summary |
shortlog |
changelog |
graph |
tags |
branches |
files |
changeset |
file |
revisions |
annotate |
diff |
raw

NEWS

author | wenzelm |

Sat Jun 04 18:20:00 2005 +0200 (2005-06-04) | |

changeset 16234 | 421c3522f160 |

parent 16181 | 22324687e2d2 |

child 16251 | 121dc80d120a |

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

major reorganization and cleanup;

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. Note that there is no change in

21 ancient non-Isar theories.

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

24 relative and absolute paths.

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

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

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

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

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

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

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

33 interpreted as pattern and selects all theorems matching the

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

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

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

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

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

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

44 *** Document preparation ***

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

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

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

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

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

51 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).

53 * There is now a flag to control hiding of proofs and some other

54 commands (such as 'ML' or 'parse/print_translation') in document

55 output. Hiding is enabled by default, and can be disabled by the

56 option '-H false' of isatool usedir or by resetting the reference

57 variable IsarOutput.hide_commands in ML. Additional commands to be

58 hidden may be declared using IsarOutput.add_hidden_commands.

60 * Several new antiquotation:

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

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

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

67 argument is a known logical constant;

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

70 theorem applying a "style" to it

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

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

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

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

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

77 document practical applications.

80 *** Pure ***

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

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

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

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

86 sequential dependencies of definitions within a single 'constdefs'

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

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

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

91 indexed syntax provides a notational device for subscripted

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

93 expressions. Secondly, in a local context with structure

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

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

96 show_structs controls printing of implicit structures. Typical

97 applications of these concepts involve record types and locales.

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

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

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

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

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

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

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

108 instead of base 26 numbers.

110 * New flag show_question_marks controls printing of leading question

111 marks in schematic variable names.

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

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

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

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

118 by simp

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

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

123 annotations as "(00...)".

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

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

127 Before that distinction was only partially implemented via type class

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

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

130 exotic syntax specifications may require further adaption

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

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

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

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

136 specifications.

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

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

140 Limit.

142 * Simplifier: simplification procedures may now take the current

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

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

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

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

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

148 allow for use in a context of fixed variables.

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

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

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

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

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

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

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

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

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

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

162 selections of theorems in named facts via index ranges.

165 *** Locales ***

167 * New commands for the interpretation of locale expressions in

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

169 take an instantiation of the locale parameters and compute proof

170 obligations from the instantiated specification. After the

171 obligations have been discharged, the instantiated theorems of the

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

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

174 obligations, neither are instantiated theorems stored in duplicate.

175 Use print_interps to inspect active interpretations of a particular

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

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

179 'interpret' instead.

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

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

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

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

185 to attribute arguments as expected.

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

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

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

190 Attribute implementations need to cooperate properly with the static

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

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

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

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

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

196 values to argument tokens explicitly.

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

199 there is no logical significance.

201 * Context expressions: renaming parameters permits syntax

202 redeclaration as well.

204 * Locale definition: 'includes' now disallowed.

206 * Changed parameter management in theorem generation for long goal

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

208 theorem statement in rare situations.

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

211 locally fixed variables as well.

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

214 alternative context used for evaluating and printing the subsequent

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

218 *** Provers ***

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

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

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

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

224 still available as 'simplesubst'.

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

227 and quasi orders.

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

230 reflexive-transitive closure of relations.

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

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

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

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

237 initial simpset configuration as before. INCOMPATIBILITY.

240 *** HOL ***

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

244 syntax (epsilon)

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

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

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

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

250 becomes available as variable, constant etc. INCOMPATIBILITY,

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

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

254 is \<ge>.

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

257 instead of ":".

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

261 Old New

262 {..n(} {..<n}

263 {)n..} {n<..}

264 {m..n(} {m..<n}

265 {)m..n} {m<..n}

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

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

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

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

272 {)\([^\.]*\)\.\. -> {\1<\.\.}

273 \.\.\([^(}]*\)(} -> \.\.<\1}

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

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

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

279 Some new syntax forms are available:

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

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

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

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

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

287 function "Summation", which has been discontinued.

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

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

291 (insert F x)'.

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

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

295 typedefs, inductive datatypes and recursion.

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

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

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

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

301 in unstructured proof scripts.

303 * Reworked implementation of records. Improved scalability for

304 records with many fields, avoiding performance problems for type

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

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

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

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

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

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

311 <record_name>_ext_type.

313 Flag record_quick_and_dirty_sensitive can be enabled to skip the

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

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

316 quite long.

318 New simproc record_upd_simproc for simplification of multiple record

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

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

321 occasionally, since simplification is more powerful by default.

323 * Simplifier: automatically reasons about transitivity chains

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

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

326 old proofs break occasionally as simplification may now solve more

327 goals than previously.

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

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

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

332 just like y <= x.

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

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

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

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

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

339 enabled/disabled by the reference use_let_simproc. Potential

340 INCOMPATIBILITY since simplification is more powerful by default.

343 *** HOLCF ***

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

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

347 full type-inference.

350 *** ZF ***

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

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

354 of a homomorphism).

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

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

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

361 *** ML ***

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

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

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

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

367 accordingly, while Option.map replaces apsome.

369 * The exception LIST has been given up in favour of the standard

370 exceptions Empty and Subscript, as well as Library.UnequalLengths.

371 Function like Library.hd and Library.tl are superceded by the standard

372 hd and tl functions etc.

374 A number of basic functions are now no longer exported to the ML

375 toplevel, as they are variants of standard functions. The following

376 suggests how one can translate existing code:

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

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

380 last_elem xs = List.last xs

381 flat xss = List.concat xss

382 seq fs = List.app fs

383 partition P xs = List.partition P xs

384 filter P xs = List.filter P xs

385 mapfilter f xs = List.mapPartial f xs

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

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

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

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

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

392 result of Pretty.string_of/str_of and derived functions

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

394 easy composition of diagnostic messages etc. Programmers rarely need

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

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

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

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

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

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

401 have no effect.

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

405 * Isar debugging: new reference Toplevel.debug; default false. Set to

406 make printing of exceptions THM, TERM, TYPE and THEORY more verbose.

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

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

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

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

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

413 name; NameSpace.extend is superceded by context dependent

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

415 the naming context. Especially note Theory.restore_naming and

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

417 Theory.add_path is no longer sufficient to recover from

418 Theory.absolute_path in particular.

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

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

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

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

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

425 with earlier declarations.

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

428 means to remove case bindings -- INCOMPATIBILITY in

429 (RAW_)METHOD_CASES.

431 * Provers: Simplifier and Classical Reasoner now support proof context

432 dependent plug-ins (simprocs, solvers, wrappers etc.). These extra

433 components are stored in the theory and patched into the

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

435 components are maintained by the following theory operations:

437 Simplifier.add_context_simprocs

438 Simplifier.del_context_simprocs

439 Simplifier.set_context_subgoaler

440 Simplifier.reset_context_subgoaler

441 Simplifier.add_context_looper

442 Simplifier.del_context_looper

443 Simplifier.add_context_unsafe_solver

444 Simplifier.add_context_safe_solver

446 Classical.add_context_safe_wrapper

447 Classical.del_context_safe_wrapper

448 Classical.add_context_unsafe_wrapper

449 Classical.del_context_unsafe_wrapper

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

452 local_simpset_of and local_claset_of to instead of the primitive

453 Simplifier.get_local_simpset and Classical.get_local_claset,

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

457 *** System ***

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

460 isabelle, isatool etc.).

462 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for

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

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

466 used by Isabelle; default is ROOT.ML.

468 * HOL: isatool dimacs2hol converts files in DIMACS CNF format

469 (containing Boolean satisfiability problems) into Isabelle/HOL

470 theories.

474 New in Isabelle2004 (April 2004)

475 --------------------------------

477 *** General ***

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

480 Replaces linorder.ML.

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

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

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

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

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

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

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

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

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

491 existing theory and ML files.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

516 (i.e. intersections of classes),

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

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

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

523 *** Isar ***

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

526 cut_tac, subgoal_tac and thin_tac:

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

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

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

530 emulations.

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

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

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

535 * Attributes "where" and "of":

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

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

538 theorems to have too special types in some circumstances.

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

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

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

543 and derived forms.

545 * Locales:

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

547 generate theorems with internal delta predicates (those ending on

548 "_axioms") in the premise.

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

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

551 specification and "includes" elements in goal statement.

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

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

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

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

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

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

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

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

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

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

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

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

564 with "locale (open)".

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

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

568 (Isar) contexts.

571 *** HOL ***

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

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

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

576 can be used like any other Isabelle image. See

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

579 * Simplifier:

580 - Much improved handling of linear and partial orders.

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

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

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

584 to solve goals from the assumptions.

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

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

587 is solved by simplification already.

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

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

592 * Numerics:

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

594 now formalized using the Ring_and_Field theory mentioned above.

595 - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently

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

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

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

599 exponentiation).

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

603 * Records:

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

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

606 the reference "print_record_type_abbr".

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

608 (not enabled by default).

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

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

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

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

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

615 introduces the new constants axiomatically.

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

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

621 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function

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

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

625 matrix theory to linear programming.

627 * Unions and Intersections:

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

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

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

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

633 * Unions and Intersections over Intervals:

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

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

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

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

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

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

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

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

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

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

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

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

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

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

652 for examples.

655 *** HOLCF ***

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

661 New in Isabelle2003 (May 2003)

662 ------------------------------

664 *** General ***

666 * Provers/simplifier:

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

669 Assumptions are now subject to complete mutual simplification,

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

671 the order of assumptions.

673 Potential INCOMPATIBILITY:

675 -- simp sometimes diverges where the old version did

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

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

680 now gives rise to the infinite reduction sequence

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

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

685 kind of problem.

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

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

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

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

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

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

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

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

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

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

699 conditions before applying the rewrite rule):

700 ML "simp_depth_limit := n"

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

702 the simplifier would diverge.

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

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

707 congruence is ignored.

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

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

711 as HOL/Extraction for some case studies.

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

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

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

716 (ML: Proof.show_main_goal).

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

719 rules whose conclusion matches subgoal 1:

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

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

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

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

724 (ML: ProofGeneral.print_intros())

726 * Pure: New flag trace_unify_fail causes unification to print

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

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

729 assumption failed.

731 * Pure: Locale specifications now produce predicate definitions

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

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

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

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

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

737 on the old view without predicates;

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

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

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

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

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

745 include local facts of proof configuration (also covers active

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

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

748 be given (the default is 40);

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

751 (batch-mode only);

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

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

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

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

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

759 for slight decrease in efficiency;

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

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

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

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

768 *** HOL ***

770 * arith(_tac)

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

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

774 of quantifier-free linear arithmetic.

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

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

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

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

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

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

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

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

787 are distributed over a sum of terms;

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

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

791 "<=", "<" and "=").

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

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

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

797 definition;

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

800 Finite_Set);

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

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

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

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

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

809 %x. None. Warning: empty_def now refers to the previously hidden definition

810 of the empty set.

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

813 any algebraic development in Isabelle. Currently covers group theory

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

815 Univariate Polynomials). Contributions welcome;

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

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

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

821 nonstandard (Jacques Fleuriot);

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

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

826 Fleuriot);

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

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

831 Gray and Kramer);

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

835 * MicroJava: bytecode verifier and lightweight bytecode verifier

836 as abstract algorithms, instantiated to the JVM;

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

839 semantics, axiomatic semantics. Supported language features:

840 classes, interfaces, objects,virtual methods, static methods,

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

842 assignment, exceptions.

845 *** ZF ***

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

848 universe, etc.);

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

853 *** ML ***

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

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

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

859 * Pure: improved error reporting of simprocs;

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

862 up simprocs;

865 *** Document preparation ***

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

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

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

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

872 other packages

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

875 broke \Rightarrow)

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

878 textcomp package)

882 New in Isabelle2002 (March 2002)

883 --------------------------------

885 *** Document preparation ***

887 * greatly simplified document preparation setup, including more

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

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

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

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

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

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

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

896 with \includegraphics of LaTeX;

898 * proper spacing of consecutive markup elements, especially text

899 blocks after section headings;

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

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

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

905 better in printed text;

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

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

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

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

912 isatool document copies the Isabelle style files to the target

913 location;

916 *** Isar ***

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

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

920 "case (Suc n)");

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

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

923 instantiation of cases;

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

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

926 rules without further ado;

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

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

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

930 statement becomes is included in the hypothesis, avoiding the

931 slightly cumbersome show "PROP ?case" form;

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

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

934 rules stemming from inductive sets to be applied in unstructured

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

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

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

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

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

940 below);

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

942 success (no backtracking);

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

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

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

946 General versions);

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

948 - generic method setup instantiated for FOL and HOL;

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

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

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

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

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

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

956 fails:

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

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

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

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

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

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

966 attributes everywhere); operations on locales include merge and

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

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

969 some examples;

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

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

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

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

975 qualified by the locale name);

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

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

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

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

981 the context elements being discharged in the obvious way;

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

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

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

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

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

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

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

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

993 use hard-wired "Trueprop";

995 * Pure: added 'corollary' command;

997 * Pure: fixed 'token_translation' command;

999 * Pure: removed obsolete 'exported' attribute;

1001 * Pure: dummy pattern "_" in is/let is now automatically lifted over

1002 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")

1003 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");

1005 * Pure: method 'atomize' presents local goal premises as object-level

1006 statements (atomic meta-level propositions); setup controlled via

1007 rewrite rules declarations of 'atomize' attribute; example

1008 application: 'induct' method with proper rule statements in improper

1009 proof *scripts*;

1011 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)

1012 now consider the syntactic context of assumptions, giving a better

1013 chance to get type-inference of the arguments right (this is

1014 especially important for locales);

1016 * Pure: "sorry" no longer requires quick_and_dirty in interactive

1017 mode;

1019 * Pure/obtain: the formal conclusion "thesis", being marked as

1020 ``internal'', may no longer be reference directly in the text;

1021 potential INCOMPATIBILITY, may need to use "?thesis" in rare

1022 situations;

1024 * Pure: generic 'sym' attribute which declares a rule both as pure

1025 'elim?' and for the 'symmetric' operation;

1027 * Pure: marginal comments ``--'' may now occur just anywhere in the

1028 text; the fixed correlation with particular command syntax has been

1029 discontinued;

1031 * Pure: new method 'rules' is particularly well-suited for proof

1032 search in intuitionistic logic; a bit slower than 'blast' or 'fast',

1033 but often produces more compact proof terms with less detours;

1035 * Pure/Provers/classical: simplified integration with pure rule

1036 attributes and methods; the classical "intro?/elim?/dest?"

1037 declarations coincide with the pure ones; the "rule" method no longer

1038 includes classically swapped intros; "intro" and "elim" methods no

1039 longer pick rules from the context; also got rid of ML declarations

1040 AddXIs/AddXEs/AddXDs; all of this has some potential for

1041 INCOMPATIBILITY;

1043 * Provers/classical: attribute 'swapped' produces classical inversions

1044 of introduction rules;

1046 * Provers/simplifier: 'simplified' attribute may refer to explicit

1047 rules instead of full simplifier context; 'iff' attribute handles

1048 conditional rules;

1050 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;

1052 * HOL: 'recdef' now fails on unfinished automated proofs, use

1053 "(permissive)" option to recover old behavior;

1055 * HOL: 'inductive' no longer features separate (collective) attributes

1056 for 'intros' (was found too confusing);

1058 * HOL: properly declared induction rules less_induct and

1059 wf_induct_rule;

1062 *** HOL ***

1064 * HOL: moved over to sane numeral syntax; the new policy is as

1065 follows:

1067 - 0 and 1 are polymorphic constants, which are defined on any

1068 numeric type (nat, int, real etc.);

1070 - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based

1071 binary representation internally;

1073 - type nat has special constructor Suc, and generally prefers Suc 0

1074 over 1::nat and Suc (Suc 0) over 2::nat;

1076 This change may cause significant problems of INCOMPATIBILITY; here

1077 are some hints on converting existing sources:

1079 - due to the new "num" token, "-0" and "-1" etc. are now atomic

1080 entities, so expressions involving "-" (unary or binary minus) need

1081 to be spaced properly;

1083 - existing occurrences of "1" may need to be constraint "1::nat" or

1084 even replaced by Suc 0; similar for old "2";

1086 - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";

1088 - remove all special provisions on numerals in proofs;

1090 * HOL: simp rules nat_number expand numerals on nat to Suc/0

1091 representation (depends on bin_arith_simps in the default context);

1093 * HOL: symbolic syntax for x^2 (numeral 2);

1095 * HOL: the class of all HOL types is now called "type" rather than

1096 "term"; INCOMPATIBILITY, need to adapt references to this type class

1097 in axclass/classes, instance/arities, and (usually rare) occurrences

1098 in typings (of consts etc.); internally the class is called

1099 "HOL.type", ML programs should refer to HOLogic.typeS;

1101 * HOL/record package improvements:

1102 - new derived operations "fields" to build a partial record section,

1103 "extend" to promote a fixed record to a record scheme, and

1104 "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*

1105 declared as simp by default;

1106 - shared operations ("more", "fields", etc.) now need to be always

1107 qualified) --- potential INCOMPATIBILITY;

1108 - removed "make_scheme" operations (use "make" with "extend") --

1109 INCOMPATIBILITY;

1110 - removed "more" class (simply use "term") -- INCOMPATIBILITY;

1111 - provides cases/induct rules for use with corresponding Isar

1112 methods (for concrete records, record schemes, concrete more

1113 parts, and schematic more parts -- in that order);

1114 - internal definitions directly based on a light-weight abstract

1115 theory of product types over typedef rather than datatype;

1117 * HOL: generic code generator for generating executable ML code from

1118 specifications; specific support for HOL constructs such as inductive

1119 datatypes and sets, as well as recursive functions; can be invoked

1120 via 'generate_code' theory section;

1122 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);

1124 * HOL: consolidated and renamed several theories. In particular:

1125 Ord.thy has been absorbed into HOL.thy

1126 String.thy has been absorbed into List.thy

1128 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"

1129 (beware of argument permutation!);

1131 * HOL: linorder_less_split superseded by linorder_cases;

1133 * HOL/List: "nodups" renamed to "distinct";

1135 * HOL: added "The" definite description operator; move Hilbert's "Eps"

1136 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:

1137 - Ex_def has changed, now need to use some_eq_ex

1139 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so

1140 in this (rare) case use:

1142 delSWrapper "split_all_tac"

1143 addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)

1145 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS

1146 MAY FAIL;

1148 * HOL: introduced f^n = f o ... o f; warning: due to the limits of

1149 Isabelle's type classes, ^ on functions and relations has too general

1150 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be

1151 necessary to attach explicit type constraints;

1153 * HOL/Relation: the prefix name of the infix "O" has been changed from

1154 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been

1155 renamed accordingly (eg "compI" -> "rel_compI").

1157 * HOL: syntax translations now work properly with numerals and records

1158 expressions;

1160 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead

1161 of "lam" -- INCOMPATIBILITY;

1163 * HOL: got rid of some global declarations (potential INCOMPATIBILITY

1164 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"

1165 renamed "Product_Type.unit";

1167 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl

1169 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or

1170 the "cases" method);

1172 * HOL/GroupTheory: group theory examples including Sylow's theorem (by

1173 Florian Kammller);

1175 * HOL/IMP: updated and converted to new-style theory format; several

1176 parts turned into readable document, with proper Isar proof texts and

1177 some explanations (by Gerwin Klein);

1179 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);

1181 * HOL-Hyperreal is now a logic image;

1184 *** HOLCF ***

1186 * Isar: consts/constdefs supports mixfix syntax for continuous

1187 operations;

1189 * Isar: domain package adapted to new-style theory format, e.g. see

1190 HOLCF/ex/Dnat.thy;

1192 * theory Lift: proper use of rep_datatype lift instead of ML hacks --

1193 potential INCOMPATIBILITY; now use plain induct_tac instead of former

1194 lift.induct_tac, always use UU instead of Undef;

1196 * HOLCF/IMP: updated and converted to new-style theory;

1199 *** ZF ***

1201 * Isar: proper integration of logic-specific tools and packages,

1202 including theory commands '(co)inductive', '(co)datatype',

1203 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',

1204 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');

1206 * theory Main no longer includes AC; for the Axiom of Choice, base

1207 your theory on Main_ZFC;

1209 * the integer library now covers quotients and remainders, with many

1210 laws relating division to addition, multiplication, etc.;

1212 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a

1213 typeless version of the formalism;

1215 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory

1216 format;

1218 * ZF/Induct: new directory for examples of inductive definitions,

1219 including theory Multiset for multiset orderings; converted to

1220 new-style theory format;

1222 * ZF: many new theorems about lists, ordinals, etc.;

1225 *** General ***

1227 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference

1228 variable proof controls level of detail: 0 = no proofs (only oracle

1229 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see

1230 also ref manual for further ML interfaces;

1232 * Pure/axclass: removed obsolete ML interface

1233 goal_subclass/goal_arity;

1235 * Pure/syntax: new token syntax "num" for plain numerals (without "#"

1236 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now

1237 separate tokens, so expressions involving minus need to be spaced

1238 properly;

1240 * Pure/syntax: support non-oriented infixes, using keyword "infix"

1241 rather than "infixl" or "infixr";

1243 * Pure/syntax: concrete syntax for dummy type variables admits genuine

1244 sort constraint specifications in type inference; e.g. "x::_::foo"

1245 ensures that the type of "x" is of sort "foo" (but not necessarily a

1246 type variable);

1248 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"

1249 control output of nested => (types); the default behavior is

1250 "type_brackets";

1252 * Pure/syntax: builtin parse translation for "_constify" turns valued

1253 tokens into AST constants;

1255 * Pure/syntax: prefer later declarations of translations and print

1256 translation functions; potential INCOMPATIBILITY: need to reverse

1257 multiple declarations for same syntax element constant;

1259 * Pure/show_hyps reset by default (in accordance to existing Isar

1260 practice);

1262 * Provers/classical: renamed addaltern to addafter, addSaltern to

1263 addSafter;

1265 * Provers/clasimp: ``iff'' declarations now handle conditional rules

1266 as well;

1268 * system: tested support for MacOS X; should be able to get Isabelle +

1269 Proof General to work in a plain Terminal after installing Poly/ML

1270 (e.g. from the Isabelle distribution area) and GNU bash alone

1271 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol

1272 support requires further installations, e.g. from

1273 http://fink.sourceforge.net/);

1275 * system: support Poly/ML 4.1.1 (able to manage larger heaps);

1277 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead

1278 of 40 MB), cf. ML_OPTIONS;

1280 * system: Proof General keywords specification is now part of the

1281 Isabelle distribution (see etc/isar-keywords.el);

1283 * system: support for persistent Proof General sessions (refrain from

1284 outdating all loaded theories on startup); user may create writable

1285 logic images like this: ``isabelle -q HOL Test'';

1287 * system: smart selection of Isabelle process versus Isabelle

1288 interface, accommodates case-insensitive file systems (e.g. HFS+); may

1289 run both "isabelle" and "Isabelle" even if file names are badly

1290 damaged (executable inspects the case of the first letter of its own

1291 name); added separate "isabelle-process" and "isabelle-interface";

1293 * system: refrain from any attempt at filtering input streams; no

1294 longer support ``8bit'' encoding of old isabelle font, instead proper

1295 iso-latin characters may now be used; the related isatools

1296 "symbolinput" and "nonascii" have disappeared as well;

1298 * system: removed old "xterm" interface (the print modes "xterm" and

1299 "xterm_color" are still available for direct use in a suitable

1300 terminal);

1304 New in Isabelle99-2 (February 2001)

1305 -----------------------------------

1307 *** Overview of INCOMPATIBILITIES ***

1309 * HOL: please note that theories in the Library and elsewhere often use the

1310 new-style (Isar) format; to refer to their theorems in an ML script you must

1311 bind them to ML identifers by e.g. val thm_name = thm "thm_name";

1313 * HOL: inductive package no longer splits induction rule aggressively,

1314 but only as far as specified by the introductions given; the old

1315 format may be recovered via ML function complete_split_rule or attribute

1316 'split_rule (complete)';

1318 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,

1319 gfp_Tarski to gfp_unfold;

1321 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;

1323 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a

1324 relation); infix "^^" has been renamed "``"; infix "``" has been

1325 renamed "`"; "univalent" has been renamed "single_valued";

1327 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"

1328 operation;

1330 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;

1332 * Isar: 'obtain' no longer declares "that" fact as simp/intro;

1334 * Isar/HOL: method 'induct' now handles non-atomic goals; as a

1335 consequence, it is no longer monotonic wrt. the local goal context

1336 (which is now passed through the inductive cases);

1338 * Document preparation: renamed standard symbols \<ll> to \<lless> and

1339 \<gg> to \<ggreater>;

1342 *** Document preparation ***

1344 * \isabellestyle{NAME} selects version of Isabelle output (currently

1345 available: are "it" for near math-mode best-style output, "sl" for

1346 slanted text style, and "tt" for plain type-writer; if no

1347 \isabellestyle command is given, output is according to slanted

1348 type-writer);

1350 * support sub/super scripts (for single symbols only), input syntax is

1351 like this: "A\<^sup>*" or "A\<^sup>\<star>";

1353 * some more standard symbols; see Appendix A of the system manual for

1354 the complete list of symbols defined in isabellesym.sty;

1356 * improved isabelle style files; more abstract symbol implementation

1357 (should now use \isamath{...} and \isatext{...} in custom symbol

1358 definitions);

1360 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals

1361 state; Note that presentation of goal states does not conform to

1362 actual human-readable proof documents. Please do not include goal

1363 states into document output unless you really know what you are doing!

1365 * proper indentation of antiquoted output with proportional LaTeX

1366 fonts;

1368 * no_document ML operator temporarily disables LaTeX document

1369 generation;

1371 * isatool unsymbolize tunes sources for plain ASCII communication;

1374 *** Isar ***

1376 * Pure: Isar now suffers initial goal statements to contain unbound

1377 schematic variables (this does not conform to actual readable proof

1378 documents, due to unpredictable outcome and non-compositional proof

1379 checking); users who know what they are doing may use schematic goals

1380 for Prolog-style synthesis of proven results;

1382 * Pure: assumption method (an implicit finishing) now handles actual

1383 rules as well;

1385 * Pure: improved 'obtain' --- moved to Pure, insert "that" into

1386 initial goal, declare "that" only as Pure intro (only for single

1387 steps); the "that" rule assumption may now be involved in implicit

1388 finishing, thus ".." becomes a feasible for trivial obtains;

1390 * Pure: default proof step now includes 'intro_classes'; thus trivial

1391 instance proofs may be performed by "..";

1393 * Pure: ?thesis / ?this / "..." now work for pure meta-level

1394 statements as well;

1396 * Pure: more robust selection of calculational rules;

1398 * Pure: the builtin notion of 'finished' goal now includes the ==-refl

1399 rule (as well as the assumption rule);

1401 * Pure: 'thm_deps' command visualizes dependencies of theorems and

1402 lemmas, using the graph browser tool;

1404 * Pure: predict failure of "show" in interactive mode;

1406 * Pure: 'thms_containing' now takes actual terms as arguments;

1408 * HOL: improved method 'induct' --- now handles non-atomic goals

1409 (potential INCOMPATIBILITY); tuned error handling;

1411 * HOL: cases and induct rules now provide explicit hints about the

1412 number of facts to be consumed (0 for "type" and 1 for "set" rules);

1413 any remaining facts are inserted into the goal verbatim;

1415 * HOL: local contexts (aka cases) may now contain term bindings as

1416 well; the 'cases' and 'induct' methods new provide a ?case binding for

1417 the result to be shown in each case;

1419 * HOL: added 'recdef_tc' command;

1421 * isatool convert assists in eliminating legacy ML scripts;

1424 *** HOL ***

1426 * HOL/Library: a collection of generic theories to be used together

1427 with main HOL; the theory loader path already includes this directory

1428 by default; the following existing theories have been moved here:

1429 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While

1430 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);

1432 * HOL/Unix: "Some aspects of Unix file-system security", a typical

1433 modelling and verification task performed in Isabelle/HOL +

1434 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).

1436 * HOL/Algebra: special summation operator SUM no longer exists, it has

1437 been replaced by setsum; infix 'assoc' now has priority 50 (like

1438 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to

1439 'domain', this makes the theory consistent with mathematical

1440 literature;

1442 * HOL basics: added overloaded operations "inverse" and "divide"

1443 (infix "/"), syntax for generic "abs" operation, generic summation

1444 operator \<Sum>;

1446 * HOL/typedef: simplified package, provide more useful rules (see also

1447 HOL/subset.thy);

1449 * HOL/datatype: induction rule for arbitrarily branching datatypes is

1450 now expressed as a proper nested rule (old-style tactic scripts may

1451 require atomize_strip_tac to cope with non-atomic premises);

1453 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule

1454 to "split_conv" (old name still available for compatibility);

1456 * HOL: improved concrete syntax for strings (e.g. allows translation

1457 rules with string literals);

1459 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals

1460 and Fleuriot's mechanization of analysis, including the transcendental

1461 functions for the reals;

1463 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;

1466 *** CTT ***

1468 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that

1469 "lam" is displayed as TWO lambda-symbols

1471 * CTT: theory Main now available, containing everything (that is, Bool

1472 and Arith);

1475 *** General ***

1477 * Pure: the Simplifier has been implemented properly as a derived rule

1478 outside of the actual kernel (at last!); the overall performance

1479 penalty in practical applications is about 50%, while reliability of

1480 the Isabelle inference kernel has been greatly improved;

1482 * print modes "brackets" and "no_brackets" control output of nested =>

1483 (types) and ==> (props); the default behaviour is "brackets";

1485 * Provers: fast_tac (and friends) now handle actual object-logic rules

1486 as assumptions as well;

1488 * system: support Poly/ML 4.0;

1490 * system: isatool install handles KDE version 1 or 2;

1494 New in Isabelle99-1 (October 2000)

1495 ----------------------------------

1497 *** Overview of INCOMPATIBILITIES ***

1499 * HOL: simplification of natural numbers is much changed; to partly

1500 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)

1501 issue the following ML commands:

1503 Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;

1504 Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];

1506 * HOL: simplification no longer dives into case-expressions; this is

1507 controlled by "t.weak_case_cong" for each datatype t;

1509 * HOL: nat_less_induct renamed to less_induct;

1511 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool

1512 fixsome to patch .thy and .ML sources automatically;

1514 select_equality -> some_equality

1515 select_eq_Ex -> some_eq_ex

1516 selectI2EX -> someI2_ex

1517 selectI2 -> someI2

1518 selectI -> someI

1519 select1_equality -> some1_equality

1520 Eps_sym_eq -> some_sym_eq_trivial

1521 Eps_eq -> some_eq_trivial

1523 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;

1525 * HOL: removed obsolete theorem binding expand_if (refer to split_if

1526 instead);

1528 * HOL: the recursion equations generated by 'recdef' are now called

1529 f.simps instead of f.rules;

1531 * HOL: qed_spec_mp now also handles bounded ALL as well;

1533 * HOL: 0 is now overloaded, so the type constraint ":: nat" may

1534 sometimes be needed;

1536 * HOL: the constant for "f``x" is now "image" rather than "op ``";

1538 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";

1540 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian

1541 product is now "<*>" instead of "Times"; the lexicographic product is

1542 now "<*lex*>" instead of "**";

1544 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part

1545 of main HOL, but was unused); better use HOL's datatype package;

1547 * HOL: removed "symbols" syntax for constant "override" of theory Map;

1548 the old syntax may be recovered as follows:

1550 syntax (symbols)

1551 override :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"

1552 (infixl "\\<oplus>" 100)

1554 * HOL/Real: "rabs" replaced by overloaded "abs" function;

1556 * HOL/ML: even fewer consts are declared as global (see theories Ord,

1557 Lfp, Gfp, WF); this only affects ML packages that refer to const names

1558 internally;

1560 * HOL and ZF: syntax for quotienting wrt an equivalence relation

1561 changed from A/r to A//r;

1563 * ZF: new treatment of arithmetic (nat & int) may break some old

1564 proofs;

1566 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,

1567 rulify -> rule_format, elimify -> elim_format, ...);

1569 * Isar/Provers: intro/elim/dest attributes changed; renamed

1570 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one

1571 should have to change intro!! to intro? only); replaced "delrule" by

1572 "rule del";

1574 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;

1576 * Provers: strengthened force_tac by using new first_best_tac;

1578 * LaTeX document preparation: several changes of isabelle.sty (see

1579 lib/texinputs);

1582 *** Document preparation ***

1584 * formal comments (text blocks etc.) in new-style theories may now

1585 contain antiquotations of thm/prop/term/typ/text to be presented

1586 according to latex print mode; concrete syntax is like this:

1587 @{term[show_types] "f(x) = a + x"};

1589 * isatool mkdir provides easy setup of Isabelle session directories,

1590 including proper document sources;

1592 * generated LaTeX sources are now deleted after successful run

1593 (isatool document -c); may retain a copy somewhere else via -D option

1594 of isatool usedir;

1596 * isatool usedir -D now lets isatool latex -o sty update the Isabelle

1597 style files, achieving self-contained LaTeX sources and simplifying

1598 LaTeX debugging;

1600 * old-style theories now produce (crude) LaTeX output as well;

1602 * browser info session directories are now self-contained (may be put

1603 on WWW server seperately); improved graphs of nested sessions; removed

1604 graph for 'all sessions';

1606 * several improvements in isabelle style files; \isabellestyle{it}

1607 produces fake math mode output; \isamarkupheader is now \section by

1608 default; see lib/texinputs/isabelle.sty etc.;

1611 *** Isar ***

1613 * Isar/Pure: local results and corresponding term bindings are now

1614 subject to Hindley-Milner polymorphism (similar to ML); this

1615 accommodates incremental type-inference very nicely;

1617 * Isar/Pure: new derived language element 'obtain' supports

1618 generalized existence reasoning;

1620 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'

1621 support accumulation of results, without applying any rules yet;

1622 useful to collect intermediate results without explicit name

1623 references, and for use with transitivity rules with more than 2

1624 premises;

1626 * Isar/Pure: scalable support for case-analysis type proofs: new

1627 'case' language element refers to local contexts symbolically, as

1628 produced by certain proof methods; internally, case names are attached

1629 to theorems as "tags";

1631 * Isar/Pure: theory command 'hide' removes declarations from

1632 class/type/const name spaces;

1634 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to

1635 indicate potential overloading;

1637 * Isar/Pure: changed syntax of local blocks from {{ }} to { };

1639 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write

1640 "{a,b,c}" instead of {a,b,c};

1642 * Isar/Pure now provides its own version of intro/elim/dest

1643 attributes; useful for building new logics, but beware of confusion

1644 with the version in Provers/classical;

1646 * Isar/Pure: the local context of (non-atomic) goals is provided via

1647 case name 'antecedent';

1649 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms

1650 to the current context is now done automatically);

1652 * Isar/Pure: theory command 'method_setup' provides a simple interface

1653 for definining proof methods in ML;

1655 * Isar/Provers: intro/elim/dest attributes changed; renamed

1656 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in

1657 most cases, one should have to change intro!! to intro? only);

1658 replaced "delrule" by "rule del";

1660 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and

1661 'symmetric' attribute (the latter supercedes [RS sym]);

1663 * Isar/Provers: splitter support (via 'split' attribute and 'simp'

1664 method modifier); 'simp' method: 'only:' modifier removes loopers as

1665 well (including splits);

1667 * Isar/Provers: Simplifier and Classical methods now support all kind

1668 of modifiers used in the past, including 'cong', 'iff', etc.

1670 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination

1671 of Simplifier and Classical reasoner);

1673 * Isar/HOL: new proof method 'cases' and improved version of 'induct'

1674 now support named cases; major packages (inductive, datatype, primrec,

1675 recdef) support case names and properly name parameters;

1677 * Isar/HOL: new transitivity rules for substitution in inequalities --

1678 monotonicity conditions are extracted to be proven at end of

1679 calculations;

1681 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof

1682 method anyway;

1684 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =

1685 split_if split_if_asm; datatype package provides theorems foo.splits =

1686 foo.split foo.split_asm for each datatype;

1688 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"

1689 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof

1690 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:

1691 use "(cases (simplified))" method in proper proof texts);

1693 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;

1695 * Isar: names of theorems etc. may be natural numbers as well;

1697 * Isar: 'pr' command: optional arguments for goals_limit and

1698 ProofContext.prems_limit; no longer prints theory contexts, but only

1699 proof states;

1701 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit

1702 additional print modes to be specified; e.g. "pr(latex)" will print

1703 proof state according to the Isabelle LaTeX style;

1705 * Isar: improved support for emulating tactic scripts, including proof

1706 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',

1707 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'

1708 (for HOL datatypes);

1710 * Isar: simplified (more robust) goal selection of proof methods: 1st

1711 goal, all goals, or explicit goal specifier (tactic emulation); thus

1712 'proof method scripts' have to be in depth-first order;

1714 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';

1716 * Isar: removed 'help' command, which hasn't been too helpful anyway;

1717 should instead use individual commands for printing items

1718 (print_commands, print_methods etc.);

1720 * Isar: added 'nothing' --- the empty list of theorems;

1723 *** HOL ***

1725 * HOL/MicroJava: formalization of a fragment of Java, together with a

1726 corresponding virtual machine and a specification of its bytecode

1727 verifier and a lightweight bytecode verifier, including proofs of

1728 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and

1729 Cornelia Pusch (see also the homepage of project Bali at

1730 http://isabelle.in.tum.de/Bali/);

1732 * HOL/Algebra: new theory of rings and univariate polynomials, by

1733 Clemens Ballarin;

1735 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese

1736 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M

1737 Rasmussen;

1739 * HOL/Lattice: fundamental concepts of lattice theory and order

1740 structures, including duals, properties of bounds versus algebraic

1741 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski

1742 Theorem for complete lattices etc.; may also serve as a demonstration

1743 for abstract algebraic reasoning using axiomatic type classes, and

1744 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;

1746 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David

1747 von Oheimb;

1749 * HOL/IMPP: extension of IMP with local variables and mutually

1750 recursive procedures, by David von Oheimb;

1752 * HOL/Lambda: converted into new-style theory and document;

1754 * HOL/ex/Multiquote: example of multiple nested quotations and

1755 anti-quotations -- basically a generalized version of de-Bruijn

1756 representation; very useful in avoiding lifting of operations;

1758 * HOL/record: added general record equality rule to simpset; fixed

1759 select-update simplification procedure to handle extended records as

1760 well; admit "r" as field name;

1762 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with

1763 other numeric types and also as the identity of groups, rings, etc.;

1765 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.

1766 Types nat and int belong to this axclass;

1768 * HOL: greatly improved simplification involving numerals of type nat, int, real:

1769 (i + #8 + j) = Suc k simplifies to #7 + (i + j) = k

1770 i*j + k + j*#3*i simplifies to #4*(i*j) + k

1771 two terms #m*u and #n*u are replaced by #(m+n)*u

1772 (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)

1773 and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y

1774 or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);

1776 * HOL: meson_tac is available (previously in ex/meson.ML); it is a

1777 powerful prover for predicate logic but knows nothing of clasets; see

1778 ex/mesontest.ML and ex/mesontest2.ML for example applications;

1780 * HOL: new version of "case_tac" subsumes both boolean case split and

1781 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer

1782 exists, may define val exhaust_tac = case_tac for ad-hoc portability;

1784 * HOL: simplification no longer dives into case-expressions: only the

1785 selector expression is simplified, but not the remaining arms; to

1786 enable full simplification of case-expressions for datatype t, you may

1787 remove t.weak_case_cong from the simpset, either globally (Delcongs

1788 [thm"t.weak_case_cong"];) or locally (delcongs [...]).

1790 * HOL/recdef: the recursion equations generated by 'recdef' for

1791 function 'f' are now called f.simps instead of f.rules; if all

1792 termination conditions are proved automatically, these simplification

1793 rules are added to the simpset, as in primrec; rules may be named

1794 individually as well, resulting in a separate list of theorems for

1795 each equation;

1797 * HOL/While is a new theory that provides a while-combinator. It

1798 permits the definition of tail-recursive functions without the

1799 provision of a termination measure. The latter is necessary once the

1800 invariant proof rule for while is applied.

1802 * HOL: new (overloaded) notation for the set of elements below/above

1803 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.

1805 * HOL: theorems impI, allI, ballI bound as "strip";

1807 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic

1808 induct_tac th "x1 ... xn" expects th to have a conclusion of the form

1809 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;

1811 * HOL/Real: "rabs" replaced by overloaded "abs" function;

1813 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of

1814 main HOL, but was unused);

1816 * HOL: fewer consts declared as global (e.g. have to refer to

1817 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);

1819 * HOL: tuned AST representation of nested pairs, avoiding bogus output

1820 in case of overlap with user translations (e.g. judgements over

1821 tuples); (note that the underlying logical represenation is still

1822 bogus);

1825 *** ZF ***

1827 * ZF: simplification automatically cancels common terms in arithmetic

1828 expressions over nat and int;

1830 * ZF: new treatment of nat to minimize type-checking: all operators

1831 coerce their operands to a natural number using the function natify,

1832 making the algebraic laws unconditional;

1834 * ZF: as above, for int: operators coerce their operands to an integer

1835 using the function intify;

1837 * ZF: the integer library now contains many of the usual laws for the

1838 orderings, including $<=, and monotonicity laws for $+ and $*;

1840 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic

1841 simplification;

1843 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q

1844 to the simplifier and classical reasoner simultaneously;

1847 *** General ***

1849 * Provers: blast_tac now handles actual object-logic rules as

1850 assumptions; note that auto_tac uses blast_tac internally as well;

1852 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning

1853 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;

1855 * Provers: delrules now handles destruct rules as well (no longer need

1856 explicit make_elim);

1858 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.

1859 [| inj ?f; ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W

1860 use instead the strong form,

1861 [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W

1862 in HOL, FOL and ZF the function cla_make_elim will create such rules

1863 from destruct-rules;

1865 * Provers: Simplifier.easy_setup provides a fast path to basic

1866 Simplifier setup for new object-logics;

1868 * Pure: AST translation rules no longer require constant head on LHS;

1870 * Pure: improved name spaces: ambiguous output is qualified; support

1871 for hiding of names;

1873 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and

1874 XSYMBOL_HOME; no longer need to do manual configuration in most

1875 situations;

1877 * system: compression of ML heaps images may now be controlled via -c

1878 option of isabelle and isatool usedir (currently only observed by

1879 Poly/ML);

1881 * system: isatool installfonts may handle X-Symbol fonts as well (very

1882 useful for remote X11);

1884 * system: provide TAGS file for Isabelle sources;

1886 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument

1887 order;

1889 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global

1890 timing flag supersedes proof_timing and Toplevel.trace;

1892 * ML: new combinators |>> and |>>> for incremental transformations

1893 with secondary results (e.g. certain theory extensions):

1895 * ML: PureThy.add_defs gets additional argument to indicate potential

1896 overloading (usually false);

1898 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as

1899 results;

1903 New in Isabelle99 (October 1999)

1904 --------------------------------

1906 *** Overview of INCOMPATIBILITIES (see below for more details) ***

1908 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)

1909 are no longer simplified. (This allows the simplifier to unfold recursive

1910 functional programs.) To restore the old behaviour, declare

1912 Delcongs [if_weak_cong];

1914 * HOL: Removed the obsolete syntax "Compl A"; use -A for set

1915 complement;

1917 * HOL: the predicate "inj" is now defined by translation to "inj_on";

1919 * HOL/datatype: mutual_induct_tac no longer exists --

1920 use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]

1922 * HOL/typedef: fixed type inference for representing set; type

1923 arguments now have to occur explicitly on the rhs as type constraints;

1925 * ZF: The con_defs part of an inductive definition may no longer refer

1926 to constants declared in the same theory;

1928 * HOL, ZF: the function mk_cases, generated by the inductive

1929 definition package, has lost an argument. To simplify its result, it

1930 uses the default simpset instead of a supplied list of theorems.

1932 * HOL/List: the constructors of type list are now Nil and Cons;

1934 * Simplifier: the type of the infix ML functions

1935 setSSolver addSSolver setSolver addSolver

1936 is now simpset * solver -> simpset where `solver' is a new abstract type

1937 for packaging solvers. A solver is created via

1938 mk_solver: string -> (thm list -> int -> tactic) -> solver

1939 where the string argument is only a comment.

1942 *** Proof tools ***

1944 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a

1945 decision procedure for linear arithmetic. Currently it is used for

1946 types `nat', `int', and `real' in HOL (see below); it can, should and

1947 will be instantiated for other types and logics as well.

1949 * The simplifier now accepts rewrite rules with flexible heads, eg

1950 hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y

1951 They are applied like any rule with a non-pattern lhs, i.e. by first-order

1952 matching.

1955 *** General ***

1957 * New Isabelle/Isar subsystem provides an alternative to traditional

1958 tactical theorem proving; together with the ProofGeneral/isar user

1959 interface it offers an interactive environment for developing human

1960 readable proof documents (Isar == Intelligible semi-automated

1961 reasoning); for further information see isatool doc isar-ref,

1962 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/

1964 * improved and simplified presentation of theories: better HTML markup

1965 (including colors), graph views in several sizes; isatool usedir now

1966 provides a proper interface for user theories (via -P option); actual

1967 document preparation based on (PDF)LaTeX is available as well (for

1968 new-style theories only); see isatool doc system for more information;

1970 * native support for Proof General, both for classic Isabelle and

1971 Isabelle/Isar;

1973 * ML function thm_deps visualizes dependencies of theorems and lemmas,

1974 using the graph browser tool;

1976 * Isabelle manuals now also available as PDF;

1978 * theory loader rewritten from scratch (may not be fully

1979 bug-compatible); old loadpath variable has been replaced by show_path,

1980 add_path, del_path, reset_path functions; new operations such as

1981 update_thy, touch_thy, remove_thy, use/update_thy_only (see also

1982 isatool doc ref);

1984 * improved isatool install: option -k creates KDE application icon,

1985 option -p DIR installs standalone binaries;

1987 * added ML_PLATFORM setting (useful for cross-platform installations);

1988 more robust handling of platform specific ML images for SML/NJ;

1990 * the settings environment is now statically scoped, i.e. it is never

1991 created again in sub-processes invoked from isabelle, isatool, or

1992 Isabelle;

1994 * path element specification '~~' refers to '$ISABELLE_HOME';

1996 * in locales, the "assumes" and "defines" parts may be omitted if

1997 empty;

1999 * new print_mode "xsymbols" for extended symbol support (e.g. genuine

2000 long arrows);

2002 * new print_mode "HTML";

2004 * new flag show_tags controls display of tags of theorems (which are

2005 basically just comments that may be attached by some tools);

2007 * Isamode 2.6 requires patch to accomodate change of Isabelle font

2008 mode and goal output format:

2010 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el

2011 244c244

2012 < (list (isa-getenv "ISABELLE") "-msymbols" logic-name)

2013 ---

2014 > (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)

2015 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el

2016 181c181

2017 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"

2018 ---

2019 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"

2021 * function bind_thms stores lists of theorems (cf. bind_thm);

2023 * new shorthand tactics ftac, eatac, datac, fatac;

2025 * qed (and friends) now accept "" as result name; in that case the

2026 theorem is not stored, but proper checks and presentation of the

2027 result still apply;

2029 * theorem database now also indexes constants "Trueprop", "all",

2030 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;

2033 *** HOL ***

2035 ** HOL arithmetic **

2037 * There are now decision procedures for linear arithmetic over nat and

2038 int:

2040 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',

2041 `+', `-', `Suc', `min', `max' and numerical constants; other subterms

2042 are treated as atomic; subformulae not involving type `nat' or `int'

2043 are ignored; quantified subformulae are ignored unless they are

2044 positive universal or negative existential. The tactic has to be

2045 invoked by hand and can be a little bit slow. In particular, the

2046 running time is exponential in the number of occurrences of `min' and

2047 `max', and `-' on `nat'.

2049 2. fast_arith_tac is a cut-down version of arith_tac: it only takes

2050 (negated) (in)equalities among the premises and the conclusion into

2051 account (i.e. no compound formulae) and does not know about `min' and

2052 `max', and `-' on `nat'. It is fast and is used automatically by the

2053 simplifier.

2055 NB: At the moment, these decision procedures do not cope with mixed

2056 nat/int formulae where the two parts interact, such as `m < n ==>

2057 int(m) < int(n)'.

2059 * HOL/Numeral provides a generic theory of numerals (encoded

2060 efficiently as bit strings); setup for types nat/int/real is in place;

2061 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than

2062 int, existing theories and proof scripts may require a few additional

2063 type constraints;

2065 * integer division and remainder can now be performed on constant

2066 arguments;

2068 * many properties of integer multiplication, division and remainder

2069 are now available;

2071 * An interface to the Stanford Validity Checker (SVC) is available through the

2072 tactic svc_tac. Propositional tautologies and theorems of linear arithmetic

2073 are proved automatically. SVC must be installed separately, and its results

2074 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any

2075 invocation of the underlying oracle). For SVC see

2076 http://verify.stanford.edu/SVC

2078 * IsaMakefile: the HOL-Real target now builds an actual image;

2081 ** HOL misc **

2083 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces

2084 (in Isabelle/Isar) -- by Gertrud Bauer;

2086 * HOL/BCV: generic model of bytecode verification, i.e. data-flow

2087 analysis for assembly languages with subtypes;

2089 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization

2090 -- avoids syntactic ambiguities and treats state, transition, and

2091 temporal levels more uniformly; introduces INCOMPATIBILITIES due to

2092 changed syntax and (many) tactics;

2094 * HOL/inductive: Now also handles more general introduction rules such

2095 as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity

2096 theorems are now maintained within the theory (maintained via the

2097 "mono" attribute);

2099 * HOL/datatype: Now also handles arbitrarily branching datatypes

2100 (using function types) such as

2102 datatype 'a tree = Atom 'a | Branch "nat => 'a tree"

2104 * HOL/record: record_simproc (part of the default simpset) takes care

2105 of selectors applied to updated records; record_split_tac is no longer

2106 part of the default claset; update_defs may now be removed from the

2107 simpset in many cases; COMPATIBILITY: old behavior achieved by

2109 claset_ref () := claset() addSWrapper record_split_wrapper;

2110 Delsimprocs [record_simproc]

2112 * HOL/typedef: fixed type inference for representing set; type

2113 arguments now have to occur explicitly on the rhs as type constraints;

2115 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem

2116 names rather than an ML expression;

2118 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be

2119 supplied later. Program schemes can be defined, such as

2120 "While B C s = (if B s then While B C (C s) else s)"

2121 where the well-founded relation can be chosen after B and C have been given.

2123 * HOL/List: the constructors of type list are now Nil and Cons;

2124 INCOMPATIBILITY: while [] and infix # syntax is still there, of

2125 course, ML tools referring to List.list.op # etc. have to be adapted;

2127 * HOL_quantifiers flag superseded by "HOL" print mode, which is

2128 disabled by default; run isabelle with option -m HOL to get back to

2129 the original Gordon/HOL-style output;

2131 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,

2132 ALL x<=y. P, EX x<y. P, EX x<=y. P;

2134 * HOL basic syntax simplified (more orthogonal): all variants of

2135 All/Ex now support plain / symbolic / HOL notation; plain syntax for

2136 Eps operator is provided as well: "SOME x. P[x]";

2138 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;

2140 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made

2141 thus available for user theories;

2143 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with

2144 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the

2145 time;

2147 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec

2148 several times and then mp;

2151 *** LK ***

2153 * the notation <<...>> is now available as a notation for sequences of

2154 formulas;

2156 * the simplifier is now installed

2158 * the axiom system has been generalized (thanks to Soren Heilmann)

2160 * the classical reasoner now has a default rule database

2163 *** ZF ***

2165 * new primrec section allows primitive recursive functions to be given

2166 directly (as in HOL) over datatypes and the natural numbers;

2168 * new tactics induct_tac and exhaust_tac for induction (or case

2169 analysis) over datatypes and the natural numbers;

2171 * the datatype declaration of type T now defines the recursor T_rec;

2173 * simplification automatically does freeness reasoning for datatype

2174 constructors;

2176 * automatic type-inference, with AddTCs command to insert new

2177 type-checking rules;

2179 * datatype introduction rules are now added as Safe Introduction rules

2180 to the claset;

2182 * the syntax "if P then x else y" is now available in addition to

2183 if(P,x,y);

2186 *** Internal programming interfaces ***

2188 * tuned simplifier trace output; new flag debug_simp;

2190 * structures Vartab / Termtab (instances of TableFun) offer efficient

2191 tables indexed by indexname_ord / term_ord (compatible with aconv);

2193 * AxClass.axclass_tac lost the theory argument;

2195 * tuned current_goals_markers semantics: begin / end goal avoids

2196 printing empty lines;

2198 * removed prs and prs_fn hook, which was broken because it did not

2199 include \n in its semantics, forcing writeln to add one

2200 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:

2201 string -> unit if you really want to output text without newline;

2203 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to

2204 plain output, interface builders may have to enable 'isabelle_font'

2205 mode to get Isabelle font glyphs as before;

2207 * refined token_translation interface; INCOMPATIBILITY: output length

2208 now of type real instead of int;

2210 * theory loader actions may be traced via new ThyInfo.add_hook

2211 interface (see src/Pure/Thy/thy_info.ML); example application: keep

2212 your own database of information attached to *whole* theories -- as

2213 opposed to intra-theory data slots offered via TheoryDataFun;

2215 * proper handling of dangling sort hypotheses (at last!);

2216 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing

2217 extra sort hypotheses that can be witnessed from the type signature;

2218 the force_strip_shyps flag is gone, any remaining shyps are simply

2219 left in the theorem (with a warning issued by strip_shyps_warning);

2223 New in Isabelle98-1 (October 1998)

2224 ----------------------------------

2226 *** Overview of INCOMPATIBILITIES (see below for more details) ***

2228 * several changes of automated proof tools;

2230 * HOL: major changes to the inductive and datatype packages, including

2231 some minor incompatibilities of theory syntax;

2233 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now

2234 called `inj_on';

2236 * HOL: removed duplicate thms in Arith:

2237 less_imp_add_less should be replaced by trans_less_add1

2238 le_imp_add_le should be replaced by trans_le_add1

2240 * HOL: unary minus is now overloaded (new type constraints may be

2241 required);

2243 * HOL and ZF: unary minus for integers is now #- instead of #~. In

2244 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is

2245 now taken as an integer constant.

2247 * Pure: ML function 'theory_of' renamed to 'theory';

2250 *** Proof tools ***

2252 * Simplifier:

2253 1. Asm_full_simp_tac is now more aggressive.

2254 1. It will sometimes reorient premises if that increases their power to

2255 simplify.

2256 2. It does no longer proceed strictly from left to right but may also

2257 rotate premises to achieve further simplification.

2258 For compatibility reasons there is now Asm_lr_simp_tac which is like the

2259 old Asm_full_simp_tac in that it does not rotate premises.

2260 2. The simplifier now knows a little bit about nat-arithmetic.

2262 * Classical reasoner: wrapper mechanism for the classical reasoner now

2263 allows for selected deletion of wrappers, by introduction of names for

2264 wrapper functionals. This implies that addbefore, addSbefore,

2265 addaltern, and addSaltern now take a pair (name, tactic) as argument,

2266 and that adding two tactics with the same name overwrites the first

2267 one (emitting a warning).

2268 type wrapper = (int -> tactic) -> (int -> tactic)

2269 setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by

2270 addWrapper, addSWrapper: claset * (string * wrapper) -> claset

2271 delWrapper, delSWrapper: claset * string -> claset

2272 getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;

2274 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE

2275 semantics; addbefore now affects only the unsafe part of step_tac

2276 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY

2277 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac

2278 by Force_tac;

2280 * Classical reasoner: setwrapper to setWrapper and compwrapper to

2281 compWrapper; added safe wrapper (and access functions for it);

2283 * HOL/split_all_tac is now much faster and fails if there is nothing

2284 to split. Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order

2285 and the names of the automatically generated variables have changed.

2286 split_all_tac has moved within claset() from unsafe wrappers to safe

2287 wrappers, which means that !!-bound variables are split much more

2288 aggressively, and safe_tac and clarify_tac now split such variables.

2289 If this splitting is not appropriate, use delSWrapper "split_all_tac".

2290 Note: the same holds for record_split_tac, which does the job of

2291 split_all_tac for record fields.

2293 * HOL/Simplifier: Rewrite rules for case distinctions can now be added

2294 permanently to the default simpset using Addsplits just like

2295 Addsimps. They can be removed via Delsplits just like

2296 Delsimps. Lower-case versions are also available.

2298 * HOL/Simplifier: The rule split_if is now part of the default

2299 simpset. This means that the simplifier will eliminate all occurrences

2300 of if-then-else in the conclusion of a goal. To prevent this, you can

2301 either remove split_if completely from the default simpset by

2302 `Delsplits [split_if]' or remove it in a specific call of the

2303 simplifier using `... delsplits [split_if]'. You can also add/delete

2304 other case splitting rules to/from the default simpset: every datatype

2305 generates suitable rules `split_t_case' and `split_t_case_asm' (where

2306 t is the name of the datatype).

2308 * Classical reasoner / Simplifier combination: new force_tac (and

2309 derivatives Force_tac, force) combines rewriting and classical

2310 reasoning (and whatever other tools) similarly to auto_tac, but is

2311 aimed to solve the given subgoal completely.

2314 *** General ***

2316 * new top-level commands `Goal' and `Goalw' that improve upon `goal'

2317 and `goalw': the theory is no longer needed as an explicit argument -

2318 the current theory context is used; assumptions are no longer returned

2319 at the ML-level unless one of them starts with ==> or !!; it is

2320 recommended to convert to these new commands using isatool fixgoal

2321 (backup your sources first!);

2323 * new top-level commands 'thm' and 'thms' for retrieving theorems from

2324 the current theory context, and 'theory' to lookup stored theories;

2326 * new theory section 'locale' for declaring constants, assumptions and

2327 definitions that have local scope;

2329 * new theory section 'nonterminals' for purely syntactic types;

2331 * new theory section 'setup' for generic ML setup functions

2332 (e.g. package initialization);

2334 * the distribution now includes Isabelle icons: see

2335 lib/logo/isabelle-{small,tiny}.xpm;

2337 * isatool install - install binaries with absolute references to

2338 ISABELLE_HOME/bin;

2340 * isatool logo -- create instances of the Isabelle logo (as EPS);

2342 * print mode 'emacs' reserved for Isamode;

2344 * support multiple print (ast) translations per constant name;

2346 * theorems involving oracles are now printed with a suffixed [!];

2349 *** HOL ***

2351 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');

2353 * HOL/inductive package reorganized and improved: now supports mutual

2354 definitions such as

2356 inductive EVEN ODD

2357 intrs

2358 null "0 : EVEN"

2359 oddI "n : EVEN ==> Suc n : ODD"

2360 evenI "n : ODD ==> Suc n : EVEN"

2362 new theorem list "elims" contains an elimination rule for each of the

2363 recursive sets; inductive definitions now handle disjunctive premises

2364 correctly (also ZF);

2366 INCOMPATIBILITIES: requires Inductive as an ancestor; component

2367 "mutual_induct" no longer exists - the induction rule is always

2368 contained in "induct";

2371 * HOL/datatype package re-implemented and greatly improved: now

2372 supports mutually recursive datatypes such as

2374 datatype

2375 'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)

2376 | SUM ('a aexp) ('a aexp)

2377 | DIFF ('a aexp) ('a aexp)

2378 | NUM 'a

2379 and

2380 'a bexp = LESS ('a aexp) ('a aexp)

2381 | AND ('a bexp) ('a bexp)

2382 | OR ('a bexp) ('a bexp)

2384 as well as indirectly recursive datatypes such as

2386 datatype

2387 ('a, 'b) term = Var 'a

2388 | App 'b ((('a, 'b) term) list)

2390 The new tactic mutual_induct_tac [<var_1>, ..., <var_n>] i performs

2391 induction on mutually / indirectly recursive datatypes.

2393 Primrec equations are now stored in theory and can be accessed via

2394 <function_name>.simps.

2396 INCOMPATIBILITIES:

2398 - Theories using datatypes must now have theory Datatype as an

2399 ancestor.

2400 - The specific <typename>.induct_tac no longer exists - use the

2401 generic induct_tac instead.

2402 - natE has been renamed to nat.exhaust - use exhaust_tac

2403 instead of res_inst_tac ... natE. Note that the variable

2404 names in nat.exhaust differ from the names in natE, this

2405 may cause some "fragile" proofs to fail.

2406 - The theorems split_<typename>_case and split_<typename>_case_asm

2407 have been renamed to <typename>.split and <typename>.split_asm.

2408 - Since default sorts of type variables are now handled correctly,

2409 some datatype definitions may have to be annotated with explicit

2410 sort constraints.

2411 - Primrec definitions no longer require function name and type

2412 of recursive argument.

2414 Consider using isatool fixdatatype to adapt your theories and proof

2415 scripts to the new package (backup your sources first!).

2418 * HOL/record package: considerably improved implementation; now

2419 includes concrete syntax for record types, terms, updates; theorems

2420 for surjective pairing and splitting !!-bound record variables; proof

2421 support is as follows:

2423 1) standard conversions (selectors or updates applied to record

2424 constructor terms) are part of the standard simpset;

2426 2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are

2427 made part of standard simpset and claset via addIffs;

2429 3) a tactic for record field splitting (record_split_tac) is part of

2430 the standard claset (addSWrapper);

2432 To get a better idea about these rules you may retrieve them via

2433 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is

2434 the name of your record type.

2436 The split tactic 3) conceptually simplifies by the following rule:

2438 "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"

2440 Thus any record variable that is bound by meta-all will automatically

2441 blow up into some record constructor term, consequently the

2442 simplifications of 1), 2) apply. Thus force_tac, auto_tac etc. shall

2443 solve record problems automatically.

2446 * reorganized the main HOL image: HOL/Integ and String loaded by

2447 default; theory Main includes everything;

2449 * automatic simplification of integer sums and comparisons, using cancellation;

2451 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;

2453 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;

2455 * many new identities for unions, intersections, set difference, etc.;

2457 * expand_if, expand_split, expand_sum_case and expand_nat_case are now

2458 called split_if, split_split, split_sum_case and split_nat_case (to go

2459 with add/delsplits);

2461 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting

2462 (?x::unit) = (); this is made part of the default simpset, which COULD

2463 MAKE EXISTING PROOFS FAIL under rare circumstances (consider

2464 'Delsimprocs [unit_eq_proc];' as last resort); also note that

2465 unit_abs_eta_conv is added in order to counter the effect of

2466 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by

2467 %u.f();

2469 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which

2470 makes more sense);

2472 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;

2473 It and 'sym RS equals0D' are now in the default claset, giving automatic

2474 disjointness reasoning but breaking a few old proofs.

2476 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1

2477 to 'converse' from 'inverse' (for compatibility with ZF and some

2478 literature);

2480 * HOL/recdef can now declare non-recursive functions, with {} supplied as

2481 the well-founded relation;

2483 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of

2484 Compl A. The "Compl" syntax remains available as input syntax for this

2485 release ONLY.

2487 * HOL/Update: new theory of function updates:

2488 f(a:=b) == %x. if x=a then b else f x

2489 may also be iterated as in f(a:=b,c:=d,...);

2491 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;

2493 * HOL/List:

2494 - new function list_update written xs[i:=v] that updates the i-th

2495 list position. May also be iterated as in xs[i:=a,j:=b,...].

2496 - new function `upt' written [i..j(] which generates the list

2497 [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper

2498 bound write [i..j], which is a shorthand for [i..j+1(].

2499 - new lexicographic orderings and corresponding wellfoundedness theorems.

2501 * HOL/Arith:

2502 - removed 'pred' (predecessor) function;

2503 - generalized some theorems about n-1;

2504 - many new laws about "div" and "mod";

2505 - new laws about greatest common divisors (see theory ex/Primes);

2507 * HOL/Relation: renamed the relational operator r^-1 "converse"

2508 instead of "inverse";

2510 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness

2511 of the multiset ordering;

2513 * directory HOL/Real: a construction of the reals using Dedekind cuts

2514 (not included by default);

2516 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;

2518 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted

2519 programs, i.e. different program variables may have different types.

2521 * calling (stac rew i) now fails if "rew" has no effect on the goal

2522 [previously, this check worked only if the rewrite rule was unconditional]

2523 Now rew can involve either definitions or equalities (either == or =).

2526 *** ZF ***

2528 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains

2529 only the theorems proved on ZF.ML;

2531 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;

2532 It and 'sym RS equals0D' are now in the default claset, giving automatic

2533 disjointness reasoning but breaking a few old proofs.

2535 * ZF/Update: new theory of function updates

2536 with default rewrite rule f(x:=y) ` z = if(z=x, y, f`z)

2537 may also be iterated as in f(a:=b,c:=d,...);

2539 * in let x=t in u(x), neither t nor u(x) has to be an FOL term.

2541 * calling (stac rew i) now fails if "rew" has no effect on the goal

2542 [previously, this check worked only if the rewrite rule was unconditional]

2543 Now rew can involve either definitions or equalities (either == or =).

2545 * case_tac provided for compatibility with HOL

2546 (like the old excluded_middle_tac, but with subgoals swapped)

2549 *** Internal programming interfaces ***

2551 * Pure: several new basic modules made available for general use, see

2552 also src/Pure/README;

2554 * improved the theory data mechanism to support encapsulation (data

2555 kind name replaced by private Object.kind, acting as authorization

2556 key); new type-safe user interface via functor TheoryDataFun; generic

2557 print_data function becomes basically useless;

2559 * removed global_names compatibility flag -- all theory declarations

2560 are qualified by default;

2562 * module Pure/Syntax now offers quote / antiquote translation

2563 functions (useful for Hoare logic etc. with implicit dependencies);

2564 see HOL/ex/Antiquote for an example use;

2566 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->

2567 cterm -> thm;

2569 * new tactical CHANGED_GOAL for checking that a tactic modifies a

2570 subgoal;

2572 * Display.print_goals function moved to Locale.print_goals;

2574 * standard print function for goals supports current_goals_markers

2575 variable for marking begin of proof, end of proof, start of goal; the

2576 default is ("", "", ""); setting current_goals_markers := ("<proof>",

2577 "</proof>", "<goal>") causes SGML like tagged proof state printing,

2578 for example;

2582 New in Isabelle98 (January 1998)

2583 --------------------------------

2585 *** Overview of INCOMPATIBILITIES (see below for more details) ***

2587 * changed lexical syntax of terms / types: dots made part of long

2588 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";

2590 * simpset (and claset) reference variable replaced by functions

2591 simpset / simpset_ref;

2593 * no longer supports theory aliases (via merge) and non-trivial

2594 implicit merge of thms' signatures;

2596 * most internal names of constants changed due to qualified names;

2598 * changed Pure/Sequence interface (see Pure/seq.ML);

2601 *** General Changes ***

2603 * hierachically structured name spaces (for consts, types, axms, thms

2604 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of

2605 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:

2606 isatool fixdots ensures space after dots (e.g. "%x. x"); set

2607 long_names for fully qualified output names; NOTE: ML programs

2608 (special tactics, packages etc.) referring to internal names may have

2609 to be adapted to cope with fully qualified names; in case of severe

2610 backward campatibility problems try setting 'global_names' at compile

2611 time to have enrything declared within a flat name space; one may also

2612 fine tune name declarations in theories via the 'global' and 'local'

2613 section;

2615 * reimplemented the implicit simpset and claset using the new anytype

2616 data filed in signatures; references simpset:simpset ref etc. are

2617 replaced by functions simpset:unit->simpset and

2618 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp

2619 to patch your ML files accordingly;

2621 * HTML output now includes theory graph data for display with Java

2622 applet or isatool browser; data generated automatically via isatool

2623 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);

2625 * defs may now be conditional; improved rewrite_goals_tac to handle

2626 conditional equations;

2628 * defs now admits additional type arguments, using TYPE('a) syntax;

2630 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always

2631 creates a new theory node; implicit merge of thms' signatures is

2632 restricted to 'trivial' ones; COMPATIBILITY: one may have to use

2633 transfer:theory->thm->thm in (rare) cases;

2635 * improved handling of draft signatures / theories; draft thms (and

2636 ctyps, cterms) are automatically promoted to real ones;

2638 * slightly changed interfaces for oracles: admit many per theory, named

2639 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;

2641 * print_goals: optional output of const types (set show_consts and

2642 show_types);

2644 * improved output of warnings (###) and errors (***);

2646 * subgoal_tac displays a warning if the new subgoal has type variables;

2648 * removed old README and Makefiles;

2650 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;

2652 * removed obsolete init_pps and init_database;

2654 * deleted the obsolete tactical STATE, which was declared by

2655 fun STATE tacfun st = tacfun st st;

2657 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~

2658 (which abbreviates $HOME);

2660 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:

2661 use isatool fixseq to adapt your ML programs (this works for fully

2662 qualified references to the Sequence structure only!);

2664 * use_thy no longer requires writable current directory; it always

2665 reloads .ML *and* .thy file, if either one is out of date;

2668 *** Classical Reasoner ***

2670 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new

2671 tactics that use classical reasoning to simplify a subgoal without

2672 splitting it into several subgoals;

2674 * Safe_tac: like safe_tac but uses the default claset;

2677 *** Simplifier ***

2679 * added simplification meta rules:

2680 (asm_)(full_)simplify: simpset -> thm -> thm;

2682 * simplifier.ML no longer part of Pure -- has to be loaded by object

2683 logics (again);

2685 * added prems argument to simplification procedures;

2687 * HOL, FOL, ZF: added infix function `addsplits':

2688 instead of `<simpset> setloop (split_tac <thms>)'

2689 you can simply write `<simpset> addsplits <thms>'

2692 *** Syntax ***

2694 * TYPE('a) syntax for type reflection terms;

2696 * no longer handles consts with name "" -- declare as 'syntax' instead;

2698 * pretty printer: changed order of mixfix annotation preference (again!);

2700 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;

2703 *** HOL ***

2705 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.

2706 with `addloop' of the simplifier to faciliate case splitting in premises.

2708 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;

2710 * HOL/Auth: new protocol proofs including some for the Internet

2711 protocol TLS;

2713 * HOL/Map: new theory of `maps' a la VDM;

2715 * HOL/simplifier: simplification procedures nat_cancel_sums for

2716 cancelling out common nat summands from =, <, <= (in)equalities, or

2717 differences; simplification procedures nat_cancel_factor for

2718 cancelling common factor from =, <, <= (in)equalities over natural

2719 sums; nat_cancel contains both kinds of procedures, it is installed by

2720 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;

2722 * HOL/simplifier: terms of the form

2723 `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)' (or t=x)

2724 are rewritten to

2725 `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',

2726 and those of the form

2727 `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)' (or t=x)

2728 are rewritten to

2729 `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',

2731 * HOL/datatype

2732 Each datatype `t' now comes with a theorem `split_t_case' of the form

2734 P(t_case f1 ... fn x) =

2735 ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &

2736 ...

2737 (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))

2738 )

2740 and a theorem `split_t_case_asm' of the form

2742 P(t_case f1 ... fn x) =

2743 ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |

2744 ...

2745 (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))

2746 )

2747 which can be added to a simpset via `addsplits'. The existing theorems

2748 expand_list_case and expand_option_case have been renamed to

2749 split_list_case and split_option_case.

2751 * HOL/Arithmetic:

2752 - `pred n' is automatically converted to `n-1'.

2753 Users are strongly encouraged not to use `pred' any longer,

2754 because it will disappear altogether at some point.

2755 - Users are strongly encouraged to write "0 < n" rather than

2756 "n ~= 0". Theorems and proof tools have been modified towards this

2757 `standard'.

2759 * HOL/Lists:

2760 the function "set_of_list" has been renamed "set" (and its theorems too);

2761 the function "nth" now takes its arguments in the reverse order and

2762 has acquired the infix notation "!" as in "xs!n".

2764 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};

2766 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its

2767 specialist theorems (like UN1_I) are gone. Similarly for (INT x.B x);

2769 * HOL/record: extensible records with schematic structural subtyping

2770 (single inheritance); EXPERIMENTAL version demonstrating the encoding,

2771 still lacks various theorems and concrete record syntax;

2774 *** HOLCF ***

2776 * removed "axioms" and "generated by" sections;

2778 * replaced "ops" section by extended "consts" section, which is capable of

2779 handling the continuous function space "->" directly;

2781 * domain package:

2782 . proves theorems immediately and stores them in the theory,

2783 . creates hierachical name space,

2784 . now uses normal mixfix annotations (instead of cinfix...),

2785 . minor changes to some names and values (for consistency),

2786 . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,

2787 . separator between mutual domain defs: changed "," to "and",

2788 . improved handling of sort constraints; now they have to

2789 appear on the left-hand side of the equations only;

2791 * fixed LAM <x,y,zs>.b syntax;

2793 * added extended adm_tac to simplifier in HOLCF -- can now discharge

2794 adm (%x. P (t x)), where P is chainfinite and t continuous;

2797 *** FOL and ZF ***

2799 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.

2800 with `addloop' of the simplifier to faciliate case splitting in premises.

2802 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as

2803 in HOL, they strip ALL and --> from proved theorems;

2807 New in Isabelle94-8 (May 1997)

2808 ------------------------------

2810 *** General Changes ***

2812 * new utilities to build / run / maintain Isabelle etc. (in parts

2813 still somewhat experimental); old Makefiles etc. still functional;

2815 * new 'Isabelle System Manual';

2817 * INSTALL text, together with ./configure and ./build scripts;

2819 * reimplemented type inference for greater efficiency, better error

2820 messages and clean internal interface;

2822 * prlim command for dealing with lots of subgoals (an easier way of

2823 setting goals_limit);

2826 *** Syntax ***

2828 * supports alternative (named) syntax tables (parser and pretty

2829 printer); internal interface is provided by add_modesyntax(_i);

2831 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to

2832 be used in conjunction with the Isabelle symbol font; uses the

2833 "symbols" syntax table;

2835 * added token_translation interface (may translate name tokens in

2836 arbitrary ways, dependent on their type (free, bound, tfree, ...) and

2837 the current print_mode); IMPORTANT: user print translation functions

2838 are responsible for marking newly introduced bounds

2839 (Syntax.mark_boundT);

2841 * token translations for modes "xterm" and "xterm_color" that display

2842 names in bold, underline etc. or colors (which requires a color

2843 version of xterm);

2845 * infixes may now be declared with names independent of their syntax;

2847 * added typed_print_translation (like print_translation, but may

2848 access type of constant);

2851 *** Classical Reasoner ***

2853 Blast_tac: a new tactic! It is often more powerful than fast_tac, but has

2854 some limitations. Blast_tac...

2855 + ignores addss, addbefore, addafter; this restriction is intrinsic

2856 + ignores elimination rules that don't have the correct format

2857 (the conclusion MUST be a formula variable)

2858 + ignores types, which can make HOL proofs fail

2859 + rules must not require higher-order unification, e.g. apply_type in ZF

2860 [message "Function Var's argument not a bound variable" relates to this]

2861 + its proof strategy is more general but can actually be slower

2863 * substitution with equality assumptions no longer permutes other

2864 assumptions;

2866 * minor changes in semantics of addafter (now called addaltern); renamed

2867 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper

2868 (and access functions for it);

2870 * improved combination of classical reasoner and simplifier:

2871 + functions for handling clasimpsets

2872 + improvement of addss: now the simplifier is called _after_ the

2873 safe steps.

2874 + safe variant of addss called addSss: uses safe simplifications

2875 _during_ the safe steps. It is more complete as it allows multiple

2876 instantiations of unknowns (e.g. with slow_tac).

2878 *** Simplifier ***

2880 * added interface for simplification procedures (functions that

2881 produce *proven* rewrite rules on the fly, depending on current

2882 redex);

2884 * ordering on terms as parameter (used for ordered rewriting);

2886 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;

2888 * the solver is now split into a safe and an unsafe part.

2889 This should be invisible for the normal user, except that the

2890 functions setsolver and addsolver have been renamed to setSolver and

2891 addSolver; added safe_asm_full_simp_tac;

2894 *** HOL ***

2896 * a generic induction tactic `induct_tac' which works for all datatypes and

2897 also for type `nat';

2899 * a generic case distinction tactic `exhaust_tac' which works for all

2900 datatypes and also for type `nat';

2902 * each datatype comes with a function `size';

2904 * patterns in case expressions allow tuple patterns as arguments to

2905 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';

2907 * primrec now also works with type nat;

2909 * recdef: a new declaration form, allows general recursive functions to be

2910 defined in theory files. See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.

2912 * the constant for negation has been renamed from "not" to "Not" to

2913 harmonize with FOL, ZF, LK, etc.;

2915 * HOL/ex/LFilter theory of a corecursive "filter" functional for

2916 infinite lists;

2918 * HOL/Modelcheck demonstrates invocation of model checker oracle;

2920 * HOL/ex/Ring.thy declares cring_simp, which solves equational

2921 problems in commutative rings, using axiomatic type classes for + and *;

2923 * more examples in HOL/MiniML and HOL/Auth;

2925 * more default rewrite rules for quantifiers, union/intersection;

2927 * a new constant `arbitrary == @x.False';

2929 * HOLCF/IOA replaces old HOL/IOA;

2931 * HOLCF changes: derived all rules and arities

2932 + axiomatic type classes instead of classes

2933 + typedef instead of faking type definitions

2934 + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.

2935 + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po

2936 + eliminated the types void, one, tr

2937 + use unit lift and bool lift (with translations) instead of one and tr

2938 + eliminated blift from Lift3.thy (use Def instead of blift)

2939 all eliminated rules are derived as theorems --> no visible changes ;

2942 *** ZF ***

2944 * ZF now has Fast_tac, Simp_tac and Auto_tac. Union_iff is a now a default

2945 rewrite rule; this may affect some proofs. eq_cs is gone but can be put back

2946 as ZF_cs addSIs [equalityI];

2950 New in Isabelle94-7 (November 96)

2951 ---------------------------------

2953 * allowing negative levels (as offsets) in prlev and choplev;

2955 * super-linear speedup for large simplifications;

2957 * FOL, ZF and HOL now use miniscoping: rewriting pushes

2958 quantifications in as far as possible (COULD MAKE EXISTING PROOFS

2959 FAIL); can suppress it using the command Delsimps (ex_simps @

2960 all_simps); De Morgan laws are also now included, by default;

2962 * improved printing of ==> : ~:

2964 * new object-logic "Sequents" adds linear logic, while replacing LK

2965 and Modal (thanks to Sara Kalvala);

2967 * HOL/Auth: correctness proofs for authentication protocols;

2969 * HOL: new auto_tac combines rewriting and classical reasoning (many

2970 examples on HOL/Auth);

2972 * HOL: new command AddIffs for declaring theorems of the form P=Q to

2973 the rewriter and classical reasoner simultaneously;

2975 * function uresult no longer returns theorems in "standard" format;

2976 regain previous version by: val uresult = standard o uresult;

2980 New in Isabelle94-6

2981 -------------------

2983 * oracles -- these establish an interface between Isabelle and trusted

2984 external reasoners, which may deliver results as theorems;

2986 * proof objects (in particular record all uses of oracles);

2988 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;

2990 * "constdefs" section in theory files;

2992 * "primrec" section (HOL) no longer requires names;

2994 * internal type "tactic" now simply "thm -> thm Sequence.seq";

2998 New in Isabelle94-5

2999 -------------------

3001 * reduced space requirements;

3003 * automatic HTML generation from theories;

3005 * theory files no longer require "..." (quotes) around most types;

3007 * new examples, including two proofs of the Church-Rosser theorem;

3009 * non-curried (1994) version of HOL is no longer distributed;

3013 New in Isabelle94-4

3014 -------------------

3016 * greatly reduced space requirements;

3018 * theory files (.thy) no longer require \...\ escapes at line breaks;

3020 * searchable theorem database (see the section "Retrieving theorems" on

3021 page 8 of the Reference Manual);

3023 * new examples, including Grabczewski's monumental case study of the

3024 Axiom of Choice;

3026 * The previous version of HOL renamed to Old_HOL;

3028 * The new version of HOL (previously called CHOL) uses a curried syntax

3029 for functions. Application looks like f a b instead of f(a,b);

3031 * Mutually recursive inductive definitions finally work in HOL;

3033 * In ZF, pattern-matching on tuples is now available in all abstractions and

3034 translates to the operator "split";

3038 New in Isabelle94-3

3039 -------------------

3041 * new infix operator, addss, allowing the classical reasoner to

3042 perform simplification at each step of its search. Example:

3043 fast_tac (cs addss ss)

3045 * a new logic, CHOL, the same as HOL, but with a curried syntax

3046 for functions. Application looks like f a b instead of f(a,b). Also pairs

3047 look like (a,b) instead of <a,b>;

3049 * PLEASE NOTE: CHOL will eventually replace HOL!

3051 * In CHOL, pattern-matching on tuples is now available in all abstractions.

3052 It translates to the operator "split". A new theory of integers is available;

3054 * In ZF, integer numerals now denote two's-complement binary integers.

3055 Arithmetic operations can be performed by rewriting. See ZF/ex/Bin.ML;

3057 * Many new examples: I/O automata, Church-Rosser theorem, equivalents

3058 of the Axiom of Choice;

3062 New in Isabelle94-2

3063 -------------------

3065 * Significantly faster resolution;

3067 * the different sections in a .thy file can now be mixed and repeated

3068 freely;

3070 * Database of theorems for FOL, HOL and ZF. New

3071 commands including qed, qed_goal and bind_thm store theorems in the database.

3073 * Simple database queries: return a named theorem (get_thm) or all theorems of

3074 a given theory (thms_of), or find out what theory a theorem was proved in

3075 (theory_of_thm);

3077 * Bugs fixed in the inductive definition and datatype packages;

3079 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs

3080 and HOL_dup_cs obsolete;

3082 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1

3083 have been removed;

3085 * Simpler definition of function space in ZF;

3087 * new results about cardinal and ordinal arithmetic in ZF;

3089 * 'subtype' facility in HOL for introducing new types as subsets of existing

3090 types;

3093 $Id$