NEWS
author wenzelm
Tue Jun 01 12:33:50 2004 +0200 (2004-06-01)
changeset 14854 61bdf2ae4dc5
parent 14816 b77cebcd7e6e
child 14878 b884a7ba7238
permissions -rw-r--r--
removed obsolete sort 'logic';
     1 Isabelle NEWS -- history user-relevant changes
     2 ==============================================
     3 
     4 New in this Isabelle release
     5 ----------------------------
     6 
     7 *** General ***
     8 
     9 * Pure: considerably improved version of 'constdefs' command.  Now
    10   performs automatic type-inference of declared constants; additional
    11   support for local structure declarations (cf. locales and HOL
    12   records), see also isar-ref manual.  Potential INCOMPATIBILITY: need
    13   to observe strictly sequential dependencies of definitions within a
    14   single 'constdefs' section; moreover, the declared name needs to be
    15   an identifier.  If all fails, consider to fall back on 'consts' and
    16   'defs' separately.
    17 
    18 * Pure: improved indexed syntax and implicit structures.  First of
    19   all, indexed syntax provides a notational device for subscripted
    20   application, using the new syntax \<^bsub>term\<^esub> for arbitrary
    21   expressions.  Secondly, in a local context with structure
    22   declarations, number indexes \<^sub>n or the empty index (default
    23   number 1) refer to a certain fixed variable implicitly; option
    24   show_structs controls printing of implicit structures.  Typical
    25   applications of these concepts involve record types and locales.
    26 
    27 * Pure: clear separation of logical types and nonterminals, where the
    28   latter may only occur in 'syntax' specifications or type
    29   abbreviations.  Before that distinction was only partially
    30   implemented via type class "logic" vs. "{}".  Potential
    31   INCOMPATIBILITY in rare cases of improper use of 'types'/'consts'
    32   instead of 'nonterminals'/'syntax'.  Some very exotic syntax
    33   specifications may require further adaption (e.g. Cube/Base.thy).
    34 
    35 * Pure: removed obsolete type class "logic", use the top sort {}
    36   instead.  Note that non-logical types should be declared as
    37   'nonterminals' rather than 'types'.  INCOMPATIBILITY for new
    38   object-logic specifications.
    39 
    40 * Pure/Syntax: inner syntax includes (*(*nested*) comments*).
    41 
    42 * Pure/Syntax: pretty pinter now supports unbreakable blocks,
    43   specified in mixfix annotations as "(00...)".
    44 
    45 * Pure/Syntax: 'advanced' translation functions (parse_translation
    46   etc.) may depend on the signature of the theory context being
    47   presently used for parsing/printing, see also isar-ref manual.
    48 
    49 * Pure: tuned internal renaming of symbolic identifiers -- attach
    50   primes instead of base 26 numbers.
    51 
    52 * ML: all output via channels of writeln/warning/error etc. is now
    53   passed through Output.output.  This gives interface builders a
    54   chance to adapt text encodings in arbitrary manners (say as XML
    55   entities); see the hook provided by Output.add_mode.  On the other
    56   hand, results of Pretty.string_of/str_of (including string_of_term,
    57   string_of_thm etc.) are still 'raw' (containing funny \<^raw...>
    58   symbols), which requires separate application of Output.output
    59   whenever strings are *not* passed on to writeln/warning/error etc.
    60 
    61 
    62 *** HOL ***
    63 
    64 * HOL/record: reimplementation of records. Improved scalability for
    65   records with many fields, avoiding performance problems for type
    66   inference. Records are no longer composed of nested field types, but
    67   of nested extension types. Therefore the record type only grows
    68   linear in the number of extensions and not in the number of fields.
    69   The top-level (users) view on records is preserved.  Potential
    70   INCOMPATIBILITY only in strange cases, where the theory depends on
    71   the old record representation. The type generated for a record is
    72   called <record_name>_ext_type.
    73 
    74 * Simplifier: "record_upd_simproc" for simplification of multiple
    75   record updates enabled by default.  INCOMPATIBILITY: old proofs
    76   break occasionally, since simplification is more powerful by
    77   default.
    78 
    79 
    80 *** HOLCF ***
    81 
    82 * HOLCF: discontinued special version of 'constdefs' (which used to
    83   support continuous functions) in favor of the general Pure one with
    84   full type-inference.
    85 
    86 
    87 
    88 New in Isabelle2004 (April 2004)
    89 --------------------------------
    90 
    91 *** General ***
    92 
    93 * Provers/order.ML:  new efficient reasoner for partial and linear orders.
    94   Replaces linorder.ML.
    95 
    96 * Pure: Greek letters (except small lambda, \<lambda>), as well as Gothic
    97   (\<aa>...\<zz>\<AA>...\<ZZ>), calligraphic (\<A>...\<Z>), and Euler
    98   (\<a>...\<z>), are now considered normal letters, and can therefore
    99   be used anywhere where an ASCII letter (a...zA...Z) has until
   100   now. COMPATIBILITY: This obviously changes the parsing of some
   101   terms, especially where a symbol has been used as a binder, say
   102   '\<Pi>x. ...', which is now a type error since \<Pi>x will be parsed
   103   as an identifier.  Fix it by inserting a space around former
   104   symbols.  Call 'isatool fixgreek' to try to fix parsing errors in
   105   existing theory and ML files.
   106 
   107 * Pure: Macintosh and Windows line-breaks are now allowed in theory files.
   108 
   109 * Pure: single letter sub/superscripts (\<^isub> and \<^isup>) are now
   110   allowed in identifiers. Similar to Greek letters \<^isub> is now considered
   111   a normal (but invisible) letter. For multiple letter subscripts repeat
   112   \<^isub> like this: x\<^isub>1\<^isub>2.
   113 
   114 * Pure: There are now sub-/superscripts that can span more than one
   115   character. Text between \<^bsub> and \<^esub> is set in subscript in
   116   ProofGeneral and LaTeX, text between \<^bsup> and \<^esup> in
   117   superscript. The new control characters are not identifier parts.
   118 
   119 * Pure: Control-symbols of the form \<^raw:...> will literally print the
   120   content of "..." to the latex file instead of \isacntrl... . The "..."
   121   may consist of any printable characters excluding the end bracket >.
   122 
   123 * Pure: Using new Isar command "finalconsts" (or the ML functions
   124   Theory.add_finals or Theory.add_finals_i) it is now possible to
   125   declare constants "final", which prevents their being given a definition
   126   later.  It is useful for constants whose behaviour is fixed axiomatically
   127   rather than definitionally, such as the meta-logic connectives.
   128 
   129 * Pure: 'instance' now handles general arities with general sorts
   130   (i.e. intersections of classes),
   131 
   132 * Presentation: generated HTML now uses a CSS style sheet to make layout
   133   (somewhat) independent of content. It is copied from lib/html/isabelle.css.
   134   It can be changed to alter the colors/layout of generated pages.
   135 
   136 
   137 *** Isar ***
   138 
   139 * Tactic emulation methods rule_tac, erule_tac, drule_tac, frule_tac,
   140   cut_tac, subgoal_tac and thin_tac:
   141   - Now understand static (Isar) contexts.  As a consequence, users of Isar
   142     locales are no longer forced to write Isar proof scripts.
   143     For details see Isar Reference Manual, paragraph 4.3.2: Further tactic
   144     emulations.
   145   - INCOMPATIBILITY: names of variables to be instantiated may no
   146     longer be enclosed in quotes.  Instead, precede variable name with `?'.
   147     This is consistent with the instantiation attribute "where".
   148 
   149 * Attributes "where" and "of":
   150   - Now take type variables of instantiated theorem into account when reading
   151     the instantiation string.  This fixes a bug that caused instantiated
   152     theorems to have too special types in some circumstances.
   153   - "where" permits explicit instantiations of type variables.
   154 
   155 * Calculation commands "moreover" and "also" no longer interfere with
   156   current facts ("this"), admitting arbitrary combinations with "then"
   157   and derived forms.
   158 
   159 * Locales:
   160   - Goal statements involving the context element "includes" no longer
   161     generate theorems with internal delta predicates (those ending on
   162     "_axioms") in the premise.
   163     Resolve particular premise with <locale>.intro to obtain old form.
   164   - Fixed bug in type inference ("unify_frozen") that prevented mix of target
   165     specification and "includes" elements in goal statement.
   166   - Rule sets <locale>.intro and <locale>.axioms no longer declared as
   167     [intro?] and [elim?] (respectively) by default.
   168   - Experimental command for instantiation of locales in proof contexts:
   169         instantiate <label>[<attrs>]: <loc>
   170     Instantiates locale <loc> and adds all its theorems to the current context
   171     taking into account their attributes.  Label and attrs are optional
   172     modifiers, like in theorem declarations.  If present, names of
   173     instantiated theorems are qualified with <label>, and the attributes
   174     <attrs> are applied after any attributes these theorems might have already.
   175       If the locale has assumptions, a chained fact of the form
   176     "<loc> t1 ... tn" is expected from which instantiations of the parameters
   177     are derived.  The command does not support old-style locales declared
   178     with "locale (open)".
   179       A few (very simple) examples can be found in FOL/ex/LocaleInst.thy.
   180 
   181 * HOL: Tactic emulation methods induct_tac and case_tac understand static
   182   (Isar) contexts.
   183 
   184 
   185 *** HOL ***
   186 
   187 * Proof import: new image HOL4 contains the imported library from
   188   the HOL4 system with about 2500 theorems. It is imported by
   189   replaying proof terms produced by HOL4 in Isabelle. The HOL4 image
   190   can be used like any other Isabelle image.  See
   191   HOL/Import/HOL/README for more information.
   192 
   193 * Simplifier:
   194   - Much improved handling of linear and partial orders.
   195     Reasoners for linear and partial orders are set up for type classes
   196     "linorder" and "order" respectively, and are added to the default simpset
   197     as solvers.  This means that the simplifier can build transitivity chains
   198     to solve goals from the assumptions.
   199   - INCOMPATIBILITY: old proofs break occasionally.  Typically, applications
   200     of blast or auto after simplification become unnecessary because the goal
   201     is solved by simplification already.
   202 
   203 * Numerics: new theory Ring_and_Field contains over 250 basic numerical laws,
   204     all proved in axiomatic type classes for semirings, rings and fields.
   205 
   206 * Numerics:
   207   - Numeric types (nat, int, and in HOL-Complex rat, real, complex, etc.) are
   208     now formalized using the Ring_and_Field theory mentioned above.
   209   - INCOMPATIBILITY: simplification and arithmetic behaves somewhat differently
   210     than before, because now they are set up once in a generic manner.
   211   - INCOMPATIBILITY: many type-specific arithmetic laws have gone.
   212     Look for the general versions in Ring_and_Field (and Power if they concern
   213     exponentiation).
   214 
   215 * Type "rat" of the rational numbers is now available in HOL-Complex.
   216 
   217 * Records:
   218   - Record types are now by default printed with their type abbreviation
   219     instead of the list of all field types. This can be configured via
   220     the reference "print_record_type_abbr".
   221   - Simproc "record_upd_simproc" for simplification of multiple updates added
   222     (not enabled by default).
   223   - Simproc "record_ex_sel_eq_simproc" to simplify EX x. sel r = x resp.
   224     EX x. x = sel r to True (not enabled by default).
   225   - Tactic "record_split_simp_tac" to split and simplify records added.
   226 
   227 * 'specification' command added, allowing for definition by
   228   specification.  There is also an 'ax_specification' command that
   229   introduces the new constants axiomatically.
   230 
   231 * arith(_tac) is now able to generate counterexamples for reals as well.
   232 
   233 * HOL-Algebra: new locale "ring" for non-commutative rings.
   234 
   235 * HOL-ex: InductiveInvariant_examples illustrates advanced recursive function
   236   definitions, thanks to Sava Krsti\'{c} and John Matthews.
   237 
   238 * HOL-Matrix: a first theory for matrices in HOL with an application of
   239   matrix theory to linear programming.
   240 
   241 * Unions and Intersections:
   242   The x-symbol output syntax of UN and INT has been changed
   243   from "\<Union>x \<in> A. B" to "\<Union\<^bsub>x \<in> A\<^esub> B"
   244   i.e. the index formulae has become a subscript, like in normal math.
   245   Similarly for "\<Union>x. B", and for \<Inter> instead of \<Union>.
   246   The subscript version is also accepted as input syntax.
   247 
   248 * Unions and Intersections over Intervals:
   249   There is new short syntax "UN i<=n. A" for "UN i:{0..n}. A". There is
   250   also an x-symbol version with subscripts "\<Union>\<^bsub>i <= n\<^esub>. A"
   251   like in normal math, and corresponding versions for < and for intersection.
   252 
   253 * ML: the legacy theory structures Int and List have been removed. They had
   254   conflicted with ML Basis Library structures having the same names.
   255 
   256 * 'refute' command added to search for (finite) countermodels.  Only works
   257   for a fragment of HOL.  The installation of an external SAT solver is
   258   highly recommended.  See "HOL/Refute.thy" for details.
   259 
   260 * 'quickcheck' command: Allows to find counterexamples by evaluating
   261   formulae under an assignment of free variables to random values.
   262   In contrast to 'refute', it can deal with inductive datatypes,
   263   but cannot handle quantifiers. See "HOL/ex/Quickcheck_Examples.thy"
   264   for examples.
   265 
   266 
   267 *** HOLCF ***
   268 
   269 * Streams now come with concatenation and are part of the HOLCF image
   270 
   271 
   272 
   273 New in Isabelle2003 (May 2003)
   274 ------------------------------
   275 
   276 *** General ***
   277 
   278 * Provers/simplifier:
   279 
   280   - Completely reimplemented method simp (ML: Asm_full_simp_tac):
   281     Assumptions are now subject to complete mutual simplification,
   282     not just from left to right. The simplifier now preserves
   283     the order of assumptions.
   284 
   285     Potential INCOMPATIBILITY:
   286 
   287     -- simp sometimes diverges where the old version did
   288        not, e.g. invoking simp on the goal
   289 
   290         [| P (f x); y = x; f x = f y |] ==> Q
   291 
   292        now gives rise to the infinite reduction sequence
   293 
   294         P(f x) --(f x = f y)--> P(f y) --(y = x)--> P(f x) --(f x = f y)--> ...
   295 
   296        Using "simp (asm_lr)" (ML: Asm_lr_simp_tac) instead often solves this
   297        kind of problem.
   298 
   299     -- Tactics combining classical reasoner and simplification (such as auto)
   300        are also affected by this change, because many of them rely on
   301        simp. They may sometimes diverge as well or yield a different numbers
   302        of subgoals. Try to use e.g. force, fastsimp, or safe instead of auto
   303        in case of problems. Sometimes subsequent calls to the classical
   304        reasoner will fail because a preceeding call to the simplifier too
   305        eagerly simplified the goal, e.g. deleted redundant premises.
   306 
   307   - The simplifier trace now shows the names of the applied rewrite rules
   308 
   309   - You can limit the number of recursive invocations of the simplifier
   310     during conditional rewriting (where the simplifie tries to solve the
   311     conditions before applying the rewrite rule):
   312     ML "simp_depth_limit := n"
   313     where n is an integer. Thus you can force termination where previously
   314     the simplifier would diverge.
   315 
   316   - Accepts free variables as head terms in congruence rules.  Useful in Isar.
   317 
   318   - No longer aborts on failed congruence proof.  Instead, the
   319     congruence is ignored.
   320 
   321 * Pure: New generic framework for extracting programs from constructive
   322   proofs. See HOL/Extraction.thy for an example instantiation, as well
   323   as HOL/Extraction for some case studies.
   324 
   325 * Pure: The main goal of the proof state is no longer shown by default, only
   326 the subgoals. This behaviour is controlled by a new flag.
   327    PG menu: Isabelle/Isar -> Settings -> Show Main Goal
   328 (ML: Proof.show_main_goal).
   329 
   330 * Pure: You can find all matching introduction rules for subgoal 1, i.e. all
   331 rules whose conclusion matches subgoal 1:
   332       PG menu: Isabelle/Isar -> Show me -> matching rules
   333 The rules are ordered by how closely they match the subgoal.
   334 In particular, rules that solve a subgoal outright are displayed first
   335 (or rather last, the way they are printed).
   336 (ML: ProofGeneral.print_intros())
   337 
   338 * Pure: New flag trace_unify_fail causes unification to print
   339 diagnostic information (PG: in trace buffer) when it fails. This is
   340 useful for figuring out why single step proofs like rule, erule or
   341 assumption failed.
   342 
   343 * Pure: Locale specifications now produce predicate definitions
   344 according to the body of text (covering assumptions modulo local
   345 definitions); predicate "loc_axioms" covers newly introduced text,
   346 while "loc" is cumulative wrt. all included locale expressions; the
   347 latter view is presented only on export into the global theory
   348 context; potential INCOMPATIBILITY, use "(open)" option to fall back
   349 on the old view without predicates;
   350 
   351 * Pure: predefined locales "var" and "struct" are useful for sharing
   352 parameters (as in CASL, for example); just specify something like
   353 ``var x + var y + struct M'' as import;
   354 
   355 * Pure: improved thms_containing: proper indexing of facts instead of
   356 raw theorems; check validity of results wrt. current name space;
   357 include local facts of proof configuration (also covers active
   358 locales), cover fixed variables in index; may use "_" in term
   359 specification; an optional limit for the number of printed facts may
   360 be given (the default is 40);
   361 
   362 * Pure: disallow duplicate fact bindings within new-style theory files
   363 (batch-mode only);
   364 
   365 * Provers: improved induct method: assumptions introduced by case
   366 "foo" are split into "foo.hyps" (from the rule) and "foo.prems" (from
   367 the goal statement); "foo" still refers to all facts collectively;
   368 
   369 * Provers: the function blast.overloaded has been removed: all constants
   370 are regarded as potentially overloaded, which improves robustness in exchange
   371 for slight decrease in efficiency;
   372 
   373 * Provers/linorder: New generic prover for transitivity reasoning over
   374 linear orders.  Note: this prover is not efficient!
   375 
   376 * Isar: preview of problems to finish 'show' now produce an error
   377 rather than just a warning (in interactive mode);
   378 
   379 
   380 *** HOL ***
   381 
   382 * arith(_tac)
   383 
   384  - Produces a counter example if it cannot prove a goal.
   385    Note that the counter example may be spurious if the goal is not a formula
   386    of quantifier-free linear arithmetic.
   387    In ProofGeneral the counter example appears in the trace buffer.
   388 
   389  - Knows about div k and mod k where k is a numeral of type nat or int.
   390 
   391  - Calls full Presburger arithmetic (by Amine Chaieb) if quantifier-free
   392    linear arithmetic fails. This takes account of quantifiers and divisibility.
   393    Presburger arithmetic can also be called explicitly via presburger(_tac).
   394 
   395 * simp's arithmetic capabilities have been enhanced a bit: it now
   396 takes ~= in premises into account (by performing a case split);
   397 
   398 * simp reduces "m*(n div m) + n mod m" to n, even if the two summands
   399 are distributed over a sum of terms;
   400 
   401 * New tactic "trans_tac" and method "trans" instantiate
   402 Provers/linorder.ML for axclasses "order" and "linorder" (predicates
   403 "<=", "<" and "=").
   404 
   405 * function INCOMPATIBILITIES: Pi-sets have been redefined and moved from main
   406 HOL to Library/FuncSet; constant "Fun.op o" is now called "Fun.comp";
   407 
   408 * 'typedef' command has new option "open" to suppress the set
   409 definition;
   410 
   411 * functions Min and Max on finite sets have been introduced (theory
   412 Finite_Set);
   413 
   414 * attribute [symmetric] now works for relations as well; it turns
   415 (x,y) : R^-1 into (y,x) : R, and vice versa;
   416 
   417 * induct over a !!-quantified statement (say !!x1..xn):
   418   each "case" automatically performs "fix x1 .. xn" with exactly those names.
   419 
   420 * Map: `empty' is no longer a constant but a syntactic abbreviation for
   421 %x. None. Warning: empty_def now refers to the previously hidden definition
   422 of the empty set.
   423 
   424 * Algebra: formalization of classical algebra.  Intended as base for
   425 any algebraic development in Isabelle.  Currently covers group theory
   426 (up to Sylow's theorem) and ring theory (Universal Property of
   427 Univariate Polynomials).  Contributions welcome;
   428 
   429 * GroupTheory: deleted, since its material has been moved to Algebra;
   430 
   431 * Complex: new directory of the complex numbers with numeric constants,
   432 nonstandard complex numbers, and some complex analysis, standard and
   433 nonstandard (Jacques Fleuriot);
   434 
   435 * HOL-Complex: new image for analysis, replacing HOL-Real and HOL-Hyperreal;
   436 
   437 * Hyperreal: introduced Gauge integration and hyperreal logarithms (Jacques
   438 Fleuriot);
   439 
   440 * Real/HahnBanach: updated and adapted to locales;
   441 
   442 * NumberTheory: added Gauss's law of quadratic reciprocity (by Avigad,
   443 Gray and Kramer);
   444 
   445 * UNITY: added the Meier-Sanders theory of progress sets;
   446 
   447 * MicroJava: bytecode verifier and lightweight bytecode verifier
   448 as abstract algorithms, instantiated to the JVM;
   449 
   450 * Bali: Java source language formalization. Type system, operational
   451 semantics, axiomatic semantics. Supported language features:
   452 classes, interfaces, objects,virtual methods, static methods,
   453 static/instance fields, arrays, access modifiers, definite
   454 assignment, exceptions.
   455 
   456 
   457 *** ZF ***
   458 
   459 * ZF/Constructible: consistency proof for AC (Gödel's constructible
   460 universe, etc.);
   461 
   462 * Main ZF: virtually all theories converted to new-style format;
   463 
   464 
   465 *** ML ***
   466 
   467 * Pure: Tactic.prove provides sane interface for internal proofs;
   468 omits the infamous "standard" operation, so this is more appropriate
   469 than prove_goalw_cterm in many situations (e.g. in simprocs);
   470 
   471 * Pure: improved error reporting of simprocs;
   472 
   473 * Provers: Simplifier.simproc(_i) provides sane interface for setting
   474 up simprocs;
   475 
   476 
   477 *** Document preparation ***
   478 
   479 * uses \par instead of \\ for line breaks in theory text. This may
   480 shift some page breaks in large documents. To get the old behaviour
   481 use \renewcommand{\isanewline}{\mbox{}\\\mbox{}} in root.tex.
   482 
   483 * minimized dependencies of isabelle.sty and isabellesym.sty on
   484 other packages
   485 
   486 * \<euro> now needs package babel/greek instead of marvosym (which
   487 broke \Rightarrow)
   488 
   489 * normal size for \<zero>...\<nine> (uses \mathbf instead of
   490 textcomp package)
   491 
   492 
   493 
   494 New in Isabelle2002 (March 2002)
   495 --------------------------------
   496 
   497 *** Document preparation ***
   498 
   499 * greatly simplified document preparation setup, including more
   500 graceful interpretation of isatool usedir -i/-d/-D options, and more
   501 instructive isatool mkdir; users should basically be able to get
   502 started with "isatool mkdir HOL Test && isatool make"; alternatively,
   503 users may run a separate document processing stage manually like this:
   504 "isatool usedir -D output HOL Test && isatool document Test/output";
   505 
   506 * theory dependency graph may now be incorporated into documents;
   507 isatool usedir -g true will produce session_graph.eps/.pdf for use
   508 with \includegraphics of LaTeX;
   509 
   510 * proper spacing of consecutive markup elements, especially text
   511 blocks after section headings;
   512 
   513 * support bold style (for single symbols only), input syntax is like
   514 this: "\<^bold>\<alpha>" or "\<^bold>A";
   515 
   516 * \<bullet> is now output as bold \cdot by default, which looks much
   517 better in printed text;
   518 
   519 * added default LaTeX bindings for \<tturnstile> and \<TTurnstile>;
   520 note that these symbols are currently unavailable in Proof General /
   521 X-Symbol; new symbols \<zero>, \<one>, ..., \<nine>, and \<euro>;
   522 
   523 * isatool latex no longer depends on changed TEXINPUTS, instead
   524 isatool document copies the Isabelle style files to the target
   525 location;
   526 
   527 
   528 *** Isar ***
   529 
   530 * Pure/Provers: improved proof by cases and induction;
   531   - 'case' command admits impromptu naming of parameters (such as
   532     "case (Suc n)");
   533   - 'induct' method divinates rule instantiation from the inductive
   534     claim; no longer requires excessive ?P bindings for proper
   535     instantiation of cases;
   536   - 'induct' method properly enumerates all possibilities of set/type
   537     rules; as a consequence facts may be also passed through *type*
   538     rules without further ado;
   539   - 'induct' method now derives symbolic cases from the *rulified*
   540     rule (before it used to rulify cases stemming from the internal
   541     atomized version); this means that the context of a non-atomic
   542     statement becomes is included in the hypothesis, avoiding the
   543     slightly cumbersome show "PROP ?case" form;
   544   - 'induct' may now use elim-style induction rules without chaining
   545     facts, using ``missing'' premises from the goal state; this allows
   546     rules stemming from inductive sets to be applied in unstructured
   547     scripts, while still benefitting from proper handling of non-atomic
   548     statements; NB: major inductive premises need to be put first, all
   549     the rest of the goal is passed through the induction;
   550   - 'induct' proper support for mutual induction involving non-atomic
   551     rule statements (uses the new concept of simultaneous goals, see
   552     below);
   553   - append all possible rule selections, but only use the first
   554     success (no backtracking);
   555   - removed obsolete "(simplified)" and "(stripped)" options of methods;
   556   - undeclared rule case names default to numbers 1, 2, 3, ...;
   557   - added 'print_induct_rules' (covered by help item in recent Proof
   558     General versions);
   559   - moved induct/cases attributes to Pure, methods to Provers;
   560   - generic method setup instantiated for FOL and HOL;
   561 
   562 * Pure: support multiple simultaneous goal statements, for example
   563 "have a: A and b: B" (same for 'theorem' etc.); being a pure
   564 meta-level mechanism, this acts as if several individual goals had
   565 been stated separately; in particular common proof methods need to be
   566 repeated in order to cover all claims; note that a single elimination
   567 step is *not* sufficient to establish the two conjunctions, so this
   568 fails:
   569 
   570   assume "A & B" then have A and B ..   (*".." fails*)
   571 
   572 better use "obtain" in situations as above; alternative refer to
   573 multi-step methods like 'auto', 'simp_all', 'blast+' etc.;
   574 
   575 * Pure: proper integration with ``locales''; unlike the original
   576 version by Florian Kammüller, Isar locales package high-level proof
   577 contexts rather than raw logical ones (e.g. we admit to include
   578 attributes everywhere); operations on locales include merge and
   579 rename; support for implicit arguments (``structures''); simultaneous
   580 type-inference over imports and text; see also HOL/ex/Locales.thy for
   581 some examples;
   582 
   583 * Pure: the following commands have been ``localized'', supporting a
   584 target locale specification "(in name)": 'lemma', 'theorem',
   585 'corollary', 'lemmas', 'theorems', 'declare'; the results will be
   586 stored both within the locale and at the theory level (exported and
   587 qualified by the locale name);
   588 
   589 * Pure: theory goals may now be specified in ``long'' form, with
   590 ad-hoc contexts consisting of arbitrary locale elements. for example
   591 ``lemma foo: fixes x assumes "A x" shows "B x"'' (local syntax and
   592 definitions may be given, too); the result is a meta-level rule with
   593 the context elements being discharged in the obvious way;
   594 
   595 * Pure: new proof command 'using' allows to augment currently used
   596 facts after a goal statement ('using' is syntactically analogous to
   597 'apply', but acts on the goal's facts only); this allows chained facts
   598 to be separated into parts given before and after a claim, as in
   599 ``from a and b have C using d and e <proof>'';
   600 
   601 * Pure: renamed "antecedent" case to "rule_context";
   602 
   603 * Pure: new 'judgment' command records explicit information about the
   604 object-logic embedding (used by several tools internally); no longer
   605 use hard-wired "Trueprop";
   606 
   607 * Pure: added 'corollary' command;
   608 
   609 * Pure: fixed 'token_translation' command;
   610 
   611 * Pure: removed obsolete 'exported' attribute;
   612 
   613 * Pure: dummy pattern "_" in is/let is now automatically lifted over
   614 bound variables: "ALL x. P x --> Q x" (is "ALL x. _ --> ?C x")
   615 supersedes more cumbersome ... (is "ALL x. _ x --> ?C x");
   616 
   617 * Pure: method 'atomize' presents local goal premises as object-level
   618 statements (atomic meta-level propositions); setup controlled via
   619 rewrite rules declarations of 'atomize' attribute; example
   620 application: 'induct' method with proper rule statements in improper
   621 proof *scripts*;
   622 
   623 * Pure: emulation of instantiation tactics (rule_tac, cut_tac, etc.)
   624 now consider the syntactic context of assumptions, giving a better
   625 chance to get type-inference of the arguments right (this is
   626 especially important for locales);
   627 
   628 * Pure: "sorry" no longer requires quick_and_dirty in interactive
   629 mode;
   630 
   631 * Pure/obtain: the formal conclusion "thesis", being marked as
   632 ``internal'', may no longer be reference directly in the text;
   633 potential INCOMPATIBILITY, may need to use "?thesis" in rare
   634 situations;
   635 
   636 * Pure: generic 'sym' attribute which declares a rule both as pure
   637 'elim?' and for the 'symmetric' operation;
   638 
   639 * Pure: marginal comments ``--'' may now occur just anywhere in the
   640 text; the fixed correlation with particular command syntax has been
   641 discontinued;
   642 
   643 * Pure: new method 'rules' is particularly well-suited for proof
   644 search in intuitionistic logic; a bit slower than 'blast' or 'fast',
   645 but often produces more compact proof terms with less detours;
   646 
   647 * Pure/Provers/classical: simplified integration with pure rule
   648 attributes and methods; the classical "intro?/elim?/dest?"
   649 declarations coincide with the pure ones; the "rule" method no longer
   650 includes classically swapped intros; "intro" and "elim" methods no
   651 longer pick rules from the context; also got rid of ML declarations
   652 AddXIs/AddXEs/AddXDs; all of this has some potential for
   653 INCOMPATIBILITY;
   654 
   655 * Provers/classical: attribute 'swapped' produces classical inversions
   656 of introduction rules;
   657 
   658 * Provers/simplifier: 'simplified' attribute may refer to explicit
   659 rules instead of full simplifier context; 'iff' attribute handles
   660 conditional rules;
   661 
   662 * HOL: 'typedef' now allows alternative names for Rep/Abs morphisms;
   663 
   664 * HOL: 'recdef' now fails on unfinished automated proofs, use
   665 "(permissive)" option to recover old behavior;
   666 
   667 * HOL: 'inductive' no longer features separate (collective) attributes
   668 for 'intros' (was found too confusing);
   669 
   670 * HOL: properly declared induction rules less_induct and
   671 wf_induct_rule;
   672 
   673 
   674 *** HOL ***
   675 
   676 * HOL: moved over to sane numeral syntax; the new policy is as
   677 follows:
   678 
   679   - 0 and 1 are polymorphic constants, which are defined on any
   680   numeric type (nat, int, real etc.);
   681 
   682   - 2, 3, 4, ... and -1, -2, -3, ... are polymorphic numerals, based
   683   binary representation internally;
   684 
   685   - type nat has special constructor Suc, and generally prefers Suc 0
   686   over 1::nat and Suc (Suc 0) over 2::nat;
   687 
   688 This change may cause significant problems of INCOMPATIBILITY; here
   689 are some hints on converting existing sources:
   690 
   691   - due to the new "num" token, "-0" and "-1" etc. are now atomic
   692   entities, so expressions involving "-" (unary or binary minus) need
   693   to be spaced properly;
   694 
   695   - existing occurrences of "1" may need to be constraint "1::nat" or
   696   even replaced by Suc 0; similar for old "2";
   697 
   698   - replace "#nnn" by "nnn", and "#-nnn" by "-nnn";
   699 
   700   - remove all special provisions on numerals in proofs;
   701 
   702 * HOL: simp rules nat_number expand numerals on nat to Suc/0
   703 representation (depends on bin_arith_simps in the default context);
   704 
   705 * HOL: symbolic syntax for x^2 (numeral 2);
   706 
   707 * HOL: the class of all HOL types is now called "type" rather than
   708 "term"; INCOMPATIBILITY, need to adapt references to this type class
   709 in axclass/classes, instance/arities, and (usually rare) occurrences
   710 in typings (of consts etc.); internally the class is called
   711 "HOL.type", ML programs should refer to HOLogic.typeS;
   712 
   713 * HOL/record package improvements:
   714   - new derived operations "fields" to build a partial record section,
   715     "extend" to promote a fixed record to a record scheme, and
   716     "truncate" for the reverse; cf. theorems "xxx.defs", which are *not*
   717     declared as simp by default;
   718   - shared operations ("more", "fields", etc.) now need to be always
   719     qualified) --- potential INCOMPATIBILITY;
   720   - removed "make_scheme" operations (use "make" with "extend") --
   721     INCOMPATIBILITY;
   722   - removed "more" class (simply use "term") -- INCOMPATIBILITY;
   723   - provides cases/induct rules for use with corresponding Isar
   724     methods (for concrete records, record schemes, concrete more
   725     parts, and schematic more parts -- in that order);
   726   - internal definitions directly based on a light-weight abstract
   727     theory of product types over typedef rather than datatype;
   728 
   729 * HOL: generic code generator for generating executable ML code from
   730 specifications; specific support for HOL constructs such as inductive
   731 datatypes and sets, as well as recursive functions; can be invoked
   732 via 'generate_code' theory section;
   733 
   734 * HOL: canonical cases/induct rules for n-tuples (n = 3..7);
   735 
   736 * HOL: consolidated and renamed several theories.  In particular:
   737         Ord.thy has been absorbed into HOL.thy
   738         String.thy has been absorbed into List.thy
   739 
   740 * HOL: concrete setsum syntax "\<Sum>i:A. b" == "setsum (%i. b) A"
   741 (beware of argument permutation!);
   742 
   743 * HOL: linorder_less_split superseded by linorder_cases;
   744 
   745 * HOL/List: "nodups" renamed to "distinct";
   746 
   747 * HOL: added "The" definite description operator; move Hilbert's "Eps"
   748 to peripheral theory "Hilbert_Choice"; some INCOMPATIBILITIES:
   749   - Ex_def has changed, now need to use some_eq_ex
   750 
   751 * HOL: made split_all_tac safe; EXISTING PROOFS MAY FAIL OR LOOP, so
   752 in this (rare) case use:
   753 
   754   delSWrapper "split_all_tac"
   755   addSbefore ("unsafe_split_all_tac", unsafe_split_all_tac)
   756 
   757 * HOL: added safe wrapper "split_conv_tac" to claset; EXISTING PROOFS
   758 MAY FAIL;
   759 
   760 * HOL: introduced f^n = f o ... o f; warning: due to the limits of
   761 Isabelle's type classes, ^ on functions and relations has too general
   762 a domain, namely ('a * 'b) set and 'a => 'b; this means that it may be
   763 necessary to attach explicit type constraints;
   764 
   765 * HOL/Relation: the prefix name of the infix "O" has been changed from
   766 "comp" to "rel_comp"; INCOMPATIBILITY: a few theorems have been
   767 renamed accordingly (eg "compI" -> "rel_compI").
   768 
   769 * HOL: syntax translations now work properly with numerals and records
   770 expressions;
   771 
   772 * HOL: bounded abstraction now uses syntax "%" / "\<lambda>" instead
   773 of "lam" -- INCOMPATIBILITY;
   774 
   775 * HOL: got rid of some global declarations (potential INCOMPATIBILITY
   776 for ML tools): const "()" renamed "Product_Type.Unity", type "unit"
   777 renamed "Product_Type.unit";
   778 
   779 * HOL: renamed rtrancl_into_rtrancl2 to converse_rtrancl_into_rtrancl
   780 
   781 * HOL: removed obsolete theorem "optionE" (use "option.exhaust", or
   782 the "cases" method);
   783 
   784 * HOL/GroupTheory: group theory examples including Sylow's theorem (by
   785 Florian Kammüller);
   786 
   787 * HOL/IMP: updated and converted to new-style theory format; several
   788 parts turned into readable document, with proper Isar proof texts and
   789 some explanations (by Gerwin Klein);
   790 
   791 * HOL-Real: added Complex_Numbers (by Gertrud Bauer);
   792 
   793 * HOL-Hyperreal is now a logic image;
   794 
   795 
   796 *** HOLCF ***
   797 
   798 * Isar: consts/constdefs supports mixfix syntax for continuous
   799 operations;
   800 
   801 * Isar: domain package adapted to new-style theory format, e.g. see
   802 HOLCF/ex/Dnat.thy;
   803 
   804 * theory Lift: proper use of rep_datatype lift instead of ML hacks --
   805 potential INCOMPATIBILITY; now use plain induct_tac instead of former
   806 lift.induct_tac, always use UU instead of Undef;
   807 
   808 * HOLCF/IMP: updated and converted to new-style theory;
   809 
   810 
   811 *** ZF ***
   812 
   813 * Isar: proper integration of logic-specific tools and packages,
   814 including theory commands '(co)inductive', '(co)datatype',
   815 'rep_datatype', 'inductive_cases', as well as methods 'ind_cases',
   816 'induct_tac', 'case_tac', and 'typecheck' (with attribute 'TC');
   817 
   818 * theory Main no longer includes AC; for the Axiom of Choice, base
   819 your theory on Main_ZFC;
   820 
   821 * the integer library now covers quotients and remainders, with many
   822 laws relating division to addition, multiplication, etc.;
   823 
   824 * ZF/UNITY: Chandy and Misra's UNITY is now available in ZF, giving a
   825 typeless version of the formalism;
   826 
   827 * ZF/AC, Coind, IMP, Resid: updated and converted to new-style theory
   828 format;
   829 
   830 * ZF/Induct: new directory for examples of inductive definitions,
   831 including theory Multiset for multiset orderings; converted to
   832 new-style theory format;
   833 
   834 * ZF: many new theorems about lists, ordinals, etc.;
   835 
   836 
   837 *** General ***
   838 
   839 * Pure/kernel: meta-level proof terms (by Stefan Berghofer); reference
   840 variable proof controls level of detail: 0 = no proofs (only oracle
   841 dependencies), 1 = lemma dependencies, 2 = compact proof terms; see
   842 also ref manual for further ML interfaces;
   843 
   844 * Pure/axclass: removed obsolete ML interface
   845 goal_subclass/goal_arity;
   846 
   847 * Pure/syntax: new token syntax "num" for plain numerals (without "#"
   848 of "xnum"); potential INCOMPATIBILITY, since -0, -1 etc. are now
   849 separate tokens, so expressions involving minus need to be spaced
   850 properly;
   851 
   852 * Pure/syntax: support non-oriented infixes, using keyword "infix"
   853 rather than "infixl" or "infixr";
   854 
   855 * Pure/syntax: concrete syntax for dummy type variables admits genuine
   856 sort constraint specifications in type inference; e.g. "x::_::foo"
   857 ensures that the type of "x" is of sort "foo" (but not necessarily a
   858 type variable);
   859 
   860 * Pure/syntax: print modes "type_brackets" and "no_type_brackets"
   861 control output of nested => (types); the default behavior is
   862 "type_brackets";
   863 
   864 * Pure/syntax: builtin parse translation for "_constify" turns valued
   865 tokens into AST constants;
   866 
   867 * Pure/syntax: prefer later declarations of translations and print
   868 translation functions; potential INCOMPATIBILITY: need to reverse
   869 multiple declarations for same syntax element constant;
   870 
   871 * Pure/show_hyps reset by default (in accordance to existing Isar
   872 practice);
   873 
   874 * Provers/classical: renamed addaltern to addafter, addSaltern to
   875 addSafter;
   876 
   877 * Provers/clasimp: ``iff'' declarations now handle conditional rules
   878 as well;
   879 
   880 * system: tested support for MacOS X; should be able to get Isabelle +
   881 Proof General to work in a plain Terminal after installing Poly/ML
   882 (e.g. from the Isabelle distribution area) and GNU bash alone
   883 (e.g. from http://www.apple.com); full X11, XEmacs and X-Symbol
   884 support requires further installations, e.g. from
   885 http://fink.sourceforge.net/);
   886 
   887 * system: support Poly/ML 4.1.1 (able to manage larger heaps);
   888 
   889 * system: reduced base memory usage by Poly/ML (approx. 20 MB instead
   890 of 40 MB), cf. ML_OPTIONS;
   891 
   892 * system: Proof General keywords specification is now part of the
   893 Isabelle distribution (see etc/isar-keywords.el);
   894 
   895 * system: support for persistent Proof General sessions (refrain from
   896 outdating all loaded theories on startup); user may create writable
   897 logic images like this: ``isabelle -q HOL Test'';
   898 
   899 * system: smart selection of Isabelle process versus Isabelle
   900 interface, accommodates case-insensitive file systems (e.g. HFS+); may
   901 run both "isabelle" and "Isabelle" even if file names are badly
   902 damaged (executable inspects the case of the first letter of its own
   903 name); added separate "isabelle-process" and "isabelle-interface";
   904 
   905 * system: refrain from any attempt at filtering input streams; no
   906 longer support ``8bit'' encoding of old isabelle font, instead proper
   907 iso-latin characters may now be used; the related isatools
   908 "symbolinput" and "nonascii" have disappeared as well;
   909 
   910 * system: removed old "xterm" interface (the print modes "xterm" and
   911 "xterm_color" are still available for direct use in a suitable
   912 terminal);
   913 
   914 
   915 
   916 New in Isabelle99-2 (February 2001)
   917 -----------------------------------
   918 
   919 *** Overview of INCOMPATIBILITIES ***
   920 
   921 * HOL: please note that theories in the Library and elsewhere often use the
   922 new-style (Isar) format; to refer to their theorems in an ML script you must
   923 bind them to ML identifers by e.g.      val thm_name = thm "thm_name";
   924 
   925 * HOL: inductive package no longer splits induction rule aggressively,
   926 but only as far as specified by the introductions given; the old
   927 format may be recovered via ML function complete_split_rule or attribute
   928 'split_rule (complete)';
   929 
   930 * HOL: induct renamed to lfp_induct, lfp_Tarski to lfp_unfold,
   931 gfp_Tarski to gfp_unfold;
   932 
   933 * HOL: contrapos, contrapos2 renamed to contrapos_nn, contrapos_pp;
   934 
   935 * HOL: infix "dvd" now has priority 50 rather than 70 (because it is a
   936 relation); infix "^^" has been renamed "``"; infix "``" has been
   937 renamed "`"; "univalent" has been renamed "single_valued";
   938 
   939 * HOL/Real: "rinv" and "hrinv" replaced by overloaded "inverse"
   940 operation;
   941 
   942 * HOLCF: infix "`" has been renamed "$"; the symbol syntax is \<cdot>;
   943 
   944 * Isar: 'obtain' no longer declares "that" fact as simp/intro;
   945 
   946 * Isar/HOL: method 'induct' now handles non-atomic goals; as a
   947 consequence, it is no longer monotonic wrt. the local goal context
   948 (which is now passed through the inductive cases);
   949 
   950 * Document preparation: renamed standard symbols \<ll> to \<lless> and
   951 \<gg> to \<ggreater>;
   952 
   953 
   954 *** Document preparation ***
   955 
   956 * \isabellestyle{NAME} selects version of Isabelle output (currently
   957 available: are "it" for near math-mode best-style output, "sl" for
   958 slanted text style, and "tt" for plain type-writer; if no
   959 \isabellestyle command is given, output is according to slanted
   960 type-writer);
   961 
   962 * support sub/super scripts (for single symbols only), input syntax is
   963 like this: "A\<^sup>*" or "A\<^sup>\<star>";
   964 
   965 * some more standard symbols; see Appendix A of the system manual for
   966 the complete list of symbols defined in isabellesym.sty;
   967 
   968 * improved isabelle style files; more abstract symbol implementation
   969 (should now use \isamath{...} and \isatext{...} in custom symbol
   970 definitions);
   971 
   972 * antiquotation @{goals} and @{subgoals} for output of *dynamic* goals
   973 state; Note that presentation of goal states does not conform to
   974 actual human-readable proof documents.  Please do not include goal
   975 states into document output unless you really know what you are doing!
   976 
   977 * proper indentation of antiquoted output with proportional LaTeX
   978 fonts;
   979 
   980 * no_document ML operator temporarily disables LaTeX document
   981 generation;
   982 
   983 * isatool unsymbolize tunes sources for plain ASCII communication;
   984 
   985 
   986 *** Isar ***
   987 
   988 * Pure: Isar now suffers initial goal statements to contain unbound
   989 schematic variables (this does not conform to actual readable proof
   990 documents, due to unpredictable outcome and non-compositional proof
   991 checking); users who know what they are doing may use schematic goals
   992 for Prolog-style synthesis of proven results;
   993 
   994 * Pure: assumption method (an implicit finishing) now handles actual
   995 rules as well;
   996 
   997 * Pure: improved 'obtain' --- moved to Pure, insert "that" into
   998 initial goal, declare "that" only as Pure intro (only for single
   999 steps); the "that" rule assumption may now be involved in implicit
  1000 finishing, thus ".." becomes a feasible for trivial obtains;
  1001 
  1002 * Pure: default proof step now includes 'intro_classes'; thus trivial
  1003 instance proofs may be performed by "..";
  1004 
  1005 * Pure: ?thesis / ?this / "..." now work for pure meta-level
  1006 statements as well;
  1007 
  1008 * Pure: more robust selection of calculational rules;
  1009 
  1010 * Pure: the builtin notion of 'finished' goal now includes the ==-refl
  1011 rule (as well as the assumption rule);
  1012 
  1013 * Pure: 'thm_deps' command visualizes dependencies of theorems and
  1014 lemmas, using the graph browser tool;
  1015 
  1016 * Pure: predict failure of "show" in interactive mode;
  1017 
  1018 * Pure: 'thms_containing' now takes actual terms as arguments;
  1019 
  1020 * HOL: improved method 'induct' --- now handles non-atomic goals
  1021 (potential INCOMPATIBILITY); tuned error handling;
  1022 
  1023 * HOL: cases and induct rules now provide explicit hints about the
  1024 number of facts to be consumed (0 for "type" and 1 for "set" rules);
  1025 any remaining facts are inserted into the goal verbatim;
  1026 
  1027 * HOL: local contexts (aka cases) may now contain term bindings as
  1028 well; the 'cases' and 'induct' methods new provide a ?case binding for
  1029 the result to be shown in each case;
  1030 
  1031 * HOL: added 'recdef_tc' command;
  1032 
  1033 * isatool convert assists in eliminating legacy ML scripts;
  1034 
  1035 
  1036 *** HOL ***
  1037 
  1038 * HOL/Library: a collection of generic theories to be used together
  1039 with main HOL; the theory loader path already includes this directory
  1040 by default; the following existing theories have been moved here:
  1041 HOL/Induct/Multiset, HOL/Induct/Acc (as Accessible_Part), HOL/While
  1042 (as While_Combinator), HOL/Lex/Prefix (as List_Prefix);
  1043 
  1044 * HOL/Unix: "Some aspects of Unix file-system security", a typical
  1045 modelling and verification task performed in Isabelle/HOL +
  1046 Isabelle/Isar + Isabelle document preparation (by Markus Wenzel).
  1047 
  1048 * HOL/Algebra: special summation operator SUM no longer exists, it has
  1049 been replaced by setsum; infix 'assoc' now has priority 50 (like
  1050 'dvd'); axiom 'one_not_zero' has been moved from axclass 'ring' to
  1051 'domain', this makes the theory consistent with mathematical
  1052 literature;
  1053 
  1054 * HOL basics: added overloaded operations "inverse" and "divide"
  1055 (infix "/"), syntax for generic "abs" operation, generic summation
  1056 operator \<Sum>;
  1057 
  1058 * HOL/typedef: simplified package, provide more useful rules (see also
  1059 HOL/subset.thy);
  1060 
  1061 * HOL/datatype: induction rule for arbitrarily branching datatypes is
  1062 now expressed as a proper nested rule (old-style tactic scripts may
  1063 require atomize_strip_tac to cope with non-atomic premises);
  1064 
  1065 * HOL: renamed theory "Prod" to "Product_Type", renamed "split" rule
  1066 to "split_conv" (old name still available for compatibility);
  1067 
  1068 * HOL: improved concrete syntax for strings (e.g. allows translation
  1069 rules with string literals);
  1070 
  1071 * HOL-Real-Hyperreal: this extends HOL-Real with the hyperreals
  1072  and Fleuriot's mechanization of analysis, including the transcendental
  1073  functions for the reals;
  1074 
  1075 * HOL/Real, HOL/Hyperreal: improved arithmetic simplification;
  1076 
  1077 
  1078 *** CTT ***
  1079 
  1080 * CTT: x-symbol support for Pi, Sigma, -->, : (membership); note that
  1081 "lam" is displayed as TWO lambda-symbols
  1082 
  1083 * CTT: theory Main now available, containing everything (that is, Bool
  1084 and Arith);
  1085 
  1086 
  1087 *** General ***
  1088 
  1089 * Pure: the Simplifier has been implemented properly as a derived rule
  1090 outside of the actual kernel (at last!); the overall performance
  1091 penalty in practical applications is about 50%, while reliability of
  1092 the Isabelle inference kernel has been greatly improved;
  1093 
  1094 * print modes "brackets" and "no_brackets" control output of nested =>
  1095 (types) and ==> (props); the default behaviour is "brackets";
  1096 
  1097 * Provers: fast_tac (and friends) now handle actual object-logic rules
  1098 as assumptions as well;
  1099 
  1100 * system: support Poly/ML 4.0;
  1101 
  1102 * system: isatool install handles KDE version 1 or 2;
  1103 
  1104 
  1105 
  1106 New in Isabelle99-1 (October 2000)
  1107 ----------------------------------
  1108 
  1109 *** Overview of INCOMPATIBILITIES ***
  1110 
  1111 * HOL: simplification of natural numbers is much changed; to partly
  1112 recover the old behaviour (e.g. to prevent n+n rewriting to #2*n)
  1113 issue the following ML commands:
  1114 
  1115   Delsimprocs Nat_Numeral_Simprocs.cancel_numerals;
  1116   Delsimprocs [Nat_Numeral_Simprocs.combine_numerals];
  1117 
  1118 * HOL: simplification no longer dives into case-expressions; this is
  1119 controlled by "t.weak_case_cong" for each datatype t;
  1120 
  1121 * HOL: nat_less_induct renamed to less_induct;
  1122 
  1123 * HOL: systematic renaming of the SOME (Eps) rules, may use isatool
  1124 fixsome to patch .thy and .ML sources automatically;
  1125 
  1126   select_equality  -> some_equality
  1127   select_eq_Ex     -> some_eq_ex
  1128   selectI2EX       -> someI2_ex
  1129   selectI2         -> someI2
  1130   selectI          -> someI
  1131   select1_equality -> some1_equality
  1132   Eps_sym_eq       -> some_sym_eq_trivial
  1133   Eps_eq           -> some_eq_trivial
  1134 
  1135 * HOL: exhaust_tac on datatypes superceded by new generic case_tac;
  1136 
  1137 * HOL: removed obsolete theorem binding expand_if (refer to split_if
  1138 instead);
  1139 
  1140 * HOL: the recursion equations generated by 'recdef' are now called
  1141 f.simps instead of f.rules;
  1142 
  1143 * HOL: qed_spec_mp now also handles bounded ALL as well;
  1144 
  1145 * HOL: 0 is now overloaded, so the type constraint ":: nat" may
  1146 sometimes be needed;
  1147 
  1148 * HOL: the constant for "f``x" is now "image" rather than "op ``";
  1149 
  1150 * HOL: the constant for "f-``x" is now "vimage" rather than "op -``";
  1151 
  1152 * HOL: the disjoint sum is now "<+>" instead of "Plus"; the cartesian
  1153 product is now "<*>" instead of "Times"; the lexicographic product is
  1154 now "<*lex*>" instead of "**";
  1155 
  1156 * HOL: theory Sexp is now in HOL/Induct examples (it used to be part
  1157 of main HOL, but was unused); better use HOL's datatype package;
  1158 
  1159 * HOL: removed "symbols" syntax for constant "override" of theory Map;
  1160 the old syntax may be recovered as follows:
  1161 
  1162   syntax (symbols)
  1163     override  :: "('a ~=> 'b) => ('a ~=> 'b) => ('a ~=> 'b)"
  1164       (infixl "\\<oplus>" 100)
  1165 
  1166 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  1167 
  1168 * HOL/ML: even fewer consts are declared as global (see theories Ord,
  1169 Lfp, Gfp, WF); this only affects ML packages that refer to const names
  1170 internally;
  1171 
  1172 * HOL and ZF: syntax for quotienting wrt an equivalence relation
  1173 changed from A/r to A//r;
  1174 
  1175 * ZF: new treatment of arithmetic (nat & int) may break some old
  1176 proofs;
  1177 
  1178 * Isar: renamed some attributes (RS -> THEN, simplify -> simplified,
  1179 rulify -> rule_format, elimify -> elim_format, ...);
  1180 
  1181 * Isar/Provers: intro/elim/dest attributes changed; renamed
  1182 intro/intro!/intro!! flags to intro!/intro/intro? (in most cases, one
  1183 should have to change intro!! to intro? only); replaced "delrule" by
  1184 "rule del";
  1185 
  1186 * Isar/HOL: renamed "intrs" to "intros" in inductive definitions;
  1187 
  1188 * Provers: strengthened force_tac by using new first_best_tac;
  1189 
  1190 * LaTeX document preparation: several changes of isabelle.sty (see
  1191 lib/texinputs);
  1192 
  1193 
  1194 *** Document preparation ***
  1195 
  1196 * formal comments (text blocks etc.) in new-style theories may now
  1197 contain antiquotations of thm/prop/term/typ/text to be presented
  1198 according to latex print mode; concrete syntax is like this:
  1199 @{term[show_types] "f(x) = a + x"};
  1200 
  1201 * isatool mkdir provides easy setup of Isabelle session directories,
  1202 including proper document sources;
  1203 
  1204 * generated LaTeX sources are now deleted after successful run
  1205 (isatool document -c); may retain a copy somewhere else via -D option
  1206 of isatool usedir;
  1207 
  1208 * isatool usedir -D now lets isatool latex -o sty update the Isabelle
  1209 style files, achieving self-contained LaTeX sources and simplifying
  1210 LaTeX debugging;
  1211 
  1212 * old-style theories now produce (crude) LaTeX output as well;
  1213 
  1214 * browser info session directories are now self-contained (may be put
  1215 on WWW server seperately); improved graphs of nested sessions; removed
  1216 graph for 'all sessions';
  1217 
  1218 * several improvements in isabelle style files; \isabellestyle{it}
  1219 produces fake math mode output; \isamarkupheader is now \section by
  1220 default; see lib/texinputs/isabelle.sty etc.;
  1221 
  1222 
  1223 *** Isar ***
  1224 
  1225 * Isar/Pure: local results and corresponding term bindings are now
  1226 subject to Hindley-Milner polymorphism (similar to ML); this
  1227 accommodates incremental type-inference very nicely;
  1228 
  1229 * Isar/Pure: new derived language element 'obtain' supports
  1230 generalized existence reasoning;
  1231 
  1232 * Isar/Pure: new calculational elements 'moreover' and 'ultimately'
  1233 support accumulation of results, without applying any rules yet;
  1234 useful to collect intermediate results without explicit name
  1235 references, and for use with transitivity rules with more than 2
  1236 premises;
  1237 
  1238 * Isar/Pure: scalable support for case-analysis type proofs: new
  1239 'case' language element refers to local contexts symbolically, as
  1240 produced by certain proof methods; internally, case names are attached
  1241 to theorems as "tags";
  1242 
  1243 * Isar/Pure: theory command 'hide' removes declarations from
  1244 class/type/const name spaces;
  1245 
  1246 * Isar/Pure: theory command 'defs' supports option "(overloaded)" to
  1247 indicate potential overloading;
  1248 
  1249 * Isar/Pure: changed syntax of local blocks from {{ }} to { };
  1250 
  1251 * Isar/Pure: syntax of sorts made 'inner', i.e. have to write
  1252 "{a,b,c}" instead of {a,b,c};
  1253 
  1254 * Isar/Pure now provides its own version of intro/elim/dest
  1255 attributes; useful for building new logics, but beware of confusion
  1256 with the version in Provers/classical;
  1257 
  1258 * Isar/Pure: the local context of (non-atomic) goals is provided via
  1259 case name 'antecedent';
  1260 
  1261 * Isar/Pure: removed obsolete 'transfer' attribute (transfer of thms
  1262 to the current context is now done automatically);
  1263 
  1264 * Isar/Pure: theory command 'method_setup' provides a simple interface
  1265 for definining proof methods in ML;
  1266 
  1267 * Isar/Provers: intro/elim/dest attributes changed; renamed
  1268 intro/intro!/intro!! flags to intro!/intro/intro? (INCOMPATIBILITY, in
  1269 most cases, one should have to change intro!! to intro? only);
  1270 replaced "delrule" by "rule del";
  1271 
  1272 * Isar/Provers: new 'hypsubst' method, plain 'subst' method and
  1273 'symmetric' attribute (the latter supercedes [RS sym]);
  1274 
  1275 * Isar/Provers: splitter support (via 'split' attribute and 'simp'
  1276 method modifier); 'simp' method: 'only:' modifier removes loopers as
  1277 well (including splits);
  1278 
  1279 * Isar/Provers: Simplifier and Classical methods now support all kind
  1280 of modifiers used in the past, including 'cong', 'iff', etc.
  1281 
  1282 * Isar/Provers: added 'fastsimp' and 'clarsimp' methods (combination
  1283 of Simplifier and Classical reasoner);
  1284 
  1285 * Isar/HOL: new proof method 'cases' and improved version of 'induct'
  1286 now support named cases; major packages (inductive, datatype, primrec,
  1287 recdef) support case names and properly name parameters;
  1288 
  1289 * Isar/HOL: new transitivity rules for substitution in inequalities --
  1290 monotonicity conditions are extracted to be proven at end of
  1291 calculations;
  1292 
  1293 * Isar/HOL: removed 'case_split' thm binding, should use 'cases' proof
  1294 method anyway;
  1295 
  1296 * Isar/HOL: removed old expand_if = split_if; theorems if_splits =
  1297 split_if split_if_asm; datatype package provides theorems foo.splits =
  1298 foo.split foo.split_asm for each datatype;
  1299 
  1300 * Isar/HOL: tuned inductive package, rename "intrs" to "intros"
  1301 (potential INCOMPATIBILITY), emulation of mk_cases feature for proof
  1302 scripts: new 'inductive_cases' command and 'ind_cases' method; (Note:
  1303 use "(cases (simplified))" method in proper proof texts);
  1304 
  1305 * Isar/HOL: added global 'arith_split' attribute for 'arith' method;
  1306 
  1307 * Isar: names of theorems etc. may be natural numbers as well;
  1308 
  1309 * Isar: 'pr' command: optional arguments for goals_limit and
  1310 ProofContext.prems_limit; no longer prints theory contexts, but only
  1311 proof states;
  1312 
  1313 * Isar: diagnostic commands 'pr', 'thm', 'prop', 'term', 'typ' admit
  1314 additional print modes to be specified; e.g. "pr(latex)" will print
  1315 proof state according to the Isabelle LaTeX style;
  1316 
  1317 * Isar: improved support for emulating tactic scripts, including proof
  1318 methods 'rule_tac' etc., 'cut_tac', 'thin_tac', 'subgoal_tac',
  1319 'rename_tac', 'rotate_tac', 'tactic', and 'case_tac' / 'induct_tac'
  1320 (for HOL datatypes);
  1321 
  1322 * Isar: simplified (more robust) goal selection of proof methods: 1st
  1323 goal, all goals, or explicit goal specifier (tactic emulation); thus
  1324 'proof method scripts' have to be in depth-first order;
  1325 
  1326 * Isar: tuned 'let' syntax: replaced 'as' keyword by 'and';
  1327 
  1328 * Isar: removed 'help' command, which hasn't been too helpful anyway;
  1329 should instead use individual commands for printing items
  1330 (print_commands, print_methods etc.);
  1331 
  1332 * Isar: added 'nothing' --- the empty list of theorems;
  1333 
  1334 
  1335 *** HOL ***
  1336 
  1337 * HOL/MicroJava: formalization of a fragment of Java, together with a
  1338 corresponding virtual machine and a specification of its bytecode
  1339 verifier and a lightweight bytecode verifier, including proofs of
  1340 type-safety; by Gerwin Klein, Tobias Nipkow, David von Oheimb, and
  1341 Cornelia Pusch (see also the homepage of project Bali at
  1342 http://isabelle.in.tum.de/Bali/);
  1343 
  1344 * HOL/Algebra: new theory of rings and univariate polynomials, by
  1345 Clemens Ballarin;
  1346 
  1347 * HOL/NumberTheory: fundamental Theorem of Arithmetic, Chinese
  1348 Remainder Theorem, Fermat/Euler Theorem, Wilson's Theorem, by Thomas M
  1349 Rasmussen;
  1350 
  1351 * HOL/Lattice: fundamental concepts of lattice theory and order
  1352 structures, including duals, properties of bounds versus algebraic
  1353 laws, lattice operations versus set-theoretic ones, the Knaster-Tarski
  1354 Theorem for complete lattices etc.; may also serve as a demonstration
  1355 for abstract algebraic reasoning using axiomatic type classes, and
  1356 mathematics-style proof in Isabelle/Isar; by Markus Wenzel;
  1357 
  1358 * HOL/Prolog: a (bare-bones) implementation of Lambda-Prolog, by David
  1359 von Oheimb;
  1360 
  1361 * HOL/IMPP: extension of IMP with local variables and mutually
  1362 recursive procedures, by David von Oheimb;
  1363 
  1364 * HOL/Lambda: converted into new-style theory and document;
  1365 
  1366 * HOL/ex/Multiquote: example of multiple nested quotations and
  1367 anti-quotations -- basically a generalized version of de-Bruijn
  1368 representation; very useful in avoiding lifting of operations;
  1369 
  1370 * HOL/record: added general record equality rule to simpset; fixed
  1371 select-update simplification procedure to handle extended records as
  1372 well; admit "r" as field name;
  1373 
  1374 * HOL: 0 is now overloaded over the new sort "zero", allowing its use with
  1375 other numeric types and also as the identity of groups, rings, etc.;
  1376 
  1377 * HOL: new axclass plus_ac0 for addition with the AC-laws and 0 as identity.
  1378 Types nat and int belong to this axclass;
  1379 
  1380 * HOL: greatly improved simplification involving numerals of type nat, int, real:
  1381    (i + #8 + j) = Suc k simplifies to  #7 + (i + j) = k
  1382    i*j + k + j*#3*i     simplifies to  #4*(i*j) + k
  1383   two terms #m*u and #n*u are replaced by #(m+n)*u
  1384     (where #m, #n and u can implicitly be 1; this is simproc combine_numerals)
  1385   and the term/formula #m*u+x ~~ #n*u+y simplifies simplifies to #(m-n)+x ~~ y
  1386     or x ~~ #(n-m)+y, where ~~ is one of = < <= or - (simproc cancel_numerals);
  1387 
  1388 * HOL: meson_tac is available (previously in ex/meson.ML); it is a
  1389 powerful prover for predicate logic but knows nothing of clasets; see
  1390 ex/mesontest.ML and ex/mesontest2.ML for example applications;
  1391 
  1392 * HOL: new version of "case_tac" subsumes both boolean case split and
  1393 "exhaust_tac" on datatypes; INCOMPATIBILITY: exhaust_tac no longer
  1394 exists, may define val exhaust_tac = case_tac for ad-hoc portability;
  1395 
  1396 * HOL: simplification no longer dives into case-expressions: only the
  1397 selector expression is simplified, but not the remaining arms; to
  1398 enable full simplification of case-expressions for datatype t, you may
  1399 remove t.weak_case_cong from the simpset, either globally (Delcongs
  1400 [thm"t.weak_case_cong"];) or locally (delcongs [...]).
  1401 
  1402 * HOL/recdef: the recursion equations generated by 'recdef' for
  1403 function 'f' are now called f.simps instead of f.rules; if all
  1404 termination conditions are proved automatically, these simplification
  1405 rules are added to the simpset, as in primrec; rules may be named
  1406 individually as well, resulting in a separate list of theorems for
  1407 each equation;
  1408 
  1409 * HOL/While is a new theory that provides a while-combinator. It
  1410 permits the definition of tail-recursive functions without the
  1411 provision of a termination measure. The latter is necessary once the
  1412 invariant proof rule for while is applied.
  1413 
  1414 * HOL: new (overloaded) notation for the set of elements below/above
  1415 some element: {..u}, {..u(}, {l..}, {)l..}. See theory SetInterval.
  1416 
  1417 * HOL: theorems impI, allI, ballI bound as "strip";
  1418 
  1419 * HOL: new tactic induct_thm_tac: thm -> string -> int -> tactic
  1420 induct_tac th "x1 ... xn" expects th to have a conclusion of the form
  1421 P v1 ... vn and abbreviates res_inst_tac [("v1","x1"),...,("vn","xn")] th;
  1422 
  1423 * HOL/Real: "rabs" replaced by overloaded "abs" function;
  1424 
  1425 * HOL: theory Sexp now in HOL/Induct examples (it used to be part of
  1426 main HOL, but was unused);
  1427 
  1428 * HOL: fewer consts declared as global (e.g. have to refer to
  1429 "Lfp.lfp" instead of "lfp" internally; affects ML packages only);
  1430 
  1431 * HOL: tuned AST representation of nested pairs, avoiding bogus output
  1432 in case of overlap with user translations (e.g. judgements over
  1433 tuples); (note that the underlying logical represenation is still
  1434 bogus);
  1435 
  1436 
  1437 *** ZF ***
  1438 
  1439 * ZF: simplification automatically cancels common terms in arithmetic
  1440 expressions over nat and int;
  1441 
  1442 * ZF: new treatment of nat to minimize type-checking: all operators
  1443 coerce their operands to a natural number using the function natify,
  1444 making the algebraic laws unconditional;
  1445 
  1446 * ZF: as above, for int: operators coerce their operands to an integer
  1447 using the function intify;
  1448 
  1449 * ZF: the integer library now contains many of the usual laws for the
  1450 orderings, including $<=, and monotonicity laws for $+ and $*;
  1451 
  1452 * ZF: new example ZF/ex/NatSum to demonstrate integer arithmetic
  1453 simplification;
  1454 
  1455 * FOL and ZF: AddIffs now available, giving theorems of the form P<->Q
  1456 to the simplifier and classical reasoner simultaneously;
  1457 
  1458 
  1459 *** General ***
  1460 
  1461 * Provers: blast_tac now handles actual object-logic rules as
  1462 assumptions; note that auto_tac uses blast_tac internally as well;
  1463 
  1464 * Provers: new functions rulify/rulify_no_asm: thm -> thm for turning
  1465 outer -->/All/Ball into ==>/!!; qed_spec_mp now uses rulify_no_asm;
  1466 
  1467 * Provers: delrules now handles destruct rules as well (no longer need
  1468 explicit make_elim);
  1469 
  1470 * Provers: Blast_tac now warns of and ignores "weak elimination rules" e.g.
  1471   [| inj ?f;          ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  1472 use instead the strong form,
  1473   [| inj ?f; ~ ?W ==> ?f ?x = ?f ?y; ?x = ?y ==> ?W |] ==> ?W
  1474 in HOL, FOL and ZF the function cla_make_elim will create such rules
  1475 from destruct-rules;
  1476 
  1477 * Provers: Simplifier.easy_setup provides a fast path to basic
  1478 Simplifier setup for new object-logics;
  1479 
  1480 * Pure: AST translation rules no longer require constant head on LHS;
  1481 
  1482 * Pure: improved name spaces: ambiguous output is qualified; support
  1483 for hiding of names;
  1484 
  1485 * system: smart setup of canonical ML_HOME, ISABELLE_INTERFACE, and
  1486 XSYMBOL_HOME; no longer need to do manual configuration in most
  1487 situations;
  1488 
  1489 * system: compression of ML heaps images may now be controlled via -c
  1490 option of isabelle and isatool usedir (currently only observed by
  1491 Poly/ML);
  1492 
  1493 * system: isatool installfonts may handle X-Symbol fonts as well (very
  1494 useful for remote X11);
  1495 
  1496 * system: provide TAGS file for Isabelle sources;
  1497 
  1498 * ML: infix 'OF' is a version of 'MRS' with more appropriate argument
  1499 order;
  1500 
  1501 * ML: renamed flags Syntax.trace_norm_ast to Syntax.trace_ast; global
  1502 timing flag supersedes proof_timing and Toplevel.trace;
  1503 
  1504 * ML: new combinators |>> and |>>> for incremental transformations
  1505 with secondary results (e.g. certain theory extensions):
  1506 
  1507 * ML: PureThy.add_defs gets additional argument to indicate potential
  1508 overloading (usually false);
  1509 
  1510 * ML: PureThy.add_thms/add_axioms/add_defs now return theorems as
  1511 results;
  1512 
  1513 
  1514 
  1515 New in Isabelle99 (October 1999)
  1516 --------------------------------
  1517 
  1518 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  1519 
  1520 * HOL: The THEN and ELSE parts of conditional expressions (if P then x else y)
  1521 are no longer simplified.  (This allows the simplifier to unfold recursive
  1522 functional programs.)  To restore the old behaviour, declare
  1523 
  1524     Delcongs [if_weak_cong];
  1525 
  1526 * HOL: Removed the obsolete syntax "Compl A"; use -A for set
  1527 complement;
  1528 
  1529 * HOL: the predicate "inj" is now defined by translation to "inj_on";
  1530 
  1531 * HOL/datatype: mutual_induct_tac no longer exists --
  1532   use induct_tac "x_1 ... x_n" instead of mutual_induct_tac ["x_1", ..., "x_n"]
  1533 
  1534 * HOL/typedef: fixed type inference for representing set; type
  1535 arguments now have to occur explicitly on the rhs as type constraints;
  1536 
  1537 * ZF: The con_defs part of an inductive definition may no longer refer
  1538 to constants declared in the same theory;
  1539 
  1540 * HOL, ZF: the function mk_cases, generated by the inductive
  1541 definition package, has lost an argument.  To simplify its result, it
  1542 uses the default simpset instead of a supplied list of theorems.
  1543 
  1544 * HOL/List: the constructors of type list are now Nil and Cons;
  1545 
  1546 * Simplifier: the type of the infix ML functions
  1547         setSSolver addSSolver setSolver addSolver
  1548 is now  simpset * solver -> simpset  where `solver' is a new abstract type
  1549 for packaging solvers. A solver is created via
  1550         mk_solver: string -> (thm list -> int -> tactic) -> solver
  1551 where the string argument is only a comment.
  1552 
  1553 
  1554 *** Proof tools ***
  1555 
  1556 * Provers/Arith/fast_lin_arith.ML contains a functor for creating a
  1557 decision procedure for linear arithmetic. Currently it is used for
  1558 types `nat', `int', and `real' in HOL (see below); it can, should and
  1559 will be instantiated for other types and logics as well.
  1560 
  1561 * The simplifier now accepts rewrite rules with flexible heads, eg
  1562      hom ?f ==> ?f(?x+?y) = ?f ?x + ?f ?y
  1563   They are applied like any rule with a non-pattern lhs, i.e. by first-order
  1564   matching.
  1565 
  1566 
  1567 *** General ***
  1568 
  1569 * New Isabelle/Isar subsystem provides an alternative to traditional
  1570 tactical theorem proving; together with the ProofGeneral/isar user
  1571 interface it offers an interactive environment for developing human
  1572 readable proof documents (Isar == Intelligible semi-automated
  1573 reasoning); for further information see isatool doc isar-ref,
  1574 src/HOL/Isar_examples and http://isabelle.in.tum.de/Isar/
  1575 
  1576 * improved and simplified presentation of theories: better HTML markup
  1577 (including colors), graph views in several sizes; isatool usedir now
  1578 provides a proper interface for user theories (via -P option); actual
  1579 document preparation based on (PDF)LaTeX is available as well (for
  1580 new-style theories only); see isatool doc system for more information;
  1581 
  1582 * native support for Proof General, both for classic Isabelle and
  1583 Isabelle/Isar;
  1584 
  1585 * ML function thm_deps visualizes dependencies of theorems and lemmas,
  1586 using the graph browser tool;
  1587 
  1588 * Isabelle manuals now also available as PDF;
  1589 
  1590 * theory loader rewritten from scratch (may not be fully
  1591 bug-compatible); old loadpath variable has been replaced by show_path,
  1592 add_path, del_path, reset_path functions; new operations such as
  1593 update_thy, touch_thy, remove_thy, use/update_thy_only (see also
  1594 isatool doc ref);
  1595 
  1596 * improved isatool install: option -k creates KDE application icon,
  1597 option -p DIR installs standalone binaries;
  1598 
  1599 * added ML_PLATFORM setting (useful for cross-platform installations);
  1600 more robust handling of platform specific ML images for SML/NJ;
  1601 
  1602 * the settings environment is now statically scoped, i.e. it is never
  1603 created again in sub-processes invoked from isabelle, isatool, or
  1604 Isabelle;
  1605 
  1606 * path element specification '~~' refers to '$ISABELLE_HOME';
  1607 
  1608 * in locales, the "assumes" and "defines" parts may be omitted if
  1609 empty;
  1610 
  1611 * new print_mode "xsymbols" for extended symbol support (e.g. genuine
  1612 long arrows);
  1613 
  1614 * new print_mode "HTML";
  1615 
  1616 * new flag show_tags controls display of tags of theorems (which are
  1617 basically just comments that may be attached by some tools);
  1618 
  1619 * Isamode 2.6 requires patch to accomodate change of Isabelle font
  1620 mode and goal output format:
  1621 
  1622 diff -r Isamode-2.6/elisp/isa-load.el Isamode/elisp/isa-load.el
  1623 244c244
  1624 <       (list (isa-getenv "ISABELLE") "-msymbols" logic-name)
  1625 ---
  1626 >       (list (isa-getenv "ISABELLE") "-misabelle_font" "-msymbols" logic-name)
  1627 diff -r Isabelle-2.6/elisp/isa-proofstate.el Isamode/elisp/isa-proofstate.el
  1628 181c181
  1629 < (defconst proofstate-proofstart-regexp "^Level [0-9]+$"
  1630 ---
  1631 > (defconst proofstate-proofstart-regexp "^Level [0-9]+"
  1632 
  1633 * function bind_thms stores lists of theorems (cf. bind_thm);
  1634 
  1635 * new shorthand tactics ftac, eatac, datac, fatac;
  1636 
  1637 * qed (and friends) now accept "" as result name; in that case the
  1638 theorem is not stored, but proper checks and presentation of the
  1639 result still apply;
  1640 
  1641 * theorem database now also indexes constants "Trueprop", "all",
  1642 "==>", "=="; thus thms_containing, findI etc. may retrieve more rules;
  1643 
  1644 
  1645 *** HOL ***
  1646 
  1647 ** HOL arithmetic **
  1648 
  1649 * There are now decision procedures for linear arithmetic over nat and
  1650 int:
  1651 
  1652 1. arith_tac copes with arbitrary formulae involving `=', `<', `<=',
  1653 `+', `-', `Suc', `min', `max' and numerical constants; other subterms
  1654 are treated as atomic; subformulae not involving type `nat' or `int'
  1655 are ignored; quantified subformulae are ignored unless they are
  1656 positive universal or negative existential. The tactic has to be
  1657 invoked by hand and can be a little bit slow. In particular, the
  1658 running time is exponential in the number of occurrences of `min' and
  1659 `max', and `-' on `nat'.
  1660 
  1661 2. fast_arith_tac is a cut-down version of arith_tac: it only takes
  1662 (negated) (in)equalities among the premises and the conclusion into
  1663 account (i.e. no compound formulae) and does not know about `min' and
  1664 `max', and `-' on `nat'. It is fast and is used automatically by the
  1665 simplifier.
  1666 
  1667 NB: At the moment, these decision procedures do not cope with mixed
  1668 nat/int formulae where the two parts interact, such as `m < n ==>
  1669 int(m) < int(n)'.
  1670 
  1671 * HOL/Numeral provides a generic theory of numerals (encoded
  1672 efficiently as bit strings); setup for types nat/int/real is in place;
  1673 INCOMPATIBILITY: since numeral syntax is now polymorphic, rather than
  1674 int, existing theories and proof scripts may require a few additional
  1675 type constraints;
  1676 
  1677 * integer division and remainder can now be performed on constant
  1678 arguments;
  1679 
  1680 * many properties of integer multiplication, division and remainder
  1681 are now available;
  1682 
  1683 * An interface to the Stanford Validity Checker (SVC) is available through the
  1684 tactic svc_tac.  Propositional tautologies and theorems of linear arithmetic
  1685 are proved automatically.  SVC must be installed separately, and its results
  1686 must be TAKEN ON TRUST (Isabelle does not check the proofs, but tags any
  1687 invocation of the underlying oracle).  For SVC see
  1688   http://verify.stanford.edu/SVC
  1689 
  1690 * IsaMakefile: the HOL-Real target now builds an actual image;
  1691 
  1692 
  1693 ** HOL misc **
  1694 
  1695 * HOL/Real/HahnBanach: the Hahn-Banach theorem for real vector spaces
  1696 (in Isabelle/Isar) -- by Gertrud Bauer;
  1697 
  1698 * HOL/BCV: generic model of bytecode verification, i.e. data-flow
  1699 analysis for assembly languages with subtypes;
  1700 
  1701 * HOL/TLA (Lamport's Temporal Logic of Actions): major reorganization
  1702 -- avoids syntactic ambiguities and treats state, transition, and
  1703 temporal levels more uniformly; introduces INCOMPATIBILITIES due to
  1704 changed syntax and (many) tactics;
  1705 
  1706 * HOL/inductive: Now also handles more general introduction rules such
  1707   as "ALL y. (y, x) : r --> y : acc r ==> x : acc r"; monotonicity
  1708   theorems are now maintained within the theory (maintained via the
  1709   "mono" attribute);
  1710 
  1711 * HOL/datatype: Now also handles arbitrarily branching datatypes
  1712   (using function types) such as
  1713 
  1714   datatype 'a tree = Atom 'a | Branch "nat => 'a tree"
  1715 
  1716 * HOL/record: record_simproc (part of the default simpset) takes care
  1717 of selectors applied to updated records; record_split_tac is no longer
  1718 part of the default claset; update_defs may now be removed from the
  1719 simpset in many cases; COMPATIBILITY: old behavior achieved by
  1720 
  1721   claset_ref () := claset() addSWrapper record_split_wrapper;
  1722   Delsimprocs [record_simproc]
  1723 
  1724 * HOL/typedef: fixed type inference for representing set; type
  1725 arguments now have to occur explicitly on the rhs as type constraints;
  1726 
  1727 * HOL/recdef (TFL): 'congs' syntax now expects comma separated list of theorem
  1728 names rather than an ML expression;
  1729 
  1730 * HOL/defer_recdef (TFL): like recdef but the well-founded relation can be
  1731 supplied later.  Program schemes can be defined, such as
  1732     "While B C s = (if B s then While B C (C s) else s)"
  1733 where the well-founded relation can be chosen after B and C have been given.
  1734 
  1735 * HOL/List: the constructors of type list are now Nil and Cons;
  1736 INCOMPATIBILITY: while [] and infix # syntax is still there, of
  1737 course, ML tools referring to List.list.op # etc. have to be adapted;
  1738 
  1739 * HOL_quantifiers flag superseded by "HOL" print mode, which is
  1740 disabled by default; run isabelle with option -m HOL to get back to
  1741 the original Gordon/HOL-style output;
  1742 
  1743 * HOL/Ord.thy: new bounded quantifier syntax (input only): ALL x<y. P,
  1744 ALL x<=y. P, EX x<y. P, EX x<=y. P;
  1745 
  1746 * HOL basic syntax simplified (more orthogonal): all variants of
  1747 All/Ex now support plain / symbolic / HOL notation; plain syntax for
  1748 Eps operator is provided as well: "SOME x. P[x]";
  1749 
  1750 * HOL/Sum.thy: sum_case has been moved to HOL/Datatype;
  1751 
  1752 * HOL/Univ.thy: infix syntax <*>, <+>, <**>, <+> eliminated and made
  1753 thus available for user theories;
  1754 
  1755 * HOLCF/IOA/Sequents: renamed 'Cons' to 'Consq' to avoid clash with
  1756 HOL/List; hardly an INCOMPATIBILITY since '>>' syntax is used all the
  1757 time;
  1758 
  1759 * HOL: new tactic smp_tac: int -> int -> tactic, which applies spec
  1760 several times and then mp;
  1761 
  1762 
  1763 *** LK ***
  1764 
  1765 * the notation <<...>> is now available as a notation for sequences of
  1766 formulas;
  1767 
  1768 * the simplifier is now installed
  1769 
  1770 * the axiom system has been generalized (thanks to Soren Heilmann)
  1771 
  1772 * the classical reasoner now has a default rule database
  1773 
  1774 
  1775 *** ZF ***
  1776 
  1777 * new primrec section allows primitive recursive functions to be given
  1778 directly (as in HOL) over datatypes and the natural numbers;
  1779 
  1780 * new tactics induct_tac and exhaust_tac for induction (or case
  1781 analysis) over datatypes and the natural numbers;
  1782 
  1783 * the datatype declaration of type T now defines the recursor T_rec;
  1784 
  1785 * simplification automatically does freeness reasoning for datatype
  1786 constructors;
  1787 
  1788 * automatic type-inference, with AddTCs command to insert new
  1789 type-checking rules;
  1790 
  1791 * datatype introduction rules are now added as Safe Introduction rules
  1792 to the claset;
  1793 
  1794 * the syntax "if P then x else y" is now available in addition to
  1795 if(P,x,y);
  1796 
  1797 
  1798 *** Internal programming interfaces ***
  1799 
  1800 * tuned simplifier trace output; new flag debug_simp;
  1801 
  1802 * structures Vartab / Termtab (instances of TableFun) offer efficient
  1803 tables indexed by indexname_ord / term_ord (compatible with aconv);
  1804 
  1805 * AxClass.axclass_tac lost the theory argument;
  1806 
  1807 * tuned current_goals_markers semantics: begin / end goal avoids
  1808 printing empty lines;
  1809 
  1810 * removed prs and prs_fn hook, which was broken because it did not
  1811 include \n in its semantics, forcing writeln to add one
  1812 uncoditionally; replaced prs_fn by writeln_fn; consider std_output:
  1813 string -> unit if you really want to output text without newline;
  1814 
  1815 * Symbol.output subject to print mode; INCOMPATIBILITY: defaults to
  1816 plain output, interface builders may have to enable 'isabelle_font'
  1817 mode to get Isabelle font glyphs as before;
  1818 
  1819 * refined token_translation interface; INCOMPATIBILITY: output length
  1820 now of type real instead of int;
  1821 
  1822 * theory loader actions may be traced via new ThyInfo.add_hook
  1823 interface (see src/Pure/Thy/thy_info.ML); example application: keep
  1824 your own database of information attached to *whole* theories -- as
  1825 opposed to intra-theory data slots offered via TheoryDataFun;
  1826 
  1827 * proper handling of dangling sort hypotheses (at last!);
  1828 Thm.strip_shyps and Drule.strip_shyps_warning take care of removing
  1829 extra sort hypotheses that can be witnessed from the type signature;
  1830 the force_strip_shyps flag is gone, any remaining shyps are simply
  1831 left in the theorem (with a warning issued by strip_shyps_warning);
  1832 
  1833 
  1834 
  1835 New in Isabelle98-1 (October 1998)
  1836 ----------------------------------
  1837 
  1838 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  1839 
  1840 * several changes of automated proof tools;
  1841 
  1842 * HOL: major changes to the inductive and datatype packages, including
  1843 some minor incompatibilities of theory syntax;
  1844 
  1845 * HOL: renamed r^-1 to 'converse' from 'inverse'; 'inj_onto' is now
  1846 called `inj_on';
  1847 
  1848 * HOL: removed duplicate thms in Arith:
  1849   less_imp_add_less  should be replaced by  trans_less_add1
  1850   le_imp_add_le      should be replaced by  trans_le_add1
  1851 
  1852 * HOL: unary minus is now overloaded (new type constraints may be
  1853 required);
  1854 
  1855 * HOL and ZF: unary minus for integers is now #- instead of #~.  In
  1856 ZF, expressions such as n#-1 must be changed to n#- 1, since #-1 is
  1857 now taken as an integer constant.
  1858 
  1859 * Pure: ML function 'theory_of' renamed to 'theory';
  1860 
  1861 
  1862 *** Proof tools ***
  1863 
  1864 * Simplifier:
  1865   1. Asm_full_simp_tac is now more aggressive.
  1866      1. It will sometimes reorient premises if that increases their power to
  1867         simplify.
  1868      2. It does no longer proceed strictly from left to right but may also
  1869         rotate premises to achieve further simplification.
  1870      For compatibility reasons there is now Asm_lr_simp_tac which is like the
  1871      old Asm_full_simp_tac in that it does not rotate premises.
  1872   2. The simplifier now knows a little bit about nat-arithmetic.
  1873 
  1874 * Classical reasoner: wrapper mechanism for the classical reasoner now
  1875 allows for selected deletion of wrappers, by introduction of names for
  1876 wrapper functionals.  This implies that addbefore, addSbefore,
  1877 addaltern, and addSaltern now take a pair (name, tactic) as argument,
  1878 and that adding two tactics with the same name overwrites the first
  1879 one (emitting a warning).
  1880   type wrapper = (int -> tactic) -> (int -> tactic)
  1881   setWrapper, setSWrapper, compWrapper and compSWrapper are replaced by
  1882   addWrapper, addSWrapper: claset * (string * wrapper) -> claset
  1883   delWrapper, delSWrapper: claset *  string            -> claset
  1884   getWrapper is renamed to appWrappers, getSWrapper to appSWrappers;
  1885 
  1886 * Classical reasoner: addbefore/addSbefore now have APPEND/ORELSE
  1887 semantics; addbefore now affects only the unsafe part of step_tac
  1888 etc.; this affects addss/auto_tac/force_tac, so EXISTING PROOFS MAY
  1889 FAIL, but proofs should be fixable easily, e.g. by replacing Auto_tac
  1890 by Force_tac;
  1891 
  1892 * Classical reasoner: setwrapper to setWrapper and compwrapper to
  1893 compWrapper; added safe wrapper (and access functions for it);
  1894 
  1895 * HOL/split_all_tac is now much faster and fails if there is nothing
  1896 to split.  Some EXISTING PROOFS MAY REQUIRE ADAPTION because the order
  1897 and the names of the automatically generated variables have changed.
  1898 split_all_tac has moved within claset() from unsafe wrappers to safe
  1899 wrappers, which means that !!-bound variables are split much more
  1900 aggressively, and safe_tac and clarify_tac now split such variables.
  1901 If this splitting is not appropriate, use delSWrapper "split_all_tac".
  1902 Note: the same holds for record_split_tac, which does the job of
  1903 split_all_tac for record fields.
  1904 
  1905 * HOL/Simplifier: Rewrite rules for case distinctions can now be added
  1906 permanently to the default simpset using Addsplits just like
  1907 Addsimps. They can be removed via Delsplits just like
  1908 Delsimps. Lower-case versions are also available.
  1909 
  1910 * HOL/Simplifier: The rule split_if is now part of the default
  1911 simpset. This means that the simplifier will eliminate all occurrences
  1912 of if-then-else in the conclusion of a goal. To prevent this, you can
  1913 either remove split_if completely from the default simpset by
  1914 `Delsplits [split_if]' or remove it in a specific call of the
  1915 simplifier using `... delsplits [split_if]'.  You can also add/delete
  1916 other case splitting rules to/from the default simpset: every datatype
  1917 generates suitable rules `split_t_case' and `split_t_case_asm' (where
  1918 t is the name of the datatype).
  1919 
  1920 * Classical reasoner / Simplifier combination: new force_tac (and
  1921 derivatives Force_tac, force) combines rewriting and classical
  1922 reasoning (and whatever other tools) similarly to auto_tac, but is
  1923 aimed to solve the given subgoal completely.
  1924 
  1925 
  1926 *** General ***
  1927 
  1928 * new top-level commands `Goal' and `Goalw' that improve upon `goal'
  1929 and `goalw': the theory is no longer needed as an explicit argument -
  1930 the current theory context is used; assumptions are no longer returned
  1931 at the ML-level unless one of them starts with ==> or !!; it is
  1932 recommended to convert to these new commands using isatool fixgoal
  1933 (backup your sources first!);
  1934 
  1935 * new top-level commands 'thm' and 'thms' for retrieving theorems from
  1936 the current theory context, and 'theory' to lookup stored theories;
  1937 
  1938 * new theory section 'locale' for declaring constants, assumptions and
  1939 definitions that have local scope;
  1940 
  1941 * new theory section 'nonterminals' for purely syntactic types;
  1942 
  1943 * new theory section 'setup' for generic ML setup functions
  1944 (e.g. package initialization);
  1945 
  1946 * the distribution now includes Isabelle icons: see
  1947 lib/logo/isabelle-{small,tiny}.xpm;
  1948 
  1949 * isatool install - install binaries with absolute references to
  1950 ISABELLE_HOME/bin;
  1951 
  1952 * isatool logo -- create instances of the Isabelle logo (as EPS);
  1953 
  1954 * print mode 'emacs' reserved for Isamode;
  1955 
  1956 * support multiple print (ast) translations per constant name;
  1957 
  1958 * theorems involving oracles are now printed with a suffixed [!];
  1959 
  1960 
  1961 *** HOL ***
  1962 
  1963 * there is now a tutorial on Isabelle/HOL (do 'isatool doc tutorial');
  1964 
  1965 * HOL/inductive package reorganized and improved: now supports mutual
  1966 definitions such as
  1967 
  1968   inductive EVEN ODD
  1969     intrs
  1970       null "0 : EVEN"
  1971       oddI "n : EVEN ==> Suc n : ODD"
  1972       evenI "n : ODD ==> Suc n : EVEN"
  1973 
  1974 new theorem list "elims" contains an elimination rule for each of the
  1975 recursive sets; inductive definitions now handle disjunctive premises
  1976 correctly (also ZF);
  1977 
  1978 INCOMPATIBILITIES: requires Inductive as an ancestor; component
  1979 "mutual_induct" no longer exists - the induction rule is always
  1980 contained in "induct";
  1981 
  1982 
  1983 * HOL/datatype package re-implemented and greatly improved: now
  1984 supports mutually recursive datatypes such as
  1985 
  1986   datatype
  1987     'a aexp = IF_THEN_ELSE ('a bexp) ('a aexp) ('a aexp)
  1988             | SUM ('a aexp) ('a aexp)
  1989             | DIFF ('a aexp) ('a aexp)
  1990             | NUM 'a
  1991   and
  1992     'a bexp = LESS ('a aexp) ('a aexp)
  1993             | AND ('a bexp) ('a bexp)
  1994             | OR ('a bexp) ('a bexp)
  1995 
  1996 as well as indirectly recursive datatypes such as
  1997 
  1998   datatype
  1999     ('a, 'b) term = Var 'a
  2000                   | App 'b ((('a, 'b) term) list)
  2001 
  2002 The new tactic  mutual_induct_tac [<var_1>, ..., <var_n>] i  performs
  2003 induction on mutually / indirectly recursive datatypes.
  2004 
  2005 Primrec equations are now stored in theory and can be accessed via
  2006 <function_name>.simps.
  2007 
  2008 INCOMPATIBILITIES:
  2009 
  2010   - Theories using datatypes must now have theory Datatype as an
  2011     ancestor.
  2012   - The specific <typename>.induct_tac no longer exists - use the
  2013     generic induct_tac instead.
  2014   - natE has been renamed to nat.exhaust - use exhaust_tac
  2015     instead of res_inst_tac ... natE. Note that the variable
  2016     names in nat.exhaust differ from the names in natE, this
  2017     may cause some "fragile" proofs to fail.
  2018   - The theorems split_<typename>_case and split_<typename>_case_asm
  2019     have been renamed to <typename>.split and <typename>.split_asm.
  2020   - Since default sorts of type variables are now handled correctly,
  2021     some datatype definitions may have to be annotated with explicit
  2022     sort constraints.
  2023   - Primrec definitions no longer require function name and type
  2024     of recursive argument.
  2025 
  2026 Consider using isatool fixdatatype to adapt your theories and proof
  2027 scripts to the new package (backup your sources first!).
  2028 
  2029 
  2030 * HOL/record package: considerably improved implementation; now
  2031 includes concrete syntax for record types, terms, updates; theorems
  2032 for surjective pairing and splitting !!-bound record variables; proof
  2033 support is as follows:
  2034 
  2035   1) standard conversions (selectors or updates applied to record
  2036 constructor terms) are part of the standard simpset;
  2037 
  2038   2) inject equations of the form ((x, y) = (x', y')) == x=x' & y=y' are
  2039 made part of standard simpset and claset via addIffs;
  2040 
  2041   3) a tactic for record field splitting (record_split_tac) is part of
  2042 the standard claset (addSWrapper);
  2043 
  2044 To get a better idea about these rules you may retrieve them via
  2045 something like 'thms "foo.simps"' or 'thms "foo.iffs"', where "foo" is
  2046 the name of your record type.
  2047 
  2048 The split tactic 3) conceptually simplifies by the following rule:
  2049 
  2050   "(!!x. PROP ?P x) == (!!a b. PROP ?P (a, b))"
  2051 
  2052 Thus any record variable that is bound by meta-all will automatically
  2053 blow up into some record constructor term, consequently the
  2054 simplifications of 1), 2) apply.  Thus force_tac, auto_tac etc. shall
  2055 solve record problems automatically.
  2056 
  2057 
  2058 * reorganized the main HOL image: HOL/Integ and String loaded by
  2059 default; theory Main includes everything;
  2060 
  2061 * automatic simplification of integer sums and comparisons, using cancellation;
  2062 
  2063 * added option_map_eq_Some and not_Some_eq to the default simpset and claset;
  2064 
  2065 * added disj_not1 = "(~P | Q) = (P --> Q)" to the default simpset;
  2066 
  2067 * many new identities for unions, intersections, set difference, etc.;
  2068 
  2069 * expand_if, expand_split, expand_sum_case and expand_nat_case are now
  2070 called split_if, split_split, split_sum_case and split_nat_case (to go
  2071 with add/delsplits);
  2072 
  2073 * HOL/Prod introduces simplification procedure unit_eq_proc rewriting
  2074 (?x::unit) = (); this is made part of the default simpset, which COULD
  2075 MAKE EXISTING PROOFS FAIL under rare circumstances (consider
  2076 'Delsimprocs [unit_eq_proc];' as last resort); also note that
  2077 unit_abs_eta_conv is added in order to counter the effect of
  2078 unit_eq_proc on (%u::unit. f u), replacing it by f rather than by
  2079 %u.f();
  2080 
  2081 * HOL/Fun INCOMPATIBILITY: `inj_onto' is now called `inj_on' (which
  2082 makes more sense);
  2083 
  2084 * HOL/Set INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  2085   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  2086   disjointness reasoning but breaking a few old proofs.
  2087 
  2088 * HOL/Relation INCOMPATIBILITY: renamed the relational operator r^-1
  2089 to 'converse' from 'inverse' (for compatibility with ZF and some
  2090 literature);
  2091 
  2092 * HOL/recdef can now declare non-recursive functions, with {} supplied as
  2093 the well-founded relation;
  2094 
  2095 * HOL/Set INCOMPATIBILITY: the complement of set A is now written -A instead of
  2096     Compl A.  The "Compl" syntax remains available as input syntax for this
  2097     release ONLY.
  2098 
  2099 * HOL/Update: new theory of function updates:
  2100     f(a:=b) == %x. if x=a then b else f x
  2101 may also be iterated as in f(a:=b,c:=d,...);
  2102 
  2103 * HOL/Vimage: new theory for inverse image of a function, syntax f-``B;
  2104 
  2105 * HOL/List:
  2106   - new function list_update written xs[i:=v] that updates the i-th
  2107     list position. May also be iterated as in xs[i:=a,j:=b,...].
  2108   - new function `upt' written [i..j(] which generates the list
  2109     [i,i+1,...,j-1], i.e. the upper bound is excluded. To include the upper
  2110     bound write [i..j], which is a shorthand for [i..j+1(].
  2111   - new lexicographic orderings and corresponding wellfoundedness theorems.
  2112 
  2113 * HOL/Arith:
  2114   - removed 'pred' (predecessor) function;
  2115   - generalized some theorems about n-1;
  2116   - many new laws about "div" and "mod";
  2117   - new laws about greatest common divisors (see theory ex/Primes);
  2118 
  2119 * HOL/Relation: renamed the relational operator r^-1 "converse"
  2120 instead of "inverse";
  2121 
  2122 * HOL/Induct/Multiset: a theory of multisets, including the wellfoundedness
  2123   of the multiset ordering;
  2124 
  2125 * directory HOL/Real: a construction of the reals using Dedekind cuts
  2126   (not included by default);
  2127 
  2128 * directory HOL/UNITY: Chandy and Misra's UNITY formalism;
  2129 
  2130 * directory HOL/Hoare: a new version of Hoare logic which permits many-sorted
  2131   programs, i.e. different program variables may have different types.
  2132 
  2133 * calling (stac rew i) now fails if "rew" has no effect on the goal
  2134   [previously, this check worked only if the rewrite rule was unconditional]
  2135   Now rew can involve either definitions or equalities (either == or =).
  2136 
  2137 
  2138 *** ZF ***
  2139 
  2140 * theory Main includes everything; INCOMPATIBILITY: theory ZF.thy contains
  2141   only the theorems proved on ZF.ML;
  2142 
  2143 * ZF INCOMPATIBILITY: rule `equals0D' is now a well-formed destruct rule;
  2144   It and 'sym RS equals0D' are now in the default  claset, giving automatic
  2145   disjointness reasoning but breaking a few old proofs.
  2146 
  2147 * ZF/Update: new theory of function updates
  2148     with default rewrite rule  f(x:=y) ` z = if(z=x, y, f`z)
  2149   may also be iterated as in f(a:=b,c:=d,...);
  2150 
  2151 * in  let x=t in u(x), neither t nor u(x) has to be an FOL term.
  2152 
  2153 * calling (stac rew i) now fails if "rew" has no effect on the goal
  2154   [previously, this check worked only if the rewrite rule was unconditional]
  2155   Now rew can involve either definitions or equalities (either == or =).
  2156 
  2157 * case_tac provided for compatibility with HOL
  2158     (like the old excluded_middle_tac, but with subgoals swapped)
  2159 
  2160 
  2161 *** Internal programming interfaces ***
  2162 
  2163 * Pure: several new basic modules made available for general use, see
  2164 also src/Pure/README;
  2165 
  2166 * improved the theory data mechanism to support encapsulation (data
  2167 kind name replaced by private Object.kind, acting as authorization
  2168 key); new type-safe user interface via functor TheoryDataFun; generic
  2169 print_data function becomes basically useless;
  2170 
  2171 * removed global_names compatibility flag -- all theory declarations
  2172 are qualified by default;
  2173 
  2174 * module Pure/Syntax now offers quote / antiquote translation
  2175 functions (useful for Hoare logic etc. with implicit dependencies);
  2176 see HOL/ex/Antiquote for an example use;
  2177 
  2178 * Simplifier now offers conversions (asm_)(full_)rewrite: simpset ->
  2179 cterm -> thm;
  2180 
  2181 * new tactical CHANGED_GOAL for checking that a tactic modifies a
  2182 subgoal;
  2183 
  2184 * Display.print_goals function moved to Locale.print_goals;
  2185 
  2186 * standard print function for goals supports current_goals_markers
  2187 variable for marking begin of proof, end of proof, start of goal; the
  2188 default is ("", "", ""); setting current_goals_markers := ("<proof>",
  2189 "</proof>", "<goal>") causes SGML like tagged proof state printing,
  2190 for example;
  2191 
  2192 
  2193 
  2194 New in Isabelle98 (January 1998)
  2195 --------------------------------
  2196 
  2197 *** Overview of INCOMPATIBILITIES (see below for more details) ***
  2198 
  2199 * changed lexical syntax of terms / types: dots made part of long
  2200 identifiers, e.g. "%x.x" no longer possible, should be "%x. x";
  2201 
  2202 * simpset (and claset) reference variable replaced by functions
  2203 simpset / simpset_ref;
  2204 
  2205 * no longer supports theory aliases (via merge) and non-trivial
  2206 implicit merge of thms' signatures;
  2207 
  2208 * most internal names of constants changed due to qualified names;
  2209 
  2210 * changed Pure/Sequence interface (see Pure/seq.ML);
  2211 
  2212 
  2213 *** General Changes ***
  2214 
  2215 * hierachically structured name spaces (for consts, types, axms, thms
  2216 etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
  2217 old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
  2218 isatool fixdots ensures space after dots (e.g. "%x. x"); set
  2219 long_names for fully qualified output names; NOTE: ML programs
  2220 (special tactics, packages etc.) referring to internal names may have
  2221 to be adapted to cope with fully qualified names; in case of severe
  2222 backward campatibility problems try setting 'global_names' at compile
  2223 time to have enrything declared within a flat name space; one may also
  2224 fine tune name declarations in theories via the 'global' and 'local'
  2225 section;
  2226 
  2227 * reimplemented the implicit simpset and claset using the new anytype
  2228 data filed in signatures; references simpset:simpset ref etc. are
  2229 replaced by functions simpset:unit->simpset and
  2230 simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
  2231 to patch your ML files accordingly;
  2232 
  2233 * HTML output now includes theory graph data for display with Java
  2234 applet or isatool browser; data generated automatically via isatool
  2235 usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
  2236 
  2237 * defs may now be conditional; improved rewrite_goals_tac to handle
  2238 conditional equations;
  2239 
  2240 * defs now admits additional type arguments, using TYPE('a) syntax;
  2241 
  2242 * theory aliases via merge (e.g. M=A+B+C) no longer supported, always
  2243 creates a new theory node; implicit merge of thms' signatures is
  2244 restricted to 'trivial' ones; COMPATIBILITY: one may have to use
  2245 transfer:theory->thm->thm in (rare) cases;
  2246 
  2247 * improved handling of draft signatures / theories; draft thms (and
  2248 ctyps, cterms) are automatically promoted to real ones;
  2249 
  2250 * slightly changed interfaces for oracles: admit many per theory, named
  2251 (e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
  2252 
  2253 * print_goals: optional output of const types (set show_consts and
  2254 show_types);
  2255 
  2256 * improved output of warnings (###) and errors (***);
  2257 
  2258 * subgoal_tac displays a warning if the new subgoal has type variables;
  2259 
  2260 * removed old README and Makefiles;
  2261 
  2262 * replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
  2263 
  2264 * removed obsolete init_pps and init_database;
  2265 
  2266 * deleted the obsolete tactical STATE, which was declared by
  2267     fun STATE tacfun st = tacfun st st;
  2268 
  2269 * cd and use now support path variables, e.g. $ISABELLE_HOME, or ~
  2270 (which abbreviates $HOME);
  2271 
  2272 * changed Pure/Sequence interface (see Pure/seq.ML); COMPATIBILITY:
  2273 use isatool fixseq to adapt your ML programs (this works for fully
  2274 qualified references to the Sequence structure only!);
  2275 
  2276 * use_thy no longer requires writable current directory; it always
  2277 reloads .ML *and* .thy file, if either one is out of date;
  2278 
  2279 
  2280 *** Classical Reasoner ***
  2281 
  2282 * Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
  2283 tactics that use classical reasoning to simplify a subgoal without
  2284 splitting it into several subgoals;
  2285 
  2286 * Safe_tac: like safe_tac but uses the default claset;
  2287 
  2288 
  2289 *** Simplifier ***
  2290 
  2291 * added simplification meta rules:
  2292     (asm_)(full_)simplify: simpset -> thm -> thm;
  2293 
  2294 * simplifier.ML no longer part of Pure -- has to be loaded by object
  2295 logics (again);
  2296 
  2297 * added prems argument to simplification procedures;
  2298 
  2299 * HOL, FOL, ZF: added infix function `addsplits':
  2300   instead of `<simpset> setloop (split_tac <thms>)'
  2301   you can simply write `<simpset> addsplits <thms>'
  2302 
  2303 
  2304 *** Syntax ***
  2305 
  2306 * TYPE('a) syntax for type reflection terms;
  2307 
  2308 * no longer handles consts with name "" -- declare as 'syntax' instead;
  2309 
  2310 * pretty printer: changed order of mixfix annotation preference (again!);
  2311 
  2312 * Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
  2313 
  2314 
  2315 *** HOL ***
  2316 
  2317 * HOL: there is a new splitter `split_asm_tac' that can be used e.g.
  2318   with `addloop' of the simplifier to faciliate case splitting in premises.
  2319 
  2320 * HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
  2321 
  2322 * HOL/Auth: new protocol proofs including some for the Internet
  2323   protocol TLS;
  2324 
  2325 * HOL/Map: new theory of `maps' a la VDM;
  2326 
  2327 * HOL/simplifier: simplification procedures nat_cancel_sums for
  2328 cancelling out common nat summands from =, <, <= (in)equalities, or
  2329 differences; simplification procedures nat_cancel_factor for
  2330 cancelling common factor from =, <, <= (in)equalities over natural
  2331 sums; nat_cancel contains both kinds of procedures, it is installed by
  2332 default in Arith.thy -- this COULD MAKE EXISTING PROOFS FAIL;
  2333 
  2334 * HOL/simplifier: terms of the form
  2335   `? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)'  (or t=x)
  2336   are rewritten to
  2337   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
  2338   and those of the form
  2339   `! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)'  (or t=x)
  2340   are rewritten to
  2341   `P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
  2342 
  2343 * HOL/datatype
  2344   Each datatype `t' now comes with a theorem `split_t_case' of the form
  2345 
  2346   P(t_case f1 ... fn x) =
  2347      ( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
  2348         ...
  2349        (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
  2350      )
  2351 
  2352   and a theorem `split_t_case_asm' of the form
  2353 
  2354   P(t_case f1 ... fn x) =
  2355     ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
  2356         ...
  2357        (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
  2358      )
  2359   which can be added to a simpset via `addsplits'. The existing theorems
  2360   expand_list_case and expand_option_case have been renamed to
  2361   split_list_case and split_option_case.
  2362 
  2363 * HOL/Arithmetic:
  2364   - `pred n' is automatically converted to `n-1'.
  2365     Users are strongly encouraged not to use `pred' any longer,
  2366     because it will disappear altogether at some point.
  2367   - Users are strongly encouraged to write "0 < n" rather than
  2368     "n ~= 0". Theorems and proof tools have been modified towards this
  2369     `standard'.
  2370 
  2371 * HOL/Lists:
  2372   the function "set_of_list" has been renamed "set" (and its theorems too);
  2373   the function "nth" now takes its arguments in the reverse order and
  2374   has acquired the infix notation "!" as in "xs!n".
  2375 
  2376 * HOL/Set: UNIV is now a constant and is no longer translated to Compl{};
  2377 
  2378 * HOL/Set: The operator (UN x.B x) now abbreviates (UN x:UNIV. B x) and its
  2379   specialist theorems (like UN1_I) are gone.  Similarly for (INT x.B x);
  2380 
  2381 * HOL/record: extensible records with schematic structural subtyping
  2382 (single inheritance); EXPERIMENTAL version demonstrating the encoding,
  2383 still lacks various theorems and concrete record syntax;
  2384 
  2385 
  2386 *** HOLCF ***
  2387 
  2388 * removed "axioms" and "generated by" sections;
  2389 
  2390 * replaced "ops" section by extended "consts" section, which is capable of
  2391   handling the continuous function space "->" directly;
  2392 
  2393 * domain package:
  2394   . proves theorems immediately and stores them in the theory,
  2395   . creates hierachical name space,
  2396   . now uses normal mixfix annotations (instead of cinfix...),
  2397   . minor changes to some names and values (for consistency),
  2398   . e.g. cases -> casedist, dists_eq -> dist_eqs, [take_lemma] -> take_lemmas,
  2399   . separator between mutual domain defs: changed "," to "and",
  2400   . improved handling of sort constraints;  now they have to
  2401     appear on the left-hand side of the equations only;
  2402 
  2403 * fixed LAM <x,y,zs>.b syntax;
  2404 
  2405 * added extended adm_tac to simplifier in HOLCF -- can now discharge
  2406 adm (%x. P (t x)), where P is chainfinite and t continuous;
  2407 
  2408 
  2409 *** FOL and ZF ***
  2410 
  2411 * FOL: there is a new splitter `split_asm_tac' that can be used e.g.
  2412   with `addloop' of the simplifier to faciliate case splitting in premises.
  2413 
  2414 * qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
  2415 in HOL, they strip ALL and --> from proved theorems;
  2416 
  2417 
  2418 
  2419 New in Isabelle94-8 (May 1997)
  2420 ------------------------------
  2421 
  2422 *** General Changes ***
  2423 
  2424 * new utilities to build / run / maintain Isabelle etc. (in parts
  2425 still somewhat experimental); old Makefiles etc. still functional;
  2426 
  2427 * new 'Isabelle System Manual';
  2428 
  2429 * INSTALL text, together with ./configure and ./build scripts;
  2430 
  2431 * reimplemented type inference for greater efficiency, better error
  2432 messages and clean internal interface;
  2433 
  2434 * prlim command for dealing with lots of subgoals (an easier way of
  2435 setting goals_limit);
  2436 
  2437 
  2438 *** Syntax ***
  2439 
  2440 * supports alternative (named) syntax tables (parser and pretty
  2441 printer); internal interface is provided by add_modesyntax(_i);
  2442 
  2443 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
  2444 be used in conjunction with the Isabelle symbol font; uses the
  2445 "symbols" syntax table;
  2446 
  2447 * added token_translation interface (may translate name tokens in
  2448 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
  2449 the current print_mode); IMPORTANT: user print translation functions
  2450 are responsible for marking newly introduced bounds
  2451 (Syntax.mark_boundT);
  2452 
  2453 * token translations for modes "xterm" and "xterm_color" that display
  2454 names in bold, underline etc. or colors (which requires a color
  2455 version of xterm);
  2456 
  2457 * infixes may now be declared with names independent of their syntax;
  2458 
  2459 * added typed_print_translation (like print_translation, but may
  2460 access type of constant);
  2461 
  2462 
  2463 *** Classical Reasoner ***
  2464 
  2465 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
  2466 some limitations.  Blast_tac...
  2467   + ignores addss, addbefore, addafter; this restriction is intrinsic
  2468   + ignores elimination rules that don't have the correct format
  2469         (the conclusion MUST be a formula variable)
  2470   + ignores types, which can make HOL proofs fail
  2471   + rules must not require higher-order unification, e.g. apply_type in ZF
  2472     [message "Function Var's argument not a bound variable" relates to this]
  2473   + its proof strategy is more general but can actually be slower
  2474 
  2475 * substitution with equality assumptions no longer permutes other
  2476 assumptions;
  2477 
  2478 * minor changes in semantics of addafter (now called addaltern); renamed
  2479 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
  2480 (and access functions for it);
  2481 
  2482 * improved combination of classical reasoner and simplifier:
  2483   + functions for handling clasimpsets
  2484   + improvement of addss: now the simplifier is called _after_ the
  2485     safe steps.
  2486   + safe variant of addss called addSss: uses safe simplifications
  2487     _during_ the safe steps. It is more complete as it allows multiple
  2488     instantiations of unknowns (e.g. with slow_tac).
  2489 
  2490 *** Simplifier ***
  2491 
  2492 * added interface for simplification procedures (functions that
  2493 produce *proven* rewrite rules on the fly, depending on current
  2494 redex);
  2495 
  2496 * ordering on terms as parameter (used for ordered rewriting);
  2497 
  2498 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
  2499 
  2500 * the solver is now split into a safe and an unsafe part.
  2501 This should be invisible for the normal user, except that the
  2502 functions setsolver and addsolver have been renamed to setSolver and
  2503 addSolver; added safe_asm_full_simp_tac;
  2504 
  2505 
  2506 *** HOL ***
  2507 
  2508 * a generic induction tactic `induct_tac' which works for all datatypes and
  2509 also for type `nat';
  2510 
  2511 * a generic case distinction tactic `exhaust_tac' which works for all
  2512 datatypes and also for type `nat';
  2513 
  2514 * each datatype comes with a function `size';
  2515 
  2516 * patterns in case expressions allow tuple patterns as arguments to
  2517 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
  2518 
  2519 * primrec now also works with type nat;
  2520 
  2521 * recdef: a new declaration form, allows general recursive functions to be
  2522 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
  2523 
  2524 * the constant for negation has been renamed from "not" to "Not" to
  2525 harmonize with FOL, ZF, LK, etc.;
  2526 
  2527 * HOL/ex/LFilter theory of a corecursive "filter" functional for
  2528 infinite lists;
  2529 
  2530 * HOL/Modelcheck demonstrates invocation of model checker oracle;
  2531 
  2532 * HOL/ex/Ring.thy declares cring_simp, which solves equational
  2533 problems in commutative rings, using axiomatic type classes for + and *;
  2534 
  2535 * more examples in HOL/MiniML and HOL/Auth;
  2536 
  2537 * more default rewrite rules for quantifiers, union/intersection;
  2538 
  2539 * a new constant `arbitrary == @x.False';
  2540 
  2541 * HOLCF/IOA replaces old HOL/IOA;
  2542 
  2543 * HOLCF changes: derived all rules and arities
  2544   + axiomatic type classes instead of classes
  2545   + typedef instead of faking type definitions
  2546   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
  2547   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
  2548   + eliminated the types void, one, tr
  2549   + use unit lift and bool lift (with translations) instead of one and tr
  2550   + eliminated blift from Lift3.thy (use Def instead of blift)
  2551   all eliminated rules are derived as theorems --> no visible changes ;
  2552 
  2553 
  2554 *** ZF ***
  2555 
  2556 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
  2557 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
  2558 as ZF_cs addSIs [equalityI];
  2559 
  2560 
  2561 
  2562 New in Isabelle94-7 (November 96)
  2563 ---------------------------------
  2564 
  2565 * allowing negative levels (as offsets) in prlev and choplev;
  2566 
  2567 * super-linear speedup for large simplifications;
  2568 
  2569 * FOL, ZF and HOL now use miniscoping: rewriting pushes
  2570 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
  2571 FAIL); can suppress it using the command Delsimps (ex_simps @
  2572 all_simps); De Morgan laws are also now included, by default;
  2573 
  2574 * improved printing of ==>  :  ~:
  2575 
  2576 * new object-logic "Sequents" adds linear logic, while replacing LK
  2577 and Modal (thanks to Sara Kalvala);
  2578 
  2579 * HOL/Auth: correctness proofs for authentication protocols;
  2580 
  2581 * HOL: new auto_tac combines rewriting and classical reasoning (many
  2582 examples on HOL/Auth);
  2583 
  2584 * HOL: new command AddIffs for declaring theorems of the form P=Q to
  2585 the rewriter and classical reasoner simultaneously;
  2586 
  2587 * function uresult no longer returns theorems in "standard" format;
  2588 regain previous version by: val uresult = standard o uresult;
  2589 
  2590 
  2591 
  2592 New in Isabelle94-6
  2593 -------------------
  2594 
  2595 * oracles -- these establish an interface between Isabelle and trusted
  2596 external reasoners, which may deliver results as theorems;
  2597 
  2598 * proof objects (in particular record all uses of oracles);
  2599 
  2600 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
  2601 
  2602 * "constdefs" section in theory files;
  2603 
  2604 * "primrec" section (HOL) no longer requires names;
  2605 
  2606 * internal type "tactic" now simply "thm -> thm Sequence.seq";
  2607 
  2608 
  2609 
  2610 New in Isabelle94-5
  2611 -------------------
  2612 
  2613 * reduced space requirements;
  2614 
  2615 * automatic HTML generation from theories;
  2616 
  2617 * theory files no longer require "..." (quotes) around most types;
  2618 
  2619 * new examples, including two proofs of the Church-Rosser theorem;
  2620 
  2621 * non-curried (1994) version of HOL is no longer distributed;
  2622 
  2623 
  2624 
  2625 New in Isabelle94-4
  2626 -------------------
  2627 
  2628 * greatly reduced space requirements;
  2629 
  2630 * theory files (.thy) no longer require \...\ escapes at line breaks;
  2631 
  2632 * searchable theorem database (see the section "Retrieving theorems" on
  2633 page 8 of the Reference Manual);
  2634 
  2635 * new examples, including Grabczewski's monumental case study of the
  2636 Axiom of Choice;
  2637 
  2638 * The previous version of HOL renamed to Old_HOL;
  2639 
  2640 * The new version of HOL (previously called CHOL) uses a curried syntax
  2641 for functions.  Application looks like f a b instead of f(a,b);
  2642 
  2643 * Mutually recursive inductive definitions finally work in HOL;
  2644 
  2645 * In ZF, pattern-matching on tuples is now available in all abstractions and
  2646 translates to the operator "split";
  2647 
  2648 
  2649 
  2650 New in Isabelle94-3
  2651 -------------------
  2652 
  2653 * new infix operator, addss, allowing the classical reasoner to
  2654 perform simplification at each step of its search.  Example:
  2655         fast_tac (cs addss ss)
  2656 
  2657 * a new logic, CHOL, the same as HOL, but with a curried syntax
  2658 for functions.  Application looks like f a b instead of f(a,b).  Also pairs
  2659 look like (a,b) instead of <a,b>;
  2660 
  2661 * PLEASE NOTE: CHOL will eventually replace HOL!
  2662 
  2663 * In CHOL, pattern-matching on tuples is now available in all abstractions.
  2664 It translates to the operator "split".  A new theory of integers is available;
  2665 
  2666 * In ZF, integer numerals now denote two's-complement binary integers.
  2667 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
  2668 
  2669 * Many new examples: I/O automata, Church-Rosser theorem, equivalents
  2670 of the Axiom of Choice;
  2671 
  2672 
  2673 
  2674 New in Isabelle94-2
  2675 -------------------
  2676 
  2677 * Significantly faster resolution;
  2678 
  2679 * the different sections in a .thy file can now be mixed and repeated
  2680 freely;
  2681 
  2682 * Database of theorems for FOL, HOL and ZF.  New
  2683 commands including qed, qed_goal and bind_thm store theorems in the database.
  2684 
  2685 * Simple database queries: return a named theorem (get_thm) or all theorems of
  2686 a given theory (thms_of), or find out what theory a theorem was proved in
  2687 (theory_of_thm);
  2688 
  2689 * Bugs fixed in the inductive definition and datatype packages;
  2690 
  2691 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
  2692 and HOL_dup_cs obsolete;
  2693 
  2694 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
  2695 have been removed;
  2696 
  2697 * Simpler definition of function space in ZF;
  2698 
  2699 * new results about cardinal and ordinal arithmetic in ZF;
  2700 
  2701 * 'subtype' facility in HOL for introducing new types as subsets of existing
  2702 types;
  2703 
  2704 
  2705 $Id$