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NEWS

author | wenzelm |

Tue Jan 23 18:05:53 2001 +0100 (2001-01-23) | |

changeset 10966 | 8f2c27041a8e |

parent 10944 | 710ddb9e8b5e |

child 10976 | 0e7cf6f9fa29 |

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

added HOL-Unix example;

2 Isabelle NEWS -- history user-relevant changes

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

5 *** Overview of INCOMPATIBILITIES ***

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

8 operation;

10 * HOL: induct renamed to lfp_induct;

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

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

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

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

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

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

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

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

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

27 *** Document preparation ***

29 * improved isabelle style files; more abstract symbol implementation

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

31 definitions);

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

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

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

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

37 type-writer);

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

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

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

43 the complete list;

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

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

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

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

50 * isatool unsymbolize tunes sources for plain ASCII communication;

53 *** Isar ***

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

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

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

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

59 for Prolog-style synthesis of proven results;

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

62 rules as well;

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

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

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

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

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

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

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

73 statements as well;

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

76 rule (as well as the assumption rule);

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

79 lemmas, using the graph browser tool;

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

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

84 (potential INCOMPATIBILITY); tuned error handling;

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

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

88 any remaining facts are inserted into the goal verbatim;

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

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

92 the result to be shown in each case;

94 * HOL: added 'recdef_tc' command;

97 *** HOL ***

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

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

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

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

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

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

106 modelling and verification task performed in Isabelle/HOL +

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

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

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

111 operator;

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

114 HOL/subset.thy);

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

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

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

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

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

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

124 rules with string literals);

126 * HOL-Hyperreal: a new target, extending HOL-Real with the hyperreals

127 and Fleuriot's mechanization of analysis;

129 * HOL-Real, HOL-Hyperreals: improved arithmetic simplification;

132 *** CTT ***

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

135 "lam" is displayed as TWO lambda-symbols

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

138 and Arith);

141 *** General ***

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

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

146 * system: support Poly/ML 4.0 (current beta versions);

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

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

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

151 the Isabelle inference kernel has been greatly improved;

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

154 as assumptions as well;

158 New in Isabelle99-1 (October 2000)

159 ----------------------------------

161 *** Overview of INCOMPATIBILITIES ***

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

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

165 issue the following ML commands:

167 Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;

168 Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];

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

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

173 * HOL: nat_less_induct renamed to less_induct;

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

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

178 select_equality -> some_equality

179 select_eq_Ex -> some_eq_ex

180 selectI2EX -> someI2_ex

181 selectI2 -> someI2

182 selectI -> someI

183 select1_equality -> some1_equality

184 Eps_sym_eq -> some_sym_eq_trivial

185 Eps_eq -> some_eq_trivial

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

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

190 instead);

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

193 f.simps instead of f.rules;

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

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

198 sometimes be needed;

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

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

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

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

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

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

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

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

212 the old syntax may be recovered as follows:

214 syntax (symbols)

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

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

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

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

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

222 internally;

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

225 changed from A/r to A//r;

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

228 proofs;

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

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

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

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

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

236 "rule del";

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

240 * Provers: strengthened force_tac by using new first_best_tac;

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

243 lib/texinputs);

246 *** Document preparation ***

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

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

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

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

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

254 including proper document sources;

256 * generated LaTeX sources are now deleted after successful run

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

258 of isatool usedir;

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

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

262 LaTeX debugging;

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

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

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

268 graph for 'all sessions';

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

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

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

275 *** Isar ***

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

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

279 accommodates incremental type-inference very nicely;

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

282 generalized existence reasoning;

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

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

286 useful to collect intermediate results without explicit name

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

288 premises;

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

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

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

293 to theorems as "tags";

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

296 class/type/const name spaces;

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

299 indicate potential overloading;

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

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

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

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

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

308 with the version in Provers/classical;

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

311 case name 'antecedent';

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

314 to the current context is now done automatically);

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

317 for definining proof methods in ML;

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

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

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

322 replaced "delrule" by "rule del";

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

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

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

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

329 well (including splits);

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

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

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

335 of Simplifier and Classical reasoner);

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

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

339 recdef) support case names and properly name parameters;

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

342 monotonicity conditions are extracted to be proven at end of

343 calculations;

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

346 method anyway;

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

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

350 foo.split foo.split_asm for each datatype;

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

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

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

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

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

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

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

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

363 proof states;

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

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

367 proof state according to the Isabelle LaTeX style;

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

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

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

372 (for HOL datatypes);

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

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

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

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

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

381 should instead use individual commands for printing items

382 (print_commands, print_methods etc.);

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

387 *** HOL ***

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

390 corresponding virtual machine and a specification of its bytecode

391 verifier and a lightweight bytecode verifier, including proofs of

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

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

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

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

397 Clemens Ballarin;

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

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

401 Rasmussen;

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

404 structures, including duals, properties of bounds versus algebraic

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

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

407 for abstract algebraic reasoning using axiomatic type classes, and

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

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

411 von Oheimb;

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

414 recursive procedures, by David von Oheimb;

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

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

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

420 representation; very useful in avoiding lifting of operations;

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

423 select-update simplification procedure to handle extended records as

424 well; admit "r" as field name;

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

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

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

430 Types nat and int belong to this axclass;

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

456 termination conditions are proved automatically, these simplification

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

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

459 each equation;

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

462 permits the definition of tail-recursive functions without the

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

464 invariant proof rule for while is applied.

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

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

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

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

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

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

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

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

478 main HOL, but was unused);

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

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

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

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

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

486 bogus);

489 *** ZF ***

491 * ZF: simplification automatically cancels common terms in arithmetic

492 expressions over nat and int;

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

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

496 making the algebraic laws unconditional;

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

499 using the function intify;

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

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

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

505 simplification;

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

508 to the simplifier and classical reasoner simultaneously;

511 *** General ***

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

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

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

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

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

520 explicit make_elim);

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

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

524 use instead the strong form,

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

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

527 from destruct-rules;

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

530 Simplifier setup for new object-logics;

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

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

535 for hiding of names;

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

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

539 situations;

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

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

543 Poly/ML);

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

546 useful for remote X11);

548 * system: provide TAGS file for Isabelle sources;

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

551 order;

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

554 timing flag supersedes proof_timing and Toplevel.trace;

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

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

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

560 overloading (usually false);

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

563 results;

567 New in Isabelle99 (October 1999)

568 --------------------------------

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

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

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

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

576 Delcongs [if_weak_cong];

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

579 complement;

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

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

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

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

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

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

590 to constants declared in the same theory;

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

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

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

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

598 * Simplifier: the type of the infix ML functions

599 setSSolver addSSolver setSolver addSolver

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

601 for packaging solvers. A solver is created via

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

603 where the string argument is only a comment.

606 *** Proof tools ***

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

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

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

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

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

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

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

616 matching.

619 *** General ***

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

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

623 interface it offers an interactive environment for developing human

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

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

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

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

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

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

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

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

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

635 Isabelle/Isar;

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

638 using the graph browser tool;

640 * Isabelle manuals now also available as PDF;

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

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

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

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

646 isatool doc ref);

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

649 option -p DIR installs standalone binaries;

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

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

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

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

656 Isabelle;

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

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

661 empty;

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

664 long arrows);

666 * new print_mode "HTML";

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

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

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

672 mode and goal output format:

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

675 244c244

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

677 ---

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

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

680 181c181

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

682 ---

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

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

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

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

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

691 result still apply;

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

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

697 *** HOL ***

699 ** HOL arithmetic **

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

702 int:

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

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

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

707 are ignored; quantified subformulae are ignored unless they are

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

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

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

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

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

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

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

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

717 simplifier.

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

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

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

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

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

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

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

727 type constraints;

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

730 arguments;

732 * many properties of integer multiplication, division and remainder

733 are now available;

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

736 tactic svc_tac. Propositional tautologies and theorems of linear arithmetic

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

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

739 invocation of the underlying oracle). For SVC see

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

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

745 ** HOL misc **

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

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

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

751 analysis for assembly languages with subtypes;

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

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

755 temporal levels more uniformly; introduces INCOMPATIBILITIES due to

756 changed syntax and (many) tactics;

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

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

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

761 "mono" attribute);

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

764 (using function types) such as

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

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

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

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

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

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

774 Delsimprocs [record_simproc]

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

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

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

780 names rather than an ML expression;

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

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

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

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

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

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

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

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

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

793 the original Gordon/HOL-style output;

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

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

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

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

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

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

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

805 thus available for user theories;

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

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

809 time;

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

812 several times and then mp;

815 *** LK ***

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

818 formulas;

820 * the simplifier is now installed

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

824 * the classical reasoner now has a default rule database

827 *** ZF ***

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

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

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

833 analysis) over datatypes and the natural numbers;

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

837 * simplification automatically does freeness reasoning for datatype

838 constructors;

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

841 type-checking rules;

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

844 to the claset;

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

847 if(P,x,y);

850 *** Internal programming interfaces ***

852 * tuned simplifier trace output; new flag debug_simp;

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

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

857 * AxClass.axclass_tac lost the theory argument;

859 * tuned current_goals_markers semantics: begin / end goal avoids

860 printing empty lines;

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

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

864 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:

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

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

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

869 mode to get Isabelle font glyphs as before;

871 * refined token_translation interface; INCOMPATIBILITY: output length

872 now of type real instead of int;

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

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

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

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

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

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

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

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

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

887 New in Isabelle98-1 (October 1998)

888 ----------------------------------

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

892 * several changes of automated proof tools;

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

895 some minor incompatibilities of theory syntax;

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

898 called `inj_on';

900 * HOL: removed duplicate thms in Arith:

901 less_imp_add_less should be replaced by trans_less_add1

902 le_imp_add_le should be replaced by trans_le_add1

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

905 required);

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

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

909 now taken as an integer constant.

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

914 *** Proof tools ***

916 * Simplifier:

917 1. Asm_full_simp_tac is now more aggressive.

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

919 simplify.

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

921 rotate premises to achieve further simplification.

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

923 old Asm_full_simp_tac in that it does not rotate premises.

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

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

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

928 wrapper functionals. This implies that addbefore, addSbefore,

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

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

931 one (emitting a warning).

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

933 setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by

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

935 delWrapper, delSWrapper: claset * string -> claset

936 getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;

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

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

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

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

942 by Force_tac;

944 * Classical reasoner: setwrapper to setWrapper and compwrapper to

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

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

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

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

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

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

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

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

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

955 split_all_tac for record fields.

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

958 permanently to the default simpset using Addsplits just like

959 Addsimps. They can be removed via Delsplits just like

960 Delsimps. Lower-case versions are also available.

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

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

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

965 either remove split_if completely from the default simpset by

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

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

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

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

970 t is the name of the datatype).

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

973 derivatives Force_tac, force) combines rewriting and classical

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

975 aimed to solve the given subgoal completely.

978 *** General ***

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

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

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

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

984 recommended to convert to these new commands using isatool fixgoal

985 (backup your sources first!);

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

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

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

991 definitions that have local scope;

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

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

996 (e.g. package initialization);

998 * the distribution now includes Isabelle icons: see

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

1001 * isatool install - install binaries with absolute references to

1002 ISABELLE_HOME/bin;

1004 * isatool logo -- create instances of the Isabelle logo (as EPS);

1006 * print mode 'emacs' reserved for Isamode;

1008 * support multiple print (ast) translations per constant name;

1010 * theorems involving oracles are now printed with a suffixed [!];

1013 *** HOL ***

1015 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');

1017 * HOL/inductive package reorganized and improved: now supports mutual

1018 definitions such as

1020 inductive EVEN ODD

1021 intrs

1022 null "0 : EVEN"

1023 oddI "n : EVEN ==> Suc n : ODD"

1024 evenI "n : ODD ==> Suc n : EVEN"

1026 new theorem list "elims" contains an elimination rule for each of the

1027 recursive sets; inductive definitions now handle disjunctive premises

1028 correctly (also ZF);

1030 INCOMPATIBILITIES: requires Inductive as an ancestor; component

1031 "mutual_induct" no longer exists - the induction rule is always

1032 contained in "induct";

1035 * HOL/datatype package re-implemented and greatly improved: now

1036 supports mutually recursive datatypes such as

1038 datatype

1039 'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)

1040 | SUM ('a aexp) ('a aexp)

1041 | DIFF ('a aexp) ('a aexp)

1042 | NUM 'a

1043 and

1044 'a bexp = LESS ('a aexp) ('a aexp)

1045 | AND ('a bexp) ('a bexp)

1046 | OR ('a bexp) ('a bexp)

1048 as well as indirectly recursive datatypes such as

1050 datatype

1051 ('a, 'b) term = Var 'a

1052 | App 'b ((('a, 'b) term) list)

1054 The new tactic mutual_induct_tac [<var_1>, ..., <var_n>] i performs

1055 induction on mutually / indirectly recursive datatypes.

1057 Primrec equations are now stored in theory and can be accessed via

1058 <function_name>.simps.

1060 INCOMPATIBILITIES:

1062 - Theories using datatypes must now have theory Datatype as an

1063 ancestor.

1064 - The specific <typename>.induct_tac no longer exists - use the

1065 generic induct_tac instead.

1066 - natE has been renamed to nat.exhaust - use exhaust_tac

1067 instead of res_inst_tac ... natE. Note that the variable

1068 names in nat.exhaust differ from the names in natE, this

1069 may cause some "fragile" proofs to fail.

1070 - The theorems split_<typename>_case and split_<typename>_case_asm

1071 have been renamed to <typename>.split and <typename>.split_asm.

1072 - Since default sorts of type variables are now handled correctly,

1073 some datatype definitions may have to be annotated with explicit

1074 sort constraints.

1075 - Primrec definitions no longer require function name and type

1076 of recursive argument.

1078 Consider using isatool fixdatatype to adapt your theories and proof

1079 scripts to the new package (backup your sources first!).

1082 * HOL/record package: considerably improved implementation; now

1083 includes concrete syntax for record types, terms, updates; theorems

1084 for surjective pairing and splitting !!-bound record variables; proof

1085 support is as follows:

1087 1) standard conversions (selectors or updates applied to record

1088 constructor terms) are part of the standard simpset;

1090 2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are

1091 made part of standard simpset and claset via addIffs;

1093 3) a tactic for record field splitting (record_split_tac) is part of

1094 the standard claset (addSWrapper);

1096 To get a better idea about these rules you may retrieve them via

1097 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is

1098 the name of your record type.

1100 The split tactic 3) conceptually simplifies by the following rule:

1102 "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"

1104 Thus any record variable that is bound by meta-all will automatically

1105 blow up into some record constructor term, consequently the

1106 simplifications of 1), 2) apply. Thus force_tac, auto_tac etc. shall

1107 solve record problems automatically.

1110 * reorganized the main HOL image: HOL/Integ and String loaded by

1111 default; theory Main includes everything;

1113 * automatic simplification of integer sums and comparisons, using cancellation;

1115 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;

1117 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;

1119 * many new identities for unions, intersections, set difference, etc.;

1121 * expand_if, expand_split, expand_sum_case and expand_nat_case are now

1122 called split_if, split_split, split_sum_case and split_nat_case (to go

1123 with add/delsplits);

1125 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting

1126 (?x::unit) = (); this is made part of the default simpset, which COULD

1127 MAKE EXISTING PROOFS FAIL under rare circumstances (consider

1128 'Delsimprocs [unit_eq_proc];' as last resort); also note that

1129 unit_abs_eta_conv is added in order to counter the effect of

1130 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by

1131 %u.f();

1133 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which

1134 makes more sense);

1136 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;

1137 It and 'sym RS equals0D' are now in the default claset, giving automatic

1138 disjointness reasoning but breaking a few old proofs.

1140 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1

1141 to 'converse' from 'inverse' (for compatibility with ZF and some

1142 literature);

1144 * HOL/recdef can now declare non-recursive functions, with {} supplied as

1145 the well-founded relation;

1147 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of

1148 Compl A. The "Compl" syntax remains available as input syntax for this

1149 release ONLY.

1151 * HOL/Update: new theory of function updates:

1152 f(a:=b) == %x. if x=a then b else f x

1153 may also be iterated as in f(a:=b,c:=d,...);

1155 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;

1157 * HOL/List:

1158 - new function list_update written xs[i:=v] that updates the i-th

1159 list position. May also be iterated as in xs[i:=a,j:=b,...].

1160 - new function `upt' written [i..j(] which generates the list

1161 [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper

1162 bound write [i..j], which is a shorthand for [i..j+1(].

1163 - new lexicographic orderings and corresponding wellfoundedness theorems.

1165 * HOL/Arith:

1166 - removed 'pred' (predecessor) function;

1167 - generalized some theorems about n-1;

1168 - many new laws about "div" and "mod";

1169 - new laws about greatest common divisors (see theory ex/Primes);

1171 * HOL/Relation: renamed the relational operator r^-1 "converse"

1172 instead of "inverse";

1174 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness

1175 of the multiset ordering;

1177 * directory HOL/Real: a construction of the reals using Dedekind cuts

1178 (not included by default);

1180 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;

1182 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted

1183 programs, i.e. different program variables may have different types.

1185 * calling (stac rew i) now fails if "rew" has no effect on the goal

1186 [previously, this check worked only if the rewrite rule was unconditional]

1187 Now rew can involve either definitions or equalities (either == or =).

1190 *** ZF ***

1192 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains

1193 only the theorems proved on ZF.ML;

1195 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;

1196 It and 'sym RS equals0D' are now in the default claset, giving automatic

1197 disjointness reasoning but breaking a few old proofs.

1199 * ZF/Update: new theory of function updates

1200 with default rewrite rule f(x:=y) ` z = if(z=x, y, f`z)

1201 may also be iterated as in f(a:=b,c:=d,...);

1203 * in let x=t in u(x), neither t nor u(x) has to be an FOL term.

1205 * calling (stac rew i) now fails if "rew" has no effect on the goal

1206 [previously, this check worked only if the rewrite rule was unconditional]

1207 Now rew can involve either definitions or equalities (either == or =).

1209 * case_tac provided for compatibility with HOL

1210 (like the old excluded_middle_tac, but with subgoals swapped)

1213 *** Internal programming interfaces ***

1215 * Pure: several new basic modules made available for general use, see

1216 also src/Pure/README;

1218 * improved the theory data mechanism to support encapsulation (data

1219 kind name replaced by private Object.kind, acting as authorization

1220 key); new type-safe user interface via functor TheoryDataFun; generic

1221 print_data function becomes basically useless;

1223 * removed global_names compatibility flag -- all theory declarations

1224 are qualified by default;

1226 * module Pure/Syntax now offers quote / antiquote translation

1227 functions (useful for Hoare logic etc. with implicit dependencies);

1228 see HOL/ex/Antiquote for an example use;

1230 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->

1231 cterm -> thm;

1233 * new tactical CHANGED_GOAL for checking that a tactic modifies a

1234 subgoal;

1236 * Display.print_goals function moved to Locale.print_goals;

1238 * standard print function for goals supports current_goals_markers

1239 variable for marking begin of proof, end of proof, start of goal; the

1240 default is ("", "", ""); setting current_goals_markers := ("<proof>",

1241 "</proof>", "<goal>") causes SGML like tagged proof state printing,

1242 for example;

1246 New in Isabelle98 (January 1998)

1247 --------------------------------

1249 *** Overview of INCOMPATIBILITIES (see below for more details) ***

1251 * changed lexical syntax of terms / types: dots made part of long

1252 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";

1254 * simpset (and claset) reference variable replaced by functions

1255 simpset / simpset_ref;

1257 * no longer supports theory aliases (via merge) and non-trivial

1258 implicit merge of thms' signatures;

1260 * most internal names of constants changed due to qualified names;

1262 * changed Pure/Sequence interface (see Pure/seq.ML);

1265 *** General Changes ***

1267 * hierachically structured name spaces (for consts, types, axms, thms

1268 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of

1269 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:

1270 isatool fixdots ensures space after dots (e.g. "%x. x"); set

1271 long_names for fully qualified output names; NOTE: ML programs

1272 (special tactics, packages etc.) referring to internal names may have

1273 to be adapted to cope with fully qualified names; in case of severe

1274 backward campatibility problems try setting 'global_names' at compile

1275 time to have enrything declared within a flat name space; one may also

1276 fine tune name declarations in theories via the 'global' and 'local'

1277 section;

1279 * reimplemented the implicit simpset and claset using the new anytype

1280 data filed in signatures; references simpset:simpset ref etc. are

1281 replaced by functions simpset:unit->simpset and

1282 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp

1283 to patch your ML files accordingly;

1285 * HTML output now includes theory graph data for display with Java

1286 applet or isatool browser; data generated automatically via isatool

1287 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);

1289 * defs may now be conditional; improved rewrite_goals_tac to handle

1290 conditional equations;

1292 * defs now admits additional type arguments, using TYPE('a) syntax;

1294 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always

1295 creates a new theory node; implicit merge of thms' signatures is

1296 restricted to 'trivial' ones; COMPATIBILITY: one may have to use

1297 transfer:theory->thm->thm in (rare) cases;

1299 * improved handling of draft signatures / theories; draft thms (and

1300 ctyps, cterms) are automatically promoted to real ones;

1302 * slightly changed interfaces for oracles: admit many per theory, named

1303 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;

1305 * print_goals: optional output of const types (set show_consts and

1306 show_types);

1308 * improved output of warnings (###) and errors (***);

1310 * subgoal_tac displays a warning if the new subgoal has type variables;

1312 * removed old README and Makefiles;

1314 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;

1316 * removed obsolete init_pps and init_database;

1318 * deleted the obsolete tactical STATE, which was declared by

1319 fun STATE tacfun st = tacfun st st;

1321 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~

1322 (which abbreviates $HOME);

1324 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:

1325 use isatool fixseq to adapt your ML programs (this works for fully

1326 qualified references to the Sequence structure only!);

1328 * use_thy no longer requires writable current directory; it always

1329 reloads .ML *and* .thy file, if either one is out of date;

1332 *** Classical Reasoner ***

1334 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new

1335 tactics that use classical reasoning to simplify a subgoal without

1336 splitting it into several subgoals;

1338 * Safe_tac: like safe_tac but uses the default claset;

1341 *** Simplifier ***

1343 * added simplification meta rules:

1344 (asm_)(full_)simplify: simpset -> thm -> thm;

1346 * simplifier.ML no longer part of Pure -- has to be loaded by object

1347 logics (again);

1349 * added prems argument to simplification procedures;

1351 * HOL, FOL, ZF: added infix function `addsplits':

1352 instead of `<simpset> setloop (split_tac <thms>)'

1353 you can simply write `<simpset> addsplits <thms>'

1356 *** Syntax ***

1358 * TYPE('a) syntax for type reflection terms;

1360 * no longer handles consts with name "" -- declare as 'syntax' instead;

1362 * pretty printer: changed order of mixfix annotation preference (again!);

1364 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;

1367 *** HOL ***

1369 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.

1370 with `addloop' of the simplifier to faciliate case splitting in premises.

1372 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;

1374 * HOL/Auth: new protocol proofs including some for the Internet

1375 protocol TLS;

1377 * HOL/Map: new theory of `maps' a la VDM;

1379 * HOL/simplifier: simplification procedures nat_cancel_sums for

1380 cancelling out common nat summands from =, <, <= (in)equalities, or

1381 differences; simplification procedures nat_cancel_factor for

1382 cancelling common factor from =, <, <= (in)equalities over natural

1383 sums; nat_cancel contains both kinds of procedures, it is installed by

1384 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;

1386 * HOL/simplifier: terms of the form

1387 `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)' (or t=x)

1388 are rewritten to

1389 `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',

1390 and those of the form

1391 `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)' (or t=x)

1392 are rewritten to

1393 `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',

1395 * HOL/datatype

1396 Each datatype `t' now comes with a theorem `split_t_case' of the form

1398 P(t_case f1 ... fn x) =

1399 ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &

1400 ...

1401 (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))

1402 )

1404 and a theorem `split_t_case_asm' of the form

1406 P(t_case f1 ... fn x) =

1407 ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |

1408 ...

1409 (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))

1410 )

1411 which can be added to a simpset via `addsplits'. The existing theorems

1412 expand_list_case and expand_option_case have been renamed to

1413 split_list_case and split_option_case.

1415 * HOL/Arithmetic:

1416 - `pred n' is automatically converted to `n-1'.

1417 Users are strongly encouraged not to use `pred' any longer,

1418 because it will disappear altogether at some point.

1419 - Users are strongly encouraged to write "0 < n" rather than

1420 "n ~= 0". Theorems and proof tools have been modified towards this

1421 `standard'.

1423 * HOL/Lists:

1424 the function "set_of_list" has been renamed "set" (and its theorems too);

1425 the function "nth" now takes its arguments in the reverse order and

1426 has acquired the infix notation "!" as in "xs!n".

1428 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};

1430 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its

1431 specialist theorems (like UN1_I) are gone. Similarly for (INT x.B x);

1433 * HOL/record: extensible records with schematic structural subtyping

1434 (single inheritance); EXPERIMENTAL version demonstrating the encoding,

1435 still lacks various theorems and concrete record syntax;

1438 *** HOLCF ***

1440 * removed "axioms" and "generated by" sections;

1442 * replaced "ops" section by extended "consts" section, which is capable of

1443 handling the continuous function space "->" directly;

1445 * domain package:

1446 . proves theorems immediately and stores them in the theory,

1447 . creates hierachical name space,

1448 . now uses normal mixfix annotations (instead of cinfix...),

1449 . minor changes to some names and values (for consistency),

1450 . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,

1451 . separator between mutual domain defs: changed "," to "and",

1452 . improved handling of sort constraints; now they have to

1453 appear on the left-hand side of the equations only;

1455 * fixed LAM <x,y,zs>.b syntax;

1457 * added extended adm_tac to simplifier in HOLCF -- can now discharge

1458 adm (%x. P (t x)), where P is chainfinite and t continuous;

1461 *** FOL and ZF ***

1463 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.

1464 with `addloop' of the simplifier to faciliate case splitting in premises.

1466 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as

1467 in HOL, they strip ALL and --> from proved theorems;

1471 New in Isabelle94-8 (May 1997)

1472 ------------------------------

1474 *** General Changes ***

1476 * new utilities to build / run / maintain Isabelle etc. (in parts

1477 still somewhat experimental); old Makefiles etc. still functional;

1479 * new 'Isabelle System Manual';

1481 * INSTALL text, together with ./configure and ./build scripts;

1483 * reimplemented type inference for greater efficiency, better error

1484 messages and clean internal interface;

1486 * prlim command for dealing with lots of subgoals (an easier way of

1487 setting goals_limit);

1490 *** Syntax ***

1492 * supports alternative (named) syntax tables (parser and pretty

1493 printer); internal interface is provided by add_modesyntax(_i);

1495 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to

1496 be used in conjunction with the Isabelle symbol font; uses the

1497 "symbols" syntax table;

1499 * added token_translation interface (may translate name tokens in

1500 arbitrary ways, dependent on their type (free, bound, tfree, ...) and

1501 the current print_mode); IMPORTANT: user print translation functions

1502 are responsible for marking newly introduced bounds

1503 (Syntax.mark_boundT);

1505 * token translations for modes "xterm" and "xterm_color" that display

1506 names in bold, underline etc. or colors (which requires a color

1507 version of xterm);

1509 * infixes may now be declared with names independent of their syntax;

1511 * added typed_print_translation (like print_translation, but may

1512 access type of constant);

1515 *** Classical Reasoner ***

1517 Blast_tac: a new tactic! It is often more powerful than fast_tac, but has

1518 some limitations. Blast_tac...

1519 + ignores addss, addbefore, addafter; this restriction is intrinsic

1520 + ignores elimination rules that don't have the correct format

1521 (the conclusion MUST be a formula variable)

1522 + ignores types, which can make HOL proofs fail

1523 + rules must not require higher-order unification, e.g. apply_type in ZF

1524 [message "Function Var's argument not a bound variable" relates to this]

1525 + its proof strategy is more general but can actually be slower

1527 * substitution with equality assumptions no longer permutes other

1528 assumptions;

1530 * minor changes in semantics of addafter (now called addaltern); renamed

1531 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper

1532 (and access functions for it);

1534 * improved combination of classical reasoner and simplifier:

1535 + functions for handling clasimpsets

1536 + improvement of addss: now the simplifier is called _after_ the

1537 safe steps.

1538 + safe variant of addss called addSss: uses safe simplifications

1539 _during_ the safe steps. It is more complete as it allows multiple

1540 instantiations of unknowns (e.g. with slow_tac).

1542 *** Simplifier ***

1544 * added interface for simplification procedures (functions that

1545 produce *proven* rewrite rules on the fly, depending on current

1546 redex);

1548 * ordering on terms as parameter (used for ordered rewriting);

1550 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;

1552 * the solver is now split into a safe and an unsafe part.

1553 This should be invisible for the normal user, except that the

1554 functions setsolver and addsolver have been renamed to setSolver and

1555 addSolver; added safe_asm_full_simp_tac;

1558 *** HOL ***

1560 * a generic induction tactic `induct_tac' which works for all datatypes and

1561 also for type `nat';

1563 * a generic case distinction tactic `exhaust_tac' which works for all

1564 datatypes and also for type `nat';

1566 * each datatype comes with a function `size';

1568 * patterns in case expressions allow tuple patterns as arguments to

1569 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';

1571 * primrec now also works with type nat;

1573 * recdef: a new declaration form, allows general recursive functions to be

1574 defined in theory files. See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.

1576 * the constant for negation has been renamed from "not" to "Not" to

1577 harmonize with FOL, ZF, LK, etc.;

1579 * HOL/ex/LFilter theory of a corecursive "filter" functional for

1580 infinite lists;

1582 * HOL/Modelcheck demonstrates invocation of model checker oracle;

1584 * HOL/ex/Ring.thy declares cring_simp, which solves equational

1585 problems in commutative rings, using axiomatic type classes for + and *;

1587 * more examples in HOL/MiniML and HOL/Auth;

1589 * more default rewrite rules for quantifiers, union/intersection;

1591 * a new constant `arbitrary == @x.False';

1593 * HOLCF/IOA replaces old HOL/IOA;

1595 * HOLCF changes: derived all rules and arities

1596 + axiomatic type classes instead of classes

1597 + typedef instead of faking type definitions

1598 + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.

1599 + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po

1600 + eliminated the types void, one, tr

1601 + use unit lift and bool lift (with translations) instead of one and tr

1602 + eliminated blift from Lift3.thy (use Def instead of blift)

1603 all eliminated rules are derived as theorems --> no visible changes ;

1606 *** ZF ***

1608 * ZF now has Fast_tac, Simp_tac and Auto_tac. Union_iff is a now a default

1609 rewrite rule; this may affect some proofs. eq_cs is gone but can be put back

1610 as ZF_cs addSIs [equalityI];

1614 New in Isabelle94-7 (November 96)

1615 ---------------------------------

1617 * allowing negative levels (as offsets) in prlev and choplev;

1619 * super-linear speedup for large simplifications;

1621 * FOL, ZF and HOL now use miniscoping: rewriting pushes

1622 quantifications in as far as possible (COULD MAKE EXISTING PROOFS

1623 FAIL); can suppress it using the command Delsimps (ex_simps @

1624 all_simps); De Morgan laws are also now included, by default;

1626 * improved printing of ==> : ~:

1628 * new object-logic "Sequents" adds linear logic, while replacing LK

1629 and Modal (thanks to Sara Kalvala);

1631 * HOL/Auth: correctness proofs for authentication protocols;

1633 * HOL: new auto_tac combines rewriting and classical reasoning (many

1634 examples on HOL/Auth);

1636 * HOL: new command AddIffs for declaring theorems of the form P=Q to

1637 the rewriter and classical reasoner simultaneously;

1639 * function uresult no longer returns theorems in "standard" format;

1640 regain previous version by: val uresult = standard o uresult;

1644 New in Isabelle94-6

1645 -------------------

1647 * oracles -- these establish an interface between Isabelle and trusted

1648 external reasoners, which may deliver results as theorems;

1650 * proof objects (in particular record all uses of oracles);

1652 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;

1654 * "constdefs" section in theory files;

1656 * "primrec" section (HOL) no longer requires names;

1658 * internal type "tactic" now simply "thm -> thm Sequence.seq";

1662 New in Isabelle94-5

1663 -------------------

1665 * reduced space requirements;

1667 * automatic HTML generation from theories;

1669 * theory files no longer require "..." (quotes) around most types;

1671 * new examples, including two proofs of the Church-Rosser theorem;

1673 * non-curried (1994) version of HOL is no longer distributed;

1677 New in Isabelle94-4

1678 -------------------

1680 * greatly reduced space requirements;

1682 * theory files (.thy) no longer require \...\ escapes at line breaks;

1684 * searchable theorem database (see the section "Retrieving theorems" on

1685 page 8 of the Reference Manual);

1687 * new examples, including Grabczewski's monumental case study of the

1688 Axiom of Choice;

1690 * The previous version of HOL renamed to Old_HOL;

1692 * The new version of HOL (previously called CHOL) uses a curried syntax

1693 for functions. Application looks like f a b instead of f(a,b);

1695 * Mutually recursive inductive definitions finally work in HOL;

1697 * In ZF, pattern-matching on tuples is now available in all abstractions and

1698 translates to the operator "split";

1702 New in Isabelle94-3

1703 -------------------

1705 * new infix operator, addss, allowing the classical reasoner to

1706 perform simplification at each step of its search. Example:

1707 fast_tac (cs addss ss)

1709 * a new logic, CHOL, the same as HOL, but with a curried syntax

1710 for functions. Application looks like f a b instead of f(a,b). Also pairs

1711 look like (a,b) instead of <a,b>;

1713 * PLEASE NOTE: CHOL will eventually replace HOL!

1715 * In CHOL, pattern-matching on tuples is now available in all abstractions.

1716 It translates to the operator "split". A new theory of integers is available;

1718 * In ZF, integer numerals now denote two's-complement binary integers.

1719 Arithmetic operations can be performed by rewriting. See ZF/ex/Bin.ML;

1721 * Many new examples: I/O automata, Church-Rosser theorem, equivalents

1722 of the Axiom of Choice;

1726 New in Isabelle94-2

1727 -------------------

1729 * Significantly faster resolution;

1731 * the different sections in a .thy file can now be mixed and repeated

1732 freely;

1734 * Database of theorems for FOL, HOL and ZF. New

1735 commands including qed, qed_goal and bind_thm store theorems in the database.

1737 * Simple database queries: return a named theorem (get_thm) or all theorems of

1738 a given theory (thms_of), or find out what theory a theorem was proved in

1739 (theory_of_thm);

1741 * Bugs fixed in the inductive definition and datatype packages;

1743 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs

1744 and HOL_dup_cs obsolete;

1746 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1

1747 have been removed;

1749 * Simpler definition of function space in ZF;

1751 * new results about cardinal and ordinal arithmetic in ZF;

1753 * 'subtype' facility in HOL for introducing new types as subsets of existing

1754 types;

1757 $Id$