summary |
shortlog |
changelog |
graph |
tags |
branches |
files |
changeset |
file |
revisions |
annotate |
diff |
raw

NEWS

author | nipkow |

Thu Feb 14 12:24:02 2002 +0100 (2002-02-14) | |

changeset 12889 | 1de4f0b824a8 |

parent 12877 | b9635eb8a448 |

child 12899 | 7d5b690253ee |

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

*** empty log message ***

1 Isabelle NEWS -- history user-relevant changes

2 ==============================================

4 New in Isabelle2002 (January 2002)

5 ----------------------------------

7 *** Document preparation ***

9 * greatly simplified document preparation setup, including more

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

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

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

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

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

16 with \includegraphics of LaTeX;

18 * proper spacing of consecutive markup elements, especially text

19 blocks after section headings;

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

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

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

25 better in printed text;

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

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

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

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

32 isatool document copies the Isabelle style files to the target

33 location;

36 *** Isar ***

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

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

40 "case (Suc n)");

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

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

43 instantiation of cases;

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

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

46 rules without further ado;

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

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

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

50 statement becomes is included in the hypothesis, avoiding the

51 slightly cumbersome show "PROP ?case" form;

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

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

54 rules stemming from inductive sets to be applied in unstructured

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

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

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

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

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

60 below);

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

62 success (no backtracking);

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

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

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

66 General versions);

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

68 - generic method setup instantiated for FOL and HOL;

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

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

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

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

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

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

76 fails:

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

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

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

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

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

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

86 attributes everywhere); operations on locales include merge and

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

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

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

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

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

93 qualified by the locale name);

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

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

97 coincides with that of a locale body;

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

101 * Pure: added 'corollary' command;

103 * Pure: fixed 'token_translation' command;

105 * Pure: removed obsolete 'exported' attribute;

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

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

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

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

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

113 rewrite rules declarations of 'atomize' attribute; example

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

115 proof *scripts*;

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

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

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

120 especially important for locales);

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

123 mode;

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

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

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

128 situations;

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

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

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

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

135 discontinued;

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

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

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

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

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

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

143 INCOMPATIBILITY;

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

146 of introduction rules;

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

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

150 conditional rules;

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

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

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

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

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

160 * HOL: properly declared induction rules less_induct and

161 wf_induct_rule;

164 *** HOL ***

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

167 follows:

169 - 0 and 1 are polymorphic constants, which are defined on any

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

172 - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based

173 binary representation internally;

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

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

178 This change may cause significant problems of INCOMPATIBILITY; here

179 are some hints on converting existing sources:

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

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

183 to be spaced properly;

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

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

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

190 - remove all special provisions on numerals in proofs;

192 * HOL: simp rules nat_number_of expand numerals on nat to Suc/0

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

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

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

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

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

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

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

203 * HOL/record package improvements:

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

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

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

207 declared as simp by default;

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

209 qualified) --- potential INCOMPATIBILITY;

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

211 INCOMPATIBILITY;

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

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

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

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

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

217 theory of product types over typedef rather than datatype;

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

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

222 (beware of argument permutation!);

224 * HOL: linorder_less_split superseded by linorder_cases;

226 * HOL/List: "nodups" renamed to "distinct"

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

229 to peripheral theory "Hilbert_Choice";

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

232 in this (rare) case use:

234 delSWrapper "split_all_tac"

235 addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)

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

238 MAY FAIL;

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

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

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

243 necessary to attach explicit type constraints;

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

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

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

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

250 expressions;

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

253 of "lam" -- INCOMPATIBILITY;

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

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

257 renamed "Product_Type.unit";

259 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl

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

262 Florian Kammüller);

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

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

266 some explanations (by Gerwin Klein);

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

270 * HOL-Hyperreal is now a logic image;

273 *** HOLCF ***

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

276 operations;

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

279 HOLCF/ex/Dnat.thy;

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

282 potential INCOMPATIBILITY; now use plain induct_tac instead of former

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

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

288 *** ZF ***

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

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

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

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

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

296 your theory on Main_ZFC;

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

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

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

302 typeless version of the formalism;

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

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

307 including theory Multiset for multiset orderings; converted to

308 new-style theory format;

310 * Many new theorems about lists, ordinals, etc.;

313 *** General ***

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

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

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

318 also ref manual for further ML interfaces;

320 * Pure/axclass: removed obsolete ML interface

321 goal_subclass/goal_arity;

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

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

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

326 properly;

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

329 rather than "infixl" or "infixr";

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

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

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

334 type variable);

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

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

338 "type_brackets";

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

341 tokens into AST constants;

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

344 translation functions; potential INCOMPATIBILITY: need to reverse

345 multiple declarations for same syntax element constant;

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

348 practice);

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

351 addSafter;

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

354 as well;

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

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

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

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

360 support requires further installations, e.g. from

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

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

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

366 of 40 MB), cf. ML_OPTIONS;

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

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

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

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

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

375 * system: smart selection of Isabelle process versus Isabelle

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

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

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

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

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

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

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

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

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

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

388 terminal);

392 New in Isabelle99-2 (February 2001)

393 -----------------------------------

395 *** Overview of INCOMPATIBILITIES ***

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

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

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

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

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

403 format may be recovered via ML function complete_split_rule or attribute

404 'split_rule (complete)';

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

407 gfp_Tarski to gfp_unfold;

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

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

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

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

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

416 operation;

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

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

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

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

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

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

427 \<gg> to \<ggreater>;

430 *** Document preparation ***

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

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

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

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

436 type-writer);

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

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

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

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

444 * improved isabelle style files; more abstract symbol implementation

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

446 definitions);

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

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

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

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

453 * proper indentation of antiquoted output with proportional LaTeX

454 fonts;

456 * no_document ML operator temporarily disables LaTeX document

457 generation;

459 * isatool unsymbolize tunes sources for plain ASCII communication;

462 *** Isar ***

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

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

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

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

468 for Prolog-style synthesis of proven results;

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

471 rules as well;

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

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

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

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

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

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

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

482 statements as well;

484 * Pure: more robust selection of calculational rules;

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

487 rule (as well as the assumption rule);

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

490 lemmas, using the graph browser tool;

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

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

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

497 (potential INCOMPATIBILITY); tuned error handling;

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

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

501 any remaining facts are inserted into the goal verbatim;

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

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

505 the result to be shown in each case;

507 * HOL: added 'recdef_tc' command;

509 * isatool convert assists in eliminating legacy ML scripts;

512 *** HOL ***

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

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

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

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

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

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

521 modelling and verification task performed in Isabelle/HOL +

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

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

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

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

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

528 literature;

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

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

532 operator \<Sum>;

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

535 HOL/subset.thy);

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

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

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

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

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

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

545 rules with string literals);

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

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

549 functions for the reals;

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

554 *** CTT ***

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

557 "lam" is displayed as TWO lambda-symbols

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

560 and Arith);

563 *** General ***

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

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

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

568 the Isabelle inference kernel has been greatly improved;

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

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

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

574 as assumptions as well;

576 * system: support Poly/ML 4.0;

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

582 New in Isabelle99-1 (October 2000)

583 ----------------------------------

585 *** Overview of INCOMPATIBILITIES ***

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

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

589 issue the following ML commands:

591 Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;

592 Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];

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

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

597 * HOL: nat_less_induct renamed to less_induct;

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

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

602 select_equality -> some_equality

603 select_eq_Ex -> some_eq_ex

604 selectI2EX -> someI2_ex

605 selectI2 -> someI2

606 selectI -> someI

607 select1_equality -> some1_equality

608 Eps_sym_eq -> some_sym_eq_trivial

609 Eps_eq -> some_eq_trivial

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

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

614 instead);

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

617 f.simps instead of f.rules;

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

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

622 sometimes be needed;

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

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

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

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

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

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

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

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

636 the old syntax may be recovered as follows:

638 syntax (symbols)

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

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

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

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

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

646 internally;

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

649 changed from A/r to A//r;

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

652 proofs;

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

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

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

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

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

660 "rule del";

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

664 * Provers: strengthened force_tac by using new first_best_tac;

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

667 lib/texinputs);

670 *** Document preparation ***

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

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

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

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

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

678 including proper document sources;

680 * generated LaTeX sources are now deleted after successful run

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

682 of isatool usedir;

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

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

686 LaTeX debugging;

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

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

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

692 graph for 'all sessions';

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

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

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

699 *** Isar ***

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

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

703 accommodates incremental type-inference very nicely;

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

706 generalized existence reasoning;

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

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

710 useful to collect intermediate results without explicit name

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

712 premises;

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

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

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

717 to theorems as "tags";

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

720 class/type/const name spaces;

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

723 indicate potential overloading;

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

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

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

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

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

732 with the version in Provers/classical;

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

735 case name 'antecedent';

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

738 to the current context is now done automatically);

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

741 for definining proof methods in ML;

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

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

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

746 replaced "delrule" by "rule del";

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

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

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

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

753 well (including splits);

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

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

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

759 of Simplifier and Classical reasoner);

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

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

763 recdef) support case names and properly name parameters;

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

766 monotonicity conditions are extracted to be proven at end of

767 calculations;

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

770 method anyway;

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

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

774 foo.split foo.split_asm for each datatype;

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

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

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

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

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

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

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

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

787 proof states;

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

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

791 proof state according to the Isabelle LaTeX style;

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

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

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

796 (for HOL datatypes);

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

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

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

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

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

805 should instead use individual commands for printing items

806 (print_commands, print_methods etc.);

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

811 *** HOL ***

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

814 corresponding virtual machine and a specification of its bytecode

815 verifier and a lightweight bytecode verifier, including proofs of

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

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

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

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

821 Clemens Ballarin;

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

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

825 Rasmussen;

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

828 structures, including duals, properties of bounds versus algebraic

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

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

831 for abstract algebraic reasoning using axiomatic type classes, and

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

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

835 von Oheimb;

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

838 recursive procedures, by David von Oheimb;

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

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

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

844 representation; very useful in avoiding lifting of operations;

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

847 select-update simplification procedure to handle extended records as

848 well; admit "r" as field name;

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

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

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

854 Types nat and int belong to this axclass;

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

880 termination conditions are proved automatically, these simplification

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

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

883 each equation;

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

886 permits the definition of tail-recursive functions without the

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

888 invariant proof rule for while is applied.

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

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

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

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

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

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

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

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

902 main HOL, but was unused);

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

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

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

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

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

910 bogus);

913 *** ZF ***

915 * ZF: simplification automatically cancels common terms in arithmetic

916 expressions over nat and int;

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

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

920 making the algebraic laws unconditional;

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

923 using the function intify;

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

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

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

929 simplification;

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

932 to the simplifier and classical reasoner simultaneously;

935 *** General ***

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

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

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

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

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

944 explicit make_elim);

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

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

948 use instead the strong form,

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

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

951 from destruct-rules;

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

954 Simplifier setup for new object-logics;

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

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

959 for hiding of names;

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

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

963 situations;

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

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

967 Poly/ML);

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

970 useful for remote X11);

972 * system: provide TAGS file for Isabelle sources;

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

975 order;

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

978 timing flag supersedes proof_timing and Toplevel.trace;

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

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

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

984 overloading (usually false);

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

987 results;

991 New in Isabelle99 (October 1999)

992 --------------------------------

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

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

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

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

1000 Delcongs [if_weak_cong];

1002 * HOL: Removed the obsolete syntax "Compl A"; use -A for set

1003 complement;

1005 * HOL: the predicate "inj" is now defined by translation to "inj_on";

1007 * HOL/datatype: mutual_induct_tac no longer exists --

1008 use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]

1010 * HOL/typedef: fixed type inference for representing set; type

1011 arguments now have to occur explicitly on the rhs as type constraints;

1013 * ZF: The con_defs part of an inductive definition may no longer refer

1014 to constants declared in the same theory;

1016 * HOL, ZF: the function mk_cases, generated by the inductive

1017 definition package, has lost an argument. To simplify its result, it

1018 uses the default simpset instead of a supplied list of theorems.

1020 * HOL/List: the constructors of type list are now Nil and Cons;

1022 * Simplifier: the type of the infix ML functions

1023 setSSolver addSSolver setSolver addSolver

1024 is now simpset * solver -> simpset where `solver' is a new abstract type

1025 for packaging solvers. A solver is created via

1026 mk_solver: string -> (thm list -> int -> tactic) -> solver

1027 where the string argument is only a comment.

1030 *** Proof tools ***

1032 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a

1033 decision procedure for linear arithmetic. Currently it is used for

1034 types `nat', `int', and `real' in HOL (see below); it can, should and

1035 will be instantiated for other types and logics as well.

1037 * The simplifier now accepts rewrite rules with flexible heads, eg

1038 hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y

1039 They are applied like any rule with a non-pattern lhs, i.e. by first-order

1040 matching.

1043 *** General ***

1045 * New Isabelle/Isar subsystem provides an alternative to traditional

1046 tactical theorem proving; together with the ProofGeneral/isar user

1047 interface it offers an interactive environment for developing human

1048 readable proof documents (Isar == Intelligible semi-automated

1049 reasoning); for further information see isatool doc isar-ref,

1050 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/

1052 * improved and simplified presentation of theories: better HTML markup

1053 (including colors), graph views in several sizes; isatool usedir now

1054 provides a proper interface for user theories (via -P option); actual

1055 document preparation based on (PDF)LaTeX is available as well (for

1056 new-style theories only); see isatool doc system for more information;

1058 * native support for Proof General, both for classic Isabelle and

1059 Isabelle/Isar;

1061 * ML function thm_deps visualizes dependencies of theorems and lemmas,

1062 using the graph browser tool;

1064 * Isabelle manuals now also available as PDF;

1066 * theory loader rewritten from scratch (may not be fully

1067 bug-compatible); old loadpath variable has been replaced by show_path,

1068 add_path, del_path, reset_path functions; new operations such as

1069 update_thy, touch_thy, remove_thy, use/update_thy_only (see also

1070 isatool doc ref);

1072 * improved isatool install: option -k creates KDE application icon,

1073 option -p DIR installs standalone binaries;

1075 * added ML_PLATFORM setting (useful for cross-platform installations);

1076 more robust handling of platform specific ML images for SML/NJ;

1078 * the settings environment is now statically scoped, i.e. it is never

1079 created again in sub-processes invoked from isabelle, isatool, or

1080 Isabelle;

1082 * path element specification '~~' refers to '$ISABELLE_HOME';

1084 * in locales, the "assumes" and "defines" parts may be omitted if

1085 empty;

1087 * new print_mode "xsymbols" for extended symbol support (e.g. genuine

1088 long arrows);

1090 * new print_mode "HTML";

1092 * new flag show_tags controls display of tags of theorems (which are

1093 basically just comments that may be attached by some tools);

1095 * Isamode 2.6 requires patch to accomodate change of Isabelle font

1096 mode and goal output format:

1098 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el

1099 244c244

1100 < (list (isa-getenv "ISABELLE") "-msymbols" logic-name)

1101 ---

1102 > (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)

1103 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el

1104 181c181

1105 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"

1106 ---

1107 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"

1109 * function bind_thms stores lists of theorems (cf. bind_thm);

1111 * new shorthand tactics ftac, eatac, datac, fatac;

1113 * qed (and friends) now accept "" as result name; in that case the

1114 theorem is not stored, but proper checks and presentation of the

1115 result still apply;

1117 * theorem database now also indexes constants "Trueprop", "all",

1118 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;

1121 *** HOL ***

1123 ** HOL arithmetic **

1125 * There are now decision procedures for linear arithmetic over nat and

1126 int:

1128 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',

1129 `+', `-', `Suc', `min', `max' and numerical constants; other subterms

1130 are treated as atomic; subformulae not involving type `nat' or `int'

1131 are ignored; quantified subformulae are ignored unless they are

1132 positive universal or negative existential. The tactic has to be

1133 invoked by hand and can be a little bit slow. In particular, the

1134 running time is exponential in the number of occurrences of `min' and

1135 `max', and `-' on `nat'.

1137 2. fast_arith_tac is a cut-down version of arith_tac: it only takes

1138 (negated) (in)equalities among the premises and the conclusion into

1139 account (i.e. no compound formulae) and does not know about `min' and

1140 `max', and `-' on `nat'. It is fast and is used automatically by the

1141 simplifier.

1143 NB: At the moment, these decision procedures do not cope with mixed

1144 nat/int formulae where the two parts interact, such as `m < n ==>

1145 int(m) < int(n)'.

1147 * HOL/Numeral provides a generic theory of numerals (encoded

1148 efficiently as bit strings); setup for types nat/int/real is in place;

1149 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than

1150 int, existing theories and proof scripts may require a few additional

1151 type constraints;

1153 * integer division and remainder can now be performed on constant

1154 arguments;

1156 * many properties of integer multiplication, division and remainder

1157 are now available;

1159 * An interface to the Stanford Validity Checker (SVC) is available through the

1160 tactic svc_tac. Propositional tautologies and theorems of linear arithmetic

1161 are proved automatically. SVC must be installed separately, and its results

1162 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any

1163 invocation of the underlying oracle). For SVC see

1164 http://verify.stanford.edu/SVC

1166 * IsaMakefile: the HOL-Real target now builds an actual image;

1169 ** HOL misc **

1171 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces

1172 (in Isabelle/Isar) -- by Gertrud Bauer;

1174 * HOL/BCV: generic model of bytecode verification, i.e. data-flow

1175 analysis for assembly languages with subtypes;

1177 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization

1178 -- avoids syntactic ambiguities and treats state, transition, and

1179 temporal levels more uniformly; introduces INCOMPATIBILITIES due to

1180 changed syntax and (many) tactics;

1182 * HOL/inductive: Now also handles more general introduction rules such

1183 as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity

1184 theorems are now maintained within the theory (maintained via the

1185 "mono" attribute);

1187 * HOL/datatype: Now also handles arbitrarily branching datatypes

1188 (using function types) such as

1190 datatype 'a tree = Atom 'a | Branch "nat => 'a tree"

1192 * HOL/record: record_simproc (part of the default simpset) takes care

1193 of selectors applied to updated records; record_split_tac is no longer

1194 part of the default claset; update_defs may now be removed from the

1195 simpset in many cases; COMPATIBILITY: old behavior achieved by

1197 claset_ref () := claset() addSWrapper record_split_wrapper;

1198 Delsimprocs [record_simproc]

1200 * HOL/typedef: fixed type inference for representing set; type

1201 arguments now have to occur explicitly on the rhs as type constraints;

1203 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem

1204 names rather than an ML expression;

1206 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be

1207 supplied later. Program schemes can be defined, such as

1208 "While B C s = (if B s then While B C (C s) else s)"

1209 where the well-founded relation can be chosen after B and C have been given.

1211 * HOL/List: the constructors of type list are now Nil and Cons;

1212 INCOMPATIBILITY: while [] and infix # syntax is still there, of

1213 course, ML tools referring to List.list.op # etc. have to be adapted;

1215 * HOL_quantifiers flag superseded by "HOL" print mode, which is

1216 disabled by default; run isabelle with option -m HOL to get back to

1217 the original Gordon/HOL-style output;

1219 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,

1220 ALL x<=y. P, EX x<y. P, EX x<=y. P;

1222 * HOL basic syntax simplified (more orthogonal): all variants of

1223 All/Ex now support plain / symbolic / HOL notation; plain syntax for

1224 Eps operator is provided as well: "SOME x. P[x]";

1226 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;

1228 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made

1229 thus available for user theories;

1231 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with

1232 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the

1233 time;

1235 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec

1236 several times and then mp;

1239 *** LK ***

1241 * the notation <<...>> is now available as a notation for sequences of

1242 formulas;

1244 * the simplifier is now installed

1246 * the axiom system has been generalized (thanks to Soren Heilmann)

1248 * the classical reasoner now has a default rule database

1251 *** ZF ***

1253 * new primrec section allows primitive recursive functions to be given

1254 directly (as in HOL) over datatypes and the natural numbers;

1256 * new tactics induct_tac and exhaust_tac for induction (or case

1257 analysis) over datatypes and the natural numbers;

1259 * the datatype declaration of type T now defines the recursor T_rec;

1261 * simplification automatically does freeness reasoning for datatype

1262 constructors;

1264 * automatic type-inference, with AddTCs command to insert new

1265 type-checking rules;

1267 * datatype introduction rules are now added as Safe Introduction rules

1268 to the claset;

1270 * the syntax "if P then x else y" is now available in addition to

1271 if(P,x,y);

1274 *** Internal programming interfaces ***

1276 * tuned simplifier trace output; new flag debug_simp;

1278 * structures Vartab / Termtab (instances of TableFun) offer efficient

1279 tables indexed by indexname_ord / term_ord (compatible with aconv);

1281 * AxClass.axclass_tac lost the theory argument;

1283 * tuned current_goals_markers semantics: begin / end goal avoids

1284 printing empty lines;

1286 * removed prs and prs_fn hook, which was broken because it did not

1287 include \n in its semantics, forcing writeln to add one

1288 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:

1289 string -> unit if you really want to output text without newline;

1291 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to

1292 plain output, interface builders may have to enable 'isabelle_font'

1293 mode to get Isabelle font glyphs as before;

1295 * refined token_translation interface; INCOMPATIBILITY: output length

1296 now of type real instead of int;

1298 * theory loader actions may be traced via new ThyInfo.add_hook

1299 interface (see src/Pure/Thy/thy_info.ML); example application: keep

1300 your own database of information attached to *whole* theories -- as

1301 opposed to intra-theory data slots offered via TheoryDataFun;

1303 * proper handling of dangling sort hypotheses (at last!);

1304 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing

1305 extra sort hypotheses that can be witnessed from the type signature;

1306 the force_strip_shyps flag is gone, any remaining shyps are simply

1307 left in the theorem (with a warning issued by strip_shyps_warning);

1311 New in Isabelle98-1 (October 1998)

1312 ----------------------------------

1314 *** Overview of INCOMPATIBILITIES (see below for more details) ***

1316 * several changes of automated proof tools;

1318 * HOL: major changes to the inductive and datatype packages, including

1319 some minor incompatibilities of theory syntax;

1321 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now

1322 called `inj_on';

1324 * HOL: removed duplicate thms in Arith:

1325 less_imp_add_less should be replaced by trans_less_add1

1326 le_imp_add_le should be replaced by trans_le_add1

1328 * HOL: unary minus is now overloaded (new type constraints may be

1329 required);

1331 * HOL and ZF: unary minus for integers is now #- instead of #~. In

1332 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is

1333 now taken as an integer constant.

1335 * Pure: ML function 'theory_of' renamed to 'theory';

1338 *** Proof tools ***

1340 * Simplifier:

1341 1. Asm_full_simp_tac is now more aggressive.

1342 1. It will sometimes reorient premises if that increases their power to

1343 simplify.

1344 2. It does no longer proceed strictly from left to right but may also

1345 rotate premises to achieve further simplification.

1346 For compatibility reasons there is now Asm_lr_simp_tac which is like the

1347 old Asm_full_simp_tac in that it does not rotate premises.

1348 2. The simplifier now knows a little bit about nat-arithmetic.

1350 * Classical reasoner: wrapper mechanism for the classical reasoner now

1351 allows for selected deletion of wrappers, by introduction of names for

1352 wrapper functionals. This implies that addbefore, addSbefore,

1353 addaltern, and addSaltern now take a pair (name, tactic) as argument,

1354 and that adding two tactics with the same name overwrites the first

1355 one (emitting a warning).

1356 type wrapper = (int -> tactic) -> (int -> tactic)

1357 setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by

1358 addWrapper, addSWrapper: claset * (string * wrapper) -> claset

1359 delWrapper, delSWrapper: claset * string -> claset

1360 getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;

1362 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE

1363 semantics; addbefore now affects only the unsafe part of step_tac

1364 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY

1365 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac

1366 by Force_tac;

1368 * Classical reasoner: setwrapper to setWrapper and compwrapper to

1369 compWrapper; added safe wrapper (and access functions for it);

1371 * HOL/split_all_tac is now much faster and fails if there is nothing

1372 to split. Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order

1373 and the names of the automatically generated variables have changed.

1374 split_all_tac has moved within claset() from unsafe wrappers to safe

1375 wrappers, which means that !!-bound variables are split much more

1376 aggressively, and safe_tac and clarify_tac now split such variables.

1377 If this splitting is not appropriate, use delSWrapper "split_all_tac".

1378 Note: the same holds for record_split_tac, which does the job of

1379 split_all_tac for record fields.

1381 * HOL/Simplifier: Rewrite rules for case distinctions can now be added

1382 permanently to the default simpset using Addsplits just like

1383 Addsimps. They can be removed via Delsplits just like

1384 Delsimps. Lower-case versions are also available.

1386 * HOL/Simplifier: The rule split_if is now part of the default

1387 simpset. This means that the simplifier will eliminate all occurrences

1388 of if-then-else in the conclusion of a goal. To prevent this, you can

1389 either remove split_if completely from the default simpset by

1390 `Delsplits [split_if]' or remove it in a specific call of the

1391 simplifier using `... delsplits [split_if]'. You can also add/delete

1392 other case splitting rules to/from the default simpset: every datatype

1393 generates suitable rules `split_t_case' and `split_t_case_asm' (where

1394 t is the name of the datatype).

1396 * Classical reasoner / Simplifier combination: new force_tac (and

1397 derivatives Force_tac, force) combines rewriting and classical

1398 reasoning (and whatever other tools) similarly to auto_tac, but is

1399 aimed to solve the given subgoal completely.

1402 *** General ***

1404 * new top-level commands `Goal' and `Goalw' that improve upon `goal'

1405 and `goalw': the theory is no longer needed as an explicit argument -

1406 the current theory context is used; assumptions are no longer returned

1407 at the ML-level unless one of them starts with ==> or !!; it is

1408 recommended to convert to these new commands using isatool fixgoal

1409 (backup your sources first!);

1411 * new top-level commands 'thm' and 'thms' for retrieving theorems from

1412 the current theory context, and 'theory' to lookup stored theories;

1414 * new theory section 'locale' for declaring constants, assumptions and

1415 definitions that have local scope;

1417 * new theory section 'nonterminals' for purely syntactic types;

1419 * new theory section 'setup' for generic ML setup functions

1420 (e.g. package initialization);

1422 * the distribution now includes Isabelle icons: see

1423 lib/logo/isabelle-{small,tiny}.xpm;

1425 * isatool install - install binaries with absolute references to

1426 ISABELLE_HOME/bin;

1428 * isatool logo -- create instances of the Isabelle logo (as EPS);

1430 * print mode 'emacs' reserved for Isamode;

1432 * support multiple print (ast) translations per constant name;

1434 * theorems involving oracles are now printed with a suffixed [!];

1437 *** HOL ***

1439 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');

1441 * HOL/inductive package reorganized and improved: now supports mutual

1442 definitions such as

1444 inductive EVEN ODD

1445 intrs

1446 null "0 : EVEN"

1447 oddI "n : EVEN ==> Suc n : ODD"

1448 evenI "n : ODD ==> Suc n : EVEN"

1450 new theorem list "elims" contains an elimination rule for each of the

1451 recursive sets; inductive definitions now handle disjunctive premises

1452 correctly (also ZF);

1454 INCOMPATIBILITIES: requires Inductive as an ancestor; component

1455 "mutual_induct" no longer exists - the induction rule is always

1456 contained in "induct";

1459 * HOL/datatype package re-implemented and greatly improved: now

1460 supports mutually recursive datatypes such as

1462 datatype

1463 'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)

1464 | SUM ('a aexp) ('a aexp)

1465 | DIFF ('a aexp) ('a aexp)

1466 | NUM 'a

1467 and

1468 'a bexp = LESS ('a aexp) ('a aexp)

1469 | AND ('a bexp) ('a bexp)

1470 | OR ('a bexp) ('a bexp)

1472 as well as indirectly recursive datatypes such as

1474 datatype

1475 ('a, 'b) term = Var 'a

1476 | App 'b ((('a, 'b) term) list)

1478 The new tactic mutual_induct_tac [<var_1>, ..., <var_n>] i performs

1479 induction on mutually / indirectly recursive datatypes.

1481 Primrec equations are now stored in theory and can be accessed via

1482 <function_name>.simps.

1484 INCOMPATIBILITIES:

1486 - Theories using datatypes must now have theory Datatype as an

1487 ancestor.

1488 - The specific <typename>.induct_tac no longer exists - use the

1489 generic induct_tac instead.

1490 - natE has been renamed to nat.exhaust - use exhaust_tac

1491 instead of res_inst_tac ... natE. Note that the variable

1492 names in nat.exhaust differ from the names in natE, this

1493 may cause some "fragile" proofs to fail.

1494 - The theorems split_<typename>_case and split_<typename>_case_asm

1495 have been renamed to <typename>.split and <typename>.split_asm.

1496 - Since default sorts of type variables are now handled correctly,

1497 some datatype definitions may have to be annotated with explicit

1498 sort constraints.

1499 - Primrec definitions no longer require function name and type

1500 of recursive argument.

1502 Consider using isatool fixdatatype to adapt your theories and proof

1503 scripts to the new package (backup your sources first!).

1506 * HOL/record package: considerably improved implementation; now

1507 includes concrete syntax for record types, terms, updates; theorems

1508 for surjective pairing and splitting !!-bound record variables; proof

1509 support is as follows:

1511 1) standard conversions (selectors or updates applied to record

1512 constructor terms) are part of the standard simpset;

1514 2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are

1515 made part of standard simpset and claset via addIffs;

1517 3) a tactic for record field splitting (record_split_tac) is part of

1518 the standard claset (addSWrapper);

1520 To get a better idea about these rules you may retrieve them via

1521 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is

1522 the name of your record type.

1524 The split tactic 3) conceptually simplifies by the following rule:

1526 "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"

1528 Thus any record variable that is bound by meta-all will automatically

1529 blow up into some record constructor term, consequently the

1530 simplifications of 1), 2) apply. Thus force_tac, auto_tac etc. shall

1531 solve record problems automatically.

1534 * reorganized the main HOL image: HOL/Integ and String loaded by

1535 default; theory Main includes everything;

1537 * automatic simplification of integer sums and comparisons, using cancellation;

1539 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;

1541 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;

1543 * many new identities for unions, intersections, set difference, etc.;

1545 * expand_if, expand_split, expand_sum_case and expand_nat_case are now

1546 called split_if, split_split, split_sum_case and split_nat_case (to go

1547 with add/delsplits);

1549 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting

1550 (?x::unit) = (); this is made part of the default simpset, which COULD

1551 MAKE EXISTING PROOFS FAIL under rare circumstances (consider

1552 'Delsimprocs [unit_eq_proc];' as last resort); also note that

1553 unit_abs_eta_conv is added in order to counter the effect of

1554 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by

1555 %u.f();

1557 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which

1558 makes more sense);

1560 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;

1561 It and 'sym RS equals0D' are now in the default claset, giving automatic

1562 disjointness reasoning but breaking a few old proofs.

1564 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1

1565 to 'converse' from 'inverse' (for compatibility with ZF and some

1566 literature);

1568 * HOL/recdef can now declare non-recursive functions, with {} supplied as

1569 the well-founded relation;

1571 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of

1572 Compl A. The "Compl" syntax remains available as input syntax for this

1573 release ONLY.

1575 * HOL/Update: new theory of function updates:

1576 f(a:=b) == %x. if x=a then b else f x

1577 may also be iterated as in f(a:=b,c:=d,...);

1579 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;

1581 * HOL/List:

1582 - new function list_update written xs[i:=v] that updates the i-th

1583 list position. May also be iterated as in xs[i:=a,j:=b,...].

1584 - new function `upt' written [i..j(] which generates the list

1585 [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper

1586 bound write [i..j], which is a shorthand for [i..j+1(].

1587 - new lexicographic orderings and corresponding wellfoundedness theorems.

1589 * HOL/Arith:

1590 - removed 'pred' (predecessor) function;

1591 - generalized some theorems about n-1;

1592 - many new laws about "div" and "mod";

1593 - new laws about greatest common divisors (see theory ex/Primes);

1595 * HOL/Relation: renamed the relational operator r^-1 "converse"

1596 instead of "inverse";

1598 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness

1599 of the multiset ordering;

1601 * directory HOL/Real: a construction of the reals using Dedekind cuts

1602 (not included by default);

1604 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;

1606 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted

1607 programs, i.e. different program variables may have different types.

1609 * calling (stac rew i) now fails if "rew" has no effect on the goal

1610 [previously, this check worked only if the rewrite rule was unconditional]

1611 Now rew can involve either definitions or equalities (either == or =).

1614 *** ZF ***

1616 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains

1617 only the theorems proved on ZF.ML;

1619 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;

1620 It and 'sym RS equals0D' are now in the default claset, giving automatic

1621 disjointness reasoning but breaking a few old proofs.

1623 * ZF/Update: new theory of function updates

1624 with default rewrite rule f(x:=y) ` z = if(z=x, y, f`z)

1625 may also be iterated as in f(a:=b,c:=d,...);

1627 * in let x=t in u(x), neither t nor u(x) has to be an FOL term.

1629 * calling (stac rew i) now fails if "rew" has no effect on the goal

1630 [previously, this check worked only if the rewrite rule was unconditional]

1631 Now rew can involve either definitions or equalities (either == or =).

1633 * case_tac provided for compatibility with HOL

1634 (like the old excluded_middle_tac, but with subgoals swapped)

1637 *** Internal programming interfaces ***

1639 * Pure: several new basic modules made available for general use, see

1640 also src/Pure/README;

1642 * improved the theory data mechanism to support encapsulation (data

1643 kind name replaced by private Object.kind, acting as authorization

1644 key); new type-safe user interface via functor TheoryDataFun; generic

1645 print_data function becomes basically useless;

1647 * removed global_names compatibility flag -- all theory declarations

1648 are qualified by default;

1650 * module Pure/Syntax now offers quote / antiquote translation

1651 functions (useful for Hoare logic etc. with implicit dependencies);

1652 see HOL/ex/Antiquote for an example use;

1654 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->

1655 cterm -> thm;

1657 * new tactical CHANGED_GOAL for checking that a tactic modifies a

1658 subgoal;

1660 * Display.print_goals function moved to Locale.print_goals;

1662 * standard print function for goals supports current_goals_markers

1663 variable for marking begin of proof, end of proof, start of goal; the

1664 default is ("", "", ""); setting current_goals_markers := ("<proof>",

1665 "</proof>", "<goal>") causes SGML like tagged proof state printing,

1666 for example;

1670 New in Isabelle98 (January 1998)

1671 --------------------------------

1673 *** Overview of INCOMPATIBILITIES (see below for more details) ***

1675 * changed lexical syntax of terms / types: dots made part of long

1676 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";

1678 * simpset (and claset) reference variable replaced by functions

1679 simpset / simpset_ref;

1681 * no longer supports theory aliases (via merge) and non-trivial

1682 implicit merge of thms' signatures;

1684 * most internal names of constants changed due to qualified names;

1686 * changed Pure/Sequence interface (see Pure/seq.ML);

1689 *** General Changes ***

1691 * hierachically structured name spaces (for consts, types, axms, thms

1692 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of

1693 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:

1694 isatool fixdots ensures space after dots (e.g. "%x. x"); set

1695 long_names for fully qualified output names; NOTE: ML programs

1696 (special tactics, packages etc.) referring to internal names may have

1697 to be adapted to cope with fully qualified names; in case of severe

1698 backward campatibility problems try setting 'global_names' at compile

1699 time to have enrything declared within a flat name space; one may also

1700 fine tune name declarations in theories via the 'global' and 'local'

1701 section;

1703 * reimplemented the implicit simpset and claset using the new anytype

1704 data filed in signatures; references simpset:simpset ref etc. are

1705 replaced by functions simpset:unit->simpset and

1706 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp

1707 to patch your ML files accordingly;

1709 * HTML output now includes theory graph data for display with Java

1710 applet or isatool browser; data generated automatically via isatool

1711 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);

1713 * defs may now be conditional; improved rewrite_goals_tac to handle

1714 conditional equations;

1716 * defs now admits additional type arguments, using TYPE('a) syntax;

1718 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always

1719 creates a new theory node; implicit merge of thms' signatures is

1720 restricted to 'trivial' ones; COMPATIBILITY: one may have to use

1721 transfer:theory->thm->thm in (rare) cases;

1723 * improved handling of draft signatures / theories; draft thms (and

1724 ctyps, cterms) are automatically promoted to real ones;

1726 * slightly changed interfaces for oracles: admit many per theory, named

1727 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;

1729 * print_goals: optional output of const types (set show_consts and

1730 show_types);

1732 * improved output of warnings (###) and errors (***);

1734 * subgoal_tac displays a warning if the new subgoal has type variables;

1736 * removed old README and Makefiles;

1738 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;

1740 * removed obsolete init_pps and init_database;

1742 * deleted the obsolete tactical STATE, which was declared by

1743 fun STATE tacfun st = tacfun st st;

1745 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~

1746 (which abbreviates $HOME);

1748 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:

1749 use isatool fixseq to adapt your ML programs (this works for fully

1750 qualified references to the Sequence structure only!);

1752 * use_thy no longer requires writable current directory; it always

1753 reloads .ML *and* .thy file, if either one is out of date;

1756 *** Classical Reasoner ***

1758 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new

1759 tactics that use classical reasoning to simplify a subgoal without

1760 splitting it into several subgoals;

1762 * Safe_tac: like safe_tac but uses the default claset;

1765 *** Simplifier ***

1767 * added simplification meta rules:

1768 (asm_)(full_)simplify: simpset -> thm -> thm;

1770 * simplifier.ML no longer part of Pure -- has to be loaded by object

1771 logics (again);

1773 * added prems argument to simplification procedures;

1775 * HOL, FOL, ZF: added infix function `addsplits':

1776 instead of `<simpset> setloop (split_tac <thms>)'

1777 you can simply write `<simpset> addsplits <thms>'

1780 *** Syntax ***

1782 * TYPE('a) syntax for type reflection terms;

1784 * no longer handles consts with name "" -- declare as 'syntax' instead;

1786 * pretty printer: changed order of mixfix annotation preference (again!);

1788 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;

1791 *** HOL ***

1793 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.

1794 with `addloop' of the simplifier to faciliate case splitting in premises.

1796 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;

1798 * HOL/Auth: new protocol proofs including some for the Internet

1799 protocol TLS;

1801 * HOL/Map: new theory of `maps' a la VDM;

1803 * HOL/simplifier: simplification procedures nat_cancel_sums for

1804 cancelling out common nat summands from =, <, <= (in)equalities, or

1805 differences; simplification procedures nat_cancel_factor for

1806 cancelling common factor from =, <, <= (in)equalities over natural

1807 sums; nat_cancel contains both kinds of procedures, it is installed by

1808 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;

1810 * HOL/simplifier: terms of the form

1811 `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)' (or t=x)

1812 are rewritten to

1813 `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',

1814 and those of the form

1815 `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)' (or t=x)

1816 are rewritten to

1817 `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',

1819 * HOL/datatype

1820 Each datatype `t' now comes with a theorem `split_t_case' of the form

1822 P(t_case f1 ... fn x) =

1823 ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &

1824 ...

1825 (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))

1826 )

1828 and a theorem `split_t_case_asm' of the form

1830 P(t_case f1 ... fn x) =

1831 ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |

1832 ...

1833 (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))

1834 )

1835 which can be added to a simpset via `addsplits'. The existing theorems

1836 expand_list_case and expand_option_case have been renamed to

1837 split_list_case and split_option_case.

1839 * HOL/Arithmetic:

1840 - `pred n' is automatically converted to `n-1'.

1841 Users are strongly encouraged not to use `pred' any longer,

1842 because it will disappear altogether at some point.

1843 - Users are strongly encouraged to write "0 < n" rather than

1844 "n ~= 0". Theorems and proof tools have been modified towards this

1845 `standard'.

1847 * HOL/Lists:

1848 the function "set_of_list" has been renamed "set" (and its theorems too);

1849 the function "nth" now takes its arguments in the reverse order and

1850 has acquired the infix notation "!" as in "xs!n".

1852 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};

1854 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its

1855 specialist theorems (like UN1_I) are gone. Similarly for (INT x.B x);

1857 * HOL/record: extensible records with schematic structural subtyping

1858 (single inheritance); EXPERIMENTAL version demonstrating the encoding,

1859 still lacks various theorems and concrete record syntax;

1862 *** HOLCF ***

1864 * removed "axioms" and "generated by" sections;

1866 * replaced "ops" section by extended "consts" section, which is capable of

1867 handling the continuous function space "->" directly;

1869 * domain package:

1870 . proves theorems immediately and stores them in the theory,

1871 . creates hierachical name space,

1872 . now uses normal mixfix annotations (instead of cinfix...),

1873 . minor changes to some names and values (for consistency),

1874 . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,

1875 . separator between mutual domain defs: changed "," to "and",

1876 . improved handling of sort constraints; now they have to

1877 appear on the left-hand side of the equations only;

1879 * fixed LAM <x,y,zs>.b syntax;

1881 * added extended adm_tac to simplifier in HOLCF -- can now discharge

1882 adm (%x. P (t x)), where P is chainfinite and t continuous;

1885 *** FOL and ZF ***

1887 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.

1888 with `addloop' of the simplifier to faciliate case splitting in premises.

1890 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as

1891 in HOL, they strip ALL and --> from proved theorems;

1895 New in Isabelle94-8 (May 1997)

1896 ------------------------------

1898 *** General Changes ***

1900 * new utilities to build / run / maintain Isabelle etc. (in parts

1901 still somewhat experimental); old Makefiles etc. still functional;

1903 * new 'Isabelle System Manual';

1905 * INSTALL text, together with ./configure and ./build scripts;

1907 * reimplemented type inference for greater efficiency, better error

1908 messages and clean internal interface;

1910 * prlim command for dealing with lots of subgoals (an easier way of

1911 setting goals_limit);

1914 *** Syntax ***

1916 * supports alternative (named) syntax tables (parser and pretty

1917 printer); internal interface is provided by add_modesyntax(_i);

1919 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to

1920 be used in conjunction with the Isabelle symbol font; uses the

1921 "symbols" syntax table;

1923 * added token_translation interface (may translate name tokens in

1924 arbitrary ways, dependent on their type (free, bound, tfree, ...) and

1925 the current print_mode); IMPORTANT: user print translation functions

1926 are responsible for marking newly introduced bounds

1927 (Syntax.mark_boundT);

1929 * token translations for modes "xterm" and "xterm_color" that display

1930 names in bold, underline etc. or colors (which requires a color

1931 version of xterm);

1933 * infixes may now be declared with names independent of their syntax;

1935 * added typed_print_translation (like print_translation, but may

1936 access type of constant);

1939 *** Classical Reasoner ***

1941 Blast_tac: a new tactic! It is often more powerful than fast_tac, but has

1942 some limitations. Blast_tac...

1943 + ignores addss, addbefore, addafter; this restriction is intrinsic

1944 + ignores elimination rules that don't have the correct format

1945 (the conclusion MUST be a formula variable)

1946 + ignores types, which can make HOL proofs fail

1947 + rules must not require higher-order unification, e.g. apply_type in ZF

1948 [message "Function Var's argument not a bound variable" relates to this]

1949 + its proof strategy is more general but can actually be slower

1951 * substitution with equality assumptions no longer permutes other

1952 assumptions;

1954 * minor changes in semantics of addafter (now called addaltern); renamed

1955 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper

1956 (and access functions for it);

1958 * improved combination of classical reasoner and simplifier:

1959 + functions for handling clasimpsets

1960 + improvement of addss: now the simplifier is called _after_ the

1961 safe steps.

1962 + safe variant of addss called addSss: uses safe simplifications

1963 _during_ the safe steps. It is more complete as it allows multiple

1964 instantiations of unknowns (e.g. with slow_tac).

1966 *** Simplifier ***

1968 * added interface for simplification procedures (functions that

1969 produce *proven* rewrite rules on the fly, depending on current

1970 redex);

1972 * ordering on terms as parameter (used for ordered rewriting);

1974 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;

1976 * the solver is now split into a safe and an unsafe part.

1977 This should be invisible for the normal user, except that the

1978 functions setsolver and addsolver have been renamed to setSolver and

1979 addSolver; added safe_asm_full_simp_tac;

1982 *** HOL ***

1984 * a generic induction tactic `induct_tac' which works for all datatypes and

1985 also for type `nat';

1987 * a generic case distinction tactic `exhaust_tac' which works for all

1988 datatypes and also for type `nat';

1990 * each datatype comes with a function `size';

1992 * patterns in case expressions allow tuple patterns as arguments to

1993 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';

1995 * primrec now also works with type nat;

1997 * recdef: a new declaration form, allows general recursive functions to be

1998 defined in theory files. See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.

2000 * the constant for negation has been renamed from "not" to "Not" to

2001 harmonize with FOL, ZF, LK, etc.;

2003 * HOL/ex/LFilter theory of a corecursive "filter" functional for

2004 infinite lists;

2006 * HOL/Modelcheck demonstrates invocation of model checker oracle;

2008 * HOL/ex/Ring.thy declares cring_simp, which solves equational

2009 problems in commutative rings, using axiomatic type classes for + and *;

2011 * more examples in HOL/MiniML and HOL/Auth;

2013 * more default rewrite rules for quantifiers, union/intersection;

2015 * a new constant `arbitrary == @x.False';

2017 * HOLCF/IOA replaces old HOL/IOA;

2019 * HOLCF changes: derived all rules and arities

2020 + axiomatic type classes instead of classes

2021 + typedef instead of faking type definitions

2022 + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.

2023 + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po

2024 + eliminated the types void, one, tr

2025 + use unit lift and bool lift (with translations) instead of one and tr

2026 + eliminated blift from Lift3.thy (use Def instead of blift)

2027 all eliminated rules are derived as theorems --> no visible changes ;

2030 *** ZF ***

2032 * ZF now has Fast_tac, Simp_tac and Auto_tac. Union_iff is a now a default

2033 rewrite rule; this may affect some proofs. eq_cs is gone but can be put back

2034 as ZF_cs addSIs [equalityI];

2038 New in Isabelle94-7 (November 96)

2039 ---------------------------------

2041 * allowing negative levels (as offsets) in prlev and choplev;

2043 * super-linear speedup for large simplifications;

2045 * FOL, ZF and HOL now use miniscoping: rewriting pushes

2046 quantifications in as far as possible (COULD MAKE EXISTING PROOFS

2047 FAIL); can suppress it using the command Delsimps (ex_simps @

2048 all_simps); De Morgan laws are also now included, by default;

2050 * improved printing of ==> : ~:

2052 * new object-logic "Sequents" adds linear logic, while replacing LK

2053 and Modal (thanks to Sara Kalvala);

2055 * HOL/Auth: correctness proofs for authentication protocols;

2057 * HOL: new auto_tac combines rewriting and classical reasoning (many

2058 examples on HOL/Auth);

2060 * HOL: new command AddIffs for declaring theorems of the form P=Q to

2061 the rewriter and classical reasoner simultaneously;

2063 * function uresult no longer returns theorems in "standard" format;

2064 regain previous version by: val uresult = standard o uresult;

2068 New in Isabelle94-6

2069 -------------------

2071 * oracles -- these establish an interface between Isabelle and trusted

2072 external reasoners, which may deliver results as theorems;

2074 * proof objects (in particular record all uses of oracles);

2076 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;

2078 * "constdefs" section in theory files;

2080 * "primrec" section (HOL) no longer requires names;

2082 * internal type "tactic" now simply "thm -> thm Sequence.seq";

2086 New in Isabelle94-5

2087 -------------------

2089 * reduced space requirements;

2091 * automatic HTML generation from theories;

2093 * theory files no longer require "..." (quotes) around most types;

2095 * new examples, including two proofs of the Church-Rosser theorem;

2097 * non-curried (1994) version of HOL is no longer distributed;

2101 New in Isabelle94-4

2102 -------------------

2104 * greatly reduced space requirements;

2106 * theory files (.thy) no longer require \...\ escapes at line breaks;

2108 * searchable theorem database (see the section "Retrieving theorems" on

2109 page 8 of the Reference Manual);

2111 * new examples, including Grabczewski's monumental case study of the

2112 Axiom of Choice;

2114 * The previous version of HOL renamed to Old_HOL;

2116 * The new version of HOL (previously called CHOL) uses a curried syntax

2117 for functions. Application looks like f a b instead of f(a,b);

2119 * Mutually recursive inductive definitions finally work in HOL;

2121 * In ZF, pattern-matching on tuples is now available in all abstractions and

2122 translates to the operator "split";

2126 New in Isabelle94-3

2127 -------------------

2129 * new infix operator, addss, allowing the classical reasoner to

2130 perform simplification at each step of its search. Example:

2131 fast_tac (cs addss ss)

2133 * a new logic, CHOL, the same as HOL, but with a curried syntax

2134 for functions. Application looks like f a b instead of f(a,b). Also pairs

2135 look like (a,b) instead of <a,b>;

2137 * PLEASE NOTE: CHOL will eventually replace HOL!

2139 * In CHOL, pattern-matching on tuples is now available in all abstractions.

2140 It translates to the operator "split". A new theory of integers is available;

2142 * In ZF, integer numerals now denote two's-complement binary integers.

2143 Arithmetic operations can be performed by rewriting. See ZF/ex/Bin.ML;

2145 * Many new examples: I/O automata, Church-Rosser theorem, equivalents

2146 of the Axiom of Choice;

2150 New in Isabelle94-2

2151 -------------------

2153 * Significantly faster resolution;

2155 * the different sections in a .thy file can now be mixed and repeated

2156 freely;

2158 * Database of theorems for FOL, HOL and ZF. New

2159 commands including qed, qed_goal and bind_thm store theorems in the database.

2161 * Simple database queries: return a named theorem (get_thm) or all theorems of

2162 a given theory (thms_of), or find out what theory a theorem was proved in

2163 (theory_of_thm);

2165 * Bugs fixed in the inductive definition and datatype packages;

2167 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs

2168 and HOL_dup_cs obsolete;

2170 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1

2171 have been removed;

2173 * Simpler definition of function space in ZF;

2175 * new results about cardinal and ordinal arithmetic in ZF;

2177 * 'subtype' facility in HOL for introducing new types as subsets of existing

2178 types;

2181 $Id$