moved adm_chfindom from Adm.thy to Fix.thy, to remove dependence on Cfun
Isabelle NEWS -- history user-relevant changes==============================================New in this Isabelle release----------------------------*** General **** Theory headers: the new header syntax for Isar theories is theory <name> imports <theory1> ... <theoryn> begin optionally also with a "files" section. The syntax theory <name> = <theory1> + ... + <theoryn>: will still be supported for some time but will eventually disappear. The syntax of old-style theories has not changed.* Theory loader: parent theories can now also be referred to via relative and absolute paths.* Provers/quasi.ML: new transitivity reasoners for transitivity only and quasi orders.* Provers/trancl.ML: new transitivity reasoner for transitive and reflexive-transitive closure of relations.* Provers/blast.ML: new reference depth_limit to make blast's depth limit (previously hard-coded with a value of 20) user-definable.* Provers: new version of the subst method, for single-step rewriting: it now works in bound variable contexts. New is subst (asm), for rewriting an assumption. Thanks to Lucas Dixon! INCOMPATIBILITY: may rewrite a different subterm than the original subst method, which is still available under the name simplesubst.* Pure: thin_tac now works even if the assumption being deleted contains !! or ==>. More generally, erule now works even if the major premise of the elimination rule contains !! or ==>.* Pure: considerably improved version of 'constdefs' command. Now performs automatic type-inference of declared constants; additional support for local structure declarations (cf. locales and HOL records), see also isar-ref manual. Potential INCOMPATIBILITY: need to observe strictly sequential dependencies of definitions within a single 'constdefs' section; moreover, the declared name needs to be an identifier. If all fails, consider to fall back on 'consts' and 'defs' separately.* Pure: improved indexed syntax and implicit structures. First of all, indexed syntax provides a notational device for subscripted application, using the new syntax \<^bsub>term\<^esub> for arbitrary expressions. Secondly, in a local context with structure declarations, number indexes \<^sub>n or the empty index (default number 1) refer to a certain fixed variable implicitly; option show_structs controls printing of implicit structures. Typical applications of these concepts involve record types and locales.* Pure: clear separation of logical types and nonterminals, where the latter may only occur in 'syntax' specifications or type abbreviations. Before that distinction was only partially implemented via type class "logic" vs. "{}". Potential INCOMPATIBILITY in rare cases of improper use of 'types'/'consts' instead of 'nonterminals'/'syntax'. Some very exotic syntax specifications may require further adaption (e.g. Cube/Base.thy).* Pure: removed obsolete type class "logic", use the top sort {} instead. Note that non-logical types should be declared as 'nonterminals' rather than 'types'. INCOMPATIBILITY for new object-logic specifications.* Pure: command 'no_syntax' removes grammar declarations (and translations) resulting from the given syntax specification, which is interpreted in the same manner as for the 'syntax' command.* Pure: print_tac now outputs the goal through the trace channel.* Pure: reference Namespace.unique_names included. If true the (shortest) namespace-prefix is printed to disambiguate conflicts (as yet). If false the first entry wins (as during parsing). Default value is true.* Pure: tuned internal renaming of symbolic identifiers -- attach primes instead of base 26 numbers.* Pure: new flag show_question_marks controls printing of leading question marks in schematic variable names.* Pure: new version of thms_containing that searches for a list of criteria instead of a list of constants. Known criteria are: intro, elim, dest, name:string, and any term. Criteria can be preceded by '-' to select theorems that do not match. Intro, elim, dest select theorems that match the current goal, name:s selects theorems whose fully qualified name contain s. Any other term is interpreted as pattern and selects all theorem matching the pattern. Available in ProofGeneral under ProofGeneral -> Find Theorems or C-c C-f. Example: C-c C-f (100) "(_::nat) + _ + _" intro -name:"HOL." prints the last 100 theorems matching the pattern "(_::nat) + _ + _", matching the current goal as introduction rule and not having "HOL." in their name (i.e. not being defined in theory HOL).* Pure/Syntax: In schematic variable names, *any* symbol following \<^isub> or \<^isup> is now treated as part of the base name. For example, the following works without printing of ugly ".0" indexes: lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1" by simp* Pure/Syntax: inner syntax includes (*(*nested*) comments*).* Pure/Syntax: pretty pinter now supports unbreakable blocks, specified in mixfix annotations as "(00...)".* Pure/Syntax: 'advanced' translation functions (parse_translation etc.) may depend on the signature of the theory context being presently used for parsing/printing, see also isar-ref manual.* Pure/Simplifier: you can control the depth to which conditional rewriting is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth Limit.* Pure/Simplifier: simplification procedures may now take the current simpset into account (cf. Simplifier.simproc(_i) / mk_simproc interface), which is very useful for calling the Simplifier recursively. Minor INCOMPATIBILITY: the 'prems' argument of simprocs is gone -- use prems_of_ss on the simpset instead. Moreover, the low-level mk_simproc no longer applies Logic.varify internally, to allow for use in a context of fixed variables.* Isar debugging: new reference Toplevel.debug; default false. Set to make printing of exceptions THM, TERM, TYPE and THEORY more verbose.* Locales: - "includes" disallowed in declaration of named locales (command "locale"). - Fixed parameter management in theorem generation for goals with "includes". INCOMPATIBILITY: rarely, the generated theorem statement is different.* Locales: new commands for the interpretation of locale expressions in theories (interpretation) and proof contexts (interpret). These take an instantiation of the locale parameters and compute proof obligations from the instantiated specification. After the obligations have been discharged, the instantiated theorems of the locale are added to the theory or proof context. Interpretation is smart in that already active interpretations do not occur in proof obligations, neither are instantiated theorems stored in duplicate. Use print_interps to inspect active interpretations of a particular locale. For details, see the Isar Reference manual.* Locales: proper static binding of attribute syntax -- i.e. types / terms / facts mentioned as arguments are always those of the locale definition context, independently of the context of later invocations. Moreover, locale operations (renaming and type / term instantiation) are applied to attribute arguments as expected. INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of actual attributes; rare situations may require Attrib.attribute to embed those attributes into Attrib.src that lack concrete syntax. Attribute implementations need to cooperate properly with the static binding mechanism. Basic parsers Args.XXX_typ/term/prop and Attrib.XXX_thm etc. already do the right thing without further intervention. Only unusual applications -- such as "where" or "of" (cf. src/Pure/Isar/attrib.ML), which process arguments depending both on the context and the facts involved -- may have to assign parsed values to argument tokens explicitly.* Attributes 'induct' and 'cases': type or set names may now be locally fixed variables as well.* Isar: new syntax 'name(i-j, i-, i, ...)' for referring to specific selections of theorems in named facts via indices.* Pure: reorganized bootstrapping of the Pure theories; CPure is now derived from Pure, which contains all common declarations already. Both theories are defined via plain Isabelle/Isar .thy files. INCOMPATIBILITY: elements of CPure (such as the CPure.intro / CPure.elim / CPure.dest attributes) now appear in the Pure name space; use isatool fixcpure to adapt your theory and ML sources.* Provers/simplifier.ML has been moved to Pure, where Simplifier.setup is peformed already. Object-logics merely need to finish their initial simpset configuration as before.*** Document preparation **** Several new antiquotation: @{term_type term} prints a term with its type annotated; @{typeof term} prints the type of a term; @{const const} is the same as @{term const}, but checks that the argument is a known logical constant; @{term_style style term} and @{thm_style style thm} print a term or theorem applying a "style" to it Predefined styles are "lhs" and "rhs" printing the lhs/rhs of definitions, equations, inequations etc. and "conclusion" printing only the conclusion of a meta-logical statement theorem. Styles may be defined via TermStyle.add_style in ML. See the "LaTeX Sugar" document for more information.* Antiquotations now provide the option 'locale=NAME' to specify an alternative context used for evaluating and printing the subsequent argument, as in @{thm [locale=LC] fold_commute}, for example.* Commands 'display_drafts' and 'print_drafts' perform simple output of raw sources. Only those symbols that do not require additional LaTeX packages (depending on comments in isabellesym.sty) are displayed properly, everything else is left verbatim. We use isatool display and isatool print as front ends; these are subject to the DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively.* Proof scripts as well as some other commands such as ML or parse/print_translation can now be hidden in the document. Hiding is enabled by default, and can be disabled either via the option '-H false' of isatool usedir or by resetting the reference variable IsarOutput.hide_commands. Additional commands to be hidden may be declared using IsarOutput.add_hidden_commands.*** HOL **** Datatype induction via method `induct' now preserves the name of the induction variable. For example, when proving P(xs::'a list) by induction on xs, the induction step is now P(xs) ==> P(a#xs) rather than P(list) ==> P(a#list) as previously.* HOL/record: reimplementation of records. Improved scalability for records with many fields, avoiding performance problems for type inference. Records are no longer composed of nested field types, but of nested extension types. Therefore the record type only grows linear in the number of extensions and not in the number of fields. The top-level (users) view on records is preserved. Potential INCOMPATIBILITY only in strange cases, where the theory depends on the old record representation. The type generated for a record is called <record_name>_ext_type.* HOL/record: Reference record_quick_and_dirty_sensitive can be enabled to skip the proofs triggered by a record definition or a simproc (if quick_and_dirty is enabled). Definitions of large records can take quite long.* HOL/record: "record_upd_simproc" for simplification of multiple record updates enabled by default. Moreover, trivial updates are also removed: r(|x := x r|) = r. INCOMPATIBILITY: old proofs break occasionally, since simplification is more powerful by default.* HOL: symbolic syntax of Hilbert Choice Operator is now as follows: syntax (epsilon) "_Eps" :: "[pttrn, bool] => 'a" ("(3\<some>_./ _)" [0, 10] 10) The symbol \<some> is displayed as the alternative epsilon of LaTeX and x-symbol; use option '-m epsilon' to get it actually printed. Moreover, the mathematically important symbolic identifier \<epsilon> becomes available as variable, constant etc.* HOL: "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x". Similarly for all quantifiers: "ALL x > y" etc. The x-symbol for >= is \<ge>.* HOL/Set: "{x:A. P}" abbreviates "{x. x:A & P}" (and similarly for "\<in>" instead of ":").* HOL/SetInterval: The syntax for open intervals has changed: Old New {..n(} -> {..<n} {)n..} -> {n<..} {m..n(} -> {m..<n} {)m..n} -> {m<..n} {)m..n(} -> {m<..<n} The old syntax is still supported but will disappear in the future. For conversion use the following emacs search and replace patterns: {)\([^\.]*\)\.\. -> {\1<\.\.} \.\.\([^(}]*\)(} -> \.\.<\1} They are not perfect but work quite well.* HOL: The syntax for 'setsum', summation over finite sets, has changed: The syntax for 'setsum (%x. e) A' used to be '\<Sum>x:A. e' and is now either 'SUM x:A. e' or '\<Sum>x\<in>A. e'. There is new syntax for summation over finite sets: '\<Sum>x | P. e' is the same as 'setsum (%x. e) {x. P}' '\<Sum>x=a..b. e' is the same as 'setsum (%x. e) {a..b}' '\<Sum>x=a..<b. e' is the same as 'setsum (%x. e) {a..<b}' '\<Sum>x<k. e' is the same as 'setsum (%x. e) {..<k}' Function 'Summation' over nat is gone, its syntax '\<Sum>i<k. e' now translates into 'setsum' as above.* HOL: Finite set induction: In Isar proofs, the insert case is now "case (insert x F)" instead of the old counterintuitive "case (insert F x)".* HOL/Simplifier: - Is now set up to reason about transitivity chains involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics provided by Provers/trancl.ML as additional solvers. INCOMPATIBILITY: old proofs break occasionally as simplification may now solve more goals than previously. - Converts x <= y into x = y if assumption y <= x is present. Works for all partial orders (class "order"), in particular numbers and sets. For linear orders (e.g. numbers) it treats ~ x < y just like y <= x. - Simproc for "let x = a in f x" If a is a free or bound variable or a constant then the let is unfolded. Otherwise first a is simplified to a', and then f a' is simplified to g. If possible we abstract a' from g arriving at "let x = a' in g' x", otherwise we unfold the let and arrive at g. The simproc can be enabled/disabled by the reference use_let_simproc. Potential INCOMPATIBILITY since simplification is more powerful by default.* HOL: The 'refute' command has been extended to support a much larger fragment of HOL, including axiomatic type classes, constdefs and typedefs, inductive datatypes and recursion.*** HOLCF **** HOLCF: discontinued special version of 'constdefs' (which used to support continuous functions) in favor of the general Pure one with full type-inference.*** ZF **** ZF/ex/{Group,Ring}: examples in abstract algebra, including the First Isomorphism Theorem (on quotienting by the kernel of a homomorphism).* ZF/Simplifier: install second copy of type solver that actually makes use of TC rules declared to Isar proof contexts (or locales); the old version is still required for ML proof scripts.*** System **** Allow symlinks to all proper Isabelle executables (Isabelle, isabelle, isatool etc.).* isabelle-process: Poly/ML no longer needs Perl to run an interactive session.* ISABELLE_DOC_FORMAT setting specifies preferred document format (for isatool doc, isatool mkdir, display_drafts etc.).* isatool usedir: option -f allows specification of the ML file to be used by Isabelle; default is ROOT.ML.* HOL: isatool dimacs2hol converts files in DIMACS CNF format (containing Boolean satisfiability problems) into Isabelle/HOL theories.*** ML **** Pure/library.ML no longer defines its own option datatype, but uses that of the SML basis, which has constructors NONE and SOME instead of None and Some, as well as exception Option.Option instead of OPTION. The functions the, if_none, is_some, is_none have been adapted accordingly, while Option.map replaces apsome.* The exception LIST is no more, the standard exceptions Empty and Subscript, as well as Library.UnequalLengths are used instead. This means that function like Library.hd and Library.tl are gone, as the standard hd and tl functions suffice. A number of basic functions are now no longer exported to the ML toplevel, as they are variants of standard functions. The following suggests how one can translate existing code: rev_append xs ys = List.revAppend (xs, ys) nth_elem (i, xs) = List.nth (xs, i) last_elem xs = List.last xs flat xss = List.concat xss seq fs = app fs partition P xs = List.partition P xs filter P xs = List.filter P xs mapfilter f xs = List.mapPartial f xs* Pure: output via the Isabelle channels of writeln/warning/error etc. is now passed through Output.output, with a hook for arbitrary transformations depending on the print_mode (cf. Output.add_mode -- the first active mode that provides a output function wins). Already formatted output may be embedded into further text via Output.raw; the result of Pretty.string_of/str_of and derived functions (string_of_term/cterm/thm etc.) is already marked raw to accommodate easy composition of diagnostic messages etc. Programmers rarely need to care about Output.output or Output.raw at all, with some notable exceptions: Output.output is required when bypassing the standard channels (writeln etc.), or in token translations to produce properly formatted results; Output.raw is required when capturing already output material that will eventually be presented to the user a second time. For the default print mode, both Output.output and Output.raw have no effect.* Provers: Simplifier and Classical Reasoner now support proof context dependent plug-ins (simprocs, solvers, wrappers etc.). These extra components are stored in the theory and patched into the simpset/claset when used in an Isar proof context. Context dependent components are maintained by the following theory operations: Simplifier.add_context_simprocs Simplifier.del_context_simprocs Simplifier.set_context_subgoaler Simplifier.reset_context_subgoaler Simplifier.add_context_looper Simplifier.del_context_looper Simplifier.add_context_unsafe_solver Simplifier.add_context_safe_solver Classical.add_context_safe_wrapper Classical.del_context_safe_wrapper Classical.add_context_unsafe_wrapper Classical.del_context_unsafe_wrapper IMPORTANT NOTE: proof tools (methods etc.) need to use local_simpset_of and local_claset_of to instead of the primitive Simplifier.get_local_simpset and Classical.get_local_claset, respectively, in order to see the context dependent fields!New in Isabelle2004 (April 2004)--------------------------------*** General **** Provers/order.ML: new efficient reasoner for partial and linear orders. Replaces linorder.ML.* Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler (\<a>...\<z>), are now considered normal letters, and can therefore be used anywhere where an ASCII letter (a...zA...Z) has until now. COMPATIBILITY: This obviously changes the parsing of some terms, especially where a symbol has been used as a binder, say '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed as an identifier. Fix it by inserting a space around former symbols. Call 'isatool fixgreek' to try to fix parsing errors in existing theory and ML files.* Pure: Macintosh and Windows line-breaks are now allowed in theory files.* Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now allowed in identifiers. Similar to Greek letters \<^isub> is now considered a normal (but invisible) letter. For multiple letter subscripts repeat \<^isub> like this: x\<^isub>1\<^isub>2.* Pure: There are now sub-/superscripts that can span more than one character. Text between \<^bsub> and \<^esub> is set in subscript in ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in superscript. The new control characters are not identifier parts.* Pure: Control-symbols of the form \<^raw:...> will literally print the content of "..." to the latex file instead of \isacntrl... . The "..." may consist of any printable characters excluding the end bracket >.* Pure: Using new Isar command "finalconsts" (or the ML functions Theory.add_finals or Theory.add_finals_i) it is now possible to declare constants "final", which prevents their being given a definition later. It is useful for constants whose behaviour is fixed axiomatically rather than definitionally, such as the meta-logic connectives.* Pure: 'instance' now handles general arities with general sorts (i.e. intersections of classes),* Presentation: generated HTML now uses a CSS style sheet to make layout (somewhat) independent of content. It is copied from lib/html/isabelle.css. It can be changed to alter the colors/layout of generated pages.*** Isar **** Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac, cut_tac, subgoal_tac and thin_tac: - Now understand static (Isar) contexts. As a consequence, users of Isar locales are no longer forced to write Isar proof scripts. For details see Isar Reference Manual, paragraph 4.3.2: Further tactic emulations. - INCOMPATIBILITY: names of variables to be instantiated may no longer be enclosed in quotes. Instead, precede variable name with `?'. This is consistent with the instantiation attribute "where".* Attributes "where" and "of": - Now take type variables of instantiated theorem into account when reading the instantiation string. This fixes a bug that caused instantiated theorems to have too special types in some circumstances. - "where" permits explicit instantiations of type variables.* Calculation commands "moreover" and "also" no longer interfere with current facts ("this"), admitting arbitrary combinations with "then" and derived forms.* Locales: - Goal statements involving the context element "includes" no longer generate theorems with internal delta predicates (those ending on "_axioms") in the premise. Resolve particular premise with <locale>.intro to obtain old form. - Fixed bug in type inference ("unify_frozen") that prevented mix of target specification and "includes" elements in goal statement. - Rule sets <locale>.intro and <locale>.axioms no longer declared as [intro?] and [elim?] (respectively) by default. - Experimental command for instantiation of locales in proof contexts: instantiate <label>[<attrs>]: <loc> Instantiates locale <loc> and adds all its theorems to the current context taking into account their attributes. Label and attrs are optional modifiers, like in theorem declarations. If present, names of instantiated theorems are qualified with <label>, and the attributes <attrs> are applied after any attributes these theorems might have already. If the locale has assumptions, a chained fact of the form "<loc> t1 ... tn" is expected from which instantiations of the parameters are derived. The command does not support old-style locales declared with "locale (open)". A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.* HOL: Tactic emulation methods induct_tac and case_tac understand static (Isar) contexts.*** HOL **** Proof import: new image HOL4 contains the imported library from the HOL4 system with about 2500 theorems. It is imported by replaying proof terms produced by HOL4 in Isabelle. The HOL4 image can be used like any other Isabelle image. See HOL/Import/HOL/README for more information.* Simplifier: - Much improved handling of linear and partial orders. Reasoners for linear and partial orders are set up for type classes "linorder" and "order" respectively, and are added to the default simpset as solvers. This means that the simplifier can build transitivity chains to solve goals from the assumptions. - INCOMPATIBILITY: old proofs break occasionally. Typically, applications of blast or auto after simplification become unnecessary because the goal is solved by simplification already.* Numerics: new theory Ring_and_Field contains over 250 basic numerical laws, all proved in axiomatic type classes for semirings, rings and fields.* Numerics: - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are now formalized using the Ring_and_Field theory mentioned above. - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently than before, because now they are set up once in a generic manner. - INCOMPATIBILITY: many type-specific arithmetic laws have gone. Look for the general versions in Ring_and_Field (and Power if they concern exponentiation).* Type "rat" of the rational numbers is now available in HOL-Complex.* Records: - Record types are now by default printed with their type abbreviation instead of the list of all field types. This can be configured via the reference "print_record_type_abbr". - Simproc "record_upd_simproc" for simplification of multiple updates added (not enabled by default). - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp. EX x. x = sel r to True (not enabled by default). - Tactic "record_split_simp_tac" to split and simplify records added.* 'specification' command added, allowing for definition by specification. There is also an 'ax_specification' command that introduces the new constants axiomatically.* arith(_tac) is now able to generate counterexamples for reals as well.* HOL-Algebra: new locale "ring" for non-commutative rings.* HOL-ex: InductiveInvariant_examples illustrates advanced recursive function definitions, thanks to Sava Krsti\'{c} and John Matthews.* HOL-Matrix: a first theory for matrices in HOL with an application of matrix theory to linear programming.* Unions and Intersections: The latex output syntax of UN and INT has been changed from "\Union x \in A. B" to "\Union_{x \in A} B" i.e. the index formulae has become a subscript. Similarly for "\Union x. B", and for \Inter instead of \Union.* Unions and Intersections over Intervals: There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A" like in normal math, and corresponding versions for < and for intersection.* HOL/List: Ordering "lexico" is renamed "lenlex" and the standard lexicographic dictonary ordering has been added as "lexord".* ML: the legacy theory structures Int and List have been removed. They had conflicted with ML Basis Library structures having the same names.* 'refute' command added to search for (finite) countermodels. Only works for a fragment of HOL. The installation of an external SAT solver is highly recommended. See "HOL/Refute.thy" for details.* 'quickcheck' command: Allows to find counterexamples by evaluating formulae under an assignment of free variables to random values. In contrast to 'refute', it can deal with inductive datatypes, but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy" for examples.*** HOLCF **** Streams now come with concatenation and are part of the HOLCF imageNew in Isabelle2003 (May 2003)------------------------------*** General **** Provers/simplifier: - Completely reimplemented method simp (ML: Asm_full_simp_tac): Assumptions are now subject to complete mutual simplification, not just from left to right. The simplifier now preserves the order of assumptions. Potential INCOMPATIBILITY: -- simp sometimes diverges where the old version did not, e.g. invoking simp on the goal [| P (f x); y = x; f x = f y |] ==> Q now gives rise to the infinite reduction sequence P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ... Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this kind of problem. -- Tactics combining classical reasoner and simplification (such as auto) are also affected by this change, because many of them rely on simp. They may sometimes diverge as well or yield a different numbers of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto in case of problems. Sometimes subsequent calls to the classical reasoner will fail because a preceeding call to the simplifier too eagerly simplified the goal, e.g. deleted redundant premises. - The simplifier trace now shows the names of the applied rewrite rules - You can limit the number of recursive invocations of the simplifier during conditional rewriting (where the simplifie tries to solve the conditions before applying the rewrite rule): ML "simp_depth_limit := n" where n is an integer. Thus you can force termination where previously the simplifier would diverge. - Accepts free variables as head terms in congruence rules. Useful in Isar. - No longer aborts on failed congruence proof. Instead, the congruence is ignored.* Pure: New generic framework for extracting programs from constructive proofs. See HOL/Extraction.thy for an example instantiation, as well as HOL/Extraction for some case studies.* Pure: The main goal of the proof state is no longer shown by default, onlythe subgoals. This behaviour is controlled by a new flag. PG menu: Isabelle/Isar -> Settings -> Show Main Goal(ML: Proof.show_main_goal).* Pure: You can find all matching introduction rules for subgoal 1, i.e. allrules whose conclusion matches subgoal 1: PG menu: Isabelle/Isar -> Show me -> matching rulesThe rules are ordered by how closely they match the subgoal.In particular, rules that solve a subgoal outright are displayed first(or rather last, the way they are printed).(ML: ProofGeneral.print_intros())* Pure: New flag trace_unify_fail causes unification to printdiagnostic information (PG: in trace buffer) when it fails. This isuseful for figuring out why single step proofs like rule, erule orassumption failed.* Pure: Locale specifications now produce predicate definitionsaccording to the body of text (covering assumptions modulo localdefinitions); predicate "loc_axioms" covers newly introduced text,while "loc" is cumulative wrt. all included locale expressions; thelatter view is presented only on export into the global theorycontext; potential INCOMPATIBILITY, use "(open)" option to fall backon the old view without predicates;* Pure: predefined locales "var" and "struct" are useful for sharingparameters (as in CASL, for example); just specify something like``var x + var y + struct M'' as import;* Pure: improved thms_containing: proper indexing of facts instead ofraw theorems; check validity of results wrt. current name space;include local facts of proof configuration (also covers activelocales), cover fixed variables in index; may use "_" in termspecification; an optional limit for the number of printed facts maybe given (the default is 40);* Pure: disallow duplicate fact bindings within new-style theory files(batch-mode only);* Provers: improved induct method: assumptions introduced by case"foo" are split into "foo.hyps" (from the rule) and "foo.prems" (fromthe goal statement); "foo" still refers to all facts collectively;* Provers: the function blast.overloaded has been removed: all constantsare regarded as potentially overloaded, which improves robustness in exchangefor slight decrease in efficiency;* Provers/linorder: New generic prover for transitivity reasoning overlinear orders. Note: this prover is not efficient!* Isar: preview of problems to finish 'show' now produce an errorrather than just a warning (in interactive mode);*** HOL **** arith(_tac) - Produces a counter example if it cannot prove a goal. Note that the counter example may be spurious if the goal is not a formula of quantifier-free linear arithmetic. In ProofGeneral the counter example appears in the trace buffer. - Knows about div k and mod k where k is a numeral of type nat or int. - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free linear arithmetic fails. This takes account of quantifiers and divisibility. Presburger arithmetic can also be called explicitly via presburger(_tac).* simp's arithmetic capabilities have been enhanced a bit: it nowtakes ~= in premises into account (by performing a case split);* simp reduces "m*(n div m) + n mod m" to n, even if the two summandsare distributed over a sum of terms;* New tactic "trans_tac" and method "trans" instantiateProvers/linorder.ML for axclasses "order" and "linorder" (predicates"<=", "<" and "=").* function INCOMPATIBILITIES: Pi-sets have been redefined and moved from mainHOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";* 'typedef' command has new option "open" to suppress the setdefinition;* functions Min and Max on finite sets have been introduced (theoryFinite_Set);* attribute [symmetric] now works for relations as well; it turns(x,y) : R^-1 into (y,x) : R, and vice versa;* induct over a !!-quantified statement (say !!x1..xn): each "case" automatically performs "fix x1 .. xn" with exactly those names.* Map: `empty' is no longer a constant but a syntactic abbreviation for%x. None. Warning: empty_def now refers to the previously hidden definitionof the empty set.* Algebra: formalization of classical algebra. Intended as base forany algebraic development in Isabelle. Currently covers group theory(up to Sylow's theorem) and ring theory (Universal Property ofUnivariate Polynomials). Contributions welcome;* GroupTheory: deleted, since its material has been moved to Algebra;* Complex: new directory of the complex numbers with numeric constants,nonstandard complex numbers, and some complex analysis, standard andnonstandard (Jacques Fleuriot);* HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;* Hyperreal: introduced Gauge integration and hyperreal logarithms (JacquesFleuriot);* Real/HahnBanach: updated and adapted to locales;* NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,Gray and Kramer);* UNITY: added the Meier-Sanders theory of progress sets;* MicroJava: bytecode verifier and lightweight bytecode verifieras abstract algorithms, instantiated to the JVM;* Bali: Java source language formalization. Type system, operationalsemantics, axiomatic semantics. Supported language features:classes, interfaces, objects,virtual methods, static methods,static/instance fields, arrays, access modifiers, definiteassignment, exceptions.*** ZF **** ZF/Constructible: consistency proof for AC (Gdel's constructibleuniverse, etc.);* Main ZF: virtually all theories converted to new-style format;*** ML **** Pure: Tactic.prove provides sane interface for internal proofs;omits the infamous "standard" operation, so this is more appropriatethan prove_goalw_cterm in many situations (e.g. in simprocs);* Pure: improved error reporting of simprocs;* Provers: Simplifier.simproc(_i) provides sane interface for settingup simprocs;*** Document preparation **** uses \par instead of \\ for line breaks in theory text. This mayshift some page breaks in large documents. To get the old behaviouruse \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.* minimized dependencies of isabelle.sty and isabellesym.sty onother packages* \<euro> now needs package babel/greek instead of marvosym (whichbroke \Rightarrow)* normal size for \<zero>...\<nine> (uses \mathbf instead oftextcomp package)New in Isabelle2002 (March 2002)--------------------------------*** Document preparation **** greatly simplified document preparation setup, including moregraceful interpretation of isatool usedir -i/-d/-D options, and moreinstructive isatool mkdir; users should basically be able to getstarted with "isatool mkdir HOL Test && isatool make"; alternatively,users may run a separate document processing stage manually like this:"isatool usedir -D output HOL Test && isatool document Test/output";* theory dependency graph may now be incorporated into documents;isatool usedir -g true will produce session_graph.eps/.pdf for usewith \includegraphics of LaTeX;* proper spacing of consecutive markup elements, especially textblocks after section headings;* support bold style (for single symbols only), input syntax is likethis: "\<^bold>\<alpha>" or "\<^bold>A";* \<bullet> is now output as bold \cdot by default, which looks muchbetter in printed text;* added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;note that these symbols are currently unavailable in Proof General /X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;* isatool latex no longer depends on changed TEXINPUTS, insteadisatool document copies the Isabelle style files to the targetlocation;*** Isar **** Pure/Provers: improved proof by cases and induction; - 'case' command admits impromptu naming of parameters (such as "case (Suc n)"); - 'induct' method divinates rule instantiation from the inductive claim; no longer requires excessive ?P bindings for proper instantiation of cases; - 'induct' method properly enumerates all possibilities of set/type rules; as a consequence facts may be also passed through *type* rules without further ado; - 'induct' method now derives symbolic cases from the *rulified* rule (before it used to rulify cases stemming from the internal atomized version); this means that the context of a non-atomic statement becomes is included in the hypothesis, avoiding the slightly cumbersome show "PROP ?case" form; - 'induct' may now use elim-style induction rules without chaining facts, using ``missing'' premises from the goal state; this allows rules stemming from inductive sets to be applied in unstructured scripts, while still benefitting from proper handling of non-atomic statements; NB: major inductive premises need to be put first, all the rest of the goal is passed through the induction; - 'induct' proper support for mutual induction involving non-atomic rule statements (uses the new concept of simultaneous goals, see below); - append all possible rule selections, but only use the first success (no backtracking); - removed obsolete "(simplified)" and "(stripped)" options of methods; - undeclared rule case names default to numbers 1, 2, 3, ...; - added 'print_induct_rules' (covered by help item in recent Proof General versions); - moved induct/cases attributes to Pure, methods to Provers; - generic method setup instantiated for FOL and HOL;* Pure: support multiple simultaneous goal statements, for example"have a: A and b: B" (same for 'theorem' etc.); being a puremeta-level mechanism, this acts as if several individual goals hadbeen stated separately; in particular common proof methods need to berepeated in order to cover all claims; note that a single eliminationstep is *not* sufficient to establish the two conjunctions, so thisfails: assume "A & B" then have A and B .. (*".." fails*)better use "obtain" in situations as above; alternative refer tomulti-step methods like 'auto', 'simp_all', 'blast+' etc.;* Pure: proper integration with ``locales''; unlike the originalversion by Florian Kammller, Isar locales package high-level proofcontexts rather than raw logical ones (e.g. we admit to includeattributes everywhere); operations on locales include merge andrename; support for implicit arguments (``structures''); simultaneoustype-inference over imports and text; see also HOL/ex/Locales.thy forsome examples;* Pure: the following commands have been ``localized'', supporting atarget locale specification "(in name)": 'lemma', 'theorem','corollary', 'lemmas', 'theorems', 'declare'; the results will bestored both within the locale and at the theory level (exported andqualified by the locale name);* Pure: theory goals may now be specified in ``long'' form, withad-hoc contexts consisting of arbitrary locale elements. for example``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax anddefinitions may be given, too); the result is a meta-level rule withthe context elements being discharged in the obvious way;* Pure: new proof command 'using' allows to augment currently usedfacts after a goal statement ('using' is syntactically analogous to'apply', but acts on the goal's facts only); this allows chained factsto be separated into parts given before and after a claim, as in``from a and b have C using d and e <proof>'';* Pure: renamed "antecedent" case to "rule_context";* Pure: new 'judgment' command records explicit information about theobject-logic embedding (used by several tools internally); no longeruse hard-wired "Trueprop";* Pure: added 'corollary' command;* Pure: fixed 'token_translation' command;* Pure: removed obsolete 'exported' attribute;* Pure: dummy pattern "_" in is/let is now automatically lifted overbound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");* Pure: method 'atomize' presents local goal premises as object-levelstatements (atomic meta-level propositions); setup controlled viarewrite rules declarations of 'atomize' attribute; exampleapplication: 'induct' method with proper rule statements in improperproof *scripts*;* Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)now consider the syntactic context of assumptions, giving a betterchance to get type-inference of the arguments right (this isespecially important for locales);* Pure: "sorry" no longer requires quick_and_dirty in interactivemode;* Pure/obtain: the formal conclusion "thesis", being marked as``internal'', may no longer be reference directly in the text;potential INCOMPATIBILITY, may need to use "?thesis" in raresituations;* Pure: generic 'sym' attribute which declares a rule both as pure'elim?' and for the 'symmetric' operation;* Pure: marginal comments ``--'' may now occur just anywhere in thetext; the fixed correlation with particular command syntax has beendiscontinued;* Pure: new method 'rules' is particularly well-suited for proofsearch in intuitionistic logic; a bit slower than 'blast' or 'fast',but often produces more compact proof terms with less detours;* Pure/Provers/classical: simplified integration with pure ruleattributes and methods; the classical "intro?/elim?/dest?"declarations coincide with the pure ones; the "rule" method no longerincludes classically swapped intros; "intro" and "elim" methods nolonger pick rules from the context; also got rid of ML declarationsAddXIs/AddXEs/AddXDs; all of this has some potential forINCOMPATIBILITY;* Provers/classical: attribute 'swapped' produces classical inversionsof introduction rules;* Provers/simplifier: 'simplified' attribute may refer to explicitrules instead of full simplifier context; 'iff' attribute handlesconditional rules;* HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;* HOL: 'recdef' now fails on unfinished automated proofs, use"(permissive)" option to recover old behavior;* HOL: 'inductive' no longer features separate (collective) attributesfor 'intros' (was found too confusing);* HOL: properly declared induction rules less_induct andwf_induct_rule;*** HOL **** HOL: moved over to sane numeral syntax; the new policy is asfollows: - 0 and 1 are polymorphic constants, which are defined on any numeric type (nat, int, real etc.); - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based binary representation internally; - type nat has special constructor Suc, and generally prefers Suc 0 over 1::nat and Suc (Suc 0) over 2::nat;This change may cause significant problems of INCOMPATIBILITY; hereare some hints on converting existing sources: - due to the new "num" token, "-0" and "-1" etc. are now atomic entities, so expressions involving "-" (unary or binary minus) need to be spaced properly; - existing occurrences of "1" may need to be constraint "1::nat" or even replaced by Suc 0; similar for old "2"; - replace "#nnn" by "nnn", and "#-nnn" by "-nnn"; - remove all special provisions on numerals in proofs;* HOL: simp rules nat_number expand numerals on nat to Suc/0representation (depends on bin_arith_simps in the default context);* HOL: symbolic syntax for x^2 (numeral 2);* HOL: the class of all HOL types is now called "type" rather than"term"; INCOMPATIBILITY, need to adapt references to this type classin axclass/classes, instance/arities, and (usually rare) occurrencesin typings (of consts etc.); internally the class is called"HOL.type", ML programs should refer to HOLogic.typeS;* HOL/record package improvements: - new derived operations "fields" to build a partial record section, "extend" to promote a fixed record to a record scheme, and "truncate" for the reverse; cf. theorems "xxx.defs", which are *not* declared as simp by default; - shared operations ("more", "fields", etc.) now need to be always qualified) --- potential INCOMPATIBILITY; - removed "make_scheme" operations (use "make" with "extend") -- INCOMPATIBILITY; - removed "more" class (simply use "term") -- INCOMPATIBILITY; - provides cases/induct rules for use with corresponding Isar methods (for concrete records, record schemes, concrete more parts, and schematic more parts -- in that order); - internal definitions directly based on a light-weight abstract theory of product types over typedef rather than datatype;* HOL: generic code generator for generating executable ML code fromspecifications; specific support for HOL constructs such as inductivedatatypes and sets, as well as recursive functions; can be invokedvia 'generate_code' theory section;* HOL: canonical cases/induct rules for n-tuples (n = 3..7);* HOL: consolidated and renamed several theories. In particular: Ord.thy has been absorbed into HOL.thy String.thy has been absorbed into List.thy* HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"(beware of argument permutation!);* HOL: linorder_less_split superseded by linorder_cases;* HOL/List: "nodups" renamed to "distinct";* HOL: added "The" definite description operator; move Hilbert's "Eps"to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES: - Ex_def has changed, now need to use some_eq_ex* HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, soin this (rare) case use: delSWrapper "split_all_tac" addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)* HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFSMAY FAIL;* HOL: introduced f^n = f o ... o f; warning: due to the limits ofIsabelle's type classes, ^ on functions and relations has too generala domain, namely ('a * 'b) set and 'a => 'b; this means that it may benecessary to attach explicit type constraints;* HOL/Relation: the prefix name of the infix "O" has been changed from"comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have beenrenamed accordingly (eg "compI" -> "rel_compI").* HOL: syntax translations now work properly with numerals and recordsexpressions;* HOL: bounded abstraction now uses syntax "%" / "\<lambda>" insteadof "lam" -- INCOMPATIBILITY;* HOL: got rid of some global declarations (potential INCOMPATIBILITYfor ML tools): const "()" renamed "Product_Type.Unity", type "unit"renamed "Product_Type.unit";* HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl* HOL: removed obsolete theorem "optionE" (use "option.exhaust", orthe "cases" method);* HOL/GroupTheory: group theory examples including Sylow's theorem (byFlorian Kammller);* HOL/IMP: updated and converted to new-style theory format; severalparts turned into readable document, with proper Isar proof texts andsome explanations (by Gerwin Klein);* HOL-Real: added Complex_Numbers (by Gertrud Bauer);* HOL-Hyperreal is now a logic image;*** HOLCF **** Isar: consts/constdefs supports mixfix syntax for continuousoperations;* Isar: domain package adapted to new-style theory format, e.g. seeHOLCF/ex/Dnat.thy;* theory Lift: proper use of rep_datatype lift instead of ML hacks --potential INCOMPATIBILITY; now use plain induct_tac instead of formerlift.induct_tac, always use UU instead of Undef;* HOLCF/IMP: updated and converted to new-style theory;*** ZF **** Isar: proper integration of logic-specific tools and packages,including theory commands '(co)inductive', '(co)datatype','rep_datatype', 'inductive_cases', as well as methods 'ind_cases','induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');* theory Main no longer includes AC; for the Axiom of Choice, baseyour theory on Main_ZFC;* the integer library now covers quotients and remainders, with manylaws relating division to addition, multiplication, etc.;* ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving atypeless version of the formalism;* ZF/AC, Coind, IMP, Resid: updated and converted to new-style theoryformat;* ZF/Induct: new directory for examples of inductive definitions,including theory Multiset for multiset orderings; converted tonew-style theory format;* ZF: many new theorems about lists, ordinals, etc.;*** General **** Pure/kernel: meta-level proof terms (by Stefan Berghofer); referencevariable proof controls level of detail: 0 = no proofs (only oracledependencies), 1 = lemma dependencies, 2 = compact proof terms; seealso ref manual for further ML interfaces;* Pure/axclass: removed obsolete ML interfacegoal_subclass/goal_arity;* Pure/syntax: new token syntax "num" for plain numerals (without "#"of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are nowseparate tokens, so expressions involving minus need to be spacedproperly;* Pure/syntax: support non-oriented infixes, using keyword "infix"rather than "infixl" or "infixr";* Pure/syntax: concrete syntax for dummy type variables admits genuinesort constraint specifications in type inference; e.g. "x::_::foo"ensures that the type of "x" is of sort "foo" (but not necessarily atype variable);* Pure/syntax: print modes "type_brackets" and "no_type_brackets"control output of nested => (types); the default behavior is"type_brackets";* Pure/syntax: builtin parse translation for "_constify" turns valuedtokens into AST constants;* Pure/syntax: prefer later declarations of translations and printtranslation functions; potential INCOMPATIBILITY: need to reversemultiple declarations for same syntax element constant;* Pure/show_hyps reset by default (in accordance to existing Isarpractice);* Provers/classical: renamed addaltern to addafter, addSaltern toaddSafter;* Provers/clasimp: ``iff'' declarations now handle conditional rulesas well;* system: tested support for MacOS X; should be able to get Isabelle +Proof General to work in a plain Terminal after installing Poly/ML(e.g. from the Isabelle distribution area) and GNU bash alone(e.g. from http://www.apple.com); full X11, XEmacs and X-Symbolsupport requires further installations, e.g. fromhttp://fink.sourceforge.net/);* system: support Poly/ML 4.1.1 (able to manage larger heaps);* system: reduced base memory usage by Poly/ML (approx. 20 MB insteadof 40 MB), cf. ML_OPTIONS;* system: Proof General keywords specification is now part of theIsabelle distribution (see etc/isar-keywords.el);* system: support for persistent Proof General sessions (refrain fromoutdating all loaded theories on startup); user may create writablelogic images like this: ``isabelle -q HOL Test'';* system: smart selection of Isabelle process versus Isabelleinterface, accommodates case-insensitive file systems (e.g. HFS+); mayrun both "isabelle" and "Isabelle" even if file names are badlydamaged (executable inspects the case of the first letter of its ownname); added separate "isabelle-process" and "isabelle-interface";* system: refrain from any attempt at filtering input streams; nolonger support ``8bit'' encoding of old isabelle font, instead properiso-latin characters may now be used; the related isatools"symbolinput" and "nonascii" have disappeared as well;* system: removed old "xterm" interface (the print modes "xterm" and"xterm_color" are still available for direct use in a suitableterminal);New in Isabelle99-2 (February 2001)-----------------------------------*** Overview of INCOMPATIBILITIES **** HOL: please note that theories in the Library and elsewhere often use thenew-style (Isar) format; to refer to their theorems in an ML script you mustbind them to ML identifers by e.g. val thm_name = thm "thm_name";* HOL: inductive package no longer splits induction rule aggressively,but only as far as specified by the introductions given; the oldformat may be recovered via ML function complete_split_rule or attribute'split_rule (complete)';* HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,gfp_Tarski to gfp_unfold;* HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;* HOL: infix "dvd" now has priority 50 rather than 70 (because it is arelation); infix "^^" has been renamed "``"; infix "``" has beenrenamed "`"; "univalent" has been renamed "single_valued";* HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"operation;* HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;* Isar: 'obtain' no longer declares "that" fact as simp/intro;* Isar/HOL: method 'induct' now handles non-atomic goals; as aconsequence, it is no longer monotonic wrt. the local goal context(which is now passed through the inductive cases);* Document preparation: renamed standard symbols \<ll> to \<lless> and\<gg> to \<ggreater>;*** Document preparation **** \isabellestyle{NAME} selects version of Isabelle output (currentlyavailable: are "it" for near math-mode best-style output, "sl" forslanted text style, and "tt" for plain type-writer; if no\isabellestyle command is given, output is according to slantedtype-writer);* support sub/super scripts (for single symbols only), input syntax islike this: "A\<^sup>*" or "A\<^sup>\<star>";* some more standard symbols; see Appendix A of the system manual forthe complete list of symbols defined in isabellesym.sty;* improved isabelle style files; more abstract symbol implementation(should now use \isamath{...} and \isatext{...} in custom symboldefinitions);* antiquotation @{goals} and @{subgoals} for output of *dynamic* goalsstate; Note that presentation of goal states does not conform toactual human-readable proof documents. Please do not include goalstates into document output unless you really know what you are doing!* proper indentation of antiquoted output with proportional LaTeXfonts;* no_document ML operator temporarily disables LaTeX documentgeneration;* isatool unsymbolize tunes sources for plain ASCII communication;*** Isar **** Pure: Isar now suffers initial goal statements to contain unboundschematic variables (this does not conform to actual readable proofdocuments, due to unpredictable outcome and non-compositional proofchecking); users who know what they are doing may use schematic goalsfor Prolog-style synthesis of proven results;* Pure: assumption method (an implicit finishing) now handles actualrules as well;* Pure: improved 'obtain' --- moved to Pure, insert "that" intoinitial goal, declare "that" only as Pure intro (only for singlesteps); the "that" rule assumption may now be involved in implicitfinishing, thus ".." becomes a feasible for trivial obtains;* Pure: default proof step now includes 'intro_classes'; thus trivialinstance proofs may be performed by "..";* Pure: ?thesis / ?this / "..." now work for pure meta-levelstatements as well;* Pure: more robust selection of calculational rules;* Pure: the builtin notion of 'finished' goal now includes the ==-reflrule (as well as the assumption rule);* Pure: 'thm_deps' command visualizes dependencies of theorems andlemmas, using the graph browser tool;* Pure: predict failure of "show" in interactive mode;* Pure: 'thms_containing' now takes actual terms as arguments;* HOL: improved method 'induct' --- now handles non-atomic goals(potential INCOMPATIBILITY); tuned error handling;* HOL: cases and induct rules now provide explicit hints about thenumber of facts to be consumed (0 for "type" and 1 for "set" rules);any remaining facts are inserted into the goal verbatim;* HOL: local contexts (aka cases) may now contain term bindings aswell; the 'cases' and 'induct' methods new provide a ?case binding forthe result to be shown in each case;* HOL: added 'recdef_tc' command;* isatool convert assists in eliminating legacy ML scripts;*** HOL **** HOL/Library: a collection of generic theories to be used togetherwith main HOL; the theory loader path already includes this directoryby default; the following existing theories have been moved here:HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While(as While_Combinator), HOL/Lex/Prefix (as List_Prefix);* HOL/Unix: "Some aspects of Unix file-system security", a typicalmodelling and verification task performed in Isabelle/HOL +Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).* HOL/Algebra: special summation operator SUM no longer exists, it hasbeen replaced by setsum; infix 'assoc' now has priority 50 (like'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to'domain', this makes the theory consistent with mathematicalliterature;* HOL basics: added overloaded operations "inverse" and "divide"(infix "/"), syntax for generic "abs" operation, generic summationoperator \<Sum>;* HOL/typedef: simplified package, provide more useful rules (see alsoHOL/subset.thy);* HOL/datatype: induction rule for arbitrarily branching datatypes isnow expressed as a proper nested rule (old-style tactic scripts mayrequire atomize_strip_tac to cope with non-atomic premises);* HOL: renamed theory "Prod" to "Product_Type", renamed "split" ruleto "split_conv" (old name still available for compatibility);* HOL: improved concrete syntax for strings (e.g. allows translationrules with string literals);* HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals and Fleuriot's mechanization of analysis, including the transcendental functions for the reals;* HOL/Real, HOL/Hyperreal: improved arithmetic simplification;*** CTT **** CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that"lam" is displayed as TWO lambda-symbols* CTT: theory Main now available, containing everything (that is, Booland Arith);*** General **** Pure: the Simplifier has been implemented properly as a derived ruleoutside of the actual kernel (at last!); the overall performancepenalty in practical applications is about 50%, while reliability ofthe Isabelle inference kernel has been greatly improved;* print modes "brackets" and "no_brackets" control output of nested =>(types) and ==> (props); the default behaviour is "brackets";* Provers: fast_tac (and friends) now handle actual object-logic rulesas assumptions as well;* system: support Poly/ML 4.0;* system: isatool install handles KDE version 1 or 2;New in Isabelle99-1 (October 2000)----------------------------------*** Overview of INCOMPATIBILITIES **** HOL: simplification of natural numbers is much changed; to partlyrecover the old behaviour (e.g. to prevent n+n rewriting to #2*n)issue the following ML commands: Delsimprocs Nat_Numeral_Simprocs.cancel_numerals; Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];* HOL: simplification no longer dives into case-expressions; this iscontrolled by "t.weak_case_cong" for each datatype t;* HOL: nat_less_induct renamed to less_induct;* HOL: systematic renaming of the SOME (Eps) rules, may use isatoolfixsome to patch .thy and .ML sources automatically; select_equality -> some_equality select_eq_Ex -> some_eq_ex selectI2EX -> someI2_ex selectI2 -> someI2 selectI -> someI select1_equality -> some1_equality Eps_sym_eq -> some_sym_eq_trivial Eps_eq -> some_eq_trivial* HOL: exhaust_tac on datatypes superceded by new generic case_tac;* HOL: removed obsolete theorem binding expand_if (refer to split_ifinstead);* HOL: the recursion equations generated by 'recdef' are now calledf.simps instead of f.rules;* HOL: qed_spec_mp now also handles bounded ALL as well;* HOL: 0 is now overloaded, so the type constraint ":: nat" maysometimes be needed;* HOL: the constant for "f``x" is now "image" rather than "op ``";* HOL: the constant for "f-``x" is now "vimage" rather than "op -``";* HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesianproduct is now "<*>" instead of "Times"; the lexicographic product isnow "<*lex*>" instead of "**";* HOL: theory Sexp is now in HOL/Induct examples (it used to be partof main HOL, but was unused); better use HOL's datatype package;* HOL: removed "symbols" syntax for constant "override" of theory Map;the old syntax may be recovered as follows: syntax (symbols) override :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)" (infixl "\\<oplus>" 100)* HOL/Real: "rabs" replaced by overloaded "abs" function;* HOL/ML: even fewer consts are declared as global (see theories Ord,Lfp, Gfp, WF); this only affects ML packages that refer to const namesinternally;* HOL and ZF: syntax for quotienting wrt an equivalence relationchanged from A/r to A//r;* ZF: new treatment of arithmetic (nat & int) may break some oldproofs;* Isar: renamed some attributes (RS -> THEN, simplify -> simplified,rulify -> rule_format, elimify -> elim_format, ...);* Isar/Provers: intro/elim/dest attributes changed; renamedintro/intro!/intro!! flags to intro!/intro/intro? (in most cases, oneshould have to change intro!! to intro? only); replaced "delrule" by"rule del";* Isar/HOL: renamed "intrs" to "intros" in inductive definitions;* Provers: strengthened force_tac by using new first_best_tac;* LaTeX document preparation: several changes of isabelle.sty (seelib/texinputs);*** Document preparation **** formal comments (text blocks etc.) in new-style theories may nowcontain antiquotations of thm/prop/term/typ/text to be presentedaccording to latex print mode; concrete syntax is like this:@{term[show_types] "f(x) = a + x"};* isatool mkdir provides easy setup of Isabelle session directories,including proper document sources;* generated LaTeX sources are now deleted after successful run(isatool document -c); may retain a copy somewhere else via -D optionof isatool usedir;* isatool usedir -D now lets isatool latex -o sty update the Isabellestyle files, achieving self-contained LaTeX sources and simplifyingLaTeX debugging;* old-style theories now produce (crude) LaTeX output as well;* browser info session directories are now self-contained (may be puton WWW server seperately); improved graphs of nested sessions; removedgraph for 'all sessions';* several improvements in isabelle style files; \isabellestyle{it}produces fake math mode output; \isamarkupheader is now \section bydefault; see lib/texinputs/isabelle.sty etc.;*** Isar **** Isar/Pure: local results and corresponding term bindings are nowsubject to Hindley-Milner polymorphism (similar to ML); thisaccommodates incremental type-inference very nicely;* Isar/Pure: new derived language element 'obtain' supportsgeneralized existence reasoning;* Isar/Pure: new calculational elements 'moreover' and 'ultimately'support accumulation of results, without applying any rules yet;useful to collect intermediate results without explicit namereferences, and for use with transitivity rules with more than 2premises;* Isar/Pure: scalable support for case-analysis type proofs: new'case' language element refers to local contexts symbolically, asproduced by certain proof methods; internally, case names are attachedto theorems as "tags";* Isar/Pure: theory command 'hide' removes declarations fromclass/type/const name spaces;* Isar/Pure: theory command 'defs' supports option "(overloaded)" toindicate potential overloading;* Isar/Pure: changed syntax of local blocks from {{ }} to { };* Isar/Pure: syntax of sorts made 'inner', i.e. have to write"{a,b,c}" instead of {a,b,c};* Isar/Pure now provides its own version of intro/elim/destattributes; useful for building new logics, but beware of confusionwith the version in Provers/classical;* Isar/Pure: the local context of (non-atomic) goals is provided viacase name 'antecedent';* Isar/Pure: removed obsolete 'transfer' attribute (transfer of thmsto the current context is now done automatically);* Isar/Pure: theory command 'method_setup' provides a simple interfacefor definining proof methods in ML;* Isar/Provers: intro/elim/dest attributes changed; renamedintro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, inmost cases, one should have to change intro!! to intro? only);replaced "delrule" by "rule del";* Isar/Provers: new 'hypsubst' method, plain 'subst' method and'symmetric' attribute (the latter supercedes [RS sym]);* Isar/Provers: splitter support (via 'split' attribute and 'simp'method modifier); 'simp' method: 'only:' modifier removes loopers aswell (including splits);* Isar/Provers: Simplifier and Classical methods now support all kindof modifiers used in the past, including 'cong', 'iff', etc.* Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combinationof Simplifier and Classical reasoner);* Isar/HOL: new proof method 'cases' and improved version of 'induct'now support named cases; major packages (inductive, datatype, primrec,recdef) support case names and properly name parameters;* Isar/HOL: new transitivity rules for substitution in inequalities --monotonicity conditions are extracted to be proven at end ofcalculations;* Isar/HOL: removed 'case_split' thm binding, should use 'cases' proofmethod anyway;* Isar/HOL: removed old expand_if = split_if; theorems if_splits =split_if split_if_asm; datatype package provides theorems foo.splits =foo.split foo.split_asm for each datatype;* Isar/HOL: tuned inductive package, rename "intrs" to "intros"(potential INCOMPATIBILITY), emulation of mk_cases feature for proofscripts: new 'inductive_cases' command and 'ind_cases' method; (Note:use "(cases (simplified))" method in proper proof texts);* Isar/HOL: added global 'arith_split' attribute for 'arith' method;* Isar: names of theorems etc. may be natural numbers as well;* Isar: 'pr' command: optional arguments for goals_limit andProofContext.prems_limit; no longer prints theory contexts, but onlyproof states;* Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admitadditional print modes to be specified; e.g. "pr(latex)" will printproof state according to the Isabelle LaTeX style;* Isar: improved support for emulating tactic scripts, including proofmethods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac','rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'(for HOL datatypes);* Isar: simplified (more robust) goal selection of proof methods: 1stgoal, all goals, or explicit goal specifier (tactic emulation); thus'proof method scripts' have to be in depth-first order;* Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';* Isar: removed 'help' command, which hasn't been too helpful anyway;should instead use individual commands for printing items(print_commands, print_methods etc.);* Isar: added 'nothing' --- the empty list of theorems;*** HOL **** HOL/MicroJava: formalization of a fragment of Java, together with acorresponding virtual machine and a specification of its bytecodeverifier and a lightweight bytecode verifier, including proofs oftype-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, andCornelia Pusch (see also the homepage of project Bali athttp://isabelle.in.tum.de/Bali/);* HOL/Algebra: new theory of rings and univariate polynomials, byClemens Ballarin;* HOL/NumberTheory: fundamental Theorem of Arithmetic, ChineseRemainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas MRasmussen;* HOL/Lattice: fundamental concepts of lattice theory and orderstructures, including duals, properties of bounds versus algebraiclaws, lattice operations versus set-theoretic ones, the Knaster-TarskiTheorem for complete lattices etc.; may also serve as a demonstrationfor abstract algebraic reasoning using axiomatic type classes, andmathematics-style proof in Isabelle/Isar; by Markus Wenzel;* HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by Davidvon Oheimb;* HOL/IMPP: extension of IMP with local variables and mutuallyrecursive procedures, by David von Oheimb;* HOL/Lambda: converted into new-style theory and document;* HOL/ex/Multiquote: example of multiple nested quotations andanti-quotations -- basically a generalized version of de-Bruijnrepresentation; very useful in avoiding lifting of operations;* HOL/record: added general record equality rule to simpset; fixedselect-update simplification procedure to handle extended records aswell; admit "r" as field name;* HOL: 0 is now overloaded over the new sort "zero", allowing its use withother numeric types and also as the identity of groups, rings, etc.;* HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.Types nat and int belong to this axclass;* HOL: greatly improved simplification involving numerals of type nat, int, real: (i + #8 + j) = Suc k simplifies to #7 + (i + j) = k i*j + k + j*#3*i simplifies to #4*(i*j) + k two terms #m*u and #n*u are replaced by #(m+n)*u (where #m, #n and u can implicitly be 1; this is simproc combine_numerals) and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);* HOL: meson_tac is available (previously in ex/meson.ML); it is apowerful prover for predicate logic but knows nothing of clasets; seeex/mesontest.ML and ex/mesontest2.ML for example applications;* HOL: new version of "case_tac" subsumes both boolean case split and"exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longerexists, may define val exhaust_tac = case_tac for ad-hoc portability;* HOL: simplification no longer dives into case-expressions: only theselector expression is simplified, but not the remaining arms; toenable full simplification of case-expressions for datatype t, you mayremove t.weak_case_cong from the simpset, either globally (Delcongs[thm"t.weak_case_cong"];) or locally (delcongs [...]).* HOL/recdef: the recursion equations generated by 'recdef' forfunction 'f' are now called f.simps instead of f.rules; if alltermination conditions are proved automatically, these simplificationrules are added to the simpset, as in primrec; rules may be namedindividually as well, resulting in a separate list of theorems foreach equation;* HOL/While is a new theory that provides a while-combinator. Itpermits the definition of tail-recursive functions without theprovision of a termination measure. The latter is necessary once theinvariant proof rule for while is applied.* HOL: new (overloaded) notation for the set of elements below/abovesome element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.* HOL: theorems impI, allI, ballI bound as "strip";* HOL: new tactic induct_thm_tac: thm -> string -> int -> tacticinduct_tac th "x1 ... xn" expects th to have a conclusion of the formP v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;* HOL/Real: "rabs" replaced by overloaded "abs" function;* HOL: theory Sexp now in HOL/Induct examples (it used to be part ofmain HOL, but was unused);* HOL: fewer consts declared as global (e.g. have to refer to"Lfp.lfp" instead of "lfp" internally; affects ML packages only);* HOL: tuned AST representation of nested pairs, avoiding bogus outputin case of overlap with user translations (e.g. judgements overtuples); (note that the underlying logical represenation is stillbogus);*** ZF **** ZF: simplification automatically cancels common terms in arithmeticexpressions over nat and int;* ZF: new treatment of nat to minimize type-checking: all operatorscoerce their operands to a natural number using the function natify,making the algebraic laws unconditional;* ZF: as above, for int: operators coerce their operands to an integerusing the function intify;* ZF: the integer library now contains many of the usual laws for theorderings, including $<=, and monotonicity laws for $+ and $*;* ZF: new example ZF/ex/NatSum to demonstrate integer arithmeticsimplification;* FOL and ZF: AddIffs now available, giving theorems of the form P<->Qto the simplifier and classical reasoner simultaneously;*** General **** Provers: blast_tac now handles actual object-logic rules asassumptions; note that auto_tac uses blast_tac internally as well;* Provers: new functions rulify/rulify_no_asm: thm -> thm for turningouter -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;* Provers: delrules now handles destruct rules as well (no longer needexplicit make_elim);* Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g. [| inj ?f; ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?Wuse instead the strong form, [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?Win HOL, FOL and ZF the function cla_make_elim will create such rulesfrom destruct-rules;* Provers: Simplifier.easy_setup provides a fast path to basicSimplifier setup for new object-logics;* Pure: AST translation rules no longer require constant head on LHS;* Pure: improved name spaces: ambiguous output is qualified; supportfor hiding of names;* system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, andXSYMBOL_HOME; no longer need to do manual configuration in mostsituations;* system: compression of ML heaps images may now be controlled via -coption of isabelle and isatool usedir (currently only observed byPoly/ML);* system: isatool installfonts may handle X-Symbol fonts as well (veryuseful for remote X11);* system: provide TAGS file for Isabelle sources;* ML: infix 'OF' is a version of 'MRS' with more appropriate argumentorder;* ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; globaltiming flag supersedes proof_timing and Toplevel.trace;* ML: new combinators |>> and |>>> for incremental transformationswith secondary results (e.g. certain theory extensions):* ML: PureThy.add_defs gets additional argument to indicate potentialoverloading (usually false);* ML: PureThy.add_thms/add_axioms/add_defs now return theorems asresults;New in Isabelle99 (October 1999)--------------------------------*** Overview of INCOMPATIBILITIES (see below for more details) **** HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)are no longer simplified. (This allows the simplifier to unfold recursivefunctional programs.) To restore the old behaviour, declare Delcongs [if_weak_cong];* HOL: Removed the obsolete syntax "Compl A"; use -A for setcomplement;* HOL: the predicate "inj" is now defined by translation to "inj_on";* HOL/datatype: mutual_induct_tac no longer exists -- use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]* HOL/typedef: fixed type inference for representing set; typearguments now have to occur explicitly on the rhs as type constraints;* ZF: The con_defs part of an inductive definition may no longer referto constants declared in the same theory;* HOL, ZF: the function mk_cases, generated by the inductivedefinition package, has lost an argument. To simplify its result, ituses the default simpset instead of a supplied list of theorems.* HOL/List: the constructors of type list are now Nil and Cons;* Simplifier: the type of the infix ML functions setSSolver addSSolver setSolver addSolveris now simpset * solver -> simpset where `solver' is a new abstract typefor packaging solvers. A solver is created via mk_solver: string -> (thm list -> int -> tactic) -> solverwhere the string argument is only a comment.*** Proof tools **** Provers/Arith/fast_lin_arith.ML contains a functor for creating adecision procedure for linear arithmetic. Currently it is used fortypes `nat', `int', and `real' in HOL (see below); it can, should andwill be instantiated for other types and logics as well.* The simplifier now accepts rewrite rules with flexible heads, eg hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y They are applied like any rule with a non-pattern lhs, i.e. by first-order matching.*** General **** New Isabelle/Isar subsystem provides an alternative to traditionaltactical theorem proving; together with the ProofGeneral/isar userinterface it offers an interactive environment for developing humanreadable proof documents (Isar == Intelligible semi-automatedreasoning); for further information see isatool doc isar-ref,src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/* improved and simplified presentation of theories: better HTML markup(including colors), graph views in several sizes; isatool usedir nowprovides a proper interface for user theories (via -P option); actualdocument preparation based on (PDF)LaTeX is available as well (fornew-style theories only); see isatool doc system for more information;* native support for Proof General, both for classic Isabelle andIsabelle/Isar;* ML function thm_deps visualizes dependencies of theorems and lemmas,using the graph browser tool;* Isabelle manuals now also available as PDF;* theory loader rewritten from scratch (may not be fullybug-compatible); old loadpath variable has been replaced by show_path,add_path, del_path, reset_path functions; new operations such asupdate_thy, touch_thy, remove_thy, use/update_thy_only (see alsoisatool doc ref);* improved isatool install: option -k creates KDE application icon,option -p DIR installs standalone binaries;* added ML_PLATFORM setting (useful for cross-platform installations);more robust handling of platform specific ML images for SML/NJ;* the settings environment is now statically scoped, i.e. it is nevercreated again in sub-processes invoked from isabelle, isatool, orIsabelle;* path element specification '~~' refers to '$ISABELLE_HOME';* in locales, the "assumes" and "defines" parts may be omitted ifempty;* new print_mode "xsymbols" for extended symbol support (e.g. genuinelong arrows);* new print_mode "HTML";* new flag show_tags controls display of tags of theorems (which arebasically just comments that may be attached by some tools);* Isamode 2.6 requires patch to accomodate change of Isabelle fontmode and goal output format:diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el244c244< (list (isa-getenv "ISABELLE") "-msymbols" logic-name)---> (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el181c181< (defconst proofstate-proofstart-regexp "^Level [0-9]+$"---> (defconst proofstate-proofstart-regexp "^Level [0-9]+"* function bind_thms stores lists of theorems (cf. bind_thm);* new shorthand tactics ftac, eatac, datac, fatac;* qed (and friends) now accept "" as result name; in that case thetheorem is not stored, but proper checks and presentation of theresult still apply;* theorem database now also indexes constants "Trueprop", "all","==>", "=="; thus thms_containing, findI etc. may retrieve more rules;*** HOL ***** HOL arithmetic *** There are now decision procedures for linear arithmetic over nat andint:1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',`+', `-', `Suc', `min', `max' and numerical constants; other subtermsare treated as atomic; subformulae not involving type `nat' or `int'are ignored; quantified subformulae are ignored unless they arepositive universal or negative existential. The tactic has to beinvoked by hand and can be a little bit slow. In particular, therunning time is exponential in the number of occurrences of `min' and`max', and `-' on `nat'.2. fast_arith_tac is a cut-down version of arith_tac: it only takes(negated) (in)equalities among the premises and the conclusion intoaccount (i.e. no compound formulae) and does not know about `min' and`max', and `-' on `nat'. It is fast and is used automatically by thesimplifier.NB: At the moment, these decision procedures do not cope with mixednat/int formulae where the two parts interact, such as `m < n ==>int(m) < int(n)'.* HOL/Numeral provides a generic theory of numerals (encodedefficiently as bit strings); setup for types nat/int/real is in place;INCOMPATIBILITY: since numeral syntax is now polymorphic, rather thanint, existing theories and proof scripts may require a few additionaltype constraints;* integer division and remainder can now be performed on constantarguments;* many properties of integer multiplication, division and remainderare now available;* An interface to the Stanford Validity Checker (SVC) is available through thetactic svc_tac. Propositional tautologies and theorems of linear arithmeticare proved automatically. SVC must be installed separately, and its resultsmust be TAKEN ON TRUST (Isabelle does not check the proofs, but tags anyinvocation of the underlying oracle). For SVC see http://verify.stanford.edu/SVC* IsaMakefile: the HOL-Real target now builds an actual image;** HOL misc *** HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces(in Isabelle/Isar) -- by Gertrud Bauer;* HOL/BCV: generic model of bytecode verification, i.e. data-flowanalysis for assembly languages with subtypes;* HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization-- avoids syntactic ambiguities and treats state, transition, andtemporal levels more uniformly; introduces INCOMPATIBILITIES due tochanged syntax and (many) tactics;* HOL/inductive: Now also handles more general introduction rules such as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity theorems are now maintained within the theory (maintained via the "mono" attribute);* HOL/datatype: Now also handles arbitrarily branching datatypes (using function types) such as datatype 'a tree = Atom 'a | Branch "nat => 'a tree"* HOL/record: record_simproc (part of the default simpset) takes careof selectors applied to updated records; record_split_tac is no longerpart of the default claset; update_defs may now be removed from thesimpset in many cases; COMPATIBILITY: old behavior achieved by claset_ref () := claset() addSWrapper record_split_wrapper; Delsimprocs [record_simproc]* HOL/typedef: fixed type inference for representing set; typearguments now have to occur explicitly on the rhs as type constraints;* HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theoremnames rather than an ML expression;* HOL/defer_recdef (TFL): like recdef but the well-founded relation can besupplied later. Program schemes can be defined, such as "While B C s = (if B s then While B C (C s) else s)"where the well-founded relation can be chosen after B and C have been given.* HOL/List: the constructors of type list are now Nil and Cons;INCOMPATIBILITY: while [] and infix # syntax is still there, ofcourse, ML tools referring to List.list.op # etc. have to be adapted;* HOL_quantifiers flag superseded by "HOL" print mode, which isdisabled by default; run isabelle with option -m HOL to get back tothe original Gordon/HOL-style output;* HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,ALL x<=y. P, EX x<y. P, EX x<=y. P;* HOL basic syntax simplified (more orthogonal): all variants ofAll/Ex now support plain / symbolic / HOL notation; plain syntax forEps operator is provided as well: "SOME x. P[x]";* HOL/Sum.thy: sum_case has been moved to HOL/Datatype;* HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and madethus available for user theories;* HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash withHOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all thetime;* HOL: new tactic smp_tac: int -> int -> tactic, which applies specseveral times and then mp;*** LK **** the notation <<...>> is now available as a notation for sequences offormulas;* the simplifier is now installed* the axiom system has been generalized (thanks to Soren Heilmann)* the classical reasoner now has a default rule database*** ZF **** new primrec section allows primitive recursive functions to be givendirectly (as in HOL) over datatypes and the natural numbers;* new tactics induct_tac and exhaust_tac for induction (or caseanalysis) over datatypes and the natural numbers;* the datatype declaration of type T now defines the recursor T_rec;* simplification automatically does freeness reasoning for datatypeconstructors;* automatic type-inference, with AddTCs command to insert newtype-checking rules;* datatype introduction rules are now added as Safe Introduction rulesto the claset;* the syntax "if P then x else y" is now available in addition toif(P,x,y);*** Internal programming interfaces **** tuned simplifier trace output; new flag debug_simp;* structures Vartab / Termtab (instances of TableFun) offer efficienttables indexed by indexname_ord / term_ord (compatible with aconv);* AxClass.axclass_tac lost the theory argument;* tuned current_goals_markers semantics: begin / end goal avoidsprinting empty lines;* removed prs and prs_fn hook, which was broken because it did notinclude \n in its semantics, forcing writeln to add oneuncoditionally; replaced prs_fn by writeln_fn; consider std_output:string -> unit if you really want to output text without newline;* Symbol.output subject to print mode; INCOMPATIBILITY: defaults toplain output, interface builders may have to enable 'isabelle_font'mode to get Isabelle font glyphs as before;* refined token_translation interface; INCOMPATIBILITY: output lengthnow of type real instead of int;* theory loader actions may be traced via new ThyInfo.add_hookinterface (see src/Pure/Thy/thy_info.ML); example application: keepyour own database of information attached to *whole* theories -- asopposed to intra-theory data slots offered via TheoryDataFun;* proper handling of dangling sort hypotheses (at last!);Thm.strip_shyps and Drule.strip_shyps_warning take care of removingextra sort hypotheses that can be witnessed from the type signature;the force_strip_shyps flag is gone, any remaining shyps are simplyleft in the theorem (with a warning issued by strip_shyps_warning);New in Isabelle98-1 (October 1998)----------------------------------*** Overview of INCOMPATIBILITIES (see below for more details) **** several changes of automated proof tools;* HOL: major changes to the inductive and datatype packages, includingsome minor incompatibilities of theory syntax;* HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is nowcalled `inj_on';* HOL: removed duplicate thms in Arith: less_imp_add_less should be replaced by trans_less_add1 le_imp_add_le should be replaced by trans_le_add1* HOL: unary minus is now overloaded (new type constraints may berequired);* HOL and ZF: unary minus for integers is now #- instead of #~. InZF, expressions such as n#-1 must be changed to n#- 1, since #-1 isnow taken as an integer constant.* Pure: ML function 'theory_of' renamed to 'theory';*** Proof tools **** Simplifier: 1. Asm_full_simp_tac is now more aggressive. 1. It will sometimes reorient premises if that increases their power to simplify. 2. It does no longer proceed strictly from left to right but may also rotate premises to achieve further simplification. For compatibility reasons there is now Asm_lr_simp_tac which is like the old Asm_full_simp_tac in that it does not rotate premises. 2. The simplifier now knows a little bit about nat-arithmetic.* Classical reasoner: wrapper mechanism for the classical reasoner nowallows for selected deletion of wrappers, by introduction of names forwrapper functionals. This implies that addbefore, addSbefore,addaltern, and addSaltern now take a pair (name, tactic) as argument,and that adding two tactics with the same name overwrites the firstone (emitting a warning). type wrapper = (int -> tactic) -> (int -> tactic) setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by addWrapper, addSWrapper: claset * (string * wrapper) -> claset delWrapper, delSWrapper: claset * string -> claset getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;* Classical reasoner: addbefore/addSbefore now have APPEND/ORELSEsemantics; addbefore now affects only the unsafe part of step_tacetc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAYFAIL, but proofs should be fixable easily, e.g. by replacing Auto_tacby Force_tac;* Classical reasoner: setwrapper to setWrapper and compwrapper tocompWrapper; added safe wrapper (and access functions for it);* HOL/split_all_tac is now much faster and fails if there is nothingto split. Some EXISTING PROOFS MAY REQUIRE ADAPTION because the orderand the names of the automatically generated variables have changed.split_all_tac has moved within claset() from unsafe wrappers to safewrappers, which means that !!-bound variables are split much moreaggressively, and safe_tac and clarify_tac now split such variables.If this splitting is not appropriate, use delSWrapper "split_all_tac".Note: the same holds for record_split_tac, which does the job ofsplit_all_tac for record fields.* HOL/Simplifier: Rewrite rules for case distinctions can now be addedpermanently to the default simpset using Addsplits just likeAddsimps. They can be removed via Delsplits just likeDelsimps. Lower-case versions are also available.* HOL/Simplifier: The rule split_if is now part of the defaultsimpset. This means that the simplifier will eliminate all occurrencesof if-then-else in the conclusion of a goal. To prevent this, you caneither remove split_if completely from the default simpset by`Delsplits [split_if]' or remove it in a specific call of thesimplifier using `... delsplits [split_if]'. You can also add/deleteother case splitting rules to/from the default simpset: every datatypegenerates suitable rules `split_t_case' and `split_t_case_asm' (wheret is the name of the datatype).* Classical reasoner / Simplifier combination: new force_tac (andderivatives Force_tac, force) combines rewriting and classicalreasoning (and whatever other tools) similarly to auto_tac, but isaimed to solve the given subgoal completely.*** General **** new top-level commands `Goal' and `Goalw' that improve upon `goal'and `goalw': the theory is no longer needed as an explicit argument -the current theory context is used; assumptions are no longer returnedat the ML-level unless one of them starts with ==> or !!; it isrecommended to convert to these new commands using isatool fixgoal(backup your sources first!);* new top-level commands 'thm' and 'thms' for retrieving theorems fromthe current theory context, and 'theory' to lookup stored theories;* new theory section 'locale' for declaring constants, assumptions anddefinitions that have local scope;* new theory section 'nonterminals' for purely syntactic types;* new theory section 'setup' for generic ML setup functions(e.g. package initialization);* the distribution now includes Isabelle icons: seelib/logo/isabelle-{small,tiny}.xpm;* isatool install - install binaries with absolute references toISABELLE_HOME/bin;* isatool logo -- create instances of the Isabelle logo (as EPS);* print mode 'emacs' reserved for Isamode;* support multiple print (ast) translations per constant name;* theorems involving oracles are now printed with a suffixed [!];*** HOL **** there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');* HOL/inductive package reorganized and improved: now supports mutualdefinitions such as inductive EVEN ODD intrs null "0 : EVEN" oddI "n : EVEN ==> Suc n : ODD" evenI "n : ODD ==> Suc n : EVEN"new theorem list "elims" contains an elimination rule for each of therecursive sets; inductive definitions now handle disjunctive premisescorrectly (also ZF);INCOMPATIBILITIES: requires Inductive as an ancestor; component"mutual_induct" no longer exists - the induction rule is alwayscontained in "induct";* HOL/datatype package re-implemented and greatly improved: nowsupports mutually recursive datatypes such as datatype 'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp) | SUM ('a aexp) ('a aexp) | DIFF ('a aexp) ('a aexp) | NUM 'a and 'a bexp = LESS ('a aexp) ('a aexp) | AND ('a bexp) ('a bexp) | OR ('a bexp) ('a bexp)as well as indirectly recursive datatypes such as datatype ('a, 'b) term = Var 'a | App 'b ((('a, 'b) term) list)The new tactic mutual_induct_tac [<var_1>, ..., <var_n>] i performsinduction on mutually / indirectly recursive datatypes.Primrec equations are now stored in theory and can be accessed via<function_name>.simps.INCOMPATIBILITIES: - Theories using datatypes must now have theory Datatype as an ancestor. - The specific <typename>.induct_tac no longer exists - use the generic induct_tac instead. - natE has been renamed to nat.exhaust - use exhaust_tac instead of res_inst_tac ... natE. Note that the variable names in nat.exhaust differ from the names in natE, this may cause some "fragile" proofs to fail. - The theorems split_<typename>_case and split_<typename>_case_asm have been renamed to <typename>.split and <typename>.split_asm. - Since default sorts of type variables are now handled correctly, some datatype definitions may have to be annotated with explicit sort constraints. - Primrec definitions no longer require function name and type of recursive argument.Consider using isatool fixdatatype to adapt your theories and proofscripts to the new package (backup your sources first!).* HOL/record package: considerably improved implementation; nowincludes concrete syntax for record types, terms, updates; theoremsfor surjective pairing and splitting !!-bound record variables; proofsupport is as follows: 1) standard conversions (selectors or updates applied to recordconstructor terms) are part of the standard simpset; 2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' aremade part of standard simpset and claset via addIffs; 3) a tactic for record field splitting (record_split_tac) is part ofthe standard claset (addSWrapper);To get a better idea about these rules you may retrieve them viasomething like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" isthe name of your record type.The split tactic 3) conceptually simplifies by the following rule: "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"Thus any record variable that is bound by meta-all will automaticallyblow up into some record constructor term, consequently thesimplifications of 1), 2) apply. Thus force_tac, auto_tac etc. shallsolve record problems automatically.* reorganized the main HOL image: HOL/Integ and String loaded bydefault; theory Main includes everything;* automatic simplification of integer sums and comparisons, using cancellation;* added option_map_eq_Some and not_Some_eq to the default simpset and claset;* added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;* many new identities for unions, intersections, set difference, etc.;* expand_if, expand_split, expand_sum_case and expand_nat_case are nowcalled split_if, split_split, split_sum_case and split_nat_case (to gowith add/delsplits);* HOL/Prod introduces simplification procedure unit_eq_proc rewriting(?x::unit) = (); this is made part of the default simpset, which COULDMAKE EXISTING PROOFS FAIL under rare circumstances (consider'Delsimprocs [unit_eq_proc];' as last resort); also note thatunit_abs_eta_conv is added in order to counter the effect ofunit_eq_proc on (%u::unit. f u), replacing it by f rather than by%u.f();* HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (whichmakes more sense);* HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule; It and 'sym RS equals0D' are now in the default claset, giving automatic disjointness reasoning but breaking a few old proofs.* HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1to 'converse' from 'inverse' (for compatibility with ZF and someliterature);* HOL/recdef can now declare non-recursive functions, with {} supplied asthe well-founded relation;* HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of Compl A. The "Compl" syntax remains available as input syntax for this release ONLY.* HOL/Update: new theory of function updates: f(a:=b) == %x. if x=a then b else f xmay also be iterated as in f(a:=b,c:=d,...);* HOL/Vimage: new theory for inverse image of a function, syntax f-``B;* HOL/List: - new function list_update written xs[i:=v] that updates the i-th list position. May also be iterated as in xs[i:=a,j:=b,...]. - new function `upt' written [i..j(] which generates the list [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper bound write [i..j], which is a shorthand for [i..j+1(]. - new lexicographic orderings and corresponding wellfoundedness theorems.* HOL/Arith: - removed 'pred' (predecessor) function; - generalized some theorems about n-1; - many new laws about "div" and "mod"; - new laws about greatest common divisors (see theory ex/Primes);* HOL/Relation: renamed the relational operator r^-1 "converse"instead of "inverse";* HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness of the multiset ordering;* directory HOL/Real: a construction of the reals using Dedekind cuts (not included by default);* directory HOL/UNITY: Chandy and Misra's UNITY formalism;* directory HOL/Hoare: a new version of Hoare logic which permits many-sorted programs, i.e. different program variables may have different types.* calling (stac rew i) now fails if "rew" has no effect on the goal [previously, this check worked only if the rewrite rule was unconditional] Now rew can involve either definitions or equalities (either == or =).*** ZF **** theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains only the theorems proved on ZF.ML;* ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule; It and 'sym RS equals0D' are now in the default claset, giving automatic disjointness reasoning but breaking a few old proofs.* ZF/Update: new theory of function updates with default rewrite rule f(x:=y) ` z = if(z=x, y, f`z) may also be iterated as in f(a:=b,c:=d,...);* in let x=t in u(x), neither t nor u(x) has to be an FOL term.* calling (stac rew i) now fails if "rew" has no effect on the goal [previously, this check worked only if the rewrite rule was unconditional] Now rew can involve either definitions or equalities (either == or =).* case_tac provided for compatibility with HOL (like the old excluded_middle_tac, but with subgoals swapped)*** Internal programming interfaces **** Pure: several new basic modules made available for general use, seealso src/Pure/README;* improved the theory data mechanism to support encapsulation (datakind name replaced by private Object.kind, acting as authorizationkey); new type-safe user interface via functor TheoryDataFun; genericprint_data function becomes basically useless;* removed global_names compatibility flag -- all theory declarationsare qualified by default;* module Pure/Syntax now offers quote / antiquote translationfunctions (useful for Hoare logic etc. with implicit dependencies);see HOL/ex/Antiquote for an example use;* Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->cterm -> thm;* new tactical CHANGED_GOAL for checking that a tactic modifies asubgoal;* Display.print_goals function moved to Locale.print_goals;* standard print function for goals supports current_goals_markersvariable for marking begin of proof, end of proof, start of goal; thedefault is ("", "", ""); setting current_goals_markers := ("<proof>","</proof>", "<goal>") causes SGML like tagged proof state printing,for example;New in Isabelle98 (January 1998)--------------------------------*** Overview of INCOMPATIBILITIES (see below for more details) **** changed lexical syntax of terms / types: dots made part of longidentifiers, e.g. "%x.x" no longer possible, should be "%x. x";* simpset (and claset) reference variable replaced by functionssimpset / simpset_ref;* no longer supports theory aliases (via merge) and non-trivialimplicit merge of thms' signatures;* most internal names of constants changed due to qualified names;* changed Pure/Sequence interface (see Pure/seq.ML);*** General Changes **** hierachically structured name spaces (for consts, types, axms, thmsetc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much ofold input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:isatool fixdots ensures space after dots (e.g. "%x. x"); setlong_names for fully qualified output names; NOTE: ML programs(special tactics, packages etc.) referring to internal names may haveto be adapted to cope with fully qualified names; in case of severebackward campatibility problems try setting 'global_names' at compiletime to have enrything declared within a flat name space; one may alsofine tune name declarations in theories via the 'global' and 'local'section;* reimplemented the implicit simpset and claset using the new anytypedata filed in signatures; references simpset:simpset ref etc. arereplaced by functions simpset:unit->simpset andsimpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimpto patch your ML files accordingly;* HTML output now includes theory graph data for display with Javaapplet or isatool browser; data generated automatically via isatoolusedir (see -i option, ISABELLE_USEDIR_OPTIONS);* defs may now be conditional; improved rewrite_goals_tac to handleconditional equations;* defs now admits additional type arguments, using TYPE('a) syntax;* theory aliases via merge (e.g. M=A+B+C) no longer supported, alwayscreates a new theory node; implicit merge of thms' signatures isrestricted to 'trivial' ones; COMPATIBILITY: one may have to usetransfer:theory->thm->thm in (rare) cases;* improved handling of draft signatures / theories; draft thms (andctyps, cterms) are automatically promoted to real ones;* slightly changed interfaces for oracles: admit many per theory, named(e.g. oracle foo = mlfun), additional name argument for invoke_oracle;* print_goals: optional output of const types (set show_consts andshow_types);* improved output of warnings (###) and errors (***);* subgoal_tac displays a warning if the new subgoal has type variables;* removed old README and Makefiles;* replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;* removed obsolete init_pps and init_database;* deleted the obsolete tactical STATE, which was declared by fun STATE tacfun st = tacfun st st;* cd and use now support path variables, e.g. $ISABELLE_HOME, or ~(which abbreviates $HOME);* changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:use isatool fixseq to adapt your ML programs (this works for fullyqualified references to the Sequence structure only!);* use_thy no longer requires writable current directory; it alwaysreloads .ML *and* .thy file, if either one is out of date;*** Classical Reasoner **** Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: newtactics that use classical reasoning to simplify a subgoal withoutsplitting it into several subgoals;* Safe_tac: like safe_tac but uses the default claset;*** Simplifier **** added simplification meta rules: (asm_)(full_)simplify: simpset -> thm -> thm;* simplifier.ML no longer part of Pure -- has to be loaded by objectlogics (again);* added prems argument to simplification procedures;* HOL, FOL, ZF: added infix function `addsplits': instead of `<simpset> setloop (split_tac <thms>)' you can simply write `<simpset> addsplits <thms>'*** Syntax **** TYPE('a) syntax for type reflection terms;* no longer handles consts with name "" -- declare as 'syntax' instead;* pretty printer: changed order of mixfix annotation preference (again!);* Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;*** HOL **** HOL: there is a new splitter `split_asm_tac' that can be used e.g. with `addloop' of the simplifier to faciliate case splitting in premises.* HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;* HOL/Auth: new protocol proofs including some for the Internet protocol TLS;* HOL/Map: new theory of `maps' a la VDM;* HOL/simplifier: simplification procedures nat_cancel_sums forcancelling out common nat summands from =, <, <= (in)equalities, ordifferences; simplification procedures nat_cancel_factor forcancelling common factor from =, <, <= (in)equalities over naturalsums; nat_cancel contains both kinds of procedures, it is installed bydefault in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;* HOL/simplifier: terms of the form `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)' (or t=x) are rewritten to `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)', and those of the form `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)' (or t=x) are rewritten to `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',* HOL/datatype Each datatype `t' now comes with a theorem `split_t_case' of the form P(t_case f1 ... fn x) = ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) & ... (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn)) ) and a theorem `split_t_case_asm' of the form P(t_case f1 ... fn x) = ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) | ... (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn)) ) which can be added to a simpset via `addsplits'. The existing theorems expand_list_case and expand_option_case have been renamed to split_list_case and split_option_case.* HOL/Arithmetic: - `pred n' is automatically converted to `n-1'. Users are strongly encouraged not to use `pred' any longer, because it will disappear altogether at some point. - Users are strongly encouraged to write "0 < n" rather than "n ~= 0". Theorems and proof tools have been modified towards this `standard'.* HOL/Lists: the function "set_of_list" has been renamed "set" (and its theorems too); the function "nth" now takes its arguments in the reverse order and has acquired the infix notation "!" as in "xs!n".* HOL/Set: UNIV is now a constant and is no longer translated to Compl{};* HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its specialist theorems (like UN1_I) are gone. Similarly for (INT x.B x);* HOL/record: extensible records with schematic structural subtyping(single inheritance); EXPERIMENTAL version demonstrating the encoding,still lacks various theorems and concrete record syntax;*** HOLCF **** removed "axioms" and "generated by" sections;* replaced "ops" section by extended "consts" section, which is capable of handling the continuous function space "->" directly;* domain package: . proves theorems immediately and stores them in the theory, . creates hierachical name space, . now uses normal mixfix annotations (instead of cinfix...), . minor changes to some names and values (for consistency), . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas, . separator between mutual domain defs: changed "," to "and", . improved handling of sort constraints; now they have to appear on the left-hand side of the equations only;* fixed LAM <x,y,zs>.b syntax;* added extended adm_tac to simplifier in HOLCF -- can now dischargeadm (%x. P (t x)), where P is chainfinite and t continuous;*** FOL and ZF **** FOL: there is a new splitter `split_asm_tac' that can be used e.g. with `addloop' of the simplifier to faciliate case splitting in premises.* qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, asin HOL, they strip ALL and --> from proved theorems;New in Isabelle94-8 (May 1997)------------------------------*** General Changes **** new utilities to build / run / maintain Isabelle etc. (in partsstill somewhat experimental); old Makefiles etc. still functional;* new 'Isabelle System Manual';* INSTALL text, together with ./configure and ./build scripts;* reimplemented type inference for greater efficiency, better errormessages and clean internal interface;* prlim command for dealing with lots of subgoals (an easier way ofsetting goals_limit);*** Syntax **** supports alternative (named) syntax tables (parser and prettyprinter); internal interface is provided by add_modesyntax(_i);* Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; tobe used in conjunction with the Isabelle symbol font; uses the"symbols" syntax table;* added token_translation interface (may translate name tokens inarbitrary ways, dependent on their type (free, bound, tfree, ...) andthe current print_mode); IMPORTANT: user print translation functionsare responsible for marking newly introduced bounds(Syntax.mark_boundT);* token translations for modes "xterm" and "xterm_color" that displaynames in bold, underline etc. or colors (which requires a colorversion of xterm);* infixes may now be declared with names independent of their syntax;* added typed_print_translation (like print_translation, but mayaccess type of constant);*** Classical Reasoner ***Blast_tac: a new tactic! It is often more powerful than fast_tac, but hassome limitations. Blast_tac... + ignores addss, addbefore, addafter; this restriction is intrinsic + ignores elimination rules that don't have the correct format (the conclusion MUST be a formula variable) + ignores types, which can make HOL proofs fail + rules must not require higher-order unification, e.g. apply_type in ZF [message "Function Var's argument not a bound variable" relates to this] + its proof strategy is more general but can actually be slower* substitution with equality assumptions no longer permutes otherassumptions;* minor changes in semantics of addafter (now called addaltern); renamedsetwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper(and access functions for it);* improved combination of classical reasoner and simplifier: + functions for handling clasimpsets + improvement of addss: now the simplifier is called _after_ the safe steps. + safe variant of addss called addSss: uses safe simplifications _during_ the safe steps. It is more complete as it allows multiple instantiations of unknowns (e.g. with slow_tac).*** Simplifier **** added interface for simplification procedures (functions thatproduce *proven* rewrite rules on the fly, depending on currentredex);* ordering on terms as parameter (used for ordered rewriting);* new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;* the solver is now split into a safe and an unsafe part.This should be invisible for the normal user, except that thefunctions setsolver and addsolver have been renamed to setSolver andaddSolver; added safe_asm_full_simp_tac;*** HOL **** a generic induction tactic `induct_tac' which works for all datatypes andalso for type `nat';* a generic case distinction tactic `exhaust_tac' which works for alldatatypes and also for type `nat';* each datatype comes with a function `size';* patterns in case expressions allow tuple patterns as arguments toconstructors, for example `case x of [] => ... | (x,y,z)#ps => ...';* primrec now also works with type nat;* recdef: a new declaration form, allows general recursive functions to bedefined in theory files. See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.* the constant for negation has been renamed from "not" to "Not" toharmonize with FOL, ZF, LK, etc.;* HOL/ex/LFilter theory of a corecursive "filter" functional forinfinite lists;* HOL/Modelcheck demonstrates invocation of model checker oracle;* HOL/ex/Ring.thy declares cring_simp, which solves equationalproblems in commutative rings, using axiomatic type classes for + and *;* more examples in HOL/MiniML and HOL/Auth;* more default rewrite rules for quantifiers, union/intersection;* a new constant `arbitrary == @x.False';* HOLCF/IOA replaces old HOL/IOA;* HOLCF changes: derived all rules and arities + axiomatic type classes instead of classes + typedef instead of faking type definitions + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc. + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po + eliminated the types void, one, tr + use unit lift and bool lift (with translations) instead of one and tr + eliminated blift from Lift3.thy (use Def instead of blift) all eliminated rules are derived as theorems --> no visible changes ;*** ZF **** ZF now has Fast_tac, Simp_tac and Auto_tac. Union_iff is a now a defaultrewrite rule; this may affect some proofs. eq_cs is gone but can be put backas ZF_cs addSIs [equalityI];New in Isabelle94-7 (November 96)---------------------------------* allowing negative levels (as offsets) in prlev and choplev;* super-linear speedup for large simplifications;* FOL, ZF and HOL now use miniscoping: rewriting pushesquantifications in as far as possible (COULD MAKE EXISTING PROOFSFAIL); can suppress it using the command Delsimps (ex_simps @all_simps); De Morgan laws are also now included, by default;* improved printing of ==> : ~:* new object-logic "Sequents" adds linear logic, while replacing LKand Modal (thanks to Sara Kalvala);* HOL/Auth: correctness proofs for authentication protocols;* HOL: new auto_tac combines rewriting and classical reasoning (manyexamples on HOL/Auth);* HOL: new command AddIffs for declaring theorems of the form P=Q tothe rewriter and classical reasoner simultaneously;* function uresult no longer returns theorems in "standard" format;regain previous version by: val uresult = standard o uresult;New in Isabelle94-6-------------------* oracles -- these establish an interface between Isabelle and trustedexternal reasoners, which may deliver results as theorems;* proof objects (in particular record all uses of oracles);* Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;* "constdefs" section in theory files;* "primrec" section (HOL) no longer requires names;* internal type "tactic" now simply "thm -> thm Sequence.seq";New in Isabelle94-5-------------------* reduced space requirements;* automatic HTML generation from theories;* theory files no longer require "..." (quotes) around most types;* new examples, including two proofs of the Church-Rosser theorem;* non-curried (1994) version of HOL is no longer distributed;New in Isabelle94-4-------------------* greatly reduced space requirements;* theory files (.thy) no longer require \...\ escapes at line breaks;* searchable theorem database (see the section "Retrieving theorems" onpage 8 of the Reference Manual);* new examples, including Grabczewski's monumental case study of theAxiom of Choice;* The previous version of HOL renamed to Old_HOL;* The new version of HOL (previously called CHOL) uses a curried syntaxfor functions. Application looks like f a b instead of f(a,b);* Mutually recursive inductive definitions finally work in HOL;* In ZF, pattern-matching on tuples is now available in all abstractions andtranslates to the operator "split";New in Isabelle94-3-------------------* new infix operator, addss, allowing the classical reasoner toperform simplification at each step of its search. Example: fast_tac (cs addss ss)* a new logic, CHOL, the same as HOL, but with a curried syntaxfor functions. Application looks like f a b instead of f(a,b). Also pairslook like (a,b) instead of <a,b>;* PLEASE NOTE: CHOL will eventually replace HOL!* In CHOL, pattern-matching on tuples is now available in all abstractions.It translates to the operator "split". A new theory of integers is available;* In ZF, integer numerals now denote two's-complement binary integers.Arithmetic operations can be performed by rewriting. See ZF/ex/Bin.ML;* Many new examples: I/O automata, Church-Rosser theorem, equivalentsof the Axiom of Choice;New in Isabelle94-2-------------------* Significantly faster resolution;* the different sections in a .thy file can now be mixed and repeatedfreely;* Database of theorems for FOL, HOL and ZF. Newcommands including qed, qed_goal and bind_thm store theorems in the database.* Simple database queries: return a named theorem (get_thm) or all theorems ofa given theory (thms_of), or find out what theory a theorem was proved in(theory_of_thm);* Bugs fixed in the inductive definition and datatype packages;* The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_csand HOL_dup_cs obsolete;* Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1have been removed;* Simpler definition of function space in ZF;* new results about cardinal and ordinal arithmetic in ZF;* 'subtype' facility in HOL for introducing new types as subsets of existingtypes;$Id$