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NEWS

author | paulson |

Mon May 26 12:34:54 1997 +0200 (1997-05-26) | |

changeset 3338 | b99d750f6a37 |

parent 3321 | c609a0119fd8 |

child 3454 | 40b1287347d7 |

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

Added recdef

2 Isabelle NEWS -- history of user-visible changes

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

5 New in Isabelle94-8 (May 1997)

6 ------------------------------

8 *** General Changes ***

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

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

13 * new 'Isabelle System Manual';

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

17 * reimplemented type inference for greater efficiency, better error

18 messages and clean internal interface;

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

21 setting goals_limit);

24 *** Syntax ***

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

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

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

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

31 "symbols" syntax table;

33 * added token_translation interface (may translate name tokens in

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

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

36 are responsible for marking newly introduced bounds

37 (Syntax.mark_boundT);

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

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

41 version of xterm);

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

45 * added typed_print_translation (like print_translation, but may

46 access type of constant);

49 *** Classical Reasoner ***

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

52 some limitations. Blast_tac...

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

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

55 (the conclusion MUST be a formula variable)

56 + ignores types, which can make HOL proofs fail

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

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

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

61 * substitution with equality assumptions no longer permutes other

62 assumptions;

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

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

66 (and access functions for it);

68 * improved combination of classical reasoner and simplifier:

69 + functions for handling clasimpsets

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

71 safe steps.

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

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

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

76 *** Simplifier ***

78 * added interface for simplification procedures (functions that

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

80 redex);

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

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

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

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

88 functions setsolver and addsolver have been renamed to setSolver and

89 addSolver; added safe_asm_full_simp_tac;

92 *** HOL ***

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

95 also for type `nat';

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

98 datatypes and also for type `nat';

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

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

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

105 * primrec now also works with type nat;

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

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

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

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

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

114 infinite lists;

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

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

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

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

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

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

127 * HOLCF/IOA replaces old HOL/IOA;

129 * HOLCF changes: derived all rules and arities

130 + axiomatic type classes instead of classes

131 + typedef instead of faking type definitions

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

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

134 + eliminated the types void, one, tr

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

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

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

140 *** ZF ***

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

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

144 as ZF_cs addSIs [equalityI];

148 New in Isabelle94-7 (November 96)

149 ---------------------------------

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

153 * super-linear speedup for large simplifications;

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

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

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

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

160 * improved printing of ==> : ~:

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

163 and Modal (thanks to Sara Kalvala);

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

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

168 examples on HOL/Auth);

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

171 the rewriter and classical reasoner simultaneously;

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

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

178 New in Isabelle94-6

179 -------------------

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

182 external reasoners, which may deliver results as theorems;

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

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

188 * "constdefs" section in theory files;

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

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

196 New in Isabelle94-5

197 -------------------

199 * reduced space requirements;

201 * automatic HTML generation from theories;

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

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

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

211 New in Isabelle94-4

212 -------------------

214 * greatly reduced space requirements;

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

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

219 page 8 of the Reference Manual);

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

222 Axiom of Choice;

224 * The previous version of HOL renamed to Old_HOL;

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

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

229 * Mutually recursive inductive definitions finally work in HOL;

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

232 translates to the operator "split";

236 New in Isabelle94-3

237 -------------------

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

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

241 fast_tac (cs addss ss)

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

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

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

247 * PLEASE NOTE: CHOL will eventually replace HOL!

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

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

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

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

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

256 of the Axiom of Choice;

260 New in Isabelle94-2

261 -------------------

263 * Significantly faster resolution;

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

266 freely;

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

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

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

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

273 (theory_of_thm);

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

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

278 and HOL_dup_cs obsolete;

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

281 have been removed;

283 * Simpler definition of function space in ZF;

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

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

288 types;

291 $Id$