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NEWS

author | nipkow |

Wed Aug 17 14:19:17 2005 +0200 (2005-08-17) | |

changeset 17092 | 16971afe75f6 |

parent 17047 | e2e2d75bb37b |

child 17095 | 669005f73b81 |

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

*** empty log message ***

1 Isabelle NEWS -- history user-relevant changes

2 ==============================================

4 New in this Isabelle release

5 ----------------------------

7 *** General ***

9 * Theory headers: the new header syntax for Isar theories is

11 theory <name>

12 imports <theory1> ... <theoryN>

13 uses <file1> ... <fileM>

14 begin

16 where the 'uses' part is optional. The previous syntax

18 theory <name> = <theory1> + ... + <theoryN>:

20 will disappear in the next release. Use isatool fixheaders to convert

21 existing theory files. Note that there is no change in ancient

22 non-Isar theories.

24 * Theory loader: parent theories can now also be referred to via

25 relative and absolute paths.

27 * Improved version of thms_containing searches for a list of criteria

28 instead of a list of constants. Known criteria are: intro, elim, dest,

29 name:string, simp:term, and any term. Criteria can be preceded by '-'

30 to select theorems that do not match. Intro, elim, dest select

31 theorems that match the current goal, name:s selects theorems whose

32 fully qualified name contain s, and simp:term selects all

33 simplification rules whose lhs match term. Any other term is

34 interpreted as pattern and selects all theorems matching the

35 pattern. Available in ProofGeneral under 'ProofGeneral -> Find

36 Theorems' or C-c C-f. Example:

38 C-c C-f (100) "(_::nat) + _ + _" intro -name:"HOL."

40 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",

41 matching the current goal as introduction rule and not having "HOL."

42 in their name (i.e. not being defined in theory HOL).

45 *** Document preparation ***

47 * Commands 'display_drafts' and 'print_drafts' perform simple output

48 of raw sources. Only those symbols that do not require additional

49 LaTeX packages (depending on comments in isabellesym.sty) are

50 displayed properly, everything else is left verbatim. isatool display

51 and isatool print are used as front ends (these are subject to the

52 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).

54 * Command tags control specific markup of certain regions of text,

55 notably folding and hiding. Predefined tags include "theory" (for

56 theory begin and end), "proof" for proof commands, and "ML" for

57 commands involving ML code; the additional tags "visible" and

58 "invisible" are unused by default. Users may give explicit tag

59 specifications in the text, e.g. ''by %invisible (auto)''. The

60 interpretation of tags is determined by the LaTeX job during document

61 preparation: see option -V of isatool usedir, or options -n and -t of

62 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,

63 \isadroptag.

65 Several document versions may be produced at the same time via isatool

66 usedir (the generated index.html will link all of them). Typical

67 specifications include ''-V document=theory,proof,ML'' to present

68 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold

69 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit

70 these parts without any formal replacement text. The Isabelle site

71 default settings produce ''document'' and ''outline'' versions as

72 specified above.

74 * Several new antiquotation:

76 @{term_type term} prints a term with its type annotated;

78 @{typeof term} prints the type of a term;

80 @{const const} is the same as @{term const}, but checks that the

81 argument is a known logical constant;

83 @{term_style style term} and @{thm_style style thm} print a term or

84 theorem applying a "style" to it

86 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of

87 definitions, equations, inequations etc., 'concl' printing only the

88 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem9'

89 to print the specified premise. TermStyle.add_style provides an ML

90 interface for introducing further styles. See also the "LaTeX Sugar"

91 document practical applications.

94 *** Pure ***

96 * Considerably improved version of 'constdefs' command. Now performs

97 automatic type-inference of declared constants; additional support for

98 local structure declarations (cf. locales and HOL records), see also

99 isar-ref manual. Potential INCOMPATIBILITY: need to observe strictly

100 sequential dependencies of definitions within a single 'constdefs'

101 section; moreover, the declared name needs to be an identifier. If

102 all fails, consider to fall back on 'consts' and 'defs' separately.

104 * Improved indexed syntax and implicit structures. First of all,

105 indexed syntax provides a notational device for subscripted

106 application, using the new syntax \<^bsub>term\<^esub> for arbitrary

107 expressions. Secondly, in a local context with structure

108 declarations, number indexes \<^sub>n or the empty index (default

109 number 1) refer to a certain fixed variable implicitly; option

110 show_structs controls printing of implicit structures. Typical

111 applications of these concepts involve record types and locales.

113 * New command 'no_syntax' removes grammar declarations (and

114 translations) resulting from the given syntax specification, which is

115 interpreted in the same manner as for the 'syntax' command.

117 * 'Advanced' translation functions (parse_translation etc.) may depend

118 on the signature of the theory context being presently used for

119 parsing/printing, see also isar-ref manual.

121 * Improved 'oracle' command provides a type-safe interface to turn an

122 ML expression of type theory -> T -> term into a primitive rule of

123 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle

124 is already included here); see also FOL/ex/IffExample.thy;

125 INCOMPATIBILITY.

127 * Improved internal renaming of symbolic identifiers -- attach primes

128 instead of base 26 numbers.

130 * New flag show_question_marks controls printing of leading question

131 marks in schematic variable names.

133 * In schematic variable names, *any* symbol following \<^isub> or

134 \<^isup> is now treated as part of the base name. For example, the

135 following works without printing of awkward ".0" indexes:

137 lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"

138 by simp

140 * Inner syntax includes (*(*nested*) comments*).

142 * Pretty pinter now supports unbreakable blocks, specified in mixfix

143 annotations as "(00...)".

145 * Clear separation of logical types and nonterminals, where the latter

146 may only occur in 'syntax' specifications or type abbreviations.

147 Before that distinction was only partially implemented via type class

148 "logic" vs. "{}". Potential INCOMPATIBILITY in rare cases of improper

149 use of 'types'/'consts' instead of 'nonterminals'/'syntax'. Some very

150 exotic syntax specifications may require further adaption

151 (e.g. Cube/Base.thy).

153 * Removed obsolete type class "logic", use the top sort {} instead.

154 Note that non-logical types should be declared as 'nonterminals'

155 rather than 'types'. INCOMPATIBILITY for new object-logic

156 specifications.

158 * Simplifier: can now control the depth to which conditional rewriting

159 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth

160 Limit.

162 * Simplifier: simplification procedures may now take the current

163 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc

164 interface), which is very useful for calling the Simplifier

165 recursively. Minor INCOMPATIBILITY: the 'prems' argument of simprocs

166 is gone -- use prems_of_ss on the simpset instead. Moreover, the

167 low-level mk_simproc no longer applies Logic.varify internally, to

168 allow for use in a context of fixed variables.

170 * thin_tac now works even if the assumption being deleted contains !!

171 or ==>. More generally, erule now works even if the major premise of

172 the elimination rule contains !! or ==>.

174 * Reorganized bootstrapping of the Pure theories; CPure is now derived

175 from Pure, which contains all common declarations already. Both

176 theories are defined via plain Isabelle/Isar .thy files.

177 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /

178 CPure.elim / CPure.dest attributes) now appear in the Pure name space;

179 use isatool fixcpure to adapt your theory and ML sources.

181 * New syntax 'name(i-j, i-, i, ...)' for referring to specific

182 selections of theorems in named facts via index ranges.

184 * More efficient treatment of intermediate checkpoints in interactive

185 theory development.

188 *** Locales ***

190 * New commands for the interpretation of locale expressions in

191 theories ('interpretation') and proof contexts ('interpret'). These

192 take an instantiation of the locale parameters and compute proof

193 obligations from the instantiated specification. After the

194 obligations have been discharged, the instantiated theorems of the

195 locale are added to the theory or proof context. Interpretation is

196 smart in that already active interpretations do not occur in proof

197 obligations, neither are instantiated theorems stored in duplicate.

198 Use print_interps to inspect active interpretations of a particular

199 locale. For details, see the Isar Reference manual.

201 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use

202 'interpret' instead.

204 * Proper static binding of attribute syntax -- i.e. types / terms /

205 facts mentioned as arguments are always those of the locale definition

206 context, independently of the context of later invocations. Moreover,

207 locale operations (renaming and type / term instantiation) are applied

208 to attribute arguments as expected.

210 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of

211 actual attributes; rare situations may require Attrib.attribute to

212 embed those attributes into Attrib.src that lack concrete syntax.

213 Attribute implementations need to cooperate properly with the static

214 binding mechanism. Basic parsers Args.XXX_typ/term/prop and

215 Attrib.XXX_thm etc. already do the right thing without further

216 intervention. Only unusual applications -- such as "where" or "of"

217 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both

218 on the context and the facts involved -- may have to assign parsed

219 values to argument tokens explicitly.

221 * New context element "constrains" adds type constraints to parameters --

222 there is no logical significance.

224 * Context expressions: renaming parameters permits syntax

225 redeclaration as well.

227 * Locale definition: 'includes' now disallowed.

229 * Changed parameter management in theorem generation for long goal

230 statements with 'includes'. INCOMPATIBILITY: produces a different

231 theorem statement in rare situations.

233 * Attributes 'induct' and 'cases': type or set names may now be

234 locally fixed variables as well.

236 * Antiquotations now provide the option 'locale=NAME' to specify an

237 alternative context used for evaluating and printing the subsequent

238 argument, as in @{thm [locale=LC] fold_commute}, for example.

241 *** Provers ***

243 * Provers/hypsubst.ML: improved version of the subst method, for

244 single-step rewriting: it now works in bound variable contexts. New is

245 'subst (asm)', for rewriting an assumption. INCOMPATIBILITY: may

246 rewrite a different subterm than the original subst method, which is

247 still available as 'simplesubst'.

249 * Provers/quasi.ML: new transitivity reasoners for transitivity only

250 and quasi orders.

252 * Provers/trancl.ML: new transitivity reasoner for transitive and

253 reflexive-transitive closure of relations.

255 * Provers/blast.ML: new reference depth_limit to make blast's depth

256 limit (previously hard-coded with a value of 20) user-definable.

258 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup

259 is peformed already. Object-logics merely need to finish their

260 initial simpset configuration as before. INCOMPATIBILITY.

263 *** HOL ***

265 * Symbolic syntax of Hilbert Choice Operator is now as follows:

267 syntax (epsilon)

268 "_Eps" :: "[pttrn, bool] => 'a" ("(3\<some>_./ _)" [0, 10] 10)

270 The symbol \<some> is displayed as the alternative epsilon of LaTeX

271 and x-symbol; use option '-m epsilon' to get it actually printed.

272 Moreover, the mathematically important symbolic identifier \<epsilon>

273 becomes available as variable, constant etc. INCOMPATIBILITY,

275 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".

276 Similarly for all quantifiers: "ALL x > y" etc. The x-symbol for >=

277 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to

278 support corresponding Isar calculations.

280 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"

281 instead of ":".

283 * theory SetInterval: changed the syntax for open intervals:

285 Old New

286 {..n(} {..<n}

287 {)n..} {n<..}

288 {m..n(} {m..<n}

289 {)m..n} {m<..n}

290 {)m..n(} {m<..<n}

292 The old syntax is still supported but will disappear in the next

293 release. For conversion use the following Emacs search and replace

294 patterns (these are not perfect but work quite well):

296 {)\([^\.]*\)\.\. -> {\1<\.\.}

297 \.\.\([^(}]*\)(} -> \.\.<\1}

299 * theory Finite_Set: changed the syntax for 'setsum', summation over

300 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is

301 now either "SUM x:A. e" or "\<Sum>x \<in> A. e".

303 Some new syntax forms are available:

305 "\<Sum>x | P. e" for "setsum (%x. e) {x. P}"

306 "\<Sum>x = a..b. e" for "setsum (%x. e) {a..b}"

307 "\<Sum>x = a..<b. e" for "setsum (%x. e) {a..<b}"

308 "\<Sum>x < k. e" for "setsum (%x. e) {..<k}"

310 The latter form "\<Sum>x < k. e" used to be based on a separate

311 function "Summation", which has been discontinued.

313 * theory Finite_Set: in structured induction proofs, the insert case

314 is now 'case (insert x F)' instead of the old counterintuitive 'case

315 (insert F x)'.

317 * The 'refute' command has been extended to support a much larger

318 fragment of HOL, including axiomatic type classes, constdefs and

319 typedefs, inductive datatypes and recursion.

321 * Datatype induction via method 'induct' now preserves the name of the

322 induction variable. For example, when proving P(xs::'a list) by

323 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather

324 than P(list) ==> P(a#list) as previously. Potential INCOMPATIBILITY

325 in unstructured proof scripts.

327 * Reworked implementation of records. Improved scalability for

328 records with many fields, avoiding performance problems for type

329 inference. Records are no longer composed of nested field types, but

330 of nested extension types. Therefore the record type only grows linear

331 in the number of extensions and not in the number of fields. The

332 top-level (users) view on records is preserved. Potential

333 INCOMPATIBILITY only in strange cases, where the theory depends on the

334 old record representation. The type generated for a record is called

335 <record_name>_ext_type.

337 Flag record_quick_and_dirty_sensitive can be enabled to skip the

338 proofs triggered by a record definition or a simproc (if

339 quick_and_dirty is enabled). Definitions of large records can take

340 quite long.

342 New simproc record_upd_simproc for simplification of multiple record

343 updates enabled by default. Moreover, trivial updates are also

344 removed: r(|x := x r|) = r. INCOMPATIBILITY: old proofs break

345 occasionally, since simplification is more powerful by default.

347 * Simplifier: automatically reasons about transitivity chains

348 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics

349 provided by Provers/trancl.ML as additional solvers. INCOMPATIBILITY:

350 old proofs break occasionally as simplification may now solve more

351 goals than previously.

353 * Simplifier: converts x <= y into x = y if assumption y <= x is

354 present. Works for all partial orders (class "order"), in particular

355 numbers and sets. For linear orders (e.g. numbers) it treats ~ x < y

356 just like y <= x.

358 * Simplifier: new simproc for "let x = a in f x". If a is a free or

359 bound variable or a constant then the let is unfolded. Otherwise

360 first a is simplified to b, and then f b is simplified to g. If

361 possible we abstract b from g arriving at "let x = b in h x",

362 otherwise we unfold the let and arrive at g. The simproc can be

363 enabled/disabled by the reference use_let_simproc. Potential

364 INCOMPATIBILITY since simplification is more powerful by default.

366 * Classical reasoning: the meson method now accepts theorems as arguments.

368 * Theory OrderedGroup and Ring_and_Field: various additions and

369 improvements to faciliate calculations involving equalities and

370 inequalities.

372 The following theorems have been eliminated or modified

373 (INCOMPATIBILITY):

375 abs_eq now named abs_of_nonneg

376 abs_of_ge_0 now named abs_of_nonneg

377 abs_minus_eq now named abs_of_nonpos

378 imp_abs_id now named abs_of_nonneg

379 imp_abs_neg_id now named abs_of_nonpos

380 mult_pos now named mult_pos_pos

381 mult_pos_le now named mult_nonneg_nonneg

382 mult_pos_neg_le now named mult_nonneg_nonpos

383 mult_pos_neg2_le now named mult_nonneg_nonpos2

384 mult_neg now named mult_neg_neg

385 mult_neg_le now named mult_nonpos_nonpos

387 * Theory Parity: added rules for simplifying exponents.

389 * Theory List:

391 The following theorems have been eliminated or modified

392 (INCOMPATIBILITY):

394 list_all_Nil now named list_all.simps(1)

395 list_all_Cons now named list_all.simps(2)

396 list_all_conv now named list_all_iff

397 set_mem_eq now named mem_iff

399 * Theories SetsAndFunctions and BigO (see HOL/Library) support

400 asymptotic "big O" calculations. See the notes in BigO.thy.

403 *** HOL-Complex ***

405 * Theory RealDef: better support for embedding natural numbers and

406 integers in the reals.

408 The following theorems have been eliminated or modified

409 (INCOMPATIBILITY):

411 exp_ge_add_one_self now requires no hypotheses

412 real_of_int_add reversed direction of equality (use [symmetric])

413 real_of_int_minus reversed direction of equality (use [symmetric])

414 real_of_int_diff reversed direction of equality (use [symmetric])

415 real_of_int_mult reversed direction of equality (use [symmetric])

417 * Theory RComplete: expanded support for floor and ceiling functions.

419 * Theory Ln is new, with properties of the natural logarithm

422 *** HOLCF ***

424 * HOLCF: discontinued special version of 'constdefs' (which used to

425 support continuous functions) in favor of the general Pure one with

426 full type-inference.

429 *** ZF ***

431 * ZF/ex: theories Group and Ring provide examples in abstract algebra,

432 including the First Isomorphism Theorem (on quotienting by the kernel

433 of a homomorphism).

435 * ZF/Simplifier: install second copy of type solver that actually

436 makes use of TC rules declared to Isar proof contexts (or locales);

437 the old version is still required for ML proof scripts.

440 *** ML ***

442 * Pure/library.ML no longer defines its own option datatype, but uses

443 that of the SML basis, which has constructors NONE and SOME instead of

444 None and Some, as well as exception Option.Option instead of OPTION.

445 The functions the, if_none, is_some, is_none have been adapted

446 accordingly, while Option.map replaces apsome.

448 * Pure/library.ML: the exception LIST has been given up in favour of

449 the standard exceptions Empty and Subscript, as well as

450 Library.UnequalLengths. Function like Library.hd and Library.tl are

451 superceded by the standard hd and tl functions etc.

453 A number of basic list functions are no longer exported to the ML

454 toplevel, as they are variants of predefined functions. The following

455 suggests how one can translate existing code:

457 rev_append xs ys = List.revAppend (xs, ys)

458 nth_elem (i, xs) = List.nth (xs, i)

459 last_elem xs = List.last xs

460 flat xss = List.concat xss

461 seq fs = List.app fs

462 partition P xs = List.partition P xs

463 mapfilter f xs = List.mapPartial f xs

465 * Pure/library.ML: several combinators for linear functional

466 transformations, notably reverse application and composition:

468 x |> f f #> g

469 (x, y) |-> f f #-> g

471 * Pure/library.ML: canonical list combinators fold, fold_rev, and

472 fold_map support linear functional transformations and nesting. For

473 example:

475 fold f [x1, ..., xN] y =

476 y |> f x1 |> ... |> f xN

478 (fold o fold) f [xs1, ..., xsN] y =

479 y |> fold f xs1 |> ... |> fold f xsN

481 fold f [x1, ..., xN] =

482 f x1 #> ... #> f xN

484 (fold o fold) f [xs1, ..., xsN] =

485 fold f xs1 #> ... #> fold f xsN

487 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,

488 fold_types traverse types/terms from left to right, observing

489 canonical argument order. Supercedes previous foldl_XXX versions,

490 add_frees, add_vars etc. have been adapted as well: INCOMPATIBILITY.

492 * Pure: output via the Isabelle channels of writeln/warning/error

493 etc. is now passed through Output.output, with a hook for arbitrary

494 transformations depending on the print_mode (cf. Output.add_mode --

495 the first active mode that provides a output function wins). Already

496 formatted output may be embedded into further text via Output.raw; the

497 result of Pretty.string_of/str_of and derived functions

498 (string_of_term/cterm/thm etc.) is already marked raw to accommodate

499 easy composition of diagnostic messages etc. Programmers rarely need

500 to care about Output.output or Output.raw at all, with some notable

501 exceptions: Output.output is required when bypassing the standard

502 channels (writeln etc.), or in token translations to produce properly

503 formatted results; Output.raw is required when capturing already

504 output material that will eventually be presented to the user a second

505 time. For the default print mode, both Output.output and Output.raw

506 have no effect.

508 * Pure: Output.time_accumulator NAME creates an operator ('a -> 'b) ->

509 'a -> 'b to measure runtime and count invocations; the cumulative

510 results are displayed at the end of a batch session.

512 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.

513 Reference Toplevel.debug (default false) controls detailed printing

514 and tracing of low-level exceptions; Toplevel.profiling (default 0)

515 controls execution profiling -- set to 1 for time and 2 for space

516 (both increase the runtime).

518 * Isar session: The initial use of ROOT.ML is now always timed,

519 i.e. the log will show the actual process times, in contrast to the

520 elapsed wall-clock time that the outer shell wrapper produces.

522 * Pure: structure OrdList (cf. Pure/General/ord_list.ML) provides a

523 reasonably efficient light-weight implementation of sets as lists.

525 * Pure: more efficient orders for basic syntactic entities: added

526 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord

527 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is

528 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast

529 orders now -- potential INCOMPATIBILITY for code that depends on a

530 particular order for Symtab.keys, Symtab.dest, etc. (consider using

531 Library.sort_strings on result).

533 * Pure: name spaces have been refined, with significant changes of the

534 internal interfaces -- INCOMPATIBILITY. Renamed cond_extern(_table)

535 to extern(_table). The plain name entry path is superceded by a

536 general 'naming' context, which also includes the 'policy' to produce

537 a fully qualified name and external accesses of a fully qualified

538 name; NameSpace.extend is superceded by context dependent

539 Sign.declare_name. Several theory and proof context operations modify

540 the naming context. Especially note Theory.restore_naming and

541 ProofContext.restore_naming to get back to a sane state; note that

542 Theory.add_path is no longer sufficient to recover from

543 Theory.absolute_path in particular.

545 * Pure: new flags short_names (default false) and unique_names

546 (default true) for controlling output of qualified names. If

547 short_names is set, names are printed unqualified. If unique_names is

548 reset, the name prefix is reduced to the minimum required to achieve

549 the original result when interning again, even if there is an overlap

550 with earlier declarations.

552 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is

553 now 'extend', and 'merge' gets an additional Pretty.pp argument

554 (useful for printing error messages). INCOMPATIBILITY.

556 * Pure: major reorganization of the theory context. Type Sign.sg and

557 Theory.theory are now identified, referring to the universal

558 Context.theory (see Pure/context.ML). Actual signature and theory

559 content is managed as theory data. The old code and interfaces were

560 spread over many files and structures; the new arrangement introduces

561 considerable INCOMPATIBILITY to gain more clarity:

563 Context -- theory management operations (name, identity, inclusion,

564 parents, ancestors, merge, etc.), plus generic theory data;

566 Sign -- logical signature and syntax operations (declaring consts,

567 types, etc.), plus certify/read for common entities;

569 Theory -- logical theory operations (stating axioms, definitions,

570 oracles), plus a copy of logical signature operations (consts,

571 types, etc.); also a few basic management operations (Theory.copy,

572 Theory.merge, etc.)

574 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm

575 etc.) as well as the sign field in Thm.rep_thm etc. have been retained

576 for convenience -- they merely return the theory.

578 * Pure: the Isar proof context type is already defined early in Pure

579 as Context.proof (note that ProofContext.context and Proof.context are

580 aliases, where the latter is the preferred name). This enables other

581 Isabelle components to refer to that type even before Isar is present.

583 * Pure/sign/theory: discontinued named name spaces (i.e. classK,

584 typeK, constK, axiomK, oracleK), but provide explicit operations for

585 any of these kinds. For example, Sign.intern typeK is now

586 Sign.intern_type, Theory.hide_space Sign.typeK is now

587 Theory.hide_types. Also note that former

588 Theory.hide_classes/types/consts are now

589 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions

590 internalize their arguments! INCOMPATIBILITY.

592 * Pure: get_thm interface (of PureThy and ProofContext) expects

593 datatype thmref (with constructors Name and NameSelection) instead of

594 plain string -- INCOMPATIBILITY;

596 * Pure: cases produced by proof methods specify options, where NONE

597 means to remove case bindings -- INCOMPATIBILITY in

598 (RAW_)METHOD_CASES.

600 * Pure: the following operations retrieve axioms or theorems from a

601 theory node or theory hierarchy, respectively:

603 Theory.axioms_of: theory -> (string * term) list

604 Theory.all_axioms_of: theory -> (string * term) list

605 PureThy.thms_of: theory -> (string * thm) list

606 PureThy.all_thms_of: theory -> (string * thm) list

608 * Pure: print_tac now outputs the goal through the trace channel.

610 * Pure/Simplifier: improved handling of bound variables (nameless

611 representation, avoid allocating new strings). Simprocs that invoke

612 the Simplifier recursively should use Simplifier.inherit_bounds to

613 avoid local name clashes.

615 * Pure/Provers: Simplifier and Classical Reasoner now support proof

616 context dependent plug-ins (simprocs, solvers, wrappers etc.). These

617 extra components are stored in the theory and patched into the

618 simpset/claset when used in an Isar proof context. Context dependent

619 components are maintained by the following theory operations:

621 Simplifier.add_context_simprocs

622 Simplifier.del_context_simprocs

623 Simplifier.set_context_subgoaler

624 Simplifier.reset_context_subgoaler

625 Simplifier.add_context_looper

626 Simplifier.del_context_looper

627 Simplifier.add_context_unsafe_solver

628 Simplifier.add_context_safe_solver

630 Classical.add_context_safe_wrapper

631 Classical.del_context_safe_wrapper

632 Classical.add_context_unsafe_wrapper

633 Classical.del_context_unsafe_wrapper

635 IMPORTANT NOTE: proof tools (methods etc.) need to use

636 local_simpset_of and local_claset_of to instead of the primitive

637 Simplifier.get_local_simpset and Classical.get_local_claset,

638 respectively, in order to see the context dependent fields!

640 * File.sysify_path and File.quote_sysify path have been replaced by

641 File.platform_path and File.shell_path (with appropriate hooks). This

642 provides a clean interface for unusual systems where the internal and

643 external process view of file names are different.

646 *** System ***

648 * Allow symlinks to all proper Isabelle executables (Isabelle,

649 isabelle, isatool etc.).

651 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for

652 isatool doc, isatool mkdir, display_drafts etc.).

654 * isatool usedir: option -f allows specification of the ML file to be

655 used by Isabelle; default is ROOT.ML.

657 * New isatool version outputs the version identifier of the Isabelle

658 distribution being used.

660 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format

661 (containing Boolean satisfiability problems) into Isabelle/HOL

662 theories.

666 New in Isabelle2004 (April 2004)

667 --------------------------------

669 *** General ***

671 * Provers/order.ML: new efficient reasoner for partial and linear orders.

672 Replaces linorder.ML.

674 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic

675 (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler

676 (\<a>...\<z>), are now considered normal letters, and can therefore

677 be used anywhere where an ASCII letter (a...zA...Z) has until

678 now. COMPATIBILITY: This obviously changes the parsing of some

679 terms, especially where a symbol has been used as a binder, say

680 '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed

681 as an identifier. Fix it by inserting a space around former

682 symbols. Call 'isatool fixgreek' to try to fix parsing errors in

683 existing theory and ML files.

685 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.

687 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now

688 allowed in identifiers. Similar to Greek letters \<^isub> is now considered

689 a normal (but invisible) letter. For multiple letter subscripts repeat

690 \<^isub> like this: x\<^isub>1\<^isub>2.

692 * Pure: There are now sub-/superscripts that can span more than one

693 character. Text between \<^bsub> and \<^esub> is set in subscript in

694 ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in

695 superscript. The new control characters are not identifier parts.

697 * Pure: Control-symbols of the form \<^raw:...> will literally print the

698 content of "..." to the latex file instead of \isacntrl... . The "..."

699 may consist of any printable characters excluding the end bracket >.

701 * Pure: Using new Isar command "finalconsts" (or the ML functions

702 Theory.add_finals or Theory.add_finals_i) it is now possible to

703 declare constants "final", which prevents their being given a definition

704 later. It is useful for constants whose behaviour is fixed axiomatically

705 rather than definitionally, such as the meta-logic connectives.

707 * Pure: 'instance' now handles general arities with general sorts

708 (i.e. intersections of classes),

710 * Presentation: generated HTML now uses a CSS style sheet to make layout

711 (somewhat) independent of content. It is copied from lib/html/isabelle.css.

712 It can be changed to alter the colors/layout of generated pages.

715 *** Isar ***

717 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,

718 cut_tac, subgoal_tac and thin_tac:

719 - Now understand static (Isar) contexts. As a consequence, users of Isar

720 locales are no longer forced to write Isar proof scripts.

721 For details see Isar Reference Manual, paragraph 4.3.2: Further tactic

722 emulations.

723 - INCOMPATIBILITY: names of variables to be instantiated may no

724 longer be enclosed in quotes. Instead, precede variable name with `?'.

725 This is consistent with the instantiation attribute "where".

727 * Attributes "where" and "of":

728 - Now take type variables of instantiated theorem into account when reading

729 the instantiation string. This fixes a bug that caused instantiated

730 theorems to have too special types in some circumstances.

731 - "where" permits explicit instantiations of type variables.

733 * Calculation commands "moreover" and "also" no longer interfere with

734 current facts ("this"), admitting arbitrary combinations with "then"

735 and derived forms.

737 * Locales:

738 - Goal statements involving the context element "includes" no longer

739 generate theorems with internal delta predicates (those ending on

740 "_axioms") in the premise.

741 Resolve particular premise with <locale>.intro to obtain old form.

742 - Fixed bug in type inference ("unify_frozen") that prevented mix of target

743 specification and "includes" elements in goal statement.

744 - Rule sets <locale>.intro and <locale>.axioms no longer declared as

745 [intro?] and [elim?] (respectively) by default.

746 - Experimental command for instantiation of locales in proof contexts:

747 instantiate <label>[<attrs>]: <loc>

748 Instantiates locale <loc> and adds all its theorems to the current context

749 taking into account their attributes. Label and attrs are optional

750 modifiers, like in theorem declarations. If present, names of

751 instantiated theorems are qualified with <label>, and the attributes

752 <attrs> are applied after any attributes these theorems might have already.

753 If the locale has assumptions, a chained fact of the form

754 "<loc> t1 ... tn" is expected from which instantiations of the parameters

755 are derived. The command does not support old-style locales declared

756 with "locale (open)".

757 A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.

759 * HOL: Tactic emulation methods induct_tac and case_tac understand static

760 (Isar) contexts.

763 *** HOL ***

765 * Proof import: new image HOL4 contains the imported library from

766 the HOL4 system with about 2500 theorems. It is imported by

767 replaying proof terms produced by HOL4 in Isabelle. The HOL4 image

768 can be used like any other Isabelle image. See

769 HOL/Import/HOL/README for more information.

771 * Simplifier:

772 - Much improved handling of linear and partial orders.

773 Reasoners for linear and partial orders are set up for type classes

774 "linorder" and "order" respectively, and are added to the default simpset

775 as solvers. This means that the simplifier can build transitivity chains

776 to solve goals from the assumptions.

777 - INCOMPATIBILITY: old proofs break occasionally. Typically, applications

778 of blast or auto after simplification become unnecessary because the goal

779 is solved by simplification already.

781 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,

782 all proved in axiomatic type classes for semirings, rings and fields.

784 * Numerics:

785 - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are

786 now formalized using the Ring_and_Field theory mentioned above.

787 - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently

788 than before, because now they are set up once in a generic manner.

789 - INCOMPATIBILITY: many type-specific arithmetic laws have gone.

790 Look for the general versions in Ring_and_Field (and Power if they concern

791 exponentiation).

793 * Type "rat" of the rational numbers is now available in HOL-Complex.

795 * Records:

796 - Record types are now by default printed with their type abbreviation

797 instead of the list of all field types. This can be configured via

798 the reference "print_record_type_abbr".

799 - Simproc "record_upd_simproc" for simplification of multiple updates added

800 (not enabled by default).

801 - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.

802 EX x. x = sel r to True (not enabled by default).

803 - Tactic "record_split_simp_tac" to split and simplify records added.

805 * 'specification' command added, allowing for definition by

806 specification. There is also an 'ax_specification' command that

807 introduces the new constants axiomatically.

809 * arith(_tac) is now able to generate counterexamples for reals as well.

811 * HOL-Algebra: new locale "ring" for non-commutative rings.

813 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function

814 definitions, thanks to Sava Krsti\'{c} and John Matthews.

816 * HOL-Matrix: a first theory for matrices in HOL with an application of

817 matrix theory to linear programming.

819 * Unions and Intersections:

820 The latex output syntax of UN and INT has been changed

821 from "\Union x \in A. B" to "\Union_{x \in A} B"

822 i.e. the index formulae has become a subscript.

823 Similarly for "\Union x. B", and for \Inter instead of \Union.

825 * Unions and Intersections over Intervals:

826 There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is

827 also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"

828 like in normal math, and corresponding versions for < and for intersection.

830 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard

831 lexicographic dictonary ordering has been added as "lexord".

833 * ML: the legacy theory structures Int and List have been removed. They had

834 conflicted with ML Basis Library structures having the same names.

836 * 'refute' command added to search for (finite) countermodels. Only works

837 for a fragment of HOL. The installation of an external SAT solver is

838 highly recommended. See "HOL/Refute.thy" for details.

840 * 'quickcheck' command: Allows to find counterexamples by evaluating

841 formulae under an assignment of free variables to random values.

842 In contrast to 'refute', it can deal with inductive datatypes,

843 but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"

844 for examples.

847 *** HOLCF ***

849 * Streams now come with concatenation and are part of the HOLCF image

853 New in Isabelle2003 (May 2003)

854 ------------------------------

856 *** General ***

858 * Provers/simplifier:

860 - Completely reimplemented method simp (ML: Asm_full_simp_tac):

861 Assumptions are now subject to complete mutual simplification,

862 not just from left to right. The simplifier now preserves

863 the order of assumptions.

865 Potential INCOMPATIBILITY:

867 -- simp sometimes diverges where the old version did

868 not, e.g. invoking simp on the goal

870 [| P (f x); y = x; f x = f y |] ==> Q

872 now gives rise to the infinite reduction sequence

874 P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...

876 Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this

877 kind of problem.

879 -- Tactics combining classical reasoner and simplification (such as auto)

880 are also affected by this change, because many of them rely on

881 simp. They may sometimes diverge as well or yield a different numbers

882 of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto

883 in case of problems. Sometimes subsequent calls to the classical

884 reasoner will fail because a preceeding call to the simplifier too

885 eagerly simplified the goal, e.g. deleted redundant premises.

887 - The simplifier trace now shows the names of the applied rewrite rules

889 - You can limit the number of recursive invocations of the simplifier

890 during conditional rewriting (where the simplifie tries to solve the

891 conditions before applying the rewrite rule):

892 ML "simp_depth_limit := n"

893 where n is an integer. Thus you can force termination where previously

894 the simplifier would diverge.

896 - Accepts free variables as head terms in congruence rules. Useful in Isar.

898 - No longer aborts on failed congruence proof. Instead, the

899 congruence is ignored.

901 * Pure: New generic framework for extracting programs from constructive

902 proofs. See HOL/Extraction.thy for an example instantiation, as well

903 as HOL/Extraction for some case studies.

905 * Pure: The main goal of the proof state is no longer shown by default, only

906 the subgoals. This behaviour is controlled by a new flag.

907 PG menu: Isabelle/Isar -> Settings -> Show Main Goal

908 (ML: Proof.show_main_goal).

910 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all

911 rules whose conclusion matches subgoal 1:

912 PG menu: Isabelle/Isar -> Show me -> matching rules

913 The rules are ordered by how closely they match the subgoal.

914 In particular, rules that solve a subgoal outright are displayed first

915 (or rather last, the way they are printed).

916 (ML: ProofGeneral.print_intros())

918 * Pure: New flag trace_unify_fail causes unification to print

919 diagnostic information (PG: in trace buffer) when it fails. This is

920 useful for figuring out why single step proofs like rule, erule or

921 assumption failed.

923 * Pure: Locale specifications now produce predicate definitions

924 according to the body of text (covering assumptions modulo local

925 definitions); predicate "loc_axioms" covers newly introduced text,

926 while "loc" is cumulative wrt. all included locale expressions; the

927 latter view is presented only on export into the global theory

928 context; potential INCOMPATIBILITY, use "(open)" option to fall back

929 on the old view without predicates;

931 * Pure: predefined locales "var" and "struct" are useful for sharing

932 parameters (as in CASL, for example); just specify something like

933 ``var x + var y + struct M'' as import;

935 * Pure: improved thms_containing: proper indexing of facts instead of

936 raw theorems; check validity of results wrt. current name space;

937 include local facts of proof configuration (also covers active

938 locales), cover fixed variables in index; may use "_" in term

939 specification; an optional limit for the number of printed facts may

940 be given (the default is 40);

942 * Pure: disallow duplicate fact bindings within new-style theory files

943 (batch-mode only);

945 * Provers: improved induct method: assumptions introduced by case

946 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from

947 the goal statement); "foo" still refers to all facts collectively;

949 * Provers: the function blast.overloaded has been removed: all constants

950 are regarded as potentially overloaded, which improves robustness in exchange

951 for slight decrease in efficiency;

953 * Provers/linorder: New generic prover for transitivity reasoning over

954 linear orders. Note: this prover is not efficient!

956 * Isar: preview of problems to finish 'show' now produce an error

957 rather than just a warning (in interactive mode);

960 *** HOL ***

962 * arith(_tac)

964 - Produces a counter example if it cannot prove a goal.

965 Note that the counter example may be spurious if the goal is not a formula

966 of quantifier-free linear arithmetic.

967 In ProofGeneral the counter example appears in the trace buffer.

969 - Knows about div k and mod k where k is a numeral of type nat or int.

971 - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free

972 linear arithmetic fails. This takes account of quantifiers and divisibility.

973 Presburger arithmetic can also be called explicitly via presburger(_tac).

975 * simp's arithmetic capabilities have been enhanced a bit: it now

976 takes ~= in premises into account (by performing a case split);

978 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands

979 are distributed over a sum of terms;

981 * New tactic "trans_tac" and method "trans" instantiate

982 Provers/linorder.ML for axclasses "order" and "linorder" (predicates

983 "<=", "<" and "=").

985 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main

986 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";

988 * 'typedef' command has new option "open" to suppress the set

989 definition;

991 * functions Min and Max on finite sets have been introduced (theory

992 Finite_Set);

994 * attribute [symmetric] now works for relations as well; it turns

995 (x,y) : R^-1 into (y,x) : R, and vice versa;

997 * induct over a !!-quantified statement (say !!x1..xn):

998 each "case" automatically performs "fix x1 .. xn" with exactly those names.

1000 * Map: `empty' is no longer a constant but a syntactic abbreviation for

1001 %x. None. Warning: empty_def now refers to the previously hidden definition

1002 of the empty set.

1004 * Algebra: formalization of classical algebra. Intended as base for

1005 any algebraic development in Isabelle. Currently covers group theory

1006 (up to Sylow's theorem) and ring theory (Universal Property of

1007 Univariate Polynomials). Contributions welcome;

1009 * GroupTheory: deleted, since its material has been moved to Algebra;

1011 * Complex: new directory of the complex numbers with numeric constants,

1012 nonstandard complex numbers, and some complex analysis, standard and

1013 nonstandard (Jacques Fleuriot);

1015 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;

1017 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques

1018 Fleuriot);

1020 * Real/HahnBanach: updated and adapted to locales;

1022 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,

1023 Gray and Kramer);

1025 * UNITY: added the Meier-Sanders theory of progress sets;

1027 * MicroJava: bytecode verifier and lightweight bytecode verifier

1028 as abstract algorithms, instantiated to the JVM;

1030 * Bali: Java source language formalization. Type system, operational

1031 semantics, axiomatic semantics. Supported language features:

1032 classes, interfaces, objects,virtual methods, static methods,

1033 static/instance fields, arrays, access modifiers, definite

1034 assignment, exceptions.

1037 *** ZF ***

1039 * ZF/Constructible: consistency proof for AC (Gdel's constructible

1040 universe, etc.);

1042 * Main ZF: virtually all theories converted to new-style format;

1045 *** ML ***

1047 * Pure: Tactic.prove provides sane interface for internal proofs;

1048 omits the infamous "standard" operation, so this is more appropriate

1049 than prove_goalw_cterm in many situations (e.g. in simprocs);

1051 * Pure: improved error reporting of simprocs;

1053 * Provers: Simplifier.simproc(_i) provides sane interface for setting

1054 up simprocs;

1057 *** Document preparation ***

1059 * uses \par instead of \\ for line breaks in theory text. This may

1060 shift some page breaks in large documents. To get the old behaviour

1061 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.

1063 * minimized dependencies of isabelle.sty and isabellesym.sty on

1064 other packages

1066 * \<euro> now needs package babel/greek instead of marvosym (which

1067 broke \Rightarrow)

1069 * normal size for \<zero>...\<nine> (uses \mathbf instead of

1070 textcomp package)

1074 New in Isabelle2002 (March 2002)

1075 --------------------------------

1077 *** Document preparation ***

1079 * greatly simplified document preparation setup, including more

1080 graceful interpretation of isatool usedir -i/-d/-D options, and more

1081 instructive isatool mkdir; users should basically be able to get

1082 started with "isatool mkdir HOL Test && isatool make"; alternatively,

1083 users may run a separate document processing stage manually like this:

1084 "isatool usedir -D output HOL Test && isatool document Test/output";

1086 * theory dependency graph may now be incorporated into documents;

1087 isatool usedir -g true will produce session_graph.eps/.pdf for use

1088 with \includegraphics of LaTeX;

1090 * proper spacing of consecutive markup elements, especially text

1091 blocks after section headings;

1093 * support bold style (for single symbols only), input syntax is like

1094 this: "\<^bold>\<alpha>" or "\<^bold>A";

1096 * \<bullet> is now output as bold \cdot by default, which looks much

1097 better in printed text;

1099 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;

1100 note that these symbols are currently unavailable in Proof General /

1101 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;

1103 * isatool latex no longer depends on changed TEXINPUTS, instead

1104 isatool document copies the Isabelle style files to the target

1105 location;

1108 *** Isar ***

1110 * Pure/Provers: improved proof by cases and induction;

1111 - 'case' command admits impromptu naming of parameters (such as

1112 "case (Suc n)");

1113 - 'induct' method divinates rule instantiation from the inductive

1114 claim; no longer requires excessive ?P bindings for proper

1115 instantiation of cases;

1116 - 'induct' method properly enumerates all possibilities of set/type

1117 rules; as a consequence facts may be also passed through *type*

1118 rules without further ado;

1119 - 'induct' method now derives symbolic cases from the *rulified*

1120 rule (before it used to rulify cases stemming from the internal

1121 atomized version); this means that the context of a non-atomic

1122 statement becomes is included in the hypothesis, avoiding the

1123 slightly cumbersome show "PROP ?case" form;

1124 - 'induct' may now use elim-style induction rules without chaining

1125 facts, using ``missing'' premises from the goal state; this allows

1126 rules stemming from inductive sets to be applied in unstructured

1127 scripts, while still benefitting from proper handling of non-atomic

1128 statements; NB: major inductive premises need to be put first, all

1129 the rest of the goal is passed through the induction;

1130 - 'induct' proper support for mutual induction involving non-atomic

1131 rule statements (uses the new concept of simultaneous goals, see

1132 below);

1133 - append all possible rule selections, but only use the first

1134 success (no backtracking);

1135 - removed obsolete "(simplified)" and "(stripped)" options of methods;

1136 - undeclared rule case names default to numbers 1, 2, 3, ...;

1137 - added 'print_induct_rules' (covered by help item in recent Proof

1138 General versions);

1139 - moved induct/cases attributes to Pure, methods to Provers;

1140 - generic method setup instantiated for FOL and HOL;

1142 * Pure: support multiple simultaneous goal statements, for example

1143 "have a: A and b: B" (same for 'theorem' etc.); being a pure

1144 meta-level mechanism, this acts as if several individual goals had

1145 been stated separately; in particular common proof methods need to be

1146 repeated in order to cover all claims; note that a single elimination

1147 step is *not* sufficient to establish the two conjunctions, so this

1148 fails:

1150 assume "A & B" then have A and B .. (*".." fails*)

1152 better use "obtain" in situations as above; alternative refer to

1153 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;

1155 * Pure: proper integration with ``locales''; unlike the original

1156 version by Florian Kammller, Isar locales package high-level proof

1157 contexts rather than raw logical ones (e.g. we admit to include

1158 attributes everywhere); operations on locales include merge and

1159 rename; support for implicit arguments (``structures''); simultaneous

1160 type-inference over imports and text; see also HOL/ex/Locales.thy for

1161 some examples;

1163 * Pure: the following commands have been ``localized'', supporting a

1164 target locale specification "(in name)": 'lemma', 'theorem',

1165 'corollary', 'lemmas', 'theorems', 'declare'; the results will be

1166 stored both within the locale and at the theory level (exported and

1167 qualified by the locale name);

1169 * Pure: theory goals may now be specified in ``long'' form, with

1170 ad-hoc contexts consisting of arbitrary locale elements. for example

1171 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and

1172 definitions may be given, too); the result is a meta-level rule with

1173 the context elements being discharged in the obvious way;

1175 * Pure: new proof command 'using' allows to augment currently used

1176 facts after a goal statement ('using' is syntactically analogous to

1177 'apply', but acts on the goal's facts only); this allows chained facts

1178 to be separated into parts given before and after a claim, as in

1179 ``from a and b have C using d and e <proof>'';

1181 * Pure: renamed "antecedent" case to "rule_context";

1183 * Pure: new 'judgment' command records explicit information about the

1184 object-logic embedding (used by several tools internally); no longer

1185 use hard-wired "Trueprop";

1187 * Pure: added 'corollary' command;

1189 * Pure: fixed 'token_translation' command;

1191 * Pure: removed obsolete 'exported' attribute;

1193 * Pure: dummy pattern "_" in is/let is now automatically lifted over

1194 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")

1195 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");

1197 * Pure: method 'atomize' presents local goal premises as object-level

1198 statements (atomic meta-level propositions); setup controlled via

1199 rewrite rules declarations of 'atomize' attribute; example

1200 application: 'induct' method with proper rule statements in improper

1201 proof *scripts*;

1203 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)

1204 now consider the syntactic context of assumptions, giving a better

1205 chance to get type-inference of the arguments right (this is

1206 especially important for locales);

1208 * Pure: "sorry" no longer requires quick_and_dirty in interactive

1209 mode;

1211 * Pure/obtain: the formal conclusion "thesis", being marked as

1212 ``internal'', may no longer be reference directly in the text;

1213 potential INCOMPATIBILITY, may need to use "?thesis" in rare

1214 situations;

1216 * Pure: generic 'sym' attribute which declares a rule both as pure

1217 'elim?' and for the 'symmetric' operation;

1219 * Pure: marginal comments ``--'' may now occur just anywhere in the

1220 text; the fixed correlation with particular command syntax has been

1221 discontinued;

1223 * Pure: new method 'rules' is particularly well-suited for proof

1224 search in intuitionistic logic; a bit slower than 'blast' or 'fast',

1225 but often produces more compact proof terms with less detours;

1227 * Pure/Provers/classical: simplified integration with pure rule

1228 attributes and methods; the classical "intro?/elim?/dest?"

1229 declarations coincide with the pure ones; the "rule" method no longer

1230 includes classically swapped intros; "intro" and "elim" methods no

1231 longer pick rules from the context; also got rid of ML declarations

1232 AddXIs/AddXEs/AddXDs; all of this has some potential for

1233 INCOMPATIBILITY;

1235 * Provers/classical: attribute 'swapped' produces classical inversions

1236 of introduction rules;

1238 * Provers/simplifier: 'simplified' attribute may refer to explicit

1239 rules instead of full simplifier context; 'iff' attribute handles

1240 conditional rules;

1242 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;

1244 * HOL: 'recdef' now fails on unfinished automated proofs, use

1245 "(permissive)" option to recover old behavior;

1247 * HOL: 'inductive' no longer features separate (collective) attributes

1248 for 'intros' (was found too confusing);

1250 * HOL: properly declared induction rules less_induct and

1251 wf_induct_rule;

1254 *** HOL ***

1256 * HOL: moved over to sane numeral syntax; the new policy is as

1257 follows:

1259 - 0 and 1 are polymorphic constants, which are defined on any

1260 numeric type (nat, int, real etc.);

1262 - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based

1263 binary representation internally;

1265 - type nat has special constructor Suc, and generally prefers Suc 0

1266 over 1::nat and Suc (Suc 0) over 2::nat;

1268 This change may cause significant problems of INCOMPATIBILITY; here

1269 are some hints on converting existing sources:

1271 - due to the new "num" token, "-0" and "-1" etc. are now atomic

1272 entities, so expressions involving "-" (unary or binary minus) need

1273 to be spaced properly;

1275 - existing occurrences of "1" may need to be constraint "1::nat" or

1276 even replaced by Suc 0; similar for old "2";

1278 - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";

1280 - remove all special provisions on numerals in proofs;

1282 * HOL: simp rules nat_number expand numerals on nat to Suc/0

1283 representation (depends on bin_arith_simps in the default context);

1285 * HOL: symbolic syntax for x^2 (numeral 2);

1287 * HOL: the class of all HOL types is now called "type" rather than

1288 "term"; INCOMPATIBILITY, need to adapt references to this type class

1289 in axclass/classes, instance/arities, and (usually rare) occurrences

1290 in typings (of consts etc.); internally the class is called

1291 "HOL.type", ML programs should refer to HOLogic.typeS;

1293 * HOL/record package improvements:

1294 - new derived operations "fields" to build a partial record section,

1295 "extend" to promote a fixed record to a record scheme, and

1296 "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*

1297 declared as simp by default;

1298 - shared operations ("more", "fields", etc.) now need to be always

1299 qualified) --- potential INCOMPATIBILITY;

1300 - removed "make_scheme" operations (use "make" with "extend") --

1301 INCOMPATIBILITY;

1302 - removed "more" class (simply use "term") -- INCOMPATIBILITY;

1303 - provides cases/induct rules for use with corresponding Isar

1304 methods (for concrete records, record schemes, concrete more

1305 parts, and schematic more parts -- in that order);

1306 - internal definitions directly based on a light-weight abstract

1307 theory of product types over typedef rather than datatype;

1309 * HOL: generic code generator for generating executable ML code from

1310 specifications; specific support for HOL constructs such as inductive

1311 datatypes and sets, as well as recursive functions; can be invoked

1312 via 'generate_code' theory section;

1314 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);

1316 * HOL: consolidated and renamed several theories. In particular:

1317 Ord.thy has been absorbed into HOL.thy

1318 String.thy has been absorbed into List.thy

1320 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"

1321 (beware of argument permutation!);

1323 * HOL: linorder_less_split superseded by linorder_cases;

1325 * HOL/List: "nodups" renamed to "distinct";

1327 * HOL: added "The" definite description operator; move Hilbert's "Eps"

1328 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:

1329 - Ex_def has changed, now need to use some_eq_ex

1331 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so

1332 in this (rare) case use:

1334 delSWrapper "split_all_tac"

1335 addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)

1337 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS

1338 MAY FAIL;

1340 * HOL: introduced f^n = f o ... o f; warning: due to the limits of

1341 Isabelle's type classes, ^ on functions and relations has too general

1342 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be

1343 necessary to attach explicit type constraints;

1345 * HOL/Relation: the prefix name of the infix "O" has been changed from

1346 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been

1347 renamed accordingly (eg "compI" -> "rel_compI").

1349 * HOL: syntax translations now work properly with numerals and records

1350 expressions;

1352 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead

1353 of "lam" -- INCOMPATIBILITY;

1355 * HOL: got rid of some global declarations (potential INCOMPATIBILITY

1356 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"

1357 renamed "Product_Type.unit";

1359 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl

1361 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or

1362 the "cases" method);

1364 * HOL/GroupTheory: group theory examples including Sylow's theorem (by

1365 Florian Kammller);

1367 * HOL/IMP: updated and converted to new-style theory format; several

1368 parts turned into readable document, with proper Isar proof texts and

1369 some explanations (by Gerwin Klein);

1371 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);

1373 * HOL-Hyperreal is now a logic image;

1376 *** HOLCF ***

1378 * Isar: consts/constdefs supports mixfix syntax for continuous

1379 operations;

1381 * Isar: domain package adapted to new-style theory format, e.g. see

1382 HOLCF/ex/Dnat.thy;

1384 * theory Lift: proper use of rep_datatype lift instead of ML hacks --

1385 potential INCOMPATIBILITY; now use plain induct_tac instead of former

1386 lift.induct_tac, always use UU instead of Undef;

1388 * HOLCF/IMP: updated and converted to new-style theory;

1391 *** ZF ***

1393 * Isar: proper integration of logic-specific tools and packages,

1394 including theory commands '(co)inductive', '(co)datatype',

1395 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',

1396 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');

1398 * theory Main no longer includes AC; for the Axiom of Choice, base

1399 your theory on Main_ZFC;

1401 * the integer library now covers quotients and remainders, with many

1402 laws relating division to addition, multiplication, etc.;

1404 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a

1405 typeless version of the formalism;

1407 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory

1408 format;

1410 * ZF/Induct: new directory for examples of inductive definitions,

1411 including theory Multiset for multiset orderings; converted to

1412 new-style theory format;

1414 * ZF: many new theorems about lists, ordinals, etc.;

1417 *** General ***

1419 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference

1420 variable proof controls level of detail: 0 = no proofs (only oracle

1421 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see

1422 also ref manual for further ML interfaces;

1424 * Pure/axclass: removed obsolete ML interface

1425 goal_subclass/goal_arity;

1427 * Pure/syntax: new token syntax "num" for plain numerals (without "#"

1428 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now

1429 separate tokens, so expressions involving minus need to be spaced

1430 properly;

1432 * Pure/syntax: support non-oriented infixes, using keyword "infix"

1433 rather than "infixl" or "infixr";

1435 * Pure/syntax: concrete syntax for dummy type variables admits genuine

1436 sort constraint specifications in type inference; e.g. "x::_::foo"

1437 ensures that the type of "x" is of sort "foo" (but not necessarily a

1438 type variable);

1440 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"

1441 control output of nested => (types); the default behavior is

1442 "type_brackets";

1444 * Pure/syntax: builtin parse translation for "_constify" turns valued

1445 tokens into AST constants;

1447 * Pure/syntax: prefer later declarations of translations and print

1448 translation functions; potential INCOMPATIBILITY: need to reverse

1449 multiple declarations for same syntax element constant;

1451 * Pure/show_hyps reset by default (in accordance to existing Isar

1452 practice);

1454 * Provers/classical: renamed addaltern to addafter, addSaltern to

1455 addSafter;

1457 * Provers/clasimp: ``iff'' declarations now handle conditional rules

1458 as well;

1460 * system: tested support for MacOS X; should be able to get Isabelle +

1461 Proof General to work in a plain Terminal after installing Poly/ML

1462 (e.g. from the Isabelle distribution area) and GNU bash alone

1463 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol

1464 support requires further installations, e.g. from

1465 http://fink.sourceforge.net/);

1467 * system: support Poly/ML 4.1.1 (able to manage larger heaps);

1469 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead

1470 of 40 MB), cf. ML_OPTIONS;

1472 * system: Proof General keywords specification is now part of the

1473 Isabelle distribution (see etc/isar-keywords.el);

1475 * system: support for persistent Proof General sessions (refrain from

1476 outdating all loaded theories on startup); user may create writable

1477 logic images like this: ``isabelle -q HOL Test'';

1479 * system: smart selection of Isabelle process versus Isabelle

1480 interface, accommodates case-insensitive file systems (e.g. HFS+); may

1481 run both "isabelle" and "Isabelle" even if file names are badly

1482 damaged (executable inspects the case of the first letter of its own

1483 name); added separate "isabelle-process" and "isabelle-interface";

1485 * system: refrain from any attempt at filtering input streams; no

1486 longer support ``8bit'' encoding of old isabelle font, instead proper

1487 iso-latin characters may now be used; the related isatools

1488 "symbolinput" and "nonascii" have disappeared as well;

1490 * system: removed old "xterm" interface (the print modes "xterm" and

1491 "xterm_color" are still available for direct use in a suitable

1492 terminal);

1496 New in Isabelle99-2 (February 2001)

1497 -----------------------------------

1499 *** Overview of INCOMPATIBILITIES ***

1501 * HOL: please note that theories in the Library and elsewhere often use the

1502 new-style (Isar) format; to refer to their theorems in an ML script you must

1503 bind them to ML identifers by e.g. val thm_name = thm "thm_name";

1505 * HOL: inductive package no longer splits induction rule aggressively,

1506 but only as far as specified by the introductions given; the old

1507 format may be recovered via ML function complete_split_rule or attribute

1508 'split_rule (complete)';

1510 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,

1511 gfp_Tarski to gfp_unfold;

1513 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;

1515 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a

1516 relation); infix "^^" has been renamed "``"; infix "``" has been

1517 renamed "`"; "univalent" has been renamed "single_valued";

1519 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"

1520 operation;

1522 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;

1524 * Isar: 'obtain' no longer declares "that" fact as simp/intro;

1526 * Isar/HOL: method 'induct' now handles non-atomic goals; as a

1527 consequence, it is no longer monotonic wrt. the local goal context

1528 (which is now passed through the inductive cases);

1530 * Document preparation: renamed standard symbols \<ll> to \<lless> and

1531 \<gg> to \<ggreater>;

1534 *** Document preparation ***

1536 * \isabellestyle{NAME} selects version of Isabelle output (currently

1537 available: are "it" for near math-mode best-style output, "sl" for

1538 slanted text style, and "tt" for plain type-writer; if no

1539 \isabellestyle command is given, output is according to slanted

1540 type-writer);

1542 * support sub/super scripts (for single symbols only), input syntax is

1543 like this: "A\<^sup>*" or "A\<^sup>\<star>";

1545 * some more standard symbols; see Appendix A of the system manual for

1546 the complete list of symbols defined in isabellesym.sty;

1548 * improved isabelle style files; more abstract symbol implementation

1549 (should now use \isamath{...} and \isatext{...} in custom symbol

1550 definitions);

1552 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals

1553 state; Note that presentation of goal states does not conform to

1554 actual human-readable proof documents. Please do not include goal

1555 states into document output unless you really know what you are doing!

1557 * proper indentation of antiquoted output with proportional LaTeX

1558 fonts;

1560 * no_document ML operator temporarily disables LaTeX document

1561 generation;

1563 * isatool unsymbolize tunes sources for plain ASCII communication;

1566 *** Isar ***

1568 * Pure: Isar now suffers initial goal statements to contain unbound

1569 schematic variables (this does not conform to actual readable proof

1570 documents, due to unpredictable outcome and non-compositional proof

1571 checking); users who know what they are doing may use schematic goals

1572 for Prolog-style synthesis of proven results;

1574 * Pure: assumption method (an implicit finishing) now handles actual

1575 rules as well;

1577 * Pure: improved 'obtain' --- moved to Pure, insert "that" into

1578 initial goal, declare "that" only as Pure intro (only for single

1579 steps); the "that" rule assumption may now be involved in implicit

1580 finishing, thus ".." becomes a feasible for trivial obtains;

1582 * Pure: default proof step now includes 'intro_classes'; thus trivial

1583 instance proofs may be performed by "..";

1585 * Pure: ?thesis / ?this / "..." now work for pure meta-level

1586 statements as well;

1588 * Pure: more robust selection of calculational rules;

1590 * Pure: the builtin notion of 'finished' goal now includes the ==-refl

1591 rule (as well as the assumption rule);

1593 * Pure: 'thm_deps' command visualizes dependencies of theorems and

1594 lemmas, using the graph browser tool;

1596 * Pure: predict failure of "show" in interactive mode;

1598 * Pure: 'thms_containing' now takes actual terms as arguments;

1600 * HOL: improved method 'induct' --- now handles non-atomic goals

1601 (potential INCOMPATIBILITY); tuned error handling;

1603 * HOL: cases and induct rules now provide explicit hints about the

1604 number of facts to be consumed (0 for "type" and 1 for "set" rules);

1605 any remaining facts are inserted into the goal verbatim;

1607 * HOL: local contexts (aka cases) may now contain term bindings as

1608 well; the 'cases' and 'induct' methods new provide a ?case binding for

1609 the result to be shown in each case;

1611 * HOL: added 'recdef_tc' command;

1613 * isatool convert assists in eliminating legacy ML scripts;

1616 *** HOL ***

1618 * HOL/Library: a collection of generic theories to be used together

1619 with main HOL; the theory loader path already includes this directory

1620 by default; the following existing theories have been moved here:

1621 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While

1622 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);

1624 * HOL/Unix: "Some aspects of Unix file-system security", a typical

1625 modelling and verification task performed in Isabelle/HOL +

1626 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).

1628 * HOL/Algebra: special summation operator SUM no longer exists, it has

1629 been replaced by setsum; infix 'assoc' now has priority 50 (like

1630 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to

1631 'domain', this makes the theory consistent with mathematical

1632 literature;

1634 * HOL basics: added overloaded operations "inverse" and "divide"

1635 (infix "/"), syntax for generic "abs" operation, generic summation

1636 operator \<Sum>;

1638 * HOL/typedef: simplified package, provide more useful rules (see also

1639 HOL/subset.thy);

1641 * HOL/datatype: induction rule for arbitrarily branching datatypes is

1642 now expressed as a proper nested rule (old-style tactic scripts may

1643 require atomize_strip_tac to cope with non-atomic premises);

1645 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule

1646 to "split_conv" (old name still available for compatibility);

1648 * HOL: improved concrete syntax for strings (e.g. allows translation

1649 rules with string literals);

1651 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals

1652 and Fleuriot's mechanization of analysis, including the transcendental

1653 functions for the reals;

1655 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;

1658 *** CTT ***

1660 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that

1661 "lam" is displayed as TWO lambda-symbols

1663 * CTT: theory Main now available, containing everything (that is, Bool

1664 and Arith);

1667 *** General ***

1669 * Pure: the Simplifier has been implemented properly as a derived rule

1670 outside of the actual kernel (at last!); the overall performance

1671 penalty in practical applications is about 50%, while reliability of

1672 the Isabelle inference kernel has been greatly improved;

1674 * print modes "brackets" and "no_brackets" control output of nested =>

1675 (types) and ==> (props); the default behaviour is "brackets";

1677 * Provers: fast_tac (and friends) now handle actual object-logic rules

1678 as assumptions as well;

1680 * system: support Poly/ML 4.0;

1682 * system: isatool install handles KDE version 1 or 2;

1686 New in Isabelle99-1 (October 2000)

1687 ----------------------------------

1689 *** Overview of INCOMPATIBILITIES ***

1691 * HOL: simplification of natural numbers is much changed; to partly

1692 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)

1693 issue the following ML commands:

1695 Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;

1696 Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];

1698 * HOL: simplification no longer dives into case-expressions; this is

1699 controlled by "t.weak_case_cong" for each datatype t;

1701 * HOL: nat_less_induct renamed to less_induct;

1703 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool

1704 fixsome to patch .thy and .ML sources automatically;

1706 select_equality -> some_equality

1707 select_eq_Ex -> some_eq_ex

1708 selectI2EX -> someI2_ex

1709 selectI2 -> someI2

1710 selectI -> someI

1711 select1_equality -> some1_equality

1712 Eps_sym_eq -> some_sym_eq_trivial

1713 Eps_eq -> some_eq_trivial

1715 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;

1717 * HOL: removed obsolete theorem binding expand_if (refer to split_if

1718 instead);

1720 * HOL: the recursion equations generated by 'recdef' are now called

1721 f.simps instead of f.rules;

1723 * HOL: qed_spec_mp now also handles bounded ALL as well;

1725 * HOL: 0 is now overloaded, so the type constraint ":: nat" may

1726 sometimes be needed;

1728 * HOL: the constant for "f``x" is now "image" rather than "op ``";

1730 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";

1732 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian

1733 product is now "<*>" instead of "Times"; the lexicographic product is

1734 now "<*lex*>" instead of "**";

1736 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part

1737 of main HOL, but was unused); better use HOL's datatype package;

1739 * HOL: removed "symbols" syntax for constant "override" of theory Map;

1740 the old syntax may be recovered as follows:

1742 syntax (symbols)

1743 override :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"

1744 (infixl "\\<oplus>" 100)

1746 * HOL/Real: "rabs" replaced by overloaded "abs" function;

1748 * HOL/ML: even fewer consts are declared as global (see theories Ord,

1749 Lfp, Gfp, WF); this only affects ML packages that refer to const names

1750 internally;

1752 * HOL and ZF: syntax for quotienting wrt an equivalence relation

1753 changed from A/r to A//r;

1755 * ZF: new treatment of arithmetic (nat & int) may break some old

1756 proofs;

1758 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,

1759 rulify -> rule_format, elimify -> elim_format, ...);

1761 * Isar/Provers: intro/elim/dest attributes changed; renamed

1762 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one

1763 should have to change intro!! to intro? only); replaced "delrule" by

1764 "rule del";

1766 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;

1768 * Provers: strengthened force_tac by using new first_best_tac;

1770 * LaTeX document preparation: several changes of isabelle.sty (see

1771 lib/texinputs);

1774 *** Document preparation ***

1776 * formal comments (text blocks etc.) in new-style theories may now

1777 contain antiquotations of thm/prop/term/typ/text to be presented

1778 according to latex print mode; concrete syntax is like this:

1779 @{term[show_types] "f(x) = a + x"};

1781 * isatool mkdir provides easy setup of Isabelle session directories,

1782 including proper document sources;

1784 * generated LaTeX sources are now deleted after successful run

1785 (isatool document -c); may retain a copy somewhere else via -D option

1786 of isatool usedir;

1788 * isatool usedir -D now lets isatool latex -o sty update the Isabelle

1789 style files, achieving self-contained LaTeX sources and simplifying

1790 LaTeX debugging;

1792 * old-style theories now produce (crude) LaTeX output as well;

1794 * browser info session directories are now self-contained (may be put

1795 on WWW server seperately); improved graphs of nested sessions; removed

1796 graph for 'all sessions';

1798 * several improvements in isabelle style files; \isabellestyle{it}

1799 produces fake math mode output; \isamarkupheader is now \section by

1800 default; see lib/texinputs/isabelle.sty etc.;

1803 *** Isar ***

1805 * Isar/Pure: local results and corresponding term bindings are now

1806 subject to Hindley-Milner polymorphism (similar to ML); this

1807 accommodates incremental type-inference very nicely;

1809 * Isar/Pure: new derived language element 'obtain' supports

1810 generalized existence reasoning;

1812 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'

1813 support accumulation of results, without applying any rules yet;

1814 useful to collect intermediate results without explicit name

1815 references, and for use with transitivity rules with more than 2

1816 premises;

1818 * Isar/Pure: scalable support for case-analysis type proofs: new

1819 'case' language element refers to local contexts symbolically, as

1820 produced by certain proof methods; internally, case names are attached

1821 to theorems as "tags";

1823 * Isar/Pure: theory command 'hide' removes declarations from

1824 class/type/const name spaces;

1826 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to

1827 indicate potential overloading;

1829 * Isar/Pure: changed syntax of local blocks from {{ }} to { };

1831 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write

1832 "{a,b,c}" instead of {a,b,c};

1834 * Isar/Pure now provides its own version of intro/elim/dest

1835 attributes; useful for building new logics, but beware of confusion

1836 with the version in Provers/classical;

1838 * Isar/Pure: the local context of (non-atomic) goals is provided via

1839 case name 'antecedent';

1841 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms

1842 to the current context is now done automatically);

1844 * Isar/Pure: theory command 'method_setup' provides a simple interface

1845 for definining proof methods in ML;

1847 * Isar/Provers: intro/elim/dest attributes changed; renamed

1848 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in

1849 most cases, one should have to change intro!! to intro? only);

1850 replaced "delrule" by "rule del";

1852 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and

1853 'symmetric' attribute (the latter supercedes [RS sym]);

1855 * Isar/Provers: splitter support (via 'split' attribute and 'simp'

1856 method modifier); 'simp' method: 'only:' modifier removes loopers as

1857 well (including splits);

1859 * Isar/Provers: Simplifier and Classical methods now support all kind

1860 of modifiers used in the past, including 'cong', 'iff', etc.

1862 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination

1863 of Simplifier and Classical reasoner);

1865 * Isar/HOL: new proof method 'cases' and improved version of 'induct'

1866 now support named cases; major packages (inductive, datatype, primrec,

1867 recdef) support case names and properly name parameters;

1869 * Isar/HOL: new transitivity rules for substitution in inequalities --

1870 monotonicity conditions are extracted to be proven at end of

1871 calculations;

1873 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof

1874 method anyway;

1876 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =

1877 split_if split_if_asm; datatype package provides theorems foo.splits =

1878 foo.split foo.split_asm for each datatype;

1880 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"

1881 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof

1882 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:

1883 use "(cases (simplified))" method in proper proof texts);

1885 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;

1887 * Isar: names of theorems etc. may be natural numbers as well;

1889 * Isar: 'pr' command: optional arguments for goals_limit and

1890 ProofContext.prems_limit; no longer prints theory contexts, but only

1891 proof states;

1893 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit

1894 additional print modes to be specified; e.g. "pr(latex)" will print

1895 proof state according to the Isabelle LaTeX style;

1897 * Isar: improved support for emulating tactic scripts, including proof

1898 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',

1899 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'

1900 (for HOL datatypes);

1902 * Isar: simplified (more robust) goal selection of proof methods: 1st

1903 goal, all goals, or explicit goal specifier (tactic emulation); thus

1904 'proof method scripts' have to be in depth-first order;

1906 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';

1908 * Isar: removed 'help' command, which hasn't been too helpful anyway;

1909 should instead use individual commands for printing items

1910 (print_commands, print_methods etc.);

1912 * Isar: added 'nothing' --- the empty list of theorems;

1915 *** HOL ***

1917 * HOL/MicroJava: formalization of a fragment of Java, together with a

1918 corresponding virtual machine and a specification of its bytecode

1919 verifier and a lightweight bytecode verifier, including proofs of

1920 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and

1921 Cornelia Pusch (see also the homepage of project Bali at

1922 http://isabelle.in.tum.de/Bali/);

1924 * HOL/Algebra: new theory of rings and univariate polynomials, by

1925 Clemens Ballarin;

1927 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese

1928 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M

1929 Rasmussen;

1931 * HOL/Lattice: fundamental concepts of lattice theory and order

1932 structures, including duals, properties of bounds versus algebraic

1933 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski

1934 Theorem for complete lattices etc.; may also serve as a demonstration

1935 for abstract algebraic reasoning using axiomatic type classes, and

1936 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;

1938 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David

1939 von Oheimb;

1941 * HOL/IMPP: extension of IMP with local variables and mutually

1942 recursive procedures, by David von Oheimb;

1944 * HOL/Lambda: converted into new-style theory and document;

1946 * HOL/ex/Multiquote: example of multiple nested quotations and

1947 anti-quotations -- basically a generalized version of de-Bruijn

1948 representation; very useful in avoiding lifting of operations;

1950 * HOL/record: added general record equality rule to simpset; fixed

1951 select-update simplification procedure to handle extended records as

1952 well; admit "r" as field name;

1954 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with

1955 other numeric types and also as the identity of groups, rings, etc.;

1957 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.

1958 Types nat and int belong to this axclass;

1960 * HOL: greatly improved simplification involving numerals of type nat, int, real:

1961 (i + #8 + j) = Suc k simplifies to #7 + (i + j) = k

1962 i*j + k + j*#3*i simplifies to #4*(i*j) + k

1963 two terms #m*u and #n*u are replaced by #(m+n)*u

1964 (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)

1965 and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y

1966 or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);

1968 * HOL: meson_tac is available (previously in ex/meson.ML); it is a

1969 powerful prover for predicate logic but knows nothing of clasets; see

1970 ex/mesontest.ML and ex/mesontest2.ML for example applications;

1972 * HOL: new version of "case_tac" subsumes both boolean case split and

1973 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer

1974 exists, may define val exhaust_tac = case_tac for ad-hoc portability;

1976 * HOL: simplification no longer dives into case-expressions: only the

1977 selector expression is simplified, but not the remaining arms; to

1978 enable full simplification of case-expressions for datatype t, you may

1979 remove t.weak_case_cong from the simpset, either globally (Delcongs

1980 [thm"t.weak_case_cong"];) or locally (delcongs [...]).

1982 * HOL/recdef: the recursion equations generated by 'recdef' for

1983 function 'f' are now called f.simps instead of f.rules; if all

1984 termination conditions are proved automatically, these simplification

1985 rules are added to the simpset, as in primrec; rules may be named

1986 individually as well, resulting in a separate list of theorems for

1987 each equation;

1989 * HOL/While is a new theory that provides a while-combinator. It

1990 permits the definition of tail-recursive functions without the

1991 provision of a termination measure. The latter is necessary once the

1992 invariant proof rule for while is applied.

1994 * HOL: new (overloaded) notation for the set of elements below/above

1995 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.

1997 * HOL: theorems impI, allI, ballI bound as "strip";

1999 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic

2000 induct_tac th "x1 ... xn" expects th to have a conclusion of the form

2001 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;

2003 * HOL/Real: "rabs" replaced by overloaded "abs" function;

2005 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of

2006 main HOL, but was unused);

2008 * HOL: fewer consts declared as global (e.g. have to refer to

2009 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);

2011 * HOL: tuned AST representation of nested pairs, avoiding bogus output

2012 in case of overlap with user translations (e.g. judgements over

2013 tuples); (note that the underlying logical represenation is still

2014 bogus);

2017 *** ZF ***

2019 * ZF: simplification automatically cancels common terms in arithmetic

2020 expressions over nat and int;

2022 * ZF: new treatment of nat to minimize type-checking: all operators

2023 coerce their operands to a natural number using the function natify,

2024 making the algebraic laws unconditional;

2026 * ZF: as above, for int: operators coerce their operands to an integer

2027 using the function intify;

2029 * ZF: the integer library now contains many of the usual laws for the

2030 orderings, including $<=, and monotonicity laws for $+ and $*;

2032 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic

2033 simplification;

2035 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q

2036 to the simplifier and classical reasoner simultaneously;

2039 *** General ***

2041 * Provers: blast_tac now handles actual object-logic rules as

2042 assumptions; note that auto_tac uses blast_tac internally as well;

2044 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning

2045 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;

2047 * Provers: delrules now handles destruct rules as well (no longer need

2048 explicit make_elim);

2050 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.

2051 [| inj ?f; ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W

2052 use instead the strong form,

2053 [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W

2054 in HOL, FOL and ZF the function cla_make_elim will create such rules

2055 from destruct-rules;

2057 * Provers: Simplifier.easy_setup provides a fast path to basic

2058 Simplifier setup for new object-logics;

2060 * Pure: AST translation rules no longer require constant head on LHS;

2062 * Pure: improved name spaces: ambiguous output is qualified; support

2063 for hiding of names;

2065 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and

2066 XSYMBOL_HOME; no longer need to do manual configuration in most

2067 situations;

2069 * system: compression of ML heaps images may now be controlled via -c

2070 option of isabelle and isatool usedir (currently only observed by

2071 Poly/ML);

2073 * system: isatool installfonts may handle X-Symbol fonts as well (very

2074 useful for remote X11);

2076 * system: provide TAGS file for Isabelle sources;

2078 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument

2079 order;

2081 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global

2082 timing flag supersedes proof_timing and Toplevel.trace;

2084 * ML: new combinators |>> and |>>> for incremental transformations

2085 with secondary results (e.g. certain theory extensions):

2087 * ML: PureThy.add_defs gets additional argument to indicate potential

2088 overloading (usually false);

2090 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as

2091 results;

2095 New in Isabelle99 (October 1999)

2096 --------------------------------

2098 *** Overview of INCOMPATIBILITIES (see below for more details) ***

2100 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)

2101 are no longer simplified. (This allows the simplifier to unfold recursive

2102 functional programs.) To restore the old behaviour, declare

2104 Delcongs [if_weak_cong];

2106 * HOL: Removed the obsolete syntax "Compl A"; use -A for set

2107 complement;

2109 * HOL: the predicate "inj" is now defined by translation to "inj_on";

2111 * HOL/datatype: mutual_induct_tac no longer exists --

2112 use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]

2114 * HOL/typedef: fixed type inference for representing set; type

2115 arguments now have to occur explicitly on the rhs as type constraints;

2117 * ZF: The con_defs part of an inductive definition may no longer refer

2118 to constants declared in the same theory;

2120 * HOL, ZF: the function mk_cases, generated by the inductive

2121 definition package, has lost an argument. To simplify its result, it

2122 uses the default simpset instead of a supplied list of theorems.

2124 * HOL/List: the constructors of type list are now Nil and Cons;

2126 * Simplifier: the type of the infix ML functions

2127 setSSolver addSSolver setSolver addSolver

2128 is now simpset * solver -> simpset where `solver' is a new abstract type

2129 for packaging solvers. A solver is created via

2130 mk_solver: string -> (thm list -> int -> tactic) -> solver

2131 where the string argument is only a comment.

2134 *** Proof tools ***

2136 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a

2137 decision procedure for linear arithmetic. Currently it is used for

2138 types `nat', `int', and `real' in HOL (see below); it can, should and

2139 will be instantiated for other types and logics as well.

2141 * The simplifier now accepts rewrite rules with flexible heads, eg

2142 hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y

2143 They are applied like any rule with a non-pattern lhs, i.e. by first-order

2144 matching.

2147 *** General ***

2149 * New Isabelle/Isar subsystem provides an alternative to traditional

2150 tactical theorem proving; together with the ProofGeneral/isar user

2151 interface it offers an interactive environment for developing human

2152 readable proof documents (Isar == Intelligible semi-automated

2153 reasoning); for further information see isatool doc isar-ref,

2154 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/

2156 * improved and simplified presentation of theories: better HTML markup

2157 (including colors), graph views in several sizes; isatool usedir now

2158 provides a proper interface for user theories (via -P option); actual

2159 document preparation based on (PDF)LaTeX is available as well (for

2160 new-style theories only); see isatool doc system for more information;

2162 * native support for Proof General, both for classic Isabelle and

2163 Isabelle/Isar;

2165 * ML function thm_deps visualizes dependencies of theorems and lemmas,

2166 using the graph browser tool;

2168 * Isabelle manuals now also available as PDF;

2170 * theory loader rewritten from scratch (may not be fully

2171 bug-compatible); old loadpath variable has been replaced by show_path,

2172 add_path, del_path, reset_path functions; new operations such as

2173 update_thy, touch_thy, remove_thy, use/update_thy_only (see also

2174 isatool doc ref);

2176 * improved isatool install: option -k creates KDE application icon,

2177 option -p DIR installs standalone binaries;

2179 * added ML_PLATFORM setting (useful for cross-platform installations);

2180 more robust handling of platform specific ML images for SML/NJ;

2182 * the settings environment is now statically scoped, i.e. it is never

2183 created again in sub-processes invoked from isabelle, isatool, or

2184 Isabelle;

2186 * path element specification '~~' refers to '$ISABELLE_HOME';

2188 * in locales, the "assumes" and "defines" parts may be omitted if

2189 empty;

2191 * new print_mode "xsymbols" for extended symbol support (e.g. genuine

2192 long arrows);

2194 * new print_mode "HTML";

2196 * new flag show_tags controls display of tags of theorems (which are

2197 basically just comments that may be attached by some tools);

2199 * Isamode 2.6 requires patch to accomodate change of Isabelle font

2200 mode and goal output format:

2202 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el

2203 244c244

2204 < (list (isa-getenv "ISABELLE") "-msymbols" logic-name)

2205 ---

2206 > (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)

2207 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el

2208 181c181

2209 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"

2210 ---

2211 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"

2213 * function bind_thms stores lists of theorems (cf. bind_thm);

2215 * new shorthand tactics ftac, eatac, datac, fatac;

2217 * qed (and friends) now accept "" as result name; in that case the

2218 theorem is not stored, but proper checks and presentation of the

2219 result still apply;

2221 * theorem database now also indexes constants "Trueprop", "all",

2222 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;

2225 *** HOL ***

2227 ** HOL arithmetic **

2229 * There are now decision procedures for linear arithmetic over nat and

2230 int:

2232 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',

2233 `+', `-', `Suc', `min', `max' and numerical constants; other subterms

2234 are treated as atomic; subformulae not involving type `nat' or `int'

2235 are ignored; quantified subformulae are ignored unless they are

2236 positive universal or negative existential. The tactic has to be

2237 invoked by hand and can be a little bit slow. In particular, the

2238 running time is exponential in the number of occurrences of `min' and

2239 `max', and `-' on `nat'.

2241 2. fast_arith_tac is a cut-down version of arith_tac: it only takes

2242 (negated) (in)equalities among the premises and the conclusion into

2243 account (i.e. no compound formulae) and does not know about `min' and

2244 `max', and `-' on `nat'. It is fast and is used automatically by the

2245 simplifier.

2247 NB: At the moment, these decision procedures do not cope with mixed

2248 nat/int formulae where the two parts interact, such as `m < n ==>

2249 int(m) < int(n)'.

2251 * HOL/Numeral provides a generic theory of numerals (encoded

2252 efficiently as bit strings); setup for types nat/int/real is in place;

2253 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than

2254 int, existing theories and proof scripts may require a few additional

2255 type constraints;

2257 * integer division and remainder can now be performed on constant

2258 arguments;

2260 * many properties of integer multiplication, division and remainder

2261 are now available;

2263 * An interface to the Stanford Validity Checker (SVC) is available through the

2264 tactic svc_tac. Propositional tautologies and theorems of linear arithmetic

2265 are proved automatically. SVC must be installed separately, and its results

2266 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any

2267 invocation of the underlying oracle). For SVC see

2268 http://verify.stanford.edu/SVC

2270 * IsaMakefile: the HOL-Real target now builds an actual image;

2273 ** HOL misc **

2275 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces

2276 (in Isabelle/Isar) -- by Gertrud Bauer;

2278 * HOL/BCV: generic model of bytecode verification, i.e. data-flow

2279 analysis for assembly languages with subtypes;

2281 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization

2282 -- avoids syntactic ambiguities and treats state, transition, and

2283 temporal levels more uniformly; introduces INCOMPATIBILITIES due to

2284 changed syntax and (many) tactics;

2286 * HOL/inductive: Now also handles more general introduction rules such

2287 as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity

2288 theorems are now maintained within the theory (maintained via the

2289 "mono" attribute);

2291 * HOL/datatype: Now also handles arbitrarily branching datatypes

2292 (using function types) such as

2294 datatype 'a tree = Atom 'a | Branch "nat => 'a tree"

2296 * HOL/record: record_simproc (part of the default simpset) takes care

2297 of selectors applied to updated records; record_split_tac is no longer

2298 part of the default claset; update_defs may now be removed from the

2299 simpset in many cases; COMPATIBILITY: old behavior achieved by

2301 claset_ref () := claset() addSWrapper record_split_wrapper;

2302 Delsimprocs [record_simproc]

2304 * HOL/typedef: fixed type inference for representing set; type

2305 arguments now have to occur explicitly on the rhs as type constraints;

2307 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem

2308 names rather than an ML expression;

2310 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be

2311 supplied later. Program schemes can be defined, such as

2312 "While B C s = (if B s then While B C (C s) else s)"

2313 where the well-founded relation can be chosen after B and C have been given.

2315 * HOL/List: the constructors of type list are now Nil and Cons;

2316 INCOMPATIBILITY: while [] and infix # syntax is still there, of

2317 course, ML tools referring to List.list.op # etc. have to be adapted;

2319 * HOL_quantifiers flag superseded by "HOL" print mode, which is

2320 disabled by default; run isabelle with option -m HOL to get back to

2321 the original Gordon/HOL-style output;

2323 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,

2324 ALL x<=y. P, EX x<y. P, EX x<=y. P;

2326 * HOL basic syntax simplified (more orthogonal): all variants of

2327 All/Ex now support plain / symbolic / HOL notation; plain syntax for

2328 Eps operator is provided as well: "SOME x. P[x]";

2330 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;

2332 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made

2333 thus available for user theories;

2335 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with

2336 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the

2337 time;

2339 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec

2340 several times and then mp;

2343 *** LK ***

2345 * the notation <<...>> is now available as a notation for sequences of

2346 formulas;

2348 * the simplifier is now installed

2350 * the axiom system has been generalized (thanks to Soren Heilmann)

2352 * the classical reasoner now has a default rule database

2355 *** ZF ***

2357 * new primrec section allows primitive recursive functions to be given

2358 directly (as in HOL) over datatypes and the natural numbers;

2360 * new tactics induct_tac and exhaust_tac for induction (or case

2361 analysis) over datatypes and the natural numbers;

2363 * the datatype declaration of type T now defines the recursor T_rec;

2365 * simplification automatically does freeness reasoning for datatype

2366 constructors;

2368 * automatic type-inference, with AddTCs command to insert new

2369 type-checking rules;

2371 * datatype introduction rules are now added as Safe Introduction rules

2372 to the claset;

2374 * the syntax "if P then x else y" is now available in addition to

2375 if(P,x,y);

2378 *** Internal programming interfaces ***

2380 * tuned simplifier trace output; new flag debug_simp;

2382 * structures Vartab / Termtab (instances of TableFun) offer efficient

2383 tables indexed by indexname_ord / term_ord (compatible with aconv);

2385 * AxClass.axclass_tac lost the theory argument;

2387 * tuned current_goals_markers semantics: begin / end goal avoids

2388 printing empty lines;

2390 * removed prs and prs_fn hook, which was broken because it did not

2391 include \n in its semantics, forcing writeln to add one

2392 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:

2393 string -> unit if you really want to output text without newline;

2395 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to

2396 plain output, interface builders may have to enable 'isabelle_font'

2397 mode to get Isabelle font glyphs as before;

2399 * refined token_translation interface; INCOMPATIBILITY: output length

2400 now of type real instead of int;

2402 * theory loader actions may be traced via new ThyInfo.add_hook

2403 interface (see src/Pure/Thy/thy_info.ML); example application: keep

2404 your own database of information attached to *whole* theories -- as

2405 opposed to intra-theory data slots offered via TheoryDataFun;

2407 * proper handling of dangling sort hypotheses (at last!);

2408 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing

2409 extra sort hypotheses that can be witnessed from the type signature;

2410 the force_strip_shyps flag is gone, any remaining shyps are simply

2411 left in the theorem (with a warning issued by strip_shyps_warning);

2415 New in Isabelle98-1 (October 1998)

2416 ----------------------------------

2418 *** Overview of INCOMPATIBILITIES (see below for more details) ***

2420 * several changes of automated proof tools;

2422 * HOL: major changes to the inductive and datatype packages, including

2423 some minor incompatibilities of theory syntax;

2425 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now

2426 called `inj_on';

2428 * HOL: removed duplicate thms in Arith:

2429 less_imp_add_less should be replaced by trans_less_add1

2430 le_imp_add_le should be replaced by trans_le_add1

2432 * HOL: unary minus is now overloaded (new type constraints may be

2433 required);

2435 * HOL and ZF: unary minus for integers is now #- instead of #~. In

2436 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is

2437 now taken as an integer constant.

2439 * Pure: ML function 'theory_of' renamed to 'theory';

2442 *** Proof tools ***

2444 * Simplifier:

2445 1. Asm_full_simp_tac is now more aggressive.

2446 1. It will sometimes reorient premises if that increases their power to

2447 simplify.

2448 2. It does no longer proceed strictly from left to right but may also

2449 rotate premises to achieve further simplification.

2450 For compatibility reasons there is now Asm_lr_simp_tac which is like the

2451 old Asm_full_simp_tac in that it does not rotate premises.

2452 2. The simplifier now knows a little bit about nat-arithmetic.

2454 * Classical reasoner: wrapper mechanism for the classical reasoner now

2455 allows for selected deletion of wrappers, by introduction of names for

2456 wrapper functionals. This implies that addbefore, addSbefore,

2457 addaltern, and addSaltern now take a pair (name, tactic) as argument,

2458 and that adding two tactics with the same name overwrites the first

2459 one (emitting a warning).

2460 type wrapper = (int -> tactic) -> (int -> tactic)

2461 setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by

2462 addWrapper, addSWrapper: claset * (string * wrapper) -> claset

2463 delWrapper, delSWrapper: claset * string -> claset

2464 getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;

2466 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE

2467 semantics; addbefore now affects only the unsafe part of step_tac

2468 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY

2469 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac

2470 by Force_tac;

2472 * Classical reasoner: setwrapper to setWrapper and compwrapper to

2473 compWrapper; added safe wrapper (and access functions for it);

2475 * HOL/split_all_tac is now much faster and fails if there is nothing

2476 to split. Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order

2477 and the names of the automatically generated variables have changed.

2478 split_all_tac has moved within claset() from unsafe wrappers to safe

2479 wrappers, which means that !!-bound variables are split much more

2480 aggressively, and safe_tac and clarify_tac now split such variables.

2481 If this splitting is not appropriate, use delSWrapper "split_all_tac".

2482 Note: the same holds for record_split_tac, which does the job of

2483 split_all_tac for record fields.

2485 * HOL/Simplifier: Rewrite rules for case distinctions can now be added

2486 permanently to the default simpset using Addsplits just like

2487 Addsimps. They can be removed via Delsplits just like

2488 Delsimps. Lower-case versions are also available.

2490 * HOL/Simplifier: The rule split_if is now part of the default

2491 simpset. This means that the simplifier will eliminate all occurrences

2492 of if-then-else in the conclusion of a goal. To prevent this, you can

2493 either remove split_if completely from the default simpset by

2494 `Delsplits [split_if]' or remove it in a specific call of the

2495 simplifier using `... delsplits [split_if]'. You can also add/delete

2496 other case splitting rules to/from the default simpset: every datatype

2497 generates suitable rules `split_t_case' and `split_t_case_asm' (where

2498 t is the name of the datatype).

2500 * Classical reasoner / Simplifier combination: new force_tac (and

2501 derivatives Force_tac, force) combines rewriting and classical

2502 reasoning (and whatever other tools) similarly to auto_tac, but is

2503 aimed to solve the given subgoal completely.

2506 *** General ***

2508 * new top-level commands `Goal' and `Goalw' that improve upon `goal'

2509 and `goalw': the theory is no longer needed as an explicit argument -

2510 the current theory context is used; assumptions are no longer returned

2511 at the ML-level unless one of them starts with ==> or !!; it is

2512 recommended to convert to these new commands using isatool fixgoal

2513 (backup your sources first!);

2515 * new top-level commands 'thm' and 'thms' for retrieving theorems from

2516 the current theory context, and 'theory' to lookup stored theories;

2518 * new theory section 'locale' for declaring constants, assumptions and

2519 definitions that have local scope;

2521 * new theory section 'nonterminals' for purely syntactic types;

2523 * new theory section 'setup' for generic ML setup functions

2524 (e.g. package initialization);

2526 * the distribution now includes Isabelle icons: see

2527 lib/logo/isabelle-{small,tiny}.xpm;

2529 * isatool install - install binaries with absolute references to

2530 ISABELLE_HOME/bin;

2532 * isatool logo -- create instances of the Isabelle logo (as EPS);

2534 * print mode 'emacs' reserved for Isamode;

2536 * support multiple print (ast) translations per constant name;

2538 * theorems involving oracles are now printed with a suffixed [!];

2541 *** HOL ***

2543 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');

2545 * HOL/inductive package reorganized and improved: now supports mutual

2546 definitions such as

2548 inductive EVEN ODD

2549 intrs

2550 null "0 : EVEN"

2551 oddI "n : EVEN ==> Suc n : ODD"

2552 evenI "n : ODD ==> Suc n : EVEN"

2554 new theorem list "elims" contains an elimination rule for each of the

2555 recursive sets; inductive definitions now handle disjunctive premises

2556 correctly (also ZF);

2558 INCOMPATIBILITIES: requires Inductive as an ancestor; component

2559 "mutual_induct" no longer exists - the induction rule is always

2560 contained in "induct";

2563 * HOL/datatype package re-implemented and greatly improved: now

2564 supports mutually recursive datatypes such as

2566 datatype

2567 'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)

2568 | SUM ('a aexp) ('a aexp)

2569 | DIFF ('a aexp) ('a aexp)

2570 | NUM 'a

2571 and

2572 'a bexp = LESS ('a aexp) ('a aexp)

2573 | AND ('a bexp) ('a bexp)

2574 | OR ('a bexp) ('a bexp)

2576 as well as indirectly recursive datatypes such as

2578 datatype

2579 ('a, 'b) term = Var 'a

2580 | App 'b ((('a, 'b) term) list)

2582 The new tactic mutual_induct_tac [<var_1>, ..., <var_n>] i performs

2583 induction on mutually / indirectly recursive datatypes.

2585 Primrec equations are now stored in theory and can be accessed via

2586 <function_name>.simps.

2588 INCOMPATIBILITIES:

2590 - Theories using datatypes must now have theory Datatype as an

2591 ancestor.

2592 - The specific <typename>.induct_tac no longer exists - use the

2593 generic induct_tac instead.

2594 - natE has been renamed to nat.exhaust - use exhaust_tac

2595 instead of res_inst_tac ... natE. Note that the variable

2596 names in nat.exhaust differ from the names in natE, this

2597 may cause some "fragile" proofs to fail.

2598 - The theorems split_<typename>_case and split_<typename>_case_asm

2599 have been renamed to <typename>.split and <typename>.split_asm.

2600 - Since default sorts of type variables are now handled correctly,

2601 some datatype definitions may have to be annotated with explicit

2602 sort constraints.

2603 - Primrec definitions no longer require function name and type

2604 of recursive argument.

2606 Consider using isatool fixdatatype to adapt your theories and proof

2607 scripts to the new package (backup your sources first!).

2610 * HOL/record package: considerably improved implementation; now

2611 includes concrete syntax for record types, terms, updates; theorems

2612 for surjective pairing and splitting !!-bound record variables; proof

2613 support is as follows:

2615 1) standard conversions (selectors or updates applied to record

2616 constructor terms) are part of the standard simpset;

2618 2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are

2619 made part of standard simpset and claset via addIffs;

2621 3) a tactic for record field splitting (record_split_tac) is part of

2622 the standard claset (addSWrapper);

2624 To get a better idea about these rules you may retrieve them via

2625 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is

2626 the name of your record type.

2628 The split tactic 3) conceptually simplifies by the following rule:

2630 "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"

2632 Thus any record variable that is bound by meta-all will automatically

2633 blow up into some record constructor term, consequently the

2634 simplifications of 1), 2) apply. Thus force_tac, auto_tac etc. shall

2635 solve record problems automatically.

2638 * reorganized the main HOL image: HOL/Integ and String loaded by

2639 default; theory Main includes everything;

2641 * automatic simplification of integer sums and comparisons, using cancellation;

2643 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;

2645 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;

2647 * many new identities for unions, intersections, set difference, etc.;

2649 * expand_if, expand_split, expand_sum_case and expand_nat_case are now

2650 called split_if, split_split, split_sum_case and split_nat_case (to go

2651 with add/delsplits);

2653 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting

2654 (?x::unit) = (); this is made part of the default simpset, which COULD

2655 MAKE EXISTING PROOFS FAIL under rare circumstances (consider

2656 'Delsimprocs [unit_eq_proc];' as last resort); also note that

2657 unit_abs_eta_conv is added in order to counter the effect of

2658 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by

2659 %u.f();

2661 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which

2662 makes more sense);

2664 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;

2665 It and 'sym RS equals0D' are now in the default claset, giving automatic

2666 disjointness reasoning but breaking a few old proofs.

2668 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1

2669 to 'converse' from 'inverse' (for compatibility with ZF and some

2670 literature);

2672 * HOL/recdef can now declare non-recursive functions, with {} supplied as

2673 the well-founded relation;

2675 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of

2676 Compl A. The "Compl" syntax remains available as input syntax for this

2677 release ONLY.

2679 * HOL/Update: new theory of function updates:

2680 f(a:=b) == %x. if x=a then b else f x

2681 may also be iterated as in f(a:=b,c:=d,...);

2683 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;

2685 * HOL/List:

2686 - new function list_update written xs[i:=v] that updates the i-th

2687 list position. May also be iterated as in xs[i:=a,j:=b,...].

2688 - new function `upt' written [i..j(] which generates the list

2689 [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper

2690 bound write [i..j], which is a shorthand for [i..j+1(].

2691 - new lexicographic orderings and corresponding wellfoundedness theorems.

2693 * HOL/Arith:

2694 - removed 'pred' (predecessor) function;

2695 - generalized some theorems about n-1;

2696 - many new laws about "div" and "mod";

2697 - new laws about greatest common divisors (see theory ex/Primes);

2699 * HOL/Relation: renamed the relational operator r^-1 "converse"

2700 instead of "inverse";

2702 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness

2703 of the multiset ordering;

2705 * directory HOL/Real: a construction of the reals using Dedekind cuts

2706 (not included by default);

2708 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;

2710 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted

2711 programs, i.e. different program variables may have different types.

2713 * calling (stac rew i) now fails if "rew" has no effect on the goal

2714 [previously, this check worked only if the rewrite rule was unconditional]

2715 Now rew can involve either definitions or equalities (either == or =).

2718 *** ZF ***

2720 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains

2721 only the theorems proved on ZF.ML;

2723 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;

2724 It and 'sym RS equals0D' are now in the default claset, giving automatic

2725 disjointness reasoning but breaking a few old proofs.

2727 * ZF/Update: new theory of function updates

2728 with default rewrite rule f(x:=y) ` z = if(z=x, y, f`z)

2729 may also be iterated as in f(a:=b,c:=d,...);

2731 * in let x=t in u(x), neither t nor u(x) has to be an FOL term.

2733 * calling (stac rew i) now fails if "rew" has no effect on the goal

2734 [previously, this check worked only if the rewrite rule was unconditional]

2735 Now rew can involve either definitions or equalities (either == or =).

2737 * case_tac provided for compatibility with HOL

2738 (like the old excluded_middle_tac, but with subgoals swapped)

2741 *** Internal programming interfaces ***

2743 * Pure: several new basic modules made available for general use, see

2744 also src/Pure/README;

2746 * improved the theory data mechanism to support encapsulation (data

2747 kind name replaced by private Object.kind, acting as authorization

2748 key); new type-safe user interface via functor TheoryDataFun; generic

2749 print_data function becomes basically useless;

2751 * removed global_names compatibility flag -- all theory declarations

2752 are qualified by default;

2754 * module Pure/Syntax now offers quote / antiquote translation

2755 functions (useful for Hoare logic etc. with implicit dependencies);

2756 see HOL/ex/Antiquote for an example use;

2758 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->

2759 cterm -> thm;

2761 * new tactical CHANGED_GOAL for checking that a tactic modifies a

2762 subgoal;

2764 * Display.print_goals function moved to Locale.print_goals;

2766 * standard print function for goals supports current_goals_markers

2767 variable for marking begin of proof, end of proof, start of goal; the

2768 default is ("", "", ""); setting current_goals_markers := ("<proof>",

2769 "</proof>", "<goal>") causes SGML like tagged proof state printing,

2770 for example;

2774 New in Isabelle98 (January 1998)

2775 --------------------------------

2777 *** Overview of INCOMPATIBILITIES (see below for more details) ***

2779 * changed lexical syntax of terms / types: dots made part of long

2780 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";

2782 * simpset (and claset) reference variable replaced by functions

2783 simpset / simpset_ref;

2785 * no longer supports theory aliases (via merge) and non-trivial

2786 implicit merge of thms' signatures;

2788 * most internal names of constants changed due to qualified names;

2790 * changed Pure/Sequence interface (see Pure/seq.ML);

2793 *** General Changes ***

2795 * hierachically structured name spaces (for consts, types, axms, thms

2796 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of

2797 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:

2798 isatool fixdots ensures space after dots (e.g. "%x. x"); set

2799 long_names for fully qualified output names; NOTE: ML programs

2800 (special tactics, packages etc.) referring to internal names may have

2801 to be adapted to cope with fully qualified names; in case of severe

2802 backward campatibility problems try setting 'global_names' at compile

2803 time to have enrything declared within a flat name space; one may also

2804 fine tune name declarations in theories via the 'global' and 'local'

2805 section;

2807 * reimplemented the implicit simpset and claset using the new anytype

2808 data filed in signatures; references simpset:simpset ref etc. are

2809 replaced by functions simpset:unit->simpset and

2810 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp

2811 to patch your ML files accordingly;

2813 * HTML output now includes theory graph data for display with Java

2814 applet or isatool browser; data generated automatically via isatool

2815 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);

2817 * defs may now be conditional; improved rewrite_goals_tac to handle

2818 conditional equations;

2820 * defs now admits additional type arguments, using TYPE('a) syntax;

2822 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always

2823 creates a new theory node; implicit merge of thms' signatures is

2824 restricted to 'trivial' ones; COMPATIBILITY: one may have to use

2825 transfer:theory->thm->thm in (rare) cases;

2827 * improved handling of draft signatures / theories; draft thms (and

2828 ctyps, cterms) are automatically promoted to real ones;

2830 * slightly changed interfaces for oracles: admit many per theory, named

2831 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;

2833 * print_goals: optional output of const types (set show_consts and

2834 show_types);

2836 * improved output of warnings (###) and errors (***);

2838 * subgoal_tac displays a warning if the new subgoal has type variables;

2840 * removed old README and Makefiles;

2842 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;

2844 * removed obsolete init_pps and init_database;

2846 * deleted the obsolete tactical STATE, which was declared by

2847 fun STATE tacfun st = tacfun st st;

2849 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~

2850 (which abbreviates $HOME);

2852 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:

2853 use isatool fixseq to adapt your ML programs (this works for fully

2854 qualified references to the Sequence structure only!);

2856 * use_thy no longer requires writable current directory; it always

2857 reloads .ML *and* .thy file, if either one is out of date;

2860 *** Classical Reasoner ***

2862 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new

2863 tactics that use classical reasoning to simplify a subgoal without

2864 splitting it into several subgoals;

2866 * Safe_tac: like safe_tac but uses the default claset;

2869 *** Simplifier ***

2871 * added simplification meta rules:

2872 (asm_)(full_)simplify: simpset -> thm -> thm;

2874 * simplifier.ML no longer part of Pure -- has to be loaded by object

2875 logics (again);

2877 * added prems argument to simplification procedures;

2879 * HOL, FOL, ZF: added infix function `addsplits':

2880 instead of `<simpset> setloop (split_tac <thms>)'

2881 you can simply write `<simpset> addsplits <thms>'

2884 *** Syntax ***

2886 * TYPE('a) syntax for type reflection terms;

2888 * no longer handles consts with name "" -- declare as 'syntax' instead;

2890 * pretty printer: changed order of mixfix annotation preference (again!);

2892 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;

2895 *** HOL ***

2897 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.

2898 with `addloop' of the simplifier to faciliate case splitting in premises.

2900 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;

2902 * HOL/Auth: new protocol proofs including some for the Internet

2903 protocol TLS;

2905 * HOL/Map: new theory of `maps' a la VDM;

2907 * HOL/simplifier: simplification procedures nat_cancel_sums for

2908 cancelling out common nat summands from =, <, <= (in)equalities, or

2909 differences; simplification procedures nat_cancel_factor for

2910 cancelling common factor from =, <, <= (in)equalities over natural

2911 sums; nat_cancel contains both kinds of procedures, it is installed by

2912 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;

2914 * HOL/simplifier: terms of the form

2915 `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)' (or t=x)

2916 are rewritten to

2917 `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',

2918 and those of the form

2919 `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)' (or t=x)

2920 are rewritten to

2921 `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',

2923 * HOL/datatype

2924 Each datatype `t' now comes with a theorem `split_t_case' of the form

2926 P(t_case f1 ... fn x) =

2927 ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &

2928 ...

2929 (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))

2930 )

2932 and a theorem `split_t_case_asm' of the form

2934 P(t_case f1 ... fn x) =

2935 ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |

2936 ...

2937 (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))

2938 )

2939 which can be added to a simpset via `addsplits'. The existing theorems

2940 expand_list_case and expand_option_case have been renamed to

2941 split_list_case and split_option_case.

2943 * HOL/Arithmetic:

2944 - `pred n' is automatically converted to `n-1'.

2945 Users are strongly encouraged not to use `pred' any longer,

2946 because it will disappear altogether at some point.

2947 - Users are strongly encouraged to write "0 < n" rather than

2948 "n ~= 0". Theorems and proof tools have been modified towards this

2949 `standard'.

2951 * HOL/Lists:

2952 the function "set_of_list" has been renamed "set" (and its theorems too);

2953 the function "nth" now takes its arguments in the reverse order and

2954 has acquired the infix notation "!" as in "xs!n".

2956 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};

2958 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its

2959 specialist theorems (like UN1_I) are gone. Similarly for (INT x.B x);

2961 * HOL/record: extensible records with schematic structural subtyping

2962 (single inheritance); EXPERIMENTAL version demonstrating the encoding,

2963 still lacks various theorems and concrete record syntax;

2966 *** HOLCF ***

2968 * removed "axioms" and "generated by" sections;

2970 * replaced "ops" section by extended "consts" section, which is capable of

2971 handling the continuous function space "->" directly;

2973 * domain package:

2974 . proves theorems immediately and stores them in the theory,

2975 . creates hierachical name space,

2976 . now uses normal mixfix annotations (instead of cinfix...),

2977 . minor changes to some names and values (for consistency),

2978 . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,

2979 . separator between mutual domain defs: changed "," to "and",

2980 . improved handling of sort constraints; now they have to

2981 appear on the left-hand side of the equations only;

2983 * fixed LAM <x,y,zs>.b syntax;

2985 * added extended adm_tac to simplifier in HOLCF -- can now discharge

2986 adm (%x. P (t x)), where P is chainfinite and t continuous;

2989 *** FOL and ZF ***

2991 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.

2992 with `addloop' of the simplifier to faciliate case splitting in premises.

2994 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as

2995 in HOL, they strip ALL and --> from proved theorems;

2999 New in Isabelle94-8 (May 1997)

3000 ------------------------------

3002 *** General Changes ***

3004 * new utilities to build / run / maintain Isabelle etc. (in parts

3005 still somewhat experimental); old Makefiles etc. still functional;

3007 * new 'Isabelle System Manual';

3009 * INSTALL text, together with ./configure and ./build scripts;

3011 * reimplemented type inference for greater efficiency, better error

3012 messages and clean internal interface;

3014 * prlim command for dealing with lots of subgoals (an easier way of

3015 setting goals_limit);

3018 *** Syntax ***

3020 * supports alternative (named) syntax tables (parser and pretty

3021 printer); internal interface is provided by add_modesyntax(_i);

3023 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to

3024 be used in conjunction with the Isabelle symbol font; uses the

3025 "symbols" syntax table;

3027 * added token_translation interface (may translate name tokens in

3028 arbitrary ways, dependent on their type (free, bound, tfree, ...) and

3029 the current print_mode); IMPORTANT: user print translation functions

3030 are responsible for marking newly introduced bounds

3031 (Syntax.mark_boundT);

3033 * token translations for modes "xterm" and "xterm_color" that display

3034 names in bold, underline etc. or colors (which requires a color

3035 version of xterm);

3037 * infixes may now be declared with names independent of their syntax;

3039 * added typed_print_translation (like print_translation, but may

3040 access type of constant);

3043 *** Classical Reasoner ***

3045 Blast_tac: a new tactic! It is often more powerful than fast_tac, but has

3046 some limitations. Blast_tac...

3047 + ignores addss, addbefore, addafter; this restriction is intrinsic

3048 + ignores elimination rules that don't have the correct format

3049 (the conclusion MUST be a formula variable)

3050 + ignores types, which can make HOL proofs fail

3051 + rules must not require higher-order unification, e.g. apply_type in ZF

3052 [message "Function Var's argument not a bound variable" relates to this]

3053 + its proof strategy is more general but can actually be slower

3055 * substitution with equality assumptions no longer permutes other

3056 assumptions;

3058 * minor changes in semantics of addafter (now called addaltern); renamed

3059 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper

3060 (and access functions for it);

3062 * improved combination of classical reasoner and simplifier:

3063 + functions for handling clasimpsets

3064 + improvement of addss: now the simplifier is called _after_ the

3065 safe steps.

3066 + safe variant of addss called addSss: uses safe simplifications

3067 _during_ the safe steps. It is more complete as it allows multiple

3068 instantiations of unknowns (e.g. with slow_tac).

3070 *** Simplifier ***

3072 * added interface for simplification procedures (functions that

3073 produce *proven* rewrite rules on the fly, depending on current

3074 redex);

3076 * ordering on terms as parameter (used for ordered rewriting);

3078 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;

3080 * the solver is now split into a safe and an unsafe part.

3081 This should be invisible for the normal user, except that the

3082 functions setsolver and addsolver have been renamed to setSolver and

3083 addSolver; added safe_asm_full_simp_tac;

3086 *** HOL ***

3088 * a generic induction tactic `induct_tac' which works for all datatypes and

3089 also for type `nat';

3091 * a generic case distinction tactic `exhaust_tac' which works for all

3092 datatypes and also for type `nat';

3094 * each datatype comes with a function `size';

3096 * patterns in case expressions allow tuple patterns as arguments to

3097 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';

3099 * primrec now also works with type nat;

3101 * recdef: a new declaration form, allows general recursive functions to be

3102 defined in theory files. See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.

3104 * the constant for negation has been renamed from "not" to "Not" to

3105 harmonize with FOL, ZF, LK, etc.;

3107 * HOL/ex/LFilter theory of a corecursive "filter" functional for

3108 infinite lists;

3110 * HOL/Modelcheck demonstrates invocation of model checker oracle;

3112 * HOL/ex/Ring.thy declares cring_simp, which solves equational

3113 problems in commutative rings, using axiomatic type classes for + and *;

3115 * more examples in HOL/MiniML and HOL/Auth;

3117 * more default rewrite rules for quantifiers, union/intersection;

3119 * a new constant `arbitrary == @x.False';

3121 * HOLCF/IOA replaces old HOL/IOA;

3123 * HOLCF changes: derived all rules and arities

3124 + axiomatic type classes instead of classes

3125 + typedef instead of faking type definitions

3126 + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.

3127 + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po

3128 + eliminated the types void, one, tr

3129 + use unit lift and bool lift (with translations) instead of one and tr

3130 + eliminated blift from Lift3.thy (use Def instead of blift)

3131 all eliminated rules are derived as theorems --> no visible changes ;

3134 *** ZF ***

3136 * ZF now has Fast_tac, Simp_tac and Auto_tac. Union_iff is a now a default

3137 rewrite rule; this may affect some proofs. eq_cs is gone but can be put back

3138 as ZF_cs addSIs [equalityI];

3142 New in Isabelle94-7 (November 96)

3143 ---------------------------------

3145 * allowing negative levels (as offsets) in prlev and choplev;

3147 * super-linear speedup for large simplifications;

3149 * FOL, ZF and HOL now use miniscoping: rewriting pushes

3150 quantifications in as far as possible (COULD MAKE EXISTING PROOFS

3151 FAIL); can suppress it using the command Delsimps (ex_simps @

3152 all_simps); De Morgan laws are also now included, by default;

3154 * improved printing of ==> : ~:

3156 * new object-logic "Sequents" adds linear logic, while replacing LK

3157 and Modal (thanks to Sara Kalvala);

3159 * HOL/Auth: correctness proofs for authentication protocols;

3161 * HOL: new auto_tac combines rewriting and classical reasoning (many

3162 examples on HOL/Auth);

3164 * HOL: new command AddIffs for declaring theorems of the form P=Q to

3165 the rewriter and classical reasoner simultaneously;

3167 * function uresult no longer returns theorems in "standard" format;

3168 regain previous version by: val uresult = standard o uresult;

3172 New in Isabelle94-6

3173 -------------------

3175 * oracles -- these establish an interface between Isabelle and trusted

3176 external reasoners, which may deliver results as theorems;

3178 * proof objects (in particular record all uses of oracles);

3180 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;

3182 * "constdefs" section in theory files;

3184 * "primrec" section (HOL) no longer requires names;

3186 * internal type "tactic" now simply "thm -> thm Sequence.seq";

3190 New in Isabelle94-5

3191 -------------------

3193 * reduced space requirements;

3195 * automatic HTML generation from theories;

3197 * theory files no longer require "..." (quotes) around most types;

3199 * new examples, including two proofs of the Church-Rosser theorem;

3201 * non-curried (1994) version of HOL is no longer distributed;

3205 New in Isabelle94-4

3206 -------------------

3208 * greatly reduced space requirements;

3210 * theory files (.thy) no longer require \...\ escapes at line breaks;

3212 * searchable theorem database (see the section "Retrieving theorems" on

3213 page 8 of the Reference Manual);

3215 * new examples, including Grabczewski's monumental case study of the

3216 Axiom of Choice;

3218 * The previous version of HOL renamed to Old_HOL;

3220 * The new version of HOL (previously called CHOL) uses a curried syntax

3221 for functions. Application looks like f a b instead of f(a,b);

3223 * Mutually recursive inductive definitions finally work in HOL;

3225 * In ZF, pattern-matching on tuples is now available in all abstractions and

3226 translates to the operator "split";

3230 New in Isabelle94-3

3231 -------------------

3233 * new infix operator, addss, allowing the classical reasoner to

3234 perform simplification at each step of its search. Example:

3235 fast_tac (cs addss ss)

3237 * a new logic, CHOL, the same as HOL, but with a curried syntax

3238 for functions. Application looks like f a b instead of f(a,b). Also pairs

3239 look like (a,b) instead of <a,b>;

3241 * PLEASE NOTE: CHOL will eventually replace HOL!

3243 * In CHOL, pattern-matching on tuples is now available in all abstractions.

3244 It translates to the operator "split". A new theory of integers is available;

3246 * In ZF, integer numerals now denote two's-complement binary integers.

3247 Arithmetic operations can be performed by rewriting. See ZF/ex/Bin.ML;

3249 * Many new examples: I/O automata, Church-Rosser theorem, equivalents

3250 of the Axiom of Choice;

3254 New in Isabelle94-2

3255 -------------------

3257 * Significantly faster resolution;

3259 * the different sections in a .thy file can now be mixed and repeated

3260 freely;

3262 * Database of theorems for FOL, HOL and ZF. New

3263 commands including qed, qed_goal and bind_thm store theorems in the database.

3265 * Simple database queries: return a named theorem (get_thm) or all theorems of

3266 a given theory (thms_of), or find out what theory a theorem was proved in

3267 (theory_of_thm);

3269 * Bugs fixed in the inductive definition and datatype packages;

3271 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs

3272 and HOL_dup_cs obsolete;

3274 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1

3275 have been removed;

3277 * Simpler definition of function space in ZF;

3279 * new results about cardinal and ordinal arithmetic in ZF;

3281 * 'subtype' facility in HOL for introducing new types as subsets of existing

3282 types;

3285 $Id$