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NEWS

author | schirmer |

Wed Mar 03 22:58:23 2004 +0100 (2004-03-03) | |

changeset 14427 | cea7d2f76112 |

parent 14418 | b62323c85134 |

child 14464 | 72ad5f2a3803 |

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

added record_ex_sel_eq_simproc

1 Isabelle NEWS -- history user-relevant changes

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

4 New in this Isabelle release

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

7 *** General ***

9 * Provers/order.ML: new efficient reasoner for partial and linear orders.

10 Replaces linorder.ML.

12 * Pure: Greek letters (except small lambda, \<lambda>), as well as gothic

13 (\<aa>...\<zz>\<AA>...\<ZZ>), caligraphic (\<A>...\<Z>), and euler

14 (\<a>...\<z>), are now considered normal letters, and can therefore

15 be used anywhere where an ASCII letter (a...zA...Z) has until

16 now. COMPATIBILITY: This obviously changes the parsing of some

17 terms, especially where a symbol has been used as a binder, say

18 '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed

19 as an identifier. Fix it by inserting a space around former

20 symbols. Call 'isatool fixgreek' to try to fix parsing errors in

21 existing theory and ML files.

23 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.

25 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now

26 allowed in identifiers. Similar to greek letters \<^isub> is now considered

27 a normal (but invisible) letter. For multiple letter subscripts repeat

28 \<^isub> like this: x\<^isub>1\<^isub>2.

30 * Pure: There are now sub-/superscripts that can span more than one

31 character. Text between \<^bsub> and \<^esub> is set in subscript in

32 PG and LaTeX, text between \<^bsup> and \<^esup> in superscript. The

33 new control characters are not identifier parts.

35 * Pure: Control-symbols of the form \<^raw...> will literally print the

36 content of ... to the latex file instead of \isacntrl... . The ...

37 accepts all printable characters excluding the end bracket >.

39 * Pure: Symbols may only start with one backslash: \<...>. \\<...> is no

40 longer accepted by the scanner.

42 * Pure: Using new Isar command "finalconsts" (or the ML functions

43 Theory.add_finals or Theory.add_finals_i) it is now possible to

44 declare constants "final", which prevents their being given a definition

45 later. It is useful for constants whose behaviour is fixed axiomatically

46 rather than definitionally, such as the meta-logic connectives.

48 *** Isar ***

50 * Tactic emulation methods ?rule_tac, cut_tac, subgoal_tac and thin_tac:

51 - Now understand static (Isar) contexts. As a consequence, users of Isar

52 locales are no longer forced to write Isar proof scripts.

53 For details see Isar Reference Manual, paragraph 4.3.2: Further tactic

54 emulations.

55 - INCOMPATIBILITY: names of variables to be instantiated may no

56 longer be enclosed in quotes. Instead, precede variable name with `?'.

57 This is consistent with the instantiation attribute "where".

59 * Attributes "where" and "of":

60 - Now take type variables of instantiated theorem into account when reading

61 the instantiation string. This fixes a bug that caused instantiated

62 theorems to have too special types in some circumstances.

63 - "where" permits explicit instantiations of type variables.

65 * Calculation commands "moreover" and "also":

66 Do not reset facts ("this") any more.

68 * Locales:

69 - Goal statements involving the context element "includes" no longer

70 generate theorems with internal delta predicates (those ending on

71 "_axioms") in the premise.

72 Resolve particular premise with <locale>.intro to obtain old form.

73 - Fixed bug in type inference ("unify_frozen") that prevented mix of target

74 specification and "includes" elements in goal statement.

75 - Rule sets <locale>.intro and <locale>.axioms no longer declared as

76 [intro?] and [elim?] (respectively) by default.

78 * HOL: Tactic emulation methods induct_tac and case_tac understand static

79 (Isar) contexts.

81 *** HOL ***

83 * Simplifier:

84 - Much improved handling of linear and partial orders.

85 Reasoners for linear and partial orders are set up for type classes

86 "linorder" and "order" respectively, and are added to the default simpset

87 as solvers. This means that the simplifier can build transitivity chains

88 to solve goals from the assumptions.

89 - INCOMPATIBILITY: old proofs break occasionally. Typically, applications

90 of blast or auto after simplification become unnecessary because the goal

91 is solved by simplification already.

93 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,

94 all proved in axiomatic type classes for semirings, rings and fields.

96 * Numerics:

97 - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are

98 now formalized using the Ring_and_Field theory mentioned above.

99 - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently

100 than before, because now they are set up once in a generic manner.

101 - INCOMPATIBILITY: many type-specific instances of laws proved in

102 Ring_and_Field are no longer available.

104 * Type "rat" of the rational numbers is now available in HOL-Complex.

106 * Records:

107 - Record types are now by default printed with their type abbreviation

108 instead of the list of all field types. This can be configured via

109 the reference "print_record_type_abbr".

110 - Simproc "record_upd_simproc" for simplification of multiple updates added

111 (not enabled by default).

112 - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.

113 EX x. x = sel r to True (not enabled by default).

114 - Tactic "record_split_simp_tac" to split and simplify records added.

116 * 'specification' command added, allowing for definition by

117 specification. There is also an 'ax_specification' command that

118 introduces the new constants axiomatically.

120 * arith(_tac) is now able to generate counterexamples for reals as well.

122 * HOL-Algebra: new locale "ring" for non-commutative rings.

124 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function

125 defintions, thanks to Sava Krsti\'{c} and John Matthews.

127 * Unions and Intersections:

128 The x-symbol output syntax of UN and INT has been changed

129 from "\<Union>x \<in> A. B" to "\<Union\<^bsub>x \<in> A\<^esub> B"

130 i.e. the index formulae has become a subscript, like in normal math.

131 Similarly for "\<Union>x. B", and for \<Inter> instead of \<Union>.

132 The subscript version is also accepted as input syntax.

134 * Unions and Intersections over Intervals:

135 There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is

136 also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"

137 like in normal math, and corresponding versions for < and for intersection.

139 * ML: the legacy theory structures Int and List have been removed. They had

140 conflicted with ML Basis Library structures having the same names.

142 New in Isabelle2003 (May 2003)

143 --------------------------------

145 *** General ***

147 * Provers/simplifier:

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

150 Assumptions are now subject to complete mutual simplification,

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

152 the order of assumptions.

154 Potential INCOMPATIBILITY:

156 -- simp sometimes diverges where the old version did

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

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

161 now gives rise to the infinite reduction sequence

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

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

166 kind of problem.

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

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

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

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

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

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

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

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

178 - You can limit the number of recursive invocations of the simplifier

179 during conditional rewriting (where the simplifie tries to solve the

180 conditions before applying the rewrite rule):

181 ML "simp_depth_limit := n"

182 where n is an integer. Thus you can force termination where previously

183 the simplifier would diverge.

185 - Accepts free variables as head terms in congruence rules. Useful in Isar.

187 - No longer aborts on failed congruence proof. Instead, the

188 congruence is ignored.

190 * Pure: New generic framework for extracting programs from constructive

191 proofs. See HOL/Extraction.thy for an example instantiation, as well

192 as HOL/Extraction for some case studies.

194 * Pure: The main goal of the proof state is no longer shown by default, only

195 the subgoals. This behaviour is controlled by a new flag.

196 PG menu: Isabelle/Isar -> Settings -> Show Main Goal

197 (ML: Proof.show_main_goal).

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

200 rules whose conclusion matches subgoal 1:

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

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

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

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

205 (ML: ProofGeneral.print_intros())

207 * Pure: New flag trace_unify_fail causes unification to print

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

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

210 assumption failed.

212 * Pure: Locale specifications now produce predicate definitions

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

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

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

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

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

218 on the old view without predicates;

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

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

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

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

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

226 include local facts of proof configuration (also covers active

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

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

229 be given (the default is 40);

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

232 (batch-mode only);

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

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

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

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

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

240 for slight decrease in efficiency;

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

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

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

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

249 *** HOL ***

251 * arith(_tac)

253 - Produces a counter example if it cannot prove a goal.

254 Note that the counter example may be spurious if the goal is not a formula

255 of quantifier-free linear arithmetic.

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

258 - Knows about div k and mod k where k is a numeral of type nat or int.

260 - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free

261 linear arithmetic fails. This takes account of quantifiers and divisibility.

262 Presburger arithmetic can also be called explicitly via presburger(_tac).

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

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

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

268 are distributed over a sum of terms;

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

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

272 "<=", "<" and "=").

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

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

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

278 definition;

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

281 Finite_Set);

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

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

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

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

289 * Map: `empty' is no longer a constant but a syntactic abbreviation for

290 %x. None. Warning: empty_def now refers to the previously hidden definition

291 of the empty set.

293 * Algebra: formalization of classical algebra. Intended as base for

294 any algebraic development in Isabelle. Currently covers group theory

295 (up to Sylow's theorem) and ring theory (Universal Property of

296 Univariate Polynomials). Contributions welcome;

298 * GroupTheory: deleted, since its material has been moved to Algebra;

300 * Complex: new directory of the complex numbers with numeric constants,

301 nonstandard complex numbers, and some complex analysis, standard and

302 nonstandard (Jacques Fleuriot);

304 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;

306 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques

307 Fleuriot);

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

311 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,

312 Gray and Kramer);

314 * UNITY: added the Meier-Sanders theory of progress sets;

316 * MicroJava: bytecode verifier and lightweight bytecode verifier

317 as abstract algorithms, instantiated to the JVM;

319 * Bali: Java source language formalization. Type system, operational

320 semantics, axiomatic semantics. Supported language features:

321 classes, interfaces, objects,virtual methods, static methods,

322 static/instance fields, arrays, access modifiers, definite

323 assignment, exceptions.

326 *** ZF ***

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

329 universe, etc.);

331 * Main ZF: virtually all theories converted to new-style format;

334 *** ML ***

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

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

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

340 * Pure: improved error reporting of simprocs;

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

343 up simprocs;

346 *** Document preparation ***

348 * uses \par instead of \\ for line breaks in theory text. This may

349 shift some page breaks in large documents. To get the old behaviour

350 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.

352 * minimized dependencies of isabelle.sty and isabellesym.sty on

353 other packages

355 * \<euro> now needs package babel/greek instead of marvosym (which

356 broke \Rightarrow)

358 * normal size for \<zero>...\<nine> (uses \mathbf instead of

359 textcomp package)

362 New in Isabelle2002 (March 2002)

363 --------------------------------

365 *** Document preparation ***

367 * greatly simplified document preparation setup, including more

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

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

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

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

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

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

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

376 with \includegraphics of LaTeX;

378 * proper spacing of consecutive markup elements, especially text

379 blocks after section headings;

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

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

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

385 better in printed text;

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

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

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

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

392 isatool document copies the Isabelle style files to the target

393 location;

396 *** Isar ***

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

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

400 "case (Suc n)");

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

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

403 instantiation of cases;

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

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

406 rules without further ado;

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

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

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

410 statement becomes is included in the hypothesis, avoiding the

411 slightly cumbersome show "PROP ?case" form;

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

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

414 rules stemming from inductive sets to be applied in unstructured

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

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

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

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

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

420 below);

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

422 success (no backtracking);

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

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

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

426 General versions);

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

428 - generic method setup instantiated for FOL and HOL;

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

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

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

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

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

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

436 fails:

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

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

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

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

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

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

446 attributes everywhere); operations on locales include merge and

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

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

449 some examples;

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

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

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

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

455 qualified by the locale name);

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

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

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

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

461 the context elements being discharged in the obvious way;

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

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

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

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

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

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

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

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

473 use hard-wired "Trueprop";

475 * Pure: added 'corollary' command;

477 * Pure: fixed 'token_translation' command;

479 * Pure: removed obsolete 'exported' attribute;

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

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

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

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

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

487 rewrite rules declarations of 'atomize' attribute; example

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

489 proof *scripts*;

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

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

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

494 especially important for locales);

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

497 mode;

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

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

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

502 situations;

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

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

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

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

509 discontinued;

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

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

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

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

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

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

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

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

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

521 INCOMPATIBILITY;

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

524 of introduction rules;

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

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

528 conditional rules;

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

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

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

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

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

538 * HOL: properly declared induction rules less_induct and

539 wf_induct_rule;

542 *** HOL ***

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

545 follows:

547 - 0 and 1 are polymorphic constants, which are defined on any

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

550 - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based

551 binary representation internally;

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

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

556 This change may cause significant problems of INCOMPATIBILITY; here

557 are some hints on converting existing sources:

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

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

561 to be spaced properly;

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

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

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

568 - remove all special provisions on numerals in proofs;

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

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

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

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

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

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

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

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

581 * HOL/record package improvements:

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

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

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

585 declared as simp by default;

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

587 qualified) --- potential INCOMPATIBILITY;

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

589 INCOMPATIBILITY;

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

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

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

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

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

595 theory of product types over typedef rather than datatype;

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

598 specifications; specific support for HOL constructs such as inductive

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

600 via 'generate_code' theory section;

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

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

605 Ord.thy has been absorbed into HOL.thy

606 String.thy has been absorbed into List.thy

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

609 (beware of argument permutation!);

611 * HOL: linorder_less_split superseded by linorder_cases;

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

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

616 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:

617 - Ex_def has changed, now need to use some_eq_ex

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

620 in this (rare) case use:

622 delSWrapper "split_all_tac"

623 addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)

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

626 MAY FAIL;

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

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

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

631 necessary to attach explicit type constraints;

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

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

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

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

638 expressions;

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

641 of "lam" -- INCOMPATIBILITY;

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

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

645 renamed "Product_Type.unit";

647 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl

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

650 the "cases" method);

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

653 Florian Kammüller);

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

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

657 some explanations (by Gerwin Klein);

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

661 * HOL-Hyperreal is now a logic image;

664 *** HOLCF ***

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

667 operations;

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

670 HOLCF/ex/Dnat.thy;

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

673 potential INCOMPATIBILITY; now use plain induct_tac instead of former

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

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

679 *** ZF ***

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

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

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

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

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

687 your theory on Main_ZFC;

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

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

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

693 typeless version of the formalism;

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

696 format;

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

699 including theory Multiset for multiset orderings; converted to

700 new-style theory format;

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

705 *** General ***

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

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

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

710 also ref manual for further ML interfaces;

712 * Pure/axclass: removed obsolete ML interface

713 goal_subclass/goal_arity;

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

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

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

718 properly;

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

721 rather than "infixl" or "infixr";

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

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

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

726 type variable);

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

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

730 "type_brackets";

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

733 tokens into AST constants;

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

736 translation functions; potential INCOMPATIBILITY: need to reverse

737 multiple declarations for same syntax element constant;

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

740 practice);

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

743 addSafter;

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

746 as well;

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

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

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

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

752 support requires further installations, e.g. from

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

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

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

758 of 40 MB), cf. ML_OPTIONS;

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

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

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

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

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

767 * system: smart selection of Isabelle process versus Isabelle

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

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

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

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

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

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

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

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

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

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

780 terminal);

784 New in Isabelle99-2 (February 2001)

785 -----------------------------------

787 *** Overview of INCOMPATIBILITIES ***

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

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

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

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

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

795 format may be recovered via ML function complete_split_rule or attribute

796 'split_rule (complete)';

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

799 gfp_Tarski to gfp_unfold;

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

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

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

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

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

808 operation;

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

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

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

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

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

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

819 \<gg> to \<ggreater>;

822 *** Document preparation ***

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

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

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

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

828 type-writer);

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

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

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

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

836 * improved isabelle style files; more abstract symbol implementation

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

838 definitions);

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

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

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

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

845 * proper indentation of antiquoted output with proportional LaTeX

846 fonts;

848 * no_document ML operator temporarily disables LaTeX document

849 generation;

851 * isatool unsymbolize tunes sources for plain ASCII communication;

854 *** Isar ***

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

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

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

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

860 for Prolog-style synthesis of proven results;

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

863 rules as well;

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

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

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

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

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

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

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

874 statements as well;

876 * Pure: more robust selection of calculational rules;

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

879 rule (as well as the assumption rule);

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

882 lemmas, using the graph browser tool;

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

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

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

889 (potential INCOMPATIBILITY); tuned error handling;

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

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

893 any remaining facts are inserted into the goal verbatim;

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

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

897 the result to be shown in each case;

899 * HOL: added 'recdef_tc' command;

901 * isatool convert assists in eliminating legacy ML scripts;

904 *** HOL ***

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

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

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

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

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

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

913 modelling and verification task performed in Isabelle/HOL +

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

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

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

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

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

920 literature;

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

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

924 operator \<Sum>;

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

927 HOL/subset.thy);

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

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

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

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

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

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

937 rules with string literals);

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

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

941 functions for the reals;

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

946 *** CTT ***

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

949 "lam" is displayed as TWO lambda-symbols

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

952 and Arith);

955 *** General ***

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

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

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

960 the Isabelle inference kernel has been greatly improved;

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

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

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

966 as assumptions as well;

968 * system: support Poly/ML 4.0;

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

974 New in Isabelle99-1 (October 2000)

975 ----------------------------------

977 *** Overview of INCOMPATIBILITIES ***

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

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

981 issue the following ML commands:

983 Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;

984 Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];

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

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

989 * HOL: nat_less_induct renamed to less_induct;

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

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

994 select_equality -> some_equality

995 select_eq_Ex -> some_eq_ex

996 selectI2EX -> someI2_ex

997 selectI2 -> someI2

998 selectI -> someI

999 select1_equality -> some1_equality

1000 Eps_sym_eq -> some_sym_eq_trivial

1001 Eps_eq -> some_eq_trivial

1003 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;

1005 * HOL: removed obsolete theorem binding expand_if (refer to split_if

1006 instead);

1008 * HOL: the recursion equations generated by 'recdef' are now called

1009 f.simps instead of f.rules;

1011 * HOL: qed_spec_mp now also handles bounded ALL as well;

1013 * HOL: 0 is now overloaded, so the type constraint ":: nat" may

1014 sometimes be needed;

1016 * HOL: the constant for "f``x" is now "image" rather than "op ``";

1018 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";

1020 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian

1021 product is now "<*>" instead of "Times"; the lexicographic product is

1022 now "<*lex*>" instead of "**";

1024 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part

1025 of main HOL, but was unused); better use HOL's datatype package;

1027 * HOL: removed "symbols" syntax for constant "override" of theory Map;

1028 the old syntax may be recovered as follows:

1030 syntax (symbols)

1031 override :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"

1032 (infixl "\\<oplus>" 100)

1034 * HOL/Real: "rabs" replaced by overloaded "abs" function;

1036 * HOL/ML: even fewer consts are declared as global (see theories Ord,

1037 Lfp, Gfp, WF); this only affects ML packages that refer to const names

1038 internally;

1040 * HOL and ZF: syntax for quotienting wrt an equivalence relation

1041 changed from A/r to A//r;

1043 * ZF: new treatment of arithmetic (nat & int) may break some old

1044 proofs;

1046 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,

1047 rulify -> rule_format, elimify -> elim_format, ...);

1049 * Isar/Provers: intro/elim/dest attributes changed; renamed

1050 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one

1051 should have to change intro!! to intro? only); replaced "delrule" by

1052 "rule del";

1054 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;

1056 * Provers: strengthened force_tac by using new first_best_tac;

1058 * LaTeX document preparation: several changes of isabelle.sty (see

1059 lib/texinputs);

1062 *** Document preparation ***

1064 * formal comments (text blocks etc.) in new-style theories may now

1065 contain antiquotations of thm/prop/term/typ/text to be presented

1066 according to latex print mode; concrete syntax is like this:

1067 @{term[show_types] "f(x) = a + x"};

1069 * isatool mkdir provides easy setup of Isabelle session directories,

1070 including proper document sources;

1072 * generated LaTeX sources are now deleted after successful run

1073 (isatool document -c); may retain a copy somewhere else via -D option

1074 of isatool usedir;

1076 * isatool usedir -D now lets isatool latex -o sty update the Isabelle

1077 style files, achieving self-contained LaTeX sources and simplifying

1078 LaTeX debugging;

1080 * old-style theories now produce (crude) LaTeX output as well;

1082 * browser info session directories are now self-contained (may be put

1083 on WWW server seperately); improved graphs of nested sessions; removed

1084 graph for 'all sessions';

1086 * several improvements in isabelle style files; \isabellestyle{it}

1087 produces fake math mode output; \isamarkupheader is now \section by

1088 default; see lib/texinputs/isabelle.sty etc.;

1091 *** Isar ***

1093 * Isar/Pure: local results and corresponding term bindings are now

1094 subject to Hindley-Milner polymorphism (similar to ML); this

1095 accommodates incremental type-inference very nicely;

1097 * Isar/Pure: new derived language element 'obtain' supports

1098 generalized existence reasoning;

1100 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'

1101 support accumulation of results, without applying any rules yet;

1102 useful to collect intermediate results without explicit name

1103 references, and for use with transitivity rules with more than 2

1104 premises;

1106 * Isar/Pure: scalable support for case-analysis type proofs: new

1107 'case' language element refers to local contexts symbolically, as

1108 produced by certain proof methods; internally, case names are attached

1109 to theorems as "tags";

1111 * Isar/Pure: theory command 'hide' removes declarations from

1112 class/type/const name spaces;

1114 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to

1115 indicate potential overloading;

1117 * Isar/Pure: changed syntax of local blocks from {{ }} to { };

1119 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write

1120 "{a,b,c}" instead of {a,b,c};

1122 * Isar/Pure now provides its own version of intro/elim/dest

1123 attributes; useful for building new logics, but beware of confusion

1124 with the version in Provers/classical;

1126 * Isar/Pure: the local context of (non-atomic) goals is provided via

1127 case name 'antecedent';

1129 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms

1130 to the current context is now done automatically);

1132 * Isar/Pure: theory command 'method_setup' provides a simple interface

1133 for definining proof methods in ML;

1135 * Isar/Provers: intro/elim/dest attributes changed; renamed

1136 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in

1137 most cases, one should have to change intro!! to intro? only);

1138 replaced "delrule" by "rule del";

1140 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and

1141 'symmetric' attribute (the latter supercedes [RS sym]);

1143 * Isar/Provers: splitter support (via 'split' attribute and 'simp'

1144 method modifier); 'simp' method: 'only:' modifier removes loopers as

1145 well (including splits);

1147 * Isar/Provers: Simplifier and Classical methods now support all kind

1148 of modifiers used in the past, including 'cong', 'iff', etc.

1150 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination

1151 of Simplifier and Classical reasoner);

1153 * Isar/HOL: new proof method 'cases' and improved version of 'induct'

1154 now support named cases; major packages (inductive, datatype, primrec,

1155 recdef) support case names and properly name parameters;

1157 * Isar/HOL: new transitivity rules for substitution in inequalities --

1158 monotonicity conditions are extracted to be proven at end of

1159 calculations;

1161 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof

1162 method anyway;

1164 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =

1165 split_if split_if_asm; datatype package provides theorems foo.splits =

1166 foo.split foo.split_asm for each datatype;

1168 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"

1169 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof

1170 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:

1171 use "(cases (simplified))" method in proper proof texts);

1173 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;

1175 * Isar: names of theorems etc. may be natural numbers as well;

1177 * Isar: 'pr' command: optional arguments for goals_limit and

1178 ProofContext.prems_limit; no longer prints theory contexts, but only

1179 proof states;

1181 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit

1182 additional print modes to be specified; e.g. "pr(latex)" will print

1183 proof state according to the Isabelle LaTeX style;

1185 * Isar: improved support for emulating tactic scripts, including proof

1186 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',

1187 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'

1188 (for HOL datatypes);

1190 * Isar: simplified (more robust) goal selection of proof methods: 1st

1191 goal, all goals, or explicit goal specifier (tactic emulation); thus

1192 'proof method scripts' have to be in depth-first order;

1194 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';

1196 * Isar: removed 'help' command, which hasn't been too helpful anyway;

1197 should instead use individual commands for printing items

1198 (print_commands, print_methods etc.);

1200 * Isar: added 'nothing' --- the empty list of theorems;

1203 *** HOL ***

1205 * HOL/MicroJava: formalization of a fragment of Java, together with a

1206 corresponding virtual machine and a specification of its bytecode

1207 verifier and a lightweight bytecode verifier, including proofs of

1208 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and

1209 Cornelia Pusch (see also the homepage of project Bali at

1210 http://isabelle.in.tum.de/Bali/);

1212 * HOL/Algebra: new theory of rings and univariate polynomials, by

1213 Clemens Ballarin;

1215 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese

1216 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M

1217 Rasmussen;

1219 * HOL/Lattice: fundamental concepts of lattice theory and order

1220 structures, including duals, properties of bounds versus algebraic

1221 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski

1222 Theorem for complete lattices etc.; may also serve as a demonstration

1223 for abstract algebraic reasoning using axiomatic type classes, and

1224 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;

1226 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David

1227 von Oheimb;

1229 * HOL/IMPP: extension of IMP with local variables and mutually

1230 recursive procedures, by David von Oheimb;

1232 * HOL/Lambda: converted into new-style theory and document;

1234 * HOL/ex/Multiquote: example of multiple nested quotations and

1235 anti-quotations -- basically a generalized version of de-Bruijn

1236 representation; very useful in avoiding lifting of operations;

1238 * HOL/record: added general record equality rule to simpset; fixed

1239 select-update simplification procedure to handle extended records as

1240 well; admit "r" as field name;

1242 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with

1243 other numeric types and also as the identity of groups, rings, etc.;

1245 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.

1246 Types nat and int belong to this axclass;

1248 * HOL: greatly improved simplification involving numerals of type nat, int, real:

1249 (i + #8 + j) = Suc k simplifies to #7 + (i + j) = k

1250 i*j + k + j*#3*i simplifies to #4*(i*j) + k

1251 two terms #m*u and #n*u are replaced by #(m+n)*u

1252 (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)

1253 and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y

1254 or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);

1256 * HOL: meson_tac is available (previously in ex/meson.ML); it is a

1257 powerful prover for predicate logic but knows nothing of clasets; see

1258 ex/mesontest.ML and ex/mesontest2.ML for example applications;

1260 * HOL: new version of "case_tac" subsumes both boolean case split and

1261 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer

1262 exists, may define val exhaust_tac = case_tac for ad-hoc portability;

1264 * HOL: simplification no longer dives into case-expressions: only the

1265 selector expression is simplified, but not the remaining arms; to

1266 enable full simplification of case-expressions for datatype t, you may

1267 remove t.weak_case_cong from the simpset, either globally (Delcongs

1268 [thm"t.weak_case_cong"];) or locally (delcongs [...]).

1270 * HOL/recdef: the recursion equations generated by 'recdef' for

1271 function 'f' are now called f.simps instead of f.rules; if all

1272 termination conditions are proved automatically, these simplification

1273 rules are added to the simpset, as in primrec; rules may be named

1274 individually as well, resulting in a separate list of theorems for

1275 each equation;

1277 * HOL/While is a new theory that provides a while-combinator. It

1278 permits the definition of tail-recursive functions without the

1279 provision of a termination measure. The latter is necessary once the

1280 invariant proof rule for while is applied.

1282 * HOL: new (overloaded) notation for the set of elements below/above

1283 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.

1285 * HOL: theorems impI, allI, ballI bound as "strip";

1287 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic

1288 induct_tac th "x1 ... xn" expects th to have a conclusion of the form

1289 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;

1291 * HOL/Real: "rabs" replaced by overloaded "abs" function;

1293 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of

1294 main HOL, but was unused);

1296 * HOL: fewer consts declared as global (e.g. have to refer to

1297 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);

1299 * HOL: tuned AST representation of nested pairs, avoiding bogus output

1300 in case of overlap with user translations (e.g. judgements over

1301 tuples); (note that the underlying logical represenation is still

1302 bogus);

1305 *** ZF ***

1307 * ZF: simplification automatically cancels common terms in arithmetic

1308 expressions over nat and int;

1310 * ZF: new treatment of nat to minimize type-checking: all operators

1311 coerce their operands to a natural number using the function natify,

1312 making the algebraic laws unconditional;

1314 * ZF: as above, for int: operators coerce their operands to an integer

1315 using the function intify;

1317 * ZF: the integer library now contains many of the usual laws for the

1318 orderings, including $<=, and monotonicity laws for $+ and $*;

1320 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic

1321 simplification;

1323 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q

1324 to the simplifier and classical reasoner simultaneously;

1327 *** General ***

1329 * Provers: blast_tac now handles actual object-logic rules as

1330 assumptions; note that auto_tac uses blast_tac internally as well;

1332 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning

1333 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;

1335 * Provers: delrules now handles destruct rules as well (no longer need

1336 explicit make_elim);

1338 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.

1339 [| inj ?f; ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W

1340 use instead the strong form,

1341 [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W

1342 in HOL, FOL and ZF the function cla_make_elim will create such rules

1343 from destruct-rules;

1345 * Provers: Simplifier.easy_setup provides a fast path to basic

1346 Simplifier setup for new object-logics;

1348 * Pure: AST translation rules no longer require constant head on LHS;

1350 * Pure: improved name spaces: ambiguous output is qualified; support

1351 for hiding of names;

1353 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and

1354 XSYMBOL_HOME; no longer need to do manual configuration in most

1355 situations;

1357 * system: compression of ML heaps images may now be controlled via -c

1358 option of isabelle and isatool usedir (currently only observed by

1359 Poly/ML);

1361 * system: isatool installfonts may handle X-Symbol fonts as well (very

1362 useful for remote X11);

1364 * system: provide TAGS file for Isabelle sources;

1366 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument

1367 order;

1369 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global

1370 timing flag supersedes proof_timing and Toplevel.trace;

1372 * ML: new combinators |>> and |>>> for incremental transformations

1373 with secondary results (e.g. certain theory extensions):

1375 * ML: PureThy.add_defs gets additional argument to indicate potential

1376 overloading (usually false);

1378 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as

1379 results;

1383 New in Isabelle99 (October 1999)

1384 --------------------------------

1386 *** Overview of INCOMPATIBILITIES (see below for more details) ***

1388 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)

1389 are no longer simplified. (This allows the simplifier to unfold recursive

1390 functional programs.) To restore the old behaviour, declare

1392 Delcongs [if_weak_cong];

1394 * HOL: Removed the obsolete syntax "Compl A"; use -A for set

1395 complement;

1397 * HOL: the predicate "inj" is now defined by translation to "inj_on";

1399 * HOL/datatype: mutual_induct_tac no longer exists --

1400 use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]

1402 * HOL/typedef: fixed type inference for representing set; type

1403 arguments now have to occur explicitly on the rhs as type constraints;

1405 * ZF: The con_defs part of an inductive definition may no longer refer

1406 to constants declared in the same theory;

1408 * HOL, ZF: the function mk_cases, generated by the inductive

1409 definition package, has lost an argument. To simplify its result, it

1410 uses the default simpset instead of a supplied list of theorems.

1412 * HOL/List: the constructors of type list are now Nil and Cons;

1414 * Simplifier: the type of the infix ML functions

1415 setSSolver addSSolver setSolver addSolver

1416 is now simpset * solver -> simpset where `solver' is a new abstract type

1417 for packaging solvers. A solver is created via

1418 mk_solver: string -> (thm list -> int -> tactic) -> solver

1419 where the string argument is only a comment.

1422 *** Proof tools ***

1424 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a

1425 decision procedure for linear arithmetic. Currently it is used for

1426 types `nat', `int', and `real' in HOL (see below); it can, should and

1427 will be instantiated for other types and logics as well.

1429 * The simplifier now accepts rewrite rules with flexible heads, eg

1430 hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y

1431 They are applied like any rule with a non-pattern lhs, i.e. by first-order

1432 matching.

1435 *** General ***

1437 * New Isabelle/Isar subsystem provides an alternative to traditional

1438 tactical theorem proving; together with the ProofGeneral/isar user

1439 interface it offers an interactive environment for developing human

1440 readable proof documents (Isar == Intelligible semi-automated

1441 reasoning); for further information see isatool doc isar-ref,

1442 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/

1444 * improved and simplified presentation of theories: better HTML markup

1445 (including colors), graph views in several sizes; isatool usedir now

1446 provides a proper interface for user theories (via -P option); actual

1447 document preparation based on (PDF)LaTeX is available as well (for

1448 new-style theories only); see isatool doc system for more information;

1450 * native support for Proof General, both for classic Isabelle and

1451 Isabelle/Isar;

1453 * ML function thm_deps visualizes dependencies of theorems and lemmas,

1454 using the graph browser tool;

1456 * Isabelle manuals now also available as PDF;

1458 * theory loader rewritten from scratch (may not be fully

1459 bug-compatible); old loadpath variable has been replaced by show_path,

1460 add_path, del_path, reset_path functions; new operations such as

1461 update_thy, touch_thy, remove_thy, use/update_thy_only (see also

1462 isatool doc ref);

1464 * improved isatool install: option -k creates KDE application icon,

1465 option -p DIR installs standalone binaries;

1467 * added ML_PLATFORM setting (useful for cross-platform installations);

1468 more robust handling of platform specific ML images for SML/NJ;

1470 * the settings environment is now statically scoped, i.e. it is never

1471 created again in sub-processes invoked from isabelle, isatool, or

1472 Isabelle;

1474 * path element specification '~~' refers to '$ISABELLE_HOME';

1476 * in locales, the "assumes" and "defines" parts may be omitted if

1477 empty;

1479 * new print_mode "xsymbols" for extended symbol support (e.g. genuine

1480 long arrows);

1482 * new print_mode "HTML";

1484 * new flag show_tags controls display of tags of theorems (which are

1485 basically just comments that may be attached by some tools);

1487 * Isamode 2.6 requires patch to accomodate change of Isabelle font

1488 mode and goal output format:

1490 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el

1491 244c244

1492 < (list (isa-getenv "ISABELLE") "-msymbols" logic-name)

1493 ---

1494 > (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)

1495 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el

1496 181c181

1497 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"

1498 ---

1499 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"

1501 * function bind_thms stores lists of theorems (cf. bind_thm);

1503 * new shorthand tactics ftac, eatac, datac, fatac;

1505 * qed (and friends) now accept "" as result name; in that case the

1506 theorem is not stored, but proper checks and presentation of the

1507 result still apply;

1509 * theorem database now also indexes constants "Trueprop", "all",

1510 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;

1513 *** HOL ***

1515 ** HOL arithmetic **

1517 * There are now decision procedures for linear arithmetic over nat and

1518 int:

1520 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',

1521 `+', `-', `Suc', `min', `max' and numerical constants; other subterms

1522 are treated as atomic; subformulae not involving type `nat' or `int'

1523 are ignored; quantified subformulae are ignored unless they are

1524 positive universal or negative existential. The tactic has to be

1525 invoked by hand and can be a little bit slow. In particular, the

1526 running time is exponential in the number of occurrences of `min' and

1527 `max', and `-' on `nat'.

1529 2. fast_arith_tac is a cut-down version of arith_tac: it only takes

1530 (negated) (in)equalities among the premises and the conclusion into

1531 account (i.e. no compound formulae) and does not know about `min' and

1532 `max', and `-' on `nat'. It is fast and is used automatically by the

1533 simplifier.

1535 NB: At the moment, these decision procedures do not cope with mixed

1536 nat/int formulae where the two parts interact, such as `m < n ==>

1537 int(m) < int(n)'.

1539 * HOL/Numeral provides a generic theory of numerals (encoded

1540 efficiently as bit strings); setup for types nat/int/real is in place;

1541 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than

1542 int, existing theories and proof scripts may require a few additional

1543 type constraints;

1545 * integer division and remainder can now be performed on constant

1546 arguments;

1548 * many properties of integer multiplication, division and remainder

1549 are now available;

1551 * An interface to the Stanford Validity Checker (SVC) is available through the

1552 tactic svc_tac. Propositional tautologies and theorems of linear arithmetic

1553 are proved automatically. SVC must be installed separately, and its results

1554 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any

1555 invocation of the underlying oracle). For SVC see

1556 http://verify.stanford.edu/SVC

1558 * IsaMakefile: the HOL-Real target now builds an actual image;

1561 ** HOL misc **

1563 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces

1564 (in Isabelle/Isar) -- by Gertrud Bauer;

1566 * HOL/BCV: generic model of bytecode verification, i.e. data-flow

1567 analysis for assembly languages with subtypes;

1569 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization

1570 -- avoids syntactic ambiguities and treats state, transition, and

1571 temporal levels more uniformly; introduces INCOMPATIBILITIES due to

1572 changed syntax and (many) tactics;

1574 * HOL/inductive: Now also handles more general introduction rules such

1575 as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity

1576 theorems are now maintained within the theory (maintained via the

1577 "mono" attribute);

1579 * HOL/datatype: Now also handles arbitrarily branching datatypes

1580 (using function types) such as

1582 datatype 'a tree = Atom 'a | Branch "nat => 'a tree"

1584 * HOL/record: record_simproc (part of the default simpset) takes care

1585 of selectors applied to updated records; record_split_tac is no longer

1586 part of the default claset; update_defs may now be removed from the

1587 simpset in many cases; COMPATIBILITY: old behavior achieved by

1589 claset_ref () := claset() addSWrapper record_split_wrapper;

1590 Delsimprocs [record_simproc]

1592 * HOL/typedef: fixed type inference for representing set; type

1593 arguments now have to occur explicitly on the rhs as type constraints;

1595 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem

1596 names rather than an ML expression;

1598 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be

1599 supplied later. Program schemes can be defined, such as

1600 "While B C s = (if B s then While B C (C s) else s)"

1601 where the well-founded relation can be chosen after B and C have been given.

1603 * HOL/List: the constructors of type list are now Nil and Cons;

1604 INCOMPATIBILITY: while [] and infix # syntax is still there, of

1605 course, ML tools referring to List.list.op # etc. have to be adapted;

1607 * HOL_quantifiers flag superseded by "HOL" print mode, which is

1608 disabled by default; run isabelle with option -m HOL to get back to

1609 the original Gordon/HOL-style output;

1611 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,

1612 ALL x<=y. P, EX x<y. P, EX x<=y. P;

1614 * HOL basic syntax simplified (more orthogonal): all variants of

1615 All/Ex now support plain / symbolic / HOL notation; plain syntax for

1616 Eps operator is provided as well: "SOME x. P[x]";

1618 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;

1620 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made

1621 thus available for user theories;

1623 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with

1624 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the

1625 time;

1627 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec

1628 several times and then mp;

1631 *** LK ***

1633 * the notation <<...>> is now available as a notation for sequences of

1634 formulas;

1636 * the simplifier is now installed

1638 * the axiom system has been generalized (thanks to Soren Heilmann)

1640 * the classical reasoner now has a default rule database

1643 *** ZF ***

1645 * new primrec section allows primitive recursive functions to be given

1646 directly (as in HOL) over datatypes and the natural numbers;

1648 * new tactics induct_tac and exhaust_tac for induction (or case

1649 analysis) over datatypes and the natural numbers;

1651 * the datatype declaration of type T now defines the recursor T_rec;

1653 * simplification automatically does freeness reasoning for datatype

1654 constructors;

1656 * automatic type-inference, with AddTCs command to insert new

1657 type-checking rules;

1659 * datatype introduction rules are now added as Safe Introduction rules

1660 to the claset;

1662 * the syntax "if P then x else y" is now available in addition to

1663 if(P,x,y);

1666 *** Internal programming interfaces ***

1668 * tuned simplifier trace output; new flag debug_simp;

1670 * structures Vartab / Termtab (instances of TableFun) offer efficient

1671 tables indexed by indexname_ord / term_ord (compatible with aconv);

1673 * AxClass.axclass_tac lost the theory argument;

1675 * tuned current_goals_markers semantics: begin / end goal avoids

1676 printing empty lines;

1678 * removed prs and prs_fn hook, which was broken because it did not

1679 include \n in its semantics, forcing writeln to add one

1680 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:

1681 string -> unit if you really want to output text without newline;

1683 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to

1684 plain output, interface builders may have to enable 'isabelle_font'

1685 mode to get Isabelle font glyphs as before;

1687 * refined token_translation interface; INCOMPATIBILITY: output length

1688 now of type real instead of int;

1690 * theory loader actions may be traced via new ThyInfo.add_hook

1691 interface (see src/Pure/Thy/thy_info.ML); example application: keep

1692 your own database of information attached to *whole* theories -- as

1693 opposed to intra-theory data slots offered via TheoryDataFun;

1695 * proper handling of dangling sort hypotheses (at last!);

1696 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing

1697 extra sort hypotheses that can be witnessed from the type signature;

1698 the force_strip_shyps flag is gone, any remaining shyps are simply

1699 left in the theorem (with a warning issued by strip_shyps_warning);

1703 New in Isabelle98-1 (October 1998)

1704 ----------------------------------

1706 *** Overview of INCOMPATIBILITIES (see below for more details) ***

1708 * several changes of automated proof tools;

1710 * HOL: major changes to the inductive and datatype packages, including

1711 some minor incompatibilities of theory syntax;

1713 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now

1714 called `inj_on';

1716 * HOL: removed duplicate thms in Arith:

1717 less_imp_add_less should be replaced by trans_less_add1

1718 le_imp_add_le should be replaced by trans_le_add1

1720 * HOL: unary minus is now overloaded (new type constraints may be

1721 required);

1723 * HOL and ZF: unary minus for integers is now #- instead of #~. In

1724 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is

1725 now taken as an integer constant.

1727 * Pure: ML function 'theory_of' renamed to 'theory';

1730 *** Proof tools ***

1732 * Simplifier:

1733 1. Asm_full_simp_tac is now more aggressive.

1734 1. It will sometimes reorient premises if that increases their power to

1735 simplify.

1736 2. It does no longer proceed strictly from left to right but may also

1737 rotate premises to achieve further simplification.

1738 For compatibility reasons there is now Asm_lr_simp_tac which is like the

1739 old Asm_full_simp_tac in that it does not rotate premises.

1740 2. The simplifier now knows a little bit about nat-arithmetic.

1742 * Classical reasoner: wrapper mechanism for the classical reasoner now

1743 allows for selected deletion of wrappers, by introduction of names for

1744 wrapper functionals. This implies that addbefore, addSbefore,

1745 addaltern, and addSaltern now take a pair (name, tactic) as argument,

1746 and that adding two tactics with the same name overwrites the first

1747 one (emitting a warning).

1748 type wrapper = (int -> tactic) -> (int -> tactic)

1749 setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by

1750 addWrapper, addSWrapper: claset * (string * wrapper) -> claset

1751 delWrapper, delSWrapper: claset * string -> claset

1752 getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;

1754 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE

1755 semantics; addbefore now affects only the unsafe part of step_tac

1756 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY

1757 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac

1758 by Force_tac;

1760 * Classical reasoner: setwrapper to setWrapper and compwrapper to

1761 compWrapper; added safe wrapper (and access functions for it);

1763 * HOL/split_all_tac is now much faster and fails if there is nothing

1764 to split. Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order

1765 and the names of the automatically generated variables have changed.

1766 split_all_tac has moved within claset() from unsafe wrappers to safe

1767 wrappers, which means that !!-bound variables are split much more

1768 aggressively, and safe_tac and clarify_tac now split such variables.

1769 If this splitting is not appropriate, use delSWrapper "split_all_tac".

1770 Note: the same holds for record_split_tac, which does the job of

1771 split_all_tac for record fields.

1773 * HOL/Simplifier: Rewrite rules for case distinctions can now be added

1774 permanently to the default simpset using Addsplits just like

1775 Addsimps. They can be removed via Delsplits just like

1776 Delsimps. Lower-case versions are also available.

1778 * HOL/Simplifier: The rule split_if is now part of the default

1779 simpset. This means that the simplifier will eliminate all occurrences

1780 of if-then-else in the conclusion of a goal. To prevent this, you can

1781 either remove split_if completely from the default simpset by

1782 `Delsplits [split_if]' or remove it in a specific call of the

1783 simplifier using `... delsplits [split_if]'. You can also add/delete

1784 other case splitting rules to/from the default simpset: every datatype

1785 generates suitable rules `split_t_case' and `split_t_case_asm' (where

1786 t is the name of the datatype).

1788 * Classical reasoner / Simplifier combination: new force_tac (and

1789 derivatives Force_tac, force) combines rewriting and classical

1790 reasoning (and whatever other tools) similarly to auto_tac, but is

1791 aimed to solve the given subgoal completely.

1794 *** General ***

1796 * new top-level commands `Goal' and `Goalw' that improve upon `goal'

1797 and `goalw': the theory is no longer needed as an explicit argument -

1798 the current theory context is used; assumptions are no longer returned

1799 at the ML-level unless one of them starts with ==> or !!; it is

1800 recommended to convert to these new commands using isatool fixgoal

1801 (backup your sources first!);

1803 * new top-level commands 'thm' and 'thms' for retrieving theorems from

1804 the current theory context, and 'theory' to lookup stored theories;

1806 * new theory section 'locale' for declaring constants, assumptions and

1807 definitions that have local scope;

1809 * new theory section 'nonterminals' for purely syntactic types;

1811 * new theory section 'setup' for generic ML setup functions

1812 (e.g. package initialization);

1814 * the distribution now includes Isabelle icons: see

1815 lib/logo/isabelle-{small,tiny}.xpm;

1817 * isatool install - install binaries with absolute references to

1818 ISABELLE_HOME/bin;

1820 * isatool logo -- create instances of the Isabelle logo (as EPS);

1822 * print mode 'emacs' reserved for Isamode;

1824 * support multiple print (ast) translations per constant name;

1826 * theorems involving oracles are now printed with a suffixed [!];

1829 *** HOL ***

1831 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');

1833 * HOL/inductive package reorganized and improved: now supports mutual

1834 definitions such as

1836 inductive EVEN ODD

1837 intrs

1838 null "0 : EVEN"

1839 oddI "n : EVEN ==> Suc n : ODD"

1840 evenI "n : ODD ==> Suc n : EVEN"

1842 new theorem list "elims" contains an elimination rule for each of the

1843 recursive sets; inductive definitions now handle disjunctive premises

1844 correctly (also ZF);

1846 INCOMPATIBILITIES: requires Inductive as an ancestor; component

1847 "mutual_induct" no longer exists - the induction rule is always

1848 contained in "induct";

1851 * HOL/datatype package re-implemented and greatly improved: now

1852 supports mutually recursive datatypes such as

1854 datatype

1855 'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)

1856 | SUM ('a aexp) ('a aexp)

1857 | DIFF ('a aexp) ('a aexp)

1858 | NUM 'a

1859 and

1860 'a bexp = LESS ('a aexp) ('a aexp)

1861 | AND ('a bexp) ('a bexp)

1862 | OR ('a bexp) ('a bexp)

1864 as well as indirectly recursive datatypes such as

1866 datatype

1867 ('a, 'b) term = Var 'a

1868 | App 'b ((('a, 'b) term) list)

1870 The new tactic mutual_induct_tac [<var_1>, ..., <var_n>] i performs

1871 induction on mutually / indirectly recursive datatypes.

1873 Primrec equations are now stored in theory and can be accessed via

1874 <function_name>.simps.

1876 INCOMPATIBILITIES:

1878 - Theories using datatypes must now have theory Datatype as an

1879 ancestor.

1880 - The specific <typename>.induct_tac no longer exists - use the

1881 generic induct_tac instead.

1882 - natE has been renamed to nat.exhaust - use exhaust_tac

1883 instead of res_inst_tac ... natE. Note that the variable

1884 names in nat.exhaust differ from the names in natE, this

1885 may cause some "fragile" proofs to fail.

1886 - The theorems split_<typename>_case and split_<typename>_case_asm

1887 have been renamed to <typename>.split and <typename>.split_asm.

1888 - Since default sorts of type variables are now handled correctly,

1889 some datatype definitions may have to be annotated with explicit

1890 sort constraints.

1891 - Primrec definitions no longer require function name and type

1892 of recursive argument.

1894 Consider using isatool fixdatatype to adapt your theories and proof

1895 scripts to the new package (backup your sources first!).

1898 * HOL/record package: considerably improved implementation; now

1899 includes concrete syntax for record types, terms, updates; theorems

1900 for surjective pairing and splitting !!-bound record variables; proof

1901 support is as follows:

1903 1) standard conversions (selectors or updates applied to record

1904 constructor terms) are part of the standard simpset;

1906 2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are

1907 made part of standard simpset and claset via addIffs;

1909 3) a tactic for record field splitting (record_split_tac) is part of

1910 the standard claset (addSWrapper);

1912 To get a better idea about these rules you may retrieve them via

1913 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is

1914 the name of your record type.

1916 The split tactic 3) conceptually simplifies by the following rule:

1918 "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"

1920 Thus any record variable that is bound by meta-all will automatically

1921 blow up into some record constructor term, consequently the

1922 simplifications of 1), 2) apply. Thus force_tac, auto_tac etc. shall

1923 solve record problems automatically.

1926 * reorganized the main HOL image: HOL/Integ and String loaded by

1927 default; theory Main includes everything;

1929 * automatic simplification of integer sums and comparisons, using cancellation;

1931 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;

1933 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;

1935 * many new identities for unions, intersections, set difference, etc.;

1937 * expand_if, expand_split, expand_sum_case and expand_nat_case are now

1938 called split_if, split_split, split_sum_case and split_nat_case (to go

1939 with add/delsplits);

1941 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting

1942 (?x::unit) = (); this is made part of the default simpset, which COULD

1943 MAKE EXISTING PROOFS FAIL under rare circumstances (consider

1944 'Delsimprocs [unit_eq_proc];' as last resort); also note that

1945 unit_abs_eta_conv is added in order to counter the effect of

1946 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by

1947 %u.f();

1949 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which

1950 makes more sense);

1952 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;

1953 It and 'sym RS equals0D' are now in the default claset, giving automatic

1954 disjointness reasoning but breaking a few old proofs.

1956 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1

1957 to 'converse' from 'inverse' (for compatibility with ZF and some

1958 literature);

1960 * HOL/recdef can now declare non-recursive functions, with {} supplied as

1961 the well-founded relation;

1963 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of

1964 Compl A. The "Compl" syntax remains available as input syntax for this

1965 release ONLY.

1967 * HOL/Update: new theory of function updates:

1968 f(a:=b) == %x. if x=a then b else f x

1969 may also be iterated as in f(a:=b,c:=d,...);

1971 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;

1973 * HOL/List:

1974 - new function list_update written xs[i:=v] that updates the i-th

1975 list position. May also be iterated as in xs[i:=a,j:=b,...].

1976 - new function `upt' written [i..j(] which generates the list

1977 [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper

1978 bound write [i..j], which is a shorthand for [i..j+1(].

1979 - new lexicographic orderings and corresponding wellfoundedness theorems.

1981 * HOL/Arith:

1982 - removed 'pred' (predecessor) function;

1983 - generalized some theorems about n-1;

1984 - many new laws about "div" and "mod";

1985 - new laws about greatest common divisors (see theory ex/Primes);

1987 * HOL/Relation: renamed the relational operator r^-1 "converse"

1988 instead of "inverse";

1990 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness

1991 of the multiset ordering;

1993 * directory HOL/Real: a construction of the reals using Dedekind cuts

1994 (not included by default);

1996 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;

1998 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted

1999 programs, i.e. different program variables may have different types.

2001 * calling (stac rew i) now fails if "rew" has no effect on the goal

2002 [previously, this check worked only if the rewrite rule was unconditional]

2003 Now rew can involve either definitions or equalities (either == or =).

2006 *** ZF ***

2008 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains

2009 only the theorems proved on ZF.ML;

2011 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;

2012 It and 'sym RS equals0D' are now in the default claset, giving automatic

2013 disjointness reasoning but breaking a few old proofs.

2015 * ZF/Update: new theory of function updates

2016 with default rewrite rule f(x:=y) ` z = if(z=x, y, f`z)

2017 may also be iterated as in f(a:=b,c:=d,...);

2019 * in let x=t in u(x), neither t nor u(x) has to be an FOL term.

2021 * calling (stac rew i) now fails if "rew" has no effect on the goal

2022 [previously, this check worked only if the rewrite rule was unconditional]

2023 Now rew can involve either definitions or equalities (either == or =).

2025 * case_tac provided for compatibility with HOL

2026 (like the old excluded_middle_tac, but with subgoals swapped)

2029 *** Internal programming interfaces ***

2031 * Pure: several new basic modules made available for general use, see

2032 also src/Pure/README;

2034 * improved the theory data mechanism to support encapsulation (data

2035 kind name replaced by private Object.kind, acting as authorization

2036 key); new type-safe user interface via functor TheoryDataFun; generic

2037 print_data function becomes basically useless;

2039 * removed global_names compatibility flag -- all theory declarations

2040 are qualified by default;

2042 * module Pure/Syntax now offers quote / antiquote translation

2043 functions (useful for Hoare logic etc. with implicit dependencies);

2044 see HOL/ex/Antiquote for an example use;

2046 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->

2047 cterm -> thm;

2049 * new tactical CHANGED_GOAL for checking that a tactic modifies a

2050 subgoal;

2052 * Display.print_goals function moved to Locale.print_goals;

2054 * standard print function for goals supports current_goals_markers

2055 variable for marking begin of proof, end of proof, start of goal; the

2056 default is ("", "", ""); setting current_goals_markers := ("<proof>",

2057 "</proof>", "<goal>") causes SGML like tagged proof state printing,

2058 for example;

2062 New in Isabelle98 (January 1998)

2063 --------------------------------

2065 *** Overview of INCOMPATIBILITIES (see below for more details) ***

2067 * changed lexical syntax of terms / types: dots made part of long

2068 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";

2070 * simpset (and claset) reference variable replaced by functions

2071 simpset / simpset_ref;

2073 * no longer supports theory aliases (via merge) and non-trivial

2074 implicit merge of thms' signatures;

2076 * most internal names of constants changed due to qualified names;

2078 * changed Pure/Sequence interface (see Pure/seq.ML);

2081 *** General Changes ***

2083 * hierachically structured name spaces (for consts, types, axms, thms

2084 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of

2085 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:

2086 isatool fixdots ensures space after dots (e.g. "%x. x"); set

2087 long_names for fully qualified output names; NOTE: ML programs

2088 (special tactics, packages etc.) referring to internal names may have

2089 to be adapted to cope with fully qualified names; in case of severe

2090 backward campatibility problems try setting 'global_names' at compile

2091 time to have enrything declared within a flat name space; one may also

2092 fine tune name declarations in theories via the 'global' and 'local'

2093 section;

2095 * reimplemented the implicit simpset and claset using the new anytype

2096 data filed in signatures; references simpset:simpset ref etc. are

2097 replaced by functions simpset:unit->simpset and

2098 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp

2099 to patch your ML files accordingly;

2101 * HTML output now includes theory graph data for display with Java

2102 applet or isatool browser; data generated automatically via isatool

2103 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);

2105 * defs may now be conditional; improved rewrite_goals_tac to handle

2106 conditional equations;

2108 * defs now admits additional type arguments, using TYPE('a) syntax;

2110 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always

2111 creates a new theory node; implicit merge of thms' signatures is

2112 restricted to 'trivial' ones; COMPATIBILITY: one may have to use

2113 transfer:theory->thm->thm in (rare) cases;

2115 * improved handling of draft signatures / theories; draft thms (and

2116 ctyps, cterms) are automatically promoted to real ones;

2118 * slightly changed interfaces for oracles: admit many per theory, named

2119 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;

2121 * print_goals: optional output of const types (set show_consts and

2122 show_types);

2124 * improved output of warnings (###) and errors (***);

2126 * subgoal_tac displays a warning if the new subgoal has type variables;

2128 * removed old README and Makefiles;

2130 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;

2132 * removed obsolete init_pps and init_database;

2134 * deleted the obsolete tactical STATE, which was declared by

2135 fun STATE tacfun st = tacfun st st;

2137 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~

2138 (which abbreviates $HOME);

2140 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:

2141 use isatool fixseq to adapt your ML programs (this works for fully

2142 qualified references to the Sequence structure only!);

2144 * use_thy no longer requires writable current directory; it always

2145 reloads .ML *and* .thy file, if either one is out of date;

2148 *** Classical Reasoner ***

2150 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new

2151 tactics that use classical reasoning to simplify a subgoal without

2152 splitting it into several subgoals;

2154 * Safe_tac: like safe_tac but uses the default claset;

2157 *** Simplifier ***

2159 * added simplification meta rules:

2160 (asm_)(full_)simplify: simpset -> thm -> thm;

2162 * simplifier.ML no longer part of Pure -- has to be loaded by object

2163 logics (again);

2165 * added prems argument to simplification procedures;

2167 * HOL, FOL, ZF: added infix function `addsplits':

2168 instead of `<simpset> setloop (split_tac <thms>)'

2169 you can simply write `<simpset> addsplits <thms>'

2172 *** Syntax ***

2174 * TYPE('a) syntax for type reflection terms;

2176 * no longer handles consts with name "" -- declare as 'syntax' instead;

2178 * pretty printer: changed order of mixfix annotation preference (again!);

2180 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;

2183 *** HOL ***

2185 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.

2186 with `addloop' of the simplifier to faciliate case splitting in premises.

2188 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;

2190 * HOL/Auth: new protocol proofs including some for the Internet

2191 protocol TLS;

2193 * HOL/Map: new theory of `maps' a la VDM;

2195 * HOL/simplifier: simplification procedures nat_cancel_sums for

2196 cancelling out common nat summands from =, <, <= (in)equalities, or

2197 differences; simplification procedures nat_cancel_factor for

2198 cancelling common factor from =, <, <= (in)equalities over natural

2199 sums; nat_cancel contains both kinds of procedures, it is installed by

2200 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;

2202 * HOL/simplifier: terms of the form

2203 `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)' (or t=x)

2204 are rewritten to

2205 `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',

2206 and those of the form

2207 `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)' (or t=x)

2208 are rewritten to

2209 `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',

2211 * HOL/datatype

2212 Each datatype `t' now comes with a theorem `split_t_case' of the form

2214 P(t_case f1 ... fn x) =

2215 ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &

2216 ...

2217 (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))

2218 )

2220 and a theorem `split_t_case_asm' of the form

2222 P(t_case f1 ... fn x) =

2223 ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |

2224 ...

2225 (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))

2226 )

2227 which can be added to a simpset via `addsplits'. The existing theorems

2228 expand_list_case and expand_option_case have been renamed to

2229 split_list_case and split_option_case.

2231 * HOL/Arithmetic:

2232 - `pred n' is automatically converted to `n-1'.

2233 Users are strongly encouraged not to use `pred' any longer,

2234 because it will disappear altogether at some point.

2235 - Users are strongly encouraged to write "0 < n" rather than

2236 "n ~= 0". Theorems and proof tools have been modified towards this

2237 `standard'.

2239 * HOL/Lists:

2240 the function "set_of_list" has been renamed "set" (and its theorems too);

2241 the function "nth" now takes its arguments in the reverse order and

2242 has acquired the infix notation "!" as in "xs!n".

2244 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};

2246 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its

2247 specialist theorems (like UN1_I) are gone. Similarly for (INT x.B x);

2249 * HOL/record: extensible records with schematic structural subtyping

2250 (single inheritance); EXPERIMENTAL version demonstrating the encoding,

2251 still lacks various theorems and concrete record syntax;

2254 *** HOLCF ***

2256 * removed "axioms" and "generated by" sections;

2258 * replaced "ops" section by extended "consts" section, which is capable of

2259 handling the continuous function space "->" directly;

2261 * domain package:

2262 . proves theorems immediately and stores them in the theory,

2263 . creates hierachical name space,

2264 . now uses normal mixfix annotations (instead of cinfix...),

2265 . minor changes to some names and values (for consistency),

2266 . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,

2267 . separator between mutual domain defs: changed "," to "and",

2268 . improved handling of sort constraints; now they have to

2269 appear on the left-hand side of the equations only;

2271 * fixed LAM <x,y,zs>.b syntax;

2273 * added extended adm_tac to simplifier in HOLCF -- can now discharge

2274 adm (%x. P (t x)), where P is chainfinite and t continuous;

2277 *** FOL and ZF ***

2279 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.

2280 with `addloop' of the simplifier to faciliate case splitting in premises.

2282 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as

2283 in HOL, they strip ALL and --> from proved theorems;

2287 New in Isabelle94-8 (May 1997)

2288 ------------------------------

2290 *** General Changes ***

2292 * new utilities to build / run / maintain Isabelle etc. (in parts

2293 still somewhat experimental); old Makefiles etc. still functional;

2295 * new 'Isabelle System Manual';

2297 * INSTALL text, together with ./configure and ./build scripts;

2299 * reimplemented type inference for greater efficiency, better error

2300 messages and clean internal interface;

2302 * prlim command for dealing with lots of subgoals (an easier way of

2303 setting goals_limit);

2306 *** Syntax ***

2308 * supports alternative (named) syntax tables (parser and pretty

2309 printer); internal interface is provided by add_modesyntax(_i);

2311 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to

2312 be used in conjunction with the Isabelle symbol font; uses the

2313 "symbols" syntax table;

2315 * added token_translation interface (may translate name tokens in

2316 arbitrary ways, dependent on their type (free, bound, tfree, ...) and

2317 the current print_mode); IMPORTANT: user print translation functions

2318 are responsible for marking newly introduced bounds

2319 (Syntax.mark_boundT);

2321 * token translations for modes "xterm" and "xterm_color" that display

2322 names in bold, underline etc. or colors (which requires a color

2323 version of xterm);

2325 * infixes may now be declared with names independent of their syntax;

2327 * added typed_print_translation (like print_translation, but may

2328 access type of constant);

2331 *** Classical Reasoner ***

2333 Blast_tac: a new tactic! It is often more powerful than fast_tac, but has

2334 some limitations. Blast_tac...

2335 + ignores addss, addbefore, addafter; this restriction is intrinsic

2336 + ignores elimination rules that don't have the correct format

2337 (the conclusion MUST be a formula variable)

2338 + ignores types, which can make HOL proofs fail

2339 + rules must not require higher-order unification, e.g. apply_type in ZF

2340 [message "Function Var's argument not a bound variable" relates to this]

2341 + its proof strategy is more general but can actually be slower

2343 * substitution with equality assumptions no longer permutes other

2344 assumptions;

2346 * minor changes in semantics of addafter (now called addaltern); renamed

2347 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper

2348 (and access functions for it);

2350 * improved combination of classical reasoner and simplifier:

2351 + functions for handling clasimpsets

2352 + improvement of addss: now the simplifier is called _after_ the

2353 safe steps.

2354 + safe variant of addss called addSss: uses safe simplifications

2355 _during_ the safe steps. It is more complete as it allows multiple

2356 instantiations of unknowns (e.g. with slow_tac).

2358 *** Simplifier ***

2360 * added interface for simplification procedures (functions that

2361 produce *proven* rewrite rules on the fly, depending on current

2362 redex);

2364 * ordering on terms as parameter (used for ordered rewriting);

2366 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;

2368 * the solver is now split into a safe and an unsafe part.

2369 This should be invisible for the normal user, except that the

2370 functions setsolver and addsolver have been renamed to setSolver and

2371 addSolver; added safe_asm_full_simp_tac;

2374 *** HOL ***

2376 * a generic induction tactic `induct_tac' which works for all datatypes and

2377 also for type `nat';

2379 * a generic case distinction tactic `exhaust_tac' which works for all

2380 datatypes and also for type `nat';

2382 * each datatype comes with a function `size';

2384 * patterns in case expressions allow tuple patterns as arguments to

2385 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';

2387 * primrec now also works with type nat;

2389 * recdef: a new declaration form, allows general recursive functions to be

2390 defined in theory files. See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.

2392 * the constant for negation has been renamed from "not" to "Not" to

2393 harmonize with FOL, ZF, LK, etc.;

2395 * HOL/ex/LFilter theory of a corecursive "filter" functional for

2396 infinite lists;

2398 * HOL/Modelcheck demonstrates invocation of model checker oracle;

2400 * HOL/ex/Ring.thy declares cring_simp, which solves equational

2401 problems in commutative rings, using axiomatic type classes for + and *;

2403 * more examples in HOL/MiniML and HOL/Auth;

2405 * more default rewrite rules for quantifiers, union/intersection;

2407 * a new constant `arbitrary == @x.False';

2409 * HOLCF/IOA replaces old HOL/IOA;

2411 * HOLCF changes: derived all rules and arities

2412 + axiomatic type classes instead of classes

2413 + typedef instead of faking type definitions

2414 + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.

2415 + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po

2416 + eliminated the types void, one, tr

2417 + use unit lift and bool lift (with translations) instead of one and tr

2418 + eliminated blift from Lift3.thy (use Def instead of blift)

2419 all eliminated rules are derived as theorems --> no visible changes ;

2422 *** ZF ***

2424 * ZF now has Fast_tac, Simp_tac and Auto_tac. Union_iff is a now a default

2425 rewrite rule; this may affect some proofs. eq_cs is gone but can be put back

2426 as ZF_cs addSIs [equalityI];

2430 New in Isabelle94-7 (November 96)

2431 ---------------------------------

2433 * allowing negative levels (as offsets) in prlev and choplev;

2435 * super-linear speedup for large simplifications;

2437 * FOL, ZF and HOL now use miniscoping: rewriting pushes

2438 quantifications in as far as possible (COULD MAKE EXISTING PROOFS

2439 FAIL); can suppress it using the command Delsimps (ex_simps @

2440 all_simps); De Morgan laws are also now included, by default;

2442 * improved printing of ==> : ~:

2444 * new object-logic "Sequents" adds linear logic, while replacing LK

2445 and Modal (thanks to Sara Kalvala);

2447 * HOL/Auth: correctness proofs for authentication protocols;

2449 * HOL: new auto_tac combines rewriting and classical reasoning (many

2450 examples on HOL/Auth);

2452 * HOL: new command AddIffs for declaring theorems of the form P=Q to

2453 the rewriter and classical reasoner simultaneously;

2455 * function uresult no longer returns theorems in "standard" format;

2456 regain previous version by: val uresult = standard o uresult;

2460 New in Isabelle94-6

2461 -------------------

2463 * oracles -- these establish an interface between Isabelle and trusted

2464 external reasoners, which may deliver results as theorems;

2466 * proof objects (in particular record all uses of oracles);

2468 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;

2470 * "constdefs" section in theory files;

2472 * "primrec" section (HOL) no longer requires names;

2474 * internal type "tactic" now simply "thm -> thm Sequence.seq";

2478 New in Isabelle94-5

2479 -------------------

2481 * reduced space requirements;

2483 * automatic HTML generation from theories;

2485 * theory files no longer require "..." (quotes) around most types;

2487 * new examples, including two proofs of the Church-Rosser theorem;

2489 * non-curried (1994) version of HOL is no longer distributed;

2493 New in Isabelle94-4

2494 -------------------

2496 * greatly reduced space requirements;

2498 * theory files (.thy) no longer require \...\ escapes at line breaks;

2500 * searchable theorem database (see the section "Retrieving theorems" on

2501 page 8 of the Reference Manual);

2503 * new examples, including Grabczewski's monumental case study of the

2504 Axiom of Choice;

2506 * The previous version of HOL renamed to Old_HOL;

2508 * The new version of HOL (previously called CHOL) uses a curried syntax

2509 for functions. Application looks like f a b instead of f(a,b);

2511 * Mutually recursive inductive definitions finally work in HOL;

2513 * In ZF, pattern-matching on tuples is now available in all abstractions and

2514 translates to the operator "split";

2518 New in Isabelle94-3

2519 -------------------

2521 * new infix operator, addss, allowing the classical reasoner to

2522 perform simplification at each step of its search. Example:

2523 fast_tac (cs addss ss)

2525 * a new logic, CHOL, the same as HOL, but with a curried syntax

2526 for functions. Application looks like f a b instead of f(a,b). Also pairs

2527 look like (a,b) instead of <a,b>;

2529 * PLEASE NOTE: CHOL will eventually replace HOL!

2531 * In CHOL, pattern-matching on tuples is now available in all abstractions.

2532 It translates to the operator "split". A new theory of integers is available;

2534 * In ZF, integer numerals now denote two's-complement binary integers.

2535 Arithmetic operations can be performed by rewriting. See ZF/ex/Bin.ML;

2537 * Many new examples: I/O automata, Church-Rosser theorem, equivalents

2538 of the Axiom of Choice;

2542 New in Isabelle94-2

2543 -------------------

2545 * Significantly faster resolution;

2547 * the different sections in a .thy file can now be mixed and repeated

2548 freely;

2550 * Database of theorems for FOL, HOL and ZF. New

2551 commands including qed, qed_goal and bind_thm store theorems in the database.

2553 * Simple database queries: return a named theorem (get_thm) or all theorems of

2554 a given theory (thms_of), or find out what theory a theorem was proved in

2555 (theory_of_thm);

2557 * Bugs fixed in the inductive definition and datatype packages;

2559 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs

2560 and HOL_dup_cs obsolete;

2562 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1

2563 have been removed;

2565 * Simpler definition of function space in ZF;

2567 * new results about cardinal and ordinal arithmetic in ZF;

2569 * 'subtype' facility in HOL for introducing new types as subsets of existing

2570 types;

2573 $Id$