1 Isabelle NEWS -- history user-relevant changes
2 ==============================================
4 New in this Isabelle release
5 ----------------------------
9 * Pure: locale specifications now produce predicate definitions
10 according to the body of text (covering assumptions modulo local
11 definitions); predicate "loc_axioms" covers newly introduced text,
12 while "loc" is cumulative wrt. all included locale expressions; the
13 latter view is presented only on export into the global theory
14 context; potential INCOMPATIBILITY, use "(open)" option to fall back
15 on the old view without predicates;
17 * Pure: predefined locales "var" and "struct" are useful for sharing
18 parameters (as in CASL, for example); just specify something like
19 ``var x + var y + struct M'' as import;
21 * Pure: improved thms_containing: proper indexing of facts instead of
22 raw theorems; check validity of results wrt. current name space;
23 include local facts of proof configuration (also covers active
24 locales); an optional limit for the number of printed facts may be
25 given (the default is 40);
27 * Provers: improved induct method: assumptions introduced by case
28 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
29 the goal statement); "foo" still refers to all facts collectively;
34 * 'typedef' command has new option "open" to suppress the set
37 * Functions Min and Max on finite sets have been introduced.
40 * attribute [symmetric] now works for relations as well; it turns
41 (x,y) : R^-1 into (y,x) : R, and vice versa;
43 * arith(_tac) now produces a counter example if it cannot prove a theorem.
44 In ProofGeneral the counter example appears in the trace buffer.
46 * arith(_tac) does now know about div k and mod k where k is a numeral
47 of type nat or int. It can solve simple goals like
49 "0 < n ==> n div 2 < (n::nat)"
51 but fails if divisibility plays a role like in
53 "n div 2 + (n+1) div 2 = (n::nat)"
55 * simp's arithmetic capabilities have been enhanced a bit: it now
56 takes ~= in premises into account (by performing a case split);
58 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands are
59 distributed over a sum of terms.
64 * Pure: Tactic.prove provides sane interface for internal proofs;
65 omits the infamous "standard" operation, so this is more appropriate
66 than prove_goalw_cterm in many situations (e.g. in simprocs);
68 * Pure: improved error reporting of simprocs;
70 * Provers: Simplifier.simproc(_i) provides sane interface for setting
75 New in Isabelle2002 (March 2002)
76 --------------------------------
78 *** Document preparation ***
80 * greatly simplified document preparation setup, including more
81 graceful interpretation of isatool usedir -i/-d/-D options, and more
82 instructive isatool mkdir; users should basically be able to get
83 started with "isatool mkdir HOL Test && isatool make"; alternatively,
84 users may run a separate document processing stage manually like this:
85 "isatool usedir -D output HOL Test && isatool document Test/output";
87 * theory dependency graph may now be incorporated into documents;
88 isatool usedir -g true will produce session_graph.eps/.pdf for use
89 with \includegraphics of LaTeX;
91 * proper spacing of consecutive markup elements, especially text
92 blocks after section headings;
94 * support bold style (for single symbols only), input syntax is like
95 this: "\<^bold>\<alpha>" or "\<^bold>A";
97 * \<bullet> is now output as bold \cdot by default, which looks much
98 better in printed text;
100 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
101 note that these symbols are currently unavailable in Proof General /
102 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
104 * isatool latex no longer depends on changed TEXINPUTS, instead
105 isatool document copies the Isabelle style files to the target
111 * Pure/Provers: improved proof by cases and induction;
112 - 'case' command admits impromptu naming of parameters (such as
114 - 'induct' method divinates rule instantiation from the inductive
115 claim; no longer requires excessive ?P bindings for proper
116 instantiation of cases;
117 - 'induct' method properly enumerates all possibilities of set/type
118 rules; as a consequence facts may be also passed through *type*
119 rules without further ado;
120 - 'induct' method now derives symbolic cases from the *rulified*
121 rule (before it used to rulify cases stemming from the internal
122 atomized version); this means that the context of a non-atomic
123 statement becomes is included in the hypothesis, avoiding the
124 slightly cumbersome show "PROP ?case" form;
125 - 'induct' may now use elim-style induction rules without chaining
126 facts, using ``missing'' premises from the goal state; this allows
127 rules stemming from inductive sets to be applied in unstructured
128 scripts, while still benefitting from proper handling of non-atomic
129 statements; NB: major inductive premises need to be put first, all
130 the rest of the goal is passed through the induction;
131 - 'induct' proper support for mutual induction involving non-atomic
132 rule statements (uses the new concept of simultaneous goals, see
134 - append all possible rule selections, but only use the first
135 success (no backtracking);
136 - removed obsolete "(simplified)" and "(stripped)" options of methods;
137 - undeclared rule case names default to numbers 1, 2, 3, ...;
138 - added 'print_induct_rules' (covered by help item in recent Proof
140 - moved induct/cases attributes to Pure, methods to Provers;
141 - generic method setup instantiated for FOL and HOL;
143 * Pure: support multiple simultaneous goal statements, for example
144 "have a: A and b: B" (same for 'theorem' etc.); being a pure
145 meta-level mechanism, this acts as if several individual goals had
146 been stated separately; in particular common proof methods need to be
147 repeated in order to cover all claims; note that a single elimination
148 step is *not* sufficient to establish the two conjunctions, so this
151 assume "A & B" then have A and B .. (*".." fails*)
153 better use "obtain" in situations as above; alternative refer to
154 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
156 * Pure: proper integration with ``locales''; unlike the original
157 version by Florian Kammüller, Isar locales package high-level proof
158 contexts rather than raw logical ones (e.g. we admit to include
159 attributes everywhere); operations on locales include merge and
160 rename; support for implicit arguments (``structures''); simultaneous
161 type-inference over imports and text; see also HOL/ex/Locales.thy for
164 * Pure: the following commands have been ``localized'', supporting a
165 target locale specification "(in name)": 'lemma', 'theorem',
166 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
167 stored both within the locale and at the theory level (exported and
168 qualified by the locale name);
170 * Pure: theory goals may now be specified in ``long'' form, with
171 ad-hoc contexts consisting of arbitrary locale elements. for example
172 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
173 definitions may be given, too); the result is a meta-level rule with
174 the context elements being discharged in the obvious way;
176 * Pure: new proof command 'using' allows to augment currently used
177 facts after a goal statement ('using' is syntactically analogous to
178 'apply', but acts on the goal's facts only); this allows chained facts
179 to be separated into parts given before and after a claim, as in
180 ``from a and b have C using d and e <proof>'';
182 * Pure: renamed "antecedent" case to "rule_context";
184 * Pure: new 'judgment' command records explicit information about the
185 object-logic embedding (used by several tools internally); no longer
186 use hard-wired "Trueprop";
188 * Pure: added 'corollary' command;
190 * Pure: fixed 'token_translation' command;
192 * Pure: removed obsolete 'exported' attribute;
194 * Pure: dummy pattern "_" in is/let is now automatically lifted over
195 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
196 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
198 * Pure: method 'atomize' presents local goal premises as object-level
199 statements (atomic meta-level propositions); setup controlled via
200 rewrite rules declarations of 'atomize' attribute; example
201 application: 'induct' method with proper rule statements in improper
204 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
205 now consider the syntactic context of assumptions, giving a better
206 chance to get type-inference of the arguments right (this is
207 especially important for locales);
209 * Pure: "sorry" no longer requires quick_and_dirty in interactive
212 * Pure/obtain: the formal conclusion "thesis", being marked as
213 ``internal'', may no longer be reference directly in the text;
214 potential INCOMPATIBILITY, may need to use "?thesis" in rare
217 * Pure: generic 'sym' attribute which declares a rule both as pure
218 'elim?' and for the 'symmetric' operation;
220 * Pure: marginal comments ``--'' may now occur just anywhere in the
221 text; the fixed correlation with particular command syntax has been
224 * Pure: new method 'rules' is particularly well-suited for proof
225 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
226 but often produces more compact proof terms with less detours;
228 * Pure/Provers/classical: simplified integration with pure rule
229 attributes and methods; the classical "intro?/elim?/dest?"
230 declarations coincide with the pure ones; the "rule" method no longer
231 includes classically swapped intros; "intro" and "elim" methods no
232 longer pick rules from the context; also got rid of ML declarations
233 AddXIs/AddXEs/AddXDs; all of this has some potential for
236 * Provers/classical: attribute 'swapped' produces classical inversions
237 of introduction rules;
239 * Provers/simplifier: 'simplified' attribute may refer to explicit
240 rules instead of full simplifier context; 'iff' attribute handles
243 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
245 * HOL: 'recdef' now fails on unfinished automated proofs, use
246 "(permissive)" option to recover old behavior;
248 * HOL: 'inductive' no longer features separate (collective) attributes
249 for 'intros' (was found too confusing);
251 * HOL: properly declared induction rules less_induct and
257 * HOL: moved over to sane numeral syntax; the new policy is as
260 - 0 and 1 are polymorphic constants, which are defined on any
261 numeric type (nat, int, real etc.);
263 - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
264 binary representation internally;
266 - type nat has special constructor Suc, and generally prefers Suc 0
267 over 1::nat and Suc (Suc 0) over 2::nat;
269 This change may cause significant problems of INCOMPATIBILITY; here
270 are some hints on converting existing sources:
272 - due to the new "num" token, "-0" and "-1" etc. are now atomic
273 entities, so expressions involving "-" (unary or binary minus) need
274 to be spaced properly;
276 - existing occurrences of "1" may need to be constraint "1::nat" or
277 even replaced by Suc 0; similar for old "2";
279 - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
281 - remove all special provisions on numerals in proofs;
283 * HOL: simp rules nat_number expand numerals on nat to Suc/0
284 representation (depends on bin_arith_simps in the default context);
286 * HOL: symbolic syntax for x^2 (numeral 2);
288 * HOL: the class of all HOL types is now called "type" rather than
289 "term"; INCOMPATIBILITY, need to adapt references to this type class
290 in axclass/classes, instance/arities, and (usually rare) occurrences
291 in typings (of consts etc.); internally the class is called
292 "HOL.type", ML programs should refer to HOLogic.typeS;
294 * HOL/record package improvements:
295 - new derived operations "fields" to build a partial record section,
296 "extend" to promote a fixed record to a record scheme, and
297 "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
298 declared as simp by default;
299 - shared operations ("more", "fields", etc.) now need to be always
300 qualified) --- potential INCOMPATIBILITY;
301 - removed "make_scheme" operations (use "make" with "extend") --
303 - removed "more" class (simply use "term") -- INCOMPATIBILITY;
304 - provides cases/induct rules for use with corresponding Isar
305 methods (for concrete records, record schemes, concrete more
306 parts, and schematic more parts -- in that order);
307 - internal definitions directly based on a light-weight abstract
308 theory of product types over typedef rather than datatype;
310 * HOL: generic code generator for generating executable ML code from
311 specifications; specific support for HOL constructs such as inductive
312 datatypes and sets, as well as recursive functions; can be invoked
313 via 'generate_code' theory section;
315 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
317 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
318 (beware of argument permutation!);
320 * HOL: linorder_less_split superseded by linorder_cases;
322 * HOL/List: "nodups" renamed to "distinct";
324 * HOL: added "The" definite description operator; move Hilbert's "Eps"
325 to peripheral theory "Hilbert_Choice";
327 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
328 in this (rare) case use:
330 delSWrapper "split_all_tac"
331 addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
333 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
336 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
337 Isabelle's type classes, ^ on functions and relations has too general
338 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
339 necessary to attach explicit type constraints;
341 * HOL/Relation: the prefix name of the infix "O" has been changed from
342 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
343 renamed accordingly (eg "compI" -> "rel_compI").
345 * HOL: syntax translations now work properly with numerals and records
348 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
349 of "lam" -- INCOMPATIBILITY;
351 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
352 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
353 renamed "Product_Type.unit";
355 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
357 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
360 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
363 * HOL/IMP: updated and converted to new-style theory format; several
364 parts turned into readable document, with proper Isar proof texts and
365 some explanations (by Gerwin Klein);
367 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
369 * HOL-Hyperreal is now a logic image;
374 * Isar: consts/constdefs supports mixfix syntax for continuous
377 * Isar: domain package adapted to new-style theory format, e.g. see
380 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
381 potential INCOMPATIBILITY; now use plain induct_tac instead of former
382 lift.induct_tac, always use UU instead of Undef;
384 * HOLCF/IMP: updated and converted to new-style theory;
389 * Isar: proper integration of logic-specific tools and packages,
390 including theory commands '(co)inductive', '(co)datatype',
391 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
392 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
394 * theory Main no longer includes AC; for the Axiom of Choice, base
395 your theory on Main_ZFC;
397 * the integer library now covers quotients and remainders, with many
398 laws relating division to addition, multiplication, etc.;
400 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
401 typeless version of the formalism;
403 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
406 * ZF/Induct: new directory for examples of inductive definitions,
407 including theory Multiset for multiset orderings; converted to
408 new-style theory format;
410 * ZF: many new theorems about lists, ordinals, etc.;
415 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
416 variable proof controls level of detail: 0 = no proofs (only oracle
417 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
418 also ref manual for further ML interfaces;
420 * Pure/axclass: removed obsolete ML interface
421 goal_subclass/goal_arity;
423 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
424 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
425 separate tokens, so expressions involving minus need to be spaced
428 * Pure/syntax: support non-oriented infixes, using keyword "infix"
429 rather than "infixl" or "infixr";
431 * Pure/syntax: concrete syntax for dummy type variables admits genuine
432 sort constraint specifications in type inference; e.g. "x::_::foo"
433 ensures that the type of "x" is of sort "foo" (but not necessarily a
436 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
437 control output of nested => (types); the default behavior is
440 * Pure/syntax: builtin parse translation for "_constify" turns valued
441 tokens into AST constants;
443 * Pure/syntax: prefer later declarations of translations and print
444 translation functions; potential INCOMPATIBILITY: need to reverse
445 multiple declarations for same syntax element constant;
447 * Pure/show_hyps reset by default (in accordance to existing Isar
450 * Provers/classical: renamed addaltern to addafter, addSaltern to
453 * Provers/clasimp: ``iff'' declarations now handle conditional rules
456 * system: tested support for MacOS X; should be able to get Isabelle +
457 Proof General to work in a plain Terminal after installing Poly/ML
458 (e.g. from the Isabelle distribution area) and GNU bash alone
459 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
460 support requires further installations, e.g. from
461 http://fink.sourceforge.net/);
463 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
465 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
466 of 40 MB), cf. ML_OPTIONS;
468 * system: Proof General keywords specification is now part of the
469 Isabelle distribution (see etc/isar-keywords.el);
471 * system: support for persistent Proof General sessions (refrain from
472 outdating all loaded theories on startup); user may create writable
473 logic images like this: ``isabelle -q HOL Test'';
475 * system: smart selection of Isabelle process versus Isabelle
476 interface, accommodates case-insensitive file systems (e.g. HFS+); may
477 run both "isabelle" and "Isabelle" even if file names are badly
478 damaged (executable inspects the case of the first letter of its own
479 name); added separate "isabelle-process" and "isabelle-interface";
481 * system: refrain from any attempt at filtering input streams; no
482 longer support ``8bit'' encoding of old isabelle font, instead proper
483 iso-latin characters may now be used; the related isatools
484 "symbolinput" and "nonascii" have disappeared as well;
486 * system: removed old "xterm" interface (the print modes "xterm" and
487 "xterm_color" are still available for direct use in a suitable
492 New in Isabelle99-2 (February 2001)
493 -----------------------------------
495 *** Overview of INCOMPATIBILITIES ***
497 * HOL: please note that theories in the Library and elsewhere often use the
498 new-style (Isar) format; to refer to their theorems in an ML script you must
499 bind them to ML identifers by e.g. val thm_name = thm "thm_name";
501 * HOL: inductive package no longer splits induction rule aggressively,
502 but only as far as specified by the introductions given; the old
503 format may be recovered via ML function complete_split_rule or attribute
504 'split_rule (complete)';
506 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
507 gfp_Tarski to gfp_unfold;
509 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
511 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
512 relation); infix "^^" has been renamed "``"; infix "``" has been
513 renamed "`"; "univalent" has been renamed "single_valued";
515 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
518 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
520 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
522 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
523 consequence, it is no longer monotonic wrt. the local goal context
524 (which is now passed through the inductive cases);
526 * Document preparation: renamed standard symbols \<ll> to \<lless> and
527 \<gg> to \<ggreater>;
530 *** Document preparation ***
532 * \isabellestyle{NAME} selects version of Isabelle output (currently
533 available: are "it" for near math-mode best-style output, "sl" for
534 slanted text style, and "tt" for plain type-writer; if no
535 \isabellestyle command is given, output is according to slanted
538 * support sub/super scripts (for single symbols only), input syntax is
539 like this: "A\<^sup>*" or "A\<^sup>\<star>";
541 * some more standard symbols; see Appendix A of the system manual for
542 the complete list of symbols defined in isabellesym.sty;
544 * improved isabelle style files; more abstract symbol implementation
545 (should now use \isamath{...} and \isatext{...} in custom symbol
548 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
549 state; Note that presentation of goal states does not conform to
550 actual human-readable proof documents. Please do not include goal
551 states into document output unless you really know what you are doing!
553 * proper indentation of antiquoted output with proportional LaTeX
556 * no_document ML operator temporarily disables LaTeX document
559 * isatool unsymbolize tunes sources for plain ASCII communication;
564 * Pure: Isar now suffers initial goal statements to contain unbound
565 schematic variables (this does not conform to actual readable proof
566 documents, due to unpredictable outcome and non-compositional proof
567 checking); users who know what they are doing may use schematic goals
568 for Prolog-style synthesis of proven results;
570 * Pure: assumption method (an implicit finishing) now handles actual
573 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
574 initial goal, declare "that" only as Pure intro (only for single
575 steps); the "that" rule assumption may now be involved in implicit
576 finishing, thus ".." becomes a feasible for trivial obtains;
578 * Pure: default proof step now includes 'intro_classes'; thus trivial
579 instance proofs may be performed by "..";
581 * Pure: ?thesis / ?this / "..." now work for pure meta-level
584 * Pure: more robust selection of calculational rules;
586 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
587 rule (as well as the assumption rule);
589 * Pure: 'thm_deps' command visualizes dependencies of theorems and
590 lemmas, using the graph browser tool;
592 * Pure: predict failure of "show" in interactive mode;
594 * Pure: 'thms_containing' now takes actual terms as arguments;
596 * HOL: improved method 'induct' --- now handles non-atomic goals
597 (potential INCOMPATIBILITY); tuned error handling;
599 * HOL: cases and induct rules now provide explicit hints about the
600 number of facts to be consumed (0 for "type" and 1 for "set" rules);
601 any remaining facts are inserted into the goal verbatim;
603 * HOL: local contexts (aka cases) may now contain term bindings as
604 well; the 'cases' and 'induct' methods new provide a ?case binding for
605 the result to be shown in each case;
607 * HOL: added 'recdef_tc' command;
609 * isatool convert assists in eliminating legacy ML scripts;
614 * HOL/Library: a collection of generic theories to be used together
615 with main HOL; the theory loader path already includes this directory
616 by default; the following existing theories have been moved here:
617 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
618 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
620 * HOL/Unix: "Some aspects of Unix file-system security", a typical
621 modelling and verification task performed in Isabelle/HOL +
622 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
624 * HOL/Algebra: special summation operator SUM no longer exists, it has
625 been replaced by setsum; infix 'assoc' now has priority 50 (like
626 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
627 'domain', this makes the theory consistent with mathematical
630 * HOL basics: added overloaded operations "inverse" and "divide"
631 (infix "/"), syntax for generic "abs" operation, generic summation
634 * HOL/typedef: simplified package, provide more useful rules (see also
637 * HOL/datatype: induction rule for arbitrarily branching datatypes is
638 now expressed as a proper nested rule (old-style tactic scripts may
639 require atomize_strip_tac to cope with non-atomic premises);
641 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
642 to "split_conv" (old name still available for compatibility);
644 * HOL: improved concrete syntax for strings (e.g. allows translation
645 rules with string literals);
647 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
648 and Fleuriot's mechanization of analysis, including the transcendental
649 functions for the reals;
651 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
656 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
657 "lam" is displayed as TWO lambda-symbols
659 * CTT: theory Main now available, containing everything (that is, Bool
665 * Pure: the Simplifier has been implemented properly as a derived rule
666 outside of the actual kernel (at last!); the overall performance
667 penalty in practical applications is about 50%, while reliability of
668 the Isabelle inference kernel has been greatly improved;
670 * print modes "brackets" and "no_brackets" control output of nested =>
671 (types) and ==> (props); the default behaviour is "brackets";
673 * Provers: fast_tac (and friends) now handle actual object-logic rules
674 as assumptions as well;
676 * system: support Poly/ML 4.0;
678 * system: isatool install handles KDE version 1 or 2;
682 New in Isabelle99-1 (October 2000)
683 ----------------------------------
685 *** Overview of INCOMPATIBILITIES ***
687 * HOL: simplification of natural numbers is much changed; to partly
688 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
689 issue the following ML commands:
691 Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
692 Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
694 * HOL: simplification no longer dives into case-expressions; this is
695 controlled by "t.weak_case_cong" for each datatype t;
697 * HOL: nat_less_induct renamed to less_induct;
699 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
700 fixsome to patch .thy and .ML sources automatically;
702 select_equality -> some_equality
703 select_eq_Ex -> some_eq_ex
704 selectI2EX -> someI2_ex
707 select1_equality -> some1_equality
708 Eps_sym_eq -> some_sym_eq_trivial
709 Eps_eq -> some_eq_trivial
711 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
713 * HOL: removed obsolete theorem binding expand_if (refer to split_if
716 * HOL: the recursion equations generated by 'recdef' are now called
717 f.simps instead of f.rules;
719 * HOL: qed_spec_mp now also handles bounded ALL as well;
721 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
724 * HOL: the constant for "f``x" is now "image" rather than "op ``";
726 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
728 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
729 product is now "<*>" instead of "Times"; the lexicographic product is
730 now "<*lex*>" instead of "**";
732 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
733 of main HOL, but was unused); better use HOL's datatype package;
735 * HOL: removed "symbols" syntax for constant "override" of theory Map;
736 the old syntax may be recovered as follows:
739 override :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
740 (infixl "\\<oplus>" 100)
742 * HOL/Real: "rabs" replaced by overloaded "abs" function;
744 * HOL/ML: even fewer consts are declared as global (see theories Ord,
745 Lfp, Gfp, WF); this only affects ML packages that refer to const names
748 * HOL and ZF: syntax for quotienting wrt an equivalence relation
749 changed from A/r to A//r;
751 * ZF: new treatment of arithmetic (nat & int) may break some old
754 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
755 rulify -> rule_format, elimify -> elim_format, ...);
757 * Isar/Provers: intro/elim/dest attributes changed; renamed
758 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
759 should have to change intro!! to intro? only); replaced "delrule" by
762 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
764 * Provers: strengthened force_tac by using new first_best_tac;
766 * LaTeX document preparation: several changes of isabelle.sty (see
770 *** Document preparation ***
772 * formal comments (text blocks etc.) in new-style theories may now
773 contain antiquotations of thm/prop/term/typ/text to be presented
774 according to latex print mode; concrete syntax is like this:
775 @{term[show_types] "f(x) = a + x"};
777 * isatool mkdir provides easy setup of Isabelle session directories,
778 including proper document sources;
780 * generated LaTeX sources are now deleted after successful run
781 (isatool document -c); may retain a copy somewhere else via -D option
784 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
785 style files, achieving self-contained LaTeX sources and simplifying
788 * old-style theories now produce (crude) LaTeX output as well;
790 * browser info session directories are now self-contained (may be put
791 on WWW server seperately); improved graphs of nested sessions; removed
792 graph for 'all sessions';
794 * several improvements in isabelle style files; \isabellestyle{it}
795 produces fake math mode output; \isamarkupheader is now \section by
796 default; see lib/texinputs/isabelle.sty etc.;
801 * Isar/Pure: local results and corresponding term bindings are now
802 subject to Hindley-Milner polymorphism (similar to ML); this
803 accommodates incremental type-inference very nicely;
805 * Isar/Pure: new derived language element 'obtain' supports
806 generalized existence reasoning;
808 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
809 support accumulation of results, without applying any rules yet;
810 useful to collect intermediate results without explicit name
811 references, and for use with transitivity rules with more than 2
814 * Isar/Pure: scalable support for case-analysis type proofs: new
815 'case' language element refers to local contexts symbolically, as
816 produced by certain proof methods; internally, case names are attached
817 to theorems as "tags";
819 * Isar/Pure: theory command 'hide' removes declarations from
820 class/type/const name spaces;
822 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
823 indicate potential overloading;
825 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
827 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
828 "{a,b,c}" instead of {a,b,c};
830 * Isar/Pure now provides its own version of intro/elim/dest
831 attributes; useful for building new logics, but beware of confusion
832 with the version in Provers/classical;
834 * Isar/Pure: the local context of (non-atomic) goals is provided via
835 case name 'antecedent';
837 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
838 to the current context is now done automatically);
840 * Isar/Pure: theory command 'method_setup' provides a simple interface
841 for definining proof methods in ML;
843 * Isar/Provers: intro/elim/dest attributes changed; renamed
844 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
845 most cases, one should have to change intro!! to intro? only);
846 replaced "delrule" by "rule del";
848 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
849 'symmetric' attribute (the latter supercedes [RS sym]);
851 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
852 method modifier); 'simp' method: 'only:' modifier removes loopers as
853 well (including splits);
855 * Isar/Provers: Simplifier and Classical methods now support all kind
856 of modifiers used in the past, including 'cong', 'iff', etc.
858 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
859 of Simplifier and Classical reasoner);
861 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
862 now support named cases; major packages (inductive, datatype, primrec,
863 recdef) support case names and properly name parameters;
865 * Isar/HOL: new transitivity rules for substitution in inequalities --
866 monotonicity conditions are extracted to be proven at end of
869 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
872 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
873 split_if split_if_asm; datatype package provides theorems foo.splits =
874 foo.split foo.split_asm for each datatype;
876 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
877 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
878 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
879 use "(cases (simplified))" method in proper proof texts);
881 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
883 * Isar: names of theorems etc. may be natural numbers as well;
885 * Isar: 'pr' command: optional arguments for goals_limit and
886 ProofContext.prems_limit; no longer prints theory contexts, but only
889 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
890 additional print modes to be specified; e.g. "pr(latex)" will print
891 proof state according to the Isabelle LaTeX style;
893 * Isar: improved support for emulating tactic scripts, including proof
894 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
895 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
898 * Isar: simplified (more robust) goal selection of proof methods: 1st
899 goal, all goals, or explicit goal specifier (tactic emulation); thus
900 'proof method scripts' have to be in depth-first order;
902 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
904 * Isar: removed 'help' command, which hasn't been too helpful anyway;
905 should instead use individual commands for printing items
906 (print_commands, print_methods etc.);
908 * Isar: added 'nothing' --- the empty list of theorems;
913 * HOL/MicroJava: formalization of a fragment of Java, together with a
914 corresponding virtual machine and a specification of its bytecode
915 verifier and a lightweight bytecode verifier, including proofs of
916 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
917 Cornelia Pusch (see also the homepage of project Bali at
918 http://isabelle.in.tum.de/Bali/);
920 * HOL/Algebra: new theory of rings and univariate polynomials, by
923 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
924 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
927 * HOL/Lattice: fundamental concepts of lattice theory and order
928 structures, including duals, properties of bounds versus algebraic
929 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
930 Theorem for complete lattices etc.; may also serve as a demonstration
931 for abstract algebraic reasoning using axiomatic type classes, and
932 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
934 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
937 * HOL/IMPP: extension of IMP with local variables and mutually
938 recursive procedures, by David von Oheimb;
940 * HOL/Lambda: converted into new-style theory and document;
942 * HOL/ex/Multiquote: example of multiple nested quotations and
943 anti-quotations -- basically a generalized version of de-Bruijn
944 representation; very useful in avoiding lifting of operations;
946 * HOL/record: added general record equality rule to simpset; fixed
947 select-update simplification procedure to handle extended records as
948 well; admit "r" as field name;
950 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
951 other numeric types and also as the identity of groups, rings, etc.;
953 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
954 Types nat and int belong to this axclass;
956 * HOL: greatly improved simplification involving numerals of type nat, int, real:
957 (i + #8 + j) = Suc k simplifies to #7 + (i + j) = k
958 i*j + k + j*#3*i simplifies to #4*(i*j) + k
959 two terms #m*u and #n*u are replaced by #(m+n)*u
960 (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
961 and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
962 or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
964 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
965 powerful prover for predicate logic but knows nothing of clasets; see
966 ex/mesontest.ML and ex/mesontest2.ML for example applications;
968 * HOL: new version of "case_tac" subsumes both boolean case split and
969 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
970 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
972 * HOL: simplification no longer dives into case-expressions: only the
973 selector expression is simplified, but not the remaining arms; to
974 enable full simplification of case-expressions for datatype t, you may
975 remove t.weak_case_cong from the simpset, either globally (Delcongs
976 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
978 * HOL/recdef: the recursion equations generated by 'recdef' for
979 function 'f' are now called f.simps instead of f.rules; if all
980 termination conditions are proved automatically, these simplification
981 rules are added to the simpset, as in primrec; rules may be named
982 individually as well, resulting in a separate list of theorems for
985 * HOL/While is a new theory that provides a while-combinator. It
986 permits the definition of tail-recursive functions without the
987 provision of a termination measure. The latter is necessary once the
988 invariant proof rule for while is applied.
990 * HOL: new (overloaded) notation for the set of elements below/above
991 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
993 * HOL: theorems impI, allI, ballI bound as "strip";
995 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
996 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
997 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
999 * HOL/Real: "rabs" replaced by overloaded "abs" function;
1001 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
1002 main HOL, but was unused);
1004 * HOL: fewer consts declared as global (e.g. have to refer to
1005 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
1007 * HOL: tuned AST representation of nested pairs, avoiding bogus output
1008 in case of overlap with user translations (e.g. judgements over
1009 tuples); (note that the underlying logical represenation is still
1015 * ZF: simplification automatically cancels common terms in arithmetic
1016 expressions over nat and int;
1018 * ZF: new treatment of nat to minimize type-checking: all operators
1019 coerce their operands to a natural number using the function natify,
1020 making the algebraic laws unconditional;
1022 * ZF: as above, for int: operators coerce their operands to an integer
1023 using the function intify;
1025 * ZF: the integer library now contains many of the usual laws for the
1026 orderings, including $<=, and monotonicity laws for $+ and $*;
1028 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
1031 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
1032 to the simplifier and classical reasoner simultaneously;
1037 * Provers: blast_tac now handles actual object-logic rules as
1038 assumptions; note that auto_tac uses blast_tac internally as well;
1040 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
1041 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
1043 * Provers: delrules now handles destruct rules as well (no longer need
1044 explicit make_elim);
1046 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
1047 [| inj ?f; ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
1048 use instead the strong form,
1049 [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
1050 in HOL, FOL and ZF the function cla_make_elim will create such rules
1051 from destruct-rules;
1053 * Provers: Simplifier.easy_setup provides a fast path to basic
1054 Simplifier setup for new object-logics;
1056 * Pure: AST translation rules no longer require constant head on LHS;
1058 * Pure: improved name spaces: ambiguous output is qualified; support
1059 for hiding of names;
1061 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
1062 XSYMBOL_HOME; no longer need to do manual configuration in most
1065 * system: compression of ML heaps images may now be controlled via -c
1066 option of isabelle and isatool usedir (currently only observed by
1069 * system: isatool installfonts may handle X-Symbol fonts as well (very
1070 useful for remote X11);
1072 * system: provide TAGS file for Isabelle sources;
1074 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
1077 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
1078 timing flag supersedes proof_timing and Toplevel.trace;
1080 * ML: new combinators |>> and |>>> for incremental transformations
1081 with secondary results (e.g. certain theory extensions):
1083 * ML: PureThy.add_defs gets additional argument to indicate potential
1084 overloading (usually false);
1086 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
1091 New in Isabelle99 (October 1999)
1092 --------------------------------
1094 *** Overview of INCOMPATIBILITIES (see below for more details) ***
1096 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
1097 are no longer simplified. (This allows the simplifier to unfold recursive
1098 functional programs.) To restore the old behaviour, declare
1100 Delcongs [if_weak_cong];
1102 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
1105 * HOL: the predicate "inj" is now defined by translation to "inj_on";
1107 * HOL/datatype: mutual_induct_tac no longer exists --
1108 use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
1110 * HOL/typedef: fixed type inference for representing set; type
1111 arguments now have to occur explicitly on the rhs as type constraints;
1113 * ZF: The con_defs part of an inductive definition may no longer refer
1114 to constants declared in the same theory;
1116 * HOL, ZF: the function mk_cases, generated by the inductive
1117 definition package, has lost an argument. To simplify its result, it
1118 uses the default simpset instead of a supplied list of theorems.
1120 * HOL/List: the constructors of type list are now Nil and Cons;
1122 * Simplifier: the type of the infix ML functions
1123 setSSolver addSSolver setSolver addSolver
1124 is now simpset * solver -> simpset where `solver' is a new abstract type
1125 for packaging solvers. A solver is created via
1126 mk_solver: string -> (thm list -> int -> tactic) -> solver
1127 where the string argument is only a comment.
1132 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
1133 decision procedure for linear arithmetic. Currently it is used for
1134 types `nat', `int', and `real' in HOL (see below); it can, should and
1135 will be instantiated for other types and logics as well.
1137 * The simplifier now accepts rewrite rules with flexible heads, eg
1138 hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
1139 They are applied like any rule with a non-pattern lhs, i.e. by first-order
1145 * New Isabelle/Isar subsystem provides an alternative to traditional
1146 tactical theorem proving; together with the ProofGeneral/isar user
1147 interface it offers an interactive environment for developing human
1148 readable proof documents (Isar == Intelligible semi-automated
1149 reasoning); for further information see isatool doc isar-ref,
1150 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
1152 * improved and simplified presentation of theories: better HTML markup
1153 (including colors), graph views in several sizes; isatool usedir now
1154 provides a proper interface for user theories (via -P option); actual
1155 document preparation based on (PDF)LaTeX is available as well (for
1156 new-style theories only); see isatool doc system for more information;
1158 * native support for Proof General, both for classic Isabelle and
1161 * ML function thm_deps visualizes dependencies of theorems and lemmas,
1162 using the graph browser tool;
1164 * Isabelle manuals now also available as PDF;
1166 * theory loader rewritten from scratch (may not be fully
1167 bug-compatible); old loadpath variable has been replaced by show_path,
1168 add_path, del_path, reset_path functions; new operations such as
1169 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
1172 * improved isatool install: option -k creates KDE application icon,
1173 option -p DIR installs standalone binaries;
1175 * added ML_PLATFORM setting (useful for cross-platform installations);
1176 more robust handling of platform specific ML images for SML/NJ;
1178 * the settings environment is now statically scoped, i.e. it is never
1179 created again in sub-processes invoked from isabelle, isatool, or
1182 * path element specification '~~' refers to '$ISABELLE_HOME';
1184 * in locales, the "assumes" and "defines" parts may be omitted if
1187 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
1190 * new print_mode "HTML";
1192 * new flag show_tags controls display of tags of theorems (which are
1193 basically just comments that may be attached by some tools);
1195 * Isamode 2.6 requires patch to accomodate change of Isabelle font
1196 mode and goal output format:
1198 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
1200 < (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
1202 > (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
1203 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
1205 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
1207 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
1209 * function bind_thms stores lists of theorems (cf. bind_thm);
1211 * new shorthand tactics ftac, eatac, datac, fatac;
1213 * qed (and friends) now accept "" as result name; in that case the
1214 theorem is not stored, but proper checks and presentation of the
1217 * theorem database now also indexes constants "Trueprop", "all",
1218 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
1223 ** HOL arithmetic **
1225 * There are now decision procedures for linear arithmetic over nat and
1228 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
1229 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
1230 are treated as atomic; subformulae not involving type `nat' or `int'
1231 are ignored; quantified subformulae are ignored unless they are
1232 positive universal or negative existential. The tactic has to be
1233 invoked by hand and can be a little bit slow. In particular, the
1234 running time is exponential in the number of occurrences of `min' and
1235 `max', and `-' on `nat'.
1237 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
1238 (negated) (in)equalities among the premises and the conclusion into
1239 account (i.e. no compound formulae) and does not know about `min' and
1240 `max', and `-' on `nat'. It is fast and is used automatically by the
1243 NB: At the moment, these decision procedures do not cope with mixed
1244 nat/int formulae where the two parts interact, such as `m < n ==>
1247 * HOL/Numeral provides a generic theory of numerals (encoded
1248 efficiently as bit strings); setup for types nat/int/real is in place;
1249 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
1250 int, existing theories and proof scripts may require a few additional
1253 * integer division and remainder can now be performed on constant
1256 * many properties of integer multiplication, division and remainder
1259 * An interface to the Stanford Validity Checker (SVC) is available through the
1260 tactic svc_tac. Propositional tautologies and theorems of linear arithmetic
1261 are proved automatically. SVC must be installed separately, and its results
1262 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
1263 invocation of the underlying oracle). For SVC see
1264 http://verify.stanford.edu/SVC
1266 * IsaMakefile: the HOL-Real target now builds an actual image;
1271 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
1272 (in Isabelle/Isar) -- by Gertrud Bauer;
1274 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
1275 analysis for assembly languages with subtypes;
1277 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
1278 -- avoids syntactic ambiguities and treats state, transition, and
1279 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
1280 changed syntax and (many) tactics;
1282 * HOL/inductive: Now also handles more general introduction rules such
1283 as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
1284 theorems are now maintained within the theory (maintained via the
1287 * HOL/datatype: Now also handles arbitrarily branching datatypes
1288 (using function types) such as
1290 datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
1292 * HOL/record: record_simproc (part of the default simpset) takes care
1293 of selectors applied to updated records; record_split_tac is no longer
1294 part of the default claset; update_defs may now be removed from the
1295 simpset in many cases; COMPATIBILITY: old behavior achieved by
1297 claset_ref () := claset() addSWrapper record_split_wrapper;
1298 Delsimprocs [record_simproc]
1300 * HOL/typedef: fixed type inference for representing set; type
1301 arguments now have to occur explicitly on the rhs as type constraints;
1303 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
1304 names rather than an ML expression;
1306 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
1307 supplied later. Program schemes can be defined, such as
1308 "While B C s = (if B s then While B C (C s) else s)"
1309 where the well-founded relation can be chosen after B and C have been given.
1311 * HOL/List: the constructors of type list are now Nil and Cons;
1312 INCOMPATIBILITY: while [] and infix # syntax is still there, of
1313 course, ML tools referring to List.list.op # etc. have to be adapted;
1315 * HOL_quantifiers flag superseded by "HOL" print mode, which is
1316 disabled by default; run isabelle with option -m HOL to get back to
1317 the original Gordon/HOL-style output;
1319 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
1320 ALL x<=y. P, EX x<y. P, EX x<=y. P;
1322 * HOL basic syntax simplified (more orthogonal): all variants of
1323 All/Ex now support plain / symbolic / HOL notation; plain syntax for
1324 Eps operator is provided as well: "SOME x. P[x]";
1326 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
1328 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
1329 thus available for user theories;
1331 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
1332 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
1335 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
1336 several times and then mp;
1341 * the notation <<...>> is now available as a notation for sequences of
1344 * the simplifier is now installed
1346 * the axiom system has been generalized (thanks to Soren Heilmann)
1348 * the classical reasoner now has a default rule database
1353 * new primrec section allows primitive recursive functions to be given
1354 directly (as in HOL) over datatypes and the natural numbers;
1356 * new tactics induct_tac and exhaust_tac for induction (or case
1357 analysis) over datatypes and the natural numbers;
1359 * the datatype declaration of type T now defines the recursor T_rec;
1361 * simplification automatically does freeness reasoning for datatype
1364 * automatic type-inference, with AddTCs command to insert new
1365 type-checking rules;
1367 * datatype introduction rules are now added as Safe Introduction rules
1370 * the syntax "if P then x else y" is now available in addition to
1374 *** Internal programming interfaces ***
1376 * tuned simplifier trace output; new flag debug_simp;
1378 * structures Vartab / Termtab (instances of TableFun) offer efficient
1379 tables indexed by indexname_ord / term_ord (compatible with aconv);
1381 * AxClass.axclass_tac lost the theory argument;
1383 * tuned current_goals_markers semantics: begin / end goal avoids
1384 printing empty lines;
1386 * removed prs and prs_fn hook, which was broken because it did not
1387 include \n in its semantics, forcing writeln to add one
1388 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
1389 string -> unit if you really want to output text without newline;
1391 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
1392 plain output, interface builders may have to enable 'isabelle_font'
1393 mode to get Isabelle font glyphs as before;
1395 * refined token_translation interface; INCOMPATIBILITY: output length
1396 now of type real instead of int;
1398 * theory loader actions may be traced via new ThyInfo.add_hook
1399 interface (see src/Pure/Thy/thy_info.ML); example application: keep
1400 your own database of information attached to *whole* theories -- as
1401 opposed to intra-theory data slots offered via TheoryDataFun;
1403 * proper handling of dangling sort hypotheses (at last!);
1404 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
1405 extra sort hypotheses that can be witnessed from the type signature;
1406 the force_strip_shyps flag is gone, any remaining shyps are simply
1407 left in the theorem (with a warning issued by strip_shyps_warning);
1411 New in Isabelle98-1 (October 1998)
1412 ----------------------------------
1414 *** Overview of INCOMPATIBILITIES (see below for more details) ***
1416 * several changes of automated proof tools;
1418 * HOL: major changes to the inductive and datatype packages, including
1419 some minor incompatibilities of theory syntax;
1421 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
1424 * HOL: removed duplicate thms in Arith:
1425 less_imp_add_less should be replaced by trans_less_add1
1426 le_imp_add_le should be replaced by trans_le_add1
1428 * HOL: unary minus is now overloaded (new type constraints may be
1431 * HOL and ZF: unary minus for integers is now #- instead of #~. In
1432 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
1433 now taken as an integer constant.
1435 * Pure: ML function 'theory_of' renamed to 'theory';
1441 1. Asm_full_simp_tac is now more aggressive.
1442 1. It will sometimes reorient premises if that increases their power to
1444 2. It does no longer proceed strictly from left to right but may also
1445 rotate premises to achieve further simplification.
1446 For compatibility reasons there is now Asm_lr_simp_tac which is like the
1447 old Asm_full_simp_tac in that it does not rotate premises.
1448 2. The simplifier now knows a little bit about nat-arithmetic.
1450 * Classical reasoner: wrapper mechanism for the classical reasoner now
1451 allows for selected deletion of wrappers, by introduction of names for
1452 wrapper functionals. This implies that addbefore, addSbefore,
1453 addaltern, and addSaltern now take a pair (name, tactic) as argument,
1454 and that adding two tactics with the same name overwrites the first
1455 one (emitting a warning).
1456 type wrapper = (int -> tactic) -> (int -> tactic)
1457 setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
1458 addWrapper, addSWrapper: claset * (string * wrapper) -> claset
1459 delWrapper, delSWrapper: claset * string -> claset
1460 getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
1462 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
1463 semantics; addbefore now affects only the unsafe part of step_tac
1464 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
1465 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
1468 * Classical reasoner: setwrapper to setWrapper and compwrapper to
1469 compWrapper; added safe wrapper (and access functions for it);
1471 * HOL/split_all_tac is now much faster and fails if there is nothing
1472 to split. Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
1473 and the names of the automatically generated variables have changed.
1474 split_all_tac has moved within claset() from unsafe wrappers to safe
1475 wrappers, which means that !!-bound variables are split much more
1476 aggressively, and safe_tac and clarify_tac now split such variables.
1477 If this splitting is not appropriate, use delSWrapper "split_all_tac".
1478 Note: the same holds for record_split_tac, which does the job of
1479 split_all_tac for record fields.
1481 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
1482 permanently to the default simpset using Addsplits just like
1483 Addsimps. They can be removed via Delsplits just like
1484 Delsimps. Lower-case versions are also available.
1486 * HOL/Simplifier: The rule split_if is now part of the default
1487 simpset. This means that the simplifier will eliminate all occurrences
1488 of if-then-else in the conclusion of a goal. To prevent this, you can
1489 either remove split_if completely from the default simpset by
1490 `Delsplits [split_if]' or remove it in a specific call of the
1491 simplifier using `... delsplits [split_if]'. You can also add/delete
1492 other case splitting rules to/from the default simpset: every datatype
1493 generates suitable rules `split_t_case' and `split_t_case_asm' (where
1494 t is the name of the datatype).
1496 * Classical reasoner / Simplifier combination: new force_tac (and
1497 derivatives Force_tac, force) combines rewriting and classical
1498 reasoning (and whatever other tools) similarly to auto_tac, but is
1499 aimed to solve the given subgoal completely.
1504 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
1505 and `goalw': the theory is no longer needed as an explicit argument -
1506 the current theory context is used; assumptions are no longer returned
1507 at the ML-level unless one of them starts with ==> or !!; it is
1508 recommended to convert to these new commands using isatool fixgoal
1509 (backup your sources first!);
1511 * new top-level commands 'thm' and 'thms' for retrieving theorems from
1512 the current theory context, and 'theory' to lookup stored theories;
1514 * new theory section 'locale' for declaring constants, assumptions and
1515 definitions that have local scope;
1517 * new theory section 'nonterminals' for purely syntactic types;
1519 * new theory section 'setup' for generic ML setup functions
1520 (e.g. package initialization);
1522 * the distribution now includes Isabelle icons: see
1523 lib/logo/isabelle-{small,tiny}.xpm;
1525 * isatool install - install binaries with absolute references to
1528 * isatool logo -- create instances of the Isabelle logo (as EPS);
1530 * print mode 'emacs' reserved for Isamode;
1532 * support multiple print (ast) translations per constant name;
1534 * theorems involving oracles are now printed with a suffixed [!];
1539 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
1541 * HOL/inductive package reorganized and improved: now supports mutual
1547 oddI "n : EVEN ==> Suc n : ODD"
1548 evenI "n : ODD ==> Suc n : EVEN"
1550 new theorem list "elims" contains an elimination rule for each of the
1551 recursive sets; inductive definitions now handle disjunctive premises
1552 correctly (also ZF);
1554 INCOMPATIBILITIES: requires Inductive as an ancestor; component
1555 "mutual_induct" no longer exists - the induction rule is always
1556 contained in "induct";
1559 * HOL/datatype package re-implemented and greatly improved: now
1560 supports mutually recursive datatypes such as
1563 'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
1564 | SUM ('a aexp) ('a aexp)
1565 | DIFF ('a aexp) ('a aexp)
1568 'a bexp = LESS ('a aexp) ('a aexp)
1569 | AND ('a bexp) ('a bexp)
1570 | OR ('a bexp) ('a bexp)
1572 as well as indirectly recursive datatypes such as
1575 ('a, 'b) term = Var 'a
1576 | App 'b ((('a, 'b) term) list)
1578 The new tactic mutual_induct_tac [<var_1>, ..., <var_n>] i performs
1579 induction on mutually / indirectly recursive datatypes.
1581 Primrec equations are now stored in theory and can be accessed via
1582 <function_name>.simps.
1586 - Theories using datatypes must now have theory Datatype as an
1588 - The specific <typename>.induct_tac no longer exists - use the
1589 generic induct_tac instead.
1590 - natE has been renamed to nat.exhaust - use exhaust_tac
1591 instead of res_inst_tac ... natE. Note that the variable
1592 names in nat.exhaust differ from the names in natE, this
1593 may cause some "fragile" proofs to fail.
1594 - The theorems split_<typename>_case and split_<typename>_case_asm
1595 have been renamed to <typename>.split and <typename>.split_asm.
1596 - Since default sorts of type variables are now handled correctly,
1597 some datatype definitions may have to be annotated with explicit
1599 - Primrec definitions no longer require function name and type
1600 of recursive argument.
1602 Consider using isatool fixdatatype to adapt your theories and proof
1603 scripts to the new package (backup your sources first!).
1606 * HOL/record package: considerably improved implementation; now
1607 includes concrete syntax for record types, terms, updates; theorems
1608 for surjective pairing and splitting !!-bound record variables; proof
1609 support is as follows:
1611 1) standard conversions (selectors or updates applied to record
1612 constructor terms) are part of the standard simpset;
1614 2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
1615 made part of standard simpset and claset via addIffs;
1617 3) a tactic for record field splitting (record_split_tac) is part of
1618 the standard claset (addSWrapper);
1620 To get a better idea about these rules you may retrieve them via
1621 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
1622 the name of your record type.
1624 The split tactic 3) conceptually simplifies by the following rule:
1626 "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
1628 Thus any record variable that is bound by meta-all will automatically
1629 blow up into some record constructor term, consequently the
1630 simplifications of 1), 2) apply. Thus force_tac, auto_tac etc. shall
1631 solve record problems automatically.
1634 * reorganized the main HOL image: HOL/Integ and String loaded by
1635 default; theory Main includes everything;
1637 * automatic simplification of integer sums and comparisons, using cancellation;
1639 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
1641 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
1643 * many new identities for unions, intersections, set difference, etc.;
1645 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
1646 called split_if, split_split, split_sum_case and split_nat_case (to go
1647 with add/delsplits);
1649 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
1650 (?x::unit) = (); this is made part of the default simpset, which COULD
1651 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
1652 'Delsimprocs [unit_eq_proc];' as last resort); also note that
1653 unit_abs_eta_conv is added in order to counter the effect of
1654 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
1657 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
1660 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
1661 It and 'sym RS equals0D' are now in the default claset, giving automatic
1662 disjointness reasoning but breaking a few old proofs.
1664 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
1665 to 'converse' from 'inverse' (for compatibility with ZF and some
1668 * HOL/recdef can now declare non-recursive functions, with {} supplied as
1669 the well-founded relation;
1671 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
1672 Compl A. The "Compl" syntax remains available as input syntax for this
1675 * HOL/Update: new theory of function updates:
1676 f(a:=b) == %x. if x=a then b else f x
1677 may also be iterated as in f(a:=b,c:=d,...);
1679 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
1682 - new function list_update written xs[i:=v] that updates the i-th
1683 list position. May also be iterated as in xs[i:=a,j:=b,...].
1684 - new function `upt' written [i..j(] which generates the list
1685 [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
1686 bound write [i..j], which is a shorthand for [i..j+1(].
1687 - new lexicographic orderings and corresponding wellfoundedness theorems.
1690 - removed 'pred' (predecessor) function;
1691 - generalized some theorems about n-1;
1692 - many new laws about "div" and "mod";
1693 - new laws about greatest common divisors (see theory ex/Primes);
1695 * HOL/Relation: renamed the relational operator r^-1 "converse"
1696 instead of "inverse";
1698 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
1699 of the multiset ordering;
1701 * directory HOL/Real: a construction of the reals using Dedekind cuts
1702 (not included by default);
1704 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
1706 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
1707 programs, i.e. different program variables may have different types.
1709 * calling (stac rew i) now fails if "rew" has no effect on the goal
1710 [previously, this check worked only if the rewrite rule was unconditional]
1711 Now rew can involve either definitions or equalities (either == or =).
1716 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
1717 only the theorems proved on ZF.ML;
1719 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
1720 It and 'sym RS equals0D' are now in the default claset, giving automatic
1721 disjointness reasoning but breaking a few old proofs.
1723 * ZF/Update: new theory of function updates
1724 with default rewrite rule f(x:=y) ` z = if(z=x, y, f`z)
1725 may also be iterated as in f(a:=b,c:=d,...);
1727 * in let x=t in u(x), neither t nor u(x) has to be an FOL term.
1729 * calling (stac rew i) now fails if "rew" has no effect on the goal
1730 [previously, this check worked only if the rewrite rule was unconditional]
1731 Now rew can involve either definitions or equalities (either == or =).
1733 * case_tac provided for compatibility with HOL
1734 (like the old excluded_middle_tac, but with subgoals swapped)
1737 *** Internal programming interfaces ***
1739 * Pure: several new basic modules made available for general use, see
1740 also src/Pure/README;
1742 * improved the theory data mechanism to support encapsulation (data
1743 kind name replaced by private Object.kind, acting as authorization
1744 key); new type-safe user interface via functor TheoryDataFun; generic
1745 print_data function becomes basically useless;
1747 * removed global_names compatibility flag -- all theory declarations
1748 are qualified by default;
1750 * module Pure/Syntax now offers quote / antiquote translation
1751 functions (useful for Hoare logic etc. with implicit dependencies);
1752 see HOL/ex/Antiquote for an example use;
1754 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
1757 * new tactical CHANGED_GOAL for checking that a tactic modifies a
1760 * Display.print_goals function moved to Locale.print_goals;
1762 * standard print function for goals supports current_goals_markers
1763 variable for marking begin of proof, end of proof, start of goal; the
1764 default is ("", "", ""); setting current_goals_markers := ("<proof>",
1765 "</proof>", "<goal>") causes SGML like tagged proof state printing,
1770 New in Isabelle98 (January 1998)
1771 --------------------------------
1773 *** Overview of INCOMPATIBILITIES (see below for more details) ***
1775 * changed lexical syntax of terms / types: dots made part of long
1776 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
1778 * simpset (and claset) reference variable replaced by functions
1779 simpset / simpset_ref;
1781 * no longer supports theory aliases (via merge) and non-trivial
1782 implicit merge of thms' signatures;
1784 * most internal names of constants changed due to qualified names;
1786 * changed Pure/Sequence interface (see Pure/seq.ML);
1789 *** General Changes ***
1791 * hierachically structured name spaces (for consts, types, axms, thms
1792 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
1793 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
1794 isatool fixdots ensures space after dots (e.g. "%x. x"); set
1795 long_names for fully qualified output names; NOTE: ML programs
1796 (special tactics, packages etc.) referring to internal names may have
1797 to be adapted to cope with fully qualified names; in case of severe
1798 backward campatibility problems try setting 'global_names' at compile
1799 time to have enrything declared within a flat name space; one may also
1800 fine tune name declarations in theories via the 'global' and 'local'
1803 * reimplemented the implicit simpset and claset using the new anytype
1804 data filed in signatures; references simpset:simpset ref etc. are
1805 replaced by functions simpset:unit->simpset and
1806 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
1807 to patch your ML files accordingly;
1809 * HTML output now includes theory graph data for display with Java
1810 applet or isatool browser; data generated automatically via isatool
1811 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
1813 * defs may now be conditional; improved rewrite_goals_tac to handle
1814 conditional equations;
1816 * defs now admits additional type arguments, using TYPE('a) syntax;
1818 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
1819 creates a new theory node; implicit merge of thms' signatures is
1820 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
1821 transfer:theory->thm->thm in (rare) cases;
1823 * improved handling of draft signatures / theories; draft thms (and
1824 ctyps, cterms) are automatically promoted to real ones;
1826 * slightly changed interfaces for oracles: admit many per theory, named
1827 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
1829 * print_goals: optional output of const types (set show_consts and
1832 * improved output of warnings (###) and errors (***);
1834 * subgoal_tac displays a warning if the new subgoal has type variables;
1836 * removed old README and Makefiles;
1838 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
1840 * removed obsolete init_pps and init_database;
1842 * deleted the obsolete tactical STATE, which was declared by
1843 fun STATE tacfun st = tacfun st st;
1845 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
1846 (which abbreviates $HOME);
1848 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
1849 use isatool fixseq to adapt your ML programs (this works for fully
1850 qualified references to the Sequence structure only!);
1852 * use_thy no longer requires writable current directory; it always
1853 reloads .ML *and* .thy file, if either one is out of date;
1856 *** Classical Reasoner ***
1858 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
1859 tactics that use classical reasoning to simplify a subgoal without
1860 splitting it into several subgoals;
1862 * Safe_tac: like safe_tac but uses the default claset;
1867 * added simplification meta rules:
1868 (asm_)(full_)simplify: simpset -> thm -> thm;
1870 * simplifier.ML no longer part of Pure -- has to be loaded by object
1873 * added prems argument to simplification procedures;
1875 * HOL, FOL, ZF: added infix function `addsplits':
1876 instead of `<simpset> setloop (split_tac <thms>)'
1877 you can simply write `<simpset> addsplits <thms>'
1882 * TYPE('a) syntax for type reflection terms;
1884 * no longer handles consts with name "" -- declare as 'syntax' instead;
1886 * pretty printer: changed order of mixfix annotation preference (again!);
1888 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
1893 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
1894 with `addloop' of the simplifier to faciliate case splitting in premises.
1896 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
1898 * HOL/Auth: new protocol proofs including some for the Internet
1901 * HOL/Map: new theory of `maps' a la VDM;
1903 * HOL/simplifier: simplification procedures nat_cancel_sums for
1904 cancelling out common nat summands from =, <, <= (in)equalities, or
1905 differences; simplification procedures nat_cancel_factor for
1906 cancelling common factor from =, <, <= (in)equalities over natural
1907 sums; nat_cancel contains both kinds of procedures, it is installed by
1908 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
1910 * HOL/simplifier: terms of the form
1911 `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)' (or t=x)
1913 `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
1914 and those of the form
1915 `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)' (or t=x)
1917 `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
1920 Each datatype `t' now comes with a theorem `split_t_case' of the form
1922 P(t_case f1 ... fn x) =
1923 ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
1925 (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
1928 and a theorem `split_t_case_asm' of the form
1930 P(t_case f1 ... fn x) =
1931 ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
1933 (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
1935 which can be added to a simpset via `addsplits'. The existing theorems
1936 expand_list_case and expand_option_case have been renamed to
1937 split_list_case and split_option_case.
1940 - `pred n' is automatically converted to `n-1'.
1941 Users are strongly encouraged not to use `pred' any longer,
1942 because it will disappear altogether at some point.
1943 - Users are strongly encouraged to write "0 < n" rather than
1944 "n ~= 0". Theorems and proof tools have been modified towards this
1948 the function "set_of_list" has been renamed "set" (and its theorems too);
1949 the function "nth" now takes its arguments in the reverse order and
1950 has acquired the infix notation "!" as in "xs!n".
1952 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
1954 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
1955 specialist theorems (like UN1_I) are gone. Similarly for (INT x.B x);
1957 * HOL/record: extensible records with schematic structural subtyping
1958 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
1959 still lacks various theorems and concrete record syntax;
1964 * removed "axioms" and "generated by" sections;
1966 * replaced "ops" section by extended "consts" section, which is capable of
1967 handling the continuous function space "->" directly;
1970 . proves theorems immediately and stores them in the theory,
1971 . creates hierachical name space,
1972 . now uses normal mixfix annotations (instead of cinfix...),
1973 . minor changes to some names and values (for consistency),
1974 . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
1975 . separator between mutual domain defs: changed "," to "and",
1976 . improved handling of sort constraints; now they have to
1977 appear on the left-hand side of the equations only;
1979 * fixed LAM <x,y,zs>.b syntax;
1981 * added extended adm_tac to simplifier in HOLCF -- can now discharge
1982 adm (%x. P (t x)), where P is chainfinite and t continuous;
1987 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
1988 with `addloop' of the simplifier to faciliate case splitting in premises.
1990 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
1991 in HOL, they strip ALL and --> from proved theorems;
1995 New in Isabelle94-8 (May 1997)
1996 ------------------------------
1998 *** General Changes ***
2000 * new utilities to build / run / maintain Isabelle etc. (in parts
2001 still somewhat experimental); old Makefiles etc. still functional;
2003 * new 'Isabelle System Manual';
2005 * INSTALL text, together with ./configure and ./build scripts;
2007 * reimplemented type inference for greater efficiency, better error
2008 messages and clean internal interface;
2010 * prlim command for dealing with lots of subgoals (an easier way of
2011 setting goals_limit);
2016 * supports alternative (named) syntax tables (parser and pretty
2017 printer); internal interface is provided by add_modesyntax(_i);
2019 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
2020 be used in conjunction with the Isabelle symbol font; uses the
2021 "symbols" syntax table;
2023 * added token_translation interface (may translate name tokens in
2024 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
2025 the current print_mode); IMPORTANT: user print translation functions
2026 are responsible for marking newly introduced bounds
2027 (Syntax.mark_boundT);
2029 * token translations for modes "xterm" and "xterm_color" that display
2030 names in bold, underline etc. or colors (which requires a color
2033 * infixes may now be declared with names independent of their syntax;
2035 * added typed_print_translation (like print_translation, but may
2036 access type of constant);
2039 *** Classical Reasoner ***
2041 Blast_tac: a new tactic! It is often more powerful than fast_tac, but has
2042 some limitations. Blast_tac...
2043 + ignores addss, addbefore, addafter; this restriction is intrinsic
2044 + ignores elimination rules that don't have the correct format
2045 (the conclusion MUST be a formula variable)
2046 + ignores types, which can make HOL proofs fail
2047 + rules must not require higher-order unification, e.g. apply_type in ZF
2048 [message "Function Var's argument not a bound variable" relates to this]
2049 + its proof strategy is more general but can actually be slower
2051 * substitution with equality assumptions no longer permutes other
2054 * minor changes in semantics of addafter (now called addaltern); renamed
2055 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
2056 (and access functions for it);
2058 * improved combination of classical reasoner and simplifier:
2059 + functions for handling clasimpsets
2060 + improvement of addss: now the simplifier is called _after_ the
2062 + safe variant of addss called addSss: uses safe simplifications
2063 _during_ the safe steps. It is more complete as it allows multiple
2064 instantiations of unknowns (e.g. with slow_tac).
2068 * added interface for simplification procedures (functions that
2069 produce *proven* rewrite rules on the fly, depending on current
2072 * ordering on terms as parameter (used for ordered rewriting);
2074 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
2076 * the solver is now split into a safe and an unsafe part.
2077 This should be invisible for the normal user, except that the
2078 functions setsolver and addsolver have been renamed to setSolver and
2079 addSolver; added safe_asm_full_simp_tac;
2084 * a generic induction tactic `induct_tac' which works for all datatypes and
2085 also for type `nat';
2087 * a generic case distinction tactic `exhaust_tac' which works for all
2088 datatypes and also for type `nat';
2090 * each datatype comes with a function `size';
2092 * patterns in case expressions allow tuple patterns as arguments to
2093 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
2095 * primrec now also works with type nat;
2097 * recdef: a new declaration form, allows general recursive functions to be
2098 defined in theory files. See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
2100 * the constant for negation has been renamed from "not" to "Not" to
2101 harmonize with FOL, ZF, LK, etc.;
2103 * HOL/ex/LFilter theory of a corecursive "filter" functional for
2106 * HOL/Modelcheck demonstrates invocation of model checker oracle;
2108 * HOL/ex/Ring.thy declares cring_simp, which solves equational
2109 problems in commutative rings, using axiomatic type classes for + and *;
2111 * more examples in HOL/MiniML and HOL/Auth;
2113 * more default rewrite rules for quantifiers, union/intersection;
2115 * a new constant `arbitrary == @x.False';
2117 * HOLCF/IOA replaces old HOL/IOA;
2119 * HOLCF changes: derived all rules and arities
2120 + axiomatic type classes instead of classes
2121 + typedef instead of faking type definitions
2122 + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
2123 + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
2124 + eliminated the types void, one, tr
2125 + use unit lift and bool lift (with translations) instead of one and tr
2126 + eliminated blift from Lift3.thy (use Def instead of blift)
2127 all eliminated rules are derived as theorems --> no visible changes ;
2132 * ZF now has Fast_tac, Simp_tac and Auto_tac. Union_iff is a now a default
2133 rewrite rule; this may affect some proofs. eq_cs is gone but can be put back
2134 as ZF_cs addSIs [equalityI];
2138 New in Isabelle94-7 (November 96)
2139 ---------------------------------
2141 * allowing negative levels (as offsets) in prlev and choplev;
2143 * super-linear speedup for large simplifications;
2145 * FOL, ZF and HOL now use miniscoping: rewriting pushes
2146 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
2147 FAIL); can suppress it using the command Delsimps (ex_simps @
2148 all_simps); De Morgan laws are also now included, by default;
2150 * improved printing of ==> : ~:
2152 * new object-logic "Sequents" adds linear logic, while replacing LK
2153 and Modal (thanks to Sara Kalvala);
2155 * HOL/Auth: correctness proofs for authentication protocols;
2157 * HOL: new auto_tac combines rewriting and classical reasoning (many
2158 examples on HOL/Auth);
2160 * HOL: new command AddIffs for declaring theorems of the form P=Q to
2161 the rewriter and classical reasoner simultaneously;
2163 * function uresult no longer returns theorems in "standard" format;
2164 regain previous version by: val uresult = standard o uresult;
2171 * oracles -- these establish an interface between Isabelle and trusted
2172 external reasoners, which may deliver results as theorems;
2174 * proof objects (in particular record all uses of oracles);
2176 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
2178 * "constdefs" section in theory files;
2180 * "primrec" section (HOL) no longer requires names;
2182 * internal type "tactic" now simply "thm -> thm Sequence.seq";
2189 * reduced space requirements;
2191 * automatic HTML generation from theories;
2193 * theory files no longer require "..." (quotes) around most types;
2195 * new examples, including two proofs of the Church-Rosser theorem;
2197 * non-curried (1994) version of HOL is no longer distributed;
2204 * greatly reduced space requirements;
2206 * theory files (.thy) no longer require \...\ escapes at line breaks;
2208 * searchable theorem database (see the section "Retrieving theorems" on
2209 page 8 of the Reference Manual);
2211 * new examples, including Grabczewski's monumental case study of the
2214 * The previous version of HOL renamed to Old_HOL;
2216 * The new version of HOL (previously called CHOL) uses a curried syntax
2217 for functions. Application looks like f a b instead of f(a,b);
2219 * Mutually recursive inductive definitions finally work in HOL;
2221 * In ZF, pattern-matching on tuples is now available in all abstractions and
2222 translates to the operator "split";
2229 * new infix operator, addss, allowing the classical reasoner to
2230 perform simplification at each step of its search. Example:
2231 fast_tac (cs addss ss)
2233 * a new logic, CHOL, the same as HOL, but with a curried syntax
2234 for functions. Application looks like f a b instead of f(a,b). Also pairs
2235 look like (a,b) instead of <a,b>;
2237 * PLEASE NOTE: CHOL will eventually replace HOL!
2239 * In CHOL, pattern-matching on tuples is now available in all abstractions.
2240 It translates to the operator "split". A new theory of integers is available;
2242 * In ZF, integer numerals now denote two's-complement binary integers.
2243 Arithmetic operations can be performed by rewriting. See ZF/ex/Bin.ML;
2245 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
2246 of the Axiom of Choice;
2253 * Significantly faster resolution;
2255 * the different sections in a .thy file can now be mixed and repeated
2258 * Database of theorems for FOL, HOL and ZF. New
2259 commands including qed, qed_goal and bind_thm store theorems in the database.
2261 * Simple database queries: return a named theorem (get_thm) or all theorems of
2262 a given theory (thms_of), or find out what theory a theorem was proved in
2265 * Bugs fixed in the inductive definition and datatype packages;
2267 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
2268 and HOL_dup_cs obsolete;
2270 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
2273 * Simpler definition of function space in ZF;
2275 * new results about cardinal and ordinal arithmetic in ZF;
2277 * 'subtype' facility in HOL for introducing new types as subsets of existing