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 - removed obsolete "(simplified)" and "(stripped)" options of methods;
45 - added 'print_induct_rules' (covered by help item in Proof General > 3.3);
46 - moved induct/cases attributes to Pure, methods to Provers;
47 - generic method setup instantiated for FOL and HOL;
49 * Pure: renamed "antecedent" case to "rule_context";
51 * Pure: added 'corollary' command;
53 * Pure: fixed 'token_translation' command;
55 * Pure: removed obsolete 'exported' attribute;
57 * Pure: dummy pattern "_" in is/let is now automatically lifted over
58 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
59 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
61 * Provers: 'simplified' attribute may refer to explicit rules instead
62 of full simplifier context; 'iff' attribute handles conditional rules;
64 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
66 * HOL: 'recdef' now fails on unfinished automated proofs, use
67 "(permissive)" option to recover old behavior;
69 * HOL: 'inductive' no longer features separate (collective) attributes
70 for 'intros' (was found too confusing);
76 * HOL: moved over to sane numeral syntax; the new policy is as
79 - 0 and 1 are polymorphic constants, which are defined on any
80 numeric type (nat, int, real etc.);
82 - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
83 binary representation internally;
85 - type nat has special constructor Suc, and generally prefers Suc 0
86 over 1::nat and Suc (Suc 0) over 2::nat;
88 This change may cause significant INCOMPATIBILITIES; here are some
89 hints on converting existing sources:
91 - due to the new "num" token, "-0" and "-1" etc. are now atomic
92 entities, so expressions involving "-" (unary or binary minus) need
93 to be spaced properly;
95 - existing occurrences of "1" may need to be constraint "1::nat" or
96 even replaced by Suc 0; similar for old "2";
98 - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
100 - remove all special provisions on numerals in proofs;
103 - removed old "make" and "make_scheme" operations -- INCOMPATIBILITY;
104 - removed "more" class (simply use "term") -- INCOMPATIBILITY;
105 - provides cases/induct rules for use with corresponding Isar methods;
106 - new derived operations "make" (for adding fields of current
107 record), "extend" to promote fixed record to record scheme, and
108 "truncate" for the reverse; cf. theorems "derived_defs", which are
109 *not* declared as simp by default;
110 - internal definitions directly based on a light-weight abstract
111 theory of product types over typedef rather than datatype;
113 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
115 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
116 (beware of argument permutation!);
118 * HOL: linorder_less_split superseded by linorder_cases;
120 * HOL: added "The" definite description operator; move Hilbert's "Eps"
121 to peripheral theory "Hilbert_Choice";
123 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
124 in this (rare) case use:
126 delSWrapper "split_all_tac"
127 addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
129 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
132 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
133 Isabelle's type classes, ^ on functions and relations has too general
134 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
135 necessary to attach explicit type constraints;
137 * HOL: syntax translations now work properly with numerals and records
140 * HOL/GroupTheory: group theory examples including Sylow's theorem, by
143 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
144 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
145 renamed "Product_Type.unit";
150 * ZF: the integer library now covers quotients and remainders, with
151 many laws relating division to addition, multiplication, etc.;
156 * kernel: meta-level proof terms (by Stefan Berghofer), see also ref
159 * classical: renamed addaltern to addafter, addSaltern to addSafter;
161 * clasimp: ``iff'' declarations now handle conditional rules as well;
163 * syntax: new token syntax "num" for plain numerals (without "#" of
164 "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now separate
165 tokens, so expressions involving minus need to be spaced properly;
167 * syntax: support non-oriented infixes;
169 * syntax: print modes "type_brackets" and "no_type_brackets" control
170 output of nested => (types); the default behavior is "type_brackets";
172 * syntax: builtin parse translation for "_constify" turns valued
173 tokens into AST constants;
175 * system: support Poly/ML 4.1.1 (now able to manage large heaps);
177 * system: Proof General keywords specification is now part of the
178 Isabelle distribution (see etc/isar-keywords.el);
180 * system: smart selection of Isabelle process versus Isabelle
181 interface, accommodates case-insensitive file systems (e.g. HFS+); may
182 run both "isabelle" and "Isabelle" even if file names are badly
183 damaged (executable inspects the case of the first letter of its own
184 name); added separate "isabelle-process" and "isabelle-interface";
188 New in Isabelle99-2 (February 2001)
189 -----------------------------------
191 *** Overview of INCOMPATIBILITIES ***
193 * HOL: please note that theories in the Library and elsewhere often use the
194 new-style (Isar) format; to refer to their theorems in an ML script you must
195 bind them to ML identifers by e.g. val thm_name = thm "thm_name";
197 * HOL: inductive package no longer splits induction rule aggressively,
198 but only as far as specified by the introductions given; the old
199 format may be recovered via ML function complete_split_rule or attribute
200 'split_rule (complete)';
202 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
203 gfp_Tarski to gfp_unfold;
205 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
207 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
208 relation); infix "^^" has been renamed "``"; infix "``" has been
209 renamed "`"; "univalent" has been renamed "single_valued";
211 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
214 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
216 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
218 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
219 consequence, it is no longer monotonic wrt. the local goal context
220 (which is now passed through the inductive cases);
222 * Document preparation: renamed standard symbols \<ll> to \<lless> and
223 \<gg> to \<ggreater>;
226 *** Document preparation ***
228 * \isabellestyle{NAME} selects version of Isabelle output (currently
229 available: are "it" for near math-mode best-style output, "sl" for
230 slanted text style, and "tt" for plain type-writer; if no
231 \isabellestyle command is given, output is according to slanted
234 * support sub/super scripts (for single symbols only), input syntax is
235 like this: "A\<^sup>*" or "A\<^sup>\<star>";
237 * some more standard symbols; see Appendix A of the system manual for
238 the complete list of symbols defined in isabellesym.sty;
240 * improved isabelle style files; more abstract symbol implementation
241 (should now use \isamath{...} and \isatext{...} in custom symbol
244 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
245 state; Note that presentation of goal states does not conform to
246 actual human-readable proof documents. Please do not include goal
247 states into document output unless you really know what you are doing!
249 * proper indentation of antiquoted output with proportional LaTeX
252 * no_document ML operator temporarily disables LaTeX document
255 * isatool unsymbolize tunes sources for plain ASCII communication;
260 * Pure: Isar now suffers initial goal statements to contain unbound
261 schematic variables (this does not conform to actual readable proof
262 documents, due to unpredictable outcome and non-compositional proof
263 checking); users who know what they are doing may use schematic goals
264 for Prolog-style synthesis of proven results;
266 * Pure: assumption method (an implicit finishing) now handles actual
269 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
270 initial goal, declare "that" only as Pure intro (only for single
271 steps); the "that" rule assumption may now be involved in implicit
272 finishing, thus ".." becomes a feasible for trivial obtains;
274 * Pure: default proof step now includes 'intro_classes'; thus trivial
275 instance proofs may be performed by "..";
277 * Pure: ?thesis / ?this / "..." now work for pure meta-level
280 * Pure: more robust selection of calculational rules;
282 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
283 rule (as well as the assumption rule);
285 * Pure: 'thm_deps' command visualizes dependencies of theorems and
286 lemmas, using the graph browser tool;
288 * Pure: predict failure of "show" in interactive mode;
290 * Pure: 'thms_containing' now takes actual terms as arguments;
292 * HOL: improved method 'induct' --- now handles non-atomic goals
293 (potential INCOMPATIBILITY); tuned error handling;
295 * HOL: cases and induct rules now provide explicit hints about the
296 number of facts to be consumed (0 for "type" and 1 for "set" rules);
297 any remaining facts are inserted into the goal verbatim;
299 * HOL: local contexts (aka cases) may now contain term bindings as
300 well; the 'cases' and 'induct' methods new provide a ?case binding for
301 the result to be shown in each case;
303 * HOL: added 'recdef_tc' command;
305 * isatool convert assists in eliminating legacy ML scripts;
310 * HOL/Library: a collection of generic theories to be used together
311 with main HOL; the theory loader path already includes this directory
312 by default; the following existing theories have been moved here:
313 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
314 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
316 * HOL/Unix: "Some aspects of Unix file-system security", a typical
317 modelling and verification task performed in Isabelle/HOL +
318 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
320 * HOL/Algebra: special summation operator SUM no longer exists, it has
321 been replaced by setsum; infix 'assoc' now has priority 50 (like
322 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
323 'domain', this makes the theory consistent with mathematical
326 * HOL basics: added overloaded operations "inverse" and "divide"
327 (infix "/"), syntax for generic "abs" operation, generic summation
330 * HOL/typedef: simplified package, provide more useful rules (see also
333 * HOL/datatype: induction rule for arbitrarily branching datatypes is
334 now expressed as a proper nested rule (old-style tactic scripts may
335 require atomize_strip_tac to cope with non-atomic premises);
337 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
338 to "split_conv" (old name still available for compatibility);
340 * HOL: improved concrete syntax for strings (e.g. allows translation
341 rules with string literals);
343 * HOL-Hyperreal: a new target, extending HOL-Real with the hyperreals
344 and Fleuriot's mechanization of analysis;
346 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
351 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
352 "lam" is displayed as TWO lambda-symbols
354 * CTT: theory Main now available, containing everything (that is, Bool
360 * Pure: the Simplifier has been implemented properly as a derived rule
361 outside of the actual kernel (at last!); the overall performance
362 penalty in practical applications is about 50%, while reliability of
363 the Isabelle inference kernel has been greatly improved;
365 * print modes "brackets" and "no_brackets" control output of nested =>
366 (types) and ==> (props); the default behaviour is "brackets";
368 * Provers: fast_tac (and friends) now handle actual object-logic rules
369 as assumptions as well;
371 * system: support Poly/ML 4.0;
373 * system: isatool install handles KDE version 1 or 2;
377 New in Isabelle99-1 (October 2000)
378 ----------------------------------
380 *** Overview of INCOMPATIBILITIES ***
382 * HOL: simplification of natural numbers is much changed; to partly
383 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
384 issue the following ML commands:
386 Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
387 Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
389 * HOL: simplification no longer dives into case-expressions; this is
390 controlled by "t.weak_case_cong" for each datatype t;
392 * HOL: nat_less_induct renamed to less_induct;
394 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
395 fixsome to patch .thy and .ML sources automatically;
397 select_equality -> some_equality
398 select_eq_Ex -> some_eq_ex
399 selectI2EX -> someI2_ex
402 select1_equality -> some1_equality
403 Eps_sym_eq -> some_sym_eq_trivial
404 Eps_eq -> some_eq_trivial
406 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
408 * HOL: removed obsolete theorem binding expand_if (refer to split_if
411 * HOL: the recursion equations generated by 'recdef' are now called
412 f.simps instead of f.rules;
414 * HOL: qed_spec_mp now also handles bounded ALL as well;
416 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
419 * HOL: the constant for "f``x" is now "image" rather than "op ``";
421 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
423 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
424 product is now "<*>" instead of "Times"; the lexicographic product is
425 now "<*lex*>" instead of "**";
427 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
428 of main HOL, but was unused); better use HOL's datatype package;
430 * HOL: removed "symbols" syntax for constant "override" of theory Map;
431 the old syntax may be recovered as follows:
434 override :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
435 (infixl "\\<oplus>" 100)
437 * HOL/Real: "rabs" replaced by overloaded "abs" function;
439 * HOL/ML: even fewer consts are declared as global (see theories Ord,
440 Lfp, Gfp, WF); this only affects ML packages that refer to const names
443 * HOL and ZF: syntax for quotienting wrt an equivalence relation
444 changed from A/r to A//r;
446 * ZF: new treatment of arithmetic (nat & int) may break some old
449 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
450 rulify -> rule_format, elimify -> elim_format, ...);
452 * Isar/Provers: intro/elim/dest attributes changed; renamed
453 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
454 should have to change intro!! to intro? only); replaced "delrule" by
457 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
459 * Provers: strengthened force_tac by using new first_best_tac;
461 * LaTeX document preparation: several changes of isabelle.sty (see
465 *** Document preparation ***
467 * formal comments (text blocks etc.) in new-style theories may now
468 contain antiquotations of thm/prop/term/typ/text to be presented
469 according to latex print mode; concrete syntax is like this:
470 @{term[show_types] "f(x) = a + x"};
472 * isatool mkdir provides easy setup of Isabelle session directories,
473 including proper document sources;
475 * generated LaTeX sources are now deleted after successful run
476 (isatool document -c); may retain a copy somewhere else via -D option
479 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
480 style files, achieving self-contained LaTeX sources and simplifying
483 * old-style theories now produce (crude) LaTeX output as well;
485 * browser info session directories are now self-contained (may be put
486 on WWW server seperately); improved graphs of nested sessions; removed
487 graph for 'all sessions';
489 * several improvements in isabelle style files; \isabellestyle{it}
490 produces fake math mode output; \isamarkupheader is now \section by
491 default; see lib/texinputs/isabelle.sty etc.;
496 * Isar/Pure: local results and corresponding term bindings are now
497 subject to Hindley-Milner polymorphism (similar to ML); this
498 accommodates incremental type-inference very nicely;
500 * Isar/Pure: new derived language element 'obtain' supports
501 generalized existence reasoning;
503 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
504 support accumulation of results, without applying any rules yet;
505 useful to collect intermediate results without explicit name
506 references, and for use with transitivity rules with more than 2
509 * Isar/Pure: scalable support for case-analysis type proofs: new
510 'case' language element refers to local contexts symbolically, as
511 produced by certain proof methods; internally, case names are attached
512 to theorems as "tags";
514 * Isar/Pure: theory command 'hide' removes declarations from
515 class/type/const name spaces;
517 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
518 indicate potential overloading;
520 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
522 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
523 "{a,b,c}" instead of {a,b,c};
525 * Isar/Pure now provides its own version of intro/elim/dest
526 attributes; useful for building new logics, but beware of confusion
527 with the version in Provers/classical;
529 * Isar/Pure: the local context of (non-atomic) goals is provided via
530 case name 'antecedent';
532 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
533 to the current context is now done automatically);
535 * Isar/Pure: theory command 'method_setup' provides a simple interface
536 for definining proof methods in ML;
538 * Isar/Provers: intro/elim/dest attributes changed; renamed
539 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
540 most cases, one should have to change intro!! to intro? only);
541 replaced "delrule" by "rule del";
543 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
544 'symmetric' attribute (the latter supercedes [RS sym]);
546 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
547 method modifier); 'simp' method: 'only:' modifier removes loopers as
548 well (including splits);
550 * Isar/Provers: Simplifier and Classical methods now support all kind
551 of modifiers used in the past, including 'cong', 'iff', etc.
553 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
554 of Simplifier and Classical reasoner);
556 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
557 now support named cases; major packages (inductive, datatype, primrec,
558 recdef) support case names and properly name parameters;
560 * Isar/HOL: new transitivity rules for substitution in inequalities --
561 monotonicity conditions are extracted to be proven at end of
564 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
567 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
568 split_if split_if_asm; datatype package provides theorems foo.splits =
569 foo.split foo.split_asm for each datatype;
571 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
572 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
573 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
574 use "(cases (simplified))" method in proper proof texts);
576 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
578 * Isar: names of theorems etc. may be natural numbers as well;
580 * Isar: 'pr' command: optional arguments for goals_limit and
581 ProofContext.prems_limit; no longer prints theory contexts, but only
584 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
585 additional print modes to be specified; e.g. "pr(latex)" will print
586 proof state according to the Isabelle LaTeX style;
588 * Isar: improved support for emulating tactic scripts, including proof
589 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
590 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
593 * Isar: simplified (more robust) goal selection of proof methods: 1st
594 goal, all goals, or explicit goal specifier (tactic emulation); thus
595 'proof method scripts' have to be in depth-first order;
597 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
599 * Isar: removed 'help' command, which hasn't been too helpful anyway;
600 should instead use individual commands for printing items
601 (print_commands, print_methods etc.);
603 * Isar: added 'nothing' --- the empty list of theorems;
608 * HOL/MicroJava: formalization of a fragment of Java, together with a
609 corresponding virtual machine and a specification of its bytecode
610 verifier and a lightweight bytecode verifier, including proofs of
611 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
612 Cornelia Pusch (see also the homepage of project Bali at
613 http://isabelle.in.tum.de/Bali/);
615 * HOL/Algebra: new theory of rings and univariate polynomials, by
618 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
619 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
622 * HOL/Lattice: fundamental concepts of lattice theory and order
623 structures, including duals, properties of bounds versus algebraic
624 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
625 Theorem for complete lattices etc.; may also serve as a demonstration
626 for abstract algebraic reasoning using axiomatic type classes, and
627 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
629 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
632 * HOL/IMPP: extension of IMP with local variables and mutually
633 recursive procedures, by David von Oheimb;
635 * HOL/Lambda: converted into new-style theory and document;
637 * HOL/ex/Multiquote: example of multiple nested quotations and
638 anti-quotations -- basically a generalized version of de-Bruijn
639 representation; very useful in avoiding lifting of operations;
641 * HOL/record: added general record equality rule to simpset; fixed
642 select-update simplification procedure to handle extended records as
643 well; admit "r" as field name;
645 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
646 other numeric types and also as the identity of groups, rings, etc.;
648 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
649 Types nat and int belong to this axclass;
651 * HOL: greatly improved simplification involving numerals of type nat, int, real:
652 (i + #8 + j) = Suc k simplifies to #7 + (i + j) = k
653 i*j + k + j*#3*i simplifies to #4*(i*j) + k
654 two terms #m*u and #n*u are replaced by #(m+n)*u
655 (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
656 and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
657 or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
659 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
660 powerful prover for predicate logic but knows nothing of clasets; see
661 ex/mesontest.ML and ex/mesontest2.ML for example applications;
663 * HOL: new version of "case_tac" subsumes both boolean case split and
664 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
665 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
667 * HOL: simplification no longer dives into case-expressions: only the
668 selector expression is simplified, but not the remaining arms; to
669 enable full simplification of case-expressions for datatype t, you may
670 remove t.weak_case_cong from the simpset, either globally (Delcongs
671 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
673 * HOL/recdef: the recursion equations generated by 'recdef' for
674 function 'f' are now called f.simps instead of f.rules; if all
675 termination conditions are proved automatically, these simplification
676 rules are added to the simpset, as in primrec; rules may be named
677 individually as well, resulting in a separate list of theorems for
680 * HOL/While is a new theory that provides a while-combinator. It
681 permits the definition of tail-recursive functions without the
682 provision of a termination measure. The latter is necessary once the
683 invariant proof rule for while is applied.
685 * HOL: new (overloaded) notation for the set of elements below/above
686 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
688 * HOL: theorems impI, allI, ballI bound as "strip";
690 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
691 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
692 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
694 * HOL/Real: "rabs" replaced by overloaded "abs" function;
696 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
697 main HOL, but was unused);
699 * HOL: fewer consts declared as global (e.g. have to refer to
700 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
702 * HOL: tuned AST representation of nested pairs, avoiding bogus output
703 in case of overlap with user translations (e.g. judgements over
704 tuples); (note that the underlying logical represenation is still
710 * ZF: simplification automatically cancels common terms in arithmetic
711 expressions over nat and int;
713 * ZF: new treatment of nat to minimize type-checking: all operators
714 coerce their operands to a natural number using the function natify,
715 making the algebraic laws unconditional;
717 * ZF: as above, for int: operators coerce their operands to an integer
718 using the function intify;
720 * ZF: the integer library now contains many of the usual laws for the
721 orderings, including $<=, and monotonicity laws for $+ and $*;
723 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
726 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
727 to the simplifier and classical reasoner simultaneously;
732 * Provers: blast_tac now handles actual object-logic rules as
733 assumptions; note that auto_tac uses blast_tac internally as well;
735 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
736 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
738 * Provers: delrules now handles destruct rules as well (no longer need
741 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
742 [| inj ?f; ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
743 use instead the strong form,
744 [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
745 in HOL, FOL and ZF the function cla_make_elim will create such rules
748 * Provers: Simplifier.easy_setup provides a fast path to basic
749 Simplifier setup for new object-logics;
751 * Pure: AST translation rules no longer require constant head on LHS;
753 * Pure: improved name spaces: ambiguous output is qualified; support
756 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
757 XSYMBOL_HOME; no longer need to do manual configuration in most
760 * system: compression of ML heaps images may now be controlled via -c
761 option of isabelle and isatool usedir (currently only observed by
764 * system: isatool installfonts may handle X-Symbol fonts as well (very
765 useful for remote X11);
767 * system: provide TAGS file for Isabelle sources;
769 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
772 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
773 timing flag supersedes proof_timing and Toplevel.trace;
775 * ML: new combinators |>> and |>>> for incremental transformations
776 with secondary results (e.g. certain theory extensions):
778 * ML: PureThy.add_defs gets additional argument to indicate potential
779 overloading (usually false);
781 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
786 New in Isabelle99 (October 1999)
787 --------------------------------
789 *** Overview of INCOMPATIBILITIES (see below for more details) ***
791 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
792 are no longer simplified. (This allows the simplifier to unfold recursive
793 functional programs.) To restore the old behaviour, declare
795 Delcongs [if_weak_cong];
797 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
800 * HOL: the predicate "inj" is now defined by translation to "inj_on";
802 * HOL/datatype: mutual_induct_tac no longer exists --
803 use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
805 * HOL/typedef: fixed type inference for representing set; type
806 arguments now have to occur explicitly on the rhs as type constraints;
808 * ZF: The con_defs part of an inductive definition may no longer refer
809 to constants declared in the same theory;
811 * HOL, ZF: the function mk_cases, generated by the inductive
812 definition package, has lost an argument. To simplify its result, it
813 uses the default simpset instead of a supplied list of theorems.
815 * HOL/List: the constructors of type list are now Nil and Cons;
817 * Simplifier: the type of the infix ML functions
818 setSSolver addSSolver setSolver addSolver
819 is now simpset * solver -> simpset where `solver' is a new abstract type
820 for packaging solvers. A solver is created via
821 mk_solver: string -> (thm list -> int -> tactic) -> solver
822 where the string argument is only a comment.
827 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
828 decision procedure for linear arithmetic. Currently it is used for
829 types `nat', `int', and `real' in HOL (see below); it can, should and
830 will be instantiated for other types and logics as well.
832 * The simplifier now accepts rewrite rules with flexible heads, eg
833 hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
834 They are applied like any rule with a non-pattern lhs, i.e. by first-order
840 * New Isabelle/Isar subsystem provides an alternative to traditional
841 tactical theorem proving; together with the ProofGeneral/isar user
842 interface it offers an interactive environment for developing human
843 readable proof documents (Isar == Intelligible semi-automated
844 reasoning); for further information see isatool doc isar-ref,
845 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
847 * improved and simplified presentation of theories: better HTML markup
848 (including colors), graph views in several sizes; isatool usedir now
849 provides a proper interface for user theories (via -P option); actual
850 document preparation based on (PDF)LaTeX is available as well (for
851 new-style theories only); see isatool doc system for more information;
853 * native support for Proof General, both for classic Isabelle and
856 * ML function thm_deps visualizes dependencies of theorems and lemmas,
857 using the graph browser tool;
859 * Isabelle manuals now also available as PDF;
861 * theory loader rewritten from scratch (may not be fully
862 bug-compatible); old loadpath variable has been replaced by show_path,
863 add_path, del_path, reset_path functions; new operations such as
864 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
867 * improved isatool install: option -k creates KDE application icon,
868 option -p DIR installs standalone binaries;
870 * added ML_PLATFORM setting (useful for cross-platform installations);
871 more robust handling of platform specific ML images for SML/NJ;
873 * the settings environment is now statically scoped, i.e. it is never
874 created again in sub-processes invoked from isabelle, isatool, or
877 * path element specification '~~' refers to '$ISABELLE_HOME';
879 * in locales, the "assumes" and "defines" parts may be omitted if
882 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
885 * new print_mode "HTML";
887 * new flag show_tags controls display of tags of theorems (which are
888 basically just comments that may be attached by some tools);
890 * Isamode 2.6 requires patch to accomodate change of Isabelle font
891 mode and goal output format:
893 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
895 < (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
897 > (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
898 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
900 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
902 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
904 * function bind_thms stores lists of theorems (cf. bind_thm);
906 * new shorthand tactics ftac, eatac, datac, fatac;
908 * qed (and friends) now accept "" as result name; in that case the
909 theorem is not stored, but proper checks and presentation of the
912 * theorem database now also indexes constants "Trueprop", "all",
913 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
920 * There are now decision procedures for linear arithmetic over nat and
923 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
924 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
925 are treated as atomic; subformulae not involving type `nat' or `int'
926 are ignored; quantified subformulae are ignored unless they are
927 positive universal or negative existential. The tactic has to be
928 invoked by hand and can be a little bit slow. In particular, the
929 running time is exponential in the number of occurrences of `min' and
930 `max', and `-' on `nat'.
932 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
933 (negated) (in)equalities among the premises and the conclusion into
934 account (i.e. no compound formulae) and does not know about `min' and
935 `max', and `-' on `nat'. It is fast and is used automatically by the
938 NB: At the moment, these decision procedures do not cope with mixed
939 nat/int formulae where the two parts interact, such as `m < n ==>
942 * HOL/Numeral provides a generic theory of numerals (encoded
943 efficiently as bit strings); setup for types nat/int/real is in place;
944 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
945 int, existing theories and proof scripts may require a few additional
948 * integer division and remainder can now be performed on constant
951 * many properties of integer multiplication, division and remainder
954 * An interface to the Stanford Validity Checker (SVC) is available through the
955 tactic svc_tac. Propositional tautologies and theorems of linear arithmetic
956 are proved automatically. SVC must be installed separately, and its results
957 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
958 invocation of the underlying oracle). For SVC see
959 http://verify.stanford.edu/SVC
961 * IsaMakefile: the HOL-Real target now builds an actual image;
966 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
967 (in Isabelle/Isar) -- by Gertrud Bauer;
969 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
970 analysis for assembly languages with subtypes;
972 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
973 -- avoids syntactic ambiguities and treats state, transition, and
974 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
975 changed syntax and (many) tactics;
977 * HOL/inductive: Now also handles more general introduction rules such
978 as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
979 theorems are now maintained within the theory (maintained via the
982 * HOL/datatype: Now also handles arbitrarily branching datatypes
983 (using function types) such as
985 datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
987 * HOL/record: record_simproc (part of the default simpset) takes care
988 of selectors applied to updated records; record_split_tac is no longer
989 part of the default claset; update_defs may now be removed from the
990 simpset in many cases; COMPATIBILITY: old behavior achieved by
992 claset_ref () := claset() addSWrapper record_split_wrapper;
993 Delsimprocs [record_simproc]
995 * HOL/typedef: fixed type inference for representing set; type
996 arguments now have to occur explicitly on the rhs as type constraints;
998 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
999 names rather than an ML expression;
1001 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
1002 supplied later. Program schemes can be defined, such as
1003 "While B C s = (if B s then While B C (C s) else s)"
1004 where the well-founded relation can be chosen after B and C have been given.
1006 * HOL/List: the constructors of type list are now Nil and Cons;
1007 INCOMPATIBILITY: while [] and infix # syntax is still there, of
1008 course, ML tools referring to List.list.op # etc. have to be adapted;
1010 * HOL_quantifiers flag superseded by "HOL" print mode, which is
1011 disabled by default; run isabelle with option -m HOL to get back to
1012 the original Gordon/HOL-style output;
1014 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
1015 ALL x<=y. P, EX x<y. P, EX x<=y. P;
1017 * HOL basic syntax simplified (more orthogonal): all variants of
1018 All/Ex now support plain / symbolic / HOL notation; plain syntax for
1019 Eps operator is provided as well: "SOME x. P[x]";
1021 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
1023 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
1024 thus available for user theories;
1026 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
1027 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
1030 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
1031 several times and then mp;
1036 * the notation <<...>> is now available as a notation for sequences of
1039 * the simplifier is now installed
1041 * the axiom system has been generalized (thanks to Soren Heilmann)
1043 * the classical reasoner now has a default rule database
1048 * new primrec section allows primitive recursive functions to be given
1049 directly (as in HOL) over datatypes and the natural numbers;
1051 * new tactics induct_tac and exhaust_tac for induction (or case
1052 analysis) over datatypes and the natural numbers;
1054 * the datatype declaration of type T now defines the recursor T_rec;
1056 * simplification automatically does freeness reasoning for datatype
1059 * automatic type-inference, with AddTCs command to insert new
1060 type-checking rules;
1062 * datatype introduction rules are now added as Safe Introduction rules
1065 * the syntax "if P then x else y" is now available in addition to
1069 *** Internal programming interfaces ***
1071 * tuned simplifier trace output; new flag debug_simp;
1073 * structures Vartab / Termtab (instances of TableFun) offer efficient
1074 tables indexed by indexname_ord / term_ord (compatible with aconv);
1076 * AxClass.axclass_tac lost the theory argument;
1078 * tuned current_goals_markers semantics: begin / end goal avoids
1079 printing empty lines;
1081 * removed prs and prs_fn hook, which was broken because it did not
1082 include \n in its semantics, forcing writeln to add one
1083 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
1084 string -> unit if you really want to output text without newline;
1086 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
1087 plain output, interface builders may have to enable 'isabelle_font'
1088 mode to get Isabelle font glyphs as before;
1090 * refined token_translation interface; INCOMPATIBILITY: output length
1091 now of type real instead of int;
1093 * theory loader actions may be traced via new ThyInfo.add_hook
1094 interface (see src/Pure/Thy/thy_info.ML); example application: keep
1095 your own database of information attached to *whole* theories -- as
1096 opposed to intra-theory data slots offered via TheoryDataFun;
1098 * proper handling of dangling sort hypotheses (at last!);
1099 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
1100 extra sort hypotheses that can be witnessed from the type signature;
1101 the force_strip_shyps flag is gone, any remaining shyps are simply
1102 left in the theorem (with a warning issued by strip_shyps_warning);
1106 New in Isabelle98-1 (October 1998)
1107 ----------------------------------
1109 *** Overview of INCOMPATIBILITIES (see below for more details) ***
1111 * several changes of automated proof tools;
1113 * HOL: major changes to the inductive and datatype packages, including
1114 some minor incompatibilities of theory syntax;
1116 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
1119 * HOL: removed duplicate thms in Arith:
1120 less_imp_add_less should be replaced by trans_less_add1
1121 le_imp_add_le should be replaced by trans_le_add1
1123 * HOL: unary minus is now overloaded (new type constraints may be
1126 * HOL and ZF: unary minus for integers is now #- instead of #~. In
1127 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
1128 now taken as an integer constant.
1130 * Pure: ML function 'theory_of' renamed to 'theory';
1136 1. Asm_full_simp_tac is now more aggressive.
1137 1. It will sometimes reorient premises if that increases their power to
1139 2. It does no longer proceed strictly from left to right but may also
1140 rotate premises to achieve further simplification.
1141 For compatibility reasons there is now Asm_lr_simp_tac which is like the
1142 old Asm_full_simp_tac in that it does not rotate premises.
1143 2. The simplifier now knows a little bit about nat-arithmetic.
1145 * Classical reasoner: wrapper mechanism for the classical reasoner now
1146 allows for selected deletion of wrappers, by introduction of names for
1147 wrapper functionals. This implies that addbefore, addSbefore,
1148 addaltern, and addSaltern now take a pair (name, tactic) as argument,
1149 and that adding two tactics with the same name overwrites the first
1150 one (emitting a warning).
1151 type wrapper = (int -> tactic) -> (int -> tactic)
1152 setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
1153 addWrapper, addSWrapper: claset * (string * wrapper) -> claset
1154 delWrapper, delSWrapper: claset * string -> claset
1155 getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
1157 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
1158 semantics; addbefore now affects only the unsafe part of step_tac
1159 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
1160 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
1163 * Classical reasoner: setwrapper to setWrapper and compwrapper to
1164 compWrapper; added safe wrapper (and access functions for it);
1166 * HOL/split_all_tac is now much faster and fails if there is nothing
1167 to split. Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
1168 and the names of the automatically generated variables have changed.
1169 split_all_tac has moved within claset() from unsafe wrappers to safe
1170 wrappers, which means that !!-bound variables are split much more
1171 aggressively, and safe_tac and clarify_tac now split such variables.
1172 If this splitting is not appropriate, use delSWrapper "split_all_tac".
1173 Note: the same holds for record_split_tac, which does the job of
1174 split_all_tac for record fields.
1176 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
1177 permanently to the default simpset using Addsplits just like
1178 Addsimps. They can be removed via Delsplits just like
1179 Delsimps. Lower-case versions are also available.
1181 * HOL/Simplifier: The rule split_if is now part of the default
1182 simpset. This means that the simplifier will eliminate all occurrences
1183 of if-then-else in the conclusion of a goal. To prevent this, you can
1184 either remove split_if completely from the default simpset by
1185 `Delsplits [split_if]' or remove it in a specific call of the
1186 simplifier using `... delsplits [split_if]'. You can also add/delete
1187 other case splitting rules to/from the default simpset: every datatype
1188 generates suitable rules `split_t_case' and `split_t_case_asm' (where
1189 t is the name of the datatype).
1191 * Classical reasoner / Simplifier combination: new force_tac (and
1192 derivatives Force_tac, force) combines rewriting and classical
1193 reasoning (and whatever other tools) similarly to auto_tac, but is
1194 aimed to solve the given subgoal completely.
1199 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
1200 and `goalw': the theory is no longer needed as an explicit argument -
1201 the current theory context is used; assumptions are no longer returned
1202 at the ML-level unless one of them starts with ==> or !!; it is
1203 recommended to convert to these new commands using isatool fixgoal
1204 (backup your sources first!);
1206 * new top-level commands 'thm' and 'thms' for retrieving theorems from
1207 the current theory context, and 'theory' to lookup stored theories;
1209 * new theory section 'locale' for declaring constants, assumptions and
1210 definitions that have local scope;
1212 * new theory section 'nonterminals' for purely syntactic types;
1214 * new theory section 'setup' for generic ML setup functions
1215 (e.g. package initialization);
1217 * the distribution now includes Isabelle icons: see
1218 lib/logo/isabelle-{small,tiny}.xpm;
1220 * isatool install - install binaries with absolute references to
1223 * isatool logo -- create instances of the Isabelle logo (as EPS);
1225 * print mode 'emacs' reserved for Isamode;
1227 * support multiple print (ast) translations per constant name;
1229 * theorems involving oracles are now printed with a suffixed [!];
1234 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
1236 * HOL/inductive package reorganized and improved: now supports mutual
1242 oddI "n : EVEN ==> Suc n : ODD"
1243 evenI "n : ODD ==> Suc n : EVEN"
1245 new theorem list "elims" contains an elimination rule for each of the
1246 recursive sets; inductive definitions now handle disjunctive premises
1247 correctly (also ZF);
1249 INCOMPATIBILITIES: requires Inductive as an ancestor; component
1250 "mutual_induct" no longer exists - the induction rule is always
1251 contained in "induct";
1254 * HOL/datatype package re-implemented and greatly improved: now
1255 supports mutually recursive datatypes such as
1258 'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
1259 | SUM ('a aexp) ('a aexp)
1260 | DIFF ('a aexp) ('a aexp)
1263 'a bexp = LESS ('a aexp) ('a aexp)
1264 | AND ('a bexp) ('a bexp)
1265 | OR ('a bexp) ('a bexp)
1267 as well as indirectly recursive datatypes such as
1270 ('a, 'b) term = Var 'a
1271 | App 'b ((('a, 'b) term) list)
1273 The new tactic mutual_induct_tac [<var_1>, ..., <var_n>] i performs
1274 induction on mutually / indirectly recursive datatypes.
1276 Primrec equations are now stored in theory and can be accessed via
1277 <function_name>.simps.
1281 - Theories using datatypes must now have theory Datatype as an
1283 - The specific <typename>.induct_tac no longer exists - use the
1284 generic induct_tac instead.
1285 - natE has been renamed to nat.exhaust - use exhaust_tac
1286 instead of res_inst_tac ... natE. Note that the variable
1287 names in nat.exhaust differ from the names in natE, this
1288 may cause some "fragile" proofs to fail.
1289 - The theorems split_<typename>_case and split_<typename>_case_asm
1290 have been renamed to <typename>.split and <typename>.split_asm.
1291 - Since default sorts of type variables are now handled correctly,
1292 some datatype definitions may have to be annotated with explicit
1294 - Primrec definitions no longer require function name and type
1295 of recursive argument.
1297 Consider using isatool fixdatatype to adapt your theories and proof
1298 scripts to the new package (backup your sources first!).
1301 * HOL/record package: considerably improved implementation; now
1302 includes concrete syntax for record types, terms, updates; theorems
1303 for surjective pairing and splitting !!-bound record variables; proof
1304 support is as follows:
1306 1) standard conversions (selectors or updates applied to record
1307 constructor terms) are part of the standard simpset;
1309 2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
1310 made part of standard simpset and claset via addIffs;
1312 3) a tactic for record field splitting (record_split_tac) is part of
1313 the standard claset (addSWrapper);
1315 To get a better idea about these rules you may retrieve them via
1316 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
1317 the name of your record type.
1319 The split tactic 3) conceptually simplifies by the following rule:
1321 "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
1323 Thus any record variable that is bound by meta-all will automatically
1324 blow up into some record constructor term, consequently the
1325 simplifications of 1), 2) apply. Thus force_tac, auto_tac etc. shall
1326 solve record problems automatically.
1329 * reorganized the main HOL image: HOL/Integ and String loaded by
1330 default; theory Main includes everything;
1332 * automatic simplification of integer sums and comparisons, using cancellation;
1334 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
1336 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
1338 * many new identities for unions, intersections, set difference, etc.;
1340 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
1341 called split_if, split_split, split_sum_case and split_nat_case (to go
1342 with add/delsplits);
1344 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
1345 (?x::unit) = (); this is made part of the default simpset, which COULD
1346 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
1347 'Delsimprocs [unit_eq_proc];' as last resort); also note that
1348 unit_abs_eta_conv is added in order to counter the effect of
1349 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
1352 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
1355 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
1356 It and 'sym RS equals0D' are now in the default claset, giving automatic
1357 disjointness reasoning but breaking a few old proofs.
1359 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
1360 to 'converse' from 'inverse' (for compatibility with ZF and some
1363 * HOL/recdef can now declare non-recursive functions, with {} supplied as
1364 the well-founded relation;
1366 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
1367 Compl A. The "Compl" syntax remains available as input syntax for this
1370 * HOL/Update: new theory of function updates:
1371 f(a:=b) == %x. if x=a then b else f x
1372 may also be iterated as in f(a:=b,c:=d,...);
1374 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
1377 - new function list_update written xs[i:=v] that updates the i-th
1378 list position. May also be iterated as in xs[i:=a,j:=b,...].
1379 - new function `upt' written [i..j(] which generates the list
1380 [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
1381 bound write [i..j], which is a shorthand for [i..j+1(].
1382 - new lexicographic orderings and corresponding wellfoundedness theorems.
1385 - removed 'pred' (predecessor) function;
1386 - generalized some theorems about n-1;
1387 - many new laws about "div" and "mod";
1388 - new laws about greatest common divisors (see theory ex/Primes);
1390 * HOL/Relation: renamed the relational operator r^-1 "converse"
1391 instead of "inverse";
1393 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
1394 of the multiset ordering;
1396 * directory HOL/Real: a construction of the reals using Dedekind cuts
1397 (not included by default);
1399 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
1401 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
1402 programs, i.e. different program variables may have different types.
1404 * calling (stac rew i) now fails if "rew" has no effect on the goal
1405 [previously, this check worked only if the rewrite rule was unconditional]
1406 Now rew can involve either definitions or equalities (either == or =).
1411 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
1412 only the theorems proved on ZF.ML;
1414 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
1415 It and 'sym RS equals0D' are now in the default claset, giving automatic
1416 disjointness reasoning but breaking a few old proofs.
1418 * ZF/Update: new theory of function updates
1419 with default rewrite rule f(x:=y) ` z = if(z=x, y, f`z)
1420 may also be iterated as in f(a:=b,c:=d,...);
1422 * in let x=t in u(x), neither t nor u(x) has to be an FOL term.
1424 * calling (stac rew i) now fails if "rew" has no effect on the goal
1425 [previously, this check worked only if the rewrite rule was unconditional]
1426 Now rew can involve either definitions or equalities (either == or =).
1428 * case_tac provided for compatibility with HOL
1429 (like the old excluded_middle_tac, but with subgoals swapped)
1432 *** Internal programming interfaces ***
1434 * Pure: several new basic modules made available for general use, see
1435 also src/Pure/README;
1437 * improved the theory data mechanism to support encapsulation (data
1438 kind name replaced by private Object.kind, acting as authorization
1439 key); new type-safe user interface via functor TheoryDataFun; generic
1440 print_data function becomes basically useless;
1442 * removed global_names compatibility flag -- all theory declarations
1443 are qualified by default;
1445 * module Pure/Syntax now offers quote / antiquote translation
1446 functions (useful for Hoare logic etc. with implicit dependencies);
1447 see HOL/ex/Antiquote for an example use;
1449 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
1452 * new tactical CHANGED_GOAL for checking that a tactic modifies a
1455 * Display.print_goals function moved to Locale.print_goals;
1457 * standard print function for goals supports current_goals_markers
1458 variable for marking begin of proof, end of proof, start of goal; the
1459 default is ("", "", ""); setting current_goals_markers := ("<proof>",
1460 "</proof>", "<goal>") causes SGML like tagged proof state printing,
1465 New in Isabelle98 (January 1998)
1466 --------------------------------
1468 *** Overview of INCOMPATIBILITIES (see below for more details) ***
1470 * changed lexical syntax of terms / types: dots made part of long
1471 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
1473 * simpset (and claset) reference variable replaced by functions
1474 simpset / simpset_ref;
1476 * no longer supports theory aliases (via merge) and non-trivial
1477 implicit merge of thms' signatures;
1479 * most internal names of constants changed due to qualified names;
1481 * changed Pure/Sequence interface (see Pure/seq.ML);
1484 *** General Changes ***
1486 * hierachically structured name spaces (for consts, types, axms, thms
1487 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
1488 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
1489 isatool fixdots ensures space after dots (e.g. "%x. x"); set
1490 long_names for fully qualified output names; NOTE: ML programs
1491 (special tactics, packages etc.) referring to internal names may have
1492 to be adapted to cope with fully qualified names; in case of severe
1493 backward campatibility problems try setting 'global_names' at compile
1494 time to have enrything declared within a flat name space; one may also
1495 fine tune name declarations in theories via the 'global' and 'local'
1498 * reimplemented the implicit simpset and claset using the new anytype
1499 data filed in signatures; references simpset:simpset ref etc. are
1500 replaced by functions simpset:unit->simpset and
1501 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
1502 to patch your ML files accordingly;
1504 * HTML output now includes theory graph data for display with Java
1505 applet or isatool browser; data generated automatically via isatool
1506 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
1508 * defs may now be conditional; improved rewrite_goals_tac to handle
1509 conditional equations;
1511 * defs now admits additional type arguments, using TYPE('a) syntax;
1513 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
1514 creates a new theory node; implicit merge of thms' signatures is
1515 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
1516 transfer:theory->thm->thm in (rare) cases;
1518 * improved handling of draft signatures / theories; draft thms (and
1519 ctyps, cterms) are automatically promoted to real ones;
1521 * slightly changed interfaces for oracles: admit many per theory, named
1522 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
1524 * print_goals: optional output of const types (set show_consts and
1527 * improved output of warnings (###) and errors (***);
1529 * subgoal_tac displays a warning if the new subgoal has type variables;
1531 * removed old README and Makefiles;
1533 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
1535 * removed obsolete init_pps and init_database;
1537 * deleted the obsolete tactical STATE, which was declared by
1538 fun STATE tacfun st = tacfun st st;
1540 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
1541 (which abbreviates $HOME);
1543 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
1544 use isatool fixseq to adapt your ML programs (this works for fully
1545 qualified references to the Sequence structure only!);
1547 * use_thy no longer requires writable current directory; it always
1548 reloads .ML *and* .thy file, if either one is out of date;
1551 *** Classical Reasoner ***
1553 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
1554 tactics that use classical reasoning to simplify a subgoal without
1555 splitting it into several subgoals;
1557 * Safe_tac: like safe_tac but uses the default claset;
1562 * added simplification meta rules:
1563 (asm_)(full_)simplify: simpset -> thm -> thm;
1565 * simplifier.ML no longer part of Pure -- has to be loaded by object
1568 * added prems argument to simplification procedures;
1570 * HOL, FOL, ZF: added infix function `addsplits':
1571 instead of `<simpset> setloop (split_tac <thms>)'
1572 you can simply write `<simpset> addsplits <thms>'
1577 * TYPE('a) syntax for type reflection terms;
1579 * no longer handles consts with name "" -- declare as 'syntax' instead;
1581 * pretty printer: changed order of mixfix annotation preference (again!);
1583 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
1588 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
1589 with `addloop' of the simplifier to faciliate case splitting in premises.
1591 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
1593 * HOL/Auth: new protocol proofs including some for the Internet
1596 * HOL/Map: new theory of `maps' a la VDM;
1598 * HOL/simplifier: simplification procedures nat_cancel_sums for
1599 cancelling out common nat summands from =, <, <= (in)equalities, or
1600 differences; simplification procedures nat_cancel_factor for
1601 cancelling common factor from =, <, <= (in)equalities over natural
1602 sums; nat_cancel contains both kinds of procedures, it is installed by
1603 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
1605 * HOL/simplifier: terms of the form
1606 `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)' (or t=x)
1608 `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
1609 and those of the form
1610 `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)' (or t=x)
1612 `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
1615 Each datatype `t' now comes with a theorem `split_t_case' of the form
1617 P(t_case f1 ... fn x) =
1618 ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
1620 (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
1623 and a theorem `split_t_case_asm' of the form
1625 P(t_case f1 ... fn x) =
1626 ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
1628 (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
1630 which can be added to a simpset via `addsplits'. The existing theorems
1631 expand_list_case and expand_option_case have been renamed to
1632 split_list_case and split_option_case.
1635 - `pred n' is automatically converted to `n-1'.
1636 Users are strongly encouraged not to use `pred' any longer,
1637 because it will disappear altogether at some point.
1638 - Users are strongly encouraged to write "0 < n" rather than
1639 "n ~= 0". Theorems and proof tools have been modified towards this
1643 the function "set_of_list" has been renamed "set" (and its theorems too);
1644 the function "nth" now takes its arguments in the reverse order and
1645 has acquired the infix notation "!" as in "xs!n".
1647 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
1649 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
1650 specialist theorems (like UN1_I) are gone. Similarly for (INT x.B x);
1652 * HOL/record: extensible records with schematic structural subtyping
1653 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
1654 still lacks various theorems and concrete record syntax;
1659 * removed "axioms" and "generated by" sections;
1661 * replaced "ops" section by extended "consts" section, which is capable of
1662 handling the continuous function space "->" directly;
1665 . proves theorems immediately and stores them in the theory,
1666 . creates hierachical name space,
1667 . now uses normal mixfix annotations (instead of cinfix...),
1668 . minor changes to some names and values (for consistency),
1669 . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
1670 . separator between mutual domain defs: changed "," to "and",
1671 . improved handling of sort constraints; now they have to
1672 appear on the left-hand side of the equations only;
1674 * fixed LAM <x,y,zs>.b syntax;
1676 * added extended adm_tac to simplifier in HOLCF -- can now discharge
1677 adm (%x. P (t x)), where P is chainfinite and t continuous;
1682 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
1683 with `addloop' of the simplifier to faciliate case splitting in premises.
1685 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
1686 in HOL, they strip ALL and --> from proved theorems;
1690 New in Isabelle94-8 (May 1997)
1691 ------------------------------
1693 *** General Changes ***
1695 * new utilities to build / run / maintain Isabelle etc. (in parts
1696 still somewhat experimental); old Makefiles etc. still functional;
1698 * new 'Isabelle System Manual';
1700 * INSTALL text, together with ./configure and ./build scripts;
1702 * reimplemented type inference for greater efficiency, better error
1703 messages and clean internal interface;
1705 * prlim command for dealing with lots of subgoals (an easier way of
1706 setting goals_limit);
1711 * supports alternative (named) syntax tables (parser and pretty
1712 printer); internal interface is provided by add_modesyntax(_i);
1714 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
1715 be used in conjunction with the Isabelle symbol font; uses the
1716 "symbols" syntax table;
1718 * added token_translation interface (may translate name tokens in
1719 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
1720 the current print_mode); IMPORTANT: user print translation functions
1721 are responsible for marking newly introduced bounds
1722 (Syntax.mark_boundT);
1724 * token translations for modes "xterm" and "xterm_color" that display
1725 names in bold, underline etc. or colors (which requires a color
1728 * infixes may now be declared with names independent of their syntax;
1730 * added typed_print_translation (like print_translation, but may
1731 access type of constant);
1734 *** Classical Reasoner ***
1736 Blast_tac: a new tactic! It is often more powerful than fast_tac, but has
1737 some limitations. Blast_tac...
1738 + ignores addss, addbefore, addafter; this restriction is intrinsic
1739 + ignores elimination rules that don't have the correct format
1740 (the conclusion MUST be a formula variable)
1741 + ignores types, which can make HOL proofs fail
1742 + rules must not require higher-order unification, e.g. apply_type in ZF
1743 [message "Function Var's argument not a bound variable" relates to this]
1744 + its proof strategy is more general but can actually be slower
1746 * substitution with equality assumptions no longer permutes other
1749 * minor changes in semantics of addafter (now called addaltern); renamed
1750 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
1751 (and access functions for it);
1753 * improved combination of classical reasoner and simplifier:
1754 + functions for handling clasimpsets
1755 + improvement of addss: now the simplifier is called _after_ the
1757 + safe variant of addss called addSss: uses safe simplifications
1758 _during_ the safe steps. It is more complete as it allows multiple
1759 instantiations of unknowns (e.g. with slow_tac).
1763 * added interface for simplification procedures (functions that
1764 produce *proven* rewrite rules on the fly, depending on current
1767 * ordering on terms as parameter (used for ordered rewriting);
1769 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
1771 * the solver is now split into a safe and an unsafe part.
1772 This should be invisible for the normal user, except that the
1773 functions setsolver and addsolver have been renamed to setSolver and
1774 addSolver; added safe_asm_full_simp_tac;
1779 * a generic induction tactic `induct_tac' which works for all datatypes and
1780 also for type `nat';
1782 * a generic case distinction tactic `exhaust_tac' which works for all
1783 datatypes and also for type `nat';
1785 * each datatype comes with a function `size';
1787 * patterns in case expressions allow tuple patterns as arguments to
1788 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
1790 * primrec now also works with type nat;
1792 * recdef: a new declaration form, allows general recursive functions to be
1793 defined in theory files. See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
1795 * the constant for negation has been renamed from "not" to "Not" to
1796 harmonize with FOL, ZF, LK, etc.;
1798 * HOL/ex/LFilter theory of a corecursive "filter" functional for
1801 * HOL/Modelcheck demonstrates invocation of model checker oracle;
1803 * HOL/ex/Ring.thy declares cring_simp, which solves equational
1804 problems in commutative rings, using axiomatic type classes for + and *;
1806 * more examples in HOL/MiniML and HOL/Auth;
1808 * more default rewrite rules for quantifiers, union/intersection;
1810 * a new constant `arbitrary == @x.False';
1812 * HOLCF/IOA replaces old HOL/IOA;
1814 * HOLCF changes: derived all rules and arities
1815 + axiomatic type classes instead of classes
1816 + typedef instead of faking type definitions
1817 + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
1818 + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
1819 + eliminated the types void, one, tr
1820 + use unit lift and bool lift (with translations) instead of one and tr
1821 + eliminated blift from Lift3.thy (use Def instead of blift)
1822 all eliminated rules are derived as theorems --> no visible changes ;
1827 * ZF now has Fast_tac, Simp_tac and Auto_tac. Union_iff is a now a default
1828 rewrite rule; this may affect some proofs. eq_cs is gone but can be put back
1829 as ZF_cs addSIs [equalityI];
1833 New in Isabelle94-7 (November 96)
1834 ---------------------------------
1836 * allowing negative levels (as offsets) in prlev and choplev;
1838 * super-linear speedup for large simplifications;
1840 * FOL, ZF and HOL now use miniscoping: rewriting pushes
1841 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
1842 FAIL); can suppress it using the command Delsimps (ex_simps @
1843 all_simps); De Morgan laws are also now included, by default;
1845 * improved printing of ==> : ~:
1847 * new object-logic "Sequents" adds linear logic, while replacing LK
1848 and Modal (thanks to Sara Kalvala);
1850 * HOL/Auth: correctness proofs for authentication protocols;
1852 * HOL: new auto_tac combines rewriting and classical reasoning (many
1853 examples on HOL/Auth);
1855 * HOL: new command AddIffs for declaring theorems of the form P=Q to
1856 the rewriter and classical reasoner simultaneously;
1858 * function uresult no longer returns theorems in "standard" format;
1859 regain previous version by: val uresult = standard o uresult;
1866 * oracles -- these establish an interface between Isabelle and trusted
1867 external reasoners, which may deliver results as theorems;
1869 * proof objects (in particular record all uses of oracles);
1871 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
1873 * "constdefs" section in theory files;
1875 * "primrec" section (HOL) no longer requires names;
1877 * internal type "tactic" now simply "thm -> thm Sequence.seq";
1884 * reduced space requirements;
1886 * automatic HTML generation from theories;
1888 * theory files no longer require "..." (quotes) around most types;
1890 * new examples, including two proofs of the Church-Rosser theorem;
1892 * non-curried (1994) version of HOL is no longer distributed;
1899 * greatly reduced space requirements;
1901 * theory files (.thy) no longer require \...\ escapes at line breaks;
1903 * searchable theorem database (see the section "Retrieving theorems" on
1904 page 8 of the Reference Manual);
1906 * new examples, including Grabczewski's monumental case study of the
1909 * The previous version of HOL renamed to Old_HOL;
1911 * The new version of HOL (previously called CHOL) uses a curried syntax
1912 for functions. Application looks like f a b instead of f(a,b);
1914 * Mutually recursive inductive definitions finally work in HOL;
1916 * In ZF, pattern-matching on tuples is now available in all abstractions and
1917 translates to the operator "split";
1924 * new infix operator, addss, allowing the classical reasoner to
1925 perform simplification at each step of its search. Example:
1926 fast_tac (cs addss ss)
1928 * a new logic, CHOL, the same as HOL, but with a curried syntax
1929 for functions. Application looks like f a b instead of f(a,b). Also pairs
1930 look like (a,b) instead of <a,b>;
1932 * PLEASE NOTE: CHOL will eventually replace HOL!
1934 * In CHOL, pattern-matching on tuples is now available in all abstractions.
1935 It translates to the operator "split". A new theory of integers is available;
1937 * In ZF, integer numerals now denote two's-complement binary integers.
1938 Arithmetic operations can be performed by rewriting. See ZF/ex/Bin.ML;
1940 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
1941 of the Axiom of Choice;
1948 * Significantly faster resolution;
1950 * the different sections in a .thy file can now be mixed and repeated
1953 * Database of theorems for FOL, HOL and ZF. New
1954 commands including qed, qed_goal and bind_thm store theorems in the database.
1956 * Simple database queries: return a named theorem (get_thm) or all theorems of
1957 a given theory (thms_of), or find out what theory a theorem was proved in
1960 * Bugs fixed in the inductive definition and datatype packages;
1962 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
1963 and HOL_dup_cs obsolete;
1965 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
1968 * Simpler definition of function space in ZF;
1970 * new results about cardinal and ordinal arithmetic in ZF;
1972 * 'subtype' facility in HOL for introducing new types as subsets of existing