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NEWS

author | wenzelm |

Fri Jan 19 22:14:23 2007 +0100 (2007-01-19) | |

changeset 22125 | cc35c948f6c5 |

parent 21960 | 0574f192b78a |

child 22126 | 420b7b102acc |

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

tuned;

1 Isabelle NEWS -- history user-relevant changes

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

4 New in this Isabelle version

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 * Theory syntax: some popular names (e.g. "class", "fun", "help",

19 "if") are now keywords. INCOMPATIBILITY, use double quotes.

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

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

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

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

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

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

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

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

31 * The ``prems limit'' option (cf. ProofContext.prems_limit) is now -1

32 by default, which means that "prems" (and also "fixed variables") are

33 suppressed from proof state output. Note that the ProofGeneral

34 settings mechanism allows to change and save options persistently, but

35 older versions of Isabelle will fail to start up if a negative prems

36 limit is imposed.

38 * Local theory targets may be specified by non-nested blocks of

39 ``context/locale/class ... begin'' followed by ``end''. The body may

40 contain definitions, theorems etc., including any derived mechanism

41 that has been implemented on top of these primitives. This concept

42 generalizes the existing ``theorem (in ...)'' towards more versatility

43 and scalability.

45 * Proof General interface: proper undo of final 'end' command;

46 discontinued Isabelle/classic mode (ML proof scripts).

49 *** Document preparation ***

51 * Added antiquotation @{theory name} which prints the given name,

52 after checking that it refers to a valid ancestor theory in the

53 current context.

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

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

58 * Added antiquotation @{abbrev "c args"} which prints the abbreviation

59 "c args == rhs" given in the current context. (Any number of

60 arguments may be given on the LHS.)

64 *** Pure ***

66 * class_package.ML offers a combination of axclasses and locales to

67 achieve Haskell-like type classes in Isabelle. See

68 HOL/ex/Classpackage.thy for examples.

70 * Yet another code generator framework allows to generate executable

71 code for ML and Haskell (including "class"es). A short usage sketch:

73 internal compilation:

74 code_gen <list of constants (term syntax)> (SML #)

75 writing SML code to a file:

76 code_gen <list of constants (term syntax)> (SML <filename>)

77 writing Haskell code to a bunch of files:

78 code_gen <list of constants (term syntax)> (Haskell <filename>)

80 Reasonable default setup of framework in HOL/Main.

82 See HOL/ex/Code*.thy for examples.

84 Theorem attributs for selecting and transforming function equations theorems:

86 [code fun]: select a theorem as function equation for a specific constant

87 [code nofun]: deselect a theorem as function equation for a specific constant

88 [code inline]: select an equation theorem for unfolding (inlining) in place

89 [code noinline]: deselect an equation theorem for unfolding (inlining) in place

91 User-defined serializations (target in {SML, Haskell}):

93 code_const <and-list of constants (term syntax)>

94 {(target) <and-list of const target syntax>}+

96 code_type <and-list of type constructors>

97 {(target) <and-list of type target syntax>}+

99 code_instance <and-list of instances>

100 {(target)}+

101 where instance ::= <type constructor> :: <class>

103 code_class <and_list of classes>

104 {(target) <and-list of class target syntax>}+

105 where class target syntax ::= <class name> {where {<classop> == <target syntax>}+}?

107 For code_instance and code_class, target SML is silently ignored.

109 See HOL theories and HOL/ex/Code*.thy for usage examples. Doc/Isar/Advanced/Codegen/

110 provides a tutorial.

112 * Command 'no_translations' removes translation rules from theory

113 syntax.

115 * Overloaded definitions are now actually checked for acyclic

116 dependencies. The overloading scheme is slightly more general than

117 that of Haskell98, although Isabelle does not demand an exact

118 correspondence to type class and instance declarations.

119 INCOMPATIBILITY, use ``defs (unchecked overloaded)'' to admit more

120 exotic versions of overloading -- at the discretion of the user!

122 Polymorphic constants are represented via type arguments, i.e. the

123 instantiation that matches an instance against the most general

124 declaration given in the signature. For example, with the declaration

125 c :: 'a => 'a => 'a, an instance c :: nat => nat => nat is represented

126 as c(nat). Overloading is essentially simultaneous structural

127 recursion over such type arguments. Incomplete specification patterns

128 impose global constraints on all occurrences, e.g. c('a * 'a) on the

129 LHS means that more general c('a * 'b) will be disallowed on any RHS.

130 Command 'print_theory' outputs the normalized system of recursive

131 equations, see section "definitions".

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

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

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

137 then guess x and y by clarify

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

140 proof tools being involved here.

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

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

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

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

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

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

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

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

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

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

153 certain special cases of literal facts:

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

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

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

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

160 * Isar: ":" (colon) is no longer a symbolic identifier character in

161 outer syntax. Thus symbolic identifiers may be used without

162 additional white space in declarations like this: ``assume *: A''.

164 * Isar: 'print_facts' prints all local facts of the current context,

165 both named and unnamed ones.

167 * Isar: 'def' now admits simultaneous definitions, e.g.:

169 def x == "t" and y == "u"

171 * Isar: added command 'unfolding', which is structurally similar to

172 'using', but affects both the goal state and facts by unfolding given

173 rewrite rules. Thus many occurrences of the 'unfold' method or

174 'unfolded' attribute may be replaced by first-class proof text.

176 * Isar: methods 'unfold' / 'fold', attributes 'unfolded' / 'folded',

177 and command 'unfolding' now all support object-level equalities

178 (potentially conditional). The underlying notion of rewrite rule is

179 analogous to the 'rule_format' attribute, but *not* that of the

180 Simplifier (which is usually more generous).

182 * Isar: the goal restriction operator [N] (default N = 1) evaluates a

183 method expression within a sandbox consisting of the first N

184 sub-goals, which need to exist. For example, ``simp_all [3]''

185 simplifies the first three sub-goals, while (rule foo, simp_all)[]

186 simplifies all new goals that emerge from applying rule foo to the

187 originally first one.

189 * Isar: schematic goals are no longer restricted to higher-order

190 patterns; e.g. ``lemma "?P(?x)" by (rule TrueI)'' now works as

191 expected.

193 * Isar: the conclusion of a long theorem statement is now either

194 'shows' (a simultaneous conjunction, as before), or 'obtains'

195 (essentially a disjunction of cases with local parameters and

196 assumptions). The latter allows to express general elimination rules

197 adequately; in this notation common elimination rules look like this:

199 lemma exE: -- "EX x. P x ==> (!!x. P x ==> thesis) ==> thesis"

200 assumes "EX x. P x"

201 obtains x where "P x"

203 lemma conjE: -- "A & B ==> (A ==> B ==> thesis) ==> thesis"

204 assumes "A & B"

205 obtains A and B

207 lemma disjE: -- "A | B ==> (A ==> thesis) ==> (B ==> thesis) ==> thesis"

208 assumes "A | B"

209 obtains

210 A

211 | B

213 The subsequent classical rules even refer to the formal "thesis"

214 explicitly:

216 lemma classical: -- "(~ thesis ==> thesis) ==> thesis"

217 obtains "~ thesis"

219 lemma Peirce's_Law: -- "((thesis ==> something) ==> thesis) ==> thesis"

220 obtains "thesis ==> something"

222 The actual proof of an 'obtains' statement is analogous to that of the

223 Isar proof element 'obtain', only that there may be several cases.

224 Optional case names may be specified in parentheses; these will be

225 available both in the present proof and as annotations in the

226 resulting rule, for later use with the 'cases' method (cf. attribute

227 case_names).

229 * Isar: the assumptions of a long theorem statement are available as

230 "assms" fact in the proof context. This is more appropriate than the

231 (historical) "prems", which refers to all assumptions of the current

232 context, including those from the target locale, proof body etc.

234 * Isar: 'print_statement' prints theorems from the current theory or

235 proof context in long statement form, according to the syntax of a

236 top-level lemma.

238 * Isar: 'obtain' takes an optional case name for the local context

239 introduction rule (default "that").

241 * Isar: removed obsolete 'concl is' patterns. INCOMPATIBILITY, use

242 explicit (is "_ ==> ?foo") in the rare cases where this still happens

243 to occur.

245 * Pure: syntax "CONST name" produces a fully internalized constant

246 according to the current context. This is particularly useful for

247 syntax translations that should refer to internal constant

248 representations independently of name spaces.

250 * Pure: syntax constant for foo (binder "FOO ") is called "foo_binder"

251 instead of "FOO ". This allows multiple binder declarations to coexist

252 in the same context. INCOMPATIBILITY.

254 * Isar/locales: 'notation' provides a robust interface to the 'syntax'

255 primitive that also works in a locale context (both for constants and

256 fixed variables). Type declaration and internal syntactic

257 representation of given constants retrieved from the context.

259 * Isar/locales: new derived specification elements 'axiomatization',

260 'definition', 'abbreviation', which support type-inference, admit

261 object-level specifications (equality, equivalence). See also the

262 isar-ref manual. Examples:

264 axiomatization

265 eq (infix "===" 50) where

266 eq_refl: "x === x" and eq_subst: "x === y ==> P x ==> P y"

268 definition "f x y = x + y + 1"

269 definition g where "g x = f x x"

271 abbreviation

272 neq (infix "=!=" 50) where

273 "x =!= y == ~ (x === y)"

275 These specifications may be also used in a locale context. Then the

276 constants being introduced depend on certain fixed parameters, and the

277 constant name is qualified by the locale base name. An internal

278 abbreviation takes care for convenient input and output, making the

279 parameters implicit and using the original short name. See also

280 HOL/ex/Abstract_NAT.thy for an example of deriving polymorphic

281 entities from a monomorphic theory.

283 Presently, abbreviations are only available 'in' a target locale, but

284 not inherited by general import expressions. Also note that

285 'abbreviation' may be used as a type-safe replacement for 'syntax' +

286 'translations' in common applications.

288 Concrete syntax is attached to specified constants in internal form,

289 independently of name spaces. The parse tree representation is

290 slightly different -- use 'notation' instead of raw 'syntax', and

291 'translations' with explicit "CONST" markup to accommodate this.

293 * Pure: command 'print_abbrevs' prints all constant abbreviations of

294 the current context. Print mode "no_abbrevs" prevents inversion of

295 abbreviations on output.

297 * Isar/locales: improved parameter handling:

298 - use of locales "var" and "struct" no longer necessary;

299 - parameter renamings are no longer required to be injective.

300 This enables, for example, to define a locale for endomorphisms thus:

301 locale endom = homom mult mult h.

303 * Isar/locales: changed the way locales with predicates are defined.

304 Instead of accumulating the specification, the imported expression is

305 now an interpretation.

306 INCOMPATIBILITY: different normal form of locale expressions.

307 In particular, in interpretations of locales with predicates,

308 goals repesenting already interpreted fragments are not removed

309 automatically. Use methods `intro_locales' and `unfold_locales'; see below.

311 * Isar/locales: new methods `intro_locales' and `unfold_locales' provide

312 backward reasoning on locales predicates. The methods are aware of

313 interpretations and discharge corresponding goals. `intro_locales' is

314 less aggressive then `unfold_locales' and does not unfold predicates to

315 assumptions.

317 * Isar/locales: the order in which locale fragments are accumulated

318 has changed. This enables to override declarations from fragments

319 due to interpretations -- for example, unwanted simp rules.

321 * Provers/induct: improved internal context management to support

322 local fixes and defines on-the-fly. Thus explicit meta-level

323 connectives !! and ==> are rarely required anymore in inductive goals

324 (using object-logic connectives for this purpose has been long

325 obsolete anyway). The subsequent proof patterns illustrate advanced

326 techniques of natural induction; general datatypes and inductive sets

327 work analogously (see also src/HOL/Lambda for realistic examples).

329 (1) This is how to ``strengthen'' an inductive goal wrt. certain

330 parameters:

332 lemma

333 fixes n :: nat and x :: 'a

334 assumes a: "A n x"

335 shows "P n x"

336 using a -- {* make induct insert fact a *}

337 proof (induct n arbitrary: x) -- {* generalize goal to "!!x. A n x ==> P n x" *}

338 case 0

339 show ?case sorry

340 next

341 case (Suc n)

342 note `!!x. A n x ==> P n x` -- {* induction hypothesis, according to induction rule *}

343 note `A (Suc n) x` -- {* induction premise, stemming from fact a *}

344 show ?case sorry

345 qed

347 (2) This is how to perform induction over ``expressions of a certain

348 form'', using a locally defined inductive parameter n == "a x"

349 together with strengthening (the latter is usually required to get

350 sufficiently flexible induction hypotheses):

352 lemma

353 fixes a :: "'a => nat"

354 assumes a: "A (a x)"

355 shows "P (a x)"

356 using a

357 proof (induct n == "a x" arbitrary: x)

358 ...

360 See also HOL/Isar_examples/Puzzle.thy for an application of the this

361 particular technique.

363 (3) This is how to perform existential reasoning ('obtains' or

364 'obtain') by induction, while avoiding explicit object-logic

365 encodings:

367 lemma

368 fixes n :: nat

369 obtains x :: 'a where "P n x" and "Q n x"

370 proof (induct n arbitrary: thesis)

371 case 0

372 obtain x where "P 0 x" and "Q 0 x" sorry

373 then show thesis by (rule 0)

374 next

375 case (Suc n)

376 obtain x where "P n x" and "Q n x" by (rule Suc.hyps)

377 obtain x where "P (Suc n) x" and "Q (Suc n) x" sorry

378 then show thesis by (rule Suc.prems)

379 qed

381 Here the 'arbitrary: thesis' specification essentially modifies the

382 scope of the formal thesis parameter, in order to the get the whole

383 existence statement through the induction as expected.

385 * Provers/induct: mutual induction rules are now specified as a list

386 of rule sharing the same induction cases. HOL packages usually

387 provide foo_bar.inducts for mutually defined items foo and bar

388 (e.g. inductive sets or datatypes). INCOMPATIBILITY, users need to

389 specify mutual induction rules differently, i.e. like this:

391 (induct rule: foo_bar.inducts)

392 (induct set: foo bar)

393 (induct type: foo bar)

395 The ML function ProjectRule.projections turns old-style rules into the

396 new format.

398 * Provers/induct: improved handling of simultaneous goals. Instead of

399 introducing object-level conjunction, the statement is now split into

400 several conclusions, while the corresponding symbolic cases are

401 nested accordingly. INCOMPATIBILITY, proofs need to be structured

402 explicitly. For example:

404 lemma

405 fixes n :: nat

406 shows "P n" and "Q n"

407 proof (induct n)

408 case 0 case 1

409 show "P 0" sorry

410 next

411 case 0 case 2

412 show "Q 0" sorry

413 next

414 case (Suc n) case 1

415 note `P n` and `Q n`

416 show "P (Suc n)" sorry

417 next

418 case (Suc n) case 2

419 note `P n` and `Q n`

420 show "Q (Suc n)" sorry

421 qed

423 The split into subcases may be deferred as follows -- this is

424 particularly relevant for goal statements with local premises.

426 lemma

427 fixes n :: nat

428 shows "A n ==> P n" and "B n ==> Q n"

429 proof (induct n)

430 case 0

431 {

432 case 1

433 note `A 0`

434 show "P 0" sorry

435 next

436 case 2

437 note `B 0`

438 show "Q 0" sorry

439 }

440 next

441 case (Suc n)

442 note `A n ==> P n` and `B n ==> Q n`

443 {

444 case 1

445 note `A (Suc n)`

446 show "P (Suc n)" sorry

447 next

448 case 2

449 note `B (Suc n)`

450 show "Q (Suc n)" sorry

451 }

452 qed

454 If simultaneous goals are to be used with mutual rules, the statement

455 needs to be structured carefully as a two-level conjunction, using

456 lists of propositions separated by 'and':

458 lemma

459 shows "a : A ==> P1 a"

460 "a : A ==> P2 a"

461 and "b : B ==> Q1 b"

462 "b : B ==> Q2 b"

463 "b : B ==> Q3 b"

464 proof (induct set: A B)

466 * Provers/induct: support coinduction as well. See

467 src/HOL/Library/Coinductive_List.thy for various examples.

469 * Attribute "symmetric" produces result with standardized schematic

470 variables (index 0). Potential INCOMPATIBILITY.

472 * Simplifier: by default the simplifier trace only shows top level rewrites

473 now. That is, trace_simp_depth_limit is set to 1 by default. Thus there is

474 less danger of being flooded by the trace. The trace indicates where parts

475 have been suppressed.

477 * Provers/classical: removed obsolete classical version of elim_format

478 attribute; classical elim/dest rules are now treated uniformly when

479 manipulating the claset.

481 * Provers/classical: stricter checks to ensure that supplied intro,

482 dest and elim rules are well-formed; dest and elim rules must have at

483 least one premise.

485 * Provers/classical: attributes dest/elim/intro take an optional

486 weight argument for the rule (just as the Pure versions). Weights are

487 ignored by automated tools, but determine the search order of single

488 rule steps.

490 * Syntax: input syntax now supports dummy variable binding "%_. b",

491 where the body does not mention the bound variable. Note that dummy

492 patterns implicitly depend on their context of bounds, which makes

493 "{_. _}" match any set comprehension as expected. Potential

494 INCOMPATIBILITY -- parse translations need to cope with syntactic

495 constant "_idtdummy" in the binding position.

497 * Syntax: removed obsolete syntactic constant "_K" and its associated

498 parse translation. INCOMPATIBILITY -- use dummy abstraction instead,

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

501 * Pure: 'class_deps' command visualizes the subclass relation, using

502 the graph browser tool.

504 * Pure: 'print_theory' now suppresses entities with internal name

505 (trailing "_") by default; use '!' option for full details.

508 *** HOL ***

510 * New syntactic class "size"; overloaded constant "size" now

511 has type "'a::size ==> bool"

513 * Constants "Divides.op div", "Divides.op mod" and "Divides.op dvd" no named

514 "Divides.div", "Divides.mod" and "Divides.dvd"

515 INCOMPATIBILITY for ML code directly refering to constant names.

517 * Replaced "auto_term" by the conceptually simpler method "relation",

518 which just applies the instantiated termination rule with no further

519 simplifications.

520 INCOMPATIBILITY:

521 Replace

522 termination by (auto_term "MYREL")

523 with

524 termination by (relation "MYREL") auto

526 * Automated termination proofs "by lexicographic_order" are now

527 included in the abbreviated function command "fun". No explicit

528 "termination" command is necessary anymore.

529 INCOMPATIBILITY: If a "fun"-definition cannot be proved terminating by

530 a lexicographic size order, then the command fails. Use the expanded

531 version "function" for these cases.

533 * New method "lexicographic_order" automatically synthesizes

534 termination relations as lexicographic combinations of size measures.

535 Usage for (function package) termination proofs:

537 termination

538 by lexicographic_order

540 * Records: generalised field-update to take a function on the field

541 rather than the new value: r(|A := x|) is translated to A_update (K x) r

542 The K-combinator that is internally used is called K_record.

543 INCOMPATIBILITY: Usage of the plain update functions has to be

544 adapted.

546 * axclass "semiring_0" now contains annihilation axioms

547 ("x * 0 = 0","0 * x = 0"), which are required for a semiring. Richer

548 structures do not inherit from semiring_0 anymore, because this property

549 is a theorem there, not an axiom.

550 INCOMPATIBILITY: In instances of semiring_0, there is more to prove, but

551 this is mostly trivial.

553 * axclass "recpower" was generalized to arbitrary monoids, not just

554 commutative semirings.

555 INCOMPATIBILITY: If you use recpower and need commutativity or a semiring

556 property, add the corresponding classes.

558 * Locale Lattic_Locales.partial_order changed (to achieve consistency with

559 axclass order):

560 - moved to Orderings.partial_order

561 - additional parameter ``less''

562 INCOMPATIBILITY.

564 * Constant "List.list_all2" in List.thy now uses authentic syntax.

565 INCOMPATIBILITY: translations containing list_all2 may go wrong. On Isar

566 level, use abbreviations instead.

568 * Constant "List.op mem" in List.thy now has proper name: "List.memberl"

569 INCOMPATIBILITY: rarely occuring name references (e.g. ``List.op mem.simps'')

570 require renaming (e.g. ``List.memberl.simps'').

572 * Renamed constants in HOL.thy:

573 0 ~> HOL.zero

574 1 ~> HOL.one

575 INCOMPATIBILITY: ML code directly refering to constant names may need adaption

576 This in general only affects hand-written proof tactics, simprocs and so on.

578 * New theory Code_Generator providing class 'eq',

579 allowing for code generation with polymorphic equality.

581 * Numeral syntax: type 'bin' which was a mere type copy of 'int' has been

582 abandoned in favour of plain 'int'. INCOMPATIBILITY -- Significant changes

583 for setting up numeral syntax for types:

585 - new constants Numeral.pred and Numeral.succ instead

586 of former Numeral.bin_pred and Numeral.bin_succ.

587 - Use integer operations instead of bin_add, bin_mult and so on.

588 - Numeral simplification theorems named Numeral.numeral_simps instead of Bin_simps.

589 - ML structure Bin_Simprocs now named Int_Numeral_Base_Simprocs.

591 See HOL/Integ/IntArith.thy for an example setup.

593 * New top level command 'normal_form' computes the normal form of a term

594 that may contain free variables. For example 'normal_form "rev[a,b,c]"'

595 prints '[b,c,a]'. This command is suitable for heavy-duty computations

596 because the functions are compiled to ML first.

597 INCOMPATIBILITY: new keywords 'normal_form' must quoted when used as

598 an identifier.

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

601 25 like -->); output depends on the "iff" print_mode, the default is

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

604 * Renamed constants in HOL.thy and Orderings.thy:

605 op + ~> HOL.plus

606 op - ~> HOL.minus

607 uminus ~> HOL.uminus

608 op * ~> HOL.times

609 op < ~> Orderings.less

610 op <= ~> Orderings.less_eq

612 Adaptions may be required in the following cases:

614 a) User-defined constants using any of the names "plus", "minus", "times",

615 "less" or "less_eq". The standard syntax translations for "+", "-" and "*"

616 may go wrong.

617 INCOMPATIBILITY: use more specific names.

619 b) Variables named "plus", "minus", "times", "less", "less_eq"

620 INCOMPATIBILITY: use more specific names.

622 c) Permutative equations (e.g. "a + b = b + a")

623 Since the change of names also changes the order of terms, permutative

624 rewrite rules may get applied in a different order. Experience shows that

625 this is rarely the case (only two adaptions in the whole Isabelle

626 distribution).

627 INCOMPATIBILITY: rewrite proofs

629 d) ML code directly refering to constant names

630 This in general only affects hand-written proof tactics, simprocs and so on.

631 INCOMPATIBILITY: grep your sourcecode and replace names.

633 * Relations less (<) and less_eq (<=) are also available on type bool.

634 Modified syntax to disallow nesting without explicit parentheses,

635 e.g. "(x < y) < z" or "x < (y < z)", but NOT "x < y < z".

637 * "LEAST x:A. P" expands to "LEAST x. x:A & P" (input only).

639 * Relation composition operator "op O" now has precedence 75 and binds

640 stronger than union and intersection. INCOMPATIBILITY.

642 * The old set interval syntax "{m..n(}" (and relatives) has been removed.

643 Use "{m..<n}" (and relatives) instead.

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

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

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

649 * "m dvd n" where m and n are numbers is evaluated to True/False by simp.

651 * Theorem Cons_eq_map_conv no longer has attribute `simp'.

653 * Theorem setsum_mult renamed to setsum_right_distrib.

655 * Prefer ex1I over ex_ex1I in single-step reasoning, e.g. by the

656 'rule' method.

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

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

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

661 are no longer reserved, significant speedup.

663 * Tactics 'sat' and 'satx' can now replay MiniSat proof traces. zChaff is

664 still supported as well.

666 * inductive and datatype: provide projections of mutual rules, bundled

667 as foo_bar.inducts;

669 * Library: moved theories Parity, GCD, Binomial, Infinite_Set to Library.

671 * Library: moved theory Accessible_Part to main HOL.

673 * Library: added theory Coinductive_List of potentially infinite lists

674 as greatest fixed-point.

676 * Library: added theory AssocList which implements (finite) maps as

677 association lists.

679 * New proof method "evaluation" for efficiently solving a goal (i.e. a

680 boolean expression) by compiling it to ML. The goal is "proved" (via

681 the oracle "Evaluation") if it evaluates to True.

683 * Linear arithmetic now splits certain operators (e.g. min, max, abs)

684 also when invoked by the simplifier. This results in the simplifier

685 being more powerful on arithmetic goals. INCOMPATIBILITY. Set

686 fast_arith_split_limit to 0 to obtain the old behavior.

688 * Support for hex (0x20) and binary (0b1001) numerals.

690 * New method: reify eqs (t), where eqs are equations for an

691 interpretation I :: 'a list => 'b => 'c and t::'c is an optional

692 parameter, computes a term s::'b and a list xs::'a list and proves the

693 theorem I xs s = t. This is also known as reification or quoting. The

694 resulting theorem is applied to the subgoal to substitute t with I xs

695 s. If t is omitted, the subgoal itself is reified.

697 * New method: reflection corr_thm eqs (t). The parameters eqs and (t)

698 are as explained above. corr_thm is a theorem for I vs (f t) = I vs t,

699 where f is supposed to be a computable function (in the sense of code

700 generattion). The method uses reify to compute s and xs as above then

701 applies corr_thm and uses normalization by evaluation to "prove" f s =

702 r and finally gets the theorem t = r, which is again applied to the

703 subgoal. An Example is available in HOL/ex/ReflectionEx.thy.

705 * Reflection: Automatic refification now handels binding, an example

706 is available in HOL/ex/ReflectionEx.thy

709 *** HOL-Algebra ***

711 * Formalisation of ideals and the quotient construction over rings.

713 * Order and lattice theory no longer based on records.

714 INCOMPATIBILITY.

716 * Renamed lemmas least_carrier -> least_closed and

717 greatest_carrier -> greatest_closed. INCOMPATIBILITY.

719 * Method algebra is now set up via an attribute. For examples see

720 Ring.thy. INCOMPATIBILITY: the method is now weaker on combinations

721 of algebraic structures.

723 * Renamed `CRing.thy' to `Ring.thy'. INCOMPATIBILITY.

726 *** HOL-Complex ***

728 * Theory Real: new method ferrack implements quantifier elimination

729 for linear arithmetic over the reals. The quantifier elimination

730 feature is used only for decision, for compatibility with arith. This

731 means a goal is either solved or left unchanged, no simplification.

733 * Real: New axiomatic classes formalize real normed vector spaces and

734 algebras, using new overloaded constants scaleR :: real => 'a => 'a

735 and norm :: 'a => real.

737 * Real: New constant of_real :: real => 'a::real_algebra_1 injects from

738 reals into other types. The overloaded constant Reals :: 'a set is now

739 defined as range of_real; potential INCOMPATIBILITY.

741 * Hyperreal: Several constants that previously worked only for the reals

742 have been generalized, so they now work over arbitrary vector spaces. Type

743 annotations may need to be added in some cases; potential INCOMPATIBILITY.

745 Infinitesimal :: ('a::real_normed_vector) star set"

746 HFinite :: ('a::real_normed_vector) star set"

747 HInfinite :: ('a::real_normed_vector) star set"

748 approx :: ('a::real_normed_vector) star => 'a star => bool

749 monad :: ('a::real_normed_vector) star => 'a star set

750 galaxy :: ('a::real_normed_vector) star => 'a star set

751 (NS)LIMSEQ :: [nat, 'a::real_normed_vector, 'a] => bool

752 (NS)convergent :: (nat => 'a::real_normed_vector) => bool

753 (NS)Bseq :: (nat => 'a::real_normed_vector) => bool

754 (NS)Cauchy :: (nat => 'a::real_normed_vector) => bool

755 (NS)LIM :: ['a::real_normed_vector => 'b::real_normed_vector, 'a, 'b] => bool

756 is(NS)Cont :: ['a::real_normed_vector => 'b::real_normed_vector, 'a] => bool

757 deriv :: ['a::real_normed_field => 'a, 'a, 'a] => bool

759 * Complex: Some complex-specific constants are now abbreviations for

760 overloaded ones: complex_of_real = of_real, cmod = norm, hcmod = hnorm.

761 Other constants have been entirely removed in favor of the polymorphic

762 versions (INCOMPATIBILITY):

764 approx <-- capprox

765 HFinite <-- CFinite

766 HInfinite <-- CInfinite

767 Infinitesimal <-- CInfinitesimal

768 monad <-- cmonad

769 galaxy <-- cgalaxy

770 (NS)LIM <-- (NS)CLIM, (NS)CRLIM

771 is(NS)Cont <-- is(NS)Contc, is(NS)contCR

772 (ns)deriv <-- (ns)cderiv

775 *** ML ***

777 * Pure/table:

779 Function `...tab.foldl` removed.

780 INCOMPATIBILITY: use `...tabfold` instead

782 * Pure/library:

784 `gen_rem(s)` abandoned in favour of `remove` / `subtract`.

785 INCOMPATIBILITY:

786 rewrite "gen_rem eq (xs, x)" to "remove (eq o swap) x xs"

787 rewrite "gen_rems eq (xs, ys)" to "subtract (eq o swap) ys xs"

788 drop "swap" if "eq" is symmetric.

790 * Pure/library:

792 infixes `ins` `ins_string` `ins_int` have been abandoned in favour of `insert`.

793 INCOMPATIBILITY: rewrite "x ins(_...) xs" to "insert (op =) x xs"

795 * Pure/General/susp.ML:

797 New module for delayed evaluations.

799 * Pure/library:

801 Semantically identical functions "equal_list" and "eq_list" have been

802 unified to "eq_list".

804 * Pure/library:

806 val burrow: ('a list -> 'b list) -> 'a list list -> 'b list list

807 val fold_burrow: ('a list -> 'c -> 'b list * 'd) -> 'a list list -> 'c -> 'b list list * 'd

809 The semantics of "burrow" is: "take a function with *simulatanously*

810 transforms a list of value, and apply it *simulatanously* to a list of

811 list of values of the appropriate type". Confer this with "map" which

812 would *not* apply its argument function simulatanously but in

813 sequence. "fold_burrow" has an additional context.

815 Both actually avoid the usage of "unflat" since they hide away

816 "unflat" from the user.

818 * Pure/library: functions map2 and fold2 with curried syntax for

819 simultanous mapping and folding:

821 val map2: ('a -> 'b -> 'c) -> 'a list -> 'b list -> 'c list

822 val fold2: ('a -> 'b -> 'c -> 'c) -> 'a list -> 'b list -> 'c -> 'c

824 * Pure/library: indexed lists - some functions in the Isabelle library

825 treating lists over 'a as finite mappings from [0...n] to 'a have been

826 given more convenient names and signatures reminiscent of similar

827 functions for alists, tables, etc:

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

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

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

833 Note that fold_index starts counting at index 0, not 1 like foldln

834 used to.

836 * Pure/library: general ``divide_and_conquer'' combinator on lists.

838 * Pure/General/name_mangler.ML provides a functor for generic name

839 mangling (bijective mapping from expression values to strings).

841 * Pure/General/rat.ML implements rational numbers.

843 * Pure/General/table.ML: the join operations now works via exceptions

844 DUP/SAME instead of type option. This is simpler in simple cases, and

845 admits slightly more efficient complex applications.

847 * Pure: datatype Context.generic joins theory/Proof.context and

848 provides some facilities for code that works in either kind of

849 context, notably GenericDataFun for uniform theory and proof data.

851 * Pure: 'advanced' translation functions (parse_translation etc.) now

852 use Context.generic instead of just theory.

854 * Pure: simplified internal attribute type, which is now always

855 Context.generic * thm -> Context.generic * thm. Global (theory)

856 vs. local (Proof.context) attributes have been discontinued, while

857 minimizing code duplication. Thm.rule_attribute and

858 Thm.declaration_attribute build canonical attributes; see also

859 structure Context for further operations on Context.generic, notably

860 GenericDataFun. INCOMPATIBILITY, need to adapt attribute type

861 declarations and definitions.

863 * Pure/kernel: consts certification ignores sort constraints given in

864 signature declarations. (This information is not relevant to the

865 logic, but only for type inference.) IMPORTANT INTERNAL CHANGE.

867 * Pure: axiomatic type classes are now purely definitional, with

868 explicit proofs of class axioms and super class relations performed

869 internally. See Pure/axclass.ML for the main internal interfaces --

870 notably AxClass.define_class supercedes AxClass.add_axclass, and

871 AxClass.axiomatize_class/classrel/arity supercede

872 Sign.add_classes/classrel/arities.

874 * Pure/Isar: Args/Attrib parsers operate on Context.generic --

875 global/local versions on theory vs. Proof.context have been

876 discontinued; Attrib.syntax and Method.syntax have been adapted

877 accordingly. INCOMPATIBILITY, need to adapt parser expressions for

878 attributes, methods, etc.

880 * Pure: several functions of signature "... -> theory -> theory * ..."

881 have been reoriented to "... -> theory -> ... * theory" in order to

882 allow natural usage in combination with the ||>, ||>>, |-> and

883 fold_map combinators.

885 * Pure: official theorem names (closed derivations) and additional

886 comments (tags) are now strictly separate. Name hints -- which are

887 maintained as tags -- may be attached any time without affecting the

888 derivation.

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

891 actual goal state (thm). Use Thm.lift_rule (Thm.cprem_of st i) to

892 achieve the old behaviour.

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

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

896 statements.

898 * Pure: Logic.(un)varify only works in a global context, which is now

899 enforced instead of silently assumed. INCOMPATIBILITY, may use

900 Logic.legacy_(un)varify as temporary workaround.

902 * Pure: structure Name provides scalable operations for generating

903 internal variable names, notably Name.variants etc. This replaces

904 some popular functions from term.ML:

906 Term.variant -> Name.variant

907 Term.variantlist -> Name.variant_list (*canonical argument order*)

908 Term.invent_names -> Name.invent_list

910 Note that low-level renaming rarely occurs in new code -- operations

911 from structure Variable are used instead (see below).

913 * Pure: structure Variable provides fundamental operations for proper

914 treatment of fixed/schematic variables in a context. For example,

915 Variable.import introduces fixes for schematics of given facts and

916 Variable.export reverses the effect (up to renaming) -- this replaces

917 various freeze_thaw operations.

919 * Pure: structure Goal provides simple interfaces for

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

921 Tactic.prove). Goal.prove is the canonical way to prove results

922 within a given context; Goal.prove_global is a degraded version for

923 theory level goals, including a global Drule.standard. Note that

924 OldGoals.prove_goalw_cterm has long been obsolete, since it is

925 ill-behaved in a local proof context (e.g. with local fixes/assumes or

926 in a locale context).

928 * Isar: simplified treatment of user-level errors, using exception

929 ERROR of string uniformly. Function error now merely raises ERROR,

930 without any side effect on output channels. The Isar toplevel takes

931 care of proper display of ERROR exceptions. ML code may use plain

932 handle/can/try; cat_error may be used to concatenate errors like this:

934 ... handle ERROR msg => cat_error msg "..."

936 Toplevel ML code (run directly or through the Isar toplevel) may be

937 embedded into the Isar toplevel with exception display/debug like

938 this:

940 Isar.toplevel (fn () => ...)

942 INCOMPATIBILITY, removed special transform_error facilities, removed

943 obsolete variants of user-level exceptions (ERROR_MESSAGE,

944 Context.PROOF, ProofContext.CONTEXT, Proof.STATE, ProofHistory.FAIL)

945 -- use plain ERROR instead.

947 * Isar: theory setup now has type (theory -> theory), instead of a

948 list. INCOMPATIBILITY, may use #> to compose setup functions.

950 * Isar: installed ML toplevel pretty printer for type Proof.context,

951 subject to ProofContext.debug/verbose flags.

953 * Isar: Toplevel.theory_to_proof admits transactions that modify the

954 theory before entering a proof state. Transactions now always see a

955 quasi-functional intermediate checkpoint, both in interactive and

956 batch mode.

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

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

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

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

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

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

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

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

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

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

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

971 * Simplifier/Classical Reasoner: more abstract interfaces

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

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

974 INCOMPATIBILITY.

976 * Provers: more generic wrt. syntax of object-logics, avoid hardwired

977 "Trueprop" etc.

980 *** System ***

982 * settings: ML_IDENTIFIER -- which is appended to user specific heap

983 locations -- now includes the Isabelle version identifier as well.

984 This simplifies use of multiple Isabelle installations.

986 * isabelle-process: option -S (secure mode) disables some critical

987 operations, notably runtime compilation and evaluation of ML source

988 code.

991 New in Isabelle2005 (October 2005)

992 ----------------------------------

994 *** General ***

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

998 theory <name>

999 imports <theory1> ... <theoryN>

1000 uses <file1> ... <fileM>

1001 begin

1003 where the 'uses' part is optional. The previous syntax

1005 theory <name> = <theory1> + ... + <theoryN>:

1007 will disappear in the next release. Use isatool fixheaders to convert

1008 existing theory files. Note that there is no change in ancient

1009 non-Isar theories now, but these will disappear soon.

1011 * Theory loader: parent theories can now also be referred to via

1012 relative and absolute paths.

1014 * Command 'find_theorems' searches for a list of criteria instead of a

1015 list of constants. Known criteria are: intro, elim, dest, name:string,

1016 simp:term, and any term. Criteria can be preceded by '-' to select

1017 theorems that do not match. Intro, elim, dest select theorems that

1018 match the current goal, name:s selects theorems whose fully qualified

1019 name contain s, and simp:term selects all simplification rules whose

1020 lhs match term. Any other term is interpreted as pattern and selects

1021 all theorems matching the pattern. Available in ProofGeneral under

1022 'ProofGeneral -> Find Theorems' or C-c C-f. Example:

1024 C-c C-f (100) "(_::nat) + _ + _" intro -name: "HOL."

1026 prints the last 100 theorems matching the pattern "(_::nat) + _ + _",

1027 matching the current goal as introduction rule and not having "HOL."

1028 in their name (i.e. not being defined in theory HOL).

1030 * Command 'thms_containing' has been discontinued in favour of

1031 'find_theorems'; INCOMPATIBILITY.

1033 * Communication with Proof General is now 8bit clean, which means that

1034 Unicode text in UTF-8 encoding may be used within theory texts (both

1035 formal and informal parts). Cf. option -U of the Isabelle Proof

1036 General interface. Here are some simple examples (cf. src/HOL/ex):

1038 http://isabelle.in.tum.de/library/HOL/ex/Hebrew.html

1039 http://isabelle.in.tum.de/library/HOL/ex/Chinese.html

1041 * Improved efficiency of the Simplifier and, to a lesser degree, the

1042 Classical Reasoner. Typical big applications run around 2 times

1043 faster.

1046 *** Document preparation ***

1048 * Commands 'display_drafts' and 'print_drafts' perform simple output

1049 of raw sources. Only those symbols that do not require additional

1050 LaTeX packages (depending on comments in isabellesym.sty) are

1051 displayed properly, everything else is left verbatim. isatool display

1052 and isatool print are used as front ends (these are subject to the

1053 DVI/PDF_VIEWER and PRINT_COMMAND settings, respectively).

1055 * Command tags control specific markup of certain regions of text,

1056 notably folding and hiding. Predefined tags include "theory" (for

1057 theory begin and end), "proof" for proof commands, and "ML" for

1058 commands involving ML code; the additional tags "visible" and

1059 "invisible" are unused by default. Users may give explicit tag

1060 specifications in the text, e.g. ''by %invisible (auto)''. The

1061 interpretation of tags is determined by the LaTeX job during document

1062 preparation: see option -V of isatool usedir, or options -n and -t of

1063 isatool document, or even the LaTeX macros \isakeeptag, \isafoldtag,

1064 \isadroptag.

1066 Several document versions may be produced at the same time via isatool

1067 usedir (the generated index.html will link all of them). Typical

1068 specifications include ''-V document=theory,proof,ML'' to present

1069 theory/proof/ML parts faithfully, ''-V outline=/proof,/ML'' to fold

1070 proof and ML commands, and ''-V mutilated=-theory,-proof,-ML'' to omit

1071 these parts without any formal replacement text. The Isabelle site

1072 default settings produce ''document'' and ''outline'' versions as

1073 specified above.

1075 * Several new antiquotations:

1077 @{term_type term} prints a term with its type annotated;

1079 @{typeof term} prints the type of a term;

1081 @{const const} is the same as @{term const}, but checks that the

1082 argument is a known logical constant;

1084 @{term_style style term} and @{thm_style style thm} print a term or

1085 theorem applying a "style" to it

1087 @{ML text}

1089 Predefined styles are 'lhs' and 'rhs' printing the lhs/rhs of

1090 definitions, equations, inequations etc., 'concl' printing only the

1091 conclusion of a meta-logical statement theorem, and 'prem1' .. 'prem19'

1092 to print the specified premise. TermStyle.add_style provides an ML

1093 interface for introducing further styles. See also the "LaTeX Sugar"

1094 document practical applications. The ML antiquotation prints

1095 type-checked ML expressions verbatim.

1097 * Markup commands 'chapter', 'section', 'subsection', 'subsubsection',

1098 and 'text' support optional locale specification '(in loc)', which

1099 specifies the default context for interpreting antiquotations. For

1100 example: 'text (in lattice) {* @{thm inf_assoc}*}'.

1102 * Option 'locale=NAME' of antiquotations specifies an alternative

1103 context interpreting the subsequent argument. For example: @{thm

1104 [locale=lattice] inf_assoc}.

1106 * Proper output of proof terms (@{prf ...} and @{full_prf ...}) within

1107 a proof context.

1109 * Proper output of antiquotations for theory commands involving a

1110 proof context (such as 'locale' or 'theorem (in loc) ...').

1112 * Delimiters of outer tokens (string etc.) now produce separate LaTeX

1113 macros (\isachardoublequoteopen, isachardoublequoteclose etc.).

1115 * isatool usedir: new option -C (default true) controls whether option

1116 -D should include a copy of the original document directory; -C false

1117 prevents unwanted effects such as copying of administrative CVS data.

1120 *** Pure ***

1122 * Considerably improved version of 'constdefs' command. Now performs

1123 automatic type-inference of declared constants; additional support for

1124 local structure declarations (cf. locales and HOL records), see also

1125 isar-ref manual. Potential INCOMPATIBILITY: need to observe strictly

1126 sequential dependencies of definitions within a single 'constdefs'

1127 section; moreover, the declared name needs to be an identifier. If

1128 all fails, consider to fall back on 'consts' and 'defs' separately.

1130 * Improved indexed syntax and implicit structures. First of all,

1131 indexed syntax provides a notational device for subscripted

1132 application, using the new syntax \<^bsub>term\<^esub> for arbitrary

1133 expressions. Secondly, in a local context with structure

1134 declarations, number indexes \<^sub>n or the empty index (default

1135 number 1) refer to a certain fixed variable implicitly; option

1136 show_structs controls printing of implicit structures. Typical

1137 applications of these concepts involve record types and locales.

1139 * New command 'no_syntax' removes grammar declarations (and

1140 translations) resulting from the given syntax specification, which is

1141 interpreted in the same manner as for the 'syntax' command.

1143 * 'Advanced' translation functions (parse_translation etc.) may depend

1144 on the signature of the theory context being presently used for

1145 parsing/printing, see also isar-ref manual.

1147 * Improved 'oracle' command provides a type-safe interface to turn an

1148 ML expression of type theory -> T -> term into a primitive rule of

1149 type theory -> T -> thm (i.e. the functionality of Thm.invoke_oracle

1150 is already included here); see also FOL/ex/IffExample.thy;

1151 INCOMPATIBILITY.

1153 * axclass: name space prefix for class "c" is now "c_class" (was "c"

1154 before); "cI" is no longer bound, use "c.intro" instead.

1155 INCOMPATIBILITY. This change avoids clashes of fact bindings for

1156 axclasses vs. locales.

1158 * Improved internal renaming of symbolic identifiers -- attach primes

1159 instead of base 26 numbers.

1161 * New flag show_question_marks controls printing of leading question

1162 marks in schematic variable names.

1164 * In schematic variable names, *any* symbol following \<^isub> or

1165 \<^isup> is now treated as part of the base name. For example, the

1166 following works without printing of awkward ".0" indexes:

1168 lemma "x\<^isub>1 = x\<^isub>2 ==> x\<^isub>2 = x\<^isub>1"

1169 by simp

1171 * Inner syntax includes (*(*nested*) comments*).

1173 * Pretty printer now supports unbreakable blocks, specified in mixfix

1174 annotations as "(00...)".

1176 * Clear separation of logical types and nonterminals, where the latter

1177 may only occur in 'syntax' specifications or type abbreviations.

1178 Before that distinction was only partially implemented via type class

1179 "logic" vs. "{}". Potential INCOMPATIBILITY in rare cases of improper

1180 use of 'types'/'consts' instead of 'nonterminals'/'syntax'. Some very

1181 exotic syntax specifications may require further adaption

1182 (e.g. Cube/Cube.thy).

1184 * Removed obsolete type class "logic", use the top sort {} instead.

1185 Note that non-logical types should be declared as 'nonterminals'

1186 rather than 'types'. INCOMPATIBILITY for new object-logic

1187 specifications.

1189 * Attributes 'induct' and 'cases': type or set names may now be

1190 locally fixed variables as well.

1192 * Simplifier: can now control the depth to which conditional rewriting

1193 is traced via the PG menu Isabelle -> Settings -> Trace Simp Depth

1194 Limit.

1196 * Simplifier: simplification procedures may now take the current

1197 simpset into account (cf. Simplifier.simproc(_i) / mk_simproc

1198 interface), which is very useful for calling the Simplifier

1199 recursively. Minor INCOMPATIBILITY: the 'prems' argument of simprocs

1200 is gone -- use prems_of_ss on the simpset instead. Moreover, the

1201 low-level mk_simproc no longer applies Logic.varify internally, to

1202 allow for use in a context of fixed variables.

1204 * thin_tac now works even if the assumption being deleted contains !!

1205 or ==>. More generally, erule now works even if the major premise of

1206 the elimination rule contains !! or ==>.

1208 * Method 'rules' has been renamed to 'iprover'. INCOMPATIBILITY.

1210 * Reorganized bootstrapping of the Pure theories; CPure is now derived

1211 from Pure, which contains all common declarations already. Both

1212 theories are defined via plain Isabelle/Isar .thy files.

1213 INCOMPATIBILITY: elements of CPure (such as the CPure.intro /

1214 CPure.elim / CPure.dest attributes) now appear in the Pure name space;

1215 use isatool fixcpure to adapt your theory and ML sources.

1217 * New syntax 'name(i-j, i-, i, ...)' for referring to specific

1218 selections of theorems in named facts via index ranges.

1220 * 'print_theorems': in theory mode, really print the difference

1221 wrt. the last state (works for interactive theory development only),

1222 in proof mode print all local facts (cf. 'print_facts');

1224 * 'hide': option '(open)' hides only base names.

1226 * More efficient treatment of intermediate checkpoints in interactive

1227 theory development.

1229 * Code generator is now invoked via code_module (incremental code

1230 generation) and code_library (modular code generation, ML structures

1231 for each theory). INCOMPATIBILITY: new keywords 'file' and 'contains'

1232 must be quoted when used as identifiers.

1234 * New 'value' command for reading, evaluating and printing terms using

1235 the code generator. INCOMPATIBILITY: command keyword 'value' must be

1236 quoted when used as identifier.

1239 *** Locales ***

1241 * New commands for the interpretation of locale expressions in

1242 theories (1), locales (2) and proof contexts (3). These generate

1243 proof obligations from the expression specification. After the

1244 obligations have been discharged, theorems of the expression are added

1245 to the theory, target locale or proof context. The synopsis of the

1246 commands is a follows:

1248 (1) interpretation expr inst

1249 (2) interpretation target < expr

1250 (3) interpret expr inst

1252 Interpretation in theories and proof contexts require a parameter

1253 instantiation of terms from the current context. This is applied to

1254 specifications and theorems of the interpreted expression.

1255 Interpretation in locales only permits parameter renaming through the

1256 locale expression. Interpretation is smart in that interpretations

1257 that are active already do not occur in proof obligations, neither are

1258 instantiated theorems stored in duplicate. Use 'print_interps' to

1259 inspect active interpretations of a particular locale. For details,

1260 see the Isar Reference manual. Examples can be found in

1261 HOL/Finite_Set.thy and HOL/Algebra/UnivPoly.thy.

1263 INCOMPATIBILITY: former 'instantiate' has been withdrawn, use

1264 'interpret' instead.

1266 * New context element 'constrains' for adding type constraints to

1267 parameters.

1269 * Context expressions: renaming of parameters with syntax

1270 redeclaration.

1272 * Locale declaration: 'includes' disallowed.

1274 * Proper static binding of attribute syntax -- i.e. types / terms /

1275 facts mentioned as arguments are always those of the locale definition

1276 context, independently of the context of later invocations. Moreover,

1277 locale operations (renaming and type / term instantiation) are applied

1278 to attribute arguments as expected.

1280 INCOMPATIBILITY of the ML interface: always pass Attrib.src instead of

1281 actual attributes; rare situations may require Attrib.attribute to

1282 embed those attributes into Attrib.src that lack concrete syntax.

1283 Attribute implementations need to cooperate properly with the static

1284 binding mechanism. Basic parsers Args.XXX_typ/term/prop and

1285 Attrib.XXX_thm etc. already do the right thing without further

1286 intervention. Only unusual applications -- such as "where" or "of"

1287 (cf. src/Pure/Isar/attrib.ML), which process arguments depending both

1288 on the context and the facts involved -- may have to assign parsed

1289 values to argument tokens explicitly.

1291 * Changed parameter management in theorem generation for long goal

1292 statements with 'includes'. INCOMPATIBILITY: produces a different

1293 theorem statement in rare situations.

1295 * Locale inspection command 'print_locale' omits notes elements. Use

1296 'print_locale!' to have them included in the output.

1299 *** Provers ***

1301 * Provers/hypsubst.ML: improved version of the subst method, for

1302 single-step rewriting: it now works in bound variable contexts. New is

1303 'subst (asm)', for rewriting an assumption. INCOMPATIBILITY: may

1304 rewrite a different subterm than the original subst method, which is

1305 still available as 'simplesubst'.

1307 * Provers/quasi.ML: new transitivity reasoners for transitivity only

1308 and quasi orders.

1310 * Provers/trancl.ML: new transitivity reasoner for transitive and

1311 reflexive-transitive closure of relations.

1313 * Provers/blast.ML: new reference depth_limit to make blast's depth

1314 limit (previously hard-coded with a value of 20) user-definable.

1316 * Provers/simplifier.ML has been moved to Pure, where Simplifier.setup

1317 is peformed already. Object-logics merely need to finish their

1318 initial simpset configuration as before. INCOMPATIBILITY.

1321 *** HOL ***

1323 * Symbolic syntax of Hilbert Choice Operator is now as follows:

1325 syntax (epsilon)

1326 "_Eps" :: "[pttrn, bool] => 'a" ("(3\<some>_./ _)" [0, 10] 10)

1328 The symbol \<some> is displayed as the alternative epsilon of LaTeX

1329 and x-symbol; use option '-m epsilon' to get it actually printed.

1330 Moreover, the mathematically important symbolic identifier \<epsilon>

1331 becomes available as variable, constant etc. INCOMPATIBILITY,

1333 * "x > y" abbreviates "y < x" and "x >= y" abbreviates "y <= x".

1334 Similarly for all quantifiers: "ALL x > y" etc. The x-symbol for >=

1335 is \<ge>. New transitivity rules have been added to HOL/Orderings.thy to

1336 support corresponding Isar calculations.

1338 * "{x:A. P}" abbreviates "{x. x:A & P}", and similarly for "\<in>"

1339 instead of ":".

1341 * theory SetInterval: changed the syntax for open intervals:

1343 Old New

1344 {..n(} {..<n}

1345 {)n..} {n<..}

1346 {m..n(} {m..<n}

1347 {)m..n} {m<..n}

1348 {)m..n(} {m<..<n}

1350 The old syntax is still supported but will disappear in the next

1351 release. For conversion use the following Emacs search and replace

1352 patterns (these are not perfect but work quite well):

1354 {)\([^\.]*\)\.\. -> {\1<\.\.}

1355 \.\.\([^(}]*\)(} -> \.\.<\1}

1357 * Theory Commutative_Ring (in Library): method comm_ring for proving

1358 equalities in commutative rings; method 'algebra' provides a generic

1359 interface.

1361 * Theory Finite_Set: changed the syntax for 'setsum', summation over

1362 finite sets: "setsum (%x. e) A", which used to be "\<Sum>x:A. e", is

1363 now either "SUM x:A. e" or "\<Sum>x \<in> A. e". The bound variable can

1364 be a tuple pattern.

1366 Some new syntax forms are available:

1368 "\<Sum>x | P. e" for "setsum (%x. e) {x. P}"

1369 "\<Sum>x = a..b. e" for "setsum (%x. e) {a..b}"

1370 "\<Sum>x = a..<b. e" for "setsum (%x. e) {a..<b}"

1371 "\<Sum>x < k. e" for "setsum (%x. e) {..<k}"

1373 The latter form "\<Sum>x < k. e" used to be based on a separate

1374 function "Summation", which has been discontinued.

1376 * theory Finite_Set: in structured induction proofs, the insert case

1377 is now 'case (insert x F)' instead of the old counterintuitive 'case

1378 (insert F x)'.

1380 * The 'refute' command has been extended to support a much larger

1381 fragment of HOL, including axiomatic type classes, constdefs and

1382 typedefs, inductive datatypes and recursion.

1384 * New tactics 'sat' and 'satx' to prove propositional tautologies.

1385 Requires zChaff with proof generation to be installed. See

1386 HOL/ex/SAT_Examples.thy for examples.

1388 * Datatype induction via method 'induct' now preserves the name of the

1389 induction variable. For example, when proving P(xs::'a list) by

1390 induction on xs, the induction step is now P(xs) ==> P(a#xs) rather

1391 than P(list) ==> P(a#list) as previously. Potential INCOMPATIBILITY

1392 in unstructured proof scripts.

1394 * Reworked implementation of records. Improved scalability for

1395 records with many fields, avoiding performance problems for type

1396 inference. Records are no longer composed of nested field types, but

1397 of nested extension types. Therefore the record type only grows linear

1398 in the number of extensions and not in the number of fields. The

1399 top-level (users) view on records is preserved. Potential

1400 INCOMPATIBILITY only in strange cases, where the theory depends on the

1401 old record representation. The type generated for a record is called

1402 <record_name>_ext_type.

1404 Flag record_quick_and_dirty_sensitive can be enabled to skip the

1405 proofs triggered by a record definition or a simproc (if

1406 quick_and_dirty is enabled). Definitions of large records can take

1407 quite long.

1409 New simproc record_upd_simproc for simplification of multiple record

1410 updates enabled by default. Moreover, trivial updates are also

1411 removed: r(|x := x r|) = r. INCOMPATIBILITY: old proofs break

1412 occasionally, since simplification is more powerful by default.

1414 * typedef: proper support for polymorphic sets, which contain extra

1415 type-variables in the term.

1417 * Simplifier: automatically reasons about transitivity chains

1418 involving "trancl" (r^+) and "rtrancl" (r^*) by setting up tactics

1419 provided by Provers/trancl.ML as additional solvers. INCOMPATIBILITY:

1420 old proofs break occasionally as simplification may now solve more

1421 goals than previously.

1423 * Simplifier: converts x <= y into x = y if assumption y <= x is

1424 present. Works for all partial orders (class "order"), in particular

1425 numbers and sets. For linear orders (e.g. numbers) it treats ~ x < y

1426 just like y <= x.

1428 * Simplifier: new simproc for "let x = a in f x". If a is a free or

1429 bound variable or a constant then the let is unfolded. Otherwise

1430 first a is simplified to b, and then f b is simplified to g. If

1431 possible we abstract b from g arriving at "let x = b in h x",

1432 otherwise we unfold the let and arrive at g. The simproc can be

1433 enabled/disabled by the reference use_let_simproc. Potential

1434 INCOMPATIBILITY since simplification is more powerful by default.

1436 * Classical reasoning: the meson method now accepts theorems as arguments.

1438 * Prover support: pre-release of the Isabelle-ATP linkup, which runs background

1439 jobs to provide advice on the provability of subgoals.

1441 * Theory OrderedGroup and Ring_and_Field: various additions and

1442 improvements to faciliate calculations involving equalities and

1443 inequalities.

1445 The following theorems have been eliminated or modified

1446 (INCOMPATIBILITY):

1448 abs_eq now named abs_of_nonneg

1449 abs_of_ge_0 now named abs_of_nonneg

1450 abs_minus_eq now named abs_of_nonpos

1451 imp_abs_id now named abs_of_nonneg

1452 imp_abs_neg_id now named abs_of_nonpos

1453 mult_pos now named mult_pos_pos

1454 mult_pos_le now named mult_nonneg_nonneg

1455 mult_pos_neg_le now named mult_nonneg_nonpos

1456 mult_pos_neg2_le now named mult_nonneg_nonpos2

1457 mult_neg now named mult_neg_neg

1458 mult_neg_le now named mult_nonpos_nonpos

1460 * Theory Parity: added rules for simplifying exponents.

1462 * Theory List:

1464 The following theorems have been eliminated or modified

1465 (INCOMPATIBILITY):

1467 list_all_Nil now named list_all.simps(1)

1468 list_all_Cons now named list_all.simps(2)

1469 list_all_conv now named list_all_iff

1470 set_mem_eq now named mem_iff

1472 * Theories SetsAndFunctions and BigO (see HOL/Library) support

1473 asymptotic "big O" calculations. See the notes in BigO.thy.

1476 *** HOL-Complex ***

1478 * Theory RealDef: better support for embedding natural numbers and

1479 integers in the reals.

1481 The following theorems have been eliminated or modified

1482 (INCOMPATIBILITY):

1484 exp_ge_add_one_self now requires no hypotheses

1485 real_of_int_add reversed direction of equality (use [symmetric])

1486 real_of_int_minus reversed direction of equality (use [symmetric])

1487 real_of_int_diff reversed direction of equality (use [symmetric])

1488 real_of_int_mult reversed direction of equality (use [symmetric])

1490 * Theory RComplete: expanded support for floor and ceiling functions.

1492 * Theory Ln is new, with properties of the natural logarithm

1494 * Hyperreal: There is a new type constructor "star" for making

1495 nonstandard types. The old type names are now type synonyms:

1497 hypreal = real star

1498 hypnat = nat star

1499 hcomplex = complex star

1501 * Hyperreal: Many groups of similarly-defined constants have been

1502 replaced by polymorphic versions (INCOMPATIBILITY):

1504 star_of <-- hypreal_of_real, hypnat_of_nat, hcomplex_of_complex

1506 starset <-- starsetNat, starsetC

1507 *s* <-- *sNat*, *sc*

1508 starset_n <-- starsetNat_n, starsetC_n

1509 *sn* <-- *sNatn*, *scn*

1510 InternalSets <-- InternalNatSets, InternalCSets

1512 starfun <-- starfun{Nat,Nat2,C,RC,CR}

1513 *f* <-- *fNat*, *fNat2*, *fc*, *fRc*, *fcR*

1514 starfun_n <-- starfun{Nat,Nat2,C,RC,CR}_n

1515 *fn* <-- *fNatn*, *fNat2n*, *fcn*, *fRcn*, *fcRn*

1516 InternalFuns <-- InternalNatFuns, InternalNatFuns2, Internal{C,RC,CR}Funs

1518 * Hyperreal: Many type-specific theorems have been removed in favor of

1519 theorems specific to various axiomatic type classes (INCOMPATIBILITY):

1521 add_commute <-- {hypreal,hypnat,hcomplex}_add_commute

1522 add_assoc <-- {hypreal,hypnat,hcomplex}_add_assocs

1523 OrderedGroup.add_0 <-- {hypreal,hypnat,hcomplex}_add_zero_left

1524 OrderedGroup.add_0_right <-- {hypreal,hcomplex}_add_zero_right

1525 right_minus <-- hypreal_add_minus

1526 left_minus <-- {hypreal,hcomplex}_add_minus_left

1527 mult_commute <-- {hypreal,hypnat,hcomplex}_mult_commute

1528 mult_assoc <-- {hypreal,hypnat,hcomplex}_mult_assoc

1529 mult_1_left <-- {hypreal,hypnat}_mult_1, hcomplex_mult_one_left

1530 mult_1_right <-- hcomplex_mult_one_right

1531 mult_zero_left <-- hcomplex_mult_zero_left

1532 left_distrib <-- {hypreal,hypnat,hcomplex}_add_mult_distrib

1533 right_distrib <-- hypnat_add_mult_distrib2

1534 zero_neq_one <-- {hypreal,hypnat,hcomplex}_zero_not_eq_one

1535 right_inverse <-- hypreal_mult_inverse

1536 left_inverse <-- hypreal_mult_inverse_left, hcomplex_mult_inv_left

1537 order_refl <-- {hypreal,hypnat}_le_refl

1538 order_trans <-- {hypreal,hypnat}_le_trans

1539 order_antisym <-- {hypreal,hypnat}_le_anti_sym

1540 order_less_le <-- {hypreal,hypnat}_less_le

1541 linorder_linear <-- {hypreal,hypnat}_le_linear

1542 add_left_mono <-- {hypreal,hypnat}_add_left_mono

1543 mult_strict_left_mono <-- {hypreal,hypnat}_mult_less_mono2

1544 add_nonneg_nonneg <-- hypreal_le_add_order

1546 * Hyperreal: Separate theorems having to do with type-specific

1547 versions of constants have been merged into theorems that apply to the

1548 new polymorphic constants (INCOMPATIBILITY):

1550 STAR_UNIV_set <-- {STAR_real,NatStar_real,STARC_complex}_set

1551 STAR_empty_set <-- {STAR,NatStar,STARC}_empty_set

1552 STAR_Un <-- {STAR,NatStar,STARC}_Un

1553 STAR_Int <-- {STAR,NatStar,STARC}_Int

1554 STAR_Compl <-- {STAR,NatStar,STARC}_Compl

1555 STAR_subset <-- {STAR,NatStar,STARC}_subset

1556 STAR_mem <-- {STAR,NatStar,STARC}_mem

1557 STAR_mem_Compl <-- {STAR,STARC}_mem_Compl

1558 STAR_diff <-- {STAR,STARC}_diff

1559 STAR_star_of_image_subset <-- {STAR_hypreal_of_real, NatStar_hypreal_of_real,

1560 STARC_hcomplex_of_complex}_image_subset

1561 starset_n_Un <-- starset{Nat,C}_n_Un

1562 starset_n_Int <-- starset{Nat,C}_n_Int

1563 starset_n_Compl <-- starset{Nat,C}_n_Compl

1564 starset_n_diff <-- starset{Nat,C}_n_diff

1565 InternalSets_Un <-- Internal{Nat,C}Sets_Un

1566 InternalSets_Int <-- Internal{Nat,C}Sets_Int

1567 InternalSets_Compl <-- Internal{Nat,C}Sets_Compl

1568 InternalSets_diff <-- Internal{Nat,C}Sets_diff

1569 InternalSets_UNIV_diff <-- Internal{Nat,C}Sets_UNIV_diff

1570 InternalSets_starset_n <-- Internal{Nat,C}Sets_starset{Nat,C}_n

1571 starset_starset_n_eq <-- starset{Nat,C}_starset{Nat,C}_n_eq

1572 starset_n_starset <-- starset{Nat,C}_n_starset{Nat,C}

1573 starfun_n_starfun <-- starfun{Nat,Nat2,C,RC,CR}_n_starfun{Nat,Nat2,C,RC,CR}

1574 starfun <-- starfun{Nat,Nat2,C,RC,CR}

1575 starfun_mult <-- starfun{Nat,Nat2,C,RC,CR}_mult

1576 starfun_add <-- starfun{Nat,Nat2,C,RC,CR}_add

1577 starfun_minus <-- starfun{Nat,Nat2,C,RC,CR}_minus

1578 starfun_diff <-- starfun{C,RC,CR}_diff

1579 starfun_o <-- starfun{NatNat2,Nat2,_stafunNat,C,C_starfunRC,_starfunCR}_o

1580 starfun_o2 <-- starfun{NatNat2,_stafunNat,C,C_starfunRC,_starfunCR}_o2

1581 starfun_const_fun <-- starfun{Nat,Nat2,C,RC,CR}_const_fun

1582 starfun_inverse <-- starfun{Nat,C,RC,CR}_inverse

1583 starfun_eq <-- starfun{Nat,Nat2,C,RC,CR}_eq

1584 starfun_eq_iff <-- starfun{C,RC,CR}_eq_iff

1585 starfun_Id <-- starfunC_Id

1586 starfun_approx <-- starfun{Nat,CR}_approx

1587 starfun_capprox <-- starfun{C,RC}_capprox

1588 starfun_abs <-- starfunNat_rabs

1589 starfun_lambda_cancel <-- starfun{C,CR,RC}_lambda_cancel

1590 starfun_lambda_cancel2 <-- starfun{C,CR,RC}_lambda_cancel2

1591 starfun_mult_HFinite_approx <-- starfunCR_mult_HFinite_capprox

1592 starfun_mult_CFinite_capprox <-- starfun{C,RC}_mult_CFinite_capprox

1593 starfun_add_capprox <-- starfun{C,RC}_add_capprox

1594 starfun_add_approx <-- starfunCR_add_approx

1595 starfun_inverse_inverse <-- starfunC_inverse_inverse

1596 starfun_divide <-- starfun{C,CR,RC}_divide

1597 starfun_n <-- starfun{Nat,C}_n

1598 starfun_n_mult <-- starfun{Nat,C}_n_mult

1599 starfun_n_add <-- starfun{Nat,C}_n_add

1600 starfun_n_add_minus <-- starfunNat_n_add_minus

1601 starfun_n_const_fun <-- starfun{Nat,C}_n_const_fun

1602 starfun_n_minus <-- starfun{Nat,C}_n_minus

1603 starfun_n_eq <-- starfun{Nat,C}_n_eq

1605 star_n_add <-- {hypreal,hypnat,hcomplex}_add

1606 star_n_minus <-- {hypreal,hcomplex}_minus

1607 star_n_diff <-- {hypreal,hcomplex}_diff

1608 star_n_mult <-- {hypreal,hcomplex}_mult

1609 star_n_inverse <-- {hypreal,hcomplex}_inverse

1610 star_n_le <-- {hypreal,hypnat}_le

1611 star_n_less <-- {hypreal,hypnat}_less

1612 star_n_zero_num <-- {hypreal,hypnat,hcomplex}_zero_num

1613 star_n_one_num <-- {hypreal,hypnat,hcomplex}_one_num

1614 star_n_abs <-- hypreal_hrabs

1615 star_n_divide <-- hcomplex_divide

1617 star_of_add <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_add

1618 star_of_minus <-- {hypreal_of_real,hcomplex_of_complex}_minus

1619 star_of_diff <-- hypreal_of_real_diff

1620 star_of_mult <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_mult

1621 star_of_one <-- {hypreal_of_real,hcomplex_of_complex}_one

1622 star_of_zero <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_zero

1623 star_of_le <-- {hypreal_of_real,hypnat_of_nat}_le_iff

1624 star_of_less <-- {hypreal_of_real,hypnat_of_nat}_less_iff

1625 star_of_eq <-- {hypreal_of_real,hypnat_of_nat,hcomplex_of_complex}_eq_iff

1626 star_of_inverse <-- {hypreal_of_real,hcomplex_of_complex}_inverse

1627 star_of_divide <-- {hypreal_of_real,hcomplex_of_complex}_divide

1628 star_of_of_nat <-- {hypreal_of_real,hcomplex_of_complex}_of_nat

1629 star_of_of_int <-- {hypreal_of_real,hcomplex_of_complex}_of_int

1630 star_of_number_of <-- {hypreal,hcomplex}_number_of

1631 star_of_number_less <-- number_of_less_hypreal_of_real_iff

1632 star_of_number_le <-- number_of_le_hypreal_of_real_iff

1633 star_of_eq_number <-- hypreal_of_real_eq_number_of_iff

1634 star_of_less_number <-- hypreal_of_real_less_number_of_iff

1635 star_of_le_number <-- hypreal_of_real_le_number_of_iff

1636 star_of_power <-- hypreal_of_real_power

1637 star_of_eq_0 <-- hcomplex_of_complex_zero_iff

1639 * Hyperreal: new method "transfer" that implements the transfer

1640 principle of nonstandard analysis. With a subgoal that mentions

1641 nonstandard types like "'a star", the command "apply transfer"

1642 replaces it with an equivalent one that mentions only standard types.

1643 To be successful, all free variables must have standard types; non-

1644 standard variables must have explicit universal quantifiers.

1646 * Hyperreal: A theory of Taylor series.

1649 *** HOLCF ***

1651 * Discontinued special version of 'constdefs' (which used to support

1652 continuous functions) in favor of the general Pure one with full

1653 type-inference.

1655 * New simplification procedure for solving continuity conditions; it

1656 is much faster on terms with many nested lambda abstractions (cubic

1657 instead of exponential time).

1659 * New syntax for domain package: selector names are now optional.

1660 Parentheses should be omitted unless argument is lazy, for example:

1662 domain 'a stream = cons "'a" (lazy "'a stream")

1664 * New command 'fixrec' for defining recursive functions with pattern

1665 matching; defining multiple functions with mutual recursion is also

1666 supported. Patterns may include the constants cpair, spair, up, sinl,

1667 sinr, or any data constructor defined by the domain package. The given

1668 equations are proven as rewrite rules. See HOLCF/ex/Fixrec_ex.thy for

1669 syntax and examples.

1671 * New commands 'cpodef' and 'pcpodef' for defining predicate subtypes

1672 of cpo and pcpo types. Syntax is exactly like the 'typedef' command,

1673 but the proof obligation additionally includes an admissibility

1674 requirement. The packages generate instances of class cpo or pcpo,

1675 with continuity and strictness theorems for Rep and Abs.

1677 * HOLCF: Many theorems have been renamed according to a more standard naming

1678 scheme (INCOMPATIBILITY):

1680 foo_inject: "foo$x = foo$y ==> x = y"

1681 foo_eq: "(foo$x = foo$y) = (x = y)"

1682 foo_less: "(foo$x << foo$y) = (x << y)"

1683 foo_strict: "foo$UU = UU"

1684 foo_defined: "... ==> foo$x ~= UU"

1685 foo_defined_iff: "(foo$x = UU) = (x = UU)"

1688 *** ZF ***

1690 * ZF/ex: theories Group and Ring provide examples in abstract algebra,

1691 including the First Isomorphism Theorem (on quotienting by the kernel

1692 of a homomorphism).

1694 * ZF/Simplifier: install second copy of type solver that actually

1695 makes use of TC rules declared to Isar proof contexts (or locales);

1696 the old version is still required for ML proof scripts.

1699 *** Cube ***

1701 * Converted to Isar theory format; use locales instead of axiomatic

1702 theories.

1705 *** ML ***

1707 * Pure/library.ML: added ##>, ##>>, #>> -- higher-order counterparts

1708 for ||>, ||>>, |>>,

1710 * Pure/library.ML no longer defines its own option datatype, but uses

1711 that of the SML basis, which has constructors NONE and SOME instead of

1712 None and Some, as well as exception Option.Option instead of OPTION.

1713 The functions the, if_none, is_some, is_none have been adapted

1714 accordingly, while Option.map replaces apsome.

1716 * Pure/library.ML: the exception LIST has been given up in favour of

1717 the standard exceptions Empty and Subscript, as well as

1718 Library.UnequalLengths. Function like Library.hd and Library.tl are

1719 superceded by the standard hd and tl functions etc.

1721 A number of basic list functions are no longer exported to the ML

1722 toplevel, as they are variants of predefined functions. The following

1723 suggests how one can translate existing code:

1725 rev_append xs ys = List.revAppend (xs, ys)

1726 nth_elem (i, xs) = List.nth (xs, i)

1727 last_elem xs = List.last xs

1728 flat xss = List.concat xss

1729 seq fs = List.app fs

1730 partition P xs = List.partition P xs

1731 mapfilter f xs = List.mapPartial f xs

1733 * Pure/library.ML: several combinators for linear functional

1734 transformations, notably reverse application and composition:

1736 x |> f f #> g

1737 (x, y) |-> f f #-> g

1739 * Pure/library.ML: introduced/changed precedence of infix operators:

1741 infix 1 |> |-> ||> ||>> |>> |>>> #> #->;

1742 infix 2 ?;

1743 infix 3 o oo ooo oooo;

1744 infix 4 ~~ upto downto;

1746 Maybe INCOMPATIBILITY when any of those is used in conjunction with other

1747 infix operators.

1749 * Pure/library.ML: natural list combinators fold, fold_rev, and

1750 fold_map support linear functional transformations and nesting. For

1751 example:

1753 fold f [x1, ..., xN] y =

1754 y |> f x1 |> ... |> f xN

1756 (fold o fold) f [xs1, ..., xsN] y =

1757 y |> fold f xs1 |> ... |> fold f xsN

1759 fold f [x1, ..., xN] =

1760 f x1 #> ... #> f xN

1762 (fold o fold) f [xs1, ..., xsN] =

1763 fold f xs1 #> ... #> fold f xsN

1765 * Pure/library.ML: the following selectors on type 'a option are

1766 available:

1768 the: 'a option -> 'a (*partial*)

1769 these: 'a option -> 'a where 'a = 'b list

1770 the_default: 'a -> 'a option -> 'a

1771 the_list: 'a option -> 'a list

1773 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides

1774 basic operations for association lists, following natural argument

1775 order; moreover the explicit equality predicate passed here avoids

1776 potentially expensive polymorphic runtime equality checks.

1777 The old functions may be expressed as follows:

1779 assoc = uncurry (AList.lookup (op =))

1780 assocs = these oo AList.lookup (op =)

1781 overwrite = uncurry (AList.update (op =)) o swap

1783 * Pure/General: structure AList (cf. Pure/General/alist.ML) provides

1785 val make: ('a -> 'b) -> 'a list -> ('a * 'b) list

1786 val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list

1788 replacing make_keylist and keyfilter (occassionally used)

1789 Naive rewrites:

1791 make_keylist = AList.make

1792 keyfilter = AList.find (op =)

1794 * eq_fst and eq_snd now take explicit equality parameter, thus

1795 avoiding eqtypes. Naive rewrites:

1797 eq_fst = eq_fst (op =)

1798 eq_snd = eq_snd (op =)

1800 * Removed deprecated apl and apr (rarely used).

1801 Naive rewrites:

1803 apl (n, op) =>>= curry op n

1804 apr (op, m) =>>= fn n => op (n, m)

1806 * Pure/General: structure OrdList (cf. Pure/General/ord_list.ML)

1807 provides a reasonably efficient light-weight implementation of sets as

1808 lists.

1810 * Pure/General: generic tables (cf. Pure/General/table.ML) provide a

1811 few new operations; existing lookup and update are now curried to

1812 follow natural argument order (for use with fold etc.);

1813 INCOMPATIBILITY, use (uncurry Symtab.lookup) etc. as last resort.

1815 * Pure/General: output via the Isabelle channels of

1816 writeln/warning/error etc. is now passed through Output.output, with a

1817 hook for arbitrary transformations depending on the print_mode

1818 (cf. Output.add_mode -- the first active mode that provides a output

1819 function wins). Already formatted output may be embedded into further

1820 text via Output.raw; the result of Pretty.string_of/str_of and derived

1821 functions (string_of_term/cterm/thm etc.) is already marked raw to

1822 accommodate easy composition of diagnostic messages etc. Programmers

1823 rarely need to care about Output.output or Output.raw at all, with

1824 some notable exceptions: Output.output is required when bypassing the

1825 standard channels (writeln etc.), or in token translations to produce

1826 properly formatted results; Output.raw is required when capturing

1827 already output material that will eventually be presented to the user

1828 a second time. For the default print mode, both Output.output and

1829 Output.raw have no effect.

1831 * Pure/General: Output.time_accumulator NAME creates an operator ('a

1832 -> 'b) -> 'a -> 'b to measure runtime and count invocations; the

1833 cumulative results are displayed at the end of a batch session.

1835 * Pure/General: File.sysify_path and File.quote_sysify path have been

1836 replaced by File.platform_path and File.shell_path (with appropriate

1837 hooks). This provides a clean interface for unusual systems where the

1838 internal and external process view of file names are different.

1840 * Pure: more efficient orders for basic syntactic entities: added

1841 fast_string_ord, fast_indexname_ord, fast_term_ord; changed sort_ord

1842 and typ_ord to use fast_string_ord and fast_indexname_ord (term_ord is

1843 NOT affected); structures Symtab, Vartab, Typtab, Termtab use the fast

1844 orders now -- potential INCOMPATIBILITY for code that depends on a

1845 particular order for Symtab.keys, Symtab.dest, etc. (consider using

1846 Library.sort_strings on result).

1848 * Pure/term.ML: combinators fold_atyps, fold_aterms, fold_term_types,

1849 fold_types traverse types/terms from left to right, observing natural

1850 argument order. Supercedes previous foldl_XXX versions, add_frees,

1851 add_vars etc. have been adapted as well: INCOMPATIBILITY.

1853 * Pure: name spaces have been refined, with significant changes of the

1854 internal interfaces -- INCOMPATIBILITY. Renamed cond_extern(_table)

1855 to extern(_table). The plain name entry path is superceded by a

1856 general 'naming' context, which also includes the 'policy' to produce

1857 a fully qualified name and external accesses of a fully qualified

1858 name; NameSpace.extend is superceded by context dependent

1859 Sign.declare_name. Several theory and proof context operations modify

1860 the naming context. Especially note Theory.restore_naming and

1861 ProofContext.restore_naming to get back to a sane state; note that

1862 Theory.add_path is no longer sufficient to recover from

1863 Theory.absolute_path in particular.

1865 * Pure: new flags short_names (default false) and unique_names

1866 (default true) for controlling output of qualified names. If

1867 short_names is set, names are printed unqualified. If unique_names is

1868 reset, the name prefix is reduced to the minimum required to achieve

1869 the original result when interning again, even if there is an overlap

1870 with earlier declarations.

1872 * Pure/TheoryDataFun: change of the argument structure; 'prep_ext' is

1873 now 'extend', and 'merge' gets an additional Pretty.pp argument

1874 (useful for printing error messages). INCOMPATIBILITY.

1876 * Pure: major reorganization of the theory context. Type Sign.sg and

1877 Theory.theory are now identified, referring to the universal

1878 Context.theory (see Pure/context.ML). Actual signature and theory

1879 content is managed as theory data. The old code and interfaces were

1880 spread over many files and structures; the new arrangement introduces

1881 considerable INCOMPATIBILITY to gain more clarity:

1883 Context -- theory management operations (name, identity, inclusion,

1884 parents, ancestors, merge, etc.), plus generic theory data;

1886 Sign -- logical signature and syntax operations (declaring consts,

1887 types, etc.), plus certify/read for common entities;

1889 Theory -- logical theory operations (stating axioms, definitions,

1890 oracles), plus a copy of logical signature operations (consts,

1891 types, etc.); also a few basic management operations (Theory.copy,

1892 Theory.merge, etc.)

1894 The most basic sign_of operations (Theory.sign_of, Thm.sign_of_thm

1895 etc.) as well as the sign field in Thm.rep_thm etc. have been retained

1896 for convenience -- they merely return the theory.

1898 * Pure: type Type.tsig is superceded by theory in most interfaces.

1900 * Pure: the Isar proof context type is already defined early in Pure

1901 as Context.proof (note that ProofContext.context and Proof.context are

1902 aliases, where the latter is the preferred name). This enables other

1903 Isabelle components to refer to that type even before Isar is present.

1905 * Pure/sign/theory: discontinued named name spaces (i.e. classK,

1906 typeK, constK, axiomK, oracleK), but provide explicit operations for

1907 any of these kinds. For example, Sign.intern typeK is now

1908 Sign.intern_type, Theory.hide_space Sign.typeK is now

1909 Theory.hide_types. Also note that former

1910 Theory.hide_classes/types/consts are now

1911 Theory.hide_classes_i/types_i/consts_i, while the non '_i' versions

1912 internalize their arguments! INCOMPATIBILITY.

1914 * Pure: get_thm interface (of PureThy and ProofContext) expects

1915 datatype thmref (with constructors Name and NameSelection) instead of

1916 plain string -- INCOMPATIBILITY;

1918 * Pure: cases produced by proof methods specify options, where NONE

1919 means to remove case bindings -- INCOMPATIBILITY in

1920 (RAW_)METHOD_CASES.

1922 * Pure: the following operations retrieve axioms or theorems from a

1923 theory node or theory hierarchy, respectively:

1925 Theory.axioms_of: theory -> (string * term) list

1926 Theory.all_axioms_of: theory -> (string * term) list

1927 PureThy.thms_of: theory -> (string * thm) list

1928 PureThy.all_thms_of: theory -> (string * thm) list

1930 * Pure: print_tac now outputs the goal through the trace channel.

1932 * Isar toplevel: improved diagnostics, mostly for Poly/ML only.

1933 Reference Toplevel.debug (default false) controls detailed printing

1934 and tracing of low-level exceptions; Toplevel.profiling (default 0)

1935 controls execution profiling -- set to 1 for time and 2 for space

1936 (both increase the runtime).

1938 * Isar session: The initial use of ROOT.ML is now always timed,

1939 i.e. the log will show the actual process times, in contrast to the

1940 elapsed wall-clock time that the outer shell wrapper produces.

1942 * Simplifier: improved handling of bound variables (nameless

1943 representation, avoid allocating new strings). Simprocs that invoke

1944 the Simplifier recursively should use Simplifier.inherit_bounds to

1945 avoid local name clashes. Failure to do so produces warnings

1946 "Simplifier: renamed bound variable ..."; set Simplifier.debug_bounds

1947 for further details.

1949 * ML functions legacy_bindings and use_legacy_bindings produce ML fact

1950 bindings for all theorems stored within a given theory; this may help

1951 in porting non-Isar theories to Isar ones, while keeping ML proof

1952 scripts for the time being.

1954 * ML operator HTML.with_charset specifies the charset begin used for

1955 generated HTML files. For example:

1957 HTML.with_charset "utf-8" use_thy "Hebrew";

1958 HTML.with_charset "utf-8" use_thy "Chinese";

1961 *** System ***

1963 * Allow symlinks to all proper Isabelle executables (Isabelle,

1964 isabelle, isatool etc.).

1966 * ISABELLE_DOC_FORMAT setting specifies preferred document format (for

1967 isatool doc, isatool mkdir, display_drafts etc.).

1969 * isatool usedir: option -f allows specification of the ML file to be

1970 used by Isabelle; default is ROOT.ML.

1972 * New isatool version outputs the version identifier of the Isabelle

1973 distribution being used.

1975 * HOL: new isatool dimacs2hol converts files in DIMACS CNF format

1976 (containing Boolean satisfiability problems) into Isabelle/HOL

1977 theories.

1981 New in Isabelle2004 (April 2004)

1982 --------------------------------

1984 *** General ***

1986 * Provers/order.ML: new efficient reasoner for partial and linear orders.

1987 Replaces linorder.ML.

1989 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic

1990 (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler

1991 (\<a>...\<z>), are now considered normal letters, and can therefore

1992 be used anywhere where an ASCII letter (a...zA...Z) has until

1993 now. COMPATIBILITY: This obviously changes the parsing of some

1994 terms, especially where a symbol has been used as a binder, say

1995 '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed

1996 as an identifier. Fix it by inserting a space around former

1997 symbols. Call 'isatool fixgreek' to try to fix parsing errors in

1998 existing theory and ML files.

2000 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.

2002 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now

2003 allowed in identifiers. Similar to Greek letters \<^isub> is now considered

2004 a normal (but invisible) letter. For multiple letter subscripts repeat

2005 \<^isub> like this: x\<^isub>1\<^isub>2.

2007 * Pure: There are now sub-/superscripts that can span more than one

2008 character. Text between \<^bsub> and \<^esub> is set in subscript in

2009 ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in

2010 superscript. The new control characters are not identifier parts.

2012 * Pure: Control-symbols of the form \<^raw:...> will literally print the

2013 content of "..." to the latex file instead of \isacntrl... . The "..."

2014 may consist of any printable characters excluding the end bracket >.

2016 * Pure: Using new Isar command "finalconsts" (or the ML functions

2017 Theory.add_finals or Theory.add_finals_i) it is now possible to

2018 declare constants "final", which prevents their being given a definition

2019 later. It is useful for constants whose behaviour is fixed axiomatically

2020 rather than definitionally, such as the meta-logic connectives.

2022 * Pure: 'instance' now handles general arities with general sorts

2023 (i.e. intersections of classes),

2025 * Presentation: generated HTML now uses a CSS style sheet to make layout

2026 (somewhat) independent of content. It is copied from lib/html/isabelle.css.

2027 It can be changed to alter the colors/layout of generated pages.

2030 *** Isar ***

2032 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,

2033 cut_tac, subgoal_tac and thin_tac:

2034 - Now understand static (Isar) contexts. As a consequence, users of Isar

2035 locales are no longer forced to write Isar proof scripts.

2036 For details see Isar Reference Manual, paragraph 4.3.2: Further tactic

2037 emulations.

2038 - INCOMPATIBILITY: names of variables to be instantiated may no

2039 longer be enclosed in quotes. Instead, precede variable name with `?'.

2040 This is consistent with the instantiation attribute "where".

2042 * Attributes "where" and "of":

2043 - Now take type variables of instantiated theorem into account when reading

2044 the instantiation string. This fixes a bug that caused instantiated

2045 theorems to have too special types in some circumstances.

2046 - "where" permits explicit instantiations of type variables.

2048 * Calculation commands "moreover" and "also" no longer interfere with

2049 current facts ("this"), admitting arbitrary combinations with "then"

2050 and derived forms.

2052 * Locales:

2053 - Goal statements involving the context element "includes" no longer

2054 generate theorems with internal delta predicates (those ending on

2055 "_axioms") in the premise.

2056 Resolve particular premise with <locale>.intro to obtain old form.

2057 - Fixed bug in type inference ("unify_frozen") that prevented mix of target

2058 specification and "includes" elements in goal statement.

2059 - Rule sets <locale>.intro and <locale>.axioms no longer declared as

2060 [intro?] and [elim?] (respectively) by default.

2061 - Experimental command for instantiation of locales in proof contexts:

2062 instantiate <label>[<attrs>]: <loc>

2063 Instantiates locale <loc> and adds all its theorems to the current context

2064 taking into account their attributes. Label and attrs are optional

2065 modifiers, like in theorem declarations. If present, names of

2066 instantiated theorems are qualified with <label>, and the attributes

2067 <attrs> are applied after any attributes these theorems might have already.

2068 If the locale has assumptions, a chained fact of the form

2069 "<loc> t1 ... tn" is expected from which instantiations of the parameters

2070 are derived. The command does not support old-style locales declared

2071 with "locale (open)".

2072 A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.

2074 * HOL: Tactic emulation methods induct_tac and case_tac understand static

2075 (Isar) contexts.

2078 *** HOL ***

2080 * Proof import: new image HOL4 contains the imported library from

2081 the HOL4 system with about 2500 theorems. It is imported by

2082 replaying proof terms produced by HOL4 in Isabelle. The HOL4 image

2083 can be used like any other Isabelle image. See

2084 HOL/Import/HOL/README for more information.

2086 * Simplifier:

2087 - Much improved handling of linear and partial orders.

2088 Reasoners for linear and partial orders are set up for type classes

2089 "linorder" and "order" respectively, and are added to the default simpset

2090 as solvers. This means that the simplifier can build transitivity chains

2091 to solve goals from the assumptions.

2092 - INCOMPATIBILITY: old proofs break occasionally. Typically, applications

2093 of blast or auto after simplification become unnecessary because the goal

2094 is solved by simplification already.

2096 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,

2097 all proved in axiomatic type classes for semirings, rings and fields.

2099 * Numerics:

2100 - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are

2101 now formalized using the Ring_and_Field theory mentioned above.

2102 - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently

2103 than before, because now they are set up once in a generic manner.

2104 - INCOMPATIBILITY: many type-specific arithmetic laws have gone.

2105 Look for the general versions in Ring_and_Field (and Power if they concern

2106 exponentiation).

2108 * Type "rat" of the rational numbers is now available in HOL-Complex.

2110 * Records:

2111 - Record types are now by default printed with their type abbreviation

2112 instead of the list of all field types. This can be configured via

2113 the reference "print_record_type_abbr".

2114 - Simproc "record_upd_simproc" for simplification of multiple updates added

2115 (not enabled by default).

2116 - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.

2117 EX x. x = sel r to True (not enabled by default).

2118 - Tactic "record_split_simp_tac" to split and simplify records added.

2120 * 'specification' command added, allowing for definition by

2121 specification. There is also an 'ax_specification' command that

2122 introduces the new constants axiomatically.

2124 * arith(_tac) is now able to generate counterexamples for reals as well.

2126 * HOL-Algebra: new locale "ring" for non-commutative rings.

2128 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function

2129 definitions, thanks to Sava Krsti\'{c} and John Matthews.

2131 * HOL-Matrix: a first theory for matrices in HOL with an application of

2132 matrix theory to linear programming.

2134 * Unions and Intersections:

2135 The latex output syntax of UN and INT has been changed

2136 from "\Union x \in A. B" to "\Union_{x \in A} B"

2137 i.e. the index formulae has become a subscript.

2138 Similarly for "\Union x. B", and for \Inter instead of \Union.

2140 * Unions and Intersections over Intervals:

2141 There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is

2142 also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"

2143 like in normal math, and corresponding versions for < and for intersection.

2145 * HOL/List: Ordering "lexico" is renamed "lenlex" and the standard

2146 lexicographic dictonary ordering has been added as "lexord".

2148 * ML: the legacy theory structures Int and List have been removed. They had

2149 conflicted with ML Basis Library structures having the same names.

2151 * 'refute' command added to search for (finite) countermodels. Only works

2152 for a fragment of HOL. The installation of an external SAT solver is

2153 highly recommended. See "HOL/Refute.thy" for details.

2155 * 'quickcheck' command: Allows to find counterexamples by evaluating

2156 formulae under an assignment of free variables to random values.

2157 In contrast to 'refute', it can deal with inductive datatypes,

2158 but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"

2159 for examples.

2162 *** HOLCF ***

2164 * Streams now come with concatenation and are part of the HOLCF image

2168 New in Isabelle2003 (May 2003)

2169 ------------------------------

2171 *** General ***

2173 * Provers/simplifier:

2175 - Completely reimplemented method simp (ML: Asm_full_simp_tac):

2176 Assumptions are now subject to complete mutual simplification,

2177 not just from left to right. The simplifier now preserves

2178 the order of assumptions.

2180 Potential INCOMPATIBILITY:

2182 -- simp sometimes diverges where the old version did

2183 not, e.g. invoking simp on the goal

2185 [| P (f x); y = x; f x = f y |] ==> Q

2187 now gives rise to the infinite reduction sequence

2189 P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...

2191 Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this

2192 kind of problem.

2194 -- Tactics combining classical reasoner and simplification (such as auto)

2195 are also affected by this change, because many of them rely on

2196 simp. They may sometimes diverge as well or yield a different numbers

2197 of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto

2198 in case of problems. Sometimes subsequent calls to the classical

2199 reasoner will fail because a preceeding call to the simplifier too

2200 eagerly simplified the goal, e.g. deleted redundant premises.

2202 - The simplifier trace now shows the names of the applied rewrite rules

2204 - You can limit the number of recursive invocations of the simplifier

2205 during conditional rewriting (where the simplifie tries to solve the

2206 conditions before applying the rewrite rule):

2207 ML "simp_depth_limit := n"

2208 where n is an integer. Thus you can force termination where previously

2209 the simplifier would diverge.

2211 - Accepts free variables as head terms in congruence rules. Useful in Isar.

2213 - No longer aborts on failed congruence proof. Instead, the

2214 congruence is ignored.

2216 * Pure: New generic framework for extracting programs from constructive

2217 proofs. See HOL/Extraction.thy for an example instantiation, as well

2218 as HOL/Extraction for some case studies.

2220 * Pure: The main goal of the proof state is no longer shown by default, only

2221 the subgoals. This behaviour is controlled by a new flag.

2222 PG menu: Isabelle/Isar -> Settings -> Show Main Goal

2223 (ML: Proof.show_main_goal).

2225 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all

2226 rules whose conclusion matches subgoal 1:

2227 PG menu: Isabelle/Isar -> Show me -> matching rules

2228 The rules are ordered by how closely they match the subgoal.

2229 In particular, rules that solve a subgoal outright are displayed first

2230 (or rather last, the way they are printed).

2231 (ML: ProofGeneral.print_intros())

2233 * Pure: New flag trace_unify_fail causes unification to print

2234 diagnostic information (PG: in trace buffer) when it fails. This is

2235 useful for figuring out why single step proofs like rule, erule or

2236 assumption failed.

2238 * Pure: Locale specifications now produce predicate definitions

2239 according to the body of text (covering assumptions modulo local

2240 definitions); predicate "loc_axioms" covers newly introduced text,

2241 while "loc" is cumulative wrt. all included locale expressions; the

2242 latter view is presented only on export into the global theory

2243 context; potential INCOMPATIBILITY, use "(open)" option to fall back

2244 on the old view without predicates;

2246 * Pure: predefined locales "var" and "struct" are useful for sharing

2247 parameters (as in CASL, for example); just specify something like

2248 ``var x + var y + struct M'' as import;

2250 * Pure: improved thms_containing: proper indexing of facts instead of

2251 raw theorems; check validity of results wrt. current name space;

2252 include local facts of proof configuration (also covers active

2253 locales), cover fixed variables in index; may use "_" in term

2254 specification; an optional limit for the number of printed facts may

2255 be given (the default is 40);

2257 * Pure: disallow duplicate fact bindings within new-style theory files

2258 (batch-mode only);

2260 * Provers: improved induct method: assumptions introduced by case

2261 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from

2262 the goal statement); "foo" still refers to all facts collectively;

2264 * Provers: the function blast.overloaded has been removed: all constants

2265 are regarded as potentially overloaded, which improves robustness in exchange

2266 for slight decrease in efficiency;

2268 * Provers/linorder: New generic prover for transitivity reasoning over

2269 linear orders. Note: this prover is not efficient!

2271 * Isar: preview of problems to finish 'show' now produce an error

2272 rather than just a warning (in interactive mode);

2275 *** HOL ***

2277 * arith(_tac)

2279 - Produces a counter example if it cannot prove a goal.

2280 Note that the counter example may be spurious if the goal is not a formula

2281 of quantifier-free linear arithmetic.

2282 In ProofGeneral the counter example appears in the trace buffer.

2284 - Knows about div k and mod k where k is a numeral of type nat or int.

2286 - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free

2287 linear arithmetic fails. This takes account of quantifiers and divisibility.

2288 Presburger arithmetic can also be called explicitly via presburger(_tac).

2290 * simp's arithmetic capabilities have been enhanced a bit: it now

2291 takes ~= in premises into account (by performing a case split);

2293 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands

2294 are distributed over a sum of terms;

2296 * New tactic "trans_tac" and method "trans" instantiate

2297 Provers/linorder.ML for axclasses "order" and "linorder" (predicates

2298 "<=", "<" and "=").

2300 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main

2301 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";

2303 * 'typedef' command has new option "open" to suppress the set

2304 definition;

2306 * functions Min and Max on finite sets have been introduced (theory

2307 Finite_Set);

2309 * attribute [symmetric] now works for relations as well; it turns

2310 (x,y) : R^-1 into (y,x) : R, and vice versa;

2312 * induct over a !!-quantified statement (say !!x1..xn):

2313 each "case" automatically performs "fix x1 .. xn" with exactly those names.

2315 * Map: `empty' is no longer a constant but a syntactic abbreviation for

2316 %x. None. Warning: empty_def now refers to the previously hidden definition

2317 of the empty set.

2319 * Algebra: formalization of classical algebra. Intended as base for

2320 any algebraic development in Isabelle. Currently covers group theory

2321 (up to Sylow's theorem) and ring theory (Universal Property of

2322 Univariate Polynomials). Contributions welcome;

2324 * GroupTheory: deleted, since its material has been moved to Algebra;

2326 * Complex: new directory of the complex numbers with numeric constants,

2327 nonstandard complex numbers, and some complex analysis, standard and

2328 nonstandard (Jacques Fleuriot);

2330 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;

2332 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques

2333 Fleuriot);

2335 * Real/HahnBanach: updated and adapted to locales;

2337 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,

2338 Gray and Kramer);

2340 * UNITY: added the Meier-Sanders theory of progress sets;

2342 * MicroJava: bytecode verifier and lightweight bytecode verifier

2343 as abstract algorithms, instantiated to the JVM;

2345 * Bali: Java source language formalization. Type system, operational

2346 semantics, axiomatic semantics. Supported language features:

2347 classes, interfaces, objects,virtual methods, static methods,

2348 static/instance fields, arrays, access modifiers, definite

2349 assignment, exceptions.

2352 *** ZF ***

2354 * ZF/Constructible: consistency proof for AC (Gdel's constructible

2355 universe, etc.);

2357 * Main ZF: virtually all theories converted to new-style format;

2360 *** ML ***

2362 * Pure: Tactic.prove provides sane interface for internal proofs;

2363 omits the infamous "standard" operation, so this is more appropriate

2364 than prove_goalw_cterm in many situations (e.g. in simprocs);

2366 * Pure: improved error reporting of simprocs;

2368 * Provers: Simplifier.simproc(_i) provides sane interface for setting

2369 up simprocs;

2372 *** Document preparation ***

2374 * uses \par instead of \\ for line breaks in theory text. This may

2375 shift some page breaks in large documents. To get the old behaviour

2376 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.

2378 * minimized dependencies of isabelle.sty and isabellesym.sty on

2379 other packages

2381 * \<euro> now needs package babel/greek instead of marvosym (which

2382 broke \Rightarrow)

2384 * normal size for \<zero>...\<nine> (uses \mathbf instead of

2385 textcomp package)

2389 New in Isabelle2002 (March 2002)

2390 --------------------------------

2392 *** Document preparation ***

2394 * greatly simplified document preparation setup, including more

2395 graceful interpretation of isatool usedir -i/-d/-D options, and more

2396 instructive isatool mkdir; users should basically be able to get

2397 started with "isatool mkdir HOL Test && isatool make"; alternatively,

2398 users may run a separate document processing stage manually like this:

2399 "isatool usedir -D output HOL Test && isatool document Test/output";

2401 * theory dependency graph may now be incorporated into documents;

2402 isatool usedir -g true will produce session_graph.eps/.pdf for use

2403 with \includegraphics of LaTeX;

2405 * proper spacing of consecutive markup elements, especially text

2406 blocks after section headings;

2408 * support bold style (for single symbols only), input syntax is like

2409 this: "\<^bold>\<alpha>" or "\<^bold>A";

2411 * \<bullet> is now output as bold \cdot by default, which looks much

2412 better in printed text;

2414 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;

2415 note that these symbols are currently unavailable in Proof General /

2416 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;

2418 * isatool latex no longer depends on changed TEXINPUTS, instead

2419 isatool document copies the Isabelle style files to the target

2420 location;

2423 *** Isar ***

2425 * Pure/Provers: improved proof by cases and induction;

2426 - 'case' command admits impromptu naming of parameters (such as

2427 "case (Suc n)");

2428 - 'induct' method divinates rule instantiation from the inductive

2429 claim; no longer requires excessive ?P bindings for proper

2430 instantiation of cases;

2431 - 'induct' method properly enumerates all possibilities of set/type

2432 rules; as a consequence facts may be also passed through *type*

2433 rules without further ado;

2434 - 'induct' method now derives symbolic cases from the *rulified*

2435 rule (before it used to rulify cases stemming from the internal

2436 atomized version); this means that the context of a non-atomic

2437 statement becomes is included in the hypothesis, avoiding the

2438 slightly cumbersome show "PROP ?case" form;

2439 - 'induct' may now use elim-style induction rules without chaining

2440 facts, using ``missing'' premises from the goal state; this allows

2441 rules stemming from inductive sets to be applied in unstructured

2442 scripts, while still benefitting from proper handling of non-atomic

2443 statements; NB: major inductive premises need to be put first, all

2444 the rest of the goal is passed through the induction;

2445 - 'induct' proper support for mutual induction involving non-atomic

2446 rule statements (uses the new concept of simultaneous goals, see

2447 below);

2448 - append all possible rule selections, but only use the first

2449 success (no backtracking);

2450 - removed obsolete "(simplified)" and "(stripped)" options of methods;

2451 - undeclared rule case names default to numbers 1, 2, 3, ...;

2452 - added 'print_induct_rules' (covered by help item in recent Proof

2453 General versions);

2454 - moved induct/cases attributes to Pure, methods to Provers;

2455 - generic method setup instantiated for FOL and HOL;

2457 * Pure: support multiple simultaneous goal statements, for example

2458 "have a: A and b: B" (same for 'theorem' etc.); being a pure

2459 meta-level mechanism, this acts as if several individual goals had

2460 been stated separately; in particular common proof methods need to be

2461 repeated in order to cover all claims; note that a single elimination

2462 step is *not* sufficient to establish the two conjunctions, so this

2463 fails:

2465 assume "A & B" then have A and B .. (*".." fails*)

2467 better use "obtain" in situations as above; alternative refer to

2468 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;

2470 * Pure: proper integration with ``locales''; unlike the original

2471 version by Florian Kammller, Isar locales package high-level proof

2472 contexts rather than raw logical ones (e.g. we admit to include

2473 attributes everywhere); operations on locales include merge and

2474 rename; support for implicit arguments (``structures''); simultaneous

2475 type-inference over imports and text; see also HOL/ex/Locales.thy for

2476 some examples;

2478 * Pure: the following commands have been ``localized'', supporting a

2479 target locale specification "(in name)": 'lemma', 'theorem',

2480 'corollary', 'lemmas', 'theorems', 'declare'; the results will be

2481 stored both within the locale and at the theory level (exported and

2482 qualified by the locale name);

2484 * Pure: theory goals may now be specified in ``long'' form, with

2485 ad-hoc contexts consisting of arbitrary locale elements. for example

2486 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and

2487 definitions may be given, too); the result is a meta-level rule with

2488 the context elements being discharged in the obvious way;

2490 * Pure: new proof command 'using' allows to augment currently used

2491 facts after a goal statement ('using' is syntactically analogous to

2492 'apply', but acts on the goal's facts only); this allows chained facts

2493 to be separated into parts given before and after a claim, as in

2494 ``from a and b have C using d and e <proof>'';

2496 * Pure: renamed "antecedent" case to "rule_context";

2498 * Pure: new 'judgment' command records explicit information about the

2499 object-logic embedding (used by several tools internally); no longer

2500 use hard-wired "Trueprop";

2502 * Pure: added 'corollary' command;

2504 * Pure: fixed 'token_translation' command;

2506 * Pure: removed obsolete 'exported' attribute;

2508 * Pure: dummy pattern "_" in is/let is now automatically lifted over

2509 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")

2510 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");

2512 * Pure: method 'atomize' presents local goal premises as object-level

2513 statements (atomic meta-level propositions); setup controlled via

2514 rewrite rules declarations of 'atomize' attribute; example

2515 application: 'induct' method with proper rule statements in improper

2516 proof *scripts*;

2518 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)

2519 now consider the syntactic context of assumptions, giving a better

2520 chance to get type-inference of the arguments right (this is

2521 especially important for locales);

2523 * Pure: "sorry" no longer requires quick_and_dirty in interactive

2524 mode;

2526 * Pure/obtain: the formal conclusion "thesis", being marked as

2527 ``internal'', may no longer be reference directly in the text;

2528 potential INCOMPATIBILITY, may need to use "?thesis" in rare

2529 situations;

2531 * Pure: generic 'sym' attribute which declares a rule both as pure

2532 'elim?' and for the 'symmetric' operation;

2534 * Pure: marginal comments ``--'' may now occur just anywhere in the

2535 text; the fixed correlation with particular command syntax has been

2536 discontinued;

2538 * Pure: new method 'rules' is particularly well-suited for proof

2539 search in intuitionistic logic; a bit slower than 'blast' or 'fast',

2540 but often produces more compact proof terms with less detours;

2542 * Pure/Provers/classical: simplified integration with pure rule

2543 attributes and methods; the classical "intro?/elim?/dest?"

2544 declarations coincide with the pure ones; the "rule" method no longer

2545 includes classically swapped intros; "intro" and "elim" methods no

2546 longer pick rules from the context; also got rid of ML declarations

2547 AddXIs/AddXEs/AddXDs; all of this has some potential for

2548 INCOMPATIBILITY;

2550 * Provers/classical: attribute 'swapped' produces classical inversions

2551 of introduction rules;

2553 * Provers/simplifier: 'simplified' attribute may refer to explicit

2554 rules instead of full simplifier context; 'iff' attribute handles

2555 conditional rules;

2557 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;

2559 * HOL: 'recdef' now fails on unfinished automated proofs, use

2560 "(permissive)" option to recover old behavior;

2562 * HOL: 'inductive' no longer features separate (collective) attributes

2563 for 'intros' (was found too confusing);

2565 * HOL: properly declared induction rules less_induct and

2566 wf_induct_rule;

2569 *** HOL ***

2571 * HOL: moved over to sane numeral syntax; the new policy is as

2572 follows:

2574 - 0 and 1 are polymorphic constants, which are defined on any

2575 numeric type (nat, int, real etc.);

2577 - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based

2578 binary representation internally;

2580 - type nat has special constructor Suc, and generally prefers Suc 0

2581 over 1::nat and Suc (Suc 0) over 2::nat;

2583 This change may cause significant problems of INCOMPATIBILITY; here

2584 are some hints on converting existing sources:

2586 - due to the new "num" token, "-0" and "-1" etc. are now atomic

2587 entities, so expressions involving "-" (unary or binary minus) need

2588 to be spaced properly;

2590 - existing occurrences of "1" may need to be constraint "1::nat" or

2591 even replaced by Suc 0; similar for old "2";

2593 - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";

2595 - remove all special provisions on numerals in proofs;

2597 * HOL: simp rules nat_number expand numerals on nat to Suc/0

2598 representation (depends on bin_arith_simps in the default context);

2600 * HOL: symbolic syntax for x^2 (numeral 2);

2602 * HOL: the class of all HOL types is now called "type" rather than

2603 "term"; INCOMPATIBILITY, need to adapt references to this type class

2604 in axclass/classes, instance/arities, and (usually rare) occurrences

2605 in typings (of consts etc.); internally the class is called

2606 "HOL.type", ML programs should refer to HOLogic.typeS;

2608 * HOL/record package improvements:

2609 - new derived operations "fields" to build a partial record section,

2610 "extend" to promote a fixed record to a record scheme, and

2611 "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*

2612 declared as simp by default;

2613 - shared operations ("more", "fields", etc.) now need to be always

2614 qualified) --- potential INCOMPATIBILITY;

2615 - removed "make_scheme" operations (use "make" with "extend") --

2616 INCOMPATIBILITY;

2617 - removed "more" class (simply use "term") -- INCOMPATIBILITY;

2618 - provides cases/induct rules for use with corresponding Isar

2619 methods (for concrete records, record schemes, concrete more

2620 parts, and schematic more parts -- in that order);

2621 - internal definitions directly based on a light-weight abstract

2622 theory of product types over typedef rather than datatype;

2624 * HOL: generic code generator for generating executable ML code from

2625 specifications; specific support for HOL constructs such as inductive

2626 datatypes and sets, as well as recursive functions; can be invoked

2627 via 'generate_code' theory section;

2629 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);

2631 * HOL: consolidated and renamed several theories. In particular:

2632 Ord.thy has been absorbed into HOL.thy

2633 String.thy has been absorbed into List.thy

2635 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"

2636 (beware of argument permutation!);

2638 * HOL: linorder_less_split superseded by linorder_cases;

2640 * HOL/List: "nodups" renamed to "distinct";

2642 * HOL: added "The" definite description operator; move Hilbert's "Eps"

2643 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:

2644 - Ex_def has changed, now need to use some_eq_ex

2646 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so

2647 in this (rare) case use:

2649 delSWrapper "split_all_tac"

2650 addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)

2652 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS

2653 MAY FAIL;

2655 * HOL: introduced f^n = f o ... o f; warning: due to the limits of

2656 Isabelle's type classes, ^ on functions and relations has too general

2657 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be

2658 necessary to attach explicit type constraints;

2660 * HOL/Relation: the prefix name of the infix "O" has been changed from

2661 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been

2662 renamed accordingly (eg "compI" -> "rel_compI").

2664 * HOL: syntax translations now work properly with numerals and records

2665 expressions;

2667 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead

2668 of "lam" -- INCOMPATIBILITY;

2670 * HOL: got rid of some global declarations (potential INCOMPATIBILITY

2671 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"

2672 renamed "Product_Type.unit";

2674 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl

2676 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or

2677 the "cases" method);

2679 * HOL/GroupTheory: group theory examples including Sylow's theorem (by

2680 Florian Kammller);

2682 * HOL/IMP: updated and converted to new-style theory format; several

2683 parts turned into readable document, with proper Isar proof texts and

2684 some explanations (by Gerwin Klein);

2686 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);

2688 * HOL-Hyperreal is now a logic image;

2691 *** HOLCF ***

2693 * Isar: consts/constdefs supports mixfix syntax for continuous

2694 operations;

2696 * Isar: domain package adapted to new-style theory format, e.g. see

2697 HOLCF/ex/Dnat.thy;

2699 * theory Lift: proper use of rep_datatype lift instead of ML hacks --

2700 potential INCOMPATIBILITY; now use plain induct_tac instead of former

2701 lift.induct_tac, always use UU instead of Undef;

2703 * HOLCF/IMP: updated and converted to new-style theory;

2706 *** ZF ***

2708 * Isar: proper integration of logic-specific tools and packages,

2709 including theory commands '(co)inductive', '(co)datatype',

2710 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',

2711 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');

2713 * theory Main no longer includes AC; for the Axiom of Choice, base

2714 your theory on Main_ZFC;

2716 * the integer library now covers quotients and remainders, with many

2717 laws relating division to addition, multiplication, etc.;

2719 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a

2720 typeless version of the formalism;

2722 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory

2723 format;

2725 * ZF/Induct: new directory for examples of inductive definitions,

2726 including theory Multiset for multiset orderings; converted to

2727 new-style theory format;

2729 * ZF: many new theorems about lists, ordinals, etc.;

2732 *** General ***

2734 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference

2735 variable proof controls level of detail: 0 = no proofs (only oracle

2736 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see

2737 also ref manual for further ML interfaces;

2739 * Pure/axclass: removed obsolete ML interface

2740 goal_subclass/goal_arity;

2742 * Pure/syntax: new token syntax "num" for plain numerals (without "#"

2743 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now

2744 separate tokens, so expressions involving minus need to be spaced

2745 properly;

2747 * Pure/syntax: support non-oriented infixes, using keyword "infix"

2748 rather than "infixl" or "infixr";

2750 * Pure/syntax: concrete syntax for dummy type variables admits genuine

2751 sort constraint specifications in type inference; e.g. "x::_::foo"

2752 ensures that the type of "x" is of sort "foo" (but not necessarily a

2753 type variable);

2755 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"

2756 control output of nested => (types); the default behavior is

2757 "type_brackets";

2759 * Pure/syntax: builtin parse translation for "_constify" turns valued

2760 tokens into AST constants;

2762 * Pure/syntax: prefer later declarations of translations and print

2763 translation functions; potential INCOMPATIBILITY: need to reverse

2764 multiple declarations for same syntax element constant;

2766 * Pure/show_hyps reset by default (in accordance to existing Isar

2767 practice);

2769 * Provers/classical: renamed addaltern to addafter, addSaltern to

2770 addSafter;

2772 * Provers/clasimp: ``iff'' declarations now handle conditional rules

2773 as well;

2775 * system: tested support for MacOS X; should be able to get Isabelle +

2776 Proof General to work in a plain Terminal after installing Poly/ML

2777 (e.g. from the Isabelle distribution area) and GNU bash alone

2778 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol

2779 support requires further installations, e.g. from

2780 http://fink.sourceforge.net/);

2782 * system: support Poly/ML 4.1.1 (able to manage larger heaps);

2784 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead

2785 of 40 MB), cf. ML_OPTIONS;

2787 * system: Proof General keywords specification is now part of the

2788 Isabelle distribution (see etc/isar-keywords.el);

2790 * system: support for persistent Proof General sessions (refrain from

2791 outdating all loaded theories on startup); user may create writable

2792 logic images like this: ``isabelle -q HOL Test'';

2794 * system: smart selection of Isabelle process versus Isabelle

2795 interface, accommodates case-insensitive file systems (e.g. HFS+); may

2796 run both "isabelle" and "Isabelle" even if file names are badly

2797 damaged (executable inspects the case of the first letter of its own

2798 name); added separate "isabelle-process" and "isabelle-interface";

2800 * system: refrain from any attempt at filtering input streams; no

2801 longer support ``8bit'' encoding of old isabelle font, instead proper

2802 iso-latin characters may now be used; the related isatools

2803 "symbolinput" and "nonascii" have disappeared as well;

2805 * system: removed old "xterm" interface (the print modes "xterm" and

2806 "xterm_color" are still available for direct use in a suitable

2807 terminal);

2811 New in Isabelle99-2 (February 2001)

2812 -----------------------------------

2814 *** Overview of INCOMPATIBILITIES ***

2816 * HOL: please note that theories in the Library and elsewhere often use the

2817 new-style (Isar) format; to refer to their theorems in an ML script you must

2818 bind them to ML identifers by e.g. val thm_name = thm "thm_name";

2820 * HOL: inductive package no longer splits induction rule aggressively,

2821 but only as far as specified by the introductions given; the old

2822 format may be recovered via ML function complete_split_rule or attribute

2823 'split_rule (complete)';

2825 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,

2826 gfp_Tarski to gfp_unfold;

2828 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;

2830 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a

2831 relation); infix "^^" has been renamed "``"; infix "``" has been

2832 renamed "`"; "univalent" has been renamed "single_valued";

2834 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"

2835 operation;

2837 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;

2839 * Isar: 'obtain' no longer declares "that" fact as simp/intro;

2841 * Isar/HOL: method 'induct' now handles non-atomic goals; as a

2842 consequence, it is no longer monotonic wrt. the local goal context

2843 (which is now passed through the inductive cases);

2845 * Document preparation: renamed standard symbols \<ll> to \<lless> and

2846 \<gg> to \<ggreater>;

2849 *** Document preparation ***

2851 * \isabellestyle{NAME} selects version of Isabelle output (currently

2852 available: are "it" for near math-mode best-style output, "sl" for

2853 slanted text style, and "tt" for plain type-writer; if no

2854 \isabellestyle command is given, output is according to slanted

2855 type-writer);

2857 * support sub/super scripts (for single symbols only), input syntax is

2858 like this: "A\<^sup>*" or "A\<^sup>\<star>";

2860 * some more standard symbols; see Appendix A of the system manual for

2861 the complete list of symbols defined in isabellesym.sty;

2863 * improved isabelle style files; more abstract symbol implementation

2864 (should now use \isamath{...} and \isatext{...} in custom symbol

2865 definitions);

2867 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals

2868 state; Note that presentation of goal states does not conform to

2869 actual human-readable proof documents. Please do not include goal

2870 states into document output unless you really know what you are doing!

2872 * proper indentation of antiquoted output with proportional LaTeX

2873 fonts;

2875 * no_document ML operator temporarily disables LaTeX document

2876 generation;

2878 * isatool unsymbolize tunes sources for plain ASCII communication;

2881 *** Isar ***

2883 * Pure: Isar now suffers initial goal statements to contain unbound

2884 schematic variables (this does not conform to actual readable proof

2885 documents, due to unpredictable outcome and non-compositional proof

2886 checking); users who know what they are doing may use schematic goals

2887 for Prolog-style synthesis of proven results;

2889 * Pure: assumption method (an implicit finishing) now handles actual

2890 rules as well;

2892 * Pure: improved 'obtain' --- moved to Pure, insert "that" into

2893 initial goal, declare "that" only as Pure intro (only for single

2894 steps); the "that" rule assumption may now be involved in implicit

2895 finishing, thus ".." becomes a feasible for trivial obtains;

2897 * Pure: default proof step now includes 'intro_classes'; thus trivial

2898 instance proofs may be performed by "..";

2900 * Pure: ?thesis / ?this / "..." now work for pure meta-level

2901 statements as well;

2903 * Pure: more robust selection of calculational rules;

2905 * Pure: the builtin notion of 'finished' goal now includes the ==-refl

2906 rule (as well as the assumption rule);

2908 * Pure: 'thm_deps' command visualizes dependencies of theorems and

2909 lemmas, using the graph browser tool;

2911 * Pure: predict failure of "show" in interactive mode;

2913 * Pure: 'thms_containing' now takes actual terms as arguments;

2915 * HOL: improved method 'induct' --- now handles non-atomic goals

2916 (potential INCOMPATIBILITY); tuned error handling;

2918 * HOL: cases and induct rules now provide explicit hints about the

2919 number of facts to be consumed (0 for "type" and 1 for "set" rules);

2920 any remaining facts are inserted into the goal verbatim;

2922 * HOL: local contexts (aka cases) may now contain term bindings as

2923 well; the 'cases' and 'induct' methods new provide a ?case binding for

2924 the result to be shown in each case;

2926 * HOL: added 'recdef_tc' command;

2928 * isatool convert assists in eliminating legacy ML scripts;

2931 *** HOL ***

2933 * HOL/Library: a collection of generic theories to be used together

2934 with main HOL; the theory loader path already includes this directory

2935 by default; the following existing theories have been moved here:

2936 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While

2937 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);

2939 * HOL/Unix: "Some aspects of Unix file-system security", a typical

2940 modelling and verification task performed in Isabelle/HOL +

2941 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).

2943 * HOL/Algebra: special summation operator SUM no longer exists, it has

2944 been replaced by setsum; infix 'assoc' now has priority 50 (like

2945 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to

2946 'domain', this makes the theory consistent with mathematical

2947 literature;

2949 * HOL basics: added overloaded operations "inverse" and "divide"

2950 (infix "/"), syntax for generic "abs" operation, generic summation

2951 operator \<Sum>;

2953 * HOL/typedef: simplified package, provide more useful rules (see also

2954 HOL/subset.thy);

2956 * HOL/datatype: induction rule for arbitrarily branching datatypes is

2957 now expressed as a proper nested rule (old-style tactic scripts may

2958 require atomize_strip_tac to cope with non-atomic premises);

2960 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule

2961 to "split_conv" (old name still available for compatibility);

2963 * HOL: improved concrete syntax for strings (e.g. allows translation

2964 rules with string literals);

2966 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals

2967 and Fleuriot's mechanization of analysis, including the transcendental

2968 functions for the reals;

2970 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;

2973 *** CTT ***

2975 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that

2976 "lam" is displayed as TWO lambda-symbols

2978 * CTT: theory Main now available, containing everything (that is, Bool

2979 and Arith);

2982 *** General ***

2984 * Pure: the Simplifier has been implemented properly as a derived rule

2985 outside of the actual kernel (at last!); the overall performance

2986 penalty in practical applications is about 50%, while reliability of

2987 the Isabelle inference kernel has been greatly improved;

2989 * print modes "brackets" and "no_brackets" control output of nested =>

2990 (types) and ==> (props); the default behaviour is "brackets";

2992 * Provers: fast_tac (and friends) now handle actual object-logic rules

2993 as assumptions as well;

2995 * system: support Poly/ML 4.0;

2997 * system: isatool install handles KDE version 1 or 2;

3001 New in Isabelle99-1 (October 2000)

3002 ----------------------------------

3004 *** Overview of INCOMPATIBILITIES ***

3006 * HOL: simplification of natural numbers is much changed; to partly

3007 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)

3008 issue the following ML commands:

3010 Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;

3011 Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];

3013 * HOL: simplification no longer dives into case-expressions; this is

3014 controlled by "t.weak_case_cong" for each datatype t;

3016 * HOL: nat_less_induct renamed to less_induct;

3018 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool

3019 fixsome to patch .thy and .ML sources automatically;

3021 select_equality -> some_equality

3022 select_eq_Ex -> some_eq_ex

3023 selectI2EX -> someI2_ex

3024 selectI2 -> someI2

3025 selectI -> someI

3026 select1_equality -> some1_equality

3027 Eps_sym_eq -> some_sym_eq_trivial

3028 Eps_eq -> some_eq_trivial

3030 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;

3032 * HOL: removed obsolete theorem binding expand_if (refer to split_if

3033 instead);

3035 * HOL: the recursion equations generated by 'recdef' are now called

3036 f.simps instead of f.rules;

3038 * HOL: qed_spec_mp now also handles bounded ALL as well;

3040 * HOL: 0 is now overloaded, so the type constraint ":: nat" may

3041 sometimes be needed;

3043 * HOL: the constant for "f``x" is now "image" rather than "op ``";

3045 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";

3047 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian

3048 product is now "<*>" instead of "Times"; the lexicographic product is

3049 now "<*lex*>" instead of "**";

3051 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part

3052 of main HOL, but was unused); better use HOL's datatype package;

3054 * HOL: removed "symbols" syntax for constant "override" of theory Map;

3055 the old syntax may be recovered as follows:

3057 syntax (symbols)

3058 override :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"

3059 (infixl "\\<oplus>" 100)

3061 * HOL/Real: "rabs" replaced by overloaded "abs" function;

3063 * HOL/ML: even fewer consts are declared as global (see theories Ord,

3064 Lfp, Gfp, WF); this only affects ML packages that refer to const names

3065 internally;

3067 * HOL and ZF: syntax for quotienting wrt an equivalence relation

3068 changed from A/r to A//r;

3070 * ZF: new treatment of arithmetic (nat & int) may break some old

3071 proofs;

3073 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,

3074 rulify -> rule_format, elimify -> elim_format, ...);

3076 * Isar/Provers: intro/elim/dest attributes changed; renamed

3077 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one

3078 should have to change intro!! to intro? only); replaced "delrule" by

3079 "rule del";

3081 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;

3083 * Provers: strengthened force_tac by using new first_best_tac;

3085 * LaTeX document preparation: several changes of isabelle.sty (see

3086 lib/texinputs);

3089 *** Document preparation ***

3091 * formal comments (text blocks etc.) in new-style theories may now

3092 contain antiquotations of thm/prop/term/typ/text to be presented

3093 according to latex print mode; concrete syntax is like this:

3094 @{term[show_types] "f(x) = a + x"};

3096 * isatool mkdir provides easy setup of Isabelle session directories,

3097 including proper document sources;

3099 * generated LaTeX sources are now deleted after successful run

3100 (isatool document -c); may retain a copy somewhere else via -D option

3101 of isatool usedir;

3103 * isatool usedir -D now lets isatool latex -o sty update the Isabelle

3104 style files, achieving self-contained LaTeX sources and simplifying

3105 LaTeX debugging;

3107 * old-style theories now produce (crude) LaTeX output as well;

3109 * browser info session directories are now self-contained (may be put

3110 on WWW server seperately); improved graphs of nested sessions; removed

3111 graph for 'all sessions';

3113 * several improvements in isabelle style files; \isabellestyle{it}

3114 produces fake math mode output; \isamarkupheader is now \section by

3115 default; see lib/texinputs/isabelle.sty etc.;

3118 *** Isar ***

3120 * Isar/Pure: local results and corresponding term bindings are now

3121 subject to Hindley-Milner polymorphism (similar to ML); this

3122 accommodates incremental type-inference very nicely;

3124 * Isar/Pure: new derived language element 'obtain' supports

3125 generalized existence reasoning;

3127 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'

3128 support accumulation of results, without applying any rules yet;

3129 useful to collect intermediate results without explicit name

3130 references, and for use with transitivity rules with more than 2

3131 premises;

3133 * Isar/Pure: scalable support for case-analysis type proofs: new

3134 'case' language element refers to local contexts symbolically, as

3135 produced by certain proof methods; internally, case names are attached

3136 to theorems as "tags";

3138 * Isar/Pure: theory command 'hide' removes declarations from

3139 class/type/const name spaces;

3141 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to

3142 indicate potential overloading;

3144 * Isar/Pure: changed syntax of local blocks from {{ }} to { };

3146 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write

3147 "{a,b,c}" instead of {a,b,c};

3149 * Isar/Pure now provides its own version of intro/elim/dest

3150 attributes; useful for building new logics, but beware of confusion

3151 with the version in Provers/classical;

3153 * Isar/Pure: the local context of (non-atomic) goals is provided via

3154 case name 'antecedent';

3156 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms

3157 to the current context is now done automatically);

3159 * Isar/Pure: theory command 'method_setup' provides a simple interface

3160 for definining proof methods in ML;

3162 * Isar/Provers: intro/elim/dest attributes changed; renamed

3163 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in

3164 most cases, one should have to change intro!! to intro? only);

3165 replaced "delrule" by "rule del";

3167 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and

3168 'symmetric' attribute (the latter supercedes [RS sym]);

3170 * Isar/Provers: splitter support (via 'split' attribute and 'simp'

3171 method modifier); 'simp' method: 'only:' modifier removes loopers as

3172 well (including splits);

3174 * Isar/Provers: Simplifier and Classical methods now support all kind

3175 of modifiers used in the past, including 'cong', 'iff', etc.

3177 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination

3178 of Simplifier and Classical reasoner);

3180 * Isar/HOL: new proof method 'cases' and improved version of 'induct'

3181 now support named cases; major packages (inductive, datatype, primrec,

3182 recdef) support case names and properly name parameters;

3184 * Isar/HOL: new transitivity rules for substitution in inequalities --

3185 monotonicity conditions are extracted to be proven at end of

3186 calculations;

3188 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof

3189 method anyway;

3191 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =

3192 split_if split_if_asm; datatype package provides theorems foo.splits =

3193 foo.split foo.split_asm for each datatype;

3195 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"

3196 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof

3197 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:

3198 use "(cases (simplified))" method in proper proof texts);

3200 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;

3202 * Isar: names of theorems etc. may be natural numbers as well;

3204 * Isar: 'pr' command: optional arguments for goals_limit and

3205 ProofContext.prems_limit; no longer prints theory contexts, but only

3206 proof states;

3208 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit

3209 additional print modes to be specified; e.g. "pr(latex)" will print

3210 proof state according to the Isabelle LaTeX style;

3212 * Isar: improved support for emulating tactic scripts, including proof

3213 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',

3214 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'

3215 (for HOL datatypes);

3217 * Isar: simplified (more robust) goal selection of proof methods: 1st

3218 goal, all goals, or explicit goal specifier (tactic emulation); thus

3219 'proof method scripts' have to be in depth-first order;

3221 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';

3223 * Isar: removed 'help' command, which hasn't been too helpful anyway;

3224 should instead use individual commands for printing items

3225 (print_commands, print_methods etc.);

3227 * Isar: added 'nothing' --- the empty list of theorems;

3230 *** HOL ***

3232 * HOL/MicroJava: formalization of a fragment of Java, together with a

3233 corresponding virtual machine and a specification of its bytecode

3234 verifier and a lightweight bytecode verifier, including proofs of

3235 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and

3236 Cornelia Pusch (see also the homepage of project Bali at

3237 http://isabelle.in.tum.de/Bali/);

3239 * HOL/Algebra: new theory of rings and univariate polynomials, by

3240 Clemens Ballarin;

3242 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese

3243 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M

3244 Rasmussen;

3246 * HOL/Lattice: fundamental concepts of lattice theory and order

3247 structures, including duals, properties of bounds versus algebraic

3248 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski

3249 Theorem for complete lattices etc.; may also serve as a demonstration

3250 for abstract algebraic reasoning using axiomatic type classes, and

3251 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;

3253 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David

3254 von Oheimb;

3256 * HOL/IMPP: extension of IMP with local variables and mutually

3257 recursive procedures, by David von Oheimb;

3259 * HOL/Lambda: converted into new-style theory and document;

3261 * HOL/ex/Multiquote: example of multiple nested quotations and

3262 anti-quotations -- basically a generalized version of de-Bruijn

3263 representation; very useful in avoiding lifting of operations;

3265 * HOL/record: added general record equality rule to simpset; fixed

3266 select-update simplification procedure to handle extended records as

3267 well; admit "r" as field name;

3269 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with

3270 other numeric types and also as the identity of groups, rings, etc.;

3272 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.

3273 Types nat and int belong to this axclass;

3275 * HOL: greatly improved simplification involving numerals of type nat, int, real:

3276 (i + #8 + j) = Suc k simplifies to #7 + (i + j) = k

3277 i*j + k + j*#3*i simplifies to #4*(i*j) + k

3278 two terms #m*u and #n*u are replaced by #(m+n)*u

3279 (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)

3280 and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y

3281 or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);

3283 * HOL: meson_tac is available (previously in ex/meson.ML); it is a

3284 powerful prover for predicate logic but knows nothing of clasets; see

3285 ex/mesontest.ML and ex/mesontest2.ML for example applications;

3287 * HOL: new version of "case_tac" subsumes both boolean case split and

3288 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer

3289 exists, may define val exhaust_tac = case_tac for ad-hoc portability;

3291 * HOL: simplification no longer dives into case-expressions: only the

3292 selector expression is simplified, but not the remaining arms; to

3293 enable full simplification of case-expressions for datatype t, you may

3294 remove t.weak_case_cong from the simpset, either globally (Delcongs

3295 [thm"t.weak_case_cong"];) or locally (delcongs [...]).

3297 * HOL/recdef: the recursion equations generated by 'recdef' for

3298 function 'f' are now called f.simps instead of f.rules; if all

3299 termination conditions are proved automatically, these simplification

3300 rules are added to the simpset, as in primrec; rules may be named

3301 individually as well, resulting in a separate list of theorems for

3302 each equation;

3304 * HOL/While is a new theory that provides a while-combinator. It

3305 permits the definition of tail-recursive functions without the

3306 provision of a termination measure. The latter is necessary once the

3307 invariant proof rule for while is applied.

3309 * HOL: new (overloaded) notation for the set of elements below/above

3310 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.

3312 * HOL: theorems impI, allI, ballI bound as "strip";

3314 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic

3315 induct_tac th "x1 ... xn" expects th to have a conclusion of the form

3316 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;

3318 * HOL/Real: "rabs" replaced by overloaded "abs" function;

3320 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of

3321 main HOL, but was unused);

3323 * HOL: fewer consts declared as global (e.g. have to refer to

3324 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);

3326 * HOL: tuned AST representation of nested pairs, avoiding bogus output

3327 in case of overlap with user translations (e.g. judgements over

3328 tuples); (note that the underlying logical represenation is still

3329 bogus);

3332 *** ZF ***

3334 * ZF: simplification automatically cancels common terms in arithmetic

3335 expressions over nat and int;

3337 * ZF: new treatment of nat to minimize type-checking: all operators

3338 coerce their operands to a natural number using the function natify,

3339 making the algebraic laws unconditional;

3341 * ZF: as above, for int: operators coerce their operands to an integer

3342 using the function intify;

3344 * ZF: the integer library now contains many of the usual laws for the

3345 orderings, including $<=, and monotonicity laws for $+ and $*;

3347 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic

3348 simplification;

3350 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q

3351 to the simplifier and classical reasoner simultaneously;

3354 *** General ***

3356 * Provers: blast_tac now handles actual object-logic rules as

3357 assumptions; note that auto_tac uses blast_tac internally as well;

3359 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning

3360 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;

3362 * Provers: delrules now handles destruct rules as well (no longer need

3363 explicit make_elim);

3365 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.

3366 [| inj ?f; ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W

3367 use instead the strong form,

3368 [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W

3369 in HOL, FOL and ZF the function cla_make_elim will create such rules

3370 from destruct-rules;

3372 * Provers: Simplifier.easy_setup provides a fast path to basic

3373 Simplifier setup for new object-logics;

3375 * Pure: AST translation rules no longer require constant head on LHS;

3377 * Pure: improved name spaces: ambiguous output is qualified; support

3378 for hiding of names;

3380 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and

3381 XSYMBOL_HOME; no longer need to do manual configuration in most

3382 situations;

3384 * system: compression of ML heaps images may now be controlled via -c

3385 option of isabelle and isatool usedir (currently only observed by

3386 Poly/ML);

3388 * system: isatool installfonts may handle X-Symbol fonts as well (very

3389 useful for remote X11);

3391 * system: provide TAGS file for Isabelle sources;

3393 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument

3394 order;

3396 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global

3397 timing flag supersedes proof_timing and Toplevel.trace;

3399 * ML: new combinators |>> and |>>> for incremental transformations

3400 with secondary results (e.g. certain theory extensions):

3402 * ML: PureThy.add_defs gets additional argument to indicate potential

3403 overloading (usually false);

3405 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as

3406 results;

3410 New in Isabelle99 (October 1999)

3411 --------------------------------

3413 *** Overview of INCOMPATIBILITIES (see below for more details) ***

3415 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)

3416 are no longer simplified. (This allows the simplifier to unfold recursive

3417 functional programs.) To restore the old behaviour, declare

3419 Delcongs [if_weak_cong];

3421 * HOL: Removed the obsolete syntax "Compl A"; use -A for set

3422 complement;

3424 * HOL: the predicate "inj" is now defined by translation to "inj_on";

3426 * HOL/datatype: mutual_induct_tac no longer exists --

3427 use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]

3429 * HOL/typedef: fixed type inference for representing set; type

3430 arguments now have to occur explicitly on the rhs as type constraints;

3432 * ZF: The con_defs part of an inductive definition may no longer refer

3433 to constants declared in the same theory;

3435 * HOL, ZF: the function mk_cases, generated by the inductive

3436 definition package, has lost an argument. To simplify its result, it

3437 uses the default simpset instead of a supplied list of theorems.

3439 * HOL/List: the constructors of type list are now Nil and Cons;

3441 * Simplifier: the type of the infix ML functions

3442 setSSolver addSSolver setSolver addSolver

3443 is now simpset * solver -> simpset where `solver' is a new abstract type

3444 for packaging solvers. A solver is created via

3445 mk_solver: string -> (thm list -> int -> tactic) -> solver

3446 where the string argument is only a comment.

3449 *** Proof tools ***

3451 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a

3452 decision procedure for linear arithmetic. Currently it is used for

3453 types `nat', `int', and `real' in HOL (see below); it can, should and

3454 will be instantiated for other types and logics as well.

3456 * The simplifier now accepts rewrite rules with flexible heads, eg

3457 hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y

3458 They are applied like any rule with a non-pattern lhs, i.e. by first-order

3459 matching.

3462 *** General ***

3464 * New Isabelle/Isar subsystem provides an alternative to traditional

3465 tactical theorem proving; together with the ProofGeneral/isar user

3466 interface it offers an interactive environment for developing human

3467 readable proof documents (Isar == Intelligible semi-automated

3468 reasoning); for further information see isatool doc isar-ref,

3469 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/

3471 * improved and simplified presentation of theories: better HTML markup

3472 (including colors), graph views in several sizes; isatool usedir now

3473 provides a proper interface for user theories (via -P option); actual

3474 document preparation based on (PDF)LaTeX is available as well (for

3475 new-style theories only); see isatool doc system for more information;

3477 * native support for Proof General, both for classic Isabelle and

3478 Isabelle/Isar;

3480 * ML function thm_deps visualizes dependencies of theorems and lemmas,

3481 using the graph browser tool;

3483 * Isabelle manuals now also available as PDF;

3485 * theory loader rewritten from scratch (may not be fully

3486 bug-compatible); old loadpath variable has been replaced by show_path,

3487 add_path, del_path, reset_path functions; new operations such as

3488 update_thy, touch_thy, remove_thy, use/update_thy_only (see also

3489 isatool doc ref);

3491 * improved isatool install: option -k creates KDE application icon,

3492 option -p DIR installs standalone binaries;

3494 * added ML_PLATFORM setting (useful for cross-platform installations);

3495 more robust handling of platform specific ML images for SML/NJ;

3497 * the settings environment is now statically scoped, i.e. it is never

3498 created again in sub-processes invoked from isabelle, isatool, or

3499 Isabelle;

3501 * path element specification '~~' refers to '$ISABELLE_HOME';

3503 * in locales, the "assumes" and "defines" parts may be omitted if

3504 empty;

3506 * new print_mode "xsymbols" for extended symbol support (e.g. genuine

3507 long arrows);

3509 * new print_mode "HTML";

3511 * new flag show_tags controls display of tags of theorems (which are

3512 basically just comments that may be attached by some tools);

3514 * Isamode 2.6 requires patch to accomodate change of Isabelle font

3515 mode and goal output format:

3517 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el

3518 244c244

3519 < (list (isa-getenv "ISABELLE") "-msymbols" logic-name)

3520 ---

3521 > (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)

3522 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el

3523 181c181

3524 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"

3525 ---

3526 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"

3528 * function bind_thms stores lists of theorems (cf. bind_thm);

3530 * new shorthand tactics ftac, eatac, datac, fatac;

3532 * qed (and friends) now accept "" as result name; in that case the

3533 theorem is not stored, but proper checks and presentation of the

3534 result still apply;

3536 * theorem database now also indexes constants "Trueprop", "all",

3537 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;

3540 *** HOL ***

3542 ** HOL arithmetic **

3544 * There are now decision procedures for linear arithmetic over nat and

3545 int:

3547 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',

3548 `+', `-', `Suc', `min', `max' and numerical constants; other subterms

3549 are treated as atomic; subformulae not involving type `nat' or `int'

3550 are ignored; quantified subformulae are ignored unless they are

3551 positive universal or negative existential. The tactic has to be

3552 invoked by hand and can be a little bit slow. In particular, the

3553 running time is exponential in the number of occurrences of `min' and

3554 `max', and `-' on `nat'.

3556 2. fast_arith_tac is a cut-down version of arith_tac: it only takes

3557 (negated) (in)equalities among the premises and the conclusion into

3558 account (i.e. no compound formulae) and does not know about `min' and

3559 `max', and `-' on `nat'. It is fast and is used automatically by the

3560 simplifier.

3562 NB: At the moment, these decision procedures do not cope with mixed

3563 nat/int formulae where the two parts interact, such as `m < n ==>

3564 int(m) < int(n)'.

3566 * HOL/Numeral provides a generic theory of numerals (encoded

3567 efficiently as bit strings); setup for types nat/int/real is in place;

3568 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than

3569 int, existing theories and proof scripts may require a few additional

3570 type constraints;

3572 * integer division and remainder can now be performed on constant

3573 arguments;

3575 * many properties of integer multiplication, division and remainder

3576 are now available;

3578 * An interface to the Stanford Validity Checker (SVC) is available through the

3579 tactic svc_tac. Propositional tautologies and theorems of linear arithmetic

3580 are proved automatically. SVC must be installed separately, and its results

3581 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any

3582 invocation of the underlying oracle). For SVC see

3583 http://verify.stanford.edu/SVC

3585 * IsaMakefile: the HOL-Real target now builds an actual image;

3588 ** HOL misc **

3590 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces

3591 (in Isabelle/Isar) -- by Gertrud Bauer;

3593 * HOL/BCV: generic model of bytecode verification, i.e. data-flow

3594 analysis for assembly languages with subtypes;

3596 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization

3597 -- avoids syntactic ambiguities and treats state, transition, and

3598 temporal levels more uniformly; introduces INCOMPATIBILITIES due to

3599 changed syntax and (many) tactics;

3601 * HOL/inductive: Now also handles more general introduction rules such

3602 as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity

3603 theorems are now maintained within the theory (maintained via the

3604 "mono" attribute);

3606 * HOL/datatype: Now also handles arbitrarily branching datatypes

3607 (using function types) such as

3609 datatype 'a tree = Atom 'a | Branch "nat => 'a tree"

3611 * HOL/record: record_simproc (part of the default simpset) takes care

3612 of selectors applied to updated records; record_split_tac is no longer

3613 part of the default claset; update_defs may now be removed from the

3614 simpset in many cases; COMPATIBILITY: old behavior achieved by

3616 claset_ref () := claset() addSWrapper record_split_wrapper;

3617 Delsimprocs [record_simproc]

3619 * HOL/typedef: fixed type inference for representing set; type

3620 arguments now have to occur explicitly on the rhs as type constraints;

3622 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem

3623 names rather than an ML expression;

3625 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be

3626 supplied later. Program schemes can be defined, such as

3627 "While B C s = (if B s then While B C (C s) else s)"

3628 where the well-founded relation can be chosen after B and C have been given.

3630 * HOL/List: the constructors of type list are now Nil and Cons;

3631 INCOMPATIBILITY: while [] and infix # syntax is still there, of

3632 course, ML tools referring to List.list.op # etc. have to be adapted;

3634 * HOL_quantifiers flag superseded by "HOL" print mode, which is

3635 disabled by default; run isabelle with option -m HOL to get back to

3636 the original Gordon/HOL-style output;

3638 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,

3639 ALL x<=y. P, EX x<y. P, EX x<=y. P;

3641 * HOL basic syntax simplified (more orthogonal): all variants of

3642 All/Ex now support plain / symbolic / HOL notation; plain syntax for

3643 Eps operator is provided as well: "SOME x. P[x]";

3645 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;

3647 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made

3648 thus available for user theories;

3650 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with

3651 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the

3652 time;

3654 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec

3655 several times and then mp;

3658 *** LK ***

3660 * the notation <<...>> is now available as a notation for sequences of

3661 formulas;

3663 * the simplifier is now installed

3665 * the axiom system has been generalized (thanks to Soren Heilmann)

3667 * the classical reasoner now has a default rule database

3670 *** ZF ***

3672 * new primrec section allows primitive recursive functions to be given

3673 directly (as in HOL) over datatypes and the natural numbers;

3675 * new tactics induct_tac and exhaust_tac for induction (or case

3676 analysis) over datatypes and the natural numbers;

3678 * the datatype declaration of type T now defines the recursor T_rec;

3680 * simplification automatically does freeness reasoning for datatype

3681 constructors;

3683 * automatic type-inference, with AddTCs command to insert new

3684 type-checking rules;

3686 * datatype introduction rules are now added as Safe Introduction rules

3687 to the claset;

3689 * the syntax "if P then x else y" is now available in addition to

3690 if(P,x,y);

3693 *** Internal programming interfaces ***

3695 * tuned simplifier trace output; new flag debug_simp;

3697 * structures Vartab / Termtab (instances of TableFun) offer efficient

3698 tables indexed by indexname_ord / term_ord (compatible with aconv);

3700 * AxClass.axclass_tac lost the theory argument;

3702 * tuned current_goals_markers semantics: begin / end goal avoids

3703 printing empty lines;

3705 * removed prs and prs_fn hook, which was broken because it did not

3706 include \n in its semantics, forcing writeln to add one

3707 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:

3708 string -> unit if you really want to output text without newline;

3710 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to

3711 plain output, interface builders may have to enable 'isabelle_font'

3712 mode to get Isabelle font glyphs as before;

3714 * refined token_translation interface; INCOMPATIBILITY: output length

3715 now of type real instead of int;

3717 * theory loader actions may be traced via new ThyInfo.add_hook

3718 interface (see src/Pure/Thy/thy_info.ML); example application: keep

3719 your own database of information attached to *whole* theories -- as

3720 opposed to intra-theory data slots offered via TheoryDataFun;

3722 * proper handling of dangling sort hypotheses (at last!);

3723 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing

3724 extra sort hypotheses that can be witnessed from the type signature;

3725 the force_strip_shyps flag is gone, any remaining shyps are simply

3726 left in the theorem (with a warning issued by strip_shyps_warning);

3730 New in Isabelle98-1 (October 1998)

3731 ----------------------------------

3733 *** Overview of INCOMPATIBILITIES (see below for more details) ***

3735 * several changes of automated proof tools;

3737 * HOL: major changes to the inductive and datatype packages, including

3738 some minor incompatibilities of theory syntax;

3740 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now

3741 called `inj_on';

3743 * HOL: removed duplicate thms in Arith:

3744 less_imp_add_less should be replaced by trans_less_add1

3745 le_imp_add_le should be replaced by trans_le_add1

3747 * HOL: unary minus is now overloaded (new type constraints may be

3748 required);

3750 * HOL and ZF: unary minus for integers is now #- instead of #~. In

3751 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is

3752 now taken as an integer constant.

3754 * Pure: ML function 'theory_of' renamed to 'theory';

3757 *** Proof tools ***

3759 * Simplifier:

3760 1. Asm_full_simp_tac is now more aggressive.

3761 1. It will sometimes reorient premises if that increases their power to

3762 simplify.

3763 2. It does no longer proceed strictly from left to right but may also

3764 rotate premises to achieve further simplification.

3765 For compatibility reasons there is now Asm_lr_simp_tac which is like the

3766 old Asm_full_simp_tac in that it does not rotate premises.

3767 2. The simplifier now knows a little bit about nat-arithmetic.

3769 * Classical reasoner: wrapper mechanism for the classical reasoner now

3770 allows for selected deletion of wrappers, by introduction of names for

3771 wrapper functionals. This implies that addbefore, addSbefore,

3772 addaltern, and addSaltern now take a pair (name, tactic) as argument,

3773 and that adding two tactics with the same name overwrites the first

3774 one (emitting a warning).

3775 type wrapper = (int -> tactic) -> (int -> tactic)

3776 setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by

3777 addWrapper, addSWrapper: claset * (string * wrapper) -> claset

3778 delWrapper, delSWrapper: claset * string -> claset

3779 getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;

3781 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE

3782 semantics; addbefore now affects only the unsafe part of step_tac

3783 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY

3784 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac

3785 by Force_tac;

3787 * Classical reasoner: setwrapper to setWrapper and compwrapper to

3788 compWrapper; added safe wrapper (and access functions for it);

3790 * HOL/split_all_tac is now much faster and fails if there is nothing

3791 to split. Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order

3792 and the names of the automatically generated variables have changed.

3793 split_all_tac has moved within claset() from unsafe wrappers to safe

3794 wrappers, which means that !!-bound variables are split much more

3795 aggressively, and safe_tac and clarify_tac now split such variables.

3796 If this splitting is not appropriate, use delSWrapper "split_all_tac".

3797 Note: the same holds for record_split_tac, which does the job of

3798 split_all_tac for record fields.

3800 * HOL/Simplifier: Rewrite rules for case distinctions can now be added

3801 permanently to the default simpset using Addsplits just like

3802 Addsimps. They can be removed via Delsplits just like

3803 Delsimps. Lower-case versions are also available.

3805 * HOL/Simplifier: The rule split_if is now part of the default

3806 simpset. This means that the simplifier will eliminate all occurrences

3807 of if-then-else in the conclusion of a goal. To prevent this, you can

3808 either remove split_if completely from the default simpset by

3809 `Delsplits [split_if]' or remove it in a specific call of the

3810 simplifier using `... delsplits [split_if]'. You can also add/delete

3811 other case splitting rules to/from the default simpset: every datatype

3812 generates suitable rules `split_t_case' and `split_t_case_asm' (where

3813 t is the name of the datatype).

3815 * Classical reasoner / Simplifier combination: new force_tac (and

3816 derivatives Force_tac, force) combines rewriting and classical

3817 reasoning (and whatever other tools) similarly to auto_tac, but is

3818 aimed to solve the given subgoal completely.

3821 *** General ***

3823 * new top-level commands `Goal' and `Goalw' that improve upon `goal'

3824 and `goalw': the theory is no longer needed as an explicit argument -

3825 the current theory context is used; assumptions are no longer returned

3826 at the ML-level unless one of them starts with ==> or !!; it is

3827 recommended to convert to these new commands using isatool fixgoal

3828 (backup your sources first!);

3830 * new top-level commands 'thm' and 'thms' for retrieving theorems from

3831 the current theory context, and 'theory' to lookup stored theories;

3833 * new theory section 'locale' for declaring constants, assumptions and

3834 definitions that have local scope;

3836 * new theory section 'nonterminals' for purely syntactic types;

3838 * new theory section 'setup' for generic ML setup functions

3839 (e.g. package initialization);

3841 * the distribution now includes Isabelle icons: see

3842 lib/logo/isabelle-{small,tiny}.xpm;

3844 * isatool install - install binaries with absolute references to

3845 ISABELLE_HOME/bin;

3847 * isatool logo -- create instances of the Isabelle logo (as EPS);

3849 * print mode 'emacs' reserved for Isamode;

3851 * support multiple print (ast) translations per constant name;

3853 * theorems involving oracles are now printed with a suffixed [!];

3856 *** HOL ***

3858 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');

3860 * HOL/inductive package reorganized and improved: now supports mutual

3861 definitions such as

3863 inductive EVEN ODD

3864 intrs

3865 null "0 : EVEN"

3866 oddI "n : EVEN ==> Suc n : ODD"

3867 evenI "n : ODD ==> Suc n : EVEN"

3869 new theorem list "elims" contains an elimination rule for each of the

3870 recursive sets; inductive definitions now handle disjunctive premises

3871 correctly (also ZF);

3873 INCOMPATIBILITIES: requires Inductive as an ancestor; component

3874 "mutual_induct" no longer exists - the induction rule is always

3875 contained in "induct";

3878 * HOL/datatype package re-implemented and greatly improved: now

3879 supports mutually recursive datatypes such as

3881 datatype

3882 'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)

3883 | SUM ('a aexp) ('a aexp)

3884 | DIFF ('a aexp) ('a aexp)

3885 | NUM 'a

3886 and

3887 'a bexp = LESS ('a aexp) ('a aexp)

3888 | AND ('a bexp) ('a bexp)

3889 | OR ('a bexp) ('a bexp)

3891 as well as indirectly recursive datatypes such as

3893 datatype

3894 ('a, 'b) term = Var 'a

3895 | App 'b ((('a, 'b) term) list)

3897 The new tactic mutual_induct_tac [<var_1>, ..., <var_n>] i performs

3898 induction on mutually / indirectly recursive datatypes.

3900 Primrec equations are now stored in theory and can be accessed via

3901 <function_name>.simps.

3903 INCOMPATIBILITIES:

3905 - Theories using datatypes must now have theory Datatype as an

3906 ancestor.

3907 - The specific <typename>.induct_tac no longer exists - use the

3908 generic induct_tac instead.

3909 - natE has been renamed to nat.exhaust - use exhaust_tac

3910 instead of res_inst_tac ... natE. Note that the variable

3911 names in nat.exhaust differ from the names in natE, this

3912 may cause some "fragile" proofs to fail.

3913 - The theorems split_<typename>_case and split_<typename>_case_asm

3914 have been renamed to <typename>.split and <typename>.split_asm.

3915 - Since default sorts of type variables are now handled correctly,

3916 some datatype definitions may have to be annotated with explicit

3917 sort constraints.

3918 - Primrec definitions no longer require function name and type

3919 of recursive argument.

3921 Consider using isatool fixdatatype to adapt your theories and proof

3922 scripts to the new package (backup your sources first!).

3925 * HOL/record package: considerably improved implementation; now

3926 includes concrete syntax for record types, terms, updates; theorems

3927 for surjective pairing and splitting !!-bound record variables; proof

3928 support is as follows:

3930 1) standard conversions (selectors or updates applied to record

3931 constructor terms) are part of the standard simpset;

3933 2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are

3934 made part of standard simpset and claset via addIffs;

3936 3) a tactic for record field splitting (record_split_tac) is part of

3937 the standard claset (addSWrapper);

3939 To get a better idea about these rules you may retrieve them via

3940 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is

3941 the name of your record type.

3943 The split tactic 3) conceptually simplifies by the following rule:

3945 "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"

3947 Thus any record variable that is bound by meta-all will automatically

3948 blow up into some record constructor term, consequently the

3949 simplifications of 1), 2) apply. Thus force_tac, auto_tac etc. shall

3950 solve record problems automatically.

3953 * reorganized the main HOL image: HOL/Integ and String loaded by

3954 default; theory Main includes everything;

3956 * automatic simplification of integer sums and comparisons, using cancellation;

3958 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;

3960 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;

3962 * many new identities for unions, intersections, set difference, etc.;

3964 * expand_if, expand_split, expand_sum_case and expand_nat_case are now

3965 called split_if, split_split, split_sum_case and split_nat_case (to go

3966 with add/delsplits);

3968 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting

3969 (?x::unit) = (); this is made part of the default simpset, which COULD

3970 MAKE EXISTING PROOFS FAIL under rare circumstances (consider

3971 'Delsimprocs [unit_eq_proc];' as last resort); also note that

3972 unit_abs_eta_conv is added in order to counter the effect of

3973 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by

3974 %u.f();

3976 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which

3977 makes more sense);

3979 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;

3980 It and 'sym RS equals0D' are now in the default claset, giving automatic

3981 disjointness reasoning but breaking a few old proofs.

3983 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1

3984 to 'converse' from 'inverse' (for compatibility with ZF and some

3985 literature);

3987 * HOL/recdef can now declare non-recursive functions, with {} supplied as

3988 the well-founded relation;

3990 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of

3991 Compl A. The "Compl" syntax remains available as input syntax for this

3992 release ONLY.

3994 * HOL/Update: new theory of function updates:

3995 f(a:=b) == %x. if x=a then b else f x

3996 may also be iterated as in f(a:=b,c:=d,...);

3998 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;

4000 * HOL/List:

4001 - new function list_update written xs[i:=v] that updates the i-th

4002 list position. May also be iterated as in xs[i:=a,j:=b,...].

4003 - new function `upt' written [i..j(] which generates the list

4004 [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper

4005 bound write [i..j], which is a shorthand for [i..j+1(].

4006 - new lexicographic orderings and corresponding wellfoundedness theorems.

4008 * HOL/Arith:

4009 - removed 'pred' (predecessor) function;

4010 - generalized some theorems about n-1;

4011 - many new laws about "div" and "mod";

4012 - new laws about greatest common divisors (see theory ex/Primes);

4014 * HOL/Relation: renamed the relational operator r^-1 "converse"

4015 instead of "inverse";

4017 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness

4018 of the multiset ordering;

4020 * directory HOL/Real: a construction of the reals using Dedekind cuts

4021 (not included by default);

4023 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;

4025 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted

4026 programs, i.e. different program variables may have different types.

4028 * calling (stac rew i) now fails if "rew" has no effect on the goal

4029 [previously, this check worked only if the rewrite rule was unconditional]

4030 Now rew can involve either definitions or equalities (either == or =).

4033 *** ZF ***

4035 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains

4036 only the theorems proved on ZF.ML;

4038 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;

4039 It and 'sym RS equals0D' are now in the default claset, giving automatic

4040 disjointness reasoning but breaking a few old proofs.

4042 * ZF/Update: new theory of function updates

4043 with default rewrite rule f(x:=y) ` z = if(z=x, y, f`z)

4044 may also be iterated as in f(a:=b,c:=d,...);

4046 * in let x=t in u(x), neither t nor u(x) has to be an FOL term.

4048 * calling (stac rew i) now fails if "rew" has no effect on the goal

4049 [previously, this check worked only if the rewrite rule was unconditional]

4050 Now rew can involve either definitions or equalities (either == or =).

4052 * case_tac provided for compatibility with HOL

4053 (like the old excluded_middle_tac, but with subgoals swapped)

4056 *** Internal programming interfaces ***

4058 * Pure: several new basic modules made available for general use, see

4059 also src/Pure/README;

4061 * improved the theory data mechanism to support encapsulation (data

4062 kind name replaced by private Object.kind, acting as authorization

4063 key); new type-safe user interface via functor TheoryDataFun; generic

4064 print_data function becomes basically useless;

4066 * removed global_names compatibility flag -- all theory declarations

4067 are qualified by default;

4069 * module Pure/Syntax now offers quote / antiquote translation

4070 functions (useful for Hoare logic etc. with implicit dependencies);

4071 see HOL/ex/Antiquote for an example use;

4073 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->

4074 cterm -> thm;

4076 * new tactical CHANGED_GOAL for checking that a tactic modifies a

4077 subgoal;

4079 * Display.print_goals function moved to Locale.print_goals;

4081 * standard print function for goals supports current_goals_markers

4082 variable for marking begin of proof, end of proof, start of goal; the

4083 default is ("", "", ""); setting current_goals_markers := ("<proof>",

4084 "</proof>", "<goal>") causes SGML like tagged proof state printing,

4085 for example;

4089 New in Isabelle98 (January 1998)

4090 --------------------------------

4092 *** Overview of INCOMPATIBILITIES (see below for more details) ***

4094 * changed lexical syntax of terms / types: dots made part of long

4095 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";

4097 * simpset (and claset) reference variable replaced by functions

4098 simpset / simpset_ref;

4100 * no longer supports theory aliases (via merge) and non-trivial

4101 implicit merge of thms' signatures;

4103 * most internal names of constants changed due to qualified names;

4105 * changed Pure/Sequence interface (see Pure/seq.ML);

4108 *** General Changes ***

4110 * hierachically structured name spaces (for consts, types, axms, thms

4111 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of

4112 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:

4113 isatool fixdots ensures space after dots (e.g. "%x. x"); set

4114 long_names for fully qualified output names; NOTE: ML programs

4115 (special tactics, packages etc.) referring to internal names may have

4116 to be adapted to cope with fully qualified names; in case of severe

4117 backward campatibility problems try setting 'global_names' at compile

4118 time to have enrything declared within a flat name space; one may also

4119 fine tune name declarations in theories via the 'global' and 'local'

4120 section;

4122 * reimplemented the implicit simpset and claset using the new anytype

4123 data filed in signatures; references simpset:simpset ref etc. are

4124 replaced by functions simpset:unit->simpset and

4125 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp

4126 to patch your ML files accordingly;

4128 * HTML output now includes theory graph data for display with Java

4129 applet or isatool browser; data generated automatically via isatool

4130 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);

4132 * defs may now be conditional; improved rewrite_goals_tac to handle

4133 conditional equations;

4135 * defs now admits additional type arguments, using TYPE('a) syntax;

4137 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always

4138 creates a new theory node; implicit merge of thms' signatures is

4139 restricted to 'trivial' ones; COMPATIBILITY: one may have to use

4140 transfer:theory->thm->thm in (rare) cases;

4142 * improved handling of draft signatures / theories; draft thms (and

4143 ctyps, cterms) are automatically promoted to real ones;

4145 * slightly changed interfaces for oracles: admit many per theory, named

4146 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;

4148 * print_goals: optional output of const types (set show_consts and

4149 show_types);

4151 * improved output of warnings (###) and errors (***);

4153 * subgoal_tac displays a warning if the new subgoal has type variables;

4155 * removed old README and Makefiles;

4157 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;

4159 * removed obsolete init_pps and init_database;

4161 * deleted the obsolete tactical STATE, which was declared by

4162 fun STATE tacfun st = tacfun st st;

4164 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~

4165 (which abbreviates $HOME);

4167 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:

4168 use isatool fixseq to adapt your ML programs (this works for fully

4169 qualified references to the Sequence structure only!);

4171 * use_thy no longer requires writable current directory; it always

4172 reloads .ML *and* .thy file, if either one is out of date;

4175 *** Classical Reasoner ***

4177 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new

4178 tactics that use classical reasoning to simplify a subgoal without

4179 splitting it into several subgoals;

4181 * Safe_tac: like safe_tac but uses the default claset;

4184 *** Simplifier ***

4186 * added simplification meta rules:

4187 (asm_)(full_)simplify: simpset -> thm -> thm;

4189 * simplifier.ML no longer part of Pure -- has to be loaded by object

4190 logics (again);

4192 * added prems argument to simplification procedures;

4194 * HOL, FOL, ZF: added infix function `addsplits':

4195 instead of `<simpset> setloop (split_tac <thms>)'

4196 you can simply write `<simpset> addsplits <thms>'

4199 *** Syntax ***

4201 * TYPE('a) syntax for type reflection terms;

4203 * no longer handles consts with name "" -- declare as 'syntax' instead;

4205 * pretty printer: changed order of mixfix annotation preference (again!);

4207 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;

4210 *** HOL ***

4212 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.

4213 with `addloop' of the simplifier to faciliate case splitting in premises.

4215 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;

4217 * HOL/Auth: new protocol proofs including some for the Internet

4218 protocol TLS;

4220 * HOL/Map: new theory of `maps' a la VDM;

4222 * HOL/simplifier: simplification procedures nat_cancel_sums for

4223 cancelling out common nat summands from =, <, <= (in)equalities, or

4224 differences; simplification procedures nat_cancel_factor for

4225 cancelling common factor from =, <, <= (in)equalities over natural

4226 sums; nat_cancel contains both kinds of procedures, it is installed by

4227 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;

4229 * HOL/simplifier: terms of the form

4230 `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)' (or t=x)

4231 are rewritten to

4232 `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',

4233 and those of the form

4234 `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)' (or t=x)

4235 are rewritten to

4236 `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',

4238 * HOL/datatype

4239 Each datatype `t' now comes with a theorem `split_t_case' of the form

4241 P(t_case f1 ... fn x) =

4242 ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &

4243 ...

4244 (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))

4245 )

4247 and a theorem `split_t_case_asm' of the form

4249 P(t_case f1 ... fn x) =

4250 ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |

4251 ...

4252 (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))

4253 )

4254 which can be added to a simpset via `addsplits'. The existing theorems

4255 expand_list_case and expand_option_case have been renamed to

4256 split_list_case and split_option_case.

4258 * HOL/Arithmetic:

4259 - `pred n' is automatically converted to `n-1'.

4260 Users are strongly encouraged not to use `pred' any longer,

4261 because it will disappear altogether at some point.

4262 - Users are strongly encouraged to write "0 < n" rather than

4263 "n ~= 0". Theorems and proof tools have been modified towards this

4264 `standard'.

4266 * HOL/Lists:

4267 the function "set_of_list" has been renamed "set" (and its theorems too);

4268 the function "nth" now takes its arguments in the reverse order and

4269 has acquired the infix notation "!" as in "xs!n".

4271 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};

4273 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its

4274 specialist theorems (like UN1_I) are gone. Similarly for (INT x.B x);

4276 * HOL/record: extensible records with schematic structural subtyping

4277 (single inheritance); EXPERIMENTAL version demonstrating the encoding,

4278 still lacks various theorems and concrete record syntax;

4281 *** HOLCF ***

4283 * removed "axioms" and "generated by" sections;

4285 * replaced "ops" section by extended "consts" section, which is capable of

4286 handling the continuous function space "->" directly;

4288 * domain package:

4289 . proves theorems immediately and stores them in the theory,

4290 . creates hierachical name space,

4291 . now uses normal mixfix annotations (instead of cinfix...),

4292 . minor changes to some names and values (for consistency),

4293 . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,

4294 . separator between mutual domain defs: changed "," to "and",

4295 . improved handling of sort constraints; now they have to

4296 appear on the left-hand side of the equations only;

4298 * fixed LAM <x,y,zs>.b syntax;

4300 * added extended adm_tac to simplifier in HOLCF -- can now discharge

4301 adm (%x. P (t x)), where P is chainfinite and t continuous;

4304 *** FOL and ZF ***

4306 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.

4307 with `addloop' of the simplifier to faciliate case splitting in premises.

4309 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as

4310 in HOL, they strip ALL and --> from proved theorems;

4314 New in Isabelle94-8 (May 1997)

4315 ------------------------------

4317 *** General Changes ***

4319 * new utilities to build / run / maintain Isabelle etc. (in parts

4320 still somewhat experimental); old Makefiles etc. still functional;

4322 * new 'Isabelle System Manual';

4324 * INSTALL text, together with ./configure and ./build scripts;

4326 * reimplemented type inference for greater efficiency, better error

4327 messages and clean internal interface;

4329 * prlim command for dealing with lots of subgoals (an easier way of

4330 setting goals_limit);

4333 *** Syntax ***

4335 * supports alternative (named) syntax tables (parser and pretty

4336 printer); internal interface is provided by add_modesyntax(_i);

4338 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to

4339 be used in conjunction with the Isabelle symbol font; uses the

4340 "symbols" syntax table;

4342 * added token_translation interface (may translate name tokens in

4343 arbitrary ways, dependent on their type (free, bound, tfree, ...) and

4344 the current print_mode); IMPORTANT: user print translation functions

4345 are responsible for marking newly introduced bounds

4346 (Syntax.mark_boundT);

4348 * token translations for modes "xterm" and "xterm_color" that display

4349 names in bold, underline etc. or colors (which requires a color

4350 version of xterm);

4352 * infixes may now be declared with names independent of their syntax;

4354 * added typed_print_translation (like print_translation, but may

4355 access type of constant);

4358 *** Classical Reasoner ***

4360 Blast_tac: a new tactic! It is often more powerful than fast_tac, but has

4361 some limitations. Blast_tac...

4362 + ignores addss, addbefore, addafter; this restriction is intrinsic

4363 + ignores elimination rules that don't have the correct format

4364 (the conclusion MUST be a formula variable)

4365 + ignores types, which can make HOL proofs fail

4366 + rules must not require higher-order unification, e.g. apply_type in ZF

4367 [message "Function Var's argument not a bound variable" relates to this]

4368 + its proof strategy is more general but can actually be slower

4370 * substitution with equality assumptions no longer permutes other

4371 assumptions;

4373 * minor changes in semantics of addafter (now called addaltern); renamed

4374 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper

4375 (and access functions for it);

4377 * improved combination of classical reasoner and simplifier:

4378 + functions for handling clasimpsets

4379 + improvement of addss: now the simplifier is called _after_ the

4380 safe steps.

4381 + safe variant of addss called addSss: uses safe simplifications

4382 _during_ the safe steps. It is more complete as it allows multiple

4383 instantiations of unknowns (e.g. with slow_tac).

4385 *** Simplifier ***

4387 * added interface for simplification procedures (functions that

4388 produce *proven* rewrite rules on the fly, depending on current

4389 redex);

4391 * ordering on terms as parameter (used for ordered rewriting);

4393 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;

4395 * the solver is now split into a safe and an unsafe part.

4396 This should be invisible for the normal user, except that the

4397 functions setsolver and addsolver have been renamed to setSolver and

4398 addSolver; added safe_asm_full_simp_tac;

4401 *** HOL ***

4403 * a generic induction tactic `induct_tac' which works for all datatypes and

4404 also for type `nat';

4406 * a generic case distinction tactic `exhaust_tac' which works for all

4407 datatypes and also for type `nat';

4409 * each datatype comes with a function `size';

4411 * patterns in case expressions allow tuple patterns as arguments to

4412 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';

4414 * primrec now also works with type nat;

4416 * recdef: a new declaration form, allows general recursive functions to be

4417 defined in theory files. See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.

4419 * the constant for negation has been renamed from "not" to "Not" to

4420 harmonize with FOL, ZF, LK, etc.;

4422 * HOL/ex/LFilter theory of a corecursive "filter" functional for

4423 infinite lists;

4425 * HOL/Modelcheck demonstrates invocation of model checker oracle;

4427 * HOL/ex/Ring.thy declares cring_simp, which solves equational

4428 problems in commutative rings, using axiomatic type classes for + and *;

4430 * more examples in HOL/MiniML and HOL/Auth;

4432 * more default rewrite rules for quantifiers, union/intersection;

4434 * a new constant `arbitrary == @x.False';

4436 * HOLCF/IOA replaces old HOL/IOA;

4438 * HOLCF changes: derived all rules and arities

4439 + axiomatic type classes instead of classes

4440 + typedef instead of faking type definitions

4441 + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.

4442 + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po

4443 + eliminated the types void, one, tr

4444 + use unit lift and bool lift (with translations) instead of one and tr

4445 + eliminated blift from Lift3.thy (use Def instead of blift)

4446 all eliminated rules are derived as theorems --> no visible changes ;

4449 *** ZF ***

4451 * ZF now has Fast_tac, Simp_tac and Auto_tac. Union_iff is a now a default

4452 rewrite rule; this may affect some proofs. eq_cs is gone but can be put back

4453 as ZF_cs addSIs [equalityI];

4457 New in Isabelle94-7 (November 96)

4458 ---------------------------------

4460 * allowing negative levels (as offsets) in prlev and choplev;

4462 * super-linear speedup for large simplifications;

4464 * FOL, ZF and HOL now use miniscoping: rewriting pushes

4465 quantifications in as far as possible (COULD MAKE EXISTING PROOFS

4466 FAIL); can suppress it using the command Delsimps (ex_simps @

4467 all_simps); De Morgan laws are also now included, by default;

4469 * improved printing of ==> : ~:

4471 * new object-logic "Sequents" adds linear logic, while replacing LK

4472 and Modal (thanks to Sara Kalvala);

4474 * HOL/Auth: correctness proofs for authentication protocols;

4476 * HOL: new auto_tac combines rewriting and classical reasoning (many

4477 examples on HOL/Auth);

4479 * HOL: new command AddIffs for declaring theorems of the form P=Q to

4480 the rewriter and classical reasoner simultaneously;

4482 * function uresult no longer returns theorems in "standard" format;

4483 regain previous version by: val uresult = standard o uresult;

4487 New in Isabelle94-6

4488 -------------------

4490 * oracles -- these establish an interface between Isabelle and trusted

4491 external reasoners, which may deliver results as theorems;

4493 * proof objects (in particular record all uses of oracles);

4495 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;

4497 * "constdefs" section in theory files;

4499 * "primrec" section (HOL) no longer requires names;

4501 * internal type "tactic" now simply "thm -> thm Sequence.seq";

4505 New in Isabelle94-5

4506 -------------------

4508 * reduced space requirements;

4510 * automatic HTML generation from theories;

4512 * theory files no longer require "..." (quotes) around most types;

4514 * new examples, including two proofs of the Church-Rosser theorem;

4516 * non-curried (1994) version of HOL is no longer distributed;

4520 New in Isabelle94-4

4521 -------------------

4523 * greatly reduced space requirements;

4525 * theory files (.thy) no longer require \...\ escapes at line breaks;

4527 * searchable theorem database (see the section "Retrieving theorems" on

4528 page 8 of the Reference Manual);

4530 * new examples, including Grabczewski's monumental case study of the

4531 Axiom of Choice;

4533 * The previous version of HOL renamed to Old_HOL;

4535 * The new version of HOL (previously called CHOL) uses a curried syntax

4536 for functions. Application looks like f a b instead of f(a,b);

4538 * Mutually recursive inductive definitions finally work in HOL;

4540 * In ZF, pattern-matching on tuples is now available in all abstractions and

4541 translates to the operator "split";

4545 New in Isabelle94-3

4546 -------------------

4548 * new infix operator, addss, allowing the classical reasoner to

4549 perform simplification at each step of its search. Example:

4550 fast_tac (cs addss ss)

4552 * a new logic, CHOL, the same as HOL, but with a curried syntax

4553 for functions. Application looks like f a b instead of f(a,b). Also pairs

4554 look like (a,b) instead of <a,b>;

4556 * PLEASE NOTE: CHOL will eventually replace HOL!

4558 * In CHOL, pattern-matching on tuples is now available in all abstractions.

4559 It translates to the operator "split". A new theory of integers is available;

4561 * In ZF, integer numerals now denote two's-complement binary integers.

4562 Arithmetic operations can be performed by rewriting. See ZF/ex/Bin.ML;

4564 * Many new examples: I/O automata, Church-Rosser theorem, equivalents

4565 of the Axiom of Choice;

4569 New in Isabelle94-2

4570 -------------------

4572 * Significantly faster resolution;

4574 * the different sections in a .thy file can now be mixed and repeated

4575 freely;

4577 * Database of theorems for FOL, HOL and ZF. New

4578 commands including qed, qed_goal and bind_thm store theorems in the database.

4580 * Simple database queries: return a named theorem (get_thm) or all theorems of

4581 a given theory (thms_of), or find out what theory a theorem was proved in

4582 (theory_of_thm);

4584 * Bugs fixed in the inductive definition and datatype packages;

4586 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs

4587 and HOL_dup_cs obsolete;

4589 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1

4590 have been removed;

4592 * Simpler definition of function space in ZF;

4594 * new results about cardinal and ordinal arithmetic in ZF;

4596 * 'subtype' facility in HOL for introducing new types as subsets of existing

4597 types;

4600 $Id$