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NEWS

author | huffman |

Sun Nov 06 00:35:24 2005 +0100 (2005-11-06) | |

changeset 18096 | 574aa0487069 |

parent 18051 | dba086ed50cb |

child 18145 | 6757627acf59 |

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

use consts for infix syntax

1 Isabelle NEWS -- history user-relevant changes

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

4 New in this Isabelle release

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

7 *** General ***

9 * Theory syntax: the header format ``theory A = B + C:'' has been

10 discontinued in favour of ``theory A imports B C begin''. Use isatool

11 fixheaders to convert existing theory files. INCOMPATIBILITY.

13 * Theory syntax: the old non-Isar theory file format has been

14 discontinued altogether. Note that ML proof scripts may still be used

15 with Isar theories; migration is usually quite simple with the ML

16 function use_legacy_bindings. INCOMPATIBILITY.

18 * Legacy goal package: reduced interface to the bare minimum required

19 to keep existing proof scripts running. Most other user-level

20 functions are now part of the OldGoals structure, which is *not* open

21 by default (consider isatool expandshort before open OldGoals).

22 Removed top_sg, prin, printyp, pprint_term/typ altogether, because

23 these tend to cause confusion about the actual goal (!) context being

24 used here, which is not necessarily the same as the_context().

26 * Command 'find_theorems': support "*" wildcard in "name:" criterion.

29 *** Document preparation ***

31 * Added antiquotations @{ML_type text} and @{ML_struct text} which

32 check the given source text as ML type/structure, printing verbatim.

35 *** Pure ***

37 * Isar: improper proof element 'guess' is like 'obtain', but derives

38 the obtained context from the course of reasoning! For example:

40 assume "EX x y. A x & B y" -- "any previous fact"

41 then guess x and y by clarify

43 This technique is potentially adventurous, depending on the facts and

44 proof tools being involved here.

46 * Isar: known facts from the proof context may be specified as literal

47 propositions, using ASCII back-quote syntax. This works wherever

48 named facts used to be allowed so far, in proof commands, proof

49 methods, attributes etc. Literal facts are retrieved from the context

50 according to unification of type and term parameters. For example,

51 provided that "A" and "A ==> B" and "!!x. P x ==> Q x" are known

52 theorems in the current context, then these are valid literal facts:

53 `A` and `A ==> B` and `!!x. P x ==> Q x" as well as `P a ==> Q a` etc.

55 There is also a proof method "fact" which does the same composition

56 for explicit goal states, e.g. the following proof texts coincide with

57 certain special cases of literal facts:

59 have "A" by fact == note `A`

60 have "A ==> B" by fact == note `A ==> B`

61 have "!!x. P x ==> Q x" by fact == note `!!x. P x ==> Q x`

62 have "P a ==> Q a" by fact == note `P a ==> Q a`

64 * Input syntax now supports dummy variable binding "%_. b", where the

65 body does not mention the bound variable. Note that dummy patterns

66 implicitly depend on their context of bounds, which makes "{_. _}"

67 match any set comprehension as expected. Potential INCOMPATIBILITY --

68 parse translations need to cope with syntactic constant "_idtdummy" in

69 the binding position.

71 * Removed obsolete syntactic constant "_K" and its associated parse

72 translation. INCOMPATIBILITY -- use dummy abstraction instead, for

73 example "A -> B" => "Pi A (%_. B)".

76 *** HOL ***

78 * Alternative iff syntax "A <-> B" for equality on bool (with priority

79 25 like -->); output depends on the "iff" print_mode, the default is

80 "A = B" (with priority 50).

82 * In the context of the assumption "~(s = t)" the Simplifier rewrites

83 "t = s" to False (by simproc "neq_simproc"). For backward

84 compatibility this can be disabled by ML "reset use_neq_simproc".

86 * Tactics 'sat' and 'satx' reimplemented, several improvements: goals

87 no longer need to be stated as "<prems> ==> False", equivalences (i.e.

88 "=" on type bool) are handled, variable names of the form "lit_<n>"

89 are no longer reserved, significant speedup.

92 *** ML ***

94 * Library: new module Pure/General/rat.ML implementing rational numbers,

95 replacing the former functions in the Isabelle library.

97 * Library: indexed lists - some functions in the Isabelle library

98 treating lists over 'a as finite mappings from [0...n] to 'a

99 have been given more convenient names and signatures reminiscent

100 of similar functions for alists, tables, etc:

102 val nth: 'a list -> int -> 'a

103 val nth_update: int * 'a -> 'a list -> 'a list

104 val nth_map: int -> ('a -> 'a) -> 'a list -> 'a list

105 val fold_index: (int * 'a -> 'b -> 'b) -> 'a list -> 'b -> 'b

107 Note that fold_index starts counting at index 0, not 1 like foldln used to.

109 * Pure: primitive rule lift_rule now takes goal cterm instead of an

110 actual goal state (thm). Use Thm.lift_rule (Thm.cgoal_of st i) to

111 achieve the old behaviour.

113 * Pure: the "Goal" constant is now called "prop", supporting a

114 slightly more general idea of ``protecting'' meta-level rule

115 statements.

117 * Internal goals: structure Goal provides simple interfaces for

118 init/conclude/finish and tactical prove operations (replacing former

119 Tactic.prove). Note that OldGoals.prove_goalw_cterm has long been

120 obsolete, it is ill-behaved in a local proof context (e.g. with local

121 fixes/assumes or in a locale context).

123 * Simplifier: the simpset of a running simplification process now

124 contains a proof context (cf. Simplifier.the_context), which is the

125 very context that the initial simpset has been retrieved from (by

126 simpset_of/local_simpset_of). Consequently, all plug-in components

127 (solver, looper etc.) may depend on arbitrary proof data.

129 * Simplifier.inherit_context inherits the proof context (plus the

130 local bounds) of the current simplification process; any simproc

131 etc. that calls the Simplifier recursively should do this! Removed

132 former Simplifier.inherit_bounds, which is already included here --

133 INCOMPATIBILITY. Tools based on low-level rewriting may even have to

134 specify an explicit context using Simplifier.context/theory_context.

136 * Simplifier/Classical Reasoner: more abstract interfaces

137 change_simpset/claset for modifying the simpset/claset reference of a

138 theory; raw versions simpset/claset_ref etc. have been discontinued --

139 INCOMPATIBILITY.

143 New in Isabelle2005 (October 2005)

144 ----------------------------------

146 *** General ***

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

150 theory <name>

151 imports <theory1> ... <theoryN>

152 uses <file1> ... <fileM>

153 begin

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

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

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

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

161 non-Isar theories now, but these will disappear soon.

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

164 relative and absolute paths.

166 * Command 'find_theorems' searches for a list of criteria instead of a

167 list of constants. Known criteria are: intro, elim, dest, name:string,

168 simp:term, and any term. Criteria can be preceded by '-' to select

169 theorems that do not match. Intro, elim, dest select theorems that

170 match the current goal, name:s selects theorems whose fully qualified

171 name contain s, and simp:term selects all simplification rules whose

172 lhs match term. Any other term is interpreted as pattern and selects

173 all theorems matching the pattern. Available in ProofGeneral under

174 'ProofGeneral -> Find Theorems' or C-c C-f. Example:

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

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

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

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

182 * Command 'thms_containing' has been discontinued in favour of

183 'find_theorems'; INCOMPATIBILITY.

185 * Communication with Proof General is now 8bit clean, which means that

186 Unicode text in UTF-8 encoding may be used within theory texts (both

187 formal and informal parts). Cf. option -U of the Isabelle Proof

188 General interface. Here are some simple examples (cf. src/HOL/ex):

190 http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html

191 http://isabelle.in.tum.de/library/HOL/ex/Chinese.html

193 * Improved efficiency of the Simplifier and, to a lesser degree, the

194 Classical Reasoner. Typical big applications run around 2 times

195 faster.

198 *** Document preparation ***

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

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

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

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

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

205 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).

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

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

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

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

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

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

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

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

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

216 \isadroptag.

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

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

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

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

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

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

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

225 specified above.

227 * Several new antiquotations:

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

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

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

234 argument is a known logical constant;

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

237 theorem applying a "style" to it

239 @{ML text}

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

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

243 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'

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

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

246 document practical applications. The ML antiquotation prints

247 type-checked ML expressions verbatim.

249 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',

250 and 'text' support optional locale specification '(in loc)', which

251 specifies the default context for interpreting antiquotations. For

252 example: 'text (in lattice) {* @{thm inf_assoc}*}'.

254 * Option 'locale=NAME' of antiquotations specifies an alternative

255 context interpreting the subsequent argument. For example: @{thm

256 [locale=lattice] inf_assoc}.

258 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within

259 a proof context.

261 * Proper output of antiquotations for theory commands involving a

262 proof context (such as 'locale' or 'theorem (in loc) ...').

264 * Delimiters of outer tokens (string etc.) now produce separate LaTeX

265 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).

267 * isatool usedir: new option -C (default true) controls whether option

268 -D should include a copy of the original document directory; -C false

269 prevents unwanted effects such as copying of administrative CVS data.

272 *** Pure ***

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

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

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

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

278 sequential dependencies of definitions within a single 'constdefs'

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

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

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

283 indexed syntax provides a notational device for subscripted

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

285 expressions. Secondly, in a local context with structure

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

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

288 show_structs controls printing of implicit structures. Typical

289 applications of these concepts involve record types and locales.

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

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

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

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

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

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

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

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

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

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

303 INCOMPATIBILITY.

305 * axclass: name space prefix for class "c" is now "c_class" (was "c"

306 before); "cI" is no longer bound, use "c.intro" instead.

307 INCOMPATIBILITY. This change avoids clashes of fact bindings for

308 axclasses vs. locales.

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

311 instead of base 26 numbers.

313 * New flag show_question_marks controls printing of leading question

314 marks in schematic variable names.

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

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

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

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

321 by simp

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

325 * Pretty printer now supports unbreakable blocks, specified in mixfix

326 annotations as "(00...)".

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

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

330 Before that distinction was only partially implemented via type class

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

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

333 exotic syntax specifications may require further adaption

334 (e.g. Cube/Cube.thy).

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

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

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

339 specifications.

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

342 locally fixed variables as well.

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

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

346 Limit.

348 * Simplifier: simplification procedures may now take the current

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

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

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

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

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

354 allow for use in a context of fixed variables.

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

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

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

360 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.

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

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

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

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

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

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

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

370 selections of theorems in named facts via index ranges.

372 * 'print_theorems': in theory mode, really print the difference

373 wrt. the last state (works for interactive theory development only),

374 in proof mode print all local facts (cf. 'print_facts');

376 * 'hide': option '(open)' hides only base names.

378 * More efficient treatment of intermediate checkpoints in interactive

379 theory development.

381 * Code generator is now invoked via code_module (incremental code

382 generation) and code_library (modular code generation, ML structures

383 for each theory). INCOMPATIBILITY: new keywords 'file' and 'contains'

384 must be quoted when used as identifiers.

386 * New 'value' command for reading, evaluating and printing terms using

387 the code generator. INCOMPATIBILITY: command keyword 'value' must be

388 quoted when used as identifier.

391 *** Locales ***

393 * New commands for the interpretation of locale expressions in

394 theories (1), locales (2) and proof contexts (3). These generate

395 proof obligations from the expression specification. After the

396 obligations have been discharged, theorems of the expression are added

397 to the theory, target locale or proof context. The synopsis of the

398 commands is a follows:

400 (1) interpretation expr inst

401 (2) interpretation target < expr

402 (3) interpret expr inst

404 Interpretation in theories and proof contexts require a parameter

405 instantiation of terms from the current context. This is applied to

406 specifications and theorems of the interpreted expression.

407 Interpretation in locales only permits parameter renaming through the

408 locale expression. Interpretation is smart in that interpretations

409 that are active already do not occur in proof obligations, neither are

410 instantiated theorems stored in duplicate. Use 'print_interps' to

411 inspect active interpretations of a particular locale. For details,

412 see the Isar Reference manual. Examples can be found in

413 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.

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

416 'interpret' instead.

418 * New context element 'constrains' for adding type constraints to

419 parameters.

421 * Context expressions: renaming of parameters with syntax

422 redeclaration.

424 * Locale declaration: 'includes' disallowed.

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

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

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

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

430 to attribute arguments as expected.

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

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

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

435 Attribute implementations need to cooperate properly with the static

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

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

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

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

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

441 values to argument tokens explicitly.

443 * Changed parameter management in theorem generation for long goal

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

445 theorem statement in rare situations.

447 * Locale inspection command 'print_locale' omits notes elements. Use

448 'print_locale!' to have them included in the output.

451 *** Provers ***

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

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

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

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

457 still available as 'simplesubst'.

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

460 and quasi orders.

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

463 reflexive-transitive closure of relations.

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

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

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

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

470 initial simpset configuration as before. INCOMPATIBILITY.

473 *** HOL ***

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

477 syntax (epsilon)

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

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

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

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

483 becomes available as variable, constant etc. INCOMPATIBILITY,

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

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

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

488 support corresponding Isar calculations.

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

491 instead of ":".

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

495 Old New

496 {..n(} {..<n}

497 {)n..} {n<..}

498 {m..n(} {m..<n}

499 {)m..n} {m<..n}

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

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

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

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

506 {)\([^\.]*\)\.\. -> {\1<\.\.}

507 \.\.\([^(}]*\)(} -> \.\.<\1}

509 * Theory Commutative_Ring (in Library): method comm_ring for proving

510 equalities in commutative rings; method 'algebra' provides a generic

511 interface.

513 * Theory Finite_Set: changed the syntax for 'setsum', summation over

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

515 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can

516 be a tuple pattern.

518 Some new syntax forms are available:

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

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

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

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

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

526 function "Summation", which has been discontinued.

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

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

530 (insert F x)'.

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

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

534 typedefs, inductive datatypes and recursion.

536 * New tactics 'sat' and 'satx' to prove propositional tautologies.

537 Requires zChaff with proof generation to be installed. See

538 HOL/ex/SAT_Examples.thy for examples.

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

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

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

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

544 in unstructured proof scripts.

546 * Reworked implementation of records. Improved scalability for

547 records with many fields, avoiding performance problems for type

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

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

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

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

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

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

554 <record_name>_ext_type.

556 Flag record_quick_and_dirty_sensitive can be enabled to skip the

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

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

559 quite long.

561 New simproc record_upd_simproc for simplification of multiple record

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

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

564 occasionally, since simplification is more powerful by default.

566 * typedef: proper support for polymorphic sets, which contain extra

567 type-variables in the term.

569 * Simplifier: automatically reasons about transitivity chains

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

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

572 old proofs break occasionally as simplification may now solve more

573 goals than previously.

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

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

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

578 just like y <= x.

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

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

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

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

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

585 enabled/disabled by the reference use_let_simproc. Potential

586 INCOMPATIBILITY since simplification is more powerful by default.

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

590 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background

591 jobs to provide advice on the provability of subgoals.

593 * Theory OrderedGroup and Ring_and_Field: various additions and

594 improvements to faciliate calculations involving equalities and

595 inequalities.

597 The following theorems have been eliminated or modified

598 (INCOMPATIBILITY):

600 abs_eq now named abs_of_nonneg

601 abs_of_ge_0 now named abs_of_nonneg

602 abs_minus_eq now named abs_of_nonpos

603 imp_abs_id now named abs_of_nonneg

604 imp_abs_neg_id now named abs_of_nonpos

605 mult_pos now named mult_pos_pos

606 mult_pos_le now named mult_nonneg_nonneg

607 mult_pos_neg_le now named mult_nonneg_nonpos

608 mult_pos_neg2_le now named mult_nonneg_nonpos2

609 mult_neg now named mult_neg_neg

610 mult_neg_le now named mult_nonpos_nonpos

612 * Theory Parity: added rules for simplifying exponents.

614 * Theory List:

616 The following theorems have been eliminated or modified

617 (INCOMPATIBILITY):

619 list_all_Nil now named list_all.simps(1)

620 list_all_Cons now named list_all.simps(2)

621 list_all_conv now named list_all_iff

622 set_mem_eq now named mem_iff

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

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

628 *** HOL-Complex ***

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

631 integers in the reals.

633 The following theorems have been eliminated or modified

634 (INCOMPATIBILITY):

636 exp_ge_add_one_self now requires no hypotheses

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

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

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

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

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

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

646 * Hyperreal: There is a new type constructor "star" for making

647 nonstandard types. The old type names are now type synonyms:

649 hypreal = real star

650 hypnat = nat star

651 hcomplex = complex star

653 * Hyperreal: Many groups of similarly-defined constants have been

654 replaced by polymorphic versions (INCOMPATIBILITY):

656 star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex

658 starset <-- starsetNat, starsetC

659 *s* <-- *sNat*, *sc*

660 starset_n <-- starsetNat_n, starsetC_n

661 *sn* <-- *sNatn*, *scn*

662 InternalSets <-- InternalNatSets, InternalCSets

664 starfun <-- starfun{Nat,Nat2,C,RC,CR}

665 *f* <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*

666 starfun_n <-- starfun{Nat,Nat2,C,RC,CR}_n

667 *fn* <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*

668 InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs

670 * Hyperreal: Many type-specific theorems have been removed in favor of

671 theorems specific to various axiomatic type classes (INCOMPATIBILITY):

673 add_commute <-- {hypreal,hypnat,hcomplex}_add_commute

674 add_assoc <-- {hypreal,hypnat,hcomplex}_add_assocs

675 OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left

676 OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right

677 right_minus <-- hypreal_add_minus

678 left_minus <-- {hypreal,hcomplex}_add_minus_left

679 mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute

680 mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc

681 mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left

682 mult_1_right <-- hcomplex_mult_one_right

683 mult_zero_left <-- hcomplex_mult_zero_left

684 left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib

685 right_distrib <-- hypnat_add_mult_distrib2

686 zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one

687 right_inverse <-- hypreal_mult_inverse

688 left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left

689 order_refl <-- {hypreal,hypnat}_le_refl

690 order_trans <-- {hypreal,hypnat}_le_trans

691 order_antisym <-- {hypreal,hypnat}_le_anti_sym

692 order_less_le <-- {hypreal,hypnat}_less_le

693 linorder_linear <-- {hypreal,hypnat}_le_linear

694 add_left_mono <-- {hypreal,hypnat}_add_left_mono

695 mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2

696 add_nonneg_nonneg <-- hypreal_le_add_order

698 * Hyperreal: Separate theorems having to do with type-specific

699 versions of constants have been merged into theorems that apply to the

700 new polymorphic constants (INCOMPATIBILITY):

702 STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set

703 STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set

704 STAR_Un <-- {STAR,NatStar,STARC}_Un

705 STAR_Int <-- {STAR,NatStar,STARC}_Int

706 STAR_Compl <-- {STAR,NatStar,STARC}_Compl

707 STAR_subset <-- {STAR,NatStar,STARC}_subset

708 STAR_mem <-- {STAR,NatStar,STARC}_mem

709 STAR_mem_Compl <-- {STAR,STARC}_mem_Compl

710 STAR_diff <-- {STAR,STARC}_diff

711 STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,

712 STARC_hcomplex_of_complex}_image_subset

713 starset_n_Un <-- starset{Nat,C}_n_Un

714 starset_n_Int <-- starset{Nat,C}_n_Int

715 starset_n_Compl <-- starset{Nat,C}_n_Compl

716 starset_n_diff <-- starset{Nat,C}_n_diff

717 InternalSets_Un <-- Internal{Nat,C}Sets_Un

718 InternalSets_Int <-- Internal{Nat,C}Sets_Int

719 InternalSets_Compl <-- Internal{Nat,C}Sets_Compl

720 InternalSets_diff <-- Internal{Nat,C}Sets_diff

721 InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff

722 InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n

723 starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq

724 starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}

725 starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}

726 starfun <-- starfun{Nat,Nat2,C,RC,CR}

727 starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult

728 starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add

729 starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus

730 starfun_diff <-- starfun{C,RC,CR}_diff

731 starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o

732 starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2

733 starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun

734 starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse

735 starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq

736 starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff

737 starfun_Id <-- starfunC_Id

738 starfun_approx <-- starfun{Nat,CR}_approx

739 starfun_capprox <-- starfun{C,RC}_capprox

740 starfun_abs <-- starfunNat_rabs

741 starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel

742 starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2

743 starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox

744 starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox

745 starfun_add_capprox <-- starfun{C,RC}_add_capprox

746 starfun_add_approx <-- starfunCR_add_approx

747 starfun_inverse_inverse <-- starfunC_inverse_inverse

748 starfun_divide <-- starfun{C,CR,RC}_divide

749 starfun_n <-- starfun{Nat,C}_n

750 starfun_n_mult <-- starfun{Nat,C}_n_mult

751 starfun_n_add <-- starfun{Nat,C}_n_add

752 starfun_n_add_minus <-- starfunNat_n_add_minus

753 starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun

754 starfun_n_minus <-- starfun{Nat,C}_n_minus

755 starfun_n_eq <-- starfun{Nat,C}_n_eq

757 star_n_add <-- {hypreal,hypnat,hcomplex}_add

758 star_n_minus <-- {hypreal,hcomplex}_minus

759 star_n_diff <-- {hypreal,hcomplex}_diff

760 star_n_mult <-- {hypreal,hcomplex}_mult

761 star_n_inverse <-- {hypreal,hcomplex}_inverse

762 star_n_le <-- {hypreal,hypnat}_le

763 star_n_less <-- {hypreal,hypnat}_less

764 star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num

765 star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num

766 star_n_abs <-- hypreal_hrabs

767 star_n_divide <-- hcomplex_divide

769 star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add

770 star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus

771 star_of_diff <-- hypreal_of_real_diff

772 star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult

773 star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one

774 star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero

775 star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff

776 star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff

777 star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff

778 star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse

779 star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide

780 star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat

781 star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int

782 star_of_number_of <-- {hypreal,hcomplex}_number_of

783 star_of_number_less <-- number_of_less_hypreal_of_real_iff

784 star_of_number_le <-- number_of_le_hypreal_of_real_iff

785 star_of_eq_number <-- hypreal_of_real_eq_number_of_iff

786 star_of_less_number <-- hypreal_of_real_less_number_of_iff

787 star_of_le_number <-- hypreal_of_real_le_number_of_iff

788 star_of_power <-- hypreal_of_real_power

789 star_of_eq_0 <-- hcomplex_of_complex_zero_iff

791 * Hyperreal: new method "transfer" that implements the transfer

792 principle of nonstandard analysis. With a subgoal that mentions

793 nonstandard types like "'a star", the command "apply transfer"

794 replaces it with an equivalent one that mentions only standard types.

795 To be successful, all free variables must have standard types; non-

796 standard variables must have explicit universal quantifiers.

798 * Hyperreal: A theory of Taylor series.

801 *** HOLCF ***

803 * Discontinued special version of 'constdefs' (which used to support

804 continuous functions) in favor of the general Pure one with full

805 type-inference.

807 * New simplification procedure for solving continuity conditions; it

808 is much faster on terms with many nested lambda abstractions (cubic

809 instead of exponential time).

811 * New syntax for domain package: selector names are now optional.

812 Parentheses should be omitted unless argument is lazy, for example:

814 domain 'a stream = cons "'a" (lazy "'a stream")

816 * New command 'fixrec' for defining recursive functions with pattern

817 matching; defining multiple functions with mutual recursion is also

818 supported. Patterns may include the constants cpair, spair, up, sinl,

819 sinr, or any data constructor defined by the domain package. The given

820 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for

821 syntax and examples.

823 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes

824 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,

825 but the proof obligation additionally includes an admissibility

826 requirement. The packages generate instances of class cpo or pcpo,

827 with continuity and strictness theorems for Rep and Abs.

829 * HOLCF: Many theorems have been renamed according to a more standard naming

830 scheme (INCOMPATIBILITY):

832 foo_inject: "foo$x = foo$y ==> x = y"

833 foo_eq: "(foo$x = foo$y) = (x = y)"

834 foo_less: "(foo$x << foo$y) = (x << y)"

835 foo_strict: "foo$UU = UU"

836 foo_defined: "... ==> foo$x ~= UU"

837 foo_defined_iff: "(foo$x = UU) = (x = UU)"

840 *** ZF ***

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

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

844 of a homomorphism).

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

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

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

851 *** Cube ***

853 * Converted to Isar theory format; use locales instead of axiomatic

854 theories.

857 *** ML ***

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

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

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

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

863 accordingly, while Option.map replaces apsome.

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

866 the standard exceptions Empty and Subscript, as well as

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

868 superceded by the standard hd and tl functions etc.

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

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

872 suggests how one can translate existing code:

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

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

876 last_elem xs = List.last xs

877 flat xss = List.concat xss

878 seq fs = List.app fs

879 partition P xs = List.partition P xs

880 mapfilter f xs = List.mapPartial f xs

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

883 transformations, notably reverse application and composition:

885 x |> f f #> g

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

888 * Pure/library.ML: introduced/changed precedence of infix operators:

890 infix 1 |> |-> ||> ||>> |>> |>>> #> #->;

891 infix 2 ?;

892 infix 3 o oo ooo oooo;

893 infix 4 ~~ upto downto;

895 Maybe INCOMPATIBILITY when any of those is used in conjunction with other

896 infix operators.

898 * Pure/library.ML: natural list combinators fold, fold_rev, and

899 fold_map support linear functional transformations and nesting. For

900 example:

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

903 y |> f x1 |> ... |> f xN

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

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

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

909 f x1 #> ... #> f xN

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

912 fold f xs1 #> ... #> fold f xsN

914 * Pure/library.ML: the following selectors on type 'a option are

915 available:

917 the: 'a option -> 'a (*partial*)

918 these: 'a option -> 'a where 'a = 'b list

919 the_default: 'a -> 'a option -> 'a

920 the_list: 'a option -> 'a list

922 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides

923 basic operations for association lists, following natural argument

924 order; moreover the explicit equality predicate passed here avoids

925 potentially expensive polymorphic runtime equality checks.

926 The old functions may be expressed as follows:

928 assoc = uncurry (AList.lookup (op =))

929 assocs = these oo AList.lookup (op =)

930 overwrite = uncurry (AList.update (op =)) o swap

932 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides

934 val make: ('a -> 'b) -> 'a list -> ('a * 'b) list

935 val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list

937 replacing make_keylist and keyfilter (occassionally used)

938 Naive rewrites:

940 make_keylist = AList.make

941 keyfilter = AList.find (op =)

943 * eq_fst and eq_snd now take explicit equality parameter, thus

944 avoiding eqtypes. Naive rewrites:

946 eq_fst = eq_fst (op =)

947 eq_snd = eq_snd (op =)

949 * Removed deprecated apl and apr (rarely used).

950 Naive rewrites:

952 apl (n, op) =>>= curry op n

953 apr (op, m) =>>= fn n => op (n, m)

955 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)

956 provides a reasonably efficient light-weight implementation of sets as

957 lists.

959 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a

960 few new operations; existing lookup and update are now curried to

961 follow natural argument order (for use with fold etc.);

962 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.

964 * Pure/General: output via the Isabelle channels of

965 writeln/warning/error etc. is now passed through Output.output, with a

966 hook for arbitrary transformations depending on the print_mode

967 (cf. Output.add_mode -- the first active mode that provides a output

968 function wins). Already formatted output may be embedded into further

969 text via Output.raw; the result of Pretty.string_of/str_of and derived

970 functions (string_of_term/cterm/thm etc.) is already marked raw to

971 accommodate easy composition of diagnostic messages etc. Programmers

972 rarely need to care about Output.output or Output.raw at all, with

973 some notable exceptions: Output.output is required when bypassing the

974 standard channels (writeln etc.), or in token translations to produce

975 properly formatted results; Output.raw is required when capturing

976 already output material that will eventually be presented to the user

977 a second time. For the default print mode, both Output.output and

978 Output.raw have no effect.

980 * Pure/General: Output.time_accumulator NAME creates an operator ('a

981 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the

982 cumulative results are displayed at the end of a batch session.

984 * Pure/General: File.sysify_path and File.quote_sysify path have been

985 replaced by File.platform_path and File.shell_path (with appropriate

986 hooks). This provides a clean interface for unusual systems where the

987 internal and external process view of file names are different.

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

990 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord

991 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is

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

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

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

995 Library.sort_strings on result).

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

998 fold_types traverse types/terms from left to right, observing natural

999 argument order. Supercedes previous foldl_XXX versions, add_frees,

1000 add_vars etc. have been adapted as well: INCOMPATIBILITY.

1002 * Pure: name spaces have been refined, with significant changes of the

1003 internal interfaces -- INCOMPATIBILITY. Renamed cond_extern(_table)

1004 to extern(_table). The plain name entry path is superceded by a

1005 general 'naming' context, which also includes the 'policy' to produce

1006 a fully qualified name and external accesses of a fully qualified

1007 name; NameSpace.extend is superceded by context dependent

1008 Sign.declare_name. Several theory and proof context operations modify

1009 the naming context. Especially note Theory.restore_naming and

1010 ProofContext.restore_naming to get back to a sane state; note that

1011 Theory.add_path is no longer sufficient to recover from

1012 Theory.absolute_path in particular.

1014 * Pure: new flags short_names (default false) and unique_names

1015 (default true) for controlling output of qualified names. If

1016 short_names is set, names are printed unqualified. If unique_names is

1017 reset, the name prefix is reduced to the minimum required to achieve

1018 the original result when interning again, even if there is an overlap

1019 with earlier declarations.

1021 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is

1022 now 'extend', and 'merge' gets an additional Pretty.pp argument

1023 (useful for printing error messages). INCOMPATIBILITY.

1025 * Pure: major reorganization of the theory context. Type Sign.sg and

1026 Theory.theory are now identified, referring to the universal

1027 Context.theory (see Pure/context.ML). Actual signature and theory

1028 content is managed as theory data. The old code and interfaces were

1029 spread over many files and structures; the new arrangement introduces

1030 considerable INCOMPATIBILITY to gain more clarity:

1032 Context -- theory management operations (name, identity, inclusion,

1033 parents, ancestors, merge, etc.), plus generic theory data;

1035 Sign -- logical signature and syntax operations (declaring consts,

1036 types, etc.), plus certify/read for common entities;

1038 Theory -- logical theory operations (stating axioms, definitions,

1039 oracles), plus a copy of logical signature operations (consts,

1040 types, etc.); also a few basic management operations (Theory.copy,

1041 Theory.merge, etc.)

1043 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm

1044 etc.) as well as the sign field in Thm.rep_thm etc. have been retained

1045 for convenience -- they merely return the theory.

1047 * Pure: type Type.tsig is superceded by theory in most interfaces.

1049 * Pure: the Isar proof context type is already defined early in Pure

1050 as Context.proof (note that ProofContext.context and Proof.context are

1051 aliases, where the latter is the preferred name). This enables other

1052 Isabelle components to refer to that type even before Isar is present.

1054 * Pure/sign/theory: discontinued named name spaces (i.e. classK,

1055 typeK, constK, axiomK, oracleK), but provide explicit operations for

1056 any of these kinds. For example, Sign.intern typeK is now

1057 Sign.intern_type, Theory.hide_space Sign.typeK is now

1058 Theory.hide_types. Also note that former

1059 Theory.hide_classes/types/consts are now

1060 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions

1061 internalize their arguments! INCOMPATIBILITY.

1063 * Pure: get_thm interface (of PureThy and ProofContext) expects

1064 datatype thmref (with constructors Name and NameSelection) instead of

1065 plain string -- INCOMPATIBILITY;

1067 * Pure: cases produced by proof methods specify options, where NONE

1068 means to remove case bindings -- INCOMPATIBILITY in

1069 (RAW_)METHOD_CASES.

1071 * Pure: the following operations retrieve axioms or theorems from a

1072 theory node or theory hierarchy, respectively:

1074 Theory.axioms_of: theory -> (string * term) list

1075 Theory.all_axioms_of: theory -> (string * term) list

1076 PureThy.thms_of: theory -> (string * thm) list

1077 PureThy.all_thms_of: theory -> (string * thm) list

1079 * Pure: print_tac now outputs the goal through the trace channel.

1081 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.

1082 Reference Toplevel.debug (default false) controls detailed printing

1083 and tracing of low-level exceptions; Toplevel.profiling (default 0)

1084 controls execution profiling -- set to 1 for time and 2 for space

1085 (both increase the runtime).

1087 * Isar session: The initial use of ROOT.ML is now always timed,

1088 i.e. the log will show the actual process times, in contrast to the

1089 elapsed wall-clock time that the outer shell wrapper produces.

1091 * Simplifier: improved handling of bound variables (nameless

1092 representation, avoid allocating new strings). Simprocs that invoke

1093 the Simplifier recursively should use Simplifier.inherit_bounds to

1094 avoid local name clashes. Failure to do so produces warnings

1095 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds

1096 for further details.

1098 * ML functions legacy_bindings and use_legacy_bindings produce ML fact

1099 bindings for all theorems stored within a given theory; this may help

1100 in porting non-Isar theories to Isar ones, while keeping ML proof

1101 scripts for the time being.

1103 * ML operator HTML.with_charset specifies the charset begin used for

1104 generated HTML files. For example:

1106 HTML.with_charset "utf-8" use_thy "Hebrew";

1107 HTML.with_charset "utf-8" use_thy "Chinese";

1110 *** System ***

1112 * Allow symlinks to all proper Isabelle executables (Isabelle,

1113 isabelle, isatool etc.).

1115 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for

1116 isatool doc, isatool mkdir, display_drafts etc.).

1118 * isatool usedir: option -f allows specification of the ML file to be

1119 used by Isabelle; default is ROOT.ML.

1121 * New isatool version outputs the version identifier of the Isabelle

1122 distribution being used.

1124 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format

1125 (containing Boolean satisfiability problems) into Isabelle/HOL

1126 theories.

1130 New in Isabelle2004 (April 2004)

1131 --------------------------------

1133 *** General ***

1135 * Provers/order.ML: new efficient reasoner for partial and linear orders.

1136 Replaces linorder.ML.

1138 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic

1139 (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler

1140 (\<a>...\<z>), are now considered normal letters, and can therefore

1141 be used anywhere where an ASCII letter (a...zA...Z) has until

1142 now. COMPATIBILITY: This obviously changes the parsing of some

1143 terms, especially where a symbol has been used as a binder, say

1144 '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed

1145 as an identifier. Fix it by inserting a space around former

1146 symbols. Call 'isatool fixgreek' to try to fix parsing errors in

1147 existing theory and ML files.

1149 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.

1151 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now

1152 allowed in identifiers. Similar to Greek letters \<^isub> is now considered

1153 a normal (but invisible) letter. For multiple letter subscripts repeat

1154 \<^isub> like this: x\<^isub>1\<^isub>2.

1156 * Pure: There are now sub-/superscripts that can span more than one

1157 character. Text between \<^bsub> and \<^esub> is set in subscript in

1158 ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in

1159 superscript. The new control characters are not identifier parts.

1161 * Pure: Control-symbols of the form \<^raw:...> will literally print the

1162 content of "..." to the latex file instead of \isacntrl... . The "..."

1163 may consist of any printable characters excluding the end bracket >.

1165 * Pure: Using new Isar command "finalconsts" (or the ML functions

1166 Theory.add_finals or Theory.add_finals_i) it is now possible to

1167 declare constants "final", which prevents their being given a definition

1168 later. It is useful for constants whose behaviour is fixed axiomatically

1169 rather than definitionally, such as the meta-logic connectives.

1171 * Pure: 'instance' now handles general arities with general sorts

1172 (i.e. intersections of classes),

1174 * Presentation: generated HTML now uses a CSS style sheet to make layout

1175 (somewhat) independent of content. It is copied from lib/html/isabelle.css.

1176 It can be changed to alter the colors/layout of generated pages.

1179 *** Isar ***

1181 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,

1182 cut_tac, subgoal_tac and thin_tac:

1183 - Now understand static (Isar) contexts. As a consequence, users of Isar

1184 locales are no longer forced to write Isar proof scripts.

1185 For details see Isar Reference Manual, paragraph 4.3.2: Further tactic

1186 emulations.

1187 - INCOMPATIBILITY: names of variables to be instantiated may no

1188 longer be enclosed in quotes. Instead, precede variable name with `?'.

1189 This is consistent with the instantiation attribute "where".

1191 * Attributes "where" and "of":

1192 - Now take type variables of instantiated theorem into account when reading

1193 the instantiation string. This fixes a bug that caused instantiated

1194 theorems to have too special types in some circumstances.

1195 - "where" permits explicit instantiations of type variables.

1197 * Calculation commands "moreover" and "also" no longer interfere with

1198 current facts ("this"), admitting arbitrary combinations with "then"

1199 and derived forms.

1201 * Locales:

1202 - Goal statements involving the context element "includes" no longer

1203 generate theorems with internal delta predicates (those ending on

1204 "_axioms") in the premise.

1205 Resolve particular premise with <locale>.intro to obtain old form.

1206 - Fixed bug in type inference ("unify_frozen") that prevented mix of target

1207 specification and "includes" elements in goal statement.

1208 - Rule sets <locale>.intro and <locale>.axioms no longer declared as

1209 [intro?] and [elim?] (respectively) by default.

1210 - Experimental command for instantiation of locales in proof contexts:

1211 instantiate <label>[<attrs>]: <loc>

1212 Instantiates locale <loc> and adds all its theorems to the current context

1213 taking into account their attributes. Label and attrs are optional

1214 modifiers, like in theorem declarations. If present, names of

1215 instantiated theorems are qualified with <label>, and the attributes

1216 <attrs> are applied after any attributes these theorems might have already.

1217 If the locale has assumptions, a chained fact of the form

1218 "<loc> t1 ... tn" is expected from which instantiations of the parameters

1219 are derived. The command does not support old-style locales declared

1220 with "locale (open)".

1221 A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.

1223 * HOL: Tactic emulation methods induct_tac and case_tac understand static

1224 (Isar) contexts.

1227 *** HOL ***

1229 * Proof import: new image HOL4 contains the imported library from

1230 the HOL4 system with about 2500 theorems. It is imported by

1231 replaying proof terms produced by HOL4 in Isabelle. The HOL4 image

1232 can be used like any other Isabelle image. See

1233 HOL/Import/HOL/README for more information.

1235 * Simplifier:

1236 - Much improved handling of linear and partial orders.

1237 Reasoners for linear and partial orders are set up for type classes

1238 "linorder" and "order" respectively, and are added to the default simpset

1239 as solvers. This means that the simplifier can build transitivity chains

1240 to solve goals from the assumptions.

1241 - INCOMPATIBILITY: old proofs break occasionally. Typically, applications

1242 of blast or auto after simplification become unnecessary because the goal

1243 is solved by simplification already.

1245 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,

1246 all proved in axiomatic type classes for semirings, rings and fields.

1248 * Numerics:

1249 - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are

1250 now formalized using the Ring_and_Field theory mentioned above.

1251 - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently

1252 than before, because now they are set up once in a generic manner.

1253 - INCOMPATIBILITY: many type-specific arithmetic laws have gone.

1254 Look for the general versions in Ring_and_Field (and Power if they concern

1255 exponentiation).

1257 * Type "rat" of the rational numbers is now available in HOL-Complex.

1259 * Records:

1260 - Record types are now by default printed with their type abbreviation

1261 instead of the list of all field types. This can be configured via

1262 the reference "print_record_type_abbr".

1263 - Simproc "record_upd_simproc" for simplification of multiple updates added

1264 (not enabled by default).

1265 - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.

1266 EX x. x = sel r to True (not enabled by default).

1267 - Tactic "record_split_simp_tac" to split and simplify records added.

1269 * 'specification' command added, allowing for definition by

1270 specification. There is also an 'ax_specification' command that

1271 introduces the new constants axiomatically.

1273 * arith(_tac) is now able to generate counterexamples for reals as well.

1275 * HOL-Algebra: new locale "ring" for non-commutative rings.

1277 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function

1278 definitions, thanks to Sava Krsti\'{c} and John Matthews.

1280 * HOL-Matrix: a first theory for matrices in HOL with an application of

1281 matrix theory to linear programming.

1283 * Unions and Intersections:

1284 The latex output syntax of UN and INT has been changed

1285 from "\Union x \in A. B" to "\Union_{x \in A} B"

1286 i.e. the index formulae has become a subscript.

1287 Similarly for "\Union x. B", and for \Inter instead of \Union.

1289 * Unions and Intersections over Intervals:

1290 There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is

1291 also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"

1292 like in normal math, and corresponding versions for < and for intersection.

1294 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard

1295 lexicographic dictonary ordering has been added as "lexord".

1297 * ML: the legacy theory structures Int and List have been removed. They had

1298 conflicted with ML Basis Library structures having the same names.

1300 * 'refute' command added to search for (finite) countermodels. Only works

1301 for a fragment of HOL. The installation of an external SAT solver is

1302 highly recommended. See "HOL/Refute.thy" for details.

1304 * 'quickcheck' command: Allows to find counterexamples by evaluating

1305 formulae under an assignment of free variables to random values.

1306 In contrast to 'refute', it can deal with inductive datatypes,

1307 but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"

1308 for examples.

1311 *** HOLCF ***

1313 * Streams now come with concatenation and are part of the HOLCF image

1317 New in Isabelle2003 (May 2003)

1318 ------------------------------

1320 *** General ***

1322 * Provers/simplifier:

1324 - Completely reimplemented method simp (ML: Asm_full_simp_tac):

1325 Assumptions are now subject to complete mutual simplification,

1326 not just from left to right. The simplifier now preserves

1327 the order of assumptions.

1329 Potential INCOMPATIBILITY:

1331 -- simp sometimes diverges where the old version did

1332 not, e.g. invoking simp on the goal

1334 [| P (f x); y = x; f x = f y |] ==> Q

1336 now gives rise to the infinite reduction sequence

1338 P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...

1340 Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this

1341 kind of problem.

1343 -- Tactics combining classical reasoner and simplification (such as auto)

1344 are also affected by this change, because many of them rely on

1345 simp. They may sometimes diverge as well or yield a different numbers

1346 of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto

1347 in case of problems. Sometimes subsequent calls to the classical

1348 reasoner will fail because a preceeding call to the simplifier too

1349 eagerly simplified the goal, e.g. deleted redundant premises.

1351 - The simplifier trace now shows the names of the applied rewrite rules

1353 - You can limit the number of recursive invocations of the simplifier

1354 during conditional rewriting (where the simplifie tries to solve the

1355 conditions before applying the rewrite rule):

1356 ML "simp_depth_limit := n"

1357 where n is an integer. Thus you can force termination where previously

1358 the simplifier would diverge.

1360 - Accepts free variables as head terms in congruence rules. Useful in Isar.

1362 - No longer aborts on failed congruence proof. Instead, the

1363 congruence is ignored.

1365 * Pure: New generic framework for extracting programs from constructive

1366 proofs. See HOL/Extraction.thy for an example instantiation, as well

1367 as HOL/Extraction for some case studies.

1369 * Pure: The main goal of the proof state is no longer shown by default, only

1370 the subgoals. This behaviour is controlled by a new flag.

1371 PG menu: Isabelle/Isar -> Settings -> Show Main Goal

1372 (ML: Proof.show_main_goal).

1374 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all

1375 rules whose conclusion matches subgoal 1:

1376 PG menu: Isabelle/Isar -> Show me -> matching rules

1377 The rules are ordered by how closely they match the subgoal.

1378 In particular, rules that solve a subgoal outright are displayed first

1379 (or rather last, the way they are printed).

1380 (ML: ProofGeneral.print_intros())

1382 * Pure: New flag trace_unify_fail causes unification to print

1383 diagnostic information (PG: in trace buffer) when it fails. This is

1384 useful for figuring out why single step proofs like rule, erule or

1385 assumption failed.

1387 * Pure: Locale specifications now produce predicate definitions

1388 according to the body of text (covering assumptions modulo local

1389 definitions); predicate "loc_axioms" covers newly introduced text,

1390 while "loc" is cumulative wrt. all included locale expressions; the

1391 latter view is presented only on export into the global theory

1392 context; potential INCOMPATIBILITY, use "(open)" option to fall back

1393 on the old view without predicates;

1395 * Pure: predefined locales "var" and "struct" are useful for sharing

1396 parameters (as in CASL, for example); just specify something like

1397 ``var x + var y + struct M'' as import;

1399 * Pure: improved thms_containing: proper indexing of facts instead of

1400 raw theorems; check validity of results wrt. current name space;

1401 include local facts of proof configuration (also covers active

1402 locales), cover fixed variables in index; may use "_" in term

1403 specification; an optional limit for the number of printed facts may

1404 be given (the default is 40);

1406 * Pure: disallow duplicate fact bindings within new-style theory files

1407 (batch-mode only);

1409 * Provers: improved induct method: assumptions introduced by case

1410 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from

1411 the goal statement); "foo" still refers to all facts collectively;

1413 * Provers: the function blast.overloaded has been removed: all constants

1414 are regarded as potentially overloaded, which improves robustness in exchange

1415 for slight decrease in efficiency;

1417 * Provers/linorder: New generic prover for transitivity reasoning over

1418 linear orders. Note: this prover is not efficient!

1420 * Isar: preview of problems to finish 'show' now produce an error

1421 rather than just a warning (in interactive mode);

1424 *** HOL ***

1426 * arith(_tac)

1428 - Produces a counter example if it cannot prove a goal.

1429 Note that the counter example may be spurious if the goal is not a formula

1430 of quantifier-free linear arithmetic.

1431 In ProofGeneral the counter example appears in the trace buffer.

1433 - Knows about div k and mod k where k is a numeral of type nat or int.

1435 - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free

1436 linear arithmetic fails. This takes account of quantifiers and divisibility.

1437 Presburger arithmetic can also be called explicitly via presburger(_tac).

1439 * simp's arithmetic capabilities have been enhanced a bit: it now

1440 takes ~= in premises into account (by performing a case split);

1442 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands

1443 are distributed over a sum of terms;

1445 * New tactic "trans_tac" and method "trans" instantiate

1446 Provers/linorder.ML for axclasses "order" and "linorder" (predicates

1447 "<=", "<" and "=").

1449 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main

1450 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";

1452 * 'typedef' command has new option "open" to suppress the set

1453 definition;

1455 * functions Min and Max on finite sets have been introduced (theory

1456 Finite_Set);

1458 * attribute [symmetric] now works for relations as well; it turns

1459 (x,y) : R^-1 into (y,x) : R, and vice versa;

1461 * induct over a !!-quantified statement (say !!x1..xn):

1462 each "case" automatically performs "fix x1 .. xn" with exactly those names.

1464 * Map: `empty' is no longer a constant but a syntactic abbreviation for

1465 %x. None. Warning: empty_def now refers to the previously hidden definition

1466 of the empty set.

1468 * Algebra: formalization of classical algebra. Intended as base for

1469 any algebraic development in Isabelle. Currently covers group theory

1470 (up to Sylow's theorem) and ring theory (Universal Property of

1471 Univariate Polynomials). Contributions welcome;

1473 * GroupTheory: deleted, since its material has been moved to Algebra;

1475 * Complex: new directory of the complex numbers with numeric constants,

1476 nonstandard complex numbers, and some complex analysis, standard and

1477 nonstandard (Jacques Fleuriot);

1479 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;

1481 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques

1482 Fleuriot);

1484 * Real/HahnBanach: updated and adapted to locales;

1486 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,

1487 Gray and Kramer);

1489 * UNITY: added the Meier-Sanders theory of progress sets;

1491 * MicroJava: bytecode verifier and lightweight bytecode verifier

1492 as abstract algorithms, instantiated to the JVM;

1494 * Bali: Java source language formalization. Type system, operational

1495 semantics, axiomatic semantics. Supported language features:

1496 classes, interfaces, objects,virtual methods, static methods,

1497 static/instance fields, arrays, access modifiers, definite

1498 assignment, exceptions.

1501 *** ZF ***

1503 * ZF/Constructible: consistency proof for AC (Gdel's constructible

1504 universe, etc.);

1506 * Main ZF: virtually all theories converted to new-style format;

1509 *** ML ***

1511 * Pure: Tactic.prove provides sane interface for internal proofs;

1512 omits the infamous "standard" operation, so this is more appropriate

1513 than prove_goalw_cterm in many situations (e.g. in simprocs);

1515 * Pure: improved error reporting of simprocs;

1517 * Provers: Simplifier.simproc(_i) provides sane interface for setting

1518 up simprocs;

1521 *** Document preparation ***

1523 * uses \par instead of \\ for line breaks in theory text. This may

1524 shift some page breaks in large documents. To get the old behaviour

1525 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.

1527 * minimized dependencies of isabelle.sty and isabellesym.sty on

1528 other packages

1530 * \<euro> now needs package babel/greek instead of marvosym (which

1531 broke \Rightarrow)

1533 * normal size for \<zero>...\<nine> (uses \mathbf instead of

1534 textcomp package)

1538 New in Isabelle2002 (March 2002)

1539 --------------------------------

1541 *** Document preparation ***

1543 * greatly simplified document preparation setup, including more

1544 graceful interpretation of isatool usedir -i/-d/-D options, and more

1545 instructive isatool mkdir; users should basically be able to get

1546 started with "isatool mkdir HOL Test && isatool make"; alternatively,

1547 users may run a separate document processing stage manually like this:

1548 "isatool usedir -D output HOL Test && isatool document Test/output";

1550 * theory dependency graph may now be incorporated into documents;

1551 isatool usedir -g true will produce session_graph.eps/.pdf for use

1552 with \includegraphics of LaTeX;

1554 * proper spacing of consecutive markup elements, especially text

1555 blocks after section headings;

1557 * support bold style (for single symbols only), input syntax is like

1558 this: "\<^bold>\<alpha>" or "\<^bold>A";

1560 * \<bullet> is now output as bold \cdot by default, which looks much

1561 better in printed text;

1563 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;

1564 note that these symbols are currently unavailable in Proof General /

1565 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;

1567 * isatool latex no longer depends on changed TEXINPUTS, instead

1568 isatool document copies the Isabelle style files to the target

1569 location;

1572 *** Isar ***

1574 * Pure/Provers: improved proof by cases and induction;

1575 - 'case' command admits impromptu naming of parameters (such as

1576 "case (Suc n)");

1577 - 'induct' method divinates rule instantiation from the inductive

1578 claim; no longer requires excessive ?P bindings for proper

1579 instantiation of cases;

1580 - 'induct' method properly enumerates all possibilities of set/type

1581 rules; as a consequence facts may be also passed through *type*

1582 rules without further ado;

1583 - 'induct' method now derives symbolic cases from the *rulified*

1584 rule (before it used to rulify cases stemming from the internal

1585 atomized version); this means that the context of a non-atomic

1586 statement becomes is included in the hypothesis, avoiding the

1587 slightly cumbersome show "PROP ?case" form;

1588 - 'induct' may now use elim-style induction rules without chaining

1589 facts, using ``missing'' premises from the goal state; this allows

1590 rules stemming from inductive sets to be applied in unstructured

1591 scripts, while still benefitting from proper handling of non-atomic

1592 statements; NB: major inductive premises need to be put first, all

1593 the rest of the goal is passed through the induction;

1594 - 'induct' proper support for mutual induction involving non-atomic

1595 rule statements (uses the new concept of simultaneous goals, see

1596 below);

1597 - append all possible rule selections, but only use the first

1598 success (no backtracking);

1599 - removed obsolete "(simplified)" and "(stripped)" options of methods;

1600 - undeclared rule case names default to numbers 1, 2, 3, ...;

1601 - added 'print_induct_rules' (covered by help item in recent Proof

1602 General versions);

1603 - moved induct/cases attributes to Pure, methods to Provers;

1604 - generic method setup instantiated for FOL and HOL;

1606 * Pure: support multiple simultaneous goal statements, for example

1607 "have a: A and b: B" (same for 'theorem' etc.); being a pure

1608 meta-level mechanism, this acts as if several individual goals had

1609 been stated separately; in particular common proof methods need to be

1610 repeated in order to cover all claims; note that a single elimination

1611 step is *not* sufficient to establish the two conjunctions, so this

1612 fails:

1614 assume "A & B" then have A and B .. (*".." fails*)

1616 better use "obtain" in situations as above; alternative refer to

1617 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;

1619 * Pure: proper integration with ``locales''; unlike the original

1620 version by Florian Kammller, Isar locales package high-level proof

1621 contexts rather than raw logical ones (e.g. we admit to include

1622 attributes everywhere); operations on locales include merge and

1623 rename; support for implicit arguments (``structures''); simultaneous

1624 type-inference over imports and text; see also HOL/ex/Locales.thy for

1625 some examples;

1627 * Pure: the following commands have been ``localized'', supporting a

1628 target locale specification "(in name)": 'lemma', 'theorem',

1629 'corollary', 'lemmas', 'theorems', 'declare'; the results will be

1630 stored both within the locale and at the theory level (exported and

1631 qualified by the locale name);

1633 * Pure: theory goals may now be specified in ``long'' form, with

1634 ad-hoc contexts consisting of arbitrary locale elements. for example

1635 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and

1636 definitions may be given, too); the result is a meta-level rule with

1637 the context elements being discharged in the obvious way;

1639 * Pure: new proof command 'using' allows to augment currently used

1640 facts after a goal statement ('using' is syntactically analogous to

1641 'apply', but acts on the goal's facts only); this allows chained facts

1642 to be separated into parts given before and after a claim, as in

1643 ``from a and b have C using d and e <proof>'';

1645 * Pure: renamed "antecedent" case to "rule_context";

1647 * Pure: new 'judgment' command records explicit information about the

1648 object-logic embedding (used by several tools internally); no longer

1649 use hard-wired "Trueprop";

1651 * Pure: added 'corollary' command;

1653 * Pure: fixed 'token_translation' command;

1655 * Pure: removed obsolete 'exported' attribute;

1657 * Pure: dummy pattern "_" in is/let is now automatically lifted over

1658 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")

1659 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");

1661 * Pure: method 'atomize' presents local goal premises as object-level

1662 statements (atomic meta-level propositions); setup controlled via

1663 rewrite rules declarations of 'atomize' attribute; example

1664 application: 'induct' method with proper rule statements in improper

1665 proof *scripts*;

1667 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)

1668 now consider the syntactic context of assumptions, giving a better

1669 chance to get type-inference of the arguments right (this is

1670 especially important for locales);

1672 * Pure: "sorry" no longer requires quick_and_dirty in interactive

1673 mode;

1675 * Pure/obtain: the formal conclusion "thesis", being marked as

1676 ``internal'', may no longer be reference directly in the text;

1677 potential INCOMPATIBILITY, may need to use "?thesis" in rare

1678 situations;

1680 * Pure: generic 'sym' attribute which declares a rule both as pure

1681 'elim?' and for the 'symmetric' operation;

1683 * Pure: marginal comments ``--'' may now occur just anywhere in the

1684 text; the fixed correlation with particular command syntax has been

1685 discontinued;

1687 * Pure: new method 'rules' is particularly well-suited for proof

1688 search in intuitionistic logic; a bit slower than 'blast' or 'fast',

1689 but often produces more compact proof terms with less detours;

1691 * Pure/Provers/classical: simplified integration with pure rule

1692 attributes and methods; the classical "intro?/elim?/dest?"

1693 declarations coincide with the pure ones; the "rule" method no longer

1694 includes classically swapped intros; "intro" and "elim" methods no

1695 longer pick rules from the context; also got rid of ML declarations

1696 AddXIs/AddXEs/AddXDs; all of this has some potential for

1697 INCOMPATIBILITY;

1699 * Provers/classical: attribute 'swapped' produces classical inversions

1700 of introduction rules;

1702 * Provers/simplifier: 'simplified' attribute may refer to explicit

1703 rules instead of full simplifier context; 'iff' attribute handles

1704 conditional rules;

1706 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;

1708 * HOL: 'recdef' now fails on unfinished automated proofs, use

1709 "(permissive)" option to recover old behavior;

1711 * HOL: 'inductive' no longer features separate (collective) attributes

1712 for 'intros' (was found too confusing);

1714 * HOL: properly declared induction rules less_induct and

1715 wf_induct_rule;

1718 *** HOL ***

1720 * HOL: moved over to sane numeral syntax; the new policy is as

1721 follows:

1723 - 0 and 1 are polymorphic constants, which are defined on any

1724 numeric type (nat, int, real etc.);

1726 - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based

1727 binary representation internally;

1729 - type nat has special constructor Suc, and generally prefers Suc 0

1730 over 1::nat and Suc (Suc 0) over 2::nat;

1732 This change may cause significant problems of INCOMPATIBILITY; here

1733 are some hints on converting existing sources:

1735 - due to the new "num" token, "-0" and "-1" etc. are now atomic

1736 entities, so expressions involving "-" (unary or binary minus) need

1737 to be spaced properly;

1739 - existing occurrences of "1" may need to be constraint "1::nat" or

1740 even replaced by Suc 0; similar for old "2";

1742 - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";

1744 - remove all special provisions on numerals in proofs;

1746 * HOL: simp rules nat_number expand numerals on nat to Suc/0

1747 representation (depends on bin_arith_simps in the default context);

1749 * HOL: symbolic syntax for x^2 (numeral 2);

1751 * HOL: the class of all HOL types is now called "type" rather than

1752 "term"; INCOMPATIBILITY, need to adapt references to this type class

1753 in axclass/classes, instance/arities, and (usually rare) occurrences

1754 in typings (of consts etc.); internally the class is called

1755 "HOL.type", ML programs should refer to HOLogic.typeS;

1757 * HOL/record package improvements:

1758 - new derived operations "fields" to build a partial record section,

1759 "extend" to promote a fixed record to a record scheme, and

1760 "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*

1761 declared as simp by default;

1762 - shared operations ("more", "fields", etc.) now need to be always

1763 qualified) --- potential INCOMPATIBILITY;

1764 - removed "make_scheme" operations (use "make" with "extend") --

1765 INCOMPATIBILITY;

1766 - removed "more" class (simply use "term") -- INCOMPATIBILITY;

1767 - provides cases/induct rules for use with corresponding Isar

1768 methods (for concrete records, record schemes, concrete more

1769 parts, and schematic more parts -- in that order);

1770 - internal definitions directly based on a light-weight abstract

1771 theory of product types over typedef rather than datatype;

1773 * HOL: generic code generator for generating executable ML code from

1774 specifications; specific support for HOL constructs such as inductive

1775 datatypes and sets, as well as recursive functions; can be invoked

1776 via 'generate_code' theory section;

1778 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);

1780 * HOL: consolidated and renamed several theories. In particular:

1781 Ord.thy has been absorbed into HOL.thy

1782 String.thy has been absorbed into List.thy

1784 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"

1785 (beware of argument permutation!);

1787 * HOL: linorder_less_split superseded by linorder_cases;

1789 * HOL/List: "nodups" renamed to "distinct";

1791 * HOL: added "The" definite description operator; move Hilbert's "Eps"

1792 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:

1793 - Ex_def has changed, now need to use some_eq_ex

1795 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so

1796 in this (rare) case use:

1798 delSWrapper "split_all_tac"

1799 addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)

1801 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS

1802 MAY FAIL;

1804 * HOL: introduced f^n = f o ... o f; warning: due to the limits of

1805 Isabelle's type classes, ^ on functions and relations has too general

1806 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be

1807 necessary to attach explicit type constraints;

1809 * HOL/Relation: the prefix name of the infix "O" has been changed from

1810 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been

1811 renamed accordingly (eg "compI" -> "rel_compI").

1813 * HOL: syntax translations now work properly with numerals and records

1814 expressions;

1816 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead

1817 of "lam" -- INCOMPATIBILITY;

1819 * HOL: got rid of some global declarations (potential INCOMPATIBILITY

1820 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"

1821 renamed "Product_Type.unit";

1823 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl

1825 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or

1826 the "cases" method);

1828 * HOL/GroupTheory: group theory examples including Sylow's theorem (by

1829 Florian Kammller);

1831 * HOL/IMP: updated and converted to new-style theory format; several

1832 parts turned into readable document, with proper Isar proof texts and

1833 some explanations (by Gerwin Klein);

1835 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);

1837 * HOL-Hyperreal is now a logic image;

1840 *** HOLCF ***

1842 * Isar: consts/constdefs supports mixfix syntax for continuous

1843 operations;

1845 * Isar: domain package adapted to new-style theory format, e.g. see

1846 HOLCF/ex/Dnat.thy;

1848 * theory Lift: proper use of rep_datatype lift instead of ML hacks --

1849 potential INCOMPATIBILITY; now use plain induct_tac instead of former

1850 lift.induct_tac, always use UU instead of Undef;

1852 * HOLCF/IMP: updated and converted to new-style theory;

1855 *** ZF ***

1857 * Isar: proper integration of logic-specific tools and packages,

1858 including theory commands '(co)inductive', '(co)datatype',

1859 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',

1860 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');

1862 * theory Main no longer includes AC; for the Axiom of Choice, base

1863 your theory on Main_ZFC;

1865 * the integer library now covers quotients and remainders, with many

1866 laws relating division to addition, multiplication, etc.;

1868 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a

1869 typeless version of the formalism;

1871 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory

1872 format;

1874 * ZF/Induct: new directory for examples of inductive definitions,

1875 including theory Multiset for multiset orderings; converted to

1876 new-style theory format;

1878 * ZF: many new theorems about lists, ordinals, etc.;

1881 *** General ***

1883 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference

1884 variable proof controls level of detail: 0 = no proofs (only oracle

1885 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see

1886 also ref manual for further ML interfaces;

1888 * Pure/axclass: removed obsolete ML interface

1889 goal_subclass/goal_arity;

1891 * Pure/syntax: new token syntax "num" for plain numerals (without "#"

1892 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now

1893 separate tokens, so expressions involving minus need to be spaced

1894 properly;

1896 * Pure/syntax: support non-oriented infixes, using keyword "infix"

1897 rather than "infixl" or "infixr";

1899 * Pure/syntax: concrete syntax for dummy type variables admits genuine

1900 sort constraint specifications in type inference; e.g. "x::_::foo"

1901 ensures that the type of "x" is of sort "foo" (but not necessarily a

1902 type variable);

1904 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"

1905 control output of nested => (types); the default behavior is

1906 "type_brackets";

1908 * Pure/syntax: builtin parse translation for "_constify" turns valued

1909 tokens into AST constants;

1911 * Pure/syntax: prefer later declarations of translations and print

1912 translation functions; potential INCOMPATIBILITY: need to reverse

1913 multiple declarations for same syntax element constant;

1915 * Pure/show_hyps reset by default (in accordance to existing Isar

1916 practice);

1918 * Provers/classical: renamed addaltern to addafter, addSaltern to

1919 addSafter;

1921 * Provers/clasimp: ``iff'' declarations now handle conditional rules

1922 as well;

1924 * system: tested support for MacOS X; should be able to get Isabelle +

1925 Proof General to work in a plain Terminal after installing Poly/ML

1926 (e.g. from the Isabelle distribution area) and GNU bash alone

1927 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol

1928 support requires further installations, e.g. from

1929 http://fink.sourceforge.net/);

1931 * system: support Poly/ML 4.1.1 (able to manage larger heaps);

1933 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead

1934 of 40 MB), cf. ML_OPTIONS;

1936 * system: Proof General keywords specification is now part of the

1937 Isabelle distribution (see etc/isar-keywords.el);

1939 * system: support for persistent Proof General sessions (refrain from

1940 outdating all loaded theories on startup); user may create writable

1941 logic images like this: ``isabelle -q HOL Test'';

1943 * system: smart selection of Isabelle process versus Isabelle

1944 interface, accommodates case-insensitive file systems (e.g. HFS+); may

1945 run both "isabelle" and "Isabelle" even if file names are badly

1946 damaged (executable inspects the case of the first letter of its own

1947 name); added separate "isabelle-process" and "isabelle-interface";

1949 * system: refrain from any attempt at filtering input streams; no

1950 longer support ``8bit'' encoding of old isabelle font, instead proper

1951 iso-latin characters may now be used; the related isatools

1952 "symbolinput" and "nonascii" have disappeared as well;

1954 * system: removed old "xterm" interface (the print modes "xterm" and

1955 "xterm_color" are still available for direct use in a suitable

1956 terminal);

1960 New in Isabelle99-2 (February 2001)

1961 -----------------------------------

1963 *** Overview of INCOMPATIBILITIES ***

1965 * HOL: please note that theories in the Library and elsewhere often use the

1966 new-style (Isar) format; to refer to their theorems in an ML script you must

1967 bind them to ML identifers by e.g. val thm_name = thm "thm_name";

1969 * HOL: inductive package no longer splits induction rule aggressively,

1970 but only as far as specified by the introductions given; the old

1971 format may be recovered via ML function complete_split_rule or attribute

1972 'split_rule (complete)';

1974 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,

1975 gfp_Tarski to gfp_unfold;

1977 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;

1979 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a

1980 relation); infix "^^" has been renamed "``"; infix "``" has been

1981 renamed "`"; "univalent" has been renamed "single_valued";

1983 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"

1984 operation;

1986 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;

1988 * Isar: 'obtain' no longer declares "that" fact as simp/intro;

1990 * Isar/HOL: method 'induct' now handles non-atomic goals; as a

1991 consequence, it is no longer monotonic wrt. the local goal context

1992 (which is now passed through the inductive cases);

1994 * Document preparation: renamed standard symbols \<ll> to \<lless> and

1995 \<gg> to \<ggreater>;

1998 *** Document preparation ***

2000 * \isabellestyle{NAME} selects version of Isabelle output (currently

2001 available: are "it" for near math-mode best-style output, "sl" for

2002 slanted text style, and "tt" for plain type-writer; if no

2003 \isabellestyle command is given, output is according to slanted

2004 type-writer);

2006 * support sub/super scripts (for single symbols only), input syntax is

2007 like this: "A\<^sup>*" or "A\<^sup>\<star>";

2009 * some more standard symbols; see Appendix A of the system manual for

2010 the complete list of symbols defined in isabellesym.sty;

2012 * improved isabelle style files; more abstract symbol implementation

2013 (should now use \isamath{...} and \isatext{...} in custom symbol

2014 definitions);

2016 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals

2017 state; Note that presentation of goal states does not conform to

2018 actual human-readable proof documents. Please do not include goal

2019 states into document output unless you really know what you are doing!

2021 * proper indentation of antiquoted output with proportional LaTeX

2022 fonts;

2024 * no_document ML operator temporarily disables LaTeX document

2025 generation;

2027 * isatool unsymbolize tunes sources for plain ASCII communication;

2030 *** Isar ***

2032 * Pure: Isar now suffers initial goal statements to contain unbound

2033 schematic variables (this does not conform to actual readable proof

2034 documents, due to unpredictable outcome and non-compositional proof

2035 checking); users who know what they are doing may use schematic goals

2036 for Prolog-style synthesis of proven results;

2038 * Pure: assumption method (an implicit finishing) now handles actual

2039 rules as well;

2041 * Pure: improved 'obtain' --- moved to Pure, insert "that" into

2042 initial goal, declare "that" only as Pure intro (only for single

2043 steps); the "that" rule assumption may now be involved in implicit

2044 finishing, thus ".." becomes a feasible for trivial obtains;

2046 * Pure: default proof step now includes 'intro_classes'; thus trivial

2047 instance proofs may be performed by "..";

2049 * Pure: ?thesis / ?this / "..." now work for pure meta-level

2050 statements as well;

2052 * Pure: more robust selection of calculational rules;

2054 * Pure: the builtin notion of 'finished' goal now includes the ==-refl

2055 rule (as well as the assumption rule);

2057 * Pure: 'thm_deps' command visualizes dependencies of theorems and

2058 lemmas, using the graph browser tool;

2060 * Pure: predict failure of "show" in interactive mode;

2062 * Pure: 'thms_containing' now takes actual terms as arguments;

2064 * HOL: improved method 'induct' --- now handles non-atomic goals

2065 (potential INCOMPATIBILITY); tuned error handling;

2067 * HOL: cases and induct rules now provide explicit hints about the

2068 number of facts to be consumed (0 for "type" and 1 for "set" rules);

2069 any remaining facts are inserted into the goal verbatim;

2071 * HOL: local contexts (aka cases) may now contain term bindings as

2072 well; the 'cases' and 'induct' methods new provide a ?case binding for

2073 the result to be shown in each case;

2075 * HOL: added 'recdef_tc' command;

2077 * isatool convert assists in eliminating legacy ML scripts;

2080 *** HOL ***

2082 * HOL/Library: a collection of generic theories to be used together

2083 with main HOL; the theory loader path already includes this directory

2084 by default; the following existing theories have been moved here:

2085 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While

2086 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);

2088 * HOL/Unix: "Some aspects of Unix file-system security", a typical

2089 modelling and verification task performed in Isabelle/HOL +

2090 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).

2092 * HOL/Algebra: special summation operator SUM no longer exists, it has

2093 been replaced by setsum; infix 'assoc' now has priority 50 (like

2094 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to

2095 'domain', this makes the theory consistent with mathematical

2096 literature;

2098 * HOL basics: added overloaded operations "inverse" and "divide"

2099 (infix "/"), syntax for generic "abs" operation, generic summation

2100 operator \<Sum>;

2102 * HOL/typedef: simplified package, provide more useful rules (see also

2103 HOL/subset.thy);

2105 * HOL/datatype: induction rule for arbitrarily branching datatypes is

2106 now expressed as a proper nested rule (old-style tactic scripts may

2107 require atomize_strip_tac to cope with non-atomic premises);

2109 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule

2110 to "split_conv" (old name still available for compatibility);

2112 * HOL: improved concrete syntax for strings (e.g. allows translation

2113 rules with string literals);

2115 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals

2116 and Fleuriot's mechanization of analysis, including the transcendental

2117 functions for the reals;

2119 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;

2122 *** CTT ***

2124 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that

2125 "lam" is displayed as TWO lambda-symbols

2127 * CTT: theory Main now available, containing everything (that is, Bool

2128 and Arith);

2131 *** General ***

2133 * Pure: the Simplifier has been implemented properly as a derived rule

2134 outside of the actual kernel (at last!); the overall performance

2135 penalty in practical applications is about 50%, while reliability of

2136 the Isabelle inference kernel has been greatly improved;

2138 * print modes "brackets" and "no_brackets" control output of nested =>

2139 (types) and ==> (props); the default behaviour is "brackets";

2141 * Provers: fast_tac (and friends) now handle actual object-logic rules

2142 as assumptions as well;

2144 * system: support Poly/ML 4.0;

2146 * system: isatool install handles KDE version 1 or 2;

2150 New in Isabelle99-1 (October 2000)

2151 ----------------------------------

2153 *** Overview of INCOMPATIBILITIES ***

2155 * HOL: simplification of natural numbers is much changed; to partly

2156 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)

2157 issue the following ML commands:

2159 Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;

2160 Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];

2162 * HOL: simplification no longer dives into case-expressions; this is

2163 controlled by "t.weak_case_cong" for each datatype t;

2165 * HOL: nat_less_induct renamed to less_induct;

2167 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool

2168 fixsome to patch .thy and .ML sources automatically;

2170 select_equality -> some_equality

2171 select_eq_Ex -> some_eq_ex

2172 selectI2EX -> someI2_ex

2173 selectI2 -> someI2

2174 selectI -> someI

2175 select1_equality -> some1_equality

2176 Eps_sym_eq -> some_sym_eq_trivial

2177 Eps_eq -> some_eq_trivial

2179 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;

2181 * HOL: removed obsolete theorem binding expand_if (refer to split_if

2182 instead);

2184 * HOL: the recursion equations generated by 'recdef' are now called

2185 f.simps instead of f.rules;

2187 * HOL: qed_spec_mp now also handles bounded ALL as well;

2189 * HOL: 0 is now overloaded, so the type constraint ":: nat" may

2190 sometimes be needed;

2192 * HOL: the constant for "f``x" is now "image" rather than "op ``";

2194 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";

2196 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian

2197 product is now "<*>" instead of "Times"; the lexicographic product is

2198 now "<*lex*>" instead of "**";

2200 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part

2201 of main HOL, but was unused); better use HOL's datatype package;

2203 * HOL: removed "symbols" syntax for constant "override" of theory Map;

2204 the old syntax may be recovered as follows:

2206 syntax (symbols)

2207 override :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"

2208 (infixl "\\<oplus>" 100)

2210 * HOL/Real: "rabs" replaced by overloaded "abs" function;

2212 * HOL/ML: even fewer consts are declared as global (see theories Ord,

2213 Lfp, Gfp, WF); this only affects ML packages that refer to const names

2214 internally;

2216 * HOL and ZF: syntax for quotienting wrt an equivalence relation

2217 changed from A/r to A//r;

2219 * ZF: new treatment of arithmetic (nat & int) may break some old

2220 proofs;

2222 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,

2223 rulify -> rule_format, elimify -> elim_format, ...);

2225 * Isar/Provers: intro/elim/dest attributes changed; renamed

2226 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one

2227 should have to change intro!! to intro? only); replaced "delrule" by

2228 "rule del";

2230 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;

2232 * Provers: strengthened force_tac by using new first_best_tac;

2234 * LaTeX document preparation: several changes of isabelle.sty (see

2235 lib/texinputs);

2238 *** Document preparation ***

2240 * formal comments (text blocks etc.) in new-style theories may now

2241 contain antiquotations of thm/prop/term/typ/text to be presented

2242 according to latex print mode; concrete syntax is like this:

2243 @{term[show_types] "f(x) = a + x"};

2245 * isatool mkdir provides easy setup of Isabelle session directories,

2246 including proper document sources;

2248 * generated LaTeX sources are now deleted after successful run

2249 (isatool document -c); may retain a copy somewhere else via -D option

2250 of isatool usedir;

2252 * isatool usedir -D now lets isatool latex -o sty update the Isabelle

2253 style files, achieving self-contained LaTeX sources and simplifying

2254 LaTeX debugging;

2256 * old-style theories now produce (crude) LaTeX output as well;

2258 * browser info session directories are now self-contained (may be put

2259 on WWW server seperately); improved graphs of nested sessions; removed

2260 graph for 'all sessions';

2262 * several improvements in isabelle style files; \isabellestyle{it}

2263 produces fake math mode output; \isamarkupheader is now \section by

2264 default; see lib/texinputs/isabelle.sty etc.;

2267 *** Isar ***

2269 * Isar/Pure: local results and corresponding term bindings are now

2270 subject to Hindley-Milner polymorphism (similar to ML); this

2271 accommodates incremental type-inference very nicely;

2273 * Isar/Pure: new derived language element 'obtain' supports

2274 generalized existence reasoning;

2276 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'

2277 support accumulation of results, without applying any rules yet;

2278 useful to collect intermediate results without explicit name

2279 references, and for use with transitivity rules with more than 2

2280 premises;

2282 * Isar/Pure: scalable support for case-analysis type proofs: new

2283 'case' language element refers to local contexts symbolically, as

2284 produced by certain proof methods; internally, case names are attached

2285 to theorems as "tags";

2287 * Isar/Pure: theory command 'hide' removes declarations from

2288 class/type/const name spaces;

2290 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to

2291 indicate potential overloading;

2293 * Isar/Pure: changed syntax of local blocks from {{ }} to { };

2295 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write

2296 "{a,b,c}" instead of {a,b,c};

2298 * Isar/Pure now provides its own version of intro/elim/dest

2299 attributes; useful for building new logics, but beware of confusion

2300 with the version in Provers/classical;

2302 * Isar/Pure: the local context of (non-atomic) goals is provided via

2303 case name 'antecedent';

2305 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms

2306 to the current context is now done automatically);

2308 * Isar/Pure: theory command 'method_setup' provides a simple interface

2309 for definining proof methods in ML;

2311 * Isar/Provers: intro/elim/dest attributes changed; renamed

2312 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in

2313 most cases, one should have to change intro!! to intro? only);

2314 replaced "delrule" by "rule del";

2316 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and

2317 'symmetric' attribute (the latter supercedes [RS sym]);

2319 * Isar/Provers: splitter support (via 'split' attribute and 'simp'

2320 method modifier); 'simp' method: 'only:' modifier removes loopers as

2321 well (including splits);

2323 * Isar/Provers: Simplifier and Classical methods now support all kind

2324 of modifiers used in the past, including 'cong', 'iff', etc.

2326 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination

2327 of Simplifier and Classical reasoner);

2329 * Isar/HOL: new proof method 'cases' and improved version of 'induct'

2330 now support named cases; major packages (inductive, datatype, primrec,

2331 recdef) support case names and properly name parameters;

2333 * Isar/HOL: new transitivity rules for substitution in inequalities --

2334 monotonicity conditions are extracted to be proven at end of

2335 calculations;

2337 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof

2338 method anyway;

2340 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =

2341 split_if split_if_asm; datatype package provides theorems foo.splits =

2342 foo.split foo.split_asm for each datatype;

2344 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"

2345 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof

2346 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:

2347 use "(cases (simplified))" method in proper proof texts);

2349 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;

2351 * Isar: names of theorems etc. may be natural numbers as well;

2353 * Isar: 'pr' command: optional arguments for goals_limit and

2354 ProofContext.prems_limit; no longer prints theory contexts, but only

2355 proof states;

2357 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit

2358 additional print modes to be specified; e.g. "pr(latex)" will print

2359 proof state according to the Isabelle LaTeX style;

2361 * Isar: improved support for emulating tactic scripts, including proof

2362 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',

2363 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'

2364 (for HOL datatypes);

2366 * Isar: simplified (more robust) goal selection of proof methods: 1st

2367 goal, all goals, or explicit goal specifier (tactic emulation); thus

2368 'proof method scripts' have to be in depth-first order;

2370 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';

2372 * Isar: removed 'help' command, which hasn't been too helpful anyway;

2373 should instead use individual commands for printing items

2374 (print_commands, print_methods etc.);

2376 * Isar: added 'nothing' --- the empty list of theorems;

2379 *** HOL ***

2381 * HOL/MicroJava: formalization of a fragment of Java, together with a

2382 corresponding virtual machine and a specification of its bytecode

2383 verifier and a lightweight bytecode verifier, including proofs of

2384 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and

2385 Cornelia Pusch (see also the homepage of project Bali at

2386 http://isabelle.in.tum.de/Bali/);

2388 * HOL/Algebra: new theory of rings and univariate polynomials, by

2389 Clemens Ballarin;

2391 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese

2392 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M

2393 Rasmussen;

2395 * HOL/Lattice: fundamental concepts of lattice theory and order

2396 structures, including duals, properties of bounds versus algebraic

2397 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski

2398 Theorem for complete lattices etc.; may also serve as a demonstration

2399 for abstract algebraic reasoning using axiomatic type classes, and

2400 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;

2402 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David

2403 von Oheimb;

2405 * HOL/IMPP: extension of IMP with local variables and mutually

2406 recursive procedures, by David von Oheimb;

2408 * HOL/Lambda: converted into new-style theory and document;

2410 * HOL/ex/Multiquote: example of multiple nested quotations and

2411 anti-quotations -- basically a generalized version of de-Bruijn

2412 representation; very useful in avoiding lifting of operations;

2414 * HOL/record: added general record equality rule to simpset; fixed

2415 select-update simplification procedure to handle extended records as

2416 well; admit "r" as field name;

2418 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with

2419 other numeric types and also as the identity of groups, rings, etc.;

2421 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.

2422 Types nat and int belong to this axclass;

2424 * HOL: greatly improved simplification involving numerals of type nat, int, real:

2425 (i + #8 + j) = Suc k simplifies to #7 + (i + j) = k

2426 i*j + k + j*#3*i simplifies to #4*(i*j) + k

2427 two terms #m*u and #n*u are replaced by #(m+n)*u

2428 (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)

2429 and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y

2430 or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);

2432 * HOL: meson_tac is available (previously in ex/meson.ML); it is a

2433 powerful prover for predicate logic but knows nothing of clasets; see

2434 ex/mesontest.ML and ex/mesontest2.ML for example applications;

2436 * HOL: new version of "case_tac" subsumes both boolean case split and

2437 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer

2438 exists, may define val exhaust_tac = case_tac for ad-hoc portability;

2440 * HOL: simplification no longer dives into case-expressions: only the

2441 selector expression is simplified, but not the remaining arms; to

2442 enable full simplification of case-expressions for datatype t, you may

2443 remove t.weak_case_cong from the simpset, either globally (Delcongs

2444 [thm"t.weak_case_cong"];) or locally (delcongs [...]).

2446 * HOL/recdef: the recursion equations generated by 'recdef' for

2447 function 'f' are now called f.simps instead of f.rules; if all

2448 termination conditions are proved automatically, these simplification

2449 rules are added to the simpset, as in primrec; rules may be named

2450 individually as well, resulting in a separate list of theorems for

2451 each equation;

2453 * HOL/While is a new theory that provides a while-combinator. It

2454 permits the definition of tail-recursive functions without the

2455 provision of a termination measure. The latter is necessary once the

2456 invariant proof rule for while is applied.

2458 * HOL: new (overloaded) notation for the set of elements below/above

2459 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.

2461 * HOL: theorems impI, allI, ballI bound as "strip";

2463 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic

2464 induct_tac th "x1 ... xn" expects th to have a conclusion of the form

2465 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;

2467 * HOL/Real: "rabs" replaced by overloaded "abs" function;

2469 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of

2470 main HOL, but was unused);

2472 * HOL: fewer consts declared as global (e.g. have to refer to

2473 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);

2475 * HOL: tuned AST representation of nested pairs, avoiding bogus output

2476 in case of overlap with user translations (e.g. judgements over

2477 tuples); (note that the underlying logical represenation is still

2478 bogus);

2481 *** ZF ***

2483 * ZF: simplification automatically cancels common terms in arithmetic

2484 expressions over nat and int;

2486 * ZF: new treatment of nat to minimize type-checking: all operators

2487 coerce their operands to a natural number using the function natify,

2488 making the algebraic laws unconditional;

2490 * ZF: as above, for int: operators coerce their operands to an integer

2491 using the function intify;

2493 * ZF: the integer library now contains many of the usual laws for the

2494 orderings, including $<=, and monotonicity laws for $+ and $*;

2496 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic

2497 simplification;

2499 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q

2500 to the simplifier and classical reasoner simultaneously;

2503 *** General ***

2505 * Provers: blast_tac now handles actual object-logic rules as

2506 assumptions; note that auto_tac uses blast_tac internally as well;

2508 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning

2509 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;

2511 * Provers: delrules now handles destruct rules as well (no longer need

2512 explicit make_elim);

2514 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.

2515 [| inj ?f; ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W

2516 use instead the strong form,

2517 [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W

2518 in HOL, FOL and ZF the function cla_make_elim will create such rules

2519 from destruct-rules;

2521 * Provers: Simplifier.easy_setup provides a fast path to basic

2522 Simplifier setup for new object-logics;

2524 * Pure: AST translation rules no longer require constant head on LHS;

2526 * Pure: improved name spaces: ambiguous output is qualified; support

2527 for hiding of names;

2529 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and

2530 XSYMBOL_HOME; no longer need to do manual configuration in most

2531 situations;

2533 * system: compression of ML heaps images may now be controlled via -c

2534 option of isabelle and isatool usedir (currently only observed by

2535 Poly/ML);

2537 * system: isatool installfonts may handle X-Symbol fonts as well (very

2538 useful for remote X11);

2540 * system: provide TAGS file for Isabelle sources;

2542 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument

2543 order;

2545 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global

2546 timing flag supersedes proof_timing and Toplevel.trace;

2548 * ML: new combinators |>> and |>>> for incremental transformations

2549 with secondary results (e.g. certain theory extensions):

2551 * ML: PureThy.add_defs gets additional argument to indicate potential

2552 overloading (usually false);

2554 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as

2555 results;

2559 New in Isabelle99 (October 1999)

2560 --------------------------------

2562 *** Overview of INCOMPATIBILITIES (see below for more details) ***

2564 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)

2565 are no longer simplified. (This allows the simplifier to unfold recursive

2566 functional programs.) To restore the old behaviour, declare

2568 Delcongs [if_weak_cong];

2570 * HOL: Removed the obsolete syntax "Compl A"; use -A for set

2571 complement;

2573 * HOL: the predicate "inj" is now defined by translation to "inj_on";

2575 * HOL/datatype: mutual_induct_tac no longer exists --

2576 use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]

2578 * HOL/typedef: fixed type inference for representing set; type

2579 arguments now have to occur explicitly on the rhs as type constraints;

2581 * ZF: The con_defs part of an inductive definition may no longer refer

2582 to constants declared in the same theory;

2584 * HOL, ZF: the function mk_cases, generated by the inductive

2585 definition package, has lost an argument. To simplify its result, it

2586 uses the default simpset instead of a supplied list of theorems.

2588 * HOL/List: the constructors of type list are now Nil and Cons;

2590 * Simplifier: the type of the infix ML functions

2591 setSSolver addSSolver setSolver addSolver

2592 is now simpset * solver -> simpset where `solver' is a new abstract type

2593 for packaging solvers. A solver is created via

2594 mk_solver: string -> (thm list -> int -> tactic) -> solver

2595 where the string argument is only a comment.

2598 *** Proof tools ***

2600 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a

2601 decision procedure for linear arithmetic. Currently it is used for

2602 types `nat', `int', and `real' in HOL (see below); it can, should and

2603 will be instantiated for other types and logics as well.

2605 * The simplifier now accepts rewrite rules with flexible heads, eg

2606 hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y

2607 They are applied like any rule with a non-pattern lhs, i.e. by first-order

2608 matching.

2611 *** General ***

2613 * New Isabelle/Isar subsystem provides an alternative to traditional

2614 tactical theorem proving; together with the ProofGeneral/isar user

2615 interface it offers an interactive environment for developing human

2616 readable proof documents (Isar == Intelligible semi-automated

2617 reasoning); for further information see isatool doc isar-ref,

2618 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/

2620 * improved and simplified presentation of theories: better HTML markup

2621 (including colors), graph views in several sizes; isatool usedir now

2622 provides a proper interface for user theories (via -P option); actual

2623 document preparation based on (PDF)LaTeX is available as well (for

2624 new-style theories only); see isatool doc system for more information;

2626 * native support for Proof General, both for classic Isabelle and

2627 Isabelle/Isar;

2629 * ML function thm_deps visualizes dependencies of theorems and lemmas,

2630 using the graph browser tool;

2632 * Isabelle manuals now also available as PDF;

2634 * theory loader rewritten from scratch (may not be fully

2635 bug-compatible); old loadpath variable has been replaced by show_path,

2636 add_path, del_path, reset_path functions; new operations such as

2637 update_thy, touch_thy, remove_thy, use/update_thy_only (see also

2638 isatool doc ref);

2640 * improved isatool install: option -k creates KDE application icon,

2641 option -p DIR installs standalone binaries;

2643 * added ML_PLATFORM setting (useful for cross-platform installations);

2644 more robust handling of platform specific ML images for SML/NJ;

2646 * the settings environment is now statically scoped, i.e. it is never

2647 created again in sub-processes invoked from isabelle, isatool, or

2648 Isabelle;

2650 * path element specification '~~' refers to '$ISABELLE_HOME';

2652 * in locales, the "assumes" and "defines" parts may be omitted if

2653 empty;

2655 * new print_mode "xsymbols" for extended symbol support (e.g. genuine

2656 long arrows);

2658 * new print_mode "HTML";

2660 * new flag show_tags controls display of tags of theorems (which are

2661 basically just comments that may be attached by some tools);

2663 * Isamode 2.6 requires patch to accomodate change of Isabelle font

2664 mode and goal output format:

2666 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el

2667 244c244

2668 < (list (isa-getenv "ISABELLE") "-msymbols" logic-name)

2669 ---

2670 > (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)

2671 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el

2672 181c181

2673 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"

2674 ---

2675 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"

2677 * function bind_thms stores lists of theorems (cf. bind_thm);

2679 * new shorthand tactics ftac, eatac, datac, fatac;

2681 * qed (and friends) now accept "" as result name; in that case the

2682 theorem is not stored, but proper checks and presentation of the

2683 result still apply;

2685 * theorem database now also indexes constants "Trueprop", "all",

2686 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;

2689 *** HOL ***

2691 ** HOL arithmetic **

2693 * There are now decision procedures for linear arithmetic over nat and

2694 int:

2696 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',

2697 `+', `-', `Suc', `min', `max' and numerical constants; other subterms

2698 are treated as atomic; subformulae not involving type `nat' or `int'

2699 are ignored; quantified subformulae are ignored unless they are

2700 positive universal or negative existential. The tactic has to be

2701 invoked by hand and can be a little bit slow. In particular, the

2702 running time is exponential in the number of occurrences of `min' and

2703 `max', and `-' on `nat'.

2705 2. fast_arith_tac is a cut-down version of arith_tac: it only takes

2706 (negated) (in)equalities among the premises and the conclusion into

2707 account (i.e. no compound formulae) and does not know about `min' and

2708 `max', and `-' on `nat'. It is fast and is used automatically by the

2709 simplifier.

2711 NB: At the moment, these decision procedures do not cope with mixed

2712 nat/int formulae where the two parts interact, such as `m < n ==>

2713 int(m) < int(n)'.

2715 * HOL/Numeral provides a generic theory of numerals (encoded

2716 efficiently as bit strings); setup for types nat/int/real is in place;

2717 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than

2718 int, existing theories and proof scripts may require a few additional

2719 type constraints;

2721 * integer division and remainder can now be performed on constant

2722 arguments;

2724 * many properties of integer multiplication, division and remainder

2725 are now available;

2727 * An interface to the Stanford Validity Checker (SVC) is available through the

2728 tactic svc_tac. Propositional tautologies and theorems of linear arithmetic

2729 are proved automatically. SVC must be installed separately, and its results

2730 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any

2731 invocation of the underlying oracle). For SVC see

2732 http://verify.stanford.edu/SVC

2734 * IsaMakefile: the HOL-Real target now builds an actual image;

2737 ** HOL misc **

2739 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces

2740 (in Isabelle/Isar) -- by Gertrud Bauer;

2742 * HOL/BCV: generic model of bytecode verification, i.e. data-flow

2743 analysis for assembly languages with subtypes;

2745 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization

2746 -- avoids syntactic ambiguities and treats state, transition, and

2747 temporal levels more uniformly; introduces INCOMPATIBILITIES due to

2748 changed syntax and (many) tactics;

2750 * HOL/inductive: Now also handles more general introduction rules such

2751 as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity

2752 theorems are now maintained within the theory (maintained via the

2753 "mono" attribute);

2755 * HOL/datatype: Now also handles arbitrarily branching datatypes

2756 (using function types) such as

2758 datatype 'a tree = Atom 'a | Branch "nat => 'a tree"

2760 * HOL/record: record_simproc (part of the default simpset) takes care

2761 of selectors applied to updated records; record_split_tac is no longer

2762 part of the default claset; update_defs may now be removed from the

2763 simpset in many cases; COMPATIBILITY: old behavior achieved by

2765 claset_ref () := claset() addSWrapper record_split_wrapper;

2766 Delsimprocs [record_simproc]

2768 * HOL/typedef: fixed type inference for representing set; type

2769 arguments now have to occur explicitly on the rhs as type constraints;

2771 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem

2772 names rather than an ML expression;

2774 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be

2775 supplied later. Program schemes can be defined, such as

2776 "While B C s = (if B s then While B C (C s) else s)"

2777 where the well-founded relation can be chosen after B and C have been given.

2779 * HOL/List: the constructors of type list are now Nil and Cons;

2780 INCOMPATIBILITY: while [] and infix # syntax is still there, of

2781 course, ML tools referring to List.list.op # etc. have to be adapted;

2783 * HOL_quantifiers flag superseded by "HOL" print mode, which is

2784 disabled by default; run isabelle with option -m HOL to get back to

2785 the original Gordon/HOL-style output;

2787 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,

2788 ALL x<=y. P, EX x<y. P, EX x<=y. P;

2790 * HOL basic syntax simplified (more orthogonal): all variants of

2791 All/Ex now support plain / symbolic / HOL notation; plain syntax for

2792 Eps operator is provided as well: "SOME x. P[x]";

2794 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;

2796 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made

2797 thus available for user theories;

2799 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with

2800 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the

2801 time;

2803 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec

2804 several times and then mp;

2807 *** LK ***

2809 * the notation <<...>> is now available as a notation for sequences of

2810 formulas;

2812 * the simplifier is now installed

2814 * the axiom system has been generalized (thanks to Soren Heilmann)

2816 * the classical reasoner now has a default rule database

2819 *** ZF ***

2821 * new primrec section allows primitive recursive functions to be given

2822 directly (as in HOL) over datatypes and the natural numbers;

2824 * new tactics induct_tac and exhaust_tac for induction (or case

2825 analysis) over datatypes and the natural numbers;

2827 * the datatype declaration of type T now defines the recursor T_rec;

2829 * simplification automatically does freeness reasoning for datatype

2830 constructors;

2832 * automatic type-inference, with AddTCs command to insert new

2833 type-checking rules;

2835 * datatype introduction rules are now added as Safe Introduction rules

2836 to the claset;

2838 * the syntax "if P then x else y" is now available in addition to

2839 if(P,x,y);

2842 *** Internal programming interfaces ***

2844 * tuned simplifier trace output; new flag debug_simp;

2846 * structures Vartab / Termtab (instances of TableFun) offer efficient

2847 tables indexed by indexname_ord / term_ord (compatible with aconv);

2849 * AxClass.axclass_tac lost the theory argument;

2851 * tuned current_goals_markers semantics: begin / end goal avoids

2852 printing empty lines;

2854 * removed prs and prs_fn hook, which was broken because it did not

2855 include \n in its semantics, forcing writeln to add one

2856 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:

2857 string -> unit if you really want to output text without newline;

2859 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to

2860 plain output, interface builders may have to enable 'isabelle_font'

2861 mode to get Isabelle font glyphs as before;

2863 * refined token_translation interface; INCOMPATIBILITY: output length

2864 now of type real instead of int;

2866 * theory loader actions may be traced via new ThyInfo.add_hook

2867 interface (see src/Pure/Thy/thy_info.ML); example application: keep

2868 your own database of information attached to *whole* theories -- as

2869 opposed to intra-theory data slots offered via TheoryDataFun;

2871 * proper handling of dangling sort hypotheses (at last!);

2872 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing

2873 extra sort hypotheses that can be witnessed from the type signature;

2874 the force_strip_shyps flag is gone, any remaining shyps are simply

2875 left in the theorem (with a warning issued by strip_shyps_warning);

2879 New in Isabelle98-1 (October 1998)

2880 ----------------------------------

2882 *** Overview of INCOMPATIBILITIES (see below for more details) ***

2884 * several changes of automated proof tools;

2886 * HOL: major changes to the inductive and datatype packages, including

2887 some minor incompatibilities of theory syntax;

2889 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now

2890 called `inj_on';

2892 * HOL: removed duplicate thms in Arith:

2893 less_imp_add_less should be replaced by trans_less_add1

2894 le_imp_add_le should be replaced by trans_le_add1

2896 * HOL: unary minus is now overloaded (new type constraints may be

2897 required);

2899 * HOL and ZF: unary minus for integers is now #- instead of #~. In

2900 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is

2901 now taken as an integer constant.

2903 * Pure: ML function 'theory_of' renamed to 'theory';

2906 *** Proof tools ***

2908 * Simplifier:

2909 1. Asm_full_simp_tac is now more aggressive.

2910 1. It will sometimes reorient premises if that increases their power to

2911 simplify.

2912 2. It does no longer proceed strictly from left to right but may also

2913 rotate premises to achieve further simplification.

2914 For compatibility reasons there is now Asm_lr_simp_tac which is like the

2915 old Asm_full_simp_tac in that it does not rotate premises.

2916 2. The simplifier now knows a little bit about nat-arithmetic.

2918 * Classical reasoner: wrapper mechanism for the classical reasoner now

2919 allows for selected deletion of wrappers, by introduction of names for

2920 wrapper functionals. This implies that addbefore, addSbefore,

2921 addaltern, and addSaltern now take a pair (name, tactic) as argument,

2922 and that adding two tactics with the same name overwrites the first

2923 one (emitting a warning).

2924 type wrapper = (int -> tactic) -> (int -> tactic)

2925 setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by

2926 addWrapper, addSWrapper: claset * (string * wrapper) -> claset

2927 delWrapper, delSWrapper: claset * string -> claset

2928 getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;

2930 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE

2931 semantics; addbefore now affects only the unsafe part of step_tac

2932 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY

2933 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac

2934 by Force_tac;

2936 * Classical reasoner: setwrapper to setWrapper and compwrapper to

2937 compWrapper; added safe wrapper (and access functions for it);

2939 * HOL/split_all_tac is now much faster and fails if there is nothing

2940 to split. Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order

2941 and the names of the automatically generated variables have changed.

2942 split_all_tac has moved within claset() from unsafe wrappers to safe

2943 wrappers, which means that !!-bound variables are split much more

2944 aggressively, and safe_tac and clarify_tac now split such variables.

2945 If this splitting is not appropriate, use delSWrapper "split_all_tac".

2946 Note: the same holds for record_split_tac, which does the job of

2947 split_all_tac for record fields.

2949 * HOL/Simplifier: Rewrite rules for case distinctions can now be added

2950 permanently to the default simpset using Addsplits just like

2951 Addsimps. They can be removed via Delsplits just like

2952 Delsimps. Lower-case versions are also available.

2954 * HOL/Simplifier: The rule split_if is now part of the default

2955 simpset. This means that the simplifier will eliminate all occurrences

2956 of if-then-else in the conclusion of a goal. To prevent this, you can

2957 either remove split_if completely from the default simpset by

2958 `Delsplits [split_if]' or remove it in a specific call of the

2959 simplifier using `... delsplits [split_if]'. You can also add/delete

2960 other case splitting rules to/from the default simpset: every datatype

2961 generates suitable rules `split_t_case' and `split_t_case_asm' (where

2962 t is the name of the datatype).

2964 * Classical reasoner / Simplifier combination: new force_tac (and

2965 derivatives Force_tac, force) combines rewriting and classical

2966 reasoning (and whatever other tools) similarly to auto_tac, but is

2967 aimed to solve the given subgoal completely.

2970 *** General ***

2972 * new top-level commands `Goal' and `Goalw' that improve upon `goal'

2973 and `goalw': the theory is no longer needed as an explicit argument -

2974 the current theory context is used; assumptions are no longer returned

2975 at the ML-level unless one of them starts with ==> or !!; it is

2976 recommended to convert to these new commands using isatool fixgoal

2977 (backup your sources first!);

2979 * new top-level commands 'thm' and 'thms' for retrieving theorems from

2980 the current theory context, and 'theory' to lookup stored theories;

2982 * new theory section 'locale' for declaring constants, assumptions and

2983 definitions that have local scope;

2985 * new theory section 'nonterminals' for purely syntactic types;

2987 * new theory section 'setup' for generic ML setup functions

2988 (e.g. package initialization);

2990 * the distribution now includes Isabelle icons: see

2991 lib/logo/isabelle-{small,tiny}.xpm;

2993 * isatool install - install binaries with absolute references to

2994 ISABELLE_HOME/bin;

2996 * isatool logo -- create instances of the Isabelle logo (as EPS);

2998 * print mode 'emacs' reserved for Isamode;

3000 * support multiple print (ast) translations per constant name;

3002 * theorems involving oracles are now printed with a suffixed [!];

3005 *** HOL ***

3007 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');

3009 * HOL/inductive package reorganized and improved: now supports mutual

3010 definitions such as

3012 inductive EVEN ODD

3013 intrs

3014 null "0 : EVEN"

3015 oddI "n : EVEN ==> Suc n : ODD"

3016 evenI "n : ODD ==> Suc n : EVEN"

3018 new theorem list "elims" contains an elimination rule for each of the

3019 recursive sets; inductive definitions now handle disjunctive premises

3020 correctly (also ZF);

3022 INCOMPATIBILITIES: requires Inductive as an ancestor; component

3023 "mutual_induct" no longer exists - the induction rule is always

3024 contained in "induct";

3027 * HOL/datatype package re-implemented and greatly improved: now

3028 supports mutually recursive datatypes such as

3030 datatype

3031 'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)

3032 | SUM ('a aexp) ('a aexp)

3033 | DIFF ('a aexp) ('a aexp)

3034 | NUM 'a

3035 and

3036 'a bexp = LESS ('a aexp) ('a aexp)

3037 | AND ('a bexp) ('a bexp)

3038 | OR ('a bexp) ('a bexp)

3040 as well as indirectly recursive datatypes such as

3042 datatype

3043 ('a, 'b) term = Var 'a

3044 | App 'b ((('a, 'b) term) list)

3046 The new tactic mutual_induct_tac [<var_1>, ..., <var_n>] i performs

3047 induction on mutually / indirectly recursive datatypes.

3049 Primrec equations are now stored in theory and can be accessed via

3050 <function_name>.simps.

3052 INCOMPATIBILITIES:

3054 - Theories using datatypes must now have theory Datatype as an

3055 ancestor.

3056 - The specific <typename>.induct_tac no longer exists - use the

3057 generic induct_tac instead.

3058 - natE has been renamed to nat.exhaust - use exhaust_tac

3059 instead of res_inst_tac ... natE. Note that the variable

3060 names in nat.exhaust differ from the names in natE, this

3061 may cause some "fragile" proofs to fail.

3062 - The theorems split_<typename>_case and split_<typename>_case_asm

3063 have been renamed to <typename>.split and <typename>.split_asm.

3064 - Since default sorts of type variables are now handled correctly,

3065 some datatype definitions may have to be annotated with explicit

3066 sort constraints.

3067 - Primrec definitions no longer require function name and type

3068 of recursive argument.

3070 Consider using isatool fixdatatype to adapt your theories and proof

3071 scripts to the new package (backup your sources first!).

3074 * HOL/record package: considerably improved implementation; now

3075 includes concrete syntax for record types, terms, updates; theorems

3076 for surjective pairing and splitting !!-bound record variables; proof

3077 support is as follows:

3079 1) standard conversions (selectors or updates applied to record

3080 constructor terms) are part of the standard simpset;

3082 2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are

3083 made part of standard simpset and claset via addIffs;

3085 3) a tactic for record field splitting (record_split_tac) is part of

3086 the standard claset (addSWrapper);

3088 To get a better idea about these rules you may retrieve them via

3089 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is

3090 the name of your record type.

3092 The split tactic 3) conceptually simplifies by the following rule:

3094 "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"

3096 Thus any record variable that is bound by meta-all will automatically

3097 blow up into some record constructor term, consequently the

3098 simplifications of 1), 2) apply. Thus force_tac, auto_tac etc. shall

3099 solve record problems automatically.

3102 * reorganized the main HOL image: HOL/Integ and String loaded by

3103 default; theory Main includes everything;

3105 * automatic simplification of integer sums and comparisons, using cancellation;

3107 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;

3109 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;

3111 * many new identities for unions, intersections, set difference, etc.;

3113 * expand_if, expand_split, expand_sum_case and expand_nat_case are now

3114 called split_if, split_split, split_sum_case and split_nat_case (to go

3115 with add/delsplits);

3117 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting

3118 (?x::unit) = (); this is made part of the default simpset, which COULD

3119 MAKE EXISTING PROOFS FAIL under rare circumstances (consider

3120 'Delsimprocs [unit_eq_proc];' as last resort); also note that

3121 unit_abs_eta_conv is added in order to counter the effect of

3122 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by

3123 %u.f();

3125 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which

3126 makes more sense);

3128 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;

3129 It and 'sym RS equals0D' are now in the default claset, giving automatic

3130 disjointness reasoning but breaking a few old proofs.

3132 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1

3133 to 'converse' from 'inverse' (for compatibility with ZF and some

3134 literature);

3136 * HOL/recdef can now declare non-recursive functions, with {} supplied as

3137 the well-founded relation;

3139 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of

3140 Compl A. The "Compl" syntax remains available as input syntax for this

3141 release ONLY.

3143 * HOL/Update: new theory of function updates:

3144 f(a:=b) == %x. if x=a then b else f x

3145 may also be iterated as in f(a:=b,c:=d,...);

3147 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;

3149 * HOL/List:

3150 - new function list_update written xs[i:=v] that updates the i-th

3151 list position. May also be iterated as in xs[i:=a,j:=b,...].

3152 - new function `upt' written [i..j(] which generates the list

3153 [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper

3154 bound write [i..j], which is a shorthand for [i..j+1(].

3155 - new lexicographic orderings and corresponding wellfoundedness theorems.

3157 * HOL/Arith:

3158 - removed 'pred' (predecessor) function;

3159 - generalized some theorems about n-1;

3160 - many new laws about "div" and "mod";

3161 - new laws about greatest common divisors (see theory ex/Primes);

3163 * HOL/Relation: renamed the relational operator r^-1 "converse"

3164 instead of "inverse";

3166 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness

3167 of the multiset ordering;

3169 * directory HOL/Real: a construction of the reals using Dedekind cuts

3170 (not included by default);

3172 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;

3174 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted

3175 programs, i.e. different program variables may have different types.

3177 * calling (stac rew i) now fails if "rew" has no effect on the goal

3178 [previously, this check worked only if the rewrite rule was unconditional]

3179 Now rew can involve either definitions or equalities (either == or =).

3182 *** ZF ***

3184 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains

3185 only the theorems proved on ZF.ML;

3187 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;

3188 It and 'sym RS equals0D' are now in the default claset, giving automatic

3189 disjointness reasoning but breaking a few old proofs.

3191 * ZF/Update: new theory of function updates

3192 with default rewrite rule f(x:=y) ` z = if(z=x, y, f`z)

3193 may also be iterated as in f(a:=b,c:=d,...);

3195 * in let x=t in u(x), neither t nor u(x) has to be an FOL term.

3197 * calling (stac rew i) now fails if "rew" has no effect on the goal

3198 [previously, this check worked only if the rewrite rule was unconditional]

3199 Now rew can involve either definitions or equalities (either == or =).

3201 * case_tac provided for compatibility with HOL

3202 (like the old excluded_middle_tac, but with subgoals swapped)

3205 *** Internal programming interfaces ***

3207 * Pure: several new basic modules made available for general use, see

3208 also src/Pure/README;

3210 * improved the theory data mechanism to support encapsulation (data

3211 kind name replaced by private Object.kind, acting as authorization

3212 key); new type-safe user interface via functor TheoryDataFun; generic

3213 print_data function becomes basically useless;

3215 * removed global_names compatibility flag -- all theory declarations

3216 are qualified by default;

3218 * module Pure/Syntax now offers quote / antiquote translation

3219 functions (useful for Hoare logic etc. with implicit dependencies);

3220 see HOL/ex/Antiquote for an example use;

3222 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->

3223 cterm -> thm;

3225 * new tactical CHANGED_GOAL for checking that a tactic modifies a

3226 subgoal;

3228 * Display.print_goals function moved to Locale.print_goals;

3230 * standard print function for goals supports current_goals_markers

3231 variable for marking begin of proof, end of proof, start of goal; the

3232 default is ("", "", ""); setting current_goals_markers := ("<proof>",

3233 "</proof>", "<goal>") causes SGML like tagged proof state printing,

3234 for example;

3238 New in Isabelle98 (January 1998)

3239 --------------------------------

3241 *** Overview of INCOMPATIBILITIES (see below for more details) ***

3243 * changed lexical syntax of terms / types: dots made part of long

3244 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";

3246 * simpset (and claset) reference variable replaced by functions

3247 simpset / simpset_ref;

3249 * no longer supports theory aliases (via merge) and non-trivial

3250 implicit merge of thms' signatures;

3252 * most internal names of constants changed due to qualified names;

3254 * changed Pure/Sequence interface (see Pure/seq.ML);

3257 *** General Changes ***

3259 * hierachically structured name spaces (for consts, types, axms, thms

3260 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of

3261 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:

3262 isatool fixdots ensures space after dots (e.g. "%x. x"); set

3263 long_names for fully qualified output names; NOTE: ML programs

3264 (special tactics, packages etc.) referring to internal names may have

3265 to be adapted to cope with fully qualified names; in case of severe

3266 backward campatibility problems try setting 'global_names' at compile

3267 time to have enrything declared within a flat name space; one may also

3268 fine tune name declarations in theories via the 'global' and 'local'

3269 section;

3271 * reimplemented the implicit simpset and claset using the new anytype

3272 data filed in signatures; references simpset:simpset ref etc. are

3273 replaced by functions simpset:unit->simpset and

3274 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp

3275 to patch your ML files accordingly;

3277 * HTML output now includes theory graph data for display with Java

3278 applet or isatool browser; data generated automatically via isatool

3279 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);

3281 * defs may now be conditional; improved rewrite_goals_tac to handle

3282 conditional equations;

3284 * defs now admits additional type arguments, using TYPE('a) syntax;

3286 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always

3287 creates a new theory node; implicit merge of thms' signatures is

3288 restricted to 'trivial' ones; COMPATIBILITY: one may have to use

3289 transfer:theory->thm->thm in (rare) cases;

3291 * improved handling of draft signatures / theories; draft thms (and

3292 ctyps, cterms) are automatically promoted to real ones;

3294 * slightly changed interfaces for oracles: admit many per theory, named

3295 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;

3297 * print_goals: optional output of const types (set show_consts and

3298 show_types);

3300 * improved output of warnings (###) and errors (***);

3302 * subgoal_tac displays a warning if the new subgoal has type variables;

3304 * removed old README and Makefiles;

3306 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;

3308 * removed obsolete init_pps and init_database;

3310 * deleted the obsolete tactical STATE, which was declared by

3311 fun STATE tacfun st = tacfun st st;

3313 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~

3314 (which abbreviates $HOME);

3316 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:

3317 use isatool fixseq to adapt your ML programs (this works for fully

3318 qualified references to the Sequence structure only!);

3320 * use_thy no longer requires writable current directory; it always

3321 reloads .ML *and* .thy file, if either one is out of date;

3324 *** Classical Reasoner ***

3326 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new

3327 tactics that use classical reasoning to simplify a subgoal without

3328 splitting it into several subgoals;

3330 * Safe_tac: like safe_tac but uses the default claset;

3333 *** Simplifier ***

3335 * added simplification meta rules:

3336 (asm_)(full_)simplify: simpset -> thm -> thm;

3338 * simplifier.ML no longer part of Pure -- has to be loaded by object

3339 logics (again);

3341 * added prems argument to simplification procedures;

3343 * HOL, FOL, ZF: added infix function `addsplits':

3344 instead of `<simpset> setloop (split_tac <thms>)'

3345 you can simply write `<simpset> addsplits <thms>'

3348 *** Syntax ***

3350 * TYPE('a) syntax for type reflection terms;

3352 * no longer handles consts with name "" -- declare as 'syntax' instead;

3354 * pretty printer: changed order of mixfix annotation preference (again!);

3356 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;

3359 *** HOL ***

3361 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.

3362 with `addloop' of the simplifier to faciliate case splitting in premises.

3364 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;

3366 * HOL/Auth: new protocol proofs including some for the Internet

3367 protocol TLS;

3369 * HOL/Map: new theory of `maps' a la VDM;

3371 * HOL/simplifier: simplification procedures nat_cancel_sums for

3372 cancelling out common nat summands from =, <, <= (in)equalities, or

3373 differences; simplification procedures nat_cancel_factor for

3374 cancelling common factor from =, <, <= (in)equalities over natural

3375 sums; nat_cancel contains both kinds of procedures, it is installed by

3376 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;

3378 * HOL/simplifier: terms of the form

3379 `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)' (or t=x)

3380 are rewritten to

3381 `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',

3382 and those of the form

3383 `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)' (or t=x)

3384 are rewritten to

3385 `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',

3387 * HOL/datatype

3388 Each datatype `t' now comes with a theorem `split_t_case' of the form

3390 P(t_case f1 ... fn x) =

3391 ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &

3392 ...

3393 (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))

3394 )

3396 and a theorem `split_t_case_asm' of the form

3398 P(t_case f1 ... fn x) =

3399 ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |

3400 ...

3401 (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))

3402 )

3403 which can be added to a simpset via `addsplits'. The existing theorems

3404 expand_list_case and expand_option_case have been renamed to

3405 split_list_case and split_option_case.

3407 * HOL/Arithmetic:

3408 - `pred n' is automatically converted to `n-1'.

3409 Users are strongly encouraged not to use `pred' any longer,

3410 because it will disappear altogether at some point.

3411 - Users are strongly encouraged to write "0 < n" rather than

3412 "n ~= 0". Theorems and proof tools have been modified towards this

3413 `standard'.

3415 * HOL/Lists:

3416 the function "set_of_list" has been renamed "set" (and its theorems too);

3417 the function "nth" now takes its arguments in the reverse order and

3418 has acquired the infix notation "!" as in "xs!n".

3420 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};

3422 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its

3423 specialist theorems (like UN1_I) are gone. Similarly for (INT x.B x);

3425 * HOL/record: extensible records with schematic structural subtyping

3426 (single inheritance); EXPERIMENTAL version demonstrating the encoding,

3427 still lacks various theorems and concrete record syntax;

3430 *** HOLCF ***

3432 * removed "axioms" and "generated by" sections;

3434 * replaced "ops" section by extended "consts" section, which is capable of

3435 handling the continuous function space "->" directly;

3437 * domain package:

3438 . proves theorems immediately and stores them in the theory,

3439 . creates hierachical name space,

3440 . now uses normal mixfix annotations (instead of cinfix...),

3441 . minor changes to some names and values (for consistency),

3442 . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,

3443 . separator between mutual domain defs: changed "," to "and",

3444 . improved handling of sort constraints; now they have to

3445 appear on the left-hand side of the equations only;

3447 * fixed LAM <x,y,zs>.b syntax;

3449 * added extended adm_tac to simplifier in HOLCF -- can now discharge

3450 adm (%x. P (t x)), where P is chainfinite and t continuous;

3453 *** FOL and ZF ***

3455 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.

3456 with `addloop' of the simplifier to faciliate case splitting in premises.

3458 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as

3459 in HOL, they strip ALL and --> from proved theorems;

3463 New in Isabelle94-8 (May 1997)

3464 ------------------------------

3466 *** General Changes ***

3468 * new utilities to build / run / maintain Isabelle etc. (in parts

3469 still somewhat experimental); old Makefiles etc. still functional;

3471 * new 'Isabelle System Manual';

3473 * INSTALL text, together with ./configure and ./build scripts;

3475 * reimplemented type inference for greater efficiency, better error

3476 messages and clean internal interface;

3478 * prlim command for dealing with lots of subgoals (an easier way of

3479 setting goals_limit);

3482 *** Syntax ***

3484 * supports alternative (named) syntax tables (parser and pretty

3485 printer); internal interface is provided by add_modesyntax(_i);

3487 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to

3488 be used in conjunction with the Isabelle symbol font; uses the

3489 "symbols" syntax table;

3491 * added token_translation interface (may translate name tokens in

3492 arbitrary ways, dependent on their type (free, bound, tfree, ...) and

3493 the current print_mode); IMPORTANT: user print translation functions

3494 are responsible for marking newly introduced bounds

3495 (Syntax.mark_boundT);

3497 * token translations for modes "xterm" and "xterm_color" that display

3498 names in bold, underline etc. or colors (which requires a color

3499 version of xterm);

3501 * infixes may now be declared with names independent of their syntax;

3503 * added typed_print_translation (like print_translation, but may

3504 access type of constant);

3507 *** Classical Reasoner ***

3509 Blast_tac: a new tactic! It is often more powerful than fast_tac, but has

3510 some limitations. Blast_tac...

3511 + ignores addss, addbefore, addafter; this restriction is intrinsic

3512 + ignores elimination rules that don't have the correct format

3513 (the conclusion MUST be a formula variable)

3514 + ignores types, which can make HOL proofs fail

3515 + rules must not require higher-order unification, e.g. apply_type in ZF

3516 [message "Function Var's argument not a bound variable" relates to this]

3517 + its proof strategy is more general but can actually be slower

3519 * substitution with equality assumptions no longer permutes other

3520 assumptions;

3522 * minor changes in semantics of addafter (now called addaltern); renamed

3523 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper

3524 (and access functions for it);

3526 * improved combination of classical reasoner and simplifier:

3527 + functions for handling clasimpsets

3528 + improvement of addss: now the simplifier is called _after_ the

3529 safe steps.

3530 + safe variant of addss called addSss: uses safe simplifications

3531 _during_ the safe steps. It is more complete as it allows multiple

3532 instantiations of unknowns (e.g. with slow_tac).

3534 *** Simplifier ***

3536 * added interface for simplification procedures (functions that

3537 produce *proven* rewrite rules on the fly, depending on current

3538 redex);

3540 * ordering on terms as parameter (used for ordered rewriting);

3542 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;

3544 * the solver is now split into a safe and an unsafe part.

3545 This should be invisible for the normal user, except that the

3546 functions setsolver and addsolver have been renamed to setSolver and

3547 addSolver; added safe_asm_full_simp_tac;

3550 *** HOL ***

3552 * a generic induction tactic `induct_tac' which works for all datatypes and

3553 also for type `nat';

3555 * a generic case distinction tactic `exhaust_tac' which works for all

3556 datatypes and also for type `nat';

3558 * each datatype comes with a function `size';

3560 * patterns in case expressions allow tuple patterns as arguments to

3561 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';

3563 * primrec now also works with type nat;

3565 * recdef: a new declaration form, allows general recursive functions to be

3566 defined in theory files. See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.

3568 * the constant for negation has been renamed from "not" to "Not" to

3569 harmonize with FOL, ZF, LK, etc.;

3571 * HOL/ex/LFilter theory of a corecursive "filter" functional for

3572 infinite lists;

3574 * HOL/Modelcheck demonstrates invocation of model checker oracle;

3576 * HOL/ex/Ring.thy declares cring_simp, which solves equational

3577 problems in commutative rings, using axiomatic type classes for + and *;

3579 * more examples in HOL/MiniML and HOL/Auth;

3581 * more default rewrite rules for quantifiers, union/intersection;

3583 * a new constant `arbitrary == @x.False';

3585 * HOLCF/IOA replaces old HOL/IOA;

3587 * HOLCF changes: derived all rules and arities

3588 + axiomatic type classes instead of classes

3589 + typedef instead of faking type definitions

3590 + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.

3591 + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po

3592 + eliminated the types void, one, tr

3593 + use unit lift and bool lift (with translations) instead of one and tr

3594 + eliminated blift from Lift3.thy (use Def instead of blift)

3595 all eliminated rules are derived as theorems --> no visible changes ;

3598 *** ZF ***

3600 * ZF now has Fast_tac, Simp_tac and Auto_tac. Union_iff is a now a default

3601 rewrite rule; this may affect some proofs. eq_cs is gone but can be put back

3602 as ZF_cs addSIs [equalityI];

3606 New in Isabelle94-7 (November 96)

3607 ---------------------------------

3609 * allowing negative levels (as offsets) in prlev and choplev;

3611 * super-linear speedup for large simplifications;

3613 * FOL, ZF and HOL now use miniscoping: rewriting pushes

3614 quantifications in as far as possible (COULD MAKE EXISTING PROOFS

3615 FAIL); can suppress it using the command Delsimps (ex_simps @

3616 all_simps); De Morgan laws are also now included, by default;

3618 * improved printing of ==> : ~:

3620 * new object-logic "Sequents" adds linear logic, while replacing LK

3621 and Modal (thanks to Sara Kalvala);

3623 * HOL/Auth: correctness proofs for authentication protocols;

3625 * HOL: new auto_tac combines rewriting and classical reasoning (many

3626 examples on HOL/Auth);

3628 * HOL: new command AddIffs for declaring theorems of the form P=Q to

3629 the rewriter and classical reasoner simultaneously;

3631 * function uresult no longer returns theorems in "standard" format;

3632 regain previous version by: val uresult = standard o uresult;

3636 New in Isabelle94-6

3637 -------------------

3639 * oracles -- these establish an interface between Isabelle and trusted

3640 external reasoners, which may deliver results as theorems;

3642 * proof objects (in particular record all uses of oracles);

3644 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;

3646 * "constdefs" section in theory files;

3648 * "primrec" section (HOL) no longer requires names;

3650 * internal type "tactic" now simply "thm -> thm Sequence.seq";

3654 New in Isabelle94-5

3655 -------------------

3657 * reduced space requirements;

3659 * automatic HTML generation from theories;

3661 * theory files no longer require "..." (quotes) around most types;

3663 * new examples, including two proofs of the Church-Rosser theorem;

3665 * non-curried (1994) version of HOL is no longer distributed;

3669 New in Isabelle94-4

3670 -------------------

3672 * greatly reduced space requirements;

3674 * theory files (.thy) no longer require \...\ escapes at line breaks;

3676 * searchable theorem database (see the section "Retrieving theorems" on

3677 page 8 of the Reference Manual);

3679 * new examples, including Grabczewski's monumental case study of the

3680 Axiom of Choice;

3682 * The previous version of HOL renamed to Old_HOL;

3684 * The new version of HOL (previously called CHOL) uses a curried syntax

3685 for functions. Application looks like f a b instead of f(a,b);

3687 * Mutually recursive inductive definitions finally work in HOL;

3689 * In ZF, pattern-matching on tuples is now available in all abstractions and

3690 translates to the operator "split";

3694 New in Isabelle94-3

3695 -------------------

3697 * new infix operator, addss, allowing the classical reasoner to

3698 perform simplification at each step of its search. Example:

3699 fast_tac (cs addss ss)

3701 * a new logic, CHOL, the same as HOL, but with a curried syntax

3702 for functions. Application looks like f a b instead of f(a,b). Also pairs

3703 look like (a,b) instead of <a,b>;

3705 * PLEASE NOTE: CHOL will eventually replace HOL!

3707 * In CHOL, pattern-matching on tuples is now available in all abstractions.

3708 It translates to the operator "split". A new theory of integers is available;

3710 * In ZF, integer numerals now denote two's-complement binary integers.

3711 Arithmetic operations can be performed by rewriting. See ZF/ex/Bin.ML;

3713 * Many new examples: I/O automata, Church-Rosser theorem, equivalents

3714 of the Axiom of Choice;

3718 New in Isabelle94-2

3719 -------------------

3721 * Significantly faster resolution;

3723 * the different sections in a .thy file can now be mixed and repeated

3724 freely;

3726 * Database of theorems for FOL, HOL and ZF. New

3727 commands including qed, qed_goal and bind_thm store theorems in the database.

3729 * Simple database queries: return a named theorem (get_thm) or all theorems of

3730 a given theory (thms_of), or find out what theory a theorem was proved in

3731 (theory_of_thm);

3733 * Bugs fixed in the inductive definition and datatype packages;

3735 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs

3736 and HOL_dup_cs obsolete;

3738 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1

3739 have been removed;

3741 * Simpler definition of function space in ZF;

3743 * new results about cardinal and ordinal arithmetic in ZF;

3745 * 'subtype' facility in HOL for introducing new types as subsets of existing

3746 types;

3749 $Id$