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NEWS

author | paulson |

Thu Feb 20 11:09:48 2003 +0100 (2003-02-20) | |

changeset 13824 | e4d8dea6dfc2 |

parent 13815 | 0832792725db |

child 13829 | af0218406395 |

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

minor updates to pre-2002 release

1 Isabelle NEWS -- history user-relevant changes

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

4 New in this Isabelle release

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

7 *** General ***

9 * Provers/simplifier:

11 - Completely reimplemented method simp (ML: Asm_full_simp_tac):

12 Assumptions are now subject to complete mutual simplification,

13 not just from left to right. The simplifier now preserves

14 the order of assumptions.

16 Potential INCOMPATIBILITY:

18 -- simp sometimes diverges where the old version did

19 not, e.g. invoking simp on the goal

21 [| P (f x); y = x; f x = f y |] ==> Q

23 now gives rise to the infinite reduction sequence

25 P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...

27 Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this

28 kind of problem.

30 -- Tactics combining classical reasoner and simplification (such as auto)

31 are also affected by this change, because many of them rely on

32 simp. They may sometimes diverge as well or yield a different numbers

33 of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto

34 in case of problems. Sometimes subsequent calls to the classical

35 reasoner will fail because a preceeding call to the simplifier too

36 eagerly simplified the goal, e.g. deleted redundant premises.

38 - The simplifier trace now shows the names of the applied rewrite rules

40 * Pure: New flag for triggering if the overall goal of a proof state should

41 be printed:

42 PG menu: Isabelle/Isar -> Settigs -> Show Main Goal

43 (ML: Proof.show_main_goal).

45 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all

46 rules whose conclusion matches subgoal 1:

47 PG menu: Isabelle/Isar -> Show me -> matching rules

48 The rules are ordered by how closely they match the subgoal.

49 In particular, rules that solve a subgoal outright are displayed first

50 (or rather last, the way they are printed).

51 (ML: ProofGeneral.print_intros())

53 * Pure: New flag trace_unify_fail causes unification to print

54 diagnostic information (PG: in trace buffer) when it fails. This is

55 useful for figuring out why single step proofs like rule, erule or

56 assumption failed.

58 * Pure: Locale specifications now produce predicate definitions

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

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

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

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

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

64 on the old view without predicates;

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

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

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

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

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

72 include local facts of proof configuration (also covers active

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

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

75 be given (the default is 40);

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

78 (batch-mode only);

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

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

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

84 * Provers: the function blast.overloaded has been removed: all constants

85 are regarded as potentially overloaded, which improves robustness in exchange

86 for slight decrease in efficiency;

88 * Provers/linorder: New generic prover for transitivity reasoning over

89 linear orders. Note: this prover is not efficient!

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

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

95 *** HOL ***

97 * GroupTheory: new, experimental summation operator for abelian groups.

99 * New tactic "trans_tac" and method "trans" instantiate

100 Provers/linorder.ML for axclasses "order" and "linorder" (predicates

101 "<=", "<" and "=").

103 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main

104 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";

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

107 definition;

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

110 Finite_Set);

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

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

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

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

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

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

121 "0 < n ==> n div 2 < (n::nat)"

123 but fails if divisibility plays a role like in

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

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

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

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

131 are distributed over a sum of terms;

133 * induct over a !!-quantified statement (say !!x1..xn):

134 each "case" automatically performs "fix x1 .. xn" with exactly those names.

136 * GroupTheory: converted to Isar theories, using locales with implicit structures;

138 * Real/HahnBanach: updated and adapted to locales;

141 *** ZF ***

143 * ZF/Constructible: consistency proof for AC (Gödel's constructible

144 universe, etc.);

146 * Main ZF: many theories converted to new-style format;

149 *** ML ***

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

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

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

155 * Pure: improved error reporting of simprocs;

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

158 up simprocs;

162 New in Isabelle2002 (March 2002)

163 --------------------------------

165 *** Document preparation ***

167 * greatly simplified document preparation setup, including more

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

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

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

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

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

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

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

176 with \includegraphics of LaTeX;

178 * proper spacing of consecutive markup elements, especially text

179 blocks after section headings;

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

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

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

185 better in printed text;

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

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

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

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

192 isatool document copies the Isabelle style files to the target

193 location;

196 *** Isar ***

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

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

200 "case (Suc n)");

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

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

203 instantiation of cases;

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

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

206 rules without further ado;

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

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

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

210 statement becomes is included in the hypothesis, avoiding the

211 slightly cumbersome show "PROP ?case" form;

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

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

214 rules stemming from inductive sets to be applied in unstructured

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

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

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

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

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

220 below);

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

222 success (no backtracking);

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

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

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

226 General versions);

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

228 - generic method setup instantiated for FOL and HOL;

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

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

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

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

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

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

236 fails:

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

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

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

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

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

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

246 attributes everywhere); operations on locales include merge and

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

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

249 some examples;

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

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

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

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

255 qualified by the locale name);

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

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

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

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

261 the context elements being discharged in the obvious way;

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

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

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

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

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

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

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

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

273 use hard-wired "Trueprop";

275 * Pure: added 'corollary' command;

277 * Pure: fixed 'token_translation' command;

279 * Pure: removed obsolete 'exported' attribute;

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

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

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

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

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

287 rewrite rules declarations of 'atomize' attribute; example

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

289 proof *scripts*;

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

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

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

294 especially important for locales);

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

297 mode;

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

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

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

302 situations;

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

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

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

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

309 discontinued;

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

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

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

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

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

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

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

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

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

321 INCOMPATIBILITY;

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

324 of introduction rules;

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

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

328 conditional rules;

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

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

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

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

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

338 * HOL: properly declared induction rules less_induct and

339 wf_induct_rule;

342 *** HOL ***

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

345 follows:

347 - 0 and 1 are polymorphic constants, which are defined on any

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

350 - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based

351 binary representation internally;

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

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

356 This change may cause significant problems of INCOMPATIBILITY; here

357 are some hints on converting existing sources:

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

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

361 to be spaced properly;

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

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

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

368 - remove all special provisions on numerals in proofs;

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

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

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

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

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

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

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

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

381 * HOL/record package improvements:

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

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

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

385 declared as simp by default;

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

387 qualified) --- potential INCOMPATIBILITY;

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

389 INCOMPATIBILITY;

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

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

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

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

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

395 theory of product types over typedef rather than datatype;

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

398 specifications; specific support for HOL constructs such as inductive

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

400 via 'generate_code' theory section;

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

404 * HOL: consolidated and renamed several theories. In particular:

405 Ord.thy has been absorbed into HOL.thy

406 String.thy has been absorbed into List.thy

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

409 (beware of argument permutation!);

411 * HOL: linorder_less_split superseded by linorder_cases;

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

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

416 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:

417 - Ex_def has changed, now need to use some_eq_ex

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

420 in this (rare) case use:

422 delSWrapper "split_all_tac"

423 addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)

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

426 MAY FAIL;

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

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

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

431 necessary to attach explicit type constraints;

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

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

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

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

438 expressions;

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

441 of "lam" -- INCOMPATIBILITY;

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

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

445 renamed "Product_Type.unit";

447 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl

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

450 the "cases" method);

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

453 Florian Kammüller);

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

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

457 some explanations (by Gerwin Klein);

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

461 * HOL-Hyperreal is now a logic image;

464 *** HOLCF ***

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

467 operations;

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

470 HOLCF/ex/Dnat.thy;

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

473 potential INCOMPATIBILITY; now use plain induct_tac instead of former

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

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

479 *** ZF ***

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

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

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

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

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

487 your theory on Main_ZFC;

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

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

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

493 typeless version of the formalism;

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

496 format;

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

499 including theory Multiset for multiset orderings; converted to

500 new-style theory format;

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

505 *** General ***

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

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

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

510 also ref manual for further ML interfaces;

512 * Pure/axclass: removed obsolete ML interface

513 goal_subclass/goal_arity;

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

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

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

518 properly;

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

521 rather than "infixl" or "infixr";

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

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

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

526 type variable);

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

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

530 "type_brackets";

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

533 tokens into AST constants;

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

536 translation functions; potential INCOMPATIBILITY: need to reverse

537 multiple declarations for same syntax element constant;

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

540 practice);

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

543 addSafter;

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

546 as well;

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

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

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

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

552 support requires further installations, e.g. from

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

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

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

558 of 40 MB), cf. ML_OPTIONS;

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

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

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

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

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

567 * system: smart selection of Isabelle process versus Isabelle

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

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

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

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

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

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

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

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

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

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

580 terminal);

584 New in Isabelle99-2 (February 2001)

585 -----------------------------------

587 *** Overview of INCOMPATIBILITIES ***

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

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

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

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

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

595 format may be recovered via ML function complete_split_rule or attribute

596 'split_rule (complete)';

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

599 gfp_Tarski to gfp_unfold;

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

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

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

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

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

608 operation;

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

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

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

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

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

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

619 \<gg> to \<ggreater>;

622 *** Document preparation ***

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

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

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

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

628 type-writer);

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

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

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

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

636 * improved isabelle style files; more abstract symbol implementation

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

638 definitions);

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

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

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

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

645 * proper indentation of antiquoted output with proportional LaTeX

646 fonts;

648 * no_document ML operator temporarily disables LaTeX document

649 generation;

651 * isatool unsymbolize tunes sources for plain ASCII communication;

654 *** Isar ***

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

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

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

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

660 for Prolog-style synthesis of proven results;

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

663 rules as well;

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

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

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

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

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

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

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

674 statements as well;

676 * Pure: more robust selection of calculational rules;

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

679 rule (as well as the assumption rule);

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

682 lemmas, using the graph browser tool;

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

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

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

689 (potential INCOMPATIBILITY); tuned error handling;

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

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

693 any remaining facts are inserted into the goal verbatim;

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

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

697 the result to be shown in each case;

699 * HOL: added 'recdef_tc' command;

701 * isatool convert assists in eliminating legacy ML scripts;

704 *** HOL ***

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

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

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

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

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

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

713 modelling and verification task performed in Isabelle/HOL +

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

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

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

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

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

720 literature;

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

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

724 operator \<Sum>;

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

727 HOL/subset.thy);

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

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

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

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

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

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

737 rules with string literals);

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

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

741 functions for the reals;

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

746 *** CTT ***

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

749 "lam" is displayed as TWO lambda-symbols

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

752 and Arith);

755 *** General ***

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

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

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

760 the Isabelle inference kernel has been greatly improved;

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

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

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

766 as assumptions as well;

768 * system: support Poly/ML 4.0;

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

774 New in Isabelle99-1 (October 2000)

775 ----------------------------------

777 *** Overview of INCOMPATIBILITIES ***

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

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

781 issue the following ML commands:

783 Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;

784 Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];

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

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

789 * HOL: nat_less_induct renamed to less_induct;

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

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

794 select_equality -> some_equality

795 select_eq_Ex -> some_eq_ex

796 selectI2EX -> someI2_ex

797 selectI2 -> someI2

798 selectI -> someI

799 select1_equality -> some1_equality

800 Eps_sym_eq -> some_sym_eq_trivial

801 Eps_eq -> some_eq_trivial

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

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

806 instead);

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

809 f.simps instead of f.rules;

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

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

814 sometimes be needed;

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

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

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

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

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

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

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

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

828 the old syntax may be recovered as follows:

830 syntax (symbols)

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

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

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

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

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

838 internally;

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

841 changed from A/r to A//r;

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

844 proofs;

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

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

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

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

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

852 "rule del";

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

856 * Provers: strengthened force_tac by using new first_best_tac;

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

859 lib/texinputs);

862 *** Document preparation ***

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

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

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

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

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

870 including proper document sources;

872 * generated LaTeX sources are now deleted after successful run

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

874 of isatool usedir;

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

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

878 LaTeX debugging;

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

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

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

884 graph for 'all sessions';

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

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

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

891 *** Isar ***

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

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

895 accommodates incremental type-inference very nicely;

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

898 generalized existence reasoning;

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

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

902 useful to collect intermediate results without explicit name

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

904 premises;

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

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

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

909 to theorems as "tags";

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

912 class/type/const name spaces;

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

915 indicate potential overloading;

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

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

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

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

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

924 with the version in Provers/classical;

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

927 case name 'antecedent';

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

930 to the current context is now done automatically);

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

933 for definining proof methods in ML;

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

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

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

938 replaced "delrule" by "rule del";

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

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

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

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

945 well (including splits);

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

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

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

951 of Simplifier and Classical reasoner);

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

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

955 recdef) support case names and properly name parameters;

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

958 monotonicity conditions are extracted to be proven at end of

959 calculations;

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

962 method anyway;

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

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

966 foo.split foo.split_asm for each datatype;

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

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

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

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

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

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

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

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

979 proof states;

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

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

983 proof state according to the Isabelle LaTeX style;

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

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

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

988 (for HOL datatypes);

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

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

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

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

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

997 should instead use individual commands for printing items

998 (print_commands, print_methods etc.);

1000 * Isar: added 'nothing' --- the empty list of theorems;

1003 *** HOL ***

1005 * HOL/MicroJava: formalization of a fragment of Java, together with a

1006 corresponding virtual machine and a specification of its bytecode

1007 verifier and a lightweight bytecode verifier, including proofs of

1008 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and

1009 Cornelia Pusch (see also the homepage of project Bali at

1010 http://isabelle.in.tum.de/Bali/);

1012 * HOL/Algebra: new theory of rings and univariate polynomials, by

1013 Clemens Ballarin;

1015 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese

1016 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M

1017 Rasmussen;

1019 * HOL/Lattice: fundamental concepts of lattice theory and order

1020 structures, including duals, properties of bounds versus algebraic

1021 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski

1022 Theorem for complete lattices etc.; may also serve as a demonstration

1023 for abstract algebraic reasoning using axiomatic type classes, and

1024 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;

1026 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David

1027 von Oheimb;

1029 * HOL/IMPP: extension of IMP with local variables and mutually

1030 recursive procedures, by David von Oheimb;

1032 * HOL/Lambda: converted into new-style theory and document;

1034 * HOL/ex/Multiquote: example of multiple nested quotations and

1035 anti-quotations -- basically a generalized version of de-Bruijn

1036 representation; very useful in avoiding lifting of operations;

1038 * HOL/record: added general record equality rule to simpset; fixed

1039 select-update simplification procedure to handle extended records as

1040 well; admit "r" as field name;

1042 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with

1043 other numeric types and also as the identity of groups, rings, etc.;

1045 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.

1046 Types nat and int belong to this axclass;

1048 * HOL: greatly improved simplification involving numerals of type nat, int, real:

1049 (i + #8 + j) = Suc k simplifies to #7 + (i + j) = k

1050 i*j + k + j*#3*i simplifies to #4*(i*j) + k

1051 two terms #m*u and #n*u are replaced by #(m+n)*u

1052 (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)

1053 and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y

1054 or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);

1056 * HOL: meson_tac is available (previously in ex/meson.ML); it is a

1057 powerful prover for predicate logic but knows nothing of clasets; see

1058 ex/mesontest.ML and ex/mesontest2.ML for example applications;

1060 * HOL: new version of "case_tac" subsumes both boolean case split and

1061 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer

1062 exists, may define val exhaust_tac = case_tac for ad-hoc portability;

1064 * HOL: simplification no longer dives into case-expressions: only the

1065 selector expression is simplified, but not the remaining arms; to

1066 enable full simplification of case-expressions for datatype t, you may

1067 remove t.weak_case_cong from the simpset, either globally (Delcongs

1068 [thm"t.weak_case_cong"];) or locally (delcongs [...]).

1070 * HOL/recdef: the recursion equations generated by 'recdef' for

1071 function 'f' are now called f.simps instead of f.rules; if all

1072 termination conditions are proved automatically, these simplification

1073 rules are added to the simpset, as in primrec; rules may be named

1074 individually as well, resulting in a separate list of theorems for

1075 each equation;

1077 * HOL/While is a new theory that provides a while-combinator. It

1078 permits the definition of tail-recursive functions without the

1079 provision of a termination measure. The latter is necessary once the

1080 invariant proof rule for while is applied.

1082 * HOL: new (overloaded) notation for the set of elements below/above

1083 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.

1085 * HOL: theorems impI, allI, ballI bound as "strip";

1087 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic

1088 induct_tac th "x1 ... xn" expects th to have a conclusion of the form

1089 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;

1091 * HOL/Real: "rabs" replaced by overloaded "abs" function;

1093 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of

1094 main HOL, but was unused);

1096 * HOL: fewer consts declared as global (e.g. have to refer to

1097 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);

1099 * HOL: tuned AST representation of nested pairs, avoiding bogus output

1100 in case of overlap with user translations (e.g. judgements over

1101 tuples); (note that the underlying logical represenation is still

1102 bogus);

1105 *** ZF ***

1107 * ZF: simplification automatically cancels common terms in arithmetic

1108 expressions over nat and int;

1110 * ZF: new treatment of nat to minimize type-checking: all operators

1111 coerce their operands to a natural number using the function natify,

1112 making the algebraic laws unconditional;

1114 * ZF: as above, for int: operators coerce their operands to an integer

1115 using the function intify;

1117 * ZF: the integer library now contains many of the usual laws for the

1118 orderings, including $<=, and monotonicity laws for $+ and $*;

1120 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic

1121 simplification;

1123 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q

1124 to the simplifier and classical reasoner simultaneously;

1127 *** General ***

1129 * Provers: blast_tac now handles actual object-logic rules as

1130 assumptions; note that auto_tac uses blast_tac internally as well;

1132 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning

1133 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;

1135 * Provers: delrules now handles destruct rules as well (no longer need

1136 explicit make_elim);

1138 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.

1139 [| inj ?f; ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W

1140 use instead the strong form,

1141 [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W

1142 in HOL, FOL and ZF the function cla_make_elim will create such rules

1143 from destruct-rules;

1145 * Provers: Simplifier.easy_setup provides a fast path to basic

1146 Simplifier setup for new object-logics;

1148 * Pure: AST translation rules no longer require constant head on LHS;

1150 * Pure: improved name spaces: ambiguous output is qualified; support

1151 for hiding of names;

1153 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and

1154 XSYMBOL_HOME; no longer need to do manual configuration in most

1155 situations;

1157 * system: compression of ML heaps images may now be controlled via -c

1158 option of isabelle and isatool usedir (currently only observed by

1159 Poly/ML);

1161 * system: isatool installfonts may handle X-Symbol fonts as well (very

1162 useful for remote X11);

1164 * system: provide TAGS file for Isabelle sources;

1166 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument

1167 order;

1169 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global

1170 timing flag supersedes proof_timing and Toplevel.trace;

1172 * ML: new combinators |>> and |>>> for incremental transformations

1173 with secondary results (e.g. certain theory extensions):

1175 * ML: PureThy.add_defs gets additional argument to indicate potential

1176 overloading (usually false);

1178 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as

1179 results;

1183 New in Isabelle99 (October 1999)

1184 --------------------------------

1186 *** Overview of INCOMPATIBILITIES (see below for more details) ***

1188 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)

1189 are no longer simplified. (This allows the simplifier to unfold recursive

1190 functional programs.) To restore the old behaviour, declare

1192 Delcongs [if_weak_cong];

1194 * HOL: Removed the obsolete syntax "Compl A"; use -A for set

1195 complement;

1197 * HOL: the predicate "inj" is now defined by translation to "inj_on";

1199 * HOL/datatype: mutual_induct_tac no longer exists --

1200 use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]

1202 * HOL/typedef: fixed type inference for representing set; type

1203 arguments now have to occur explicitly on the rhs as type constraints;

1205 * ZF: The con_defs part of an inductive definition may no longer refer

1206 to constants declared in the same theory;

1208 * HOL, ZF: the function mk_cases, generated by the inductive

1209 definition package, has lost an argument. To simplify its result, it

1210 uses the default simpset instead of a supplied list of theorems.

1212 * HOL/List: the constructors of type list are now Nil and Cons;

1214 * Simplifier: the type of the infix ML functions

1215 setSSolver addSSolver setSolver addSolver

1216 is now simpset * solver -> simpset where `solver' is a new abstract type

1217 for packaging solvers. A solver is created via

1218 mk_solver: string -> (thm list -> int -> tactic) -> solver

1219 where the string argument is only a comment.

1222 *** Proof tools ***

1224 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a

1225 decision procedure for linear arithmetic. Currently it is used for

1226 types `nat', `int', and `real' in HOL (see below); it can, should and

1227 will be instantiated for other types and logics as well.

1229 * The simplifier now accepts rewrite rules with flexible heads, eg

1230 hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y

1231 They are applied like any rule with a non-pattern lhs, i.e. by first-order

1232 matching.

1235 *** General ***

1237 * New Isabelle/Isar subsystem provides an alternative to traditional

1238 tactical theorem proving; together with the ProofGeneral/isar user

1239 interface it offers an interactive environment for developing human

1240 readable proof documents (Isar == Intelligible semi-automated

1241 reasoning); for further information see isatool doc isar-ref,

1242 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/

1244 * improved and simplified presentation of theories: better HTML markup

1245 (including colors), graph views in several sizes; isatool usedir now

1246 provides a proper interface for user theories (via -P option); actual

1247 document preparation based on (PDF)LaTeX is available as well (for

1248 new-style theories only); see isatool doc system for more information;

1250 * native support for Proof General, both for classic Isabelle and

1251 Isabelle/Isar;

1253 * ML function thm_deps visualizes dependencies of theorems and lemmas,

1254 using the graph browser tool;

1256 * Isabelle manuals now also available as PDF;

1258 * theory loader rewritten from scratch (may not be fully

1259 bug-compatible); old loadpath variable has been replaced by show_path,

1260 add_path, del_path, reset_path functions; new operations such as

1261 update_thy, touch_thy, remove_thy, use/update_thy_only (see also

1262 isatool doc ref);

1264 * improved isatool install: option -k creates KDE application icon,

1265 option -p DIR installs standalone binaries;

1267 * added ML_PLATFORM setting (useful for cross-platform installations);

1268 more robust handling of platform specific ML images for SML/NJ;

1270 * the settings environment is now statically scoped, i.e. it is never

1271 created again in sub-processes invoked from isabelle, isatool, or

1272 Isabelle;

1274 * path element specification '~~' refers to '$ISABELLE_HOME';

1276 * in locales, the "assumes" and "defines" parts may be omitted if

1277 empty;

1279 * new print_mode "xsymbols" for extended symbol support (e.g. genuine

1280 long arrows);

1282 * new print_mode "HTML";

1284 * new flag show_tags controls display of tags of theorems (which are

1285 basically just comments that may be attached by some tools);

1287 * Isamode 2.6 requires patch to accomodate change of Isabelle font

1288 mode and goal output format:

1290 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el

1291 244c244

1292 < (list (isa-getenv "ISABELLE") "-msymbols" logic-name)

1293 ---

1294 > (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)

1295 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el

1296 181c181

1297 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"

1298 ---

1299 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"

1301 * function bind_thms stores lists of theorems (cf. bind_thm);

1303 * new shorthand tactics ftac, eatac, datac, fatac;

1305 * qed (and friends) now accept "" as result name; in that case the

1306 theorem is not stored, but proper checks and presentation of the

1307 result still apply;

1309 * theorem database now also indexes constants "Trueprop", "all",

1310 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;

1313 *** HOL ***

1315 ** HOL arithmetic **

1317 * There are now decision procedures for linear arithmetic over nat and

1318 int:

1320 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',

1321 `+', `-', `Suc', `min', `max' and numerical constants; other subterms

1322 are treated as atomic; subformulae not involving type `nat' or `int'

1323 are ignored; quantified subformulae are ignored unless they are

1324 positive universal or negative existential. The tactic has to be

1325 invoked by hand and can be a little bit slow. In particular, the

1326 running time is exponential in the number of occurrences of `min' and

1327 `max', and `-' on `nat'.

1329 2. fast_arith_tac is a cut-down version of arith_tac: it only takes

1330 (negated) (in)equalities among the premises and the conclusion into

1331 account (i.e. no compound formulae) and does not know about `min' and

1332 `max', and `-' on `nat'. It is fast and is used automatically by the

1333 simplifier.

1335 NB: At the moment, these decision procedures do not cope with mixed

1336 nat/int formulae where the two parts interact, such as `m < n ==>

1337 int(m) < int(n)'.

1339 * HOL/Numeral provides a generic theory of numerals (encoded

1340 efficiently as bit strings); setup for types nat/int/real is in place;

1341 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than

1342 int, existing theories and proof scripts may require a few additional

1343 type constraints;

1345 * integer division and remainder can now be performed on constant

1346 arguments;

1348 * many properties of integer multiplication, division and remainder

1349 are now available;

1351 * An interface to the Stanford Validity Checker (SVC) is available through the

1352 tactic svc_tac. Propositional tautologies and theorems of linear arithmetic

1353 are proved automatically. SVC must be installed separately, and its results

1354 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any

1355 invocation of the underlying oracle). For SVC see

1356 http://verify.stanford.edu/SVC

1358 * IsaMakefile: the HOL-Real target now builds an actual image;

1361 ** HOL misc **

1363 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces

1364 (in Isabelle/Isar) -- by Gertrud Bauer;

1366 * HOL/BCV: generic model of bytecode verification, i.e. data-flow

1367 analysis for assembly languages with subtypes;

1369 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization

1370 -- avoids syntactic ambiguities and treats state, transition, and

1371 temporal levels more uniformly; introduces INCOMPATIBILITIES due to

1372 changed syntax and (many) tactics;

1374 * HOL/inductive: Now also handles more general introduction rules such

1375 as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity

1376 theorems are now maintained within the theory (maintained via the

1377 "mono" attribute);

1379 * HOL/datatype: Now also handles arbitrarily branching datatypes

1380 (using function types) such as

1382 datatype 'a tree = Atom 'a | Branch "nat => 'a tree"

1384 * HOL/record: record_simproc (part of the default simpset) takes care

1385 of selectors applied to updated records; record_split_tac is no longer

1386 part of the default claset; update_defs may now be removed from the

1387 simpset in many cases; COMPATIBILITY: old behavior achieved by

1389 claset_ref () := claset() addSWrapper record_split_wrapper;

1390 Delsimprocs [record_simproc]

1392 * HOL/typedef: fixed type inference for representing set; type

1393 arguments now have to occur explicitly on the rhs as type constraints;

1395 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem

1396 names rather than an ML expression;

1398 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be

1399 supplied later. Program schemes can be defined, such as

1400 "While B C s = (if B s then While B C (C s) else s)"

1401 where the well-founded relation can be chosen after B and C have been given.

1403 * HOL/List: the constructors of type list are now Nil and Cons;

1404 INCOMPATIBILITY: while [] and infix # syntax is still there, of

1405 course, ML tools referring to List.list.op # etc. have to be adapted;

1407 * HOL_quantifiers flag superseded by "HOL" print mode, which is

1408 disabled by default; run isabelle with option -m HOL to get back to

1409 the original Gordon/HOL-style output;

1411 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,

1412 ALL x<=y. P, EX x<y. P, EX x<=y. P;

1414 * HOL basic syntax simplified (more orthogonal): all variants of

1415 All/Ex now support plain / symbolic / HOL notation; plain syntax for

1416 Eps operator is provided as well: "SOME x. P[x]";

1418 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;

1420 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made

1421 thus available for user theories;

1423 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with

1424 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the

1425 time;

1427 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec

1428 several times and then mp;

1431 *** LK ***

1433 * the notation <<...>> is now available as a notation for sequences of

1434 formulas;

1436 * the simplifier is now installed

1438 * the axiom system has been generalized (thanks to Soren Heilmann)

1440 * the classical reasoner now has a default rule database

1443 *** ZF ***

1445 * new primrec section allows primitive recursive functions to be given

1446 directly (as in HOL) over datatypes and the natural numbers;

1448 * new tactics induct_tac and exhaust_tac for induction (or case

1449 analysis) over datatypes and the natural numbers;

1451 * the datatype declaration of type T now defines the recursor T_rec;

1453 * simplification automatically does freeness reasoning for datatype

1454 constructors;

1456 * automatic type-inference, with AddTCs command to insert new

1457 type-checking rules;

1459 * datatype introduction rules are now added as Safe Introduction rules

1460 to the claset;

1462 * the syntax "if P then x else y" is now available in addition to

1463 if(P,x,y);

1466 *** Internal programming interfaces ***

1468 * tuned simplifier trace output; new flag debug_simp;

1470 * structures Vartab / Termtab (instances of TableFun) offer efficient

1471 tables indexed by indexname_ord / term_ord (compatible with aconv);

1473 * AxClass.axclass_tac lost the theory argument;

1475 * tuned current_goals_markers semantics: begin / end goal avoids

1476 printing empty lines;

1478 * removed prs and prs_fn hook, which was broken because it did not

1479 include \n in its semantics, forcing writeln to add one

1480 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:

1481 string -> unit if you really want to output text without newline;

1483 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to

1484 plain output, interface builders may have to enable 'isabelle_font'

1485 mode to get Isabelle font glyphs as before;

1487 * refined token_translation interface; INCOMPATIBILITY: output length

1488 now of type real instead of int;

1490 * theory loader actions may be traced via new ThyInfo.add_hook

1491 interface (see src/Pure/Thy/thy_info.ML); example application: keep

1492 your own database of information attached to *whole* theories -- as

1493 opposed to intra-theory data slots offered via TheoryDataFun;

1495 * proper handling of dangling sort hypotheses (at last!);

1496 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing

1497 extra sort hypotheses that can be witnessed from the type signature;

1498 the force_strip_shyps flag is gone, any remaining shyps are simply

1499 left in the theorem (with a warning issued by strip_shyps_warning);

1503 New in Isabelle98-1 (October 1998)

1504 ----------------------------------

1506 *** Overview of INCOMPATIBILITIES (see below for more details) ***

1508 * several changes of automated proof tools;

1510 * HOL: major changes to the inductive and datatype packages, including

1511 some minor incompatibilities of theory syntax;

1513 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now

1514 called `inj_on';

1516 * HOL: removed duplicate thms in Arith:

1517 less_imp_add_less should be replaced by trans_less_add1

1518 le_imp_add_le should be replaced by trans_le_add1

1520 * HOL: unary minus is now overloaded (new type constraints may be

1521 required);

1523 * HOL and ZF: unary minus for integers is now #- instead of #~. In

1524 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is

1525 now taken as an integer constant.

1527 * Pure: ML function 'theory_of' renamed to 'theory';

1530 *** Proof tools ***

1532 * Simplifier:

1533 1. Asm_full_simp_tac is now more aggressive.

1534 1. It will sometimes reorient premises if that increases their power to

1535 simplify.

1536 2. It does no longer proceed strictly from left to right but may also

1537 rotate premises to achieve further simplification.

1538 For compatibility reasons there is now Asm_lr_simp_tac which is like the

1539 old Asm_full_simp_tac in that it does not rotate premises.

1540 2. The simplifier now knows a little bit about nat-arithmetic.

1542 * Classical reasoner: wrapper mechanism for the classical reasoner now

1543 allows for selected deletion of wrappers, by introduction of names for

1544 wrapper functionals. This implies that addbefore, addSbefore,

1545 addaltern, and addSaltern now take a pair (name, tactic) as argument,

1546 and that adding two tactics with the same name overwrites the first

1547 one (emitting a warning).

1548 type wrapper = (int -> tactic) -> (int -> tactic)

1549 setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by

1550 addWrapper, addSWrapper: claset * (string * wrapper) -> claset

1551 delWrapper, delSWrapper: claset * string -> claset

1552 getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;

1554 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE

1555 semantics; addbefore now affects only the unsafe part of step_tac

1556 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY

1557 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac

1558 by Force_tac;

1560 * Classical reasoner: setwrapper to setWrapper and compwrapper to

1561 compWrapper; added safe wrapper (and access functions for it);

1563 * HOL/split_all_tac is now much faster and fails if there is nothing

1564 to split. Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order

1565 and the names of the automatically generated variables have changed.

1566 split_all_tac has moved within claset() from unsafe wrappers to safe

1567 wrappers, which means that !!-bound variables are split much more

1568 aggressively, and safe_tac and clarify_tac now split such variables.

1569 If this splitting is not appropriate, use delSWrapper "split_all_tac".

1570 Note: the same holds for record_split_tac, which does the job of

1571 split_all_tac for record fields.

1573 * HOL/Simplifier: Rewrite rules for case distinctions can now be added

1574 permanently to the default simpset using Addsplits just like

1575 Addsimps. They can be removed via Delsplits just like

1576 Delsimps. Lower-case versions are also available.

1578 * HOL/Simplifier: The rule split_if is now part of the default

1579 simpset. This means that the simplifier will eliminate all occurrences

1580 of if-then-else in the conclusion of a goal. To prevent this, you can

1581 either remove split_if completely from the default simpset by

1582 `Delsplits [split_if]' or remove it in a specific call of the

1583 simplifier using `... delsplits [split_if]'. You can also add/delete

1584 other case splitting rules to/from the default simpset: every datatype

1585 generates suitable rules `split_t_case' and `split_t_case_asm' (where

1586 t is the name of the datatype).

1588 * Classical reasoner / Simplifier combination: new force_tac (and

1589 derivatives Force_tac, force) combines rewriting and classical

1590 reasoning (and whatever other tools) similarly to auto_tac, but is

1591 aimed to solve the given subgoal completely.

1594 *** General ***

1596 * new top-level commands `Goal' and `Goalw' that improve upon `goal'

1597 and `goalw': the theory is no longer needed as an explicit argument -

1598 the current theory context is used; assumptions are no longer returned

1599 at the ML-level unless one of them starts with ==> or !!; it is

1600 recommended to convert to these new commands using isatool fixgoal

1601 (backup your sources first!);

1603 * new top-level commands 'thm' and 'thms' for retrieving theorems from

1604 the current theory context, and 'theory' to lookup stored theories;

1606 * new theory section 'locale' for declaring constants, assumptions and

1607 definitions that have local scope;

1609 * new theory section 'nonterminals' for purely syntactic types;

1611 * new theory section 'setup' for generic ML setup functions

1612 (e.g. package initialization);

1614 * the distribution now includes Isabelle icons: see

1615 lib/logo/isabelle-{small,tiny}.xpm;

1617 * isatool install - install binaries with absolute references to

1618 ISABELLE_HOME/bin;

1620 * isatool logo -- create instances of the Isabelle logo (as EPS);

1622 * print mode 'emacs' reserved for Isamode;

1624 * support multiple print (ast) translations per constant name;

1626 * theorems involving oracles are now printed with a suffixed [!];

1629 *** HOL ***

1631 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');

1633 * HOL/inductive package reorganized and improved: now supports mutual

1634 definitions such as

1636 inductive EVEN ODD

1637 intrs

1638 null "0 : EVEN"

1639 oddI "n : EVEN ==> Suc n : ODD"

1640 evenI "n : ODD ==> Suc n : EVEN"

1642 new theorem list "elims" contains an elimination rule for each of the

1643 recursive sets; inductive definitions now handle disjunctive premises

1644 correctly (also ZF);

1646 INCOMPATIBILITIES: requires Inductive as an ancestor; component

1647 "mutual_induct" no longer exists - the induction rule is always

1648 contained in "induct";

1651 * HOL/datatype package re-implemented and greatly improved: now

1652 supports mutually recursive datatypes such as

1654 datatype

1655 'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)

1656 | SUM ('a aexp) ('a aexp)

1657 | DIFF ('a aexp) ('a aexp)

1658 | NUM 'a

1659 and

1660 'a bexp = LESS ('a aexp) ('a aexp)

1661 | AND ('a bexp) ('a bexp)

1662 | OR ('a bexp) ('a bexp)

1664 as well as indirectly recursive datatypes such as

1666 datatype

1667 ('a, 'b) term = Var 'a

1668 | App 'b ((('a, 'b) term) list)

1670 The new tactic mutual_induct_tac [<var_1>, ..., <var_n>] i performs

1671 induction on mutually / indirectly recursive datatypes.

1673 Primrec equations are now stored in theory and can be accessed via

1674 <function_name>.simps.

1676 INCOMPATIBILITIES:

1678 - Theories using datatypes must now have theory Datatype as an

1679 ancestor.

1680 - The specific <typename>.induct_tac no longer exists - use the

1681 generic induct_tac instead.

1682 - natE has been renamed to nat.exhaust - use exhaust_tac

1683 instead of res_inst_tac ... natE. Note that the variable

1684 names in nat.exhaust differ from the names in natE, this

1685 may cause some "fragile" proofs to fail.

1686 - The theorems split_<typename>_case and split_<typename>_case_asm

1687 have been renamed to <typename>.split and <typename>.split_asm.

1688 - Since default sorts of type variables are now handled correctly,

1689 some datatype definitions may have to be annotated with explicit

1690 sort constraints.

1691 - Primrec definitions no longer require function name and type

1692 of recursive argument.

1694 Consider using isatool fixdatatype to adapt your theories and proof

1695 scripts to the new package (backup your sources first!).

1698 * HOL/record package: considerably improved implementation; now

1699 includes concrete syntax for record types, terms, updates; theorems

1700 for surjective pairing and splitting !!-bound record variables; proof

1701 support is as follows:

1703 1) standard conversions (selectors or updates applied to record

1704 constructor terms) are part of the standard simpset;

1706 2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are

1707 made part of standard simpset and claset via addIffs;

1709 3) a tactic for record field splitting (record_split_tac) is part of

1710 the standard claset (addSWrapper);

1712 To get a better idea about these rules you may retrieve them via

1713 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is

1714 the name of your record type.

1716 The split tactic 3) conceptually simplifies by the following rule:

1718 "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"

1720 Thus any record variable that is bound by meta-all will automatically

1721 blow up into some record constructor term, consequently the

1722 simplifications of 1), 2) apply. Thus force_tac, auto_tac etc. shall

1723 solve record problems automatically.

1726 * reorganized the main HOL image: HOL/Integ and String loaded by

1727 default; theory Main includes everything;

1729 * automatic simplification of integer sums and comparisons, using cancellation;

1731 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;

1733 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;

1735 * many new identities for unions, intersections, set difference, etc.;

1737 * expand_if, expand_split, expand_sum_case and expand_nat_case are now

1738 called split_if, split_split, split_sum_case and split_nat_case (to go

1739 with add/delsplits);

1741 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting

1742 (?x::unit) = (); this is made part of the default simpset, which COULD

1743 MAKE EXISTING PROOFS FAIL under rare circumstances (consider

1744 'Delsimprocs [unit_eq_proc];' as last resort); also note that

1745 unit_abs_eta_conv is added in order to counter the effect of

1746 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by

1747 %u.f();

1749 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which

1750 makes more sense);

1752 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;

1753 It and 'sym RS equals0D' are now in the default claset, giving automatic

1754 disjointness reasoning but breaking a few old proofs.

1756 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1

1757 to 'converse' from 'inverse' (for compatibility with ZF and some

1758 literature);

1760 * HOL/recdef can now declare non-recursive functions, with {} supplied as

1761 the well-founded relation;

1763 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of

1764 Compl A. The "Compl" syntax remains available as input syntax for this

1765 release ONLY.

1767 * HOL/Update: new theory of function updates:

1768 f(a:=b) == %x. if x=a then b else f x

1769 may also be iterated as in f(a:=b,c:=d,...);

1771 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;

1773 * HOL/List:

1774 - new function list_update written xs[i:=v] that updates the i-th

1775 list position. May also be iterated as in xs[i:=a,j:=b,...].

1776 - new function `upt' written [i..j(] which generates the list

1777 [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper

1778 bound write [i..j], which is a shorthand for [i..j+1(].

1779 - new lexicographic orderings and corresponding wellfoundedness theorems.

1781 * HOL/Arith:

1782 - removed 'pred' (predecessor) function;

1783 - generalized some theorems about n-1;

1784 - many new laws about "div" and "mod";

1785 - new laws about greatest common divisors (see theory ex/Primes);

1787 * HOL/Relation: renamed the relational operator r^-1 "converse"

1788 instead of "inverse";

1790 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness

1791 of the multiset ordering;

1793 * directory HOL/Real: a construction of the reals using Dedekind cuts

1794 (not included by default);

1796 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;

1798 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted

1799 programs, i.e. different program variables may have different types.

1801 * calling (stac rew i) now fails if "rew" has no effect on the goal

1802 [previously, this check worked only if the rewrite rule was unconditional]

1803 Now rew can involve either definitions or equalities (either == or =).

1806 *** ZF ***

1808 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains

1809 only the theorems proved on ZF.ML;

1811 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;

1812 It and 'sym RS equals0D' are now in the default claset, giving automatic

1813 disjointness reasoning but breaking a few old proofs.

1815 * ZF/Update: new theory of function updates

1816 with default rewrite rule f(x:=y) ` z = if(z=x, y, f`z)

1817 may also be iterated as in f(a:=b,c:=d,...);

1819 * in let x=t in u(x), neither t nor u(x) has to be an FOL term.

1821 * calling (stac rew i) now fails if "rew" has no effect on the goal

1822 [previously, this check worked only if the rewrite rule was unconditional]

1823 Now rew can involve either definitions or equalities (either == or =).

1825 * case_tac provided for compatibility with HOL

1826 (like the old excluded_middle_tac, but with subgoals swapped)

1829 *** Internal programming interfaces ***

1831 * Pure: several new basic modules made available for general use, see

1832 also src/Pure/README;

1834 * improved the theory data mechanism to support encapsulation (data

1835 kind name replaced by private Object.kind, acting as authorization

1836 key); new type-safe user interface via functor TheoryDataFun; generic

1837 print_data function becomes basically useless;

1839 * removed global_names compatibility flag -- all theory declarations

1840 are qualified by default;

1842 * module Pure/Syntax now offers quote / antiquote translation

1843 functions (useful for Hoare logic etc. with implicit dependencies);

1844 see HOL/ex/Antiquote for an example use;

1846 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->

1847 cterm -> thm;

1849 * new tactical CHANGED_GOAL for checking that a tactic modifies a

1850 subgoal;

1852 * Display.print_goals function moved to Locale.print_goals;

1854 * standard print function for goals supports current_goals_markers

1855 variable for marking begin of proof, end of proof, start of goal; the

1856 default is ("", "", ""); setting current_goals_markers := ("<proof>",

1857 "</proof>", "<goal>") causes SGML like tagged proof state printing,

1858 for example;

1862 New in Isabelle98 (January 1998)

1863 --------------------------------

1865 *** Overview of INCOMPATIBILITIES (see below for more details) ***

1867 * changed lexical syntax of terms / types: dots made part of long

1868 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";

1870 * simpset (and claset) reference variable replaced by functions

1871 simpset / simpset_ref;

1873 * no longer supports theory aliases (via merge) and non-trivial

1874 implicit merge of thms' signatures;

1876 * most internal names of constants changed due to qualified names;

1878 * changed Pure/Sequence interface (see Pure/seq.ML);

1881 *** General Changes ***

1883 * hierachically structured name spaces (for consts, types, axms, thms

1884 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of

1885 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:

1886 isatool fixdots ensures space after dots (e.g. "%x. x"); set

1887 long_names for fully qualified output names; NOTE: ML programs

1888 (special tactics, packages etc.) referring to internal names may have

1889 to be adapted to cope with fully qualified names; in case of severe

1890 backward campatibility problems try setting 'global_names' at compile

1891 time to have enrything declared within a flat name space; one may also

1892 fine tune name declarations in theories via the 'global' and 'local'

1893 section;

1895 * reimplemented the implicit simpset and claset using the new anytype

1896 data filed in signatures; references simpset:simpset ref etc. are

1897 replaced by functions simpset:unit->simpset and

1898 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp

1899 to patch your ML files accordingly;

1901 * HTML output now includes theory graph data for display with Java

1902 applet or isatool browser; data generated automatically via isatool

1903 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);

1905 * defs may now be conditional; improved rewrite_goals_tac to handle

1906 conditional equations;

1908 * defs now admits additional type arguments, using TYPE('a) syntax;

1910 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always

1911 creates a new theory node; implicit merge of thms' signatures is

1912 restricted to 'trivial' ones; COMPATIBILITY: one may have to use

1913 transfer:theory->thm->thm in (rare) cases;

1915 * improved handling of draft signatures / theories; draft thms (and

1916 ctyps, cterms) are automatically promoted to real ones;

1918 * slightly changed interfaces for oracles: admit many per theory, named

1919 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;

1921 * print_goals: optional output of const types (set show_consts and

1922 show_types);

1924 * improved output of warnings (###) and errors (***);

1926 * subgoal_tac displays a warning if the new subgoal has type variables;

1928 * removed old README and Makefiles;

1930 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;

1932 * removed obsolete init_pps and init_database;

1934 * deleted the obsolete tactical STATE, which was declared by

1935 fun STATE tacfun st = tacfun st st;

1937 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~

1938 (which abbreviates $HOME);

1940 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:

1941 use isatool fixseq to adapt your ML programs (this works for fully

1942 qualified references to the Sequence structure only!);

1944 * use_thy no longer requires writable current directory; it always

1945 reloads .ML *and* .thy file, if either one is out of date;

1948 *** Classical Reasoner ***

1950 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new

1951 tactics that use classical reasoning to simplify a subgoal without

1952 splitting it into several subgoals;

1954 * Safe_tac: like safe_tac but uses the default claset;

1957 *** Simplifier ***

1959 * added simplification meta rules:

1960 (asm_)(full_)simplify: simpset -> thm -> thm;

1962 * simplifier.ML no longer part of Pure -- has to be loaded by object

1963 logics (again);

1965 * added prems argument to simplification procedures;

1967 * HOL, FOL, ZF: added infix function `addsplits':

1968 instead of `<simpset> setloop (split_tac <thms>)'

1969 you can simply write `<simpset> addsplits <thms>'

1972 *** Syntax ***

1974 * TYPE('a) syntax for type reflection terms;

1976 * no longer handles consts with name "" -- declare as 'syntax' instead;

1978 * pretty printer: changed order of mixfix annotation preference (again!);

1980 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;

1983 *** HOL ***

1985 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.

1986 with `addloop' of the simplifier to faciliate case splitting in premises.

1988 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;

1990 * HOL/Auth: new protocol proofs including some for the Internet

1991 protocol TLS;

1993 * HOL/Map: new theory of `maps' a la VDM;

1995 * HOL/simplifier: simplification procedures nat_cancel_sums for

1996 cancelling out common nat summands from =, <, <= (in)equalities, or

1997 differences; simplification procedures nat_cancel_factor for

1998 cancelling common factor from =, <, <= (in)equalities over natural

1999 sums; nat_cancel contains both kinds of procedures, it is installed by

2000 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;

2002 * HOL/simplifier: terms of the form

2003 `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)' (or t=x)

2004 are rewritten to

2005 `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',

2006 and those of the form

2007 `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)' (or t=x)

2008 are rewritten to

2009 `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',

2011 * HOL/datatype

2012 Each datatype `t' now comes with a theorem `split_t_case' of the form

2014 P(t_case f1 ... fn x) =

2015 ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &

2016 ...

2017 (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))

2018 )

2020 and a theorem `split_t_case_asm' of the form

2022 P(t_case f1 ... fn x) =

2023 ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |

2024 ...

2025 (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))

2026 )

2027 which can be added to a simpset via `addsplits'. The existing theorems

2028 expand_list_case and expand_option_case have been renamed to

2029 split_list_case and split_option_case.

2031 * HOL/Arithmetic:

2032 - `pred n' is automatically converted to `n-1'.

2033 Users are strongly encouraged not to use `pred' any longer,

2034 because it will disappear altogether at some point.

2035 - Users are strongly encouraged to write "0 < n" rather than

2036 "n ~= 0". Theorems and proof tools have been modified towards this

2037 `standard'.

2039 * HOL/Lists:

2040 the function "set_of_list" has been renamed "set" (and its theorems too);

2041 the function "nth" now takes its arguments in the reverse order and

2042 has acquired the infix notation "!" as in "xs!n".

2044 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};

2046 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its

2047 specialist theorems (like UN1_I) are gone. Similarly for (INT x.B x);

2049 * HOL/record: extensible records with schematic structural subtyping

2050 (single inheritance); EXPERIMENTAL version demonstrating the encoding,

2051 still lacks various theorems and concrete record syntax;

2054 *** HOLCF ***

2056 * removed "axioms" and "generated by" sections;

2058 * replaced "ops" section by extended "consts" section, which is capable of

2059 handling the continuous function space "->" directly;

2061 * domain package:

2062 . proves theorems immediately and stores them in the theory,

2063 . creates hierachical name space,

2064 . now uses normal mixfix annotations (instead of cinfix...),

2065 . minor changes to some names and values (for consistency),

2066 . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,

2067 . separator between mutual domain defs: changed "," to "and",

2068 . improved handling of sort constraints; now they have to

2069 appear on the left-hand side of the equations only;

2071 * fixed LAM <x,y,zs>.b syntax;

2073 * added extended adm_tac to simplifier in HOLCF -- can now discharge

2074 adm (%x. P (t x)), where P is chainfinite and t continuous;

2077 *** FOL and ZF ***

2079 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.

2080 with `addloop' of the simplifier to faciliate case splitting in premises.

2082 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as

2083 in HOL, they strip ALL and --> from proved theorems;

2087 New in Isabelle94-8 (May 1997)

2088 ------------------------------

2090 *** General Changes ***

2092 * new utilities to build / run / maintain Isabelle etc. (in parts

2093 still somewhat experimental); old Makefiles etc. still functional;

2095 * new 'Isabelle System Manual';

2097 * INSTALL text, together with ./configure and ./build scripts;

2099 * reimplemented type inference for greater efficiency, better error

2100 messages and clean internal interface;

2102 * prlim command for dealing with lots of subgoals (an easier way of

2103 setting goals_limit);

2106 *** Syntax ***

2108 * supports alternative (named) syntax tables (parser and pretty

2109 printer); internal interface is provided by add_modesyntax(_i);

2111 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to

2112 be used in conjunction with the Isabelle symbol font; uses the

2113 "symbols" syntax table;

2115 * added token_translation interface (may translate name tokens in

2116 arbitrary ways, dependent on their type (free, bound, tfree, ...) and

2117 the current print_mode); IMPORTANT: user print translation functions

2118 are responsible for marking newly introduced bounds

2119 (Syntax.mark_boundT);

2121 * token translations for modes "xterm" and "xterm_color" that display

2122 names in bold, underline etc. or colors (which requires a color

2123 version of xterm);

2125 * infixes may now be declared with names independent of their syntax;

2127 * added typed_print_translation (like print_translation, but may

2128 access type of constant);

2131 *** Classical Reasoner ***

2133 Blast_tac: a new tactic! It is often more powerful than fast_tac, but has

2134 some limitations. Blast_tac...

2135 + ignores addss, addbefore, addafter; this restriction is intrinsic

2136 + ignores elimination rules that don't have the correct format

2137 (the conclusion MUST be a formula variable)

2138 + ignores types, which can make HOL proofs fail

2139 + rules must not require higher-order unification, e.g. apply_type in ZF

2140 [message "Function Var's argument not a bound variable" relates to this]

2141 + its proof strategy is more general but can actually be slower

2143 * substitution with equality assumptions no longer permutes other

2144 assumptions;

2146 * minor changes in semantics of addafter (now called addaltern); renamed

2147 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper

2148 (and access functions for it);

2150 * improved combination of classical reasoner and simplifier:

2151 + functions for handling clasimpsets

2152 + improvement of addss: now the simplifier is called _after_ the

2153 safe steps.

2154 + safe variant of addss called addSss: uses safe simplifications

2155 _during_ the safe steps. It is more complete as it allows multiple

2156 instantiations of unknowns (e.g. with slow_tac).

2158 *** Simplifier ***

2160 * added interface for simplification procedures (functions that

2161 produce *proven* rewrite rules on the fly, depending on current

2162 redex);

2164 * ordering on terms as parameter (used for ordered rewriting);

2166 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;

2168 * the solver is now split into a safe and an unsafe part.

2169 This should be invisible for the normal user, except that the

2170 functions setsolver and addsolver have been renamed to setSolver and

2171 addSolver; added safe_asm_full_simp_tac;

2174 *** HOL ***

2176 * a generic induction tactic `induct_tac' which works for all datatypes and

2177 also for type `nat';

2179 * a generic case distinction tactic `exhaust_tac' which works for all

2180 datatypes and also for type `nat';

2182 * each datatype comes with a function `size';

2184 * patterns in case expressions allow tuple patterns as arguments to

2185 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';

2187 * primrec now also works with type nat;

2189 * recdef: a new declaration form, allows general recursive functions to be

2190 defined in theory files. See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.

2192 * the constant for negation has been renamed from "not" to "Not" to

2193 harmonize with FOL, ZF, LK, etc.;

2195 * HOL/ex/LFilter theory of a corecursive "filter" functional for

2196 infinite lists;

2198 * HOL/Modelcheck demonstrates invocation of model checker oracle;

2200 * HOL/ex/Ring.thy declares cring_simp, which solves equational

2201 problems in commutative rings, using axiomatic type classes for + and *;

2203 * more examples in HOL/MiniML and HOL/Auth;

2205 * more default rewrite rules for quantifiers, union/intersection;

2207 * a new constant `arbitrary == @x.False';

2209 * HOLCF/IOA replaces old HOL/IOA;

2211 * HOLCF changes: derived all rules and arities

2212 + axiomatic type classes instead of classes

2213 + typedef instead of faking type definitions

2214 + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.

2215 + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po

2216 + eliminated the types void, one, tr

2217 + use unit lift and bool lift (with translations) instead of one and tr

2218 + eliminated blift from Lift3.thy (use Def instead of blift)

2219 all eliminated rules are derived as theorems --> no visible changes ;

2222 *** ZF ***

2224 * ZF now has Fast_tac, Simp_tac and Auto_tac. Union_iff is a now a default

2225 rewrite rule; this may affect some proofs. eq_cs is gone but can be put back

2226 as ZF_cs addSIs [equalityI];

2230 New in Isabelle94-7 (November 96)

2231 ---------------------------------

2233 * allowing negative levels (as offsets) in prlev and choplev;

2235 * super-linear speedup for large simplifications;

2237 * FOL, ZF and HOL now use miniscoping: rewriting pushes

2238 quantifications in as far as possible (COULD MAKE EXISTING PROOFS

2239 FAIL); can suppress it using the command Delsimps (ex_simps @

2240 all_simps); De Morgan laws are also now included, by default;

2242 * improved printing of ==> : ~:

2244 * new object-logic "Sequents" adds linear logic, while replacing LK

2245 and Modal (thanks to Sara Kalvala);

2247 * HOL/Auth: correctness proofs for authentication protocols;

2249 * HOL: new auto_tac combines rewriting and classical reasoning (many

2250 examples on HOL/Auth);

2252 * HOL: new command AddIffs for declaring theorems of the form P=Q to

2253 the rewriter and classical reasoner simultaneously;

2255 * function uresult no longer returns theorems in "standard" format;

2256 regain previous version by: val uresult = standard o uresult;

2260 New in Isabelle94-6

2261 -------------------

2263 * oracles -- these establish an interface between Isabelle and trusted

2264 external reasoners, which may deliver results as theorems;

2266 * proof objects (in particular record all uses of oracles);

2268 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;

2270 * "constdefs" section in theory files;

2272 * "primrec" section (HOL) no longer requires names;

2274 * internal type "tactic" now simply "thm -> thm Sequence.seq";

2278 New in Isabelle94-5

2279 -------------------

2281 * reduced space requirements;

2283 * automatic HTML generation from theories;

2285 * theory files no longer require "..." (quotes) around most types;

2287 * new examples, including two proofs of the Church-Rosser theorem;

2289 * non-curried (1994) version of HOL is no longer distributed;

2293 New in Isabelle94-4

2294 -------------------

2296 * greatly reduced space requirements;

2298 * theory files (.thy) no longer require \...\ escapes at line breaks;

2300 * searchable theorem database (see the section "Retrieving theorems" on

2301 page 8 of the Reference Manual);

2303 * new examples, including Grabczewski's monumental case study of the

2304 Axiom of Choice;

2306 * The previous version of HOL renamed to Old_HOL;

2308 * The new version of HOL (previously called CHOL) uses a curried syntax

2309 for functions. Application looks like f a b instead of f(a,b);

2311 * Mutually recursive inductive definitions finally work in HOL;

2313 * In ZF, pattern-matching on tuples is now available in all abstractions and

2314 translates to the operator "split";

2318 New in Isabelle94-3

2319 -------------------

2321 * new infix operator, addss, allowing the classical reasoner to

2322 perform simplification at each step of its search. Example:

2323 fast_tac (cs addss ss)

2325 * a new logic, CHOL, the same as HOL, but with a curried syntax

2326 for functions. Application looks like f a b instead of f(a,b). Also pairs

2327 look like (a,b) instead of <a,b>;

2329 * PLEASE NOTE: CHOL will eventually replace HOL!

2331 * In CHOL, pattern-matching on tuples is now available in all abstractions.

2332 It translates to the operator "split". A new theory of integers is available;

2334 * In ZF, integer numerals now denote two's-complement binary integers.

2335 Arithmetic operations can be performed by rewriting. See ZF/ex/Bin.ML;

2337 * Many new examples: I/O automata, Church-Rosser theorem, equivalents

2338 of the Axiom of Choice;

2342 New in Isabelle94-2

2343 -------------------

2345 * Significantly faster resolution;

2347 * the different sections in a .thy file can now be mixed and repeated

2348 freely;

2350 * Database of theorems for FOL, HOL and ZF. New

2351 commands including qed, qed_goal and bind_thm store theorems in the database.

2353 * Simple database queries: return a named theorem (get_thm) or all theorems of

2354 a given theory (thms_of), or find out what theory a theorem was proved in

2355 (theory_of_thm);

2357 * Bugs fixed in the inductive definition and datatype packages;

2359 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs

2360 and HOL_dup_cs obsolete;

2362 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1

2363 have been removed;

2365 * Simpler definition of function space in ZF;

2367 * new results about cardinal and ordinal arithmetic in ZF;

2369 * 'subtype' facility in HOL for introducing new types as subsets of existing

2370 types;

2373 $Id$