NEWS
author wenzelm
Mon Dec 01 18:27:06 1997 +0100 (1997-12-01)
changeset 4335 b0acd74da01d
parent 4325 e72cba5af6c5
child 4357 b852e2d2a39a
permissions -rw-r--r--
nat_cancel simprocs;
     1 
     2 Isabelle NEWS -- history of user-visible changes
     3 ================================================
     4 
     5 New in Isabelle???? (DATE ????)
     6 -------------------------------
     7 
     8 *** General Changes ***
     9 
    10 * hierachically structured name spaces (for consts, types, axms, thms
    11 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
    12 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
    13 isatool fixdots ensures space after dots (e.g. "%x. x"); set
    14 long_names for fully qualified output names; NOTE: ML programs
    15 (special tactics, packages etc.) referring to internal names may have
    16 to be adapted to cope with fully qualified names; in case of severe
    17 backward campatibility problems try setting 'global_names' at compile
    18 time to have enrything declared within a flat name space; one may also
    19 fine tune name declarations in theories via the 'global' and 'local'
    20 section;
    21 
    22 * reimplemented the implicit simpset and claset using the new anytype
    23 data filed in signatures; references simpset:simpset ref etc. are
    24 replaced by functions simpset:unit->simpset and
    25 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
    26 to patch your ML files accordingly;
    27 
    28 * HTML output now includes theory graph data for display with Java
    29 applet or isatool browser; data generated automatically via isatool
    30 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
    31 
    32 * defs may now be conditional; improved rewrite_goals_tac to handle
    33 conditional equations;
    34 
    35 * defs now admits additional type arguments, using TYPE('a) syntax;
    36 
    37 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
    38 creates a new theory node; implicit merge of thms' signatures is
    39 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
    40 transfer:theory->thm->thm in (rare) cases;
    41 
    42 * improved handling of draft signatures / theories; draft thms (and
    43 ctyps, cterms) are automatically promoted to real ones;
    44 
    45 * slightly changed interfaces for oracles: admit many per theory, named
    46 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
    47 
    48 * print_goals: optional output of const types (set show_consts and
    49 show_types);
    50 
    51 * improved output of warnings (###) / errors (***);
    52 
    53 * subgoal_tac displays a warning if the new subgoal has type variables;
    54 
    55 * removed old README and Makefiles;
    56 
    57 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
    58 
    59 * removed obsolete init_pps and init_database;
    60 
    61 * deleted the obsolete tactical STATE, which was declared by
    62     fun STATE tacfun st = tacfun st st;
    63 
    64 * cd, use, use etc. now support path variables, e.g. ~ (which
    65 abbreviates $HOME), or $ISABELLE_HOME;
    66 
    67 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
    68 use isatool fixseq to adapt your ML programs (this works for fully
    69 qualified references to the Sequence structure only!);
    70 
    71 
    72 
    73 *** Classical Reasoner ***
    74 
    75 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
    76 tactics that use classical reasoning to simplify a subgoal without
    77 splitting it into several subgoals;
    78 
    79 * Safe_tac: like safe_tac but uses the default claset;
    80 
    81 
    82 *** Simplifier ***
    83 
    84 * added simplification meta rules:
    85     (asm_)(full_)simplify: simpset -> thm -> thm;
    86 
    87 * simplifier.ML no longer part of Pure -- has to be loaded by object
    88 logics (again);
    89 
    90 * added prems argument to simplification procedures;
    91 
    92 * HOL, FOL, ZF: added infix function `addsplits':
    93   instead of `<simpset> setloop (split_tac <thms>)'
    94   you can simply write `<simpset> addsplits <thms>'
    95 
    96 
    97 *** Syntax ***
    98 
    99 * TYPE('a) syntax for type reflection terms;
   100 
   101 * no longer handles consts with name "" -- declare as 'syntax' instead;
   102 
   103 * pretty printer: changed order of mixfix annotation preference (again!);
   104 
   105 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
   106 
   107 
   108 *** HOL ***
   109 
   110 * HOL: there is a new splitter `split_asm_tac' that can be used e.g. 
   111   with `addloop' of the simplifier to faciliate case splitting in premises.
   112 
   113 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
   114 
   115 * HOL/Auth: new protocol proofs including some for the Internet
   116   protocol TLS;
   117 
   118 * HOL/Map: new theory of `maps' a la VDM;
   119 
   120 * HOL/simplifier: simplification procedures nat_cancel_sums for
   121 cancelling out common nat summands from =, <, <= (in)equalities, or
   122 differences; simplification procedures nat_cancel_factor for
   123 cancelling common factor from =, <, <= (in)equalities over natural
   124 sums;  nat_cancel contains both kinds of procedures;
   125 
   126 * HOL/simplifier: terms of the form
   127   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
   128   are rewritten to
   129   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
   130   and those of the form
   131   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
   132   are rewritten to
   133   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
   134 
   135 * HOL/datatype
   136   Each datatype `t' now comes with a theorem `split_t_case' of the form
   137 
   138   P(t_case f1 ... fn x) =
   139      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
   140         ...
   141        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
   142      )
   143 
   144   which can be added to a simpset via `addsplits'. The existing theorems
   145   expand_list_case and expand_option_case have been renamed to
   146   split_list_case and split_option_case.
   147 
   148   Additionally, there is a theorem `split_t_case_asm' of the form
   149 
   150   P(t_case f1 ... fn x) =
   151     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
   152         ...
   153        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
   154      )
   155 
   156   it be used with the new `split_asm_tac'.
   157 
   158 * HOL/Lists: the function "set_of_list" has been renamed "set"
   159   (and its theorems too);
   160 
   161 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
   162 
   163 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
   164   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
   165 
   166 
   167 *** HOLCF ***
   168 
   169 * removed "axioms" and "generated by" sections;
   170 
   171 * replaced "ops" section by extended "consts" section, which is capable of
   172   handling the continuous function space "->" directly;
   173 
   174 * domain package:
   175   . proves theorems immediately and stores them in the theory,
   176   . creates hierachical name space,
   177   . now uses normal mixfix annotations (instead of cinfix...),
   178   . minor changes to some names and values (for consistency),
   179   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
   180   . separator between mutual domain defs: changed "," to "and",
   181   . improved handling of sort constraints;  now they have to
   182     appear on the left-hand side of the equations only;
   183 
   184 * fixed LAM <x,y,zs>.b syntax;
   185 
   186 * added extended adm_tac to simplifier in HOLCF -- can now discharge
   187 adm (%x. P (t x)), where P is chainfinite and t continuous;
   188 
   189 
   190 *** FOL and ZF ***
   191 
   192 * FOL: there is a new splitter `split_asm_tac' that can be used e.g. 
   193   with `addloop' of the simplifier to faciliate case splitting in premises.
   194 
   195 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
   196 in HOL, they strip ALL and --> from proved theorems;
   197 
   198 
   199 
   200 New in Isabelle94-8 (May 1997)
   201 ------------------------------
   202 
   203 *** General Changes ***
   204 
   205 * new utilities to build / run / maintain Isabelle etc. (in parts
   206 still somewhat experimental); old Makefiles etc. still functional;
   207 
   208 * new 'Isabelle System Manual';
   209 
   210 * INSTALL text, together with ./configure and ./build scripts;
   211 
   212 * reimplemented type inference for greater efficiency, better error
   213 messages and clean internal interface;
   214 
   215 * prlim command for dealing with lots of subgoals (an easier way of
   216 setting goals_limit);
   217 
   218 
   219 *** Syntax ***
   220 
   221 * supports alternative (named) syntax tables (parser and pretty
   222 printer); internal interface is provided by add_modesyntax(_i);
   223 
   224 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
   225 be used in conjunction with the Isabelle symbol font; uses the
   226 "symbols" syntax table;
   227 
   228 * added token_translation interface (may translate name tokens in
   229 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
   230 the current print_mode); IMPORTANT: user print translation functions
   231 are responsible for marking newly introduced bounds
   232 (Syntax.mark_boundT);
   233 
   234 * token translations for modes "xterm" and "xterm_color" that display
   235 names in bold, underline etc. or colors (which requires a color
   236 version of xterm);
   237 
   238 * infixes may now be declared with names independent of their syntax;
   239 
   240 * added typed_print_translation (like print_translation, but may
   241 access type of constant);
   242 
   243 
   244 *** Classical Reasoner ***
   245 
   246 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
   247 some limitations.  Blast_tac...
   248   + ignores addss, addbefore, addafter; this restriction is intrinsic
   249   + ignores elimination rules that don't have the correct format
   250 	(the conclusion MUST be a formula variable)
   251   + ignores types, which can make HOL proofs fail
   252   + rules must not require higher-order unification, e.g. apply_type in ZF
   253     [message "Function Var's argument not a bound variable" relates to this]
   254   + its proof strategy is more general but can actually be slower
   255 
   256 * substitution with equality assumptions no longer permutes other
   257 assumptions;
   258 
   259 * minor changes in semantics of addafter (now called addaltern); renamed
   260 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
   261 (and access functions for it);
   262 
   263 * improved combination of classical reasoner and simplifier: 
   264   + functions for handling clasimpsets
   265   + improvement of addss: now the simplifier is called _after_ the
   266     safe steps.
   267   + safe variant of addss called addSss: uses safe simplifications
   268     _during_ the safe steps. It is more complete as it allows multiple 
   269     instantiations of unknowns (e.g. with slow_tac).
   270 
   271 *** Simplifier ***
   272 
   273 * added interface for simplification procedures (functions that
   274 produce *proven* rewrite rules on the fly, depending on current
   275 redex);
   276 
   277 * ordering on terms as parameter (used for ordered rewriting);
   278 
   279 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
   280 
   281 * the solver is now split into a safe and an unsafe part.
   282 This should be invisible for the normal user, except that the
   283 functions setsolver and addsolver have been renamed to setSolver and
   284 addSolver; added safe_asm_full_simp_tac;
   285 
   286 
   287 *** HOL ***
   288 
   289 * a generic induction tactic `induct_tac' which works for all datatypes and
   290 also for type `nat';
   291 
   292 * a generic case distinction tactic `exhaust_tac' which works for all
   293 datatypes and also for type `nat';
   294 
   295 * each datatype comes with a function `size';
   296 
   297 * patterns in case expressions allow tuple patterns as arguments to
   298 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
   299 
   300 * primrec now also works with type nat;
   301 
   302 * recdef: a new declaration form, allows general recursive functions to be
   303 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
   304 
   305 * the constant for negation has been renamed from "not" to "Not" to
   306 harmonize with FOL, ZF, LK, etc.;
   307 
   308 * HOL/ex/LFilter theory of a corecursive "filter" functional for
   309 infinite lists;
   310 
   311 * HOL/Modelcheck demonstrates invocation of model checker oracle;
   312 
   313 * HOL/ex/Ring.thy declares cring_simp, which solves equational
   314 problems in commutative rings, using axiomatic type classes for + and *;
   315 
   316 * more examples in HOL/MiniML and HOL/Auth;
   317 
   318 * more default rewrite rules for quantifiers, union/intersection;
   319 
   320 * a new constant `arbitrary == @x.False';
   321 
   322 * HOLCF/IOA replaces old HOL/IOA;
   323 
   324 * HOLCF changes: derived all rules and arities 
   325   + axiomatic type classes instead of classes 
   326   + typedef instead of faking type definitions
   327   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
   328   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
   329   + eliminated the types void, one, tr
   330   + use unit lift and bool lift (with translations) instead of one and tr
   331   + eliminated blift from Lift3.thy (use Def instead of blift)
   332   all eliminated rules are derived as theorems --> no visible changes ;
   333 
   334 
   335 *** ZF ***
   336 
   337 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
   338 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
   339 as ZF_cs addSIs [equalityI];
   340 
   341 
   342 
   343 New in Isabelle94-7 (November 96)
   344 ---------------------------------
   345 
   346 * allowing negative levels (as offsets) in prlev and choplev;
   347 
   348 * super-linear speedup for large simplifications;
   349 
   350 * FOL, ZF and HOL now use miniscoping: rewriting pushes
   351 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
   352 FAIL); can suppress it using the command Delsimps (ex_simps @
   353 all_simps); De Morgan laws are also now included, by default;
   354 
   355 * improved printing of ==>  :  ~:
   356 
   357 * new object-logic "Sequents" adds linear logic, while replacing LK
   358 and Modal (thanks to Sara Kalvala);
   359 
   360 * HOL/Auth: correctness proofs for authentication protocols;
   361 
   362 * HOL: new auto_tac combines rewriting and classical reasoning (many
   363 examples on HOL/Auth);
   364 
   365 * HOL: new command AddIffs for declaring theorems of the form P=Q to
   366 the rewriter and classical reasoner simultaneously;
   367 
   368 * function uresult no longer returns theorems in "standard" format;
   369 regain previous version by: val uresult = standard o uresult;
   370 
   371 
   372 
   373 New in Isabelle94-6
   374 -------------------
   375 
   376 * oracles -- these establish an interface between Isabelle and trusted
   377 external reasoners, which may deliver results as theorems;
   378 
   379 * proof objects (in particular record all uses of oracles);
   380 
   381 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
   382 
   383 * "constdefs" section in theory files;
   384 
   385 * "primrec" section (HOL) no longer requires names;
   386 
   387 * internal type "tactic" now simply "thm -> thm Sequence.seq";
   388 
   389 
   390 
   391 New in Isabelle94-5
   392 -------------------
   393 
   394 * reduced space requirements;
   395 
   396 * automatic HTML generation from theories;
   397 
   398 * theory files no longer require "..." (quotes) around most types;
   399 
   400 * new examples, including two proofs of the Church-Rosser theorem;
   401 
   402 * non-curried (1994) version of HOL is no longer distributed;
   403 
   404 
   405 
   406 New in Isabelle94-4
   407 -------------------
   408 
   409 * greatly reduced space requirements;
   410 
   411 * theory files (.thy) no longer require \...\ escapes at line breaks;
   412 
   413 * searchable theorem database (see the section "Retrieving theorems" on 
   414 page 8 of the Reference Manual);
   415 
   416 * new examples, including Grabczewski's monumental case study of the
   417 Axiom of Choice;
   418 
   419 * The previous version of HOL renamed to Old_HOL;
   420 
   421 * The new version of HOL (previously called CHOL) uses a curried syntax 
   422 for functions.  Application looks like f a b instead of f(a,b);
   423 
   424 * Mutually recursive inductive definitions finally work in HOL;
   425 
   426 * In ZF, pattern-matching on tuples is now available in all abstractions and
   427 translates to the operator "split";
   428 
   429 
   430 
   431 New in Isabelle94-3
   432 -------------------
   433 
   434 * new infix operator, addss, allowing the classical reasoner to 
   435 perform simplification at each step of its search.  Example:
   436 	fast_tac (cs addss ss)
   437 
   438 * a new logic, CHOL, the same as HOL, but with a curried syntax 
   439 for functions.  Application looks like f a b instead of f(a,b).  Also pairs 
   440 look like (a,b) instead of <a,b>;
   441 
   442 * PLEASE NOTE: CHOL will eventually replace HOL!
   443 
   444 * In CHOL, pattern-matching on tuples is now available in all abstractions.
   445 It translates to the operator "split".  A new theory of integers is available;
   446 
   447 * In ZF, integer numerals now denote two's-complement binary integers.
   448 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
   449 
   450 * Many new examples: I/O automata, Church-Rosser theorem, equivalents 
   451 of the Axiom of Choice;
   452 
   453 
   454 
   455 New in Isabelle94-2
   456 -------------------
   457 
   458 * Significantly faster resolution;  
   459 
   460 * the different sections in a .thy file can now be mixed and repeated
   461 freely;
   462 
   463 * Database of theorems for FOL, HOL and ZF.  New
   464 commands including qed, qed_goal and bind_thm store theorems in the database.
   465 
   466 * Simple database queries: return a named theorem (get_thm) or all theorems of
   467 a given theory (thms_of), or find out what theory a theorem was proved in
   468 (theory_of_thm);
   469 
   470 * Bugs fixed in the inductive definition and datatype packages;
   471 
   472 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
   473 and HOL_dup_cs obsolete;
   474 
   475 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
   476 have been removed;
   477 
   478 * Simpler definition of function space in ZF;
   479 
   480 * new results about cardinal and ordinal arithmetic in ZF;
   481 
   482 * 'subtype' facility in HOL for introducing new types as subsets of existing
   483 types;
   484 
   485 
   486 $Id$