NEWS
author wenzelm
Tue Sep 12 17:35:09 2000 +0200 (2000-09-12)
changeset 9937 431c96ac997e
parent 9908 7c7ff65b6846
child 9941 fe05af7ec816
permissions -rw-r--r--
replaced "delrule" by "rule del";
     1 
     2 Isabelle NEWS -- history user-relevant changes
     3 ==============================================
     4 
     5 New in this Isabelle version
     6 ----------------------------
     7 
     8 *** Overview of INCOMPATIBILITIES (see below for more details) ***
     9 
    10 * HOL: simplification of natural numbers is much changed; to partly
    11 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
    12 issue the following ML commands:
    13 
    14   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
    15   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
    16 
    17 * HOL: 0 is now overloaded, so the type constraint ::nat may sometimes be
    18 needed;
    19 
    20 * HOL: the constant for f``x is now "image" rather than "op ``";
    21 
    22 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
    23 product is now "<*>" instead of "Times"; the lexicographic product is
    24 now "<*lex*>" instead of "**";
    25 
    26 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
    27 
    28 * HOL: simplification no longer dives into case-expressions;
    29 
    30 * HOL: the recursion equations generated by 'recdef' are now called
    31 f.simps instead of f.rules;
    32 
    33 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
    34 main HOL, but was unused); should better use HOL's datatype package
    35 anyway;
    36 
    37 * HOL: removed obsolete theorem binding expand_if (refer to split_if
    38 instead);
    39 
    40 * HOL: less_induct is renamed nat_less_induct
    41 
    42 * HOL/Real: "rabs" replaced by overloaded "abs" function;
    43 
    44 * HOL/ML: even fewer consts are declared as global (see theories Ord,
    45 Lfp, Gfp, WF); this only affects ML packages that refer to const names
    46 internally;
    47 
    48 * HOL, ZF: syntax for quotienting wrt an equivalence relation changed
    49 from A/r to A//r;
    50 
    51 * HOL: qed_spec_mp now also removes bounded ALL;
    52 
    53 * ZF: new treatment of arithmetic (nat & int) may break some old proofs;
    54 
    55 * Isar/Provers: intro/elim/dest attributes: changed
    56 intro/intro!/intro!!  flags to intro!/intro/intro? (in most cases, one
    57 should have to change intro!! to intro? only); replaced "delrule" by
    58 "rule del";
    59 
    60 * Isar: changed syntax of local blocks from {{ }} to { };
    61 
    62 * Isar: renamed 'RS' attribute to 'THEN';
    63 
    64 * Isar: renamed some attributes (rulify -> rulified, elimify -> elimified, ...);
    65 
    66 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
    67 
    68 * Provers: strengthened force_tac by using new first_best_tac;
    69 
    70 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
    71   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
    72 use instead the strong form,
    73   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
    74 In HOL, FOL and ZF the function cla_make_elim will create such rules
    75 from destruct-rules;
    76 
    77 * Provers: safe_asm_full_simp_tac is no longer in the simplifier signature. Use
    78   val safe_asm_full_simp_tac = generic_simp_tac true (true,true,true);
    79   if required.
    80 
    81 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
    82 timing flag supersedes proof_timing and Toplevel.trace;
    83 
    84 * ML: PureThy.add_thms/add_axioms/add_defs return theorems as well;
    85 
    86 * ML: PureThy.add_defs gets additional argument to indicate potential
    87 overloading (usually false);
    88 
    89 * LaTeX: several changes of isabelle.sty;
    90 
    91 
    92 *** Document preparation ***
    93 
    94 * formal comments (text blocks etc.) in new-style theories may now
    95 contain antiquotations of thm/prop/term/typ/text to be presented
    96 according to latex print mode; concrete syntax is like this:
    97 @{term[show_types] "f(x) = a + x"};
    98 
    99 * isatool mkdir provides easy setup of Isabelle session directories,
   100 including proper document sources;
   101 
   102 * generated LaTeX sources are now deleted after successful run
   103 (isatool document -c); may retain a copy somewhere else via -D option
   104 of isatool usedir;
   105 
   106 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
   107 style files, achieving self-contained LaTeX sources;
   108 
   109 * old-style theories now produce (crude) LaTeX output as well;
   110 
   111 * browser info session directories are now self-contained (may be put
   112 on WWW server seperately); improved graphs of nested sessions; removed
   113 graph for 'all sessions';
   114 
   115 * several improvements in isabelle.sty; \isabellestyle{it} produces
   116 near math mode output; \isamarkupheader is now \section by default;
   117 
   118 
   119 *** Isar ***
   120 
   121 * Pure: local results and corresponding term bindings are now subject
   122 to Hindley-Milner polymorphism (similar to ML); this accommodates
   123 incremental type-inference nicely;
   124 
   125 * Pure: new derived language element 'obtain' supports generalized
   126 existence reasoning;
   127 
   128 * Pure: new calculational elements 'moreover' and 'ultimately' support
   129 accumulation of results, without applying any rules yet;
   130 
   131 * Pure: scalable support for case-analysis type proofs: new 'case'
   132 language element refers to local contexts symbolically, as produced by
   133 certain proof methods; internally, case names are attached to theorems
   134 as "tags";
   135 
   136 * Pure: theory command 'hide' removes declarations from
   137 class/type/const name spaces;
   138 
   139 * Pure: theory command 'defs' supports option "(overloaded)" to
   140 indicate potential overloading;
   141 
   142 * Pure: changed syntax of local blocks from {{ }} to { };
   143 
   144 * Pure: renamed 'RS' attribute to 'THEN';
   145 
   146 * Pure: syntax of sorts made 'inner', i.e. have to write "{a, b, c}"
   147 instead of {a, b, c};
   148 
   149 * Pure now provides its own version of intro/elim/dest attributes;
   150 useful for building new logics, but beware of confusion with the
   151 version in Provers/classical;
   152 
   153 * Pure: the local context of (non-atomic) goals is provided via case
   154 name 'antecedent';
   155 
   156 * Pure: removed obsolete 'transfer' attribute (transfer of thms to the
   157 current context is now done automatically);
   158 
   159 * Pure: theory command 'method_setup' provides a simple interface for
   160 definining proof methods in ML;
   161 
   162 * Provers: 'simp' method now supports 'cong' modifiers;
   163 
   164 * Provers: hypsubst support; also plain subst and symmetric attribute
   165 (the latter supercedes [RS sym]);
   166 
   167 * Provers: splitter support (via 'split' attribute and 'simp' method
   168 modifier); 'simp' method: 'only:' modifier removes loopers as well
   169 (including splits);
   170 
   171 * Provers: added 'fastsimp' and 'clarsimp' methods (combination of
   172 Simplifier and Classical reasoner);
   173 
   174 * Provers: added 'arith_split' attribute;
   175 
   176 * HOL: new proof method 'cases' and improved version of 'induct' now
   177 support named cases; major packages (inductive, datatype, primrec,
   178 recdef) support case names and properly name parameters;
   179 
   180 * HOL: removed 'case_split' thm binding, should use 'cases' proof
   181 method anyway;
   182 
   183 * HOL: removed obsolete expand_if = split_if; theorems if_splits =
   184 split_if split_if_asm; datatype package provides theorems foo.splits =
   185 foo.split foo.split_asm for each datatype;
   186 
   187 * HOL/Calculation: new rules for substitution in inequalities
   188 (monotonicity conditions are extracted to be proven at end);
   189 
   190 * HOL/inductive: rename "intrs" to "intros" (potential
   191 INCOMPATIBILITY); emulation of mk_cases feature for proof scripts:
   192 'inductive_cases' command and 'ind_cases' method; NOTE: use (cases
   193 (simplified)) method in proper proofs;
   194 
   195 * Provers: intro/elim/dest attributes: changed intro/intro!/intro!!
   196 flags to intro!/intro/intro? (in most cases, one should have to change
   197 intro!! to intro? only); replaced "delrule" by "rule del";
   198 
   199 * names of theorems etc. may be natural numbers as well;
   200 
   201 * 'pr' command: optional arguments for goals_limit and
   202 ProofContext.prems_limit; no longer prints theory contexts, but only
   203 proof states;
   204 
   205 * diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
   206 additional print modes to be specified; e.g. "pr(latex)" will print
   207 proof state according to the Isabelle LaTeX style;
   208 
   209 * improved support for emulating tactic scripts, including proof
   210 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
   211 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
   212 (for HOL datatypes);
   213 
   214 * simplified (more robust) goal selection of proof methods: 1st goal,
   215 all goals, or explicit goal specifier (tactic emulation); thus 'proof
   216 method scripts' have to be in depth-first order;
   217 
   218 * tuned 'let' syntax: replaced 'as' keyword by 'and';
   219 
   220 * removed 'help' command, which hasn't been too helpful anyway; should
   221 instead use individual commands for printing items (print_commands,
   222 print_methods etc.);
   223 
   224 * added 'nothing' --- the empty list of theorems;
   225 
   226 
   227 *** HOL ***
   228 
   229 * HOL/Lambda: converted into new-style theory and document;
   230 
   231 * HOL/Algebra: new theory of rings and univariate polynomials, by
   232 Clemens Ballarin;
   233 
   234 * HOL/ex: new theory Factorization proving the Fundamental Theorem of
   235 Arithmetic, by Thomas M Rasmussen;
   236 
   237 * HOL/ex/Multiquote: multiple nested quotations and anti-quotations --
   238 basically a generalized version of de-Bruijn representation; very
   239 useful in avoiding lifting of operations;
   240 
   241 * HOL/NumberTheory: Chinese Remainder Theorem, Fermat/Euler Theorem, Wilson's
   242 Theorem, by Thomas M Rasmussen;
   243 
   244 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog;
   245 
   246 * HOL/Real: "rabs" replaced by overloaded "abs" function;
   247 
   248 * HOL/record: added general record equality rule to simpset; fixed
   249 select-update simplification procedure to handle extended records as
   250 well; admit "r" as field name;
   251 
   252 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
   253 other numeric types and also as the identity of groups, rings, etc.;
   254 
   255 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
   256 Types nat and int belong to this axclass;
   257 
   258 * greatly improved simplification involving numerals of type nat, int, real:
   259    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
   260    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
   261   two terms #m*u and #n*u are replaced by #(m+n)*u
   262     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
   263   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
   264     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
   265 
   266 * HOL: meson_tac is available (previously in ex/meson.ML).  It is a powerful
   267    prover for predicate logic but knows nothing of clasets.  For examples of
   268    what it can do, see ex/mesontest.ML and ex/mesontest2.ML;
   269 
   270 * HOL: new version of "case_tac" subsumes both boolean case split and
   271 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
   272 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
   273 
   274 * HOL: simplification no longer dives into case-expressions: only the
   275 selector expression is simplified, but not the remaining arms. To
   276 enable full simplification of case-expressions for datatype t, you
   277 need to remove t.weak_case_cong from the simpset, either permanently
   278 (Delcongs[thm"t.weak_case_cong"];) or locally (delcongs [...]).
   279 
   280 * HOL/recdef: the recursion equations generated by 'recdef' for
   281 function 'f' are now called f.simps instead of f.rules; if all
   282 termination conditions are proved automatically, these simplification
   283 rules are added to the simpset, as in primrec; rules may be named
   284 individually as well, resulting in a separate list of theorems for
   285 each equation;
   286 
   287 * HOL/While is a new theory that provides a while-combinator. It
   288 permits the definition of tail-recursive functions without the
   289 provision of a termination measure. The latter is necessary once the
   290 invariant proof rule for while is applied.
   291 
   292 * HOL: new (overloaded) notation for the set of elements below/above some
   293 element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
   294 
   295 * HOL: theorems impI, allI, ballI bound as "strip";
   296 
   297 * new tactic induct_thm_tac: thm -> string -> int -> tactic
   298 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
   299 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
   300 
   301 * new functions rulify/rulify_no_asm: thm -> thm for turning outer
   302 -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
   303 
   304 * theory Sexp now in HOL/Induct examples (it used to be part of main
   305 HOL, but was unused);
   306 
   307 * fewer consts declared as global (e.g. have to refer to "Lfp.lfp"
   308 instead of "lfp" internally; affects ML packages only);
   309 
   310 * tuned AST representation of nested pairs, avoiding bogus output in
   311 case of overlap with user translations (e.g. judgements over tuples);
   312 
   313 
   314 *** ZF ***
   315 
   316 * simplification automatically cancels common terms in arithmetic expressions
   317 over nat and int;
   318 
   319 * new treatment of nat to minimize type-checking: all operators coerce their 
   320 operands to a natural number using the function natify, making the algebraic
   321 laws unconditional;
   322 
   323 * as above, for int: operators coerce their operands to an integer using the
   324 function intify;
   325 
   326 * the integer library now contains many of the usual laws for the orderings, 
   327 including $<=, and monotonicity laws for $+ and $*; 
   328 
   329 * new example ZF/ex/NatSum to demonstrate integer arithmetic simplification;
   330 
   331 *** FOL & ZF ***
   332 
   333 * AddIffs now available, giving theorems of the form P<->Q to the
   334 simplifier and classical reasoner simultaneously;
   335 
   336 
   337 *** General ***
   338 
   339 * Provers: blast(_tac) now handles actual object-logic rules as
   340 assumptions; note that auto(_tac) uses blast(_tac) internally as well;
   341 
   342 * Provers: Simplifier.easy_setup provides a fast path to basic
   343 Simplifier setup for new object-logics;
   344 
   345 * Pure: AST translation rules no longer require constant head on LHS;
   346 
   347 * Pure: improved name spaces: ambiguous output is qualified; support
   348 for hiding of names;
   349 
   350 * system: compression of ML heaps images may now be controlled via -c
   351 option of isabelle and isatool usedir (currently only observed by
   352 Poly/ML);
   353 
   354 * system: provide TAGS file for Isabelle sources;
   355 
   356 * settings: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
   357 XSYMBOL_HOME; no longer need to do manual configuration in most
   358 situations;
   359 
   360 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
   361 order;
   362 
   363 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
   364 timing flag supersedes proof_timing and Toplevel.trace;
   365 
   366 * ML: PureThy.add_defs gets additional argument to indicate potential
   367 overloading (usually false);
   368 
   369 * ML: new combinators |>> and |>>> for incremental transformations
   370 with secondary results (e.g. certain theory extensions):
   371 
   372 
   373 
   374 New in Isabelle99 (October 1999)
   375 --------------------------------
   376 
   377 *** Overview of INCOMPATIBILITIES (see below for more details) ***
   378 
   379 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
   380 are no longer simplified.  (This allows the simplifier to unfold recursive
   381 functional programs.)  To restore the old behaviour, declare
   382 
   383     Delcongs [if_weak_cong];
   384 
   385 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
   386 complement;
   387 
   388 * HOL: the predicate "inj" is now defined by translation to "inj_on";
   389 
   390 * HOL/datatype: mutual_induct_tac no longer exists --
   391   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
   392 
   393 * HOL/typedef: fixed type inference for representing set; type
   394 arguments now have to occur explicitly on the rhs as type constraints;
   395 
   396 * ZF: The con_defs part of an inductive definition may no longer refer
   397 to constants declared in the same theory;
   398 
   399 * HOL, ZF: the function mk_cases, generated by the inductive
   400 definition package, has lost an argument.  To simplify its result, it
   401 uses the default simpset instead of a supplied list of theorems.
   402 
   403 * HOL/List: the constructors of type list are now Nil and Cons;
   404 
   405 * Simplifier: the type of the infix ML functions
   406         setSSolver addSSolver setSolver addSolver
   407 is now  simpset * solver -> simpset  where `solver' is a new abstract type
   408 for packaging solvers. A solver is created via
   409         mk_solver: string -> (thm list -> int -> tactic) -> solver
   410 where the string argument is only a comment.
   411 
   412 
   413 *** Proof tools ***
   414 
   415 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
   416 decision procedure for linear arithmetic. Currently it is used for
   417 types `nat', `int', and `real' in HOL (see below); it can, should and
   418 will be instantiated for other types and logics as well.
   419 
   420 * The simplifier now accepts rewrite rules with flexible heads, eg
   421      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
   422   They are applied like any rule with a non-pattern lhs, i.e. by first-order
   423   matching.
   424 
   425 
   426 *** General ***
   427 
   428 * New Isabelle/Isar subsystem provides an alternative to traditional
   429 tactical theorem proving; together with the ProofGeneral/isar user
   430 interface it offers an interactive environment for developing human
   431 readable proof documents (Isar == Intelligible semi-automated
   432 reasoning); for further information see isatool doc isar-ref,
   433 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
   434 
   435 * improved and simplified presentation of theories: better HTML markup
   436 (including colors), graph views in several sizes; isatool usedir now
   437 provides a proper interface for user theories (via -P option); actual
   438 document preparation based on (PDF)LaTeX is available as well (for
   439 new-style theories only); see isatool doc system for more information;
   440 
   441 * native support for Proof General, both for classic Isabelle and
   442 Isabelle/Isar;
   443 
   444 * ML function thm_deps visualizes dependencies of theorems and lemmas,
   445 using the graph browser tool;
   446 
   447 * Isabelle manuals now also available as PDF;
   448 
   449 * theory loader rewritten from scratch (may not be fully
   450 bug-compatible); old loadpath variable has been replaced by show_path,
   451 add_path, del_path, reset_path functions; new operations such as
   452 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
   453 isatool doc ref);
   454 
   455 * improved isatool install: option -k creates KDE application icon,
   456 option -p DIR installs standalone binaries;
   457 
   458 * added ML_PLATFORM setting (useful for cross-platform installations);
   459 more robust handling of platform specific ML images for SML/NJ;
   460 
   461 * the settings environment is now statically scoped, i.e. it is never
   462 created again in sub-processes invoked from isabelle, isatool, or
   463 Isabelle;
   464 
   465 * path element specification '~~' refers to '$ISABELLE_HOME';
   466 
   467 * in locales, the "assumes" and "defines" parts may be omitted if
   468 empty;
   469 
   470 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
   471 long arrows);
   472 
   473 * new print_mode "HTML";
   474 
   475 * new flag show_tags controls display of tags of theorems (which are
   476 basically just comments that may be attached by some tools);
   477 
   478 * Isamode 2.6 requires patch to accomodate change of Isabelle font
   479 mode and goal output format:
   480 
   481 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
   482 244c244
   483 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
   484 ---
   485 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
   486 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
   487 181c181
   488 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
   489 ---
   490 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
   491 
   492 * function bind_thms stores lists of theorems (cf. bind_thm);
   493 
   494 * new shorthand tactics ftac, eatac, datac, fatac;
   495 
   496 * qed (and friends) now accept "" as result name; in that case the
   497 theorem is not stored, but proper checks and presentation of the
   498 result still apply;
   499 
   500 * theorem database now also indexes constants "Trueprop", "all",
   501 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
   502 
   503 
   504 *** HOL ***
   505 
   506 ** HOL arithmetic **
   507 
   508 * There are now decision procedures for linear arithmetic over nat and
   509 int:
   510 
   511 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
   512 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
   513 are treated as atomic; subformulae not involving type `nat' or `int'
   514 are ignored; quantified subformulae are ignored unless they are
   515 positive universal or negative existential. The tactic has to be
   516 invoked by hand and can be a little bit slow. In particular, the
   517 running time is exponential in the number of occurrences of `min' and
   518 `max', and `-' on `nat'.
   519 
   520 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
   521 (negated) (in)equalities among the premises and the conclusion into
   522 account (i.e. no compound formulae) and does not know about `min' and
   523 `max', and `-' on `nat'. It is fast and is used automatically by the
   524 simplifier.
   525 
   526 NB: At the moment, these decision procedures do not cope with mixed
   527 nat/int formulae where the two parts interact, such as `m < n ==>
   528 int(m) < int(n)'.
   529 
   530 * HOL/Numeral provides a generic theory of numerals (encoded
   531 efficiently as bit strings); setup for types nat/int/real is in place;
   532 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
   533 int, existing theories and proof scripts may require a few additional
   534 type constraints;
   535 
   536 * integer division and remainder can now be performed on constant
   537 arguments;
   538 
   539 * many properties of integer multiplication, division and remainder
   540 are now available;
   541 
   542 * An interface to the Stanford Validity Checker (SVC) is available through the
   543 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
   544 are proved automatically.  SVC must be installed separately, and its results
   545 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
   546 invocation of the underlying oracle).  For SVC see
   547   http://verify.stanford.edu/SVC
   548 
   549 * IsaMakefile: the HOL-Real target now builds an actual image;
   550 
   551 
   552 ** HOL misc **
   553 
   554 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
   555 (in Isabelle/Isar) -- by Gertrud Bauer;
   556 
   557 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
   558 analysis for assembly languages with subtypes;
   559 
   560 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
   561 -- avoids syntactic ambiguities and treats state, transition, and
   562 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
   563 changed syntax and (many) tactics;
   564 
   565 * HOL/inductive: Now also handles more general introduction rules such
   566   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
   567   theorems are now maintained within the theory (maintained via the
   568   "mono" attribute);
   569 
   570 * HOL/datatype: Now also handles arbitrarily branching datatypes
   571   (using function types) such as
   572 
   573   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
   574 
   575 * HOL/record: record_simproc (part of the default simpset) takes care
   576 of selectors applied to updated records; record_split_tac is no longer
   577 part of the default claset; update_defs may now be removed from the
   578 simpset in many cases; COMPATIBILITY: old behavior achieved by
   579 
   580   claset_ref () := claset() addSWrapper record_split_wrapper;
   581   Delsimprocs [record_simproc]
   582 
   583 * HOL/typedef: fixed type inference for representing set; type
   584 arguments now have to occur explicitly on the rhs as type constraints;
   585 
   586 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
   587 names rather than an ML expression;
   588 
   589 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
   590 supplied later.  Program schemes can be defined, such as
   591     "While B C s = (if B s then While B C (C s) else s)"
   592 where the well-founded relation can be chosen after B and C have been given.
   593 
   594 * HOL/List: the constructors of type list are now Nil and Cons;
   595 INCOMPATIBILITY: while [] and infix # syntax is still there, of
   596 course, ML tools referring to List.list.op # etc. have to be adapted;
   597 
   598 * HOL_quantifiers flag superseded by "HOL" print mode, which is
   599 disabled by default; run isabelle with option -m HOL to get back to
   600 the original Gordon/HOL-style output;
   601 
   602 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
   603 ALL x<=y. P, EX x<y. P, EX x<=y. P;
   604 
   605 * HOL basic syntax simplified (more orthogonal): all variants of
   606 All/Ex now support plain / symbolic / HOL notation; plain syntax for
   607 Eps operator is provided as well: "SOME x. P[x]";
   608 
   609 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
   610 
   611 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
   612 thus available for user theories;
   613 
   614 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
   615 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
   616 time;
   617 
   618 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
   619 several times and then mp;
   620 
   621 
   622 *** LK ***
   623 
   624 * the notation <<...>> is now available as a notation for sequences of
   625 formulas;
   626 
   627 * the simplifier is now installed
   628 
   629 * the axiom system has been generalized (thanks to Soren Heilmann)
   630 
   631 * the classical reasoner now has a default rule database
   632 
   633 
   634 *** ZF ***
   635 
   636 * new primrec section allows primitive recursive functions to be given
   637 directly (as in HOL) over datatypes and the natural numbers;
   638 
   639 * new tactics induct_tac and exhaust_tac for induction (or case
   640 analysis) over datatypes and the natural numbers;
   641 
   642 * the datatype declaration of type T now defines the recursor T_rec;
   643 
   644 * simplification automatically does freeness reasoning for datatype
   645 constructors;
   646 
   647 * automatic type-inference, with AddTCs command to insert new
   648 type-checking rules;
   649 
   650 * datatype introduction rules are now added as Safe Introduction rules
   651 to the claset;
   652 
   653 * the syntax "if P then x else y" is now available in addition to
   654 if(P,x,y);
   655 
   656 
   657 *** Internal programming interfaces ***
   658 
   659 * tuned simplifier trace output; new flag debug_simp;
   660 
   661 * structures Vartab / Termtab (instances of TableFun) offer efficient
   662 tables indexed by indexname_ord / term_ord (compatible with aconv);
   663 
   664 * AxClass.axclass_tac lost the theory argument;
   665 
   666 * tuned current_goals_markers semantics: begin / end goal avoids
   667 printing empty lines;
   668 
   669 * removed prs and prs_fn hook, which was broken because it did not
   670 include \n in its semantics, forcing writeln to add one
   671 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
   672 string -> unit if you really want to output text without newline;
   673 
   674 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
   675 plain output, interface builders may have to enable 'isabelle_font'
   676 mode to get Isabelle font glyphs as before;
   677 
   678 * refined token_translation interface; INCOMPATIBILITY: output length
   679 now of type real instead of int;
   680 
   681 * theory loader actions may be traced via new ThyInfo.add_hook
   682 interface (see src/Pure/Thy/thy_info.ML); example application: keep
   683 your own database of information attached to *whole* theories -- as
   684 opposed to intra-theory data slots offered via TheoryDataFun;
   685 
   686 * proper handling of dangling sort hypotheses (at last!);
   687 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
   688 extra sort hypotheses that can be witnessed from the type signature;
   689 the force_strip_shyps flag is gone, any remaining shyps are simply
   690 left in the theorem (with a warning issued by strip_shyps_warning);
   691 
   692 
   693 
   694 New in Isabelle98-1 (October 1998)
   695 ----------------------------------
   696 
   697 *** Overview of INCOMPATIBILITIES (see below for more details) ***
   698 
   699 * several changes of automated proof tools;
   700 
   701 * HOL: major changes to the inductive and datatype packages, including
   702 some minor incompatibilities of theory syntax;
   703 
   704 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
   705 called `inj_on';
   706 
   707 * HOL: removed duplicate thms in Arith:
   708   less_imp_add_less  should be replaced by  trans_less_add1
   709   le_imp_add_le      should be replaced by  trans_le_add1
   710 
   711 * HOL: unary minus is now overloaded (new type constraints may be
   712 required);
   713 
   714 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
   715 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
   716 now taken as an integer constant.
   717 
   718 * Pure: ML function 'theory_of' renamed to 'theory';
   719 
   720 
   721 *** Proof tools ***
   722 
   723 * Simplifier:
   724   1. Asm_full_simp_tac is now more aggressive.
   725      1. It will sometimes reorient premises if that increases their power to
   726         simplify.
   727      2. It does no longer proceed strictly from left to right but may also
   728         rotate premises to achieve further simplification.
   729      For compatibility reasons there is now Asm_lr_simp_tac which is like the
   730      old Asm_full_simp_tac in that it does not rotate premises.
   731   2. The simplifier now knows a little bit about nat-arithmetic.
   732 
   733 * Classical reasoner: wrapper mechanism for the classical reasoner now
   734 allows for selected deletion of wrappers, by introduction of names for
   735 wrapper functionals.  This implies that addbefore, addSbefore,
   736 addaltern, and addSaltern now take a pair (name, tactic) as argument,
   737 and that adding two tactics with the same name overwrites the first
   738 one (emitting a warning).
   739   type wrapper = (int -> tactic) -> (int -> tactic)
   740   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
   741   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
   742   delWrapper, delSWrapper: claset *  string            -> claset
   743   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
   744 
   745 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
   746 semantics; addbefore now affects only the unsafe part of step_tac
   747 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
   748 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
   749 by Force_tac;
   750 
   751 * Classical reasoner: setwrapper to setWrapper and compwrapper to
   752 compWrapper; added safe wrapper (and access functions for it);
   753 
   754 * HOL/split_all_tac is now much faster and fails if there is nothing
   755 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
   756 and the names of the automatically generated variables have changed.
   757 split_all_tac has moved within claset() from unsafe wrappers to safe
   758 wrappers, which means that !!-bound variables are split much more
   759 aggressively, and safe_tac and clarify_tac now split such variables.
   760 If this splitting is not appropriate, use delSWrapper "split_all_tac".
   761 Note: the same holds for record_split_tac, which does the job of
   762 split_all_tac for record fields.
   763 
   764 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
   765 permanently to the default simpset using Addsplits just like
   766 Addsimps. They can be removed via Delsplits just like
   767 Delsimps. Lower-case versions are also available.
   768 
   769 * HOL/Simplifier: The rule split_if is now part of the default
   770 simpset. This means that the simplifier will eliminate all occurrences
   771 of if-then-else in the conclusion of a goal. To prevent this, you can
   772 either remove split_if completely from the default simpset by
   773 `Delsplits [split_if]' or remove it in a specific call of the
   774 simplifier using `... delsplits [split_if]'.  You can also add/delete
   775 other case splitting rules to/from the default simpset: every datatype
   776 generates suitable rules `split_t_case' and `split_t_case_asm' (where
   777 t is the name of the datatype).
   778 
   779 * Classical reasoner / Simplifier combination: new force_tac (and
   780 derivatives Force_tac, force) combines rewriting and classical
   781 reasoning (and whatever other tools) similarly to auto_tac, but is
   782 aimed to solve the given subgoal completely.
   783 
   784 
   785 *** General ***
   786 
   787 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
   788 and `goalw': the theory is no longer needed as an explicit argument -
   789 the current theory context is used; assumptions are no longer returned
   790 at the ML-level unless one of them starts with ==> or !!; it is
   791 recommended to convert to these new commands using isatool fixgoal
   792 (backup your sources first!);
   793 
   794 * new top-level commands 'thm' and 'thms' for retrieving theorems from
   795 the current theory context, and 'theory' to lookup stored theories;
   796 
   797 * new theory section 'locale' for declaring constants, assumptions and
   798 definitions that have local scope;
   799 
   800 * new theory section 'nonterminals' for purely syntactic types;
   801 
   802 * new theory section 'setup' for generic ML setup functions
   803 (e.g. package initialization);
   804 
   805 * the distribution now includes Isabelle icons: see
   806 lib/logo/isabelle-{small,tiny}.xpm;
   807 
   808 * isatool install - install binaries with absolute references to
   809 ISABELLE_HOME/bin;
   810 
   811 * isatool logo -- create instances of the Isabelle logo (as EPS);
   812 
   813 * print mode 'emacs' reserved for Isamode;
   814 
   815 * support multiple print (ast) translations per constant name;
   816 
   817 * theorems involving oracles are now printed with a suffixed [!];
   818 
   819 
   820 *** HOL ***
   821 
   822 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
   823 
   824 * HOL/inductive package reorganized and improved: now supports mutual
   825 definitions such as
   826 
   827   inductive EVEN ODD
   828     intrs
   829       null "0 : EVEN"
   830       oddI "n : EVEN ==> Suc n : ODD"
   831       evenI "n : ODD ==> Suc n : EVEN"
   832 
   833 new theorem list "elims" contains an elimination rule for each of the
   834 recursive sets; inductive definitions now handle disjunctive premises
   835 correctly (also ZF);
   836 
   837 INCOMPATIBILITIES: requires Inductive as an ancestor; component
   838 "mutual_induct" no longer exists - the induction rule is always
   839 contained in "induct";
   840 
   841 
   842 * HOL/datatype package re-implemented and greatly improved: now
   843 supports mutually recursive datatypes such as
   844 
   845   datatype
   846     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
   847             | SUM ('a aexp) ('a aexp)
   848             | DIFF ('a aexp) ('a aexp)
   849             | NUM 'a
   850   and
   851     'a bexp = LESS ('a aexp) ('a aexp)
   852             | AND ('a bexp) ('a bexp)
   853             | OR ('a bexp) ('a bexp)
   854 
   855 as well as indirectly recursive datatypes such as
   856 
   857   datatype
   858     ('a, 'b) term = Var 'a
   859                   | App 'b ((('a, 'b) term) list)
   860 
   861 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
   862 induction on mutually / indirectly recursive datatypes.
   863 
   864 Primrec equations are now stored in theory and can be accessed via
   865 <function_name>.simps.
   866 
   867 INCOMPATIBILITIES:
   868 
   869   - Theories using datatypes must now have theory Datatype as an
   870     ancestor.
   871   - The specific <typename>.induct_tac no longer exists - use the
   872     generic induct_tac instead.
   873   - natE has been renamed to nat.exhaust - use exhaust_tac
   874     instead of res_inst_tac ... natE. Note that the variable
   875     names in nat.exhaust differ from the names in natE, this
   876     may cause some "fragile" proofs to fail.
   877   - The theorems split_<typename>_case and split_<typename>_case_asm
   878     have been renamed to <typename>.split and <typename>.split_asm.
   879   - Since default sorts of type variables are now handled correctly,
   880     some datatype definitions may have to be annotated with explicit
   881     sort constraints.
   882   - Primrec definitions no longer require function name and type
   883     of recursive argument.
   884 
   885 Consider using isatool fixdatatype to adapt your theories and proof
   886 scripts to the new package (backup your sources first!).
   887 
   888 
   889 * HOL/record package: considerably improved implementation; now
   890 includes concrete syntax for record types, terms, updates; theorems
   891 for surjective pairing and splitting !!-bound record variables; proof
   892 support is as follows:
   893 
   894   1) standard conversions (selectors or updates applied to record
   895 constructor terms) are part of the standard simpset;
   896 
   897   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
   898 made part of standard simpset and claset via addIffs;
   899 
   900   3) a tactic for record field splitting (record_split_tac) is part of
   901 the standard claset (addSWrapper);
   902 
   903 To get a better idea about these rules you may retrieve them via
   904 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
   905 the name of your record type.
   906 
   907 The split tactic 3) conceptually simplifies by the following rule:
   908 
   909   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
   910 
   911 Thus any record variable that is bound by meta-all will automatically
   912 blow up into some record constructor term, consequently the
   913 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
   914 solve record problems automatically.
   915 
   916 
   917 * reorganized the main HOL image: HOL/Integ and String loaded by
   918 default; theory Main includes everything;
   919 
   920 * automatic simplification of integer sums and comparisons, using cancellation;
   921 
   922 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
   923 
   924 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
   925 
   926 * many new identities for unions, intersections, set difference, etc.;
   927 
   928 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
   929 called split_if, split_split, split_sum_case and split_nat_case (to go
   930 with add/delsplits);
   931 
   932 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
   933 (?x::unit) = (); this is made part of the default simpset, which COULD
   934 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
   935 'Delsimprocs [unit_eq_proc];' as last resort); also note that
   936 unit_abs_eta_conv is added in order to counter the effect of
   937 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
   938 %u.f();
   939 
   940 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
   941 makes more sense);
   942 
   943 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
   944   It and 'sym RS equals0D' are now in the default  claset, giving automatic
   945   disjointness reasoning but breaking a few old proofs.
   946 
   947 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
   948 to 'converse' from 'inverse' (for compatibility with ZF and some
   949 literature);
   950 
   951 * HOL/recdef can now declare non-recursive functions, with {} supplied as
   952 the well-founded relation;
   953 
   954 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
   955     Compl A.  The "Compl" syntax remains available as input syntax for this
   956     release ONLY.
   957 
   958 * HOL/Update: new theory of function updates:
   959     f(a:=b) == %x. if x=a then b else f x
   960 may also be iterated as in f(a:=b,c:=d,...);
   961 
   962 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
   963 
   964 * HOL/List:
   965   - new function list_update written xs[i:=v] that updates the i-th
   966     list position. May also be iterated as in xs[i:=a,j:=b,...].
   967   - new function `upt' written [i..j(] which generates the list
   968     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
   969     bound write [i..j], which is a shorthand for [i..j+1(].
   970   - new lexicographic orderings and corresponding wellfoundedness theorems.
   971 
   972 * HOL/Arith:
   973   - removed 'pred' (predecessor) function;
   974   - generalized some theorems about n-1;
   975   - many new laws about "div" and "mod";
   976   - new laws about greatest common divisors (see theory ex/Primes);
   977 
   978 * HOL/Relation: renamed the relational operator r^-1 "converse"
   979 instead of "inverse";
   980 
   981 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
   982   of the multiset ordering;
   983 
   984 * directory HOL/Real: a construction of the reals using Dedekind cuts
   985   (not included by default);
   986 
   987 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
   988 
   989 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
   990   programs, i.e. different program variables may have different types.
   991 
   992 * calling (stac rew i) now fails if "rew" has no effect on the goal
   993   [previously, this check worked only if the rewrite rule was unconditional]
   994   Now rew can involve either definitions or equalities (either == or =).
   995 
   996 
   997 *** ZF ***
   998 
   999 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  1000   only the theorems proved on ZF.ML;
  1001 
  1002 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  1003   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  1004   disjointness reasoning but breaking a few old proofs.
  1005 
  1006 * ZF/Update: new theory of function updates
  1007     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  1008   may also be iterated as in f(a:=b,c:=d,...);
  1009 
  1010 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  1011 
  1012 * calling (stac rew i) now fails if "rew" has no effect on the goal
  1013   [previously, this check worked only if the rewrite rule was unconditional]
  1014   Now rew can involve either definitions or equalities (either == or =).
  1015 
  1016 * case_tac provided for compatibility with HOL
  1017     (like the old excluded_middle_tac, but with subgoals swapped)
  1018 
  1019 
  1020 *** Internal programming interfaces ***
  1021 
  1022 * Pure: several new basic modules made available for general use, see
  1023 also src/Pure/README;
  1024 
  1025 * improved the theory data mechanism to support encapsulation (data
  1026 kind name replaced by private Object.kind, acting as authorization
  1027 key); new type-safe user interface via functor TheoryDataFun; generic
  1028 print_data function becomes basically useless;
  1029 
  1030 * removed global_names compatibility flag -- all theory declarations
  1031 are qualified by default;
  1032 
  1033 * module Pure/Syntax now offers quote / antiquote translation
  1034 functions (useful for Hoare logic etc. with implicit dependencies);
  1035 see HOL/ex/Antiquote for an example use;
  1036 
  1037 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  1038 cterm -> thm;
  1039 
  1040 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  1041 subgoal;
  1042 
  1043 * Display.print_goals function moved to Locale.print_goals;
  1044 
  1045 * standard print function for goals supports current_goals_markers
  1046 variable for marking begin of proof, end of proof, start of goal; the
  1047 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  1048 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  1049 for example;
  1050 
  1051 
  1052 
  1053 New in Isabelle98 (January 1998)
  1054 --------------------------------
  1055 
  1056 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  1057 
  1058 * changed lexical syntax of terms / types: dots made part of long
  1059 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  1060 
  1061 * simpset (and claset) reference variable replaced by functions
  1062 simpset / simpset_ref;
  1063 
  1064 * no longer supports theory aliases (via merge) and non-trivial
  1065 implicit merge of thms' signatures;
  1066 
  1067 * most internal names of constants changed due to qualified names;
  1068 
  1069 * changed Pure/Sequence interface (see Pure/seq.ML);
  1070 
  1071 
  1072 *** General Changes ***
  1073 
  1074 * hierachically structured name spaces (for consts, types, axms, thms
  1075 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  1076 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  1077 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  1078 long_names for fully qualified output names; NOTE: ML programs
  1079 (special tactics, packages etc.) referring to internal names may have
  1080 to be adapted to cope with fully qualified names; in case of severe
  1081 backward campatibility problems try setting 'global_names' at compile
  1082 time to have enrything declared within a flat name space; one may also
  1083 fine tune name declarations in theories via the 'global' and 'local'
  1084 section;
  1085 
  1086 * reimplemented the implicit simpset and claset using the new anytype
  1087 data filed in signatures; references simpset:simpset ref etc. are
  1088 replaced by functions simpset:unit->simpset and
  1089 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  1090 to patch your ML files accordingly;
  1091 
  1092 * HTML output now includes theory graph data for display with Java
  1093 applet or isatool browser; data generated automatically via isatool
  1094 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  1095 
  1096 * defs may now be conditional; improved rewrite_goals_tac to handle
  1097 conditional equations;
  1098 
  1099 * defs now admits additional type arguments, using TYPE('a) syntax;
  1100 
  1101 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  1102 creates a new theory node; implicit merge of thms' signatures is
  1103 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  1104 transfer:theory->thm->thm in (rare) cases;
  1105 
  1106 * improved handling of draft signatures / theories; draft thms (and
  1107 ctyps, cterms) are automatically promoted to real ones;
  1108 
  1109 * slightly changed interfaces for oracles: admit many per theory, named
  1110 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  1111 
  1112 * print_goals: optional output of const types (set show_consts and
  1113 show_types);
  1114 
  1115 * improved output of warnings (###) and errors (***);
  1116 
  1117 * subgoal_tac displays a warning if the new subgoal has type variables;
  1118 
  1119 * removed old README and Makefiles;
  1120 
  1121 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  1122 
  1123 * removed obsolete init_pps and init_database;
  1124 
  1125 * deleted the obsolete tactical STATE, which was declared by
  1126     fun STATE tacfun st = tacfun st st;
  1127 
  1128 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  1129 (which abbreviates $HOME);
  1130 
  1131 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  1132 use isatool fixseq to adapt your ML programs (this works for fully
  1133 qualified references to the Sequence structure only!);
  1134 
  1135 * use_thy no longer requires writable current directory; it always
  1136 reloads .ML *and* .thy file, if either one is out of date;
  1137 
  1138 
  1139 *** Classical Reasoner ***
  1140 
  1141 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  1142 tactics that use classical reasoning to simplify a subgoal without
  1143 splitting it into several subgoals;
  1144 
  1145 * Safe_tac: like safe_tac but uses the default claset;
  1146 
  1147 
  1148 *** Simplifier ***
  1149 
  1150 * added simplification meta rules:
  1151     (asm_)(full_)simplify: simpset -> thm -> thm;
  1152 
  1153 * simplifier.ML no longer part of Pure -- has to be loaded by object
  1154 logics (again);
  1155 
  1156 * added prems argument to simplification procedures;
  1157 
  1158 * HOL, FOL, ZF: added infix function `addsplits':
  1159   instead of `<simpset> setloop (split_tac <thms>)'
  1160   you can simply write `<simpset> addsplits <thms>'
  1161 
  1162 
  1163 *** Syntax ***
  1164 
  1165 * TYPE('a) syntax for type reflection terms;
  1166 
  1167 * no longer handles consts with name "" -- declare as 'syntax' instead;
  1168 
  1169 * pretty printer: changed order of mixfix annotation preference (again!);
  1170 
  1171 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  1172 
  1173 
  1174 *** HOL ***
  1175 
  1176 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  1177   with `addloop' of the simplifier to faciliate case splitting in premises.
  1178 
  1179 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  1180 
  1181 * HOL/Auth: new protocol proofs including some for the Internet
  1182   protocol TLS;
  1183 
  1184 * HOL/Map: new theory of `maps' a la VDM;
  1185 
  1186 * HOL/simplifier: simplification procedures nat_cancel_sums for
  1187 cancelling out common nat summands from =, <, <= (in)equalities, or
  1188 differences; simplification procedures nat_cancel_factor for
  1189 cancelling common factor from =, <, <= (in)equalities over natural
  1190 sums; nat_cancel contains both kinds of procedures, it is installed by
  1191 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  1192 
  1193 * HOL/simplifier: terms of the form
  1194   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  1195   are rewritten to
  1196   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  1197   and those of the form
  1198   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  1199   are rewritten to
  1200   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  1201 
  1202 * HOL/datatype
  1203   Each datatype `t' now comes with a theorem `split_t_case' of the form
  1204 
  1205   P(t_case f1 ... fn x) =
  1206      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  1207         ...
  1208        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  1209      )
  1210 
  1211   and a theorem `split_t_case_asm' of the form
  1212 
  1213   P(t_case f1 ... fn x) =
  1214     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  1215         ...
  1216        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  1217      )
  1218   which can be added to a simpset via `addsplits'. The existing theorems
  1219   expand_list_case and expand_option_case have been renamed to
  1220   split_list_case and split_option_case.
  1221 
  1222 * HOL/Arithmetic:
  1223   - `pred n' is automatically converted to `n-1'.
  1224     Users are strongly encouraged not to use `pred' any longer,
  1225     because it will disappear altogether at some point.
  1226   - Users are strongly encouraged to write "0 < n" rather than
  1227     "n ~= 0". Theorems and proof tools have been modified towards this
  1228     `standard'.
  1229 
  1230 * HOL/Lists:
  1231   the function "set_of_list" has been renamed "set" (and its theorems too);
  1232   the function "nth" now takes its arguments in the reverse order and
  1233   has acquired the infix notation "!" as in "xs!n".
  1234 
  1235 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  1236 
  1237 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  1238   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  1239 
  1240 * HOL/record: extensible records with schematic structural subtyping
  1241 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  1242 still lacks various theorems and concrete record syntax;
  1243 
  1244 
  1245 *** HOLCF ***
  1246 
  1247 * removed "axioms" and "generated by" sections;
  1248 
  1249 * replaced "ops" section by extended "consts" section, which is capable of
  1250   handling the continuous function space "->" directly;
  1251 
  1252 * domain package:
  1253   . proves theorems immediately and stores them in the theory,
  1254   . creates hierachical name space,
  1255   . now uses normal mixfix annotations (instead of cinfix...),
  1256   . minor changes to some names and values (for consistency),
  1257   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  1258   . separator between mutual domain defs: changed "," to "and",
  1259   . improved handling of sort constraints;  now they have to
  1260     appear on the left-hand side of the equations only;
  1261 
  1262 * fixed LAM <x,y,zs>.b syntax;
  1263 
  1264 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  1265 adm (%x. P (t x)), where P is chainfinite and t continuous;
  1266 
  1267 
  1268 *** FOL and ZF ***
  1269 
  1270 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  1271   with `addloop' of the simplifier to faciliate case splitting in premises.
  1272 
  1273 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  1274 in HOL, they strip ALL and --> from proved theorems;
  1275 
  1276 
  1277 
  1278 New in Isabelle94-8 (May 1997)
  1279 ------------------------------
  1280 
  1281 *** General Changes ***
  1282 
  1283 * new utilities to build / run / maintain Isabelle etc. (in parts
  1284 still somewhat experimental); old Makefiles etc. still functional;
  1285 
  1286 * new 'Isabelle System Manual';
  1287 
  1288 * INSTALL text, together with ./configure and ./build scripts;
  1289 
  1290 * reimplemented type inference for greater efficiency, better error
  1291 messages and clean internal interface;
  1292 
  1293 * prlim command for dealing with lots of subgoals (an easier way of
  1294 setting goals_limit);
  1295 
  1296 
  1297 *** Syntax ***
  1298 
  1299 * supports alternative (named) syntax tables (parser and pretty
  1300 printer); internal interface is provided by add_modesyntax(_i);
  1301 
  1302 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  1303 be used in conjunction with the Isabelle symbol font; uses the
  1304 "symbols" syntax table;
  1305 
  1306 * added token_translation interface (may translate name tokens in
  1307 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  1308 the current print_mode); IMPORTANT: user print translation functions
  1309 are responsible for marking newly introduced bounds
  1310 (Syntax.mark_boundT);
  1311 
  1312 * token translations for modes "xterm" and "xterm_color" that display
  1313 names in bold, underline etc. or colors (which requires a color
  1314 version of xterm);
  1315 
  1316 * infixes may now be declared with names independent of their syntax;
  1317 
  1318 * added typed_print_translation (like print_translation, but may
  1319 access type of constant);
  1320 
  1321 
  1322 *** Classical Reasoner ***
  1323 
  1324 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  1325 some limitations.  Blast_tac...
  1326   + ignores addss, addbefore, addafter; this restriction is intrinsic
  1327   + ignores elimination rules that don't have the correct format
  1328         (the conclusion MUST be a formula variable)
  1329   + ignores types, which can make HOL proofs fail
  1330   + rules must not require higher-order unification, e.g. apply_type in ZF
  1331     [message "Function Var's argument not a bound variable" relates to this]
  1332   + its proof strategy is more general but can actually be slower
  1333 
  1334 * substitution with equality assumptions no longer permutes other
  1335 assumptions;
  1336 
  1337 * minor changes in semantics of addafter (now called addaltern); renamed
  1338 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  1339 (and access functions for it);
  1340 
  1341 * improved combination of classical reasoner and simplifier:
  1342   + functions for handling clasimpsets
  1343   + improvement of addss: now the simplifier is called _after_ the
  1344     safe steps.
  1345   + safe variant of addss called addSss: uses safe simplifications
  1346     _during_ the safe steps. It is more complete as it allows multiple
  1347     instantiations of unknowns (e.g. with slow_tac).
  1348 
  1349 *** Simplifier ***
  1350 
  1351 * added interface for simplification procedures (functions that
  1352 produce *proven* rewrite rules on the fly, depending on current
  1353 redex);
  1354 
  1355 * ordering on terms as parameter (used for ordered rewriting);
  1356 
  1357 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  1358 
  1359 * the solver is now split into a safe and an unsafe part.
  1360 This should be invisible for the normal user, except that the
  1361 functions setsolver and addsolver have been renamed to setSolver and
  1362 addSolver; added safe_asm_full_simp_tac;
  1363 
  1364 
  1365 *** HOL ***
  1366 
  1367 * a generic induction tactic `induct_tac' which works for all datatypes and
  1368 also for type `nat';
  1369 
  1370 * a generic case distinction tactic `exhaust_tac' which works for all
  1371 datatypes and also for type `nat';
  1372 
  1373 * each datatype comes with a function `size';
  1374 
  1375 * patterns in case expressions allow tuple patterns as arguments to
  1376 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  1377 
  1378 * primrec now also works with type nat;
  1379 
  1380 * recdef: a new declaration form, allows general recursive functions to be
  1381 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  1382 
  1383 * the constant for negation has been renamed from "not" to "Not" to
  1384 harmonize with FOL, ZF, LK, etc.;
  1385 
  1386 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  1387 infinite lists;
  1388 
  1389 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  1390 
  1391 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  1392 problems in commutative rings, using axiomatic type classes for + and *;
  1393 
  1394 * more examples in HOL/MiniML and HOL/Auth;
  1395 
  1396 * more default rewrite rules for quantifiers, union/intersection;
  1397 
  1398 * a new constant `arbitrary == @x.False';
  1399 
  1400 * HOLCF/IOA replaces old HOL/IOA;
  1401 
  1402 * HOLCF changes: derived all rules and arities
  1403   + axiomatic type classes instead of classes
  1404   + typedef instead of faking type definitions
  1405   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  1406   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  1407   + eliminated the types void, one, tr
  1408   + use unit lift and bool lift (with translations) instead of one and tr
  1409   + eliminated blift from Lift3.thy (use Def instead of blift)
  1410   all eliminated rules are derived as theorems --> no visible changes ;
  1411 
  1412 
  1413 *** ZF ***
  1414 
  1415 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  1416 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  1417 as ZF_cs addSIs [equalityI];
  1418 
  1419 
  1420 
  1421 New in Isabelle94-7 (November 96)
  1422 ---------------------------------
  1423 
  1424 * allowing negative levels (as offsets) in prlev and choplev;
  1425 
  1426 * super-linear speedup for large simplifications;
  1427 
  1428 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  1429 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  1430 FAIL); can suppress it using the command Delsimps (ex_simps @
  1431 all_simps); De Morgan laws are also now included, by default;
  1432 
  1433 * improved printing of ==>  :  ~:
  1434 
  1435 * new object-logic "Sequents" adds linear logic, while replacing LK
  1436 and Modal (thanks to Sara Kalvala);
  1437 
  1438 * HOL/Auth: correctness proofs for authentication protocols;
  1439 
  1440 * HOL: new auto_tac combines rewriting and classical reasoning (many
  1441 examples on HOL/Auth);
  1442 
  1443 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  1444 the rewriter and classical reasoner simultaneously;
  1445 
  1446 * function uresult no longer returns theorems in "standard" format;
  1447 regain previous version by: val uresult = standard o uresult;
  1448 
  1449 
  1450 
  1451 New in Isabelle94-6
  1452 -------------------
  1453 
  1454 * oracles -- these establish an interface between Isabelle and trusted
  1455 external reasoners, which may deliver results as theorems;
  1456 
  1457 * proof objects (in particular record all uses of oracles);
  1458 
  1459 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  1460 
  1461 * "constdefs" section in theory files;
  1462 
  1463 * "primrec" section (HOL) no longer requires names;
  1464 
  1465 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  1466 
  1467 
  1468 
  1469 New in Isabelle94-5
  1470 -------------------
  1471 
  1472 * reduced space requirements;
  1473 
  1474 * automatic HTML generation from theories;
  1475 
  1476 * theory files no longer require "..." (quotes) around most types;
  1477 
  1478 * new examples, including two proofs of the Church-Rosser theorem;
  1479 
  1480 * non-curried (1994) version of HOL is no longer distributed;
  1481 
  1482 
  1483 
  1484 New in Isabelle94-4
  1485 -------------------
  1486 
  1487 * greatly reduced space requirements;
  1488 
  1489 * theory files (.thy) no longer require \...\ escapes at line breaks;
  1490 
  1491 * searchable theorem database (see the section "Retrieving theorems" on
  1492 page 8 of the Reference Manual);
  1493 
  1494 * new examples, including Grabczewski's monumental case study of the
  1495 Axiom of Choice;
  1496 
  1497 * The previous version of HOL renamed to Old_HOL;
  1498 
  1499 * The new version of HOL (previously called CHOL) uses a curried syntax
  1500 for functions.  Application looks like f a b instead of f(a,b);
  1501 
  1502 * Mutually recursive inductive definitions finally work in HOL;
  1503 
  1504 * In ZF, pattern-matching on tuples is now available in all abstractions and
  1505 translates to the operator "split";
  1506 
  1507 
  1508 
  1509 New in Isabelle94-3
  1510 -------------------
  1511 
  1512 * new infix operator, addss, allowing the classical reasoner to
  1513 perform simplification at each step of its search.  Example:
  1514         fast_tac (cs addss ss)
  1515 
  1516 * a new logic, CHOL, the same as HOL, but with a curried syntax
  1517 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  1518 look like (a,b) instead of <a,b>;
  1519 
  1520 * PLEASE NOTE: CHOL will eventually replace HOL!
  1521 
  1522 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  1523 It translates to the operator "split".  A new theory of integers is available;
  1524 
  1525 * In ZF, integer numerals now denote two's-complement binary integers.
  1526 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  1527 
  1528 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  1529 of the Axiom of Choice;
  1530 
  1531 
  1532 
  1533 New in Isabelle94-2
  1534 -------------------
  1535 
  1536 * Significantly faster resolution;
  1537 
  1538 * the different sections in a .thy file can now be mixed and repeated
  1539 freely;
  1540 
  1541 * Database of theorems for FOL, HOL and ZF.  New
  1542 commands including qed, qed_goal and bind_thm store theorems in the database.
  1543 
  1544 * Simple database queries: return a named theorem (get_thm) or all theorems of
  1545 a given theory (thms_of), or find out what theory a theorem was proved in
  1546 (theory_of_thm);
  1547 
  1548 * Bugs fixed in the inductive definition and datatype packages;
  1549 
  1550 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  1551 and HOL_dup_cs obsolete;
  1552 
  1553 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  1554 have been removed;
  1555 
  1556 * Simpler definition of function space in ZF;
  1557 
  1558 * new results about cardinal and ordinal arithmetic in ZF;
  1559 
  1560 * 'subtype' facility in HOL for introducing new types as subsets of existing
  1561 types;
  1562 
  1563 
  1564 $Id$