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NEWS

author | wenzelm |

Fri Mar 24 13:48:01 2000 +0100 (2000-03-24) | |

changeset 8566 | 30261b1917b5 |

parent 8534 | fdbabfbc3829 |

child 8570 | 63d4f3ea2e70 |

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

usedir -D: update styles;

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: the constant for f``x is now "image" rather than "op ``".

12 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;

14 * ML: PureThy.add_thms/add_axioms/add_defs return theorems as well;

17 *** Document preparation ***

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

20 including proper document sources;

22 * generated LaTeX sources are now deleted after successful run

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

24 of isatool usedir;

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

27 style files, achieving self-contained LaTeX sources;

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

32 *** Isar ***

34 * Pure now provides its own version of intro/elim/dest attributes;

35 useful for building new logics, but beware of confusion with the

36 Provers/classical ones;

38 * Pure: new 'obtain' language element supports generalized elimination

39 proofs;

41 * Pure: scalable support for case-analysis type proofs: new 'case'

42 language element refers to local contexts symbolically, as produced by

43 certain proof methods; internally, case names are attached to theorems

44 as "tags";

46 * Provers: splitter support (via 'split' attribute and 'simp' method

47 modifier); 'simp' method: 'only:' modifier removes loopers as well

48 (including splits);

50 * HOL: new proof method 'cases' and improved version of 'induct' now

51 support named cases; major packages (inductive, datatype, primrec,

52 recdef) support case names and properly name parameters;

54 * HOL: removed 'case_split' thm binding, should use 'cases' proof

55 method anyway;

57 * names of theorems etc. may be natural numbers as well;

59 * Provers: intro/elim/dest attributes: changed ! / !! flags to ? / ??;

61 * 'pr' command: optional goals_limit argument;

63 * diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit

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

65 proof state according to the Isabelle LaTeX style;

67 * improved support for emulating tactic scripts, including proof

68 methods 'tactic', 'res_inst_tac' etc., 'subgoal_tac', and 'case_tac' /

69 'induct_tac' (for HOL datatypes);

73 *** HOL ***

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

76 Clemens Ballarin;

78 * HOL/record: fixed select-update simplification procedure to handle

79 extended records as well; admit "r" as field name;

81 * HOL/ex: new theory Factorization proving the Fundamental Theorem of

82 Arithmetic, by Thomas M Rasmussen;

84 * new version of "case_tac" subsumes both boolean case split and

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

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

89 *** General ***

91 * compression of ML heaps images may now be controlled via -c option

92 of isabelle and isatool usedir (currently only observed by Poly/ML);

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

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

99 New in Isabelle99 (October 1999)

100 --------------------------------

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

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

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

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

108 Delcongs [if_weak_cong];

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

111 complement;

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

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

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

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

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

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

122 to constants declared in the same theory;

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

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

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

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

130 * Simplifier: the type of the infix ML functions

131 setSSolver addSSolver setSolver addSolver

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

133 for packaging solvers. A solver is created via

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

135 where the string argument is only a comment.

138 *** Proof tools ***

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

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

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

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

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

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

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

148 matching.

151 *** General ***

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

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

155 interface it offers an interactive environment for developing human

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

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

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

160 * improved presentation of theories: better HTML markup (including

161 colors), graph views in several sizes; isatool usedir now provides a

162 proper interface for user theories (via -P option); actual document

163 preparation based on (PDF)LaTeX is available as well (for new-style

164 theories only); see isatool doc system for more information;

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

167 Isabelle/Isar;

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

170 using the graph browser tool;

172 * Isabelle manuals now also available as PDF;

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

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

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

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

178 isatool doc ref);

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

181 option -p DIR installs standalone binaries;

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

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

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

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

188 Isabelle;

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

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

193 empty;

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

196 long arrows);

198 * new print_mode "HTML";

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

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

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

204 mode and goal output format:

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

207 244c244

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

209 ---

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

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

212 181c181

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

214 ---

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

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

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

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

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

223 result still apply;

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

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

229 *** HOL ***

231 ** HOL arithmetic **

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

234 int:

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

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

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

239 are ignored; quantified subformulae are ignored unless they are

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

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

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

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

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

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

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

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

249 simplifier.

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

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

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

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

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

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

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

259 type constraints;

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

262 arguments;

264 * many properties of integer multiplication, division and remainder

265 are now available;

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

268 tactic svc_tac. Propositional tautologies and theorems of linear arithmetic

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

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

271 invocation of the underlying oracle). For SVC see

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

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

277 ** HOL misc **

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

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

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

283 analysis for assembly languages with subtypes;

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

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

287 temporal levels more uniformly; introduces INCOMPATIBILITIES due to

288 changed syntax and (many) tactics;

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

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

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

293 "mono" attribute);

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

296 (using function types) such as

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

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

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

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

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

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

306 Delsimprocs [record_simproc]

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

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

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

312 names rather than an ML expression;

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

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

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

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

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

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

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

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

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

325 the original Gordon/HOL-style output;

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

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

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

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

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

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

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

337 thus available for user theories;

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

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

341 time;

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

344 several times and then mp;

347 *** LK ***

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

350 formulas;

352 * the simplifier is now installed

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

356 * the classical reasoner now has a default rule database

359 *** ZF ***

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

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

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

365 analysis) over datatypes and the natural numbers;

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

369 * simplification automatically does freeness reasoning for datatype

370 constructors;

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

373 type-checking rules;

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

376 to the claset;

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

379 if(P,x,y);

382 *** Internal programming interfaces ***

384 * tuned simplifier trace output; new flag debug_simp;

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

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

389 * AxClass.axclass_tac lost the theory argument;

391 * tuned current_goals_markers semantics: begin / end goal avoids

392 printing empty lines;

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

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

396 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:

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

399 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to

400 plain output, interface builders may have to enable 'isabelle_font'

401 mode to get Isabelle font glyphs as before;

403 * refined token_translation interface; INCOMPATIBILITY: output length

404 now of type real instead of int;

406 * theory loader actions may be traced via new ThyInfo.add_hook

407 interface (see src/Pure/Thy/thy_info.ML); example application: keep

408 your own database of information attached to *whole* theories -- as

409 opposed to intra-theory data slots offered via TheoryDataFun;

411 * proper handling of dangling sort hypotheses (at last!);

412 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing

413 extra sort hypotheses that can be witnessed from the type signature;

414 the force_strip_shyps flag is gone, any remaining shyps are simply

415 left in the theorem (with a warning issued by strip_shyps_warning);

419 New in Isabelle98-1 (October 1998)

420 ----------------------------------

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

424 * several changes of automated proof tools;

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

427 some minor incompatibilities of theory syntax;

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

430 called `inj_on';

432 * HOL: removed duplicate thms in Arith:

433 less_imp_add_less should be replaced by trans_less_add1

434 le_imp_add_le should be replaced by trans_le_add1

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

437 required);

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

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

441 now taken as an integer constant.

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

446 *** Proof tools ***

448 * Simplifier:

449 1. Asm_full_simp_tac is now more aggressive.

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

451 simplify.

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

453 rotate premises to achieve further simplification.

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

455 old Asm_full_simp_tac in that it does not rotate premises.

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

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

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

460 wrapper functionals. This implies that addbefore, addSbefore,

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

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

463 one (emitting a warning).

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

465 setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by

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

467 delWrapper, delSWrapper: claset * string -> claset

468 getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;

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

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

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

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

474 by Force_tac;

476 * Classical reasoner: setwrapper to setWrapper and compwrapper to

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

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

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

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

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

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

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

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

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

487 split_all_tac for record fields.

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

490 permanently to the default simpset using Addsplits just like

491 Addsimps. They can be removed via Delsplits just like

492 Delsimps. Lower-case versions are also available.

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

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

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

497 either remove split_if completely from the default simpset by

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

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

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

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

502 t is the name of the datatype).

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

505 derivatives Force_tac, force) combines rewriting and classical

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

507 aimed to solve the given subgoal completely.

510 *** General ***

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

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

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

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

516 recommended to convert to these new commands using isatool fixgoal

517 (backup your sources first!);

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

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

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

523 definitions that have local scope;

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

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

528 (e.g. package initialization);

530 * the distribution now includes Isabelle icons: see

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

533 * isatool install - install binaries with absolute references to

534 ISABELLE_HOME/bin;

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

538 * print mode 'emacs' reserved for Isamode;

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

542 * theorems involving oracles are now printed with a suffixed [!];

545 *** HOL ***

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

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

550 definitions such as

552 inductive EVEN ODD

553 intrs

554 null "0 : EVEN"

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

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

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

559 recursive sets; inductive definitions now handle disjunctive premises

560 correctly (also ZF);

562 INCOMPATIBILITIES: requires Inductive as an ancestor; component

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

564 contained in "induct";

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

568 supports mutually recursive datatypes such as

570 datatype

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

572 | SUM ('a aexp) ('a aexp)

573 | DIFF ('a aexp) ('a aexp)

574 | NUM 'a

575 and

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

577 | AND ('a bexp) ('a bexp)

578 | OR ('a bexp) ('a bexp)

580 as well as indirectly recursive datatypes such as

582 datatype

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

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

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

587 induction on mutually / indirectly recursive datatypes.

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

590 <function_name>.simps.

592 INCOMPATIBILITIES:

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

595 ancestor.

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

597 generic induct_tac instead.

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

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

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

601 may cause some "fragile" proofs to fail.

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

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

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

605 some datatype definitions may have to be annotated with explicit

606 sort constraints.

607 - Primrec definitions no longer require function name and type

608 of recursive argument.

610 Consider using isatool fixdatatype to adapt your theories and proof

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

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

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

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

617 support is as follows:

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

620 constructor terms) are part of the standard simpset;

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

623 made part of standard simpset and claset via addIffs;

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

626 the standard claset (addSWrapper);

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

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

630 the name of your record type.

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

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

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

637 blow up into some record constructor term, consequently the

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

639 solve record problems automatically.

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

643 default; theory Main includes everything;

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

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

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

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

653 * expand_if, expand_split, expand_sum_case and expand_nat_case are now

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

655 with add/delsplits);

657 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting

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

659 MAKE EXISTING PROOFS FAIL under rare circumstances (consider

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

661 unit_abs_eta_conv is added in order to counter the effect of

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

663 %u.f();

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

666 makes more sense);

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

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

670 disjointness reasoning but breaking a few old proofs.

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

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

674 literature);

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

677 the well-founded relation;

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

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

681 release ONLY.

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

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

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

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

689 * HOL/List:

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

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

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

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

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

695 - new lexicographic orderings and corresponding wellfoundedness theorems.

697 * HOL/Arith:

698 - removed 'pred' (predecessor) function;

699 - generalized some theorems about n-1;

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

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

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

704 instead of "inverse";

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

707 of the multiset ordering;

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

710 (not included by default);

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

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

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

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

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

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

722 *** ZF ***

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

725 only the theorems proved on ZF.ML;

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

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

729 disjointness reasoning but breaking a few old proofs.

731 * ZF/Update: new theory of function updates

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

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

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

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

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

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

741 * case_tac provided for compatibility with HOL

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

745 *** Internal programming interfaces ***

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

748 also src/Pure/README;

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

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

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

753 print_data function becomes basically useless;

755 * removed global_names compatibility flag -- all theory declarations

756 are qualified by default;

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

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

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

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

763 cterm -> thm;

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

766 subgoal;

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

770 * standard print function for goals supports current_goals_markers

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

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

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

774 for example;

778 New in Isabelle98 (January 1998)

779 --------------------------------

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

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

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

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

787 simpset / simpset_ref;

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

790 implicit merge of thms' signatures;

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

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

797 *** General Changes ***

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

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

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

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

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

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

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

806 backward campatibility problems try setting 'global_names' at compile

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

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

809 section;

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

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

813 replaced by functions simpset:unit->simpset and

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

815 to patch your ML files accordingly;

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

818 applet or isatool browser; data generated automatically via isatool

819 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);

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

822 conditional equations;

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

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

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

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

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

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

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

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

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

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

838 show_types);

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

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

844 * removed old README and Makefiles;

846 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;

848 * removed obsolete init_pps and init_database;

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

851 fun STATE tacfun st = tacfun st st;

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

854 (which abbreviates $HOME);

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

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

858 qualified references to the Sequence structure only!);

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

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

864 *** Classical Reasoner ***

866 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new

867 tactics that use classical reasoning to simplify a subgoal without

868 splitting it into several subgoals;

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

873 *** Simplifier ***

875 * added simplification meta rules:

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

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

879 logics (again);

881 * added prems argument to simplification procedures;

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

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

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

888 *** Syntax ***

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

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

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

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

899 *** HOL ***

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

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

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

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

907 protocol TLS;

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

911 * HOL/simplifier: simplification procedures nat_cancel_sums for

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

913 differences; simplification procedures nat_cancel_factor for

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

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

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

918 * HOL/simplifier: terms of the form

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

920 are rewritten to

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

922 and those of the form

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

924 are rewritten to

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

927 * HOL/datatype

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

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

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

932 ...

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

934 )

936 and a theorem `split_t_case_asm' of the form

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

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

940 ...

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

942 )

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

944 expand_list_case and expand_option_case have been renamed to

945 split_list_case and split_option_case.

947 * HOL/Arithmetic:

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

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

950 because it will disappear altogether at some point.

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

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

953 `standard'.

955 * HOL/Lists:

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

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

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

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

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

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

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

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

967 still lacks various theorems and concrete record syntax;

970 *** HOLCF ***

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

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

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

977 * domain package:

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

979 . creates hierachical name space,

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

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

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

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

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

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

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

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

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

993 *** FOL and ZF ***

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

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

998 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as

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

1003 New in Isabelle94-8 (May 1997)

1004 ------------------------------

1006 *** General Changes ***

1008 * new utilities to build / run / maintain Isabelle etc. (in parts

1009 still somewhat experimental); old Makefiles etc. still functional;

1011 * new 'Isabelle System Manual';

1013 * INSTALL text, together with ./configure and ./build scripts;

1015 * reimplemented type inference for greater efficiency, better error

1016 messages and clean internal interface;

1018 * prlim command for dealing with lots of subgoals (an easier way of

1019 setting goals_limit);

1022 *** Syntax ***

1024 * supports alternative (named) syntax tables (parser and pretty

1025 printer); internal interface is provided by add_modesyntax(_i);

1027 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to

1028 be used in conjunction with the Isabelle symbol font; uses the

1029 "symbols" syntax table;

1031 * added token_translation interface (may translate name tokens in

1032 arbitrary ways, dependent on their type (free, bound, tfree, ...) and

1033 the current print_mode); IMPORTANT: user print translation functions

1034 are responsible for marking newly introduced bounds

1035 (Syntax.mark_boundT);

1037 * token translations for modes "xterm" and "xterm_color" that display

1038 names in bold, underline etc. or colors (which requires a color

1039 version of xterm);

1041 * infixes may now be declared with names independent of their syntax;

1043 * added typed_print_translation (like print_translation, but may

1044 access type of constant);

1047 *** Classical Reasoner ***

1049 Blast_tac: a new tactic! It is often more powerful than fast_tac, but has

1050 some limitations. Blast_tac...

1051 + ignores addss, addbefore, addafter; this restriction is intrinsic

1052 + ignores elimination rules that don't have the correct format

1053 (the conclusion MUST be a formula variable)

1054 + ignores types, which can make HOL proofs fail

1055 + rules must not require higher-order unification, e.g. apply_type in ZF

1056 [message "Function Var's argument not a bound variable" relates to this]

1057 + its proof strategy is more general but can actually be slower

1059 * substitution with equality assumptions no longer permutes other

1060 assumptions;

1062 * minor changes in semantics of addafter (now called addaltern); renamed

1063 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper

1064 (and access functions for it);

1066 * improved combination of classical reasoner and simplifier:

1067 + functions for handling clasimpsets

1068 + improvement of addss: now the simplifier is called _after_ the

1069 safe steps.

1070 + safe variant of addss called addSss: uses safe simplifications

1071 _during_ the safe steps. It is more complete as it allows multiple

1072 instantiations of unknowns (e.g. with slow_tac).

1074 *** Simplifier ***

1076 * added interface for simplification procedures (functions that

1077 produce *proven* rewrite rules on the fly, depending on current

1078 redex);

1080 * ordering on terms as parameter (used for ordered rewriting);

1082 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;

1084 * the solver is now split into a safe and an unsafe part.

1085 This should be invisible for the normal user, except that the

1086 functions setsolver and addsolver have been renamed to setSolver and

1087 addSolver; added safe_asm_full_simp_tac;

1090 *** HOL ***

1092 * a generic induction tactic `induct_tac' which works for all datatypes and

1093 also for type `nat';

1095 * a generic case distinction tactic `exhaust_tac' which works for all

1096 datatypes and also for type `nat';

1098 * each datatype comes with a function `size';

1100 * patterns in case expressions allow tuple patterns as arguments to

1101 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';

1103 * primrec now also works with type nat;

1105 * recdef: a new declaration form, allows general recursive functions to be

1106 defined in theory files. See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.

1108 * the constant for negation has been renamed from "not" to "Not" to

1109 harmonize with FOL, ZF, LK, etc.;

1111 * HOL/ex/LFilter theory of a corecursive "filter" functional for

1112 infinite lists;

1114 * HOL/Modelcheck demonstrates invocation of model checker oracle;

1116 * HOL/ex/Ring.thy declares cring_simp, which solves equational

1117 problems in commutative rings, using axiomatic type classes for + and *;

1119 * more examples in HOL/MiniML and HOL/Auth;

1121 * more default rewrite rules for quantifiers, union/intersection;

1123 * a new constant `arbitrary == @x.False';

1125 * HOLCF/IOA replaces old HOL/IOA;

1127 * HOLCF changes: derived all rules and arities

1128 + axiomatic type classes instead of classes

1129 + typedef instead of faking type definitions

1130 + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.

1131 + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po

1132 + eliminated the types void, one, tr

1133 + use unit lift and bool lift (with translations) instead of one and tr

1134 + eliminated blift from Lift3.thy (use Def instead of blift)

1135 all eliminated rules are derived as theorems --> no visible changes ;

1138 *** ZF ***

1140 * ZF now has Fast_tac, Simp_tac and Auto_tac. Union_iff is a now a default

1141 rewrite rule; this may affect some proofs. eq_cs is gone but can be put back

1142 as ZF_cs addSIs [equalityI];

1146 New in Isabelle94-7 (November 96)

1147 ---------------------------------

1149 * allowing negative levels (as offsets) in prlev and choplev;

1151 * super-linear speedup for large simplifications;

1153 * FOL, ZF and HOL now use miniscoping: rewriting pushes

1154 quantifications in as far as possible (COULD MAKE EXISTING PROOFS

1155 FAIL); can suppress it using the command Delsimps (ex_simps @

1156 all_simps); De Morgan laws are also now included, by default;

1158 * improved printing of ==> : ~:

1160 * new object-logic "Sequents" adds linear logic, while replacing LK

1161 and Modal (thanks to Sara Kalvala);

1163 * HOL/Auth: correctness proofs for authentication protocols;

1165 * HOL: new auto_tac combines rewriting and classical reasoning (many

1166 examples on HOL/Auth);

1168 * HOL: new command AddIffs for declaring theorems of the form P=Q to

1169 the rewriter and classical reasoner simultaneously;

1171 * function uresult no longer returns theorems in "standard" format;

1172 regain previous version by: val uresult = standard o uresult;

1176 New in Isabelle94-6

1177 -------------------

1179 * oracles -- these establish an interface between Isabelle and trusted

1180 external reasoners, which may deliver results as theorems;

1182 * proof objects (in particular record all uses of oracles);

1184 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;

1186 * "constdefs" section in theory files;

1188 * "primrec" section (HOL) no longer requires names;

1190 * internal type "tactic" now simply "thm -> thm Sequence.seq";

1194 New in Isabelle94-5

1195 -------------------

1197 * reduced space requirements;

1199 * automatic HTML generation from theories;

1201 * theory files no longer require "..." (quotes) around most types;

1203 * new examples, including two proofs of the Church-Rosser theorem;

1205 * non-curried (1994) version of HOL is no longer distributed;

1209 New in Isabelle94-4

1210 -------------------

1212 * greatly reduced space requirements;

1214 * theory files (.thy) no longer require \...\ escapes at line breaks;

1216 * searchable theorem database (see the section "Retrieving theorems" on

1217 page 8 of the Reference Manual);

1219 * new examples, including Grabczewski's monumental case study of the

1220 Axiom of Choice;

1222 * The previous version of HOL renamed to Old_HOL;

1224 * The new version of HOL (previously called CHOL) uses a curried syntax

1225 for functions. Application looks like f a b instead of f(a,b);

1227 * Mutually recursive inductive definitions finally work in HOL;

1229 * In ZF, pattern-matching on tuples is now available in all abstractions and

1230 translates to the operator "split";

1234 New in Isabelle94-3

1235 -------------------

1237 * new infix operator, addss, allowing the classical reasoner to

1238 perform simplification at each step of its search. Example:

1239 fast_tac (cs addss ss)

1241 * a new logic, CHOL, the same as HOL, but with a curried syntax

1242 for functions. Application looks like f a b instead of f(a,b). Also pairs

1243 look like (a,b) instead of <a,b>;

1245 * PLEASE NOTE: CHOL will eventually replace HOL!

1247 * In CHOL, pattern-matching on tuples is now available in all abstractions.

1248 It translates to the operator "split". A new theory of integers is available;

1250 * In ZF, integer numerals now denote two's-complement binary integers.

1251 Arithmetic operations can be performed by rewriting. See ZF/ex/Bin.ML;

1253 * Many new examples: I/O automata, Church-Rosser theorem, equivalents

1254 of the Axiom of Choice;

1258 New in Isabelle94-2

1259 -------------------

1261 * Significantly faster resolution;

1263 * the different sections in a .thy file can now be mixed and repeated

1264 freely;

1266 * Database of theorems for FOL, HOL and ZF. New

1267 commands including qed, qed_goal and bind_thm store theorems in the database.

1269 * Simple database queries: return a named theorem (get_thm) or all theorems of

1270 a given theory (thms_of), or find out what theory a theorem was proved in

1271 (theory_of_thm);

1273 * Bugs fixed in the inductive definition and datatype packages;

1275 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs

1276 and HOL_dup_cs obsolete;

1278 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1

1279 have been removed;

1281 * Simpler definition of function space in ZF;

1283 * new results about cardinal and ordinal arithmetic in ZF;

1285 * 'subtype' facility in HOL for introducing new types as subsets of existing

1286 types;

1289 $Id$