2 Isabelle NEWS -- history user-relevant changes
3 ==============================================
5 New in Isabelle2001 (?? 2001)
6 -----------------------------
8 *** Document preparation ***
10 * greatly simplified document preparation setup, including more
11 graceful interpretation of isatool usedir -i/-d/-D options, and more
12 instructive isatool mkdir; users should basically be able to get
13 started with "isatool mkdir Test && isatool make";
15 * theory dependency graph may now be incorporated into documents;
16 isatool usedir -g true will produce session_graph.eps/.pdf for use
17 with \includegraphics of LaTeX;
19 * proper spacing of consecutive markup elements, especially text
20 blocks after section headings;
22 * support bold style (for single symbols only), input syntax is like
23 this: "\<^bold>\<alpha>" or "\<^bold>A";
25 * \<bullet> is now output as bold \cdot by default, which looks much
26 better in printed text;
28 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
29 note that these symbols are currently unavailable in Proof General /
35 * improved proof by cases and induction:
36 - removed obsolete "(simplified)" and "(stripped)" options of methods;
37 - added 'print_induct_rules' (covered by help item in Proof General > 3.3);
38 - moved induct/cases attributes to Pure, methods to Provers;
39 - generic method setup instantiated for FOL and HOL;
41 - 'case' command admits impromptu naming of parameters (such as
44 - 'induct' method divinates rule instantiation from the inductive
45 claim; no longer requires excessive ?P bindings for proper
46 instantiation of cases;
48 - 'induct' method properly enumerates all possibilities of set/type
49 rules; as a consequence facts may be also passed through *type* rules
52 - 'induct' method now derives symbolic cases from the *rulified*
53 rule (before it used to rulify cases stemming from the internal
54 atomized version); this means that the context of a non-atomic
55 statement becomes is included in the hypothesis, avoiding the slightly
56 cumbersome show "PROP ?case" form;
58 - 'induct' may now use elim-style induction rules without chaining
59 facts, using ``missing'' premises from the goal state; this allows
60 rules stemming from inductive sets to be applied in unstructured
61 scripts, while still benefitting from proper handling of non-atomic
62 statements; NB: major inductive premises need to be put first, all the
63 rest of the goal is passed through the induction;
65 - 'induct' proper support for mutual induction involving non-atomic
66 rule statements (uses the new concept of simultaneous goals, see
69 * Pure: support multiple simultaneous goal statements, for example
70 "have a: A and b: B" (same for 'theorem' etc.); being a pure
71 meta-level mechanism, this acts as if several individual goals had
72 been stated separately; in particular common proof methods need to be
73 repeated in order to cover all claims; note that a single elimination
74 step is *not* sufficient to establish the two conjunctions, so this
77 assume "A & B" then have A and B .. (*".." fails*)
79 better use "obtain" in situations as above; alternative refer to
80 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
82 * Pure: proper integration with ``locales''; unlike the original
83 version by Florian Kammüller, Isar locales package high-level proof
84 contexts rather than raw logical ones (e.g. we admit to include
85 attributes everywhere);
87 * Pure: theory goals now support ad-hoc contexts, which are discharged
88 in the result, as in ``lemma (assumes A and B) K: A .''; syntax
89 coincides with that of a locale body;
91 * Pure: renamed "antecedent" case to "rule_context";
93 * Pure: added 'corollary' command;
95 * Pure: fixed 'token_translation' command;
97 * Pure: removed obsolete 'exported' attribute;
99 * Pure: dummy pattern "_" in is/let is now automatically lifted over
100 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
101 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
103 * Pure: method 'atomize' presents local goal premises as object-level
104 statements (atomic meta-level propositions); setup controlled via
105 rewrite rules declarations of 'atomize' attribute; example
106 application: 'induct' method with proper rule statements in improper
109 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
110 now consider the syntactic context of assumptions, giving a better
111 chance to get type-inference of the arguments right (this is
112 especially important for locales);
114 * Provers: 'simplified' attribute may refer to explicit rules instead
115 of full simplifier context; 'iff' attribute handles conditional rules;
117 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
119 * HOL: 'recdef' now fails on unfinished automated proofs, use
120 "(permissive)" option to recover old behavior;
122 * HOL: 'inductive' no longer features separate (collective) attributes
123 for 'intros' (was found too confusing);
129 * HOL: moved over to sane numeral syntax; the new policy is as
132 - 0 and 1 are polymorphic constants, which are defined on any
133 numeric type (nat, int, real etc.);
135 - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
136 binary representation internally;
138 - type nat has special constructor Suc, and generally prefers Suc 0
139 over 1::nat and Suc (Suc 0) over 2::nat;
141 This change may cause significant INCOMPATIBILITIES; here are some
142 hints on converting existing sources:
144 - due to the new "num" token, "-0" and "-1" etc. are now atomic
145 entities, so expressions involving "-" (unary or binary minus) need
146 to be spaced properly;
148 - existing occurrences of "1" may need to be constraint "1::nat" or
149 even replaced by Suc 0; similar for old "2";
151 - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
153 - remove all special provisions on numerals in proofs;
156 - removed old "make" and "make_scheme" operations -- INCOMPATIBILITY;
157 - removed "more" class (simply use "term") -- INCOMPATIBILITY;
158 - provides cases/induct rules for use with corresponding Isar
159 methods (for concrete records, record schemes, concrete more
160 parts, schematic more parts -- in that order);
161 - new derived operations "make" (for adding fields of current
162 record), "extend" to promote fixed record to record scheme, and
163 "truncate" for the reverse; cf. theorems "derived_defs", which are
164 *not* declared as simp by default;
165 - internal definitions directly based on a light-weight abstract
166 theory of product types over typedef rather than datatype;
168 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
170 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
171 (beware of argument permutation!);
173 * HOL: linorder_less_split superseded by linorder_cases;
175 * HOL: added "The" definite description operator; move Hilbert's "Eps"
176 to peripheral theory "Hilbert_Choice";
178 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
179 in this (rare) case use:
181 delSWrapper "split_all_tac"
182 addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
184 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
187 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
188 Isabelle's type classes, ^ on functions and relations has too general
189 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
190 necessary to attach explicit type constraints;
192 * HOL: syntax translations now work properly with numerals and records
195 * HOL/GroupTheory: group theory examples including Sylow's theorem, by
198 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
199 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
200 renamed "Product_Type.unit";
205 * proper rep_datatype lift (see theory Lift); use plain induct_tac
206 instead of former lift.induct_tac; always use UU instead of Undef;
208 * 'domain' package adapted to new-style theories, e.g. see
214 * ZF: new-style theory commands '(co)inductive', '(co)datatype',
215 'rep_datatype', 'inductive_cases'; also methods 'ind_cases',
216 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
218 * ZF: the integer library now covers quotients and remainders, with
219 many laws relating division to addition, multiplication, etc.;
221 * ZF/Induct: new directory for examples of inductive definitions,
222 including theory Multiset for multiset orderings;
224 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
225 typeless version of the formalism;
230 * kernel: meta-level proof terms (by Stefan Berghofer), see also ref
233 * Pure/axclass: removed obsolete ML interface goal_subclass/goal_arity;
235 * classical: renamed addaltern to addafter, addSaltern to addSafter;
237 * clasimp: ``iff'' declarations now handle conditional rules as well;
239 * syntax: new token syntax "num" for plain numerals (without "#" of
240 "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now separate
241 tokens, so expressions involving minus need to be spaced properly;
243 * syntax: support non-oriented infixes;
245 * syntax: print modes "type_brackets" and "no_type_brackets" control
246 output of nested => (types); the default behavior is "type_brackets";
248 * syntax: builtin parse translation for "_constify" turns valued
249 tokens into AST constants;
251 * syntax: prefer later print_translation functions; potential
252 INCOMPATIBILITY: need to reverse declarations of multiple translation
253 functions for same constant;
255 * system: refrain from any attempt at filtering input streams; no
256 longer support ``8bit'' encoding of old isabelle font, instead proper
257 iso-latin characters may now be used;
259 * system: support Poly/ML 4.1.1 (now able to manage large heaps);
261 * system: Proof General keywords specification is now part of the
262 Isabelle distribution (see etc/isar-keywords.el);
264 * system: smart selection of Isabelle process versus Isabelle
265 interface, accommodates case-insensitive file systems (e.g. HFS+); may
266 run both "isabelle" and "Isabelle" even if file names are badly
267 damaged (executable inspects the case of the first letter of its own
268 name); added separate "isabelle-process" and "isabelle-interface";
272 New in Isabelle99-2 (February 2001)
273 -----------------------------------
275 *** Overview of INCOMPATIBILITIES ***
277 * HOL: please note that theories in the Library and elsewhere often use the
278 new-style (Isar) format; to refer to their theorems in an ML script you must
279 bind them to ML identifers by e.g. val thm_name = thm "thm_name";
281 * HOL: inductive package no longer splits induction rule aggressively,
282 but only as far as specified by the introductions given; the old
283 format may be recovered via ML function complete_split_rule or attribute
284 'split_rule (complete)';
286 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
287 gfp_Tarski to gfp_unfold;
289 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
291 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
292 relation); infix "^^" has been renamed "``"; infix "``" has been
293 renamed "`"; "univalent" has been renamed "single_valued";
295 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
298 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
300 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
302 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
303 consequence, it is no longer monotonic wrt. the local goal context
304 (which is now passed through the inductive cases);
306 * Document preparation: renamed standard symbols \<ll> to \<lless> and
307 \<gg> to \<ggreater>;
310 *** Document preparation ***
312 * \isabellestyle{NAME} selects version of Isabelle output (currently
313 available: are "it" for near math-mode best-style output, "sl" for
314 slanted text style, and "tt" for plain type-writer; if no
315 \isabellestyle command is given, output is according to slanted
318 * support sub/super scripts (for single symbols only), input syntax is
319 like this: "A\<^sup>*" or "A\<^sup>\<star>";
321 * some more standard symbols; see Appendix A of the system manual for
322 the complete list of symbols defined in isabellesym.sty;
324 * improved isabelle style files; more abstract symbol implementation
325 (should now use \isamath{...} and \isatext{...} in custom symbol
328 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
329 state; Note that presentation of goal states does not conform to
330 actual human-readable proof documents. Please do not include goal
331 states into document output unless you really know what you are doing!
333 * proper indentation of antiquoted output with proportional LaTeX
336 * no_document ML operator temporarily disables LaTeX document
339 * isatool unsymbolize tunes sources for plain ASCII communication;
344 * Pure: Isar now suffers initial goal statements to contain unbound
345 schematic variables (this does not conform to actual readable proof
346 documents, due to unpredictable outcome and non-compositional proof
347 checking); users who know what they are doing may use schematic goals
348 for Prolog-style synthesis of proven results;
350 * Pure: assumption method (an implicit finishing) now handles actual
353 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
354 initial goal, declare "that" only as Pure intro (only for single
355 steps); the "that" rule assumption may now be involved in implicit
356 finishing, thus ".." becomes a feasible for trivial obtains;
358 * Pure: default proof step now includes 'intro_classes'; thus trivial
359 instance proofs may be performed by "..";
361 * Pure: ?thesis / ?this / "..." now work for pure meta-level
364 * Pure: more robust selection of calculational rules;
366 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
367 rule (as well as the assumption rule);
369 * Pure: 'thm_deps' command visualizes dependencies of theorems and
370 lemmas, using the graph browser tool;
372 * Pure: predict failure of "show" in interactive mode;
374 * Pure: 'thms_containing' now takes actual terms as arguments;
376 * HOL: improved method 'induct' --- now handles non-atomic goals
377 (potential INCOMPATIBILITY); tuned error handling;
379 * HOL: cases and induct rules now provide explicit hints about the
380 number of facts to be consumed (0 for "type" and 1 for "set" rules);
381 any remaining facts are inserted into the goal verbatim;
383 * HOL: local contexts (aka cases) may now contain term bindings as
384 well; the 'cases' and 'induct' methods new provide a ?case binding for
385 the result to be shown in each case;
387 * HOL: added 'recdef_tc' command;
389 * isatool convert assists in eliminating legacy ML scripts;
394 * HOL/Library: a collection of generic theories to be used together
395 with main HOL; the theory loader path already includes this directory
396 by default; the following existing theories have been moved here:
397 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
398 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
400 * HOL/Unix: "Some aspects of Unix file-system security", a typical
401 modelling and verification task performed in Isabelle/HOL +
402 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
404 * HOL/Algebra: special summation operator SUM no longer exists, it has
405 been replaced by setsum; infix 'assoc' now has priority 50 (like
406 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
407 'domain', this makes the theory consistent with mathematical
410 * HOL basics: added overloaded operations "inverse" and "divide"
411 (infix "/"), syntax for generic "abs" operation, generic summation
414 * HOL/typedef: simplified package, provide more useful rules (see also
417 * HOL/datatype: induction rule for arbitrarily branching datatypes is
418 now expressed as a proper nested rule (old-style tactic scripts may
419 require atomize_strip_tac to cope with non-atomic premises);
421 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
422 to "split_conv" (old name still available for compatibility);
424 * HOL: improved concrete syntax for strings (e.g. allows translation
425 rules with string literals);
427 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
428 and Fleuriot's mechanization of analysis, including the transcendental
429 functions for the reals;
431 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
436 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
437 "lam" is displayed as TWO lambda-symbols
439 * CTT: theory Main now available, containing everything (that is, Bool
445 * Pure: the Simplifier has been implemented properly as a derived rule
446 outside of the actual kernel (at last!); the overall performance
447 penalty in practical applications is about 50%, while reliability of
448 the Isabelle inference kernel has been greatly improved;
450 * print modes "brackets" and "no_brackets" control output of nested =>
451 (types) and ==> (props); the default behaviour is "brackets";
453 * Provers: fast_tac (and friends) now handle actual object-logic rules
454 as assumptions as well;
456 * system: support Poly/ML 4.0;
458 * system: isatool install handles KDE version 1 or 2;
462 New in Isabelle99-1 (October 2000)
463 ----------------------------------
465 *** Overview of INCOMPATIBILITIES ***
467 * HOL: simplification of natural numbers is much changed; to partly
468 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
469 issue the following ML commands:
471 Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
472 Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
474 * HOL: simplification no longer dives into case-expressions; this is
475 controlled by "t.weak_case_cong" for each datatype t;
477 * HOL: nat_less_induct renamed to less_induct;
479 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
480 fixsome to patch .thy and .ML sources automatically;
482 select_equality -> some_equality
483 select_eq_Ex -> some_eq_ex
484 selectI2EX -> someI2_ex
487 select1_equality -> some1_equality
488 Eps_sym_eq -> some_sym_eq_trivial
489 Eps_eq -> some_eq_trivial
491 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
493 * HOL: removed obsolete theorem binding expand_if (refer to split_if
496 * HOL: the recursion equations generated by 'recdef' are now called
497 f.simps instead of f.rules;
499 * HOL: qed_spec_mp now also handles bounded ALL as well;
501 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
504 * HOL: the constant for "f``x" is now "image" rather than "op ``";
506 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
508 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
509 product is now "<*>" instead of "Times"; the lexicographic product is
510 now "<*lex*>" instead of "**";
512 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
513 of main HOL, but was unused); better use HOL's datatype package;
515 * HOL: removed "symbols" syntax for constant "override" of theory Map;
516 the old syntax may be recovered as follows:
519 override :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
520 (infixl "\\<oplus>" 100)
522 * HOL/Real: "rabs" replaced by overloaded "abs" function;
524 * HOL/ML: even fewer consts are declared as global (see theories Ord,
525 Lfp, Gfp, WF); this only affects ML packages that refer to const names
528 * HOL and ZF: syntax for quotienting wrt an equivalence relation
529 changed from A/r to A//r;
531 * ZF: new treatment of arithmetic (nat & int) may break some old
534 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
535 rulify -> rule_format, elimify -> elim_format, ...);
537 * Isar/Provers: intro/elim/dest attributes changed; renamed
538 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
539 should have to change intro!! to intro? only); replaced "delrule" by
542 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
544 * Provers: strengthened force_tac by using new first_best_tac;
546 * LaTeX document preparation: several changes of isabelle.sty (see
550 *** Document preparation ***
552 * formal comments (text blocks etc.) in new-style theories may now
553 contain antiquotations of thm/prop/term/typ/text to be presented
554 according to latex print mode; concrete syntax is like this:
555 @{term[show_types] "f(x) = a + x"};
557 * isatool mkdir provides easy setup of Isabelle session directories,
558 including proper document sources;
560 * generated LaTeX sources are now deleted after successful run
561 (isatool document -c); may retain a copy somewhere else via -D option
564 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
565 style files, achieving self-contained LaTeX sources and simplifying
568 * old-style theories now produce (crude) LaTeX output as well;
570 * browser info session directories are now self-contained (may be put
571 on WWW server seperately); improved graphs of nested sessions; removed
572 graph for 'all sessions';
574 * several improvements in isabelle style files; \isabellestyle{it}
575 produces fake math mode output; \isamarkupheader is now \section by
576 default; see lib/texinputs/isabelle.sty etc.;
581 * Isar/Pure: local results and corresponding term bindings are now
582 subject to Hindley-Milner polymorphism (similar to ML); this
583 accommodates incremental type-inference very nicely;
585 * Isar/Pure: new derived language element 'obtain' supports
586 generalized existence reasoning;
588 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
589 support accumulation of results, without applying any rules yet;
590 useful to collect intermediate results without explicit name
591 references, and for use with transitivity rules with more than 2
594 * Isar/Pure: scalable support for case-analysis type proofs: new
595 'case' language element refers to local contexts symbolically, as
596 produced by certain proof methods; internally, case names are attached
597 to theorems as "tags";
599 * Isar/Pure: theory command 'hide' removes declarations from
600 class/type/const name spaces;
602 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
603 indicate potential overloading;
605 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
607 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
608 "{a,b,c}" instead of {a,b,c};
610 * Isar/Pure now provides its own version of intro/elim/dest
611 attributes; useful for building new logics, but beware of confusion
612 with the version in Provers/classical;
614 * Isar/Pure: the local context of (non-atomic) goals is provided via
615 case name 'antecedent';
617 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
618 to the current context is now done automatically);
620 * Isar/Pure: theory command 'method_setup' provides a simple interface
621 for definining proof methods in ML;
623 * Isar/Provers: intro/elim/dest attributes changed; renamed
624 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
625 most cases, one should have to change intro!! to intro? only);
626 replaced "delrule" by "rule del";
628 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
629 'symmetric' attribute (the latter supercedes [RS sym]);
631 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
632 method modifier); 'simp' method: 'only:' modifier removes loopers as
633 well (including splits);
635 * Isar/Provers: Simplifier and Classical methods now support all kind
636 of modifiers used in the past, including 'cong', 'iff', etc.
638 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
639 of Simplifier and Classical reasoner);
641 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
642 now support named cases; major packages (inductive, datatype, primrec,
643 recdef) support case names and properly name parameters;
645 * Isar/HOL: new transitivity rules for substitution in inequalities --
646 monotonicity conditions are extracted to be proven at end of
649 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
652 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
653 split_if split_if_asm; datatype package provides theorems foo.splits =
654 foo.split foo.split_asm for each datatype;
656 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
657 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
658 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
659 use "(cases (simplified))" method in proper proof texts);
661 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
663 * Isar: names of theorems etc. may be natural numbers as well;
665 * Isar: 'pr' command: optional arguments for goals_limit and
666 ProofContext.prems_limit; no longer prints theory contexts, but only
669 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
670 additional print modes to be specified; e.g. "pr(latex)" will print
671 proof state according to the Isabelle LaTeX style;
673 * Isar: improved support for emulating tactic scripts, including proof
674 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
675 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
678 * Isar: simplified (more robust) goal selection of proof methods: 1st
679 goal, all goals, or explicit goal specifier (tactic emulation); thus
680 'proof method scripts' have to be in depth-first order;
682 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
684 * Isar: removed 'help' command, which hasn't been too helpful anyway;
685 should instead use individual commands for printing items
686 (print_commands, print_methods etc.);
688 * Isar: added 'nothing' --- the empty list of theorems;
693 * HOL/MicroJava: formalization of a fragment of Java, together with a
694 corresponding virtual machine and a specification of its bytecode
695 verifier and a lightweight bytecode verifier, including proofs of
696 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
697 Cornelia Pusch (see also the homepage of project Bali at
698 http://isabelle.in.tum.de/Bali/);
700 * HOL/Algebra: new theory of rings and univariate polynomials, by
703 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
704 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
707 * HOL/Lattice: fundamental concepts of lattice theory and order
708 structures, including duals, properties of bounds versus algebraic
709 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
710 Theorem for complete lattices etc.; may also serve as a demonstration
711 for abstract algebraic reasoning using axiomatic type classes, and
712 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
714 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
717 * HOL/IMPP: extension of IMP with local variables and mutually
718 recursive procedures, by David von Oheimb;
720 * HOL/Lambda: converted into new-style theory and document;
722 * HOL/ex/Multiquote: example of multiple nested quotations and
723 anti-quotations -- basically a generalized version of de-Bruijn
724 representation; very useful in avoiding lifting of operations;
726 * HOL/record: added general record equality rule to simpset; fixed
727 select-update simplification procedure to handle extended records as
728 well; admit "r" as field name;
730 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
731 other numeric types and also as the identity of groups, rings, etc.;
733 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
734 Types nat and int belong to this axclass;
736 * HOL: greatly improved simplification involving numerals of type nat, int, real:
737 (i + #8 + j) = Suc k simplifies to #7 + (i + j) = k
738 i*j + k + j*#3*i simplifies to #4*(i*j) + k
739 two terms #m*u and #n*u are replaced by #(m+n)*u
740 (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
741 and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
742 or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
744 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
745 powerful prover for predicate logic but knows nothing of clasets; see
746 ex/mesontest.ML and ex/mesontest2.ML for example applications;
748 * HOL: new version of "case_tac" subsumes both boolean case split and
749 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
750 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
752 * HOL: simplification no longer dives into case-expressions: only the
753 selector expression is simplified, but not the remaining arms; to
754 enable full simplification of case-expressions for datatype t, you may
755 remove t.weak_case_cong from the simpset, either globally (Delcongs
756 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
758 * HOL/recdef: the recursion equations generated by 'recdef' for
759 function 'f' are now called f.simps instead of f.rules; if all
760 termination conditions are proved automatically, these simplification
761 rules are added to the simpset, as in primrec; rules may be named
762 individually as well, resulting in a separate list of theorems for
765 * HOL/While is a new theory that provides a while-combinator. It
766 permits the definition of tail-recursive functions without the
767 provision of a termination measure. The latter is necessary once the
768 invariant proof rule for while is applied.
770 * HOL: new (overloaded) notation for the set of elements below/above
771 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
773 * HOL: theorems impI, allI, ballI bound as "strip";
775 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
776 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
777 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
779 * HOL/Real: "rabs" replaced by overloaded "abs" function;
781 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
782 main HOL, but was unused);
784 * HOL: fewer consts declared as global (e.g. have to refer to
785 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
787 * HOL: tuned AST representation of nested pairs, avoiding bogus output
788 in case of overlap with user translations (e.g. judgements over
789 tuples); (note that the underlying logical represenation is still
795 * ZF: simplification automatically cancels common terms in arithmetic
796 expressions over nat and int;
798 * ZF: new treatment of nat to minimize type-checking: all operators
799 coerce their operands to a natural number using the function natify,
800 making the algebraic laws unconditional;
802 * ZF: as above, for int: operators coerce their operands to an integer
803 using the function intify;
805 * ZF: the integer library now contains many of the usual laws for the
806 orderings, including $<=, and monotonicity laws for $+ and $*;
808 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
811 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
812 to the simplifier and classical reasoner simultaneously;
817 * Provers: blast_tac now handles actual object-logic rules as
818 assumptions; note that auto_tac uses blast_tac internally as well;
820 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
821 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
823 * Provers: delrules now handles destruct rules as well (no longer need
826 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
827 [| inj ?f; ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
828 use instead the strong form,
829 [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
830 in HOL, FOL and ZF the function cla_make_elim will create such rules
833 * Provers: Simplifier.easy_setup provides a fast path to basic
834 Simplifier setup for new object-logics;
836 * Pure: AST translation rules no longer require constant head on LHS;
838 * Pure: improved name spaces: ambiguous output is qualified; support
841 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
842 XSYMBOL_HOME; no longer need to do manual configuration in most
845 * system: compression of ML heaps images may now be controlled via -c
846 option of isabelle and isatool usedir (currently only observed by
849 * system: isatool installfonts may handle X-Symbol fonts as well (very
850 useful for remote X11);
852 * system: provide TAGS file for Isabelle sources;
854 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
857 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
858 timing flag supersedes proof_timing and Toplevel.trace;
860 * ML: new combinators |>> and |>>> for incremental transformations
861 with secondary results (e.g. certain theory extensions):
863 * ML: PureThy.add_defs gets additional argument to indicate potential
864 overloading (usually false);
866 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
871 New in Isabelle99 (October 1999)
872 --------------------------------
874 *** Overview of INCOMPATIBILITIES (see below for more details) ***
876 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
877 are no longer simplified. (This allows the simplifier to unfold recursive
878 functional programs.) To restore the old behaviour, declare
880 Delcongs [if_weak_cong];
882 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
885 * HOL: the predicate "inj" is now defined by translation to "inj_on";
887 * HOL/datatype: mutual_induct_tac no longer exists --
888 use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
890 * HOL/typedef: fixed type inference for representing set; type
891 arguments now have to occur explicitly on the rhs as type constraints;
893 * ZF: The con_defs part of an inductive definition may no longer refer
894 to constants declared in the same theory;
896 * HOL, ZF: the function mk_cases, generated by the inductive
897 definition package, has lost an argument. To simplify its result, it
898 uses the default simpset instead of a supplied list of theorems.
900 * HOL/List: the constructors of type list are now Nil and Cons;
902 * Simplifier: the type of the infix ML functions
903 setSSolver addSSolver setSolver addSolver
904 is now simpset * solver -> simpset where `solver' is a new abstract type
905 for packaging solvers. A solver is created via
906 mk_solver: string -> (thm list -> int -> tactic) -> solver
907 where the string argument is only a comment.
912 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
913 decision procedure for linear arithmetic. Currently it is used for
914 types `nat', `int', and `real' in HOL (see below); it can, should and
915 will be instantiated for other types and logics as well.
917 * The simplifier now accepts rewrite rules with flexible heads, eg
918 hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
919 They are applied like any rule with a non-pattern lhs, i.e. by first-order
925 * New Isabelle/Isar subsystem provides an alternative to traditional
926 tactical theorem proving; together with the ProofGeneral/isar user
927 interface it offers an interactive environment for developing human
928 readable proof documents (Isar == Intelligible semi-automated
929 reasoning); for further information see isatool doc isar-ref,
930 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
932 * improved and simplified presentation of theories: better HTML markup
933 (including colors), graph views in several sizes; isatool usedir now
934 provides a proper interface for user theories (via -P option); actual
935 document preparation based on (PDF)LaTeX is available as well (for
936 new-style theories only); see isatool doc system for more information;
938 * native support for Proof General, both for classic Isabelle and
941 * ML function thm_deps visualizes dependencies of theorems and lemmas,
942 using the graph browser tool;
944 * Isabelle manuals now also available as PDF;
946 * theory loader rewritten from scratch (may not be fully
947 bug-compatible); old loadpath variable has been replaced by show_path,
948 add_path, del_path, reset_path functions; new operations such as
949 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
952 * improved isatool install: option -k creates KDE application icon,
953 option -p DIR installs standalone binaries;
955 * added ML_PLATFORM setting (useful for cross-platform installations);
956 more robust handling of platform specific ML images for SML/NJ;
958 * the settings environment is now statically scoped, i.e. it is never
959 created again in sub-processes invoked from isabelle, isatool, or
962 * path element specification '~~' refers to '$ISABELLE_HOME';
964 * in locales, the "assumes" and "defines" parts may be omitted if
967 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
970 * new print_mode "HTML";
972 * new flag show_tags controls display of tags of theorems (which are
973 basically just comments that may be attached by some tools);
975 * Isamode 2.6 requires patch to accomodate change of Isabelle font
976 mode and goal output format:
978 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
980 < (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
982 > (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
983 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
985 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
987 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
989 * function bind_thms stores lists of theorems (cf. bind_thm);
991 * new shorthand tactics ftac, eatac, datac, fatac;
993 * qed (and friends) now accept "" as result name; in that case the
994 theorem is not stored, but proper checks and presentation of the
997 * theorem database now also indexes constants "Trueprop", "all",
998 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
1003 ** HOL arithmetic **
1005 * There are now decision procedures for linear arithmetic over nat and
1008 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
1009 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
1010 are treated as atomic; subformulae not involving type `nat' or `int'
1011 are ignored; quantified subformulae are ignored unless they are
1012 positive universal or negative existential. The tactic has to be
1013 invoked by hand and can be a little bit slow. In particular, the
1014 running time is exponential in the number of occurrences of `min' and
1015 `max', and `-' on `nat'.
1017 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
1018 (negated) (in)equalities among the premises and the conclusion into
1019 account (i.e. no compound formulae) and does not know about `min' and
1020 `max', and `-' on `nat'. It is fast and is used automatically by the
1023 NB: At the moment, these decision procedures do not cope with mixed
1024 nat/int formulae where the two parts interact, such as `m < n ==>
1027 * HOL/Numeral provides a generic theory of numerals (encoded
1028 efficiently as bit strings); setup for types nat/int/real is in place;
1029 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
1030 int, existing theories and proof scripts may require a few additional
1033 * integer division and remainder can now be performed on constant
1036 * many properties of integer multiplication, division and remainder
1039 * An interface to the Stanford Validity Checker (SVC) is available through the
1040 tactic svc_tac. Propositional tautologies and theorems of linear arithmetic
1041 are proved automatically. SVC must be installed separately, and its results
1042 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
1043 invocation of the underlying oracle). For SVC see
1044 http://verify.stanford.edu/SVC
1046 * IsaMakefile: the HOL-Real target now builds an actual image;
1051 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
1052 (in Isabelle/Isar) -- by Gertrud Bauer;
1054 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
1055 analysis for assembly languages with subtypes;
1057 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
1058 -- avoids syntactic ambiguities and treats state, transition, and
1059 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
1060 changed syntax and (many) tactics;
1062 * HOL/inductive: Now also handles more general introduction rules such
1063 as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
1064 theorems are now maintained within the theory (maintained via the
1067 * HOL/datatype: Now also handles arbitrarily branching datatypes
1068 (using function types) such as
1070 datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
1072 * HOL/record: record_simproc (part of the default simpset) takes care
1073 of selectors applied to updated records; record_split_tac is no longer
1074 part of the default claset; update_defs may now be removed from the
1075 simpset in many cases; COMPATIBILITY: old behavior achieved by
1077 claset_ref () := claset() addSWrapper record_split_wrapper;
1078 Delsimprocs [record_simproc]
1080 * HOL/typedef: fixed type inference for representing set; type
1081 arguments now have to occur explicitly on the rhs as type constraints;
1083 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
1084 names rather than an ML expression;
1086 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
1087 supplied later. Program schemes can be defined, such as
1088 "While B C s = (if B s then While B C (C s) else s)"
1089 where the well-founded relation can be chosen after B and C have been given.
1091 * HOL/List: the constructors of type list are now Nil and Cons;
1092 INCOMPATIBILITY: while [] and infix # syntax is still there, of
1093 course, ML tools referring to List.list.op # etc. have to be adapted;
1095 * HOL_quantifiers flag superseded by "HOL" print mode, which is
1096 disabled by default; run isabelle with option -m HOL to get back to
1097 the original Gordon/HOL-style output;
1099 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
1100 ALL x<=y. P, EX x<y. P, EX x<=y. P;
1102 * HOL basic syntax simplified (more orthogonal): all variants of
1103 All/Ex now support plain / symbolic / HOL notation; plain syntax for
1104 Eps operator is provided as well: "SOME x. P[x]";
1106 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
1108 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
1109 thus available for user theories;
1111 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
1112 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
1115 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
1116 several times and then mp;
1121 * the notation <<...>> is now available as a notation for sequences of
1124 * the simplifier is now installed
1126 * the axiom system has been generalized (thanks to Soren Heilmann)
1128 * the classical reasoner now has a default rule database
1133 * new primrec section allows primitive recursive functions to be given
1134 directly (as in HOL) over datatypes and the natural numbers;
1136 * new tactics induct_tac and exhaust_tac for induction (or case
1137 analysis) over datatypes and the natural numbers;
1139 * the datatype declaration of type T now defines the recursor T_rec;
1141 * simplification automatically does freeness reasoning for datatype
1144 * automatic type-inference, with AddTCs command to insert new
1145 type-checking rules;
1147 * datatype introduction rules are now added as Safe Introduction rules
1150 * the syntax "if P then x else y" is now available in addition to
1154 *** Internal programming interfaces ***
1156 * tuned simplifier trace output; new flag debug_simp;
1158 * structures Vartab / Termtab (instances of TableFun) offer efficient
1159 tables indexed by indexname_ord / term_ord (compatible with aconv);
1161 * AxClass.axclass_tac lost the theory argument;
1163 * tuned current_goals_markers semantics: begin / end goal avoids
1164 printing empty lines;
1166 * removed prs and prs_fn hook, which was broken because it did not
1167 include \n in its semantics, forcing writeln to add one
1168 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
1169 string -> unit if you really want to output text without newline;
1171 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
1172 plain output, interface builders may have to enable 'isabelle_font'
1173 mode to get Isabelle font glyphs as before;
1175 * refined token_translation interface; INCOMPATIBILITY: output length
1176 now of type real instead of int;
1178 * theory loader actions may be traced via new ThyInfo.add_hook
1179 interface (see src/Pure/Thy/thy_info.ML); example application: keep
1180 your own database of information attached to *whole* theories -- as
1181 opposed to intra-theory data slots offered via TheoryDataFun;
1183 * proper handling of dangling sort hypotheses (at last!);
1184 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
1185 extra sort hypotheses that can be witnessed from the type signature;
1186 the force_strip_shyps flag is gone, any remaining shyps are simply
1187 left in the theorem (with a warning issued by strip_shyps_warning);
1191 New in Isabelle98-1 (October 1998)
1192 ----------------------------------
1194 *** Overview of INCOMPATIBILITIES (see below for more details) ***
1196 * several changes of automated proof tools;
1198 * HOL: major changes to the inductive and datatype packages, including
1199 some minor incompatibilities of theory syntax;
1201 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
1204 * HOL: removed duplicate thms in Arith:
1205 less_imp_add_less should be replaced by trans_less_add1
1206 le_imp_add_le should be replaced by trans_le_add1
1208 * HOL: unary minus is now overloaded (new type constraints may be
1211 * HOL and ZF: unary minus for integers is now #- instead of #~. In
1212 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
1213 now taken as an integer constant.
1215 * Pure: ML function 'theory_of' renamed to 'theory';
1221 1. Asm_full_simp_tac is now more aggressive.
1222 1. It will sometimes reorient premises if that increases their power to
1224 2. It does no longer proceed strictly from left to right but may also
1225 rotate premises to achieve further simplification.
1226 For compatibility reasons there is now Asm_lr_simp_tac which is like the
1227 old Asm_full_simp_tac in that it does not rotate premises.
1228 2. The simplifier now knows a little bit about nat-arithmetic.
1230 * Classical reasoner: wrapper mechanism for the classical reasoner now
1231 allows for selected deletion of wrappers, by introduction of names for
1232 wrapper functionals. This implies that addbefore, addSbefore,
1233 addaltern, and addSaltern now take a pair (name, tactic) as argument,
1234 and that adding two tactics with the same name overwrites the first
1235 one (emitting a warning).
1236 type wrapper = (int -> tactic) -> (int -> tactic)
1237 setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
1238 addWrapper, addSWrapper: claset * (string * wrapper) -> claset
1239 delWrapper, delSWrapper: claset * string -> claset
1240 getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
1242 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
1243 semantics; addbefore now affects only the unsafe part of step_tac
1244 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
1245 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
1248 * Classical reasoner: setwrapper to setWrapper and compwrapper to
1249 compWrapper; added safe wrapper (and access functions for it);
1251 * HOL/split_all_tac is now much faster and fails if there is nothing
1252 to split. Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
1253 and the names of the automatically generated variables have changed.
1254 split_all_tac has moved within claset() from unsafe wrappers to safe
1255 wrappers, which means that !!-bound variables are split much more
1256 aggressively, and safe_tac and clarify_tac now split such variables.
1257 If this splitting is not appropriate, use delSWrapper "split_all_tac".
1258 Note: the same holds for record_split_tac, which does the job of
1259 split_all_tac for record fields.
1261 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
1262 permanently to the default simpset using Addsplits just like
1263 Addsimps. They can be removed via Delsplits just like
1264 Delsimps. Lower-case versions are also available.
1266 * HOL/Simplifier: The rule split_if is now part of the default
1267 simpset. This means that the simplifier will eliminate all occurrences
1268 of if-then-else in the conclusion of a goal. To prevent this, you can
1269 either remove split_if completely from the default simpset by
1270 `Delsplits [split_if]' or remove it in a specific call of the
1271 simplifier using `... delsplits [split_if]'. You can also add/delete
1272 other case splitting rules to/from the default simpset: every datatype
1273 generates suitable rules `split_t_case' and `split_t_case_asm' (where
1274 t is the name of the datatype).
1276 * Classical reasoner / Simplifier combination: new force_tac (and
1277 derivatives Force_tac, force) combines rewriting and classical
1278 reasoning (and whatever other tools) similarly to auto_tac, but is
1279 aimed to solve the given subgoal completely.
1284 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
1285 and `goalw': the theory is no longer needed as an explicit argument -
1286 the current theory context is used; assumptions are no longer returned
1287 at the ML-level unless one of them starts with ==> or !!; it is
1288 recommended to convert to these new commands using isatool fixgoal
1289 (backup your sources first!);
1291 * new top-level commands 'thm' and 'thms' for retrieving theorems from
1292 the current theory context, and 'theory' to lookup stored theories;
1294 * new theory section 'locale' for declaring constants, assumptions and
1295 definitions that have local scope;
1297 * new theory section 'nonterminals' for purely syntactic types;
1299 * new theory section 'setup' for generic ML setup functions
1300 (e.g. package initialization);
1302 * the distribution now includes Isabelle icons: see
1303 lib/logo/isabelle-{small,tiny}.xpm;
1305 * isatool install - install binaries with absolute references to
1308 * isatool logo -- create instances of the Isabelle logo (as EPS);
1310 * print mode 'emacs' reserved for Isamode;
1312 * support multiple print (ast) translations per constant name;
1314 * theorems involving oracles are now printed with a suffixed [!];
1319 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
1321 * HOL/inductive package reorganized and improved: now supports mutual
1327 oddI "n : EVEN ==> Suc n : ODD"
1328 evenI "n : ODD ==> Suc n : EVEN"
1330 new theorem list "elims" contains an elimination rule for each of the
1331 recursive sets; inductive definitions now handle disjunctive premises
1332 correctly (also ZF);
1334 INCOMPATIBILITIES: requires Inductive as an ancestor; component
1335 "mutual_induct" no longer exists - the induction rule is always
1336 contained in "induct";
1339 * HOL/datatype package re-implemented and greatly improved: now
1340 supports mutually recursive datatypes such as
1343 'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
1344 | SUM ('a aexp) ('a aexp)
1345 | DIFF ('a aexp) ('a aexp)
1348 'a bexp = LESS ('a aexp) ('a aexp)
1349 | AND ('a bexp) ('a bexp)
1350 | OR ('a bexp) ('a bexp)
1352 as well as indirectly recursive datatypes such as
1355 ('a, 'b) term = Var 'a
1356 | App 'b ((('a, 'b) term) list)
1358 The new tactic mutual_induct_tac [<var_1>, ..., <var_n>] i performs
1359 induction on mutually / indirectly recursive datatypes.
1361 Primrec equations are now stored in theory and can be accessed via
1362 <function_name>.simps.
1366 - Theories using datatypes must now have theory Datatype as an
1368 - The specific <typename>.induct_tac no longer exists - use the
1369 generic induct_tac instead.
1370 - natE has been renamed to nat.exhaust - use exhaust_tac
1371 instead of res_inst_tac ... natE. Note that the variable
1372 names in nat.exhaust differ from the names in natE, this
1373 may cause some "fragile" proofs to fail.
1374 - The theorems split_<typename>_case and split_<typename>_case_asm
1375 have been renamed to <typename>.split and <typename>.split_asm.
1376 - Since default sorts of type variables are now handled correctly,
1377 some datatype definitions may have to be annotated with explicit
1379 - Primrec definitions no longer require function name and type
1380 of recursive argument.
1382 Consider using isatool fixdatatype to adapt your theories and proof
1383 scripts to the new package (backup your sources first!).
1386 * HOL/record package: considerably improved implementation; now
1387 includes concrete syntax for record types, terms, updates; theorems
1388 for surjective pairing and splitting !!-bound record variables; proof
1389 support is as follows:
1391 1) standard conversions (selectors or updates applied to record
1392 constructor terms) are part of the standard simpset;
1394 2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
1395 made part of standard simpset and claset via addIffs;
1397 3) a tactic for record field splitting (record_split_tac) is part of
1398 the standard claset (addSWrapper);
1400 To get a better idea about these rules you may retrieve them via
1401 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
1402 the name of your record type.
1404 The split tactic 3) conceptually simplifies by the following rule:
1406 "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
1408 Thus any record variable that is bound by meta-all will automatically
1409 blow up into some record constructor term, consequently the
1410 simplifications of 1), 2) apply. Thus force_tac, auto_tac etc. shall
1411 solve record problems automatically.
1414 * reorganized the main HOL image: HOL/Integ and String loaded by
1415 default; theory Main includes everything;
1417 * automatic simplification of integer sums and comparisons, using cancellation;
1419 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
1421 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
1423 * many new identities for unions, intersections, set difference, etc.;
1425 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
1426 called split_if, split_split, split_sum_case and split_nat_case (to go
1427 with add/delsplits);
1429 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
1430 (?x::unit) = (); this is made part of the default simpset, which COULD
1431 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
1432 'Delsimprocs [unit_eq_proc];' as last resort); also note that
1433 unit_abs_eta_conv is added in order to counter the effect of
1434 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
1437 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
1440 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
1441 It and 'sym RS equals0D' are now in the default claset, giving automatic
1442 disjointness reasoning but breaking a few old proofs.
1444 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
1445 to 'converse' from 'inverse' (for compatibility with ZF and some
1448 * HOL/recdef can now declare non-recursive functions, with {} supplied as
1449 the well-founded relation;
1451 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
1452 Compl A. The "Compl" syntax remains available as input syntax for this
1455 * HOL/Update: new theory of function updates:
1456 f(a:=b) == %x. if x=a then b else f x
1457 may also be iterated as in f(a:=b,c:=d,...);
1459 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
1462 - new function list_update written xs[i:=v] that updates the i-th
1463 list position. May also be iterated as in xs[i:=a,j:=b,...].
1464 - new function `upt' written [i..j(] which generates the list
1465 [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
1466 bound write [i..j], which is a shorthand for [i..j+1(].
1467 - new lexicographic orderings and corresponding wellfoundedness theorems.
1470 - removed 'pred' (predecessor) function;
1471 - generalized some theorems about n-1;
1472 - many new laws about "div" and "mod";
1473 - new laws about greatest common divisors (see theory ex/Primes);
1475 * HOL/Relation: renamed the relational operator r^-1 "converse"
1476 instead of "inverse";
1478 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
1479 of the multiset ordering;
1481 * directory HOL/Real: a construction of the reals using Dedekind cuts
1482 (not included by default);
1484 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
1486 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
1487 programs, i.e. different program variables may have different types.
1489 * calling (stac rew i) now fails if "rew" has no effect on the goal
1490 [previously, this check worked only if the rewrite rule was unconditional]
1491 Now rew can involve either definitions or equalities (either == or =).
1496 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
1497 only the theorems proved on ZF.ML;
1499 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
1500 It and 'sym RS equals0D' are now in the default claset, giving automatic
1501 disjointness reasoning but breaking a few old proofs.
1503 * ZF/Update: new theory of function updates
1504 with default rewrite rule f(x:=y) ` z = if(z=x, y, f`z)
1505 may also be iterated as in f(a:=b,c:=d,...);
1507 * in let x=t in u(x), neither t nor u(x) has to be an FOL term.
1509 * calling (stac rew i) now fails if "rew" has no effect on the goal
1510 [previously, this check worked only if the rewrite rule was unconditional]
1511 Now rew can involve either definitions or equalities (either == or =).
1513 * case_tac provided for compatibility with HOL
1514 (like the old excluded_middle_tac, but with subgoals swapped)
1517 *** Internal programming interfaces ***
1519 * Pure: several new basic modules made available for general use, see
1520 also src/Pure/README;
1522 * improved the theory data mechanism to support encapsulation (data
1523 kind name replaced by private Object.kind, acting as authorization
1524 key); new type-safe user interface via functor TheoryDataFun; generic
1525 print_data function becomes basically useless;
1527 * removed global_names compatibility flag -- all theory declarations
1528 are qualified by default;
1530 * module Pure/Syntax now offers quote / antiquote translation
1531 functions (useful for Hoare logic etc. with implicit dependencies);
1532 see HOL/ex/Antiquote for an example use;
1534 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
1537 * new tactical CHANGED_GOAL for checking that a tactic modifies a
1540 * Display.print_goals function moved to Locale.print_goals;
1542 * standard print function for goals supports current_goals_markers
1543 variable for marking begin of proof, end of proof, start of goal; the
1544 default is ("", "", ""); setting current_goals_markers := ("<proof>",
1545 "</proof>", "<goal>") causes SGML like tagged proof state printing,
1550 New in Isabelle98 (January 1998)
1551 --------------------------------
1553 *** Overview of INCOMPATIBILITIES (see below for more details) ***
1555 * changed lexical syntax of terms / types: dots made part of long
1556 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
1558 * simpset (and claset) reference variable replaced by functions
1559 simpset / simpset_ref;
1561 * no longer supports theory aliases (via merge) and non-trivial
1562 implicit merge of thms' signatures;
1564 * most internal names of constants changed due to qualified names;
1566 * changed Pure/Sequence interface (see Pure/seq.ML);
1569 *** General Changes ***
1571 * hierachically structured name spaces (for consts, types, axms, thms
1572 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
1573 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
1574 isatool fixdots ensures space after dots (e.g. "%x. x"); set
1575 long_names for fully qualified output names; NOTE: ML programs
1576 (special tactics, packages etc.) referring to internal names may have
1577 to be adapted to cope with fully qualified names; in case of severe
1578 backward campatibility problems try setting 'global_names' at compile
1579 time to have enrything declared within a flat name space; one may also
1580 fine tune name declarations in theories via the 'global' and 'local'
1583 * reimplemented the implicit simpset and claset using the new anytype
1584 data filed in signatures; references simpset:simpset ref etc. are
1585 replaced by functions simpset:unit->simpset and
1586 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
1587 to patch your ML files accordingly;
1589 * HTML output now includes theory graph data for display with Java
1590 applet or isatool browser; data generated automatically via isatool
1591 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
1593 * defs may now be conditional; improved rewrite_goals_tac to handle
1594 conditional equations;
1596 * defs now admits additional type arguments, using TYPE('a) syntax;
1598 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
1599 creates a new theory node; implicit merge of thms' signatures is
1600 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
1601 transfer:theory->thm->thm in (rare) cases;
1603 * improved handling of draft signatures / theories; draft thms (and
1604 ctyps, cterms) are automatically promoted to real ones;
1606 * slightly changed interfaces for oracles: admit many per theory, named
1607 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
1609 * print_goals: optional output of const types (set show_consts and
1612 * improved output of warnings (###) and errors (***);
1614 * subgoal_tac displays a warning if the new subgoal has type variables;
1616 * removed old README and Makefiles;
1618 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
1620 * removed obsolete init_pps and init_database;
1622 * deleted the obsolete tactical STATE, which was declared by
1623 fun STATE tacfun st = tacfun st st;
1625 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
1626 (which abbreviates $HOME);
1628 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
1629 use isatool fixseq to adapt your ML programs (this works for fully
1630 qualified references to the Sequence structure only!);
1632 * use_thy no longer requires writable current directory; it always
1633 reloads .ML *and* .thy file, if either one is out of date;
1636 *** Classical Reasoner ***
1638 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
1639 tactics that use classical reasoning to simplify a subgoal without
1640 splitting it into several subgoals;
1642 * Safe_tac: like safe_tac but uses the default claset;
1647 * added simplification meta rules:
1648 (asm_)(full_)simplify: simpset -> thm -> thm;
1650 * simplifier.ML no longer part of Pure -- has to be loaded by object
1653 * added prems argument to simplification procedures;
1655 * HOL, FOL, ZF: added infix function `addsplits':
1656 instead of `<simpset> setloop (split_tac <thms>)'
1657 you can simply write `<simpset> addsplits <thms>'
1662 * TYPE('a) syntax for type reflection terms;
1664 * no longer handles consts with name "" -- declare as 'syntax' instead;
1666 * pretty printer: changed order of mixfix annotation preference (again!);
1668 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
1673 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
1674 with `addloop' of the simplifier to faciliate case splitting in premises.
1676 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
1678 * HOL/Auth: new protocol proofs including some for the Internet
1681 * HOL/Map: new theory of `maps' a la VDM;
1683 * HOL/simplifier: simplification procedures nat_cancel_sums for
1684 cancelling out common nat summands from =, <, <= (in)equalities, or
1685 differences; simplification procedures nat_cancel_factor for
1686 cancelling common factor from =, <, <= (in)equalities over natural
1687 sums; nat_cancel contains both kinds of procedures, it is installed by
1688 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
1690 * HOL/simplifier: terms of the form
1691 `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)' (or t=x)
1693 `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
1694 and those of the form
1695 `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)' (or t=x)
1697 `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
1700 Each datatype `t' now comes with a theorem `split_t_case' of the form
1702 P(t_case f1 ... fn x) =
1703 ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
1705 (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
1708 and a theorem `split_t_case_asm' of the form
1710 P(t_case f1 ... fn x) =
1711 ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
1713 (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
1715 which can be added to a simpset via `addsplits'. The existing theorems
1716 expand_list_case and expand_option_case have been renamed to
1717 split_list_case and split_option_case.
1720 - `pred n' is automatically converted to `n-1'.
1721 Users are strongly encouraged not to use `pred' any longer,
1722 because it will disappear altogether at some point.
1723 - Users are strongly encouraged to write "0 < n" rather than
1724 "n ~= 0". Theorems and proof tools have been modified towards this
1728 the function "set_of_list" has been renamed "set" (and its theorems too);
1729 the function "nth" now takes its arguments in the reverse order and
1730 has acquired the infix notation "!" as in "xs!n".
1732 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
1734 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
1735 specialist theorems (like UN1_I) are gone. Similarly for (INT x.B x);
1737 * HOL/record: extensible records with schematic structural subtyping
1738 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
1739 still lacks various theorems and concrete record syntax;
1744 * removed "axioms" and "generated by" sections;
1746 * replaced "ops" section by extended "consts" section, which is capable of
1747 handling the continuous function space "->" directly;
1750 . proves theorems immediately and stores them in the theory,
1751 . creates hierachical name space,
1752 . now uses normal mixfix annotations (instead of cinfix...),
1753 . minor changes to some names and values (for consistency),
1754 . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
1755 . separator between mutual domain defs: changed "," to "and",
1756 . improved handling of sort constraints; now they have to
1757 appear on the left-hand side of the equations only;
1759 * fixed LAM <x,y,zs>.b syntax;
1761 * added extended adm_tac to simplifier in HOLCF -- can now discharge
1762 adm (%x. P (t x)), where P is chainfinite and t continuous;
1767 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
1768 with `addloop' of the simplifier to faciliate case splitting in premises.
1770 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
1771 in HOL, they strip ALL and --> from proved theorems;
1775 New in Isabelle94-8 (May 1997)
1776 ------------------------------
1778 *** General Changes ***
1780 * new utilities to build / run / maintain Isabelle etc. (in parts
1781 still somewhat experimental); old Makefiles etc. still functional;
1783 * new 'Isabelle System Manual';
1785 * INSTALL text, together with ./configure and ./build scripts;
1787 * reimplemented type inference for greater efficiency, better error
1788 messages and clean internal interface;
1790 * prlim command for dealing with lots of subgoals (an easier way of
1791 setting goals_limit);
1796 * supports alternative (named) syntax tables (parser and pretty
1797 printer); internal interface is provided by add_modesyntax(_i);
1799 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
1800 be used in conjunction with the Isabelle symbol font; uses the
1801 "symbols" syntax table;
1803 * added token_translation interface (may translate name tokens in
1804 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
1805 the current print_mode); IMPORTANT: user print translation functions
1806 are responsible for marking newly introduced bounds
1807 (Syntax.mark_boundT);
1809 * token translations for modes "xterm" and "xterm_color" that display
1810 names in bold, underline etc. or colors (which requires a color
1813 * infixes may now be declared with names independent of their syntax;
1815 * added typed_print_translation (like print_translation, but may
1816 access type of constant);
1819 *** Classical Reasoner ***
1821 Blast_tac: a new tactic! It is often more powerful than fast_tac, but has
1822 some limitations. Blast_tac...
1823 + ignores addss, addbefore, addafter; this restriction is intrinsic
1824 + ignores elimination rules that don't have the correct format
1825 (the conclusion MUST be a formula variable)
1826 + ignores types, which can make HOL proofs fail
1827 + rules must not require higher-order unification, e.g. apply_type in ZF
1828 [message "Function Var's argument not a bound variable" relates to this]
1829 + its proof strategy is more general but can actually be slower
1831 * substitution with equality assumptions no longer permutes other
1834 * minor changes in semantics of addafter (now called addaltern); renamed
1835 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
1836 (and access functions for it);
1838 * improved combination of classical reasoner and simplifier:
1839 + functions for handling clasimpsets
1840 + improvement of addss: now the simplifier is called _after_ the
1842 + safe variant of addss called addSss: uses safe simplifications
1843 _during_ the safe steps. It is more complete as it allows multiple
1844 instantiations of unknowns (e.g. with slow_tac).
1848 * added interface for simplification procedures (functions that
1849 produce *proven* rewrite rules on the fly, depending on current
1852 * ordering on terms as parameter (used for ordered rewriting);
1854 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
1856 * the solver is now split into a safe and an unsafe part.
1857 This should be invisible for the normal user, except that the
1858 functions setsolver and addsolver have been renamed to setSolver and
1859 addSolver; added safe_asm_full_simp_tac;
1864 * a generic induction tactic `induct_tac' which works for all datatypes and
1865 also for type `nat';
1867 * a generic case distinction tactic `exhaust_tac' which works for all
1868 datatypes and also for type `nat';
1870 * each datatype comes with a function `size';
1872 * patterns in case expressions allow tuple patterns as arguments to
1873 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
1875 * primrec now also works with type nat;
1877 * recdef: a new declaration form, allows general recursive functions to be
1878 defined in theory files. See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
1880 * the constant for negation has been renamed from "not" to "Not" to
1881 harmonize with FOL, ZF, LK, etc.;
1883 * HOL/ex/LFilter theory of a corecursive "filter" functional for
1886 * HOL/Modelcheck demonstrates invocation of model checker oracle;
1888 * HOL/ex/Ring.thy declares cring_simp, which solves equational
1889 problems in commutative rings, using axiomatic type classes for + and *;
1891 * more examples in HOL/MiniML and HOL/Auth;
1893 * more default rewrite rules for quantifiers, union/intersection;
1895 * a new constant `arbitrary == @x.False';
1897 * HOLCF/IOA replaces old HOL/IOA;
1899 * HOLCF changes: derived all rules and arities
1900 + axiomatic type classes instead of classes
1901 + typedef instead of faking type definitions
1902 + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
1903 + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
1904 + eliminated the types void, one, tr
1905 + use unit lift and bool lift (with translations) instead of one and tr
1906 + eliminated blift from Lift3.thy (use Def instead of blift)
1907 all eliminated rules are derived as theorems --> no visible changes ;
1912 * ZF now has Fast_tac, Simp_tac and Auto_tac. Union_iff is a now a default
1913 rewrite rule; this may affect some proofs. eq_cs is gone but can be put back
1914 as ZF_cs addSIs [equalityI];
1918 New in Isabelle94-7 (November 96)
1919 ---------------------------------
1921 * allowing negative levels (as offsets) in prlev and choplev;
1923 * super-linear speedup for large simplifications;
1925 * FOL, ZF and HOL now use miniscoping: rewriting pushes
1926 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
1927 FAIL); can suppress it using the command Delsimps (ex_simps @
1928 all_simps); De Morgan laws are also now included, by default;
1930 * improved printing of ==> : ~:
1932 * new object-logic "Sequents" adds linear logic, while replacing LK
1933 and Modal (thanks to Sara Kalvala);
1935 * HOL/Auth: correctness proofs for authentication protocols;
1937 * HOL: new auto_tac combines rewriting and classical reasoning (many
1938 examples on HOL/Auth);
1940 * HOL: new command AddIffs for declaring theorems of the form P=Q to
1941 the rewriter and classical reasoner simultaneously;
1943 * function uresult no longer returns theorems in "standard" format;
1944 regain previous version by: val uresult = standard o uresult;
1951 * oracles -- these establish an interface between Isabelle and trusted
1952 external reasoners, which may deliver results as theorems;
1954 * proof objects (in particular record all uses of oracles);
1956 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
1958 * "constdefs" section in theory files;
1960 * "primrec" section (HOL) no longer requires names;
1962 * internal type "tactic" now simply "thm -> thm Sequence.seq";
1969 * reduced space requirements;
1971 * automatic HTML generation from theories;
1973 * theory files no longer require "..." (quotes) around most types;
1975 * new examples, including two proofs of the Church-Rosser theorem;
1977 * non-curried (1994) version of HOL is no longer distributed;
1984 * greatly reduced space requirements;
1986 * theory files (.thy) no longer require \...\ escapes at line breaks;
1988 * searchable theorem database (see the section "Retrieving theorems" on
1989 page 8 of the Reference Manual);
1991 * new examples, including Grabczewski's monumental case study of the
1994 * The previous version of HOL renamed to Old_HOL;
1996 * The new version of HOL (previously called CHOL) uses a curried syntax
1997 for functions. Application looks like f a b instead of f(a,b);
1999 * Mutually recursive inductive definitions finally work in HOL;
2001 * In ZF, pattern-matching on tuples is now available in all abstractions and
2002 translates to the operator "split";
2009 * new infix operator, addss, allowing the classical reasoner to
2010 perform simplification at each step of its search. Example:
2011 fast_tac (cs addss ss)
2013 * a new logic, CHOL, the same as HOL, but with a curried syntax
2014 for functions. Application looks like f a b instead of f(a,b). Also pairs
2015 look like (a,b) instead of <a,b>;
2017 * PLEASE NOTE: CHOL will eventually replace HOL!
2019 * In CHOL, pattern-matching on tuples is now available in all abstractions.
2020 It translates to the operator "split". A new theory of integers is available;
2022 * In ZF, integer numerals now denote two's-complement binary integers.
2023 Arithmetic operations can be performed by rewriting. See ZF/ex/Bin.ML;
2025 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
2026 of the Axiom of Choice;
2033 * Significantly faster resolution;
2035 * the different sections in a .thy file can now be mixed and repeated
2038 * Database of theorems for FOL, HOL and ZF. New
2039 commands including qed, qed_goal and bind_thm store theorems in the database.
2041 * Simple database queries: return a named theorem (get_thm) or all theorems of
2042 a given theory (thms_of), or find out what theory a theorem was proved in
2045 * Bugs fixed in the inductive definition and datatype packages;
2047 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
2048 and HOL_dup_cs obsolete;
2050 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
2053 * Simpler definition of function space in ZF;
2055 * new results about cardinal and ordinal arithmetic in ZF;
2057 * 'subtype' facility in HOL for introducing new types as subsets of existing