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 - 'case' command admits impromptu naming of parameters (such as
38 - 'induct' method divinates rule instantiation from the inductive
39 claim; no longer requires excessive ?P bindings for proper
40 instantiation of cases;
41 - 'induct' method properly enumerates all possibilities of set/type
42 rules; as a consequence facts may be also passed through *type*
43 rules without further ado;
44 - 'induct' method now derives symbolic cases from the *rulified*
45 rule (before it used to rulify cases stemming from the internal
46 atomized version); this means that the context of a non-atomic
47 statement becomes is included in the hypothesis, avoiding the
48 slightly cumbersome show "PROP ?case" form;
49 - 'induct' may now use elim-style induction rules without chaining
50 facts, using ``missing'' premises from the goal state; this allows
51 rules stemming from inductive sets to be applied in unstructured
52 scripts, while still benefitting from proper handling of non-atomic
53 statements; NB: major inductive premises need to be put first, all
54 the rest of the goal is passed through the induction;
55 - 'induct' proper support for mutual induction involving non-atomic
56 rule statements (uses the new concept of simultaneous goals, see
58 - removed obsolete "(simplified)" and "(stripped)" options of methods;
59 - added 'print_induct_rules' (covered by help item in Proof General > 3.3);
60 - moved induct/cases attributes to Pure, methods to Provers;
61 - generic method setup instantiated for FOL and HOL;
63 * Pure: support multiple simultaneous goal statements, for example
64 "have a: A and b: B" (same for 'theorem' etc.); being a pure
65 meta-level mechanism, this acts as if several individual goals had
66 been stated separately; in particular common proof methods need to be
67 repeated in order to cover all claims; note that a single elimination
68 step is *not* sufficient to establish the two conjunctions, so this
71 assume "A & B" then have A and B .. (*".." fails*)
73 better use "obtain" in situations as above; alternative refer to
74 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
76 * Pure: proper integration with ``locales''; unlike the original
77 version by Florian Kammüller, Isar locales package high-level proof
78 contexts rather than raw logical ones (e.g. we admit to include
79 attributes everywhere); operations on locales include merge and
80 rename; e.g. see HOL/ex/Locales.thy;
82 * Pure: theory goals now support ad-hoc contexts, which are discharged
83 in the result, as in ``lemma (assumes A and B) K: A .''; syntax
84 coincides with that of a locale body;
86 * Pure: renamed "antecedent" case to "rule_context";
88 * Pure: added 'corollary' command;
90 * Pure: fixed 'token_translation' command;
92 * Pure: removed obsolete 'exported' attribute;
94 * Pure: dummy pattern "_" in is/let is now automatically lifted over
95 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
96 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
98 * Pure: method 'atomize' presents local goal premises as object-level
99 statements (atomic meta-level propositions); setup controlled via
100 rewrite rules declarations of 'atomize' attribute; example
101 application: 'induct' method with proper rule statements in improper
104 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
105 now consider the syntactic context of assumptions, giving a better
106 chance to get type-inference of the arguments right (this is
107 especially important for locales);
109 * Provers: 'simplified' attribute may refer to explicit rules instead
110 of full simplifier context; 'iff' attribute handles conditional rules;
112 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
114 * HOL: 'recdef' now fails on unfinished automated proofs, use
115 "(permissive)" option to recover old behavior;
117 * HOL: 'inductive' no longer features separate (collective) attributes
118 for 'intros' (was found too confusing);
120 * HOLCF: domain package adapted to new-style theories, e.g. see
123 * ZF: proper integration of logic-specific tools and packages,
124 including theory commands '(co)inductive', '(co)datatype',
125 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
126 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
132 * HOL: moved over to sane numeral syntax; the new policy is as
135 - 0 and 1 are polymorphic constants, which are defined on any
136 numeric type (nat, int, real etc.);
138 - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
139 binary representation internally;
141 - type nat has special constructor Suc, and generally prefers Suc 0
142 over 1::nat and Suc (Suc 0) over 2::nat;
144 This change may cause significant INCOMPATIBILITIES; here are some
145 hints on converting existing sources:
147 - due to the new "num" token, "-0" and "-1" etc. are now atomic
148 entities, so expressions involving "-" (unary or binary minus) need
149 to be spaced properly;
151 - existing occurrences of "1" may need to be constraint "1::nat" or
152 even replaced by Suc 0; similar for old "2";
154 - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
156 - remove all special provisions on numerals in proofs;
158 * HOL/record package improvements:
159 - new derived operations "fields" to build a partial record section,
160 "extend" to promote a fixed record to a record scheme, and
161 "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
162 declared as simp by default;
163 - removed "make_scheme" operations (use "make" with "extend") --
165 - removed "more" class (simply use "term") -- INCOMPATIBILITY;
166 - provides cases/induct rules for use with corresponding Isar
167 methods (for concrete records, record schemes, concrete more
168 parts, and schematic more parts -- in that order);
169 - internal definitions directly based on a light-weight abstract
170 theory of product types over typedef rather than datatype;
172 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
174 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
175 (beware of argument permutation!);
177 * HOL: linorder_less_split superseded by linorder_cases;
179 * HOL: added "The" definite description operator; move Hilbert's "Eps"
180 to peripheral theory "Hilbert_Choice";
182 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
183 in this (rare) case use:
185 delSWrapper "split_all_tac"
186 addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
188 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
191 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
192 Isabelle's type classes, ^ on functions and relations has too general
193 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
194 necessary to attach explicit type constraints;
196 * HOL: syntax translations now work properly with numerals and records
199 * HOL/GroupTheory: group theory examples including Sylow's theorem, by
202 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
203 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
204 renamed "Product_Type.unit";
209 * proper rep_datatype lift (see theory Lift) instead of ML hacks --
210 potential INCOMPATIBILITY; now use plain induct_tac instead of former
211 lift.induct_tac, always use UU instead of Undef;
216 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
217 typeless version of the formalism;
219 * ZF/Induct: new directory for examples of inductive definitions,
220 including theory Multiset for multiset orderings;
222 * ZF: the integer library now covers quotients and remainders, with
223 many laws relating division to addition, multiplication, etc.;
228 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
229 variable proof controls level of detail: 0 = no proofs (only oracle
230 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
231 also ref manual for further ML interfaces;
233 * Pure/axclass: removed obsolete ML interface
234 goal_subclass/goal_arity;
236 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
237 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
238 separate tokens, so expressions involving minus need to be spaced
241 * Pure/syntax: support non-oriented infixes;
243 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
244 control output of nested => (types); the default behavior is
247 * Pure/syntax: builtin parse translation for "_constify" turns valued
248 tokens into AST constants;
250 * Pure/syntax: prefer later declarations of translations and print
251 translation functions; potential INCOMPATIBILITY: need to reverse
252 multiple declarations for same syntax element constant;
254 * Provers/classical: renamed addaltern to addafter, addSaltern to
257 * Provers/clasimp: ``iff'' declarations now handle conditional rules
260 * system: refrain from any attempt at filtering input streams; no
261 longer support ``8bit'' encoding of old isabelle font, instead proper
262 iso-latin characters may now be used;
264 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
266 * system: Proof General keywords specification is now part of the
267 Isabelle distribution (see etc/isar-keywords.el);
269 * system: smart selection of Isabelle process versus Isabelle
270 interface, accommodates case-insensitive file systems (e.g. HFS+); may
271 run both "isabelle" and "Isabelle" even if file names are badly
272 damaged (executable inspects the case of the first letter of its own
273 name); added separate "isabelle-process" and "isabelle-interface";
277 New in Isabelle99-2 (February 2001)
278 -----------------------------------
280 *** Overview of INCOMPATIBILITIES ***
282 * HOL: please note that theories in the Library and elsewhere often use the
283 new-style (Isar) format; to refer to their theorems in an ML script you must
284 bind them to ML identifers by e.g. val thm_name = thm "thm_name";
286 * HOL: inductive package no longer splits induction rule aggressively,
287 but only as far as specified by the introductions given; the old
288 format may be recovered via ML function complete_split_rule or attribute
289 'split_rule (complete)';
291 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
292 gfp_Tarski to gfp_unfold;
294 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
296 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
297 relation); infix "^^" has been renamed "``"; infix "``" has been
298 renamed "`"; "univalent" has been renamed "single_valued";
300 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
303 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
305 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
307 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
308 consequence, it is no longer monotonic wrt. the local goal context
309 (which is now passed through the inductive cases);
311 * Document preparation: renamed standard symbols \<ll> to \<lless> and
312 \<gg> to \<ggreater>;
315 *** Document preparation ***
317 * \isabellestyle{NAME} selects version of Isabelle output (currently
318 available: are "it" for near math-mode best-style output, "sl" for
319 slanted text style, and "tt" for plain type-writer; if no
320 \isabellestyle command is given, output is according to slanted
323 * support sub/super scripts (for single symbols only), input syntax is
324 like this: "A\<^sup>*" or "A\<^sup>\<star>";
326 * some more standard symbols; see Appendix A of the system manual for
327 the complete list of symbols defined in isabellesym.sty;
329 * improved isabelle style files; more abstract symbol implementation
330 (should now use \isamath{...} and \isatext{...} in custom symbol
333 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
334 state; Note that presentation of goal states does not conform to
335 actual human-readable proof documents. Please do not include goal
336 states into document output unless you really know what you are doing!
338 * proper indentation of antiquoted output with proportional LaTeX
341 * no_document ML operator temporarily disables LaTeX document
344 * isatool unsymbolize tunes sources for plain ASCII communication;
349 * Pure: Isar now suffers initial goal statements to contain unbound
350 schematic variables (this does not conform to actual readable proof
351 documents, due to unpredictable outcome and non-compositional proof
352 checking); users who know what they are doing may use schematic goals
353 for Prolog-style synthesis of proven results;
355 * Pure: assumption method (an implicit finishing) now handles actual
358 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
359 initial goal, declare "that" only as Pure intro (only for single
360 steps); the "that" rule assumption may now be involved in implicit
361 finishing, thus ".." becomes a feasible for trivial obtains;
363 * Pure: default proof step now includes 'intro_classes'; thus trivial
364 instance proofs may be performed by "..";
366 * Pure: ?thesis / ?this / "..." now work for pure meta-level
369 * Pure: more robust selection of calculational rules;
371 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
372 rule (as well as the assumption rule);
374 * Pure: 'thm_deps' command visualizes dependencies of theorems and
375 lemmas, using the graph browser tool;
377 * Pure: predict failure of "show" in interactive mode;
379 * Pure: 'thms_containing' now takes actual terms as arguments;
381 * HOL: improved method 'induct' --- now handles non-atomic goals
382 (potential INCOMPATIBILITY); tuned error handling;
384 * HOL: cases and induct rules now provide explicit hints about the
385 number of facts to be consumed (0 for "type" and 1 for "set" rules);
386 any remaining facts are inserted into the goal verbatim;
388 * HOL: local contexts (aka cases) may now contain term bindings as
389 well; the 'cases' and 'induct' methods new provide a ?case binding for
390 the result to be shown in each case;
392 * HOL: added 'recdef_tc' command;
394 * isatool convert assists in eliminating legacy ML scripts;
399 * HOL/Library: a collection of generic theories to be used together
400 with main HOL; the theory loader path already includes this directory
401 by default; the following existing theories have been moved here:
402 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
403 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
405 * HOL/Unix: "Some aspects of Unix file-system security", a typical
406 modelling and verification task performed in Isabelle/HOL +
407 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
409 * HOL/Algebra: special summation operator SUM no longer exists, it has
410 been replaced by setsum; infix 'assoc' now has priority 50 (like
411 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
412 'domain', this makes the theory consistent with mathematical
415 * HOL basics: added overloaded operations "inverse" and "divide"
416 (infix "/"), syntax for generic "abs" operation, generic summation
419 * HOL/typedef: simplified package, provide more useful rules (see also
422 * HOL/datatype: induction rule for arbitrarily branching datatypes is
423 now expressed as a proper nested rule (old-style tactic scripts may
424 require atomize_strip_tac to cope with non-atomic premises);
426 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
427 to "split_conv" (old name still available for compatibility);
429 * HOL: improved concrete syntax for strings (e.g. allows translation
430 rules with string literals);
432 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
433 and Fleuriot's mechanization of analysis, including the transcendental
434 functions for the reals;
436 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
441 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
442 "lam" is displayed as TWO lambda-symbols
444 * CTT: theory Main now available, containing everything (that is, Bool
450 * Pure: the Simplifier has been implemented properly as a derived rule
451 outside of the actual kernel (at last!); the overall performance
452 penalty in practical applications is about 50%, while reliability of
453 the Isabelle inference kernel has been greatly improved;
455 * print modes "brackets" and "no_brackets" control output of nested =>
456 (types) and ==> (props); the default behaviour is "brackets";
458 * Provers: fast_tac (and friends) now handle actual object-logic rules
459 as assumptions as well;
461 * system: support Poly/ML 4.0;
463 * system: isatool install handles KDE version 1 or 2;
467 New in Isabelle99-1 (October 2000)
468 ----------------------------------
470 *** Overview of INCOMPATIBILITIES ***
472 * HOL: simplification of natural numbers is much changed; to partly
473 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
474 issue the following ML commands:
476 Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
477 Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
479 * HOL: simplification no longer dives into case-expressions; this is
480 controlled by "t.weak_case_cong" for each datatype t;
482 * HOL: nat_less_induct renamed to less_induct;
484 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
485 fixsome to patch .thy and .ML sources automatically;
487 select_equality -> some_equality
488 select_eq_Ex -> some_eq_ex
489 selectI2EX -> someI2_ex
492 select1_equality -> some1_equality
493 Eps_sym_eq -> some_sym_eq_trivial
494 Eps_eq -> some_eq_trivial
496 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
498 * HOL: removed obsolete theorem binding expand_if (refer to split_if
501 * HOL: the recursion equations generated by 'recdef' are now called
502 f.simps instead of f.rules;
504 * HOL: qed_spec_mp now also handles bounded ALL as well;
506 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
509 * HOL: the constant for "f``x" is now "image" rather than "op ``";
511 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
513 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
514 product is now "<*>" instead of "Times"; the lexicographic product is
515 now "<*lex*>" instead of "**";
517 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
518 of main HOL, but was unused); better use HOL's datatype package;
520 * HOL: removed "symbols" syntax for constant "override" of theory Map;
521 the old syntax may be recovered as follows:
524 override :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
525 (infixl "\\<oplus>" 100)
527 * HOL/Real: "rabs" replaced by overloaded "abs" function;
529 * HOL/ML: even fewer consts are declared as global (see theories Ord,
530 Lfp, Gfp, WF); this only affects ML packages that refer to const names
533 * HOL and ZF: syntax for quotienting wrt an equivalence relation
534 changed from A/r to A//r;
536 * ZF: new treatment of arithmetic (nat & int) may break some old
539 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
540 rulify -> rule_format, elimify -> elim_format, ...);
542 * Isar/Provers: intro/elim/dest attributes changed; renamed
543 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
544 should have to change intro!! to intro? only); replaced "delrule" by
547 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
549 * Provers: strengthened force_tac by using new first_best_tac;
551 * LaTeX document preparation: several changes of isabelle.sty (see
555 *** Document preparation ***
557 * formal comments (text blocks etc.) in new-style theories may now
558 contain antiquotations of thm/prop/term/typ/text to be presented
559 according to latex print mode; concrete syntax is like this:
560 @{term[show_types] "f(x) = a + x"};
562 * isatool mkdir provides easy setup of Isabelle session directories,
563 including proper document sources;
565 * generated LaTeX sources are now deleted after successful run
566 (isatool document -c); may retain a copy somewhere else via -D option
569 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
570 style files, achieving self-contained LaTeX sources and simplifying
573 * old-style theories now produce (crude) LaTeX output as well;
575 * browser info session directories are now self-contained (may be put
576 on WWW server seperately); improved graphs of nested sessions; removed
577 graph for 'all sessions';
579 * several improvements in isabelle style files; \isabellestyle{it}
580 produces fake math mode output; \isamarkupheader is now \section by
581 default; see lib/texinputs/isabelle.sty etc.;
586 * Isar/Pure: local results and corresponding term bindings are now
587 subject to Hindley-Milner polymorphism (similar to ML); this
588 accommodates incremental type-inference very nicely;
590 * Isar/Pure: new derived language element 'obtain' supports
591 generalized existence reasoning;
593 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
594 support accumulation of results, without applying any rules yet;
595 useful to collect intermediate results without explicit name
596 references, and for use with transitivity rules with more than 2
599 * Isar/Pure: scalable support for case-analysis type proofs: new
600 'case' language element refers to local contexts symbolically, as
601 produced by certain proof methods; internally, case names are attached
602 to theorems as "tags";
604 * Isar/Pure: theory command 'hide' removes declarations from
605 class/type/const name spaces;
607 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
608 indicate potential overloading;
610 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
612 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
613 "{a,b,c}" instead of {a,b,c};
615 * Isar/Pure now provides its own version of intro/elim/dest
616 attributes; useful for building new logics, but beware of confusion
617 with the version in Provers/classical;
619 * Isar/Pure: the local context of (non-atomic) goals is provided via
620 case name 'antecedent';
622 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
623 to the current context is now done automatically);
625 * Isar/Pure: theory command 'method_setup' provides a simple interface
626 for definining proof methods in ML;
628 * Isar/Provers: intro/elim/dest attributes changed; renamed
629 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
630 most cases, one should have to change intro!! to intro? only);
631 replaced "delrule" by "rule del";
633 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
634 'symmetric' attribute (the latter supercedes [RS sym]);
636 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
637 method modifier); 'simp' method: 'only:' modifier removes loopers as
638 well (including splits);
640 * Isar/Provers: Simplifier and Classical methods now support all kind
641 of modifiers used in the past, including 'cong', 'iff', etc.
643 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
644 of Simplifier and Classical reasoner);
646 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
647 now support named cases; major packages (inductive, datatype, primrec,
648 recdef) support case names and properly name parameters;
650 * Isar/HOL: new transitivity rules for substitution in inequalities --
651 monotonicity conditions are extracted to be proven at end of
654 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
657 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
658 split_if split_if_asm; datatype package provides theorems foo.splits =
659 foo.split foo.split_asm for each datatype;
661 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
662 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
663 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
664 use "(cases (simplified))" method in proper proof texts);
666 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
668 * Isar: names of theorems etc. may be natural numbers as well;
670 * Isar: 'pr' command: optional arguments for goals_limit and
671 ProofContext.prems_limit; no longer prints theory contexts, but only
674 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
675 additional print modes to be specified; e.g. "pr(latex)" will print
676 proof state according to the Isabelle LaTeX style;
678 * Isar: improved support for emulating tactic scripts, including proof
679 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
680 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
683 * Isar: simplified (more robust) goal selection of proof methods: 1st
684 goal, all goals, or explicit goal specifier (tactic emulation); thus
685 'proof method scripts' have to be in depth-first order;
687 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
689 * Isar: removed 'help' command, which hasn't been too helpful anyway;
690 should instead use individual commands for printing items
691 (print_commands, print_methods etc.);
693 * Isar: added 'nothing' --- the empty list of theorems;
698 * HOL/MicroJava: formalization of a fragment of Java, together with a
699 corresponding virtual machine and a specification of its bytecode
700 verifier and a lightweight bytecode verifier, including proofs of
701 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
702 Cornelia Pusch (see also the homepage of project Bali at
703 http://isabelle.in.tum.de/Bali/);
705 * HOL/Algebra: new theory of rings and univariate polynomials, by
708 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
709 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
712 * HOL/Lattice: fundamental concepts of lattice theory and order
713 structures, including duals, properties of bounds versus algebraic
714 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
715 Theorem for complete lattices etc.; may also serve as a demonstration
716 for abstract algebraic reasoning using axiomatic type classes, and
717 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
719 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
722 * HOL/IMPP: extension of IMP with local variables and mutually
723 recursive procedures, by David von Oheimb;
725 * HOL/Lambda: converted into new-style theory and document;
727 * HOL/ex/Multiquote: example of multiple nested quotations and
728 anti-quotations -- basically a generalized version of de-Bruijn
729 representation; very useful in avoiding lifting of operations;
731 * HOL/record: added general record equality rule to simpset; fixed
732 select-update simplification procedure to handle extended records as
733 well; admit "r" as field name;
735 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
736 other numeric types and also as the identity of groups, rings, etc.;
738 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
739 Types nat and int belong to this axclass;
741 * HOL: greatly improved simplification involving numerals of type nat, int, real:
742 (i + #8 + j) = Suc k simplifies to #7 + (i + j) = k
743 i*j + k + j*#3*i simplifies to #4*(i*j) + k
744 two terms #m*u and #n*u are replaced by #(m+n)*u
745 (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
746 and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
747 or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
749 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
750 powerful prover for predicate logic but knows nothing of clasets; see
751 ex/mesontest.ML and ex/mesontest2.ML for example applications;
753 * HOL: new version of "case_tac" subsumes both boolean case split and
754 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
755 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
757 * HOL: simplification no longer dives into case-expressions: only the
758 selector expression is simplified, but not the remaining arms; to
759 enable full simplification of case-expressions for datatype t, you may
760 remove t.weak_case_cong from the simpset, either globally (Delcongs
761 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
763 * HOL/recdef: the recursion equations generated by 'recdef' for
764 function 'f' are now called f.simps instead of f.rules; if all
765 termination conditions are proved automatically, these simplification
766 rules are added to the simpset, as in primrec; rules may be named
767 individually as well, resulting in a separate list of theorems for
770 * HOL/While is a new theory that provides a while-combinator. It
771 permits the definition of tail-recursive functions without the
772 provision of a termination measure. The latter is necessary once the
773 invariant proof rule for while is applied.
775 * HOL: new (overloaded) notation for the set of elements below/above
776 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
778 * HOL: theorems impI, allI, ballI bound as "strip";
780 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
781 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
782 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
784 * HOL/Real: "rabs" replaced by overloaded "abs" function;
786 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
787 main HOL, but was unused);
789 * HOL: fewer consts declared as global (e.g. have to refer to
790 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
792 * HOL: tuned AST representation of nested pairs, avoiding bogus output
793 in case of overlap with user translations (e.g. judgements over
794 tuples); (note that the underlying logical represenation is still
800 * ZF: simplification automatically cancels common terms in arithmetic
801 expressions over nat and int;
803 * ZF: new treatment of nat to minimize type-checking: all operators
804 coerce their operands to a natural number using the function natify,
805 making the algebraic laws unconditional;
807 * ZF: as above, for int: operators coerce their operands to an integer
808 using the function intify;
810 * ZF: the integer library now contains many of the usual laws for the
811 orderings, including $<=, and monotonicity laws for $+ and $*;
813 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
816 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
817 to the simplifier and classical reasoner simultaneously;
822 * Provers: blast_tac now handles actual object-logic rules as
823 assumptions; note that auto_tac uses blast_tac internally as well;
825 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
826 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
828 * Provers: delrules now handles destruct rules as well (no longer need
831 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
832 [| inj ?f; ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
833 use instead the strong form,
834 [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
835 in HOL, FOL and ZF the function cla_make_elim will create such rules
838 * Provers: Simplifier.easy_setup provides a fast path to basic
839 Simplifier setup for new object-logics;
841 * Pure: AST translation rules no longer require constant head on LHS;
843 * Pure: improved name spaces: ambiguous output is qualified; support
846 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
847 XSYMBOL_HOME; no longer need to do manual configuration in most
850 * system: compression of ML heaps images may now be controlled via -c
851 option of isabelle and isatool usedir (currently only observed by
854 * system: isatool installfonts may handle X-Symbol fonts as well (very
855 useful for remote X11);
857 * system: provide TAGS file for Isabelle sources;
859 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
862 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
863 timing flag supersedes proof_timing and Toplevel.trace;
865 * ML: new combinators |>> and |>>> for incremental transformations
866 with secondary results (e.g. certain theory extensions):
868 * ML: PureThy.add_defs gets additional argument to indicate potential
869 overloading (usually false);
871 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
876 New in Isabelle99 (October 1999)
877 --------------------------------
879 *** Overview of INCOMPATIBILITIES (see below for more details) ***
881 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
882 are no longer simplified. (This allows the simplifier to unfold recursive
883 functional programs.) To restore the old behaviour, declare
885 Delcongs [if_weak_cong];
887 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
890 * HOL: the predicate "inj" is now defined by translation to "inj_on";
892 * HOL/datatype: mutual_induct_tac no longer exists --
893 use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
895 * HOL/typedef: fixed type inference for representing set; type
896 arguments now have to occur explicitly on the rhs as type constraints;
898 * ZF: The con_defs part of an inductive definition may no longer refer
899 to constants declared in the same theory;
901 * HOL, ZF: the function mk_cases, generated by the inductive
902 definition package, has lost an argument. To simplify its result, it
903 uses the default simpset instead of a supplied list of theorems.
905 * HOL/List: the constructors of type list are now Nil and Cons;
907 * Simplifier: the type of the infix ML functions
908 setSSolver addSSolver setSolver addSolver
909 is now simpset * solver -> simpset where `solver' is a new abstract type
910 for packaging solvers. A solver is created via
911 mk_solver: string -> (thm list -> int -> tactic) -> solver
912 where the string argument is only a comment.
917 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
918 decision procedure for linear arithmetic. Currently it is used for
919 types `nat', `int', and `real' in HOL (see below); it can, should and
920 will be instantiated for other types and logics as well.
922 * The simplifier now accepts rewrite rules with flexible heads, eg
923 hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
924 They are applied like any rule with a non-pattern lhs, i.e. by first-order
930 * New Isabelle/Isar subsystem provides an alternative to traditional
931 tactical theorem proving; together with the ProofGeneral/isar user
932 interface it offers an interactive environment for developing human
933 readable proof documents (Isar == Intelligible semi-automated
934 reasoning); for further information see isatool doc isar-ref,
935 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
937 * improved and simplified presentation of theories: better HTML markup
938 (including colors), graph views in several sizes; isatool usedir now
939 provides a proper interface for user theories (via -P option); actual
940 document preparation based on (PDF)LaTeX is available as well (for
941 new-style theories only); see isatool doc system for more information;
943 * native support for Proof General, both for classic Isabelle and
946 * ML function thm_deps visualizes dependencies of theorems and lemmas,
947 using the graph browser tool;
949 * Isabelle manuals now also available as PDF;
951 * theory loader rewritten from scratch (may not be fully
952 bug-compatible); old loadpath variable has been replaced by show_path,
953 add_path, del_path, reset_path functions; new operations such as
954 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
957 * improved isatool install: option -k creates KDE application icon,
958 option -p DIR installs standalone binaries;
960 * added ML_PLATFORM setting (useful for cross-platform installations);
961 more robust handling of platform specific ML images for SML/NJ;
963 * the settings environment is now statically scoped, i.e. it is never
964 created again in sub-processes invoked from isabelle, isatool, or
967 * path element specification '~~' refers to '$ISABELLE_HOME';
969 * in locales, the "assumes" and "defines" parts may be omitted if
972 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
975 * new print_mode "HTML";
977 * new flag show_tags controls display of tags of theorems (which are
978 basically just comments that may be attached by some tools);
980 * Isamode 2.6 requires patch to accomodate change of Isabelle font
981 mode and goal output format:
983 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
985 < (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
987 > (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
988 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
990 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
992 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
994 * function bind_thms stores lists of theorems (cf. bind_thm);
996 * new shorthand tactics ftac, eatac, datac, fatac;
998 * qed (and friends) now accept "" as result name; in that case the
999 theorem is not stored, but proper checks and presentation of the
1002 * theorem database now also indexes constants "Trueprop", "all",
1003 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
1008 ** HOL arithmetic **
1010 * There are now decision procedures for linear arithmetic over nat and
1013 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
1014 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
1015 are treated as atomic; subformulae not involving type `nat' or `int'
1016 are ignored; quantified subformulae are ignored unless they are
1017 positive universal or negative existential. The tactic has to be
1018 invoked by hand and can be a little bit slow. In particular, the
1019 running time is exponential in the number of occurrences of `min' and
1020 `max', and `-' on `nat'.
1022 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
1023 (negated) (in)equalities among the premises and the conclusion into
1024 account (i.e. no compound formulae) and does not know about `min' and
1025 `max', and `-' on `nat'. It is fast and is used automatically by the
1028 NB: At the moment, these decision procedures do not cope with mixed
1029 nat/int formulae where the two parts interact, such as `m < n ==>
1032 * HOL/Numeral provides a generic theory of numerals (encoded
1033 efficiently as bit strings); setup for types nat/int/real is in place;
1034 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
1035 int, existing theories and proof scripts may require a few additional
1038 * integer division and remainder can now be performed on constant
1041 * many properties of integer multiplication, division and remainder
1044 * An interface to the Stanford Validity Checker (SVC) is available through the
1045 tactic svc_tac. Propositional tautologies and theorems of linear arithmetic
1046 are proved automatically. SVC must be installed separately, and its results
1047 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
1048 invocation of the underlying oracle). For SVC see
1049 http://verify.stanford.edu/SVC
1051 * IsaMakefile: the HOL-Real target now builds an actual image;
1056 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
1057 (in Isabelle/Isar) -- by Gertrud Bauer;
1059 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
1060 analysis for assembly languages with subtypes;
1062 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
1063 -- avoids syntactic ambiguities and treats state, transition, and
1064 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
1065 changed syntax and (many) tactics;
1067 * HOL/inductive: Now also handles more general introduction rules such
1068 as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
1069 theorems are now maintained within the theory (maintained via the
1072 * HOL/datatype: Now also handles arbitrarily branching datatypes
1073 (using function types) such as
1075 datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
1077 * HOL/record: record_simproc (part of the default simpset) takes care
1078 of selectors applied to updated records; record_split_tac is no longer
1079 part of the default claset; update_defs may now be removed from the
1080 simpset in many cases; COMPATIBILITY: old behavior achieved by
1082 claset_ref () := claset() addSWrapper record_split_wrapper;
1083 Delsimprocs [record_simproc]
1085 * HOL/typedef: fixed type inference for representing set; type
1086 arguments now have to occur explicitly on the rhs as type constraints;
1088 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
1089 names rather than an ML expression;
1091 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
1092 supplied later. Program schemes can be defined, such as
1093 "While B C s = (if B s then While B C (C s) else s)"
1094 where the well-founded relation can be chosen after B and C have been given.
1096 * HOL/List: the constructors of type list are now Nil and Cons;
1097 INCOMPATIBILITY: while [] and infix # syntax is still there, of
1098 course, ML tools referring to List.list.op # etc. have to be adapted;
1100 * HOL_quantifiers flag superseded by "HOL" print mode, which is
1101 disabled by default; run isabelle with option -m HOL to get back to
1102 the original Gordon/HOL-style output;
1104 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
1105 ALL x<=y. P, EX x<y. P, EX x<=y. P;
1107 * HOL basic syntax simplified (more orthogonal): all variants of
1108 All/Ex now support plain / symbolic / HOL notation; plain syntax for
1109 Eps operator is provided as well: "SOME x. P[x]";
1111 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
1113 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
1114 thus available for user theories;
1116 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
1117 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
1120 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
1121 several times and then mp;
1126 * the notation <<...>> is now available as a notation for sequences of
1129 * the simplifier is now installed
1131 * the axiom system has been generalized (thanks to Soren Heilmann)
1133 * the classical reasoner now has a default rule database
1138 * new primrec section allows primitive recursive functions to be given
1139 directly (as in HOL) over datatypes and the natural numbers;
1141 * new tactics induct_tac and exhaust_tac for induction (or case
1142 analysis) over datatypes and the natural numbers;
1144 * the datatype declaration of type T now defines the recursor T_rec;
1146 * simplification automatically does freeness reasoning for datatype
1149 * automatic type-inference, with AddTCs command to insert new
1150 type-checking rules;
1152 * datatype introduction rules are now added as Safe Introduction rules
1155 * the syntax "if P then x else y" is now available in addition to
1159 *** Internal programming interfaces ***
1161 * tuned simplifier trace output; new flag debug_simp;
1163 * structures Vartab / Termtab (instances of TableFun) offer efficient
1164 tables indexed by indexname_ord / term_ord (compatible with aconv);
1166 * AxClass.axclass_tac lost the theory argument;
1168 * tuned current_goals_markers semantics: begin / end goal avoids
1169 printing empty lines;
1171 * removed prs and prs_fn hook, which was broken because it did not
1172 include \n in its semantics, forcing writeln to add one
1173 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
1174 string -> unit if you really want to output text without newline;
1176 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
1177 plain output, interface builders may have to enable 'isabelle_font'
1178 mode to get Isabelle font glyphs as before;
1180 * refined token_translation interface; INCOMPATIBILITY: output length
1181 now of type real instead of int;
1183 * theory loader actions may be traced via new ThyInfo.add_hook
1184 interface (see src/Pure/Thy/thy_info.ML); example application: keep
1185 your own database of information attached to *whole* theories -- as
1186 opposed to intra-theory data slots offered via TheoryDataFun;
1188 * proper handling of dangling sort hypotheses (at last!);
1189 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
1190 extra sort hypotheses that can be witnessed from the type signature;
1191 the force_strip_shyps flag is gone, any remaining shyps are simply
1192 left in the theorem (with a warning issued by strip_shyps_warning);
1196 New in Isabelle98-1 (October 1998)
1197 ----------------------------------
1199 *** Overview of INCOMPATIBILITIES (see below for more details) ***
1201 * several changes of automated proof tools;
1203 * HOL: major changes to the inductive and datatype packages, including
1204 some minor incompatibilities of theory syntax;
1206 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
1209 * HOL: removed duplicate thms in Arith:
1210 less_imp_add_less should be replaced by trans_less_add1
1211 le_imp_add_le should be replaced by trans_le_add1
1213 * HOL: unary minus is now overloaded (new type constraints may be
1216 * HOL and ZF: unary minus for integers is now #- instead of #~. In
1217 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
1218 now taken as an integer constant.
1220 * Pure: ML function 'theory_of' renamed to 'theory';
1226 1. Asm_full_simp_tac is now more aggressive.
1227 1. It will sometimes reorient premises if that increases their power to
1229 2. It does no longer proceed strictly from left to right but may also
1230 rotate premises to achieve further simplification.
1231 For compatibility reasons there is now Asm_lr_simp_tac which is like the
1232 old Asm_full_simp_tac in that it does not rotate premises.
1233 2. The simplifier now knows a little bit about nat-arithmetic.
1235 * Classical reasoner: wrapper mechanism for the classical reasoner now
1236 allows for selected deletion of wrappers, by introduction of names for
1237 wrapper functionals. This implies that addbefore, addSbefore,
1238 addaltern, and addSaltern now take a pair (name, tactic) as argument,
1239 and that adding two tactics with the same name overwrites the first
1240 one (emitting a warning).
1241 type wrapper = (int -> tactic) -> (int -> tactic)
1242 setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
1243 addWrapper, addSWrapper: claset * (string * wrapper) -> claset
1244 delWrapper, delSWrapper: claset * string -> claset
1245 getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
1247 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
1248 semantics; addbefore now affects only the unsafe part of step_tac
1249 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
1250 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
1253 * Classical reasoner: setwrapper to setWrapper and compwrapper to
1254 compWrapper; added safe wrapper (and access functions for it);
1256 * HOL/split_all_tac is now much faster and fails if there is nothing
1257 to split. Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
1258 and the names of the automatically generated variables have changed.
1259 split_all_tac has moved within claset() from unsafe wrappers to safe
1260 wrappers, which means that !!-bound variables are split much more
1261 aggressively, and safe_tac and clarify_tac now split such variables.
1262 If this splitting is not appropriate, use delSWrapper "split_all_tac".
1263 Note: the same holds for record_split_tac, which does the job of
1264 split_all_tac for record fields.
1266 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
1267 permanently to the default simpset using Addsplits just like
1268 Addsimps. They can be removed via Delsplits just like
1269 Delsimps. Lower-case versions are also available.
1271 * HOL/Simplifier: The rule split_if is now part of the default
1272 simpset. This means that the simplifier will eliminate all occurrences
1273 of if-then-else in the conclusion of a goal. To prevent this, you can
1274 either remove split_if completely from the default simpset by
1275 `Delsplits [split_if]' or remove it in a specific call of the
1276 simplifier using `... delsplits [split_if]'. You can also add/delete
1277 other case splitting rules to/from the default simpset: every datatype
1278 generates suitable rules `split_t_case' and `split_t_case_asm' (where
1279 t is the name of the datatype).
1281 * Classical reasoner / Simplifier combination: new force_tac (and
1282 derivatives Force_tac, force) combines rewriting and classical
1283 reasoning (and whatever other tools) similarly to auto_tac, but is
1284 aimed to solve the given subgoal completely.
1289 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
1290 and `goalw': the theory is no longer needed as an explicit argument -
1291 the current theory context is used; assumptions are no longer returned
1292 at the ML-level unless one of them starts with ==> or !!; it is
1293 recommended to convert to these new commands using isatool fixgoal
1294 (backup your sources first!);
1296 * new top-level commands 'thm' and 'thms' for retrieving theorems from
1297 the current theory context, and 'theory' to lookup stored theories;
1299 * new theory section 'locale' for declaring constants, assumptions and
1300 definitions that have local scope;
1302 * new theory section 'nonterminals' for purely syntactic types;
1304 * new theory section 'setup' for generic ML setup functions
1305 (e.g. package initialization);
1307 * the distribution now includes Isabelle icons: see
1308 lib/logo/isabelle-{small,tiny}.xpm;
1310 * isatool install - install binaries with absolute references to
1313 * isatool logo -- create instances of the Isabelle logo (as EPS);
1315 * print mode 'emacs' reserved for Isamode;
1317 * support multiple print (ast) translations per constant name;
1319 * theorems involving oracles are now printed with a suffixed [!];
1324 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
1326 * HOL/inductive package reorganized and improved: now supports mutual
1332 oddI "n : EVEN ==> Suc n : ODD"
1333 evenI "n : ODD ==> Suc n : EVEN"
1335 new theorem list "elims" contains an elimination rule for each of the
1336 recursive sets; inductive definitions now handle disjunctive premises
1337 correctly (also ZF);
1339 INCOMPATIBILITIES: requires Inductive as an ancestor; component
1340 "mutual_induct" no longer exists - the induction rule is always
1341 contained in "induct";
1344 * HOL/datatype package re-implemented and greatly improved: now
1345 supports mutually recursive datatypes such as
1348 'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
1349 | SUM ('a aexp) ('a aexp)
1350 | DIFF ('a aexp) ('a aexp)
1353 'a bexp = LESS ('a aexp) ('a aexp)
1354 | AND ('a bexp) ('a bexp)
1355 | OR ('a bexp) ('a bexp)
1357 as well as indirectly recursive datatypes such as
1360 ('a, 'b) term = Var 'a
1361 | App 'b ((('a, 'b) term) list)
1363 The new tactic mutual_induct_tac [<var_1>, ..., <var_n>] i performs
1364 induction on mutually / indirectly recursive datatypes.
1366 Primrec equations are now stored in theory and can be accessed via
1367 <function_name>.simps.
1371 - Theories using datatypes must now have theory Datatype as an
1373 - The specific <typename>.induct_tac no longer exists - use the
1374 generic induct_tac instead.
1375 - natE has been renamed to nat.exhaust - use exhaust_tac
1376 instead of res_inst_tac ... natE. Note that the variable
1377 names in nat.exhaust differ from the names in natE, this
1378 may cause some "fragile" proofs to fail.
1379 - The theorems split_<typename>_case and split_<typename>_case_asm
1380 have been renamed to <typename>.split and <typename>.split_asm.
1381 - Since default sorts of type variables are now handled correctly,
1382 some datatype definitions may have to be annotated with explicit
1384 - Primrec definitions no longer require function name and type
1385 of recursive argument.
1387 Consider using isatool fixdatatype to adapt your theories and proof
1388 scripts to the new package (backup your sources first!).
1391 * HOL/record package: considerably improved implementation; now
1392 includes concrete syntax for record types, terms, updates; theorems
1393 for surjective pairing and splitting !!-bound record variables; proof
1394 support is as follows:
1396 1) standard conversions (selectors or updates applied to record
1397 constructor terms) are part of the standard simpset;
1399 2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
1400 made part of standard simpset and claset via addIffs;
1402 3) a tactic for record field splitting (record_split_tac) is part of
1403 the standard claset (addSWrapper);
1405 To get a better idea about these rules you may retrieve them via
1406 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
1407 the name of your record type.
1409 The split tactic 3) conceptually simplifies by the following rule:
1411 "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
1413 Thus any record variable that is bound by meta-all will automatically
1414 blow up into some record constructor term, consequently the
1415 simplifications of 1), 2) apply. Thus force_tac, auto_tac etc. shall
1416 solve record problems automatically.
1419 * reorganized the main HOL image: HOL/Integ and String loaded by
1420 default; theory Main includes everything;
1422 * automatic simplification of integer sums and comparisons, using cancellation;
1424 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
1426 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
1428 * many new identities for unions, intersections, set difference, etc.;
1430 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
1431 called split_if, split_split, split_sum_case and split_nat_case (to go
1432 with add/delsplits);
1434 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
1435 (?x::unit) = (); this is made part of the default simpset, which COULD
1436 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
1437 'Delsimprocs [unit_eq_proc];' as last resort); also note that
1438 unit_abs_eta_conv is added in order to counter the effect of
1439 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
1442 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
1445 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
1446 It and 'sym RS equals0D' are now in the default claset, giving automatic
1447 disjointness reasoning but breaking a few old proofs.
1449 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
1450 to 'converse' from 'inverse' (for compatibility with ZF and some
1453 * HOL/recdef can now declare non-recursive functions, with {} supplied as
1454 the well-founded relation;
1456 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
1457 Compl A. The "Compl" syntax remains available as input syntax for this
1460 * HOL/Update: new theory of function updates:
1461 f(a:=b) == %x. if x=a then b else f x
1462 may also be iterated as in f(a:=b,c:=d,...);
1464 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
1467 - new function list_update written xs[i:=v] that updates the i-th
1468 list position. May also be iterated as in xs[i:=a,j:=b,...].
1469 - new function `upt' written [i..j(] which generates the list
1470 [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
1471 bound write [i..j], which is a shorthand for [i..j+1(].
1472 - new lexicographic orderings and corresponding wellfoundedness theorems.
1475 - removed 'pred' (predecessor) function;
1476 - generalized some theorems about n-1;
1477 - many new laws about "div" and "mod";
1478 - new laws about greatest common divisors (see theory ex/Primes);
1480 * HOL/Relation: renamed the relational operator r^-1 "converse"
1481 instead of "inverse";
1483 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
1484 of the multiset ordering;
1486 * directory HOL/Real: a construction of the reals using Dedekind cuts
1487 (not included by default);
1489 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
1491 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
1492 programs, i.e. different program variables may have different types.
1494 * calling (stac rew i) now fails if "rew" has no effect on the goal
1495 [previously, this check worked only if the rewrite rule was unconditional]
1496 Now rew can involve either definitions or equalities (either == or =).
1501 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
1502 only the theorems proved on ZF.ML;
1504 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
1505 It and 'sym RS equals0D' are now in the default claset, giving automatic
1506 disjointness reasoning but breaking a few old proofs.
1508 * ZF/Update: new theory of function updates
1509 with default rewrite rule f(x:=y) ` z = if(z=x, y, f`z)
1510 may also be iterated as in f(a:=b,c:=d,...);
1512 * in let x=t in u(x), neither t nor u(x) has to be an FOL term.
1514 * calling (stac rew i) now fails if "rew" has no effect on the goal
1515 [previously, this check worked only if the rewrite rule was unconditional]
1516 Now rew can involve either definitions or equalities (either == or =).
1518 * case_tac provided for compatibility with HOL
1519 (like the old excluded_middle_tac, but with subgoals swapped)
1522 *** Internal programming interfaces ***
1524 * Pure: several new basic modules made available for general use, see
1525 also src/Pure/README;
1527 * improved the theory data mechanism to support encapsulation (data
1528 kind name replaced by private Object.kind, acting as authorization
1529 key); new type-safe user interface via functor TheoryDataFun; generic
1530 print_data function becomes basically useless;
1532 * removed global_names compatibility flag -- all theory declarations
1533 are qualified by default;
1535 * module Pure/Syntax now offers quote / antiquote translation
1536 functions (useful for Hoare logic etc. with implicit dependencies);
1537 see HOL/ex/Antiquote for an example use;
1539 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
1542 * new tactical CHANGED_GOAL for checking that a tactic modifies a
1545 * Display.print_goals function moved to Locale.print_goals;
1547 * standard print function for goals supports current_goals_markers
1548 variable for marking begin of proof, end of proof, start of goal; the
1549 default is ("", "", ""); setting current_goals_markers := ("<proof>",
1550 "</proof>", "<goal>") causes SGML like tagged proof state printing,
1555 New in Isabelle98 (January 1998)
1556 --------------------------------
1558 *** Overview of INCOMPATIBILITIES (see below for more details) ***
1560 * changed lexical syntax of terms / types: dots made part of long
1561 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
1563 * simpset (and claset) reference variable replaced by functions
1564 simpset / simpset_ref;
1566 * no longer supports theory aliases (via merge) and non-trivial
1567 implicit merge of thms' signatures;
1569 * most internal names of constants changed due to qualified names;
1571 * changed Pure/Sequence interface (see Pure/seq.ML);
1574 *** General Changes ***
1576 * hierachically structured name spaces (for consts, types, axms, thms
1577 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
1578 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
1579 isatool fixdots ensures space after dots (e.g. "%x. x"); set
1580 long_names for fully qualified output names; NOTE: ML programs
1581 (special tactics, packages etc.) referring to internal names may have
1582 to be adapted to cope with fully qualified names; in case of severe
1583 backward campatibility problems try setting 'global_names' at compile
1584 time to have enrything declared within a flat name space; one may also
1585 fine tune name declarations in theories via the 'global' and 'local'
1588 * reimplemented the implicit simpset and claset using the new anytype
1589 data filed in signatures; references simpset:simpset ref etc. are
1590 replaced by functions simpset:unit->simpset and
1591 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
1592 to patch your ML files accordingly;
1594 * HTML output now includes theory graph data for display with Java
1595 applet or isatool browser; data generated automatically via isatool
1596 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
1598 * defs may now be conditional; improved rewrite_goals_tac to handle
1599 conditional equations;
1601 * defs now admits additional type arguments, using TYPE('a) syntax;
1603 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
1604 creates a new theory node; implicit merge of thms' signatures is
1605 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
1606 transfer:theory->thm->thm in (rare) cases;
1608 * improved handling of draft signatures / theories; draft thms (and
1609 ctyps, cterms) are automatically promoted to real ones;
1611 * slightly changed interfaces for oracles: admit many per theory, named
1612 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
1614 * print_goals: optional output of const types (set show_consts and
1617 * improved output of warnings (###) and errors (***);
1619 * subgoal_tac displays a warning if the new subgoal has type variables;
1621 * removed old README and Makefiles;
1623 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
1625 * removed obsolete init_pps and init_database;
1627 * deleted the obsolete tactical STATE, which was declared by
1628 fun STATE tacfun st = tacfun st st;
1630 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
1631 (which abbreviates $HOME);
1633 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
1634 use isatool fixseq to adapt your ML programs (this works for fully
1635 qualified references to the Sequence structure only!);
1637 * use_thy no longer requires writable current directory; it always
1638 reloads .ML *and* .thy file, if either one is out of date;
1641 *** Classical Reasoner ***
1643 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
1644 tactics that use classical reasoning to simplify a subgoal without
1645 splitting it into several subgoals;
1647 * Safe_tac: like safe_tac but uses the default claset;
1652 * added simplification meta rules:
1653 (asm_)(full_)simplify: simpset -> thm -> thm;
1655 * simplifier.ML no longer part of Pure -- has to be loaded by object
1658 * added prems argument to simplification procedures;
1660 * HOL, FOL, ZF: added infix function `addsplits':
1661 instead of `<simpset> setloop (split_tac <thms>)'
1662 you can simply write `<simpset> addsplits <thms>'
1667 * TYPE('a) syntax for type reflection terms;
1669 * no longer handles consts with name "" -- declare as 'syntax' instead;
1671 * pretty printer: changed order of mixfix annotation preference (again!);
1673 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
1678 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
1679 with `addloop' of the simplifier to faciliate case splitting in premises.
1681 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
1683 * HOL/Auth: new protocol proofs including some for the Internet
1686 * HOL/Map: new theory of `maps' a la VDM;
1688 * HOL/simplifier: simplification procedures nat_cancel_sums for
1689 cancelling out common nat summands from =, <, <= (in)equalities, or
1690 differences; simplification procedures nat_cancel_factor for
1691 cancelling common factor from =, <, <= (in)equalities over natural
1692 sums; nat_cancel contains both kinds of procedures, it is installed by
1693 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
1695 * HOL/simplifier: terms of the form
1696 `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)' (or t=x)
1698 `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
1699 and those of the form
1700 `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)' (or t=x)
1702 `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
1705 Each datatype `t' now comes with a theorem `split_t_case' of the form
1707 P(t_case f1 ... fn x) =
1708 ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
1710 (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
1713 and a theorem `split_t_case_asm' of the form
1715 P(t_case f1 ... fn x) =
1716 ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
1718 (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
1720 which can be added to a simpset via `addsplits'. The existing theorems
1721 expand_list_case and expand_option_case have been renamed to
1722 split_list_case and split_option_case.
1725 - `pred n' is automatically converted to `n-1'.
1726 Users are strongly encouraged not to use `pred' any longer,
1727 because it will disappear altogether at some point.
1728 - Users are strongly encouraged to write "0 < n" rather than
1729 "n ~= 0". Theorems and proof tools have been modified towards this
1733 the function "set_of_list" has been renamed "set" (and its theorems too);
1734 the function "nth" now takes its arguments in the reverse order and
1735 has acquired the infix notation "!" as in "xs!n".
1737 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
1739 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
1740 specialist theorems (like UN1_I) are gone. Similarly for (INT x.B x);
1742 * HOL/record: extensible records with schematic structural subtyping
1743 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
1744 still lacks various theorems and concrete record syntax;
1749 * removed "axioms" and "generated by" sections;
1751 * replaced "ops" section by extended "consts" section, which is capable of
1752 handling the continuous function space "->" directly;
1755 . proves theorems immediately and stores them in the theory,
1756 . creates hierachical name space,
1757 . now uses normal mixfix annotations (instead of cinfix...),
1758 . minor changes to some names and values (for consistency),
1759 . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
1760 . separator between mutual domain defs: changed "," to "and",
1761 . improved handling of sort constraints; now they have to
1762 appear on the left-hand side of the equations only;
1764 * fixed LAM <x,y,zs>.b syntax;
1766 * added extended adm_tac to simplifier in HOLCF -- can now discharge
1767 adm (%x. P (t x)), where P is chainfinite and t continuous;
1772 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
1773 with `addloop' of the simplifier to faciliate case splitting in premises.
1775 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
1776 in HOL, they strip ALL and --> from proved theorems;
1780 New in Isabelle94-8 (May 1997)
1781 ------------------------------
1783 *** General Changes ***
1785 * new utilities to build / run / maintain Isabelle etc. (in parts
1786 still somewhat experimental); old Makefiles etc. still functional;
1788 * new 'Isabelle System Manual';
1790 * INSTALL text, together with ./configure and ./build scripts;
1792 * reimplemented type inference for greater efficiency, better error
1793 messages and clean internal interface;
1795 * prlim command for dealing with lots of subgoals (an easier way of
1796 setting goals_limit);
1801 * supports alternative (named) syntax tables (parser and pretty
1802 printer); internal interface is provided by add_modesyntax(_i);
1804 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
1805 be used in conjunction with the Isabelle symbol font; uses the
1806 "symbols" syntax table;
1808 * added token_translation interface (may translate name tokens in
1809 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
1810 the current print_mode); IMPORTANT: user print translation functions
1811 are responsible for marking newly introduced bounds
1812 (Syntax.mark_boundT);
1814 * token translations for modes "xterm" and "xterm_color" that display
1815 names in bold, underline etc. or colors (which requires a color
1818 * infixes may now be declared with names independent of their syntax;
1820 * added typed_print_translation (like print_translation, but may
1821 access type of constant);
1824 *** Classical Reasoner ***
1826 Blast_tac: a new tactic! It is often more powerful than fast_tac, but has
1827 some limitations. Blast_tac...
1828 + ignores addss, addbefore, addafter; this restriction is intrinsic
1829 + ignores elimination rules that don't have the correct format
1830 (the conclusion MUST be a formula variable)
1831 + ignores types, which can make HOL proofs fail
1832 + rules must not require higher-order unification, e.g. apply_type in ZF
1833 [message "Function Var's argument not a bound variable" relates to this]
1834 + its proof strategy is more general but can actually be slower
1836 * substitution with equality assumptions no longer permutes other
1839 * minor changes in semantics of addafter (now called addaltern); renamed
1840 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
1841 (and access functions for it);
1843 * improved combination of classical reasoner and simplifier:
1844 + functions for handling clasimpsets
1845 + improvement of addss: now the simplifier is called _after_ the
1847 + safe variant of addss called addSss: uses safe simplifications
1848 _during_ the safe steps. It is more complete as it allows multiple
1849 instantiations of unknowns (e.g. with slow_tac).
1853 * added interface for simplification procedures (functions that
1854 produce *proven* rewrite rules on the fly, depending on current
1857 * ordering on terms as parameter (used for ordered rewriting);
1859 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
1861 * the solver is now split into a safe and an unsafe part.
1862 This should be invisible for the normal user, except that the
1863 functions setsolver and addsolver have been renamed to setSolver and
1864 addSolver; added safe_asm_full_simp_tac;
1869 * a generic induction tactic `induct_tac' which works for all datatypes and
1870 also for type `nat';
1872 * a generic case distinction tactic `exhaust_tac' which works for all
1873 datatypes and also for type `nat';
1875 * each datatype comes with a function `size';
1877 * patterns in case expressions allow tuple patterns as arguments to
1878 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
1880 * primrec now also works with type nat;
1882 * recdef: a new declaration form, allows general recursive functions to be
1883 defined in theory files. See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
1885 * the constant for negation has been renamed from "not" to "Not" to
1886 harmonize with FOL, ZF, LK, etc.;
1888 * HOL/ex/LFilter theory of a corecursive "filter" functional for
1891 * HOL/Modelcheck demonstrates invocation of model checker oracle;
1893 * HOL/ex/Ring.thy declares cring_simp, which solves equational
1894 problems in commutative rings, using axiomatic type classes for + and *;
1896 * more examples in HOL/MiniML and HOL/Auth;
1898 * more default rewrite rules for quantifiers, union/intersection;
1900 * a new constant `arbitrary == @x.False';
1902 * HOLCF/IOA replaces old HOL/IOA;
1904 * HOLCF changes: derived all rules and arities
1905 + axiomatic type classes instead of classes
1906 + typedef instead of faking type definitions
1907 + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
1908 + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
1909 + eliminated the types void, one, tr
1910 + use unit lift and bool lift (with translations) instead of one and tr
1911 + eliminated blift from Lift3.thy (use Def instead of blift)
1912 all eliminated rules are derived as theorems --> no visible changes ;
1917 * ZF now has Fast_tac, Simp_tac and Auto_tac. Union_iff is a now a default
1918 rewrite rule; this may affect some proofs. eq_cs is gone but can be put back
1919 as ZF_cs addSIs [equalityI];
1923 New in Isabelle94-7 (November 96)
1924 ---------------------------------
1926 * allowing negative levels (as offsets) in prlev and choplev;
1928 * super-linear speedup for large simplifications;
1930 * FOL, ZF and HOL now use miniscoping: rewriting pushes
1931 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
1932 FAIL); can suppress it using the command Delsimps (ex_simps @
1933 all_simps); De Morgan laws are also now included, by default;
1935 * improved printing of ==> : ~:
1937 * new object-logic "Sequents" adds linear logic, while replacing LK
1938 and Modal (thanks to Sara Kalvala);
1940 * HOL/Auth: correctness proofs for authentication protocols;
1942 * HOL: new auto_tac combines rewriting and classical reasoning (many
1943 examples on HOL/Auth);
1945 * HOL: new command AddIffs for declaring theorems of the form P=Q to
1946 the rewriter and classical reasoner simultaneously;
1948 * function uresult no longer returns theorems in "standard" format;
1949 regain previous version by: val uresult = standard o uresult;
1956 * oracles -- these establish an interface between Isabelle and trusted
1957 external reasoners, which may deliver results as theorems;
1959 * proof objects (in particular record all uses of oracles);
1961 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
1963 * "constdefs" section in theory files;
1965 * "primrec" section (HOL) no longer requires names;
1967 * internal type "tactic" now simply "thm -> thm Sequence.seq";
1974 * reduced space requirements;
1976 * automatic HTML generation from theories;
1978 * theory files no longer require "..." (quotes) around most types;
1980 * new examples, including two proofs of the Church-Rosser theorem;
1982 * non-curried (1994) version of HOL is no longer distributed;
1989 * greatly reduced space requirements;
1991 * theory files (.thy) no longer require \...\ escapes at line breaks;
1993 * searchable theorem database (see the section "Retrieving theorems" on
1994 page 8 of the Reference Manual);
1996 * new examples, including Grabczewski's monumental case study of the
1999 * The previous version of HOL renamed to Old_HOL;
2001 * The new version of HOL (previously called CHOL) uses a curried syntax
2002 for functions. Application looks like f a b instead of f(a,b);
2004 * Mutually recursive inductive definitions finally work in HOL;
2006 * In ZF, pattern-matching on tuples is now available in all abstractions and
2007 translates to the operator "split";
2014 * new infix operator, addss, allowing the classical reasoner to
2015 perform simplification at each step of its search. Example:
2016 fast_tac (cs addss ss)
2018 * a new logic, CHOL, the same as HOL, but with a curried syntax
2019 for functions. Application looks like f a b instead of f(a,b). Also pairs
2020 look like (a,b) instead of <a,b>;
2022 * PLEASE NOTE: CHOL will eventually replace HOL!
2024 * In CHOL, pattern-matching on tuples is now available in all abstractions.
2025 It translates to the operator "split". A new theory of integers is available;
2027 * In ZF, integer numerals now denote two's-complement binary integers.
2028 Arithmetic operations can be performed by rewriting. See ZF/ex/Bin.ML;
2030 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
2031 of the Axiom of Choice;
2038 * Significantly faster resolution;
2040 * the different sections in a .thy file can now be mixed and repeated
2043 * Database of theorems for FOL, HOL and ZF. New
2044 commands including qed, qed_goal and bind_thm store theorems in the database.
2046 * Simple database queries: return a named theorem (get_thm) or all theorems of
2047 a given theory (thms_of), or find out what theory a theorem was proved in
2050 * Bugs fixed in the inductive definition and datatype packages;
2052 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
2053 and HOL_dup_cs obsolete;
2055 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
2058 * Simpler definition of function space in ZF;
2060 * new results about cardinal and ordinal arithmetic in ZF;
2062 * 'subtype' facility in HOL for introducing new types as subsets of existing