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NEWS

author | wenzelm |

Fri Mar 08 16:24:06 2002 +0100 (2002-03-08) | |

changeset 13049 | ce180e5b7fa0 |

parent 13042 | d8a345d9e067 |

child 13158 | 8e86582a90d1 |

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

tuned;

2 Isabelle NEWS -- history user-relevant changes

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

5 New in Isabelle2002 (March 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 HOL Test && isatool make"; alternatively,

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

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

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

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

19 with \includegraphics of LaTeX;

21 * proper spacing of consecutive markup elements, especially text

22 blocks after section headings;

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

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

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

28 better in printed text;

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

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

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

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

35 isatool document copies the Isabelle style files to the target

36 location;

39 *** Isar ***

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

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

43 "case (Suc n)");

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

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

46 instantiation of cases;

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

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

49 rules without further ado;

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

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

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

53 statement becomes is included in the hypothesis, avoiding the

54 slightly cumbersome show "PROP ?case" form;

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

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

57 rules stemming from inductive sets to be applied in unstructured

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

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

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

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

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

63 below);

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

65 success (no backtracking);

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

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

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

69 General versions);

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

71 - generic method setup instantiated for FOL and HOL;

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

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

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

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

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

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

79 fails:

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

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

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

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

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

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

89 attributes everywhere); operations on locales include merge and

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

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

92 some examples;

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

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

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

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

98 qualified by the locale name);

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

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

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

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

104 the context elements being discharged in the obvious way;

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

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

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

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

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

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

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

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

116 use hard-wired "Trueprop";

118 * Pure: added 'corollary' command;

120 * Pure: fixed 'token_translation' command;

122 * Pure: removed obsolete 'exported' attribute;

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

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

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

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

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

130 rewrite rules declarations of 'atomize' attribute; example

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

132 proof *scripts*;

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

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

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

137 especially important for locales);

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

140 mode;

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

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

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

145 situations;

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

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

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

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

152 discontinued;

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

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

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

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

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

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

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

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

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

164 INCOMPATIBILITY;

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

167 of introduction rules;

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

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

171 conditional rules;

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

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

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

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

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

181 * HOL: properly declared induction rules less_induct and

182 wf_induct_rule;

185 *** HOL ***

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

188 follows:

190 - 0 and 1 are polymorphic constants, which are defined on any

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

193 - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based

194 binary representation internally;

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

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

199 This change may cause significant problems of INCOMPATIBILITY; here

200 are some hints on converting existing sources:

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

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

204 to be spaced properly;

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

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

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

211 - remove all special provisions on numerals in proofs;

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

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

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

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

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

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

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

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

224 * HOL/record package improvements:

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

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

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

228 declared as simp by default;

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

230 qualified) --- potential INCOMPATIBILITY;

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

232 INCOMPATIBILITY;

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

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

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

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

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

238 theory of product types over typedef rather than datatype;

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

241 specifications; specific support for HOL constructs such as inductive

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

243 via 'generate_code' theory section;

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

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

248 (beware of argument permutation!);

250 * HOL: linorder_less_split superseded by linorder_cases;

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

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

255 to peripheral theory "Hilbert_Choice";

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

258 in this (rare) case use:

260 delSWrapper "split_all_tac"

261 addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)

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

264 MAY FAIL;

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

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

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

269 necessary to attach explicit type constraints;

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

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

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

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

276 expressions;

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

279 of "lam" -- INCOMPATIBILITY;

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

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

283 renamed "Product_Type.unit";

285 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl

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

288 the "cases" method);

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

291 Florian Kammüller);

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

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

295 some explanations (by Gerwin Klein);

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

299 * HOL-Hyperreal is now a logic image;

302 *** HOLCF ***

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

305 operations;

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

308 HOLCF/ex/Dnat.thy;

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

311 potential INCOMPATIBILITY; now use plain induct_tac instead of former

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

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

317 *** ZF ***

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

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

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

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

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

325 your theory on Main_ZFC;

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

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

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

331 typeless version of the formalism;

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

334 format;

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

337 including theory Multiset for multiset orderings; converted to

338 new-style theory format;

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

343 *** General ***

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

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

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

348 also ref manual for further ML interfaces;

350 * Pure/axclass: removed obsolete ML interface

351 goal_subclass/goal_arity;

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

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

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

356 properly;

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

359 rather than "infixl" or "infixr";

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

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

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

364 type variable);

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

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

368 "type_brackets";

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

371 tokens into AST constants;

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

374 translation functions; potential INCOMPATIBILITY: need to reverse

375 multiple declarations for same syntax element constant;

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

378 practice);

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

381 addSafter;

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

384 as well;

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

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

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

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

390 support requires further installations, e.g. from

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

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

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

396 of 40 MB), cf. ML_OPTIONS;

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

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

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

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

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

405 * system: smart selection of Isabelle process versus Isabelle

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

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

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

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

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

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

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

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

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

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

418 terminal);

422 New in Isabelle99-2 (February 2001)

423 -----------------------------------

425 *** Overview of INCOMPATIBILITIES ***

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

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

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

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

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

433 format may be recovered via ML function complete_split_rule or attribute

434 'split_rule (complete)';

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

437 gfp_Tarski to gfp_unfold;

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

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

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

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

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

446 operation;

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

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

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

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

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

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

457 \<gg> to \<ggreater>;

460 *** Document preparation ***

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

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

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

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

466 type-writer);

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

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

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

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

474 * improved isabelle style files; more abstract symbol implementation

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

476 definitions);

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

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

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

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

483 * proper indentation of antiquoted output with proportional LaTeX

484 fonts;

486 * no_document ML operator temporarily disables LaTeX document

487 generation;

489 * isatool unsymbolize tunes sources for plain ASCII communication;

492 *** Isar ***

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

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

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

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

498 for Prolog-style synthesis of proven results;

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

501 rules as well;

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

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

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

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

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

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

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

512 statements as well;

514 * Pure: more robust selection of calculational rules;

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

517 rule (as well as the assumption rule);

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

520 lemmas, using the graph browser tool;

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

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

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

527 (potential INCOMPATIBILITY); tuned error handling;

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

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

531 any remaining facts are inserted into the goal verbatim;

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

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

535 the result to be shown in each case;

537 * HOL: added 'recdef_tc' command;

539 * isatool convert assists in eliminating legacy ML scripts;

542 *** HOL ***

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

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

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

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

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

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

551 modelling and verification task performed in Isabelle/HOL +

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

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

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

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

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

558 literature;

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

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

562 operator \<Sum>;

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

565 HOL/subset.thy);

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

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

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

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

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

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

575 rules with string literals);

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

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

579 functions for the reals;

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

584 *** CTT ***

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

587 "lam" is displayed as TWO lambda-symbols

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

590 and Arith);

593 *** General ***

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

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

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

598 the Isabelle inference kernel has been greatly improved;

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

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

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

604 as assumptions as well;

606 * system: support Poly/ML 4.0;

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

612 New in Isabelle99-1 (October 2000)

613 ----------------------------------

615 *** Overview of INCOMPATIBILITIES ***

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

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

619 issue the following ML commands:

621 Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;

622 Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];

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

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

627 * HOL: nat_less_induct renamed to less_induct;

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

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

632 select_equality -> some_equality

633 select_eq_Ex -> some_eq_ex

634 selectI2EX -> someI2_ex

635 selectI2 -> someI2

636 selectI -> someI

637 select1_equality -> some1_equality

638 Eps_sym_eq -> some_sym_eq_trivial

639 Eps_eq -> some_eq_trivial

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

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

644 instead);

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

647 f.simps instead of f.rules;

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

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

652 sometimes be needed;

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

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

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

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

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

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

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

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

666 the old syntax may be recovered as follows:

668 syntax (symbols)

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

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

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

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

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

676 internally;

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

679 changed from A/r to A//r;

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

682 proofs;

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

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

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

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

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

690 "rule del";

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

694 * Provers: strengthened force_tac by using new first_best_tac;

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

697 lib/texinputs);

700 *** Document preparation ***

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

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

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

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

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

708 including proper document sources;

710 * generated LaTeX sources are now deleted after successful run

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

712 of isatool usedir;

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

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

716 LaTeX debugging;

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

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

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

722 graph for 'all sessions';

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

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

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

729 *** Isar ***

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

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

733 accommodates incremental type-inference very nicely;

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

736 generalized existence reasoning;

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

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

740 useful to collect intermediate results without explicit name

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

742 premises;

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

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

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

747 to theorems as "tags";

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

750 class/type/const name spaces;

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

753 indicate potential overloading;

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

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

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

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

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

762 with the version in Provers/classical;

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

765 case name 'antecedent';

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

768 to the current context is now done automatically);

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

771 for definining proof methods in ML;

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

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

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

776 replaced "delrule" by "rule del";

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

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

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

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

783 well (including splits);

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

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

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

789 of Simplifier and Classical reasoner);

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

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

793 recdef) support case names and properly name parameters;

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

796 monotonicity conditions are extracted to be proven at end of

797 calculations;

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

800 method anyway;

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

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

804 foo.split foo.split_asm for each datatype;

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

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

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

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

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

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

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

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

817 proof states;

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

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

821 proof state according to the Isabelle LaTeX style;

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

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

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

826 (for HOL datatypes);

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

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

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

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

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

835 should instead use individual commands for printing items

836 (print_commands, print_methods etc.);

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

841 *** HOL ***

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

844 corresponding virtual machine and a specification of its bytecode

845 verifier and a lightweight bytecode verifier, including proofs of

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

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

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

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

851 Clemens Ballarin;

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

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

855 Rasmussen;

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

858 structures, including duals, properties of bounds versus algebraic

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

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

861 for abstract algebraic reasoning using axiomatic type classes, and

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

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

865 von Oheimb;

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

868 recursive procedures, by David von Oheimb;

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

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

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

874 representation; very useful in avoiding lifting of operations;

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

877 select-update simplification procedure to handle extended records as

878 well; admit "r" as field name;

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

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

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

884 Types nat and int belong to this axclass;

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

910 termination conditions are proved automatically, these simplification

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

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

913 each equation;

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

916 permits the definition of tail-recursive functions without the

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

918 invariant proof rule for while is applied.

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

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

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

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

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

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

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

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

932 main HOL, but was unused);

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

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

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

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

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

940 bogus);

943 *** ZF ***

945 * ZF: simplification automatically cancels common terms in arithmetic

946 expressions over nat and int;

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

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

950 making the algebraic laws unconditional;

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

953 using the function intify;

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

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

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

959 simplification;

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

962 to the simplifier and classical reasoner simultaneously;

965 *** General ***

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

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

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

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

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

974 explicit make_elim);

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

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

978 use instead the strong form,

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

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

981 from destruct-rules;

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

984 Simplifier setup for new object-logics;

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

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

989 for hiding of names;

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

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

993 situations;

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

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

997 Poly/ML);

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

1000 useful for remote X11);

1002 * system: provide TAGS file for Isabelle sources;

1004 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument

1005 order;

1007 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global

1008 timing flag supersedes proof_timing and Toplevel.trace;

1010 * ML: new combinators |>> and |>>> for incremental transformations

1011 with secondary results (e.g. certain theory extensions):

1013 * ML: PureThy.add_defs gets additional argument to indicate potential

1014 overloading (usually false);

1016 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as

1017 results;

1021 New in Isabelle99 (October 1999)

1022 --------------------------------

1024 *** Overview of INCOMPATIBILITIES (see below for more details) ***

1026 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)

1027 are no longer simplified. (This allows the simplifier to unfold recursive

1028 functional programs.) To restore the old behaviour, declare

1030 Delcongs [if_weak_cong];

1032 * HOL: Removed the obsolete syntax "Compl A"; use -A for set

1033 complement;

1035 * HOL: the predicate "inj" is now defined by translation to "inj_on";

1037 * HOL/datatype: mutual_induct_tac no longer exists --

1038 use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]

1040 * HOL/typedef: fixed type inference for representing set; type

1041 arguments now have to occur explicitly on the rhs as type constraints;

1043 * ZF: The con_defs part of an inductive definition may no longer refer

1044 to constants declared in the same theory;

1046 * HOL, ZF: the function mk_cases, generated by the inductive

1047 definition package, has lost an argument. To simplify its result, it

1048 uses the default simpset instead of a supplied list of theorems.

1050 * HOL/List: the constructors of type list are now Nil and Cons;

1052 * Simplifier: the type of the infix ML functions

1053 setSSolver addSSolver setSolver addSolver

1054 is now simpset * solver -> simpset where `solver' is a new abstract type

1055 for packaging solvers. A solver is created via

1056 mk_solver: string -> (thm list -> int -> tactic) -> solver

1057 where the string argument is only a comment.

1060 *** Proof tools ***

1062 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a

1063 decision procedure for linear arithmetic. Currently it is used for

1064 types `nat', `int', and `real' in HOL (see below); it can, should and

1065 will be instantiated for other types and logics as well.

1067 * The simplifier now accepts rewrite rules with flexible heads, eg

1068 hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y

1069 They are applied like any rule with a non-pattern lhs, i.e. by first-order

1070 matching.

1073 *** General ***

1075 * New Isabelle/Isar subsystem provides an alternative to traditional

1076 tactical theorem proving; together with the ProofGeneral/isar user

1077 interface it offers an interactive environment for developing human

1078 readable proof documents (Isar == Intelligible semi-automated

1079 reasoning); for further information see isatool doc isar-ref,

1080 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/

1082 * improved and simplified presentation of theories: better HTML markup

1083 (including colors), graph views in several sizes; isatool usedir now

1084 provides a proper interface for user theories (via -P option); actual

1085 document preparation based on (PDF)LaTeX is available as well (for

1086 new-style theories only); see isatool doc system for more information;

1088 * native support for Proof General, both for classic Isabelle and

1089 Isabelle/Isar;

1091 * ML function thm_deps visualizes dependencies of theorems and lemmas,

1092 using the graph browser tool;

1094 * Isabelle manuals now also available as PDF;

1096 * theory loader rewritten from scratch (may not be fully

1097 bug-compatible); old loadpath variable has been replaced by show_path,

1098 add_path, del_path, reset_path functions; new operations such as

1099 update_thy, touch_thy, remove_thy, use/update_thy_only (see also

1100 isatool doc ref);

1102 * improved isatool install: option -k creates KDE application icon,

1103 option -p DIR installs standalone binaries;

1105 * added ML_PLATFORM setting (useful for cross-platform installations);

1106 more robust handling of platform specific ML images for SML/NJ;

1108 * the settings environment is now statically scoped, i.e. it is never

1109 created again in sub-processes invoked from isabelle, isatool, or

1110 Isabelle;

1112 * path element specification '~~' refers to '$ISABELLE_HOME';

1114 * in locales, the "assumes" and "defines" parts may be omitted if

1115 empty;

1117 * new print_mode "xsymbols" for extended symbol support (e.g. genuine

1118 long arrows);

1120 * new print_mode "HTML";

1122 * new flag show_tags controls display of tags of theorems (which are

1123 basically just comments that may be attached by some tools);

1125 * Isamode 2.6 requires patch to accomodate change of Isabelle font

1126 mode and goal output format:

1128 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el

1129 244c244

1130 < (list (isa-getenv "ISABELLE") "-msymbols" logic-name)

1131 ---

1132 > (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)

1133 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el

1134 181c181

1135 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"

1136 ---

1137 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"

1139 * function bind_thms stores lists of theorems (cf. bind_thm);

1141 * new shorthand tactics ftac, eatac, datac, fatac;

1143 * qed (and friends) now accept "" as result name; in that case the

1144 theorem is not stored, but proper checks and presentation of the

1145 result still apply;

1147 * theorem database now also indexes constants "Trueprop", "all",

1148 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;

1151 *** HOL ***

1153 ** HOL arithmetic **

1155 * There are now decision procedures for linear arithmetic over nat and

1156 int:

1158 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',

1159 `+', `-', `Suc', `min', `max' and numerical constants; other subterms

1160 are treated as atomic; subformulae not involving type `nat' or `int'

1161 are ignored; quantified subformulae are ignored unless they are

1162 positive universal or negative existential. The tactic has to be

1163 invoked by hand and can be a little bit slow. In particular, the

1164 running time is exponential in the number of occurrences of `min' and

1165 `max', and `-' on `nat'.

1167 2. fast_arith_tac is a cut-down version of arith_tac: it only takes

1168 (negated) (in)equalities among the premises and the conclusion into

1169 account (i.e. no compound formulae) and does not know about `min' and

1170 `max', and `-' on `nat'. It is fast and is used automatically by the

1171 simplifier.

1173 NB: At the moment, these decision procedures do not cope with mixed

1174 nat/int formulae where the two parts interact, such as `m < n ==>

1175 int(m) < int(n)'.

1177 * HOL/Numeral provides a generic theory of numerals (encoded

1178 efficiently as bit strings); setup for types nat/int/real is in place;

1179 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than

1180 int, existing theories and proof scripts may require a few additional

1181 type constraints;

1183 * integer division and remainder can now be performed on constant

1184 arguments;

1186 * many properties of integer multiplication, division and remainder

1187 are now available;

1189 * An interface to the Stanford Validity Checker (SVC) is available through the

1190 tactic svc_tac. Propositional tautologies and theorems of linear arithmetic

1191 are proved automatically. SVC must be installed separately, and its results

1192 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any

1193 invocation of the underlying oracle). For SVC see

1194 http://verify.stanford.edu/SVC

1196 * IsaMakefile: the HOL-Real target now builds an actual image;

1199 ** HOL misc **

1201 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces

1202 (in Isabelle/Isar) -- by Gertrud Bauer;

1204 * HOL/BCV: generic model of bytecode verification, i.e. data-flow

1205 analysis for assembly languages with subtypes;

1207 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization

1208 -- avoids syntactic ambiguities and treats state, transition, and

1209 temporal levels more uniformly; introduces INCOMPATIBILITIES due to

1210 changed syntax and (many) tactics;

1212 * HOL/inductive: Now also handles more general introduction rules such

1213 as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity

1214 theorems are now maintained within the theory (maintained via the

1215 "mono" attribute);

1217 * HOL/datatype: Now also handles arbitrarily branching datatypes

1218 (using function types) such as

1220 datatype 'a tree = Atom 'a | Branch "nat => 'a tree"

1222 * HOL/record: record_simproc (part of the default simpset) takes care

1223 of selectors applied to updated records; record_split_tac is no longer

1224 part of the default claset; update_defs may now be removed from the

1225 simpset in many cases; COMPATIBILITY: old behavior achieved by

1227 claset_ref () := claset() addSWrapper record_split_wrapper;

1228 Delsimprocs [record_simproc]

1230 * HOL/typedef: fixed type inference for representing set; type

1231 arguments now have to occur explicitly on the rhs as type constraints;

1233 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem

1234 names rather than an ML expression;

1236 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be

1237 supplied later. Program schemes can be defined, such as

1238 "While B C s = (if B s then While B C (C s) else s)"

1239 where the well-founded relation can be chosen after B and C have been given.

1241 * HOL/List: the constructors of type list are now Nil and Cons;

1242 INCOMPATIBILITY: while [] and infix # syntax is still there, of

1243 course, ML tools referring to List.list.op # etc. have to be adapted;

1245 * HOL_quantifiers flag superseded by "HOL" print mode, which is

1246 disabled by default; run isabelle with option -m HOL to get back to

1247 the original Gordon/HOL-style output;

1249 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,

1250 ALL x<=y. P, EX x<y. P, EX x<=y. P;

1252 * HOL basic syntax simplified (more orthogonal): all variants of

1253 All/Ex now support plain / symbolic / HOL notation; plain syntax for

1254 Eps operator is provided as well: "SOME x. P[x]";

1256 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;

1258 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made

1259 thus available for user theories;

1261 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with

1262 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the

1263 time;

1265 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec

1266 several times and then mp;

1269 *** LK ***

1271 * the notation <<...>> is now available as a notation for sequences of

1272 formulas;

1274 * the simplifier is now installed

1276 * the axiom system has been generalized (thanks to Soren Heilmann)

1278 * the classical reasoner now has a default rule database

1281 *** ZF ***

1283 * new primrec section allows primitive recursive functions to be given

1284 directly (as in HOL) over datatypes and the natural numbers;

1286 * new tactics induct_tac and exhaust_tac for induction (or case

1287 analysis) over datatypes and the natural numbers;

1289 * the datatype declaration of type T now defines the recursor T_rec;

1291 * simplification automatically does freeness reasoning for datatype

1292 constructors;

1294 * automatic type-inference, with AddTCs command to insert new

1295 type-checking rules;

1297 * datatype introduction rules are now added as Safe Introduction rules

1298 to the claset;

1300 * the syntax "if P then x else y" is now available in addition to

1301 if(P,x,y);

1304 *** Internal programming interfaces ***

1306 * tuned simplifier trace output; new flag debug_simp;

1308 * structures Vartab / Termtab (instances of TableFun) offer efficient

1309 tables indexed by indexname_ord / term_ord (compatible with aconv);

1311 * AxClass.axclass_tac lost the theory argument;

1313 * tuned current_goals_markers semantics: begin / end goal avoids

1314 printing empty lines;

1316 * removed prs and prs_fn hook, which was broken because it did not

1317 include \n in its semantics, forcing writeln to add one

1318 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:

1319 string -> unit if you really want to output text without newline;

1321 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to

1322 plain output, interface builders may have to enable 'isabelle_font'

1323 mode to get Isabelle font glyphs as before;

1325 * refined token_translation interface; INCOMPATIBILITY: output length

1326 now of type real instead of int;

1328 * theory loader actions may be traced via new ThyInfo.add_hook

1329 interface (see src/Pure/Thy/thy_info.ML); example application: keep

1330 your own database of information attached to *whole* theories -- as

1331 opposed to intra-theory data slots offered via TheoryDataFun;

1333 * proper handling of dangling sort hypotheses (at last!);

1334 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing

1335 extra sort hypotheses that can be witnessed from the type signature;

1336 the force_strip_shyps flag is gone, any remaining shyps are simply

1337 left in the theorem (with a warning issued by strip_shyps_warning);

1341 New in Isabelle98-1 (October 1998)

1342 ----------------------------------

1344 *** Overview of INCOMPATIBILITIES (see below for more details) ***

1346 * several changes of automated proof tools;

1348 * HOL: major changes to the inductive and datatype packages, including

1349 some minor incompatibilities of theory syntax;

1351 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now

1352 called `inj_on';

1354 * HOL: removed duplicate thms in Arith:

1355 less_imp_add_less should be replaced by trans_less_add1

1356 le_imp_add_le should be replaced by trans_le_add1

1358 * HOL: unary minus is now overloaded (new type constraints may be

1359 required);

1361 * HOL and ZF: unary minus for integers is now #- instead of #~. In

1362 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is

1363 now taken as an integer constant.

1365 * Pure: ML function 'theory_of' renamed to 'theory';

1368 *** Proof tools ***

1370 * Simplifier:

1371 1. Asm_full_simp_tac is now more aggressive.

1372 1. It will sometimes reorient premises if that increases their power to

1373 simplify.

1374 2. It does no longer proceed strictly from left to right but may also

1375 rotate premises to achieve further simplification.

1376 For compatibility reasons there is now Asm_lr_simp_tac which is like the

1377 old Asm_full_simp_tac in that it does not rotate premises.

1378 2. The simplifier now knows a little bit about nat-arithmetic.

1380 * Classical reasoner: wrapper mechanism for the classical reasoner now

1381 allows for selected deletion of wrappers, by introduction of names for

1382 wrapper functionals. This implies that addbefore, addSbefore,

1383 addaltern, and addSaltern now take a pair (name, tactic) as argument,

1384 and that adding two tactics with the same name overwrites the first

1385 one (emitting a warning).

1386 type wrapper = (int -> tactic) -> (int -> tactic)

1387 setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by

1388 addWrapper, addSWrapper: claset * (string * wrapper) -> claset

1389 delWrapper, delSWrapper: claset * string -> claset

1390 getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;

1392 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE

1393 semantics; addbefore now affects only the unsafe part of step_tac

1394 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY

1395 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac

1396 by Force_tac;

1398 * Classical reasoner: setwrapper to setWrapper and compwrapper to

1399 compWrapper; added safe wrapper (and access functions for it);

1401 * HOL/split_all_tac is now much faster and fails if there is nothing

1402 to split. Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order

1403 and the names of the automatically generated variables have changed.

1404 split_all_tac has moved within claset() from unsafe wrappers to safe

1405 wrappers, which means that !!-bound variables are split much more

1406 aggressively, and safe_tac and clarify_tac now split such variables.

1407 If this splitting is not appropriate, use delSWrapper "split_all_tac".

1408 Note: the same holds for record_split_tac, which does the job of

1409 split_all_tac for record fields.

1411 * HOL/Simplifier: Rewrite rules for case distinctions can now be added

1412 permanently to the default simpset using Addsplits just like

1413 Addsimps. They can be removed via Delsplits just like

1414 Delsimps. Lower-case versions are also available.

1416 * HOL/Simplifier: The rule split_if is now part of the default

1417 simpset. This means that the simplifier will eliminate all occurrences

1418 of if-then-else in the conclusion of a goal. To prevent this, you can

1419 either remove split_if completely from the default simpset by

1420 `Delsplits [split_if]' or remove it in a specific call of the

1421 simplifier using `... delsplits [split_if]'. You can also add/delete

1422 other case splitting rules to/from the default simpset: every datatype

1423 generates suitable rules `split_t_case' and `split_t_case_asm' (where

1424 t is the name of the datatype).

1426 * Classical reasoner / Simplifier combination: new force_tac (and

1427 derivatives Force_tac, force) combines rewriting and classical

1428 reasoning (and whatever other tools) similarly to auto_tac, but is

1429 aimed to solve the given subgoal completely.

1432 *** General ***

1434 * new top-level commands `Goal' and `Goalw' that improve upon `goal'

1435 and `goalw': the theory is no longer needed as an explicit argument -

1436 the current theory context is used; assumptions are no longer returned

1437 at the ML-level unless one of them starts with ==> or !!; it is

1438 recommended to convert to these new commands using isatool fixgoal

1439 (backup your sources first!);

1441 * new top-level commands 'thm' and 'thms' for retrieving theorems from

1442 the current theory context, and 'theory' to lookup stored theories;

1444 * new theory section 'locale' for declaring constants, assumptions and

1445 definitions that have local scope;

1447 * new theory section 'nonterminals' for purely syntactic types;

1449 * new theory section 'setup' for generic ML setup functions

1450 (e.g. package initialization);

1452 * the distribution now includes Isabelle icons: see

1453 lib/logo/isabelle-{small,tiny}.xpm;

1455 * isatool install - install binaries with absolute references to

1456 ISABELLE_HOME/bin;

1458 * isatool logo -- create instances of the Isabelle logo (as EPS);

1460 * print mode 'emacs' reserved for Isamode;

1462 * support multiple print (ast) translations per constant name;

1464 * theorems involving oracles are now printed with a suffixed [!];

1467 *** HOL ***

1469 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');

1471 * HOL/inductive package reorganized and improved: now supports mutual

1472 definitions such as

1474 inductive EVEN ODD

1475 intrs

1476 null "0 : EVEN"

1477 oddI "n : EVEN ==> Suc n : ODD"

1478 evenI "n : ODD ==> Suc n : EVEN"

1480 new theorem list "elims" contains an elimination rule for each of the

1481 recursive sets; inductive definitions now handle disjunctive premises

1482 correctly (also ZF);

1484 INCOMPATIBILITIES: requires Inductive as an ancestor; component

1485 "mutual_induct" no longer exists - the induction rule is always

1486 contained in "induct";

1489 * HOL/datatype package re-implemented and greatly improved: now

1490 supports mutually recursive datatypes such as

1492 datatype

1493 'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)

1494 | SUM ('a aexp) ('a aexp)

1495 | DIFF ('a aexp) ('a aexp)

1496 | NUM 'a

1497 and

1498 'a bexp = LESS ('a aexp) ('a aexp)

1499 | AND ('a bexp) ('a bexp)

1500 | OR ('a bexp) ('a bexp)

1502 as well as indirectly recursive datatypes such as

1504 datatype

1505 ('a, 'b) term = Var 'a

1506 | App 'b ((('a, 'b) term) list)

1508 The new tactic mutual_induct_tac [<var_1>, ..., <var_n>] i performs

1509 induction on mutually / indirectly recursive datatypes.

1511 Primrec equations are now stored in theory and can be accessed via

1512 <function_name>.simps.

1514 INCOMPATIBILITIES:

1516 - Theories using datatypes must now have theory Datatype as an

1517 ancestor.

1518 - The specific <typename>.induct_tac no longer exists - use the

1519 generic induct_tac instead.

1520 - natE has been renamed to nat.exhaust - use exhaust_tac

1521 instead of res_inst_tac ... natE. Note that the variable

1522 names in nat.exhaust differ from the names in natE, this

1523 may cause some "fragile" proofs to fail.

1524 - The theorems split_<typename>_case and split_<typename>_case_asm

1525 have been renamed to <typename>.split and <typename>.split_asm.

1526 - Since default sorts of type variables are now handled correctly,

1527 some datatype definitions may have to be annotated with explicit

1528 sort constraints.

1529 - Primrec definitions no longer require function name and type

1530 of recursive argument.

1532 Consider using isatool fixdatatype to adapt your theories and proof

1533 scripts to the new package (backup your sources first!).

1536 * HOL/record package: considerably improved implementation; now

1537 includes concrete syntax for record types, terms, updates; theorems

1538 for surjective pairing and splitting !!-bound record variables; proof

1539 support is as follows:

1541 1) standard conversions (selectors or updates applied to record

1542 constructor terms) are part of the standard simpset;

1544 2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are

1545 made part of standard simpset and claset via addIffs;

1547 3) a tactic for record field splitting (record_split_tac) is part of

1548 the standard claset (addSWrapper);

1550 To get a better idea about these rules you may retrieve them via

1551 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is

1552 the name of your record type.

1554 The split tactic 3) conceptually simplifies by the following rule:

1556 "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"

1558 Thus any record variable that is bound by meta-all will automatically

1559 blow up into some record constructor term, consequently the

1560 simplifications of 1), 2) apply. Thus force_tac, auto_tac etc. shall

1561 solve record problems automatically.

1564 * reorganized the main HOL image: HOL/Integ and String loaded by

1565 default; theory Main includes everything;

1567 * automatic simplification of integer sums and comparisons, using cancellation;

1569 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;

1571 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;

1573 * many new identities for unions, intersections, set difference, etc.;

1575 * expand_if, expand_split, expand_sum_case and expand_nat_case are now

1576 called split_if, split_split, split_sum_case and split_nat_case (to go

1577 with add/delsplits);

1579 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting

1580 (?x::unit) = (); this is made part of the default simpset, which COULD

1581 MAKE EXISTING PROOFS FAIL under rare circumstances (consider

1582 'Delsimprocs [unit_eq_proc];' as last resort); also note that

1583 unit_abs_eta_conv is added in order to counter the effect of

1584 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by

1585 %u.f();

1587 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which

1588 makes more sense);

1590 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;

1591 It and 'sym RS equals0D' are now in the default claset, giving automatic

1592 disjointness reasoning but breaking a few old proofs.

1594 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1

1595 to 'converse' from 'inverse' (for compatibility with ZF and some

1596 literature);

1598 * HOL/recdef can now declare non-recursive functions, with {} supplied as

1599 the well-founded relation;

1601 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of

1602 Compl A. The "Compl" syntax remains available as input syntax for this

1603 release ONLY.

1605 * HOL/Update: new theory of function updates:

1606 f(a:=b) == %x. if x=a then b else f x

1607 may also be iterated as in f(a:=b,c:=d,...);

1609 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;

1611 * HOL/List:

1612 - new function list_update written xs[i:=v] that updates the i-th

1613 list position. May also be iterated as in xs[i:=a,j:=b,...].

1614 - new function `upt' written [i..j(] which generates the list

1615 [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper

1616 bound write [i..j], which is a shorthand for [i..j+1(].

1617 - new lexicographic orderings and corresponding wellfoundedness theorems.

1619 * HOL/Arith:

1620 - removed 'pred' (predecessor) function;

1621 - generalized some theorems about n-1;

1622 - many new laws about "div" and "mod";

1623 - new laws about greatest common divisors (see theory ex/Primes);

1625 * HOL/Relation: renamed the relational operator r^-1 "converse"

1626 instead of "inverse";

1628 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness

1629 of the multiset ordering;

1631 * directory HOL/Real: a construction of the reals using Dedekind cuts

1632 (not included by default);

1634 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;

1636 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted

1637 programs, i.e. different program variables may have different types.

1639 * calling (stac rew i) now fails if "rew" has no effect on the goal

1640 [previously, this check worked only if the rewrite rule was unconditional]

1641 Now rew can involve either definitions or equalities (either == or =).

1644 *** ZF ***

1646 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains

1647 only the theorems proved on ZF.ML;

1649 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;

1650 It and 'sym RS equals0D' are now in the default claset, giving automatic

1651 disjointness reasoning but breaking a few old proofs.

1653 * ZF/Update: new theory of function updates

1654 with default rewrite rule f(x:=y) ` z = if(z=x, y, f`z)

1655 may also be iterated as in f(a:=b,c:=d,...);

1657 * in let x=t in u(x), neither t nor u(x) has to be an FOL term.

1659 * calling (stac rew i) now fails if "rew" has no effect on the goal

1660 [previously, this check worked only if the rewrite rule was unconditional]

1661 Now rew can involve either definitions or equalities (either == or =).

1663 * case_tac provided for compatibility with HOL

1664 (like the old excluded_middle_tac, but with subgoals swapped)

1667 *** Internal programming interfaces ***

1669 * Pure: several new basic modules made available for general use, see

1670 also src/Pure/README;

1672 * improved the theory data mechanism to support encapsulation (data

1673 kind name replaced by private Object.kind, acting as authorization

1674 key); new type-safe user interface via functor TheoryDataFun; generic

1675 print_data function becomes basically useless;

1677 * removed global_names compatibility flag -- all theory declarations

1678 are qualified by default;

1680 * module Pure/Syntax now offers quote / antiquote translation

1681 functions (useful for Hoare logic etc. with implicit dependencies);

1682 see HOL/ex/Antiquote for an example use;

1684 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->

1685 cterm -> thm;

1687 * new tactical CHANGED_GOAL for checking that a tactic modifies a

1688 subgoal;

1690 * Display.print_goals function moved to Locale.print_goals;

1692 * standard print function for goals supports current_goals_markers

1693 variable for marking begin of proof, end of proof, start of goal; the

1694 default is ("", "", ""); setting current_goals_markers := ("<proof>",

1695 "</proof>", "<goal>") causes SGML like tagged proof state printing,

1696 for example;

1700 New in Isabelle98 (January 1998)

1701 --------------------------------

1703 *** Overview of INCOMPATIBILITIES (see below for more details) ***

1705 * changed lexical syntax of terms / types: dots made part of long

1706 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";

1708 * simpset (and claset) reference variable replaced by functions

1709 simpset / simpset_ref;

1711 * no longer supports theory aliases (via merge) and non-trivial

1712 implicit merge of thms' signatures;

1714 * most internal names of constants changed due to qualified names;

1716 * changed Pure/Sequence interface (see Pure/seq.ML);

1719 *** General Changes ***

1721 * hierachically structured name spaces (for consts, types, axms, thms

1722 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of

1723 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:

1724 isatool fixdots ensures space after dots (e.g. "%x. x"); set

1725 long_names for fully qualified output names; NOTE: ML programs

1726 (special tactics, packages etc.) referring to internal names may have

1727 to be adapted to cope with fully qualified names; in case of severe

1728 backward campatibility problems try setting 'global_names' at compile

1729 time to have enrything declared within a flat name space; one may also

1730 fine tune name declarations in theories via the 'global' and 'local'

1731 section;

1733 * reimplemented the implicit simpset and claset using the new anytype

1734 data filed in signatures; references simpset:simpset ref etc. are

1735 replaced by functions simpset:unit->simpset and

1736 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp

1737 to patch your ML files accordingly;

1739 * HTML output now includes theory graph data for display with Java

1740 applet or isatool browser; data generated automatically via isatool

1741 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);

1743 * defs may now be conditional; improved rewrite_goals_tac to handle

1744 conditional equations;

1746 * defs now admits additional type arguments, using TYPE('a) syntax;

1748 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always

1749 creates a new theory node; implicit merge of thms' signatures is

1750 restricted to 'trivial' ones; COMPATIBILITY: one may have to use

1751 transfer:theory->thm->thm in (rare) cases;

1753 * improved handling of draft signatures / theories; draft thms (and

1754 ctyps, cterms) are automatically promoted to real ones;

1756 * slightly changed interfaces for oracles: admit many per theory, named

1757 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;

1759 * print_goals: optional output of const types (set show_consts and

1760 show_types);

1762 * improved output of warnings (###) and errors (***);

1764 * subgoal_tac displays a warning if the new subgoal has type variables;

1766 * removed old README and Makefiles;

1768 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;

1770 * removed obsolete init_pps and init_database;

1772 * deleted the obsolete tactical STATE, which was declared by

1773 fun STATE tacfun st = tacfun st st;

1775 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~

1776 (which abbreviates $HOME);

1778 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:

1779 use isatool fixseq to adapt your ML programs (this works for fully

1780 qualified references to the Sequence structure only!);

1782 * use_thy no longer requires writable current directory; it always

1783 reloads .ML *and* .thy file, if either one is out of date;

1786 *** Classical Reasoner ***

1788 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new

1789 tactics that use classical reasoning to simplify a subgoal without

1790 splitting it into several subgoals;

1792 * Safe_tac: like safe_tac but uses the default claset;

1795 *** Simplifier ***

1797 * added simplification meta rules:

1798 (asm_)(full_)simplify: simpset -> thm -> thm;

1800 * simplifier.ML no longer part of Pure -- has to be loaded by object

1801 logics (again);

1803 * added prems argument to simplification procedures;

1805 * HOL, FOL, ZF: added infix function `addsplits':

1806 instead of `<simpset> setloop (split_tac <thms>)'

1807 you can simply write `<simpset> addsplits <thms>'

1810 *** Syntax ***

1812 * TYPE('a) syntax for type reflection terms;

1814 * no longer handles consts with name "" -- declare as 'syntax' instead;

1816 * pretty printer: changed order of mixfix annotation preference (again!);

1818 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;

1821 *** HOL ***

1823 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.

1824 with `addloop' of the simplifier to faciliate case splitting in premises.

1826 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;

1828 * HOL/Auth: new protocol proofs including some for the Internet

1829 protocol TLS;

1831 * HOL/Map: new theory of `maps' a la VDM;

1833 * HOL/simplifier: simplification procedures nat_cancel_sums for

1834 cancelling out common nat summands from =, <, <= (in)equalities, or

1835 differences; simplification procedures nat_cancel_factor for

1836 cancelling common factor from =, <, <= (in)equalities over natural

1837 sums; nat_cancel contains both kinds of procedures, it is installed by

1838 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;

1840 * HOL/simplifier: terms of the form

1841 `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)' (or t=x)

1842 are rewritten to

1843 `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',

1844 and those of the form

1845 `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)' (or t=x)

1846 are rewritten to

1847 `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',

1849 * HOL/datatype

1850 Each datatype `t' now comes with a theorem `split_t_case' of the form

1852 P(t_case f1 ... fn x) =

1853 ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &

1854 ...

1855 (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))

1856 )

1858 and a theorem `split_t_case_asm' of the form

1860 P(t_case f1 ... fn x) =

1861 ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |

1862 ...

1863 (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))

1864 )

1865 which can be added to a simpset via `addsplits'. The existing theorems

1866 expand_list_case and expand_option_case have been renamed to

1867 split_list_case and split_option_case.

1869 * HOL/Arithmetic:

1870 - `pred n' is automatically converted to `n-1'.

1871 Users are strongly encouraged not to use `pred' any longer,

1872 because it will disappear altogether at some point.

1873 - Users are strongly encouraged to write "0 < n" rather than

1874 "n ~= 0". Theorems and proof tools have been modified towards this

1875 `standard'.

1877 * HOL/Lists:

1878 the function "set_of_list" has been renamed "set" (and its theorems too);

1879 the function "nth" now takes its arguments in the reverse order and

1880 has acquired the infix notation "!" as in "xs!n".

1882 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};

1884 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its

1885 specialist theorems (like UN1_I) are gone. Similarly for (INT x.B x);

1887 * HOL/record: extensible records with schematic structural subtyping

1888 (single inheritance); EXPERIMENTAL version demonstrating the encoding,

1889 still lacks various theorems and concrete record syntax;

1892 *** HOLCF ***

1894 * removed "axioms" and "generated by" sections;

1896 * replaced "ops" section by extended "consts" section, which is capable of

1897 handling the continuous function space "->" directly;

1899 * domain package:

1900 . proves theorems immediately and stores them in the theory,

1901 . creates hierachical name space,

1902 . now uses normal mixfix annotations (instead of cinfix...),

1903 . minor changes to some names and values (for consistency),

1904 . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,

1905 . separator between mutual domain defs: changed "," to "and",

1906 . improved handling of sort constraints; now they have to

1907 appear on the left-hand side of the equations only;

1909 * fixed LAM <x,y,zs>.b syntax;

1911 * added extended adm_tac to simplifier in HOLCF -- can now discharge

1912 adm (%x. P (t x)), where P is chainfinite and t continuous;

1915 *** FOL and ZF ***

1917 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.

1918 with `addloop' of the simplifier to faciliate case splitting in premises.

1920 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as

1921 in HOL, they strip ALL and --> from proved theorems;

1925 New in Isabelle94-8 (May 1997)

1926 ------------------------------

1928 *** General Changes ***

1930 * new utilities to build / run / maintain Isabelle etc. (in parts

1931 still somewhat experimental); old Makefiles etc. still functional;

1933 * new 'Isabelle System Manual';

1935 * INSTALL text, together with ./configure and ./build scripts;

1937 * reimplemented type inference for greater efficiency, better error

1938 messages and clean internal interface;

1940 * prlim command for dealing with lots of subgoals (an easier way of

1941 setting goals_limit);

1944 *** Syntax ***

1946 * supports alternative (named) syntax tables (parser and pretty

1947 printer); internal interface is provided by add_modesyntax(_i);

1949 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to

1950 be used in conjunction with the Isabelle symbol font; uses the

1951 "symbols" syntax table;

1953 * added token_translation interface (may translate name tokens in

1954 arbitrary ways, dependent on their type (free, bound, tfree, ...) and

1955 the current print_mode); IMPORTANT: user print translation functions

1956 are responsible for marking newly introduced bounds

1957 (Syntax.mark_boundT);

1959 * token translations for modes "xterm" and "xterm_color" that display

1960 names in bold, underline etc. or colors (which requires a color

1961 version of xterm);

1963 * infixes may now be declared with names independent of their syntax;

1965 * added typed_print_translation (like print_translation, but may

1966 access type of constant);

1969 *** Classical Reasoner ***

1971 Blast_tac: a new tactic! It is often more powerful than fast_tac, but has

1972 some limitations. Blast_tac...

1973 + ignores addss, addbefore, addafter; this restriction is intrinsic

1974 + ignores elimination rules that don't have the correct format

1975 (the conclusion MUST be a formula variable)

1976 + ignores types, which can make HOL proofs fail

1977 + rules must not require higher-order unification, e.g. apply_type in ZF

1978 [message "Function Var's argument not a bound variable" relates to this]

1979 + its proof strategy is more general but can actually be slower

1981 * substitution with equality assumptions no longer permutes other

1982 assumptions;

1984 * minor changes in semantics of addafter (now called addaltern); renamed

1985 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper

1986 (and access functions for it);

1988 * improved combination of classical reasoner and simplifier:

1989 + functions for handling clasimpsets

1990 + improvement of addss: now the simplifier is called _after_ the

1991 safe steps.

1992 + safe variant of addss called addSss: uses safe simplifications

1993 _during_ the safe steps. It is more complete as it allows multiple

1994 instantiations of unknowns (e.g. with slow_tac).

1996 *** Simplifier ***

1998 * added interface for simplification procedures (functions that

1999 produce *proven* rewrite rules on the fly, depending on current

2000 redex);

2002 * ordering on terms as parameter (used for ordered rewriting);

2004 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;

2006 * the solver is now split into a safe and an unsafe part.

2007 This should be invisible for the normal user, except that the

2008 functions setsolver and addsolver have been renamed to setSolver and

2009 addSolver; added safe_asm_full_simp_tac;

2012 *** HOL ***

2014 * a generic induction tactic `induct_tac' which works for all datatypes and

2015 also for type `nat';

2017 * a generic case distinction tactic `exhaust_tac' which works for all

2018 datatypes and also for type `nat';

2020 * each datatype comes with a function `size';

2022 * patterns in case expressions allow tuple patterns as arguments to

2023 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';

2025 * primrec now also works with type nat;

2027 * recdef: a new declaration form, allows general recursive functions to be

2028 defined in theory files. See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.

2030 * the constant for negation has been renamed from "not" to "Not" to

2031 harmonize with FOL, ZF, LK, etc.;

2033 * HOL/ex/LFilter theory of a corecursive "filter" functional for

2034 infinite lists;

2036 * HOL/Modelcheck demonstrates invocation of model checker oracle;

2038 * HOL/ex/Ring.thy declares cring_simp, which solves equational

2039 problems in commutative rings, using axiomatic type classes for + and *;

2041 * more examples in HOL/MiniML and HOL/Auth;

2043 * more default rewrite rules for quantifiers, union/intersection;

2045 * a new constant `arbitrary == @x.False';

2047 * HOLCF/IOA replaces old HOL/IOA;

2049 * HOLCF changes: derived all rules and arities

2050 + axiomatic type classes instead of classes

2051 + typedef instead of faking type definitions

2052 + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.

2053 + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po

2054 + eliminated the types void, one, tr

2055 + use unit lift and bool lift (with translations) instead of one and tr

2056 + eliminated blift from Lift3.thy (use Def instead of blift)

2057 all eliminated rules are derived as theorems --> no visible changes ;

2060 *** ZF ***

2062 * ZF now has Fast_tac, Simp_tac and Auto_tac. Union_iff is a now a default

2063 rewrite rule; this may affect some proofs. eq_cs is gone but can be put back

2064 as ZF_cs addSIs [equalityI];

2068 New in Isabelle94-7 (November 96)

2069 ---------------------------------

2071 * allowing negative levels (as offsets) in prlev and choplev;

2073 * super-linear speedup for large simplifications;

2075 * FOL, ZF and HOL now use miniscoping: rewriting pushes

2076 quantifications in as far as possible (COULD MAKE EXISTING PROOFS

2077 FAIL); can suppress it using the command Delsimps (ex_simps @

2078 all_simps); De Morgan laws are also now included, by default;

2080 * improved printing of ==> : ~:

2082 * new object-logic "Sequents" adds linear logic, while replacing LK

2083 and Modal (thanks to Sara Kalvala);

2085 * HOL/Auth: correctness proofs for authentication protocols;

2087 * HOL: new auto_tac combines rewriting and classical reasoning (many

2088 examples on HOL/Auth);

2090 * HOL: new command AddIffs for declaring theorems of the form P=Q to

2091 the rewriter and classical reasoner simultaneously;

2093 * function uresult no longer returns theorems in "standard" format;

2094 regain previous version by: val uresult = standard o uresult;

2098 New in Isabelle94-6

2099 -------------------

2101 * oracles -- these establish an interface between Isabelle and trusted

2102 external reasoners, which may deliver results as theorems;

2104 * proof objects (in particular record all uses of oracles);

2106 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;

2108 * "constdefs" section in theory files;

2110 * "primrec" section (HOL) no longer requires names;

2112 * internal type "tactic" now simply "thm -> thm Sequence.seq";

2116 New in Isabelle94-5

2117 -------------------

2119 * reduced space requirements;

2121 * automatic HTML generation from theories;

2123 * theory files no longer require "..." (quotes) around most types;

2125 * new examples, including two proofs of the Church-Rosser theorem;

2127 * non-curried (1994) version of HOL is no longer distributed;

2131 New in Isabelle94-4

2132 -------------------

2134 * greatly reduced space requirements;

2136 * theory files (.thy) no longer require \...\ escapes at line breaks;

2138 * searchable theorem database (see the section "Retrieving theorems" on

2139 page 8 of the Reference Manual);

2141 * new examples, including Grabczewski's monumental case study of the

2142 Axiom of Choice;

2144 * The previous version of HOL renamed to Old_HOL;

2146 * The new version of HOL (previously called CHOL) uses a curried syntax

2147 for functions. Application looks like f a b instead of f(a,b);

2149 * Mutually recursive inductive definitions finally work in HOL;

2151 * In ZF, pattern-matching on tuples is now available in all abstractions and

2152 translates to the operator "split";

2156 New in Isabelle94-3

2157 -------------------

2159 * new infix operator, addss, allowing the classical reasoner to

2160 perform simplification at each step of its search. Example:

2161 fast_tac (cs addss ss)

2163 * a new logic, CHOL, the same as HOL, but with a curried syntax

2164 for functions. Application looks like f a b instead of f(a,b). Also pairs

2165 look like (a,b) instead of <a,b>;

2167 * PLEASE NOTE: CHOL will eventually replace HOL!

2169 * In CHOL, pattern-matching on tuples is now available in all abstractions.

2170 It translates to the operator "split". A new theory of integers is available;

2172 * In ZF, integer numerals now denote two's-complement binary integers.

2173 Arithmetic operations can be performed by rewriting. See ZF/ex/Bin.ML;

2175 * Many new examples: I/O automata, Church-Rosser theorem, equivalents

2176 of the Axiom of Choice;

2180 New in Isabelle94-2

2181 -------------------

2183 * Significantly faster resolution;

2185 * the different sections in a .thy file can now be mixed and repeated

2186 freely;

2188 * Database of theorems for FOL, HOL and ZF. New

2189 commands including qed, qed_goal and bind_thm store theorems in the database.

2191 * Simple database queries: return a named theorem (get_thm) or all theorems of

2192 a given theory (thms_of), or find out what theory a theorem was proved in

2193 (theory_of_thm);

2195 * Bugs fixed in the inductive definition and datatype packages;

2197 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs

2198 and HOL_dup_cs obsolete;

2200 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1

2201 have been removed;

2203 * Simpler definition of function space in ZF;

2205 * new results about cardinal and ordinal arithmetic in ZF;

2207 * 'subtype' facility in HOL for introducing new types as subsets of existing

2208 types;

2211 $Id$