NEWS
author nipkow
Thu Apr 13 15:02:57 2000 +0200 (2000-04-13)
changeset 8705 a3da5538d924
parent 8673 987ea1a559d0
child 8729 094dbd0fad0c
permissions -rw-r--r--
*** empty log message ***
     1 Isabelle NEWS -- history user-relevant changes
     2 ==============================================
     3 
     4 New in this Isabelle version
     5 ----------------------------
     6 
     7 *** Overview of INCOMPATIBILITIES (see below for more details) ***
     8 
     9 * HOL: the constant for f``x is now "image" rather than "op ``".
    10 
    11 * HOL: the cartesian product is now "<*>" instead of "Times".
    12        the lexicographic product is now "<*lex*>" instead of "**".
    13 
    14 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
    15 
    16 * HOL: simplification no longer dives into case-expressions
    17 
    18 * HOL: the recursion equations generated by 'recdef' are now called
    19 f.simps instead of f.rules;
    20 
    21 * ML: PureThy.add_thms/add_axioms/add_defs return theorems as well;
    22 
    23 
    24 *** Document preparation ***
    25 
    26 * isatool mkdir provides easy setup of Isabelle session directories,
    27 including proper document sources;
    28 
    29 * generated LaTeX sources are now deleted after successful run
    30 (isatool document -c); may retain a copy somewhere else via -D option
    31 of isatool usedir;
    32 
    33 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
    34 style files, achieving self-contained LaTeX sources;
    35 
    36 * old-style theories now produce (crude) LaTeX output as well;
    37 
    38 
    39 *** Isar ***
    40 
    41 * Pure: local results and corresponding term bindings are now subject
    42 to Hindley-Milner polymorphism (similar to ML); this accommodates
    43 incremental type-inference nicely;
    44 
    45 * Pure: new 'obtain' language element supports generalized existence
    46 reasoning;
    47 
    48 * Pure: new calculational elements 'moreover' and 'ultimately' support
    49 plain accumulation of results, without applying any rules yet;
    50 
    51 * Pure: scalable support for case-analysis type proofs: new 'case'
    52 language element refers to local contexts symbolically, as produced by
    53 certain proof methods; internally, case names are attached to theorems
    54 as "tags";
    55 
    56 * Pure now provides its own version of intro/elim/dest attributes;
    57 useful for building new logics, but beware of confusion with the
    58 Provers/classical ones;
    59 
    60 * Provers: splitter support (via 'split' attribute and 'simp' method
    61 modifier); 'simp' method: 'only:' modifier removes loopers as well
    62 (including splits);
    63 
    64 * HOL: new proof method 'cases' and improved version of 'induct' now
    65 support named cases; major packages (inductive, datatype, primrec,
    66 recdef) support case names and properly name parameters;
    67 
    68 * HOL: removed 'case_split' thm binding, should use 'cases' proof
    69 method anyway;
    70 
    71 * names of theorems etc. may be natural numbers as well;
    72 
    73 * Provers: intro/elim/dest attributes: changed ! / !! flags to ? / ??;
    74 
    75 * 'pr' command: optional goals_limit argument;
    76 
    77 * diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
    78 additional print modes to be specified; e.g. "pr(latex)" will print
    79 proof state according to the Isabelle LaTeX style;
    80 
    81 * improved support for emulating tactic scripts, including proof
    82 methods 'tactic', 'res_inst_tac' etc., 'subgoal_tac', and 'case_tac' /
    83 'induct_tac' (for HOL datatypes);
    84 
    85 * simplified (more robust) goal selection of proof methods: 1st goal,
    86 all goals, or explicit goal specifier (tactic emulation); thus 'proof
    87 method scripts' have to be in depth-first order;
    88 
    89 * tuned 'let' syntax: replace 'as' keyword by 'and';
    90 
    91 
    92 *** HOL ***
    93 
    94 * HOL/Algebra: new theory of rings and univariate polynomials, by
    95 Clemens Ballarin;
    96 
    97 * HOL/record: fixed select-update simplification procedure to handle
    98 extended records as well; admit "r" as field name;
    99 
   100 * HOL/ex: new theory Factorization proving the Fundamental Theorem of
   101 Arithmetic, by Thomas M Rasmussen;
   102 
   103 * HOL/ex/Multiquote: multiple nested quotations and anti-quotations --
   104 basically a generalized version of de-Bruijn representation; very
   105 useful in avoiding lifting all operations;
   106 
   107 * new version of "case_tac" subsumes both boolean case split and
   108 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
   109 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
   110 
   111 * simplification no longer dives into case-expressions: only the selector
   112 expression is simplified, but not the remaining arms. To enable full
   113 simplification of case-expressions for datatype t, you need to remove
   114 t.weak_case_cong from the simpset, either permanently
   115 (Delcongs[thm"t.weak_case_cong"];) or locally (delcongs [...]).
   116 
   117 * the recursion equations generated by 'recdef' for function 'f' are
   118 now called f.simps instead of f.rules; if all termination conditions
   119 are proved automatically, these simplification rules are added to the
   120 simpset, as in primrec; rules may be named individually as well,
   121 resulting in a separate list of theorems for each equation;
   122 
   123 
   124 *** General ***
   125 
   126 * compression of ML heaps images may now be controlled via -c option
   127 of isabelle and isatool usedir (currently only observed by Poly/ML);
   128 
   129 * ML: new combinators |>> and |>>> for incremental transformations
   130 with secondary results (e.g. certain theory extensions):
   131 
   132 
   133 
   134 New in Isabelle99 (October 1999)
   135 --------------------------------
   136 
   137 *** Overview of INCOMPATIBILITIES (see below for more details) ***
   138 
   139 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
   140 are no longer simplified.  (This allows the simplifier to unfold recursive
   141 functional programs.)  To restore the old behaviour, declare
   142 
   143     Delcongs [if_weak_cong];
   144 
   145 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
   146 complement;
   147 
   148 * HOL: the predicate "inj" is now defined by translation to "inj_on";
   149 
   150 * HOL/datatype: mutual_induct_tac no longer exists --
   151   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
   152 
   153 * HOL/typedef: fixed type inference for representing set; type
   154 arguments now have to occur explicitly on the rhs as type constraints;
   155 
   156 * ZF: The con_defs part of an inductive definition may no longer refer
   157 to constants declared in the same theory;
   158 
   159 * HOL, ZF: the function mk_cases, generated by the inductive
   160 definition package, has lost an argument.  To simplify its result, it
   161 uses the default simpset instead of a supplied list of theorems.
   162 
   163 * HOL/List: the constructors of type list are now Nil and Cons;
   164 
   165 * Simplifier: the type of the infix ML functions
   166 	setSSolver addSSolver setSolver addSolver
   167 is now  simpset * solver -> simpset  where `solver' is a new abstract type
   168 for packaging solvers. A solver is created via
   169 	mk_solver: string -> (thm list -> int -> tactic) -> solver
   170 where the string argument is only a comment.
   171 
   172 
   173 *** Proof tools ***
   174 
   175 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
   176 decision procedure for linear arithmetic. Currently it is used for
   177 types `nat', `int', and `real' in HOL (see below); it can, should and
   178 will be instantiated for other types and logics as well.
   179 
   180 * The simplifier now accepts rewrite rules with flexible heads, eg
   181      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
   182   They are applied like any rule with a non-pattern lhs, i.e. by first-order
   183   matching.
   184 
   185 
   186 *** General ***
   187 
   188 * New Isabelle/Isar subsystem provides an alternative to traditional
   189 tactical theorem proving; together with the ProofGeneral/isar user
   190 interface it offers an interactive environment for developing human
   191 readable proof documents (Isar == Intelligible semi-automated
   192 reasoning); for further information see isatool doc isar-ref,
   193 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
   194 
   195 * improved presentation of theories: better HTML markup (including
   196 colors), graph views in several sizes; isatool usedir now provides a
   197 proper interface for user theories (via -P option); actual document
   198 preparation based on (PDF)LaTeX is available as well (for new-style
   199 theories only); see isatool doc system for more information;
   200 
   201 * native support for Proof General, both for classic Isabelle and
   202 Isabelle/Isar;
   203 
   204 * ML function thm_deps visualizes dependencies of theorems and lemmas,
   205 using the graph browser tool;
   206 
   207 * Isabelle manuals now also available as PDF;
   208 
   209 * theory loader rewritten from scratch (may not be fully
   210 bug-compatible); old loadpath variable has been replaced by show_path,
   211 add_path, del_path, reset_path functions; new operations such as
   212 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
   213 isatool doc ref);
   214 
   215 * improved isatool install: option -k creates KDE application icon,
   216 option -p DIR installs standalone binaries;
   217 
   218 * added ML_PLATFORM setting (useful for cross-platform installations);
   219 more robust handling of platform specific ML images for SML/NJ;
   220 
   221 * the settings environment is now statically scoped, i.e. it is never
   222 created again in sub-processes invoked from isabelle, isatool, or
   223 Isabelle;
   224 
   225 * path element specification '~~' refers to '$ISABELLE_HOME';
   226 
   227 * in locales, the "assumes" and "defines" parts may be omitted if
   228 empty;
   229 
   230 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
   231 long arrows);
   232 
   233 * new print_mode "HTML";
   234 
   235 * new flag show_tags controls display of tags of theorems (which are
   236 basically just comments that may be attached by some tools);
   237 
   238 * Isamode 2.6 requires patch to accomodate change of Isabelle font
   239 mode and goal output format:
   240 
   241 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
   242 244c244
   243 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
   244 ---
   245 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
   246 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
   247 181c181
   248 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
   249 ---
   250 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
   251 
   252 * function bind_thms stores lists of theorems (cf. bind_thm);
   253 
   254 * new shorthand tactics ftac, eatac, datac, fatac;
   255 
   256 * qed (and friends) now accept "" as result name; in that case the
   257 theorem is not stored, but proper checks and presentation of the
   258 result still apply;
   259 
   260 * theorem database now also indexes constants "Trueprop", "all",
   261 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
   262 
   263 
   264 *** HOL ***
   265 
   266 ** HOL arithmetic **
   267 
   268 * There are now decision procedures for linear arithmetic over nat and
   269 int:
   270 
   271 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
   272 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
   273 are treated as atomic; subformulae not involving type `nat' or `int'
   274 are ignored; quantified subformulae are ignored unless they are
   275 positive universal or negative existential. The tactic has to be
   276 invoked by hand and can be a little bit slow. In particular, the
   277 running time is exponential in the number of occurrences of `min' and
   278 `max', and `-' on `nat'.
   279 
   280 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
   281 (negated) (in)equalities among the premises and the conclusion into
   282 account (i.e. no compound formulae) and does not know about `min' and
   283 `max', and `-' on `nat'. It is fast and is used automatically by the
   284 simplifier.
   285 
   286 NB: At the moment, these decision procedures do not cope with mixed
   287 nat/int formulae where the two parts interact, such as `m < n ==>
   288 int(m) < int(n)'.
   289 
   290 * HOL/Numeral provides a generic theory of numerals (encoded
   291 efficiently as bit strings); setup for types nat/int/real is in place;
   292 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
   293 int, existing theories and proof scripts may require a few additional
   294 type constraints;
   295 
   296 * integer division and remainder can now be performed on constant
   297 arguments;
   298 
   299 * many properties of integer multiplication, division and remainder
   300 are now available;
   301 
   302 * An interface to the Stanford Validity Checker (SVC) is available through the
   303 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
   304 are proved automatically.  SVC must be installed separately, and its results
   305 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
   306 invocation of the underlying oracle).  For SVC see
   307   http://verify.stanford.edu/SVC
   308 
   309 * IsaMakefile: the HOL-Real target now builds an actual image;
   310 
   311 
   312 ** HOL misc **
   313 
   314 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
   315 (in Isabelle/Isar) -- by Gertrud Bauer;
   316 
   317 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
   318 analysis for assembly languages with subtypes;
   319 
   320 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
   321 -- avoids syntactic ambiguities and treats state, transition, and
   322 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
   323 changed syntax and (many) tactics;
   324 
   325 * HOL/inductive: Now also handles more general introduction rules such
   326   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
   327   theorems are now maintained within the theory (maintained via the
   328   "mono" attribute);
   329 
   330 * HOL/datatype: Now also handles arbitrarily branching datatypes
   331   (using function types) such as
   332 
   333   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
   334 
   335 * HOL/record: record_simproc (part of the default simpset) takes care
   336 of selectors applied to updated records; record_split_tac is no longer
   337 part of the default claset; update_defs may now be removed from the
   338 simpset in many cases; COMPATIBILITY: old behavior achieved by
   339 
   340   claset_ref () := claset() addSWrapper record_split_wrapper;
   341   Delsimprocs [record_simproc]
   342 
   343 * HOL/typedef: fixed type inference for representing set; type
   344 arguments now have to occur explicitly on the rhs as type constraints;
   345 
   346 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
   347 names rather than an ML expression;
   348 
   349 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
   350 supplied later.  Program schemes can be defined, such as
   351     "While B C s = (if B s then While B C (C s) else s)"
   352 where the well-founded relation can be chosen after B and C have been given.
   353 
   354 * HOL/List: the constructors of type list are now Nil and Cons;
   355 INCOMPATIBILITY: while [] and infix # syntax is still there, of
   356 course, ML tools referring to List.list.op # etc. have to be adapted;
   357 
   358 * HOL_quantifiers flag superseded by "HOL" print mode, which is
   359 disabled by default; run isabelle with option -m HOL to get back to
   360 the original Gordon/HOL-style output;
   361 
   362 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
   363 ALL x<=y. P, EX x<y. P, EX x<=y. P;
   364 
   365 * HOL basic syntax simplified (more orthogonal): all variants of
   366 All/Ex now support plain / symbolic / HOL notation; plain syntax for
   367 Eps operator is provided as well: "SOME x. P[x]";
   368 
   369 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
   370 
   371 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
   372 thus available for user theories;
   373 
   374 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
   375 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
   376 time;
   377 
   378 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
   379 several times and then mp;
   380 
   381 
   382 *** LK ***
   383 
   384 * the notation <<...>> is now available as a notation for sequences of
   385 formulas;
   386 
   387 * the simplifier is now installed
   388 
   389 * the axiom system has been generalized (thanks to Soren Heilmann) 
   390 
   391 * the classical reasoner now has a default rule database
   392 
   393 
   394 *** ZF ***
   395 
   396 * new primrec section allows primitive recursive functions to be given
   397 directly (as in HOL) over datatypes and the natural numbers;
   398 
   399 * new tactics induct_tac and exhaust_tac for induction (or case
   400 analysis) over datatypes and the natural numbers;
   401 
   402 * the datatype declaration of type T now defines the recursor T_rec;
   403 
   404 * simplification automatically does freeness reasoning for datatype
   405 constructors;
   406 
   407 * automatic type-inference, with AddTCs command to insert new
   408 type-checking rules;
   409 
   410 * datatype introduction rules are now added as Safe Introduction rules
   411 to the claset;
   412 
   413 * the syntax "if P then x else y" is now available in addition to
   414 if(P,x,y);
   415 
   416 
   417 *** Internal programming interfaces ***
   418 
   419 * tuned simplifier trace output; new flag debug_simp;
   420 
   421 * structures Vartab / Termtab (instances of TableFun) offer efficient
   422 tables indexed by indexname_ord / term_ord (compatible with aconv);
   423 
   424 * AxClass.axclass_tac lost the theory argument;
   425 
   426 * tuned current_goals_markers semantics: begin / end goal avoids
   427 printing empty lines;
   428 
   429 * removed prs and prs_fn hook, which was broken because it did not
   430 include \n in its semantics, forcing writeln to add one
   431 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
   432 string -> unit if you really want to output text without newline;
   433 
   434 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
   435 plain output, interface builders may have to enable 'isabelle_font'
   436 mode to get Isabelle font glyphs as before;
   437 
   438 * refined token_translation interface; INCOMPATIBILITY: output length
   439 now of type real instead of int;
   440 
   441 * theory loader actions may be traced via new ThyInfo.add_hook
   442 interface (see src/Pure/Thy/thy_info.ML); example application: keep
   443 your own database of information attached to *whole* theories -- as
   444 opposed to intra-theory data slots offered via TheoryDataFun;
   445 
   446 * proper handling of dangling sort hypotheses (at last!);
   447 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
   448 extra sort hypotheses that can be witnessed from the type signature;
   449 the force_strip_shyps flag is gone, any remaining shyps are simply
   450 left in the theorem (with a warning issued by strip_shyps_warning);
   451 
   452 
   453 
   454 New in Isabelle98-1 (October 1998)
   455 ----------------------------------
   456 
   457 *** Overview of INCOMPATIBILITIES (see below for more details) ***
   458 
   459 * several changes of automated proof tools;
   460 
   461 * HOL: major changes to the inductive and datatype packages, including
   462 some minor incompatibilities of theory syntax;
   463 
   464 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
   465 called `inj_on';
   466 
   467 * HOL: removed duplicate thms in Arith:
   468   less_imp_add_less  should be replaced by  trans_less_add1
   469   le_imp_add_le      should be replaced by  trans_le_add1
   470 
   471 * HOL: unary minus is now overloaded (new type constraints may be
   472 required);
   473 
   474 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
   475 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
   476 now taken as an integer constant.
   477 
   478 * Pure: ML function 'theory_of' renamed to 'theory';
   479 
   480 
   481 *** Proof tools ***
   482 
   483 * Simplifier:
   484   1. Asm_full_simp_tac is now more aggressive.
   485      1. It will sometimes reorient premises if that increases their power to
   486         simplify.
   487      2. It does no longer proceed strictly from left to right but may also
   488         rotate premises to achieve further simplification.
   489      For compatibility reasons there is now Asm_lr_simp_tac which is like the
   490      old Asm_full_simp_tac in that it does not rotate premises.
   491   2. The simplifier now knows a little bit about nat-arithmetic.
   492 
   493 * Classical reasoner: wrapper mechanism for the classical reasoner now
   494 allows for selected deletion of wrappers, by introduction of names for
   495 wrapper functionals.  This implies that addbefore, addSbefore,
   496 addaltern, and addSaltern now take a pair (name, tactic) as argument,
   497 and that adding two tactics with the same name overwrites the first
   498 one (emitting a warning).
   499   type wrapper = (int -> tactic) -> (int -> tactic)
   500   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
   501   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
   502   delWrapper, delSWrapper: claset *  string            -> claset
   503   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
   504 
   505 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
   506 semantics; addbefore now affects only the unsafe part of step_tac
   507 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
   508 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
   509 by Force_tac;
   510 
   511 * Classical reasoner: setwrapper to setWrapper and compwrapper to
   512 compWrapper; added safe wrapper (and access functions for it);
   513 
   514 * HOL/split_all_tac is now much faster and fails if there is nothing
   515 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
   516 and the names of the automatically generated variables have changed.
   517 split_all_tac has moved within claset() from unsafe wrappers to safe
   518 wrappers, which means that !!-bound variables are split much more
   519 aggressively, and safe_tac and clarify_tac now split such variables.
   520 If this splitting is not appropriate, use delSWrapper "split_all_tac".
   521 Note: the same holds for record_split_tac, which does the job of
   522 split_all_tac for record fields.
   523 
   524 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
   525 permanently to the default simpset using Addsplits just like
   526 Addsimps. They can be removed via Delsplits just like
   527 Delsimps. Lower-case versions are also available.
   528 
   529 * HOL/Simplifier: The rule split_if is now part of the default
   530 simpset. This means that the simplifier will eliminate all occurrences
   531 of if-then-else in the conclusion of a goal. To prevent this, you can
   532 either remove split_if completely from the default simpset by
   533 `Delsplits [split_if]' or remove it in a specific call of the
   534 simplifier using `... delsplits [split_if]'.  You can also add/delete
   535 other case splitting rules to/from the default simpset: every datatype
   536 generates suitable rules `split_t_case' and `split_t_case_asm' (where
   537 t is the name of the datatype).
   538 
   539 * Classical reasoner / Simplifier combination: new force_tac (and
   540 derivatives Force_tac, force) combines rewriting and classical
   541 reasoning (and whatever other tools) similarly to auto_tac, but is
   542 aimed to solve the given subgoal completely.
   543 
   544 
   545 *** General ***
   546 
   547 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
   548 and `goalw': the theory is no longer needed as an explicit argument -
   549 the current theory context is used; assumptions are no longer returned
   550 at the ML-level unless one of them starts with ==> or !!; it is
   551 recommended to convert to these new commands using isatool fixgoal
   552 (backup your sources first!);
   553 
   554 * new top-level commands 'thm' and 'thms' for retrieving theorems from
   555 the current theory context, and 'theory' to lookup stored theories;
   556 
   557 * new theory section 'locale' for declaring constants, assumptions and
   558 definitions that have local scope;
   559 
   560 * new theory section 'nonterminals' for purely syntactic types;
   561 
   562 * new theory section 'setup' for generic ML setup functions
   563 (e.g. package initialization);
   564 
   565 * the distribution now includes Isabelle icons: see
   566 lib/logo/isabelle-{small,tiny}.xpm;
   567 
   568 * isatool install - install binaries with absolute references to
   569 ISABELLE_HOME/bin;
   570 
   571 * isatool logo -- create instances of the Isabelle logo (as EPS);
   572 
   573 * print mode 'emacs' reserved for Isamode;
   574 
   575 * support multiple print (ast) translations per constant name;
   576 
   577 * theorems involving oracles are now printed with a suffixed [!];
   578 
   579 
   580 *** HOL ***
   581 
   582 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
   583 
   584 * HOL/inductive package reorganized and improved: now supports mutual
   585 definitions such as
   586 
   587   inductive EVEN ODD
   588     intrs
   589       null "0 : EVEN"
   590       oddI "n : EVEN ==> Suc n : ODD"
   591       evenI "n : ODD ==> Suc n : EVEN"
   592 
   593 new theorem list "elims" contains an elimination rule for each of the
   594 recursive sets; inductive definitions now handle disjunctive premises
   595 correctly (also ZF);
   596 
   597 INCOMPATIBILITIES: requires Inductive as an ancestor; component
   598 "mutual_induct" no longer exists - the induction rule is always
   599 contained in "induct";
   600 
   601 
   602 * HOL/datatype package re-implemented and greatly improved: now
   603 supports mutually recursive datatypes such as
   604 
   605   datatype
   606     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
   607             | SUM ('a aexp) ('a aexp)
   608             | DIFF ('a aexp) ('a aexp)
   609             | NUM 'a
   610   and
   611     'a bexp = LESS ('a aexp) ('a aexp)
   612             | AND ('a bexp) ('a bexp)
   613             | OR ('a bexp) ('a bexp)
   614 
   615 as well as indirectly recursive datatypes such as
   616 
   617   datatype
   618     ('a, 'b) term = Var 'a
   619                   | App 'b ((('a, 'b) term) list)
   620 
   621 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
   622 induction on mutually / indirectly recursive datatypes.
   623 
   624 Primrec equations are now stored in theory and can be accessed via
   625 <function_name>.simps.
   626 
   627 INCOMPATIBILITIES:
   628 
   629   - Theories using datatypes must now have theory Datatype as an
   630     ancestor.
   631   - The specific <typename>.induct_tac no longer exists - use the
   632     generic induct_tac instead.
   633   - natE has been renamed to nat.exhaust - use exhaust_tac
   634     instead of res_inst_tac ... natE. Note that the variable
   635     names in nat.exhaust differ from the names in natE, this
   636     may cause some "fragile" proofs to fail.
   637   - The theorems split_<typename>_case and split_<typename>_case_asm
   638     have been renamed to <typename>.split and <typename>.split_asm.
   639   - Since default sorts of type variables are now handled correctly,
   640     some datatype definitions may have to be annotated with explicit
   641     sort constraints.
   642   - Primrec definitions no longer require function name and type
   643     of recursive argument.
   644 
   645 Consider using isatool fixdatatype to adapt your theories and proof
   646 scripts to the new package (backup your sources first!).
   647 
   648 
   649 * HOL/record package: considerably improved implementation; now
   650 includes concrete syntax for record types, terms, updates; theorems
   651 for surjective pairing and splitting !!-bound record variables; proof
   652 support is as follows:
   653 
   654   1) standard conversions (selectors or updates applied to record
   655 constructor terms) are part of the standard simpset;
   656 
   657   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
   658 made part of standard simpset and claset via addIffs;
   659 
   660   3) a tactic for record field splitting (record_split_tac) is part of
   661 the standard claset (addSWrapper);
   662 
   663 To get a better idea about these rules you may retrieve them via
   664 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
   665 the name of your record type.
   666 
   667 The split tactic 3) conceptually simplifies by the following rule:
   668 
   669   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
   670 
   671 Thus any record variable that is bound by meta-all will automatically
   672 blow up into some record constructor term, consequently the
   673 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
   674 solve record problems automatically.
   675 
   676 
   677 * reorganized the main HOL image: HOL/Integ and String loaded by
   678 default; theory Main includes everything;
   679 
   680 * automatic simplification of integer sums and comparisons, using cancellation;
   681 
   682 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
   683 
   684 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
   685 
   686 * many new identities for unions, intersections, set difference, etc.;
   687 
   688 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
   689 called split_if, split_split, split_sum_case and split_nat_case (to go
   690 with add/delsplits);
   691 
   692 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
   693 (?x::unit) = (); this is made part of the default simpset, which COULD
   694 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
   695 'Delsimprocs [unit_eq_proc];' as last resort); also note that
   696 unit_abs_eta_conv is added in order to counter the effect of
   697 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
   698 %u.f();
   699 
   700 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
   701 makes more sense);
   702 
   703 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
   704   It and 'sym RS equals0D' are now in the default  claset, giving automatic
   705   disjointness reasoning but breaking a few old proofs.
   706 
   707 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
   708 to 'converse' from 'inverse' (for compatibility with ZF and some
   709 literature);
   710 
   711 * HOL/recdef can now declare non-recursive functions, with {} supplied as
   712 the well-founded relation;
   713 
   714 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
   715     Compl A.  The "Compl" syntax remains available as input syntax for this
   716     release ONLY.
   717 
   718 * HOL/Update: new theory of function updates:
   719     f(a:=b) == %x. if x=a then b else f x
   720 may also be iterated as in f(a:=b,c:=d,...);
   721 
   722 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
   723 
   724 * HOL/List:
   725   - new function list_update written xs[i:=v] that updates the i-th
   726     list position. May also be iterated as in xs[i:=a,j:=b,...].
   727   - new function `upt' written [i..j(] which generates the list
   728     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
   729     bound write [i..j], which is a shorthand for [i..j+1(].
   730   - new lexicographic orderings and corresponding wellfoundedness theorems.
   731 
   732 * HOL/Arith:
   733   - removed 'pred' (predecessor) function;
   734   - generalized some theorems about n-1;
   735   - many new laws about "div" and "mod";
   736   - new laws about greatest common divisors (see theory ex/Primes);
   737 
   738 * HOL/Relation: renamed the relational operator r^-1 "converse"
   739 instead of "inverse";
   740 
   741 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
   742   of the multiset ordering;
   743 
   744 * directory HOL/Real: a construction of the reals using Dedekind cuts
   745   (not included by default);
   746 
   747 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
   748 
   749 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
   750   programs, i.e. different program variables may have different types.
   751 
   752 * calling (stac rew i) now fails if "rew" has no effect on the goal
   753   [previously, this check worked only if the rewrite rule was unconditional]
   754   Now rew can involve either definitions or equalities (either == or =).
   755 
   756 
   757 *** ZF ***
   758 
   759 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
   760   only the theorems proved on ZF.ML;
   761 
   762 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
   763   It and 'sym RS equals0D' are now in the default  claset, giving automatic
   764   disjointness reasoning but breaking a few old proofs.
   765 
   766 * ZF/Update: new theory of function updates
   767     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
   768   may also be iterated as in f(a:=b,c:=d,...);
   769 
   770 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
   771 
   772 * calling (stac rew i) now fails if "rew" has no effect on the goal
   773   [previously, this check worked only if the rewrite rule was unconditional]
   774   Now rew can involve either definitions or equalities (either == or =).
   775 
   776 * case_tac provided for compatibility with HOL
   777     (like the old excluded_middle_tac, but with subgoals swapped)
   778 
   779 
   780 *** Internal programming interfaces ***
   781 
   782 * Pure: several new basic modules made available for general use, see
   783 also src/Pure/README;
   784 
   785 * improved the theory data mechanism to support encapsulation (data
   786 kind name replaced by private Object.kind, acting as authorization
   787 key); new type-safe user interface via functor TheoryDataFun; generic
   788 print_data function becomes basically useless;
   789 
   790 * removed global_names compatibility flag -- all theory declarations
   791 are qualified by default;
   792 
   793 * module Pure/Syntax now offers quote / antiquote translation
   794 functions (useful for Hoare logic etc. with implicit dependencies);
   795 see HOL/ex/Antiquote for an example use;
   796 
   797 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
   798 cterm -> thm;
   799 
   800 * new tactical CHANGED_GOAL for checking that a tactic modifies a
   801 subgoal;
   802 
   803 * Display.print_goals function moved to Locale.print_goals;
   804 
   805 * standard print function for goals supports current_goals_markers
   806 variable for marking begin of proof, end of proof, start of goal; the
   807 default is ("", "", ""); setting current_goals_markers := ("<proof>",
   808 "</proof>", "<goal>") causes SGML like tagged proof state printing,
   809 for example;
   810 
   811 
   812 
   813 New in Isabelle98 (January 1998)
   814 --------------------------------
   815 
   816 *** Overview of INCOMPATIBILITIES (see below for more details) ***
   817 
   818 * changed lexical syntax of terms / types: dots made part of long
   819 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
   820 
   821 * simpset (and claset) reference variable replaced by functions
   822 simpset / simpset_ref;
   823 
   824 * no longer supports theory aliases (via merge) and non-trivial
   825 implicit merge of thms' signatures;
   826 
   827 * most internal names of constants changed due to qualified names;
   828 
   829 * changed Pure/Sequence interface (see Pure/seq.ML);
   830 
   831 
   832 *** General Changes ***
   833 
   834 * hierachically structured name spaces (for consts, types, axms, thms
   835 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
   836 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
   837 isatool fixdots ensures space after dots (e.g. "%x. x"); set
   838 long_names for fully qualified output names; NOTE: ML programs
   839 (special tactics, packages etc.) referring to internal names may have
   840 to be adapted to cope with fully qualified names; in case of severe
   841 backward campatibility problems try setting 'global_names' at compile
   842 time to have enrything declared within a flat name space; one may also
   843 fine tune name declarations in theories via the 'global' and 'local'
   844 section;
   845 
   846 * reimplemented the implicit simpset and claset using the new anytype
   847 data filed in signatures; references simpset:simpset ref etc. are
   848 replaced by functions simpset:unit->simpset and
   849 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
   850 to patch your ML files accordingly;
   851 
   852 * HTML output now includes theory graph data for display with Java
   853 applet or isatool browser; data generated automatically via isatool
   854 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
   855 
   856 * defs may now be conditional; improved rewrite_goals_tac to handle
   857 conditional equations;
   858 
   859 * defs now admits additional type arguments, using TYPE('a) syntax;
   860 
   861 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
   862 creates a new theory node; implicit merge of thms' signatures is
   863 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
   864 transfer:theory->thm->thm in (rare) cases;
   865 
   866 * improved handling of draft signatures / theories; draft thms (and
   867 ctyps, cterms) are automatically promoted to real ones;
   868 
   869 * slightly changed interfaces for oracles: admit many per theory, named
   870 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
   871 
   872 * print_goals: optional output of const types (set show_consts and
   873 show_types);
   874 
   875 * improved output of warnings (###) and errors (***);
   876 
   877 * subgoal_tac displays a warning if the new subgoal has type variables;
   878 
   879 * removed old README and Makefiles;
   880 
   881 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
   882 
   883 * removed obsolete init_pps and init_database;
   884 
   885 * deleted the obsolete tactical STATE, which was declared by
   886     fun STATE tacfun st = tacfun st st;
   887 
   888 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
   889 (which abbreviates $HOME);
   890 
   891 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
   892 use isatool fixseq to adapt your ML programs (this works for fully
   893 qualified references to the Sequence structure only!);
   894 
   895 * use_thy no longer requires writable current directory; it always
   896 reloads .ML *and* .thy file, if either one is out of date;
   897 
   898 
   899 *** Classical Reasoner ***
   900 
   901 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
   902 tactics that use classical reasoning to simplify a subgoal without
   903 splitting it into several subgoals;
   904 
   905 * Safe_tac: like safe_tac but uses the default claset;
   906 
   907 
   908 *** Simplifier ***
   909 
   910 * added simplification meta rules:
   911     (asm_)(full_)simplify: simpset -> thm -> thm;
   912 
   913 * simplifier.ML no longer part of Pure -- has to be loaded by object
   914 logics (again);
   915 
   916 * added prems argument to simplification procedures;
   917 
   918 * HOL, FOL, ZF: added infix function `addsplits':
   919   instead of `<simpset> setloop (split_tac <thms>)'
   920   you can simply write `<simpset> addsplits <thms>'
   921 
   922 
   923 *** Syntax ***
   924 
   925 * TYPE('a) syntax for type reflection terms;
   926 
   927 * no longer handles consts with name "" -- declare as 'syntax' instead;
   928 
   929 * pretty printer: changed order of mixfix annotation preference (again!);
   930 
   931 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
   932 
   933 
   934 *** HOL ***
   935 
   936 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
   937   with `addloop' of the simplifier to faciliate case splitting in premises.
   938 
   939 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
   940 
   941 * HOL/Auth: new protocol proofs including some for the Internet
   942   protocol TLS;
   943 
   944 * HOL/Map: new theory of `maps' a la VDM;
   945 
   946 * HOL/simplifier: simplification procedures nat_cancel_sums for
   947 cancelling out common nat summands from =, <, <= (in)equalities, or
   948 differences; simplification procedures nat_cancel_factor for
   949 cancelling common factor from =, <, <= (in)equalities over natural
   950 sums; nat_cancel contains both kinds of procedures, it is installed by
   951 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
   952 
   953 * HOL/simplifier: terms of the form
   954   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
   955   are rewritten to
   956   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
   957   and those of the form
   958   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
   959   are rewritten to
   960   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
   961 
   962 * HOL/datatype
   963   Each datatype `t' now comes with a theorem `split_t_case' of the form
   964 
   965   P(t_case f1 ... fn x) =
   966      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
   967         ...
   968        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
   969      )
   970 
   971   and a theorem `split_t_case_asm' of the form
   972 
   973   P(t_case f1 ... fn x) =
   974     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
   975         ...
   976        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
   977      )
   978   which can be added to a simpset via `addsplits'. The existing theorems
   979   expand_list_case and expand_option_case have been renamed to
   980   split_list_case and split_option_case.
   981 
   982 * HOL/Arithmetic:
   983   - `pred n' is automatically converted to `n-1'.
   984     Users are strongly encouraged not to use `pred' any longer,
   985     because it will disappear altogether at some point.
   986   - Users are strongly encouraged to write "0 < n" rather than
   987     "n ~= 0". Theorems and proof tools have been modified towards this
   988     `standard'.
   989 
   990 * HOL/Lists:
   991   the function "set_of_list" has been renamed "set" (and its theorems too);
   992   the function "nth" now takes its arguments in the reverse order and
   993   has acquired the infix notation "!" as in "xs!n".
   994 
   995 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
   996 
   997 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
   998   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
   999 
  1000 * HOL/record: extensible records with schematic structural subtyping
  1001 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  1002 still lacks various theorems and concrete record syntax;
  1003 
  1004 
  1005 *** HOLCF ***
  1006 
  1007 * removed "axioms" and "generated by" sections;
  1008 
  1009 * replaced "ops" section by extended "consts" section, which is capable of
  1010   handling the continuous function space "->" directly;
  1011 
  1012 * domain package:
  1013   . proves theorems immediately and stores them in the theory,
  1014   . creates hierachical name space,
  1015   . now uses normal mixfix annotations (instead of cinfix...),
  1016   . minor changes to some names and values (for consistency),
  1017   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  1018   . separator between mutual domain defs: changed "," to "and",
  1019   . improved handling of sort constraints;  now they have to
  1020     appear on the left-hand side of the equations only;
  1021 
  1022 * fixed LAM <x,y,zs>.b syntax;
  1023 
  1024 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  1025 adm (%x. P (t x)), where P is chainfinite and t continuous;
  1026 
  1027 
  1028 *** FOL and ZF ***
  1029 
  1030 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  1031   with `addloop' of the simplifier to faciliate case splitting in premises.
  1032 
  1033 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  1034 in HOL, they strip ALL and --> from proved theorems;
  1035 
  1036 
  1037 
  1038 New in Isabelle94-8 (May 1997)
  1039 ------------------------------
  1040 
  1041 *** General Changes ***
  1042 
  1043 * new utilities to build / run / maintain Isabelle etc. (in parts
  1044 still somewhat experimental); old Makefiles etc. still functional;
  1045 
  1046 * new 'Isabelle System Manual';
  1047 
  1048 * INSTALL text, together with ./configure and ./build scripts;
  1049 
  1050 * reimplemented type inference for greater efficiency, better error
  1051 messages and clean internal interface;
  1052 
  1053 * prlim command for dealing with lots of subgoals (an easier way of
  1054 setting goals_limit);
  1055 
  1056 
  1057 *** Syntax ***
  1058 
  1059 * supports alternative (named) syntax tables (parser and pretty
  1060 printer); internal interface is provided by add_modesyntax(_i);
  1061 
  1062 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  1063 be used in conjunction with the Isabelle symbol font; uses the
  1064 "symbols" syntax table;
  1065 
  1066 * added token_translation interface (may translate name tokens in
  1067 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  1068 the current print_mode); IMPORTANT: user print translation functions
  1069 are responsible for marking newly introduced bounds
  1070 (Syntax.mark_boundT);
  1071 
  1072 * token translations for modes "xterm" and "xterm_color" that display
  1073 names in bold, underline etc. or colors (which requires a color
  1074 version of xterm);
  1075 
  1076 * infixes may now be declared with names independent of their syntax;
  1077 
  1078 * added typed_print_translation (like print_translation, but may
  1079 access type of constant);
  1080 
  1081 
  1082 *** Classical Reasoner ***
  1083 
  1084 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  1085 some limitations.  Blast_tac...
  1086   + ignores addss, addbefore, addafter; this restriction is intrinsic
  1087   + ignores elimination rules that don't have the correct format
  1088         (the conclusion MUST be a formula variable)
  1089   + ignores types, which can make HOL proofs fail
  1090   + rules must not require higher-order unification, e.g. apply_type in ZF
  1091     [message "Function Var's argument not a bound variable" relates to this]
  1092   + its proof strategy is more general but can actually be slower
  1093 
  1094 * substitution with equality assumptions no longer permutes other
  1095 assumptions;
  1096 
  1097 * minor changes in semantics of addafter (now called addaltern); renamed
  1098 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  1099 (and access functions for it);
  1100 
  1101 * improved combination of classical reasoner and simplifier:
  1102   + functions for handling clasimpsets
  1103   + improvement of addss: now the simplifier is called _after_ the
  1104     safe steps.
  1105   + safe variant of addss called addSss: uses safe simplifications
  1106     _during_ the safe steps. It is more complete as it allows multiple
  1107     instantiations of unknowns (e.g. with slow_tac).
  1108 
  1109 *** Simplifier ***
  1110 
  1111 * added interface for simplification procedures (functions that
  1112 produce *proven* rewrite rules on the fly, depending on current
  1113 redex);
  1114 
  1115 * ordering on terms as parameter (used for ordered rewriting);
  1116 
  1117 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  1118 
  1119 * the solver is now split into a safe and an unsafe part.
  1120 This should be invisible for the normal user, except that the
  1121 functions setsolver and addsolver have been renamed to setSolver and
  1122 addSolver; added safe_asm_full_simp_tac;
  1123 
  1124 
  1125 *** HOL ***
  1126 
  1127 * a generic induction tactic `induct_tac' which works for all datatypes and
  1128 also for type `nat';
  1129 
  1130 * a generic case distinction tactic `exhaust_tac' which works for all
  1131 datatypes and also for type `nat';
  1132 
  1133 * each datatype comes with a function `size';
  1134 
  1135 * patterns in case expressions allow tuple patterns as arguments to
  1136 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  1137 
  1138 * primrec now also works with type nat;
  1139 
  1140 * recdef: a new declaration form, allows general recursive functions to be
  1141 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  1142 
  1143 * the constant for negation has been renamed from "not" to "Not" to
  1144 harmonize with FOL, ZF, LK, etc.;
  1145 
  1146 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  1147 infinite lists;
  1148 
  1149 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  1150 
  1151 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  1152 problems in commutative rings, using axiomatic type classes for + and *;
  1153 
  1154 * more examples in HOL/MiniML and HOL/Auth;
  1155 
  1156 * more default rewrite rules for quantifiers, union/intersection;
  1157 
  1158 * a new constant `arbitrary == @x.False';
  1159 
  1160 * HOLCF/IOA replaces old HOL/IOA;
  1161 
  1162 * HOLCF changes: derived all rules and arities
  1163   + axiomatic type classes instead of classes
  1164   + typedef instead of faking type definitions
  1165   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  1166   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  1167   + eliminated the types void, one, tr
  1168   + use unit lift and bool lift (with translations) instead of one and tr
  1169   + eliminated blift from Lift3.thy (use Def instead of blift)
  1170   all eliminated rules are derived as theorems --> no visible changes ;
  1171 
  1172 
  1173 *** ZF ***
  1174 
  1175 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  1176 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  1177 as ZF_cs addSIs [equalityI];
  1178 
  1179 
  1180 
  1181 New in Isabelle94-7 (November 96)
  1182 ---------------------------------
  1183 
  1184 * allowing negative levels (as offsets) in prlev and choplev;
  1185 
  1186 * super-linear speedup for large simplifications;
  1187 
  1188 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  1189 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  1190 FAIL); can suppress it using the command Delsimps (ex_simps @
  1191 all_simps); De Morgan laws are also now included, by default;
  1192 
  1193 * improved printing of ==>  :  ~:
  1194 
  1195 * new object-logic "Sequents" adds linear logic, while replacing LK
  1196 and Modal (thanks to Sara Kalvala);
  1197 
  1198 * HOL/Auth: correctness proofs for authentication protocols;
  1199 
  1200 * HOL: new auto_tac combines rewriting and classical reasoning (many
  1201 examples on HOL/Auth);
  1202 
  1203 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  1204 the rewriter and classical reasoner simultaneously;
  1205 
  1206 * function uresult no longer returns theorems in "standard" format;
  1207 regain previous version by: val uresult = standard o uresult;
  1208 
  1209 
  1210 
  1211 New in Isabelle94-6
  1212 -------------------
  1213 
  1214 * oracles -- these establish an interface between Isabelle and trusted
  1215 external reasoners, which may deliver results as theorems;
  1216 
  1217 * proof objects (in particular record all uses of oracles);
  1218 
  1219 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  1220 
  1221 * "constdefs" section in theory files;
  1222 
  1223 * "primrec" section (HOL) no longer requires names;
  1224 
  1225 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  1226 
  1227 
  1228 
  1229 New in Isabelle94-5
  1230 -------------------
  1231 
  1232 * reduced space requirements;
  1233 
  1234 * automatic HTML generation from theories;
  1235 
  1236 * theory files no longer require "..." (quotes) around most types;
  1237 
  1238 * new examples, including two proofs of the Church-Rosser theorem;
  1239 
  1240 * non-curried (1994) version of HOL is no longer distributed;
  1241 
  1242 
  1243 
  1244 New in Isabelle94-4
  1245 -------------------
  1246 
  1247 * greatly reduced space requirements;
  1248 
  1249 * theory files (.thy) no longer require \...\ escapes at line breaks;
  1250 
  1251 * searchable theorem database (see the section "Retrieving theorems" on
  1252 page 8 of the Reference Manual);
  1253 
  1254 * new examples, including Grabczewski's monumental case study of the
  1255 Axiom of Choice;
  1256 
  1257 * The previous version of HOL renamed to Old_HOL;
  1258 
  1259 * The new version of HOL (previously called CHOL) uses a curried syntax
  1260 for functions.  Application looks like f a b instead of f(a,b);
  1261 
  1262 * Mutually recursive inductive definitions finally work in HOL;
  1263 
  1264 * In ZF, pattern-matching on tuples is now available in all abstractions and
  1265 translates to the operator "split";
  1266 
  1267 
  1268 
  1269 New in Isabelle94-3
  1270 -------------------
  1271 
  1272 * new infix operator, addss, allowing the classical reasoner to
  1273 perform simplification at each step of its search.  Example:
  1274         fast_tac (cs addss ss)
  1275 
  1276 * a new logic, CHOL, the same as HOL, but with a curried syntax
  1277 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  1278 look like (a,b) instead of <a,b>;
  1279 
  1280 * PLEASE NOTE: CHOL will eventually replace HOL!
  1281 
  1282 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  1283 It translates to the operator "split".  A new theory of integers is available;
  1284 
  1285 * In ZF, integer numerals now denote two's-complement binary integers.
  1286 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  1287 
  1288 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  1289 of the Axiom of Choice;
  1290 
  1291 
  1292 
  1293 New in Isabelle94-2
  1294 -------------------
  1295 
  1296 * Significantly faster resolution;
  1297 
  1298 * the different sections in a .thy file can now be mixed and repeated
  1299 freely;
  1300 
  1301 * Database of theorems for FOL, HOL and ZF.  New
  1302 commands including qed, qed_goal and bind_thm store theorems in the database.
  1303 
  1304 * Simple database queries: return a named theorem (get_thm) or all theorems of
  1305 a given theory (thms_of), or find out what theory a theorem was proved in
  1306 (theory_of_thm);
  1307 
  1308 * Bugs fixed in the inductive definition and datatype packages;
  1309 
  1310 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  1311 and HOL_dup_cs obsolete;
  1312 
  1313 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  1314 have been removed;
  1315 
  1316 * Simpler definition of function space in ZF;
  1317 
  1318 * new results about cardinal and ordinal arithmetic in ZF;
  1319 
  1320 * 'subtype' facility in HOL for introducing new types as subsets of existing
  1321 types;
  1322 
  1323 
  1324 $Id$