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NEWS

author | wenzelm |

Tue Jan 30 14:21:50 2001 +0100 (2001-01-30) | |

changeset 10998 | fece8333adfc |

parent 10976 | 0e7cf6f9fa29 |

child 11016 | 8f8ba41a5e7a |

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

tuned;

2 Isabelle NEWS -- history user-relevant changes

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

5 *** Overview of INCOMPATIBILITIES ***

7 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,

8 gfp_Tarski to gfp_unfold;

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

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

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

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

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

17 operation;

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

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

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

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

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

27 * Document preparation: renamed standard symbols \<ll> to \<lless> and

28 \<gg> to \<ggreater>;

31 *** Document preparation ***

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 * improved isabelle style files; more abstract symbol implementation

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

47 definitions);

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

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

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

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

54 * isatool unsymbolize tunes sources for plain ASCII communication;

57 *** Isar ***

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

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

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

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

63 for Prolog-style synthesis of proven results;

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

66 rules as well;

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

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

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

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

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

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

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

77 statements as well;

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

80 rule (as well as the assumption rule);

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

83 lemmas, using the graph browser tool;

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

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

88 (potential INCOMPATIBILITY); tuned error handling;

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

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

92 any remaining facts are inserted into the goal verbatim;

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

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

96 the result to be shown in each case;

98 * HOL: added 'recdef_tc' command;

101 *** HOL ***

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

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

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

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

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

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

110 modelling and verification task performed in Isabelle/HOL +

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

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

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

115 operator;

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

118 HOL/subset.thy);

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

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

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

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

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

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

128 rules with string literals);

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

131 and Fleuriot's mechanization of analysis;

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

136 *** CTT ***

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

139 "lam" is displayed as TWO lambda-symbols

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

142 and Arith);

145 *** General ***

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

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

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

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

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

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

155 the Isabelle inference kernel has been greatly improved;

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

158 as assumptions as well;

162 New in Isabelle99-1 (October 2000)

163 ----------------------------------

165 *** Overview of INCOMPATIBILITIES ***

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

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

169 issue the following ML commands:

171 Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;

172 Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];

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

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

177 * HOL: nat_less_induct renamed to less_induct;

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

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

182 select_equality -> some_equality

183 select_eq_Ex -> some_eq_ex

184 selectI2EX -> someI2_ex

185 selectI2 -> someI2

186 selectI -> someI

187 select1_equality -> some1_equality

188 Eps_sym_eq -> some_sym_eq_trivial

189 Eps_eq -> some_eq_trivial

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

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

194 instead);

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

197 f.simps instead of f.rules;

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

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

202 sometimes be needed;

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

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

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

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

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

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

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

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

216 the old syntax may be recovered as follows:

218 syntax (symbols)

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

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

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

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

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

226 internally;

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

229 changed from A/r to A//r;

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

232 proofs;

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

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

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

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

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

240 "rule del";

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

244 * Provers: strengthened force_tac by using new first_best_tac;

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

247 lib/texinputs);

250 *** Document preparation ***

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

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

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

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

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

258 including proper document sources;

260 * generated LaTeX sources are now deleted after successful run

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

262 of isatool usedir;

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

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

266 LaTeX debugging;

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

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

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

272 graph for 'all sessions';

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

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

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

279 *** Isar ***

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

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

283 accommodates incremental type-inference very nicely;

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

286 generalized existence reasoning;

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

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

290 useful to collect intermediate results without explicit name

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

292 premises;

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

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

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

297 to theorems as "tags";

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

300 class/type/const name spaces;

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

303 indicate potential overloading;

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

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

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

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

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

312 with the version in Provers/classical;

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

315 case name 'antecedent';

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

318 to the current context is now done automatically);

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

321 for definining proof methods in ML;

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

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

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

326 replaced "delrule" by "rule del";

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

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

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

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

333 well (including splits);

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

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

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

339 of Simplifier and Classical reasoner);

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

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

343 recdef) support case names and properly name parameters;

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

346 monotonicity conditions are extracted to be proven at end of

347 calculations;

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

350 method anyway;

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

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

354 foo.split foo.split_asm for each datatype;

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

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

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

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

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

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

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

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

367 proof states;

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

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

371 proof state according to the Isabelle LaTeX style;

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

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

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

376 (for HOL datatypes);

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

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

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

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

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

385 should instead use individual commands for printing items

386 (print_commands, print_methods etc.);

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

391 *** HOL ***

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

394 corresponding virtual machine and a specification of its bytecode

395 verifier and a lightweight bytecode verifier, including proofs of

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

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

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

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

401 Clemens Ballarin;

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

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

405 Rasmussen;

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

408 structures, including duals, properties of bounds versus algebraic

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

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

411 for abstract algebraic reasoning using axiomatic type classes, and

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

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

415 von Oheimb;

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

418 recursive procedures, by David von Oheimb;

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

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

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

424 representation; very useful in avoiding lifting of operations;

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

427 select-update simplification procedure to handle extended records as

428 well; admit "r" as field name;

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

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

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

434 Types nat and int belong to this axclass;

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

460 termination conditions are proved automatically, these simplification

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

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

463 each equation;

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

466 permits the definition of tail-recursive functions without the

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

468 invariant proof rule for while is applied.

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

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

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

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

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

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

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

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

482 main HOL, but was unused);

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

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

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

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

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

490 bogus);

493 *** ZF ***

495 * ZF: simplification automatically cancels common terms in arithmetic

496 expressions over nat and int;

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

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

500 making the algebraic laws unconditional;

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

503 using the function intify;

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

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

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

509 simplification;

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

512 to the simplifier and classical reasoner simultaneously;

515 *** General ***

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

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

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

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

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

524 explicit make_elim);

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

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

528 use instead the strong form,

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

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

531 from destruct-rules;

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

534 Simplifier setup for new object-logics;

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

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

539 for hiding of names;

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

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

543 situations;

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

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

547 Poly/ML);

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

550 useful for remote X11);

552 * system: provide TAGS file for Isabelle sources;

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

555 order;

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

558 timing flag supersedes proof_timing and Toplevel.trace;

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

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

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

564 overloading (usually false);

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

567 results;

571 New in Isabelle99 (October 1999)

572 --------------------------------

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

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

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

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

580 Delcongs [if_weak_cong];

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

583 complement;

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

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

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

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

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

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

594 to constants declared in the same theory;

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

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

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

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

602 * Simplifier: the type of the infix ML functions

603 setSSolver addSSolver setSolver addSolver

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

605 for packaging solvers. A solver is created via

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

607 where the string argument is only a comment.

610 *** Proof tools ***

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

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

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

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

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

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

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

620 matching.

623 *** General ***

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

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

627 interface it offers an interactive environment for developing human

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

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

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

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

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

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

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

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

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

639 Isabelle/Isar;

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

642 using the graph browser tool;

644 * Isabelle manuals now also available as PDF;

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

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

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

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

650 isatool doc ref);

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

653 option -p DIR installs standalone binaries;

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

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

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

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

660 Isabelle;

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

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

665 empty;

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

668 long arrows);

670 * new print_mode "HTML";

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

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

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

676 mode and goal output format:

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

679 244c244

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

681 ---

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

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

684 181c181

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

686 ---

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

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

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

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

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

695 result still apply;

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

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

701 *** HOL ***

703 ** HOL arithmetic **

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

706 int:

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

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

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

711 are ignored; quantified subformulae are ignored unless they are

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

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

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

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

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

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

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

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

721 simplifier.

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

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

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

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

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

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

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

731 type constraints;

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

734 arguments;

736 * many properties of integer multiplication, division and remainder

737 are now available;

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

740 tactic svc_tac. Propositional tautologies and theorems of linear arithmetic

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

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

743 invocation of the underlying oracle). For SVC see

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

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

749 ** HOL misc **

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

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

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

755 analysis for assembly languages with subtypes;

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

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

759 temporal levels more uniformly; introduces INCOMPATIBILITIES due to

760 changed syntax and (many) tactics;

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

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

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

765 "mono" attribute);

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

768 (using function types) such as

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

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

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

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

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

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

778 Delsimprocs [record_simproc]

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

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

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

784 names rather than an ML expression;

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

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

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

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

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

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

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

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

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

797 the original Gordon/HOL-style output;

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

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

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

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

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

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

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

809 thus available for user theories;

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

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

813 time;

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

816 several times and then mp;

819 *** LK ***

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

822 formulas;

824 * the simplifier is now installed

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

828 * the classical reasoner now has a default rule database

831 *** ZF ***

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

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

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

837 analysis) over datatypes and the natural numbers;

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

841 * simplification automatically does freeness reasoning for datatype

842 constructors;

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

845 type-checking rules;

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

848 to the claset;

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

851 if(P,x,y);

854 *** Internal programming interfaces ***

856 * tuned simplifier trace output; new flag debug_simp;

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

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

861 * AxClass.axclass_tac lost the theory argument;

863 * tuned current_goals_markers semantics: begin / end goal avoids

864 printing empty lines;

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

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

868 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:

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

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

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

873 mode to get Isabelle font glyphs as before;

875 * refined token_translation interface; INCOMPATIBILITY: output length

876 now of type real instead of int;

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

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

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

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

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

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

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

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

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

891 New in Isabelle98-1 (October 1998)

892 ----------------------------------

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

896 * several changes of automated proof tools;

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

899 some minor incompatibilities of theory syntax;

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

902 called `inj_on';

904 * HOL: removed duplicate thms in Arith:

905 less_imp_add_less should be replaced by trans_less_add1

906 le_imp_add_le should be replaced by trans_le_add1

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

909 required);

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

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

913 now taken as an integer constant.

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

918 *** Proof tools ***

920 * Simplifier:

921 1. Asm_full_simp_tac is now more aggressive.

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

923 simplify.

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

925 rotate premises to achieve further simplification.

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

927 old Asm_full_simp_tac in that it does not rotate premises.

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

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

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

932 wrapper functionals. This implies that addbefore, addSbefore,

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

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

935 one (emitting a warning).

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

937 setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by

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

939 delWrapper, delSWrapper: claset * string -> claset

940 getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;

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

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

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

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

946 by Force_tac;

948 * Classical reasoner: setwrapper to setWrapper and compwrapper to

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

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

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

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

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

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

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

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

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

959 split_all_tac for record fields.

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

962 permanently to the default simpset using Addsplits just like

963 Addsimps. They can be removed via Delsplits just like

964 Delsimps. Lower-case versions are also available.

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

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

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

969 either remove split_if completely from the default simpset by

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

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

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

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

974 t is the name of the datatype).

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

977 derivatives Force_tac, force) combines rewriting and classical

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

979 aimed to solve the given subgoal completely.

982 *** General ***

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

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

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

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

988 recommended to convert to these new commands using isatool fixgoal

989 (backup your sources first!);

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

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

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

995 definitions that have local scope;

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

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

1000 (e.g. package initialization);

1002 * the distribution now includes Isabelle icons: see

1003 lib/logo/isabelle-{small,tiny}.xpm;

1005 * isatool install - install binaries with absolute references to

1006 ISABELLE_HOME/bin;

1008 * isatool logo -- create instances of the Isabelle logo (as EPS);

1010 * print mode 'emacs' reserved for Isamode;

1012 * support multiple print (ast) translations per constant name;

1014 * theorems involving oracles are now printed with a suffixed [!];

1017 *** HOL ***

1019 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');

1021 * HOL/inductive package reorganized and improved: now supports mutual

1022 definitions such as

1024 inductive EVEN ODD

1025 intrs

1026 null "0 : EVEN"

1027 oddI "n : EVEN ==> Suc n : ODD"

1028 evenI "n : ODD ==> Suc n : EVEN"

1030 new theorem list "elims" contains an elimination rule for each of the

1031 recursive sets; inductive definitions now handle disjunctive premises

1032 correctly (also ZF);

1034 INCOMPATIBILITIES: requires Inductive as an ancestor; component

1035 "mutual_induct" no longer exists - the induction rule is always

1036 contained in "induct";

1039 * HOL/datatype package re-implemented and greatly improved: now

1040 supports mutually recursive datatypes such as

1042 datatype

1043 'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)

1044 | SUM ('a aexp) ('a aexp)

1045 | DIFF ('a aexp) ('a aexp)

1046 | NUM 'a

1047 and

1048 'a bexp = LESS ('a aexp) ('a aexp)

1049 | AND ('a bexp) ('a bexp)

1050 | OR ('a bexp) ('a bexp)

1052 as well as indirectly recursive datatypes such as

1054 datatype

1055 ('a, 'b) term = Var 'a

1056 | App 'b ((('a, 'b) term) list)

1058 The new tactic mutual_induct_tac [<var_1>, ..., <var_n>] i performs

1059 induction on mutually / indirectly recursive datatypes.

1061 Primrec equations are now stored in theory and can be accessed via

1062 <function_name>.simps.

1064 INCOMPATIBILITIES:

1066 - Theories using datatypes must now have theory Datatype as an

1067 ancestor.

1068 - The specific <typename>.induct_tac no longer exists - use the

1069 generic induct_tac instead.

1070 - natE has been renamed to nat.exhaust - use exhaust_tac

1071 instead of res_inst_tac ... natE. Note that the variable

1072 names in nat.exhaust differ from the names in natE, this

1073 may cause some "fragile" proofs to fail.

1074 - The theorems split_<typename>_case and split_<typename>_case_asm

1075 have been renamed to <typename>.split and <typename>.split_asm.

1076 - Since default sorts of type variables are now handled correctly,

1077 some datatype definitions may have to be annotated with explicit

1078 sort constraints.

1079 - Primrec definitions no longer require function name and type

1080 of recursive argument.

1082 Consider using isatool fixdatatype to adapt your theories and proof

1083 scripts to the new package (backup your sources first!).

1086 * HOL/record package: considerably improved implementation; now

1087 includes concrete syntax for record types, terms, updates; theorems

1088 for surjective pairing and splitting !!-bound record variables; proof

1089 support is as follows:

1091 1) standard conversions (selectors or updates applied to record

1092 constructor terms) are part of the standard simpset;

1094 2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are

1095 made part of standard simpset and claset via addIffs;

1097 3) a tactic for record field splitting (record_split_tac) is part of

1098 the standard claset (addSWrapper);

1100 To get a better idea about these rules you may retrieve them via

1101 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is

1102 the name of your record type.

1104 The split tactic 3) conceptually simplifies by the following rule:

1106 "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"

1108 Thus any record variable that is bound by meta-all will automatically

1109 blow up into some record constructor term, consequently the

1110 simplifications of 1), 2) apply. Thus force_tac, auto_tac etc. shall

1111 solve record problems automatically.

1114 * reorganized the main HOL image: HOL/Integ and String loaded by

1115 default; theory Main includes everything;

1117 * automatic simplification of integer sums and comparisons, using cancellation;

1119 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;

1121 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;

1123 * many new identities for unions, intersections, set difference, etc.;

1125 * expand_if, expand_split, expand_sum_case and expand_nat_case are now

1126 called split_if, split_split, split_sum_case and split_nat_case (to go

1127 with add/delsplits);

1129 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting

1130 (?x::unit) = (); this is made part of the default simpset, which COULD

1131 MAKE EXISTING PROOFS FAIL under rare circumstances (consider

1132 'Delsimprocs [unit_eq_proc];' as last resort); also note that

1133 unit_abs_eta_conv is added in order to counter the effect of

1134 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by

1135 %u.f();

1137 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which

1138 makes more sense);

1140 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;

1141 It and 'sym RS equals0D' are now in the default claset, giving automatic

1142 disjointness reasoning but breaking a few old proofs.

1144 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1

1145 to 'converse' from 'inverse' (for compatibility with ZF and some

1146 literature);

1148 * HOL/recdef can now declare non-recursive functions, with {} supplied as

1149 the well-founded relation;

1151 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of

1152 Compl A. The "Compl" syntax remains available as input syntax for this

1153 release ONLY.

1155 * HOL/Update: new theory of function updates:

1156 f(a:=b) == %x. if x=a then b else f x

1157 may also be iterated as in f(a:=b,c:=d,...);

1159 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;

1161 * HOL/List:

1162 - new function list_update written xs[i:=v] that updates the i-th

1163 list position. May also be iterated as in xs[i:=a,j:=b,...].

1164 - new function `upt' written [i..j(] which generates the list

1165 [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper

1166 bound write [i..j], which is a shorthand for [i..j+1(].

1167 - new lexicographic orderings and corresponding wellfoundedness theorems.

1169 * HOL/Arith:

1170 - removed 'pred' (predecessor) function;

1171 - generalized some theorems about n-1;

1172 - many new laws about "div" and "mod";

1173 - new laws about greatest common divisors (see theory ex/Primes);

1175 * HOL/Relation: renamed the relational operator r^-1 "converse"

1176 instead of "inverse";

1178 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness

1179 of the multiset ordering;

1181 * directory HOL/Real: a construction of the reals using Dedekind cuts

1182 (not included by default);

1184 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;

1186 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted

1187 programs, i.e. different program variables may have different types.

1189 * calling (stac rew i) now fails if "rew" has no effect on the goal

1190 [previously, this check worked only if the rewrite rule was unconditional]

1191 Now rew can involve either definitions or equalities (either == or =).

1194 *** ZF ***

1196 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains

1197 only the theorems proved on ZF.ML;

1199 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;

1200 It and 'sym RS equals0D' are now in the default claset, giving automatic

1201 disjointness reasoning but breaking a few old proofs.

1203 * ZF/Update: new theory of function updates

1204 with default rewrite rule f(x:=y) ` z = if(z=x, y, f`z)

1205 may also be iterated as in f(a:=b,c:=d,...);

1207 * in let x=t in u(x), neither t nor u(x) has to be an FOL term.

1209 * calling (stac rew i) now fails if "rew" has no effect on the goal

1210 [previously, this check worked only if the rewrite rule was unconditional]

1211 Now rew can involve either definitions or equalities (either == or =).

1213 * case_tac provided for compatibility with HOL

1214 (like the old excluded_middle_tac, but with subgoals swapped)

1217 *** Internal programming interfaces ***

1219 * Pure: several new basic modules made available for general use, see

1220 also src/Pure/README;

1222 * improved the theory data mechanism to support encapsulation (data

1223 kind name replaced by private Object.kind, acting as authorization

1224 key); new type-safe user interface via functor TheoryDataFun; generic

1225 print_data function becomes basically useless;

1227 * removed global_names compatibility flag -- all theory declarations

1228 are qualified by default;

1230 * module Pure/Syntax now offers quote / antiquote translation

1231 functions (useful for Hoare logic etc. with implicit dependencies);

1232 see HOL/ex/Antiquote for an example use;

1234 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->

1235 cterm -> thm;

1237 * new tactical CHANGED_GOAL for checking that a tactic modifies a

1238 subgoal;

1240 * Display.print_goals function moved to Locale.print_goals;

1242 * standard print function for goals supports current_goals_markers

1243 variable for marking begin of proof, end of proof, start of goal; the

1244 default is ("", "", ""); setting current_goals_markers := ("<proof>",

1245 "</proof>", "<goal>") causes SGML like tagged proof state printing,

1246 for example;

1250 New in Isabelle98 (January 1998)

1251 --------------------------------

1253 *** Overview of INCOMPATIBILITIES (see below for more details) ***

1255 * changed lexical syntax of terms / types: dots made part of long

1256 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";

1258 * simpset (and claset) reference variable replaced by functions

1259 simpset / simpset_ref;

1261 * no longer supports theory aliases (via merge) and non-trivial

1262 implicit merge of thms' signatures;

1264 * most internal names of constants changed due to qualified names;

1266 * changed Pure/Sequence interface (see Pure/seq.ML);

1269 *** General Changes ***

1271 * hierachically structured name spaces (for consts, types, axms, thms

1272 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of

1273 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:

1274 isatool fixdots ensures space after dots (e.g. "%x. x"); set

1275 long_names for fully qualified output names; NOTE: ML programs

1276 (special tactics, packages etc.) referring to internal names may have

1277 to be adapted to cope with fully qualified names; in case of severe

1278 backward campatibility problems try setting 'global_names' at compile

1279 time to have enrything declared within a flat name space; one may also

1280 fine tune name declarations in theories via the 'global' and 'local'

1281 section;

1283 * reimplemented the implicit simpset and claset using the new anytype

1284 data filed in signatures; references simpset:simpset ref etc. are

1285 replaced by functions simpset:unit->simpset and

1286 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp

1287 to patch your ML files accordingly;

1289 * HTML output now includes theory graph data for display with Java

1290 applet or isatool browser; data generated automatically via isatool

1291 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);

1293 * defs may now be conditional; improved rewrite_goals_tac to handle

1294 conditional equations;

1296 * defs now admits additional type arguments, using TYPE('a) syntax;

1298 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always

1299 creates a new theory node; implicit merge of thms' signatures is

1300 restricted to 'trivial' ones; COMPATIBILITY: one may have to use

1301 transfer:theory->thm->thm in (rare) cases;

1303 * improved handling of draft signatures / theories; draft thms (and

1304 ctyps, cterms) are automatically promoted to real ones;

1306 * slightly changed interfaces for oracles: admit many per theory, named

1307 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;

1309 * print_goals: optional output of const types (set show_consts and

1310 show_types);

1312 * improved output of warnings (###) and errors (***);

1314 * subgoal_tac displays a warning if the new subgoal has type variables;

1316 * removed old README and Makefiles;

1318 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;

1320 * removed obsolete init_pps and init_database;

1322 * deleted the obsolete tactical STATE, which was declared by

1323 fun STATE tacfun st = tacfun st st;

1325 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~

1326 (which abbreviates $HOME);

1328 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:

1329 use isatool fixseq to adapt your ML programs (this works for fully

1330 qualified references to the Sequence structure only!);

1332 * use_thy no longer requires writable current directory; it always

1333 reloads .ML *and* .thy file, if either one is out of date;

1336 *** Classical Reasoner ***

1338 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new

1339 tactics that use classical reasoning to simplify a subgoal without

1340 splitting it into several subgoals;

1342 * Safe_tac: like safe_tac but uses the default claset;

1345 *** Simplifier ***

1347 * added simplification meta rules:

1348 (asm_)(full_)simplify: simpset -> thm -> thm;

1350 * simplifier.ML no longer part of Pure -- has to be loaded by object

1351 logics (again);

1353 * added prems argument to simplification procedures;

1355 * HOL, FOL, ZF: added infix function `addsplits':

1356 instead of `<simpset> setloop (split_tac <thms>)'

1357 you can simply write `<simpset> addsplits <thms>'

1360 *** Syntax ***

1362 * TYPE('a) syntax for type reflection terms;

1364 * no longer handles consts with name "" -- declare as 'syntax' instead;

1366 * pretty printer: changed order of mixfix annotation preference (again!);

1368 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;

1371 *** HOL ***

1373 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.

1374 with `addloop' of the simplifier to faciliate case splitting in premises.

1376 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;

1378 * HOL/Auth: new protocol proofs including some for the Internet

1379 protocol TLS;

1381 * HOL/Map: new theory of `maps' a la VDM;

1383 * HOL/simplifier: simplification procedures nat_cancel_sums for

1384 cancelling out common nat summands from =, <, <= (in)equalities, or

1385 differences; simplification procedures nat_cancel_factor for

1386 cancelling common factor from =, <, <= (in)equalities over natural

1387 sums; nat_cancel contains both kinds of procedures, it is installed by

1388 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;

1390 * HOL/simplifier: terms of the form

1391 `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)' (or t=x)

1392 are rewritten to

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

1394 and those of the form

1395 `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)' (or t=x)

1396 are rewritten to

1397 `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',

1399 * HOL/datatype

1400 Each datatype `t' now comes with a theorem `split_t_case' of the form

1402 P(t_case f1 ... fn x) =

1403 ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &

1404 ...

1405 (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))

1406 )

1408 and a theorem `split_t_case_asm' of the form

1410 P(t_case f1 ... fn x) =

1411 ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |

1412 ...

1413 (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))

1414 )

1415 which can be added to a simpset via `addsplits'. The existing theorems

1416 expand_list_case and expand_option_case have been renamed to

1417 split_list_case and split_option_case.

1419 * HOL/Arithmetic:

1420 - `pred n' is automatically converted to `n-1'.

1421 Users are strongly encouraged not to use `pred' any longer,

1422 because it will disappear altogether at some point.

1423 - Users are strongly encouraged to write "0 < n" rather than

1424 "n ~= 0". Theorems and proof tools have been modified towards this

1425 `standard'.

1427 * HOL/Lists:

1428 the function "set_of_list" has been renamed "set" (and its theorems too);

1429 the function "nth" now takes its arguments in the reverse order and

1430 has acquired the infix notation "!" as in "xs!n".

1432 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};

1434 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its

1435 specialist theorems (like UN1_I) are gone. Similarly for (INT x.B x);

1437 * HOL/record: extensible records with schematic structural subtyping

1438 (single inheritance); EXPERIMENTAL version demonstrating the encoding,

1439 still lacks various theorems and concrete record syntax;

1442 *** HOLCF ***

1444 * removed "axioms" and "generated by" sections;

1446 * replaced "ops" section by extended "consts" section, which is capable of

1447 handling the continuous function space "->" directly;

1449 * domain package:

1450 . proves theorems immediately and stores them in the theory,

1451 . creates hierachical name space,

1452 . now uses normal mixfix annotations (instead of cinfix...),

1453 . minor changes to some names and values (for consistency),

1454 . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,

1455 . separator between mutual domain defs: changed "," to "and",

1456 . improved handling of sort constraints; now they have to

1457 appear on the left-hand side of the equations only;

1459 * fixed LAM <x,y,zs>.b syntax;

1461 * added extended adm_tac to simplifier in HOLCF -- can now discharge

1462 adm (%x. P (t x)), where P is chainfinite and t continuous;

1465 *** FOL and ZF ***

1467 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.

1468 with `addloop' of the simplifier to faciliate case splitting in premises.

1470 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as

1471 in HOL, they strip ALL and --> from proved theorems;

1475 New in Isabelle94-8 (May 1997)

1476 ------------------------------

1478 *** General Changes ***

1480 * new utilities to build / run / maintain Isabelle etc. (in parts

1481 still somewhat experimental); old Makefiles etc. still functional;

1483 * new 'Isabelle System Manual';

1485 * INSTALL text, together with ./configure and ./build scripts;

1487 * reimplemented type inference for greater efficiency, better error

1488 messages and clean internal interface;

1490 * prlim command for dealing with lots of subgoals (an easier way of

1491 setting goals_limit);

1494 *** Syntax ***

1496 * supports alternative (named) syntax tables (parser and pretty

1497 printer); internal interface is provided by add_modesyntax(_i);

1499 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to

1500 be used in conjunction with the Isabelle symbol font; uses the

1501 "symbols" syntax table;

1503 * added token_translation interface (may translate name tokens in

1504 arbitrary ways, dependent on their type (free, bound, tfree, ...) and

1505 the current print_mode); IMPORTANT: user print translation functions

1506 are responsible for marking newly introduced bounds

1507 (Syntax.mark_boundT);

1509 * token translations for modes "xterm" and "xterm_color" that display

1510 names in bold, underline etc. or colors (which requires a color

1511 version of xterm);

1513 * infixes may now be declared with names independent of their syntax;

1515 * added typed_print_translation (like print_translation, but may

1516 access type of constant);

1519 *** Classical Reasoner ***

1521 Blast_tac: a new tactic! It is often more powerful than fast_tac, but has

1522 some limitations. Blast_tac...

1523 + ignores addss, addbefore, addafter; this restriction is intrinsic

1524 + ignores elimination rules that don't have the correct format

1525 (the conclusion MUST be a formula variable)

1526 + ignores types, which can make HOL proofs fail

1527 + rules must not require higher-order unification, e.g. apply_type in ZF

1528 [message "Function Var's argument not a bound variable" relates to this]

1529 + its proof strategy is more general but can actually be slower

1531 * substitution with equality assumptions no longer permutes other

1532 assumptions;

1534 * minor changes in semantics of addafter (now called addaltern); renamed

1535 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper

1536 (and access functions for it);

1538 * improved combination of classical reasoner and simplifier:

1539 + functions for handling clasimpsets

1540 + improvement of addss: now the simplifier is called _after_ the

1541 safe steps.

1542 + safe variant of addss called addSss: uses safe simplifications

1543 _during_ the safe steps. It is more complete as it allows multiple

1544 instantiations of unknowns (e.g. with slow_tac).

1546 *** Simplifier ***

1548 * added interface for simplification procedures (functions that

1549 produce *proven* rewrite rules on the fly, depending on current

1550 redex);

1552 * ordering on terms as parameter (used for ordered rewriting);

1554 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;

1556 * the solver is now split into a safe and an unsafe part.

1557 This should be invisible for the normal user, except that the

1558 functions setsolver and addsolver have been renamed to setSolver and

1559 addSolver; added safe_asm_full_simp_tac;

1562 *** HOL ***

1564 * a generic induction tactic `induct_tac' which works for all datatypes and

1565 also for type `nat';

1567 * a generic case distinction tactic `exhaust_tac' which works for all

1568 datatypes and also for type `nat';

1570 * each datatype comes with a function `size';

1572 * patterns in case expressions allow tuple patterns as arguments to

1573 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';

1575 * primrec now also works with type nat;

1577 * recdef: a new declaration form, allows general recursive functions to be

1578 defined in theory files. See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.

1580 * the constant for negation has been renamed from "not" to "Not" to

1581 harmonize with FOL, ZF, LK, etc.;

1583 * HOL/ex/LFilter theory of a corecursive "filter" functional for

1584 infinite lists;

1586 * HOL/Modelcheck demonstrates invocation of model checker oracle;

1588 * HOL/ex/Ring.thy declares cring_simp, which solves equational

1589 problems in commutative rings, using axiomatic type classes for + and *;

1591 * more examples in HOL/MiniML and HOL/Auth;

1593 * more default rewrite rules for quantifiers, union/intersection;

1595 * a new constant `arbitrary == @x.False';

1597 * HOLCF/IOA replaces old HOL/IOA;

1599 * HOLCF changes: derived all rules and arities

1600 + axiomatic type classes instead of classes

1601 + typedef instead of faking type definitions

1602 + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.

1603 + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po

1604 + eliminated the types void, one, tr

1605 + use unit lift and bool lift (with translations) instead of one and tr

1606 + eliminated blift from Lift3.thy (use Def instead of blift)

1607 all eliminated rules are derived as theorems --> no visible changes ;

1610 *** ZF ***

1612 * ZF now has Fast_tac, Simp_tac and Auto_tac. Union_iff is a now a default

1613 rewrite rule; this may affect some proofs. eq_cs is gone but can be put back

1614 as ZF_cs addSIs [equalityI];

1618 New in Isabelle94-7 (November 96)

1619 ---------------------------------

1621 * allowing negative levels (as offsets) in prlev and choplev;

1623 * super-linear speedup for large simplifications;

1625 * FOL, ZF and HOL now use miniscoping: rewriting pushes

1626 quantifications in as far as possible (COULD MAKE EXISTING PROOFS

1627 FAIL); can suppress it using the command Delsimps (ex_simps @

1628 all_simps); De Morgan laws are also now included, by default;

1630 * improved printing of ==> : ~:

1632 * new object-logic "Sequents" adds linear logic, while replacing LK

1633 and Modal (thanks to Sara Kalvala);

1635 * HOL/Auth: correctness proofs for authentication protocols;

1637 * HOL: new auto_tac combines rewriting and classical reasoning (many

1638 examples on HOL/Auth);

1640 * HOL: new command AddIffs for declaring theorems of the form P=Q to

1641 the rewriter and classical reasoner simultaneously;

1643 * function uresult no longer returns theorems in "standard" format;

1644 regain previous version by: val uresult = standard o uresult;

1648 New in Isabelle94-6

1649 -------------------

1651 * oracles -- these establish an interface between Isabelle and trusted

1652 external reasoners, which may deliver results as theorems;

1654 * proof objects (in particular record all uses of oracles);

1656 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;

1658 * "constdefs" section in theory files;

1660 * "primrec" section (HOL) no longer requires names;

1662 * internal type "tactic" now simply "thm -> thm Sequence.seq";

1666 New in Isabelle94-5

1667 -------------------

1669 * reduced space requirements;

1671 * automatic HTML generation from theories;

1673 * theory files no longer require "..." (quotes) around most types;

1675 * new examples, including two proofs of the Church-Rosser theorem;

1677 * non-curried (1994) version of HOL is no longer distributed;

1681 New in Isabelle94-4

1682 -------------------

1684 * greatly reduced space requirements;

1686 * theory files (.thy) no longer require \...\ escapes at line breaks;

1688 * searchable theorem database (see the section "Retrieving theorems" on

1689 page 8 of the Reference Manual);

1691 * new examples, including Grabczewski's monumental case study of the

1692 Axiom of Choice;

1694 * The previous version of HOL renamed to Old_HOL;

1696 * The new version of HOL (previously called CHOL) uses a curried syntax

1697 for functions. Application looks like f a b instead of f(a,b);

1699 * Mutually recursive inductive definitions finally work in HOL;

1701 * In ZF, pattern-matching on tuples is now available in all abstractions and

1702 translates to the operator "split";

1706 New in Isabelle94-3

1707 -------------------

1709 * new infix operator, addss, allowing the classical reasoner to

1710 perform simplification at each step of its search. Example:

1711 fast_tac (cs addss ss)

1713 * a new logic, CHOL, the same as HOL, but with a curried syntax

1714 for functions. Application looks like f a b instead of f(a,b). Also pairs

1715 look like (a,b) instead of <a,b>;

1717 * PLEASE NOTE: CHOL will eventually replace HOL!

1719 * In CHOL, pattern-matching on tuples is now available in all abstractions.

1720 It translates to the operator "split". A new theory of integers is available;

1722 * In ZF, integer numerals now denote two's-complement binary integers.

1723 Arithmetic operations can be performed by rewriting. See ZF/ex/Bin.ML;

1725 * Many new examples: I/O automata, Church-Rosser theorem, equivalents

1726 of the Axiom of Choice;

1730 New in Isabelle94-2

1731 -------------------

1733 * Significantly faster resolution;

1735 * the different sections in a .thy file can now be mixed and repeated

1736 freely;

1738 * Database of theorems for FOL, HOL and ZF. New

1739 commands including qed, qed_goal and bind_thm store theorems in the database.

1741 * Simple database queries: return a named theorem (get_thm) or all theorems of

1742 a given theory (thms_of), or find out what theory a theorem was proved in

1743 (theory_of_thm);

1745 * Bugs fixed in the inductive definition and datatype packages;

1747 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs

1748 and HOL_dup_cs obsolete;

1750 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1

1751 have been removed;

1753 * Simpler definition of function space in ZF;

1755 * new results about cardinal and ordinal arithmetic in ZF;

1757 * 'subtype' facility in HOL for introducing new types as subsets of existing

1758 types;

1761 $Id$