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NEWS

author | wenzelm |

Sun Nov 29 13:15:17 1998 +0100 (1998-11-29) | |

changeset 5987 | 389d03e6e093 |

parent 5973 | 040f6d2af50d |

child 6014 | bfd4923b0957 |

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

eliminated "Trying to recover ..." msg;

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

13 *** Internal programming interfaces ***

15 * tuned current_goals_markers semantics: begin / end goal avoids

16 printing empty lines;

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

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

20 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:

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

24 New in Isabelle98-1 (October 1998)

25 ----------------------------------

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

29 * several changes of automated proof tools;

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

32 some minor incompatibilities of theory syntax;

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

35 called `inj_on';

37 * HOL: removed duplicate thms in Arith:

38 less_imp_add_less should be replaced by trans_less_add1

39 le_imp_add_le should be replaced by trans_le_add1

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

42 required);

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

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

46 now taken as an integer constant.

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

51 *** Proof tools ***

53 * Simplifier:

54 1. Asm_full_simp_tac is now more aggressive.

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

56 simplify.

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

58 rotate premises to achieve further simplification.

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

60 old Asm_full_simp_tac in that it does not rotate premises.

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

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

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

65 wrapper functionals. This implies that addbefore, addSbefore,

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

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

68 one (emitting a warning).

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

70 setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by

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

72 delWrapper, delSWrapper: claset * string -> claset

73 getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;

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

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

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

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

79 by Force_tac;

81 * Classical reasoner: setwrapper to setWrapper and compwrapper to

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

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

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

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

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

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

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

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

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

92 split_all_tac for record fields.

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

95 permanently to the default simpset using Addsplits just like

96 Addsimps. They can be removed via Delsplits just like

97 Delsimps. Lower-case versions are also available.

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

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

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

102 either remove split_if completely from the default simpset by

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

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

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

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

107 t is the name of the datatype).

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

110 derivatives Force_tac, force) combines rewriting and classical

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

112 aimed to solve the given subgoal completely.

115 *** General ***

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

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

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

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

121 recommended to convert to these new commands using isatool fixgoal

122 (backup your sources first!);

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

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

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

128 definitions that have local scope;

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

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

133 (e.g. package initialization);

135 * the distribution now includes Isabelle icons: see

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

138 * isatool install - install binaries with absolute references to

139 ISABELLE_HOME/bin;

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

143 * print mode 'emacs' reserved for Isamode;

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

148 *** HOL ***

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

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

153 definitions such as

155 inductive EVEN ODD

156 intrs

157 null "0 : EVEN"

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

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

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

162 recursive sets; inductive definitions now handle disjunctive premises

163 correctly (also ZF);

165 INCOMPATIBILITIES: requires Inductive as an ancestor; component

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

167 contained in "induct";

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

171 supports mutually recursive datatypes such as

173 datatype

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

175 | SUM ('a aexp) ('a aexp)

176 | DIFF ('a aexp) ('a aexp)

177 | NUM 'a

178 and

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

180 | AND ('a bexp) ('a bexp)

181 | OR ('a bexp) ('a bexp)

183 as well as indirectly recursive datatypes such as

185 datatype

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

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

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

190 induction on mutually / indirectly recursive datatypes.

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

193 <function_name>.simps.

195 INCOMPATIBILITIES:

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

198 ancestor.

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

200 generic induct_tac instead.

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

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

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

204 may cause some "fragile" proofs to fail.

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

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

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

208 some datatype definitions may have to be annotated with explicit

209 sort constraints.

210 - Primrec definitions no longer require function name and type

211 of recursive argument.

213 Consider using isatool fixdatatype to adapt your theories and proof

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

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

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

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

220 support is as follows:

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

223 constructor terms) are part of the standard simpset;

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

226 made part of standard simpset and claset via addIffs;

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

229 the standard claset (addSWrapper);

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

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

233 the name of your record type.

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

237 "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"

239 Thus any record variable that is bound by meta-all will automatically

240 blow up into some record constructor term, consequently the

241 simplifications of 1), 2) apply. Thus force_tac, auto_tac etc. shall

242 solve record problems automatically.

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

246 default; theory Main includes everything;

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

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

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

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

256 * expand_if, expand_split, expand_sum_case and expand_nat_case are now

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

258 with add/delsplits);

260 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting

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

262 MAKE EXISTING PROOFS FAIL under rare circumstances (consider

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

264 unit_abs_eta_conv is added in order to counter the effect of

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

266 %u.f();

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

269 makes more sense);

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

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

273 disjointness reasoning but breaking a few old proofs.

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

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

277 literature);

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

280 the well-founded relation;

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

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

284 release ONLY.

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

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

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

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

292 * HOL/List:

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

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

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

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

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

298 - new lexicographic orderings and corresponding wellfoundedness theorems.

300 * HOL/Arith:

301 - removed 'pred' (predecessor) function;

302 - generalized some theorems about n-1;

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

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

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

307 instead of "inverse";

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

310 of the multiset ordering;

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

313 (not included by default);

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

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

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

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

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

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

325 *** ZF ***

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

328 only the theorems proved on ZF.ML;

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

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

332 disjointness reasoning but breaking a few old proofs.

334 * ZF/Update: new theory of function updates

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

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

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

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

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

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

344 * case_tac provided for compatibility with HOL

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

348 *** Internal programming interfaces ***

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

351 also src/Pure/README;

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

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

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

356 print_data function becomes basically useless;

358 * removed global_names compatibility flag -- all theory declarations

359 are qualified by default;

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

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

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

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

366 cterm -> thm;

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

369 subgoal;

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

373 * standard print function for goals supports current_goals_markers

374 variable for marking begin of proof, end of proof, start of goal; the

375 default is ("", "", ""); setting current_goals_markers := ("<proof>",

376 "</proof>", "<goal>") causes SGML like tagged proof state printing,

377 for example;

381 New in Isabelle98 (January 1998)

382 --------------------------------

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

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

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

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

390 simpset / simpset_ref;

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

393 implicit merge of thms' signatures;

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

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

400 *** General Changes ***

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

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

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

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

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

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

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

409 backward campatibility problems try setting 'global_names' at compile

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

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

412 section;

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

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

416 replaced by functions simpset:unit->simpset and

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

418 to patch your ML files accordingly;

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

421 applet or isatool browser; data generated automatically via isatool

422 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);

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

425 conditional equations;

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

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

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

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

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

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

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

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

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

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

441 show_types);

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

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

447 * removed old README and Makefiles;

449 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;

451 * removed obsolete init_pps and init_database;

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

454 fun STATE tacfun st = tacfun st st;

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

457 (which abbreviates $HOME);

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

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

461 qualified references to the Sequence structure only!);

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

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

467 *** Classical Reasoner ***

469 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new

470 tactics that use classical reasoning to simplify a subgoal without

471 splitting it into several subgoals;

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

476 *** Simplifier ***

478 * added simplification meta rules:

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

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

482 logics (again);

484 * added prems argument to simplification procedures;

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

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

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

491 *** Syntax ***

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

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

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

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

502 *** HOL ***

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

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

510 protocol TLS;

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

514 * HOL/simplifier: simplification procedures nat_cancel_sums for

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

516 differences; simplification procedures nat_cancel_factor for

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

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

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

521 * HOL/simplifier: terms of the form

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

523 are rewritten to

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

525 and those of the form

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

527 are rewritten to

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

530 * HOL/datatype

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

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

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

535 ...

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

537 )

539 and a theorem `split_t_case_asm' of the form

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

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

543 ...

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

545 )

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

547 expand_list_case and expand_option_case have been renamed to

548 split_list_case and split_option_case.

550 * HOL/Arithmetic:

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

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

553 because it will disappear altogether at some point.

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

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

556 `standard'.

558 * HOL/Lists:

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

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

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

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

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

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

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

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

570 still lacks various theorems and concrete record syntax;

573 *** HOLCF ***

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

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

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

580 * domain package:

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

582 . creates hierachical name space,

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

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

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

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

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

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

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

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

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

596 *** FOL and ZF ***

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

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

601 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as

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

606 New in Isabelle94-8 (May 1997)

607 ------------------------------

609 *** General Changes ***

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

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

614 * new 'Isabelle System Manual';

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

618 * reimplemented type inference for greater efficiency, better error

619 messages and clean internal interface;

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

622 setting goals_limit);

625 *** Syntax ***

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

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

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

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

632 "symbols" syntax table;

634 * added token_translation interface (may translate name tokens in

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

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

637 are responsible for marking newly introduced bounds

638 (Syntax.mark_boundT);

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

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

642 version of xterm);

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

646 * added typed_print_translation (like print_translation, but may

647 access type of constant);

650 *** Classical Reasoner ***

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

653 some limitations. Blast_tac...

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

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

656 (the conclusion MUST be a formula variable)

657 + ignores types, which can make HOL proofs fail

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

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

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

662 * substitution with equality assumptions no longer permutes other

663 assumptions;

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

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

667 (and access functions for it);

669 * improved combination of classical reasoner and simplifier:

670 + functions for handling clasimpsets

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

672 safe steps.

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

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

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

677 *** Simplifier ***

679 * added interface for simplification procedures (functions that

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

681 redex);

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

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

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

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

689 functions setsolver and addsolver have been renamed to setSolver and

690 addSolver; added safe_asm_full_simp_tac;

693 *** HOL ***

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

696 also for type `nat';

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

699 datatypes and also for type `nat';

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

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

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

706 * primrec now also works with type nat;

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

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

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

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

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

715 infinite lists;

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

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

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

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

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

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

728 * HOLCF/IOA replaces old HOL/IOA;

730 * HOLCF changes: derived all rules and arities

731 + axiomatic type classes instead of classes

732 + typedef instead of faking type definitions

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

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

735 + eliminated the types void, one, tr

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

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

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

741 *** ZF ***

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

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

745 as ZF_cs addSIs [equalityI];

749 New in Isabelle94-7 (November 96)

750 ---------------------------------

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

754 * super-linear speedup for large simplifications;

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

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

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

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

761 * improved printing of ==> : ~:

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

764 and Modal (thanks to Sara Kalvala);

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

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

769 examples on HOL/Auth);

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

772 the rewriter and classical reasoner simultaneously;

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

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

779 New in Isabelle94-6

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

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

783 external reasoners, which may deliver results as theorems;

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

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

789 * "constdefs" section in theory files;

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

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

797 New in Isabelle94-5

798 -------------------

800 * reduced space requirements;

802 * automatic HTML generation from theories;

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

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

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

812 New in Isabelle94-4

813 -------------------

815 * greatly reduced space requirements;

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

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

820 page 8 of the Reference Manual);

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

823 Axiom of Choice;

825 * The previous version of HOL renamed to Old_HOL;

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

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

830 * Mutually recursive inductive definitions finally work in HOL;

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

833 translates to the operator "split";

837 New in Isabelle94-3

838 -------------------

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

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

842 fast_tac (cs addss ss)

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

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

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

848 * PLEASE NOTE: CHOL will eventually replace HOL!

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

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

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

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

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

857 of the Axiom of Choice;

861 New in Isabelle94-2

862 -------------------

864 * Significantly faster resolution;

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

867 freely;

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

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

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

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

874 (theory_of_thm);

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

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

879 and HOL_dup_cs obsolete;

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

882 have been removed;

884 * Simpler definition of function space in ZF;

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

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

889 types;

892 $Id$