2 Isabelle NEWS -- history user-relevant changes
3 ==============================================
5 New in this Isabelle version
6 ----------------------------
8 *** Overview of INCOMPATIBILITIES (see below for more details) ***
10 * HOL: simplification of natural numbers is much changed; to partly
11 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
12 issue the following ML commands:
14 Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
15 Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
17 * HOL: 0 is now overloaded, so the type constraint ::nat may sometimes be
20 * HOL: the constant for f``x is now "image" rather than "op ``";
22 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
23 product is now "<*>" instead of "Times"; the lexicographic product is
24 now "<*lex*>" instead of "**";
26 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
28 * HOL: simplification no longer dives into case-expressions;
30 * HOL: the recursion equations generated by 'recdef' are now called
31 f.simps instead of f.rules;
33 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
34 main HOL, but was unused); should better use HOL's datatype package
37 * HOL: removed obsolete theorem binding expand_if (refer to split_if
40 * HOL/Real: "rabs" replaced by overloaded "abs" function;
42 * HOL/ML: even fewer consts are declared as global (see theories Ord,
43 Lfp, Gfp, WF); this only affects ML packages that refer to const names
46 * HOL, ZF: syntax for quotienting wrt an equivalence relation changed from
49 * ZF: new treatment of arithmetic (nat & int) may break some old proofs;
51 * Isar/Provers: intro/elim/dest attributes: changed
52 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
53 should have to change intro!! to intro? only);
55 * Isar: changed syntax of local blocks from {{ }} to { };
57 * Isar: renamed 'RS' attribute to 'THEN';
59 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
61 * Provers: strengthened force_tac by using new first_best_tac;
63 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
64 [| inj ?f; ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
65 use instead the strong form,
66 [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
67 In HOL, FOL and ZF the function cla_make_elim will create such rules
70 * Provers: safe_asm_full_simp_tac is no longer in the simplifier signature. Use
71 val safe_asm_full_simp_tac = generic_simp_tac true (true,true,true);
74 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
75 timing flag supersedes proof_timing and Toplevel.trace;
77 * ML: PureThy.add_thms/add_axioms/add_defs return theorems as well;
79 * ML: PureThy.add_defs gets additional argument to indicate potential
80 overloading (usually false);
82 * LaTeX: several changes of isabelle.sty;
85 *** Document preparation ***
87 * formal comments (text blocks etc.) in new-style theories may now
88 contain antiquotations of thm/prop/term/typ/text to be presented
89 according to latex print mode; concrete syntax is like this:
90 @{term[show_types] "f(x) = a + x"};
92 * isatool mkdir provides easy setup of Isabelle session directories,
93 including proper document sources;
95 * generated LaTeX sources are now deleted after successful run
96 (isatool document -c); may retain a copy somewhere else via -D option
99 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
100 style files, achieving self-contained LaTeX sources;
102 * old-style theories now produce (crude) LaTeX output as well;
104 * browser info session directories are now self-contained (may be put
105 on WWW server seperately); improved graphs of nested sessions; removed
106 graph for 'all sessions';
108 * several improvements in isabelle.sty; \isabellestyle{it} produces
109 near math mode output; \isamarkupheader is now \section by default;
114 * Pure: local results and corresponding term bindings are now subject
115 to Hindley-Milner polymorphism (similar to ML); this accommodates
116 incremental type-inference nicely;
118 * Pure: new derived language element 'obtain' supports generalized
121 * Pure: new calculational elements 'moreover' and 'ultimately' support
122 accumulation of results, without applying any rules yet;
124 * Pure: scalable support for case-analysis type proofs: new 'case'
125 language element refers to local contexts symbolically, as produced by
126 certain proof methods; internally, case names are attached to theorems
129 * Pure: theory command 'hide' removes declarations from
130 class/type/const name spaces;
132 * Pure: theory command 'defs' supports option "(overloaded)" to
133 indicate potential overloading;
135 * Pure: changed syntax of local blocks from {{ }} to { };
137 * Pure: renamed 'RS' attribute to 'THEN';
139 * Pure: syntax of sorts made 'inner', i.e. have to write "{a, b, c}"
140 instead of {a, b, c};
142 * Pure now provides its own version of intro/elim/dest attributes;
143 useful for building new logics, but beware of confusion with the
144 version in Provers/classical;
146 * Pure: the local context of (non-atomic) goals is provided via case
149 * Pure: removed obsolete 'transfer' attribute (transfer of thms to the
150 current context is now done automatically);
152 * Pure: theory command 'method_setup' provides a simple interface for
153 definining proof methods in ML;
155 * Provers: 'simp' method now supports 'cong' modifiers;
157 * Provers: hypsubst support; also plain subst and symmetric attribute
158 (the latter supercedes [RS sym]);
160 * Provers: splitter support (via 'split' attribute and 'simp' method
161 modifier); 'simp' method: 'only:' modifier removes loopers as well
164 * Provers: added 'fastsimp' and 'clarsimp' methods (combination of
165 Simplifier and Classical reasoner);
167 * Provers: added 'arith_split' attribute;
169 * HOL: new proof method 'cases' and improved version of 'induct' now
170 support named cases; major packages (inductive, datatype, primrec,
171 recdef) support case names and properly name parameters;
173 * HOL: removed 'case_split' thm binding, should use 'cases' proof
176 * HOL: removed obsolete expand_if = split_if; theorems if_splits =
177 split_if split_if_asm; datatype package provides theorems foo.splits =
178 foo.split foo.split_asm for each datatype;
180 * HOL/Calculation: new rules for substitution in inequalities
181 (monotonicity conditions are extracted to be proven at end);
183 * HOL/inductive: rename "intrs" to "intros" (potential
184 INCOMPATIBILITY); emulation of mk_cases feature for proof scripts:
185 'inductive_cases' command and 'ind_cases' method; NOTE: use (cases
186 (simplified)) method in proper proofs;
188 * Provers: intro/elim/dest attributes: changed intro/intro!/intro!!
189 flags to intro!/intro/intro? (in most cases, one should have to change
190 intro!! to intro? only);
192 * names of theorems etc. may be natural numbers as well;
194 * 'pr' command: optional arguments for goals_limit and
195 ProofContext.prems_limit; no longer prints theory contexts, but only
198 * diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
199 additional print modes to be specified; e.g. "pr(latex)" will print
200 proof state according to the Isabelle LaTeX style;
202 * improved support for emulating tactic scripts, including proof
203 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
204 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
207 * simplified (more robust) goal selection of proof methods: 1st goal,
208 all goals, or explicit goal specifier (tactic emulation); thus 'proof
209 method scripts' have to be in depth-first order;
211 * tuned 'let' syntax: replaced 'as' keyword by 'and';
213 * removed 'help' command, which hasn't been too helpful anyway; should
214 instead use individual commands for printing items (print_commands,
217 * added 'nothing' --- the empty list of theorems;
222 * HOL/Lambda: converted into new-style theory and document;
224 * HOL/Algebra: new theory of rings and univariate polynomials, by
227 * HOL/ex: new theory Factorization proving the Fundamental Theorem of
228 Arithmetic, by Thomas M Rasmussen;
230 * HOL/ex/Multiquote: multiple nested quotations and anti-quotations --
231 basically a generalized version of de-Bruijn representation; very
232 useful in avoiding lifting of operations;
234 * HOL/NumberTheory: Chinese Remainder Theorem, Fermat/Euler Theorem, Wilson's
235 Theorem, by Thomas M Rasmussen;
237 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog;
239 * HOL/Real: "rabs" replaced by overloaded "abs" function;
241 * HOL/record: added general record equality rule to simpset; fixed
242 select-update simplification procedure to handle extended records as
243 well; admit "r" as field name;
245 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
246 other numeric types and also as the identity of groups, rings, etc.;
248 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
249 Types nat and int belong to this axclass;
251 * greatly improved simplification involving numerals of type nat, int, real:
252 (i + #8 + j) = Suc k simplifies to #7 + (i + j) = k
253 i*j + k + j*#3*i simplifies to #4*(i*j) + k
254 two terms #m*u and #n*u are replaced by #(m+n)*u
255 (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
256 and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
257 or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
259 * HOL: new version of "case_tac" subsumes both boolean case split and
260 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
261 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
263 * HOL: simplification no longer dives into case-expressions: only the
264 selector expression is simplified, but not the remaining arms. To
265 enable full simplification of case-expressions for datatype t, you
266 need to remove t.weak_case_cong from the simpset, either permanently
267 (Delcongs[thm"t.weak_case_cong"];) or locally (delcongs [...]).
269 * HOL/recdef: the recursion equations generated by 'recdef' for
270 function 'f' are now called f.simps instead of f.rules; if all
271 termination conditions are proved automatically, these simplification
272 rules are added to the simpset, as in primrec; rules may be named
273 individually as well, resulting in a separate list of theorems for
276 * HOL/While is a new theory that provides a while-combinator. It
277 permits the definition of tail-recursive functions without the
278 provision of a termination measure. The latter is necessary once the
279 invariant proof rule for while is applied.
281 * HOL: new (overloaded) notation for the set of elements below/above some
282 element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
284 * HOL: theorems impI, allI, ballI bound as "strip";
286 * new tactic induct_thm_tac: thm -> string -> int -> tactic
287 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
288 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
290 * new function rulify: thm -> thm for turning outer -->/! into ==>/?;
291 behaves like qed_spec_mp;
293 * theory Sexp now in HOL/Induct examples (it used to be part of main
294 HOL, but was unused);
296 * fewer consts declared as global (e.g. have to refer to "Lfp.lfp"
297 instead of "lfp" internally; affects ML packages only);
299 * tuned AST representation of nested pairs, avoiding bogus output in
300 case of overlap with user translations (e.g. judgements over tuples);
305 * simplification automatically cancels common terms in arithmetic expressions
308 * new treatment of nat to minimize type-checking: all operators coerce their
309 operands to a natural number using the function natify, making the algebraic
312 * as above, for int: operators coerce their operands to an integer using the
315 * the integer library now contains many of the usual laws for the orderings,
316 including $<=, and monotonicity laws for $+ and $*;
318 * new example ZF/ex/NatSum to demonstrate integer arithmetic simplification;
322 * AddIffs now available, giving theorems of the form P<->Q to the
323 simplifier and classical reasoner simultaneously;
328 * Provers: blast(_tac) now handles actual object-logic rules as
329 assumptions; note that auto(_tac) uses blast(_tac) internally as well;
331 * Provers: Simplifier.easy_setup provides a fast path to basic
332 Simplifier setup for new object-logics;
334 * Pure: AST translation rules no longer require constant head on LHS;
336 * Pure: improved name spaces: ambiguous output is qualified; support
339 * system: compression of ML heaps images may now be controlled via -c
340 option of isabelle and isatool usedir (currently only observed by
343 * system: provide TAGS file for Isabelle sources;
345 * settings: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
346 XSYMBOL_HOME; no longer need to do manual configuration in most
349 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
352 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
353 timing flag supersedes proof_timing and Toplevel.trace;
355 * ML: PureThy.add_defs gets additional argument to indicate potential
356 overloading (usually false);
358 * ML: new combinators |>> and |>>> for incremental transformations
359 with secondary results (e.g. certain theory extensions):
363 New in Isabelle99 (October 1999)
364 --------------------------------
366 *** Overview of INCOMPATIBILITIES (see below for more details) ***
368 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
369 are no longer simplified. (This allows the simplifier to unfold recursive
370 functional programs.) To restore the old behaviour, declare
372 Delcongs [if_weak_cong];
374 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
377 * HOL: the predicate "inj" is now defined by translation to "inj_on";
379 * HOL/datatype: mutual_induct_tac no longer exists --
380 use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
382 * HOL/typedef: fixed type inference for representing set; type
383 arguments now have to occur explicitly on the rhs as type constraints;
385 * ZF: The con_defs part of an inductive definition may no longer refer
386 to constants declared in the same theory;
388 * HOL, ZF: the function mk_cases, generated by the inductive
389 definition package, has lost an argument. To simplify its result, it
390 uses the default simpset instead of a supplied list of theorems.
392 * HOL/List: the constructors of type list are now Nil and Cons;
394 * Simplifier: the type of the infix ML functions
395 setSSolver addSSolver setSolver addSolver
396 is now simpset * solver -> simpset where `solver' is a new abstract type
397 for packaging solvers. A solver is created via
398 mk_solver: string -> (thm list -> int -> tactic) -> solver
399 where the string argument is only a comment.
404 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
405 decision procedure for linear arithmetic. Currently it is used for
406 types `nat', `int', and `real' in HOL (see below); it can, should and
407 will be instantiated for other types and logics as well.
409 * The simplifier now accepts rewrite rules with flexible heads, eg
410 hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
411 They are applied like any rule with a non-pattern lhs, i.e. by first-order
417 * New Isabelle/Isar subsystem provides an alternative to traditional
418 tactical theorem proving; together with the ProofGeneral/isar user
419 interface it offers an interactive environment for developing human
420 readable proof documents (Isar == Intelligible semi-automated
421 reasoning); for further information see isatool doc isar-ref,
422 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
424 * improved and simplified presentation of theories: better HTML markup
425 (including colors), graph views in several sizes; isatool usedir now
426 provides a proper interface for user theories (via -P option); actual
427 document preparation based on (PDF)LaTeX is available as well (for
428 new-style theories only); see isatool doc system for more information;
430 * native support for Proof General, both for classic Isabelle and
433 * ML function thm_deps visualizes dependencies of theorems and lemmas,
434 using the graph browser tool;
436 * Isabelle manuals now also available as PDF;
438 * theory loader rewritten from scratch (may not be fully
439 bug-compatible); old loadpath variable has been replaced by show_path,
440 add_path, del_path, reset_path functions; new operations such as
441 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
444 * improved isatool install: option -k creates KDE application icon,
445 option -p DIR installs standalone binaries;
447 * added ML_PLATFORM setting (useful for cross-platform installations);
448 more robust handling of platform specific ML images for SML/NJ;
450 * the settings environment is now statically scoped, i.e. it is never
451 created again in sub-processes invoked from isabelle, isatool, or
454 * path element specification '~~' refers to '$ISABELLE_HOME';
456 * in locales, the "assumes" and "defines" parts may be omitted if
459 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
462 * new print_mode "HTML";
464 * new flag show_tags controls display of tags of theorems (which are
465 basically just comments that may be attached by some tools);
467 * Isamode 2.6 requires patch to accomodate change of Isabelle font
468 mode and goal output format:
470 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
472 < (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
474 > (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
475 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
477 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
479 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
481 * function bind_thms stores lists of theorems (cf. bind_thm);
483 * new shorthand tactics ftac, eatac, datac, fatac;
485 * qed (and friends) now accept "" as result name; in that case the
486 theorem is not stored, but proper checks and presentation of the
489 * theorem database now also indexes constants "Trueprop", "all",
490 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
497 * There are now decision procedures for linear arithmetic over nat and
500 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
501 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
502 are treated as atomic; subformulae not involving type `nat' or `int'
503 are ignored; quantified subformulae are ignored unless they are
504 positive universal or negative existential. The tactic has to be
505 invoked by hand and can be a little bit slow. In particular, the
506 running time is exponential in the number of occurrences of `min' and
507 `max', and `-' on `nat'.
509 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
510 (negated) (in)equalities among the premises and the conclusion into
511 account (i.e. no compound formulae) and does not know about `min' and
512 `max', and `-' on `nat'. It is fast and is used automatically by the
515 NB: At the moment, these decision procedures do not cope with mixed
516 nat/int formulae where the two parts interact, such as `m < n ==>
519 * HOL/Numeral provides a generic theory of numerals (encoded
520 efficiently as bit strings); setup for types nat/int/real is in place;
521 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
522 int, existing theories and proof scripts may require a few additional
525 * integer division and remainder can now be performed on constant
528 * many properties of integer multiplication, division and remainder
531 * An interface to the Stanford Validity Checker (SVC) is available through the
532 tactic svc_tac. Propositional tautologies and theorems of linear arithmetic
533 are proved automatically. SVC must be installed separately, and its results
534 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
535 invocation of the underlying oracle). For SVC see
536 http://verify.stanford.edu/SVC
538 * IsaMakefile: the HOL-Real target now builds an actual image;
543 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
544 (in Isabelle/Isar) -- by Gertrud Bauer;
546 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
547 analysis for assembly languages with subtypes;
549 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
550 -- avoids syntactic ambiguities and treats state, transition, and
551 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
552 changed syntax and (many) tactics;
554 * HOL/inductive: Now also handles more general introduction rules such
555 as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
556 theorems are now maintained within the theory (maintained via the
559 * HOL/datatype: Now also handles arbitrarily branching datatypes
560 (using function types) such as
562 datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
564 * HOL/record: record_simproc (part of the default simpset) takes care
565 of selectors applied to updated records; record_split_tac is no longer
566 part of the default claset; update_defs may now be removed from the
567 simpset in many cases; COMPATIBILITY: old behavior achieved by
569 claset_ref () := claset() addSWrapper record_split_wrapper;
570 Delsimprocs [record_simproc]
572 * HOL/typedef: fixed type inference for representing set; type
573 arguments now have to occur explicitly on the rhs as type constraints;
575 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
576 names rather than an ML expression;
578 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
579 supplied later. Program schemes can be defined, such as
580 "While B C s = (if B s then While B C (C s) else s)"
581 where the well-founded relation can be chosen after B and C have been given.
583 * HOL/List: the constructors of type list are now Nil and Cons;
584 INCOMPATIBILITY: while [] and infix # syntax is still there, of
585 course, ML tools referring to List.list.op # etc. have to be adapted;
587 * HOL_quantifiers flag superseded by "HOL" print mode, which is
588 disabled by default; run isabelle with option -m HOL to get back to
589 the original Gordon/HOL-style output;
591 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
592 ALL x<=y. P, EX x<y. P, EX x<=y. P;
594 * HOL basic syntax simplified (more orthogonal): all variants of
595 All/Ex now support plain / symbolic / HOL notation; plain syntax for
596 Eps operator is provided as well: "SOME x. P[x]";
598 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
600 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
601 thus available for user theories;
603 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
604 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
607 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
608 several times and then mp;
613 * the notation <<...>> is now available as a notation for sequences of
616 * the simplifier is now installed
618 * the axiom system has been generalized (thanks to Soren Heilmann)
620 * the classical reasoner now has a default rule database
625 * new primrec section allows primitive recursive functions to be given
626 directly (as in HOL) over datatypes and the natural numbers;
628 * new tactics induct_tac and exhaust_tac for induction (or case
629 analysis) over datatypes and the natural numbers;
631 * the datatype declaration of type T now defines the recursor T_rec;
633 * simplification automatically does freeness reasoning for datatype
636 * automatic type-inference, with AddTCs command to insert new
639 * datatype introduction rules are now added as Safe Introduction rules
642 * the syntax "if P then x else y" is now available in addition to
646 *** Internal programming interfaces ***
648 * tuned simplifier trace output; new flag debug_simp;
650 * structures Vartab / Termtab (instances of TableFun) offer efficient
651 tables indexed by indexname_ord / term_ord (compatible with aconv);
653 * AxClass.axclass_tac lost the theory argument;
655 * tuned current_goals_markers semantics: begin / end goal avoids
656 printing empty lines;
658 * removed prs and prs_fn hook, which was broken because it did not
659 include \n in its semantics, forcing writeln to add one
660 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
661 string -> unit if you really want to output text without newline;
663 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
664 plain output, interface builders may have to enable 'isabelle_font'
665 mode to get Isabelle font glyphs as before;
667 * refined token_translation interface; INCOMPATIBILITY: output length
668 now of type real instead of int;
670 * theory loader actions may be traced via new ThyInfo.add_hook
671 interface (see src/Pure/Thy/thy_info.ML); example application: keep
672 your own database of information attached to *whole* theories -- as
673 opposed to intra-theory data slots offered via TheoryDataFun;
675 * proper handling of dangling sort hypotheses (at last!);
676 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
677 extra sort hypotheses that can be witnessed from the type signature;
678 the force_strip_shyps flag is gone, any remaining shyps are simply
679 left in the theorem (with a warning issued by strip_shyps_warning);
683 New in Isabelle98-1 (October 1998)
684 ----------------------------------
686 *** Overview of INCOMPATIBILITIES (see below for more details) ***
688 * several changes of automated proof tools;
690 * HOL: major changes to the inductive and datatype packages, including
691 some minor incompatibilities of theory syntax;
693 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
696 * HOL: removed duplicate thms in Arith:
697 less_imp_add_less should be replaced by trans_less_add1
698 le_imp_add_le should be replaced by trans_le_add1
700 * HOL: unary minus is now overloaded (new type constraints may be
703 * HOL and ZF: unary minus for integers is now #- instead of #~. In
704 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
705 now taken as an integer constant.
707 * Pure: ML function 'theory_of' renamed to 'theory';
713 1. Asm_full_simp_tac is now more aggressive.
714 1. It will sometimes reorient premises if that increases their power to
716 2. It does no longer proceed strictly from left to right but may also
717 rotate premises to achieve further simplification.
718 For compatibility reasons there is now Asm_lr_simp_tac which is like the
719 old Asm_full_simp_tac in that it does not rotate premises.
720 2. The simplifier now knows a little bit about nat-arithmetic.
722 * Classical reasoner: wrapper mechanism for the classical reasoner now
723 allows for selected deletion of wrappers, by introduction of names for
724 wrapper functionals. This implies that addbefore, addSbefore,
725 addaltern, and addSaltern now take a pair (name, tactic) as argument,
726 and that adding two tactics with the same name overwrites the first
727 one (emitting a warning).
728 type wrapper = (int -> tactic) -> (int -> tactic)
729 setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
730 addWrapper, addSWrapper: claset * (string * wrapper) -> claset
731 delWrapper, delSWrapper: claset * string -> claset
732 getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
734 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
735 semantics; addbefore now affects only the unsafe part of step_tac
736 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
737 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
740 * Classical reasoner: setwrapper to setWrapper and compwrapper to
741 compWrapper; added safe wrapper (and access functions for it);
743 * HOL/split_all_tac is now much faster and fails if there is nothing
744 to split. Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
745 and the names of the automatically generated variables have changed.
746 split_all_tac has moved within claset() from unsafe wrappers to safe
747 wrappers, which means that !!-bound variables are split much more
748 aggressively, and safe_tac and clarify_tac now split such variables.
749 If this splitting is not appropriate, use delSWrapper "split_all_tac".
750 Note: the same holds for record_split_tac, which does the job of
751 split_all_tac for record fields.
753 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
754 permanently to the default simpset using Addsplits just like
755 Addsimps. They can be removed via Delsplits just like
756 Delsimps. Lower-case versions are also available.
758 * HOL/Simplifier: The rule split_if is now part of the default
759 simpset. This means that the simplifier will eliminate all occurrences
760 of if-then-else in the conclusion of a goal. To prevent this, you can
761 either remove split_if completely from the default simpset by
762 `Delsplits [split_if]' or remove it in a specific call of the
763 simplifier using `... delsplits [split_if]'. You can also add/delete
764 other case splitting rules to/from the default simpset: every datatype
765 generates suitable rules `split_t_case' and `split_t_case_asm' (where
766 t is the name of the datatype).
768 * Classical reasoner / Simplifier combination: new force_tac (and
769 derivatives Force_tac, force) combines rewriting and classical
770 reasoning (and whatever other tools) similarly to auto_tac, but is
771 aimed to solve the given subgoal completely.
776 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
777 and `goalw': the theory is no longer needed as an explicit argument -
778 the current theory context is used; assumptions are no longer returned
779 at the ML-level unless one of them starts with ==> or !!; it is
780 recommended to convert to these new commands using isatool fixgoal
781 (backup your sources first!);
783 * new top-level commands 'thm' and 'thms' for retrieving theorems from
784 the current theory context, and 'theory' to lookup stored theories;
786 * new theory section 'locale' for declaring constants, assumptions and
787 definitions that have local scope;
789 * new theory section 'nonterminals' for purely syntactic types;
791 * new theory section 'setup' for generic ML setup functions
792 (e.g. package initialization);
794 * the distribution now includes Isabelle icons: see
795 lib/logo/isabelle-{small,tiny}.xpm;
797 * isatool install - install binaries with absolute references to
800 * isatool logo -- create instances of the Isabelle logo (as EPS);
802 * print mode 'emacs' reserved for Isamode;
804 * support multiple print (ast) translations per constant name;
806 * theorems involving oracles are now printed with a suffixed [!];
811 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
813 * HOL/inductive package reorganized and improved: now supports mutual
819 oddI "n : EVEN ==> Suc n : ODD"
820 evenI "n : ODD ==> Suc n : EVEN"
822 new theorem list "elims" contains an elimination rule for each of the
823 recursive sets; inductive definitions now handle disjunctive premises
826 INCOMPATIBILITIES: requires Inductive as an ancestor; component
827 "mutual_induct" no longer exists - the induction rule is always
828 contained in "induct";
831 * HOL/datatype package re-implemented and greatly improved: now
832 supports mutually recursive datatypes such as
835 'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
836 | SUM ('a aexp) ('a aexp)
837 | DIFF ('a aexp) ('a aexp)
840 'a bexp = LESS ('a aexp) ('a aexp)
841 | AND ('a bexp) ('a bexp)
842 | OR ('a bexp) ('a bexp)
844 as well as indirectly recursive datatypes such as
847 ('a, 'b) term = Var 'a
848 | App 'b ((('a, 'b) term) list)
850 The new tactic mutual_induct_tac [<var_1>, ..., <var_n>] i performs
851 induction on mutually / indirectly recursive datatypes.
853 Primrec equations are now stored in theory and can be accessed via
854 <function_name>.simps.
858 - Theories using datatypes must now have theory Datatype as an
860 - The specific <typename>.induct_tac no longer exists - use the
861 generic induct_tac instead.
862 - natE has been renamed to nat.exhaust - use exhaust_tac
863 instead of res_inst_tac ... natE. Note that the variable
864 names in nat.exhaust differ from the names in natE, this
865 may cause some "fragile" proofs to fail.
866 - The theorems split_<typename>_case and split_<typename>_case_asm
867 have been renamed to <typename>.split and <typename>.split_asm.
868 - Since default sorts of type variables are now handled correctly,
869 some datatype definitions may have to be annotated with explicit
871 - Primrec definitions no longer require function name and type
872 of recursive argument.
874 Consider using isatool fixdatatype to adapt your theories and proof
875 scripts to the new package (backup your sources first!).
878 * HOL/record package: considerably improved implementation; now
879 includes concrete syntax for record types, terms, updates; theorems
880 for surjective pairing and splitting !!-bound record variables; proof
881 support is as follows:
883 1) standard conversions (selectors or updates applied to record
884 constructor terms) are part of the standard simpset;
886 2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
887 made part of standard simpset and claset via addIffs;
889 3) a tactic for record field splitting (record_split_tac) is part of
890 the standard claset (addSWrapper);
892 To get a better idea about these rules you may retrieve them via
893 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
894 the name of your record type.
896 The split tactic 3) conceptually simplifies by the following rule:
898 "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
900 Thus any record variable that is bound by meta-all will automatically
901 blow up into some record constructor term, consequently the
902 simplifications of 1), 2) apply. Thus force_tac, auto_tac etc. shall
903 solve record problems automatically.
906 * reorganized the main HOL image: HOL/Integ and String loaded by
907 default; theory Main includes everything;
909 * automatic simplification of integer sums and comparisons, using cancellation;
911 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
913 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
915 * many new identities for unions, intersections, set difference, etc.;
917 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
918 called split_if, split_split, split_sum_case and split_nat_case (to go
921 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
922 (?x::unit) = (); this is made part of the default simpset, which COULD
923 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
924 'Delsimprocs [unit_eq_proc];' as last resort); also note that
925 unit_abs_eta_conv is added in order to counter the effect of
926 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
929 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
932 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
933 It and 'sym RS equals0D' are now in the default claset, giving automatic
934 disjointness reasoning but breaking a few old proofs.
936 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
937 to 'converse' from 'inverse' (for compatibility with ZF and some
940 * HOL/recdef can now declare non-recursive functions, with {} supplied as
941 the well-founded relation;
943 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
944 Compl A. The "Compl" syntax remains available as input syntax for this
947 * HOL/Update: new theory of function updates:
948 f(a:=b) == %x. if x=a then b else f x
949 may also be iterated as in f(a:=b,c:=d,...);
951 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
954 - new function list_update written xs[i:=v] that updates the i-th
955 list position. May also be iterated as in xs[i:=a,j:=b,...].
956 - new function `upt' written [i..j(] which generates the list
957 [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
958 bound write [i..j], which is a shorthand for [i..j+1(].
959 - new lexicographic orderings and corresponding wellfoundedness theorems.
962 - removed 'pred' (predecessor) function;
963 - generalized some theorems about n-1;
964 - many new laws about "div" and "mod";
965 - new laws about greatest common divisors (see theory ex/Primes);
967 * HOL/Relation: renamed the relational operator r^-1 "converse"
968 instead of "inverse";
970 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
971 of the multiset ordering;
973 * directory HOL/Real: a construction of the reals using Dedekind cuts
974 (not included by default);
976 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
978 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
979 programs, i.e. different program variables may have different types.
981 * calling (stac rew i) now fails if "rew" has no effect on the goal
982 [previously, this check worked only if the rewrite rule was unconditional]
983 Now rew can involve either definitions or equalities (either == or =).
988 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
989 only the theorems proved on ZF.ML;
991 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
992 It and 'sym RS equals0D' are now in the default claset, giving automatic
993 disjointness reasoning but breaking a few old proofs.
995 * ZF/Update: new theory of function updates
996 with default rewrite rule f(x:=y) ` z = if(z=x, y, f`z)
997 may also be iterated as in f(a:=b,c:=d,...);
999 * in let x=t in u(x), neither t nor u(x) has to be an FOL term.
1001 * calling (stac rew i) now fails if "rew" has no effect on the goal
1002 [previously, this check worked only if the rewrite rule was unconditional]
1003 Now rew can involve either definitions or equalities (either == or =).
1005 * case_tac provided for compatibility with HOL
1006 (like the old excluded_middle_tac, but with subgoals swapped)
1009 *** Internal programming interfaces ***
1011 * Pure: several new basic modules made available for general use, see
1012 also src/Pure/README;
1014 * improved the theory data mechanism to support encapsulation (data
1015 kind name replaced by private Object.kind, acting as authorization
1016 key); new type-safe user interface via functor TheoryDataFun; generic
1017 print_data function becomes basically useless;
1019 * removed global_names compatibility flag -- all theory declarations
1020 are qualified by default;
1022 * module Pure/Syntax now offers quote / antiquote translation
1023 functions (useful for Hoare logic etc. with implicit dependencies);
1024 see HOL/ex/Antiquote for an example use;
1026 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
1029 * new tactical CHANGED_GOAL for checking that a tactic modifies a
1032 * Display.print_goals function moved to Locale.print_goals;
1034 * standard print function for goals supports current_goals_markers
1035 variable for marking begin of proof, end of proof, start of goal; the
1036 default is ("", "", ""); setting current_goals_markers := ("<proof>",
1037 "</proof>", "<goal>") causes SGML like tagged proof state printing,
1042 New in Isabelle98 (January 1998)
1043 --------------------------------
1045 *** Overview of INCOMPATIBILITIES (see below for more details) ***
1047 * changed lexical syntax of terms / types: dots made part of long
1048 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
1050 * simpset (and claset) reference variable replaced by functions
1051 simpset / simpset_ref;
1053 * no longer supports theory aliases (via merge) and non-trivial
1054 implicit merge of thms' signatures;
1056 * most internal names of constants changed due to qualified names;
1058 * changed Pure/Sequence interface (see Pure/seq.ML);
1061 *** General Changes ***
1063 * hierachically structured name spaces (for consts, types, axms, thms
1064 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
1065 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
1066 isatool fixdots ensures space after dots (e.g. "%x. x"); set
1067 long_names for fully qualified output names; NOTE: ML programs
1068 (special tactics, packages etc.) referring to internal names may have
1069 to be adapted to cope with fully qualified names; in case of severe
1070 backward campatibility problems try setting 'global_names' at compile
1071 time to have enrything declared within a flat name space; one may also
1072 fine tune name declarations in theories via the 'global' and 'local'
1075 * reimplemented the implicit simpset and claset using the new anytype
1076 data filed in signatures; references simpset:simpset ref etc. are
1077 replaced by functions simpset:unit->simpset and
1078 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
1079 to patch your ML files accordingly;
1081 * HTML output now includes theory graph data for display with Java
1082 applet or isatool browser; data generated automatically via isatool
1083 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
1085 * defs may now be conditional; improved rewrite_goals_tac to handle
1086 conditional equations;
1088 * defs now admits additional type arguments, using TYPE('a) syntax;
1090 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
1091 creates a new theory node; implicit merge of thms' signatures is
1092 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
1093 transfer:theory->thm->thm in (rare) cases;
1095 * improved handling of draft signatures / theories; draft thms (and
1096 ctyps, cterms) are automatically promoted to real ones;
1098 * slightly changed interfaces for oracles: admit many per theory, named
1099 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
1101 * print_goals: optional output of const types (set show_consts and
1104 * improved output of warnings (###) and errors (***);
1106 * subgoal_tac displays a warning if the new subgoal has type variables;
1108 * removed old README and Makefiles;
1110 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
1112 * removed obsolete init_pps and init_database;
1114 * deleted the obsolete tactical STATE, which was declared by
1115 fun STATE tacfun st = tacfun st st;
1117 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
1118 (which abbreviates $HOME);
1120 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
1121 use isatool fixseq to adapt your ML programs (this works for fully
1122 qualified references to the Sequence structure only!);
1124 * use_thy no longer requires writable current directory; it always
1125 reloads .ML *and* .thy file, if either one is out of date;
1128 *** Classical Reasoner ***
1130 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
1131 tactics that use classical reasoning to simplify a subgoal without
1132 splitting it into several subgoals;
1134 * Safe_tac: like safe_tac but uses the default claset;
1139 * added simplification meta rules:
1140 (asm_)(full_)simplify: simpset -> thm -> thm;
1142 * simplifier.ML no longer part of Pure -- has to be loaded by object
1145 * added prems argument to simplification procedures;
1147 * HOL, FOL, ZF: added infix function `addsplits':
1148 instead of `<simpset> setloop (split_tac <thms>)'
1149 you can simply write `<simpset> addsplits <thms>'
1154 * TYPE('a) syntax for type reflection terms;
1156 * no longer handles consts with name "" -- declare as 'syntax' instead;
1158 * pretty printer: changed order of mixfix annotation preference (again!);
1160 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
1165 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
1166 with `addloop' of the simplifier to faciliate case splitting in premises.
1168 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
1170 * HOL/Auth: new protocol proofs including some for the Internet
1173 * HOL/Map: new theory of `maps' a la VDM;
1175 * HOL/simplifier: simplification procedures nat_cancel_sums for
1176 cancelling out common nat summands from =, <, <= (in)equalities, or
1177 differences; simplification procedures nat_cancel_factor for
1178 cancelling common factor from =, <, <= (in)equalities over natural
1179 sums; nat_cancel contains both kinds of procedures, it is installed by
1180 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
1182 * HOL/simplifier: terms of the form
1183 `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)' (or t=x)
1185 `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
1186 and those of the form
1187 `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)' (or t=x)
1189 `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
1192 Each datatype `t' now comes with a theorem `split_t_case' of the form
1194 P(t_case f1 ... fn x) =
1195 ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
1197 (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
1200 and a theorem `split_t_case_asm' of the form
1202 P(t_case f1 ... fn x) =
1203 ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
1205 (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
1207 which can be added to a simpset via `addsplits'. The existing theorems
1208 expand_list_case and expand_option_case have been renamed to
1209 split_list_case and split_option_case.
1212 - `pred n' is automatically converted to `n-1'.
1213 Users are strongly encouraged not to use `pred' any longer,
1214 because it will disappear altogether at some point.
1215 - Users are strongly encouraged to write "0 < n" rather than
1216 "n ~= 0". Theorems and proof tools have been modified towards this
1220 the function "set_of_list" has been renamed "set" (and its theorems too);
1221 the function "nth" now takes its arguments in the reverse order and
1222 has acquired the infix notation "!" as in "xs!n".
1224 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
1226 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
1227 specialist theorems (like UN1_I) are gone. Similarly for (INT x.B x);
1229 * HOL/record: extensible records with schematic structural subtyping
1230 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
1231 still lacks various theorems and concrete record syntax;
1236 * removed "axioms" and "generated by" sections;
1238 * replaced "ops" section by extended "consts" section, which is capable of
1239 handling the continuous function space "->" directly;
1242 . proves theorems immediately and stores them in the theory,
1243 . creates hierachical name space,
1244 . now uses normal mixfix annotations (instead of cinfix...),
1245 . minor changes to some names and values (for consistency),
1246 . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
1247 . separator between mutual domain defs: changed "," to "and",
1248 . improved handling of sort constraints; now they have to
1249 appear on the left-hand side of the equations only;
1251 * fixed LAM <x,y,zs>.b syntax;
1253 * added extended adm_tac to simplifier in HOLCF -- can now discharge
1254 adm (%x. P (t x)), where P is chainfinite and t continuous;
1259 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
1260 with `addloop' of the simplifier to faciliate case splitting in premises.
1262 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
1263 in HOL, they strip ALL and --> from proved theorems;
1267 New in Isabelle94-8 (May 1997)
1268 ------------------------------
1270 *** General Changes ***
1272 * new utilities to build / run / maintain Isabelle etc. (in parts
1273 still somewhat experimental); old Makefiles etc. still functional;
1275 * new 'Isabelle System Manual';
1277 * INSTALL text, together with ./configure and ./build scripts;
1279 * reimplemented type inference for greater efficiency, better error
1280 messages and clean internal interface;
1282 * prlim command for dealing with lots of subgoals (an easier way of
1283 setting goals_limit);
1288 * supports alternative (named) syntax tables (parser and pretty
1289 printer); internal interface is provided by add_modesyntax(_i);
1291 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
1292 be used in conjunction with the Isabelle symbol font; uses the
1293 "symbols" syntax table;
1295 * added token_translation interface (may translate name tokens in
1296 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
1297 the current print_mode); IMPORTANT: user print translation functions
1298 are responsible for marking newly introduced bounds
1299 (Syntax.mark_boundT);
1301 * token translations for modes "xterm" and "xterm_color" that display
1302 names in bold, underline etc. or colors (which requires a color
1305 * infixes may now be declared with names independent of their syntax;
1307 * added typed_print_translation (like print_translation, but may
1308 access type of constant);
1311 *** Classical Reasoner ***
1313 Blast_tac: a new tactic! It is often more powerful than fast_tac, but has
1314 some limitations. Blast_tac...
1315 + ignores addss, addbefore, addafter; this restriction is intrinsic
1316 + ignores elimination rules that don't have the correct format
1317 (the conclusion MUST be a formula variable)
1318 + ignores types, which can make HOL proofs fail
1319 + rules must not require higher-order unification, e.g. apply_type in ZF
1320 [message "Function Var's argument not a bound variable" relates to this]
1321 + its proof strategy is more general but can actually be slower
1323 * substitution with equality assumptions no longer permutes other
1326 * minor changes in semantics of addafter (now called addaltern); renamed
1327 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
1328 (and access functions for it);
1330 * improved combination of classical reasoner and simplifier:
1331 + functions for handling clasimpsets
1332 + improvement of addss: now the simplifier is called _after_ the
1334 + safe variant of addss called addSss: uses safe simplifications
1335 _during_ the safe steps. It is more complete as it allows multiple
1336 instantiations of unknowns (e.g. with slow_tac).
1340 * added interface for simplification procedures (functions that
1341 produce *proven* rewrite rules on the fly, depending on current
1344 * ordering on terms as parameter (used for ordered rewriting);
1346 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
1348 * the solver is now split into a safe and an unsafe part.
1349 This should be invisible for the normal user, except that the
1350 functions setsolver and addsolver have been renamed to setSolver and
1351 addSolver; added safe_asm_full_simp_tac;
1356 * a generic induction tactic `induct_tac' which works for all datatypes and
1357 also for type `nat';
1359 * a generic case distinction tactic `exhaust_tac' which works for all
1360 datatypes and also for type `nat';
1362 * each datatype comes with a function `size';
1364 * patterns in case expressions allow tuple patterns as arguments to
1365 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
1367 * primrec now also works with type nat;
1369 * recdef: a new declaration form, allows general recursive functions to be
1370 defined in theory files. See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
1372 * the constant for negation has been renamed from "not" to "Not" to
1373 harmonize with FOL, ZF, LK, etc.;
1375 * HOL/ex/LFilter theory of a corecursive "filter" functional for
1378 * HOL/Modelcheck demonstrates invocation of model checker oracle;
1380 * HOL/ex/Ring.thy declares cring_simp, which solves equational
1381 problems in commutative rings, using axiomatic type classes for + and *;
1383 * more examples in HOL/MiniML and HOL/Auth;
1385 * more default rewrite rules for quantifiers, union/intersection;
1387 * a new constant `arbitrary == @x.False';
1389 * HOLCF/IOA replaces old HOL/IOA;
1391 * HOLCF changes: derived all rules and arities
1392 + axiomatic type classes instead of classes
1393 + typedef instead of faking type definitions
1394 + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
1395 + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
1396 + eliminated the types void, one, tr
1397 + use unit lift and bool lift (with translations) instead of one and tr
1398 + eliminated blift from Lift3.thy (use Def instead of blift)
1399 all eliminated rules are derived as theorems --> no visible changes ;
1404 * ZF now has Fast_tac, Simp_tac and Auto_tac. Union_iff is a now a default
1405 rewrite rule; this may affect some proofs. eq_cs is gone but can be put back
1406 as ZF_cs addSIs [equalityI];
1410 New in Isabelle94-7 (November 96)
1411 ---------------------------------
1413 * allowing negative levels (as offsets) in prlev and choplev;
1415 * super-linear speedup for large simplifications;
1417 * FOL, ZF and HOL now use miniscoping: rewriting pushes
1418 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
1419 FAIL); can suppress it using the command Delsimps (ex_simps @
1420 all_simps); De Morgan laws are also now included, by default;
1422 * improved printing of ==> : ~:
1424 * new object-logic "Sequents" adds linear logic, while replacing LK
1425 and Modal (thanks to Sara Kalvala);
1427 * HOL/Auth: correctness proofs for authentication protocols;
1429 * HOL: new auto_tac combines rewriting and classical reasoning (many
1430 examples on HOL/Auth);
1432 * HOL: new command AddIffs for declaring theorems of the form P=Q to
1433 the rewriter and classical reasoner simultaneously;
1435 * function uresult no longer returns theorems in "standard" format;
1436 regain previous version by: val uresult = standard o uresult;
1443 * oracles -- these establish an interface between Isabelle and trusted
1444 external reasoners, which may deliver results as theorems;
1446 * proof objects (in particular record all uses of oracles);
1448 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
1450 * "constdefs" section in theory files;
1452 * "primrec" section (HOL) no longer requires names;
1454 * internal type "tactic" now simply "thm -> thm Sequence.seq";
1461 * reduced space requirements;
1463 * automatic HTML generation from theories;
1465 * theory files no longer require "..." (quotes) around most types;
1467 * new examples, including two proofs of the Church-Rosser theorem;
1469 * non-curried (1994) version of HOL is no longer distributed;
1476 * greatly reduced space requirements;
1478 * theory files (.thy) no longer require \...\ escapes at line breaks;
1480 * searchable theorem database (see the section "Retrieving theorems" on
1481 page 8 of the Reference Manual);
1483 * new examples, including Grabczewski's monumental case study of the
1486 * The previous version of HOL renamed to Old_HOL;
1488 * The new version of HOL (previously called CHOL) uses a curried syntax
1489 for functions. Application looks like f a b instead of f(a,b);
1491 * Mutually recursive inductive definitions finally work in HOL;
1493 * In ZF, pattern-matching on tuples is now available in all abstractions and
1494 translates to the operator "split";
1501 * new infix operator, addss, allowing the classical reasoner to
1502 perform simplification at each step of its search. Example:
1503 fast_tac (cs addss ss)
1505 * a new logic, CHOL, the same as HOL, but with a curried syntax
1506 for functions. Application looks like f a b instead of f(a,b). Also pairs
1507 look like (a,b) instead of <a,b>;
1509 * PLEASE NOTE: CHOL will eventually replace HOL!
1511 * In CHOL, pattern-matching on tuples is now available in all abstractions.
1512 It translates to the operator "split". A new theory of integers is available;
1514 * In ZF, integer numerals now denote two's-complement binary integers.
1515 Arithmetic operations can be performed by rewriting. See ZF/ex/Bin.ML;
1517 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
1518 of the Axiom of Choice;
1525 * Significantly faster resolution;
1527 * the different sections in a .thy file can now be mixed and repeated
1530 * Database of theorems for FOL, HOL and ZF. New
1531 commands including qed, qed_goal and bind_thm store theorems in the database.
1533 * Simple database queries: return a named theorem (get_thm) or all theorems of
1534 a given theory (thms_of), or find out what theory a theorem was proved in
1537 * Bugs fixed in the inductive definition and datatype packages;
1539 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
1540 and HOL_dup_cs obsolete;
1542 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
1545 * Simpler definition of function space in ZF;
1547 * new results about cardinal and ordinal arithmetic in ZF;
1549 * 'subtype' facility in HOL for introducing new types as subsets of existing