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NEWS

author | nipkow |

Fri Oct 16 08:48:05 1998 +0200 (1998-10-16) | |

changeset 5651 | ca45d6126c8a |

parent 5650 | 38bda28c68a2 |

child 5657 | 1a6c9c6a3f8e |

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

*** empty log message ***

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

23 * HOL: unary - is now overloaded (new type constraints may be required);

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

26 expressions such as n#-1 must be changed to n#- 1, since #-1 is now taken

27 as an integer constant.

29 * Pure: ML function 'theory_of' replaced by 'theory';

32 *** Proof tools ***

34 * Simplifier: Asm_full_simp_tac is now more aggressive.

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

36 simplify.

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

38 rotate premises to achieve further simplification.

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

40 old Asm_full_simp_tac in that it does not rotate premises.

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

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

44 wrapper functionals. This implies that addbefore, addSbefore,

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

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

47 one (emitting a warning).

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

49 setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by

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

51 delWrapper, delSWrapper: claset * string -> claset

52 getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;

54 * Classical reasoner: addbefore / addSbefore now have APPEND / ORELSE semantics;

55 addbefore now affects only the unsafe part of step_tac etc.;

56 This affects addss/auto_tac/force_tac, so EXISTING (INSTABLE) PROOFS MAY FAIL, but

57 most proofs should be fixable easily, e.g. by replacing Auto_tac by Force_tac.

59 * Classical reasoner: setwrapper to setWrapper and compwrapper to compWrapper;

60 added safe wrapper (and access functions for it);

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

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

64 order and the names of the automatically generated variables have

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

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

67 more aggressively, and safe_tac and clarify_tac now split such

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

69 "split_all_tac".

71 * HOL/Simplifier:

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

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

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

76 also available.

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

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

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

81 split_if completely from the default simpset by `Delsplits

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

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

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

85 generates suitable rules `split_t_case' and `split_t_case_asm'

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

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

89 derivatives Force_tac, force) combines rewriting and classical

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

91 aimed to solve the given subgoal completely;

94 *** General ***

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

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

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

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

100 recommended to convert to these new commands using isatool fixgoal

101 (backup your sources first!);

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

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

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

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

109 (e.g. package initialization);

111 * the distribution now includes Isabelle icons: see

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

114 * isatool install - install binaries with absolute references to

115 ISABELLE_HOME/bin;

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

119 * print mode 'emacs' reserved for Isamode;

122 *** HOL ***

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

125 definitions such as

127 inductive EVEN ODD

128 intrs

129 null "0 : EVEN"

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

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

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

134 recursive sets; inductive definitions now handle disjunctive premises

135 correctly (also ZF);

137 INCOMPATIBILITIES: requires Inductive as an ancestor; component

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

139 contained in "induct";

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

143 supports mutually recursive datatypes such as

145 datatype

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

147 | SUM ('a aexp) ('a aexp)

148 | DIFF ('a aexp) ('a aexp)

149 | NUM 'a

150 and

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

152 | AND ('a bexp) ('a bexp)

153 | OR ('a bexp) ('a bexp)

155 as well as indirectly recursive datatypes such as

157 datatype

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

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

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

162 induction on mutually / indirectly recursive datatypes.

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

165 <function_name>.simps.

167 INCOMPATIBILITIES:

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

170 ancestor.

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

172 generic induct_tac instead.

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

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

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

176 may cause some "fragile" proofs to fail.

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

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

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

180 some datatype definitions may have to be annotated with explicit

181 sort constraints.

182 - Primrec definitions no longer require function name and type

183 of recursive argument.

185 Consider using isatool fixdatatype to adapt your theories and proof

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

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

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

191 pairing and split;

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

194 default; theory Main includes everything;

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

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

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

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

204 * expand_if, expand_split, expand_sum_case and expand_nat_case are now

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

206 with add/delsplits);

208 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting

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

210 MAKE EXISTING PROOFS FAIL under rare circumstances (consider

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

212 unit_abs_eta_conv is added in order to counter the effect of

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

214 %u.f();

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

217 makes more sense);

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

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

221 disjointness reasoning but breaking a few old proofs.

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

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

225 literature);

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

228 the well-founded relation;

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

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

232 release ONLY.

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

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

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

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

240 * HOL/List:

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

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

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

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

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

246 - new lexicographic orderings and corresponding wellfoundedness theorems.

248 * HOL/Arith:

249 - removed 'pred' (predecessor) function;

250 - generalized some theorems about n-1;

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

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

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

255 instead of "inverse";

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

258 of the multiset ordering;

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

261 (not included by default);

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

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

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

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

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

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

273 *** ZF ***

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

276 only the theorems proved on ZF.ML;

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

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

280 disjointness reasoning but breaking a few old proofs.

282 * ZF/Update: new theory of function updates

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

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

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

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

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

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

292 * case_tac provided for compatibility with HOL

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

296 *** Internal programming interfaces ***

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

299 also src/Pure/README;

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

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

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

304 print_data function becomes basically useless;

306 * removed global_names compatibility flag -- all theory declarations

307 are qualified by default;

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

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

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

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

314 cterm -> thm;

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

317 subgoal;

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

323 New in Isabelle98 (January 1998)

324 --------------------------------

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

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

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

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

332 simpset / simpset_ref;

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

335 implicit merge of thms' signatures;

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

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

342 *** General Changes ***

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

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

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

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

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

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

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

351 backward campatibility problems try setting 'global_names' at compile

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

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

354 section;

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

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

358 replaced by functions simpset:unit->simpset and

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

360 to patch your ML files accordingly;

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

363 applet or isatool browser; data generated automatically via isatool

364 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);

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

367 conditional equations;

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

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

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

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

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

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

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

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

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

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

383 show_types);

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

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

389 * removed old README and Makefiles;

391 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;

393 * removed obsolete init_pps and init_database;

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

396 fun STATE tacfun st = tacfun st st;

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

399 (which abbreviates $HOME);

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

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

403 qualified references to the Sequence structure only!);

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

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

409 *** Classical Reasoner ***

411 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new

412 tactics that use classical reasoning to simplify a subgoal without

413 splitting it into several subgoals;

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

418 *** Simplifier ***

420 * added simplification meta rules:

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

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

424 logics (again);

426 * added prems argument to simplification procedures;

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

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

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

433 *** Syntax ***

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

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

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

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

444 *** HOL ***

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

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

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

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

452 protocol TLS;

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

456 * HOL/simplifier: simplification procedures nat_cancel_sums for

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

458 differences; simplification procedures nat_cancel_factor for

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

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

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

463 * HOL/simplifier: terms of the form

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

465 are rewritten to

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

467 and those of the form

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

469 are rewritten to

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

472 * HOL/datatype

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

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

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

477 ...

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

479 )

481 and a theorem `split_t_case_asm' of the form

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

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

485 ...

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

487 )

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

489 expand_list_case and expand_option_case have been renamed to

490 split_list_case and split_option_case.

492 * HOL/Arithmetic:

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

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

495 because it will disappear altogether at some point.

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

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

498 `standard'.

500 * HOL/Lists:

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

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

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

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

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

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

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

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

512 still lacks various theorems and concrete record syntax;

515 *** HOLCF ***

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

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

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

522 * domain package:

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

524 . creates hierachical name space,

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

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

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

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

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

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

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

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

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

538 *** FOL and ZF ***

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

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

543 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as

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

548 New in Isabelle94-8 (May 1997)

549 ------------------------------

551 *** General Changes ***

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

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

556 * new 'Isabelle System Manual';

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

560 * reimplemented type inference for greater efficiency, better error

561 messages and clean internal interface;

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

564 setting goals_limit);

567 *** Syntax ***

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

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

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

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

574 "symbols" syntax table;

576 * added token_translation interface (may translate name tokens in

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

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

579 are responsible for marking newly introduced bounds

580 (Syntax.mark_boundT);

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

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

584 version of xterm);

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

588 * added typed_print_translation (like print_translation, but may

589 access type of constant);

592 *** Classical Reasoner ***

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

595 some limitations. Blast_tac...

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

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

598 (the conclusion MUST be a formula variable)

599 + ignores types, which can make HOL proofs fail

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

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

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

604 * substitution with equality assumptions no longer permutes other

605 assumptions;

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

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

609 (and access functions for it);

611 * improved combination of classical reasoner and simplifier:

612 + functions for handling clasimpsets

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

614 safe steps.

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

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

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

619 *** Simplifier ***

621 * added interface for simplification procedures (functions that

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

623 redex);

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

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

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

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

631 functions setsolver and addsolver have been renamed to setSolver and

632 addSolver; added safe_asm_full_simp_tac;

635 *** HOL ***

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

638 also for type `nat';

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

641 datatypes and also for type `nat';

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

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

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

648 * primrec now also works with type nat;

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

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

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

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

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

657 infinite lists;

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

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

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

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

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

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

670 * HOLCF/IOA replaces old HOL/IOA;

672 * HOLCF changes: derived all rules and arities

673 + axiomatic type classes instead of classes

674 + typedef instead of faking type definitions

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

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

677 + eliminated the types void, one, tr

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

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

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

683 *** ZF ***

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

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

687 as ZF_cs addSIs [equalityI];

691 New in Isabelle94-7 (November 96)

692 ---------------------------------

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

696 * super-linear speedup for large simplifications;

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

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

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

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

703 * improved printing of ==> : ~:

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

706 and Modal (thanks to Sara Kalvala);

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

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

711 examples on HOL/Auth);

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

714 the rewriter and classical reasoner simultaneously;

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

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

721 New in Isabelle94-6

722 -------------------

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

725 external reasoners, which may deliver results as theorems;

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

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

731 * "constdefs" section in theory files;

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

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

739 New in Isabelle94-5

740 -------------------

742 * reduced space requirements;

744 * automatic HTML generation from theories;

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

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

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

754 New in Isabelle94-4

755 -------------------

757 * greatly reduced space requirements;

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

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

762 page 8 of the Reference Manual);

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

765 Axiom of Choice;

767 * The previous version of HOL renamed to Old_HOL;

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

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

772 * Mutually recursive inductive definitions finally work in HOL;

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

775 translates to the operator "split";

779 New in Isabelle94-3

780 -------------------

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

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

784 fast_tac (cs addss ss)

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

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

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

790 * PLEASE NOTE: CHOL will eventually replace HOL!

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

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

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

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

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

799 of the Axiom of Choice;

803 New in Isabelle94-2

804 -------------------

806 * Significantly faster resolution;

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

809 freely;

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

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

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

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

816 (theory_of_thm);

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

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

821 and HOL_dup_cs obsolete;

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

824 have been removed;

826 * Simpler definition of function space in ZF;

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

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

831 types;

834 $Id$