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NEWS

author | wenzelm |

Tue Aug 27 17:24:41 2002 +0200 (2002-08-27) | |

changeset 13541 | 44efea0e21fa |

parent 13540 | aede0306e214 |

child 13549 | f1522b892a4c |

permissions | -rw-r--r-- |

*** empty log message ***

2 Isabelle NEWS -- history user-relevant changes

3 ==============================================

5 New in this Isabelle release

6 ----------------------------

8 *** General ***

10 * Pure: locale specifications now produce predicate definitions

11 according to the body of text (covering assumptions modulo local

12 definitions); predicate "loc_axioms" covers newly introduced text,

13 while "loc" is cumulative wrt. all included locale expressions; the

14 latter view is presented only on export into the global theory

15 context; potential INCOMPATIBILITY, use "(open)" option to fall back

16 on the old view without predicates;

18 * Pure: predefined locales "var" and "struct" are useful for sharing

19 parameters (as in CASL, for example); just specify something like

20 ``var x + var y + struct M'' as import;

22 * Pure: improved thms_containing: proper indexing of facts instead of

23 raw theorems; check validity of results wrt. current name space;

24 include local facts of proof configuration (also covers active

25 locales), cover fixed variables in index; may use "_" in term

26 specification; an optional limit for the number of printed facts may

27 be given (the default is 40);

29 * Pure: disallow duplicate fact bindings within new-style theory files

30 (batch-mode only);

32 * Provers: improved induct method: assumptions introduced by case

33 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from

34 the goal statement); "foo" still refers to all facts collectively;

36 * Isar: preview of problems to finish 'show' now produce an error

37 rather than just a warning (in interactive mode);

40 *** HOL ***

42 * 'typedef' command has new option "open" to suppress the set

43 definition;

45 * functions Min and Max on finite sets have been introduced (theory

46 Finite_Set);

48 * attribute [symmetric] now works for relations as well; it turns

49 (x,y) : R^-1 into (y,x) : R, and vice versa;

51 * arith(_tac) now produces a counter example if it cannot prove a theorem.

52 In ProofGeneral the counter example appears in the trace buffer.

54 * arith(_tac) does now know about div k and mod k where k is a numeral

55 of type nat or int. It can solve simple goals like

57 "0 < n ==> n div 2 < (n::nat)"

59 but fails if divisibility plays a role like in

61 "n div 2 + (n+1) div 2 = (n::nat)"

63 * simp's arithmetic capabilities have been enhanced a bit: it now

64 takes ~= in premises into account (by performing a case split);

66 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands are

67 distributed over a sum of terms.

70 *** ML ***

72 * Pure: Tactic.prove provides sane interface for internal proofs;

73 omits the infamous "standard" operation, so this is more appropriate

74 than prove_goalw_cterm in many situations (e.g. in simprocs);

76 * Pure: improved error reporting of simprocs;

78 * Provers: Simplifier.simproc(_i) provides sane interface for setting

79 up simprocs;

83 New in Isabelle2002 (March 2002)

84 --------------------------------

86 *** Document preparation ***

88 * greatly simplified document preparation setup, including more

89 graceful interpretation of isatool usedir -i/-d/-D options, and more

90 instructive isatool mkdir; users should basically be able to get

91 started with "isatool mkdir HOL Test && isatool make"; alternatively,

92 users may run a separate document processing stage manually like this:

93 "isatool usedir -D output HOL Test && isatool document Test/output";

95 * theory dependency graph may now be incorporated into documents;

96 isatool usedir -g true will produce session_graph.eps/.pdf for use

97 with \includegraphics of LaTeX;

99 * proper spacing of consecutive markup elements, especially text

100 blocks after section headings;

102 * support bold style (for single symbols only), input syntax is like

103 this: "\<^bold>\<alpha>" or "\<^bold>A";

105 * \<bullet> is now output as bold \cdot by default, which looks much

106 better in printed text;

108 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;

109 note that these symbols are currently unavailable in Proof General /

110 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;

112 * isatool latex no longer depends on changed TEXINPUTS, instead

113 isatool document copies the Isabelle style files to the target

114 location;

117 *** Isar ***

119 * Pure/Provers: improved proof by cases and induction;

120 - 'case' command admits impromptu naming of parameters (such as

121 "case (Suc n)");

122 - 'induct' method divinates rule instantiation from the inductive

123 claim; no longer requires excessive ?P bindings for proper

124 instantiation of cases;

125 - 'induct' method properly enumerates all possibilities of set/type

126 rules; as a consequence facts may be also passed through *type*

127 rules without further ado;

128 - 'induct' method now derives symbolic cases from the *rulified*

129 rule (before it used to rulify cases stemming from the internal

130 atomized version); this means that the context of a non-atomic

131 statement becomes is included in the hypothesis, avoiding the

132 slightly cumbersome show "PROP ?case" form;

133 - 'induct' may now use elim-style induction rules without chaining

134 facts, using ``missing'' premises from the goal state; this allows

135 rules stemming from inductive sets to be applied in unstructured

136 scripts, while still benefitting from proper handling of non-atomic

137 statements; NB: major inductive premises need to be put first, all

138 the rest of the goal is passed through the induction;

139 - 'induct' proper support for mutual induction involving non-atomic

140 rule statements (uses the new concept of simultaneous goals, see

141 below);

142 - append all possible rule selections, but only use the first

143 success (no backtracking);

144 - removed obsolete "(simplified)" and "(stripped)" options of methods;

145 - undeclared rule case names default to numbers 1, 2, 3, ...;

146 - added 'print_induct_rules' (covered by help item in recent Proof

147 General versions);

148 - moved induct/cases attributes to Pure, methods to Provers;

149 - generic method setup instantiated for FOL and HOL;

151 * Pure: support multiple simultaneous goal statements, for example

152 "have a: A and b: B" (same for 'theorem' etc.); being a pure

153 meta-level mechanism, this acts as if several individual goals had

154 been stated separately; in particular common proof methods need to be

155 repeated in order to cover all claims; note that a single elimination

156 step is *not* sufficient to establish the two conjunctions, so this

157 fails:

159 assume "A & B" then have A and B .. (*".." fails*)

161 better use "obtain" in situations as above; alternative refer to

162 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;

164 * Pure: proper integration with ``locales''; unlike the original

165 version by Florian Kammüller, Isar locales package high-level proof

166 contexts rather than raw logical ones (e.g. we admit to include

167 attributes everywhere); operations on locales include merge and

168 rename; support for implicit arguments (``structures''); simultaneous

169 type-inference over imports and text; see also HOL/ex/Locales.thy for

170 some examples;

172 * Pure: the following commands have been ``localized'', supporting a

173 target locale specification "(in name)": 'lemma', 'theorem',

174 'corollary', 'lemmas', 'theorems', 'declare'; the results will be

175 stored both within the locale and at the theory level (exported and

176 qualified by the locale name);

178 * Pure: theory goals may now be specified in ``long'' form, with

179 ad-hoc contexts consisting of arbitrary locale elements. for example

180 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and

181 definitions may be given, too); the result is a meta-level rule with

182 the context elements being discharged in the obvious way;

184 * Pure: new proof command 'using' allows to augment currently used

185 facts after a goal statement ('using' is syntactically analogous to

186 'apply', but acts on the goal's facts only); this allows chained facts

187 to be separated into parts given before and after a claim, as in

188 ``from a and b have C using d and e <proof>'';

190 * Pure: renamed "antecedent" case to "rule_context";

192 * Pure: new 'judgment' command records explicit information about the

193 object-logic embedding (used by several tools internally); no longer

194 use hard-wired "Trueprop";

196 * Pure: added 'corollary' command;

198 * Pure: fixed 'token_translation' command;

200 * Pure: removed obsolete 'exported' attribute;

202 * Pure: dummy pattern "_" in is/let is now automatically lifted over

203 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")

204 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");

206 * Pure: method 'atomize' presents local goal premises as object-level

207 statements (atomic meta-level propositions); setup controlled via

208 rewrite rules declarations of 'atomize' attribute; example

209 application: 'induct' method with proper rule statements in improper

210 proof *scripts*;

212 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)

213 now consider the syntactic context of assumptions, giving a better

214 chance to get type-inference of the arguments right (this is

215 especially important for locales);

217 * Pure: "sorry" no longer requires quick_and_dirty in interactive

218 mode;

220 * Pure/obtain: the formal conclusion "thesis", being marked as

221 ``internal'', may no longer be reference directly in the text;

222 potential INCOMPATIBILITY, may need to use "?thesis" in rare

223 situations;

225 * Pure: generic 'sym' attribute which declares a rule both as pure

226 'elim?' and for the 'symmetric' operation;

228 * Pure: marginal comments ``--'' may now occur just anywhere in the

229 text; the fixed correlation with particular command syntax has been

230 discontinued;

232 * Pure: new method 'rules' is particularly well-suited for proof

233 search in intuitionistic logic; a bit slower than 'blast' or 'fast',

234 but often produces more compact proof terms with less detours;

236 * Pure/Provers/classical: simplified integration with pure rule

237 attributes and methods; the classical "intro?/elim?/dest?"

238 declarations coincide with the pure ones; the "rule" method no longer

239 includes classically swapped intros; "intro" and "elim" methods no

240 longer pick rules from the context; also got rid of ML declarations

241 AddXIs/AddXEs/AddXDs; all of this has some potential for

242 INCOMPATIBILITY;

244 * Provers/classical: attribute 'swapped' produces classical inversions

245 of introduction rules;

247 * Provers/simplifier: 'simplified' attribute may refer to explicit

248 rules instead of full simplifier context; 'iff' attribute handles

249 conditional rules;

251 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;

253 * HOL: 'recdef' now fails on unfinished automated proofs, use

254 "(permissive)" option to recover old behavior;

256 * HOL: 'inductive' no longer features separate (collective) attributes

257 for 'intros' (was found too confusing);

259 * HOL: properly declared induction rules less_induct and

260 wf_induct_rule;

263 *** HOL ***

265 * HOL: moved over to sane numeral syntax; the new policy is as

266 follows:

268 - 0 and 1 are polymorphic constants, which are defined on any

269 numeric type (nat, int, real etc.);

271 - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based

272 binary representation internally;

274 - type nat has special constructor Suc, and generally prefers Suc 0

275 over 1::nat and Suc (Suc 0) over 2::nat;

277 This change may cause significant problems of INCOMPATIBILITY; here

278 are some hints on converting existing sources:

280 - due to the new "num" token, "-0" and "-1" etc. are now atomic

281 entities, so expressions involving "-" (unary or binary minus) need

282 to be spaced properly;

284 - existing occurrences of "1" may need to be constraint "1::nat" or

285 even replaced by Suc 0; similar for old "2";

287 - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";

289 - remove all special provisions on numerals in proofs;

291 * HOL: simp rules nat_number expand numerals on nat to Suc/0

292 representation (depends on bin_arith_simps in the default context);

294 * HOL: symbolic syntax for x^2 (numeral 2);

296 * HOL: the class of all HOL types is now called "type" rather than

297 "term"; INCOMPATIBILITY, need to adapt references to this type class

298 in axclass/classes, instance/arities, and (usually rare) occurrences

299 in typings (of consts etc.); internally the class is called

300 "HOL.type", ML programs should refer to HOLogic.typeS;

302 * HOL/record package improvements:

303 - new derived operations "fields" to build a partial record section,

304 "extend" to promote a fixed record to a record scheme, and

305 "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*

306 declared as simp by default;

307 - shared operations ("more", "fields", etc.) now need to be always

308 qualified) --- potential INCOMPATIBILITY;

309 - removed "make_scheme" operations (use "make" with "extend") --

310 INCOMPATIBILITY;

311 - removed "more" class (simply use "term") -- INCOMPATIBILITY;

312 - provides cases/induct rules for use with corresponding Isar

313 methods (for concrete records, record schemes, concrete more

314 parts, and schematic more parts -- in that order);

315 - internal definitions directly based on a light-weight abstract

316 theory of product types over typedef rather than datatype;

318 * HOL: generic code generator for generating executable ML code from

319 specifications; specific support for HOL constructs such as inductive

320 datatypes and sets, as well as recursive functions; can be invoked

321 via 'generate_code' theory section;

323 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);

325 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"

326 (beware of argument permutation!);

328 * HOL: linorder_less_split superseded by linorder_cases;

330 * HOL/List: "nodups" renamed to "distinct";

332 * HOL: added "The" definite description operator; move Hilbert's "Eps"

333 to peripheral theory "Hilbert_Choice";

335 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so

336 in this (rare) case use:

338 delSWrapper "split_all_tac"

339 addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)

341 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS

342 MAY FAIL;

344 * HOL: introduced f^n = f o ... o f; warning: due to the limits of

345 Isabelle's type classes, ^ on functions and relations has too general

346 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be

347 necessary to attach explicit type constraints;

349 * HOL/Relation: the prefix name of the infix "O" has been changed from

350 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been

351 renamed accordingly (eg "compI" -> "rel_compI").

353 * HOL: syntax translations now work properly with numerals and records

354 expressions;

356 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead

357 of "lam" -- INCOMPATIBILITY;

359 * HOL: got rid of some global declarations (potential INCOMPATIBILITY

360 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"

361 renamed "Product_Type.unit";

363 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl

365 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or

366 the "cases" method);

368 * HOL/GroupTheory: group theory examples including Sylow's theorem (by

369 Florian Kammüller);

371 * HOL/IMP: updated and converted to new-style theory format; several

372 parts turned into readable document, with proper Isar proof texts and

373 some explanations (by Gerwin Klein);

375 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);

377 * HOL-Hyperreal is now a logic image;

380 *** HOLCF ***

382 * Isar: consts/constdefs supports mixfix syntax for continuous

383 operations;

385 * Isar: domain package adapted to new-style theory format, e.g. see

386 HOLCF/ex/Dnat.thy;

388 * theory Lift: proper use of rep_datatype lift instead of ML hacks --

389 potential INCOMPATIBILITY; now use plain induct_tac instead of former

390 lift.induct_tac, always use UU instead of Undef;

392 * HOLCF/IMP: updated and converted to new-style theory;

395 *** ZF ***

397 * Isar: proper integration of logic-specific tools and packages,

398 including theory commands '(co)inductive', '(co)datatype',

399 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',

400 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');

402 * theory Main no longer includes AC; for the Axiom of Choice, base

403 your theory on Main_ZFC;

405 * the integer library now covers quotients and remainders, with many

406 laws relating division to addition, multiplication, etc.;

408 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a

409 typeless version of the formalism;

411 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory

412 format;

414 * ZF/Induct: new directory for examples of inductive definitions,

415 including theory Multiset for multiset orderings; converted to

416 new-style theory format;

418 * ZF: many new theorems about lists, ordinals, etc.;

421 *** General ***

423 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference

424 variable proof controls level of detail: 0 = no proofs (only oracle

425 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see

426 also ref manual for further ML interfaces;

428 * Pure/axclass: removed obsolete ML interface

429 goal_subclass/goal_arity;

431 * Pure/syntax: new token syntax "num" for plain numerals (without "#"

432 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now

433 separate tokens, so expressions involving minus need to be spaced

434 properly;

436 * Pure/syntax: support non-oriented infixes, using keyword "infix"

437 rather than "infixl" or "infixr";

439 * Pure/syntax: concrete syntax for dummy type variables admits genuine

440 sort constraint specifications in type inference; e.g. "x::_::foo"

441 ensures that the type of "x" is of sort "foo" (but not necessarily a

442 type variable);

444 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"

445 control output of nested => (types); the default behavior is

446 "type_brackets";

448 * Pure/syntax: builtin parse translation for "_constify" turns valued

449 tokens into AST constants;

451 * Pure/syntax: prefer later declarations of translations and print

452 translation functions; potential INCOMPATIBILITY: need to reverse

453 multiple declarations for same syntax element constant;

455 * Pure/show_hyps reset by default (in accordance to existing Isar

456 practice);

458 * Provers/classical: renamed addaltern to addafter, addSaltern to

459 addSafter;

461 * Provers/clasimp: ``iff'' declarations now handle conditional rules

462 as well;

464 * system: tested support for MacOS X; should be able to get Isabelle +

465 Proof General to work in a plain Terminal after installing Poly/ML

466 (e.g. from the Isabelle distribution area) and GNU bash alone

467 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol

468 support requires further installations, e.g. from

469 http://fink.sourceforge.net/);

471 * system: support Poly/ML 4.1.1 (able to manage larger heaps);

473 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead

474 of 40 MB), cf. ML_OPTIONS;

476 * system: Proof General keywords specification is now part of the

477 Isabelle distribution (see etc/isar-keywords.el);

479 * system: support for persistent Proof General sessions (refrain from

480 outdating all loaded theories on startup); user may create writable

481 logic images like this: ``isabelle -q HOL Test'';

483 * system: smart selection of Isabelle process versus Isabelle

484 interface, accommodates case-insensitive file systems (e.g. HFS+); may

485 run both "isabelle" and "Isabelle" even if file names are badly

486 damaged (executable inspects the case of the first letter of its own

487 name); added separate "isabelle-process" and "isabelle-interface";

489 * system: refrain from any attempt at filtering input streams; no

490 longer support ``8bit'' encoding of old isabelle font, instead proper

491 iso-latin characters may now be used; the related isatools

492 "symbolinput" and "nonascii" have disappeared as well;

494 * system: removed old "xterm" interface (the print modes "xterm" and

495 "xterm_color" are still available for direct use in a suitable

496 terminal);

500 New in Isabelle99-2 (February 2001)

501 -----------------------------------

503 *** Overview of INCOMPATIBILITIES ***

505 * HOL: please note that theories in the Library and elsewhere often use the

506 new-style (Isar) format; to refer to their theorems in an ML script you must

507 bind them to ML identifers by e.g. val thm_name = thm "thm_name";

509 * HOL: inductive package no longer splits induction rule aggressively,

510 but only as far as specified by the introductions given; the old

511 format may be recovered via ML function complete_split_rule or attribute

512 'split_rule (complete)';

514 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,

515 gfp_Tarski to gfp_unfold;

517 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;

519 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a

520 relation); infix "^^" has been renamed "``"; infix "``" has been

521 renamed "`"; "univalent" has been renamed "single_valued";

523 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"

524 operation;

526 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;

528 * Isar: 'obtain' no longer declares "that" fact as simp/intro;

530 * Isar/HOL: method 'induct' now handles non-atomic goals; as a

531 consequence, it is no longer monotonic wrt. the local goal context

532 (which is now passed through the inductive cases);

534 * Document preparation: renamed standard symbols \<ll> to \<lless> and

535 \<gg> to \<ggreater>;

538 *** Document preparation ***

540 * \isabellestyle{NAME} selects version of Isabelle output (currently

541 available: are "it" for near math-mode best-style output, "sl" for

542 slanted text style, and "tt" for plain type-writer; if no

543 \isabellestyle command is given, output is according to slanted

544 type-writer);

546 * support sub/super scripts (for single symbols only), input syntax is

547 like this: "A\<^sup>*" or "A\<^sup>\<star>";

549 * some more standard symbols; see Appendix A of the system manual for

550 the complete list of symbols defined in isabellesym.sty;

552 * improved isabelle style files; more abstract symbol implementation

553 (should now use \isamath{...} and \isatext{...} in custom symbol

554 definitions);

556 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals

557 state; Note that presentation of goal states does not conform to

558 actual human-readable proof documents. Please do not include goal

559 states into document output unless you really know what you are doing!

561 * proper indentation of antiquoted output with proportional LaTeX

562 fonts;

564 * no_document ML operator temporarily disables LaTeX document

565 generation;

567 * isatool unsymbolize tunes sources for plain ASCII communication;

570 *** Isar ***

572 * Pure: Isar now suffers initial goal statements to contain unbound

573 schematic variables (this does not conform to actual readable proof

574 documents, due to unpredictable outcome and non-compositional proof

575 checking); users who know what they are doing may use schematic goals

576 for Prolog-style synthesis of proven results;

578 * Pure: assumption method (an implicit finishing) now handles actual

579 rules as well;

581 * Pure: improved 'obtain' --- moved to Pure, insert "that" into

582 initial goal, declare "that" only as Pure intro (only for single

583 steps); the "that" rule assumption may now be involved in implicit

584 finishing, thus ".." becomes a feasible for trivial obtains;

586 * Pure: default proof step now includes 'intro_classes'; thus trivial

587 instance proofs may be performed by "..";

589 * Pure: ?thesis / ?this / "..." now work for pure meta-level

590 statements as well;

592 * Pure: more robust selection of calculational rules;

594 * Pure: the builtin notion of 'finished' goal now includes the ==-refl

595 rule (as well as the assumption rule);

597 * Pure: 'thm_deps' command visualizes dependencies of theorems and

598 lemmas, using the graph browser tool;

600 * Pure: predict failure of "show" in interactive mode;

602 * Pure: 'thms_containing' now takes actual terms as arguments;

604 * HOL: improved method 'induct' --- now handles non-atomic goals

605 (potential INCOMPATIBILITY); tuned error handling;

607 * HOL: cases and induct rules now provide explicit hints about the

608 number of facts to be consumed (0 for "type" and 1 for "set" rules);

609 any remaining facts are inserted into the goal verbatim;

611 * HOL: local contexts (aka cases) may now contain term bindings as

612 well; the 'cases' and 'induct' methods new provide a ?case binding for

613 the result to be shown in each case;

615 * HOL: added 'recdef_tc' command;

617 * isatool convert assists in eliminating legacy ML scripts;

620 *** HOL ***

622 * HOL/Library: a collection of generic theories to be used together

623 with main HOL; the theory loader path already includes this directory

624 by default; the following existing theories have been moved here:

625 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While

626 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);

628 * HOL/Unix: "Some aspects of Unix file-system security", a typical

629 modelling and verification task performed in Isabelle/HOL +

630 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).

632 * HOL/Algebra: special summation operator SUM no longer exists, it has

633 been replaced by setsum; infix 'assoc' now has priority 50 (like

634 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to

635 'domain', this makes the theory consistent with mathematical

636 literature;

638 * HOL basics: added overloaded operations "inverse" and "divide"

639 (infix "/"), syntax for generic "abs" operation, generic summation

640 operator \<Sum>;

642 * HOL/typedef: simplified package, provide more useful rules (see also

643 HOL/subset.thy);

645 * HOL/datatype: induction rule for arbitrarily branching datatypes is

646 now expressed as a proper nested rule (old-style tactic scripts may

647 require atomize_strip_tac to cope with non-atomic premises);

649 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule

650 to "split_conv" (old name still available for compatibility);

652 * HOL: improved concrete syntax for strings (e.g. allows translation

653 rules with string literals);

655 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals

656 and Fleuriot's mechanization of analysis, including the transcendental

657 functions for the reals;

659 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;

662 *** CTT ***

664 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that

665 "lam" is displayed as TWO lambda-symbols

667 * CTT: theory Main now available, containing everything (that is, Bool

668 and Arith);

671 *** General ***

673 * Pure: the Simplifier has been implemented properly as a derived rule

674 outside of the actual kernel (at last!); the overall performance

675 penalty in practical applications is about 50%, while reliability of

676 the Isabelle inference kernel has been greatly improved;

678 * print modes "brackets" and "no_brackets" control output of nested =>

679 (types) and ==> (props); the default behaviour is "brackets";

681 * Provers: fast_tac (and friends) now handle actual object-logic rules

682 as assumptions as well;

684 * system: support Poly/ML 4.0;

686 * system: isatool install handles KDE version 1 or 2;

690 New in Isabelle99-1 (October 2000)

691 ----------------------------------

693 *** Overview of INCOMPATIBILITIES ***

695 * HOL: simplification of natural numbers is much changed; to partly

696 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)

697 issue the following ML commands:

699 Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;

700 Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];

702 * HOL: simplification no longer dives into case-expressions; this is

703 controlled by "t.weak_case_cong" for each datatype t;

705 * HOL: nat_less_induct renamed to less_induct;

707 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool

708 fixsome to patch .thy and .ML sources automatically;

710 select_equality -> some_equality

711 select_eq_Ex -> some_eq_ex

712 selectI2EX -> someI2_ex

713 selectI2 -> someI2

714 selectI -> someI

715 select1_equality -> some1_equality

716 Eps_sym_eq -> some_sym_eq_trivial

717 Eps_eq -> some_eq_trivial

719 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;

721 * HOL: removed obsolete theorem binding expand_if (refer to split_if

722 instead);

724 * HOL: the recursion equations generated by 'recdef' are now called

725 f.simps instead of f.rules;

727 * HOL: qed_spec_mp now also handles bounded ALL as well;

729 * HOL: 0 is now overloaded, so the type constraint ":: nat" may

730 sometimes be needed;

732 * HOL: the constant for "f``x" is now "image" rather than "op ``";

734 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";

736 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian

737 product is now "<*>" instead of "Times"; the lexicographic product is

738 now "<*lex*>" instead of "**";

740 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part

741 of main HOL, but was unused); better use HOL's datatype package;

743 * HOL: removed "symbols" syntax for constant "override" of theory Map;

744 the old syntax may be recovered as follows:

746 syntax (symbols)

747 override :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"

748 (infixl "\\<oplus>" 100)

750 * HOL/Real: "rabs" replaced by overloaded "abs" function;

752 * HOL/ML: even fewer consts are declared as global (see theories Ord,

753 Lfp, Gfp, WF); this only affects ML packages that refer to const names

754 internally;

756 * HOL and ZF: syntax for quotienting wrt an equivalence relation

757 changed from A/r to A//r;

759 * ZF: new treatment of arithmetic (nat & int) may break some old

760 proofs;

762 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,

763 rulify -> rule_format, elimify -> elim_format, ...);

765 * Isar/Provers: intro/elim/dest attributes changed; renamed

766 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one

767 should have to change intro!! to intro? only); replaced "delrule" by

768 "rule del";

770 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;

772 * Provers: strengthened force_tac by using new first_best_tac;

774 * LaTeX document preparation: several changes of isabelle.sty (see

775 lib/texinputs);

778 *** Document preparation ***

780 * formal comments (text blocks etc.) in new-style theories may now

781 contain antiquotations of thm/prop/term/typ/text to be presented

782 according to latex print mode; concrete syntax is like this:

783 @{term[show_types] "f(x) = a + x"};

785 * isatool mkdir provides easy setup of Isabelle session directories,

786 including proper document sources;

788 * generated LaTeX sources are now deleted after successful run

789 (isatool document -c); may retain a copy somewhere else via -D option

790 of isatool usedir;

792 * isatool usedir -D now lets isatool latex -o sty update the Isabelle

793 style files, achieving self-contained LaTeX sources and simplifying

794 LaTeX debugging;

796 * old-style theories now produce (crude) LaTeX output as well;

798 * browser info session directories are now self-contained (may be put

799 on WWW server seperately); improved graphs of nested sessions; removed

800 graph for 'all sessions';

802 * several improvements in isabelle style files; \isabellestyle{it}

803 produces fake math mode output; \isamarkupheader is now \section by

804 default; see lib/texinputs/isabelle.sty etc.;

807 *** Isar ***

809 * Isar/Pure: local results and corresponding term bindings are now

810 subject to Hindley-Milner polymorphism (similar to ML); this

811 accommodates incremental type-inference very nicely;

813 * Isar/Pure: new derived language element 'obtain' supports

814 generalized existence reasoning;

816 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'

817 support accumulation of results, without applying any rules yet;

818 useful to collect intermediate results without explicit name

819 references, and for use with transitivity rules with more than 2

820 premises;

822 * Isar/Pure: scalable support for case-analysis type proofs: new

823 'case' language element refers to local contexts symbolically, as

824 produced by certain proof methods; internally, case names are attached

825 to theorems as "tags";

827 * Isar/Pure: theory command 'hide' removes declarations from

828 class/type/const name spaces;

830 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to

831 indicate potential overloading;

833 * Isar/Pure: changed syntax of local blocks from {{ }} to { };

835 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write

836 "{a,b,c}" instead of {a,b,c};

838 * Isar/Pure now provides its own version of intro/elim/dest

839 attributes; useful for building new logics, but beware of confusion

840 with the version in Provers/classical;

842 * Isar/Pure: the local context of (non-atomic) goals is provided via

843 case name 'antecedent';

845 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms

846 to the current context is now done automatically);

848 * Isar/Pure: theory command 'method_setup' provides a simple interface

849 for definining proof methods in ML;

851 * Isar/Provers: intro/elim/dest attributes changed; renamed

852 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in

853 most cases, one should have to change intro!! to intro? only);

854 replaced "delrule" by "rule del";

856 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and

857 'symmetric' attribute (the latter supercedes [RS sym]);

859 * Isar/Provers: splitter support (via 'split' attribute and 'simp'

860 method modifier); 'simp' method: 'only:' modifier removes loopers as

861 well (including splits);

863 * Isar/Provers: Simplifier and Classical methods now support all kind

864 of modifiers used in the past, including 'cong', 'iff', etc.

866 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination

867 of Simplifier and Classical reasoner);

869 * Isar/HOL: new proof method 'cases' and improved version of 'induct'

870 now support named cases; major packages (inductive, datatype, primrec,

871 recdef) support case names and properly name parameters;

873 * Isar/HOL: new transitivity rules for substitution in inequalities --

874 monotonicity conditions are extracted to be proven at end of

875 calculations;

877 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof

878 method anyway;

880 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =

881 split_if split_if_asm; datatype package provides theorems foo.splits =

882 foo.split foo.split_asm for each datatype;

884 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"

885 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof

886 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:

887 use "(cases (simplified))" method in proper proof texts);

889 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;

891 * Isar: names of theorems etc. may be natural numbers as well;

893 * Isar: 'pr' command: optional arguments for goals_limit and

894 ProofContext.prems_limit; no longer prints theory contexts, but only

895 proof states;

897 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit

898 additional print modes to be specified; e.g. "pr(latex)" will print

899 proof state according to the Isabelle LaTeX style;

901 * Isar: improved support for emulating tactic scripts, including proof

902 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',

903 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'

904 (for HOL datatypes);

906 * Isar: simplified (more robust) goal selection of proof methods: 1st

907 goal, all goals, or explicit goal specifier (tactic emulation); thus

908 'proof method scripts' have to be in depth-first order;

910 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';

912 * Isar: removed 'help' command, which hasn't been too helpful anyway;

913 should instead use individual commands for printing items

914 (print_commands, print_methods etc.);

916 * Isar: added 'nothing' --- the empty list of theorems;

919 *** HOL ***

921 * HOL/MicroJava: formalization of a fragment of Java, together with a

922 corresponding virtual machine and a specification of its bytecode

923 verifier and a lightweight bytecode verifier, including proofs of

924 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and

925 Cornelia Pusch (see also the homepage of project Bali at

926 http://isabelle.in.tum.de/Bali/);

928 * HOL/Algebra: new theory of rings and univariate polynomials, by

929 Clemens Ballarin;

931 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese

932 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M

933 Rasmussen;

935 * HOL/Lattice: fundamental concepts of lattice theory and order

936 structures, including duals, properties of bounds versus algebraic

937 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski

938 Theorem for complete lattices etc.; may also serve as a demonstration

939 for abstract algebraic reasoning using axiomatic type classes, and

940 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;

942 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David

943 von Oheimb;

945 * HOL/IMPP: extension of IMP with local variables and mutually

946 recursive procedures, by David von Oheimb;

948 * HOL/Lambda: converted into new-style theory and document;

950 * HOL/ex/Multiquote: example of multiple nested quotations and

951 anti-quotations -- basically a generalized version of de-Bruijn

952 representation; very useful in avoiding lifting of operations;

954 * HOL/record: added general record equality rule to simpset; fixed

955 select-update simplification procedure to handle extended records as

956 well; admit "r" as field name;

958 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with

959 other numeric types and also as the identity of groups, rings, etc.;

961 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.

962 Types nat and int belong to this axclass;

964 * HOL: greatly improved simplification involving numerals of type nat, int, real:

965 (i + #8 + j) = Suc k simplifies to #7 + (i + j) = k

966 i*j + k + j*#3*i simplifies to #4*(i*j) + k

967 two terms #m*u and #n*u are replaced by #(m+n)*u

968 (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)

969 and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y

970 or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);

972 * HOL: meson_tac is available (previously in ex/meson.ML); it is a

973 powerful prover for predicate logic but knows nothing of clasets; see

974 ex/mesontest.ML and ex/mesontest2.ML for example applications;

976 * HOL: new version of "case_tac" subsumes both boolean case split and

977 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer

978 exists, may define val exhaust_tac = case_tac for ad-hoc portability;

980 * HOL: simplification no longer dives into case-expressions: only the

981 selector expression is simplified, but not the remaining arms; to

982 enable full simplification of case-expressions for datatype t, you may

983 remove t.weak_case_cong from the simpset, either globally (Delcongs

984 [thm"t.weak_case_cong"];) or locally (delcongs [...]).

986 * HOL/recdef: the recursion equations generated by 'recdef' for

987 function 'f' are now called f.simps instead of f.rules; if all

988 termination conditions are proved automatically, these simplification

989 rules are added to the simpset, as in primrec; rules may be named

990 individually as well, resulting in a separate list of theorems for

991 each equation;

993 * HOL/While is a new theory that provides a while-combinator. It

994 permits the definition of tail-recursive functions without the

995 provision of a termination measure. The latter is necessary once the

996 invariant proof rule for while is applied.

998 * HOL: new (overloaded) notation for the set of elements below/above

999 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.

1001 * HOL: theorems impI, allI, ballI bound as "strip";

1003 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic

1004 induct_tac th "x1 ... xn" expects th to have a conclusion of the form

1005 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;

1007 * HOL/Real: "rabs" replaced by overloaded "abs" function;

1009 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of

1010 main HOL, but was unused);

1012 * HOL: fewer consts declared as global (e.g. have to refer to

1013 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);

1015 * HOL: tuned AST representation of nested pairs, avoiding bogus output

1016 in case of overlap with user translations (e.g. judgements over

1017 tuples); (note that the underlying logical represenation is still

1018 bogus);

1021 *** ZF ***

1023 * ZF: simplification automatically cancels common terms in arithmetic

1024 expressions over nat and int;

1026 * ZF: new treatment of nat to minimize type-checking: all operators

1027 coerce their operands to a natural number using the function natify,

1028 making the algebraic laws unconditional;

1030 * ZF: as above, for int: operators coerce their operands to an integer

1031 using the function intify;

1033 * ZF: the integer library now contains many of the usual laws for the

1034 orderings, including $<=, and monotonicity laws for $+ and $*;

1036 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic

1037 simplification;

1039 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q

1040 to the simplifier and classical reasoner simultaneously;

1043 *** General ***

1045 * Provers: blast_tac now handles actual object-logic rules as

1046 assumptions; note that auto_tac uses blast_tac internally as well;

1048 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning

1049 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;

1051 * Provers: delrules now handles destruct rules as well (no longer need

1052 explicit make_elim);

1054 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.

1055 [| inj ?f; ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W

1056 use instead the strong form,

1057 [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W

1058 in HOL, FOL and ZF the function cla_make_elim will create such rules

1059 from destruct-rules;

1061 * Provers: Simplifier.easy_setup provides a fast path to basic

1062 Simplifier setup for new object-logics;

1064 * Pure: AST translation rules no longer require constant head on LHS;

1066 * Pure: improved name spaces: ambiguous output is qualified; support

1067 for hiding of names;

1069 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and

1070 XSYMBOL_HOME; no longer need to do manual configuration in most

1071 situations;

1073 * system: compression of ML heaps images may now be controlled via -c

1074 option of isabelle and isatool usedir (currently only observed by

1075 Poly/ML);

1077 * system: isatool installfonts may handle X-Symbol fonts as well (very

1078 useful for remote X11);

1080 * system: provide TAGS file for Isabelle sources;

1082 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument

1083 order;

1085 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global

1086 timing flag supersedes proof_timing and Toplevel.trace;

1088 * ML: new combinators |>> and |>>> for incremental transformations

1089 with secondary results (e.g. certain theory extensions):

1091 * ML: PureThy.add_defs gets additional argument to indicate potential

1092 overloading (usually false);

1094 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as

1095 results;

1099 New in Isabelle99 (October 1999)

1100 --------------------------------

1102 *** Overview of INCOMPATIBILITIES (see below for more details) ***

1104 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)

1105 are no longer simplified. (This allows the simplifier to unfold recursive

1106 functional programs.) To restore the old behaviour, declare

1108 Delcongs [if_weak_cong];

1110 * HOL: Removed the obsolete syntax "Compl A"; use -A for set

1111 complement;

1113 * HOL: the predicate "inj" is now defined by translation to "inj_on";

1115 * HOL/datatype: mutual_induct_tac no longer exists --

1116 use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]

1118 * HOL/typedef: fixed type inference for representing set; type

1119 arguments now have to occur explicitly on the rhs as type constraints;

1121 * ZF: The con_defs part of an inductive definition may no longer refer

1122 to constants declared in the same theory;

1124 * HOL, ZF: the function mk_cases, generated by the inductive

1125 definition package, has lost an argument. To simplify its result, it

1126 uses the default simpset instead of a supplied list of theorems.

1128 * HOL/List: the constructors of type list are now Nil and Cons;

1130 * Simplifier: the type of the infix ML functions

1131 setSSolver addSSolver setSolver addSolver

1132 is now simpset * solver -> simpset where `solver' is a new abstract type

1133 for packaging solvers. A solver is created via

1134 mk_solver: string -> (thm list -> int -> tactic) -> solver

1135 where the string argument is only a comment.

1138 *** Proof tools ***

1140 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a

1141 decision procedure for linear arithmetic. Currently it is used for

1142 types `nat', `int', and `real' in HOL (see below); it can, should and

1143 will be instantiated for other types and logics as well.

1145 * The simplifier now accepts rewrite rules with flexible heads, eg

1146 hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y

1147 They are applied like any rule with a non-pattern lhs, i.e. by first-order

1148 matching.

1151 *** General ***

1153 * New Isabelle/Isar subsystem provides an alternative to traditional

1154 tactical theorem proving; together with the ProofGeneral/isar user

1155 interface it offers an interactive environment for developing human

1156 readable proof documents (Isar == Intelligible semi-automated

1157 reasoning); for further information see isatool doc isar-ref,

1158 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/

1160 * improved and simplified presentation of theories: better HTML markup

1161 (including colors), graph views in several sizes; isatool usedir now

1162 provides a proper interface for user theories (via -P option); actual

1163 document preparation based on (PDF)LaTeX is available as well (for

1164 new-style theories only); see isatool doc system for more information;

1166 * native support for Proof General, both for classic Isabelle and

1167 Isabelle/Isar;

1169 * ML function thm_deps visualizes dependencies of theorems and lemmas,

1170 using the graph browser tool;

1172 * Isabelle manuals now also available as PDF;

1174 * theory loader rewritten from scratch (may not be fully

1175 bug-compatible); old loadpath variable has been replaced by show_path,

1176 add_path, del_path, reset_path functions; new operations such as

1177 update_thy, touch_thy, remove_thy, use/update_thy_only (see also

1178 isatool doc ref);

1180 * improved isatool install: option -k creates KDE application icon,

1181 option -p DIR installs standalone binaries;

1183 * added ML_PLATFORM setting (useful for cross-platform installations);

1184 more robust handling of platform specific ML images for SML/NJ;

1186 * the settings environment is now statically scoped, i.e. it is never

1187 created again in sub-processes invoked from isabelle, isatool, or

1188 Isabelle;

1190 * path element specification '~~' refers to '$ISABELLE_HOME';

1192 * in locales, the "assumes" and "defines" parts may be omitted if

1193 empty;

1195 * new print_mode "xsymbols" for extended symbol support (e.g. genuine

1196 long arrows);

1198 * new print_mode "HTML";

1200 * new flag show_tags controls display of tags of theorems (which are

1201 basically just comments that may be attached by some tools);

1203 * Isamode 2.6 requires patch to accomodate change of Isabelle font

1204 mode and goal output format:

1206 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el

1207 244c244

1208 < (list (isa-getenv "ISABELLE") "-msymbols" logic-name)

1209 ---

1210 > (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)

1211 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el

1212 181c181

1213 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"

1214 ---

1215 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"

1217 * function bind_thms stores lists of theorems (cf. bind_thm);

1219 * new shorthand tactics ftac, eatac, datac, fatac;

1221 * qed (and friends) now accept "" as result name; in that case the

1222 theorem is not stored, but proper checks and presentation of the

1223 result still apply;

1225 * theorem database now also indexes constants "Trueprop", "all",

1226 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;

1229 *** HOL ***

1231 ** HOL arithmetic **

1233 * There are now decision procedures for linear arithmetic over nat and

1234 int:

1236 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',

1237 `+', `-', `Suc', `min', `max' and numerical constants; other subterms

1238 are treated as atomic; subformulae not involving type `nat' or `int'

1239 are ignored; quantified subformulae are ignored unless they are

1240 positive universal or negative existential. The tactic has to be

1241 invoked by hand and can be a little bit slow. In particular, the

1242 running time is exponential in the number of occurrences of `min' and

1243 `max', and `-' on `nat'.

1245 2. fast_arith_tac is a cut-down version of arith_tac: it only takes

1246 (negated) (in)equalities among the premises and the conclusion into

1247 account (i.e. no compound formulae) and does not know about `min' and

1248 `max', and `-' on `nat'. It is fast and is used automatically by the

1249 simplifier.

1251 NB: At the moment, these decision procedures do not cope with mixed

1252 nat/int formulae where the two parts interact, such as `m < n ==>

1253 int(m) < int(n)'.

1255 * HOL/Numeral provides a generic theory of numerals (encoded

1256 efficiently as bit strings); setup for types nat/int/real is in place;

1257 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than

1258 int, existing theories and proof scripts may require a few additional

1259 type constraints;

1261 * integer division and remainder can now be performed on constant

1262 arguments;

1264 * many properties of integer multiplication, division and remainder

1265 are now available;

1267 * An interface to the Stanford Validity Checker (SVC) is available through the

1268 tactic svc_tac. Propositional tautologies and theorems of linear arithmetic

1269 are proved automatically. SVC must be installed separately, and its results

1270 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any

1271 invocation of the underlying oracle). For SVC see

1272 http://verify.stanford.edu/SVC

1274 * IsaMakefile: the HOL-Real target now builds an actual image;

1277 ** HOL misc **

1279 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces

1280 (in Isabelle/Isar) -- by Gertrud Bauer;

1282 * HOL/BCV: generic model of bytecode verification, i.e. data-flow

1283 analysis for assembly languages with subtypes;

1285 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization

1286 -- avoids syntactic ambiguities and treats state, transition, and

1287 temporal levels more uniformly; introduces INCOMPATIBILITIES due to

1288 changed syntax and (many) tactics;

1290 * HOL/inductive: Now also handles more general introduction rules such

1291 as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity

1292 theorems are now maintained within the theory (maintained via the

1293 "mono" attribute);

1295 * HOL/datatype: Now also handles arbitrarily branching datatypes

1296 (using function types) such as

1298 datatype 'a tree = Atom 'a | Branch "nat => 'a tree"

1300 * HOL/record: record_simproc (part of the default simpset) takes care

1301 of selectors applied to updated records; record_split_tac is no longer

1302 part of the default claset; update_defs may now be removed from the

1303 simpset in many cases; COMPATIBILITY: old behavior achieved by

1305 claset_ref () := claset() addSWrapper record_split_wrapper;

1306 Delsimprocs [record_simproc]

1308 * HOL/typedef: fixed type inference for representing set; type

1309 arguments now have to occur explicitly on the rhs as type constraints;

1311 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem

1312 names rather than an ML expression;

1314 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be

1315 supplied later. Program schemes can be defined, such as

1316 "While B C s = (if B s then While B C (C s) else s)"

1317 where the well-founded relation can be chosen after B and C have been given.

1319 * HOL/List: the constructors of type list are now Nil and Cons;

1320 INCOMPATIBILITY: while [] and infix # syntax is still there, of

1321 course, ML tools referring to List.list.op # etc. have to be adapted;

1323 * HOL_quantifiers flag superseded by "HOL" print mode, which is

1324 disabled by default; run isabelle with option -m HOL to get back to

1325 the original Gordon/HOL-style output;

1327 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,

1328 ALL x<=y. P, EX x<y. P, EX x<=y. P;

1330 * HOL basic syntax simplified (more orthogonal): all variants of

1331 All/Ex now support plain / symbolic / HOL notation; plain syntax for

1332 Eps operator is provided as well: "SOME x. P[x]";

1334 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;

1336 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made

1337 thus available for user theories;

1339 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with

1340 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the

1341 time;

1343 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec

1344 several times and then mp;

1347 *** LK ***

1349 * the notation <<...>> is now available as a notation for sequences of

1350 formulas;

1352 * the simplifier is now installed

1354 * the axiom system has been generalized (thanks to Soren Heilmann)

1356 * the classical reasoner now has a default rule database

1359 *** ZF ***

1361 * new primrec section allows primitive recursive functions to be given

1362 directly (as in HOL) over datatypes and the natural numbers;

1364 * new tactics induct_tac and exhaust_tac for induction (or case

1365 analysis) over datatypes and the natural numbers;

1367 * the datatype declaration of type T now defines the recursor T_rec;

1369 * simplification automatically does freeness reasoning for datatype

1370 constructors;

1372 * automatic type-inference, with AddTCs command to insert new

1373 type-checking rules;

1375 * datatype introduction rules are now added as Safe Introduction rules

1376 to the claset;

1378 * the syntax "if P then x else y" is now available in addition to

1379 if(P,x,y);

1382 *** Internal programming interfaces ***

1384 * tuned simplifier trace output; new flag debug_simp;

1386 * structures Vartab / Termtab (instances of TableFun) offer efficient

1387 tables indexed by indexname_ord / term_ord (compatible with aconv);

1389 * AxClass.axclass_tac lost the theory argument;

1391 * tuned current_goals_markers semantics: begin / end goal avoids

1392 printing empty lines;

1394 * removed prs and prs_fn hook, which was broken because it did not

1395 include \n in its semantics, forcing writeln to add one

1396 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:

1397 string -> unit if you really want to output text without newline;

1399 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to

1400 plain output, interface builders may have to enable 'isabelle_font'

1401 mode to get Isabelle font glyphs as before;

1403 * refined token_translation interface; INCOMPATIBILITY: output length

1404 now of type real instead of int;

1406 * theory loader actions may be traced via new ThyInfo.add_hook

1407 interface (see src/Pure/Thy/thy_info.ML); example application: keep

1408 your own database of information attached to *whole* theories -- as

1409 opposed to intra-theory data slots offered via TheoryDataFun;

1411 * proper handling of dangling sort hypotheses (at last!);

1412 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing

1413 extra sort hypotheses that can be witnessed from the type signature;

1414 the force_strip_shyps flag is gone, any remaining shyps are simply

1415 left in the theorem (with a warning issued by strip_shyps_warning);

1419 New in Isabelle98-1 (October 1998)

1420 ----------------------------------

1422 *** Overview of INCOMPATIBILITIES (see below for more details) ***

1424 * several changes of automated proof tools;

1426 * HOL: major changes to the inductive and datatype packages, including

1427 some minor incompatibilities of theory syntax;

1429 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now

1430 called `inj_on';

1432 * HOL: removed duplicate thms in Arith:

1433 less_imp_add_less should be replaced by trans_less_add1

1434 le_imp_add_le should be replaced by trans_le_add1

1436 * HOL: unary minus is now overloaded (new type constraints may be

1437 required);

1439 * HOL and ZF: unary minus for integers is now #- instead of #~. In

1440 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is

1441 now taken as an integer constant.

1443 * Pure: ML function 'theory_of' renamed to 'theory';

1446 *** Proof tools ***

1448 * Simplifier:

1449 1. Asm_full_simp_tac is now more aggressive.

1450 1. It will sometimes reorient premises if that increases their power to

1451 simplify.

1452 2. It does no longer proceed strictly from left to right but may also

1453 rotate premises to achieve further simplification.

1454 For compatibility reasons there is now Asm_lr_simp_tac which is like the

1455 old Asm_full_simp_tac in that it does not rotate premises.

1456 2. The simplifier now knows a little bit about nat-arithmetic.

1458 * Classical reasoner: wrapper mechanism for the classical reasoner now

1459 allows for selected deletion of wrappers, by introduction of names for

1460 wrapper functionals. This implies that addbefore, addSbefore,

1461 addaltern, and addSaltern now take a pair (name, tactic) as argument,

1462 and that adding two tactics with the same name overwrites the first

1463 one (emitting a warning).

1464 type wrapper = (int -> tactic) -> (int -> tactic)

1465 setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by

1466 addWrapper, addSWrapper: claset * (string * wrapper) -> claset

1467 delWrapper, delSWrapper: claset * string -> claset

1468 getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;

1470 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE

1471 semantics; addbefore now affects only the unsafe part of step_tac

1472 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY

1473 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac

1474 by Force_tac;

1476 * Classical reasoner: setwrapper to setWrapper and compwrapper to

1477 compWrapper; added safe wrapper (and access functions for it);

1479 * HOL/split_all_tac is now much faster and fails if there is nothing

1480 to split. Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order

1481 and the names of the automatically generated variables have changed.

1482 split_all_tac has moved within claset() from unsafe wrappers to safe

1483 wrappers, which means that !!-bound variables are split much more

1484 aggressively, and safe_tac and clarify_tac now split such variables.

1485 If this splitting is not appropriate, use delSWrapper "split_all_tac".

1486 Note: the same holds for record_split_tac, which does the job of

1487 split_all_tac for record fields.

1489 * HOL/Simplifier: Rewrite rules for case distinctions can now be added

1490 permanently to the default simpset using Addsplits just like

1491 Addsimps. They can be removed via Delsplits just like

1492 Delsimps. Lower-case versions are also available.

1494 * HOL/Simplifier: The rule split_if is now part of the default

1495 simpset. This means that the simplifier will eliminate all occurrences

1496 of if-then-else in the conclusion of a goal. To prevent this, you can

1497 either remove split_if completely from the default simpset by

1498 `Delsplits [split_if]' or remove it in a specific call of the

1499 simplifier using `... delsplits [split_if]'. You can also add/delete

1500 other case splitting rules to/from the default simpset: every datatype

1501 generates suitable rules `split_t_case' and `split_t_case_asm' (where

1502 t is the name of the datatype).

1504 * Classical reasoner / Simplifier combination: new force_tac (and

1505 derivatives Force_tac, force) combines rewriting and classical

1506 reasoning (and whatever other tools) similarly to auto_tac, but is

1507 aimed to solve the given subgoal completely.

1510 *** General ***

1512 * new top-level commands `Goal' and `Goalw' that improve upon `goal'

1513 and `goalw': the theory is no longer needed as an explicit argument -

1514 the current theory context is used; assumptions are no longer returned

1515 at the ML-level unless one of them starts with ==> or !!; it is

1516 recommended to convert to these new commands using isatool fixgoal

1517 (backup your sources first!);

1519 * new top-level commands 'thm' and 'thms' for retrieving theorems from

1520 the current theory context, and 'theory' to lookup stored theories;

1522 * new theory section 'locale' for declaring constants, assumptions and

1523 definitions that have local scope;

1525 * new theory section 'nonterminals' for purely syntactic types;

1527 * new theory section 'setup' for generic ML setup functions

1528 (e.g. package initialization);

1530 * the distribution now includes Isabelle icons: see

1531 lib/logo/isabelle-{small,tiny}.xpm;

1533 * isatool install - install binaries with absolute references to

1534 ISABELLE_HOME/bin;

1536 * isatool logo -- create instances of the Isabelle logo (as EPS);

1538 * print mode 'emacs' reserved for Isamode;

1540 * support multiple print (ast) translations per constant name;

1542 * theorems involving oracles are now printed with a suffixed [!];

1545 *** HOL ***

1547 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');

1549 * HOL/inductive package reorganized and improved: now supports mutual

1550 definitions such as

1552 inductive EVEN ODD

1553 intrs

1554 null "0 : EVEN"

1555 oddI "n : EVEN ==> Suc n : ODD"

1556 evenI "n : ODD ==> Suc n : EVEN"

1558 new theorem list "elims" contains an elimination rule for each of the

1559 recursive sets; inductive definitions now handle disjunctive premises

1560 correctly (also ZF);

1562 INCOMPATIBILITIES: requires Inductive as an ancestor; component

1563 "mutual_induct" no longer exists - the induction rule is always

1564 contained in "induct";

1567 * HOL/datatype package re-implemented and greatly improved: now

1568 supports mutually recursive datatypes such as

1570 datatype

1571 'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)

1572 | SUM ('a aexp) ('a aexp)

1573 | DIFF ('a aexp) ('a aexp)

1574 | NUM 'a

1575 and

1576 'a bexp = LESS ('a aexp) ('a aexp)

1577 | AND ('a bexp) ('a bexp)

1578 | OR ('a bexp) ('a bexp)

1580 as well as indirectly recursive datatypes such as

1582 datatype

1583 ('a, 'b) term = Var 'a

1584 | App 'b ((('a, 'b) term) list)

1586 The new tactic mutual_induct_tac [<var_1>, ..., <var_n>] i performs

1587 induction on mutually / indirectly recursive datatypes.

1589 Primrec equations are now stored in theory and can be accessed via

1590 <function_name>.simps.

1592 INCOMPATIBILITIES:

1594 - Theories using datatypes must now have theory Datatype as an

1595 ancestor.

1596 - The specific <typename>.induct_tac no longer exists - use the

1597 generic induct_tac instead.

1598 - natE has been renamed to nat.exhaust - use exhaust_tac

1599 instead of res_inst_tac ... natE. Note that the variable

1600 names in nat.exhaust differ from the names in natE, this

1601 may cause some "fragile" proofs to fail.

1602 - The theorems split_<typename>_case and split_<typename>_case_asm

1603 have been renamed to <typename>.split and <typename>.split_asm.

1604 - Since default sorts of type variables are now handled correctly,

1605 some datatype definitions may have to be annotated with explicit

1606 sort constraints.

1607 - Primrec definitions no longer require function name and type

1608 of recursive argument.

1610 Consider using isatool fixdatatype to adapt your theories and proof

1611 scripts to the new package (backup your sources first!).

1614 * HOL/record package: considerably improved implementation; now

1615 includes concrete syntax for record types, terms, updates; theorems

1616 for surjective pairing and splitting !!-bound record variables; proof

1617 support is as follows:

1619 1) standard conversions (selectors or updates applied to record

1620 constructor terms) are part of the standard simpset;

1622 2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are

1623 made part of standard simpset and claset via addIffs;

1625 3) a tactic for record field splitting (record_split_tac) is part of

1626 the standard claset (addSWrapper);

1628 To get a better idea about these rules you may retrieve them via

1629 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is

1630 the name of your record type.

1632 The split tactic 3) conceptually simplifies by the following rule:

1634 "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"

1636 Thus any record variable that is bound by meta-all will automatically

1637 blow up into some record constructor term, consequently the

1638 simplifications of 1), 2) apply. Thus force_tac, auto_tac etc. shall

1639 solve record problems automatically.

1642 * reorganized the main HOL image: HOL/Integ and String loaded by

1643 default; theory Main includes everything;

1645 * automatic simplification of integer sums and comparisons, using cancellation;

1647 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;

1649 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;

1651 * many new identities for unions, intersections, set difference, etc.;

1653 * expand_if, expand_split, expand_sum_case and expand_nat_case are now

1654 called split_if, split_split, split_sum_case and split_nat_case (to go

1655 with add/delsplits);

1657 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting

1658 (?x::unit) = (); this is made part of the default simpset, which COULD

1659 MAKE EXISTING PROOFS FAIL under rare circumstances (consider

1660 'Delsimprocs [unit_eq_proc];' as last resort); also note that

1661 unit_abs_eta_conv is added in order to counter the effect of

1662 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by

1663 %u.f();

1665 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which

1666 makes more sense);

1668 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;

1669 It and 'sym RS equals0D' are now in the default claset, giving automatic

1670 disjointness reasoning but breaking a few old proofs.

1672 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1

1673 to 'converse' from 'inverse' (for compatibility with ZF and some

1674 literature);

1676 * HOL/recdef can now declare non-recursive functions, with {} supplied as

1677 the well-founded relation;

1679 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of

1680 Compl A. The "Compl" syntax remains available as input syntax for this

1681 release ONLY.

1683 * HOL/Update: new theory of function updates:

1684 f(a:=b) == %x. if x=a then b else f x

1685 may also be iterated as in f(a:=b,c:=d,...);

1687 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;

1689 * HOL/List:

1690 - new function list_update written xs[i:=v] that updates the i-th

1691 list position. May also be iterated as in xs[i:=a,j:=b,...].

1692 - new function `upt' written [i..j(] which generates the list

1693 [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper

1694 bound write [i..j], which is a shorthand for [i..j+1(].

1695 - new lexicographic orderings and corresponding wellfoundedness theorems.

1697 * HOL/Arith:

1698 - removed 'pred' (predecessor) function;

1699 - generalized some theorems about n-1;

1700 - many new laws about "div" and "mod";

1701 - new laws about greatest common divisors (see theory ex/Primes);

1703 * HOL/Relation: renamed the relational operator r^-1 "converse"

1704 instead of "inverse";

1706 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness

1707 of the multiset ordering;

1709 * directory HOL/Real: a construction of the reals using Dedekind cuts

1710 (not included by default);

1712 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;

1714 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted

1715 programs, i.e. different program variables may have different types.

1717 * calling (stac rew i) now fails if "rew" has no effect on the goal

1718 [previously, this check worked only if the rewrite rule was unconditional]

1719 Now rew can involve either definitions or equalities (either == or =).

1722 *** ZF ***

1724 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains

1725 only the theorems proved on ZF.ML;

1727 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;

1728 It and 'sym RS equals0D' are now in the default claset, giving automatic

1729 disjointness reasoning but breaking a few old proofs.

1731 * ZF/Update: new theory of function updates

1732 with default rewrite rule f(x:=y) ` z = if(z=x, y, f`z)

1733 may also be iterated as in f(a:=b,c:=d,...);

1735 * in let x=t in u(x), neither t nor u(x) has to be an FOL term.

1737 * calling (stac rew i) now fails if "rew" has no effect on the goal

1738 [previously, this check worked only if the rewrite rule was unconditional]

1739 Now rew can involve either definitions or equalities (either == or =).

1741 * case_tac provided for compatibility with HOL

1742 (like the old excluded_middle_tac, but with subgoals swapped)

1745 *** Internal programming interfaces ***

1747 * Pure: several new basic modules made available for general use, see

1748 also src/Pure/README;

1750 * improved the theory data mechanism to support encapsulation (data

1751 kind name replaced by private Object.kind, acting as authorization

1752 key); new type-safe user interface via functor TheoryDataFun; generic

1753 print_data function becomes basically useless;

1755 * removed global_names compatibility flag -- all theory declarations

1756 are qualified by default;

1758 * module Pure/Syntax now offers quote / antiquote translation

1759 functions (useful for Hoare logic etc. with implicit dependencies);

1760 see HOL/ex/Antiquote for an example use;

1762 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->

1763 cterm -> thm;

1765 * new tactical CHANGED_GOAL for checking that a tactic modifies a

1766 subgoal;

1768 * Display.print_goals function moved to Locale.print_goals;

1770 * standard print function for goals supports current_goals_markers

1771 variable for marking begin of proof, end of proof, start of goal; the

1772 default is ("", "", ""); setting current_goals_markers := ("<proof>",

1773 "</proof>", "<goal>") causes SGML like tagged proof state printing,

1774 for example;

1778 New in Isabelle98 (January 1998)

1779 --------------------------------

1781 *** Overview of INCOMPATIBILITIES (see below for more details) ***

1783 * changed lexical syntax of terms / types: dots made part of long

1784 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";

1786 * simpset (and claset) reference variable replaced by functions

1787 simpset / simpset_ref;

1789 * no longer supports theory aliases (via merge) and non-trivial

1790 implicit merge of thms' signatures;

1792 * most internal names of constants changed due to qualified names;

1794 * changed Pure/Sequence interface (see Pure/seq.ML);

1797 *** General Changes ***

1799 * hierachically structured name spaces (for consts, types, axms, thms

1800 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of

1801 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:

1802 isatool fixdots ensures space after dots (e.g. "%x. x"); set

1803 long_names for fully qualified output names; NOTE: ML programs

1804 (special tactics, packages etc.) referring to internal names may have

1805 to be adapted to cope with fully qualified names; in case of severe

1806 backward campatibility problems try setting 'global_names' at compile

1807 time to have enrything declared within a flat name space; one may also

1808 fine tune name declarations in theories via the 'global' and 'local'

1809 section;

1811 * reimplemented the implicit simpset and claset using the new anytype

1812 data filed in signatures; references simpset:simpset ref etc. are

1813 replaced by functions simpset:unit->simpset and

1814 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp

1815 to patch your ML files accordingly;

1817 * HTML output now includes theory graph data for display with Java

1818 applet or isatool browser; data generated automatically via isatool

1819 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);

1821 * defs may now be conditional; improved rewrite_goals_tac to handle

1822 conditional equations;

1824 * defs now admits additional type arguments, using TYPE('a) syntax;

1826 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always

1827 creates a new theory node; implicit merge of thms' signatures is

1828 restricted to 'trivial' ones; COMPATIBILITY: one may have to use

1829 transfer:theory->thm->thm in (rare) cases;

1831 * improved handling of draft signatures / theories; draft thms (and

1832 ctyps, cterms) are automatically promoted to real ones;

1834 * slightly changed interfaces for oracles: admit many per theory, named

1835 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;

1837 * print_goals: optional output of const types (set show_consts and

1838 show_types);

1840 * improved output of warnings (###) and errors (***);

1842 * subgoal_tac displays a warning if the new subgoal has type variables;

1844 * removed old README and Makefiles;

1846 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;

1848 * removed obsolete init_pps and init_database;

1850 * deleted the obsolete tactical STATE, which was declared by

1851 fun STATE tacfun st = tacfun st st;

1853 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~

1854 (which abbreviates $HOME);

1856 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:

1857 use isatool fixseq to adapt your ML programs (this works for fully

1858 qualified references to the Sequence structure only!);

1860 * use_thy no longer requires writable current directory; it always

1861 reloads .ML *and* .thy file, if either one is out of date;

1864 *** Classical Reasoner ***

1866 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new

1867 tactics that use classical reasoning to simplify a subgoal without

1868 splitting it into several subgoals;

1870 * Safe_tac: like safe_tac but uses the default claset;

1873 *** Simplifier ***

1875 * added simplification meta rules:

1876 (asm_)(full_)simplify: simpset -> thm -> thm;

1878 * simplifier.ML no longer part of Pure -- has to be loaded by object

1879 logics (again);

1881 * added prems argument to simplification procedures;

1883 * HOL, FOL, ZF: added infix function `addsplits':

1884 instead of `<simpset> setloop (split_tac <thms>)'

1885 you can simply write `<simpset> addsplits <thms>'

1888 *** Syntax ***

1890 * TYPE('a) syntax for type reflection terms;

1892 * no longer handles consts with name "" -- declare as 'syntax' instead;

1894 * pretty printer: changed order of mixfix annotation preference (again!);

1896 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;

1899 *** HOL ***

1901 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.

1902 with `addloop' of the simplifier to faciliate case splitting in premises.

1904 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;

1906 * HOL/Auth: new protocol proofs including some for the Internet

1907 protocol TLS;

1909 * HOL/Map: new theory of `maps' a la VDM;

1911 * HOL/simplifier: simplification procedures nat_cancel_sums for

1912 cancelling out common nat summands from =, <, <= (in)equalities, or

1913 differences; simplification procedures nat_cancel_factor for

1914 cancelling common factor from =, <, <= (in)equalities over natural

1915 sums; nat_cancel contains both kinds of procedures, it is installed by

1916 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;

1918 * HOL/simplifier: terms of the form

1919 `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)' (or t=x)

1920 are rewritten to

1921 `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',

1922 and those of the form

1923 `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)' (or t=x)

1924 are rewritten to

1925 `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',

1927 * HOL/datatype

1928 Each datatype `t' now comes with a theorem `split_t_case' of the form

1930 P(t_case f1 ... fn x) =

1931 ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &

1932 ...

1933 (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))

1934 )

1936 and a theorem `split_t_case_asm' of the form

1938 P(t_case f1 ... fn x) =

1939 ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |

1940 ...

1941 (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))

1942 )

1943 which can be added to a simpset via `addsplits'. The existing theorems

1944 expand_list_case and expand_option_case have been renamed to

1945 split_list_case and split_option_case.

1947 * HOL/Arithmetic:

1948 - `pred n' is automatically converted to `n-1'.

1949 Users are strongly encouraged not to use `pred' any longer,

1950 because it will disappear altogether at some point.

1951 - Users are strongly encouraged to write "0 < n" rather than

1952 "n ~= 0". Theorems and proof tools have been modified towards this

1953 `standard'.

1955 * HOL/Lists:

1956 the function "set_of_list" has been renamed "set" (and its theorems too);

1957 the function "nth" now takes its arguments in the reverse order and

1958 has acquired the infix notation "!" as in "xs!n".

1960 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};

1962 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its

1963 specialist theorems (like UN1_I) are gone. Similarly for (INT x.B x);

1965 * HOL/record: extensible records with schematic structural subtyping

1966 (single inheritance); EXPERIMENTAL version demonstrating the encoding,

1967 still lacks various theorems and concrete record syntax;

1970 *** HOLCF ***

1972 * removed "axioms" and "generated by" sections;

1974 * replaced "ops" section by extended "consts" section, which is capable of

1975 handling the continuous function space "->" directly;

1977 * domain package:

1978 . proves theorems immediately and stores them in the theory,

1979 . creates hierachical name space,

1980 . now uses normal mixfix annotations (instead of cinfix...),

1981 . minor changes to some names and values (for consistency),

1982 . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,

1983 . separator between mutual domain defs: changed "," to "and",

1984 . improved handling of sort constraints; now they have to

1985 appear on the left-hand side of the equations only;

1987 * fixed LAM <x,y,zs>.b syntax;

1989 * added extended adm_tac to simplifier in HOLCF -- can now discharge

1990 adm (%x. P (t x)), where P is chainfinite and t continuous;

1993 *** FOL and ZF ***

1995 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.

1996 with `addloop' of the simplifier to faciliate case splitting in premises.

1998 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as

1999 in HOL, they strip ALL and --> from proved theorems;

2003 New in Isabelle94-8 (May 1997)

2004 ------------------------------

2006 *** General Changes ***

2008 * new utilities to build / run / maintain Isabelle etc. (in parts

2009 still somewhat experimental); old Makefiles etc. still functional;

2011 * new 'Isabelle System Manual';

2013 * INSTALL text, together with ./configure and ./build scripts;

2015 * reimplemented type inference for greater efficiency, better error

2016 messages and clean internal interface;

2018 * prlim command for dealing with lots of subgoals (an easier way of

2019 setting goals_limit);

2022 *** Syntax ***

2024 * supports alternative (named) syntax tables (parser and pretty

2025 printer); internal interface is provided by add_modesyntax(_i);

2027 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to

2028 be used in conjunction with the Isabelle symbol font; uses the

2029 "symbols" syntax table;

2031 * added token_translation interface (may translate name tokens in

2032 arbitrary ways, dependent on their type (free, bound, tfree, ...) and

2033 the current print_mode); IMPORTANT: user print translation functions

2034 are responsible for marking newly introduced bounds

2035 (Syntax.mark_boundT);

2037 * token translations for modes "xterm" and "xterm_color" that display

2038 names in bold, underline etc. or colors (which requires a color

2039 version of xterm);

2041 * infixes may now be declared with names independent of their syntax;

2043 * added typed_print_translation (like print_translation, but may

2044 access type of constant);

2047 *** Classical Reasoner ***

2049 Blast_tac: a new tactic! It is often more powerful than fast_tac, but has

2050 some limitations. Blast_tac...

2051 + ignores addss, addbefore, addafter; this restriction is intrinsic

2052 + ignores elimination rules that don't have the correct format

2053 (the conclusion MUST be a formula variable)

2054 + ignores types, which can make HOL proofs fail

2055 + rules must not require higher-order unification, e.g. apply_type in ZF

2056 [message "Function Var's argument not a bound variable" relates to this]

2057 + its proof strategy is more general but can actually be slower

2059 * substitution with equality assumptions no longer permutes other

2060 assumptions;

2062 * minor changes in semantics of addafter (now called addaltern); renamed

2063 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper

2064 (and access functions for it);

2066 * improved combination of classical reasoner and simplifier:

2067 + functions for handling clasimpsets

2068 + improvement of addss: now the simplifier is called _after_ the

2069 safe steps.

2070 + safe variant of addss called addSss: uses safe simplifications

2071 _during_ the safe steps. It is more complete as it allows multiple

2072 instantiations of unknowns (e.g. with slow_tac).

2074 *** Simplifier ***

2076 * added interface for simplification procedures (functions that

2077 produce *proven* rewrite rules on the fly, depending on current

2078 redex);

2080 * ordering on terms as parameter (used for ordered rewriting);

2082 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;

2084 * the solver is now split into a safe and an unsafe part.

2085 This should be invisible for the normal user, except that the

2086 functions setsolver and addsolver have been renamed to setSolver and

2087 addSolver; added safe_asm_full_simp_tac;

2090 *** HOL ***

2092 * a generic induction tactic `induct_tac' which works for all datatypes and

2093 also for type `nat';

2095 * a generic case distinction tactic `exhaust_tac' which works for all

2096 datatypes and also for type `nat';

2098 * each datatype comes with a function `size';

2100 * patterns in case expressions allow tuple patterns as arguments to

2101 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';

2103 * primrec now also works with type nat;

2105 * recdef: a new declaration form, allows general recursive functions to be

2106 defined in theory files. See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.

2108 * the constant for negation has been renamed from "not" to "Not" to

2109 harmonize with FOL, ZF, LK, etc.;

2111 * HOL/ex/LFilter theory of a corecursive "filter" functional for

2112 infinite lists;

2114 * HOL/Modelcheck demonstrates invocation of model checker oracle;

2116 * HOL/ex/Ring.thy declares cring_simp, which solves equational

2117 problems in commutative rings, using axiomatic type classes for + and *;

2119 * more examples in HOL/MiniML and HOL/Auth;

2121 * more default rewrite rules for quantifiers, union/intersection;

2123 * a new constant `arbitrary == @x.False';

2125 * HOLCF/IOA replaces old HOL/IOA;

2127 * HOLCF changes: derived all rules and arities

2128 + axiomatic type classes instead of classes

2129 + typedef instead of faking type definitions

2130 + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.

2131 + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po

2132 + eliminated the types void, one, tr

2133 + use unit lift and bool lift (with translations) instead of one and tr

2134 + eliminated blift from Lift3.thy (use Def instead of blift)

2135 all eliminated rules are derived as theorems --> no visible changes ;

2138 *** ZF ***

2140 * ZF now has Fast_tac, Simp_tac and Auto_tac. Union_iff is a now a default

2141 rewrite rule; this may affect some proofs. eq_cs is gone but can be put back

2142 as ZF_cs addSIs [equalityI];

2146 New in Isabelle94-7 (November 96)

2147 ---------------------------------

2149 * allowing negative levels (as offsets) in prlev and choplev;

2151 * super-linear speedup for large simplifications;

2153 * FOL, ZF and HOL now use miniscoping: rewriting pushes

2154 quantifications in as far as possible (COULD MAKE EXISTING PROOFS

2155 FAIL); can suppress it using the command Delsimps (ex_simps @

2156 all_simps); De Morgan laws are also now included, by default;

2158 * improved printing of ==> : ~:

2160 * new object-logic "Sequents" adds linear logic, while replacing LK

2161 and Modal (thanks to Sara Kalvala);

2163 * HOL/Auth: correctness proofs for authentication protocols;

2165 * HOL: new auto_tac combines rewriting and classical reasoning (many

2166 examples on HOL/Auth);

2168 * HOL: new command AddIffs for declaring theorems of the form P=Q to

2169 the rewriter and classical reasoner simultaneously;

2171 * function uresult no longer returns theorems in "standard" format;

2172 regain previous version by: val uresult = standard o uresult;

2176 New in Isabelle94-6

2177 -------------------

2179 * oracles -- these establish an interface between Isabelle and trusted

2180 external reasoners, which may deliver results as theorems;

2182 * proof objects (in particular record all uses of oracles);

2184 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;

2186 * "constdefs" section in theory files;

2188 * "primrec" section (HOL) no longer requires names;

2190 * internal type "tactic" now simply "thm -> thm Sequence.seq";

2194 New in Isabelle94-5

2195 -------------------

2197 * reduced space requirements;

2199 * automatic HTML generation from theories;

2201 * theory files no longer require "..." (quotes) around most types;

2203 * new examples, including two proofs of the Church-Rosser theorem;

2205 * non-curried (1994) version of HOL is no longer distributed;

2209 New in Isabelle94-4

2210 -------------------

2212 * greatly reduced space requirements;

2214 * theory files (.thy) no longer require \...\ escapes at line breaks;

2216 * searchable theorem database (see the section "Retrieving theorems" on

2217 page 8 of the Reference Manual);

2219 * new examples, including Grabczewski's monumental case study of the

2220 Axiom of Choice;

2222 * The previous version of HOL renamed to Old_HOL;

2224 * The new version of HOL (previously called CHOL) uses a curried syntax

2225 for functions. Application looks like f a b instead of f(a,b);

2227 * Mutually recursive inductive definitions finally work in HOL;

2229 * In ZF, pattern-matching on tuples is now available in all abstractions and

2230 translates to the operator "split";

2234 New in Isabelle94-3

2235 -------------------

2237 * new infix operator, addss, allowing the classical reasoner to

2238 perform simplification at each step of its search. Example:

2239 fast_tac (cs addss ss)

2241 * a new logic, CHOL, the same as HOL, but with a curried syntax

2242 for functions. Application looks like f a b instead of f(a,b). Also pairs

2243 look like (a,b) instead of <a,b>;

2245 * PLEASE NOTE: CHOL will eventually replace HOL!

2247 * In CHOL, pattern-matching on tuples is now available in all abstractions.

2248 It translates to the operator "split". A new theory of integers is available;

2250 * In ZF, integer numerals now denote two's-complement binary integers.

2251 Arithmetic operations can be performed by rewriting. See ZF/ex/Bin.ML;

2253 * Many new examples: I/O automata, Church-Rosser theorem, equivalents

2254 of the Axiom of Choice;

2258 New in Isabelle94-2

2259 -------------------

2261 * Significantly faster resolution;

2263 * the different sections in a .thy file can now be mixed and repeated

2264 freely;

2266 * Database of theorems for FOL, HOL and ZF. New

2267 commands including qed, qed_goal and bind_thm store theorems in the database.

2269 * Simple database queries: return a named theorem (get_thm) or all theorems of

2270 a given theory (thms_of), or find out what theory a theorem was proved in

2271 (theory_of_thm);

2273 * Bugs fixed in the inductive definition and datatype packages;

2275 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs

2276 and HOL_dup_cs obsolete;

2278 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1

2279 have been removed;

2281 * Simpler definition of function space in ZF;

2283 * new results about cardinal and ordinal arithmetic in ZF;

2285 * 'subtype' facility in HOL for introducing new types as subsets of existing

2286 types;

2289 $Id$