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NEWS

author | wenzelm |

Sat May 01 22:28:51 2004 +0200 (2004-05-01) | |

changeset 14699 | 2c9b463044ec |

parent 14698 | 7e4dec3fd515 |

child 14700 | 2f885b7e5ba7 |

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

tuned;

1 Isabelle NEWS -- history user-relevant changes

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

4 New in this Isabelle release

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

7 *** General ***

9 * Pure: considerably improved version of 'constdefs' command. Now

10 performs automatic type-inference of declared constants; additional

11 support for local structure declarations (cf. locales and HOL

12 records), see also isar-ref manual. Potential INCOMPATIBILITY: need

13 to observe strictly sequential dependencies of definitions within a

14 single 'constdefs' section; moreover, the declared name needs to be an

15 identifier. If all fails, consider to fall back on 'consts' and

16 'defs' separately.

18 * Pure: 'advanced' translation functions (parse_translation etc.) may

19 depend on the signature of the theory context being presently used for

20 parsing/printing, see also isar-ref manual.

22 * Pure: improved indexed syntax and implicit structures. First of

23 all, indexed syntax provides a notational device for subscripted

24 application, using the new syntax \<^bsub>term\<^esub> for arbitrary

25 expressions. Secondly, in a local context with structure

26 declarations, number indexes \<^sub>n or the empty index (default

27 number 1) refer to a certain fixed variable implicitly. Typical

28 applications of these concepts involve record types and locales.

30 * Pure: tuned internal renaming of symbolic identifiers -- attach

31 primes instead of base 26 numbers.

34 *** HOLCF ***

36 * HOLCF: discontinued special version of 'constdefs' (which used to

37 support continuous functions) in favor of the general Pure one with

38 full type-inference.

42 New in Isabelle2004 (April 2004)

43 --------------------------------

45 *** General ***

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

48 Replaces linorder.ML.

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

51 (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler

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

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

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

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

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

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

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

59 existing theory and ML files.

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

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

64 allowed in identifiers. Similar to Greek letters \<^isub> is now considered

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

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

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

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

70 ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in

71 superscript. The new control characters are not identifier parts.

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

74 content of "..." to the latex file instead of \isacntrl... . The "..."

75 may consist of any printable characters excluding the end bracket >.

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

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

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

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

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

83 * Pure: 'instance' now handles general arities with general sorts

84 (i.e. intersections of classes),

86 * Presentation: generated HTML now uses a CSS style sheet to make layout

87 (somewhat) independent of content. It is copied from lib/html/isabelle.css.

88 It can be changed to alter the colors/layout of generated pages.

91 *** Isar ***

93 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,

94 cut_tac, subgoal_tac and thin_tac:

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

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

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

98 emulations.

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

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

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

103 * Attributes "where" and "of":

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

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

106 theorems to have too special types in some circumstances.

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

109 * Calculation commands "moreover" and "also" no longer interfere with

110 current facts ("this"), admitting arbitrary combinations with "then"

111 and derived forms.

113 * Locales:

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

115 generate theorems with internal delta predicates (those ending on

116 "_axioms") in the premise.

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

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

119 specification and "includes" elements in goal statement.

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

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

122 - Experimental command for instantiation of locales in proof contexts:

123 instantiate <label>[<attrs>]: <loc>

124 Instantiates locale <loc> and adds all its theorems to the current context

125 taking into account their attributes. Label and attrs are optional

126 modifiers, like in theorem declarations. If present, names of

127 instantiated theorems are qualified with <label>, and the attributes

128 <attrs> are applied after any attributes these theorems might have already.

129 If the locale has assumptions, a chained fact of the form

130 "<loc> t1 ... tn" is expected from which instantiations of the parameters

131 are derived. The command does not support old-style locales declared

132 with "locale (open)".

133 A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.

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

136 (Isar) contexts.

139 *** HOL ***

141 * Proof import: new image HOL4 contains the imported library from

142 the HOL4 system with about 2500 theorems. It is imported by

143 replaying proof terms produced by HOL4 in Isabelle. The HOL4 image

144 can be used like any other Isabelle image. See

145 HOL/Import/HOL/README for more information.

147 * Simplifier:

148 - Much improved handling of linear and partial orders.

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

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

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

152 to solve goals from the assumptions.

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

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

155 is solved by simplification already.

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

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

160 * Numerics:

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

162 now formalized using the Ring_and_Field theory mentioned above.

163 - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently

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

165 - INCOMPATIBILITY: many type-specific arithmetic laws have gone.

166 Look for the general versions in Ring_and_Field (and Power if they concern

167 exponentiation).

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

171 * Records:

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

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

174 the reference "print_record_type_abbr".

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

176 (not enabled by default).

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

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

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

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

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

183 introduces the new constants axiomatically.

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

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

189 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function

190 definitions, thanks to Sava Krsti\'{c} and John Matthews.

192 * HOL-Matrix: a first theory for matrices in HOL with an application of

193 matrix theory to linear programming.

195 * Unions and Intersections:

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

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

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

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

200 The subscript version is also accepted as input syntax.

202 * Unions and Intersections over Intervals:

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

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

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

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

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

210 * 'refute' command added to search for (finite) countermodels. Only works

211 for a fragment of HOL. The installation of an external SAT solver is

212 highly recommended. See "HOL/Refute.thy" for details.

214 * 'quickcheck' command: Allows to find counterexamples by evaluating

215 formulae under an assignment of free variables to random values.

216 In contrast to 'refute', it can deal with inductive datatypes,

217 but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"

218 for examples.

221 *** HOLCF ***

223 * Streams now come with concatenation and are part of the HOLCF image

227 New in Isabelle2003 (May 2003)

228 ------------------------------

230 *** General ***

232 * Provers/simplifier:

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

235 Assumptions are now subject to complete mutual simplification,

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

237 the order of assumptions.

239 Potential INCOMPATIBILITY:

241 -- simp sometimes diverges where the old version did

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

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

246 now gives rise to the infinite reduction sequence

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

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

251 kind of problem.

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

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

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

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

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

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

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

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

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

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

265 conditions before applying the rewrite rule):

266 ML "simp_depth_limit := n"

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

268 the simplifier would diverge.

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

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

273 congruence is ignored.

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

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

277 as HOL/Extraction for some case studies.

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

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

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

282 (ML: Proof.show_main_goal).

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

285 rules whose conclusion matches subgoal 1:

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

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

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

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

290 (ML: ProofGeneral.print_intros())

292 * Pure: New flag trace_unify_fail causes unification to print

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

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

295 assumption failed.

297 * Pure: Locale specifications now produce predicate definitions

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

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

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

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

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

303 on the old view without predicates;

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

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

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

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

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

311 include local facts of proof configuration (also covers active

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

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

314 be given (the default is 40);

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

317 (batch-mode only);

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

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

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

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

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

325 for slight decrease in efficiency;

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

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

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

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

334 *** HOL ***

336 * arith(_tac)

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

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

340 of quantifier-free linear arithmetic.

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

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

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

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

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

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

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

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

353 are distributed over a sum of terms;

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

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

357 "<=", "<" and "=").

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

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

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

363 definition;

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

366 Finite_Set);

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

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

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

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

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

375 %x. None. Warning: empty_def now refers to the previously hidden definition

376 of the empty set.

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

379 any algebraic development in Isabelle. Currently covers group theory

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

381 Univariate Polynomials). Contributions welcome;

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

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

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

387 nonstandard (Jacques Fleuriot);

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

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

392 Fleuriot);

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

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

397 Gray and Kramer);

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

401 * MicroJava: bytecode verifier and lightweight bytecode verifier

402 as abstract algorithms, instantiated to the JVM;

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

405 semantics, axiomatic semantics. Supported language features:

406 classes, interfaces, objects,virtual methods, static methods,

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

408 assignment, exceptions.

411 *** ZF ***

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

414 universe, etc.);

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

419 *** ML ***

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

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

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

425 * Pure: improved error reporting of simprocs;

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

428 up simprocs;

431 *** Document preparation ***

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

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

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

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

438 other packages

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

441 broke \Rightarrow)

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

444 textcomp package)

448 New in Isabelle2002 (March 2002)

449 --------------------------------

451 *** Document preparation ***

453 * greatly simplified document preparation setup, including more

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

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

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

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

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

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

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

462 with \includegraphics of LaTeX;

464 * proper spacing of consecutive markup elements, especially text

465 blocks after section headings;

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

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

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

471 better in printed text;

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

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

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

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

478 isatool document copies the Isabelle style files to the target

479 location;

482 *** Isar ***

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

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

486 "case (Suc n)");

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

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

489 instantiation of cases;

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

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

492 rules without further ado;

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

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

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

496 statement becomes is included in the hypothesis, avoiding the

497 slightly cumbersome show "PROP ?case" form;

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

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

500 rules stemming from inductive sets to be applied in unstructured

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

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

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

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

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

506 below);

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

508 success (no backtracking);

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

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

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

512 General versions);

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

514 - generic method setup instantiated for FOL and HOL;

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

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

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

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

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

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

522 fails:

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

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

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

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

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

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

532 attributes everywhere); operations on locales include merge and

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

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

535 some examples;

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

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

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

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

541 qualified by the locale name);

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

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

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

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

547 the context elements being discharged in the obvious way;

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

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

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

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

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

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

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

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

559 use hard-wired "Trueprop";

561 * Pure: added 'corollary' command;

563 * Pure: fixed 'token_translation' command;

565 * Pure: removed obsolete 'exported' attribute;

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

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

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

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

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

573 rewrite rules declarations of 'atomize' attribute; example

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

575 proof *scripts*;

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

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

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

580 especially important for locales);

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

583 mode;

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

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

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

588 situations;

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

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

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

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

595 discontinued;

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

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

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

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

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

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

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

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

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

607 INCOMPATIBILITY;

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

610 of introduction rules;

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

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

614 conditional rules;

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

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

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

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

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

624 * HOL: properly declared induction rules less_induct and

625 wf_induct_rule;

628 *** HOL ***

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

631 follows:

633 - 0 and 1 are polymorphic constants, which are defined on any

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

636 - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based

637 binary representation internally;

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

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

642 This change may cause significant problems of INCOMPATIBILITY; here

643 are some hints on converting existing sources:

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

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

647 to be spaced properly;

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

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

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

654 - remove all special provisions on numerals in proofs;

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

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

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

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

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

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

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

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

667 * HOL/record package improvements:

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

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

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

671 declared as simp by default;

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

673 qualified) --- potential INCOMPATIBILITY;

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

675 INCOMPATIBILITY;

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

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

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

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

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

681 theory of product types over typedef rather than datatype;

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

684 specifications; specific support for HOL constructs such as inductive

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

686 via 'generate_code' theory section;

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

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

691 Ord.thy has been absorbed into HOL.thy

692 String.thy has been absorbed into List.thy

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

695 (beware of argument permutation!);

697 * HOL: linorder_less_split superseded by linorder_cases;

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

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

702 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:

703 - Ex_def has changed, now need to use some_eq_ex

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

706 in this (rare) case use:

708 delSWrapper "split_all_tac"

709 addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)

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

712 MAY FAIL;

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

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

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

717 necessary to attach explicit type constraints;

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

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

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

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

724 expressions;

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

727 of "lam" -- INCOMPATIBILITY;

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

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

731 renamed "Product_Type.unit";

733 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl

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

736 the "cases" method);

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

739 Florian Kammüller);

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

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

743 some explanations (by Gerwin Klein);

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

747 * HOL-Hyperreal is now a logic image;

750 *** HOLCF ***

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

753 operations;

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

756 HOLCF/ex/Dnat.thy;

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

759 potential INCOMPATIBILITY; now use plain induct_tac instead of former

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

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

765 *** ZF ***

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

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

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

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

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

773 your theory on Main_ZFC;

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

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

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

779 typeless version of the formalism;

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

782 format;

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

785 including theory Multiset for multiset orderings; converted to

786 new-style theory format;

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

791 *** General ***

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

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

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

796 also ref manual for further ML interfaces;

798 * Pure/axclass: removed obsolete ML interface

799 goal_subclass/goal_arity;

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

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

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

804 properly;

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

807 rather than "infixl" or "infixr";

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

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

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

812 type variable);

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

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

816 "type_brackets";

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

819 tokens into AST constants;

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

822 translation functions; potential INCOMPATIBILITY: need to reverse

823 multiple declarations for same syntax element constant;

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

826 practice);

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

829 addSafter;

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

832 as well;

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

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

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

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

838 support requires further installations, e.g. from

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

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

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

844 of 40 MB), cf. ML_OPTIONS;

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

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

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

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

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

853 * system: smart selection of Isabelle process versus Isabelle

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

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

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

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

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

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

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

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

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

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

866 terminal);

870 New in Isabelle99-2 (February 2001)

871 -----------------------------------

873 *** Overview of INCOMPATIBILITIES ***

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

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

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

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

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

881 format may be recovered via ML function complete_split_rule or attribute

882 'split_rule (complete)';

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

885 gfp_Tarski to gfp_unfold;

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

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

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

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

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

894 operation;

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

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

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

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

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

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

905 \<gg> to \<ggreater>;

908 *** Document preparation ***

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

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

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

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

914 type-writer);

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

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

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

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

922 * improved isabelle style files; more abstract symbol implementation

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

924 definitions);

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

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

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

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

931 * proper indentation of antiquoted output with proportional LaTeX

932 fonts;

934 * no_document ML operator temporarily disables LaTeX document

935 generation;

937 * isatool unsymbolize tunes sources for plain ASCII communication;

940 *** Isar ***

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

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

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

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

946 for Prolog-style synthesis of proven results;

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

949 rules as well;

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

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

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

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

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

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

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

960 statements as well;

962 * Pure: more robust selection of calculational rules;

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

965 rule (as well as the assumption rule);

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

968 lemmas, using the graph browser tool;

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

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

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

975 (potential INCOMPATIBILITY); tuned error handling;

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

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

979 any remaining facts are inserted into the goal verbatim;

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

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

983 the result to be shown in each case;

985 * HOL: added 'recdef_tc' command;

987 * isatool convert assists in eliminating legacy ML scripts;

990 *** HOL ***

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

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

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

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

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

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

999 modelling and verification task performed in Isabelle/HOL +

1000 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).

1002 * HOL/Algebra: special summation operator SUM no longer exists, it has

1003 been replaced by setsum; infix 'assoc' now has priority 50 (like

1004 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to

1005 'domain', this makes the theory consistent with mathematical

1006 literature;

1008 * HOL basics: added overloaded operations "inverse" and "divide"

1009 (infix "/"), syntax for generic "abs" operation, generic summation

1010 operator \<Sum>;

1012 * HOL/typedef: simplified package, provide more useful rules (see also

1013 HOL/subset.thy);

1015 * HOL/datatype: induction rule for arbitrarily branching datatypes is

1016 now expressed as a proper nested rule (old-style tactic scripts may

1017 require atomize_strip_tac to cope with non-atomic premises);

1019 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule

1020 to "split_conv" (old name still available for compatibility);

1022 * HOL: improved concrete syntax for strings (e.g. allows translation

1023 rules with string literals);

1025 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals

1026 and Fleuriot's mechanization of analysis, including the transcendental

1027 functions for the reals;

1029 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;

1032 *** CTT ***

1034 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that

1035 "lam" is displayed as TWO lambda-symbols

1037 * CTT: theory Main now available, containing everything (that is, Bool

1038 and Arith);

1041 *** General ***

1043 * Pure: the Simplifier has been implemented properly as a derived rule

1044 outside of the actual kernel (at last!); the overall performance

1045 penalty in practical applications is about 50%, while reliability of

1046 the Isabelle inference kernel has been greatly improved;

1048 * print modes "brackets" and "no_brackets" control output of nested =>

1049 (types) and ==> (props); the default behaviour is "brackets";

1051 * Provers: fast_tac (and friends) now handle actual object-logic rules

1052 as assumptions as well;

1054 * system: support Poly/ML 4.0;

1056 * system: isatool install handles KDE version 1 or 2;

1060 New in Isabelle99-1 (October 2000)

1061 ----------------------------------

1063 *** Overview of INCOMPATIBILITIES ***

1065 * HOL: simplification of natural numbers is much changed; to partly

1066 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)

1067 issue the following ML commands:

1069 Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;

1070 Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];

1072 * HOL: simplification no longer dives into case-expressions; this is

1073 controlled by "t.weak_case_cong" for each datatype t;

1075 * HOL: nat_less_induct renamed to less_induct;

1077 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool

1078 fixsome to patch .thy and .ML sources automatically;

1080 select_equality -> some_equality

1081 select_eq_Ex -> some_eq_ex

1082 selectI2EX -> someI2_ex

1083 selectI2 -> someI2

1084 selectI -> someI

1085 select1_equality -> some1_equality

1086 Eps_sym_eq -> some_sym_eq_trivial

1087 Eps_eq -> some_eq_trivial

1089 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;

1091 * HOL: removed obsolete theorem binding expand_if (refer to split_if

1092 instead);

1094 * HOL: the recursion equations generated by 'recdef' are now called

1095 f.simps instead of f.rules;

1097 * HOL: qed_spec_mp now also handles bounded ALL as well;

1099 * HOL: 0 is now overloaded, so the type constraint ":: nat" may

1100 sometimes be needed;

1102 * HOL: the constant for "f``x" is now "image" rather than "op ``";

1104 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";

1106 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian

1107 product is now "<*>" instead of "Times"; the lexicographic product is

1108 now "<*lex*>" instead of "**";

1110 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part

1111 of main HOL, but was unused); better use HOL's datatype package;

1113 * HOL: removed "symbols" syntax for constant "override" of theory Map;

1114 the old syntax may be recovered as follows:

1116 syntax (symbols)

1117 override :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"

1118 (infixl "\\<oplus>" 100)

1120 * HOL/Real: "rabs" replaced by overloaded "abs" function;

1122 * HOL/ML: even fewer consts are declared as global (see theories Ord,

1123 Lfp, Gfp, WF); this only affects ML packages that refer to const names

1124 internally;

1126 * HOL and ZF: syntax for quotienting wrt an equivalence relation

1127 changed from A/r to A//r;

1129 * ZF: new treatment of arithmetic (nat & int) may break some old

1130 proofs;

1132 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,

1133 rulify -> rule_format, elimify -> elim_format, ...);

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

1136 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one

1137 should have to change intro!! to intro? only); replaced "delrule" by

1138 "rule del";

1140 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;

1142 * Provers: strengthened force_tac by using new first_best_tac;

1144 * LaTeX document preparation: several changes of isabelle.sty (see

1145 lib/texinputs);

1148 *** Document preparation ***

1150 * formal comments (text blocks etc.) in new-style theories may now

1151 contain antiquotations of thm/prop/term/typ/text to be presented

1152 according to latex print mode; concrete syntax is like this:

1153 @{term[show_types] "f(x) = a + x"};

1155 * isatool mkdir provides easy setup of Isabelle session directories,

1156 including proper document sources;

1158 * generated LaTeX sources are now deleted after successful run

1159 (isatool document -c); may retain a copy somewhere else via -D option

1160 of isatool usedir;

1162 * isatool usedir -D now lets isatool latex -o sty update the Isabelle

1163 style files, achieving self-contained LaTeX sources and simplifying

1164 LaTeX debugging;

1166 * old-style theories now produce (crude) LaTeX output as well;

1168 * browser info session directories are now self-contained (may be put

1169 on WWW server seperately); improved graphs of nested sessions; removed

1170 graph for 'all sessions';

1172 * several improvements in isabelle style files; \isabellestyle{it}

1173 produces fake math mode output; \isamarkupheader is now \section by

1174 default; see lib/texinputs/isabelle.sty etc.;

1177 *** Isar ***

1179 * Isar/Pure: local results and corresponding term bindings are now

1180 subject to Hindley-Milner polymorphism (similar to ML); this

1181 accommodates incremental type-inference very nicely;

1183 * Isar/Pure: new derived language element 'obtain' supports

1184 generalized existence reasoning;

1186 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'

1187 support accumulation of results, without applying any rules yet;

1188 useful to collect intermediate results without explicit name

1189 references, and for use with transitivity rules with more than 2

1190 premises;

1192 * Isar/Pure: scalable support for case-analysis type proofs: new

1193 'case' language element refers to local contexts symbolically, as

1194 produced by certain proof methods; internally, case names are attached

1195 to theorems as "tags";

1197 * Isar/Pure: theory command 'hide' removes declarations from

1198 class/type/const name spaces;

1200 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to

1201 indicate potential overloading;

1203 * Isar/Pure: changed syntax of local blocks from {{ }} to { };

1205 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write

1206 "{a,b,c}" instead of {a,b,c};

1208 * Isar/Pure now provides its own version of intro/elim/dest

1209 attributes; useful for building new logics, but beware of confusion

1210 with the version in Provers/classical;

1212 * Isar/Pure: the local context of (non-atomic) goals is provided via

1213 case name 'antecedent';

1215 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms

1216 to the current context is now done automatically);

1218 * Isar/Pure: theory command 'method_setup' provides a simple interface

1219 for definining proof methods in ML;

1221 * Isar/Provers: intro/elim/dest attributes changed; renamed

1222 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in

1223 most cases, one should have to change intro!! to intro? only);

1224 replaced "delrule" by "rule del";

1226 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and

1227 'symmetric' attribute (the latter supercedes [RS sym]);

1229 * Isar/Provers: splitter support (via 'split' attribute and 'simp'

1230 method modifier); 'simp' method: 'only:' modifier removes loopers as

1231 well (including splits);

1233 * Isar/Provers: Simplifier and Classical methods now support all kind

1234 of modifiers used in the past, including 'cong', 'iff', etc.

1236 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination

1237 of Simplifier and Classical reasoner);

1239 * Isar/HOL: new proof method 'cases' and improved version of 'induct'

1240 now support named cases; major packages (inductive, datatype, primrec,

1241 recdef) support case names and properly name parameters;

1243 * Isar/HOL: new transitivity rules for substitution in inequalities --

1244 monotonicity conditions are extracted to be proven at end of

1245 calculations;

1247 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof

1248 method anyway;

1250 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =

1251 split_if split_if_asm; datatype package provides theorems foo.splits =

1252 foo.split foo.split_asm for each datatype;

1254 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"

1255 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof

1256 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:

1257 use "(cases (simplified))" method in proper proof texts);

1259 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;

1261 * Isar: names of theorems etc. may be natural numbers as well;

1263 * Isar: 'pr' command: optional arguments for goals_limit and

1264 ProofContext.prems_limit; no longer prints theory contexts, but only

1265 proof states;

1267 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit

1268 additional print modes to be specified; e.g. "pr(latex)" will print

1269 proof state according to the Isabelle LaTeX style;

1271 * Isar: improved support for emulating tactic scripts, including proof

1272 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',

1273 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'

1274 (for HOL datatypes);

1276 * Isar: simplified (more robust) goal selection of proof methods: 1st

1277 goal, all goals, or explicit goal specifier (tactic emulation); thus

1278 'proof method scripts' have to be in depth-first order;

1280 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';

1282 * Isar: removed 'help' command, which hasn't been too helpful anyway;

1283 should instead use individual commands for printing items

1284 (print_commands, print_methods etc.);

1286 * Isar: added 'nothing' --- the empty list of theorems;

1289 *** HOL ***

1291 * HOL/MicroJava: formalization of a fragment of Java, together with a

1292 corresponding virtual machine and a specification of its bytecode

1293 verifier and a lightweight bytecode verifier, including proofs of

1294 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and

1295 Cornelia Pusch (see also the homepage of project Bali at

1296 http://isabelle.in.tum.de/Bali/);

1298 * HOL/Algebra: new theory of rings and univariate polynomials, by

1299 Clemens Ballarin;

1301 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese

1302 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M

1303 Rasmussen;

1305 * HOL/Lattice: fundamental concepts of lattice theory and order

1306 structures, including duals, properties of bounds versus algebraic

1307 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski

1308 Theorem for complete lattices etc.; may also serve as a demonstration

1309 for abstract algebraic reasoning using axiomatic type classes, and

1310 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;

1312 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David

1313 von Oheimb;

1315 * HOL/IMPP: extension of IMP with local variables and mutually

1316 recursive procedures, by David von Oheimb;

1318 * HOL/Lambda: converted into new-style theory and document;

1320 * HOL/ex/Multiquote: example of multiple nested quotations and

1321 anti-quotations -- basically a generalized version of de-Bruijn

1322 representation; very useful in avoiding lifting of operations;

1324 * HOL/record: added general record equality rule to simpset; fixed

1325 select-update simplification procedure to handle extended records as

1326 well; admit "r" as field name;

1328 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with

1329 other numeric types and also as the identity of groups, rings, etc.;

1331 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.

1332 Types nat and int belong to this axclass;

1334 * HOL: greatly improved simplification involving numerals of type nat, int, real:

1335 (i + #8 + j) = Suc k simplifies to #7 + (i + j) = k

1336 i*j + k + j*#3*i simplifies to #4*(i*j) + k

1337 two terms #m*u and #n*u are replaced by #(m+n)*u

1338 (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)

1339 and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y

1340 or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);

1342 * HOL: meson_tac is available (previously in ex/meson.ML); it is a

1343 powerful prover for predicate logic but knows nothing of clasets; see

1344 ex/mesontest.ML and ex/mesontest2.ML for example applications;

1346 * HOL: new version of "case_tac" subsumes both boolean case split and

1347 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer

1348 exists, may define val exhaust_tac = case_tac for ad-hoc portability;

1350 * HOL: simplification no longer dives into case-expressions: only the

1351 selector expression is simplified, but not the remaining arms; to

1352 enable full simplification of case-expressions for datatype t, you may

1353 remove t.weak_case_cong from the simpset, either globally (Delcongs

1354 [thm"t.weak_case_cong"];) or locally (delcongs [...]).

1356 * HOL/recdef: the recursion equations generated by 'recdef' for

1357 function 'f' are now called f.simps instead of f.rules; if all

1358 termination conditions are proved automatically, these simplification

1359 rules are added to the simpset, as in primrec; rules may be named

1360 individually as well, resulting in a separate list of theorems for

1361 each equation;

1363 * HOL/While is a new theory that provides a while-combinator. It

1364 permits the definition of tail-recursive functions without the

1365 provision of a termination measure. The latter is necessary once the

1366 invariant proof rule for while is applied.

1368 * HOL: new (overloaded) notation for the set of elements below/above

1369 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.

1371 * HOL: theorems impI, allI, ballI bound as "strip";

1373 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic

1374 induct_tac th "x1 ... xn" expects th to have a conclusion of the form

1375 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;

1377 * HOL/Real: "rabs" replaced by overloaded "abs" function;

1379 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of

1380 main HOL, but was unused);

1382 * HOL: fewer consts declared as global (e.g. have to refer to

1383 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);

1385 * HOL: tuned AST representation of nested pairs, avoiding bogus output

1386 in case of overlap with user translations (e.g. judgements over

1387 tuples); (note that the underlying logical represenation is still

1388 bogus);

1391 *** ZF ***

1393 * ZF: simplification automatically cancels common terms in arithmetic

1394 expressions over nat and int;

1396 * ZF: new treatment of nat to minimize type-checking: all operators

1397 coerce their operands to a natural number using the function natify,

1398 making the algebraic laws unconditional;

1400 * ZF: as above, for int: operators coerce their operands to an integer

1401 using the function intify;

1403 * ZF: the integer library now contains many of the usual laws for the

1404 orderings, including $<=, and monotonicity laws for $+ and $*;

1406 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic

1407 simplification;

1409 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q

1410 to the simplifier and classical reasoner simultaneously;

1413 *** General ***

1415 * Provers: blast_tac now handles actual object-logic rules as

1416 assumptions; note that auto_tac uses blast_tac internally as well;

1418 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning

1419 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;

1421 * Provers: delrules now handles destruct rules as well (no longer need

1422 explicit make_elim);

1424 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.

1425 [| inj ?f; ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W

1426 use instead the strong form,

1427 [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W

1428 in HOL, FOL and ZF the function cla_make_elim will create such rules

1429 from destruct-rules;

1431 * Provers: Simplifier.easy_setup provides a fast path to basic

1432 Simplifier setup for new object-logics;

1434 * Pure: AST translation rules no longer require constant head on LHS;

1436 * Pure: improved name spaces: ambiguous output is qualified; support

1437 for hiding of names;

1439 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and

1440 XSYMBOL_HOME; no longer need to do manual configuration in most

1441 situations;

1443 * system: compression of ML heaps images may now be controlled via -c

1444 option of isabelle and isatool usedir (currently only observed by

1445 Poly/ML);

1447 * system: isatool installfonts may handle X-Symbol fonts as well (very

1448 useful for remote X11);

1450 * system: provide TAGS file for Isabelle sources;

1452 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument

1453 order;

1455 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global

1456 timing flag supersedes proof_timing and Toplevel.trace;

1458 * ML: new combinators |>> and |>>> for incremental transformations

1459 with secondary results (e.g. certain theory extensions):

1461 * ML: PureThy.add_defs gets additional argument to indicate potential

1462 overloading (usually false);

1464 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as

1465 results;

1469 New in Isabelle99 (October 1999)

1470 --------------------------------

1472 *** Overview of INCOMPATIBILITIES (see below for more details) ***

1474 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)

1475 are no longer simplified. (This allows the simplifier to unfold recursive

1476 functional programs.) To restore the old behaviour, declare

1478 Delcongs [if_weak_cong];

1480 * HOL: Removed the obsolete syntax "Compl A"; use -A for set

1481 complement;

1483 * HOL: the predicate "inj" is now defined by translation to "inj_on";

1485 * HOL/datatype: mutual_induct_tac no longer exists --

1486 use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]

1488 * HOL/typedef: fixed type inference for representing set; type

1489 arguments now have to occur explicitly on the rhs as type constraints;

1491 * ZF: The con_defs part of an inductive definition may no longer refer

1492 to constants declared in the same theory;

1494 * HOL, ZF: the function mk_cases, generated by the inductive

1495 definition package, has lost an argument. To simplify its result, it

1496 uses the default simpset instead of a supplied list of theorems.

1498 * HOL/List: the constructors of type list are now Nil and Cons;

1500 * Simplifier: the type of the infix ML functions

1501 setSSolver addSSolver setSolver addSolver

1502 is now simpset * solver -> simpset where `solver' is a new abstract type

1503 for packaging solvers. A solver is created via

1504 mk_solver: string -> (thm list -> int -> tactic) -> solver

1505 where the string argument is only a comment.

1508 *** Proof tools ***

1510 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a

1511 decision procedure for linear arithmetic. Currently it is used for

1512 types `nat', `int', and `real' in HOL (see below); it can, should and

1513 will be instantiated for other types and logics as well.

1515 * The simplifier now accepts rewrite rules with flexible heads, eg

1516 hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y

1517 They are applied like any rule with a non-pattern lhs, i.e. by first-order

1518 matching.

1521 *** General ***

1523 * New Isabelle/Isar subsystem provides an alternative to traditional

1524 tactical theorem proving; together with the ProofGeneral/isar user

1525 interface it offers an interactive environment for developing human

1526 readable proof documents (Isar == Intelligible semi-automated

1527 reasoning); for further information see isatool doc isar-ref,

1528 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/

1530 * improved and simplified presentation of theories: better HTML markup

1531 (including colors), graph views in several sizes; isatool usedir now

1532 provides a proper interface for user theories (via -P option); actual

1533 document preparation based on (PDF)LaTeX is available as well (for

1534 new-style theories only); see isatool doc system for more information;

1536 * native support for Proof General, both for classic Isabelle and

1537 Isabelle/Isar;

1539 * ML function thm_deps visualizes dependencies of theorems and lemmas,

1540 using the graph browser tool;

1542 * Isabelle manuals now also available as PDF;

1544 * theory loader rewritten from scratch (may not be fully

1545 bug-compatible); old loadpath variable has been replaced by show_path,

1546 add_path, del_path, reset_path functions; new operations such as

1547 update_thy, touch_thy, remove_thy, use/update_thy_only (see also

1548 isatool doc ref);

1550 * improved isatool install: option -k creates KDE application icon,

1551 option -p DIR installs standalone binaries;

1553 * added ML_PLATFORM setting (useful for cross-platform installations);

1554 more robust handling of platform specific ML images for SML/NJ;

1556 * the settings environment is now statically scoped, i.e. it is never

1557 created again in sub-processes invoked from isabelle, isatool, or

1558 Isabelle;

1560 * path element specification '~~' refers to '$ISABELLE_HOME';

1562 * in locales, the "assumes" and "defines" parts may be omitted if

1563 empty;

1565 * new print_mode "xsymbols" for extended symbol support (e.g. genuine

1566 long arrows);

1568 * new print_mode "HTML";

1570 * new flag show_tags controls display of tags of theorems (which are

1571 basically just comments that may be attached by some tools);

1573 * Isamode 2.6 requires patch to accomodate change of Isabelle font

1574 mode and goal output format:

1576 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el

1577 244c244

1578 < (list (isa-getenv "ISABELLE") "-msymbols" logic-name)

1579 ---

1580 > (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)

1581 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el

1582 181c181

1583 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"

1584 ---

1585 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"

1587 * function bind_thms stores lists of theorems (cf. bind_thm);

1589 * new shorthand tactics ftac, eatac, datac, fatac;

1591 * qed (and friends) now accept "" as result name; in that case the

1592 theorem is not stored, but proper checks and presentation of the

1593 result still apply;

1595 * theorem database now also indexes constants "Trueprop", "all",

1596 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;

1599 *** HOL ***

1601 ** HOL arithmetic **

1603 * There are now decision procedures for linear arithmetic over nat and

1604 int:

1606 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',

1607 `+', `-', `Suc', `min', `max' and numerical constants; other subterms

1608 are treated as atomic; subformulae not involving type `nat' or `int'

1609 are ignored; quantified subformulae are ignored unless they are

1610 positive universal or negative existential. The tactic has to be

1611 invoked by hand and can be a little bit slow. In particular, the

1612 running time is exponential in the number of occurrences of `min' and

1613 `max', and `-' on `nat'.

1615 2. fast_arith_tac is a cut-down version of arith_tac: it only takes

1616 (negated) (in)equalities among the premises and the conclusion into

1617 account (i.e. no compound formulae) and does not know about `min' and

1618 `max', and `-' on `nat'. It is fast and is used automatically by the

1619 simplifier.

1621 NB: At the moment, these decision procedures do not cope with mixed

1622 nat/int formulae where the two parts interact, such as `m < n ==>

1623 int(m) < int(n)'.

1625 * HOL/Numeral provides a generic theory of numerals (encoded

1626 efficiently as bit strings); setup for types nat/int/real is in place;

1627 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than

1628 int, existing theories and proof scripts may require a few additional

1629 type constraints;

1631 * integer division and remainder can now be performed on constant

1632 arguments;

1634 * many properties of integer multiplication, division and remainder

1635 are now available;

1637 * An interface to the Stanford Validity Checker (SVC) is available through the

1638 tactic svc_tac. Propositional tautologies and theorems of linear arithmetic

1639 are proved automatically. SVC must be installed separately, and its results

1640 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any

1641 invocation of the underlying oracle). For SVC see

1642 http://verify.stanford.edu/SVC

1644 * IsaMakefile: the HOL-Real target now builds an actual image;

1647 ** HOL misc **

1649 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces

1650 (in Isabelle/Isar) -- by Gertrud Bauer;

1652 * HOL/BCV: generic model of bytecode verification, i.e. data-flow

1653 analysis for assembly languages with subtypes;

1655 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization

1656 -- avoids syntactic ambiguities and treats state, transition, and

1657 temporal levels more uniformly; introduces INCOMPATIBILITIES due to

1658 changed syntax and (many) tactics;

1660 * HOL/inductive: Now also handles more general introduction rules such

1661 as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity

1662 theorems are now maintained within the theory (maintained via the

1663 "mono" attribute);

1665 * HOL/datatype: Now also handles arbitrarily branching datatypes

1666 (using function types) such as

1668 datatype 'a tree = Atom 'a | Branch "nat => 'a tree"

1670 * HOL/record: record_simproc (part of the default simpset) takes care

1671 of selectors applied to updated records; record_split_tac is no longer

1672 part of the default claset; update_defs may now be removed from the

1673 simpset in many cases; COMPATIBILITY: old behavior achieved by

1675 claset_ref () := claset() addSWrapper record_split_wrapper;

1676 Delsimprocs [record_simproc]

1678 * HOL/typedef: fixed type inference for representing set; type

1679 arguments now have to occur explicitly on the rhs as type constraints;

1681 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem

1682 names rather than an ML expression;

1684 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be

1685 supplied later. Program schemes can be defined, such as

1686 "While B C s = (if B s then While B C (C s) else s)"

1687 where the well-founded relation can be chosen after B and C have been given.

1689 * HOL/List: the constructors of type list are now Nil and Cons;

1690 INCOMPATIBILITY: while [] and infix # syntax is still there, of

1691 course, ML tools referring to List.list.op # etc. have to be adapted;

1693 * HOL_quantifiers flag superseded by "HOL" print mode, which is

1694 disabled by default; run isabelle with option -m HOL to get back to

1695 the original Gordon/HOL-style output;

1697 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,

1698 ALL x<=y. P, EX x<y. P, EX x<=y. P;

1700 * HOL basic syntax simplified (more orthogonal): all variants of

1701 All/Ex now support plain / symbolic / HOL notation; plain syntax for

1702 Eps operator is provided as well: "SOME x. P[x]";

1704 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;

1706 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made

1707 thus available for user theories;

1709 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with

1710 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the

1711 time;

1713 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec

1714 several times and then mp;

1717 *** LK ***

1719 * the notation <<...>> is now available as a notation for sequences of

1720 formulas;

1722 * the simplifier is now installed

1724 * the axiom system has been generalized (thanks to Soren Heilmann)

1726 * the classical reasoner now has a default rule database

1729 *** ZF ***

1731 * new primrec section allows primitive recursive functions to be given

1732 directly (as in HOL) over datatypes and the natural numbers;

1734 * new tactics induct_tac and exhaust_tac for induction (or case

1735 analysis) over datatypes and the natural numbers;

1737 * the datatype declaration of type T now defines the recursor T_rec;

1739 * simplification automatically does freeness reasoning for datatype

1740 constructors;

1742 * automatic type-inference, with AddTCs command to insert new

1743 type-checking rules;

1745 * datatype introduction rules are now added as Safe Introduction rules

1746 to the claset;

1748 * the syntax "if P then x else y" is now available in addition to

1749 if(P,x,y);

1752 *** Internal programming interfaces ***

1754 * tuned simplifier trace output; new flag debug_simp;

1756 * structures Vartab / Termtab (instances of TableFun) offer efficient

1757 tables indexed by indexname_ord / term_ord (compatible with aconv);

1759 * AxClass.axclass_tac lost the theory argument;

1761 * tuned current_goals_markers semantics: begin / end goal avoids

1762 printing empty lines;

1764 * removed prs and prs_fn hook, which was broken because it did not

1765 include \n in its semantics, forcing writeln to add one

1766 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:

1767 string -> unit if you really want to output text without newline;

1769 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to

1770 plain output, interface builders may have to enable 'isabelle_font'

1771 mode to get Isabelle font glyphs as before;

1773 * refined token_translation interface; INCOMPATIBILITY: output length

1774 now of type real instead of int;

1776 * theory loader actions may be traced via new ThyInfo.add_hook

1777 interface (see src/Pure/Thy/thy_info.ML); example application: keep

1778 your own database of information attached to *whole* theories -- as

1779 opposed to intra-theory data slots offered via TheoryDataFun;

1781 * proper handling of dangling sort hypotheses (at last!);

1782 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing

1783 extra sort hypotheses that can be witnessed from the type signature;

1784 the force_strip_shyps flag is gone, any remaining shyps are simply

1785 left in the theorem (with a warning issued by strip_shyps_warning);

1789 New in Isabelle98-1 (October 1998)

1790 ----------------------------------

1792 *** Overview of INCOMPATIBILITIES (see below for more details) ***

1794 * several changes of automated proof tools;

1796 * HOL: major changes to the inductive and datatype packages, including

1797 some minor incompatibilities of theory syntax;

1799 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now

1800 called `inj_on';

1802 * HOL: removed duplicate thms in Arith:

1803 less_imp_add_less should be replaced by trans_less_add1

1804 le_imp_add_le should be replaced by trans_le_add1

1806 * HOL: unary minus is now overloaded (new type constraints may be

1807 required);

1809 * HOL and ZF: unary minus for integers is now #- instead of #~. In

1810 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is

1811 now taken as an integer constant.

1813 * Pure: ML function 'theory_of' renamed to 'theory';

1816 *** Proof tools ***

1818 * Simplifier:

1819 1. Asm_full_simp_tac is now more aggressive.

1820 1. It will sometimes reorient premises if that increases their power to

1821 simplify.

1822 2. It does no longer proceed strictly from left to right but may also

1823 rotate premises to achieve further simplification.

1824 For compatibility reasons there is now Asm_lr_simp_tac which is like the

1825 old Asm_full_simp_tac in that it does not rotate premises.

1826 2. The simplifier now knows a little bit about nat-arithmetic.

1828 * Classical reasoner: wrapper mechanism for the classical reasoner now

1829 allows for selected deletion of wrappers, by introduction of names for

1830 wrapper functionals. This implies that addbefore, addSbefore,

1831 addaltern, and addSaltern now take a pair (name, tactic) as argument,

1832 and that adding two tactics with the same name overwrites the first

1833 one (emitting a warning).

1834 type wrapper = (int -> tactic) -> (int -> tactic)

1835 setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by

1836 addWrapper, addSWrapper: claset * (string * wrapper) -> claset

1837 delWrapper, delSWrapper: claset * string -> claset

1838 getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;

1840 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE

1841 semantics; addbefore now affects only the unsafe part of step_tac

1842 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY

1843 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac

1844 by Force_tac;

1846 * Classical reasoner: setwrapper to setWrapper and compwrapper to

1847 compWrapper; added safe wrapper (and access functions for it);

1849 * HOL/split_all_tac is now much faster and fails if there is nothing

1850 to split. Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order

1851 and the names of the automatically generated variables have changed.

1852 split_all_tac has moved within claset() from unsafe wrappers to safe

1853 wrappers, which means that !!-bound variables are split much more

1854 aggressively, and safe_tac and clarify_tac now split such variables.

1855 If this splitting is not appropriate, use delSWrapper "split_all_tac".

1856 Note: the same holds for record_split_tac, which does the job of

1857 split_all_tac for record fields.

1859 * HOL/Simplifier: Rewrite rules for case distinctions can now be added

1860 permanently to the default simpset using Addsplits just like

1861 Addsimps. They can be removed via Delsplits just like

1862 Delsimps. Lower-case versions are also available.

1864 * HOL/Simplifier: The rule split_if is now part of the default

1865 simpset. This means that the simplifier will eliminate all occurrences

1866 of if-then-else in the conclusion of a goal. To prevent this, you can

1867 either remove split_if completely from the default simpset by

1868 `Delsplits [split_if]' or remove it in a specific call of the

1869 simplifier using `... delsplits [split_if]'. You can also add/delete

1870 other case splitting rules to/from the default simpset: every datatype

1871 generates suitable rules `split_t_case' and `split_t_case_asm' (where

1872 t is the name of the datatype).

1874 * Classical reasoner / Simplifier combination: new force_tac (and

1875 derivatives Force_tac, force) combines rewriting and classical

1876 reasoning (and whatever other tools) similarly to auto_tac, but is

1877 aimed to solve the given subgoal completely.

1880 *** General ***

1882 * new top-level commands `Goal' and `Goalw' that improve upon `goal'

1883 and `goalw': the theory is no longer needed as an explicit argument -

1884 the current theory context is used; assumptions are no longer returned

1885 at the ML-level unless one of them starts with ==> or !!; it is

1886 recommended to convert to these new commands using isatool fixgoal

1887 (backup your sources first!);

1889 * new top-level commands 'thm' and 'thms' for retrieving theorems from

1890 the current theory context, and 'theory' to lookup stored theories;

1892 * new theory section 'locale' for declaring constants, assumptions and

1893 definitions that have local scope;

1895 * new theory section 'nonterminals' for purely syntactic types;

1897 * new theory section 'setup' for generic ML setup functions

1898 (e.g. package initialization);

1900 * the distribution now includes Isabelle icons: see

1901 lib/logo/isabelle-{small,tiny}.xpm;

1903 * isatool install - install binaries with absolute references to

1904 ISABELLE_HOME/bin;

1906 * isatool logo -- create instances of the Isabelle logo (as EPS);

1908 * print mode 'emacs' reserved for Isamode;

1910 * support multiple print (ast) translations per constant name;

1912 * theorems involving oracles are now printed with a suffixed [!];

1915 *** HOL ***

1917 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');

1919 * HOL/inductive package reorganized and improved: now supports mutual

1920 definitions such as

1922 inductive EVEN ODD

1923 intrs

1924 null "0 : EVEN"

1925 oddI "n : EVEN ==> Suc n : ODD"

1926 evenI "n : ODD ==> Suc n : EVEN"

1928 new theorem list "elims" contains an elimination rule for each of the

1929 recursive sets; inductive definitions now handle disjunctive premises

1930 correctly (also ZF);

1932 INCOMPATIBILITIES: requires Inductive as an ancestor; component

1933 "mutual_induct" no longer exists - the induction rule is always

1934 contained in "induct";

1937 * HOL/datatype package re-implemented and greatly improved: now

1938 supports mutually recursive datatypes such as

1940 datatype

1941 'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)

1942 | SUM ('a aexp) ('a aexp)

1943 | DIFF ('a aexp) ('a aexp)

1944 | NUM 'a

1945 and

1946 'a bexp = LESS ('a aexp) ('a aexp)

1947 | AND ('a bexp) ('a bexp)

1948 | OR ('a bexp) ('a bexp)

1950 as well as indirectly recursive datatypes such as

1952 datatype

1953 ('a, 'b) term = Var 'a

1954 | App 'b ((('a, 'b) term) list)

1956 The new tactic mutual_induct_tac [<var_1>, ..., <var_n>] i performs

1957 induction on mutually / indirectly recursive datatypes.

1959 Primrec equations are now stored in theory and can be accessed via

1960 <function_name>.simps.

1962 INCOMPATIBILITIES:

1964 - Theories using datatypes must now have theory Datatype as an

1965 ancestor.

1966 - The specific <typename>.induct_tac no longer exists - use the

1967 generic induct_tac instead.

1968 - natE has been renamed to nat.exhaust - use exhaust_tac

1969 instead of res_inst_tac ... natE. Note that the variable

1970 names in nat.exhaust differ from the names in natE, this

1971 may cause some "fragile" proofs to fail.

1972 - The theorems split_<typename>_case and split_<typename>_case_asm

1973 have been renamed to <typename>.split and <typename>.split_asm.

1974 - Since default sorts of type variables are now handled correctly,

1975 some datatype definitions may have to be annotated with explicit

1976 sort constraints.

1977 - Primrec definitions no longer require function name and type

1978 of recursive argument.

1980 Consider using isatool fixdatatype to adapt your theories and proof

1981 scripts to the new package (backup your sources first!).

1984 * HOL/record package: considerably improved implementation; now

1985 includes concrete syntax for record types, terms, updates; theorems

1986 for surjective pairing and splitting !!-bound record variables; proof

1987 support is as follows:

1989 1) standard conversions (selectors or updates applied to record

1990 constructor terms) are part of the standard simpset;

1992 2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are

1993 made part of standard simpset and claset via addIffs;

1995 3) a tactic for record field splitting (record_split_tac) is part of

1996 the standard claset (addSWrapper);

1998 To get a better idea about these rules you may retrieve them via

1999 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is

2000 the name of your record type.

2002 The split tactic 3) conceptually simplifies by the following rule:

2004 "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"

2006 Thus any record variable that is bound by meta-all will automatically

2007 blow up into some record constructor term, consequently the

2008 simplifications of 1), 2) apply. Thus force_tac, auto_tac etc. shall

2009 solve record problems automatically.

2012 * reorganized the main HOL image: HOL/Integ and String loaded by

2013 default; theory Main includes everything;

2015 * automatic simplification of integer sums and comparisons, using cancellation;

2017 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;

2019 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;

2021 * many new identities for unions, intersections, set difference, etc.;

2023 * expand_if, expand_split, expand_sum_case and expand_nat_case are now

2024 called split_if, split_split, split_sum_case and split_nat_case (to go

2025 with add/delsplits);

2027 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting

2028 (?x::unit) = (); this is made part of the default simpset, which COULD

2029 MAKE EXISTING PROOFS FAIL under rare circumstances (consider

2030 'Delsimprocs [unit_eq_proc];' as last resort); also note that

2031 unit_abs_eta_conv is added in order to counter the effect of

2032 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by

2033 %u.f();

2035 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which

2036 makes more sense);

2038 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;

2039 It and 'sym RS equals0D' are now in the default claset, giving automatic

2040 disjointness reasoning but breaking a few old proofs.

2042 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1

2043 to 'converse' from 'inverse' (for compatibility with ZF and some

2044 literature);

2046 * HOL/recdef can now declare non-recursive functions, with {} supplied as

2047 the well-founded relation;

2049 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of

2050 Compl A. The "Compl" syntax remains available as input syntax for this

2051 release ONLY.

2053 * HOL/Update: new theory of function updates:

2054 f(a:=b) == %x. if x=a then b else f x

2055 may also be iterated as in f(a:=b,c:=d,...);

2057 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;

2059 * HOL/List:

2060 - new function list_update written xs[i:=v] that updates the i-th

2061 list position. May also be iterated as in xs[i:=a,j:=b,...].

2062 - new function `upt' written [i..j(] which generates the list

2063 [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper

2064 bound write [i..j], which is a shorthand for [i..j+1(].

2065 - new lexicographic orderings and corresponding wellfoundedness theorems.

2067 * HOL/Arith:

2068 - removed 'pred' (predecessor) function;

2069 - generalized some theorems about n-1;

2070 - many new laws about "div" and "mod";

2071 - new laws about greatest common divisors (see theory ex/Primes);

2073 * HOL/Relation: renamed the relational operator r^-1 "converse"

2074 instead of "inverse";

2076 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness

2077 of the multiset ordering;

2079 * directory HOL/Real: a construction of the reals using Dedekind cuts

2080 (not included by default);

2082 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;

2084 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted

2085 programs, i.e. different program variables may have different types.

2087 * calling (stac rew i) now fails if "rew" has no effect on the goal

2088 [previously, this check worked only if the rewrite rule was unconditional]

2089 Now rew can involve either definitions or equalities (either == or =).

2092 *** ZF ***

2094 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains

2095 only the theorems proved on ZF.ML;

2097 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;

2098 It and 'sym RS equals0D' are now in the default claset, giving automatic

2099 disjointness reasoning but breaking a few old proofs.

2101 * ZF/Update: new theory of function updates

2102 with default rewrite rule f(x:=y) ` z = if(z=x, y, f`z)

2103 may also be iterated as in f(a:=b,c:=d,...);

2105 * in let x=t in u(x), neither t nor u(x) has to be an FOL term.

2107 * calling (stac rew i) now fails if "rew" has no effect on the goal

2108 [previously, this check worked only if the rewrite rule was unconditional]

2109 Now rew can involve either definitions or equalities (either == or =).

2111 * case_tac provided for compatibility with HOL

2112 (like the old excluded_middle_tac, but with subgoals swapped)

2115 *** Internal programming interfaces ***

2117 * Pure: several new basic modules made available for general use, see

2118 also src/Pure/README;

2120 * improved the theory data mechanism to support encapsulation (data

2121 kind name replaced by private Object.kind, acting as authorization

2122 key); new type-safe user interface via functor TheoryDataFun; generic

2123 print_data function becomes basically useless;

2125 * removed global_names compatibility flag -- all theory declarations

2126 are qualified by default;

2128 * module Pure/Syntax now offers quote / antiquote translation

2129 functions (useful for Hoare logic etc. with implicit dependencies);

2130 see HOL/ex/Antiquote for an example use;

2132 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->

2133 cterm -> thm;

2135 * new tactical CHANGED_GOAL for checking that a tactic modifies a

2136 subgoal;

2138 * Display.print_goals function moved to Locale.print_goals;

2140 * standard print function for goals supports current_goals_markers

2141 variable for marking begin of proof, end of proof, start of goal; the

2142 default is ("", "", ""); setting current_goals_markers := ("<proof>",

2143 "</proof>", "<goal>") causes SGML like tagged proof state printing,

2144 for example;

2148 New in Isabelle98 (January 1998)

2149 --------------------------------

2151 *** Overview of INCOMPATIBILITIES (see below for more details) ***

2153 * changed lexical syntax of terms / types: dots made part of long

2154 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";

2156 * simpset (and claset) reference variable replaced by functions

2157 simpset / simpset_ref;

2159 * no longer supports theory aliases (via merge) and non-trivial

2160 implicit merge of thms' signatures;

2162 * most internal names of constants changed due to qualified names;

2164 * changed Pure/Sequence interface (see Pure/seq.ML);

2167 *** General Changes ***

2169 * hierachically structured name spaces (for consts, types, axms, thms

2170 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of

2171 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:

2172 isatool fixdots ensures space after dots (e.g. "%x. x"); set

2173 long_names for fully qualified output names; NOTE: ML programs

2174 (special tactics, packages etc.) referring to internal names may have

2175 to be adapted to cope with fully qualified names; in case of severe

2176 backward campatibility problems try setting 'global_names' at compile

2177 time to have enrything declared within a flat name space; one may also

2178 fine tune name declarations in theories via the 'global' and 'local'

2179 section;

2181 * reimplemented the implicit simpset and claset using the new anytype

2182 data filed in signatures; references simpset:simpset ref etc. are

2183 replaced by functions simpset:unit->simpset and

2184 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp

2185 to patch your ML files accordingly;

2187 * HTML output now includes theory graph data for display with Java

2188 applet or isatool browser; data generated automatically via isatool

2189 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);

2191 * defs may now be conditional; improved rewrite_goals_tac to handle

2192 conditional equations;

2194 * defs now admits additional type arguments, using TYPE('a) syntax;

2196 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always

2197 creates a new theory node; implicit merge of thms' signatures is

2198 restricted to 'trivial' ones; COMPATIBILITY: one may have to use

2199 transfer:theory->thm->thm in (rare) cases;

2201 * improved handling of draft signatures / theories; draft thms (and

2202 ctyps, cterms) are automatically promoted to real ones;

2204 * slightly changed interfaces for oracles: admit many per theory, named

2205 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;

2207 * print_goals: optional output of const types (set show_consts and

2208 show_types);

2210 * improved output of warnings (###) and errors (***);

2212 * subgoal_tac displays a warning if the new subgoal has type variables;

2214 * removed old README and Makefiles;

2216 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;

2218 * removed obsolete init_pps and init_database;

2220 * deleted the obsolete tactical STATE, which was declared by

2221 fun STATE tacfun st = tacfun st st;

2223 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~

2224 (which abbreviates $HOME);

2226 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:

2227 use isatool fixseq to adapt your ML programs (this works for fully

2228 qualified references to the Sequence structure only!);

2230 * use_thy no longer requires writable current directory; it always

2231 reloads .ML *and* .thy file, if either one is out of date;

2234 *** Classical Reasoner ***

2236 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new

2237 tactics that use classical reasoning to simplify a subgoal without

2238 splitting it into several subgoals;

2240 * Safe_tac: like safe_tac but uses the default claset;

2243 *** Simplifier ***

2245 * added simplification meta rules:

2246 (asm_)(full_)simplify: simpset -> thm -> thm;

2248 * simplifier.ML no longer part of Pure -- has to be loaded by object

2249 logics (again);

2251 * added prems argument to simplification procedures;

2253 * HOL, FOL, ZF: added infix function `addsplits':

2254 instead of `<simpset> setloop (split_tac <thms>)'

2255 you can simply write `<simpset> addsplits <thms>'

2258 *** Syntax ***

2260 * TYPE('a) syntax for type reflection terms;

2262 * no longer handles consts with name "" -- declare as 'syntax' instead;

2264 * pretty printer: changed order of mixfix annotation preference (again!);

2266 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;

2269 *** HOL ***

2271 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.

2272 with `addloop' of the simplifier to faciliate case splitting in premises.

2274 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;

2276 * HOL/Auth: new protocol proofs including some for the Internet

2277 protocol TLS;

2279 * HOL/Map: new theory of `maps' a la VDM;

2281 * HOL/simplifier: simplification procedures nat_cancel_sums for

2282 cancelling out common nat summands from =, <, <= (in)equalities, or

2283 differences; simplification procedures nat_cancel_factor for

2284 cancelling common factor from =, <, <= (in)equalities over natural

2285 sums; nat_cancel contains both kinds of procedures, it is installed by

2286 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;

2288 * HOL/simplifier: terms of the form

2289 `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)' (or t=x)

2290 are rewritten to

2291 `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',

2292 and those of the form

2293 `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)' (or t=x)

2294 are rewritten to

2295 `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',

2297 * HOL/datatype

2298 Each datatype `t' now comes with a theorem `split_t_case' of the form

2300 P(t_case f1 ... fn x) =

2301 ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &

2302 ...

2303 (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))

2304 )

2306 and a theorem `split_t_case_asm' of the form

2308 P(t_case f1 ... fn x) =

2309 ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |

2310 ...

2311 (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))

2312 )

2313 which can be added to a simpset via `addsplits'. The existing theorems

2314 expand_list_case and expand_option_case have been renamed to

2315 split_list_case and split_option_case.

2317 * HOL/Arithmetic:

2318 - `pred n' is automatically converted to `n-1'.

2319 Users are strongly encouraged not to use `pred' any longer,

2320 because it will disappear altogether at some point.

2321 - Users are strongly encouraged to write "0 < n" rather than

2322 "n ~= 0". Theorems and proof tools have been modified towards this

2323 `standard'.

2325 * HOL/Lists:

2326 the function "set_of_list" has been renamed "set" (and its theorems too);

2327 the function "nth" now takes its arguments in the reverse order and

2328 has acquired the infix notation "!" as in "xs!n".

2330 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};

2332 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its

2333 specialist theorems (like UN1_I) are gone. Similarly for (INT x.B x);

2335 * HOL/record: extensible records with schematic structural subtyping

2336 (single inheritance); EXPERIMENTAL version demonstrating the encoding,

2337 still lacks various theorems and concrete record syntax;

2340 *** HOLCF ***

2342 * removed "axioms" and "generated by" sections;

2344 * replaced "ops" section by extended "consts" section, which is capable of

2345 handling the continuous function space "->" directly;

2347 * domain package:

2348 . proves theorems immediately and stores them in the theory,

2349 . creates hierachical name space,

2350 . now uses normal mixfix annotations (instead of cinfix...),

2351 . minor changes to some names and values (for consistency),

2352 . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,

2353 . separator between mutual domain defs: changed "," to "and",

2354 . improved handling of sort constraints; now they have to

2355 appear on the left-hand side of the equations only;

2357 * fixed LAM <x,y,zs>.b syntax;

2359 * added extended adm_tac to simplifier in HOLCF -- can now discharge

2360 adm (%x. P (t x)), where P is chainfinite and t continuous;

2363 *** FOL and ZF ***

2365 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.

2366 with `addloop' of the simplifier to faciliate case splitting in premises.

2368 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as

2369 in HOL, they strip ALL and --> from proved theorems;

2373 New in Isabelle94-8 (May 1997)

2374 ------------------------------

2376 *** General Changes ***

2378 * new utilities to build / run / maintain Isabelle etc. (in parts

2379 still somewhat experimental); old Makefiles etc. still functional;

2381 * new 'Isabelle System Manual';

2383 * INSTALL text, together with ./configure and ./build scripts;

2385 * reimplemented type inference for greater efficiency, better error

2386 messages and clean internal interface;

2388 * prlim command for dealing with lots of subgoals (an easier way of

2389 setting goals_limit);

2392 *** Syntax ***

2394 * supports alternative (named) syntax tables (parser and pretty

2395 printer); internal interface is provided by add_modesyntax(_i);

2397 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to

2398 be used in conjunction with the Isabelle symbol font; uses the

2399 "symbols" syntax table;

2401 * added token_translation interface (may translate name tokens in

2402 arbitrary ways, dependent on their type (free, bound, tfree, ...) and

2403 the current print_mode); IMPORTANT: user print translation functions

2404 are responsible for marking newly introduced bounds

2405 (Syntax.mark_boundT);

2407 * token translations for modes "xterm" and "xterm_color" that display

2408 names in bold, underline etc. or colors (which requires a color

2409 version of xterm);

2411 * infixes may now be declared with names independent of their syntax;

2413 * added typed_print_translation (like print_translation, but may

2414 access type of constant);

2417 *** Classical Reasoner ***

2419 Blast_tac: a new tactic! It is often more powerful than fast_tac, but has

2420 some limitations. Blast_tac...

2421 + ignores addss, addbefore, addafter; this restriction is intrinsic

2422 + ignores elimination rules that don't have the correct format

2423 (the conclusion MUST be a formula variable)

2424 + ignores types, which can make HOL proofs fail

2425 + rules must not require higher-order unification, e.g. apply_type in ZF

2426 [message "Function Var's argument not a bound variable" relates to this]

2427 + its proof strategy is more general but can actually be slower

2429 * substitution with equality assumptions no longer permutes other

2430 assumptions;

2432 * minor changes in semantics of addafter (now called addaltern); renamed

2433 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper

2434 (and access functions for it);

2436 * improved combination of classical reasoner and simplifier:

2437 + functions for handling clasimpsets

2438 + improvement of addss: now the simplifier is called _after_ the

2439 safe steps.

2440 + safe variant of addss called addSss: uses safe simplifications

2441 _during_ the safe steps. It is more complete as it allows multiple

2442 instantiations of unknowns (e.g. with slow_tac).

2444 *** Simplifier ***

2446 * added interface for simplification procedures (functions that

2447 produce *proven* rewrite rules on the fly, depending on current

2448 redex);

2450 * ordering on terms as parameter (used for ordered rewriting);

2452 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;

2454 * the solver is now split into a safe and an unsafe part.

2455 This should be invisible for the normal user, except that the

2456 functions setsolver and addsolver have been renamed to setSolver and

2457 addSolver; added safe_asm_full_simp_tac;

2460 *** HOL ***

2462 * a generic induction tactic `induct_tac' which works for all datatypes and

2463 also for type `nat';

2465 * a generic case distinction tactic `exhaust_tac' which works for all

2466 datatypes and also for type `nat';

2468 * each datatype comes with a function `size';

2470 * patterns in case expressions allow tuple patterns as arguments to

2471 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';

2473 * primrec now also works with type nat;

2475 * recdef: a new declaration form, allows general recursive functions to be

2476 defined in theory files. See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.

2478 * the constant for negation has been renamed from "not" to "Not" to

2479 harmonize with FOL, ZF, LK, etc.;

2481 * HOL/ex/LFilter theory of a corecursive "filter" functional for

2482 infinite lists;

2484 * HOL/Modelcheck demonstrates invocation of model checker oracle;

2486 * HOL/ex/Ring.thy declares cring_simp, which solves equational

2487 problems in commutative rings, using axiomatic type classes for + and *;

2489 * more examples in HOL/MiniML and HOL/Auth;

2491 * more default rewrite rules for quantifiers, union/intersection;

2493 * a new constant `arbitrary == @x.False';

2495 * HOLCF/IOA replaces old HOL/IOA;

2497 * HOLCF changes: derived all rules and arities

2498 + axiomatic type classes instead of classes

2499 + typedef instead of faking type definitions

2500 + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.

2501 + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po

2502 + eliminated the types void, one, tr

2503 + use unit lift and bool lift (with translations) instead of one and tr

2504 + eliminated blift from Lift3.thy (use Def instead of blift)

2505 all eliminated rules are derived as theorems --> no visible changes ;

2508 *** ZF ***

2510 * ZF now has Fast_tac, Simp_tac and Auto_tac. Union_iff is a now a default

2511 rewrite rule; this may affect some proofs. eq_cs is gone but can be put back

2512 as ZF_cs addSIs [equalityI];

2516 New in Isabelle94-7 (November 96)

2517 ---------------------------------

2519 * allowing negative levels (as offsets) in prlev and choplev;

2521 * super-linear speedup for large simplifications;

2523 * FOL, ZF and HOL now use miniscoping: rewriting pushes

2524 quantifications in as far as possible (COULD MAKE EXISTING PROOFS

2525 FAIL); can suppress it using the command Delsimps (ex_simps @

2526 all_simps); De Morgan laws are also now included, by default;

2528 * improved printing of ==> : ~:

2530 * new object-logic "Sequents" adds linear logic, while replacing LK

2531 and Modal (thanks to Sara Kalvala);

2533 * HOL/Auth: correctness proofs for authentication protocols;

2535 * HOL: new auto_tac combines rewriting and classical reasoning (many

2536 examples on HOL/Auth);

2538 * HOL: new command AddIffs for declaring theorems of the form P=Q to

2539 the rewriter and classical reasoner simultaneously;

2541 * function uresult no longer returns theorems in "standard" format;

2542 regain previous version by: val uresult = standard o uresult;

2546 New in Isabelle94-6

2547 -------------------

2549 * oracles -- these establish an interface between Isabelle and trusted

2550 external reasoners, which may deliver results as theorems;

2552 * proof objects (in particular record all uses of oracles);

2554 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;

2556 * "constdefs" section in theory files;

2558 * "primrec" section (HOL) no longer requires names;

2560 * internal type "tactic" now simply "thm -> thm Sequence.seq";

2564 New in Isabelle94-5

2565 -------------------

2567 * reduced space requirements;

2569 * automatic HTML generation from theories;

2571 * theory files no longer require "..." (quotes) around most types;

2573 * new examples, including two proofs of the Church-Rosser theorem;

2575 * non-curried (1994) version of HOL is no longer distributed;

2579 New in Isabelle94-4

2580 -------------------

2582 * greatly reduced space requirements;

2584 * theory files (.thy) no longer require \...\ escapes at line breaks;

2586 * searchable theorem database (see the section "Retrieving theorems" on

2587 page 8 of the Reference Manual);

2589 * new examples, including Grabczewski's monumental case study of the

2590 Axiom of Choice;

2592 * The previous version of HOL renamed to Old_HOL;

2594 * The new version of HOL (previously called CHOL) uses a curried syntax

2595 for functions. Application looks like f a b instead of f(a,b);

2597 * Mutually recursive inductive definitions finally work in HOL;

2599 * In ZF, pattern-matching on tuples is now available in all abstractions and

2600 translates to the operator "split";

2604 New in Isabelle94-3

2605 -------------------

2607 * new infix operator, addss, allowing the classical reasoner to

2608 perform simplification at each step of its search. Example:

2609 fast_tac (cs addss ss)

2611 * a new logic, CHOL, the same as HOL, but with a curried syntax

2612 for functions. Application looks like f a b instead of f(a,b). Also pairs

2613 look like (a,b) instead of <a,b>;

2615 * PLEASE NOTE: CHOL will eventually replace HOL!

2617 * In CHOL, pattern-matching on tuples is now available in all abstractions.

2618 It translates to the operator "split". A new theory of integers is available;

2620 * In ZF, integer numerals now denote two's-complement binary integers.

2621 Arithmetic operations can be performed by rewriting. See ZF/ex/Bin.ML;

2623 * Many new examples: I/O automata, Church-Rosser theorem, equivalents

2624 of the Axiom of Choice;

2628 New in Isabelle94-2

2629 -------------------

2631 * Significantly faster resolution;

2633 * the different sections in a .thy file can now be mixed and repeated

2634 freely;

2636 * Database of theorems for FOL, HOL and ZF. New

2637 commands including qed, qed_goal and bind_thm store theorems in the database.

2639 * Simple database queries: return a named theorem (get_thm) or all theorems of

2640 a given theory (thms_of), or find out what theory a theorem was proved in

2641 (theory_of_thm);

2643 * Bugs fixed in the inductive definition and datatype packages;

2645 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs

2646 and HOL_dup_cs obsolete;

2648 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1

2649 have been removed;

2651 * Simpler definition of function space in ZF;

2653 * new results about cardinal and ordinal arithmetic in ZF;

2655 * 'subtype' facility in HOL for introducing new types as subsets of existing

2656 types;

2659 $Id$