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:
37 - 'case' command admits impromptu naming of parameters (such as
40 - 'induct' method divinates rule instantiation from the inductive
41 claim; no longer requires excessive ?P bindings for proper
42 instantiation of cases;
44 - 'induct' method properly enumerates all possibilities of set/type
45 rules; as a consequence facts may be also passed through *type* rules
48 - 'induct' method now derives symbolic cases from the *rulified*
49 rule (before it used to rulify cases stemming from the internal
50 atomized version); this means that the context of a non-atomic
51 statement becomes is included in the hypothesis, avoiding the slightly
52 cumbersome show "PROP ?case" form;
54 - removed obsolete "(simplified)" and "(stripped)" options of methods;
55 - added 'print_induct_rules' (covered by help item in Proof General > 3.3);
56 - moved induct/cases attributes to Pure, methods to Provers;
57 - generic method setup instantiated for FOL and HOL;
59 * Pure: renamed "antecedent" case to "rule_context";
61 * Pure: added 'corollary' command;
63 * Pure: fixed 'token_translation' command;
65 * Pure: removed obsolete 'exported' attribute;
67 * Pure: dummy pattern "_" in is/let is now automatically lifted over
68 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
69 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
71 * Pure: method 'atomize' presents local goal premises as object-level
72 statements (atomic meta-level propositions); setup controlled via
73 rewrite rules declarations of 'atomize' attribute; example
74 application: 'induct' method with proper rule statements in improper
77 * Provers: 'simplified' attribute may refer to explicit rules instead
78 of full simplifier context; 'iff' attribute handles conditional rules;
80 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
82 * HOL: 'recdef' now fails on unfinished automated proofs, use
83 "(permissive)" option to recover old behavior;
85 * HOL: 'inductive' no longer features separate (collective) attributes
86 for 'intros' (was found too confusing);
92 * HOL: moved over to sane numeral syntax; the new policy is as
95 - 0 and 1 are polymorphic constants, which are defined on any
96 numeric type (nat, int, real etc.);
98 - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
99 binary representation internally;
101 - type nat has special constructor Suc, and generally prefers Suc 0
102 over 1::nat and Suc (Suc 0) over 2::nat;
104 This change may cause significant INCOMPATIBILITIES; here are some
105 hints on converting existing sources:
107 - due to the new "num" token, "-0" and "-1" etc. are now atomic
108 entities, so expressions involving "-" (unary or binary minus) need
109 to be spaced properly;
111 - existing occurrences of "1" may need to be constraint "1::nat" or
112 even replaced by Suc 0; similar for old "2";
114 - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
116 - remove all special provisions on numerals in proofs;
119 - removed old "make" and "make_scheme" operations -- INCOMPATIBILITY;
120 - removed "more" class (simply use "term") -- INCOMPATIBILITY;
121 - provides cases/induct rules for use with corresponding Isar methods;
122 - new derived operations "make" (for adding fields of current
123 record), "extend" to promote fixed record to record scheme, and
124 "truncate" for the reverse; cf. theorems "derived_defs", which are
125 *not* declared as simp by default;
126 - internal definitions directly based on a light-weight abstract
127 theory of product types over typedef rather than datatype;
129 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
131 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
132 (beware of argument permutation!);
134 * HOL: linorder_less_split superseded by linorder_cases;
136 * HOL: added "The" definite description operator; move Hilbert's "Eps"
137 to peripheral theory "Hilbert_Choice";
139 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
140 in this (rare) case use:
142 delSWrapper "split_all_tac"
143 addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
145 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
148 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
149 Isabelle's type classes, ^ on functions and relations has too general
150 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
151 necessary to attach explicit type constraints;
153 * HOL: syntax translations now work properly with numerals and records
156 * HOL/GroupTheory: group theory examples including Sylow's theorem, by
159 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
160 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
161 renamed "Product_Type.unit";
166 * ZF: the integer library now covers quotients and remainders, with
167 many laws relating division to addition, multiplication, etc.;
172 * kernel: meta-level proof terms (by Stefan Berghofer), see also ref
175 * Pure/axclass: removed obsolete ML interface goal_subclass/goal_arity;
177 * classical: renamed addaltern to addafter, addSaltern to addSafter;
179 * clasimp: ``iff'' declarations now handle conditional rules as well;
181 * syntax: new token syntax "num" for plain numerals (without "#" of
182 "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now separate
183 tokens, so expressions involving minus need to be spaced properly;
185 * syntax: support non-oriented infixes;
187 * syntax: print modes "type_brackets" and "no_type_brackets" control
188 output of nested => (types); the default behavior is "type_brackets";
190 * syntax: builtin parse translation for "_constify" turns valued
191 tokens into AST constants;
193 * system: support Poly/ML 4.1.1 (now able to manage large heaps);
195 * system: Proof General keywords specification is now part of the
196 Isabelle distribution (see etc/isar-keywords.el);
198 * system: smart selection of Isabelle process versus Isabelle
199 interface, accommodates case-insensitive file systems (e.g. HFS+); may
200 run both "isabelle" and "Isabelle" even if file names are badly
201 damaged (executable inspects the case of the first letter of its own
202 name); added separate "isabelle-process" and "isabelle-interface";
206 New in Isabelle99-2 (February 2001)
207 -----------------------------------
209 *** Overview of INCOMPATIBILITIES ***
211 * HOL: please note that theories in the Library and elsewhere often use the
212 new-style (Isar) format; to refer to their theorems in an ML script you must
213 bind them to ML identifers by e.g. val thm_name = thm "thm_name";
215 * HOL: inductive package no longer splits induction rule aggressively,
216 but only as far as specified by the introductions given; the old
217 format may be recovered via ML function complete_split_rule or attribute
218 'split_rule (complete)';
220 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
221 gfp_Tarski to gfp_unfold;
223 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
225 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
226 relation); infix "^^" has been renamed "``"; infix "``" has been
227 renamed "`"; "univalent" has been renamed "single_valued";
229 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
232 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
234 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
236 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
237 consequence, it is no longer monotonic wrt. the local goal context
238 (which is now passed through the inductive cases);
240 * Document preparation: renamed standard symbols \<ll> to \<lless> and
241 \<gg> to \<ggreater>;
244 *** Document preparation ***
246 * \isabellestyle{NAME} selects version of Isabelle output (currently
247 available: are "it" for near math-mode best-style output, "sl" for
248 slanted text style, and "tt" for plain type-writer; if no
249 \isabellestyle command is given, output is according to slanted
252 * support sub/super scripts (for single symbols only), input syntax is
253 like this: "A\<^sup>*" or "A\<^sup>\<star>";
255 * some more standard symbols; see Appendix A of the system manual for
256 the complete list of symbols defined in isabellesym.sty;
258 * improved isabelle style files; more abstract symbol implementation
259 (should now use \isamath{...} and \isatext{...} in custom symbol
262 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
263 state; Note that presentation of goal states does not conform to
264 actual human-readable proof documents. Please do not include goal
265 states into document output unless you really know what you are doing!
267 * proper indentation of antiquoted output with proportional LaTeX
270 * no_document ML operator temporarily disables LaTeX document
273 * isatool unsymbolize tunes sources for plain ASCII communication;
278 * Pure: Isar now suffers initial goal statements to contain unbound
279 schematic variables (this does not conform to actual readable proof
280 documents, due to unpredictable outcome and non-compositional proof
281 checking); users who know what they are doing may use schematic goals
282 for Prolog-style synthesis of proven results;
284 * Pure: assumption method (an implicit finishing) now handles actual
287 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
288 initial goal, declare "that" only as Pure intro (only for single
289 steps); the "that" rule assumption may now be involved in implicit
290 finishing, thus ".." becomes a feasible for trivial obtains;
292 * Pure: default proof step now includes 'intro_classes'; thus trivial
293 instance proofs may be performed by "..";
295 * Pure: ?thesis / ?this / "..." now work for pure meta-level
298 * Pure: more robust selection of calculational rules;
300 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
301 rule (as well as the assumption rule);
303 * Pure: 'thm_deps' command visualizes dependencies of theorems and
304 lemmas, using the graph browser tool;
306 * Pure: predict failure of "show" in interactive mode;
308 * Pure: 'thms_containing' now takes actual terms as arguments;
310 * HOL: improved method 'induct' --- now handles non-atomic goals
311 (potential INCOMPATIBILITY); tuned error handling;
313 * HOL: cases and induct rules now provide explicit hints about the
314 number of facts to be consumed (0 for "type" and 1 for "set" rules);
315 any remaining facts are inserted into the goal verbatim;
317 * HOL: local contexts (aka cases) may now contain term bindings as
318 well; the 'cases' and 'induct' methods new provide a ?case binding for
319 the result to be shown in each case;
321 * HOL: added 'recdef_tc' command;
323 * isatool convert assists in eliminating legacy ML scripts;
328 * HOL/Library: a collection of generic theories to be used together
329 with main HOL; the theory loader path already includes this directory
330 by default; the following existing theories have been moved here:
331 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
332 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
334 * HOL/Unix: "Some aspects of Unix file-system security", a typical
335 modelling and verification task performed in Isabelle/HOL +
336 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
338 * HOL/Algebra: special summation operator SUM no longer exists, it has
339 been replaced by setsum; infix 'assoc' now has priority 50 (like
340 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
341 'domain', this makes the theory consistent with mathematical
344 * HOL basics: added overloaded operations "inverse" and "divide"
345 (infix "/"), syntax for generic "abs" operation, generic summation
348 * HOL/typedef: simplified package, provide more useful rules (see also
351 * HOL/datatype: induction rule for arbitrarily branching datatypes is
352 now expressed as a proper nested rule (old-style tactic scripts may
353 require atomize_strip_tac to cope with non-atomic premises);
355 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
356 to "split_conv" (old name still available for compatibility);
358 * HOL: improved concrete syntax for strings (e.g. allows translation
359 rules with string literals);
361 * HOL-Hyperreal: a new target, extending HOL-Real with the hyperreals
362 and Fleuriot's mechanization of analysis;
364 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
369 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
370 "lam" is displayed as TWO lambda-symbols
372 * CTT: theory Main now available, containing everything (that is, Bool
378 * Pure: the Simplifier has been implemented properly as a derived rule
379 outside of the actual kernel (at last!); the overall performance
380 penalty in practical applications is about 50%, while reliability of
381 the Isabelle inference kernel has been greatly improved;
383 * print modes "brackets" and "no_brackets" control output of nested =>
384 (types) and ==> (props); the default behaviour is "brackets";
386 * Provers: fast_tac (and friends) now handle actual object-logic rules
387 as assumptions as well;
389 * system: support Poly/ML 4.0;
391 * system: isatool install handles KDE version 1 or 2;
395 New in Isabelle99-1 (October 2000)
396 ----------------------------------
398 *** Overview of INCOMPATIBILITIES ***
400 * HOL: simplification of natural numbers is much changed; to partly
401 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
402 issue the following ML commands:
404 Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
405 Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
407 * HOL: simplification no longer dives into case-expressions; this is
408 controlled by "t.weak_case_cong" for each datatype t;
410 * HOL: nat_less_induct renamed to less_induct;
412 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
413 fixsome to patch .thy and .ML sources automatically;
415 select_equality -> some_equality
416 select_eq_Ex -> some_eq_ex
417 selectI2EX -> someI2_ex
420 select1_equality -> some1_equality
421 Eps_sym_eq -> some_sym_eq_trivial
422 Eps_eq -> some_eq_trivial
424 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
426 * HOL: removed obsolete theorem binding expand_if (refer to split_if
429 * HOL: the recursion equations generated by 'recdef' are now called
430 f.simps instead of f.rules;
432 * HOL: qed_spec_mp now also handles bounded ALL as well;
434 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
437 * HOL: the constant for "f``x" is now "image" rather than "op ``";
439 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
441 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
442 product is now "<*>" instead of "Times"; the lexicographic product is
443 now "<*lex*>" instead of "**";
445 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
446 of main HOL, but was unused); better use HOL's datatype package;
448 * HOL: removed "symbols" syntax for constant "override" of theory Map;
449 the old syntax may be recovered as follows:
452 override :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
453 (infixl "\\<oplus>" 100)
455 * HOL/Real: "rabs" replaced by overloaded "abs" function;
457 * HOL/ML: even fewer consts are declared as global (see theories Ord,
458 Lfp, Gfp, WF); this only affects ML packages that refer to const names
461 * HOL and ZF: syntax for quotienting wrt an equivalence relation
462 changed from A/r to A//r;
464 * ZF: new treatment of arithmetic (nat & int) may break some old
467 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
468 rulify -> rule_format, elimify -> elim_format, ...);
470 * Isar/Provers: intro/elim/dest attributes changed; renamed
471 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
472 should have to change intro!! to intro? only); replaced "delrule" by
475 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
477 * Provers: strengthened force_tac by using new first_best_tac;
479 * LaTeX document preparation: several changes of isabelle.sty (see
483 *** Document preparation ***
485 * formal comments (text blocks etc.) in new-style theories may now
486 contain antiquotations of thm/prop/term/typ/text to be presented
487 according to latex print mode; concrete syntax is like this:
488 @{term[show_types] "f(x) = a + x"};
490 * isatool mkdir provides easy setup of Isabelle session directories,
491 including proper document sources;
493 * generated LaTeX sources are now deleted after successful run
494 (isatool document -c); may retain a copy somewhere else via -D option
497 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
498 style files, achieving self-contained LaTeX sources and simplifying
501 * old-style theories now produce (crude) LaTeX output as well;
503 * browser info session directories are now self-contained (may be put
504 on WWW server seperately); improved graphs of nested sessions; removed
505 graph for 'all sessions';
507 * several improvements in isabelle style files; \isabellestyle{it}
508 produces fake math mode output; \isamarkupheader is now \section by
509 default; see lib/texinputs/isabelle.sty etc.;
514 * Isar/Pure: local results and corresponding term bindings are now
515 subject to Hindley-Milner polymorphism (similar to ML); this
516 accommodates incremental type-inference very nicely;
518 * Isar/Pure: new derived language element 'obtain' supports
519 generalized existence reasoning;
521 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
522 support accumulation of results, without applying any rules yet;
523 useful to collect intermediate results without explicit name
524 references, and for use with transitivity rules with more than 2
527 * Isar/Pure: scalable support for case-analysis type proofs: new
528 'case' language element refers to local contexts symbolically, as
529 produced by certain proof methods; internally, case names are attached
530 to theorems as "tags";
532 * Isar/Pure: theory command 'hide' removes declarations from
533 class/type/const name spaces;
535 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
536 indicate potential overloading;
538 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
540 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
541 "{a,b,c}" instead of {a,b,c};
543 * Isar/Pure now provides its own version of intro/elim/dest
544 attributes; useful for building new logics, but beware of confusion
545 with the version in Provers/classical;
547 * Isar/Pure: the local context of (non-atomic) goals is provided via
548 case name 'antecedent';
550 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
551 to the current context is now done automatically);
553 * Isar/Pure: theory command 'method_setup' provides a simple interface
554 for definining proof methods in ML;
556 * Isar/Provers: intro/elim/dest attributes changed; renamed
557 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
558 most cases, one should have to change intro!! to intro? only);
559 replaced "delrule" by "rule del";
561 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
562 'symmetric' attribute (the latter supercedes [RS sym]);
564 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
565 method modifier); 'simp' method: 'only:' modifier removes loopers as
566 well (including splits);
568 * Isar/Provers: Simplifier and Classical methods now support all kind
569 of modifiers used in the past, including 'cong', 'iff', etc.
571 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
572 of Simplifier and Classical reasoner);
574 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
575 now support named cases; major packages (inductive, datatype, primrec,
576 recdef) support case names and properly name parameters;
578 * Isar/HOL: new transitivity rules for substitution in inequalities --
579 monotonicity conditions are extracted to be proven at end of
582 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
585 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
586 split_if split_if_asm; datatype package provides theorems foo.splits =
587 foo.split foo.split_asm for each datatype;
589 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
590 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
591 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
592 use "(cases (simplified))" method in proper proof texts);
594 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
596 * Isar: names of theorems etc. may be natural numbers as well;
598 * Isar: 'pr' command: optional arguments for goals_limit and
599 ProofContext.prems_limit; no longer prints theory contexts, but only
602 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
603 additional print modes to be specified; e.g. "pr(latex)" will print
604 proof state according to the Isabelle LaTeX style;
606 * Isar: improved support for emulating tactic scripts, including proof
607 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
608 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
611 * Isar: simplified (more robust) goal selection of proof methods: 1st
612 goal, all goals, or explicit goal specifier (tactic emulation); thus
613 'proof method scripts' have to be in depth-first order;
615 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
617 * Isar: removed 'help' command, which hasn't been too helpful anyway;
618 should instead use individual commands for printing items
619 (print_commands, print_methods etc.);
621 * Isar: added 'nothing' --- the empty list of theorems;
626 * HOL/MicroJava: formalization of a fragment of Java, together with a
627 corresponding virtual machine and a specification of its bytecode
628 verifier and a lightweight bytecode verifier, including proofs of
629 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
630 Cornelia Pusch (see also the homepage of project Bali at
631 http://isabelle.in.tum.de/Bali/);
633 * HOL/Algebra: new theory of rings and univariate polynomials, by
636 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
637 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
640 * HOL/Lattice: fundamental concepts of lattice theory and order
641 structures, including duals, properties of bounds versus algebraic
642 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
643 Theorem for complete lattices etc.; may also serve as a demonstration
644 for abstract algebraic reasoning using axiomatic type classes, and
645 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
647 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
650 * HOL/IMPP: extension of IMP with local variables and mutually
651 recursive procedures, by David von Oheimb;
653 * HOL/Lambda: converted into new-style theory and document;
655 * HOL/ex/Multiquote: example of multiple nested quotations and
656 anti-quotations -- basically a generalized version of de-Bruijn
657 representation; very useful in avoiding lifting of operations;
659 * HOL/record: added general record equality rule to simpset; fixed
660 select-update simplification procedure to handle extended records as
661 well; admit "r" as field name;
663 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
664 other numeric types and also as the identity of groups, rings, etc.;
666 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
667 Types nat and int belong to this axclass;
669 * HOL: greatly improved simplification involving numerals of type nat, int, real:
670 (i + #8 + j) = Suc k simplifies to #7 + (i + j) = k
671 i*j + k + j*#3*i simplifies to #4*(i*j) + k
672 two terms #m*u and #n*u are replaced by #(m+n)*u
673 (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
674 and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
675 or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
677 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
678 powerful prover for predicate logic but knows nothing of clasets; see
679 ex/mesontest.ML and ex/mesontest2.ML for example applications;
681 * HOL: new version of "case_tac" subsumes both boolean case split and
682 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
683 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
685 * HOL: simplification no longer dives into case-expressions: only the
686 selector expression is simplified, but not the remaining arms; to
687 enable full simplification of case-expressions for datatype t, you may
688 remove t.weak_case_cong from the simpset, either globally (Delcongs
689 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
691 * HOL/recdef: the recursion equations generated by 'recdef' for
692 function 'f' are now called f.simps instead of f.rules; if all
693 termination conditions are proved automatically, these simplification
694 rules are added to the simpset, as in primrec; rules may be named
695 individually as well, resulting in a separate list of theorems for
698 * HOL/While is a new theory that provides a while-combinator. It
699 permits the definition of tail-recursive functions without the
700 provision of a termination measure. The latter is necessary once the
701 invariant proof rule for while is applied.
703 * HOL: new (overloaded) notation for the set of elements below/above
704 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
706 * HOL: theorems impI, allI, ballI bound as "strip";
708 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
709 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
710 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
712 * HOL/Real: "rabs" replaced by overloaded "abs" function;
714 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
715 main HOL, but was unused);
717 * HOL: fewer consts declared as global (e.g. have to refer to
718 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
720 * HOL: tuned AST representation of nested pairs, avoiding bogus output
721 in case of overlap with user translations (e.g. judgements over
722 tuples); (note that the underlying logical represenation is still
728 * ZF: simplification automatically cancels common terms in arithmetic
729 expressions over nat and int;
731 * ZF: new treatment of nat to minimize type-checking: all operators
732 coerce their operands to a natural number using the function natify,
733 making the algebraic laws unconditional;
735 * ZF: as above, for int: operators coerce their operands to an integer
736 using the function intify;
738 * ZF: the integer library now contains many of the usual laws for the
739 orderings, including $<=, and monotonicity laws for $+ and $*;
741 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
744 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
745 to the simplifier and classical reasoner simultaneously;
750 * Provers: blast_tac now handles actual object-logic rules as
751 assumptions; note that auto_tac uses blast_tac internally as well;
753 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
754 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
756 * Provers: delrules now handles destruct rules as well (no longer need
759 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
760 [| inj ?f; ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
761 use instead the strong form,
762 [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
763 in HOL, FOL and ZF the function cla_make_elim will create such rules
766 * Provers: Simplifier.easy_setup provides a fast path to basic
767 Simplifier setup for new object-logics;
769 * Pure: AST translation rules no longer require constant head on LHS;
771 * Pure: improved name spaces: ambiguous output is qualified; support
774 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
775 XSYMBOL_HOME; no longer need to do manual configuration in most
778 * system: compression of ML heaps images may now be controlled via -c
779 option of isabelle and isatool usedir (currently only observed by
782 * system: isatool installfonts may handle X-Symbol fonts as well (very
783 useful for remote X11);
785 * system: provide TAGS file for Isabelle sources;
787 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
790 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
791 timing flag supersedes proof_timing and Toplevel.trace;
793 * ML: new combinators |>> and |>>> for incremental transformations
794 with secondary results (e.g. certain theory extensions):
796 * ML: PureThy.add_defs gets additional argument to indicate potential
797 overloading (usually false);
799 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
804 New in Isabelle99 (October 1999)
805 --------------------------------
807 *** Overview of INCOMPATIBILITIES (see below for more details) ***
809 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
810 are no longer simplified. (This allows the simplifier to unfold recursive
811 functional programs.) To restore the old behaviour, declare
813 Delcongs [if_weak_cong];
815 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
818 * HOL: the predicate "inj" is now defined by translation to "inj_on";
820 * HOL/datatype: mutual_induct_tac no longer exists --
821 use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
823 * HOL/typedef: fixed type inference for representing set; type
824 arguments now have to occur explicitly on the rhs as type constraints;
826 * ZF: The con_defs part of an inductive definition may no longer refer
827 to constants declared in the same theory;
829 * HOL, ZF: the function mk_cases, generated by the inductive
830 definition package, has lost an argument. To simplify its result, it
831 uses the default simpset instead of a supplied list of theorems.
833 * HOL/List: the constructors of type list are now Nil and Cons;
835 * Simplifier: the type of the infix ML functions
836 setSSolver addSSolver setSolver addSolver
837 is now simpset * solver -> simpset where `solver' is a new abstract type
838 for packaging solvers. A solver is created via
839 mk_solver: string -> (thm list -> int -> tactic) -> solver
840 where the string argument is only a comment.
845 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
846 decision procedure for linear arithmetic. Currently it is used for
847 types `nat', `int', and `real' in HOL (see below); it can, should and
848 will be instantiated for other types and logics as well.
850 * The simplifier now accepts rewrite rules with flexible heads, eg
851 hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
852 They are applied like any rule with a non-pattern lhs, i.e. by first-order
858 * New Isabelle/Isar subsystem provides an alternative to traditional
859 tactical theorem proving; together with the ProofGeneral/isar user
860 interface it offers an interactive environment for developing human
861 readable proof documents (Isar == Intelligible semi-automated
862 reasoning); for further information see isatool doc isar-ref,
863 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
865 * improved and simplified presentation of theories: better HTML markup
866 (including colors), graph views in several sizes; isatool usedir now
867 provides a proper interface for user theories (via -P option); actual
868 document preparation based on (PDF)LaTeX is available as well (for
869 new-style theories only); see isatool doc system for more information;
871 * native support for Proof General, both for classic Isabelle and
874 * ML function thm_deps visualizes dependencies of theorems and lemmas,
875 using the graph browser tool;
877 * Isabelle manuals now also available as PDF;
879 * theory loader rewritten from scratch (may not be fully
880 bug-compatible); old loadpath variable has been replaced by show_path,
881 add_path, del_path, reset_path functions; new operations such as
882 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
885 * improved isatool install: option -k creates KDE application icon,
886 option -p DIR installs standalone binaries;
888 * added ML_PLATFORM setting (useful for cross-platform installations);
889 more robust handling of platform specific ML images for SML/NJ;
891 * the settings environment is now statically scoped, i.e. it is never
892 created again in sub-processes invoked from isabelle, isatool, or
895 * path element specification '~~' refers to '$ISABELLE_HOME';
897 * in locales, the "assumes" and "defines" parts may be omitted if
900 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
903 * new print_mode "HTML";
905 * new flag show_tags controls display of tags of theorems (which are
906 basically just comments that may be attached by some tools);
908 * Isamode 2.6 requires patch to accomodate change of Isabelle font
909 mode and goal output format:
911 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
913 < (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
915 > (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
916 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
918 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
920 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
922 * function bind_thms stores lists of theorems (cf. bind_thm);
924 * new shorthand tactics ftac, eatac, datac, fatac;
926 * qed (and friends) now accept "" as result name; in that case the
927 theorem is not stored, but proper checks and presentation of the
930 * theorem database now also indexes constants "Trueprop", "all",
931 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
938 * There are now decision procedures for linear arithmetic over nat and
941 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
942 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
943 are treated as atomic; subformulae not involving type `nat' or `int'
944 are ignored; quantified subformulae are ignored unless they are
945 positive universal or negative existential. The tactic has to be
946 invoked by hand and can be a little bit slow. In particular, the
947 running time is exponential in the number of occurrences of `min' and
948 `max', and `-' on `nat'.
950 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
951 (negated) (in)equalities among the premises and the conclusion into
952 account (i.e. no compound formulae) and does not know about `min' and
953 `max', and `-' on `nat'. It is fast and is used automatically by the
956 NB: At the moment, these decision procedures do not cope with mixed
957 nat/int formulae where the two parts interact, such as `m < n ==>
960 * HOL/Numeral provides a generic theory of numerals (encoded
961 efficiently as bit strings); setup for types nat/int/real is in place;
962 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
963 int, existing theories and proof scripts may require a few additional
966 * integer division and remainder can now be performed on constant
969 * many properties of integer multiplication, division and remainder
972 * An interface to the Stanford Validity Checker (SVC) is available through the
973 tactic svc_tac. Propositional tautologies and theorems of linear arithmetic
974 are proved automatically. SVC must be installed separately, and its results
975 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
976 invocation of the underlying oracle). For SVC see
977 http://verify.stanford.edu/SVC
979 * IsaMakefile: the HOL-Real target now builds an actual image;
984 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
985 (in Isabelle/Isar) -- by Gertrud Bauer;
987 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
988 analysis for assembly languages with subtypes;
990 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
991 -- avoids syntactic ambiguities and treats state, transition, and
992 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
993 changed syntax and (many) tactics;
995 * HOL/inductive: Now also handles more general introduction rules such
996 as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
997 theorems are now maintained within the theory (maintained via the
1000 * HOL/datatype: Now also handles arbitrarily branching datatypes
1001 (using function types) such as
1003 datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
1005 * HOL/record: record_simproc (part of the default simpset) takes care
1006 of selectors applied to updated records; record_split_tac is no longer
1007 part of the default claset; update_defs may now be removed from the
1008 simpset in many cases; COMPATIBILITY: old behavior achieved by
1010 claset_ref () := claset() addSWrapper record_split_wrapper;
1011 Delsimprocs [record_simproc]
1013 * HOL/typedef: fixed type inference for representing set; type
1014 arguments now have to occur explicitly on the rhs as type constraints;
1016 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
1017 names rather than an ML expression;
1019 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
1020 supplied later. Program schemes can be defined, such as
1021 "While B C s = (if B s then While B C (C s) else s)"
1022 where the well-founded relation can be chosen after B and C have been given.
1024 * HOL/List: the constructors of type list are now Nil and Cons;
1025 INCOMPATIBILITY: while [] and infix # syntax is still there, of
1026 course, ML tools referring to List.list.op # etc. have to be adapted;
1028 * HOL_quantifiers flag superseded by "HOL" print mode, which is
1029 disabled by default; run isabelle with option -m HOL to get back to
1030 the original Gordon/HOL-style output;
1032 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
1033 ALL x<=y. P, EX x<y. P, EX x<=y. P;
1035 * HOL basic syntax simplified (more orthogonal): all variants of
1036 All/Ex now support plain / symbolic / HOL notation; plain syntax for
1037 Eps operator is provided as well: "SOME x. P[x]";
1039 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
1041 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
1042 thus available for user theories;
1044 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
1045 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
1048 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
1049 several times and then mp;
1054 * the notation <<...>> is now available as a notation for sequences of
1057 * the simplifier is now installed
1059 * the axiom system has been generalized (thanks to Soren Heilmann)
1061 * the classical reasoner now has a default rule database
1066 * new primrec section allows primitive recursive functions to be given
1067 directly (as in HOL) over datatypes and the natural numbers;
1069 * new tactics induct_tac and exhaust_tac for induction (or case
1070 analysis) over datatypes and the natural numbers;
1072 * the datatype declaration of type T now defines the recursor T_rec;
1074 * simplification automatically does freeness reasoning for datatype
1077 * automatic type-inference, with AddTCs command to insert new
1078 type-checking rules;
1080 * datatype introduction rules are now added as Safe Introduction rules
1083 * the syntax "if P then x else y" is now available in addition to
1087 *** Internal programming interfaces ***
1089 * tuned simplifier trace output; new flag debug_simp;
1091 * structures Vartab / Termtab (instances of TableFun) offer efficient
1092 tables indexed by indexname_ord / term_ord (compatible with aconv);
1094 * AxClass.axclass_tac lost the theory argument;
1096 * tuned current_goals_markers semantics: begin / end goal avoids
1097 printing empty lines;
1099 * removed prs and prs_fn hook, which was broken because it did not
1100 include \n in its semantics, forcing writeln to add one
1101 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
1102 string -> unit if you really want to output text without newline;
1104 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
1105 plain output, interface builders may have to enable 'isabelle_font'
1106 mode to get Isabelle font glyphs as before;
1108 * refined token_translation interface; INCOMPATIBILITY: output length
1109 now of type real instead of int;
1111 * theory loader actions may be traced via new ThyInfo.add_hook
1112 interface (see src/Pure/Thy/thy_info.ML); example application: keep
1113 your own database of information attached to *whole* theories -- as
1114 opposed to intra-theory data slots offered via TheoryDataFun;
1116 * proper handling of dangling sort hypotheses (at last!);
1117 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
1118 extra sort hypotheses that can be witnessed from the type signature;
1119 the force_strip_shyps flag is gone, any remaining shyps are simply
1120 left in the theorem (with a warning issued by strip_shyps_warning);
1124 New in Isabelle98-1 (October 1998)
1125 ----------------------------------
1127 *** Overview of INCOMPATIBILITIES (see below for more details) ***
1129 * several changes of automated proof tools;
1131 * HOL: major changes to the inductive and datatype packages, including
1132 some minor incompatibilities of theory syntax;
1134 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
1137 * HOL: removed duplicate thms in Arith:
1138 less_imp_add_less should be replaced by trans_less_add1
1139 le_imp_add_le should be replaced by trans_le_add1
1141 * HOL: unary minus is now overloaded (new type constraints may be
1144 * HOL and ZF: unary minus for integers is now #- instead of #~. In
1145 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
1146 now taken as an integer constant.
1148 * Pure: ML function 'theory_of' renamed to 'theory';
1154 1. Asm_full_simp_tac is now more aggressive.
1155 1. It will sometimes reorient premises if that increases their power to
1157 2. It does no longer proceed strictly from left to right but may also
1158 rotate premises to achieve further simplification.
1159 For compatibility reasons there is now Asm_lr_simp_tac which is like the
1160 old Asm_full_simp_tac in that it does not rotate premises.
1161 2. The simplifier now knows a little bit about nat-arithmetic.
1163 * Classical reasoner: wrapper mechanism for the classical reasoner now
1164 allows for selected deletion of wrappers, by introduction of names for
1165 wrapper functionals. This implies that addbefore, addSbefore,
1166 addaltern, and addSaltern now take a pair (name, tactic) as argument,
1167 and that adding two tactics with the same name overwrites the first
1168 one (emitting a warning).
1169 type wrapper = (int -> tactic) -> (int -> tactic)
1170 setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
1171 addWrapper, addSWrapper: claset * (string * wrapper) -> claset
1172 delWrapper, delSWrapper: claset * string -> claset
1173 getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
1175 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
1176 semantics; addbefore now affects only the unsafe part of step_tac
1177 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
1178 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
1181 * Classical reasoner: setwrapper to setWrapper and compwrapper to
1182 compWrapper; added safe wrapper (and access functions for it);
1184 * HOL/split_all_tac is now much faster and fails if there is nothing
1185 to split. Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
1186 and the names of the automatically generated variables have changed.
1187 split_all_tac has moved within claset() from unsafe wrappers to safe
1188 wrappers, which means that !!-bound variables are split much more
1189 aggressively, and safe_tac and clarify_tac now split such variables.
1190 If this splitting is not appropriate, use delSWrapper "split_all_tac".
1191 Note: the same holds for record_split_tac, which does the job of
1192 split_all_tac for record fields.
1194 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
1195 permanently to the default simpset using Addsplits just like
1196 Addsimps. They can be removed via Delsplits just like
1197 Delsimps. Lower-case versions are also available.
1199 * HOL/Simplifier: The rule split_if is now part of the default
1200 simpset. This means that the simplifier will eliminate all occurrences
1201 of if-then-else in the conclusion of a goal. To prevent this, you can
1202 either remove split_if completely from the default simpset by
1203 `Delsplits [split_if]' or remove it in a specific call of the
1204 simplifier using `... delsplits [split_if]'. You can also add/delete
1205 other case splitting rules to/from the default simpset: every datatype
1206 generates suitable rules `split_t_case' and `split_t_case_asm' (where
1207 t is the name of the datatype).
1209 * Classical reasoner / Simplifier combination: new force_tac (and
1210 derivatives Force_tac, force) combines rewriting and classical
1211 reasoning (and whatever other tools) similarly to auto_tac, but is
1212 aimed to solve the given subgoal completely.
1217 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
1218 and `goalw': the theory is no longer needed as an explicit argument -
1219 the current theory context is used; assumptions are no longer returned
1220 at the ML-level unless one of them starts with ==> or !!; it is
1221 recommended to convert to these new commands using isatool fixgoal
1222 (backup your sources first!);
1224 * new top-level commands 'thm' and 'thms' for retrieving theorems from
1225 the current theory context, and 'theory' to lookup stored theories;
1227 * new theory section 'locale' for declaring constants, assumptions and
1228 definitions that have local scope;
1230 * new theory section 'nonterminals' for purely syntactic types;
1232 * new theory section 'setup' for generic ML setup functions
1233 (e.g. package initialization);
1235 * the distribution now includes Isabelle icons: see
1236 lib/logo/isabelle-{small,tiny}.xpm;
1238 * isatool install - install binaries with absolute references to
1241 * isatool logo -- create instances of the Isabelle logo (as EPS);
1243 * print mode 'emacs' reserved for Isamode;
1245 * support multiple print (ast) translations per constant name;
1247 * theorems involving oracles are now printed with a suffixed [!];
1252 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
1254 * HOL/inductive package reorganized and improved: now supports mutual
1260 oddI "n : EVEN ==> Suc n : ODD"
1261 evenI "n : ODD ==> Suc n : EVEN"
1263 new theorem list "elims" contains an elimination rule for each of the
1264 recursive sets; inductive definitions now handle disjunctive premises
1265 correctly (also ZF);
1267 INCOMPATIBILITIES: requires Inductive as an ancestor; component
1268 "mutual_induct" no longer exists - the induction rule is always
1269 contained in "induct";
1272 * HOL/datatype package re-implemented and greatly improved: now
1273 supports mutually recursive datatypes such as
1276 'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
1277 | SUM ('a aexp) ('a aexp)
1278 | DIFF ('a aexp) ('a aexp)
1281 'a bexp = LESS ('a aexp) ('a aexp)
1282 | AND ('a bexp) ('a bexp)
1283 | OR ('a bexp) ('a bexp)
1285 as well as indirectly recursive datatypes such as
1288 ('a, 'b) term = Var 'a
1289 | App 'b ((('a, 'b) term) list)
1291 The new tactic mutual_induct_tac [<var_1>, ..., <var_n>] i performs
1292 induction on mutually / indirectly recursive datatypes.
1294 Primrec equations are now stored in theory and can be accessed via
1295 <function_name>.simps.
1299 - Theories using datatypes must now have theory Datatype as an
1301 - The specific <typename>.induct_tac no longer exists - use the
1302 generic induct_tac instead.
1303 - natE has been renamed to nat.exhaust - use exhaust_tac
1304 instead of res_inst_tac ... natE. Note that the variable
1305 names in nat.exhaust differ from the names in natE, this
1306 may cause some "fragile" proofs to fail.
1307 - The theorems split_<typename>_case and split_<typename>_case_asm
1308 have been renamed to <typename>.split and <typename>.split_asm.
1309 - Since default sorts of type variables are now handled correctly,
1310 some datatype definitions may have to be annotated with explicit
1312 - Primrec definitions no longer require function name and type
1313 of recursive argument.
1315 Consider using isatool fixdatatype to adapt your theories and proof
1316 scripts to the new package (backup your sources first!).
1319 * HOL/record package: considerably improved implementation; now
1320 includes concrete syntax for record types, terms, updates; theorems
1321 for surjective pairing and splitting !!-bound record variables; proof
1322 support is as follows:
1324 1) standard conversions (selectors or updates applied to record
1325 constructor terms) are part of the standard simpset;
1327 2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
1328 made part of standard simpset and claset via addIffs;
1330 3) a tactic for record field splitting (record_split_tac) is part of
1331 the standard claset (addSWrapper);
1333 To get a better idea about these rules you may retrieve them via
1334 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
1335 the name of your record type.
1337 The split tactic 3) conceptually simplifies by the following rule:
1339 "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
1341 Thus any record variable that is bound by meta-all will automatically
1342 blow up into some record constructor term, consequently the
1343 simplifications of 1), 2) apply. Thus force_tac, auto_tac etc. shall
1344 solve record problems automatically.
1347 * reorganized the main HOL image: HOL/Integ and String loaded by
1348 default; theory Main includes everything;
1350 * automatic simplification of integer sums and comparisons, using cancellation;
1352 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
1354 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
1356 * many new identities for unions, intersections, set difference, etc.;
1358 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
1359 called split_if, split_split, split_sum_case and split_nat_case (to go
1360 with add/delsplits);
1362 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
1363 (?x::unit) = (); this is made part of the default simpset, which COULD
1364 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
1365 'Delsimprocs [unit_eq_proc];' as last resort); also note that
1366 unit_abs_eta_conv is added in order to counter the effect of
1367 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
1370 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
1373 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
1374 It and 'sym RS equals0D' are now in the default claset, giving automatic
1375 disjointness reasoning but breaking a few old proofs.
1377 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
1378 to 'converse' from 'inverse' (for compatibility with ZF and some
1381 * HOL/recdef can now declare non-recursive functions, with {} supplied as
1382 the well-founded relation;
1384 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
1385 Compl A. The "Compl" syntax remains available as input syntax for this
1388 * HOL/Update: new theory of function updates:
1389 f(a:=b) == %x. if x=a then b else f x
1390 may also be iterated as in f(a:=b,c:=d,...);
1392 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
1395 - new function list_update written xs[i:=v] that updates the i-th
1396 list position. May also be iterated as in xs[i:=a,j:=b,...].
1397 - new function `upt' written [i..j(] which generates the list
1398 [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
1399 bound write [i..j], which is a shorthand for [i..j+1(].
1400 - new lexicographic orderings and corresponding wellfoundedness theorems.
1403 - removed 'pred' (predecessor) function;
1404 - generalized some theorems about n-1;
1405 - many new laws about "div" and "mod";
1406 - new laws about greatest common divisors (see theory ex/Primes);
1408 * HOL/Relation: renamed the relational operator r^-1 "converse"
1409 instead of "inverse";
1411 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
1412 of the multiset ordering;
1414 * directory HOL/Real: a construction of the reals using Dedekind cuts
1415 (not included by default);
1417 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
1419 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
1420 programs, i.e. different program variables may have different types.
1422 * calling (stac rew i) now fails if "rew" has no effect on the goal
1423 [previously, this check worked only if the rewrite rule was unconditional]
1424 Now rew can involve either definitions or equalities (either == or =).
1429 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
1430 only the theorems proved on ZF.ML;
1432 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
1433 It and 'sym RS equals0D' are now in the default claset, giving automatic
1434 disjointness reasoning but breaking a few old proofs.
1436 * ZF/Update: new theory of function updates
1437 with default rewrite rule f(x:=y) ` z = if(z=x, y, f`z)
1438 may also be iterated as in f(a:=b,c:=d,...);
1440 * in let x=t in u(x), neither t nor u(x) has to be an FOL term.
1442 * calling (stac rew i) now fails if "rew" has no effect on the goal
1443 [previously, this check worked only if the rewrite rule was unconditional]
1444 Now rew can involve either definitions or equalities (either == or =).
1446 * case_tac provided for compatibility with HOL
1447 (like the old excluded_middle_tac, but with subgoals swapped)
1450 *** Internal programming interfaces ***
1452 * Pure: several new basic modules made available for general use, see
1453 also src/Pure/README;
1455 * improved the theory data mechanism to support encapsulation (data
1456 kind name replaced by private Object.kind, acting as authorization
1457 key); new type-safe user interface via functor TheoryDataFun; generic
1458 print_data function becomes basically useless;
1460 * removed global_names compatibility flag -- all theory declarations
1461 are qualified by default;
1463 * module Pure/Syntax now offers quote / antiquote translation
1464 functions (useful for Hoare logic etc. with implicit dependencies);
1465 see HOL/ex/Antiquote for an example use;
1467 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
1470 * new tactical CHANGED_GOAL for checking that a tactic modifies a
1473 * Display.print_goals function moved to Locale.print_goals;
1475 * standard print function for goals supports current_goals_markers
1476 variable for marking begin of proof, end of proof, start of goal; the
1477 default is ("", "", ""); setting current_goals_markers := ("<proof>",
1478 "</proof>", "<goal>") causes SGML like tagged proof state printing,
1483 New in Isabelle98 (January 1998)
1484 --------------------------------
1486 *** Overview of INCOMPATIBILITIES (see below for more details) ***
1488 * changed lexical syntax of terms / types: dots made part of long
1489 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
1491 * simpset (and claset) reference variable replaced by functions
1492 simpset / simpset_ref;
1494 * no longer supports theory aliases (via merge) and non-trivial
1495 implicit merge of thms' signatures;
1497 * most internal names of constants changed due to qualified names;
1499 * changed Pure/Sequence interface (see Pure/seq.ML);
1502 *** General Changes ***
1504 * hierachically structured name spaces (for consts, types, axms, thms
1505 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
1506 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
1507 isatool fixdots ensures space after dots (e.g. "%x. x"); set
1508 long_names for fully qualified output names; NOTE: ML programs
1509 (special tactics, packages etc.) referring to internal names may have
1510 to be adapted to cope with fully qualified names; in case of severe
1511 backward campatibility problems try setting 'global_names' at compile
1512 time to have enrything declared within a flat name space; one may also
1513 fine tune name declarations in theories via the 'global' and 'local'
1516 * reimplemented the implicit simpset and claset using the new anytype
1517 data filed in signatures; references simpset:simpset ref etc. are
1518 replaced by functions simpset:unit->simpset and
1519 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
1520 to patch your ML files accordingly;
1522 * HTML output now includes theory graph data for display with Java
1523 applet or isatool browser; data generated automatically via isatool
1524 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
1526 * defs may now be conditional; improved rewrite_goals_tac to handle
1527 conditional equations;
1529 * defs now admits additional type arguments, using TYPE('a) syntax;
1531 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
1532 creates a new theory node; implicit merge of thms' signatures is
1533 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
1534 transfer:theory->thm->thm in (rare) cases;
1536 * improved handling of draft signatures / theories; draft thms (and
1537 ctyps, cterms) are automatically promoted to real ones;
1539 * slightly changed interfaces for oracles: admit many per theory, named
1540 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
1542 * print_goals: optional output of const types (set show_consts and
1545 * improved output of warnings (###) and errors (***);
1547 * subgoal_tac displays a warning if the new subgoal has type variables;
1549 * removed old README and Makefiles;
1551 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
1553 * removed obsolete init_pps and init_database;
1555 * deleted the obsolete tactical STATE, which was declared by
1556 fun STATE tacfun st = tacfun st st;
1558 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
1559 (which abbreviates $HOME);
1561 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
1562 use isatool fixseq to adapt your ML programs (this works for fully
1563 qualified references to the Sequence structure only!);
1565 * use_thy no longer requires writable current directory; it always
1566 reloads .ML *and* .thy file, if either one is out of date;
1569 *** Classical Reasoner ***
1571 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
1572 tactics that use classical reasoning to simplify a subgoal without
1573 splitting it into several subgoals;
1575 * Safe_tac: like safe_tac but uses the default claset;
1580 * added simplification meta rules:
1581 (asm_)(full_)simplify: simpset -> thm -> thm;
1583 * simplifier.ML no longer part of Pure -- has to be loaded by object
1586 * added prems argument to simplification procedures;
1588 * HOL, FOL, ZF: added infix function `addsplits':
1589 instead of `<simpset> setloop (split_tac <thms>)'
1590 you can simply write `<simpset> addsplits <thms>'
1595 * TYPE('a) syntax for type reflection terms;
1597 * no longer handles consts with name "" -- declare as 'syntax' instead;
1599 * pretty printer: changed order of mixfix annotation preference (again!);
1601 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
1606 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
1607 with `addloop' of the simplifier to faciliate case splitting in premises.
1609 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
1611 * HOL/Auth: new protocol proofs including some for the Internet
1614 * HOL/Map: new theory of `maps' a la VDM;
1616 * HOL/simplifier: simplification procedures nat_cancel_sums for
1617 cancelling out common nat summands from =, <, <= (in)equalities, or
1618 differences; simplification procedures nat_cancel_factor for
1619 cancelling common factor from =, <, <= (in)equalities over natural
1620 sums; nat_cancel contains both kinds of procedures, it is installed by
1621 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
1623 * HOL/simplifier: terms of the form
1624 `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)' (or t=x)
1626 `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
1627 and those of the form
1628 `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)' (or t=x)
1630 `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
1633 Each datatype `t' now comes with a theorem `split_t_case' of the form
1635 P(t_case f1 ... fn x) =
1636 ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
1638 (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
1641 and a theorem `split_t_case_asm' of the form
1643 P(t_case f1 ... fn x) =
1644 ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
1646 (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
1648 which can be added to a simpset via `addsplits'. The existing theorems
1649 expand_list_case and expand_option_case have been renamed to
1650 split_list_case and split_option_case.
1653 - `pred n' is automatically converted to `n-1'.
1654 Users are strongly encouraged not to use `pred' any longer,
1655 because it will disappear altogether at some point.
1656 - Users are strongly encouraged to write "0 < n" rather than
1657 "n ~= 0". Theorems and proof tools have been modified towards this
1661 the function "set_of_list" has been renamed "set" (and its theorems too);
1662 the function "nth" now takes its arguments in the reverse order and
1663 has acquired the infix notation "!" as in "xs!n".
1665 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
1667 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
1668 specialist theorems (like UN1_I) are gone. Similarly for (INT x.B x);
1670 * HOL/record: extensible records with schematic structural subtyping
1671 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
1672 still lacks various theorems and concrete record syntax;
1677 * removed "axioms" and "generated by" sections;
1679 * replaced "ops" section by extended "consts" section, which is capable of
1680 handling the continuous function space "->" directly;
1683 . proves theorems immediately and stores them in the theory,
1684 . creates hierachical name space,
1685 . now uses normal mixfix annotations (instead of cinfix...),
1686 . minor changes to some names and values (for consistency),
1687 . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
1688 . separator between mutual domain defs: changed "," to "and",
1689 . improved handling of sort constraints; now they have to
1690 appear on the left-hand side of the equations only;
1692 * fixed LAM <x,y,zs>.b syntax;
1694 * added extended adm_tac to simplifier in HOLCF -- can now discharge
1695 adm (%x. P (t x)), where P is chainfinite and t continuous;
1700 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
1701 with `addloop' of the simplifier to faciliate case splitting in premises.
1703 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
1704 in HOL, they strip ALL and --> from proved theorems;
1708 New in Isabelle94-8 (May 1997)
1709 ------------------------------
1711 *** General Changes ***
1713 * new utilities to build / run / maintain Isabelle etc. (in parts
1714 still somewhat experimental); old Makefiles etc. still functional;
1716 * new 'Isabelle System Manual';
1718 * INSTALL text, together with ./configure and ./build scripts;
1720 * reimplemented type inference for greater efficiency, better error
1721 messages and clean internal interface;
1723 * prlim command for dealing with lots of subgoals (an easier way of
1724 setting goals_limit);
1729 * supports alternative (named) syntax tables (parser and pretty
1730 printer); internal interface is provided by add_modesyntax(_i);
1732 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
1733 be used in conjunction with the Isabelle symbol font; uses the
1734 "symbols" syntax table;
1736 * added token_translation interface (may translate name tokens in
1737 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
1738 the current print_mode); IMPORTANT: user print translation functions
1739 are responsible for marking newly introduced bounds
1740 (Syntax.mark_boundT);
1742 * token translations for modes "xterm" and "xterm_color" that display
1743 names in bold, underline etc. or colors (which requires a color
1746 * infixes may now be declared with names independent of their syntax;
1748 * added typed_print_translation (like print_translation, but may
1749 access type of constant);
1752 *** Classical Reasoner ***
1754 Blast_tac: a new tactic! It is often more powerful than fast_tac, but has
1755 some limitations. Blast_tac...
1756 + ignores addss, addbefore, addafter; this restriction is intrinsic
1757 + ignores elimination rules that don't have the correct format
1758 (the conclusion MUST be a formula variable)
1759 + ignores types, which can make HOL proofs fail
1760 + rules must not require higher-order unification, e.g. apply_type in ZF
1761 [message "Function Var's argument not a bound variable" relates to this]
1762 + its proof strategy is more general but can actually be slower
1764 * substitution with equality assumptions no longer permutes other
1767 * minor changes in semantics of addafter (now called addaltern); renamed
1768 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
1769 (and access functions for it);
1771 * improved combination of classical reasoner and simplifier:
1772 + functions for handling clasimpsets
1773 + improvement of addss: now the simplifier is called _after_ the
1775 + safe variant of addss called addSss: uses safe simplifications
1776 _during_ the safe steps. It is more complete as it allows multiple
1777 instantiations of unknowns (e.g. with slow_tac).
1781 * added interface for simplification procedures (functions that
1782 produce *proven* rewrite rules on the fly, depending on current
1785 * ordering on terms as parameter (used for ordered rewriting);
1787 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
1789 * the solver is now split into a safe and an unsafe part.
1790 This should be invisible for the normal user, except that the
1791 functions setsolver and addsolver have been renamed to setSolver and
1792 addSolver; added safe_asm_full_simp_tac;
1797 * a generic induction tactic `induct_tac' which works for all datatypes and
1798 also for type `nat';
1800 * a generic case distinction tactic `exhaust_tac' which works for all
1801 datatypes and also for type `nat';
1803 * each datatype comes with a function `size';
1805 * patterns in case expressions allow tuple patterns as arguments to
1806 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
1808 * primrec now also works with type nat;
1810 * recdef: a new declaration form, allows general recursive functions to be
1811 defined in theory files. See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
1813 * the constant for negation has been renamed from "not" to "Not" to
1814 harmonize with FOL, ZF, LK, etc.;
1816 * HOL/ex/LFilter theory of a corecursive "filter" functional for
1819 * HOL/Modelcheck demonstrates invocation of model checker oracle;
1821 * HOL/ex/Ring.thy declares cring_simp, which solves equational
1822 problems in commutative rings, using axiomatic type classes for + and *;
1824 * more examples in HOL/MiniML and HOL/Auth;
1826 * more default rewrite rules for quantifiers, union/intersection;
1828 * a new constant `arbitrary == @x.False';
1830 * HOLCF/IOA replaces old HOL/IOA;
1832 * HOLCF changes: derived all rules and arities
1833 + axiomatic type classes instead of classes
1834 + typedef instead of faking type definitions
1835 + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
1836 + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
1837 + eliminated the types void, one, tr
1838 + use unit lift and bool lift (with translations) instead of one and tr
1839 + eliminated blift from Lift3.thy (use Def instead of blift)
1840 all eliminated rules are derived as theorems --> no visible changes ;
1845 * ZF now has Fast_tac, Simp_tac and Auto_tac. Union_iff is a now a default
1846 rewrite rule; this may affect some proofs. eq_cs is gone but can be put back
1847 as ZF_cs addSIs [equalityI];
1851 New in Isabelle94-7 (November 96)
1852 ---------------------------------
1854 * allowing negative levels (as offsets) in prlev and choplev;
1856 * super-linear speedup for large simplifications;
1858 * FOL, ZF and HOL now use miniscoping: rewriting pushes
1859 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
1860 FAIL); can suppress it using the command Delsimps (ex_simps @
1861 all_simps); De Morgan laws are also now included, by default;
1863 * improved printing of ==> : ~:
1865 * new object-logic "Sequents" adds linear logic, while replacing LK
1866 and Modal (thanks to Sara Kalvala);
1868 * HOL/Auth: correctness proofs for authentication protocols;
1870 * HOL: new auto_tac combines rewriting and classical reasoning (many
1871 examples on HOL/Auth);
1873 * HOL: new command AddIffs for declaring theorems of the form P=Q to
1874 the rewriter and classical reasoner simultaneously;
1876 * function uresult no longer returns theorems in "standard" format;
1877 regain previous version by: val uresult = standard o uresult;
1884 * oracles -- these establish an interface between Isabelle and trusted
1885 external reasoners, which may deliver results as theorems;
1887 * proof objects (in particular record all uses of oracles);
1889 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
1891 * "constdefs" section in theory files;
1893 * "primrec" section (HOL) no longer requires names;
1895 * internal type "tactic" now simply "thm -> thm Sequence.seq";
1902 * reduced space requirements;
1904 * automatic HTML generation from theories;
1906 * theory files no longer require "..." (quotes) around most types;
1908 * new examples, including two proofs of the Church-Rosser theorem;
1910 * non-curried (1994) version of HOL is no longer distributed;
1917 * greatly reduced space requirements;
1919 * theory files (.thy) no longer require \...\ escapes at line breaks;
1921 * searchable theorem database (see the section "Retrieving theorems" on
1922 page 8 of the Reference Manual);
1924 * new examples, including Grabczewski's monumental case study of the
1927 * The previous version of HOL renamed to Old_HOL;
1929 * The new version of HOL (previously called CHOL) uses a curried syntax
1930 for functions. Application looks like f a b instead of f(a,b);
1932 * Mutually recursive inductive definitions finally work in HOL;
1934 * In ZF, pattern-matching on tuples is now available in all abstractions and
1935 translates to the operator "split";
1942 * new infix operator, addss, allowing the classical reasoner to
1943 perform simplification at each step of its search. Example:
1944 fast_tac (cs addss ss)
1946 * a new logic, CHOL, the same as HOL, but with a curried syntax
1947 for functions. Application looks like f a b instead of f(a,b). Also pairs
1948 look like (a,b) instead of <a,b>;
1950 * PLEASE NOTE: CHOL will eventually replace HOL!
1952 * In CHOL, pattern-matching on tuples is now available in all abstractions.
1953 It translates to the operator "split". A new theory of integers is available;
1955 * In ZF, integer numerals now denote two's-complement binary integers.
1956 Arithmetic operations can be performed by rewriting. See ZF/ex/Bin.ML;
1958 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
1959 of the Axiom of Choice;
1966 * Significantly faster resolution;
1968 * the different sections in a .thy file can now be mixed and repeated
1971 * Database of theorems for FOL, HOL and ZF. New
1972 commands including qed, qed_goal and bind_thm store theorems in the database.
1974 * Simple database queries: return a named theorem (get_thm) or all theorems of
1975 a given theory (thms_of), or find out what theory a theorem was proved in
1978 * Bugs fixed in the inductive definition and datatype packages;
1980 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
1981 and HOL_dup_cs obsolete;
1983 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
1986 * Simpler definition of function space in ZF;
1988 * new results about cardinal and ordinal arithmetic in ZF;
1990 * 'subtype' facility in HOL for introducing new types as subsets of existing