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NEWS

author | wenzelm |

Tue Jan 15 00:08:11 2002 +0100 (2002-01-15) | |

changeset 12754 | 044a59921f3b |

parent 12753 | 3a62df7ae926 |

child 12769 | 0f70bfe510ee |

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

Isar: undeclared rule case names default to numbers 1, 2, 3, ...;

2 Isabelle NEWS -- history user-relevant changes

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

5 New in Isabelle2002 (January 2002)

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

8 *** Document preparation ***

10 * greatly simplified document preparation setup, including more

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

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

13 started with "isatool mkdir Test && isatool make";

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

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

17 with \includegraphics of LaTeX;

19 * proper spacing of consecutive markup elements, especially text

20 blocks after section headings;

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

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

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

26 better in printed text;

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

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

30 X-Symbol; added \<euro> symbol;

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

33 isatool document copies the Isabelle style files to the target

34 location;

37 *** Isar ***

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

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

41 "case (Suc n)");

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

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

44 instantiation of cases;

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

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

47 rules without further ado;

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

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

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

51 statement becomes is included in the hypothesis, avoiding the

52 slightly cumbersome show "PROP ?case" form;

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

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

55 rules stemming from inductive sets to be applied in unstructured

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

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

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

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

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

61 below);

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

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

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

65 General versions);

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

67 - generic method setup instantiated for FOL and HOL;

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

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

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

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

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

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

75 fails:

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

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

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

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

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

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

85 attributes everywhere); operations on locales include merge and

86 rename; e.g. see HOL/ex/Locales.thy;

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

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

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

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

92 qualified by the locale name);

94 * Pure: theory goals now support ad-hoc contexts, which are discharged

95 in the result, as in ``lemma (assumes A and B) K: A .''; syntax

96 coincides with that of a locale body;

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

100 * Pure: added 'corollary' command;

102 * Pure: fixed 'token_translation' command;

104 * Pure: removed obsolete 'exported' attribute;

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

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

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

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

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

112 rewrite rules declarations of 'atomize' attribute; example

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

114 proof *scripts*;

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

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

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

119 especially important for locales);

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

122 mode;

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

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

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

127 situations;

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

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

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

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

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

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

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

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

138 INCOMPATIBILITY;

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

141 of introduction rules;

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

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

145 conditional rules;

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

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

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

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

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

155 * HOL: properly declared induction rules less_induct and

156 wf_induct_rule;

159 *** HOL ***

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

162 follows:

164 - 0 and 1 are polymorphic constants, which are defined on any

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

167 - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based

168 binary representation internally;

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

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

173 This change may cause significant problems of INCOMPATIBILITY; here

174 are some hints on converting existing sources:

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

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

178 to be spaced properly;

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

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

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

185 - remove all special provisions on numerals in proofs;

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

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

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

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

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

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

195 * HOL/record package improvements:

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

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

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

199 declared as simp by default;

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

201 qualified) --- potential INCOMPATIBILITY;

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

203 INCOMPATIBILITY;

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

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

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

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

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

209 theory of product types over typedef rather than datatype;

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

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

214 (beware of argument permutation!);

216 * HOL: linorder_less_split superseded by linorder_cases;

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

219 to peripheral theory "Hilbert_Choice";

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

222 in this (rare) case use:

224 delSWrapper "split_all_tac"

225 addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)

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

228 MAY FAIL;

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

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

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

233 necessary to attach explicit type constraints;

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

236 to "rel_comp"; INCOMPATIBILITY: a few theorems have been renamed accordingly

237 (eg "compI" -> "rel_compI").

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

240 expressions;

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

243 of "lam" -- INCOMPATIBILITY;

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

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

247 renamed "Product_Type.unit";

249 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl

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

252 Florian Kammüller);

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

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

256 some explanations (by Gerwin Klein);

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

260 * HOL-Hyperreal is now a logic image;

263 *** HOLCF ***

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

266 operations;

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

269 HOLCF/ex/Dnat.thy;

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

272 potential INCOMPATIBILITY; now use plain induct_tac instead of former

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

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

278 *** ZF ***

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

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

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

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

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

286 your theory on Main_ZFC;

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

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

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

292 typeless version of the formalism;

294 * ZF/IMP: updated and converted to new-style theory format;

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

297 including theory Multiset for multiset orderings; converted to

298 new-style theory format;

301 *** General ***

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

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

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

306 also ref manual for further ML interfaces;

308 * Pure/axclass: removed obsolete ML interface

309 goal_subclass/goal_arity;

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

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

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

314 properly;

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

317 rather than "infixl" or "infixr";

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

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

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

322 type variable);

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

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

326 "type_brackets";

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

329 tokens into AST constants;

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

332 translation functions; potential INCOMPATIBILITY: need to reverse

333 multiple declarations for same syntax element constant;

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

336 addSafter;

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

339 as well;

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

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

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

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

345 support requires further installations, e.g. from

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

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

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

351 of 40 MB), cf. ML_OPTIONS;

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

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

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

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

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

360 * system: smart selection of Isabelle process versus Isabelle

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

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

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

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

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

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

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

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

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

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

373 terminal);

377 New in Isabelle99-2 (February 2001)

378 -----------------------------------

380 *** Overview of INCOMPATIBILITIES ***

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

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

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

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

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

388 format may be recovered via ML function complete_split_rule or attribute

389 'split_rule (complete)';

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

392 gfp_Tarski to gfp_unfold;

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

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

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

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

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

401 operation;

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

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

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

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

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

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

412 \<gg> to \<ggreater>;

415 *** Document preparation ***

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

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

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

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

421 type-writer);

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

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

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

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

429 * improved isabelle style files; more abstract symbol implementation

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

431 definitions);

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

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

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

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

438 * proper indentation of antiquoted output with proportional LaTeX

439 fonts;

441 * no_document ML operator temporarily disables LaTeX document

442 generation;

444 * isatool unsymbolize tunes sources for plain ASCII communication;

447 *** Isar ***

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

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

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

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

453 for Prolog-style synthesis of proven results;

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

456 rules as well;

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

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

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

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

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

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

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

467 statements as well;

469 * Pure: more robust selection of calculational rules;

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

472 rule (as well as the assumption rule);

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

475 lemmas, using the graph browser tool;

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

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

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

482 (potential INCOMPATIBILITY); tuned error handling;

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

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

486 any remaining facts are inserted into the goal verbatim;

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

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

490 the result to be shown in each case;

492 * HOL: added 'recdef_tc' command;

494 * isatool convert assists in eliminating legacy ML scripts;

497 *** HOL ***

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

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

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

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

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

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

506 modelling and verification task performed in Isabelle/HOL +

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

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

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

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

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

513 literature;

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

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

517 operator \<Sum>;

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

520 HOL/subset.thy);

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

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

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

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

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

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

530 rules with string literals);

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

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

534 functions for the reals;

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

539 *** CTT ***

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

542 "lam" is displayed as TWO lambda-symbols

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

545 and Arith);

548 *** General ***

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

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

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

553 the Isabelle inference kernel has been greatly improved;

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

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

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

559 as assumptions as well;

561 * system: support Poly/ML 4.0;

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

567 New in Isabelle99-1 (October 2000)

568 ----------------------------------

570 *** Overview of INCOMPATIBILITIES ***

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

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

574 issue the following ML commands:

576 Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;

577 Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];

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

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

582 * HOL: nat_less_induct renamed to less_induct;

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

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

587 select_equality -> some_equality

588 select_eq_Ex -> some_eq_ex

589 selectI2EX -> someI2_ex

590 selectI2 -> someI2

591 selectI -> someI

592 select1_equality -> some1_equality

593 Eps_sym_eq -> some_sym_eq_trivial

594 Eps_eq -> some_eq_trivial

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

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

599 instead);

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

602 f.simps instead of f.rules;

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

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

607 sometimes be needed;

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

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

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

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

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

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

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

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

621 the old syntax may be recovered as follows:

623 syntax (symbols)

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

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

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

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

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

631 internally;

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

634 changed from A/r to A//r;

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

637 proofs;

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

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

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

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

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

645 "rule del";

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

649 * Provers: strengthened force_tac by using new first_best_tac;

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

652 lib/texinputs);

655 *** Document preparation ***

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

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

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

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

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

663 including proper document sources;

665 * generated LaTeX sources are now deleted after successful run

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

667 of isatool usedir;

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

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

671 LaTeX debugging;

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

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

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

677 graph for 'all sessions';

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

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

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

684 *** Isar ***

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

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

688 accommodates incremental type-inference very nicely;

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

691 generalized existence reasoning;

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

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

695 useful to collect intermediate results without explicit name

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

697 premises;

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

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

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

702 to theorems as "tags";

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

705 class/type/const name spaces;

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

708 indicate potential overloading;

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

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

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

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

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

717 with the version in Provers/classical;

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

720 case name 'antecedent';

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

723 to the current context is now done automatically);

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

726 for definining proof methods in ML;

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

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

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

731 replaced "delrule" by "rule del";

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

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

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

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

738 well (including splits);

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

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

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

744 of Simplifier and Classical reasoner);

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

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

748 recdef) support case names and properly name parameters;

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

751 monotonicity conditions are extracted to be proven at end of

752 calculations;

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

755 method anyway;

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

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

759 foo.split foo.split_asm for each datatype;

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

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

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

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

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

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

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

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

772 proof states;

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

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

776 proof state according to the Isabelle LaTeX style;

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

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

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

781 (for HOL datatypes);

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

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

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

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

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

790 should instead use individual commands for printing items

791 (print_commands, print_methods etc.);

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

796 *** HOL ***

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

799 corresponding virtual machine and a specification of its bytecode

800 verifier and a lightweight bytecode verifier, including proofs of

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

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

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

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

806 Clemens Ballarin;

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

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

810 Rasmussen;

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

813 structures, including duals, properties of bounds versus algebraic

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

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

816 for abstract algebraic reasoning using axiomatic type classes, and

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

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

820 von Oheimb;

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

823 recursive procedures, by David von Oheimb;

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

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

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

829 representation; very useful in avoiding lifting of operations;

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

832 select-update simplification procedure to handle extended records as

833 well; admit "r" as field name;

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

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

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

839 Types nat and int belong to this axclass;

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

865 termination conditions are proved automatically, these simplification

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

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

868 each equation;

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

871 permits the definition of tail-recursive functions without the

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

873 invariant proof rule for while is applied.

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

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

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

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

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

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

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

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

887 main HOL, but was unused);

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

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

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

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

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

895 bogus);

898 *** ZF ***

900 * ZF: simplification automatically cancels common terms in arithmetic

901 expressions over nat and int;

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

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

905 making the algebraic laws unconditional;

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

908 using the function intify;

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

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

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

914 simplification;

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

917 to the simplifier and classical reasoner simultaneously;

920 *** General ***

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

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

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

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

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

929 explicit make_elim);

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

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

933 use instead the strong form,

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

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

936 from destruct-rules;

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

939 Simplifier setup for new object-logics;

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

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

944 for hiding of names;

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

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

948 situations;

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

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

952 Poly/ML);

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

955 useful for remote X11);

957 * system: provide TAGS file for Isabelle sources;

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

960 order;

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

963 timing flag supersedes proof_timing and Toplevel.trace;

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

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

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

969 overloading (usually false);

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

972 results;

976 New in Isabelle99 (October 1999)

977 --------------------------------

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

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

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

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

985 Delcongs [if_weak_cong];

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

988 complement;

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

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

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

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

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

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

999 to constants declared in the same theory;

1001 * HOL, ZF: the function mk_cases, generated by the inductive

1002 definition package, has lost an argument. To simplify its result, it

1003 uses the default simpset instead of a supplied list of theorems.

1005 * HOL/List: the constructors of type list are now Nil and Cons;

1007 * Simplifier: the type of the infix ML functions

1008 setSSolver addSSolver setSolver addSolver

1009 is now simpset * solver -> simpset where `solver' is a new abstract type

1010 for packaging solvers. A solver is created via

1011 mk_solver: string -> (thm list -> int -> tactic) -> solver

1012 where the string argument is only a comment.

1015 *** Proof tools ***

1017 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a

1018 decision procedure for linear arithmetic. Currently it is used for

1019 types `nat', `int', and `real' in HOL (see below); it can, should and

1020 will be instantiated for other types and logics as well.

1022 * The simplifier now accepts rewrite rules with flexible heads, eg

1023 hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y

1024 They are applied like any rule with a non-pattern lhs, i.e. by first-order

1025 matching.

1028 *** General ***

1030 * New Isabelle/Isar subsystem provides an alternative to traditional

1031 tactical theorem proving; together with the ProofGeneral/isar user

1032 interface it offers an interactive environment for developing human

1033 readable proof documents (Isar == Intelligible semi-automated

1034 reasoning); for further information see isatool doc isar-ref,

1035 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/

1037 * improved and simplified presentation of theories: better HTML markup

1038 (including colors), graph views in several sizes; isatool usedir now

1039 provides a proper interface for user theories (via -P option); actual

1040 document preparation based on (PDF)LaTeX is available as well (for

1041 new-style theories only); see isatool doc system for more information;

1043 * native support for Proof General, both for classic Isabelle and

1044 Isabelle/Isar;

1046 * ML function thm_deps visualizes dependencies of theorems and lemmas,

1047 using the graph browser tool;

1049 * Isabelle manuals now also available as PDF;

1051 * theory loader rewritten from scratch (may not be fully

1052 bug-compatible); old loadpath variable has been replaced by show_path,

1053 add_path, del_path, reset_path functions; new operations such as

1054 update_thy, touch_thy, remove_thy, use/update_thy_only (see also

1055 isatool doc ref);

1057 * improved isatool install: option -k creates KDE application icon,

1058 option -p DIR installs standalone binaries;

1060 * added ML_PLATFORM setting (useful for cross-platform installations);

1061 more robust handling of platform specific ML images for SML/NJ;

1063 * the settings environment is now statically scoped, i.e. it is never

1064 created again in sub-processes invoked from isabelle, isatool, or

1065 Isabelle;

1067 * path element specification '~~' refers to '$ISABELLE_HOME';

1069 * in locales, the "assumes" and "defines" parts may be omitted if

1070 empty;

1072 * new print_mode "xsymbols" for extended symbol support (e.g. genuine

1073 long arrows);

1075 * new print_mode "HTML";

1077 * new flag show_tags controls display of tags of theorems (which are

1078 basically just comments that may be attached by some tools);

1080 * Isamode 2.6 requires patch to accomodate change of Isabelle font

1081 mode and goal output format:

1083 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el

1084 244c244

1085 < (list (isa-getenv "ISABELLE") "-msymbols" logic-name)

1086 ---

1087 > (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)

1088 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el

1089 181c181

1090 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"

1091 ---

1092 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"

1094 * function bind_thms stores lists of theorems (cf. bind_thm);

1096 * new shorthand tactics ftac, eatac, datac, fatac;

1098 * qed (and friends) now accept "" as result name; in that case the

1099 theorem is not stored, but proper checks and presentation of the

1100 result still apply;

1102 * theorem database now also indexes constants "Trueprop", "all",

1103 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;

1106 *** HOL ***

1108 ** HOL arithmetic **

1110 * There are now decision procedures for linear arithmetic over nat and

1111 int:

1113 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',

1114 `+', `-', `Suc', `min', `max' and numerical constants; other subterms

1115 are treated as atomic; subformulae not involving type `nat' or `int'

1116 are ignored; quantified subformulae are ignored unless they are

1117 positive universal or negative existential. The tactic has to be

1118 invoked by hand and can be a little bit slow. In particular, the

1119 running time is exponential in the number of occurrences of `min' and

1120 `max', and `-' on `nat'.

1122 2. fast_arith_tac is a cut-down version of arith_tac: it only takes

1123 (negated) (in)equalities among the premises and the conclusion into

1124 account (i.e. no compound formulae) and does not know about `min' and

1125 `max', and `-' on `nat'. It is fast and is used automatically by the

1126 simplifier.

1128 NB: At the moment, these decision procedures do not cope with mixed

1129 nat/int formulae where the two parts interact, such as `m < n ==>

1130 int(m) < int(n)'.

1132 * HOL/Numeral provides a generic theory of numerals (encoded

1133 efficiently as bit strings); setup for types nat/int/real is in place;

1134 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than

1135 int, existing theories and proof scripts may require a few additional

1136 type constraints;

1138 * integer division and remainder can now be performed on constant

1139 arguments;

1141 * many properties of integer multiplication, division and remainder

1142 are now available;

1144 * An interface to the Stanford Validity Checker (SVC) is available through the

1145 tactic svc_tac. Propositional tautologies and theorems of linear arithmetic

1146 are proved automatically. SVC must be installed separately, and its results

1147 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any

1148 invocation of the underlying oracle). For SVC see

1149 http://verify.stanford.edu/SVC

1151 * IsaMakefile: the HOL-Real target now builds an actual image;

1154 ** HOL misc **

1156 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces

1157 (in Isabelle/Isar) -- by Gertrud Bauer;

1159 * HOL/BCV: generic model of bytecode verification, i.e. data-flow

1160 analysis for assembly languages with subtypes;

1162 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization

1163 -- avoids syntactic ambiguities and treats state, transition, and

1164 temporal levels more uniformly; introduces INCOMPATIBILITIES due to

1165 changed syntax and (many) tactics;

1167 * HOL/inductive: Now also handles more general introduction rules such

1168 as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity

1169 theorems are now maintained within the theory (maintained via the

1170 "mono" attribute);

1172 * HOL/datatype: Now also handles arbitrarily branching datatypes

1173 (using function types) such as

1175 datatype 'a tree = Atom 'a | Branch "nat => 'a tree"

1177 * HOL/record: record_simproc (part of the default simpset) takes care

1178 of selectors applied to updated records; record_split_tac is no longer

1179 part of the default claset; update_defs may now be removed from the

1180 simpset in many cases; COMPATIBILITY: old behavior achieved by

1182 claset_ref () := claset() addSWrapper record_split_wrapper;

1183 Delsimprocs [record_simproc]

1185 * HOL/typedef: fixed type inference for representing set; type

1186 arguments now have to occur explicitly on the rhs as type constraints;

1188 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem

1189 names rather than an ML expression;

1191 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be

1192 supplied later. Program schemes can be defined, such as

1193 "While B C s = (if B s then While B C (C s) else s)"

1194 where the well-founded relation can be chosen after B and C have been given.

1196 * HOL/List: the constructors of type list are now Nil and Cons;

1197 INCOMPATIBILITY: while [] and infix # syntax is still there, of

1198 course, ML tools referring to List.list.op # etc. have to be adapted;

1200 * HOL_quantifiers flag superseded by "HOL" print mode, which is

1201 disabled by default; run isabelle with option -m HOL to get back to

1202 the original Gordon/HOL-style output;

1204 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,

1205 ALL x<=y. P, EX x<y. P, EX x<=y. P;

1207 * HOL basic syntax simplified (more orthogonal): all variants of

1208 All/Ex now support plain / symbolic / HOL notation; plain syntax for

1209 Eps operator is provided as well: "SOME x. P[x]";

1211 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;

1213 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made

1214 thus available for user theories;

1216 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with

1217 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the

1218 time;

1220 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec

1221 several times and then mp;

1224 *** LK ***

1226 * the notation <<...>> is now available as a notation for sequences of

1227 formulas;

1229 * the simplifier is now installed

1231 * the axiom system has been generalized (thanks to Soren Heilmann)

1233 * the classical reasoner now has a default rule database

1236 *** ZF ***

1238 * new primrec section allows primitive recursive functions to be given

1239 directly (as in HOL) over datatypes and the natural numbers;

1241 * new tactics induct_tac and exhaust_tac for induction (or case

1242 analysis) over datatypes and the natural numbers;

1244 * the datatype declaration of type T now defines the recursor T_rec;

1246 * simplification automatically does freeness reasoning for datatype

1247 constructors;

1249 * automatic type-inference, with AddTCs command to insert new

1250 type-checking rules;

1252 * datatype introduction rules are now added as Safe Introduction rules

1253 to the claset;

1255 * the syntax "if P then x else y" is now available in addition to

1256 if(P,x,y);

1259 *** Internal programming interfaces ***

1261 * tuned simplifier trace output; new flag debug_simp;

1263 * structures Vartab / Termtab (instances of TableFun) offer efficient

1264 tables indexed by indexname_ord / term_ord (compatible with aconv);

1266 * AxClass.axclass_tac lost the theory argument;

1268 * tuned current_goals_markers semantics: begin / end goal avoids

1269 printing empty lines;

1271 * removed prs and prs_fn hook, which was broken because it did not

1272 include \n in its semantics, forcing writeln to add one

1273 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:

1274 string -> unit if you really want to output text without newline;

1276 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to

1277 plain output, interface builders may have to enable 'isabelle_font'

1278 mode to get Isabelle font glyphs as before;

1280 * refined token_translation interface; INCOMPATIBILITY: output length

1281 now of type real instead of int;

1283 * theory loader actions may be traced via new ThyInfo.add_hook

1284 interface (see src/Pure/Thy/thy_info.ML); example application: keep

1285 your own database of information attached to *whole* theories -- as

1286 opposed to intra-theory data slots offered via TheoryDataFun;

1288 * proper handling of dangling sort hypotheses (at last!);

1289 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing

1290 extra sort hypotheses that can be witnessed from the type signature;

1291 the force_strip_shyps flag is gone, any remaining shyps are simply

1292 left in the theorem (with a warning issued by strip_shyps_warning);

1296 New in Isabelle98-1 (October 1998)

1297 ----------------------------------

1299 *** Overview of INCOMPATIBILITIES (see below for more details) ***

1301 * several changes of automated proof tools;

1303 * HOL: major changes to the inductive and datatype packages, including

1304 some minor incompatibilities of theory syntax;

1306 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now

1307 called `inj_on';

1309 * HOL: removed duplicate thms in Arith:

1310 less_imp_add_less should be replaced by trans_less_add1

1311 le_imp_add_le should be replaced by trans_le_add1

1313 * HOL: unary minus is now overloaded (new type constraints may be

1314 required);

1316 * HOL and ZF: unary minus for integers is now #- instead of #~. In

1317 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is

1318 now taken as an integer constant.

1320 * Pure: ML function 'theory_of' renamed to 'theory';

1323 *** Proof tools ***

1325 * Simplifier:

1326 1. Asm_full_simp_tac is now more aggressive.

1327 1. It will sometimes reorient premises if that increases their power to

1328 simplify.

1329 2. It does no longer proceed strictly from left to right but may also

1330 rotate premises to achieve further simplification.

1331 For compatibility reasons there is now Asm_lr_simp_tac which is like the

1332 old Asm_full_simp_tac in that it does not rotate premises.

1333 2. The simplifier now knows a little bit about nat-arithmetic.

1335 * Classical reasoner: wrapper mechanism for the classical reasoner now

1336 allows for selected deletion of wrappers, by introduction of names for

1337 wrapper functionals. This implies that addbefore, addSbefore,

1338 addaltern, and addSaltern now take a pair (name, tactic) as argument,

1339 and that adding two tactics with the same name overwrites the first

1340 one (emitting a warning).

1341 type wrapper = (int -> tactic) -> (int -> tactic)

1342 setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by

1343 addWrapper, addSWrapper: claset * (string * wrapper) -> claset

1344 delWrapper, delSWrapper: claset * string -> claset

1345 getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;

1347 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE

1348 semantics; addbefore now affects only the unsafe part of step_tac

1349 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY

1350 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac

1351 by Force_tac;

1353 * Classical reasoner: setwrapper to setWrapper and compwrapper to

1354 compWrapper; added safe wrapper (and access functions for it);

1356 * HOL/split_all_tac is now much faster and fails if there is nothing

1357 to split. Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order

1358 and the names of the automatically generated variables have changed.

1359 split_all_tac has moved within claset() from unsafe wrappers to safe

1360 wrappers, which means that !!-bound variables are split much more

1361 aggressively, and safe_tac and clarify_tac now split such variables.

1362 If this splitting is not appropriate, use delSWrapper "split_all_tac".

1363 Note: the same holds for record_split_tac, which does the job of

1364 split_all_tac for record fields.

1366 * HOL/Simplifier: Rewrite rules for case distinctions can now be added

1367 permanently to the default simpset using Addsplits just like

1368 Addsimps. They can be removed via Delsplits just like

1369 Delsimps. Lower-case versions are also available.

1371 * HOL/Simplifier: The rule split_if is now part of the default

1372 simpset. This means that the simplifier will eliminate all occurrences

1373 of if-then-else in the conclusion of a goal. To prevent this, you can

1374 either remove split_if completely from the default simpset by

1375 `Delsplits [split_if]' or remove it in a specific call of the

1376 simplifier using `... delsplits [split_if]'. You can also add/delete

1377 other case splitting rules to/from the default simpset: every datatype

1378 generates suitable rules `split_t_case' and `split_t_case_asm' (where

1379 t is the name of the datatype).

1381 * Classical reasoner / Simplifier combination: new force_tac (and

1382 derivatives Force_tac, force) combines rewriting and classical

1383 reasoning (and whatever other tools) similarly to auto_tac, but is

1384 aimed to solve the given subgoal completely.

1387 *** General ***

1389 * new top-level commands `Goal' and `Goalw' that improve upon `goal'

1390 and `goalw': the theory is no longer needed as an explicit argument -

1391 the current theory context is used; assumptions are no longer returned

1392 at the ML-level unless one of them starts with ==> or !!; it is

1393 recommended to convert to these new commands using isatool fixgoal

1394 (backup your sources first!);

1396 * new top-level commands 'thm' and 'thms' for retrieving theorems from

1397 the current theory context, and 'theory' to lookup stored theories;

1399 * new theory section 'locale' for declaring constants, assumptions and

1400 definitions that have local scope;

1402 * new theory section 'nonterminals' for purely syntactic types;

1404 * new theory section 'setup' for generic ML setup functions

1405 (e.g. package initialization);

1407 * the distribution now includes Isabelle icons: see

1408 lib/logo/isabelle-{small,tiny}.xpm;

1410 * isatool install - install binaries with absolute references to

1411 ISABELLE_HOME/bin;

1413 * isatool logo -- create instances of the Isabelle logo (as EPS);

1415 * print mode 'emacs' reserved for Isamode;

1417 * support multiple print (ast) translations per constant name;

1419 * theorems involving oracles are now printed with a suffixed [!];

1422 *** HOL ***

1424 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');

1426 * HOL/inductive package reorganized and improved: now supports mutual

1427 definitions such as

1429 inductive EVEN ODD

1430 intrs

1431 null "0 : EVEN"

1432 oddI "n : EVEN ==> Suc n : ODD"

1433 evenI "n : ODD ==> Suc n : EVEN"

1435 new theorem list "elims" contains an elimination rule for each of the

1436 recursive sets; inductive definitions now handle disjunctive premises

1437 correctly (also ZF);

1439 INCOMPATIBILITIES: requires Inductive as an ancestor; component

1440 "mutual_induct" no longer exists - the induction rule is always

1441 contained in "induct";

1444 * HOL/datatype package re-implemented and greatly improved: now

1445 supports mutually recursive datatypes such as

1447 datatype

1448 'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)

1449 | SUM ('a aexp) ('a aexp)

1450 | DIFF ('a aexp) ('a aexp)

1451 | NUM 'a

1452 and

1453 'a bexp = LESS ('a aexp) ('a aexp)

1454 | AND ('a bexp) ('a bexp)

1455 | OR ('a bexp) ('a bexp)

1457 as well as indirectly recursive datatypes such as

1459 datatype

1460 ('a, 'b) term = Var 'a

1461 | App 'b ((('a, 'b) term) list)

1463 The new tactic mutual_induct_tac [<var_1>, ..., <var_n>] i performs

1464 induction on mutually / indirectly recursive datatypes.

1466 Primrec equations are now stored in theory and can be accessed via

1467 <function_name>.simps.

1469 INCOMPATIBILITIES:

1471 - Theories using datatypes must now have theory Datatype as an

1472 ancestor.

1473 - The specific <typename>.induct_tac no longer exists - use the

1474 generic induct_tac instead.

1475 - natE has been renamed to nat.exhaust - use exhaust_tac

1476 instead of res_inst_tac ... natE. Note that the variable

1477 names in nat.exhaust differ from the names in natE, this

1478 may cause some "fragile" proofs to fail.

1479 - The theorems split_<typename>_case and split_<typename>_case_asm

1480 have been renamed to <typename>.split and <typename>.split_asm.

1481 - Since default sorts of type variables are now handled correctly,

1482 some datatype definitions may have to be annotated with explicit

1483 sort constraints.

1484 - Primrec definitions no longer require function name and type

1485 of recursive argument.

1487 Consider using isatool fixdatatype to adapt your theories and proof

1488 scripts to the new package (backup your sources first!).

1491 * HOL/record package: considerably improved implementation; now

1492 includes concrete syntax for record types, terms, updates; theorems

1493 for surjective pairing and splitting !!-bound record variables; proof

1494 support is as follows:

1496 1) standard conversions (selectors or updates applied to record

1497 constructor terms) are part of the standard simpset;

1499 2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are

1500 made part of standard simpset and claset via addIffs;

1502 3) a tactic for record field splitting (record_split_tac) is part of

1503 the standard claset (addSWrapper);

1505 To get a better idea about these rules you may retrieve them via

1506 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is

1507 the name of your record type.

1509 The split tactic 3) conceptually simplifies by the following rule:

1511 "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"

1513 Thus any record variable that is bound by meta-all will automatically

1514 blow up into some record constructor term, consequently the

1515 simplifications of 1), 2) apply. Thus force_tac, auto_tac etc. shall

1516 solve record problems automatically.

1519 * reorganized the main HOL image: HOL/Integ and String loaded by

1520 default; theory Main includes everything;

1522 * automatic simplification of integer sums and comparisons, using cancellation;

1524 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;

1526 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;

1528 * many new identities for unions, intersections, set difference, etc.;

1530 * expand_if, expand_split, expand_sum_case and expand_nat_case are now

1531 called split_if, split_split, split_sum_case and split_nat_case (to go

1532 with add/delsplits);

1534 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting

1535 (?x::unit) = (); this is made part of the default simpset, which COULD

1536 MAKE EXISTING PROOFS FAIL under rare circumstances (consider

1537 'Delsimprocs [unit_eq_proc];' as last resort); also note that

1538 unit_abs_eta_conv is added in order to counter the effect of

1539 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by

1540 %u.f();

1542 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which

1543 makes more sense);

1545 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;

1546 It and 'sym RS equals0D' are now in the default claset, giving automatic

1547 disjointness reasoning but breaking a few old proofs.

1549 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1

1550 to 'converse' from 'inverse' (for compatibility with ZF and some

1551 literature);

1553 * HOL/recdef can now declare non-recursive functions, with {} supplied as

1554 the well-founded relation;

1556 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of

1557 Compl A. The "Compl" syntax remains available as input syntax for this

1558 release ONLY.

1560 * HOL/Update: new theory of function updates:

1561 f(a:=b) == %x. if x=a then b else f x

1562 may also be iterated as in f(a:=b,c:=d,...);

1564 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;

1566 * HOL/List:

1567 - new function list_update written xs[i:=v] that updates the i-th

1568 list position. May also be iterated as in xs[i:=a,j:=b,...].

1569 - new function `upt' written [i..j(] which generates the list

1570 [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper

1571 bound write [i..j], which is a shorthand for [i..j+1(].

1572 - new lexicographic orderings and corresponding wellfoundedness theorems.

1574 * HOL/Arith:

1575 - removed 'pred' (predecessor) function;

1576 - generalized some theorems about n-1;

1577 - many new laws about "div" and "mod";

1578 - new laws about greatest common divisors (see theory ex/Primes);

1580 * HOL/Relation: renamed the relational operator r^-1 "converse"

1581 instead of "inverse";

1583 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness

1584 of the multiset ordering;

1586 * directory HOL/Real: a construction of the reals using Dedekind cuts

1587 (not included by default);

1589 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;

1591 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted

1592 programs, i.e. different program variables may have different types.

1594 * calling (stac rew i) now fails if "rew" has no effect on the goal

1595 [previously, this check worked only if the rewrite rule was unconditional]

1596 Now rew can involve either definitions or equalities (either == or =).

1599 *** ZF ***

1601 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains

1602 only the theorems proved on ZF.ML;

1604 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;

1605 It and 'sym RS equals0D' are now in the default claset, giving automatic

1606 disjointness reasoning but breaking a few old proofs.

1608 * ZF/Update: new theory of function updates

1609 with default rewrite rule f(x:=y) ` z = if(z=x, y, f`z)

1610 may also be iterated as in f(a:=b,c:=d,...);

1612 * in let x=t in u(x), neither t nor u(x) has to be an FOL term.

1614 * calling (stac rew i) now fails if "rew" has no effect on the goal

1615 [previously, this check worked only if the rewrite rule was unconditional]

1616 Now rew can involve either definitions or equalities (either == or =).

1618 * case_tac provided for compatibility with HOL

1619 (like the old excluded_middle_tac, but with subgoals swapped)

1622 *** Internal programming interfaces ***

1624 * Pure: several new basic modules made available for general use, see

1625 also src/Pure/README;

1627 * improved the theory data mechanism to support encapsulation (data

1628 kind name replaced by private Object.kind, acting as authorization

1629 key); new type-safe user interface via functor TheoryDataFun; generic

1630 print_data function becomes basically useless;

1632 * removed global_names compatibility flag -- all theory declarations

1633 are qualified by default;

1635 * module Pure/Syntax now offers quote / antiquote translation

1636 functions (useful for Hoare logic etc. with implicit dependencies);

1637 see HOL/ex/Antiquote for an example use;

1639 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->

1640 cterm -> thm;

1642 * new tactical CHANGED_GOAL for checking that a tactic modifies a

1643 subgoal;

1645 * Display.print_goals function moved to Locale.print_goals;

1647 * standard print function for goals supports current_goals_markers

1648 variable for marking begin of proof, end of proof, start of goal; the

1649 default is ("", "", ""); setting current_goals_markers := ("<proof>",

1650 "</proof>", "<goal>") causes SGML like tagged proof state printing,

1651 for example;

1655 New in Isabelle98 (January 1998)

1656 --------------------------------

1658 *** Overview of INCOMPATIBILITIES (see below for more details) ***

1660 * changed lexical syntax of terms / types: dots made part of long

1661 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";

1663 * simpset (and claset) reference variable replaced by functions

1664 simpset / simpset_ref;

1666 * no longer supports theory aliases (via merge) and non-trivial

1667 implicit merge of thms' signatures;

1669 * most internal names of constants changed due to qualified names;

1671 * changed Pure/Sequence interface (see Pure/seq.ML);

1674 *** General Changes ***

1676 * hierachically structured name spaces (for consts, types, axms, thms

1677 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of

1678 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:

1679 isatool fixdots ensures space after dots (e.g. "%x. x"); set

1680 long_names for fully qualified output names; NOTE: ML programs

1681 (special tactics, packages etc.) referring to internal names may have

1682 to be adapted to cope with fully qualified names; in case of severe

1683 backward campatibility problems try setting 'global_names' at compile

1684 time to have enrything declared within a flat name space; one may also

1685 fine tune name declarations in theories via the 'global' and 'local'

1686 section;

1688 * reimplemented the implicit simpset and claset using the new anytype

1689 data filed in signatures; references simpset:simpset ref etc. are

1690 replaced by functions simpset:unit->simpset and

1691 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp

1692 to patch your ML files accordingly;

1694 * HTML output now includes theory graph data for display with Java

1695 applet or isatool browser; data generated automatically via isatool

1696 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);

1698 * defs may now be conditional; improved rewrite_goals_tac to handle

1699 conditional equations;

1701 * defs now admits additional type arguments, using TYPE('a) syntax;

1703 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always

1704 creates a new theory node; implicit merge of thms' signatures is

1705 restricted to 'trivial' ones; COMPATIBILITY: one may have to use

1706 transfer:theory->thm->thm in (rare) cases;

1708 * improved handling of draft signatures / theories; draft thms (and

1709 ctyps, cterms) are automatically promoted to real ones;

1711 * slightly changed interfaces for oracles: admit many per theory, named

1712 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;

1714 * print_goals: optional output of const types (set show_consts and

1715 show_types);

1717 * improved output of warnings (###) and errors (***);

1719 * subgoal_tac displays a warning if the new subgoal has type variables;

1721 * removed old README and Makefiles;

1723 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;

1725 * removed obsolete init_pps and init_database;

1727 * deleted the obsolete tactical STATE, which was declared by

1728 fun STATE tacfun st = tacfun st st;

1730 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~

1731 (which abbreviates $HOME);

1733 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:

1734 use isatool fixseq to adapt your ML programs (this works for fully

1735 qualified references to the Sequence structure only!);

1737 * use_thy no longer requires writable current directory; it always

1738 reloads .ML *and* .thy file, if either one is out of date;

1741 *** Classical Reasoner ***

1743 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new

1744 tactics that use classical reasoning to simplify a subgoal without

1745 splitting it into several subgoals;

1747 * Safe_tac: like safe_tac but uses the default claset;

1750 *** Simplifier ***

1752 * added simplification meta rules:

1753 (asm_)(full_)simplify: simpset -> thm -> thm;

1755 * simplifier.ML no longer part of Pure -- has to be loaded by object

1756 logics (again);

1758 * added prems argument to simplification procedures;

1760 * HOL, FOL, ZF: added infix function `addsplits':

1761 instead of `<simpset> setloop (split_tac <thms>)'

1762 you can simply write `<simpset> addsplits <thms>'

1765 *** Syntax ***

1767 * TYPE('a) syntax for type reflection terms;

1769 * no longer handles consts with name "" -- declare as 'syntax' instead;

1771 * pretty printer: changed order of mixfix annotation preference (again!);

1773 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;

1776 *** HOL ***

1778 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.

1779 with `addloop' of the simplifier to faciliate case splitting in premises.

1781 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;

1783 * HOL/Auth: new protocol proofs including some for the Internet

1784 protocol TLS;

1786 * HOL/Map: new theory of `maps' a la VDM;

1788 * HOL/simplifier: simplification procedures nat_cancel_sums for

1789 cancelling out common nat summands from =, <, <= (in)equalities, or

1790 differences; simplification procedures nat_cancel_factor for

1791 cancelling common factor from =, <, <= (in)equalities over natural

1792 sums; nat_cancel contains both kinds of procedures, it is installed by

1793 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;

1795 * HOL/simplifier: terms of the form

1796 `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)' (or t=x)

1797 are rewritten to

1798 `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',

1799 and those of the form

1800 `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)' (or t=x)

1801 are rewritten to

1802 `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',

1804 * HOL/datatype

1805 Each datatype `t' now comes with a theorem `split_t_case' of the form

1807 P(t_case f1 ... fn x) =

1808 ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &

1809 ...

1810 (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))

1811 )

1813 and a theorem `split_t_case_asm' of the form

1815 P(t_case f1 ... fn x) =

1816 ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |

1817 ...

1818 (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))

1819 )

1820 which can be added to a simpset via `addsplits'. The existing theorems

1821 expand_list_case and expand_option_case have been renamed to

1822 split_list_case and split_option_case.

1824 * HOL/Arithmetic:

1825 - `pred n' is automatically converted to `n-1'.

1826 Users are strongly encouraged not to use `pred' any longer,

1827 because it will disappear altogether at some point.

1828 - Users are strongly encouraged to write "0 < n" rather than

1829 "n ~= 0". Theorems and proof tools have been modified towards this

1830 `standard'.

1832 * HOL/Lists:

1833 the function "set_of_list" has been renamed "set" (and its theorems too);

1834 the function "nth" now takes its arguments in the reverse order and

1835 has acquired the infix notation "!" as in "xs!n".

1837 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};

1839 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its

1840 specialist theorems (like UN1_I) are gone. Similarly for (INT x.B x);

1842 * HOL/record: extensible records with schematic structural subtyping

1843 (single inheritance); EXPERIMENTAL version demonstrating the encoding,

1844 still lacks various theorems and concrete record syntax;

1847 *** HOLCF ***

1849 * removed "axioms" and "generated by" sections;

1851 * replaced "ops" section by extended "consts" section, which is capable of

1852 handling the continuous function space "->" directly;

1854 * domain package:

1855 . proves theorems immediately and stores them in the theory,

1856 . creates hierachical name space,

1857 . now uses normal mixfix annotations (instead of cinfix...),

1858 . minor changes to some names and values (for consistency),

1859 . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,

1860 . separator between mutual domain defs: changed "," to "and",

1861 . improved handling of sort constraints; now they have to

1862 appear on the left-hand side of the equations only;

1864 * fixed LAM <x,y,zs>.b syntax;

1866 * added extended adm_tac to simplifier in HOLCF -- can now discharge

1867 adm (%x. P (t x)), where P is chainfinite and t continuous;

1870 *** FOL and ZF ***

1872 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.

1873 with `addloop' of the simplifier to faciliate case splitting in premises.

1875 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as

1876 in HOL, they strip ALL and --> from proved theorems;

1880 New in Isabelle94-8 (May 1997)

1881 ------------------------------

1883 *** General Changes ***

1885 * new utilities to build / run / maintain Isabelle etc. (in parts

1886 still somewhat experimental); old Makefiles etc. still functional;

1888 * new 'Isabelle System Manual';

1890 * INSTALL text, together with ./configure and ./build scripts;

1892 * reimplemented type inference for greater efficiency, better error

1893 messages and clean internal interface;

1895 * prlim command for dealing with lots of subgoals (an easier way of

1896 setting goals_limit);

1899 *** Syntax ***

1901 * supports alternative (named) syntax tables (parser and pretty

1902 printer); internal interface is provided by add_modesyntax(_i);

1904 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to

1905 be used in conjunction with the Isabelle symbol font; uses the

1906 "symbols" syntax table;

1908 * added token_translation interface (may translate name tokens in

1909 arbitrary ways, dependent on their type (free, bound, tfree, ...) and

1910 the current print_mode); IMPORTANT: user print translation functions

1911 are responsible for marking newly introduced bounds

1912 (Syntax.mark_boundT);

1914 * token translations for modes "xterm" and "xterm_color" that display

1915 names in bold, underline etc. or colors (which requires a color

1916 version of xterm);

1918 * infixes may now be declared with names independent of their syntax;

1920 * added typed_print_translation (like print_translation, but may

1921 access type of constant);

1924 *** Classical Reasoner ***

1926 Blast_tac: a new tactic! It is often more powerful than fast_tac, but has

1927 some limitations. Blast_tac...

1928 + ignores addss, addbefore, addafter; this restriction is intrinsic

1929 + ignores elimination rules that don't have the correct format

1930 (the conclusion MUST be a formula variable)

1931 + ignores types, which can make HOL proofs fail

1932 + rules must not require higher-order unification, e.g. apply_type in ZF

1933 [message "Function Var's argument not a bound variable" relates to this]

1934 + its proof strategy is more general but can actually be slower

1936 * substitution with equality assumptions no longer permutes other

1937 assumptions;

1939 * minor changes in semantics of addafter (now called addaltern); renamed

1940 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper

1941 (and access functions for it);

1943 * improved combination of classical reasoner and simplifier:

1944 + functions for handling clasimpsets

1945 + improvement of addss: now the simplifier is called _after_ the

1946 safe steps.

1947 + safe variant of addss called addSss: uses safe simplifications

1948 _during_ the safe steps. It is more complete as it allows multiple

1949 instantiations of unknowns (e.g. with slow_tac).

1951 *** Simplifier ***

1953 * added interface for simplification procedures (functions that

1954 produce *proven* rewrite rules on the fly, depending on current

1955 redex);

1957 * ordering on terms as parameter (used for ordered rewriting);

1959 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;

1961 * the solver is now split into a safe and an unsafe part.

1962 This should be invisible for the normal user, except that the

1963 functions setsolver and addsolver have been renamed to setSolver and

1964 addSolver; added safe_asm_full_simp_tac;

1967 *** HOL ***

1969 * a generic induction tactic `induct_tac' which works for all datatypes and

1970 also for type `nat';

1972 * a generic case distinction tactic `exhaust_tac' which works for all

1973 datatypes and also for type `nat';

1975 * each datatype comes with a function `size';

1977 * patterns in case expressions allow tuple patterns as arguments to

1978 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';

1980 * primrec now also works with type nat;

1982 * recdef: a new declaration form, allows general recursive functions to be

1983 defined in theory files. See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.

1985 * the constant for negation has been renamed from "not" to "Not" to

1986 harmonize with FOL, ZF, LK, etc.;

1988 * HOL/ex/LFilter theory of a corecursive "filter" functional for

1989 infinite lists;

1991 * HOL/Modelcheck demonstrates invocation of model checker oracle;

1993 * HOL/ex/Ring.thy declares cring_simp, which solves equational

1994 problems in commutative rings, using axiomatic type classes for + and *;

1996 * more examples in HOL/MiniML and HOL/Auth;

1998 * more default rewrite rules for quantifiers, union/intersection;

2000 * a new constant `arbitrary == @x.False';

2002 * HOLCF/IOA replaces old HOL/IOA;

2004 * HOLCF changes: derived all rules and arities

2005 + axiomatic type classes instead of classes

2006 + typedef instead of faking type definitions

2007 + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.

2008 + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po

2009 + eliminated the types void, one, tr

2010 + use unit lift and bool lift (with translations) instead of one and tr

2011 + eliminated blift from Lift3.thy (use Def instead of blift)

2012 all eliminated rules are derived as theorems --> no visible changes ;

2015 *** ZF ***

2017 * ZF now has Fast_tac, Simp_tac and Auto_tac. Union_iff is a now a default

2018 rewrite rule; this may affect some proofs. eq_cs is gone but can be put back

2019 as ZF_cs addSIs [equalityI];

2023 New in Isabelle94-7 (November 96)

2024 ---------------------------------

2026 * allowing negative levels (as offsets) in prlev and choplev;

2028 * super-linear speedup for large simplifications;

2030 * FOL, ZF and HOL now use miniscoping: rewriting pushes

2031 quantifications in as far as possible (COULD MAKE EXISTING PROOFS

2032 FAIL); can suppress it using the command Delsimps (ex_simps @

2033 all_simps); De Morgan laws are also now included, by default;

2035 * improved printing of ==> : ~:

2037 * new object-logic "Sequents" adds linear logic, while replacing LK

2038 and Modal (thanks to Sara Kalvala);

2040 * HOL/Auth: correctness proofs for authentication protocols;

2042 * HOL: new auto_tac combines rewriting and classical reasoning (many

2043 examples on HOL/Auth);

2045 * HOL: new command AddIffs for declaring theorems of the form P=Q to

2046 the rewriter and classical reasoner simultaneously;

2048 * function uresult no longer returns theorems in "standard" format;

2049 regain previous version by: val uresult = standard o uresult;

2053 New in Isabelle94-6

2054 -------------------

2056 * oracles -- these establish an interface between Isabelle and trusted

2057 external reasoners, which may deliver results as theorems;

2059 * proof objects (in particular record all uses of oracles);

2061 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;

2063 * "constdefs" section in theory files;

2065 * "primrec" section (HOL) no longer requires names;

2067 * internal type "tactic" now simply "thm -> thm Sequence.seq";

2071 New in Isabelle94-5

2072 -------------------

2074 * reduced space requirements;

2076 * automatic HTML generation from theories;

2078 * theory files no longer require "..." (quotes) around most types;

2080 * new examples, including two proofs of the Church-Rosser theorem;

2082 * non-curried (1994) version of HOL is no longer distributed;

2086 New in Isabelle94-4

2087 -------------------

2089 * greatly reduced space requirements;

2091 * theory files (.thy) no longer require \...\ escapes at line breaks;

2093 * searchable theorem database (see the section "Retrieving theorems" on

2094 page 8 of the Reference Manual);

2096 * new examples, including Grabczewski's monumental case study of the

2097 Axiom of Choice;

2099 * The previous version of HOL renamed to Old_HOL;

2101 * The new version of HOL (previously called CHOL) uses a curried syntax

2102 for functions. Application looks like f a b instead of f(a,b);

2104 * Mutually recursive inductive definitions finally work in HOL;

2106 * In ZF, pattern-matching on tuples is now available in all abstractions and

2107 translates to the operator "split";

2111 New in Isabelle94-3

2112 -------------------

2114 * new infix operator, addss, allowing the classical reasoner to

2115 perform simplification at each step of its search. Example:

2116 fast_tac (cs addss ss)

2118 * a new logic, CHOL, the same as HOL, but with a curried syntax

2119 for functions. Application looks like f a b instead of f(a,b). Also pairs

2120 look like (a,b) instead of <a,b>;

2122 * PLEASE NOTE: CHOL will eventually replace HOL!

2124 * In CHOL, pattern-matching on tuples is now available in all abstractions.

2125 It translates to the operator "split". A new theory of integers is available;

2127 * In ZF, integer numerals now denote two's-complement binary integers.

2128 Arithmetic operations can be performed by rewriting. See ZF/ex/Bin.ML;

2130 * Many new examples: I/O automata, Church-Rosser theorem, equivalents

2131 of the Axiom of Choice;

2135 New in Isabelle94-2

2136 -------------------

2138 * Significantly faster resolution;

2140 * the different sections in a .thy file can now be mixed and repeated

2141 freely;

2143 * Database of theorems for FOL, HOL and ZF. New

2144 commands including qed, qed_goal and bind_thm store theorems in the database.

2146 * Simple database queries: return a named theorem (get_thm) or all theorems of

2147 a given theory (thms_of), or find out what theory a theorem was proved in

2148 (theory_of_thm);

2150 * Bugs fixed in the inductive definition and datatype packages;

2152 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs

2153 and HOL_dup_cs obsolete;

2155 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1

2156 have been removed;

2158 * Simpler definition of function space in ZF;

2160 * new results about cardinal and ordinal arithmetic in ZF;

2162 * 'subtype' facility in HOL for introducing new types as subsets of existing

2163 types;

2166 $Id$