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NEWS

author | wenzelm |

Mon Aug 24 21:09:59 1998 +0200 (1998-08-24) | |

changeset 5373 | 57165d7271b5 |

parent 5363 | 0cf15843b82f |

child 5397 | 034ed25535b9 |

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

tuned;

2 Isabelle NEWS -- history user-relevant changes

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

5 New in this Isabelle version

6 ----------------------------

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

10 * several changes of proof tools;

12 * HOL: new version of inductive and datatype;

14 * HOL: major changes to the inductive and datatype packages;

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

17 called `inj_on';

19 * HOL: removed duplicate thms in Arith:

20 less_imp_add_less should be replaced by trans_less_add1

21 le_imp_add_le should be replaced by trans_le_add1

24 *** Proof tools ***

26 * Simplifier: Asm_full_simp_tac is now more aggressive.

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

28 simplify.

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

30 rotate premises to achieve further simplification.

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

32 old Asm_full_simp_tac in that it does not rotate premises.

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

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

36 wrapper functionals. This implies that addbefore, addSbefore,

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

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

39 one (emitting a warning).

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

41 setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by

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

43 delWrapper, delSWrapper: claset * string -> claset

44 getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;

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

47 to split. Existing (fragile) proofs may require adaption because the

48 order and the names of the automatically generated variables have

49 changed. split_all_tac has moved within claset() from unsafe wrappers

50 to safe wrappers, which means that !!-bound variables are split much

51 more aggressively, and safe_tac and clarify_tac now split such

52 variables. If this splitting is not appropriate, use delSWrapper

53 "split_all_tac".

55 * HOL/Simplifier:

57 - Rewrite rules for case distinctions can now be added permanently to

58 the default simpset using Addsplits just like Addsimps. They can be

59 removed via Delsplits just like Delsimps. Lower-case versions are

60 also available.

62 - The rule split_if is now part of the default simpset. This means

63 that the simplifier will eliminate all occurrences of if-then-else

64 in the conclusion of a goal. To prevent this, you can either remove

65 split_if completely from the default simpset by `Delsplits

66 [split_if]' or remove it in a specific call of the simplifier using

67 `... delsplits [split_if]'. You can also add/delete other case

68 splitting rules to/from the default simpset: every datatype

69 generates suitable rules `split_t_case' and `split_t_case_asm'

70 (where t is the name of the datatype).

72 * Classical reasoner - Simplifier combination: new force_tac (and

73 derivatives Force_tac, force) combines rewriting and classical

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

75 aimed to solve the given subgoal completely;

78 *** General ***

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

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

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

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

84 recommended to convert to these new commands using isatool fixgoal

85 (backup your sources first!);

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

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

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

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

93 (e.g. package initialization);

95 * the distribution now includes Isabelle icons: see

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

98 * isatool install - install binaries with absolute references to

99 ISABELLE_HOME/bin;

102 *** HOL ***

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

105 definitions such as

107 inductive EVEN ODD

108 intrs

109 null "0 : EVEN"

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

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

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

114 recursive sets; inductive definitions now handle disjunctive premises

115 correctly (also ZF);

117 INCOMPATIBILITIES: requires Inductive as an ancestor; component

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

119 contained in "induct";

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

123 supports mutually recursive datatypes such as

125 datatype

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

127 | SUM ('a aexp) ('a aexp)

128 | DIFF ('a aexp) ('a aexp)

129 | NUM 'a

130 and

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

132 | AND ('a bexp) ('a bexp)

133 | OR ('a bexp) ('a bexp)

135 as well as indirectly recursive datatypes such as

137 datatype

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

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

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

142 induction on mutually / indirectly recursive datatypes.

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

145 <function_name>.simps.

147 INCOMPATIBILITIES:

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

150 ancestor.

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

152 generic induct_tac instead.

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

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

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

156 may cause some "fragile" proofs to fail.

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

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

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

160 some datatype definitions may have to be annotated with explicit

161 sort constraints.

162 - Primrec definitions no longer require function name and type

163 of recursive argument.

165 Consider using isatool fixdatatype to adapt your theories and proof

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

169 * HOL/record package: now includes concrete syntax for record types,

170 terms, updates; still lacks important theorems, like surjective

171 pairing and split;

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

174 default; theory Main includes everything;

176 * added option_map_eq_Some to the default simpset claset;

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

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

182 * expand_if, expand_split, expand_sum_case and expand_nat_case are now

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

184 with add/delsplits);

186 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting

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

188 MAKE EXISTING PROOFS FAIL under rare circumstances (consider

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

190 unit_abs_eta_conv is added in order to counter the effect of

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

192 %u.f();

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

195 makes more sense);

197 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now called `equals0E' (the old name was misleading);

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

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

201 literature);

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

204 the well-founded relation;

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

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

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

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

212 * HOL/List:

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

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

215 - new lexicographic orderings and corresponding wellfoundedness theorems.

217 * HOL/Arith:

218 - removed 'pred' (predecessor) function;

219 - generalized some theorems about n-1;

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

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

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

224 instead of "inverse";

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

227 (not included by default);

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

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

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

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

236 *** ZF ***

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

239 only the theorems proved on ZF.ML;

241 * ZF INCOMPATIBILITY: rule `equals0D' is now called `equals0E' (the old name

242 was misleading). The rule and 'sym RS equals0E' are now in the default

243 claset, giving automatic disjointness reasoning but breaking a few old

244 proofs.

246 * ZF/Update: new theory of function updates

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

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

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

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

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

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

256 * case_tac provided for compatibility with HOL

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

260 *** Internal programming interfaces ***

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

263 also src/Pure/README;

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

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

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

268 print_data function becomes basically useless;

270 * removed global_names compatibility flag -- all theory declarations

271 are qualified by default;

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

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

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

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

278 cterm -> thm;

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

281 subgoal;

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

287 New in Isabelle98 (January 1998)

288 --------------------------------

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

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

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

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

296 simpset / simpset_ref;

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

299 implicit merge of thms' signatures;

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

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

306 *** General Changes ***

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

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

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

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

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

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

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

315 backward campatibility problems try setting 'global_names' at compile

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

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

318 section;

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

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

322 replaced by functions simpset:unit->simpset and

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

324 to patch your ML files accordingly;

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

327 applet or isatool browser; data generated automatically via isatool

328 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);

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

331 conditional equations;

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

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

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

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

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

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

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

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

344 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;

346 * print_goals: optional output of const types (set show_consts and

347 show_types);

349 * improved output of warnings (###) and errors (***);

351 * subgoal_tac displays a warning if the new subgoal has type variables;

353 * removed old README and Makefiles;

355 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;

357 * removed obsolete init_pps and init_database;

359 * deleted the obsolete tactical STATE, which was declared by

360 fun STATE tacfun st = tacfun st st;

362 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~

363 (which abbreviates $HOME);

365 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:

366 use isatool fixseq to adapt your ML programs (this works for fully

367 qualified references to the Sequence structure only!);

369 * use_thy no longer requires writable current directory; it always

370 reloads .ML *and* .thy file, if either one is out of date;

373 *** Classical Reasoner ***

375 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new

376 tactics that use classical reasoning to simplify a subgoal without

377 splitting it into several subgoals;

379 * Safe_tac: like safe_tac but uses the default claset;

382 *** Simplifier ***

384 * added simplification meta rules:

385 (asm_)(full_)simplify: simpset -> thm -> thm;

387 * simplifier.ML no longer part of Pure -- has to be loaded by object

388 logics (again);

390 * added prems argument to simplification procedures;

392 * HOL, FOL, ZF: added infix function `addsplits':

393 instead of `<simpset> setloop (split_tac <thms>)'

394 you can simply write `<simpset> addsplits <thms>'

397 *** Syntax ***

399 * TYPE('a) syntax for type reflection terms;

401 * no longer handles consts with name "" -- declare as 'syntax' instead;

403 * pretty printer: changed order of mixfix annotation preference (again!);

405 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;

408 *** HOL ***

410 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.

411 with `addloop' of the simplifier to faciliate case splitting in premises.

413 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;

415 * HOL/Auth: new protocol proofs including some for the Internet

416 protocol TLS;

418 * HOL/Map: new theory of `maps' a la VDM;

420 * HOL/simplifier: simplification procedures nat_cancel_sums for

421 cancelling out common nat summands from =, <, <= (in)equalities, or

422 differences; simplification procedures nat_cancel_factor for

423 cancelling common factor from =, <, <= (in)equalities over natural

424 sums; nat_cancel contains both kinds of procedures, it is installed by

425 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;

427 * HOL/simplifier: terms of the form

428 `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)' (or t=x)

429 are rewritten to

430 `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',

431 and those of the form

432 `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)' (or t=x)

433 are rewritten to

434 `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',

436 * HOL/datatype

437 Each datatype `t' now comes with a theorem `split_t_case' of the form

439 P(t_case f1 ... fn x) =

440 ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &

441 ...

442 (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))

443 )

445 and a theorem `split_t_case_asm' of the form

447 P(t_case f1 ... fn x) =

448 ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |

449 ...

450 (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))

451 )

452 which can be added to a simpset via `addsplits'. The existing theorems

453 expand_list_case and expand_option_case have been renamed to

454 split_list_case and split_option_case.

456 * HOL/Arithmetic:

457 - `pred n' is automatically converted to `n-1'.

458 Users are strongly encouraged not to use `pred' any longer,

459 because it will disappear altogether at some point.

460 - Users are strongly encouraged to write "0 < n" rather than

461 "n ~= 0". Theorems and proof tools have been modified towards this

462 `standard'.

464 * HOL/Lists:

465 the function "set_of_list" has been renamed "set" (and its theorems too);

466 the function "nth" now takes its arguments in the reverse order and

467 has acquired the infix notation "!" as in "xs!n".

469 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};

471 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its

472 specialist theorems (like UN1_I) are gone. Similarly for (INT x.B x);

474 * HOL/record: extensible records with schematic structural subtyping

475 (single inheritance); EXPERIMENTAL version demonstrating the encoding,

476 still lacks various theorems and concrete record syntax;

479 *** HOLCF ***

481 * removed "axioms" and "generated by" sections;

483 * replaced "ops" section by extended "consts" section, which is capable of

484 handling the continuous function space "->" directly;

486 * domain package:

487 . proves theorems immediately and stores them in the theory,

488 . creates hierachical name space,

489 . now uses normal mixfix annotations (instead of cinfix...),

490 . minor changes to some names and values (for consistency),

491 . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,

492 . separator between mutual domain defs: changed "," to "and",

493 . improved handling of sort constraints; now they have to

494 appear on the left-hand side of the equations only;

496 * fixed LAM <x,y,zs>.b syntax;

498 * added extended adm_tac to simplifier in HOLCF -- can now discharge

499 adm (%x. P (t x)), where P is chainfinite and t continuous;

502 *** FOL and ZF ***

504 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.

505 with `addloop' of the simplifier to faciliate case splitting in premises.

507 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as

508 in HOL, they strip ALL and --> from proved theorems;

512 New in Isabelle94-8 (May 1997)

513 ------------------------------

515 *** General Changes ***

517 * new utilities to build / run / maintain Isabelle etc. (in parts

518 still somewhat experimental); old Makefiles etc. still functional;

520 * new 'Isabelle System Manual';

522 * INSTALL text, together with ./configure and ./build scripts;

524 * reimplemented type inference for greater efficiency, better error

525 messages and clean internal interface;

527 * prlim command for dealing with lots of subgoals (an easier way of

528 setting goals_limit);

531 *** Syntax ***

533 * supports alternative (named) syntax tables (parser and pretty

534 printer); internal interface is provided by add_modesyntax(_i);

536 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to

537 be used in conjunction with the Isabelle symbol font; uses the

538 "symbols" syntax table;

540 * added token_translation interface (may translate name tokens in

541 arbitrary ways, dependent on their type (free, bound, tfree, ...) and

542 the current print_mode); IMPORTANT: user print translation functions

543 are responsible for marking newly introduced bounds

544 (Syntax.mark_boundT);

546 * token translations for modes "xterm" and "xterm_color" that display

547 names in bold, underline etc. or colors (which requires a color

548 version of xterm);

550 * infixes may now be declared with names independent of their syntax;

552 * added typed_print_translation (like print_translation, but may

553 access type of constant);

556 *** Classical Reasoner ***

558 Blast_tac: a new tactic! It is often more powerful than fast_tac, but has

559 some limitations. Blast_tac...

560 + ignores addss, addbefore, addafter; this restriction is intrinsic

561 + ignores elimination rules that don't have the correct format

562 (the conclusion MUST be a formula variable)

563 + ignores types, which can make HOL proofs fail

564 + rules must not require higher-order unification, e.g. apply_type in ZF

565 [message "Function Var's argument not a bound variable" relates to this]

566 + its proof strategy is more general but can actually be slower

568 * substitution with equality assumptions no longer permutes other

569 assumptions;

571 * minor changes in semantics of addafter (now called addaltern); renamed

572 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper

573 (and access functions for it);

575 * improved combination of classical reasoner and simplifier:

576 + functions for handling clasimpsets

577 + improvement of addss: now the simplifier is called _after_ the

578 safe steps.

579 + safe variant of addss called addSss: uses safe simplifications

580 _during_ the safe steps. It is more complete as it allows multiple

581 instantiations of unknowns (e.g. with slow_tac).

583 *** Simplifier ***

585 * added interface for simplification procedures (functions that

586 produce *proven* rewrite rules on the fly, depending on current

587 redex);

589 * ordering on terms as parameter (used for ordered rewriting);

591 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;

593 * the solver is now split into a safe and an unsafe part.

594 This should be invisible for the normal user, except that the

595 functions setsolver and addsolver have been renamed to setSolver and

596 addSolver; added safe_asm_full_simp_tac;

599 *** HOL ***

601 * a generic induction tactic `induct_tac' which works for all datatypes and

602 also for type `nat';

604 * a generic case distinction tactic `exhaust_tac' which works for all

605 datatypes and also for type `nat';

607 * each datatype comes with a function `size';

609 * patterns in case expressions allow tuple patterns as arguments to

610 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';

612 * primrec now also works with type nat;

614 * recdef: a new declaration form, allows general recursive functions to be

615 defined in theory files. See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.

617 * the constant for negation has been renamed from "not" to "Not" to

618 harmonize with FOL, ZF, LK, etc.;

620 * HOL/ex/LFilter theory of a corecursive "filter" functional for

621 infinite lists;

623 * HOL/Modelcheck demonstrates invocation of model checker oracle;

625 * HOL/ex/Ring.thy declares cring_simp, which solves equational

626 problems in commutative rings, using axiomatic type classes for + and *;

628 * more examples in HOL/MiniML and HOL/Auth;

630 * more default rewrite rules for quantifiers, union/intersection;

632 * a new constant `arbitrary == @x.False';

634 * HOLCF/IOA replaces old HOL/IOA;

636 * HOLCF changes: derived all rules and arities

637 + axiomatic type classes instead of classes

638 + typedef instead of faking type definitions

639 + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.

640 + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po

641 + eliminated the types void, one, tr

642 + use unit lift and bool lift (with translations) instead of one and tr

643 + eliminated blift from Lift3.thy (use Def instead of blift)

644 all eliminated rules are derived as theorems --> no visible changes ;

647 *** ZF ***

649 * ZF now has Fast_tac, Simp_tac and Auto_tac. Union_iff is a now a default

650 rewrite rule; this may affect some proofs. eq_cs is gone but can be put back

651 as ZF_cs addSIs [equalityI];

655 New in Isabelle94-7 (November 96)

656 ---------------------------------

658 * allowing negative levels (as offsets) in prlev and choplev;

660 * super-linear speedup for large simplifications;

662 * FOL, ZF and HOL now use miniscoping: rewriting pushes

663 quantifications in as far as possible (COULD MAKE EXISTING PROOFS

664 FAIL); can suppress it using the command Delsimps (ex_simps @

665 all_simps); De Morgan laws are also now included, by default;

667 * improved printing of ==> : ~:

669 * new object-logic "Sequents" adds linear logic, while replacing LK

670 and Modal (thanks to Sara Kalvala);

672 * HOL/Auth: correctness proofs for authentication protocols;

674 * HOL: new auto_tac combines rewriting and classical reasoning (many

675 examples on HOL/Auth);

677 * HOL: new command AddIffs for declaring theorems of the form P=Q to

678 the rewriter and classical reasoner simultaneously;

680 * function uresult no longer returns theorems in "standard" format;

681 regain previous version by: val uresult = standard o uresult;

685 New in Isabelle94-6

686 -------------------

688 * oracles -- these establish an interface between Isabelle and trusted

689 external reasoners, which may deliver results as theorems;

691 * proof objects (in particular record all uses of oracles);

693 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;

695 * "constdefs" section in theory files;

697 * "primrec" section (HOL) no longer requires names;

699 * internal type "tactic" now simply "thm -> thm Sequence.seq";

703 New in Isabelle94-5

704 -------------------

706 * reduced space requirements;

708 * automatic HTML generation from theories;

710 * theory files no longer require "..." (quotes) around most types;

712 * new examples, including two proofs of the Church-Rosser theorem;

714 * non-curried (1994) version of HOL is no longer distributed;

718 New in Isabelle94-4

719 -------------------

721 * greatly reduced space requirements;

723 * theory files (.thy) no longer require \...\ escapes at line breaks;

725 * searchable theorem database (see the section "Retrieving theorems" on

726 page 8 of the Reference Manual);

728 * new examples, including Grabczewski's monumental case study of the

729 Axiom of Choice;

731 * The previous version of HOL renamed to Old_HOL;

733 * The new version of HOL (previously called CHOL) uses a curried syntax

734 for functions. Application looks like f a b instead of f(a,b);

736 * Mutually recursive inductive definitions finally work in HOL;

738 * In ZF, pattern-matching on tuples is now available in all abstractions and

739 translates to the operator "split";

743 New in Isabelle94-3

744 -------------------

746 * new infix operator, addss, allowing the classical reasoner to

747 perform simplification at each step of its search. Example:

748 fast_tac (cs addss ss)

750 * a new logic, CHOL, the same as HOL, but with a curried syntax

751 for functions. Application looks like f a b instead of f(a,b). Also pairs

752 look like (a,b) instead of <a,b>;

754 * PLEASE NOTE: CHOL will eventually replace HOL!

756 * In CHOL, pattern-matching on tuples is now available in all abstractions.

757 It translates to the operator "split". A new theory of integers is available;

759 * In ZF, integer numerals now denote two's-complement binary integers.

760 Arithmetic operations can be performed by rewriting. See ZF/ex/Bin.ML;

762 * Many new examples: I/O automata, Church-Rosser theorem, equivalents

763 of the Axiom of Choice;

767 New in Isabelle94-2

768 -------------------

770 * Significantly faster resolution;

772 * the different sections in a .thy file can now be mixed and repeated

773 freely;

775 * Database of theorems for FOL, HOL and ZF. New

776 commands including qed, qed_goal and bind_thm store theorems in the database.

778 * Simple database queries: return a named theorem (get_thm) or all theorems of

779 a given theory (thms_of), or find out what theory a theorem was proved in

780 (theory_of_thm);

782 * Bugs fixed in the inductive definition and datatype packages;

784 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs

785 and HOL_dup_cs obsolete;

787 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1

788 have been removed;

790 * Simpler definition of function space in ZF;

792 * new results about cardinal and ordinal arithmetic in ZF;

794 * 'subtype' facility in HOL for introducing new types as subsets of existing

795 types;

798 $Id$