2 Isabelle NEWS -- history user-relevant changes
3 ==============================================
5 New in Isabelle2001 (?? 2001)
6 -----------------------------
8 *** Document preparation ***
10 * support bold style (for single symbols only), input syntax is like
11 this: "\<^bold>\<alpha>" or "\<^bold>A";
13 * \<bullet> is no output as bold \cdot by default, which looks much
14 better in printed text;
16 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
17 note that these symbols are currently unavailable in Proof General /
23 * improved proof by cases and induction:
24 - moved induct/cases attributes to Pure;
25 - added 'print_induct_rules' (covered by help item in Proof General > 3.3);
26 - generic setup instantiated for FOL and HOL;
27 - removed obsolete "(simplified)" and "(stripped)" options;
29 * Pure: renamed "antecedent" case to "rule_context";
31 * Pure: added 'corollary' command;
33 * Pure: fixed 'token_translation' command;
35 * HOL: 'recdef' now fails on unfinished automated proofs, use
36 "(permissive)" option to recover old behavior;
38 * HOL: 'inductive' now longer features separate (collective)
39 attributes for 'intros';
44 * HOL: moved over to sane numeral syntax; the new policy is as
47 - 0 and 1 are polymorphic constants, which are defined on any
48 numeric type (nat, int, real etc.);
50 - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
51 binary representation internally;
53 - type nat has special constructor Suc, and generally prefers Suc 0
54 over 1::nat and Suc (Suc 0) over 2::nat;
56 This change may cause significant INCOMPATIBILITIES; here are some
57 hints on converting existing sources:
59 - due to the new "num" token, "-0" and "-1" etc. are now atomic
60 entities, so expressions involving "-" (unary or binary minus) need
61 to be spaced properly;
63 - existing occurrences of "1" may need to be constraint "1::nat" or
64 even replaced by Suc 0; similar for old "2";
66 - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
68 - remove all special provisions on numerals in proofs;
70 * HOL: linorder_less_split superseded by linorder_cases;
72 * HOL: added "The" definite description operator; move Hilbert's "Eps"
73 to peripheral theory "Hilbert_Choice";
75 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
76 in this (rare) case use:
78 delSWrapper "split_all_tac"
79 addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
81 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
84 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
85 Isabelle's type classes, ^ on functions and relations has too general
86 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
87 necessary to attach explicit type constraints;
89 * HOL: syntax translations now work properly with numerals and records
92 * HOL/GroupTheory: group theory examples including Sylow's theorem, by
95 * HOL: eliminated global items
97 const "()" -> "Product_Type.Unity"
98 type "unit" -> "Product_Type.unit"
103 * ZF: the integer library now covers quotients and remainders, with
104 many laws relating division to addition, multiplication, etc.;
109 * Meta-level proof terms (by Stefan Berghofer), see also ref manual;
111 * new token syntax "num" for plain numerals (without "#" of "xnum");
112 potential INCOMPATIBILITY, since -0, -1 etc. are now separate tokens,
113 so expressions involving minus need to be spaced properly;
115 * Classical reasoner: renamed addaltern to addafter, addSaltern to
118 * syntax: support non-oriented infixes;
120 * print modes "type_brackets" and "no_type_brackets" control output of
121 nested => (types); the default behavior is "brackets";
123 * system: support Poly/ML 4.1.1 (now able to manage large heaps);
125 * system: Proof General keywords specification is now part of the
126 Isabelle distribution (see etc/isar-keywords.el);
128 * system: smart selection of Isabelle process versus Isabelle
129 interface, accommodates case-insensitive file systems (e.g. HFS+); may
130 run both "isabelle" and "Isabelle" even if file names are badly
131 damaged (executable inspects the case of the first letter of its own
132 name); added separate "isabelle-process" and "isabelle-interface";
136 New in Isabelle99-2 (February 2001)
137 -----------------------------------
139 *** Overview of INCOMPATIBILITIES ***
141 * HOL: please note that theories in the Library and elsewhere often use the
142 new-style (Isar) format; to refer to their theorems in an ML script you must
143 bind them to ML identifers by e.g. val thm_name = thm "thm_name";
145 * HOL: inductive package no longer splits induction rule aggressively,
146 but only as far as specified by the introductions given; the old
147 format may be recovered via ML function complete_split_rule or attribute
148 'split_rule (complete)';
150 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
151 gfp_Tarski to gfp_unfold;
153 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
155 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
156 relation); infix "^^" has been renamed "``"; infix "``" has been
157 renamed "`"; "univalent" has been renamed "single_valued";
159 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
162 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
164 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
166 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
167 consequence, it is no longer monotonic wrt. the local goal context
168 (which is now passed through the inductive cases);
170 * Document preparation: renamed standard symbols \<ll> to \<lless> and
171 \<gg> to \<ggreater>;
174 *** Document preparation ***
176 * \isabellestyle{NAME} selects version of Isabelle output (currently
177 available: are "it" for near math-mode best-style output, "sl" for
178 slanted text style, and "tt" for plain type-writer; if no
179 \isabellestyle command is given, output is according to slanted
182 * support sub/super scripts (for single symbols only), input syntax is
183 like this: "A\<^sup>*" or "A\<^sup>\<star>";
185 * some more standard symbols; see Appendix A of the system manual for
186 the complete list of symbols defined in isabellesym.sty;
188 * improved isabelle style files; more abstract symbol implementation
189 (should now use \isamath{...} and \isatext{...} in custom symbol
192 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
193 state; Note that presentation of goal states does not conform to
194 actual human-readable proof documents. Please do not include goal
195 states into document output unless you really know what you are doing!
197 * proper indentation of antiquoted output with proportional LaTeX
200 * no_document ML operator temporarily disables LaTeX document
203 * isatool unsymbolize tunes sources for plain ASCII communication;
208 * Pure: Isar now suffers initial goal statements to contain unbound
209 schematic variables (this does not conform to actual readable proof
210 documents, due to unpredictable outcome and non-compositional proof
211 checking); users who know what they are doing may use schematic goals
212 for Prolog-style synthesis of proven results;
214 * Pure: assumption method (an implicit finishing) now handles actual
217 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
218 initial goal, declare "that" only as Pure intro (only for single
219 steps); the "that" rule assumption may now be involved in implicit
220 finishing, thus ".." becomes a feasible for trivial obtains;
222 * Pure: default proof step now includes 'intro_classes'; thus trivial
223 instance proofs may be performed by "..";
225 * Pure: ?thesis / ?this / "..." now work for pure meta-level
228 * Pure: more robust selection of calculational rules;
230 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
231 rule (as well as the assumption rule);
233 * Pure: 'thm_deps' command visualizes dependencies of theorems and
234 lemmas, using the graph browser tool;
236 * Pure: predict failure of "show" in interactive mode;
238 * Pure: 'thms_containing' now takes actual terms as arguments;
240 * HOL: improved method 'induct' --- now handles non-atomic goals
241 (potential INCOMPATIBILITY); tuned error handling;
243 * HOL: cases and induct rules now provide explicit hints about the
244 number of facts to be consumed (0 for "type" and 1 for "set" rules);
245 any remaining facts are inserted into the goal verbatim;
247 * HOL: local contexts (aka cases) may now contain term bindings as
248 well; the 'cases' and 'induct' methods new provide a ?case binding for
249 the result to be shown in each case;
251 * HOL: added 'recdef_tc' command;
253 * isatool convert assists in eliminating legacy ML scripts;
258 * HOL/Library: a collection of generic theories to be used together
259 with main HOL; the theory loader path already includes this directory
260 by default; the following existing theories have been moved here:
261 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
262 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
264 * HOL/Unix: "Some aspects of Unix file-system security", a typical
265 modelling and verification task performed in Isabelle/HOL +
266 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
268 * HOL/Algebra: special summation operator SUM no longer exists, it has
269 been replaced by setsum; infix 'assoc' now has priority 50 (like
270 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
271 'domain', this makes the theory consistent with mathematical
274 * HOL basics: added overloaded operations "inverse" and "divide"
275 (infix "/"), syntax for generic "abs" operation, generic summation
278 * HOL/typedef: simplified package, provide more useful rules (see also
281 * HOL/datatype: induction rule for arbitrarily branching datatypes is
282 now expressed as a proper nested rule (old-style tactic scripts may
283 require atomize_strip_tac to cope with non-atomic premises);
285 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
286 to "split_conv" (old name still available for compatibility);
288 * HOL: improved concrete syntax for strings (e.g. allows translation
289 rules with string literals);
291 * HOL-Hyperreal: a new target, extending HOL-Real with the hyperreals
292 and Fleuriot's mechanization of analysis;
294 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
299 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
300 "lam" is displayed as TWO lambda-symbols
302 * CTT: theory Main now available, containing everything (that is, Bool
308 * Pure: the Simplifier has been implemented properly as a derived rule
309 outside of the actual kernel (at last!); the overall performance
310 penalty in practical applications is about 50%, while reliability of
311 the Isabelle inference kernel has been greatly improved;
313 * print modes "brackets" and "no_brackets" control output of nested =>
314 (types) and ==> (props); the default behaviour is "brackets";
316 * Provers: fast_tac (and friends) now handle actual object-logic rules
317 as assumptions as well;
319 * system: support Poly/ML 4.0;
321 * system: isatool install handles KDE version 1 or 2;
325 New in Isabelle99-1 (October 2000)
326 ----------------------------------
328 *** Overview of INCOMPATIBILITIES ***
330 * HOL: simplification of natural numbers is much changed; to partly
331 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
332 issue the following ML commands:
334 Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
335 Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
337 * HOL: simplification no longer dives into case-expressions; this is
338 controlled by "t.weak_case_cong" for each datatype t;
340 * HOL: nat_less_induct renamed to less_induct;
342 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
343 fixsome to patch .thy and .ML sources automatically;
345 select_equality -> some_equality
346 select_eq_Ex -> some_eq_ex
347 selectI2EX -> someI2_ex
350 select1_equality -> some1_equality
351 Eps_sym_eq -> some_sym_eq_trivial
352 Eps_eq -> some_eq_trivial
354 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
356 * HOL: removed obsolete theorem binding expand_if (refer to split_if
359 * HOL: the recursion equations generated by 'recdef' are now called
360 f.simps instead of f.rules;
362 * HOL: qed_spec_mp now also handles bounded ALL as well;
364 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
367 * HOL: the constant for "f``x" is now "image" rather than "op ``";
369 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
371 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
372 product is now "<*>" instead of "Times"; the lexicographic product is
373 now "<*lex*>" instead of "**";
375 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
376 of main HOL, but was unused); better use HOL's datatype package;
378 * HOL: removed "symbols" syntax for constant "override" of theory Map;
379 the old syntax may be recovered as follows:
382 override :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
383 (infixl "\\<oplus>" 100)
385 * HOL/Real: "rabs" replaced by overloaded "abs" function;
387 * HOL/ML: even fewer consts are declared as global (see theories Ord,
388 Lfp, Gfp, WF); this only affects ML packages that refer to const names
391 * HOL and ZF: syntax for quotienting wrt an equivalence relation
392 changed from A/r to A//r;
394 * ZF: new treatment of arithmetic (nat & int) may break some old
397 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
398 rulify -> rule_format, elimify -> elim_format, ...);
400 * Isar/Provers: intro/elim/dest attributes changed; renamed
401 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
402 should have to change intro!! to intro? only); replaced "delrule" by
405 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
407 * Provers: strengthened force_tac by using new first_best_tac;
409 * LaTeX document preparation: several changes of isabelle.sty (see
413 *** Document preparation ***
415 * formal comments (text blocks etc.) in new-style theories may now
416 contain antiquotations of thm/prop/term/typ/text to be presented
417 according to latex print mode; concrete syntax is like this:
418 @{term[show_types] "f(x) = a + x"};
420 * isatool mkdir provides easy setup of Isabelle session directories,
421 including proper document sources;
423 * generated LaTeX sources are now deleted after successful run
424 (isatool document -c); may retain a copy somewhere else via -D option
427 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
428 style files, achieving self-contained LaTeX sources and simplifying
431 * old-style theories now produce (crude) LaTeX output as well;
433 * browser info session directories are now self-contained (may be put
434 on WWW server seperately); improved graphs of nested sessions; removed
435 graph for 'all sessions';
437 * several improvements in isabelle style files; \isabellestyle{it}
438 produces fake math mode output; \isamarkupheader is now \section by
439 default; see lib/texinputs/isabelle.sty etc.;
444 * Isar/Pure: local results and corresponding term bindings are now
445 subject to Hindley-Milner polymorphism (similar to ML); this
446 accommodates incremental type-inference very nicely;
448 * Isar/Pure: new derived language element 'obtain' supports
449 generalized existence reasoning;
451 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
452 support accumulation of results, without applying any rules yet;
453 useful to collect intermediate results without explicit name
454 references, and for use with transitivity rules with more than 2
457 * Isar/Pure: scalable support for case-analysis type proofs: new
458 'case' language element refers to local contexts symbolically, as
459 produced by certain proof methods; internally, case names are attached
460 to theorems as "tags";
462 * Isar/Pure: theory command 'hide' removes declarations from
463 class/type/const name spaces;
465 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
466 indicate potential overloading;
468 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
470 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
471 "{a,b,c}" instead of {a,b,c};
473 * Isar/Pure now provides its own version of intro/elim/dest
474 attributes; useful for building new logics, but beware of confusion
475 with the version in Provers/classical;
477 * Isar/Pure: the local context of (non-atomic) goals is provided via
478 case name 'antecedent';
480 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
481 to the current context is now done automatically);
483 * Isar/Pure: theory command 'method_setup' provides a simple interface
484 for definining proof methods in ML;
486 * Isar/Provers: intro/elim/dest attributes changed; renamed
487 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
488 most cases, one should have to change intro!! to intro? only);
489 replaced "delrule" by "rule del";
491 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
492 'symmetric' attribute (the latter supercedes [RS sym]);
494 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
495 method modifier); 'simp' method: 'only:' modifier removes loopers as
496 well (including splits);
498 * Isar/Provers: Simplifier and Classical methods now support all kind
499 of modifiers used in the past, including 'cong', 'iff', etc.
501 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
502 of Simplifier and Classical reasoner);
504 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
505 now support named cases; major packages (inductive, datatype, primrec,
506 recdef) support case names and properly name parameters;
508 * Isar/HOL: new transitivity rules for substitution in inequalities --
509 monotonicity conditions are extracted to be proven at end of
512 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
515 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
516 split_if split_if_asm; datatype package provides theorems foo.splits =
517 foo.split foo.split_asm for each datatype;
519 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
520 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
521 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
522 use "(cases (simplified))" method in proper proof texts);
524 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
526 * Isar: names of theorems etc. may be natural numbers as well;
528 * Isar: 'pr' command: optional arguments for goals_limit and
529 ProofContext.prems_limit; no longer prints theory contexts, but only
532 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
533 additional print modes to be specified; e.g. "pr(latex)" will print
534 proof state according to the Isabelle LaTeX style;
536 * Isar: improved support for emulating tactic scripts, including proof
537 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
538 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
541 * Isar: simplified (more robust) goal selection of proof methods: 1st
542 goal, all goals, or explicit goal specifier (tactic emulation); thus
543 'proof method scripts' have to be in depth-first order;
545 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
547 * Isar: removed 'help' command, which hasn't been too helpful anyway;
548 should instead use individual commands for printing items
549 (print_commands, print_methods etc.);
551 * Isar: added 'nothing' --- the empty list of theorems;
556 * HOL/MicroJava: formalization of a fragment of Java, together with a
557 corresponding virtual machine and a specification of its bytecode
558 verifier and a lightweight bytecode verifier, including proofs of
559 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
560 Cornelia Pusch (see also the homepage of project Bali at
561 http://isabelle.in.tum.de/Bali/);
563 * HOL/Algebra: new theory of rings and univariate polynomials, by
566 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
567 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
570 * HOL/Lattice: fundamental concepts of lattice theory and order
571 structures, including duals, properties of bounds versus algebraic
572 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
573 Theorem for complete lattices etc.; may also serve as a demonstration
574 for abstract algebraic reasoning using axiomatic type classes, and
575 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
577 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
580 * HOL/IMPP: extension of IMP with local variables and mutually
581 recursive procedures, by David von Oheimb;
583 * HOL/Lambda: converted into new-style theory and document;
585 * HOL/ex/Multiquote: example of multiple nested quotations and
586 anti-quotations -- basically a generalized version of de-Bruijn
587 representation; very useful in avoiding lifting of operations;
589 * HOL/record: added general record equality rule to simpset; fixed
590 select-update simplification procedure to handle extended records as
591 well; admit "r" as field name;
593 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
594 other numeric types and also as the identity of groups, rings, etc.;
596 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
597 Types nat and int belong to this axclass;
599 * HOL: greatly improved simplification involving numerals of type nat, int, real:
600 (i + #8 + j) = Suc k simplifies to #7 + (i + j) = k
601 i*j + k + j*#3*i simplifies to #4*(i*j) + k
602 two terms #m*u and #n*u are replaced by #(m+n)*u
603 (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
604 and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
605 or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
607 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
608 powerful prover for predicate logic but knows nothing of clasets; see
609 ex/mesontest.ML and ex/mesontest2.ML for example applications;
611 * HOL: new version of "case_tac" subsumes both boolean case split and
612 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
613 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
615 * HOL: simplification no longer dives into case-expressions: only the
616 selector expression is simplified, but not the remaining arms; to
617 enable full simplification of case-expressions for datatype t, you may
618 remove t.weak_case_cong from the simpset, either globally (Delcongs
619 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
621 * HOL/recdef: the recursion equations generated by 'recdef' for
622 function 'f' are now called f.simps instead of f.rules; if all
623 termination conditions are proved automatically, these simplification
624 rules are added to the simpset, as in primrec; rules may be named
625 individually as well, resulting in a separate list of theorems for
628 * HOL/While is a new theory that provides a while-combinator. It
629 permits the definition of tail-recursive functions without the
630 provision of a termination measure. The latter is necessary once the
631 invariant proof rule for while is applied.
633 * HOL: new (overloaded) notation for the set of elements below/above
634 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
636 * HOL: theorems impI, allI, ballI bound as "strip";
638 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
639 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
640 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
642 * HOL/Real: "rabs" replaced by overloaded "abs" function;
644 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
645 main HOL, but was unused);
647 * HOL: fewer consts declared as global (e.g. have to refer to
648 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
650 * HOL: tuned AST representation of nested pairs, avoiding bogus output
651 in case of overlap with user translations (e.g. judgements over
652 tuples); (note that the underlying logical represenation is still
658 * ZF: simplification automatically cancels common terms in arithmetic
659 expressions over nat and int;
661 * ZF: new treatment of nat to minimize type-checking: all operators
662 coerce their operands to a natural number using the function natify,
663 making the algebraic laws unconditional;
665 * ZF: as above, for int: operators coerce their operands to an integer
666 using the function intify;
668 * ZF: the integer library now contains many of the usual laws for the
669 orderings, including $<=, and monotonicity laws for $+ and $*;
671 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
674 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
675 to the simplifier and classical reasoner simultaneously;
680 * Provers: blast_tac now handles actual object-logic rules as
681 assumptions; note that auto_tac uses blast_tac internally as well;
683 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
684 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
686 * Provers: delrules now handles destruct rules as well (no longer need
689 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
690 [| inj ?f; ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
691 use instead the strong form,
692 [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
693 in HOL, FOL and ZF the function cla_make_elim will create such rules
696 * Provers: Simplifier.easy_setup provides a fast path to basic
697 Simplifier setup for new object-logics;
699 * Pure: AST translation rules no longer require constant head on LHS;
701 * Pure: improved name spaces: ambiguous output is qualified; support
704 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
705 XSYMBOL_HOME; no longer need to do manual configuration in most
708 * system: compression of ML heaps images may now be controlled via -c
709 option of isabelle and isatool usedir (currently only observed by
712 * system: isatool installfonts may handle X-Symbol fonts as well (very
713 useful for remote X11);
715 * system: provide TAGS file for Isabelle sources;
717 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
720 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
721 timing flag supersedes proof_timing and Toplevel.trace;
723 * ML: new combinators |>> and |>>> for incremental transformations
724 with secondary results (e.g. certain theory extensions):
726 * ML: PureThy.add_defs gets additional argument to indicate potential
727 overloading (usually false);
729 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
734 New in Isabelle99 (October 1999)
735 --------------------------------
737 *** Overview of INCOMPATIBILITIES (see below for more details) ***
739 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
740 are no longer simplified. (This allows the simplifier to unfold recursive
741 functional programs.) To restore the old behaviour, declare
743 Delcongs [if_weak_cong];
745 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
748 * HOL: the predicate "inj" is now defined by translation to "inj_on";
750 * HOL/datatype: mutual_induct_tac no longer exists --
751 use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
753 * HOL/typedef: fixed type inference for representing set; type
754 arguments now have to occur explicitly on the rhs as type constraints;
756 * ZF: The con_defs part of an inductive definition may no longer refer
757 to constants declared in the same theory;
759 * HOL, ZF: the function mk_cases, generated by the inductive
760 definition package, has lost an argument. To simplify its result, it
761 uses the default simpset instead of a supplied list of theorems.
763 * HOL/List: the constructors of type list are now Nil and Cons;
765 * Simplifier: the type of the infix ML functions
766 setSSolver addSSolver setSolver addSolver
767 is now simpset * solver -> simpset where `solver' is a new abstract type
768 for packaging solvers. A solver is created via
769 mk_solver: string -> (thm list -> int -> tactic) -> solver
770 where the string argument is only a comment.
775 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
776 decision procedure for linear arithmetic. Currently it is used for
777 types `nat', `int', and `real' in HOL (see below); it can, should and
778 will be instantiated for other types and logics as well.
780 * The simplifier now accepts rewrite rules with flexible heads, eg
781 hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
782 They are applied like any rule with a non-pattern lhs, i.e. by first-order
788 * New Isabelle/Isar subsystem provides an alternative to traditional
789 tactical theorem proving; together with the ProofGeneral/isar user
790 interface it offers an interactive environment for developing human
791 readable proof documents (Isar == Intelligible semi-automated
792 reasoning); for further information see isatool doc isar-ref,
793 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
795 * improved and simplified presentation of theories: better HTML markup
796 (including colors), graph views in several sizes; isatool usedir now
797 provides a proper interface for user theories (via -P option); actual
798 document preparation based on (PDF)LaTeX is available as well (for
799 new-style theories only); see isatool doc system for more information;
801 * native support for Proof General, both for classic Isabelle and
804 * ML function thm_deps visualizes dependencies of theorems and lemmas,
805 using the graph browser tool;
807 * Isabelle manuals now also available as PDF;
809 * theory loader rewritten from scratch (may not be fully
810 bug-compatible); old loadpath variable has been replaced by show_path,
811 add_path, del_path, reset_path functions; new operations such as
812 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
815 * improved isatool install: option -k creates KDE application icon,
816 option -p DIR installs standalone binaries;
818 * added ML_PLATFORM setting (useful for cross-platform installations);
819 more robust handling of platform specific ML images for SML/NJ;
821 * the settings environment is now statically scoped, i.e. it is never
822 created again in sub-processes invoked from isabelle, isatool, or
825 * path element specification '~~' refers to '$ISABELLE_HOME';
827 * in locales, the "assumes" and "defines" parts may be omitted if
830 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
833 * new print_mode "HTML";
835 * new flag show_tags controls display of tags of theorems (which are
836 basically just comments that may be attached by some tools);
838 * Isamode 2.6 requires patch to accomodate change of Isabelle font
839 mode and goal output format:
841 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
843 < (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
845 > (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
846 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
848 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
850 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
852 * function bind_thms stores lists of theorems (cf. bind_thm);
854 * new shorthand tactics ftac, eatac, datac, fatac;
856 * qed (and friends) now accept "" as result name; in that case the
857 theorem is not stored, but proper checks and presentation of the
860 * theorem database now also indexes constants "Trueprop", "all",
861 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
868 * There are now decision procedures for linear arithmetic over nat and
871 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
872 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
873 are treated as atomic; subformulae not involving type `nat' or `int'
874 are ignored; quantified subformulae are ignored unless they are
875 positive universal or negative existential. The tactic has to be
876 invoked by hand and can be a little bit slow. In particular, the
877 running time is exponential in the number of occurrences of `min' and
878 `max', and `-' on `nat'.
880 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
881 (negated) (in)equalities among the premises and the conclusion into
882 account (i.e. no compound formulae) and does not know about `min' and
883 `max', and `-' on `nat'. It is fast and is used automatically by the
886 NB: At the moment, these decision procedures do not cope with mixed
887 nat/int formulae where the two parts interact, such as `m < n ==>
890 * HOL/Numeral provides a generic theory of numerals (encoded
891 efficiently as bit strings); setup for types nat/int/real is in place;
892 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
893 int, existing theories and proof scripts may require a few additional
896 * integer division and remainder can now be performed on constant
899 * many properties of integer multiplication, division and remainder
902 * An interface to the Stanford Validity Checker (SVC) is available through the
903 tactic svc_tac. Propositional tautologies and theorems of linear arithmetic
904 are proved automatically. SVC must be installed separately, and its results
905 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
906 invocation of the underlying oracle). For SVC see
907 http://verify.stanford.edu/SVC
909 * IsaMakefile: the HOL-Real target now builds an actual image;
914 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
915 (in Isabelle/Isar) -- by Gertrud Bauer;
917 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
918 analysis for assembly languages with subtypes;
920 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
921 -- avoids syntactic ambiguities and treats state, transition, and
922 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
923 changed syntax and (many) tactics;
925 * HOL/inductive: Now also handles more general introduction rules such
926 as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
927 theorems are now maintained within the theory (maintained via the
930 * HOL/datatype: Now also handles arbitrarily branching datatypes
931 (using function types) such as
933 datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
935 * HOL/record: record_simproc (part of the default simpset) takes care
936 of selectors applied to updated records; record_split_tac is no longer
937 part of the default claset; update_defs may now be removed from the
938 simpset in many cases; COMPATIBILITY: old behavior achieved by
940 claset_ref () := claset() addSWrapper record_split_wrapper;
941 Delsimprocs [record_simproc]
943 * HOL/typedef: fixed type inference for representing set; type
944 arguments now have to occur explicitly on the rhs as type constraints;
946 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
947 names rather than an ML expression;
949 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
950 supplied later. Program schemes can be defined, such as
951 "While B C s = (if B s then While B C (C s) else s)"
952 where the well-founded relation can be chosen after B and C have been given.
954 * HOL/List: the constructors of type list are now Nil and Cons;
955 INCOMPATIBILITY: while [] and infix # syntax is still there, of
956 course, ML tools referring to List.list.op # etc. have to be adapted;
958 * HOL_quantifiers flag superseded by "HOL" print mode, which is
959 disabled by default; run isabelle with option -m HOL to get back to
960 the original Gordon/HOL-style output;
962 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
963 ALL x<=y. P, EX x<y. P, EX x<=y. P;
965 * HOL basic syntax simplified (more orthogonal): all variants of
966 All/Ex now support plain / symbolic / HOL notation; plain syntax for
967 Eps operator is provided as well: "SOME x. P[x]";
969 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
971 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
972 thus available for user theories;
974 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
975 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
978 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
979 several times and then mp;
984 * the notation <<...>> is now available as a notation for sequences of
987 * the simplifier is now installed
989 * the axiom system has been generalized (thanks to Soren Heilmann)
991 * the classical reasoner now has a default rule database
996 * new primrec section allows primitive recursive functions to be given
997 directly (as in HOL) over datatypes and the natural numbers;
999 * new tactics induct_tac and exhaust_tac for induction (or case
1000 analysis) over datatypes and the natural numbers;
1002 * the datatype declaration of type T now defines the recursor T_rec;
1004 * simplification automatically does freeness reasoning for datatype
1007 * automatic type-inference, with AddTCs command to insert new
1008 type-checking rules;
1010 * datatype introduction rules are now added as Safe Introduction rules
1013 * the syntax "if P then x else y" is now available in addition to
1017 *** Internal programming interfaces ***
1019 * tuned simplifier trace output; new flag debug_simp;
1021 * structures Vartab / Termtab (instances of TableFun) offer efficient
1022 tables indexed by indexname_ord / term_ord (compatible with aconv);
1024 * AxClass.axclass_tac lost the theory argument;
1026 * tuned current_goals_markers semantics: begin / end goal avoids
1027 printing empty lines;
1029 * removed prs and prs_fn hook, which was broken because it did not
1030 include \n in its semantics, forcing writeln to add one
1031 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
1032 string -> unit if you really want to output text without newline;
1034 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
1035 plain output, interface builders may have to enable 'isabelle_font'
1036 mode to get Isabelle font glyphs as before;
1038 * refined token_translation interface; INCOMPATIBILITY: output length
1039 now of type real instead of int;
1041 * theory loader actions may be traced via new ThyInfo.add_hook
1042 interface (see src/Pure/Thy/thy_info.ML); example application: keep
1043 your own database of information attached to *whole* theories -- as
1044 opposed to intra-theory data slots offered via TheoryDataFun;
1046 * proper handling of dangling sort hypotheses (at last!);
1047 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
1048 extra sort hypotheses that can be witnessed from the type signature;
1049 the force_strip_shyps flag is gone, any remaining shyps are simply
1050 left in the theorem (with a warning issued by strip_shyps_warning);
1054 New in Isabelle98-1 (October 1998)
1055 ----------------------------------
1057 *** Overview of INCOMPATIBILITIES (see below for more details) ***
1059 * several changes of automated proof tools;
1061 * HOL: major changes to the inductive and datatype packages, including
1062 some minor incompatibilities of theory syntax;
1064 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
1067 * HOL: removed duplicate thms in Arith:
1068 less_imp_add_less should be replaced by trans_less_add1
1069 le_imp_add_le should be replaced by trans_le_add1
1071 * HOL: unary minus is now overloaded (new type constraints may be
1074 * HOL and ZF: unary minus for integers is now #- instead of #~. In
1075 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
1076 now taken as an integer constant.
1078 * Pure: ML function 'theory_of' renamed to 'theory';
1084 1. Asm_full_simp_tac is now more aggressive.
1085 1. It will sometimes reorient premises if that increases their power to
1087 2. It does no longer proceed strictly from left to right but may also
1088 rotate premises to achieve further simplification.
1089 For compatibility reasons there is now Asm_lr_simp_tac which is like the
1090 old Asm_full_simp_tac in that it does not rotate premises.
1091 2. The simplifier now knows a little bit about nat-arithmetic.
1093 * Classical reasoner: wrapper mechanism for the classical reasoner now
1094 allows for selected deletion of wrappers, by introduction of names for
1095 wrapper functionals. This implies that addbefore, addSbefore,
1096 addaltern, and addSaltern now take a pair (name, tactic) as argument,
1097 and that adding two tactics with the same name overwrites the first
1098 one (emitting a warning).
1099 type wrapper = (int -> tactic) -> (int -> tactic)
1100 setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
1101 addWrapper, addSWrapper: claset * (string * wrapper) -> claset
1102 delWrapper, delSWrapper: claset * string -> claset
1103 getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
1105 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
1106 semantics; addbefore now affects only the unsafe part of step_tac
1107 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
1108 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
1111 * Classical reasoner: setwrapper to setWrapper and compwrapper to
1112 compWrapper; added safe wrapper (and access functions for it);
1114 * HOL/split_all_tac is now much faster and fails if there is nothing
1115 to split. Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
1116 and the names of the automatically generated variables have changed.
1117 split_all_tac has moved within claset() from unsafe wrappers to safe
1118 wrappers, which means that !!-bound variables are split much more
1119 aggressively, and safe_tac and clarify_tac now split such variables.
1120 If this splitting is not appropriate, use delSWrapper "split_all_tac".
1121 Note: the same holds for record_split_tac, which does the job of
1122 split_all_tac for record fields.
1124 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
1125 permanently to the default simpset using Addsplits just like
1126 Addsimps. They can be removed via Delsplits just like
1127 Delsimps. Lower-case versions are also available.
1129 * HOL/Simplifier: The rule split_if is now part of the default
1130 simpset. This means that the simplifier will eliminate all occurrences
1131 of if-then-else in the conclusion of a goal. To prevent this, you can
1132 either remove split_if completely from the default simpset by
1133 `Delsplits [split_if]' or remove it in a specific call of the
1134 simplifier using `... delsplits [split_if]'. You can also add/delete
1135 other case splitting rules to/from the default simpset: every datatype
1136 generates suitable rules `split_t_case' and `split_t_case_asm' (where
1137 t is the name of the datatype).
1139 * Classical reasoner / Simplifier combination: new force_tac (and
1140 derivatives Force_tac, force) combines rewriting and classical
1141 reasoning (and whatever other tools) similarly to auto_tac, but is
1142 aimed to solve the given subgoal completely.
1147 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
1148 and `goalw': the theory is no longer needed as an explicit argument -
1149 the current theory context is used; assumptions are no longer returned
1150 at the ML-level unless one of them starts with ==> or !!; it is
1151 recommended to convert to these new commands using isatool fixgoal
1152 (backup your sources first!);
1154 * new top-level commands 'thm' and 'thms' for retrieving theorems from
1155 the current theory context, and 'theory' to lookup stored theories;
1157 * new theory section 'locale' for declaring constants, assumptions and
1158 definitions that have local scope;
1160 * new theory section 'nonterminals' for purely syntactic types;
1162 * new theory section 'setup' for generic ML setup functions
1163 (e.g. package initialization);
1165 * the distribution now includes Isabelle icons: see
1166 lib/logo/isabelle-{small,tiny}.xpm;
1168 * isatool install - install binaries with absolute references to
1171 * isatool logo -- create instances of the Isabelle logo (as EPS);
1173 * print mode 'emacs' reserved for Isamode;
1175 * support multiple print (ast) translations per constant name;
1177 * theorems involving oracles are now printed with a suffixed [!];
1182 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
1184 * HOL/inductive package reorganized and improved: now supports mutual
1190 oddI "n : EVEN ==> Suc n : ODD"
1191 evenI "n : ODD ==> Suc n : EVEN"
1193 new theorem list "elims" contains an elimination rule for each of the
1194 recursive sets; inductive definitions now handle disjunctive premises
1195 correctly (also ZF);
1197 INCOMPATIBILITIES: requires Inductive as an ancestor; component
1198 "mutual_induct" no longer exists - the induction rule is always
1199 contained in "induct";
1202 * HOL/datatype package re-implemented and greatly improved: now
1203 supports mutually recursive datatypes such as
1206 'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
1207 | SUM ('a aexp) ('a aexp)
1208 | DIFF ('a aexp) ('a aexp)
1211 'a bexp = LESS ('a aexp) ('a aexp)
1212 | AND ('a bexp) ('a bexp)
1213 | OR ('a bexp) ('a bexp)
1215 as well as indirectly recursive datatypes such as
1218 ('a, 'b) term = Var 'a
1219 | App 'b ((('a, 'b) term) list)
1221 The new tactic mutual_induct_tac [<var_1>, ..., <var_n>] i performs
1222 induction on mutually / indirectly recursive datatypes.
1224 Primrec equations are now stored in theory and can be accessed via
1225 <function_name>.simps.
1229 - Theories using datatypes must now have theory Datatype as an
1231 - The specific <typename>.induct_tac no longer exists - use the
1232 generic induct_tac instead.
1233 - natE has been renamed to nat.exhaust - use exhaust_tac
1234 instead of res_inst_tac ... natE. Note that the variable
1235 names in nat.exhaust differ from the names in natE, this
1236 may cause some "fragile" proofs to fail.
1237 - The theorems split_<typename>_case and split_<typename>_case_asm
1238 have been renamed to <typename>.split and <typename>.split_asm.
1239 - Since default sorts of type variables are now handled correctly,
1240 some datatype definitions may have to be annotated with explicit
1242 - Primrec definitions no longer require function name and type
1243 of recursive argument.
1245 Consider using isatool fixdatatype to adapt your theories and proof
1246 scripts to the new package (backup your sources first!).
1249 * HOL/record package: considerably improved implementation; now
1250 includes concrete syntax for record types, terms, updates; theorems
1251 for surjective pairing and splitting !!-bound record variables; proof
1252 support is as follows:
1254 1) standard conversions (selectors or updates applied to record
1255 constructor terms) are part of the standard simpset;
1257 2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
1258 made part of standard simpset and claset via addIffs;
1260 3) a tactic for record field splitting (record_split_tac) is part of
1261 the standard claset (addSWrapper);
1263 To get a better idea about these rules you may retrieve them via
1264 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
1265 the name of your record type.
1267 The split tactic 3) conceptually simplifies by the following rule:
1269 "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
1271 Thus any record variable that is bound by meta-all will automatically
1272 blow up into some record constructor term, consequently the
1273 simplifications of 1), 2) apply. Thus force_tac, auto_tac etc. shall
1274 solve record problems automatically.
1277 * reorganized the main HOL image: HOL/Integ and String loaded by
1278 default; theory Main includes everything;
1280 * automatic simplification of integer sums and comparisons, using cancellation;
1282 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
1284 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
1286 * many new identities for unions, intersections, set difference, etc.;
1288 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
1289 called split_if, split_split, split_sum_case and split_nat_case (to go
1290 with add/delsplits);
1292 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
1293 (?x::unit) = (); this is made part of the default simpset, which COULD
1294 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
1295 'Delsimprocs [unit_eq_proc];' as last resort); also note that
1296 unit_abs_eta_conv is added in order to counter the effect of
1297 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
1300 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
1303 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
1304 It and 'sym RS equals0D' are now in the default claset, giving automatic
1305 disjointness reasoning but breaking a few old proofs.
1307 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
1308 to 'converse' from 'inverse' (for compatibility with ZF and some
1311 * HOL/recdef can now declare non-recursive functions, with {} supplied as
1312 the well-founded relation;
1314 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
1315 Compl A. The "Compl" syntax remains available as input syntax for this
1318 * HOL/Update: new theory of function updates:
1319 f(a:=b) == %x. if x=a then b else f x
1320 may also be iterated as in f(a:=b,c:=d,...);
1322 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
1325 - new function list_update written xs[i:=v] that updates the i-th
1326 list position. May also be iterated as in xs[i:=a,j:=b,...].
1327 - new function `upt' written [i..j(] which generates the list
1328 [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
1329 bound write [i..j], which is a shorthand for [i..j+1(].
1330 - new lexicographic orderings and corresponding wellfoundedness theorems.
1333 - removed 'pred' (predecessor) function;
1334 - generalized some theorems about n-1;
1335 - many new laws about "div" and "mod";
1336 - new laws about greatest common divisors (see theory ex/Primes);
1338 * HOL/Relation: renamed the relational operator r^-1 "converse"
1339 instead of "inverse";
1341 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
1342 of the multiset ordering;
1344 * directory HOL/Real: a construction of the reals using Dedekind cuts
1345 (not included by default);
1347 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
1349 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
1350 programs, i.e. different program variables may have different types.
1352 * calling (stac rew i) now fails if "rew" has no effect on the goal
1353 [previously, this check worked only if the rewrite rule was unconditional]
1354 Now rew can involve either definitions or equalities (either == or =).
1359 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
1360 only the theorems proved on ZF.ML;
1362 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
1363 It and 'sym RS equals0D' are now in the default claset, giving automatic
1364 disjointness reasoning but breaking a few old proofs.
1366 * ZF/Update: new theory of function updates
1367 with default rewrite rule f(x:=y) ` z = if(z=x, y, f`z)
1368 may also be iterated as in f(a:=b,c:=d,...);
1370 * in let x=t in u(x), neither t nor u(x) has to be an FOL term.
1372 * calling (stac rew i) now fails if "rew" has no effect on the goal
1373 [previously, this check worked only if the rewrite rule was unconditional]
1374 Now rew can involve either definitions or equalities (either == or =).
1376 * case_tac provided for compatibility with HOL
1377 (like the old excluded_middle_tac, but with subgoals swapped)
1380 *** Internal programming interfaces ***
1382 * Pure: several new basic modules made available for general use, see
1383 also src/Pure/README;
1385 * improved the theory data mechanism to support encapsulation (data
1386 kind name replaced by private Object.kind, acting as authorization
1387 key); new type-safe user interface via functor TheoryDataFun; generic
1388 print_data function becomes basically useless;
1390 * removed global_names compatibility flag -- all theory declarations
1391 are qualified by default;
1393 * module Pure/Syntax now offers quote / antiquote translation
1394 functions (useful for Hoare logic etc. with implicit dependencies);
1395 see HOL/ex/Antiquote for an example use;
1397 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
1400 * new tactical CHANGED_GOAL for checking that a tactic modifies a
1403 * Display.print_goals function moved to Locale.print_goals;
1405 * standard print function for goals supports current_goals_markers
1406 variable for marking begin of proof, end of proof, start of goal; the
1407 default is ("", "", ""); setting current_goals_markers := ("<proof>",
1408 "</proof>", "<goal>") causes SGML like tagged proof state printing,
1413 New in Isabelle98 (January 1998)
1414 --------------------------------
1416 *** Overview of INCOMPATIBILITIES (see below for more details) ***
1418 * changed lexical syntax of terms / types: dots made part of long
1419 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
1421 * simpset (and claset) reference variable replaced by functions
1422 simpset / simpset_ref;
1424 * no longer supports theory aliases (via merge) and non-trivial
1425 implicit merge of thms' signatures;
1427 * most internal names of constants changed due to qualified names;
1429 * changed Pure/Sequence interface (see Pure/seq.ML);
1432 *** General Changes ***
1434 * hierachically structured name spaces (for consts, types, axms, thms
1435 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
1436 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
1437 isatool fixdots ensures space after dots (e.g. "%x. x"); set
1438 long_names for fully qualified output names; NOTE: ML programs
1439 (special tactics, packages etc.) referring to internal names may have
1440 to be adapted to cope with fully qualified names; in case of severe
1441 backward campatibility problems try setting 'global_names' at compile
1442 time to have enrything declared within a flat name space; one may also
1443 fine tune name declarations in theories via the 'global' and 'local'
1446 * reimplemented the implicit simpset and claset using the new anytype
1447 data filed in signatures; references simpset:simpset ref etc. are
1448 replaced by functions simpset:unit->simpset and
1449 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
1450 to patch your ML files accordingly;
1452 * HTML output now includes theory graph data for display with Java
1453 applet or isatool browser; data generated automatically via isatool
1454 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
1456 * defs may now be conditional; improved rewrite_goals_tac to handle
1457 conditional equations;
1459 * defs now admits additional type arguments, using TYPE('a) syntax;
1461 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
1462 creates a new theory node; implicit merge of thms' signatures is
1463 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
1464 transfer:theory->thm->thm in (rare) cases;
1466 * improved handling of draft signatures / theories; draft thms (and
1467 ctyps, cterms) are automatically promoted to real ones;
1469 * slightly changed interfaces for oracles: admit many per theory, named
1470 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
1472 * print_goals: optional output of const types (set show_consts and
1475 * improved output of warnings (###) and errors (***);
1477 * subgoal_tac displays a warning if the new subgoal has type variables;
1479 * removed old README and Makefiles;
1481 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
1483 * removed obsolete init_pps and init_database;
1485 * deleted the obsolete tactical STATE, which was declared by
1486 fun STATE tacfun st = tacfun st st;
1488 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
1489 (which abbreviates $HOME);
1491 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
1492 use isatool fixseq to adapt your ML programs (this works for fully
1493 qualified references to the Sequence structure only!);
1495 * use_thy no longer requires writable current directory; it always
1496 reloads .ML *and* .thy file, if either one is out of date;
1499 *** Classical Reasoner ***
1501 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
1502 tactics that use classical reasoning to simplify a subgoal without
1503 splitting it into several subgoals;
1505 * Safe_tac: like safe_tac but uses the default claset;
1510 * added simplification meta rules:
1511 (asm_)(full_)simplify: simpset -> thm -> thm;
1513 * simplifier.ML no longer part of Pure -- has to be loaded by object
1516 * added prems argument to simplification procedures;
1518 * HOL, FOL, ZF: added infix function `addsplits':
1519 instead of `<simpset> setloop (split_tac <thms>)'
1520 you can simply write `<simpset> addsplits <thms>'
1525 * TYPE('a) syntax for type reflection terms;
1527 * no longer handles consts with name "" -- declare as 'syntax' instead;
1529 * pretty printer: changed order of mixfix annotation preference (again!);
1531 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
1536 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
1537 with `addloop' of the simplifier to faciliate case splitting in premises.
1539 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
1541 * HOL/Auth: new protocol proofs including some for the Internet
1544 * HOL/Map: new theory of `maps' a la VDM;
1546 * HOL/simplifier: simplification procedures nat_cancel_sums for
1547 cancelling out common nat summands from =, <, <= (in)equalities, or
1548 differences; simplification procedures nat_cancel_factor for
1549 cancelling common factor from =, <, <= (in)equalities over natural
1550 sums; nat_cancel contains both kinds of procedures, it is installed by
1551 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
1553 * HOL/simplifier: terms of the form
1554 `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)' (or t=x)
1556 `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
1557 and those of the form
1558 `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)' (or t=x)
1560 `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
1563 Each datatype `t' now comes with a theorem `split_t_case' of the form
1565 P(t_case f1 ... fn x) =
1566 ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
1568 (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
1571 and a theorem `split_t_case_asm' of the form
1573 P(t_case f1 ... fn x) =
1574 ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
1576 (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
1578 which can be added to a simpset via `addsplits'. The existing theorems
1579 expand_list_case and expand_option_case have been renamed to
1580 split_list_case and split_option_case.
1583 - `pred n' is automatically converted to `n-1'.
1584 Users are strongly encouraged not to use `pred' any longer,
1585 because it will disappear altogether at some point.
1586 - Users are strongly encouraged to write "0 < n" rather than
1587 "n ~= 0". Theorems and proof tools have been modified towards this
1591 the function "set_of_list" has been renamed "set" (and its theorems too);
1592 the function "nth" now takes its arguments in the reverse order and
1593 has acquired the infix notation "!" as in "xs!n".
1595 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
1597 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
1598 specialist theorems (like UN1_I) are gone. Similarly for (INT x.B x);
1600 * HOL/record: extensible records with schematic structural subtyping
1601 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
1602 still lacks various theorems and concrete record syntax;
1607 * removed "axioms" and "generated by" sections;
1609 * replaced "ops" section by extended "consts" section, which is capable of
1610 handling the continuous function space "->" directly;
1613 . proves theorems immediately and stores them in the theory,
1614 . creates hierachical name space,
1615 . now uses normal mixfix annotations (instead of cinfix...),
1616 . minor changes to some names and values (for consistency),
1617 . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
1618 . separator between mutual domain defs: changed "," to "and",
1619 . improved handling of sort constraints; now they have to
1620 appear on the left-hand side of the equations only;
1622 * fixed LAM <x,y,zs>.b syntax;
1624 * added extended adm_tac to simplifier in HOLCF -- can now discharge
1625 adm (%x. P (t x)), where P is chainfinite and t continuous;
1630 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
1631 with `addloop' of the simplifier to faciliate case splitting in premises.
1633 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
1634 in HOL, they strip ALL and --> from proved theorems;
1638 New in Isabelle94-8 (May 1997)
1639 ------------------------------
1641 *** General Changes ***
1643 * new utilities to build / run / maintain Isabelle etc. (in parts
1644 still somewhat experimental); old Makefiles etc. still functional;
1646 * new 'Isabelle System Manual';
1648 * INSTALL text, together with ./configure and ./build scripts;
1650 * reimplemented type inference for greater efficiency, better error
1651 messages and clean internal interface;
1653 * prlim command for dealing with lots of subgoals (an easier way of
1654 setting goals_limit);
1659 * supports alternative (named) syntax tables (parser and pretty
1660 printer); internal interface is provided by add_modesyntax(_i);
1662 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
1663 be used in conjunction with the Isabelle symbol font; uses the
1664 "symbols" syntax table;
1666 * added token_translation interface (may translate name tokens in
1667 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
1668 the current print_mode); IMPORTANT: user print translation functions
1669 are responsible for marking newly introduced bounds
1670 (Syntax.mark_boundT);
1672 * token translations for modes "xterm" and "xterm_color" that display
1673 names in bold, underline etc. or colors (which requires a color
1676 * infixes may now be declared with names independent of their syntax;
1678 * added typed_print_translation (like print_translation, but may
1679 access type of constant);
1682 *** Classical Reasoner ***
1684 Blast_tac: a new tactic! It is often more powerful than fast_tac, but has
1685 some limitations. Blast_tac...
1686 + ignores addss, addbefore, addafter; this restriction is intrinsic
1687 + ignores elimination rules that don't have the correct format
1688 (the conclusion MUST be a formula variable)
1689 + ignores types, which can make HOL proofs fail
1690 + rules must not require higher-order unification, e.g. apply_type in ZF
1691 [message "Function Var's argument not a bound variable" relates to this]
1692 + its proof strategy is more general but can actually be slower
1694 * substitution with equality assumptions no longer permutes other
1697 * minor changes in semantics of addafter (now called addaltern); renamed
1698 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
1699 (and access functions for it);
1701 * improved combination of classical reasoner and simplifier:
1702 + functions for handling clasimpsets
1703 + improvement of addss: now the simplifier is called _after_ the
1705 + safe variant of addss called addSss: uses safe simplifications
1706 _during_ the safe steps. It is more complete as it allows multiple
1707 instantiations of unknowns (e.g. with slow_tac).
1711 * added interface for simplification procedures (functions that
1712 produce *proven* rewrite rules on the fly, depending on current
1715 * ordering on terms as parameter (used for ordered rewriting);
1717 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
1719 * the solver is now split into a safe and an unsafe part.
1720 This should be invisible for the normal user, except that the
1721 functions setsolver and addsolver have been renamed to setSolver and
1722 addSolver; added safe_asm_full_simp_tac;
1727 * a generic induction tactic `induct_tac' which works for all datatypes and
1728 also for type `nat';
1730 * a generic case distinction tactic `exhaust_tac' which works for all
1731 datatypes and also for type `nat';
1733 * each datatype comes with a function `size';
1735 * patterns in case expressions allow tuple patterns as arguments to
1736 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
1738 * primrec now also works with type nat;
1740 * recdef: a new declaration form, allows general recursive functions to be
1741 defined in theory files. See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
1743 * the constant for negation has been renamed from "not" to "Not" to
1744 harmonize with FOL, ZF, LK, etc.;
1746 * HOL/ex/LFilter theory of a corecursive "filter" functional for
1749 * HOL/Modelcheck demonstrates invocation of model checker oracle;
1751 * HOL/ex/Ring.thy declares cring_simp, which solves equational
1752 problems in commutative rings, using axiomatic type classes for + and *;
1754 * more examples in HOL/MiniML and HOL/Auth;
1756 * more default rewrite rules for quantifiers, union/intersection;
1758 * a new constant `arbitrary == @x.False';
1760 * HOLCF/IOA replaces old HOL/IOA;
1762 * HOLCF changes: derived all rules and arities
1763 + axiomatic type classes instead of classes
1764 + typedef instead of faking type definitions
1765 + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
1766 + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
1767 + eliminated the types void, one, tr
1768 + use unit lift and bool lift (with translations) instead of one and tr
1769 + eliminated blift from Lift3.thy (use Def instead of blift)
1770 all eliminated rules are derived as theorems --> no visible changes ;
1775 * ZF now has Fast_tac, Simp_tac and Auto_tac. Union_iff is a now a default
1776 rewrite rule; this may affect some proofs. eq_cs is gone but can be put back
1777 as ZF_cs addSIs [equalityI];
1781 New in Isabelle94-7 (November 96)
1782 ---------------------------------
1784 * allowing negative levels (as offsets) in prlev and choplev;
1786 * super-linear speedup for large simplifications;
1788 * FOL, ZF and HOL now use miniscoping: rewriting pushes
1789 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
1790 FAIL); can suppress it using the command Delsimps (ex_simps @
1791 all_simps); De Morgan laws are also now included, by default;
1793 * improved printing of ==> : ~:
1795 * new object-logic "Sequents" adds linear logic, while replacing LK
1796 and Modal (thanks to Sara Kalvala);
1798 * HOL/Auth: correctness proofs for authentication protocols;
1800 * HOL: new auto_tac combines rewriting and classical reasoning (many
1801 examples on HOL/Auth);
1803 * HOL: new command AddIffs for declaring theorems of the form P=Q to
1804 the rewriter and classical reasoner simultaneously;
1806 * function uresult no longer returns theorems in "standard" format;
1807 regain previous version by: val uresult = standard o uresult;
1814 * oracles -- these establish an interface between Isabelle and trusted
1815 external reasoners, which may deliver results as theorems;
1817 * proof objects (in particular record all uses of oracles);
1819 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
1821 * "constdefs" section in theory files;
1823 * "primrec" section (HOL) no longer requires names;
1825 * internal type "tactic" now simply "thm -> thm Sequence.seq";
1832 * reduced space requirements;
1834 * automatic HTML generation from theories;
1836 * theory files no longer require "..." (quotes) around most types;
1838 * new examples, including two proofs of the Church-Rosser theorem;
1840 * non-curried (1994) version of HOL is no longer distributed;
1847 * greatly reduced space requirements;
1849 * theory files (.thy) no longer require \...\ escapes at line breaks;
1851 * searchable theorem database (see the section "Retrieving theorems" on
1852 page 8 of the Reference Manual);
1854 * new examples, including Grabczewski's monumental case study of the
1857 * The previous version of HOL renamed to Old_HOL;
1859 * The new version of HOL (previously called CHOL) uses a curried syntax
1860 for functions. Application looks like f a b instead of f(a,b);
1862 * Mutually recursive inductive definitions finally work in HOL;
1864 * In ZF, pattern-matching on tuples is now available in all abstractions and
1865 translates to the operator "split";
1872 * new infix operator, addss, allowing the classical reasoner to
1873 perform simplification at each step of its search. Example:
1874 fast_tac (cs addss ss)
1876 * a new logic, CHOL, the same as HOL, but with a curried syntax
1877 for functions. Application looks like f a b instead of f(a,b). Also pairs
1878 look like (a,b) instead of <a,b>;
1880 * PLEASE NOTE: CHOL will eventually replace HOL!
1882 * In CHOL, pattern-matching on tuples is now available in all abstractions.
1883 It translates to the operator "split". A new theory of integers is available;
1885 * In ZF, integer numerals now denote two's-complement binary integers.
1886 Arithmetic operations can be performed by rewriting. See ZF/ex/Bin.ML;
1888 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
1889 of the Axiom of Choice;
1896 * Significantly faster resolution;
1898 * the different sections in a .thy file can now be mixed and repeated
1901 * Database of theorems for FOL, HOL and ZF. New
1902 commands including qed, qed_goal and bind_thm store theorems in the database.
1904 * Simple database queries: return a named theorem (get_thm) or all theorems of
1905 a given theory (thms_of), or find out what theory a theorem was proved in
1908 * Bugs fixed in the inductive definition and datatype packages;
1910 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
1911 and HOL_dup_cs obsolete;
1913 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
1916 * Simpler definition of function space in ZF;
1918 * new results about cardinal and ordinal arithmetic in ZF;
1920 * 'subtype' facility in HOL for introducing new types as subsets of existing