in conjunction with drule.
   299 
   300 * Isar: the goal restriction operator [N] (default N = 1) evaluates a
   301 method expression within a sandbox consisting of the first N
   302 sub-goals, which need to exist.  For example, ``simp_all [3]''
   303 simplifies the first three sub-goals, while (rule foo, simp_all)[]
   304 simplifies all new goals that emerge from applying rule foo to the
   305 originally first one.
   306 
   307 * Isar: schematic goals are no longer restricted to higher-order
   308 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as
   309 expected.
   310 
   311 * Isar: the conclusion of a long theorem statement is now either
   312 'shows' (a simultaneous conjunction, as before), or 'obtains'
   313 (essentially a disjunction of cases with local parameters and
   314 assumptions).  The latter allows to express general elimination rules
   315 adequately; in this notation common elimination rules look like this:
   316 
   317   lemma exE:    -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"
   318     assumes "EX x. P x"
   319     obtains x where "P x"
   320 
   321   lemma conjE:  -- "A & B ==> (A ==> B ==> thesis) ==> thesis"
   322     assumes "A & B"
   323     obtains A and B
   324 
   325   lemma disjE:  -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"
   326     assumes "A | B"
   327     obtains
   328       A
   329     | B
   330 
   331 The subsequent classical rules even refer to the formal "thesis"
   332 explicitly:
   333 
   334   lemma classical:     -- "(~ thesis ==> thesis) ==> thesis"
   335     obtains "~ thesis"
   336 
   337   lemma Peirce's_Law:  -- "((thesis ==> something) ==> thesis) ==> thesis"
   338     obtains "thesis ==> something"
   339 
   340 The actual proof of an 'obtains' statement is analogous to that of the
   341 Isar proof element 'obtain', only that there may be several cases.
   342 Optional case names may be specified in parentheses; these will be
   343 available both in the present proof and as annotations in the
   344 resulting rule, for later use with the 'cases' method (cf. attribute
   345 case_names).
   346 
   347 * Isar: the assumptions of a long theorem statement are available as
   348 "assms" fact in the proof context.  This is more appropriate than the
   349 (historical) "prems", which refers to all assumptions of the current
   350 context, including those from the target locale, proof body etc.
   351 
   352 * Isar: 'print_statement' prints theorems from the current theory or
   353 proof context in long statement form, according to the syntax of a
   354 top-level lemma.
   355 
   356 * Isar: 'obtain' takes an optional case name for the local context
   357 introduction rule (default "that").
   358 
   359 * Isar: removed obsolete 'concl is' patterns.  INCOMPATIBILITY, use
   360 explicit (is "_ ==> ?foo") in the rare cases where this still happens
   361 to occur.
   362 
   363 * Pure: syntax "CONST name" produces a fully internalized constant
   364 according to the current context.  This is particularly useful for
   365 syntax translations that should refer to internal constant
   366 representations independently of name spaces.
   367 
   368 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"
   369 instead of "FOO ". This allows multiple binder declarations to coexist
   370 in the same context.  INCOMPATIBILITY.
   371 
   372 * Isar/locales: 'notation' provides a robust interface to the 'syntax'
   373 primitive that also works in a locale context (both for constants and
   374 fixed variables).  Type declaration and internal syntactic
   375 representation of given constants retrieved from the context.
   376 
   377 * Isar/locales: new derived specification elements 'axiomatization',
   378 'definition', 'abbreviation', which support type-inference, admit
   379 object-level specifications (equality, equivalence).  See also the
   380 isar-ref manual.  Examples:
   381 
   382   axiomatization
   383     eq  (infix "===" 50) where
   384     eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"
   385 
   386   definition "f x y = x + y + 1"
   387   definition g where "g x = f x x"
   388 
   389   abbreviation
   390     neq  (infix "=!=" 50) where
   391     "x =!= y == ~ (x === y)"
   392 
   393 These specifications may be also used in a locale context.  Then the
   394 constants being introduced depend on certain fixed parameters, and the
   395 constant name is qualified by the locale base name.  An internal
   396 abbreviation takes care for convenient input and output, making the
   397 parameters implicit and using the original short name.  See also
   398 HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic
   399 entities from a monomorphic theory.
   400 
   401 Presently, abbreviations are only available 'in' a target locale, but
   402 not inherited by general import expressions.  Also note that
   403 'abbreviation' may be used as a type-safe replacement for 'syntax' +
   404 'translations' in common applications.  The "no_abbrevs" print mode
   405 prevents folding of abbreviations in term output.
   406 
   407 Concrete syntax is attached to specified constants in internal form,
   408 independently of name spaces.  The parse tree representation is
   409 slightly different -- use 'notation' instead of raw 'syntax', and
   410 'translations' with explicit "CONST" markup to accommodate this.
   411 
   412 * Pure/Isar: unified syntax for new-style specification mechanisms
   413 (e.g.  'definition', 'abbreviation', or 'inductive' in HOL) admits
   414 full type inference and dummy patterns ("_").  For example:
   415 
   416   definition "K x _ = x"
   417 
   418   inductive conj for A B
   419   where "A ==> B ==> conj A B"
   420 
   421 * Pure: command 'print_abbrevs' prints all constant abbreviations of
   422 the current context.  Print mode "no_abbrevs" prevents inversion of
   423 abbreviations on output.
   424 
   425 * Isar/locales: improved parameter handling: use of locales "var" and
   426 "struct" no longer necessary; - parameter renamings are no longer
   427 required to be injective.  For example, this allows to define
   428 endomorphisms as locale endom = homom mult mult h.
   429 
   430 * Isar/locales: changed the way locales with predicates are defined.
   431 Instead of accumulating the specification, the imported expression is
   432 now an interpretation.  INCOMPATIBILITY: different normal form of
   433 locale expressions.  In particular, in interpretations of locales with
   434 predicates, goals repesenting already interpreted fragments are not
   435 removed automatically.  Use methods `intro_locales' and
   436 `unfold_locales'; see below.
   437 
   438 * Isar/locales: new methods `intro_locales' and `unfold_locales'
   439 provide backward reasoning on locales predicates.  The methods are
   440 aware of interpretations and discharge corresponding goals.
   441 `intro_locales' is less aggressive then `unfold_locales' and does not
   442 unfold predicates to assumptions.
   443 
   444 * Isar/locales: the order in which locale fragments are accumulated
   445 has changed.  This enables to override declarations from fragments due
   446 to interpretations -- for example, unwanted simp rules.
   447 
   448 * Isar/locales: interpretation in theories and proof contexts has been
   449 extended.  One may now specify (and prove) equations, which are
   450 unfolded in interpreted theorems.  This is useful for replacing
   451 defined concepts (constants depending on locale parameters) by
   452 concepts already existing in the target context.  Example:
   453 
   454   interpretation partial_order ["op <= :: [int, int] => bool"]
   455     where "partial_order.less (op <=) (x::int) y = (x < y)"
   456 
   457 Typically, the constant `partial_order.less' is created by a
   458 definition specification element in the context of locale
   459 partial_order.
   460 
   461 * Method "induct": improved internal context management to support
   462 local fixes and defines on-the-fly. Thus explicit meta-level
   463 connectives !!  and ==> are rarely required anymore in inductive goals
   464 (using object-logic connectives for this purpose has been long
   465 obsolete anyway). Common proof patterns are explained in
   466 HOL/Induct/Common_Patterns.thy, see also HOL/Isar_examples/Puzzle.thy
   467 and src/HOL/Lambda for realistic examples.
   468 
   469 * Method "induct": improved handling of simultaneous goals. Instead of
   470 introducing object-level conjunction, the statement is now split into
   471 several conclusions, while the corresponding symbolic cases are nested
   472 accordingly. INCOMPATIBILITY, proofs need to be structured explicitly,
   473 see HOL/Induct/Common_Patterns.thy, for example.
   474 
   475 * Method "induct": mutual induction rules are now specified as a list
   476 of rule sharing the same induction cases. HOL packages usually provide
   477 foo_bar.inducts for mutually defined items foo and bar (e.g. inductive
   478 predicates/sets or datatypes). INCOMPATIBILITY, users need to specify
   479 mutual induction rules differently, i.e. like this:
   480 
   481   (induct rule: foo_bar.inducts)
   482   (induct set: foo bar)
   483   (induct pred: foo bar)
   484   (induct type: foo bar)
   485 
   486 The ML function ProjectRule.projections turns old-style rules into the
   487 new format.
   488 
   489 * Method "coinduct": dual of induction, see
   490 src/HOL/Library/Coinductive_List.thy for various examples.
   491 
   492 * Method "cases", "induct", "coinduct": the ``(open)'' option is
   493 considered a legacy feature.
   494 
   495 * Attribute "symmetric" produces result with standardized schematic
   496 variables (index 0).  Potential INCOMPATIBILITY.
   497 
   498 * Simplifier: by default the simplifier trace only shows top level
   499 rewrites now. That is, trace_simp_depth_limit is set to 1 by
   500 default. Thus there is less danger of being flooded by the trace. The
   501 trace indicates where parts have been suppressed.
   502   
   503 * Provers/classical: removed obsolete classical version of elim_format
   504 attribute; classical elim/dest rules are now treated uniformly when
   505 manipulating the claset.
   506 
   507 * Provers/classical: stricter checks to ensure that supplied intro,
   508 dest and elim rules are well-formed; dest and elim rules must have at
   509 least one premise.
   510 
   511 * Provers/classical: attributes dest/elim/intro take an optional
   512 weight argument for the rule (just as the Pure versions).  Weights are
   513 ignored by automated tools, but determine the search order of single
   514 rule steps.
   515 
   516 * Syntax: input syntax now supports dummy variable binding "%_. b",
   517 where the body does not mention the bound variable.  Note that dummy
   518 patterns implicitly depend on their context of bounds, which makes
   519 "{_. _}" match any set comprehension as expected.  Potential
   520 INCOMPATIBILITY -- parse translations need to cope with syntactic
   521 constant "_idtdummy" in the binding position.
   522 
   523 * Syntax: removed obsolete syntactic constant "_K" and its associated
   524 parse translation.  INCOMPATIBILITY -- use dummy abstraction instead,
   525 for example "A -> B" => "Pi A (%_. B)".
   526 
   527 * Pure: 'class_deps' command visualizes the subclass relation, using
   528 the graph browser tool.
   529 
   530 * Pure: 'print_theory' now suppresses certain internal declarations by
   531 default; use '!' option for full details.
   532 
   533 
   534 *** HOL ***
   535 
   536 * New "auto_quickcheck" feature tests outermost goal statements for
   537 potential counter-examples.  Controlled by ML references
   538 auto_quickcheck (default true) and auto_quickcheck_time_limit (default
   539 5000 milliseconds).
   540 
   541 * Internal reorganisation of `size' of datatypes: size theorems
   542 "foo.size" are no longer subsumed by "foo.simps" (but are still
   543 simplification rules by default!); theorems "prod.size" now named
   544 "*.size"
   545 
   546 * The transitivity reasoner for partial and linear orders is set up
   547 for locales "order" and "linorder" generated by the new class package
   548 (instead of axiomatic type classes used before).  Instances of the
   549 reasoner are available in all contexts importing or interpreting these
   550 locales.  Method "order" invokes the reasoner separately; the reasoner
   551 is also integrated with the Simplifier as a solver.  Diagnostic
   552 command 'print_orders' shows the available instances of the reasoner
   553 in the current context.
   554 
   555 * Formulation of theorem "dense" changed slightly due to integration
   556 with new class dense_linear_order.
   557 
   558 * HOL/Finite_Set: "name-space" locales Lattice, Distrib_lattice,
   559 Linorder etc.  have disappeared; operations defined in terms of
   560 fold_set now are named Inf_fin, Sup_fin.  INCOMPATIBILITY.
   561 
   562 * HOL-Word: New extensive library and type for generic, fixed size
   563 machine words, with arithemtic, bit-wise, shifting and rotating
   564 operations, reflection into int, nat, and bool lists, automation for
   565 linear arithmetic (by automatic reflection into nat or int), including
   566 lemmas on overflow and monotonicity.  Instantiated to all appropriate
   567 arithmetic type classes, supporting automatic simplification of
   568 numerals on all operations.
   569 
   570 * Library/Boolean_Algebra: locales for abstract boolean algebras.
   571 
   572 * Library/Numeral_Type: numbers as types, e.g. TYPE(32).
   573 
   574 * Code generator library theories:
   575   - Pretty_Int represents HOL integers by big integer literals in target
   576     languages.
   577   - Pretty_Char represents HOL characters by character literals in target
   578     languages.
   579   - Pretty_Char_chr like Pretty_Char, but also offers treatment of character
   580     codes; includes Pretty_Int.
   581   - Executable_Set allows to generate code for finite sets using lists.
   582   - Executable_Rat implements rational numbers as triples (sign, enumerator,
   583     denominator).
   584   - Executable_Real implements a subset of real numbers, namly those
   585     representable by rational numbers.
   586   - Efficient_Nat implements natural numbers by integers, which in general will
   587     result in higher efficency; pattern matching with 0/Suc is eliminated;
   588     includes Pretty_Int.
   589   - ML_String provides an additional datatype ml_string; in the HOL default
   590     setup, strings in HOL are mapped to lists of HOL characters in SML; values
   591     of type ml_string are mapped to strings in SML.
   592   - ML_Int provides an additional datatype ml_int which is mapped to to SML
   593     built-in integers.
   594 
   595 * New package for inductive predicates
   596 
   597   An n-ary predicate p with m parameters z_1, ..., z_m can now be defined via
   598 
   599     inductive
   600       p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
   601       for z_1 :: U_1 and ... and z_n :: U_m
   602     where
   603       rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
   604     | ...
   605 
   606   with full support for type-inference, rather than
   607 
   608     consts s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
   609 
   610     abbreviation p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
   611     where "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
   612 
   613     inductive "s z_1 ... z_m"
   614     intros
   615       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
   616       ...
   617 
   618   For backward compatibility, there is a wrapper allowing inductive
   619   sets to be defined with the new package via
   620 
   621     inductive_set
   622       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
   623       for z_1 :: U_1 and ... and z_n :: U_m
   624     where
   625       rule_1: "... ==> (t_1_1, ..., t_1_n) : s z_1 ... z_m"
   626     | ...
   627 
   628   or
   629 
   630     inductive_set
   631       s :: "U_1 => ... => U_m => (T_1 * ... * T_n) set"
   632       and p :: "U_1 => ... => U_m => T_1 => ... => T_n => bool"
   633       for z_1 :: U_1 and ... and z_n :: U_m
   634     where
   635       "p z_1 ... z_m x_1 ... x_n == (x_1, ..., x_n) : s z_1 ... z_m"
   636     | rule_1: "... ==> p z_1 ... z_m t_1_1 ... t_1_n"
   637     | ...
   638 
   639   if the additional syntax "p ..." is required.
   640 
   641   Numerous examples can be found in the subdirectories HOL/Auth, HOL/Bali,
   642   HOL/Induct, and HOL/MicroJava.
   643 
   644   INCOMPATIBILITIES:
   645 
   646   - Since declaration and definition of inductive sets or predicates
   647     is no longer separated, abbreviations involving the newly
   648     introduced sets or predicates must be specified together with the
   649     introduction rules after the 'where' keyword (see above), rather
   650     than before the actual inductive definition.
   651 
   652   - The variables in induction and elimination rules are now
   653     quantified in the order of their occurrence in the introduction
   654     rules, rather than in alphabetical order. Since this may break
   655     some proofs, these proofs either have to be repaired, e.g. by
   656     reordering the variables a_i_1 ... a_i_{k_i} in Isar 'case'
   657     statements of the form
   658 
   659       case (rule_i a_i_1 ... a_i_{k_i})
   660 
   661     or the old order of quantification has to be restored by explicitly adding
   662     meta-level quantifiers in the introduction rules, i.e.
   663 
   664       | rule_i: "!!a_i_1 ... a_i_{k_i}. ... ==> p z_1 ... z_m t_i_1 ... t_i_n"
   665 
   666   - The format of the elimination rules is now
   667 
   668       p z_1 ... z_m x_1 ... x_n ==>
   669         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
   670         ==> ... ==> P
   671 
   672     for predicates and
   673 
   674       (x_1, ..., x_n) : s z_1 ... z_m ==>
   675         (!!a_1_1 ... a_1_{k_1}. x_1 = t_1_1 ==> ... ==> x_n = t_1_n ==> ... ==> P)
   676         ==> ... ==> P
   677 
   678     for sets rather than
   679 
   680       x : s z_1 ... z_m ==>
   681         (!!a_1_1 ... a_1_{k_1}. x = (t_1_1, ..., t_1_n) ==> ... ==> P)
   682         ==> ... ==> P
   683 
   684     This may require terms in goals to be expanded to n-tuples
   685     (e.g. using case_tac or simplification with the split_paired_all
   686     rule) before the above elimination rule is applicable.
   687 
   688   - The elimination or case analysis rules for (mutually) inductive
   689     sets or predicates are now called "p_1.cases" ... "p_k.cases". The
   690     list of rules "p_1_..._p_k.elims" is no longer available.
   691 
   692 * Method "metis" proves goals by applying the Metis general-purpose
   693 resolution prover.  Examples are in the directory MetisExamples.  See
   694 also http://gilith.com/software/metis/
   695 
   696 WARNING: the Isabelle/HOL-Metis integration does not yet work properly
   697 with multi-threading.
   698   
   699 * Command 'sledgehammer' invokes external automatic theorem provers as
   700 background processes.  It generates calls to the "metis" method if
   701 successful. These can be pasted into the proof.  Users do not have to
   702 wait for the automatic provers to return.
   703 
   704 * Case-expressions allow arbitrary constructor-patterns (including
   705 "_") and take their order into account, like in functional
   706 programming.  Internally, this is translated into nested
   707 case-expressions; missing cases are added and mapped to the predefined
   708 constant "undefined". In complicated cases printing may no longer show
   709 the original input but the internal form. Lambda-abstractions allow
   710 the same form of pattern matching: "% pat1 => e1 | ..." is an
   711 abbreviation for "%x. case x of pat1 => e1 | ..." where x is a new
   712 variable.
   713 
   714 * IntDef: The constant "int :: nat => int" has been removed; now "int"
   715 is an abbreviation for "of_nat :: nat => int". The simplification
   716 rules for "of_nat" have been changed to work like "int" did
   717 previously.  Potential INCOMPATIBILITY:
   718   - "of_nat (Suc m)" simplifies to "1 + of_nat m" instead of "of_nat m + 1"
   719   - of_nat_diff and of_nat_mult are no longer default simp rules
   720 
   721 * Method "algebra" solves polynomial equations over (semi)rings using
   722 Groebner bases. The (semi)ring structure is defined by locales and the
   723 tool setup depends on that generic context. Installing the method for
   724 a specific type involves instantiating the locale and possibly adding
   725 declarations for computation on the coefficients.  The method is
   726 already instantiated for natural numbers and for the axiomatic class
   727 of idoms with numerals.  See also the paper by Chaieb and Wenzel at
   728 CALCULEMUS 2007 for the general principles underlying this
   729 architecture of context-aware proof-tools.
   730 
   731 * Former constant "List.op @" now named "List.append".  Use ML
   732 antiquotations @{const_name List.append} or @{term " ... @ ... "} to
   733 circumvent possible incompatibilities when working on ML level.
   734 
   735 * Some renaming of class constants due to canonical name prefixing in
   736 the new 'class' package:
   737 
   738     HOL.abs ~> HOL.minus_class.abs
   739     HOL.divide ~> HOL.divide_class.divide
   740     Nat.power ~> Nat.power_class.power
   741     Nat.size ~> Nat.size_class.size
   742     Numeral.number_of ~> Numeral.number_class.number_of
   743     FixedPoint.Inf ~> FixedPoint.complete_lattice_class.Inf
   744     FixedPoint.Sup ~> FixedPoint.complete_lattice_class.Sup
   745     Orderings.min ~> Orderings.ord_class.min
   746     Orderings.max ~> Orderings.ord_class.max
   747 
   748 * New class "default" with associated constant "default".
   749 
   750 * New constant "undefined" with axiom "undefined x = undefined".
   751 
   752 * primrec: missing cases mapped to "undefined" instead of "arbitrary"
   753 
   754 * New function listsum :: 'a list => 'a for arbitrary monoids.
   755 Special syntax: "SUM x <- xs. f x" (and latex variants)
   756 
   757 * New syntax for Haskell-like list comprehension (input only), eg.
   758 [(x,y). x <- xs, y <- ys, x ~= y], see also HOL/List.thy.
   759 
   760 * The special syntax for function "filter" has changed from [x :
   761 xs. P] to [x <- xs. P] to avoid an ambiguity caused by list
   762 comprehension syntax, and for uniformity.  INCOMPATIBILITY.
   763 
   764 * [a..b] is now defined for arbitrary linear orders.  It used to be
   765 defined on nat only, as an abbreviation for [a..<Suc b]
   766 INCOMPATIBILITY.
   767 
   768 * Renamed lemma "set_take_whileD"  to "set_takeWhileD".
   769 
   770 * New functions "sorted" and "sort" in HOL/List.thy.
   771 
   772 * Function "sgn" is now overloaded and available on int, real, complex
   773 (and other numeric types), using class "sgn".  Two possible defs of
   774 sgn are given as equational assumptions in the classes sgn_if and
   775 sgn_div_norm; ordered_idom now also inherits from sgn_if.
   776 INCOMPATIBILITY.
   777 
   778 * New lemma collection field_simps (an extension of ring_simps) for
   779 manipulating (in)equations involving division. Multiplies with all
   780 denominators that can be proved to be non-zero (in equations) or
   781 positive/negative (in inequations).
   782 
   783 * Lemma collections ring_eq_simps, group_eq_simps and ring_distrib
   784 have been improved and renamed to ring_simps, group_simps and
   785 ring_distribs.  Removed lemmas field_xyz in theory Ring_and_Field
   786 because they were subsumed by lemmas xyz.  INCOMPATIBILITY.
   787 
   788 * Library/Pretty_Int.thy: maps HOL numerals on target language integer
   789 literals when generating code.
   790 
   791 * Library/Pretty_Char.thy: maps HOL characters on target language
   792 character literals when generating code.
   793 
   794 * Library/Commutative_Ring.thy: switched from recdef to function
   795 package; constants add, mul, pow now curried.  Infix syntax for
   796 algebraic operations.
   797 
   798 * Some steps towards more uniform lattice theory development in HOL.
   799 
   800     constants "meet" and "join" now named "inf" and "sup"
   801     constant "Meet" now named "Inf"
   802 
   803     classes "meet_semilorder" and "join_semilorder" now named
   804       "lower_semilattice" and "upper_semilattice"
   805     class "lorder" now named "lattice"
   806     class "comp_lat" now named "complete_lattice"
   807 
   808     Instantiation of lattice classes allows explicit definitions
   809     for "inf" and "sup" operations (or "Inf" and "Sup" for complete lattices).
   810 
   811   INCOMPATIBILITY.  Theorem renames:
   812 
   813     meet_left_le            ~> inf_le1
   814     meet_right_le           ~> inf_le2
   815     join_left_le            ~> sup_ge1
   816     join_right_le           ~> sup_ge2
   817     meet_join_le            ~> inf_sup_ord
   818     le_meetI                ~> le_infI
   819     join_leI                ~> le_supI
   820     le_meet                 ~> le_inf_iff
   821     le_join                 ~> ge_sup_conv
   822     meet_idempotent         ~> inf_idem
   823     join_idempotent         ~> sup_idem
   824     meet_comm               ~> inf_commute
   825     join_comm               ~> sup_commute
   826     meet_leI1               ~> le_infI1
   827     meet_leI2               ~> le_infI2
   828     le_joinI1               ~> le_supI1
   829     le_joinI2               ~> le_supI2
   830     meet_assoc              ~> inf_assoc
   831     join_assoc              ~> sup_assoc
   832     meet_left_comm          ~> inf_left_commute
   833     meet_left_idempotent    ~> inf_left_idem
   834     join_left_comm          ~> sup_left_commute
   835     join_left_idempotent    ~> sup_left_idem
   836     meet_aci                ~> inf_aci
   837     join_aci                ~> sup_aci
   838     le_def_meet             ~> le_iff_inf
   839     le_def_join             ~> le_iff_sup
   840     join_absorp2            ~> sup_absorb2
   841     join_absorp1            ~> sup_absorb1
   842     meet_absorp1            ~> inf_absorb1
   843     meet_absorp2            ~> inf_absorb2
   844     meet_join_absorp        ~> inf_sup_absorb
   845     join_meet_absorp        ~> sup_inf_absorb
   846     distrib_join_le         ~> distrib_sup_le
   847     distrib_meet_le         ~> distrib_inf_le
   848 
   849     add_meet_distrib_left   ~> add_inf_distrib_left
   850     add_join_distrib_left   ~> add_sup_distrib_left
   851     is_join_neg_meet        ~> is_join_neg_inf
   852     is_meet_neg_join        ~> is_meet_neg_sup
   853     add_meet_distrib_right  ~> add_inf_distrib_right
   854     add_join_distrib_right  ~> add_sup_distrib_right
   855     add_meet_join_distribs  ~> add_sup_inf_distribs
   856     join_eq_neg_meet        ~> sup_eq_neg_inf
   857     meet_eq_neg_join        ~> inf_eq_neg_sup
   858     add_eq_meet_join        ~> add_eq_inf_sup
   859     meet_0_imp_0            ~> inf_0_imp_0
   860     join_0_imp_0            ~> sup_0_imp_0
   861     meet_0_eq_0             ~> inf_0_eq_0
   862     join_0_eq_0             ~> sup_0_eq_0
   863     neg_meet_eq_join        ~> neg_inf_eq_sup
   864     neg_join_eq_meet        ~> neg_sup_eq_inf
   865     join_eq_if              ~> sup_eq_if
   866 
   867     mono_meet               ~> mono_inf
   868     mono_join               ~> mono_sup
   869     meet_bool_eq            ~> inf_bool_eq
   870     join_bool_eq            ~> sup_bool_eq
   871     meet_fun_eq             ~> inf_fun_eq
   872     join_fun_eq             ~> sup_fun_eq
   873     meet_set_eq             ~> inf_set_eq
   874     join_set_eq             ~> sup_set_eq
   875     meet1_iff               ~> inf1_iff
   876     meet2_iff               ~> inf2_iff
   877     meet1I                  ~> inf1I
   878     meet2I                  ~> inf2I
   879     meet1D1                 ~> inf1D1
   880     meet2D1                 ~> inf2D1
   881     meet1D2                 ~> inf1D2
   882     meet2D2                 ~> inf2D2
   883     meet1E                  ~> inf1E
   884     meet2E                  ~> inf2E
   885     join1_iff               ~> sup1_iff
   886     join2_iff               ~> sup2_iff
   887     join1I1                 ~> sup1I1
   888     join2I1                 ~> sup2I1
   889     join1I1                 ~> sup1I1
   890     join2I2                 ~> sup1I2
   891     join1CI                 ~> sup1CI
   892     join2CI                 ~> sup2CI
   893     join1E                  ~> sup1E
   894     join2E                  ~> sup2E
   895 
   896     is_meet_Meet            ~> is_meet_Inf
   897     Meet_bool_def           ~> Inf_bool_def
   898     Meet_fun_def            ~> Inf_fun_def
   899     Meet_greatest           ~> Inf_greatest
   900     Meet_lower              ~> Inf_lower
   901     Meet_set_def            ~> Inf_set_def
   902 
   903     Sup_def                 ~> Sup_Inf
   904     Sup_bool_eq             ~> Sup_bool_def
   905     Sup_fun_eq              ~> Sup_fun_def
   906     Sup_set_eq              ~> Sup_set_def
   907 
   908     listsp_meetI            ~> listsp_infI
   909     listsp_meet_eq          ~> listsp_inf_eq
   910 
   911     meet_min                ~> inf_min
   912     join_max                ~> sup_max
   913 
   914 * Renamed classes "order" and "linorder": facts "refl", "trans" and
   915 "cases" to "order_refl", "order_trans" and "linorder_cases", to avoid
   916 clashes with HOL "refl" and "trans".  INCOMPATIBILITY.
   917 
   918 * Classes "order" and "linorder": potential INCOMPATIBILITY due to
   919 changed order of proof goals instance proofs.
   920 
   921 * Dropped redundant lemma def_imp_eq in favor of meta_eq_to_obj_eq.
   922 INCOMPATIBILITY.
   923 
   924 * Dropped redundant lemma if_def2 in favor of if_bool_eq_conj.
   925 INCOMPATIBILITY.
   926 
   927 * Added syntactic class "size"; overloaded constant "size" now has
   928 type "'a::size ==> bool"
   929 
   930 * Renamed constants "Divides.op div", "Divides.op mod" and "Divides.op
   931 dvd" to "Divides.div_class.div", "Divides.div_class.mod" and
   932 "Divides.dvd". INCOMPATIBILITY.
   933 
   934 * Method "lexicographic_order" automatically synthesizes termination
   935 relations as lexicographic combinations of size measures -- 'function'
   936 package.
   937 
   938 * HOL/records: generalised field-update to take a function on the
   939 field rather than the new value: r(|A := x|) is translated to A_update
   940 (K x) r The K-combinator that is internally used is called K_record.
   941 INCOMPATIBILITY: Usage of the plain update functions has to be
   942 adapted.
   943  
   944 * Class "semiring_0" now contains annihilation axioms x * 0 = 0 and 0
   945 * x = 0, which are required for a semiring.  Richer structures do not
   946 inherit from semiring_0 anymore, because this property is a theorem
   947 there, not an axiom.  INCOMPATIBILITY: In instances of semiring_0,
   948 there is more to prove, but this is mostly trivial.
   949 
   950 * Class "recpower" is generalized to arbitrary monoids, not just
   951 commutative semirings.  INCOMPATIBILITY: may need to incorporate
   952 commutativity or a semiring properties additionally.
   953 
   954 * Unified locale "partial_order" with class definition (cf. theory
   955 Orderings), added parameter "less".  INCOMPATIBILITY.
   956 
   957 * Constant "List.list_all2" in List.thy now uses authentic syntax.
   958 INCOMPATIBILITY: translations containing list_all2 may go wrong,
   959 better use 'abbreviation'.
   960 
   961 * Renamed constant "List.op mem" to "List.member".  INCOMPATIBILITY.
   962 
   963 * Renamed constants "0" to "HOL.zero_class.zero" and "1" to
   964 "HOL.one_class.one".  INCOMPATIBILITY.
   965 
   966 * Added class "HOL.eq", allowing for code generation with polymorphic
   967 equality.
   968 
   969 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has
   970 been abandoned in favour of plain 'int'.  INCOMPATIBILITY --
   971 significant changes for setting up numeral syntax for types:
   972   - New constants Numeral.pred and Numeral.succ instead
   973       of former Numeral.bin_pred and Numeral.bin_succ.
   974   - Use integer operations instead of bin_add, bin_mult and so on.
   975   - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.
   976   - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.
   977 
   978 See HOL/Integ/IntArith.thy for an example setup.
   979 
   980 * New top level command 'normal_form' computes the normal form of a
   981 term that may contain free variables.  For example ``normal_form
   982 "rev[a,b,c]"'' produces ``[b,c,a]'' (without proof).  This command is
   983 suitable for heavy-duty computations because the functions are
   984 compiled to ML first.
   985 
   986 * Alternative iff syntax "A <-> B" for equality on bool (with priority
   987 25 like -->); output depends on the "iff" print_mode, the default is
   988 "A = B" (with priority 50).
   989 
   990 * Renamed constants in HOL.thy and Orderings.thy:
   991     op +   ~> HOL.plus_class.plus
   992     op -   ~> HOL.minus_class.minus
   993     uminus ~> HOL.minus_class.uminus
   994     abs    ~> HOL.abs_class.abs
   995     op *   ~> HOL.times_class.times
   996     op <   ~> HOL.ord_class.less
   997     op <=  ~> HOL.ord_class.less_eq
   998 
   999 Adaptions may be required in the following cases:
  1000 
  1001 a) User-defined constants using any of the names "plus", "minus",
  1002 "times", "less" or "less_eq". The standard syntax translations for
  1003 "+", "-" and "*" may go wrong.  INCOMPATIBILITY: use more specific
  1004 names.
  1005 
  1006 b) Variables named "plus", "minus", "times", "less", "less_eq"
  1007 INCOMPATIBILITY: use more specific names.
  1008 
  1009 c) Permutative equations (e.g. "a + b = b + a")
  1010 Since the change of names also changes the order of terms, permutative
  1011 rewrite rules may get applied in a different order. Experience shows
  1012 that this is rarely the case (only two adaptions in the whole Isabelle
  1013 distribution).  INCOMPATIBILITY: rewrite proofs
  1014 
  1015 d) ML code directly refering to constant names
  1016 This in general only affects hand-written proof tactics, simprocs and
  1017 so on.  INCOMPATIBILITY: grep your sourcecode and replace names.
  1018 Consider using @{const_name} antiquotation.
  1019 
  1020 * Relations less (<) and less_eq (<=) are also available on type bool.
  1021 Modified syntax to disallow nesting without explicit parentheses,
  1022 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".  Potential
  1023 INCOMPATIBILITY.
  1024 
  1025 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).
  1026 
  1027 * Relation composition operator "op O" now has precedence 75 and binds
  1028 stronger than union and intersection. INCOMPATIBILITY.
  1029 
  1030 * The old set interval syntax "{m..n(}" (and relatives) has been
  1031 removed.  Use "{m..<n}" (and relatives) instead.
  1032 
  1033 * In the context of the assumption "~(s = t)" the Simplifier rewrites
  1034 "t = s" to False (by simproc "neq").  INCOMPATIBILITY, consider using
  1035 ``declare [[simproc del: neq]]''.
  1036 
  1037 * Simplifier: "m dvd n" where m and n are numbers is evaluated to
  1038 True/False.
  1039 
  1040 * Theorem Cons_eq_map_conv no longer declared as "simp".
  1041 
  1042 * Theorem setsum_mult renamed to setsum_right_distrib.
  1043 
  1044 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the
  1045 ``rule'' method.
  1046 
  1047 * Reimplemented methods "sat" and "satx", with several improvements:
  1048 goals no longer need to be stated as "<prems> ==> False", equivalences
  1049 (i.e. "=" on type bool) are handled, variable names of the form
  1050 "lit_<n>" are no longer reserved, significant speedup.
  1051 
  1052 * Methods "sat" and "satx" can now replay MiniSat proof traces.
  1053 zChaff is still supported as well.
  1054 
  1055 * 'inductive' and 'datatype': provide projections of mutual rules,
  1056 bundled as foo_bar.inducts;
  1057 
  1058 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to
  1059 Library.
  1060 
  1061 * Library: moved theory Accessible_Part to main HOL.
  1062 
  1063 * Library: added theory Coinductive_List of potentially infinite lists
  1064 as greatest fixed-point.
  1065 
  1066 * Library: added theory AssocList which implements (finite) maps as
  1067 association lists.
  1068 
  1069 * Method "evaluation" solves goals (i.e. a boolean expression)
  1070 efficiently by compiling it to ML.  The goal is "proved" (via an
  1071 oracle) if it evaluates to True.
  1072 
  1073 * Linear arithmetic now splits certain operators (e.g. min, max, abs)
  1074 also when invoked by the simplifier.  This results in the Simplifier
  1075 being more powerful on arithmetic goals.  INCOMPATIBILITY.
  1076 Configuration option fast_arith_split_limit=0 recovers the old
  1077 behavior.
  1078 
  1079 * Support for hex (0x20) and binary (0b1001) numerals.
  1080 
  1081 * New method: reify eqs (t), where eqs are equations for an
  1082 interpretation I :: 'a list => 'b => 'c and t::'c is an optional
  1083 parameter, computes a term s::'b and a list xs::'a list and proves the
  1084 theorem I xs s = t. This is also known as reification or quoting. The
  1085 resulting theorem is applied to the subgoal to substitute t with I xs
  1086 s.  If t is omitted, the subgoal itself is reified.
  1087 
  1088 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)
  1089 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,
  1090 where f is supposed to be a computable function (in the sense of code
  1091 generattion). The method uses reify to compute s and xs as above then
  1092 applies corr_thm and uses normalization by evaluation to "prove" f s =
  1093 r and finally gets the theorem t = r, which is again applied to the
  1094 subgoal. An Example is available in HOL/ex/ReflectionEx.thy.
  1095 
  1096 * Reflection: Automatic reification now handels binding, an example
  1097 is available in HOL/ex/ReflectionEx.thy
  1098 
  1099 
  1100 *** HOL-Complex ***
  1101 
  1102 * Hyperreal: Functions root and sqrt are now defined on negative real
  1103 inputs so that root n (- x) = - root n x and sqrt (- x) = - sqrt x.
  1104 Nonnegativity side conditions have been removed from many lemmas, so
  1105 that more subgoals may now be solved by simplification; potential
  1106 INCOMPATIBILITY.
  1107 
  1108 * Real: new type classes formalize real normed vector spaces and
  1109 algebras, using new overloaded constants scaleR :: real => 'a => 'a
  1110 and norm :: 'a => real.
  1111 
  1112 * Real: constant of_real :: real => 'a::real_algebra_1 injects from
  1113 reals into other types. The overloaded constant Reals :: 'a set is now
  1114 defined as range of_real; potential INCOMPATIBILITY.
  1115 
  1116 * Real: proper support for ML code generation, including 'quickcheck'.
  1117 Reals are implemented as arbitrary precision rationals.
  1118 
  1119 * Hyperreal: Several constants that previously worked only for the
  1120 reals have been generalized, so they now work over arbitrary vector
  1121 spaces. Type annotations may need to be added in some cases; potential
  1122 INCOMPATIBILITY.
  1123 
  1124   Infinitesimal  :: ('a::real_normed_vector) star set
  1125   HFinite        :: ('a::real_normed_vector) star set
  1126   HInfinite      :: ('a::real_normed_vector) star set
  1127   approx         :: ('a::real_normed_vector) star => 'a star => bool
  1128   monad          :: ('a::real_normed_vector) star => 'a star set
  1129   galaxy         :: ('a::real_normed_vector) star => 'a star set
  1130   (NS)LIMSEQ     :: [nat => 'a::real_normed_vector, 'a] => bool
  1131   (NS)convergent :: (nat => 'a::real_normed_vector) => bool
  1132   (NS)Bseq       :: (nat => 'a::real_normed_vector) => bool
  1133   (NS)Cauchy     :: (nat => 'a::real_normed_vector) => bool
  1134   (NS)LIM        :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool
  1135   is(NS)Cont     :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool
  1136   deriv          :: ['a::real_normed_field => 'a, 'a, 'a] => bool
  1137   sgn            :: 'a::real_normed_vector => 'a
  1138   exp            :: 'a::{recpower,real_normed_field,banach} => 'a
  1139 
  1140 * Complex: Some complex-specific constants are now abbreviations for
  1141 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod =
  1142 hnorm.  Other constants have been entirely removed in favor of the
  1143 polymorphic versions (INCOMPATIBILITY):
  1144 
  1145   approx        <-- capprox
  1146   HFinite       <-- CFinite
  1147   HInfinite     <-- CInfinite
  1148   Infinitesimal <-- CInfinitesimal
  1149   monad         <-- cmonad
  1150   galaxy        <-- cgalaxy
  1151   (NS)LIM       <-- (NS)CLIM, (NS)CRLIM
  1152   is(NS)Cont    <-- is(NS)Contc, is(NS)contCR
  1153   (ns)deriv     <-- (ns)cderiv
  1154 
  1155 
  1156 *** HOL-Algebra ***
  1157 
  1158 * Formalisation of ideals and the quotient construction over rings.
  1159 
  1160 * Order and lattice theory no longer based on records.
  1161 INCOMPATIBILITY.
  1162 
  1163 * Renamed lemmas least_carrier -> least_closed and greatest_carrier ->
  1164 greatest_closed.  INCOMPATIBILITY.
  1165 
  1166 * Method algebra is now set up via an attribute.  For examples see
  1167 Ring.thy.  INCOMPATIBILITY: the method is now weaker on combinations
  1168 of algebraic structures.
  1169 
  1170 * Renamed theory CRing to Ring.
  1171 
  1172 
  1173 *** HOL-Nominal ***
  1174 
  1175 * Fully featured support for nominal datatypes (binding structures)
  1176 due to the HOL-Nominal logic.  See HOL/Nominal, HOL/Nominal/Examples,
  1177 and http://isabelle.in.tum.de/nominal/download.html
  1178 
  1179 
  1180 *** ML ***
  1181 
  1182 * ML basics: just one true type int, which coincides with IntInf.int
  1183 (even on SML/NJ).
  1184 
  1185 * ML within Isar: antiquotations allow to embed statically-checked
  1186 formal entities in the source, referring to the context available at
  1187 compile-time.  For example:
  1188 
  1189 ML {* @{typ "'a => 'b"} *}
  1190 ML {* @{term "%x. x"} *}
  1191 ML {* @{prop "x == y"} *}
  1192 ML {* @{ctyp "'a => 'b"} *}
  1193 ML {* @{cterm "%x. x"} *}
  1194 ML {* @{cprop "x == y"} *}
  1195 ML {* @{thm asm_rl} *}
  1196 ML {* @{thms asm_rl} *}
  1197 ML {* @{type_name c} *}
  1198 ML {* @{const_name c} *}
  1199 ML {* @{const_syntax c} *}
  1200 ML {* @{context} *}
  1201 ML {* @{theory} *}
  1202 ML {* @{theory Pure} *}
  1203 ML {* @{theory_ref} *}
  1204 ML {* @{theory_ref Pure} *}
  1205 ML {* @{simpset} *}
  1206 ML {* @{claset} *}
  1207 ML {* @{clasimpset} *}
  1208 
  1209 The same works for sources being ``used'' within an Isar context.
  1210 
  1211 * ML in Isar: improved error reporting; extra verbosity with
  1212 ML_Context.trace enabled.
  1213 
  1214 * Pure/General/table.ML: the join operations now works via exceptions
  1215 DUP/SAME instead of type option. This is simpler in simple cases, and
  1216 admits slightly more efficient complex applications.
  1217 
  1218 * Pure: 'advanced' translation functions (parse_translation etc.) now
  1219 use Context.generic instead of just theory.
  1220 
  1221 * Pure: datatype Context.generic joins theory/Proof.context and
  1222 provides some facilities for code that works in either kind of
  1223 context, notably GenericDataFun for uniform theory and proof data.
  1224 
  1225 * Pure: simplified internal attribute type, which is now always
  1226 Context.generic * thm -> Context.generic * thm. Global (theory) vs.
  1227 local (Proof.context) attributes have been discontinued, while
  1228 minimizing code duplication. Thm.rule_attribute and
  1229 Thm.declaration_attribute build canonical attributes; see also structure
  1230 Context for further operations on Context.generic, notably
  1231 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type
  1232 declarations and definitions.
  1233 
  1234 * Context data interfaces (Theory/Proof/GenericDataFun): removed
  1235 name/print, uninitialized data defaults to ad-hoc copy of empty value,
  1236 init only required for impure data. INCOMPATIBILITY: empty really need
  1237 to be empty (no dependencies on theory content!)
  1238 
  1239 * Pure/kernel: consts certification ignores sort constraints given in
  1240 signature declarations. (This information is not relevant to the
  1241 logic, but only for type inference.) SIGNIFICANT INTERNAL CHANGE,
  1242 potential INCOMPATIBILITY.
  1243 
  1244 * Pure: axiomatic type classes are now purely definitional, with
  1245 explicit proofs of class axioms and super class relations performed
  1246 internally. See Pure/axclass.ML for the main internal interfaces --
  1247 notably AxClass.define_class supercedes AxClass.add_axclass, and
  1248 AxClass.axiomatize_class/classrel/arity supersede
  1249 Sign.add_classes/classrel/arities.
  1250 
  1251 * Pure/Isar: Args/Attrib parsers operate on Context.generic --
  1252 global/local versions on theory vs. Proof.context have been
  1253 discontinued; Attrib.syntax and Method.syntax have been adapted
  1254 accordingly.  INCOMPATIBILITY, need to adapt parser expressions for
  1255 attributes, methods, etc.
  1256 
  1257 * Pure: several functions of signature "... -> theory -> theory * ..."
  1258 have been reoriented to "... -> theory -> ... * theory" in order to
  1259 allow natural usage in combination with the ||>, ||>>, |-> and
  1260 fold_map combinators.
  1261 
  1262 * Pure: official theorem names (closed derivations) and additional
  1263 comments (tags) are now strictly separate.  Name hints -- which are
  1264 maintained as tags -- may be attached any time without affecting the
  1265 derivation.
  1266 
  1267 * Pure: primitive rule lift_rule now takes goal cterm instead of an
  1268 actual goal state (thm).  Use Thm.lift_rule (Thm.cprem_of st i) to
  1269 achieve the old behaviour.
  1270 
  1271 * Pure: the "Goal" constant is now called "prop", supporting a
  1272 slightly more general idea of ``protecting'' meta-level rule
  1273 statements.
  1274 
  1275 * Pure: Logic.(un)varify only works in a global context, which is now
  1276 enforced instead of silently assumed.  INCOMPATIBILITY, may use
  1277 Logic.legacy_(un)varify as temporary workaround.
  1278 
  1279 * Pure: structure Name provides scalable operations for generating
  1280 internal variable names, notably Name.variants etc.  This replaces
  1281 some popular functions from term.ML:
  1282 
  1283   Term.variant		->  Name.variant
  1284   Term.variantlist	->  Name.variant_list
  1285   Term.invent_names	->  Name.invent_list
  1286 
  1287 Note that low-level renaming rarely occurs in new code -- operations
  1288 from structure Variable are used instead (see below).
  1289 
  1290 * Pure: structure Variable provides fundamental operations for proper
  1291 treatment of fixed/schematic variables in a context.  For example,
  1292 Variable.import introduces fixes for schematics of given facts and
  1293 Variable.export reverses the effect (up to renaming) -- this replaces
  1294 various freeze_thaw operations.
  1295 
  1296 * Pure: structure Goal provides simple interfaces for
  1297 init/conclude/finish and tactical prove operations (replacing former
  1298 Tactic.prove).  Goal.prove is the canonical way to prove results
  1299 within a given context; Goal.prove_global is a degraded version for
  1300 theory level goals, including a global Drule.standard.  Note that
  1301 OldGoals.prove_goalw_cterm has long been obsolete, since it is
  1302 ill-behaved in a local proof context (e.g. with local fixes/assumes or
  1303 in a locale context).
  1304 
  1305 * Pure/Syntax: generic interfaces for parsing (Syntax.parse_term etc.)
  1306 and type checking (Syntax.check_term etc.), with common combinations
  1307 (Syntax.read_term etc.). These supersede former Sign.read_term etc.
  1308 which are considered legacy and await removal.
  1309 
  1310 * Isar: simplified treatment of user-level errors, using exception
  1311 ERROR of string uniformly.  Function error now merely raises ERROR,
  1312 without any side effect on output channels.  The Isar toplevel takes
  1313 care of proper display of ERROR exceptions.  ML code may use plain
  1314 handle/can/try; cat_error may be used to concatenate errors like this:
  1315 
  1316   ... handle ERROR msg => cat_error msg "..."
  1317 
  1318 Toplevel ML code (run directly or through the Isar toplevel) may be
  1319 embedded into the Isar toplevel with exception display/debug like
  1320 this:
  1321 
  1322   Isar.toplevel (fn () => ...)
  1323 
  1324 INCOMPATIBILITY, removed special transform_error facilities, removed
  1325 obsolete variants of user-level exceptions (ERROR_MESSAGE,
  1326 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)
  1327 -- use plain ERROR instead.
  1328 
  1329 * Isar: theory setup now has type (theory -> theory), instead of a
  1330 list.  INCOMPATIBILITY, may use #> to compose setup functions.
  1331 
  1332 * Isar: ML toplevel pretty printer for type Proof.context, subject to
  1333 ProofContext.debug/verbose flags.
  1334 
  1335 * Isar: Toplevel.theory_to_proof admits transactions that modify the
  1336 theory before entering a proof state.  Transactions now always see a
  1337 quasi-functional intermediate checkpoint, both in interactive and
  1338 batch mode.
  1339 
  1340 * Isar: simplified interfaces for outer syntax.  Renamed
  1341 OuterSyntax.add_keywords to OuterSyntax.keywords.  Removed
  1342 OuterSyntax.add_parsers -- this functionality is now included in
  1343 OuterSyntax.command etc.  INCOMPATIBILITY.
  1344 
  1345 * Simplifier: the simpset of a running simplification process now
  1346 contains a proof context (cf. Simplifier.the_context), which is the
  1347 very context that the initial simpset has been retrieved from (by
  1348 simpset_of/local_simpset_of).  Consequently, all plug-in components
  1349 (solver, looper etc.) may depend on arbitrary proof data.
  1350 
  1351 * Simplifier.inherit_context inherits the proof context (plus the
  1352 local bounds) of the current simplification process; any simproc
  1353 etc. that calls the Simplifier recursively should do this!  Removed
  1354 former Simplifier.inherit_bounds, which is already included here --
  1355 INCOMPATIBILITY.  Tools based on low-level rewriting may even have to
  1356 specify an explicit context using Simplifier.context/theory_context.
  1357 
  1358 * Simplifier/Classical Reasoner: more abstract interfaces
  1359 change_simpset/claset for modifying the simpset/claset reference of a
  1360 theory; raw versions simpset/claset_ref etc. have been discontinued --
  1361 INCOMPATIBILITY.
  1362 
  1363 * Provers: more generic wrt. syntax of object-logics, avoid hardwired
  1364 "Trueprop" etc.
  1365 
  1366 
  1367 *** System ***
  1368 
  1369 * settings: ML_IDENTIFIER -- which is appended to user specific heap
  1370 locations -- now includes the Isabelle version identifier as well.
  1371 This simplifies use of multiple Isabelle installations.
  1372 
  1373 * isabelle-process: option -S (secure mode) disables some critical
  1374 operations, notably runtime compilation and evaluation of ML source
  1375 code.
  1376 
  1377 * Support for parallel execution, using native multicore support of
  1378 Poly/ML 5.1.  The theory loader exploits parallelism when processing
  1379 independent theories, according to the given theory header
  1380 specifications. The maximum number of worker threads is specified via
  1381 usedir option -M or the "max-threads" setting in Proof General. A
  1382 speedup factor of 1.5--3.5 can be expected on a 4-core machine, and up
  1383 to 6 on a 8-core machine.  User-code needs to observe certain
  1384 guidelines for thread-safe programming, see appendix A in the Isar
  1385 Implementation manual.
  1386 
  1387 
  1388 New in Isabelle2005 (October 2005)
  1389 ----------------------------------
  1390 
  1391 *** General ***
  1392 
  1393 * Theory headers: the new header syntax for Isar theories is
  1394 
  1395   theory <name>
  1396   imports <theory1> ... <theoryN>
  1397   uses <file1> ... <fileM>
  1398   begin
  1399 
  1400 where the 'uses' part is optional.  The previous syntax
  1401 
  1402   theory <name> = <theory1> + ... + <theoryN>:
  1403 
  1404 will disappear in the next release.  Use isatool fixheaders to convert
  1405 existing theory files.  Note that there is no change in ancient
  1406 non-Isar theories now, but these will disappear soon.
  1407 
  1408 * Theory loader: parent theories can now also be referred to via
  1409 relative and absolute paths.
  1410 
  1411 * Command 'find_theorems' searches for a list of criteria instead of a
  1412 list of constants. Known criteria are: intro, elim, dest, name:string,
  1413 simp:term, and any term. Criteria can be preceded by '-' to select
  1414 theorems that do not match. Intro, elim, dest select theorems that
  1415 match the current goal, name:s selects theorems whose fully qualified
  1416 name contain s, and simp:term selects all simplification rules whose
  1417 lhs match term.  Any other term is interpreted as pattern and selects
  1418 all theorems matching the pattern. Available in ProofGeneral under
  1419 'ProofGeneral -> Find Theorems' or C-c C-f.  Example:
  1420 
  1421   C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."
  1422 
  1423 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",
  1424 matching the current goal as introduction rule and not having "HOL."
  1425 in their name (i.e. not being defined in theory HOL).
  1426 
  1427 * Command 'thms_containing' has been discontinued in favour of
  1428 'find_theorems'; INCOMPATIBILITY.
  1429 
  1430 * Communication with Proof General is now 8bit clean, which means that
  1431 Unicode text in UTF-8 encoding may be used within theory texts (both
  1432 formal and informal parts).  Cf. option -U of the Isabelle Proof
  1433 General interface.  Here are some simple examples (cf. src/HOL/ex):
  1434 
  1435   http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html
  1436   http://isabelle.in.tum.de/library/HOL/ex/Chinese.html
  1437 
  1438 * Improved efficiency of the Simplifier and, to a lesser degree, the
  1439 Classical Reasoner.  Typical big applications run around 2 times
  1440 faster.
  1441 
  1442 
  1443 *** Document preparation ***
  1444 
  1445 * Commands 'display_drafts' and 'print_drafts' perform simple output
  1446 of raw sources.  Only those symbols that do not require additional
  1447 LaTeX packages (depending on comments in isabellesym.sty) are
  1448 displayed properly, everything else is left verbatim.  isatool display
  1449 and isatool print are used as front ends (these are subject to the
  1450 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).
  1451 
  1452 * Command tags control specific markup of certain regions of text,
  1453 notably folding and hiding.  Predefined tags include "theory" (for
  1454 theory begin and end), "proof" for proof commands, and "ML" for
  1455 commands involving ML code; the additional tags "visible" and
  1456 "invisible" are unused by default.  Users may give explicit tag
  1457 specifications in the text, e.g. ''by %invisible (auto)''.  The
  1458 interpretation of tags is determined by the LaTeX job during document
  1459 preparation: see option -V of isatool usedir, or options -n and -t of
  1460 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,
  1461 \isadroptag.
  1462 
  1463 Several document versions may be produced at the same time via isatool
  1464 usedir (the generated index.html will link all of them).  Typical
  1465 specifications include ''-V document=theory,proof,ML'' to present
  1466 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold
  1467 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit
  1468 these parts without any formal replacement text.  The Isabelle site
  1469 default settings produce ''document'' and ''outline'' versions as
  1470 specified above.
  1471 
  1472 * Several new antiquotations:
  1473 
  1474   @{term_type term} prints a term with its type annotated;
  1475 
  1476   @{typeof term} prints the type of a term;
  1477 
  1478   @{const const} is the same as @{term const}, but checks that the
  1479   argument is a known logical constant;
  1480 
  1481   @{term_style style term} and @{thm_style style thm} print a term or
  1482   theorem applying a "style" to it
  1483 
  1484   @{ML text}
  1485 
  1486 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of
  1487 definitions, equations, inequations etc., 'concl' printing only the
  1488 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'
  1489 to print the specified premise.  TermStyle.add_style provides an ML
  1490 interface for introducing further styles.  See also the "LaTeX Sugar"
  1491 document practical applications.  The ML antiquotation prints
  1492 type-checked ML expressions verbatim.
  1493 
  1494 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',
  1495 and 'text' support optional locale specification '(in loc)', which
  1496 specifies the default context for interpreting antiquotations.  For
  1497 example: 'text (in lattice) {* @{thm inf_assoc}*}'.
  1498 
  1499 * Option 'locale=NAME' of antiquotations specifies an alternative
  1500 context interpreting the subsequent argument.  For example: @{thm
  1501 [locale=lattice] inf_assoc}.
  1502 
  1503 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within
  1504 a proof context.
  1505 
  1506 * Proper output of antiquotations for theory commands involving a
  1507 proof context (such as 'locale' or 'theorem (in loc) ...').
  1508 
  1509 * Delimiters of outer tokens (string etc.) now produce separate LaTeX
  1510 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).
  1511 
  1512 * isatool usedir: new option -C (default true) controls whether option
  1513 -D should include a copy of the original document directory; -C false
  1514 prevents unwanted effects such as copying of administrative CVS data.
  1515 
  1516 
  1517 *** Pure ***
  1518 
  1519 * Considerably improved version of 'constdefs' command.  Now performs
  1520 automatic type-inference of declared constants; additional support for
  1521 local structure declarations (cf. locales and HOL records), see also
  1522 isar-ref manual.  Potential INCOMPATIBILITY: need to observe strictly
  1523 sequential dependencies of definitions within a single 'constdefs'
  1524 section; moreover, the declared name needs to be an identifier.  If
  1525 all fails, consider to fall back on 'consts' and 'defs' separately.
  1526 
  1527 * Improved indexed syntax and implicit structures.  First of all,
  1528 indexed syntax provides a notational device for subscripted
  1529 application, using the new syntax \<^bsub>term\<^esub> for arbitrary
  1530 expressions.  Secondly, in a local context with structure
  1531 declarations, number indexes \<^sub>n or the empty index (default
  1532 number 1) refer to a certain fixed variable implicitly; option
  1533 show_structs controls printing of implicit structures.  Typical
  1534 applications of these concepts involve record types and locales.
  1535 
  1536 * New command 'no_syntax' removes grammar declarations (and
  1537 translations) resulting from the given syntax specification, which is
  1538 interpreted in the same manner as for the 'syntax' command.
  1539 
  1540 * 'Advanced' translation functions (parse_translation etc.) may depend
  1541 on the signature of the theory context being presently used for
  1542 parsing/printing, see also isar-ref manual.
  1543 
  1544 * Improved 'oracle' command provides a type-safe interface to turn an
  1545 ML expression of type theory -> T -> term into a primitive rule of
  1546 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle
  1547 is already included here); see also FOL/ex/IffExample.thy;
  1548 INCOMPATIBILITY.
  1549 
  1550 * axclass: name space prefix for class "c" is now "c_class" (was "c"
  1551 before); "cI" is no longer bound, use "c.intro" instead.
  1552 INCOMPATIBILITY.  This change avoids clashes of fact bindings for
  1553 axclasses vs. locales.
  1554 
  1555 * Improved internal renaming of symbolic identifiers -- attach primes
  1556 instead of base 26 numbers.
  1557 
  1558 * New flag show_question_marks controls printing of leading question
  1559 marks in schematic variable names.
  1560 
  1561 * In schematic variable names, *any* symbol following \<^isub> or
  1562 \<^isup> is now treated as part of the base name.  For example, the
  1563 following works without printing of awkward ".0" indexes:
  1564 
  1565   lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"
  1566     by simp
  1567 
  1568 * Inner syntax includes (*(*nested*) comments*).
  1569 
  1570 * Pretty printer now supports unbreakable blocks, specified in mixfix
  1571 annotations as "(00...)".
  1572 
  1573 * Clear separation of logical types and nonterminals, where the latter
  1574 may only occur in 'syntax' specifications or type abbreviations.
  1575 Before that distinction was only partially implemented via type class
  1576 "logic" vs. "{}".  Potential INCOMPATIBILITY in rare cases of improper
  1577 use of 'types'/'consts' instead of 'nonterminals'/'syntax'.  Some very
  1578 exotic syntax specifications may require further adaption
  1579 (e.g. Cube/Cube.thy).
  1580 
  1581 * Removed obsolete type class "logic", use the top sort {} instead.
  1582 Note that non-logical types should be declared as 'nonterminals'
  1583 rather than 'types'.  INCOMPATIBILITY for new object-logic
  1584 specifications.
  1585 
  1586 * Attributes 'induct' and 'cases': type or set names may now be
  1587 locally fixed variables as well.
  1588 
  1589 * Simplifier: can now control the depth to which conditional rewriting
  1590 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth
  1591 Limit.
  1592 
  1593 * Simplifier: simplification procedures may now take the current
  1594 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc
  1595 interface), which is very useful for calling the Simplifier
  1596 recursively.  Minor INCOMPATIBILITY: the 'prems' argument of simprocs
  1597 is gone -- use prems_of_ss on the simpset instead.  Moreover, the
  1598 low-level mk_simproc no longer applies Logic.varify internally, to
  1599 allow for use in a context of fixed variables.
  1600 
  1601 * thin_tac now works even if the assumption being deleted contains !!
  1602 or ==>.  More generally, erule now works even if the major premise of
  1603 the elimination rule contains !! or ==>.
  1604 
  1605 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.
  1606 
  1607 * Reorganized bootstrapping of the Pure theories; CPure is now derived
  1608 from Pure, which contains all common declarations already.  Both
  1609 theories are defined via plain Isabelle/Isar .thy files.
  1610 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /
  1611 CPure.elim / CPure.dest attributes) now appear in the Pure name space;
  1612 use isatool fixcpure to adapt your theory and ML sources.
  1613 
  1614 * New syntax 'name(i-j, i-, i, ...)' for referring to specific
  1615 selections of theorems in named facts via index ranges.
  1616 
  1617 * 'print_theorems': in theory mode, really print the difference
  1618 wrt. the last state (works for interactive theory development only),
  1619 in proof mode print all local facts (cf. 'print_facts');
  1620 
  1621 * 'hide': option '(open)' hides only base names.
  1622 
  1623 * More efficient treatment of intermediate checkpoints in interactive
  1624 theory development.
  1625 
  1626 * Code generator is now invoked via code_module (incremental code
  1627 generation) and code_library (modular code generation, ML structures
  1628 for each theory).  INCOMPATIBILITY: new keywords 'file' and 'contains'
  1629 must be quoted when used as identifiers.
  1630 
  1631 * New 'value' command for reading, evaluating and printing terms using
  1632 the code generator.  INCOMPATIBILITY: command keyword 'value' must be
  1633 quoted when used as identifier.
  1634 
  1635 
  1636 *** Locales ***
  1637 
  1638 * New commands for the interpretation of locale expressions in
  1639 theories (1), locales (2) and proof contexts (3).  These generate
  1640 proof obligations from the expression specification.  After the
  1641 obligations have been discharged, theorems of the expression are added
  1642 to the theory, target locale or proof context.  The synopsis of the
  1643 commands is a follows:
  1644 
  1645   (1) interpretation expr inst
  1646   (2) interpretation target < expr
  1647   (3) interpret expr inst
  1648 
  1649 Interpretation in theories and proof contexts require a parameter
  1650 instantiation of terms from the current context.  This is applied to
  1651 specifications and theorems of the interpreted expression.
  1652 Interpretation in locales only permits parameter renaming through the
  1653 locale expression.  Interpretation is smart in that interpretations
  1654 that are active already do not occur in proof obligations, neither are
  1655 instantiated theorems stored in duplicate.  Use 'print_interps' to
  1656 inspect active interpretations of a particular locale.  For details,
  1657 see the Isar Reference manual.  Examples can be found in
  1658 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.
  1659 
  1660 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use
  1661 'interpret' instead.
  1662 
  1663 * New context element 'constrains' for adding type constraints to
  1664 parameters.
  1665 
  1666 * Context expressions: renaming of parameters with syntax
  1667 redeclaration.
  1668 
  1669 * Locale declaration: 'includes' disallowed.
  1670 
  1671 * Proper static binding of attribute syntax -- i.e. types / terms /
  1672 facts mentioned as arguments are always those of the locale definition
  1673 context, independently of the context of later invocations.  Moreover,
  1674 locale operations (renaming and type / term instantiation) are applied
  1675 to attribute arguments as expected.
  1676 
  1677 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of
  1678 actual attributes; rare situations may require Attrib.attribute to
  1679 embed those attributes into Attrib.src that lack concrete syntax.
  1680 Attribute implementations need to cooperate properly with the static
  1681 binding mechanism.  Basic parsers Args.XXX_typ/term/prop and
  1682 Attrib.XXX_thm etc. already do the right thing without further
  1683 intervention.  Only unusual applications -- such as "where" or "of"
  1684 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both
  1685 on the context and the facts involved -- may have to assign parsed
  1686 values to argument tokens explicitly.
  1687 
  1688 * Changed parameter management in theorem generation for long goal
  1689 statements with 'includes'.  INCOMPATIBILITY: produces a different
  1690 theorem statement in rare situations.
  1691 
  1692 * Locale inspection command 'print_locale' omits notes elements.  Use
  1693 'print_locale!' to have them included in the output.
  1694 
  1695 
  1696 *** Provers ***
  1697 
  1698 * Provers/hypsubst.ML: improved version of the subst method, for
  1699 single-step rewriting: it now works in bound variable contexts. New is
  1700 'subst (asm)', for rewriting an assumption.  INCOMPATIBILITY: may
  1701 rewrite a different subterm than the original subst method, which is
  1702 still available as 'simplesubst'.
  1703 
  1704 * Provers/quasi.ML: new transitivity reasoners for transitivity only
  1705 and quasi orders.
  1706 
  1707 * Provers/trancl.ML: new transitivity reasoner for transitive and
  1708 reflexive-transitive closure of relations.
  1709 
  1710 * Provers/blast.ML: new reference depth_limit to make blast's depth
  1711 limit (previously hard-coded with a value of 20) user-definable.
  1712 
  1713 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup
  1714 is peformed already.  Object-logics merely need to finish their
  1715 initial simpset configuration as before.  INCOMPATIBILITY.
  1716 
  1717 
  1718 *** HOL ***
  1719 
  1720 * Symbolic syntax of Hilbert Choice Operator is now as follows:
  1721 
  1722   syntax (epsilon)
  1723     "_Eps" :: "[pttrn, bool] => 'a"    ("(3\<some>_./ _)" [0, 10] 10)
  1724 
  1725 The symbol \<some> is displayed as the alternative epsilon of LaTeX
  1726 and x-symbol; use option '-m epsilon' to get it actually printed.
  1727 Moreover, the mathematically important symbolic identifier \<epsilon>
  1728 becomes available as variable, constant etc.  INCOMPATIBILITY,
  1729 
  1730 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".
  1731 Similarly for all quantifiers: "ALL x > y" etc.  The x-symbol for >=
  1732 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to
  1733 support corresponding Isar calculations.
  1734 
  1735 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"
  1736 instead of ":".
  1737 
  1738 * theory SetInterval: changed the syntax for open intervals:
  1739 
  1740   Old       New
  1741   {..n(}    {..<n}
  1742   {)n..}    {n<..}
  1743   {m..n(}   {m..<n}
  1744   {)m..n}   {m<..n}
  1745   {)m..n(}  {m<..<n}
  1746 
  1747 The old syntax is still supported but will disappear in the next
  1748 release.  For conversion use the following Emacs search and replace
  1749 patterns (these are not perfect but work quite well):
  1750 
  1751   {)\([^\.]*\)\.\.  ->  {\1<\.\.}
  1752   \.\.\([^(}]*\)(}  ->  \.\.<\1}
  1753 
  1754 * Theory Commutative_Ring (in Library): method comm_ring for proving
  1755 equalities in commutative rings; method 'algebra' provides a generic
  1756 interface.
  1757 
  1758 * Theory Finite_Set: changed the syntax for 'setsum', summation over
  1759 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is
  1760 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can
  1761 be a tuple pattern.
  1762 
  1763 Some new syntax forms are available:
  1764 
  1765   "\<Sum>x | P. e"      for     "setsum (%x. e) {x. P}"
  1766   "\<Sum>x = a..b. e"   for     "setsum (%x. e) {a..b}"
  1767   "\<Sum>x = a..<b. e"  for     "setsum (%x. e) {a..<b}"
  1768   "\<Sum>x < k. e"      for     "setsum (%x. e) {..<k}"
  1769 
  1770 The latter form "\<Sum>x < k. e" used to be based on a separate
  1771 function "Summation", which has been discontinued.
  1772 
  1773 * theory Finite_Set: in structured induction proofs, the insert case
  1774 is now 'case (insert x F)' instead of the old counterintuitive 'case
  1775 (insert F x)'.
  1776 
  1777 * The 'refute' command has been extended to support a much larger
  1778 fragment of HOL, including axiomatic type classes, constdefs and
  1779 typedefs, inductive datatypes and recursion.
  1780 
  1781 * New tactics 'sat' and 'satx' to prove propositional tautologies.
  1782 Requires zChaff with proof generation to be installed.  See
  1783 HOL/ex/SAT_Examples.thy for examples.
  1784 
  1785 * Datatype induction via method 'induct' now preserves the name of the
  1786 induction variable. For example, when proving P(xs::'a list) by
  1787 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather
  1788 than P(list) ==> P(a#list) as previously.  Potential INCOMPATIBILITY
  1789 in unstructured proof scripts.
  1790 
  1791 * Reworked implementation of records.  Improved scalability for
  1792 records with many fields, avoiding performance problems for type
  1793 inference. Records are no longer composed of nested field types, but
  1794 of nested extension types. Therefore the record type only grows linear
  1795 in the number of extensions and not in the number of fields.  The
  1796 top-level (users) view on records is preserved.  Potential
  1797 INCOMPATIBILITY only in strange cases, where the theory depends on the
  1798 old record representation. The type generated for a record is called
  1799 <record_name>_ext_type.
  1800 
  1801 Flag record_quick_and_dirty_sensitive can be enabled to skip the
  1802 proofs triggered by a record definition or a simproc (if
  1803 quick_and_dirty is enabled).  Definitions of large records can take
  1804 quite long.
  1805 
  1806 New simproc record_upd_simproc for simplification of multiple record
  1807 updates enabled by default.  Moreover, trivial updates are also
  1808 removed: r(|x := x r|) = r.  INCOMPATIBILITY: old proofs break
  1809 occasionally, since simplification is more powerful by default.
  1810 
  1811 * typedef: proper support for polymorphic sets, which contain extra
  1812 type-variables in the term.
  1813 
  1814 * Simplifier: automatically reasons about transitivity chains
  1815 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics
  1816 provided by Provers/trancl.ML as additional solvers.  INCOMPATIBILITY:
  1817 old proofs break occasionally as simplification may now solve more
  1818 goals than previously.
  1819 
  1820 * Simplifier: converts x <= y into x = y if assumption y <= x is
  1821 present.  Works for all partial orders (class "order"), in particular
  1822 numbers and sets.  For linear orders (e.g. numbers) it treats ~ x < y
  1823 just like y <= x.
  1824 
  1825 * Simplifier: new simproc for "let x = a in f x".  If a is a free or
  1826 bound variable or a constant then the let is unfolded.  Otherwise
  1827 first a is simplified to b, and then f b is simplified to g. If
  1828 possible we abstract b from g arriving at "let x = b in h x",
  1829 otherwise we unfold the let and arrive at g.  The simproc can be
  1830 enabled/disabled by the reference use_let_simproc.  Potential
  1831 INCOMPATIBILITY since simplification is more powerful by default.
  1832 
  1833 * Classical reasoning: the meson method now accepts theorems as arguments.
  1834 
  1835 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background
  1836 jobs to provide advice on the provability of subgoals.
  1837 
  1838 * Theory OrderedGroup and Ring_and_Field: various additions and
  1839 improvements to faciliate calculations involving equalities and
  1840 inequalities.
  1841 
  1842 The following theorems have been eliminated or modified
  1843 (INCOMPATIBILITY):
  1844 
  1845   abs_eq             now named abs_of_nonneg
  1846   abs_of_ge_0        now named abs_of_nonneg
  1847   abs_minus_eq       now named abs_of_nonpos
  1848   imp_abs_id         now named abs_of_nonneg
  1849   imp_abs_neg_id     now named abs_of_nonpos
  1850   mult_pos           now named mult_pos_pos
  1851   mult_pos_le        now named mult_nonneg_nonneg
  1852   mult_pos_neg_le    now named mult_nonneg_nonpos
  1853   mult_pos_neg2_le   now named mult_nonneg_nonpos2
  1854   mult_neg           now named mult_neg_neg
  1855   mult_neg_le        now named mult_nonpos_nonpos
  1856 
  1857 * The following lemmas in Ring_and_Field have been added to the simplifier:
  1858      
  1859      zero_le_square
  1860      not_square_less_zero 
  1861 
  1862   The following lemmas have been deleted from Real/RealPow:
  1863   
  1864      realpow_zero_zero
  1865      realpow_two
  1866      realpow_less
  1867      zero_le_power
  1868      realpow_two_le
  1869      abs_realpow_two
  1870      realpow_two_abs     
  1871 
  1872 * Theory Parity: added rules for simplifying exponents.
  1873 
  1874 * Theory List:
  1875 
  1876 The following theorems have been eliminated or modified
  1877 (INCOMPATIBILITY):
  1878 
  1879   list_all_Nil       now named list_all.simps(1)
  1880   list_all_Cons      now named list_all.simps(2)
  1881   list_all_conv      now named list_all_iff
  1882   set_mem_eq         now named mem_iff
  1883 
  1884 * Theories SetsAndFunctions and BigO (see HOL/Library) support
  1885 asymptotic "big O" calculations.  See the notes in BigO.thy.
  1886 
  1887 
  1888 *** HOL-Complex ***
  1889 
  1890 * Theory RealDef: better support for embedding natural numbers and
  1891 integers in the reals.
  1892 
  1893 The following theorems have been eliminated or modified
  1894 (INCOMPATIBILITY):
  1895 
  1896   exp_ge_add_one_self  now requires no hypotheses
  1897   real_of_int_add      reversed direction of equality (use [symmetric])
  1898   real_of_int_minus    reversed direction of equality (use [symmetric])
  1899   real_of_int_diff     reversed direction of equality (use [symmetric])
  1900   real_of_int_mult     reversed direction of equality (use [symmetric])
  1901 
  1902 * Theory RComplete: expanded support for floor and ceiling functions.
  1903 
  1904 * Theory Ln is new, with properties of the natural logarithm
  1905 
  1906 * Hyperreal: There is a new type constructor "star" for making
  1907 nonstandard types.  The old type names are now type synonyms:
  1908 
  1909   hypreal = real star
  1910   hypnat = nat star
  1911   hcomplex = complex star
  1912 
  1913 * Hyperreal: Many groups of similarly-defined constants have been
  1914 replaced by polymorphic versions (INCOMPATIBILITY):
  1915 
  1916   star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex
  1917 
  1918   starset      <-- starsetNat, starsetC
  1919   *s*          <-- *sNat*, *sc*
  1920   starset_n    <-- starsetNat_n, starsetC_n
  1921   *sn*         <-- *sNatn*, *scn*
  1922   InternalSets <-- InternalNatSets, InternalCSets
  1923 
  1924   starfun      <-- starfun{Nat,Nat2,C,RC,CR}
  1925   *f*          <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*
  1926   starfun_n    <-- starfun{Nat,Nat2,C,RC,CR}_n
  1927   *fn*         <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*
  1928   InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs
  1929 
  1930 * Hyperreal: Many type-specific theorems have been removed in favor of
  1931 theorems specific to various axiomatic type classes (INCOMPATIBILITY):
  1932 
  1933   add_commute <-- {hypreal,hypnat,hcomplex}_add_commute
  1934   add_assoc   <-- {hypreal,hypnat,hcomplex}_add_assocs
  1935   OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left
  1936   OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right
  1937   right_minus <-- hypreal_add_minus
  1938   left_minus <-- {hypreal,hcomplex}_add_minus_left
  1939   mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute
  1940   mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc
  1941   mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left
  1942   mult_1_right <-- hcomplex_mult_one_right
  1943   mult_zero_left <-- hcomplex_mult_zero_left
  1944   left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib
  1945   right_distrib <-- hypnat_add_mult_distrib2
  1946   zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one
  1947   right_inverse <-- hypreal_mult_inverse
  1948   left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left
  1949   order_refl <-- {hypreal,hypnat}_le_refl
  1950   order_trans <-- {hypreal,hypnat}_le_trans
  1951   order_antisym <-- {hypreal,hypnat}_le_anti_sym
  1952   order_less_le <-- {hypreal,hypnat}_less_le
  1953   linorder_linear <-- {hypreal,hypnat}_le_linear
  1954   add_left_mono <-- {hypreal,hypnat}_add_left_mono
  1955   mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2
  1956   add_nonneg_nonneg <-- hypreal_le_add_order
  1957 
  1958 * Hyperreal: Separate theorems having to do with type-specific
  1959 versions of constants have been merged into theorems that apply to the
  1960 new polymorphic constants (INCOMPATIBILITY):
  1961 
  1962   STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set
  1963   STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set
  1964   STAR_Un <-- {STAR,NatStar,STARC}_Un
  1965   STAR_Int <-- {STAR,NatStar,STARC}_Int
  1966   STAR_Compl <-- {STAR,NatStar,STARC}_Compl
  1967   STAR_subset <-- {STAR,NatStar,STARC}_subset
  1968   STAR_mem <-- {STAR,NatStar,STARC}_mem
  1969   STAR_mem_Compl <-- {STAR,STARC}_mem_Compl
  1970   STAR_diff <-- {STAR,STARC}_diff
  1971   STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,
  1972     STARC_hcomplex_of_complex}_image_subset
  1973   starset_n_Un <-- starset{Nat,C}_n_Un
  1974   starset_n_Int <-- starset{Nat,C}_n_Int
  1975   starset_n_Compl <-- starset{Nat,C}_n_Compl
  1976   starset_n_diff <-- starset{Nat,C}_n_diff
  1977   InternalSets_Un <-- Internal{Nat,C}Sets_Un
  1978   InternalSets_Int <-- Internal{Nat,C}Sets_Int
  1979   InternalSets_Compl <-- Internal{Nat,C}Sets_Compl
  1980   InternalSets_diff <-- Internal{Nat,C}Sets_diff
  1981   InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff
  1982   InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n
  1983   starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq
  1984   starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}
  1985   starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}
  1986   starfun <-- starfun{Nat,Nat2,C,RC,CR}
  1987   starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult
  1988   starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add
  1989   starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus
  1990   starfun_diff <-- starfun{C,RC,CR}_diff
  1991   starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o
  1992   starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2
  1993   starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun
  1994   starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse
  1995   starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq
  1996   starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff
  1997   starfun_Id <-- starfunC_Id
  1998   starfun_approx <-- starfun{Nat,CR}_approx
  1999   starfun_capprox <-- starfun{C,RC}_capprox
  2000   starfun_abs <-- starfunNat_rabs
  2001   starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel
  2002   starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2
  2003   starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox
  2004   starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox
  2005   starfun_add_capprox <-- starfun{C,RC}_add_capprox
  2006   starfun_add_approx <-- starfunCR_add_approx
  2007   starfun_inverse_inverse <-- starfunC_inverse_inverse
  2008   starfun_divide <-- starfun{C,CR,RC}_divide
  2009   starfun_n <-- starfun{Nat,C}_n
  2010   starfun_n_mult <-- starfun{Nat,C}_n_mult
  2011   starfun_n_add <-- starfun{Nat,C}_n_add
  2012   starfun_n_add_minus <-- starfunNat_n_add_minus
  2013   starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun
  2014   starfun_n_minus <-- starfun{Nat,C}_n_minus
  2015   starfun_n_eq <-- starfun{Nat,C}_n_eq
  2016 
  2017   star_n_add <-- {hypreal,hypnat,hcomplex}_add
  2018   star_n_minus <-- {hypreal,hcomplex}_minus
  2019   star_n_diff <-- {hypreal,hcomplex}_diff
  2020   star_n_mult <-- {hypreal,hcomplex}_mult
  2021   star_n_inverse <-- {hypreal,hcomplex}_inverse
  2022   star_n_le <-- {hypreal,hypnat}_le
  2023   star_n_less <-- {hypreal,hypnat}_less
  2024   star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num
  2025   star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num
  2026   star_n_abs <-- hypreal_hrabs
  2027   star_n_divide <-- hcomplex_divide
  2028 
  2029   star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add
  2030   star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus
  2031   star_of_diff <-- hypreal_of_real_diff
  2032   star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult
  2033   star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one
  2034   star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero
  2035   star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff
  2036   star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff
  2037   star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff
  2038   star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse
  2039   star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide
  2040   star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat
  2041   star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int
  2042   star_of_number_of <-- {hypreal,hcomplex}_number_of
  2043   star_of_number_less <-- number_of_less_hypreal_of_real_iff
  2044   star_of_number_le <-- number_of_le_hypreal_of_real_iff
  2045   star_of_eq_number <-- hypreal_of_real_eq_number_of_iff
  2046   star_of_less_number <-- hypreal_of_real_less_number_of_iff
  2047   star_of_le_number <-- hypreal_of_real_le_number_of_iff
  2048   star_of_power <-- hypreal_of_real_power
  2049   star_of_eq_0 <-- hcomplex_of_complex_zero_iff
  2050 
  2051 * Hyperreal: new method "transfer" that implements the transfer
  2052 principle of nonstandard analysis. With a subgoal that mentions
  2053 nonstandard types like "'a star", the command "apply transfer"
  2054 replaces it with an equivalent one that mentions only standard types.
  2055 To be successful, all free variables must have standard types; non-
  2056 standard variables must have explicit universal quantifiers.
  2057 
  2058 * Hyperreal: A theory of Taylor series.
  2059 
  2060 
  2061 *** HOLCF ***
  2062 
  2063 * Discontinued special version of 'constdefs' (which used to support
  2064 continuous functions) in favor of the general Pure one with full
  2065 type-inference.
  2066 
  2067 * New simplification procedure for solving continuity conditions; it
  2068 is much faster on terms with many nested lambda abstractions (cubic
  2069 instead of exponential time).
  2070 
  2071 * New syntax for domain package: selector names are now optional.
  2072 Parentheses should be omitted unless argument is lazy, for example:
  2073 
  2074   domain 'a stream = cons "'a" (lazy "'a stream")
  2075 
  2076 * New command 'fixrec' for defining recursive functions with pattern
  2077 matching; defining multiple functions with mutual recursion is also
  2078 supported.  Patterns may include the constants cpair, spair, up, sinl,
  2079 sinr, or any data constructor defined by the domain package. The given
  2080 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for
  2081 syntax and examples.
  2082 
  2083 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes
  2084 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,
  2085 but the proof obligation additionally includes an admissibility
  2086 requirement. The packages generate instances of class cpo or pcpo,
  2087 with continuity and strictness theorems for Rep and Abs.
  2088 
  2089 * HOLCF: Many theorems have been renamed according to a more standard naming
  2090 scheme (INCOMPATIBILITY):
  2091 
  2092   foo_inject:  "foo$x = foo$y ==> x = y"
  2093   foo_eq:      "(foo$x = foo$y) = (x = y)"
  2094   foo_less:    "(foo$x << foo$y) = (x << y)"
  2095   foo_strict:  "foo$UU = UU"
  2096   foo_defined: "... ==> foo$x ~= UU"
  2097   foo_defined_iff: "(foo$x = UU) = (x = UU)"
  2098 
  2099 
  2100 *** ZF ***
  2101 
  2102 * ZF/ex: theories Group and Ring provide examples in abstract algebra,
  2103 including the First Isomorphism Theorem (on quotienting by the kernel
  2104 of a homomorphism).
  2105 
  2106 * ZF/Simplifier: install second copy of type solver that actually
  2107 makes use of TC rules declared to Isar proof contexts (or locales);
  2108 the old version is still required for ML proof scripts.
  2109 
  2110 
  2111 *** Cube ***
  2112 
  2113 * Converted to Isar theory format; use locales instead of axiomatic
  2114 theories.
  2115 
  2116 
  2117 *** ML ***
  2118 
  2119 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts
  2120 for ||>, ||>>, |>>,
  2121 
  2122 * Pure/library.ML no longer defines its own option datatype, but uses
  2123 that of the SML basis, which has constructors NONE and SOME instead of
  2124 None and Some, as well as exception Option.Option instead of OPTION.
  2125 The functions the, if_none, is_some, is_none have been adapted
  2126 accordingly, while Option.map replaces apsome.
  2127 
  2128 * Pure/library.ML: the exception LIST has been given up in favour of
  2129 the standard exceptions Empty and Subscript, as well as
  2130 Library.UnequalLengths.  Function like Library.hd and Library.tl are
  2131 superceded by the standard hd and tl functions etc.
  2132 
  2133 A number of basic list functions are no longer exported to the ML
  2134 toplevel, as they are variants of predefined functions.  The following
  2135 suggests how one can translate existing code:
  2136 
  2137     rev_append xs ys = List.revAppend (xs, ys)
  2138     nth_elem (i, xs) = List.nth (xs, i)
  2139     last_elem xs = List.last xs
  2140     flat xss = List.concat xss
  2141     seq fs = List.app fs
  2142     partition P xs = List.partition P xs
  2143     mapfilter f xs = List.mapPartial f xs
  2144 
  2145 * Pure/library.ML: several combinators for linear functional
  2146 transformations, notably reverse application and composition:
  2147 
  2148   x |> f                f #> g
  2149   (x, y) |-> f          f #-> g
  2150 
  2151 * Pure/library.ML: introduced/changed precedence of infix operators:
  2152 
  2153   infix 1 |> |-> ||> ||>> |>> |>>> #> #->;
  2154   infix 2 ?;
  2155   infix 3 o oo ooo oooo;
  2156   infix 4 ~~ upto downto;
  2157 
  2158 Maybe INCOMPATIBILITY when any of those is used in conjunction with other
  2159 infix operators.
  2160 
  2161 * Pure/library.ML: natural list combinators fold, fold_rev, and
  2162 fold_map support linear functional transformations and nesting.  For
  2163 example:
  2164 
  2165   fold f [x1, ..., xN] y =
  2166     y |> f x1 |> ... |> f xN
  2167 
  2168   (fold o fold) f [xs1, ..., xsN] y =
  2169     y |> fold f xs1 |> ... |> fold f xsN
  2170 
  2171   fold f [x1, ..., xN] =
  2172     f x1 #> ... #> f xN
  2173 
  2174   (fold o fold) f [xs1, ..., xsN] =
  2175     fold f xs1 #> ... #> fold f xsN
  2176 
  2177 * Pure/library.ML: the following selectors on type 'a option are
  2178 available:
  2179 
  2180   the:               'a option -> 'a  (*partial*)
  2181   these:             'a option -> 'a  where 'a = 'b list
  2182   the_default: 'a -> 'a option -> 'a
  2183   the_list:          'a option -> 'a list
  2184 
  2185 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  2186 basic operations for association lists, following natural argument
  2187 order; moreover the explicit equality predicate passed here avoids
  2188 potentially expensive polymorphic runtime equality checks.
  2189 The old functions may be expressed as follows:
  2190 
  2191   assoc = uncurry (AList.lookup (op =))
  2192   assocs = these oo AList.lookup (op =)
  2193   overwrite = uncurry (AList.update (op =)) o swap
  2194 
  2195 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides
  2196 
  2197   val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
  2198   val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
  2199 
  2200 replacing make_keylist and keyfilter (occassionally used)
  2201 Naive rewrites:
  2202 
  2203   make_keylist = AList.make
  2204   keyfilter = AList.find (op =)
  2205 
  2206 * eq_fst and eq_snd now take explicit equality parameter, thus
  2207   avoiding eqtypes. Naive rewrites:
  2208 
  2209     eq_fst = eq_fst (op =)
  2210     eq_snd = eq_snd (op =)
  2211 
  2212 * Removed deprecated apl and apr (rarely used).
  2213   Naive rewrites:
  2214 
  2215     apl (n, op) =>>= curry op n
  2216     apr (op, m) =>>= fn n => op (n, m)
  2217 
  2218 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)
  2219 provides a reasonably efficient light-weight implementation of sets as
  2220 lists.
  2221 
  2222 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a
  2223 few new operations; existing lookup and update are now curried to
  2224 follow natural argument order (for use with fold etc.);
  2225 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.
  2226 
  2227 * Pure/General: output via the Isabelle channels of
  2228 writeln/warning/error etc. is now passed through Output.output, with a
  2229 hook for arbitrary transformations depending on the print_mode
  2230 (cf. Output.add_mode -- the first active mode that provides a output
  2231 function wins).  Already formatted output may be embedded into further
  2232 text via Output.raw; the result of Pretty.string_of/str_of and derived
  2233 functions (string_of_term/cterm/thm etc.) is already marked raw to
  2234 accommodate easy composition of diagnostic messages etc.  Programmers
  2235 rarely need to care about Output.output or Output.raw at all, with
  2236 some notable exceptions: Output.output is required when bypassing the
  2237 standard channels (writeln etc.), or in token translations to produce
  2238 properly formatted results; Output.raw is required when capturing
  2239 already output material that will eventually be presented to the user
  2240 a second time.  For the default print mode, both Output.output and
  2241 Output.raw have no effect.
  2242 
  2243 * Pure/General: Output.time_accumulator NAME creates an operator ('a
  2244 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the
  2245 cumulative results are displayed at the end of a batch session.
  2246 
  2247 * Pure/General: File.sysify_path and File.quote_sysify path have been
  2248 replaced by File.platform_path and File.shell_path (with appropriate
  2249 hooks).  This provides a clean interface for unusual systems where the
  2250 internal and external process view of file names are different.
  2251 
  2252 * Pure: more efficient orders for basic syntactic entities: added
  2253 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord
  2254 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is
  2255 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast
  2256 orders now -- potential INCOMPATIBILITY for code that depends on a
  2257 particular order for Symtab.keys, Symtab.dest, etc. (consider using
  2258 Library.sort_strings on result).
  2259 
  2260 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,
  2261 fold_types traverse types/terms from left to right, observing natural
  2262 argument order.  Supercedes previous foldl_XXX versions, add_frees,
  2263 add_vars etc. have been adapted as well: INCOMPATIBILITY.
  2264 
  2265 * Pure: name spaces have been refined, with significant changes of the
  2266 internal interfaces -- INCOMPATIBILITY.  Renamed cond_extern(_table)
  2267 to extern(_table).  The plain name entry path is superceded by a
  2268 general 'naming' context, which also includes the 'policy' to produce
  2269 a fully qualified name and external accesses of a fully qualified
  2270 name; NameSpace.extend is superceded by context dependent
  2271 Sign.declare_name.  Several theory and proof context operations modify
  2272 the naming context.  Especially note Theory.restore_naming and
  2273 ProofContext.restore_naming to get back to a sane state; note that
  2274 Theory.add_path is no longer sufficient to recover from
  2275 Theory.absolute_path in particular.
  2276 
  2277 * Pure: new flags short_names (default false) and unique_names
  2278 (default true) for controlling output of qualified names.  If
  2279 short_names is set, names are printed unqualified.  If unique_names is
  2280 reset, the name prefix is reduced to the minimum required to achieve
  2281 the original result when interning again, even if there is an overlap
  2282 with earlier declarations.
  2283 
  2284 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is
  2285 now 'extend', and 'merge' gets an additional Pretty.pp argument
  2286 (useful for printing error messages).  INCOMPATIBILITY.
  2287 
  2288 * Pure: major reorganization of the theory context.  Type Sign.sg and
  2289 Theory.theory are now identified, referring to the universal
  2290 Context.theory (see Pure/context.ML).  Actual signature and theory
  2291 content is managed as theory data.  The old code and interfaces were
  2292 spread over many files and structures; the new arrangement introduces
  2293 considerable INCOMPATIBILITY to gain more clarity:
  2294 
  2295   Context -- theory management operations (name, identity, inclusion,
  2296     parents, ancestors, merge, etc.), plus generic theory data;
  2297 
  2298   Sign -- logical signature and syntax operations (declaring consts,
  2299     types, etc.), plus certify/read for common entities;
  2300 
  2301   Theory -- logical theory operations (stating axioms, definitions,
  2302     oracles), plus a copy of logical signature operations (consts,
  2303     types, etc.); also a few basic management operations (Theory.copy,
  2304     Theory.merge, etc.)
  2305 
  2306 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm
  2307 etc.) as well as the sign field in Thm.rep_thm etc. have been retained
  2308 for convenience -- they merely return the theory.
  2309 
  2310 * Pure: type Type.tsig is superceded by theory in most interfaces.
  2311 
  2312 * Pure: the Isar proof context type is already defined early in Pure
  2313 as Context.proof (note that ProofContext.context and Proof.context are
  2314 aliases, where the latter is the preferred name).  This enables other
  2315 Isabelle components to refer to that type even before Isar is present.
  2316 
  2317 * Pure/sign/theory: discontinued named name spaces (i.e. classK,
  2318 typeK, constK, axiomK, oracleK), but provide explicit operations for
  2319 any of these kinds.  For example, Sign.intern typeK is now
  2320 Sign.intern_type, Theory.hide_space Sign.typeK is now
  2321 Theory.hide_types.  Also note that former
  2322 Theory.hide_classes/types/consts are now
  2323 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions
  2324 internalize their arguments!  INCOMPATIBILITY.
  2325 
  2326 * Pure: get_thm interface (of PureThy and ProofContext) expects
  2327 datatype thmref (with constructors Name and NameSelection) instead of
  2328 plain string -- INCOMPATIBILITY;
  2329 
  2330 * Pure: cases produced by proof methods specify options, where NONE
  2331 means to remove case bindings -- INCOMPATIBILITY in
  2332 (RAW_)METHOD_CASES.
  2333 
  2334 * Pure: the following operations retrieve axioms or theorems from a
  2335 theory node or theory hierarchy, respectively:
  2336 
  2337   Theory.axioms_of: theory -> (string * term) list
  2338   Theory.all_axioms_of: theory -> (string * term) list
  2339   PureThy.thms_of: theory -> (string * thm) list
  2340   PureThy.all_thms_of: theory -> (string * thm) list
  2341 
  2342 * Pure: print_tac now outputs the goal through the trace channel.
  2343 
  2344 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.
  2345 Reference Toplevel.debug (default false) controls detailed printing
  2346 and tracing of low-level exceptions; Toplevel.profiling (default 0)
  2347 controls execution profiling -- set to 1 for time and 2 for space
  2348 (both increase the runtime).
  2349 
  2350 * Isar session: The initial use of ROOT.ML is now always timed,
  2351 i.e. the log will show the actual process times, in contrast to the
  2352 elapsed wall-clock time that the outer shell wrapper produces.
  2353 
  2354 * Simplifier: improved handling of bound variables (nameless
  2355 representation, avoid allocating new strings).  Simprocs that invoke
  2356 the Simplifier recursively should use Simplifier.inherit_bounds to
  2357 avoid local name clashes.  Failure to do so produces warnings
  2358 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds
  2359 for further details.
  2360 
  2361 * ML functions legacy_bindings and use_legacy_bindings produce ML fact
  2362 bindings for all theorems stored within a given theory; this may help
  2363 in porting non-Isar theories to Isar ones, while keeping ML proof
  2364 scripts for the time being.
  2365 
  2366 * ML operator HTML.with_charset specifies the charset begin used for
  2367 generated HTML files.  For example:
  2368 
  2369   HTML.with_charset "utf-8" use_thy "Hebrew";
  2370   HTML.with_charset "utf-8" use_thy "Chinese";
  2371 
  2372 
  2373 *** System ***
  2374 
  2375 * Allow symlinks to all proper Isabelle executables (Isabelle,
  2376 isabelle, isatool etc.).
  2377 
  2378 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for
  2379 isatool doc, isatool mkdir, display_drafts etc.).
  2380 
  2381 * isatool usedir: option -f allows specification of the ML file to be
  2382 used by Isabelle; default is ROOT.ML.
  2383 
  2384 * New isatool version outputs the version identifier of the Isabelle
  2385 distribution being used.
  2386 
  2387 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format
  2388 (containing Boolean satisfiability problems) into Isabelle/HOL
  2389 theories.
  2390 
  2391 
  2392 
  2393 New in Isabelle2004 (April 2004)
  2394 --------------------------------
  2395 
  2396 *** General ***
  2397 
  2398 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
  2399   Replaces linorder.ML.
  2400 
  2401 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
  2402   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
  2403   (\<a>...\<z>), are now considered normal letters, and can therefore
  2404   be used anywhere where an ASCII letter (a...zA...Z) has until
  2405   now. COMPATIBILITY: This obviously changes the parsing of some
  2406   terms, especially where a symbol has been used as a binder, say
  2407   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
  2408   as an identifier.  Fix it by inserting a space around former
  2409   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
  2410   existing theory and ML files.
  2411 
  2412 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
  2413 
  2414 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
  2415   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
  2416   a normal (but invisible) letter. For multiple letter subscripts repeat
  2417   \<^isub> like this: x\<^isub>1\<^isub>2.
  2418 
  2419 * Pure: There are now sub-/superscripts that can span more than one
  2420   character. Text between \<^bsub> and \<^esub> is set in subscript in
  2421   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
  2422   superscript. The new control characters are not identifier parts.
  2423 
  2424 * Pure: Control-symbols of the form \<^raw:...> will literally print the
  2425   content of "..." to the latex file instead of \isacntrl... . The "..."
  2426   may consist of any printable characters excluding the end bracket >.
  2427 
  2428 * Pure: Using new Isar command "finalconsts" (or the ML functions
  2429   Theory.add_finals or Theory.add_finals_i) it is now possible to
  2430   declare constants "final", which prevents their being given a definition
  2431   later.  It is useful for constants whose behaviour is fixed axiomatically
  2432   rather than definitionally, such as the meta-logic connectives.
  2433 
  2434 * Pure: 'instance' now handles general arities with general sorts
  2435   (i.e. intersections of classes),
  2436 
  2437 * Presentation: generated HTML now uses a CSS style sheet to make layout
  2438   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
  2439   It can be changed to alter the colors/layout of generated pages.
  2440 
  2441 
  2442 *** Isar ***
  2443 
  2444 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
  2445   cut_tac, subgoal_tac and thin_tac:
  2446   - Now understand static (Isar) contexts.  As a consequence, users of Isar
  2447     locales are no longer forced to write Isar proof scripts.
  2448     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
  2449     emulations.
  2450   - INCOMPATIBILITY: names of variables to be instantiated may no
  2451     longer be enclosed in quotes.  Instead, precede variable name with `?'.
  2452     This is consistent with the instantiation attribute "where".
  2453 
  2454 * Attributes "where" and "of":
  2455   - Now take type variables of instantiated theorem into account when reading
  2456     the instantiation string.  This fixes a bug that caused instantiated
  2457     theorems to have too special types in some circumstances.
  2458   - "where" permits explicit instantiations of type variables.
  2459 
  2460 * Calculation commands "moreover" and "also" no longer interfere with
  2461   current facts ("this"), admitting arbitrary combinations with "then"
  2462   and derived forms.
  2463 
  2464 * Locales:
  2465   - Goal statements involving the context element "includes" no longer
  2466     generate theorems with internal delta predicates (those ending on
  2467     "_axioms") in the premise.
  2468     Resolve particular premise with <locale>.intro to obtain old form.
  2469   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
  2470     specification and "includes" elements in goal statement.
  2471   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
  2472     [intro?] and [elim?] (respectively) by default.
  2473   - Experimental command for instantiation of locales in proof contexts:
  2474         instantiate <label>[<attrs>]: <loc>
  2475     Instantiates locale <loc> and adds all its theorems to the current context
  2476     taking into account their attributes.  Label and attrs are optional
  2477     modifiers, like in theorem declarations.  If present, names of
  2478     instantiated theorems are qualified with <label>, and the attributes
  2479     <attrs> are applied after any attributes these theorems might have already.
  2480       If the locale has assumptions, a chained fact of the form
  2481     "<loc> t1 ... tn" is expected from which instantiations of the parameters
  2482     are derived.  The command does not support old-style locales declared
  2483     with "locale (open)".
  2484       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
  2485 
  2486 * HOL: Tactic emulation methods induct_tac and case_tac understand static
  2487   (Isar) contexts.
  2488 
  2489 
  2490 *** HOL ***
  2491 
  2492 * Proof import: new image HOL4 contains the imported library from
  2493   the HOL4 system with about 2500 theorems. It is imported by
  2494   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
  2495   can be used like any other Isabelle image.  See
  2496   HOL/Import/HOL/README for more information.
  2497 
  2498 * Simplifier:
  2499   - Much improved handling of linear and partial orders.
  2500     Reasoners for linear and partial orders are set up for type classes
  2501     "linorder" and "order" respectively, and are added to the default simpset
  2502     as solvers.  This means that the simplifier can build transitivity chains
  2503     to solve goals from the assumptions.
  2504   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
  2505     of blast or auto after simplification become unnecessary because the goal
  2506     is solved by simplification already.
  2507 
  2508 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
  2509     all proved in axiomatic type classes for semirings, rings and fields.
  2510 
  2511 * Numerics:
  2512   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
  2513     now formalized using the Ring_and_Field theory mentioned above.
  2514   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
  2515     than before, because now they are set up once in a generic manner.
  2516   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
  2517     Look for the general versions in Ring_and_Field (and Power if they concern
  2518     exponentiation).
  2519 
  2520 * Type "rat" of the rational numbers is now available in HOL-Complex.
  2521 
  2522 * Records:
  2523   - Record types are now by default printed with their type abbreviation
  2524     instead of the list of all field types. This can be configured via
  2525     the reference "print_record_type_abbr".
  2526   - Simproc "record_upd_simproc" for simplification of multiple updates added
  2527     (not enabled by default).
  2528   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
  2529     EX x. x = sel r to True (not enabled by default).
  2530   - Tactic "record_split_simp_tac" to split and simplify records added.
  2531 
  2532 * 'specification' command added, allowing for definition by
  2533   specification.  There is also an 'ax_specification' command that
  2534   introduces the new constants axiomatically.
  2535 
  2536 * arith(_tac) is now able to generate counterexamples for reals as well.
  2537 
  2538 * HOL-Algebra: new locale "ring" for non-commutative rings.
  2539 
  2540 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
  2541   definitions, thanks to Sava Krsti\'{c} and John Matthews.
  2542 
  2543 * HOL-Matrix: a first theory for matrices in HOL with an application of
  2544   matrix theory to linear programming.
  2545 
  2546 * Unions and Intersections:
  2547   The latex output syntax of UN and INT has been changed
  2548   from "\Union x \in A. B" to "\Union_{x \in A} B"
  2549   i.e. the index formulae has become a subscript.
  2550   Similarly for "\Union x. B", and for \Inter instead of \Union.
  2551 
  2552 * Unions and Intersections over Intervals:
  2553   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
  2554   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
  2555   like in normal math, and corresponding versions for < and for intersection.
  2556 
  2557 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard
  2558   lexicographic dictonary ordering has been added as "lexord".
  2559 
  2560 * ML: the legacy theory structures Int and List have been removed. They had
  2561   conflicted with ML Basis Library structures having the same names.
  2562 
  2563 * 'refute' command added to search for (finite) countermodels.  Only works
  2564   for a fragment of HOL.  The installation of an external SAT solver is
  2565   highly recommended.  See "HOL/Refute.thy" for details.
  2566 
  2567 * 'quickcheck' command: Allows to find counterexamples by evaluating
  2568   formulae under an assignment of free variables to random values.
  2569   In contrast to 'refute', it can deal with inductive datatypes,
  2570   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
  2571   for examples.
  2572 
  2573 
  2574 *** HOLCF ***
  2575 
  2576 * Streams now come with concatenation and are part of the HOLCF image
  2577 
  2578 
  2579 
  2580 New in Isabelle2003 (May 2003)
  2581 ------------------------------
  2582 
  2583 *** General ***
  2584 
  2585 * Provers/simplifier:
  2586 
  2587   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
  2588     Assumptions are now subject to complete mutual simplification,
  2589     not just from left to right. The simplifier now preserves
  2590     the order of assumptions.
  2591 
  2592     Potential INCOMPATIBILITY:
  2593 
  2594     -- simp sometimes diverges where the old version did
  2595        not, e.g. invoking simp on the goal
  2596 
  2597         [| P (f x); y = x; f x = f y |] ==> Q
  2598 
  2599        now gives rise to the infinite reduction sequence
  2600 
  2601         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
  2602 
  2603        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
  2604        kind of problem.
  2605 
  2606     -- Tactics combining classical reasoner and simplification (such as auto)
  2607        are also affected by this change, because many of them rely on
  2608        simp. They may sometimes diverge as well or yield a different numbers
  2609        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
  2610        in case of problems. Sometimes subsequent calls to the classical
  2611        reasoner will fail because a preceeding call to the simplifier too
  2612        eagerly simplified the goal, e.g. deleted redundant premises.
  2613 
  2614   - The simplifier trace now shows the names of the applied rewrite rules
  2615 
  2616   - You can limit the number of recursive invocations of the simplifier
  2617     during conditional rewriting (where the simplifie tries to solve the
  2618     conditions before applying the rewrite rule):
  2619     ML "simp_depth_limit := n"
  2620     where n is an integer. Thus you can force termination where previously
  2621     the simplifier would diverge.
  2622 
  2623   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
  2624 
  2625   - No longer aborts on failed congruence proof.  Instead, the
  2626     congruence is ignored.
  2627 
  2628 * Pure: New generic framework for extracting programs from constructive
  2629   proofs. See HOL/Extraction.thy for an example instantiation, as well
  2630   as HOL/Extraction for some case studies.
  2631 
  2632 * Pure: The main goal of the proof state is no longer shown by default, only
  2633 the subgoals. This behaviour is controlled by a new flag.
  2634    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
  2635 (ML: Proof.show_main_goal).
  2636 
  2637 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
  2638 rules whose conclusion matches subgoal 1:
  2639       PG menu: Isabelle/Isar -> Show me -> matching rules
  2640 The rules are ordered by how closely they match the subgoal.
  2641 In particular, rules that solve a subgoal outright are displayed first
  2642 (or rather last, the way they are printed).
  2643 (ML: ProofGeneral.print_intros())
  2644 
  2645 * Pure: New flag trace_unify_fail causes unification to print
  2646 diagnostic information (PG: in trace buffer) when it fails. This is
  2647 useful for figuring out why single step proofs like rule, erule or
  2648 assumption failed.
  2649 
  2650 * Pure: Locale specifications now produce predicate definitions
  2651 according to the body of text (covering assumptions modulo local
  2652 definitions); predicate "loc_axioms" covers newly introduced text,
  2653 while "loc" is cumulative wrt. all included locale expressions; the
  2654 latter view is presented only on export into the global theory
  2655 context; potential INCOMPATIBILITY, use "(open)" option to fall back
  2656 on the old view without predicates;
  2657 
  2658 * Pure: predefined locales "var" and "struct" are useful for sharing
  2659 parameters (as in CASL, for example); just specify something like
  2660 ``var x + var y + struct M'' as import;
  2661 
  2662 * Pure: improved thms_containing: proper indexing of facts instead of
  2663 raw theorems; check validity of results wrt. current name space;
  2664 include local facts of proof configuration (also covers active
  2665 locales), cover fixed variables in index; may use "_" in term
  2666 specification; an optional limit for the number of printed facts may
  2667 be given (the default is 40);
  2668 
  2669 * Pure: disallow duplicate fact bindings within new-style theory files
  2670 (batch-mode only);
  2671 
  2672 * Provers: improved induct method: assumptions introduced by case
  2673 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
  2674 the goal statement); "foo" still refers to all facts collectively;
  2675 
  2676 * Provers: the function blast.overloaded has been removed: all constants
  2677 are regarded as potentially overloaded, which improves robustness in exchange
  2678 for slight decrease in efficiency;
  2679 
  2680 * Provers/linorder: New generic prover for transitivity reasoning over
  2681 linear orders.  Note: this prover is not efficient!
  2682 
  2683 * Isar: preview of problems to finish 'show' now produce an error
  2684 rather than just a warning (in interactive mode);
  2685 
  2686 
  2687 *** HOL ***
  2688 
  2689 * arith(_tac)
  2690 
  2691  - Produces a counter example if it cannot prove a goal.
  2692    Note that the counter example may be spurious if the goal is not a formula
  2693    of quantifier-free linear arithmetic.
  2694    In ProofGeneral the counter example appears in the trace buffer.
  2695 
  2696  - Knows about div k and mod k where k is a numeral of type nat or int.
  2697 
  2698  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
  2699    linear arithmetic fails. This takes account of quantifiers and divisibility.
  2700    Presburger arithmetic can also be called explicitly via presburger(_tac).
  2701 
  2702 * simp's arithmetic capabilities have been enhanced a bit: it now
  2703 takes ~= in premises into account (by performing a case split);
  2704 
  2705 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
  2706 are distributed over a sum of terms;
  2707 
  2708 * New tactic "trans_tac" and method "trans" instantiate
  2709 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
  2710 "<=", "<" and "=").
  2711 
  2712 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
  2713 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
  2714 
  2715 * 'typedef' command has new option "open" to suppress the set
  2716 definition;
  2717 
  2718 * functions Min and Max on finite sets have been introduced (theory
  2719 Finite_Set);
  2720 
  2721 * attribute [symmetric] now works for relations as well; it turns
  2722 (x,y) : R^-1 into (y,x) : R, and vice versa;
  2723 
  2724 * induct over a !!-quantified statement (say !!x1..xn):
  2725   each "case" automatically performs "fix x1 .. xn" with exactly those names.
  2726 
  2727 * Map: `empty' is no longer a constant but a syntactic abbreviation for
  2728 %x. None. Warning: empty_def now refers to the previously hidden definition
  2729 of the empty set.
  2730 
  2731 * Algebra: formalization of classical algebra.  Intended as base for
  2732 any algebraic development in Isabelle.  Currently covers group theory
  2733 (up to Sylow's theorem) and ring theory (Universal Property of
  2734 Univariate Polynomials).  Contributions welcome;
  2735 
  2736 * GroupTheory: deleted, since its material has been moved to Algebra;
  2737 
  2738 * Complex: new directory of the complex numbers with numeric constants,
  2739 nonstandard complex numbers, and some complex analysis, standard and
  2740 nonstandard (Jacques Fleuriot);
  2741 
  2742 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
  2743 
  2744 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
  2745 Fleuriot);
  2746 
  2747 * Real/HahnBanach: updated and adapted to locales;
  2748 
  2749 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
  2750 Gray and Kramer);
  2751 
  2752 * UNITY: added the Meier-Sanders theory of progress sets;
  2753 
  2754 * MicroJava: bytecode verifier and lightweight bytecode verifier
  2755 as abstract algorithms, instantiated to the JVM;
  2756 
  2757 * Bali: Java source language formalization. Type system, operational
  2758 semantics, axiomatic semantics. Supported language features:
  2759 classes, interfaces, objects,virtual methods, static methods,
  2760 static/instance fields, arrays, access modifiers, definite
  2761 assignment, exceptions.
  2762 
  2763 
  2764 *** ZF ***
  2765 
  2766 * ZF/Constructible: consistency proof for AC (Gdel's constructible
  2767 universe, etc.);
  2768 
  2769 * Main ZF: virtually all theories converted to new-style format;
  2770 
  2771 
  2772 *** ML ***
  2773 
  2774 * Pure: Tactic.prove provides sane interface for internal proofs;
  2775 omits the infamous "standard" operation, so this is more appropriate
  2776 than prove_goalw_cterm in many situations (e.g. in simprocs);
  2777 
  2778 * Pure: improved error reporting of simprocs;
  2779 
  2780 * Provers: Simplifier.simproc(_i) provides sane interface for setting
  2781 up simprocs;
  2782 
  2783 
  2784 *** Document preparation ***
  2785 
  2786 * uses \par instead of \\ for line breaks in theory text. This may
  2787 shift some page breaks in large documents. To get the old behaviour
  2788 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
  2789 
  2790 * minimized dependencies of isabelle.sty and isabellesym.sty on
  2791 other packages
  2792 
  2793 * \<euro> now needs package babel/greek instead of marvosym (which
  2794 broke \Rightarrow)
  2795 
  2796 * normal size for \<zero>...\<nine> (uses \mathbf instead of
  2797 textcomp package)
  2798 
  2799 
  2800 
  2801 New in Isabelle2002 (March 2002)
  2802 --------------------------------
  2803 
  2804 *** Document preparation ***
  2805 
  2806 * greatly simplified document preparation setup, including more
  2807 graceful interpretation of isatool usedir -i/-d/-D options, and more
  2808 instructive isatool mkdir; users should basically be able to get
  2809 started with "isatool mkdir HOL Test && isatool make"; alternatively,
  2810 users may run a separate document processing stage manually like this:
  2811 "isatool usedir -D output HOL Test && isatool document Test/output";
  2812 
  2813 * theory dependency graph may now be incorporated into documents;
  2814 isatool usedir -g true will produce session_graph.eps/.pdf for use
  2815 with \includegraphics of LaTeX;
  2816 
  2817 * proper spacing of consecutive markup elements, especially text
  2818 blocks after section headings;
  2819 
  2820 * support bold style (for single symbols only), input syntax is like
  2821 this: "\<^bold>\<alpha>" or "\<^bold>A";
  2822 
  2823 * \<bullet> is now output as bold \cdot by default, which looks much
  2824 better in printed text;
  2825 
  2826 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
  2827 note that these symbols are currently unavailable in Proof General /
  2828 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
  2829 
  2830 * isatool latex no longer depends on changed TEXINPUTS, instead
  2831 isatool document copies the Isabelle style files to the target
  2832 location;
  2833 
  2834 
  2835 *** Isar ***
  2836 
  2837 * Pure/Provers: improved proof by cases and induction;
  2838   - 'case' command admits impromptu naming of parameters (such as
  2839     "case (Suc n)");
  2840   - 'induct' method divinates rule instantiation from the inductive
  2841     claim; no longer requires excessive ?P bindings for proper
  2842     instantiation of cases;
  2843   - 'induct' method properly enumerates all possibilities of set/type
  2844     rules; as a consequence facts may be also passed through *type*
  2845     rules without further ado;
  2846   - 'induct' method now derives symbolic cases from the *rulified*
  2847     rule (before it used to rulify cases stemming from the internal
  2848     atomized version); this means that the context of a non-atomic
  2849     statement becomes is included in the hypothesis, avoiding the
  2850     slightly cumbersome show "PROP ?case" form;
  2851   - 'induct' may now use elim-style induction rules without chaining
  2852     facts, using ``missing'' premises from the goal state; this allows
  2853     rules stemming from inductive sets to be applied in unstructured
  2854     scripts, while still benefitting from proper handling of non-atomic
  2855     statements; NB: major inductive premises need to be put first, all
  2856     the rest of the goal is passed through the induction;
  2857   - 'induct' proper support for mutual induction involving non-atomic
  2858     rule statements (uses the new concept of simultaneous goals, see
  2859     below);
  2860   - append all possible rule selections, but only use the first
  2861     success (no backtracking);
  2862   - removed obsolete "(simplified)" and "(stripped)" options of methods;
  2863   - undeclared rule case names default to numbers 1, 2, 3, ...;
  2864   - added 'print_induct_rules' (covered by help item in recent Proof
  2865     General versions);
  2866   - moved induct/cases attributes to Pure, methods to Provers;
  2867   - generic method setup instantiated for FOL and HOL;
  2868 
  2869 * Pure: support multiple simultaneous goal statements, for example
  2870 "have a: A and b: B" (same for 'theorem' etc.); being a pure
  2871 meta-level mechanism, this acts as if several individual goals had
  2872 been stated separately; in particular common proof methods need to be
  2873 repeated in order to cover all claims; note that a single elimination
  2874 step is *not* sufficient to establish the two conjunctions, so this
  2875 fails:
  2876 
  2877   assume "A & B" then have A and B ..   (*".." fails*)
  2878 
  2879 better use "obtain" in situations as above; alternative refer to
  2880 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
  2881 
  2882 * Pure: proper integration with ``locales''; unlike the original
  2883 version by Florian Kammller, Isar locales package high-level proof
  2884 contexts rather than raw logical ones (e.g. we admit to include
  2885 attributes everywhere); operations on locales include merge and
  2886 rename; support for implicit arguments (``structures''); simultaneous
  2887 type-inference over imports and text; see also HOL/ex/Locales.thy for
  2888 some examples;
  2889 
  2890 * Pure: the following commands have been ``localized'', supporting a
  2891 target locale specification "(in name)": 'lemma', 'theorem',
  2892 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
  2893 stored both within the locale and at the theory level (exported and
  2894 qualified by the locale name);
  2895 
  2896 * Pure: theory goals may now be specified in ``long'' form, with
  2897 ad-hoc contexts consisting of arbitrary locale elements. for example
  2898 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
  2899 definitions may be given, too); the result is a meta-level rule with
  2900 the context elements being discharged in the obvious way;
  2901 
  2902 * Pure: new proof command 'using' allows to augment currently used
  2903 facts after a goal statement ('using' is syntactically analogous to
  2904 'apply', but acts on the goal's facts only); this allows chained facts
  2905 to be separated into parts given before and after a claim, as in
  2906 ``from a and b have C using d and e <proof>'';
  2907 
  2908 * Pure: renamed "antecedent" case to "rule_context";
  2909 
  2910 * Pure: new 'judgment' command records explicit information about the
  2911 object-logic embedding (used by several tools internally); no longer
  2912 use hard-wired "Trueprop";
  2913 
  2914 * Pure: added 'corollary' command;
  2915 
  2916 * Pure: fixed 'token_translation' command;
  2917 
  2918 * Pure: removed obsolete 'exported' attribute;
  2919 
  2920 * Pure: dummy pattern "_" in is/let is now automatically lifted over
  2921 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
  2922 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
  2923 
  2924 * Pure: method 'atomize' presents local goal premises as object-level
  2925 statements (atomic meta-level propositions); setup controlled via
  2926 rewrite rules declarations of 'atomize' attribute; example
  2927 application: 'induct' method with proper rule statements in improper
  2928 proof *scripts*;
  2929 
  2930 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
  2931 now consider the syntactic context of assumptions, giving a better
  2932 chance to get type-inference of the arguments right (this is
  2933 especially important for locales);
  2934 
  2935 * Pure: "sorry" no longer requires quick_and_dirty in interactive
  2936 mode;
  2937 
  2938 * Pure/obtain: the formal conclusion "thesis", being marked as
  2939 ``internal'', may no longer be reference directly in the text;
  2940 potential INCOMPATIBILITY, may need to use "?thesis" in rare
  2941 situations;
  2942 
  2943 * Pure: generic 'sym' attribute which declares a rule both as pure
  2944 'elim?' and for the 'symmetric' operation;
  2945 
  2946 * Pure: marginal comments ``--'' may now occur just anywhere in the
  2947 text; the fixed correlation with particular command syntax has been
  2948 discontinued;
  2949 
  2950 * Pure: new method 'rules' is particularly well-suited for proof
  2951 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
  2952 but often produces more compact proof terms with less detours;
  2953 
  2954 * Pure/Provers/classical: simplified integration with pure rule
  2955 attributes and methods; the classical "intro?/elim?/dest?"
  2956 declarations coincide with the pure ones; the "rule" method no longer
  2957 includes classically swapped intros; "intro" and "elim" methods no
  2958 longer pick rules from the context; also got rid of ML declarations
  2959 AddXIs/AddXEs/AddXDs; all of this has some potential for
  2960 INCOMPATIBILITY;
  2961 
  2962 * Provers/classical: attribute 'swapped' produces classical inversions
  2963 of introduction rules;
  2964 
  2965 * Provers/simplifier: 'simplified' attribute may refer to explicit
  2966 rules instead of full simplifier context; 'iff' attribute handles
  2967 conditional rules;
  2968 
  2969 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
  2970 
  2971 * HOL: 'recdef' now fails on unfinished automated proofs, use
  2972 "(permissive)" option to recover old behavior;
  2973 
  2974 * HOL: 'inductive' no longer features separate (collective) attributes
  2975 for 'intros' (was found too confusing);
  2976 
  2977 * HOL: properly declared induction rules less_induct and
  2978 wf_induct_rule;
  2979 
  2980 
  2981 *** HOL ***
  2982 
  2983 * HOL: moved over to sane numeral syntax; the new policy is as
  2984 follows:
  2985 
  2986   - 0 and 1 are polymorphic constants, which are defined on any
  2987   numeric type (nat, int, real etc.);
  2988 
  2989   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
  2990   binary representation internally;
  2991 
  2992   - type nat has special constructor Suc, and generally prefers Suc 0
  2993   over 1::nat and Suc (Suc 0) over 2::nat;
  2994 
  2995 This change may cause significant problems of INCOMPATIBILITY; here
  2996 are some hints on converting existing sources:
  2997 
  2998   - due to the new "num" token, "-0" and "-1" etc. are now atomic
  2999   entities, so expressions involving "-" (unary or binary minus) need
  3000   to be spaced properly;
  3001 
  3002   - existing occurrences of "1" may need to be constraint "1::nat" or
  3003   even replaced by Suc 0; similar for old "2";
  3004 
  3005   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
  3006 
  3007   - remove all special provisions on numerals in proofs;
  3008 
  3009 * HOL: simp rules nat_number expand numerals on nat to Suc/0
  3010 representation (depends on bin_arith_simps in the default context);
  3011 
  3012 * HOL: symbolic syntax for x^2 (numeral 2);
  3013 
  3014 * HOL: the class of all HOL types is now called "type" rather than
  3015 "term"; INCOMPATIBILITY, need to adapt references to this type class
  3016 in axclass/classes, instance/arities, and (usually rare) occurrences
  3017 in typings (of consts etc.); internally the class is called
  3018 "HOL.type", ML programs should refer to HOLogic.typeS;
  3019 
  3020 * HOL/record package improvements:
  3021   - new derived operations "fields" to build a partial record section,
  3022     "extend" to promote a fixed record to a record scheme, and
  3023     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
  3024     declared as simp by default;
  3025   - shared operations ("more", "fields", etc.) now need to be always
  3026     qualified) --- potential INCOMPATIBILITY;
  3027   - removed "make_scheme" operations (use "make" with "extend") --
  3028     INCOMPATIBILITY;
  3029   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
  3030   - provides cases/induct rules for use with corresponding Isar
  3031     methods (for concrete records, record schemes, concrete more
  3032     parts, and schematic more parts -- in that order);
  3033   - internal definitions directly based on a light-weight abstract
  3034     theory of product types over typedef rather than datatype;
  3035 
  3036 * HOL: generic code generator for generating executable ML code from
  3037 specifications; specific support for HOL constructs such as inductive
  3038 datatypes and sets, as well as recursive functions; can be invoked
  3039 via 'generate_code' theory section;
  3040 
  3041 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
  3042 
  3043 * HOL: consolidated and renamed several theories.  In particular:
  3044         Ord.thy has been absorbed into HOL.thy
  3045         String.thy has been absorbed into List.thy
  3046 
  3047 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
  3048 (beware of argument permutation!);
  3049 
  3050 * HOL: linorder_less_split superseded by linorder_cases;
  3051 
  3052 * HOL/List: "nodups" renamed to "distinct";
  3053 
  3054 * HOL: added "The" definite description operator; move Hilbert's "Eps"
  3055 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
  3056   - Ex_def has changed, now need to use some_eq_ex
  3057 
  3058 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
  3059 in this (rare) case use:
  3060 
  3061   delSWrapper "split_all_tac"
  3062   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
  3063 
  3064 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
  3065 MAY FAIL;
  3066 
  3067 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
  3068 Isabelle's type classes, ^ on functions and relations has too general
  3069 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
  3070 necessary to attach explicit type constraints;
  3071 
  3072 * HOL/Relation: the prefix name of the infix "O" has been changed from
  3073 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
  3074 renamed accordingly (eg "compI" -> "rel_compI").
  3075 
  3076 * HOL: syntax translations now work properly with numerals and records
  3077 expressions;
  3078 
  3079 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
  3080 of "lam" -- INCOMPATIBILITY;
  3081 
  3082 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
  3083 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
  3084 renamed "Product_Type.unit";
  3085 
  3086 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
  3087 
  3088 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
  3089 the "cases" method);
  3090 
  3091 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
  3092 Florian Kammller);
  3093 
  3094 * HOL/IMP: updated and converted to new-style theory format; several
  3095 parts turned into readable document, with proper Isar proof texts and
  3096 some explanations (by Gerwin Klein);
  3097 
  3098 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
  3099 
  3100 * HOL-Hyperreal is now a logic image;
  3101 
  3102 
  3103 *** HOLCF ***
  3104 
  3105 * Isar: consts/constdefs supports mixfix syntax for continuous
  3106 operations;
  3107 
  3108 * Isar: domain package adapted to new-style theory format, e.g. see
  3109 HOLCF/ex/Dnat.thy;
  3110 
  3111 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
  3112 potential INCOMPATIBILITY; now use plain induct_tac instead of former
  3113 lift.induct_tac, always use UU instead of Undef;
  3114 
  3115 * HOLCF/IMP: updated and converted to new-style theory;
  3116 
  3117 
  3118 *** ZF ***
  3119 
  3120 * Isar: proper integration of logic-specific tools and packages,
  3121 including theory commands '(co)inductive', '(co)datatype',
  3122 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
  3123 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
  3124 
  3125 * theory Main no longer includes AC; for the Axiom of Choice, base
  3126 your theory on Main_ZFC;
  3127 
  3128 * the integer library now covers quotients and remainders, with many
  3129 laws relating division to addition, multiplication, etc.;
  3130 
  3131 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
  3132 typeless version of the formalism;
  3133 
  3134 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
  3135 format;
  3136 
  3137 * ZF/Induct: new directory for examples of inductive definitions,
  3138 including theory Multiset for multiset orderings; converted to
  3139 new-style theory format;
  3140 
  3141 * ZF: many new theorems about lists, ordinals, etc.;
  3142 
  3143 
  3144 *** General ***
  3145 
  3146 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
  3147 variable proof controls level of detail: 0 = no proofs (only oracle
  3148 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
  3149 also ref manual for further ML interfaces;
  3150 
  3151 * Pure/axclass: removed obsolete ML interface
  3152 goal_subclass/goal_arity;
  3153 
  3154 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
  3155 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
  3156 separate tokens, so expressions involving minus need to be spaced
  3157 properly;
  3158 
  3159 * Pure/syntax: support non-oriented infixes, using keyword "infix"
  3160 rather than "infixl" or "infixr";
  3161 
  3162 * Pure/syntax: concrete syntax for dummy type variables admits genuine
  3163 sort constraint specifications in type inference; e.g. "x::_::foo"
  3164 ensures that the type of "x" is of sort "foo" (but not necessarily a
  3165 type variable);
  3166 
  3167 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
  3168 control output of nested => (types); the default behavior is
  3169 "type_brackets";
  3170 
  3171 * Pure/syntax: builtin parse translation for "_constify" turns valued
  3172 tokens into AST constants;
  3173 
  3174 * Pure/syntax: prefer later declarations of translations and print
  3175 translation functions; potential INCOMPATIBILITY: need to reverse
  3176 multiple declarations for same syntax element constant;
  3177 
  3178 * Pure/show_hyps reset by default (in accordance to existing Isar
  3179 practice);
  3180 
  3181 * Provers/classical: renamed addaltern to addafter, addSaltern to
  3182 addSafter;
  3183 
  3184 * Provers/clasimp: ``iff'' declarations now handle conditional rules
  3185 as well;
  3186 
  3187 * system: tested support for MacOS X; should be able to get Isabelle +
  3188 Proof General to work in a plain Terminal after installing Poly/ML
  3189 (e.g. from the Isabelle distribution area) and GNU bash alone
  3190 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
  3191 support requires further installations, e.g. from
  3192 http://fink.sourceforge.net/);
  3193 
  3194 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
  3195 
  3196 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
  3197 of 40 MB), cf. ML_OPTIONS;
  3198 
  3199 * system: Proof General keywords specification is now part of the
  3200 Isabelle distribution (see etc/isar-keywords.el);
  3201 
  3202 * system: support for persistent Proof General sessions (refrain from
  3203 outdating all loaded theories on startup); user may create writable
  3204 logic images like this: ``isabelle -q HOL Test'';
  3205 
  3206 * system: smart selection of Isabelle process versus Isabelle
  3207 interface, accommodates case-insensitive file systems (e.g. HFS+); may
  3208 run both "isabelle" and "Isabelle" even if file names are badly
  3209 damaged (executable inspects the case of the first letter of its own
  3210 name); added separate "isabelle-process" and "isabelle-interface";
  3211 
  3212 * system: refrain from any attempt at filtering input streams; no
  3213 longer support ``8bit'' encoding of old isabelle font, instead proper
  3214 iso-latin characters may now be used; the related isatools
  3215 "symbolinput" and "nonascii" have disappeared as well;
  3216 
  3217 * system: removed old "xterm" interface (the print modes "xterm" and
  3218 "xterm_color" are still available for direct use in a suitable
  3219 terminal);
  3220 
  3221 
  3222 
  3223 New in Isabelle99-2 (February 2001)
  3224 -----------------------------------
  3225 
  3226 *** Overview of INCOMPATIBILITIES ***
  3227 
  3228 * HOL: please note that theories in the Library and elsewhere often use the
  3229 new-style (Isar) format; to refer to their theorems in an ML script you must
  3230 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
  3231 
  3232 * HOL: inductive package no longer splits induction rule aggressively,
  3233 but only as far as specified by the introductions given; the old
  3234 format may be recovered via ML function complete_split_rule or attribute
  3235 'split_rule (complete)';
  3236 
  3237 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
  3238 gfp_Tarski to gfp_unfold;
  3239 
  3240 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
  3241 
  3242 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
  3243 relation); infix "^^" has been renamed "``"; infix "``" has been
  3244 renamed "`"; "univalent" has been renamed "single_valued";
  3245 
  3246 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
  3247 operation;
  3248 
  3249 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
  3250 
  3251 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
  3252 
  3253 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
  3254 consequence, it is no longer monotonic wrt. the local goal context
  3255 (which is now passed through the inductive cases);
  3256 
  3257 * Document preparation: renamed standard symbols \<ll> to \<lless> and
  3258 \<gg> to \<ggreater>;
  3259 
  3260 
  3261 *** Document preparation ***
  3262 
  3263 * \isabellestyle{NAME} selects version of Isabelle output (currently
  3264 available: are "it" for near math-mode best-style output, "sl" for
  3265 slanted text style, and "tt" for plain type-writer; if no
  3266 \isabellestyle command is given, output is according to slanted
  3267 type-writer);
  3268 
  3269 * support sub/super scripts (for single symbols only), input syntax is
  3270 like this: "A\<^sup>*" or "A\<^sup>\<star>";
  3271 
  3272 * some more standard symbols; see Appendix A of the system manual for
  3273 the complete list of symbols defined in isabellesym.sty;
  3274 
  3275 * improved isabelle style files; more abstract symbol implementation
  3276 (should now use \isamath{...} and \isatext{...} in custom symbol
  3277 definitions);
  3278 
  3279 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
  3280 state; Note that presentation of goal states does not conform to
  3281 actual human-readable proof documents.  Please do not include goal
  3282 states into document output unless you really know what you are doing!
  3283 
  3284 * proper indentation of antiquoted output with proportional LaTeX
  3285 fonts;
  3286 
  3287 * no_document ML operator temporarily disables LaTeX document
  3288 generation;
  3289 
  3290 * isatool unsymbolize tunes sources for plain ASCII communication;
  3291 
  3292 
  3293 *** Isar ***
  3294 
  3295 * Pure: Isar now suffers initial goal statements to contain unbound
  3296 schematic variables (this does not conform to actual readable proof
  3297 documents, due to unpredictable outcome and non-compositional proof
  3298 checking); users who know what they are doing may use schematic goals
  3299 for Prolog-style synthesis of proven results;
  3300 
  3301 * Pure: assumption method (an implicit finishing) now handles actual
  3302 rules as well;
  3303 
  3304 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
  3305 initial goal, declare "that" only as Pure intro (only for single
  3306 steps); the "that" rule assumption may now be involved in implicit
  3307 finishing, thus ".." becomes a feasible for trivial obtains;
  3308 
  3309 * Pure: default proof step now includes 'intro_classes'; thus trivial
  3310 instance proofs may be performed by "..";
  3311 
  3312 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  3313 statements as well;
  3314 
  3315 * Pure: more robust selection of calculational rules;
  3316 
  3317 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  3318 rule (as well as the assumption rule);
  3319 
  3320 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  3321 lemmas, using the graph browser tool;
  3322 
  3323 * Pure: predict failure of "show" in interactive mode;
  3324 
  3325 * Pure: 'thms_containing' now takes actual terms as arguments;
  3326 
  3327 * HOL: improved method 'induct' --- now handles non-atomic goals
  3328 (potential INCOMPATIBILITY); tuned error handling;
  3329 
  3330 * HOL: cases and induct rules now provide explicit hints about the
  3331 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  3332 any remaining facts are inserted into the goal verbatim;
  3333 
  3334 * HOL: local contexts (aka cases) may now contain term bindings as
  3335 well; the 'cases' and 'induct' methods new provide a ?case binding for
  3336 the result to be shown in each case;
  3337 
  3338 * HOL: added 'recdef_tc' command;
  3339 
  3340 * isatool convert assists in eliminating legacy ML scripts;
  3341 
  3342 
  3343 *** HOL ***
  3344 
  3345 * HOL/Library: a collection of generic theories to be used together
  3346 with main HOL; the theory loader path already includes this directory
  3347 by default; the following existing theories have been moved here:
  3348 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  3349 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  3350 
  3351 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  3352 modelling and verification task performed in Isabelle/HOL +
  3353 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  3354 
  3355 * HOL/Algebra: special summation operator SUM no longer exists, it has
  3356 been replaced by setsum; infix 'assoc' now has priority 50 (like
  3357 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  3358 'domain', this makes the theory consistent with mathematical
  3359 literature;
  3360 
  3361 * HOL basics: added overloaded operations "inverse" and "divide"
  3362 (infix "/"), syntax for generic "abs" operation, generic summation
  3363 operator \<Sum>;
  3364 
  3365 * HOL/typedef: simplified package, provide more useful rules (see also
  3366 HOL/subset.thy);
  3367 
  3368 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  3369 now expressed as a proper nested rule (old-style tactic scripts may
  3370 require atomize_strip_tac to cope with non-atomic premises);
  3371 
  3372 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  3373 to "split_conv" (old name still available for compatibility);
  3374 
  3375 * HOL: improved concrete syntax for strings (e.g. allows translation
  3376 rules with string literals);
  3377 
  3378 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  3379  and Fleuriot's mechanization of analysis, including the transcendental
  3380  functions for the reals;
  3381 
  3382 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  3383 
  3384 
  3385 *** CTT ***
  3386 
  3387 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  3388 "lam" is displayed as TWO lambda-symbols
  3389 
  3390 * CTT: theory Main now available, containing everything (that is, Bool
  3391 and Arith);
  3392 
  3393 
  3394 *** General ***
  3395 
  3396 * Pure: the Simplifier has been implemented properly as a derived rule
  3397 outside of the actual kernel (at last!); the overall performance
  3398 penalty in practical applications is about 50%, while reliability of
  3399 the Isabelle inference kernel has been greatly improved;
  3400 
  3401 * print modes "brackets" and "no_brackets" control output of nested =>
  3402 (types) and ==> (props); the default behaviour is "brackets";
  3403 
  3404 * Provers: fast_tac (and friends) now handle actual object-logic rules
  3405 as assumptions as well;
  3406 
  3407 * system: support Poly/ML 4.0;
  3408 
  3409 * system: isatool install handles KDE version 1 or 2;
  3410 
  3411 
  3412 
  3413 New in Isabelle99-1 (October 2000)
  3414 ----------------------------------
  3415 
  3416 *** Overview of INCOMPATIBILITIES ***
  3417 
  3418 * HOL: simplification of natural numbers is much changed; to partly
  3419 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  3420 issue the following ML commands:
  3421 
  3422   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  3423   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  3424 
  3425 * HOL: simplification no longer dives into case-expressions; this is
  3426 controlled by "t.weak_case_cong" for each datatype t;
  3427 
  3428 * HOL: nat_less_induct renamed to less_induct;
  3429 
  3430 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  3431 fixsome to patch .thy and .ML sources automatically;
  3432 
  3433   select_equality  -> some_equality
  3434   select_eq_Ex     -> some_eq_ex
  3435   selectI2EX       -> someI2_ex
  3436   selectI2         -> someI2
  3437   selectI          -> someI
  3438   select1_equality -> some1_equality
  3439   Eps_sym_eq       -> some_sym_eq_trivial
  3440   Eps_eq           -> some_eq_trivial
  3441 
  3442 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  3443 
  3444 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  3445 instead);
  3446 
  3447 * HOL: the recursion equations generated by 'recdef' are now called
  3448 f.simps instead of f.rules;
  3449 
  3450 * HOL: qed_spec_mp now also handles bounded ALL as well;
  3451 
  3452 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  3453 sometimes be needed;
  3454 
  3455 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  3456 
  3457 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  3458 
  3459 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  3460 product is now "<*>" instead of "Times"; the lexicographic product is
  3461 now "<*lex*>" instead of "**";
  3462 
  3463 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  3464 of main HOL, but was unused); better use HOL's datatype package;
  3465 
  3466 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  3467 the old syntax may be recovered as follows:
  3468 
  3469   syntax (symbols)
  3470     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  3471       (infixl "\\<oplus>" 100)
  3472 
  3473 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  3474 
  3475 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  3476 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  3477 internally;
  3478 
  3479 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  3480 changed from A/r to A//r;
  3481 
  3482 * ZF: new treatment of arithmetic (nat & int) may break some old
  3483 proofs;
  3484 
  3485 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  3486 rulify -> rule_format, elimify -> elim_format, ...);
  3487 
  3488 * Isar/Provers: intro/elim/dest attributes changed; renamed
  3489 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  3490 should have to change intro!! to intro? only); replaced "delrule" by
  3491 "rule del";
  3492 
  3493 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  3494 
  3495 * Provers: strengthened force_tac by using new first_best_tac;
  3496 
  3497 * LaTeX document preparation: several changes of isabelle.sty (see
  3498 lib/texinputs);
  3499 
  3500 
  3501 *** Document preparation ***
  3502 
  3503 * formal comments (text blocks etc.) in new-style theories may now
  3504 contain antiquotations of thm/prop/term/typ/text to be presented
  3505 according to latex print mode; concrete syntax is like this:
  3506 @{term[show_types] "f(x) = a + x"};
  3507 
  3508 * isatool mkdir provides easy setup of Isabelle session directories,
  3509 including proper document sources;
  3510 
  3511 * generated LaTeX sources are now deleted after successful run
  3512 (isatool document -c); may retain a copy somewhere else via -D option
  3513 of isatool usedir;
  3514 
  3515 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  3516 style files, achieving self-contained LaTeX sources and simplifying
  3517 LaTeX debugging;
  3518 
  3519 * old-style theories now produce (crude) LaTeX output as well;
  3520 
  3521 * browser info session directories are now self-contained (may be put
  3522 on WWW server seperately); improved graphs of nested sessions; removed
  3523 graph for 'all sessions';
  3524 
  3525 * several improvements in isabelle style files; \isabellestyle{it}
  3526 produces fake math mode output; \isamarkupheader is now \section by
  3527 default; see lib/texinputs/isabelle.sty etc.;
  3528 
  3529 
  3530 *** Isar ***
  3531 
  3532 * Isar/Pure: local results and corresponding term bindings are now
  3533 subject to Hindley-Milner polymorphism (similar to ML); this
  3534 accommodates incremental type-inference very nicely;
  3535 
  3536 * Isar/Pure: new derived language element 'obtain' supports
  3537 generalized existence reasoning;
  3538 
  3539 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  3540 support accumulation of results, without applying any rules yet;
  3541 useful to collect intermediate results without explicit name
  3542 references, and for use with transitivity rules with more than 2
  3543 premises;
  3544 
  3545 * Isar/Pure: scalable support for case-analysis type proofs: new
  3546 'case' language element refers to local contexts symbolically, as
  3547 produced by certain proof methods; internally, case names are attached
  3548 to theorems as "tags";
  3549 
  3550 * Isar/Pure: theory command 'hide' removes declarations from
  3551 class/type/const name spaces;
  3552 
  3553 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  3554 indicate potential overloading;
  3555 
  3556 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  3557 
  3558 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  3559 "{a,b,c}" instead of {a,b,c};
  3560 
  3561 * Isar/Pure now provides its own version of intro/elim/dest
  3562 attributes; useful for building new logics, but beware of confusion
  3563 with the version in Provers/classical;
  3564 
  3565 * Isar/Pure: the local context of (non-atomic) goals is provided via
  3566 case name 'antecedent';
  3567 
  3568 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  3569 to the current context is now done automatically);
  3570 
  3571 * Isar/Pure: theory command 'method_setup' provides a simple interface
  3572 for definining proof methods in ML;
  3573 
  3574 * Isar/Provers: intro/elim/dest attributes changed; renamed
  3575 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  3576 most cases, one should have to change intro!! to intro? only);
  3577 replaced "delrule" by "rule del";
  3578 
  3579 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  3580 'symmetric' attribute (the latter supercedes [RS sym]);
  3581 
  3582 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  3583 method modifier); 'simp' method: 'only:' modifier removes loopers as
  3584 well (including splits);
  3585 
  3586 * Isar/Provers: Simplifier and Classical methods now support all kind
  3587 of modifiers used in the past, including 'cong', 'iff', etc.
  3588 
  3589 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  3590 of Simplifier and Classical reasoner);
  3591 
  3592 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  3593 now support named cases; major packages (inductive, datatype, primrec,
  3594 recdef) support case names and properly name parameters;
  3595 
  3596 * Isar/HOL: new transitivity rules for substitution in inequalities --
  3597 monotonicity conditions are extracted to be proven at end of
  3598 calculations;
  3599 
  3600 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  3601 method anyway;
  3602 
  3603 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  3604 split_if split_if_asm; datatype package provides theorems foo.splits =
  3605 foo.split foo.split_asm for each datatype;
  3606 
  3607 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  3608 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  3609 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  3610 use "(cases (simplified))" method in proper proof texts);
  3611 
  3612 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  3613 
  3614 * Isar: names of theorems etc. may be natural numbers as well;
  3615 
  3616 * Isar: 'pr' command: optional arguments for goals_limit and
  3617 ProofContext.prems_limit; no longer prints theory contexts, but only
  3618 proof states;
  3619 
  3620 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  3621 additional print modes to be specified; e.g. "pr(latex)" will print
  3622 proof state according to the Isabelle LaTeX style;
  3623 
  3624 * Isar: improved support for emulating tactic scripts, including proof
  3625 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  3626 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  3627 (for HOL datatypes);
  3628 
  3629 * Isar: simplified (more robust) goal selection of proof methods: 1st
  3630 goal, all goals, or explicit goal specifier (tactic emulation); thus
  3631 'proof method scripts' have to be in depth-first order;
  3632 
  3633 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  3634 
  3635 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  3636 should instead use individual commands for printing items
  3637 (print_commands, print_methods etc.);
  3638 
  3639 * Isar: added 'nothing' --- the empty list of theorems;
  3640 
  3641 
  3642 *** HOL ***
  3643 
  3644 * HOL/MicroJava: formalization of a fragment of Java, together with a
  3645 corresponding virtual machine and a specification of its bytecode
  3646 verifier and a lightweight bytecode verifier, including proofs of
  3647 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  3648 Cornelia Pusch (see also the homepage of project Bali at
  3649 http://isabelle.in.tum.de/Bali/);
  3650 
  3651 * HOL/Algebra: new theory of rings and univariate polynomials, by
  3652 Clemens Ballarin;
  3653 
  3654 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  3655 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  3656 Rasmussen;
  3657 
  3658 * HOL/Lattice: fundamental concepts of lattice theory and order
  3659 structures, including duals, properties of bounds versus algebraic
  3660 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  3661 Theorem for complete lattices etc.; may also serve as a demonstration
  3662 for abstract algebraic reasoning using axiomatic type classes, and
  3663 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  3664 
  3665 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  3666 von Oheimb;
  3667 
  3668 * HOL/IMPP: extension of IMP with local variables and mutually
  3669 recursive procedures, by David von Oheimb;
  3670 
  3671 * HOL/Lambda: converted into new-style theory and document;
  3672 
  3673 * HOL/ex/Multiquote: example of multiple nested quotations and
  3674 anti-quotations -- basically a generalized version of de-Bruijn
  3675 representation; very useful in avoiding lifting of operations;
  3676 
  3677 * HOL/record: added general record equality rule to simpset; fixed
  3678 select-update simplification procedure to handle extended records as
  3679 well; admit "r" as field name;
  3680 
  3681 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  3682 other numeric types and also as the identity of groups, rings, etc.;
  3683 
  3684 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  3685 Types nat and int belong to this axclass;
  3686 
  3687 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  3688    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  3689    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  3690   two terms #m*u and #n*u are replaced by #(m+n)*u
  3691     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  3692   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  3693     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  3694 
  3695 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  3696 powerful prover for predicate logic but knows nothing of clasets; see
  3697 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  3698 
  3699 * HOL: new version of "case_tac" subsumes both boolean case split and
  3700 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  3701 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  3702 
  3703 * HOL: simplification no longer dives into case-expressions: only the
  3704 selector expression is simplified, but not the remaining arms; to
  3705 enable full simplification of case-expressions for datatype t, you may
  3706 remove t.weak_case_cong from the simpset, either globally (Delcongs
  3707 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  3708 
  3709 * HOL/recdef: the recursion equations generated by 'recdef' for
  3710 function 'f' are now called f.simps instead of f.rules; if all
  3711 termination conditions are proved automatically, these simplification
  3712 rules are added to the simpset, as in primrec; rules may be named
  3713 individually as well, resulting in a separate list of theorems for
  3714 each equation;
  3715 
  3716 * HOL/While is a new theory that provides a while-combinator. It
  3717 permits the definition of tail-recursive functions without the
  3718 provision of a termination measure. The latter is necessary once the
  3719 invariant proof rule for while is applied.
  3720 
  3721 * HOL: new (overloaded) notation for the set of elements below/above
  3722 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  3723 
  3724 * HOL: theorems impI, allI, ballI bound as "strip";
  3725 
  3726 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  3727 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  3728 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  3729 
  3730 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  3731 
  3732 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  3733 main HOL, but was unused);
  3734 
  3735 * HOL: fewer consts declared as global (e.g. have to refer to
  3736 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  3737 
  3738 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  3739 in case of overlap with user translations (e.g. judgements over
  3740 tuples); (note that the underlying logical represenation is still
  3741 bogus);
  3742 
  3743 
  3744 *** ZF ***
  3745 
  3746 * ZF: simplification automatically cancels common terms in arithmetic
  3747 expressions over nat and int;
  3748 
  3749 * ZF: new treatment of nat to minimize type-checking: all operators
  3750 coerce their operands to a natural number using the function natify,
  3751 making the algebraic laws unconditional;
  3752 
  3753 * ZF: as above, for int: operators coerce their operands to an integer
  3754 using the function intify;
  3755 
  3756 * ZF: the integer library now contains many of the usual laws for the
  3757 orderings, including $<=, and monotonicity laws for $+ and $*;
  3758 
  3759 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  3760 simplification;
  3761 
  3762 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  3763 to the simplifier and classical reasoner simultaneously;
  3764 
  3765 
  3766 *** General ***
  3767 
  3768 * Provers: blast_tac now handles actual object-logic rules as
  3769 assumptions; note that auto_tac uses blast_tac internally as well;
  3770 
  3771 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  3772 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  3773 
  3774 * Provers: delrules now handles destruct rules as well (no longer need
  3775 explicit make_elim);
  3776 
  3777 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  3778   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  3779 use instead the strong form,
  3780   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  3781 in HOL, FOL and ZF the function cla_make_elim will create such rules
  3782 from destruct-rules;
  3783 
  3784 * Provers: Simplifier.easy_setup provides a fast path to basic
  3785 Simplifier setup for new object-logics;
  3786 
  3787 * Pure: AST translation rules no longer require constant head on LHS;
  3788 
  3789 * Pure: improved name spaces: ambiguous output is qualified; support
  3790 for hiding of names;
  3791 
  3792 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  3793 XSYMBOL_HOME; no longer need to do manual configuration in most
  3794 situations;
  3795 
  3796 * system: compression of ML heaps images may now be controlled via -c
  3797 option of isabelle and isatool usedir (currently only observed by
  3798 Poly/ML);
  3799 
  3800 * system: isatool installfonts may handle X-Symbol fonts as well (very
  3801 useful for remote X11);
  3802 
  3803 * system: provide TAGS file for Isabelle sources;
  3804 
  3805 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  3806 order;
  3807 
  3808 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  3809 timing flag supersedes proof_timing and Toplevel.trace;
  3810 
  3811 * ML: new combinators |>> and |>>> for incremental transformations
  3812 with secondary results (e.g. certain theory extensions):
  3813 
  3814 * ML: PureThy.add_defs gets additional argument to indicate potential
  3815 overloading (usually false);
  3816 
  3817 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  3818 results;
  3819 
  3820 
  3821 
  3822 New in Isabelle99 (October 1999)
  3823 --------------------------------
  3824 
  3825 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  3826 
  3827 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  3828 are no longer simplified.  (This allows the simplifier to unfold recursive
  3829 functional programs.)  To restore the old behaviour, declare
  3830 
  3831     Delcongs [if_weak_cong];
  3832 
  3833 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  3834 complement;
  3835 
  3836 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  3837 
  3838 * HOL/datatype: mutual_induct_tac no longer exists --
  3839   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  3840 
  3841 * HOL/typedef: fixed type inference for representing set; type
  3842 arguments now have to occur explicitly on the rhs as type constraints;
  3843 
  3844 * ZF: The con_defs part of an inductive definition may no longer refer
  3845 to constants declared in the same theory;
  3846 
  3847 * HOL, ZF: the function mk_cases, generated by the inductive
  3848 definition package, has lost an argument.  To simplify its result, it
  3849 uses the default simpset instead of a supplied list of theorems.
  3850 
  3851 * HOL/List: the constructors of type list are now Nil and Cons;
  3852 
  3853 * Simplifier: the type of the infix ML functions
  3854         setSSolver addSSolver setSolver addSolver
  3855 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  3856 for packaging solvers. A solver is created via
  3857         mk_solver: string -> (thm list -> int -> tactic) -> solver
  3858 where the string argument is only a comment.
  3859 
  3860 
  3861 *** Proof tools ***
  3862 
  3863 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  3864 decision procedure for linear arithmetic. Currently it is used for
  3865 types `nat', `int', and `real' in HOL (see below); it can, should and
  3866 will be instantiated for other types and logics as well.
  3867 
  3868 * The simplifier now accepts rewrite rules with flexible heads, eg
  3869      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  3870   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  3871   matching.
  3872 
  3873 
  3874 *** General ***
  3875 
  3876 * New Isabelle/Isar subsystem provides an alternative to traditional
  3877 tactical theorem proving; together with the ProofGeneral/isar user
  3878 interface it offers an interactive environment for developing human
  3879 readable proof documents (Isar == Intelligible semi-automated
  3880 reasoning); for further information see isatool doc isar-ref,
  3881 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  3882 
  3883 * improved and simplified presentation of theories: better HTML markup
  3884 (including colors), graph views in several sizes; isatool usedir now
  3885 provides a proper interface for user theories (via -P option); actual
  3886 document preparation based on (PDF)LaTeX is available as well (for
  3887 new-style theories only); see isatool doc system for more information;
  3888 
  3889 * native support for Proof General, both for classic Isabelle and
  3890 Isabelle/Isar;
  3891 
  3892 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  3893 using the graph browser tool;
  3894 
  3895 * Isabelle manuals now also available as PDF;
  3896 
  3897 * theory loader rewritten from scratch (may not be fully
  3898 bug-compatible); old loadpath variable has been replaced by show_path,
  3899 add_path, del_path, reset_path functions; new operations such as
  3900 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  3901 isatool doc ref);
  3902 
  3903 * improved isatool install: option -k creates KDE application icon,
  3904 option -p DIR installs standalone binaries;
  3905 
  3906 * added ML_PLATFORM setting (useful for cross-platform installations);
  3907 more robust handling of platform specific ML images for SML/NJ;
  3908 
  3909 * the settings environment is now statically scoped, i.e. it is never
  3910 created again in sub-processes invoked from isabelle, isatool, or
  3911 Isabelle;
  3912 
  3913 * path element specification '~~' refers to '$ISABELLE_HOME';
  3914 
  3915 * in locales, the "assumes" and "defines" parts may be omitted if
  3916 empty;
  3917 
  3918 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  3919 long arrows);
  3920 
  3921 * new print_mode "HTML";
  3922 
  3923 * new flag show_tags controls display of tags of theorems (which are
  3924 basically just comments that may be attached by some tools);
  3925 
  3926 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  3927 mode and goal output format:
  3928 
  3929 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  3930 244c244
  3931 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  3932 ---
  3933 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  3934 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  3935 181c181
  3936 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  3937 ---
  3938 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  3939 
  3940 * function bind_thms stores lists of theorems (cf. bind_thm);
  3941 
  3942 * new shorthand tactics ftac, eatac, datac, fatac;
  3943 
  3944 * qed (and friends) now accept "" as result name; in that case the
  3945 theorem is not stored, but proper checks and presentation of the
  3946 result still apply;
  3947 
  3948 * theorem database now also indexes constants "Trueprop", "all",
  3949 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  3950 
  3951 
  3952 *** HOL ***
  3953 
  3954 ** HOL arithmetic **
  3955 
  3956 * There are now decision procedures for linear arithmetic over nat and
  3957 int:
  3958 
  3959 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  3960 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  3961 are treated as atomic; subformulae not involving type `nat' or `int'
  3962 are ignored; quantified subformulae are ignored unless they are
  3963 positive universal or negative existential. The tactic has to be
  3964 invoked by hand and can be a little bit slow. In particular, the
  3965 running time is exponential in the number of occurrences of `min' and
  3966 `max', and `-' on `nat'.
  3967 
  3968 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  3969 (negated) (in)equalities among the premises and the conclusion into
  3970 account (i.e. no compound formulae) and does not know about `min' and
  3971 `max', and `-' on `nat'. It is fast and is used automatically by the
  3972 simplifier.
  3973 
  3974 NB: At the moment, these decision procedures do not cope with mixed
  3975 nat/int formulae where the two parts interact, such as `m < n ==>
  3976 int(m) < int(n)'.
  3977 
  3978 * HOL/Numeral provides a generic theory of numerals (encoded
  3979 efficiently as bit strings); setup for types nat/int/real is in place;
  3980 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  3981 int, existing theories and proof scripts may require a few additional
  3982 type constraints;
  3983 
  3984 * integer division and remainder can now be performed on constant
  3985 arguments;
  3986 
  3987 * many properties of integer multiplication, division and remainder
  3988 are now available;
  3989 
  3990 * An interface to the Stanford Validity Checker (SVC) is available through the
  3991 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  3992 are proved automatically.  SVC must be installed separately, and its results
  3993 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  3994 invocation of the underlying oracle).  For SVC see
  3995   http://verify.stanford.edu/SVC
  3996 
  3997 * IsaMakefile: the HOL-Real target now builds an actual image;
  3998 
  3999 
  4000 ** HOL misc **
  4001 
  4002 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  4003 (in Isabelle/Isar) -- by Gertrud Bauer;
  4004 
  4005 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  4006 analysis for assembly languages with subtypes;
  4007 
  4008 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  4009 -- avoids syntactic ambiguities and treats state, transition, and
  4010 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  4011 changed syntax and (many) tactics;
  4012 
  4013 * HOL/inductive: Now also handles more general introduction rules such
  4014   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  4015   theorems are now maintained within the theory (maintained via the
  4016   "mono" attribute);
  4017 
  4018 * HOL/datatype: Now also handles arbitrarily branching datatypes
  4019   (using function types) such as
  4020 
  4021   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  4022 
  4023 * HOL/record: record_simproc (part of the default simpset) takes care
  4024 of selectors applied to updated records; record_split_tac is no longer
  4025 part of the default claset; update_defs may now be removed from the
  4026 simpset in many cases; COMPATIBILITY: old behavior achieved by
  4027 
  4028   claset_ref () := claset() addSWrapper record_split_wrapper;
  4029   Delsimprocs [record_simproc]
  4030 
  4031 * HOL/typedef: fixed type inference for representing set; type
  4032 arguments now have to occur explicitly on the rhs as type constraints;
  4033 
  4034 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  4035 names rather than an ML expression;
  4036 
  4037 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  4038 supplied later.  Program schemes can be defined, such as
  4039     "While B C s = (if B s then While B C (C s) else s)"
  4040 where the well-founded relation can be chosen after B and C have been given.
  4041 
  4042 * HOL/List: the constructors of type list are now Nil and Cons;
  4043 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  4044 course, ML tools referring to List.list.op # etc. have to be adapted;
  4045 
  4046 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  4047 disabled by default; run isabelle with option -m HOL to get back to
  4048 the original Gordon/HOL-style output;
  4049 
  4050 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  4051 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  4052 
  4053 * HOL basic syntax simplified (more orthogonal): all variants of
  4054 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  4055 Eps operator is provided as well: "SOME x. P[x]";
  4056 
  4057 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  4058 
  4059 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  4060 thus available for user theories;
  4061 
  4062 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  4063 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  4064 time;
  4065 
  4066 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  4067 several times and then mp;
  4068 
  4069 
  4070 *** LK ***
  4071 
  4072 * the notation <<...>> is now available as a notation for sequences of
  4073 formulas;
  4074 
  4075 * the simplifier is now installed
  4076 
  4077 * the axiom system has been generalized (thanks to Soren Heilmann)
  4078 
  4079 * the classical reasoner now has a default rule database
  4080 
  4081 
  4082 *** ZF ***
  4083 
  4084 * new primrec section allows primitive recursive functions to be given
  4085 directly (as in HOL) over datatypes and the natural numbers;
  4086 
  4087 * new tactics induct_tac and exhaust_tac for induction (or case
  4088 analysis) over datatypes and the natural numbers;
  4089 
  4090 * the datatype declaration of type T now defines the recursor T_rec;
  4091 
  4092 * simplification automatically does freeness reasoning for datatype
  4093 constructors;
  4094 
  4095 * automatic type-inference, with AddTCs command to insert new
  4096 type-checking rules;
  4097 
  4098 * datatype introduction rules are now added as Safe Introduction rules
  4099 to the claset;
  4100 
  4101 * the syntax "if P then x else y" is now available in addition to
  4102 if(P,x,y);
  4103 
  4104 
  4105 *** Internal programming interfaces ***
  4106 
  4107 * tuned simplifier trace output; new flag debug_simp;
  4108 
  4109 * structures Vartab / Termtab (instances of TableFun) offer efficient
  4110 tables indexed by indexname_ord / term_ord (compatible with aconv);
  4111 
  4112 * AxClass.axclass_tac lost the theory argument;
  4113 
  4114 * tuned current_goals_markers semantics: begin / end goal avoids
  4115 printing empty lines;
  4116 
  4117 * removed prs and prs_fn hook, which was broken because it did not
  4118 include \n in its semantics, forcing writeln to add one
  4119 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  4120 string -> unit if you really want to output text without newline;
  4121 
  4122 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  4123 plain output, interface builders may have to enable 'isabelle_font'
  4124 mode to get Isabelle font glyphs as before;
  4125 
  4126 * refined token_translation interface; INCOMPATIBILITY: output length
  4127 now of type real instead of int;
  4128 
  4129 * theory loader actions may be traced via new ThyInfo.add_hook
  4130 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  4131 your own database of information attached to *whole* theories -- as
  4132 opposed to intra-theory data slots offered via TheoryDataFun;
  4133 
  4134 * proper handling of dangling sort hypotheses (at last!);
  4135 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  4136 extra sort hypotheses that can be witnessed from the type signature;
  4137 the force_strip_shyps flag is gone, any remaining shyps are simply
  4138 left in the theorem (with a warning issued by strip_shyps_warning);
  4139 
  4140 
  4141 
  4142 New in Isabelle98-1 (October 1998)
  4143 ----------------------------------
  4144 
  4145 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  4146 
  4147 * several changes of automated proof tools;
  4148 
  4149 * HOL: major changes to the inductive and datatype packages, including
  4150 some minor incompatibilities of theory syntax;
  4151 
  4152 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  4153 called `inj_on';
  4154 
  4155 * HOL: removed duplicate thms in Arith:
  4156   less_imp_add_less  should be replaced by  trans_less_add1
  4157   le_imp_add_le      should be replaced by  trans_le_add1
  4158 
  4159 * HOL: unary minus is now overloaded (new type constraints may be
  4160 required);
  4161 
  4162 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  4163 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  4164 now taken as an integer constant.
  4165 
  4166 * Pure: ML function 'theory_of' renamed to 'theory';
  4167 
  4168 
  4169 *** Proof tools ***
  4170 
  4171 * Simplifier:
  4172   1. Asm_full_simp_tac is now more aggressive.
  4173      1. It will sometimes reorient premises if that increases their power to
  4174         simplify.
  4175      2. It does no longer proceed strictly from left to right but may also
  4176         rotate premises to achieve further simplification.
  4177      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  4178      old Asm_full_simp_tac in that it does not rotate premises.
  4179   2. The simplifier now knows a little bit about nat-arithmetic.
  4180 
  4181 * Classical reasoner: wrapper mechanism for the classical reasoner now
  4182 allows for selected deletion of wrappers, by introduction of names for
  4183 wrapper functionals.  This implies that addbefore, addSbefore,
  4184 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  4185 and that adding two tactics with the same name overwrites the first
  4186 one (emitting a warning).
  4187   type wrapper = (int -> tactic) -> (int -> tactic)
  4188   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  4189   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  4190   delWrapper, delSWrapper: claset *  string            -> claset
  4191   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  4192 
  4193 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  4194 semantics; addbefore now affects only the unsafe part of step_tac
  4195 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  4196 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  4197 by Force_tac;
  4198 
  4199 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  4200 compWrapper; added safe wrapper (and access functions for it);
  4201 
  4202 * HOL/split_all_tac is now much faster and fails if there is nothing
  4203 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  4204 and the names of the automatically generated variables have changed.
  4205 split_all_tac has moved within claset() from unsafe wrappers to safe
  4206 wrappers, which means that !!-bound variables are split much more
  4207 aggressively, and safe_tac and clarify_tac now split such variables.
  4208 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  4209 Note: the same holds for record_split_tac, which does the job of
  4210 split_all_tac for record fields.
  4211 
  4212 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  4213 permanently to the default simpset using Addsplits just like
  4214 Addsimps. They can be removed via Delsplits just like
  4215 Delsimps. Lower-case versions are also available.
  4216 
  4217 * HOL/Simplifier: The rule split_if is now part of the default
  4218 simpset. This means that the simplifier will eliminate all occurrences
  4219 of if-then-else in the conclusion of a goal. To prevent this, you can
  4220 either remove split_if completely from the default simpset by
  4221 `Delsplits [split_if]' or remove it in a specific call of the
  4222 simplifier using `... delsplits [split_if]'.  You can also add/delete
  4223 other case splitting rules to/from the default simpset: every datatype
  4224 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  4225 t is the name of the datatype).
  4226 
  4227 * Classical reasoner / Simplifier combination: new force_tac (and
  4228 derivatives Force_tac, force) combines rewriting and classical
  4229 reasoning (and whatever other tools) similarly to auto_tac, but is
  4230 aimed to solve the given subgoal completely.
  4231 
  4232 
  4233 *** General ***
  4234 
  4235 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  4236 and `goalw': the theory is no longer needed as an explicit argument -
  4237 the current theory context is used; assumptions are no longer returned
  4238 at the ML-level unless one of them starts with ==> or !!; it is
  4239 recommended to convert to these new commands using isatool fixgoal
  4240 (backup your sources first!);
  4241 
  4242 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  4243 the current theory context, and 'theory' to lookup stored theories;
  4244 
  4245 * new theory section 'locale' for declaring constants, assumptions and
  4246 definitions that have local scope;
  4247 
  4248 * new theory section 'nonterminals' for purely syntactic types;
  4249 
  4250 * new theory section 'setup' for generic ML setup functions
  4251 (e.g. package initialization);
  4252 
  4253 * the distribution now includes Isabelle icons: see
  4254 lib/logo/isabelle-{small,tiny}.xpm;
  4255 
  4256 * isatool install - install binaries with absolute references to
  4257 ISABELLE_HOME/bin;
  4258 
  4259 * isatool logo -- create instances of the Isabelle logo (as EPS);
  4260 
  4261 * print mode 'emacs' reserved for Isamode;
  4262 
  4263 * support multiple print (ast) translations per constant name;
  4264 
  4265 * theorems involving oracles are now printed with a suffixed [!];
  4266 
  4267 
  4268 *** HOL ***
  4269 
  4270 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  4271 
  4272 * HOL/inductive package reorganized and improved: now supports mutual
  4273 definitions such as
  4274 
  4275   inductive EVEN ODD
  4276     intrs
  4277       null "0 : EVEN"
  4278       oddI "n : EVEN ==> Suc n : ODD"
  4279       evenI "n : ODD ==> Suc n : EVEN"
  4280 
  4281 new theorem list "elims" contains an elimination rule for each of the
  4282 recursive sets; inductive definitions now handle disjunctive premises
  4283 correctly (also ZF);
  4284 
  4285 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  4286 "mutual_induct" no longer exists - the induction rule is always
  4287 contained in "induct";
  4288 
  4289 
  4290 * HOL/datatype package re-implemented and greatly improved: now
  4291 supports mutually recursive datatypes such as
  4292 
  4293   datatype
  4294     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  4295             | SUM ('a aexp) ('a aexp)
  4296             | DIFF ('a aexp) ('a aexp)
  4297             | NUM 'a
  4298   and
  4299     'a bexp = LESS ('a aexp) ('a aexp)
  4300             | AND ('a bexp) ('a bexp)
  4301             | OR ('a bexp) ('a bexp)
  4302 
  4303 as well as indirectly recursive datatypes such as
  4304 
  4305   datatype
  4306     ('a, 'b) term = Var 'a
  4307                   | App 'b ((('a, 'b) term) list)
  4308 
  4309 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  4310 induction on mutually / indirectly recursive datatypes.
  4311 
  4312 Primrec equations are now stored in theory and can be accessed via
  4313 <function_name>.simps.
  4314 
  4315 INCOMPATIBILITIES:
  4316 
  4317   - Theories using datatypes must now have theory Datatype as an
  4318     ancestor.
  4319   - The specific <typename>.induct_tac no longer exists - use the
  4320     generic induct_tac instead.
  4321   - natE has been renamed to nat.exhaust - use exhaust_tac
  4322     instead of res_inst_tac ... natE. Note that the variable
  4323     names in nat.exhaust differ from the names in natE, this
  4324     may cause some "fragile" proofs to fail.
  4325   - The theorems split_<typename>_case and split_<typename>_case_asm
  4326     have been renamed to <typename>.split and <typename>.split_asm.
  4327   - Since default sorts of type variables are now handled correctly,
  4328     some datatype definitions may have to be annotated with explicit
  4329     sort constraints.
  4330   - Primrec definitions no longer require function name and type
  4331     of recursive argument.
  4332 
  4333 Consider using isatool fixdatatype to adapt your theories and proof
  4334 scripts to the new package (backup your sources first!).
  4335 
  4336 
  4337 * HOL/record package: considerably improved implementation; now
  4338 includes concrete syntax for record types, terms, updates; theorems
  4339 for surjective pairing and splitting !!-bound record variables; proof
  4340 support is as follows:
  4341 
  4342   1) standard conversions (selectors or updates applied to record
  4343 constructor terms) are part of the standard simpset;
  4344 
  4345   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  4346 made part of standard simpset and claset via addIffs;
  4347 
  4348   3) a tactic for record field splitting (record_split_tac) is part of
  4349 the standard claset (addSWrapper);
  4350 
  4351 To get a better idea about these rules you may retrieve them via
  4352 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  4353 the name of your record type.
  4354 
  4355 The split tactic 3) conceptually simplifies by the following rule:
  4356 
  4357   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  4358 
  4359 Thus any record variable that is bound by meta-all will automatically
  4360 blow up into some record constructor term, consequently the
  4361 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  4362 solve record problems automatically.
  4363 
  4364 
  4365 * reorganized the main HOL image: HOL/Integ and String loaded by
  4366 default; theory Main includes everything;
  4367 
  4368 * automatic simplification of integer sums and comparisons, using cancellation;
  4369 
  4370 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  4371 
  4372 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  4373 
  4374 * many new identities for unions, intersections, set difference, etc.;
  4375 
  4376 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  4377 called split_if, split_split, split_sum_case and split_nat_case (to go
  4378 with add/delsplits);
  4379 
  4380 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  4381 (?x::unit) = (); this is made part of the default simpset, which COULD
  4382 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  4383 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  4384 unit_abs_eta_conv is added in order to counter the effect of
  4385 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  4386 %u.f();
  4387 
  4388 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  4389 makes more sense);
  4390 
  4391 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  4392   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  4393   disjointness reasoning but breaking a few old proofs.
  4394 
  4395 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  4396 to 'converse' from 'inverse' (for compatibility with ZF and some
  4397 literature);
  4398 
  4399 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  4400 the well-founded relation;
  4401 
  4402 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  4403     Compl A.  The "Compl" syntax remains available as input syntax for this
  4404     release ONLY.
  4405 
  4406 * HOL/Update: new theory of function updates:
  4407     f(a:=b) == %x. if x=a then b else f x
  4408 may also be iterated as in f(a:=b,c:=d,...);
  4409 
  4410 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  4411 
  4412 * HOL/List:
  4413   - new function list_update written xs[i:=v] that updates the i-th
  4414     list position. May also be iterated as in xs[i:=a,j:=b,...].
  4415   - new function `upt' written [i..j(] which generates the list
  4416     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  4417     bound write [i..j], which is a shorthand for [i..j+1(].
  4418   - new lexicographic orderings and corresponding wellfoundedness theorems.
  4419 
  4420 * HOL/Arith:
  4421   - removed 'pred' (predecessor) function;
  4422   - generalized some theorems about n-1;
  4423   - many new laws about "div" and "mod";
  4424   - new laws about greatest common divisors (see theory ex/Primes);
  4425 
  4426 * HOL/Relation: renamed the relational operator r^-1 "converse"
  4427 instead of "inverse";
  4428 
  4429 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  4430   of the multiset ordering;
  4431 
  4432 * directory HOL/Real: a construction of the reals using Dedekind cuts
  4433   (not included by default);
  4434 
  4435 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  4436 
  4437 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  4438   programs, i.e. different program variables may have different types.
  4439 
  4440 * calling (stac rew i) now fails if "rew" has no effect on the goal
  4441   [previously, this check worked only if the rewrite rule was unconditional]
  4442   Now rew can involve either definitions or equalities (either == or =).
  4443 
  4444 
  4445 *** ZF ***
  4446 
  4447 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  4448   only the theorems proved on ZF.ML;
  4449 
  4450 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  4451   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  4452   disjointness reasoning but breaking a few old proofs.
  4453 
  4454 * ZF/Update: new theory of function updates
  4455     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  4456   may also be iterated as in f(a:=b,c:=d,...);
  4457 
  4458 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  4459 
  4460 * calling (stac rew i) now fails if "rew" has no effect on the goal
  4461   [previously, this check worked only if the rewrite rule was unconditional]
  4462   Now rew can involve either definitions or equalities (either == or =).
  4463 
  4464 * case_tac provided for compatibility with HOL
  4465     (like the old excluded_middle_tac, but with subgoals swapped)
  4466 
  4467 
  4468 *** Internal programming interfaces ***
  4469 
  4470 * Pure: several new basic modules made available for general use, see
  4471 also src/Pure/README;
  4472 
  4473 * improved the theory data mechanism to support encapsulation (data
  4474 kind name replaced by private Object.kind, acting as authorization
  4475 key); new type-safe user interface via functor TheoryDataFun; generic
  4476 print_data function becomes basically useless;
  4477 
  4478 * removed global_names compatibility flag -- all theory declarations
  4479 are qualified by default;
  4480 
  4481 * module Pure/Syntax now offers quote / antiquote translation
  4482 functions (useful for Hoare logic etc. with implicit dependencies);
  4483 see HOL/ex/Antiquote for an example use;
  4484 
  4485 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  4486 cterm -> thm;
  4487 
  4488 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  4489 subgoal;
  4490 
  4491 * Display.print_goals function moved to Locale.print_goals;
  4492 
  4493 * standard print function for goals supports current_goals_markers
  4494 variable for marking begin of proof, end of proof, start of goal; the
  4495 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  4496 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  4497 for example;
  4498 
  4499 
  4500 
  4501 New in Isabelle98 (January 1998)
  4502 --------------------------------
  4503 
  4504 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  4505 
  4506 * changed lexical syntax of terms / types: dots made part of long
  4507 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  4508 
  4509 * simpset (and claset) reference variable replaced by functions
  4510 simpset / simpset_ref;
  4511 
  4512 * no longer supports theory aliases (via merge) and non-trivial
  4513 implicit merge of thms' signatures;
  4514 
  4515 * most internal names of constants changed due to qualified names;
  4516 
  4517 * changed Pure/Sequence interface (see Pure/seq.ML);
  4518 
  4519 
  4520 *** General Changes ***
  4521 
  4522 * hierachically structured name spaces (for consts, types, axms, thms
  4523 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  4524 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  4525 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  4526 long_names for fully qualified output names; NOTE: ML programs
  4527 (special tactics, packages etc.) referring to internal names may have
  4528 to be adapted to cope with fully qualified names; in case of severe
  4529 backward campatibility problems try setting 'global_names' at compile
  4530 time to have enrything declared within a flat name space; one may also
  4531 fine tune name declarations in theories via the 'global' and 'local'
  4532 section;
  4533 
  4534 * reimplemented the implicit simpset and claset using the new anytype
  4535 data filed in signatures; references simpset:simpset ref etc. are
  4536 replaced by functions simpset:unit->simpset and
  4537 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  4538 to patch your ML files accordingly;
  4539 
  4540 * HTML output now includes theory graph data for display with Java
  4541 applet or isatool browser; data generated automatically via isatool
  4542 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  4543 
  4544 * defs may now be conditional; improved rewrite_goals_tac to handle
  4545 conditional equations;
  4546 
  4547 * defs now admits additional type arguments, using TYPE('a) syntax;
  4548 
  4549 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  4550 creates a new theory node; implicit merge of thms' signatures is
  4551 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  4552 transfer:theory->thm->thm in (rare) cases;
  4553 
  4554 * improved handling of draft signatures / theories; draft thms (and
  4555 ctyps, cterms) are automatically promoted to real ones;
  4556 
  4557 * slightly changed interfaces for oracles: admit many per theory, named
  4558 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  4559 
  4560 * print_goals: optional output of const types (set show_consts and
  4561 show_types);
  4562 
  4563 * improved output of warnings (###) and errors (***);
  4564 
  4565 * subgoal_tac displays a warning if the new subgoal has type variables;
  4566 
  4567 * removed old README and Makefiles;
  4568 
  4569 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  4570 
  4571 * removed obsolete init_pps and init_database;
  4572 
  4573 * deleted the obsolete tactical STATE, which was declared by
  4574     fun STATE tacfun st = tacfun st st;
  4575 
  4576 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  4577 (which abbreviates $HOME);
  4578 
  4579 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  4580 use isatool fixseq to adapt your ML programs (this works for fully
  4581 qualified references to the Sequence structure only!);
  4582 
  4583 * use_thy no longer requires writable current directory; it always
  4584 reloads .ML *and* .thy file, if either one is out of date;
  4585 
  4586 
  4587 *** Classical Reasoner ***
  4588 
  4589 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  4590 tactics that use classical reasoning to simplify a subgoal without
  4591 splitting it into several subgoals;
  4592 
  4593 * Safe_tac: like safe_tac but uses the default claset;
  4594 
  4595 
  4596 *** Simplifier ***
  4597 
  4598 * added simplification meta rules:
  4599     (asm_)(full_)simplify: simpset -> thm -> thm;
  4600 
  4601 * simplifier.ML no longer part of Pure -- has to be loaded by object
  4602 logics (again);
  4603 
  4604 * added prems argument to simplification procedures;
  4605 
  4606 * HOL, FOL, ZF: added infix function `addsplits':
  4607   instead of `<simpset> setloop (split_tac <thms>)'
  4608   you can simply write `<simpset> addsplits <thms>'
  4609 
  4610 
  4611 *** Syntax ***
  4612 
  4613 * TYPE('a) syntax for type reflection terms;
  4614 
  4615 * no longer handles consts with name "" -- declare as 'syntax' instead;
  4616 
  4617 * pretty printer: changed order of mixfix annotation preference (again!);
  4618 
  4619 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  4620 
  4621 
  4622 *** HOL ***
  4623 
  4624 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  4625   with `addloop' of the simplifier to faciliate case splitting in premises.
  4626 
  4627 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  4628 
  4629 * HOL/Auth: new protocol proofs including some for the Internet
  4630   protocol TLS;
  4631 
  4632 * HOL/Map: new theory of `maps' a la VDM;
  4633 
  4634 * HOL/simplifier: simplification procedures nat_cancel_sums for
  4635 cancelling out common nat summands from =, <, <= (in)equalities, or
  4636 differences; simplification procedures nat_cancel_factor for
  4637 cancelling common factor from =, <, <= (in)equalities over natural
  4638 sums; nat_cancel contains both kinds of procedures, it is installed by
  4639 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  4640 
  4641 * HOL/simplifier: terms of the form
  4642   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  4643   are rewritten to
  4644   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  4645   and those of the form
  4646   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  4647   are rewritten to
  4648   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  4649 
  4650 * HOL/datatype
  4651   Each datatype `t' now comes with a theorem `split_t_case' of the form
  4652 
  4653   P(t_case f1 ... fn x) =
  4654      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  4655         ...
  4656        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  4657      )
  4658 
  4659   and a theorem `split_t_case_asm' of the form
  4660 
  4661   P(t_case f1 ... fn x) =
  4662     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  4663         ...
  4664        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  4665      )
  4666   which can be added to a simpset via `addsplits'. The existing theorems
  4667   expand_list_case and expand_option_case have been renamed to
  4668   split_list_case and split_option_case.
  4669 
  4670 * HOL/Arithmetic:
  4671   - `pred n' is automatically converted to `n-1'.
  4672     Users are strongly encouraged not to use `pred' any longer,
  4673     because it will disappear altogether at some point.
  4674   - Users are strongly encouraged to write "0 < n" rather than
  4675     "n ~= 0". Theorems and proof tools have been modified towards this
  4676     `standard'.
  4677 
  4678 * HOL/Lists:
  4679   the function "set_of_list" has been renamed "set" (and its theorems too);
  4680   the function "nth" now takes its arguments in the reverse order and
  4681   has acquired the infix notation "!" as in "xs!n".
  4682 
  4683 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  4684 
  4685 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  4686   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  4687 
  4688 * HOL/record: extensible records with schematic structural subtyping
  4689 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  4690 still lacks various theorems and concrete record syntax;
  4691 
  4692 
  4693 *** HOLCF ***
  4694 
  4695 * removed "axioms" and "generated by" sections;
  4696 
  4697 * replaced "ops" section by extended "consts" section, which is capable of
  4698   handling the continuous function space "->" directly;
  4699 
  4700 * domain package:
  4701   . proves theorems immediately and stores them in the theory,
  4702   . creates hierachical name space,
  4703   . now uses normal mixfix annotations (instead of cinfix...),
  4704   . minor changes to some names and values (for consistency),
  4705   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  4706   . separator between mutual domain defs: changed "," to "and",
  4707   . improved handling of sort constraints;  now they have to
  4708     appear on the left-hand side of the equations only;
  4709 
  4710 * fixed LAM <x,y,zs>.b syntax;
  4711 
  4712 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  4713 adm (%x. P (t x)), where P is chainfinite and t continuous;
  4714 
  4715 
  4716 *** FOL and ZF ***
  4717 
  4718 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  4719   with `addloop' of the simplifier to faciliate case splitting in premises.
  4720 
  4721 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  4722 in HOL, they strip ALL and --> from proved theorems;
  4723 
  4724 
  4725 
  4726 New in Isabelle94-8 (May 1997)
  4727 ------------------------------
  4728 
  4729 *** General Changes ***
  4730 
  4731 * new utilities to build / run / maintain Isabelle etc. (in parts
  4732 still somewhat experimental); old Makefiles etc. still functional;
  4733 
  4734 * new 'Isabelle System Manual';
  4735 
  4736 * INSTALL text, together with ./configure and ./build scripts;
  4737 
  4738 * reimplemented type inference for greater efficiency, better error
  4739 messages and clean internal interface;
  4740 
  4741 * prlim command for dealing with lots of subgoals (an easier way of
  4742 setting goals_limit);
  4743 
  4744 
  4745 *** Syntax ***
  4746 
  4747 * supports alternative (named) syntax tables (parser and pretty
  4748 printer); internal interface is provided by add_modesyntax(_i);
  4749 
  4750 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  4751 be used in conjunction with the Isabelle symbol font; uses the
  4752 "symbols" syntax table;
  4753 
  4754 * added token_translation interface (may translate name tokens in
  4755 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  4756 the current print_mode); IMPORTANT: user print translation functions
  4757 are responsible for marking newly introduced bounds
  4758 (Syntax.mark_boundT);
  4759 
  4760 * token translations for modes "xterm" and "xterm_color" that display
  4761 names in bold, underline etc. or colors (which requires a color
  4762 version of xterm);
  4763 
  4764 * infixes may now be declared with names independent of their syntax;
  4765 
  4766 * added typed_print_translation (like print_translation, but may
  4767 access type of constant);
  4768 
  4769 
  4770 *** Classical Reasoner ***
  4771 
  4772 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  4773 some limitations.  Blast_tac...
  4774   + ignores addss, addbefore, addafter; this restriction is intrinsic
  4775   + ignores elimination rules that don't have the correct format
  4776         (the conclusion MUST be a formula variable)
  4777   + ignores types, which can make HOL proofs fail
  4778   + rules must not require higher-order unification, e.g. apply_type in ZF
  4779     [message "Function Var's argument not a bound variable" relates to this]
  4780   + its proof strategy is more general but can actually be slower
  4781 
  4782 * substitution with equality assumptions no longer permutes other
  4783 assumptions;
  4784 
  4785 * minor changes in semantics of addafter (now called addaltern); renamed
  4786 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  4787 (and access functions for it);
  4788 
  4789 * improved combination of classical reasoner and simplifier:
  4790   + functions for handling clasimpsets
  4791   + improvement of addss: now the simplifier is called _after_ the
  4792     safe steps.
  4793   + safe variant of addss called addSss: uses safe simplifications
  4794     _during_ the safe steps. It is more complete as it allows multiple
  4795     instantiations of unknowns (e.g. with slow_tac).
  4796 
  4797 *** Simplifier ***
  4798 
  4799 * added interface for simplification procedures (functions that
  4800 produce *proven* rewrite rules on the fly, depending on current
  4801 redex);
  4802 
  4803 * ordering on terms as parameter (used for ordered rewriting);
  4804 
  4805 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  4806 
  4807 * the solver is now split into a safe and an unsafe part.
  4808 This should be invisible for the normal user, except that the
  4809 functions setsolver and addsolver have been renamed to setSolver and
  4810 addSolver; added safe_asm_full_simp_tac;
  4811 
  4812 
  4813 *** HOL ***
  4814 
  4815 * a generic induction tactic `induct_tac' which works for all datatypes and
  4816 also for type `nat';
  4817 
  4818 * a generic case distinction tactic `exhaust_tac' which works for all
  4819 datatypes and also for type `nat';
  4820 
  4821 * each datatype comes with a function `size';
  4822 
  4823 * patterns in case expressions allow tuple patterns as arguments to
  4824 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  4825 
  4826 * primrec now also works with type nat;
  4827 
  4828 * recdef: a new declaration form, allows general recursive functions to be
  4829 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  4830 
  4831 * the constant for negation has been renamed from "not" to "Not" to
  4832 harmonize with FOL, ZF, LK, etc.;
  4833 
  4834 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  4835 infinite lists;
  4836 
  4837 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  4838 
  4839 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  4840 problems in commutative rings, using axiomatic type classes for + and *;
  4841 
  4842 * more examples in HOL/MiniML and HOL/Auth;
  4843 
  4844 * more default rewrite rules for quantifiers, union/intersection;
  4845 
  4846 * a new constant `arbitrary == @x.False';
  4847 
  4848 * HOLCF/IOA replaces old HOL/IOA;
  4849 
  4850 * HOLCF changes: derived all rules and arities
  4851   + axiomatic type classes instead of classes
  4852   + typedef instead of faking type definitions
  4853   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  4854   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  4855   + eliminated the types void, one, tr
  4856   + use unit lift and bool lift (with translations) instead of one and tr
  4857   + eliminated blift from Lift3.thy (use Def instead of blift)
  4858   all eliminated rules are derived as theorems --> no visible changes ;
  4859 
  4860 
  4861 *** ZF ***
  4862 
  4863 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  4864 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  4865 as ZF_cs addSIs [equalityI];
  4866 
  4867 
  4868 
  4869 New in Isabelle94-7 (November 96)
  4870 ---------------------------------
  4871 
  4872 * allowing negative levels (as offsets) in prlev and choplev;
  4873 
  4874 * super-linear speedup for large simplifications;
  4875 
  4876 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  4877 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  4878 FAIL); can suppress it using the command Delsimps (ex_simps @
  4879 all_simps); De Morgan laws are also now included, by default;
  4880 
  4881 * improved printing of ==>  :  ~:
  4882 
  4883 * new object-logic "Sequents" adds linear logic, while replacing LK
  4884 and Modal (thanks to Sara Kalvala);
  4885 
  4886 * HOL/Auth: correctness proofs for authentication protocols;
  4887 
  4888 * HOL: new auto_tac combines rewriting and classical reasoning (many
  4889 examples on HOL/Auth);
  4890 
  4891 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  4892 the rewriter and classical reasoner simultaneously;
  4893 
  4894 * function uresult no longer returns theorems in "standard" format;
  4895 regain previous version by: val uresult = standard o uresult;
  4896 
  4897 
  4898 
  4899 New in Isabelle94-6
  4900 -------------------
  4901 
  4902 * oracles -- these establish an interface between Isabelle and trusted
  4903 external reasoners, which may deliver results as theorems;
  4904 
  4905 * proof objects (in particular record all uses of oracles);
  4906 
  4907 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  4908 
  4909 * "constdefs" section in theory files;
  4910 
  4911 * "primrec" section (HOL) no longer requires names;
  4912 
  4913 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  4914 
  4915 
  4916 
  4917 New in Isabelle94-5
  4918 -------------------
  4919 
  4920 * reduced space requirements;
  4921 
  4922 * automatic HTML generation from theories;
  4923 
  4924 * theory files no longer require "..." (quotes) around most types;
  4925 
  4926 * new examples, including two proofs of the Church-Rosser theorem;
  4927 
  4928 * non-curried (1994) version of HOL is no longer distributed;
  4929 
  4930 
  4931 
  4932 New in Isabelle94-4
  4933 -------------------
  4934 
  4935 * greatly reduced space requirements;
  4936 
  4937 * theory files (.thy) no longer require \...\ escapes at line breaks;
  4938 
  4939 * searchable theorem database (see the section "Retrieving theorems" on
  4940 page 8 of the Reference Manual);
  4941 
  4942 * new examples, including Grabczewski's monumental case study of the
  4943 Axiom of Choice;
  4944 
  4945 * The previous version of HOL renamed to Old_HOL;
  4946 
  4947 * The new version of HOL (previously called CHOL) uses a curried syntax
  4948 for functions.  Application looks like f a b instead of f(a,b);
  4949 
  4950 * Mutually recursive inductive definitions finally work in HOL;
  4951 
  4952 * In ZF, pattern-matching on tuples is now available in all abstractions and
  4953 translates to the operator "split";
  4954 
  4955 
  4956 
  4957 New in Isabelle94-3
  4958 -------------------
  4959 
  4960 * new infix operator, addss, allowing the classical reasoner to
  4961 perform simplification at each step of its search.  Example:
  4962         fast_tac (cs addss ss)
  4963 
  4964 * a new logic, CHOL, the same as HOL, but with a curried syntax
  4965 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  4966 look like (a,b) instead of <a,b>;
  4967 
  4968 * PLEASE NOTE: CHOL will eventually replace HOL!
  4969 
  4970 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  4971 It translates to the operator "split".  A new theory of integers is available;
  4972 
  4973 * In ZF, integer numerals now denote two's-complement binary integers.
  4974 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  4975 
  4976 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  4977 of the Axiom of Choice;
  4978 
  4979 
  4980 
  4981 New in Isabelle94-2
  4982 -------------------
  4983 
  4984 * Significantly faster resolution;
  4985 
  4986 * the different sections in a .thy file can now be mixed and repeated
  4987 freely;
  4988 
  4989 * Database of theorems for FOL, HOL and ZF.  New
  4990 commands including qed, qed_goal and bind_thm store theorems in the database.
  4991 
  4992 * Simple database queries: return a named theorem (get_thm) or all theorems of
  4993 a given theory (thms_of), or find out what theory a theorem was proved in
  4994 (theory_of_thm);
  4995 
  4996 * Bugs fixed in the inductive definition and datatype packages;
  4997 
  4998 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  4999 and HOL_dup_cs obsolete;
  5000 
  5001 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  5002 have been removed;
  5003 
  5004 * Simpler definition of function space in ZF;
  5005 
  5006 * new results about cardinal and ordinal arithmetic in ZF;
  5007 
  5008 * 'subtype' facility in HOL for introducing new types as subsets of existing
  5009 types;
  5010 
  5011 :mode=text:wrap=hard:maxLineLen=72:
  5012 $Id$