2 Isabelle NEWS -- history of user-visible changes
3 ================================================
5 New in Isabelle??? (FIXME)
6 --------------------------
8 * Rewrite rules for case distinctions can now be added permanently to the
9 default simpset using Addsplits just like Addsimps. They can be removed via
10 Delsplits just like Delsimps. Lower-case versions are also available.
11 For applications see HOL below.
13 * Changed wrapper mechanism for the classical reasoner now allows for selected
14 deletion of wrappers, by introduction of names for wrapper functionals.
15 This implies that addbefore, addSbefore, addaltern, and addSaltern now take
16 a pair (name, tactic) as argument, and that adding two tactics with the same
17 name overwrites the first one (emitting a warning).
18 type wrapper = (int -> tactic) -> (int -> tactic)
19 setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
20 addWrapper, addSWrapper: claset * (string * wrapper) -> claset
21 delWrapper, delSWrapper: claset * string -> claset
22 getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
24 * Inductive definitions now handle disjunctive premises correctly (HOL and ZF)
29 * new force_tac (and its derivations Force_tac, force)
30 combines rewriting and classical reasoning (and whatever other tools)
31 similarly to auto_tac, but is aimed to solve the given subgoal totally.
33 * added option_map_eq_Some to simpset(), option_map_eq_Some RS iffD1 to claset()
34 * New directory HOL/UNITY: Chandy and Misra's UNITY formalism
36 * split_all_tac is now much faster and fails if there is nothing to split
37 split_all_tac has moved within claset() from usafe wrappers to safe wrappers,
38 which means that !!-bound variables are splitted much more aggressively.
39 If this splitting is not appropriate, use delSWrapper "split_all_tac".
41 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset
43 * HOL/Arithmetic: removed 'pred' (predecessor) function; and generalized
44 some theorems about n-1
46 * HOL/Relation: renamed the relational operatotr r^-1 "converse" instead of
49 * HOL/equalities: added many new laws involving unions, intersectinos,
52 * recdef can now declare non-recursive functions, with {} supplied as the
57 -The rule expand_if is now part of the default simpset. This means that
58 the simplifier will eliminate all ocurrences of if-then-else in the
59 conclusion of a goal. To prevent this, you can either remove expand_if
60 completely from the default simpset by `Delsplits [expand_if]' or
61 remove it in a specific call of the simplifier using
62 `... delsplits [expand_if]'.
63 You can also add/delete other case splitting rules to/from the default
64 simpset: every datatype generates a suitable rule `split_t_case' (where t
65 is the name of the datatype).
67 -Asm_full_simp_tac is now more aggressive:
68 1. It will sometimes reorient premises if that increases their power to
70 2. It does no longer proceed strictly from left to right but may also
71 rotate premises to achieve further simplification.
72 For compatibility reasons there is now Asm_lr_simp_tac which is like the
73 old Asm_full_simp_tac in that it does not rotate premises.
75 * new theory Vimage (inverse image of a function, syntax f-``B);
77 * many new identities for unions, intersections, etc.;
80 New in Isabelle98 (January 1998)
81 --------------------------------
83 *** Overview of INCOMPATIBILITIES (see below for more details) ***
85 * changed lexical syntax of terms / types: dots made part of long
86 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
88 * simpset (and claset) reference variable replaced by functions
89 simpset / simpset_ref;
91 * no longer supports theory aliases (via merge) and non-trivial
92 implicit merge of thms' signatures;
94 * most internal names of constants changed due to qualified names;
96 * changed Pure/Sequence interface (see Pure/seq.ML);
99 *** General Changes ***
101 * hierachically structured name spaces (for consts, types, axms, thms
102 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
103 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
104 isatool fixdots ensures space after dots (e.g. "%x. x"); set
105 long_names for fully qualified output names; NOTE: ML programs
106 (special tactics, packages etc.) referring to internal names may have
107 to be adapted to cope with fully qualified names; in case of severe
108 backward campatibility problems try setting 'global_names' at compile
109 time to have enrything declared within a flat name space; one may also
110 fine tune name declarations in theories via the 'global' and 'local'
113 * reimplemented the implicit simpset and claset using the new anytype
114 data filed in signatures; references simpset:simpset ref etc. are
115 replaced by functions simpset:unit->simpset and
116 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
117 to patch your ML files accordingly;
119 * HTML output now includes theory graph data for display with Java
120 applet or isatool browser; data generated automatically via isatool
121 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
123 * defs may now be conditional; improved rewrite_goals_tac to handle
124 conditional equations;
126 * defs now admits additional type arguments, using TYPE('a) syntax;
128 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
129 creates a new theory node; implicit merge of thms' signatures is
130 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
131 transfer:theory->thm->thm in (rare) cases;
133 * improved handling of draft signatures / theories; draft thms (and
134 ctyps, cterms) are automatically promoted to real ones;
136 * slightly changed interfaces for oracles: admit many per theory, named
137 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
139 * print_goals: optional output of const types (set show_consts and
142 * improved output of warnings (###) and errors (***);
144 * subgoal_tac displays a warning if the new subgoal has type variables;
146 * removed old README and Makefiles;
148 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
150 * removed obsolete init_pps and init_database;
152 * deleted the obsolete tactical STATE, which was declared by
153 fun STATE tacfun st = tacfun st st;
155 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
156 (which abbreviates $HOME);
158 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
159 use isatool fixseq to adapt your ML programs (this works for fully
160 qualified references to the Sequence structure only!);
162 * use_thy no longer requires writable current directory; it always
163 reloads .ML *and* .thy file, if either one is out of date;
166 *** Classical Reasoner ***
168 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
169 tactics that use classical reasoning to simplify a subgoal without
170 splitting it into several subgoals;
172 * Safe_tac: like safe_tac but uses the default claset;
177 * added simplification meta rules:
178 (asm_)(full_)simplify: simpset -> thm -> thm;
180 * simplifier.ML no longer part of Pure -- has to be loaded by object
183 * added prems argument to simplification procedures;
185 * HOL, FOL, ZF: added infix function `addsplits':
186 instead of `<simpset> setloop (split_tac <thms>)'
187 you can simply write `<simpset> addsplits <thms>'
192 * TYPE('a) syntax for type reflection terms;
194 * no longer handles consts with name "" -- declare as 'syntax' instead;
196 * pretty printer: changed order of mixfix annotation preference (again!);
198 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
203 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
204 with `addloop' of the simplifier to faciliate case splitting in premises.
206 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
208 * HOL/Auth: new protocol proofs including some for the Internet
211 * HOL/Map: new theory of `maps' a la VDM;
213 * HOL/simplifier: simplification procedures nat_cancel_sums for
214 cancelling out common nat summands from =, <, <= (in)equalities, or
215 differences; simplification procedures nat_cancel_factor for
216 cancelling common factor from =, <, <= (in)equalities over natural
217 sums; nat_cancel contains both kinds of procedures, it is installed by
218 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
220 * HOL/simplifier: terms of the form
221 `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)' (or t=x)
223 `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
224 and those of the form
225 `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)' (or t=x)
227 `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
230 Each datatype `t' now comes with a theorem `split_t_case' of the form
232 P(t_case f1 ... fn x) =
233 ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
235 (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
238 which can be added to a simpset via `addsplits'. The existing theorems
239 expand_list_case and expand_option_case have been renamed to
240 split_list_case and split_option_case.
242 Additionally, there is a theorem `split_t_case_asm' of the form
244 P(t_case f1 ... fn x) =
245 ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
247 (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
250 it be used with the new `split_asm_tac'.
253 - `pred n' is automatically converted to `n-1'.
254 Users are strongly encouraged not to use `pred' any longer,
255 because it will disappear altogether at some point.
256 - Users are strongly encouraged to write "0 < n" rather than
257 "n ~= 0". Theorems and proof tools have been modified towards this
261 the function "set_of_list" has been renamed "set" (and its theorems too);
262 the function "nth" now takes its arguments in the reverse order and
263 has acquired the infix notation "!" as in "xs!n".
265 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
267 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
268 specialist theorems (like UN1_I) are gone. Similarly for (INT x.B x);
270 * HOL/record: extensible records with schematic structural subtyping
271 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
272 still lacks various theorems and concrete record syntax;
277 * removed "axioms" and "generated by" sections;
279 * replaced "ops" section by extended "consts" section, which is capable of
280 handling the continuous function space "->" directly;
283 . proves theorems immediately and stores them in the theory,
284 . creates hierachical name space,
285 . now uses normal mixfix annotations (instead of cinfix...),
286 . minor changes to some names and values (for consistency),
287 . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
288 . separator between mutual domain defs: changed "," to "and",
289 . improved handling of sort constraints; now they have to
290 appear on the left-hand side of the equations only;
292 * fixed LAM <x,y,zs>.b syntax;
294 * added extended adm_tac to simplifier in HOLCF -- can now discharge
295 adm (%x. P (t x)), where P is chainfinite and t continuous;
300 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
301 with `addloop' of the simplifier to faciliate case splitting in premises.
303 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
304 in HOL, they strip ALL and --> from proved theorems;
308 New in Isabelle94-8 (May 1997)
309 ------------------------------
311 *** General Changes ***
313 * new utilities to build / run / maintain Isabelle etc. (in parts
314 still somewhat experimental); old Makefiles etc. still functional;
316 * new 'Isabelle System Manual';
318 * INSTALL text, together with ./configure and ./build scripts;
320 * reimplemented type inference for greater efficiency, better error
321 messages and clean internal interface;
323 * prlim command for dealing with lots of subgoals (an easier way of
324 setting goals_limit);
329 * supports alternative (named) syntax tables (parser and pretty
330 printer); internal interface is provided by add_modesyntax(_i);
332 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
333 be used in conjunction with the Isabelle symbol font; uses the
334 "symbols" syntax table;
336 * added token_translation interface (may translate name tokens in
337 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
338 the current print_mode); IMPORTANT: user print translation functions
339 are responsible for marking newly introduced bounds
340 (Syntax.mark_boundT);
342 * token translations for modes "xterm" and "xterm_color" that display
343 names in bold, underline etc. or colors (which requires a color
346 * infixes may now be declared with names independent of their syntax;
348 * added typed_print_translation (like print_translation, but may
349 access type of constant);
352 *** Classical Reasoner ***
354 Blast_tac: a new tactic! It is often more powerful than fast_tac, but has
355 some limitations. Blast_tac...
356 + ignores addss, addbefore, addafter; this restriction is intrinsic
357 + ignores elimination rules that don't have the correct format
358 (the conclusion MUST be a formula variable)
359 + ignores types, which can make HOL proofs fail
360 + rules must not require higher-order unification, e.g. apply_type in ZF
361 [message "Function Var's argument not a bound variable" relates to this]
362 + its proof strategy is more general but can actually be slower
364 * substitution with equality assumptions no longer permutes other
367 * minor changes in semantics of addafter (now called addaltern); renamed
368 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
369 (and access functions for it);
371 * improved combination of classical reasoner and simplifier:
372 + functions for handling clasimpsets
373 + improvement of addss: now the simplifier is called _after_ the
375 + safe variant of addss called addSss: uses safe simplifications
376 _during_ the safe steps. It is more complete as it allows multiple
377 instantiations of unknowns (e.g. with slow_tac).
381 * added interface for simplification procedures (functions that
382 produce *proven* rewrite rules on the fly, depending on current
385 * ordering on terms as parameter (used for ordered rewriting);
387 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
389 * the solver is now split into a safe and an unsafe part.
390 This should be invisible for the normal user, except that the
391 functions setsolver and addsolver have been renamed to setSolver and
392 addSolver; added safe_asm_full_simp_tac;
397 * a generic induction tactic `induct_tac' which works for all datatypes and
400 * a generic case distinction tactic `exhaust_tac' which works for all
401 datatypes and also for type `nat';
403 * each datatype comes with a function `size';
405 * patterns in case expressions allow tuple patterns as arguments to
406 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
408 * primrec now also works with type nat;
410 * recdef: a new declaration form, allows general recursive functions to be
411 defined in theory files. See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
413 * the constant for negation has been renamed from "not" to "Not" to
414 harmonize with FOL, ZF, LK, etc.;
416 * HOL/ex/LFilter theory of a corecursive "filter" functional for
419 * HOL/Modelcheck demonstrates invocation of model checker oracle;
421 * HOL/ex/Ring.thy declares cring_simp, which solves equational
422 problems in commutative rings, using axiomatic type classes for + and *;
424 * more examples in HOL/MiniML and HOL/Auth;
426 * more default rewrite rules for quantifiers, union/intersection;
428 * a new constant `arbitrary == @x.False';
430 * HOLCF/IOA replaces old HOL/IOA;
432 * HOLCF changes: derived all rules and arities
433 + axiomatic type classes instead of classes
434 + typedef instead of faking type definitions
435 + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
436 + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
437 + eliminated the types void, one, tr
438 + use unit lift and bool lift (with translations) instead of one and tr
439 + eliminated blift from Lift3.thy (use Def instead of blift)
440 all eliminated rules are derived as theorems --> no visible changes ;
445 * ZF now has Fast_tac, Simp_tac and Auto_tac. Union_iff is a now a default
446 rewrite rule; this may affect some proofs. eq_cs is gone but can be put back
447 as ZF_cs addSIs [equalityI];
451 New in Isabelle94-7 (November 96)
452 ---------------------------------
454 * allowing negative levels (as offsets) in prlev and choplev;
456 * super-linear speedup for large simplifications;
458 * FOL, ZF and HOL now use miniscoping: rewriting pushes
459 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
460 FAIL); can suppress it using the command Delsimps (ex_simps @
461 all_simps); De Morgan laws are also now included, by default;
463 * improved printing of ==> : ~:
465 * new object-logic "Sequents" adds linear logic, while replacing LK
466 and Modal (thanks to Sara Kalvala);
468 * HOL/Auth: correctness proofs for authentication protocols;
470 * HOL: new auto_tac combines rewriting and classical reasoning (many
471 examples on HOL/Auth);
473 * HOL: new command AddIffs for declaring theorems of the form P=Q to
474 the rewriter and classical reasoner simultaneously;
476 * function uresult no longer returns theorems in "standard" format;
477 regain previous version by: val uresult = standard o uresult;
484 * oracles -- these establish an interface between Isabelle and trusted
485 external reasoners, which may deliver results as theorems;
487 * proof objects (in particular record all uses of oracles);
489 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
491 * "constdefs" section in theory files;
493 * "primrec" section (HOL) no longer requires names;
495 * internal type "tactic" now simply "thm -> thm Sequence.seq";
502 * reduced space requirements;
504 * automatic HTML generation from theories;
506 * theory files no longer require "..." (quotes) around most types;
508 * new examples, including two proofs of the Church-Rosser theorem;
510 * non-curried (1994) version of HOL is no longer distributed;
517 * greatly reduced space requirements;
519 * theory files (.thy) no longer require \...\ escapes at line breaks;
521 * searchable theorem database (see the section "Retrieving theorems" on
522 page 8 of the Reference Manual);
524 * new examples, including Grabczewski's monumental case study of the
527 * The previous version of HOL renamed to Old_HOL;
529 * The new version of HOL (previously called CHOL) uses a curried syntax
530 for functions. Application looks like f a b instead of f(a,b);
532 * Mutually recursive inductive definitions finally work in HOL;
534 * In ZF, pattern-matching on tuples is now available in all abstractions and
535 translates to the operator "split";
542 * new infix operator, addss, allowing the classical reasoner to
543 perform simplification at each step of its search. Example:
544 fast_tac (cs addss ss)
546 * a new logic, CHOL, the same as HOL, but with a curried syntax
547 for functions. Application looks like f a b instead of f(a,b). Also pairs
548 look like (a,b) instead of <a,b>;
550 * PLEASE NOTE: CHOL will eventually replace HOL!
552 * In CHOL, pattern-matching on tuples is now available in all abstractions.
553 It translates to the operator "split". A new theory of integers is available;
555 * In ZF, integer numerals now denote two's-complement binary integers.
556 Arithmetic operations can be performed by rewriting. See ZF/ex/Bin.ML;
558 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
559 of the Axiom of Choice;
566 * Significantly faster resolution;
568 * the different sections in a .thy file can now be mixed and repeated
571 * Database of theorems for FOL, HOL and ZF. New
572 commands including qed, qed_goal and bind_thm store theorems in the database.
574 * Simple database queries: return a named theorem (get_thm) or all theorems of
575 a given theory (thms_of), or find out what theory a theorem was proved in
578 * Bugs fixed in the inductive definition and datatype packages;
580 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
581 and HOL_dup_cs obsolete;
583 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
586 * Simpler definition of function space in ZF;
588 * new results about cardinal and ordinal arithmetic in ZF;
590 * 'subtype' facility in HOL for introducing new types as subsets of existing